Chevrolet - S10 - Workshop Manual - 1984 - 1984

Factory Workshop Manual Make Chevrolet Model S10 Engine and year S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994) Please navigate through the PDF using the options provided by OnlyManuals.com on the sidebar. This manual was submitted by Anonymous Date 1st January 2018 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Accessories and Optional Equipment > Keyless Entry Module > Component Information > Locations Keyless Entry Module Wiring Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Accessories and Optional Equipment > Keyless Entry Module > Component Information > Locations > Page 7 C350 - Remote Keyless Entry Module Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Accessories and Optional Equipment > Relay Module > Component Information > Technical Service Bulletins > Customer Interest for Relay Module: > 09-06-03-004D > Dec > 10 > Electrical - MIL ON/DTC's Set By Various Control Modules Relay Module: Customer Interest Electrical - MIL ON/DTC's Set By Various Control Modules TECHNICAL Bulletin No.: 09-06-03-004D Date: December 08, 2010 Subject: Intermittent No Crank/No Start, No Module Communication, MIL, Warning Lights, Vehicle Messages or DTCs Set by Various Control Modules - Diagnosing and Repairing Fretting Corrosion (Disconnect Affected Connector and Apply Dielectric Lubricant) Models: 2011 and Prior GM Passenger Cars and Trucks Attention: This repair can be applied to ANY electrical connection including, but not limited to: lighting, body electrical, in-line connections, powertrain control sensors, etc. DO NOT over apply lubricant to the point where it prevents the full engagement of sealed connectors. A light coating on the terminal surfaces is sufficient to correct the condition. Supercede: This bulletin is being revised to update the Attention statement and add the 2011 model year. Please discard Corporate Bulletin Number 09-06-03-004C (Section 06 Engine/Propulsion System). Condition Some customers may comment on any of the following conditions: - An intermittent no crank/no start - Intermittent malfunction indicator lamp (MIL) illumination - Intermittent service lamp illumination - Intermittent service message(s) being displayed The technician may determine that he is unable to duplicate the intermittent condition. Cause This condition may be caused by a buildup of nonconductive insulating oxidized debris known as fretting corrosion, occurring between two electrical contact surfaces of the connection or connector. This may be caused by any of the following conditions: - Vibration - Thermal cycling - Poor connection/terminal retention - Micro motion - A connector, component or wiring harness not properly secured resulting in movement On low current signal circuits this condition may cause high resistance, resulting in intermittent connections. On high current power circuits this condition may cause permanent increases in the resistance and may cause a device to become inoperative. Representative List of Control Modules and Components The following is only a representative list of control modules and components that may be affected by this connection or connector condition and DOES NOT include every possible module or component for every vehicle. - Blower Control Module - Body Control Module (BCM) - Communication Interface Module (CIM) - Cooling Fan Control Module - Electronic Brake Control Module (EBCM) - Electronic Brake and Traction Control Module (EBTCM) - Electronic Suspension Control (ESC) Module - Engine Control Module (ECM) - Heating, Ventilation and Air Conditioning (HVAC) Control Module Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Accessories and Optional Equipment > Relay Module > Component Information > Technical Service Bulletins > Customer Interest for Relay Module: > 09-06-03-004D > Dec > 10 > Electrical - MIL ON/DTC's Set By Various Control Modules > Page 16 - HVAC Actuator - Inflatable Restraint Sensing and Diagnostic Module (SDM) - Any AIR BAG module - Seatbelt Lap Anchor Pretensioner - Seatbelt Retractor Pretensioner - An SIR system connection or connector condition resulting in the following DTCs being set: B0015, B0016, B0019, B0020, B0022, or B0023 - Powertrain Control Module (PCM) - Remote Control Door Lock Receiver (RCDLR) - Transmission Control Module (TCM) Correction Important DO NOT replace the control module, wiring or component for the following conditions: - The condition is intermittent and cannot be duplicated. - The condition is present and by disconnecting and reconnecting the connector the condition can no longer be duplicated. Use the following procedure to correct the conditions listed above. 1. Install a scan tool and perform the Diagnostic System Check - Vehicle. Retrieve and record any existing history or current DTCs from all of the control modules (refer to SI). ‹› If any DTC(s) are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). ‹› If DTCs are not set, refer to Symptoms - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). 2. When identified, use the appropriate DTC Diagnostics, Symptoms, Schematics, Component Connector End Views and Component Locator documents to locate and disconnect the affected harness connector(s) which are causing the condition. Note Fretting corrosion looks like little dark smudges on electrical terminals and appear where the actual electrical contact is being made. In less severe cases it may be unable to be seen or identified without the use of a magnifying glass. Important DO NOT apply an excessive amount of dielectric lubricant to the connectors as shown, as hydrolock may result when attempting to mate the connectors. Use ONLY a clean nylon brush that is dedicated to the repair of the conditions in this bulletin. 3. With a one-inch nylon bristle brush, apply dielectric lubricant to both the module/component side and the harness side of the affected connector(s). 4. Reconnect the affected connector(s) and wipe away any excess lubricant that may be present. 5. Attempt to duplicate the condition by using the following information: - DTC Diagnostic Procedure - Circuit/System Description - Conditions for Running the DTC - Conditions for Setting the DTC - Diagnostic Aids - Circuit/System Verification ‹› If the condition cannot be duplicated, the repair is complete. ‹› If the condition can be duplicated, then follow the appropriate DTC, Symptom or Circuit/System Testing procedure (refer to SI). Repair Order Documentation Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Accessories and Optional Equipment > Relay Module > Component Information > Technical Service Bulletins > Customer Interest for Relay Module: > 09-06-03-004D > Dec > 10 > Electrical - MIL ON/DTC's Set By Various Control Modules > Page 17 Important The following information MUST be documented on the repair order. Failure to do so may result in a chargeback. - Customer vehicle condition. - Was a Service Lamp or Service Message illuminated? If yes, specify which Service Lamp or Service Message. - Was a DTC(s) set? If yes, specify which DTC(s) were set. - After following the procedure contained within this bulletin, could the condition be duplicated? ‹› If the condition was not duplicated, then document the affected module/component connector name and number on the repair order. - If the condition was duplicated after the procedure contained within this bulletin was followed, and additional diagnosis led to the replacement of a module or component, the SI Document ID Number MUST be written on the repair order. Parts Information Alternate Distributor For All of North America Note NyoGel(R) 760G Lubricant* is equivalent to GMSPO P/N 12377900, and P/N 10953529 (Canada), specified for use to correct the condition in this bulletin. *We believe this source and their products to be reliable. There may be additional manufacturers of such products/materials. General Motors does not endorse, indicate any preference for, or assume any responsibility for the products or material from this firm or for any such items that may be available from other sources. Warranty Information (excluding Saab Models) For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to: Warranty Information (Saab Models) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Accessories and Optional Equipment > Relay Module > Component Information > Technical Service Bulletins > Customer Interest for Relay Module: > 09-06-03-004D > Dec > 10 > Electrical - MIL ON/DTC's Set By Various Control Modules > Page 18 For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to refer to the table above. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Accessories and Optional Equipment > Relay Module > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Relay Module: > 09-06-03-004D > Dec > 10 > Electrical - MIL ON/DTC's Set By Various Control Modules Relay Module: All Technical Service Bulletins Electrical - MIL ON/DTC's Set By Various Control Modules TECHNICAL Bulletin No.: 09-06-03-004D Date: December 08, 2010 Subject: Intermittent No Crank/No Start, No Module Communication, MIL, Warning Lights, Vehicle Messages or DTCs Set by Various Control Modules - Diagnosing and Repairing Fretting Corrosion (Disconnect Affected Connector and Apply Dielectric Lubricant) Models: 2011 and Prior GM Passenger Cars and Trucks Attention: This repair can be applied to ANY electrical connection including, but not limited to: lighting, body electrical, in-line connections, powertrain control sensors, etc. DO NOT over apply lubricant to the point where it prevents the full engagement of sealed connectors. A light coating on the terminal surfaces is sufficient to correct the condition. Supercede: This bulletin is being revised to update the Attention statement and add the 2011 model year. Please discard Corporate Bulletin Number 09-06-03-004C (Section 06 Engine/Propulsion System). Condition Some customers may comment on any of the following conditions: - An intermittent no crank/no start - Intermittent malfunction indicator lamp (MIL) illumination - Intermittent service lamp illumination - Intermittent service message(s) being displayed The technician may determine that he is unable to duplicate the intermittent condition. Cause This condition may be caused by a buildup of nonconductive insulating oxidized debris known as fretting corrosion, occurring between two electrical contact surfaces of the connection or connector. This may be caused by any of the following conditions: - Vibration - Thermal cycling - Poor connection/terminal retention - Micro motion - A connector, component or wiring harness not properly secured resulting in movement On low current signal circuits this condition may cause high resistance, resulting in intermittent connections. On high current power circuits this condition may cause permanent increases in the resistance and may cause a device to become inoperative. Representative List of Control Modules and Components The following is only a representative list of control modules and components that may be affected by this connection or connector condition and DOES NOT include every possible module or component for every vehicle. - Blower Control Module - Body Control Module (BCM) - Communication Interface Module (CIM) - Cooling Fan Control Module - Electronic Brake Control Module (EBCM) - Electronic Brake and Traction Control Module (EBTCM) - Electronic Suspension Control (ESC) Module - Engine Control Module (ECM) - Heating, Ventilation and Air Conditioning (HVAC) Control Module Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Accessories and Optional Equipment > Relay Module > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Relay Module: > 09-06-03-004D > Dec > 10 > Electrical - MIL ON/DTC's Set By Various Control Modules > Page 24 - HVAC Actuator - Inflatable Restraint Sensing and Diagnostic Module (SDM) - Any AIR BAG module - Seatbelt Lap Anchor Pretensioner - Seatbelt Retractor Pretensioner - An SIR system connection or connector condition resulting in the following DTCs being set: B0015, B0016, B0019, B0020, B0022, or B0023 - Powertrain Control Module (PCM) - Remote Control Door Lock Receiver (RCDLR) - Transmission Control Module (TCM) Correction Important DO NOT replace the control module, wiring or component for the following conditions: - The condition is intermittent and cannot be duplicated. - The condition is present and by disconnecting and reconnecting the connector the condition can no longer be duplicated. Use the following procedure to correct the conditions listed above. 1. Install a scan tool and perform the Diagnostic System Check - Vehicle. Retrieve and record any existing history or current DTCs from all of the control modules (refer to SI). ‹› If any DTC(s) are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). ‹› If DTCs are not set, refer to Symptoms - Vehicle to identify the connector(s) of the control module/component which may be causing the condition (refer to SI). 2. When identified, use the appropriate DTC Diagnostics, Symptoms, Schematics, Component Connector End Views and Component Locator documents to locate and disconnect the affected harness connector(s) which are causing the condition. Note Fretting corrosion looks like little dark smudges on electrical terminals and appear where the actual electrical contact is being made. In less severe cases it may be unable to be seen or identified without the use of a magnifying glass. Important DO NOT apply an excessive amount of dielectric lubricant to the connectors as shown, as hydrolock may result when attempting to mate the connectors. Use ONLY a clean nylon brush that is dedicated to the repair of the conditions in this bulletin. 3. With a one-inch nylon bristle brush, apply dielectric lubricant to both the module/component side and the harness side of the affected connector(s). 4. Reconnect the affected connector(s) and wipe away any excess lubricant that may be present. 5. Attempt to duplicate the condition by using the following information: - DTC Diagnostic Procedure - Circuit/System Description - Conditions for Running the DTC - Conditions for Setting the DTC - Diagnostic Aids - Circuit/System Verification ‹› If the condition cannot be duplicated, the repair is complete. ‹› If the condition can be duplicated, then follow the appropriate DTC, Symptom or Circuit/System Testing procedure (refer to SI). Repair Order Documentation Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Accessories and Optional Equipment > Relay Module > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Relay Module: > 09-06-03-004D > Dec > 10 > Electrical - MIL ON/DTC's Set By Various Control Modules > Page 25 Important The following information MUST be documented on the repair order. Failure to do so may result in a chargeback. - Customer vehicle condition. - Was a Service Lamp or Service Message illuminated? If yes, specify which Service Lamp or Service Message. - Was a DTC(s) set? If yes, specify which DTC(s) were set. - After following the procedure contained within this bulletin, could the condition be duplicated? ‹› If the condition was not duplicated, then document the affected module/component connector name and number on the repair order. - If the condition was duplicated after the procedure contained within this bulletin was followed, and additional diagnosis led to the replacement of a module or component, the SI Document ID Number MUST be written on the repair order. Parts Information Alternate Distributor For All of North America Note NyoGel(R) 760G Lubricant* is equivalent to GMSPO P/N 12377900, and P/N 10953529 (Canada), specified for use to correct the condition in this bulletin. *We believe this source and their products to be reliable. There may be additional manufacturers of such products/materials. General Motors does not endorse, indicate any preference for, or assume any responsibility for the products or material from this firm or for any such items that may be available from other sources. Warranty Information (excluding Saab Models) For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to: Warranty Information (Saab Models) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Accessories and Optional Equipment > Relay Module > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Relay Module: > 09-06-03-004D > Dec > 10 > Electrical - MIL ON/DTC's Set By Various Control Modules > Page 26 For vehicles repaired under warranty, use the appropriate/closest labor operation depending upon the module/component connection that the dielectric lubricant was applied to refer to the table above. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Body and Frame > Keyless Entry Module > Component Information > Locations Keyless Entry Module Wiring Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Body and Frame > Keyless Entry Module > Component Information > Locations > Page 31 C350 - Remote Keyless Entry Module Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Body and Frame > Power Door Lock Relay > Component Information > Locations Power Window And Door Lock Body Wiring-4-Door Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Body and Frame > Power Door Lock Relay > Component Information > Locations > Page 35 C240A - Power Door Lock Relay Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Body and Frame > Trunk / Liftgate Relay > Component Information > Locations Rear Window Release Forward Wiring Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Body and Frame > Trunk / Liftgate Relay > Component Information > Locations > Page 39 C246 - Liftgate Release Relay Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Brakes and Traction Control > ABS Main Relay > Component Information > Locations ABS Main Relay: Locations FOUR WHEEL ANTILOCK BRAKE SYSTEM (4WAL) Brake Pressure Modulator Valve The relay is located inside the Brake Pressure Modulator Valve (BPMV) and is not serviced seperately. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Brakes and Traction Control > Electronic Brake Control Module > Component Information > Locations Forward Lamps Harness, LH Side Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Brakes and Traction Control > Electronic Brake Control Module > Component Information > Diagrams > Four-Wheel Antilock Brake Module (EHCU) Electronic Brake Control Module: Diagrams Four-Wheel Antilock Brake Module (EHCU) Fig. 34 ABS Connector Terminal Identification. Fig. 32 ALDL Connector Terminal Identification. ABS Connector Terminals. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Brakes and Traction Control > Electronic Brake Control Module > Component Information > Diagrams > Four-Wheel Antilock Brake Module (EHCU) > Page 49 Electronic Brake Control Module: Diagrams Rear Wheel Antilock Brake Module (RWAL EHCU) Fig. 13 RWAL System Electrical Connectors. RWAL system electrical connectors. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Brakes and Traction Control > Electronic Brake Control Module > Component Information > Diagrams > Page 50 Electronic Brake Control Module: Service and Repair Fig. 225 EHCU/BPMV Mounting. (EHCU) Electro-Hydraulic Control Unit / (BPMV) Brake Pressure Modulator Valve Module is not serviceable and must be replaced as a unit. 1. Remove washer tank attaching bolts, then position aside. 2. Remove EHCU/BPMV electrical connectors. 3. Disconnect module brake lines. Use caution not to get brake fluid on paint or electrical connections. 4. Remove upper to lower bracket assembly attaching bolts. 5. Remove EHCU/BPMV module and upper bracket assembly from vehicle. 6. Remove upper mounting bracket to EHCU/BPMV module attaching bolts, Fig. 225. 7. Reverse procedure to install, noting the following: a. Torque EHCU/BPMV module to bracket attaching bolts to 5 ft. lbs. b. Torque EHCU/BPMV bracket assembly attaching bolts to 20 ft. lbs. c. Torque brake line fittings to 16 ft. lbs. d. Bleed EHCU/BPMV module. See: Brakes and Traction Control/Brake Bleeding Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Technical Service Bulletins > Customer Interest for Cruise Control Module: > 569002A > Jul > 95 > Stepper Motor Cruise Control - Will Not Resume/Reset Cruise Control Module: Customer Interest Stepper Motor Cruise Control - Will Not Resume/Reset FILE IN SECTION: 9 - Accessories BULLETIN NO.: 56-90-02A DATE: July, 1995 SUBJECT: Stepper Motor Cruise Control will not Resume or Reset (Replace SMCC Module) MODELS: 1993-95 Chevrolet Camaro 1993-95 Pontiac Firebird with 3.4L V6 Engine (VIN S - RPO L32) and Automatic Transmission (M30) only OR with 5.7L V8 Engine (VIN P - RPO LT1) and any Transmission 1994-95 Chevrolet and GMC Truck C/K, S/T, M/L Models This bulletin is being revised to add F car information. Please discard Corporate Bulletin Number 56-90-02 (Section 9 - Accessories). CONDITION Some owners may comment that the Stepper Motor Cruise Control (SMCC) will intermittently cut out and will not resume or reset unless the ignition key is cycled. CAUSE The SMCC is sensitive to any brake switch contact bounce of less than 32 milliseconds. This contact bounce may cause the SMCC to go into a diagnostic shut down mode until the module is reset by turning the ignition off. For trucks, the 1994 Zero Adjust Brake switches tend to aggravate this sensitivity. CORRECTION Replace the SMCC module only if the diagnosis in the Service Manual, Section 8A Cruise Control does not resolve the concern. Service Procedure For 1994-95 Chevrolet and GMC Truck C/K, S/T, M/L Models: Follow the SMCC MODULE remove and install procedure using the appropriate service manual. For F-car models, use the following procedure. Remove Before removing cruise control module, disconnect cruise control cable to obtain the necessary clearance. 1. Disconnect cruise control cable end fitting from throttle body lever stud. If vehicle is equipped with accelerator control/cruise control cable adjuster (throttle relaxer), remove cruise control cable end fitting from adjuster. Note location of pulley for end fitting. 2. Unlock cruise control cable conduit by pulling up on unlock button. 3. Push conduit together to obtain the additional cable slack. 4. Remove cruise control module per Section 9B of the Service Manual. Important: It is not necessary to remove cruise control cable from vehicle. Install 1. Install cruise control cable to cruise control module per Section 9B of the Service Manual, Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Technical Service Bulletins > Customer Interest for Cruise Control Module: > 569002A > Jul > 95 > Stepper Motor Cruise Control - Will Not Resume/Reset > Page 60 Important: Cruise control module ribbon must not be twisted when installed to cruise control module. 2. Install cruise control module per Section 9B of the Service Manual. 3. Connect cruise control cable end fitting to throttle body lever stud. If vehicle is equipped with accelerator control/cruise control cable adjuster (throttle relaxer), connect cruise control cable end fitting to adjuster. Note correct location of pulley for end fitting. 4. Adjust cruise cable per "Cable Assembly Adjustment" procedure in Section 9B of the Service Manual. Important: Excessive cable slack in cruise control cable will result in perceived slow module response. PARTS INFORMATION Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty, use: Labor Operation Description Labor Time R1220 Module, C/C Replace Use Published Labor Operation time Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Cruise Control Module: > 569002A > Jul > 95 > Stepper Motor Cruise Control - Will Not Resume/Reset Cruise Control Module: All Technical Service Bulletins Stepper Motor Cruise Control - Will Not Resume/Reset FILE IN SECTION: 9 - Accessories BULLETIN NO.: 56-90-02A DATE: July, 1995 SUBJECT: Stepper Motor Cruise Control will not Resume or Reset (Replace SMCC Module) MODELS: 1993-95 Chevrolet Camaro 1993-95 Pontiac Firebird with 3.4L V6 Engine (VIN S - RPO L32) and Automatic Transmission (M30) only OR with 5.7L V8 Engine (VIN P - RPO LT1) and any Transmission 1994-95 Chevrolet and GMC Truck C/K, S/T, M/L Models This bulletin is being revised to add F car information. Please discard Corporate Bulletin Number 56-90-02 (Section 9 - Accessories). CONDITION Some owners may comment that the Stepper Motor Cruise Control (SMCC) will intermittently cut out and will not resume or reset unless the ignition key is cycled. CAUSE The SMCC is sensitive to any brake switch contact bounce of less than 32 milliseconds. This contact bounce may cause the SMCC to go into a diagnostic shut down mode until the module is reset by turning the ignition off. For trucks, the 1994 Zero Adjust Brake switches tend to aggravate this sensitivity. CORRECTION Replace the SMCC module only if the diagnosis in the Service Manual, Section 8A Cruise Control does not resolve the concern. Service Procedure For 1994-95 Chevrolet and GMC Truck C/K, S/T, M/L Models: Follow the SMCC MODULE remove and install procedure using the appropriate service manual. For F-car models, use the following procedure. Remove Before removing cruise control module, disconnect cruise control cable to obtain the necessary clearance. 1. Disconnect cruise control cable end fitting from throttle body lever stud. If vehicle is equipped with accelerator control/cruise control cable adjuster (throttle relaxer), remove cruise control cable end fitting from adjuster. Note location of pulley for end fitting. 2. Unlock cruise control cable conduit by pulling up on unlock button. 3. Push conduit together to obtain the additional cable slack. 4. Remove cruise control module per Section 9B of the Service Manual. Important: It is not necessary to remove cruise control cable from vehicle. Install 1. Install cruise control cable to cruise control module per Section 9B of the Service Manual, Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Cruise Control Module: > 569002A > Jul > 95 > Stepper Motor Cruise Control - Will Not Resume/Reset > Page 66 Important: Cruise control module ribbon must not be twisted when installed to cruise control module. 2. Install cruise control module per Section 9B of the Service Manual. 3. Connect cruise control cable end fitting to throttle body lever stud. If vehicle is equipped with accelerator control/cruise control cable adjuster (throttle relaxer), connect cruise control cable end fitting to adjuster. Note correct location of pulley for end fitting. 4. Adjust cruise cable per "Cable Assembly Adjustment" procedure in Section 9B of the Service Manual. Important: Excessive cable slack in cruise control cable will result in perceived slow module response. PARTS INFORMATION Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty, use: Labor Operation Description Labor Time R1220 Module, C/C Replace Use Published Labor Operation time Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Technical Service Bulletins > Page 67 Cruise Control Module: Locations Cruise Control I/P Wiring Under the L/H side of the I/P, left of the steering column. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Diagrams > Diagram Information and Instructions Cruise Control Module: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. Use this page as a reference to determine the meaning of an abbreviation if necessary. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery Bi-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CHMSL Center High Mount Stoplamp CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRO Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 70 F-PUMP Fuel Pump FLASH Flasher FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 71 SIR Supplemental Inflatable Restraint SKT Socket SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature TIL Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 72 example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE (ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: ^ Slide across the vehicle seat. ^ Sit down or stand up. ^ Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: ^ They are bumped or dropped. ^ They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 73 Symbols (Part 1 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 74 Symbols (Part 2 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 75 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 76 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 77 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 78 Cruise Control Module: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 79 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 80 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 81 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 82 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 83 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. ^ If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. ^ A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 84 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 85 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 86 Ohmmeter Meter Scales Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 87 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. ^ An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. ^ On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: ^ A range selector switch which permits the selection of different ranges of resistance. ^ A set adjust control which allows the meter to be set at zero for accurate measurements. ^ Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 88 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: ^ Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. ^ Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. ^ Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 89 be less than 10 percent of the total drop. When using a voltmeter: ^ Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. ^ Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. ^ The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: ^ Check the accuracy and completeness of the complaint. ^ Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 90 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. ^ The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 91 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 92 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 93 Twisted/Shielded Wire Repair Twisted Wires Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 94 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 95 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 96 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). ^ Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean ^ Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. ^ Roll crimp (13) and solder the terminal. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 97 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 98 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 99 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. ^ Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean ^ Terminal cavity of the connector body. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 100 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. ^ Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Cruise Control > Cruise Control Module > Component Information > Diagrams > Diagram Information and Instructions > Page 101 C250 - Cruise Control Module Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - HVAC > Blower Motor Relay > Component Information > Locations Blower Motor Relay: Locations A/C And Heater Wiring Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - HVAC > Blower Motor Relay > Component Information > Locations > Page 106 A/C And Heater Wiring Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - HVAC > Blower Motor Relay > Component Information > Locations > Page 107 Blower Motor Relay: Diagrams C158 - Inline To High Blower Relay C158 - Inline To High Blower Relay Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - HVAC > Blower Motor Relay > Component Information > Locations > Page 108 Blower Motor Relay: Description and Operation The blower motor relay is used to provide battery voltage to the blower motor assembly only during high blower motor assembly speed. The blower motor resistor is used to provide power to the blower motor assembly in all other speed settings. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - HVAC > Blower Motor Relay > Component Information > Locations > Page 109 Blower Motor Relay: Service and Repair Figure 52: Evaporator And Blower Assembly REMOVE OR DISCONNECT 1. Negative battery cable. 2. Electrical connectors, as necessary. 3. Screws (34). 4. Relay (42). INSTALL OR CONNECT 1. Relay (42). NOTICE: Refer to "Fasteners" under "Vehicle Damage Warnings." 2. Screws (34). - Tighten screws (34) to 1.4 Nm (12 lbs. in.). 3. Electrical connectors, as necessary. 4. Negative battery cable. - Check circuit operation. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - HVAC > Compressor Clutch Relay > Component Information > Locations Compressor Clutch Relay: Locations A/C COMPRESSOR CONTROL RELAY Fender Wiring RH The A/C Compressor Control Relay is located in Engine Compartment, on LH side of cowl. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - HVAC > Compressor Clutch Relay > Component Information > Locations > Page 113 Compressor Clutch Relay: Description and Operation The compressor relay is used to provide battery voltage to the compressor clutch coil. The relay is controlled by the engine control module (ECM). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Lighting and Horns > Daytime Running Lamp Control Unit > Component Information > Locations Daytime Running Lamps-I/P Wiring Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Lighting and Horns > Daytime Running Lamp Control Unit > Component Information > Locations > Page 118 Daytime Running Lamp Control Unit: Diagrams C239 - DEL Module C238 - DRL Relay Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Lighting and Horns > Daytime Running Lamp Relay > Component Information > Locations Daytime Running Lamps-I/P Wiring Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Lighting and Horns > Fog/Driving Lamp Relay > Component Information > Diagrams Fog/Driving Lamp Relay: Diagrams C227 - Fog Lamp Relay C225 - Fog Lamp Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Lighting and Horns > Horn Relay > Component Information > Locations Relay Convenience Center, Under LH Side Of I/Panel Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Locations Relay Box: Locations I/P Harness Wiring, LH Side Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Locations > Page 132 Turn Signal And Hazard Flashers Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Locations > Page 133 Horn Relay Installation Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Diagrams > Diagram Information and Instructions Relay Box: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. Use this page as a reference to determine the meaning of an abbreviation if necessary. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery Bi-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CHMSL Center High Mount Stoplamp CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRO Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 136 F-PUMP Fuel Pump FLASH Flasher FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 137 SIR Supplemental Inflatable Restraint SKT Socket SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature TIL Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 138 example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE (ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: ^ Slide across the vehicle seat. ^ Sit down or stand up. ^ Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: ^ They are bumped or dropped. ^ They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 139 Symbols (Part 1 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 140 Symbols (Part 2 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 141 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 142 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 143 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 144 Relay Box: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 145 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 146 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 147 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 148 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 149 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. ^ If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. ^ A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 150 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 151 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 152 Ohmmeter Meter Scales Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 153 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. ^ An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. ^ On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: ^ A range selector switch which permits the selection of different ranges of resistance. ^ A set adjust control which allows the meter to be set at zero for accurate measurements. ^ Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 154 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: ^ Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. ^ Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. ^ Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 155 be less than 10 percent of the total drop. When using a voltmeter: ^ Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. ^ Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. ^ The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: ^ Check the accuracy and completeness of the complaint. ^ Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 156 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. ^ The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 157 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 158 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 159 Twisted/Shielded Wire Repair Twisted Wires Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 160 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 161 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 162 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). ^ Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean ^ Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. ^ Roll crimp (13) and solder the terminal. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 163 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 164 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 165 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. ^ Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean ^ Terminal cavity of the connector body. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 166 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. ^ Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 167 Relay Box: Electrical Diagrams Convenience Center Details (Part 1 Of 2) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Power and Ground Distribution > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 168 Convenience Center Details (Part 2 Of 2) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Air Flow Meter/Sensor Relay > Component Information > Technical Service Bulletins > Shift Indicator Light Application and Operation Air Flow Meter/Sensor Relay: Technical Service Bulletins Shift Indicator Light Application and Operation File In Section: 7 - Transmission Bulletin No.: 36-72-07A Date: February, 1995 Subject: Manual Transmission Shift Indicator Light Application and Operation Models: 1993-95 Chevrolet and GMC Truck C/K and S/T Models with Manual Transmission This bulletin is being revised to add the 1995 model year. Please discard bulletin number 367207 (Group Reference - Transmission). Certain trucks are not equipped with a shift indicator light. The shift light is commonly used to achieve improved fuel economy by prompting the driver when to upshift. Depending on the engine/transmission installed in the vehicle, the shift light can have the following characteristics: ^ Indicates proper shift point for maximum fuel economy. ^ Indicates engine over-speed. ^ Shift light is inoperative. The following charts detail normal shift light operation: 1993 Models: Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Air Flow Meter/Sensor Relay > Component Information > Technical Service Bulletins > Shift Indicator Light Application and Operation > Page 175 1994 Models: 1995 Models: Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage Engine Control Module: Technical Service Bulletins Engine Controls - Aftermarket Accessory Usage INFORMATION Bulletin No.: 04-06-04-054B Date: November 18, 2010 Subject: Info - Non-GM Parts and Accessories (Aftermarket) Models: 2011 and Prior GM Passenger Cars and Trucks Supercede: This bulletin is being revised to add model years and update to the new U.S. Fixed Operation Manager (FOM) and Canada Warranty Manager (WM) names. Please discard Corporate Bulletin Number 04-06-04-054A (Section 06 - Engine/Propulsion System). The recent rise and expansion of companies selling non-GM parts and accessories has made it necessary to issue this reminder to dealers regarding GM's policy on the use and installation of these aftermarket components. When a dealer is performing a repair under the New Vehicle Limited Warranty, they are required to use only genuine GM or GM-approved parts and accessories. This applies to all warranty repairs, special policy repairs or any repairs paid for by GM. Parts and accessories advertised as being "the same" as parts manufactured by GM, but not sold through GM, do not qualify for use in warranty repairs, special policy repairs or any repairs paid for by GM. During a warranty repair, if a GM original equipment part is not available through GM Customer Care and Aftersales (GM CC&A;), ACDelco(R) distributors, other GM dealers or approved sources, the dealer is to obtain comparable, non-GM parts and clearly indicate, in detail, on the repair order the circumstances surrounding why non-GM parts were used. The dealer must give customers written notice, prior to the sale or service, that such parts or accessories are not marketed or warranted by General Motors. It should also be noted that dealers modifying new vehicles and installing equipment, parts and accessories obtained from sources not authorized by GM are responsible for complying with the National Traffic and Motor Vehicle Safety Act. Certain non-approved parts or assemblies, installed by the dealer or its agent not authorized by GM, may result in a change to the vehicle's design characteristics and may affect the vehicle's ability to conform to federal law. Dealers must fully understand that non-GM approved parts may not have been validated, tested or certified for use. This puts the dealer at risk for potential liability in the event of a part or vehicle failure. If a GM part failure occurs as the result of the installation or use of a non-GM approved part, the warranty will not be honored. A good example of non-authorized modification of vehicles is the result of an ever increasing supply of aftermarket devices available to the customer, which claim to increase the horsepower and torque of the Duramax(TM) Diesel Engines. These include the addition of, but are not limited to one or more of the following modifications: - Propane injection - Nitrous oxide injection - Additional modules (black boxes) that connect to the vehicle wiring systems - Revised engine calibrations downloaded for the engine control module - Calibration modules which connect to the vehicle diagnostic connector - Modification to the engine turbocharger waste gate Although the installation of these devices, or modification of vehicle components, can increase engine horsepower and torque, they may also negatively affect the engine emissions, reliability and/or durability. In addition, other powertrain components, such as transmissions, universal joints, drive shafts, and front/rear axle components, can be stressed beyond design safety limits by the installation of these devices. General Motors does not support or endorse the use of devices or modifications that, when installed, increase the engine horsepower and torque. It is because of these unknown stresses, and the potential to alter reliability, durability and emissions performance, that GM has adopted a policy that prevents any UNAUTHORIZED dealer warranty claim submissions to any remaining warranty coverage, to the powertrain and driveline components whenever the presence of a non-GM (aftermarket) calibration is confirmed - even if the non-GM control module calibration is subsequently removed. Refer to the latest version of Bulletin 09-06-04-026 (V8 Gas Engines) or 06-06-01-007 (Duramax(TM) Diesel Engines) for more information on dealer requirements for calibration verification. These same policies apply as they relate to the use of non-GM accessories. Damage or failure from the use or installation of a non-GM accessory will not be covered under warranty. Failure resulting from the alteration or modification of the vehicle, including the cutting, welding or disconnecting of the vehicle's original equipment parts and components will void the warranty. Additionally, dealers will NOT be reimbursed or compensated by GM in the event of any legal inquiry at either the local, state or federal level that Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 180 results from the alteration or modification of a vehicle using non-GM approved parts or accessories. Dealers should be especially cautious of accessory companies that claim the installation of their product will not void the factory warranty. Many times these companies have even given direction on how to quickly disassemble the accessory in an attempt to preclude the manufacturer from finding out that is has been installed. Any suspect repairs should be reviewed by the Fixed Operations Manager (FOM), and in Canada by the Warranty Manager (WM) for appropriate repair direction. If it is decided that a goodwill repair is to be made on the vehicle, even with the installation of such non-GM approved components, the customer is to be made aware of General Motors position on this issue and is to sign the appropriate goodwill documentation required by General Motors. It is imperative for dealers to understand that by installing such devices, they are jeopardizing not only the warranty coverage, but also the performance and reliability of the customer's vehicle. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 181 Engine Control Module: Technical Service Bulletins PROM - Reprogram Using Off Board Program Adapter File In Section: 6E - Engine Fuel & Emission Bulletin No.: 73-65-13 Date: March, 1997 INFORMATION Subject: Reprogramming Capability using the Off Board Programming Adapter Models: 1993-97 Passenger Cars and Trucks (Applicable Reprogrammable Vehicles) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 182 The General Motors vehicles contain Electronically Reprogrammable Devices (i.e. PCM, VCM, ECM). These vehicles cannot be programmed through PROM replacement, however service programming capability is available through the Tech 1/1A, Tech 2 and Techline terminals via direct or remote programming. The Environmental Protection Agency (EPA) has requested that all new vehicle manufacturers ensure their dealers/retailers are aware that they are responsible for providing customers access to reprogramming services at a reasonable cost and in a timely manner. Although programming of controllers has become a common service practice at GM dealers/retailers, the EPA has received reports from consumers and the aftermarket repair industry that they were unable to purchase a new (programmed) Electronically Reprogrammable Device (ERD) over-the-counter. As a result, on August 1, 1995, the Federal Government issued a regulation requiring all manufacturers to make available reprogramming to the independent aftermarket by December 1, 1997. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 183 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 184 Today, the Off Board Programming Adapter (OBPA) is used to reprogram ERD's sold over-the-counter. For all practical purposes, the OBPA takes the place of the vehicle when the vehicle is not available. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 185 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 186 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 187 The list of dealerships/retailers currently own the OBPA (see Attachments 1 - 3). These locations are equipped to provide over-the-counter preprogrammed ERD's. The hardware required to perform reprogramming in addition to the OBPA is a Techline terminal, Tech 1/1A and associated cables and adapters. THE TECH 2 SHOULD NOT BE USED WITH THE OBPA AT THIS TIME BECAUSE OF INADEQUATE OBPA GROUNDING. The current OBPA can support reprogramming on all late model General Motor's vehicles except: ^ Premium V-8's ^ 1996 Diesel Truck ^ Cadillac Catera Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 188 ^ All 1997 programmable vehicles (requires use of the Tech 2) A modification to the OBPA is being offered by Kent-Moore to support these additional vehicles and to allow reprogramming using the Tech 2. The revisions to the OBPA for the Tech 2 is very important as the Tech 2 is the only tool used for service programming for 1997 and future vehicles. To have the modifications performed, contact Kent-Moore at (800) 345-2233. The revisions (part number J 41207 REV-C) are free of charge for GM dealerships/retailers. A dealership/retailer can purchase the OBPA by contacting Kent-Moore (part number J 41207-C). Support on how to use the OBPA is provided by the Techline Customer Support Center (TCSC) at (800) 828-6860 (English) or (800) 503-3222 (French). If you need to purchase an OBPA and/or cable, contact Kent-Moore at (800) 345-2233. The OBPA retails for $695.00 (includes all revisions 1-4) under part number J 41207-C. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 189 Engine Control Module: Technical Service Bulletins PCM - Replacement Component Text Deletion File in Section: 6E - Engine Fuel & Emission Bulletin No.: 41-65-33 Date: October, 1994 SERVICE MANUAL UPDATE Subject: Section 3A - Driveability, Emissions and Electrical Diagnosis - Text Deletion Models: 1994 Chevrolet and GMC Truck & T Models with 2.2L Gasoline Engine (VIN 4 - RPO LN2) or 4.3L Engine (VINs Z, W - RPOs LB4, L35) 1994-95 Chevrolet and GMC Truck C/K, M/L, G, P3, PG Models with 4.3L Engine (VIN Z - RPO LB4), 5.0L Engine (VIN H - RPO L03), 5.7L Engine VIN K - RPO L05) or 7.4L Engine (VIN N - RPO L19) 1994-95 Chevrolet and GMC Truck C/K, G, P3 Models with 6.5L Diesel Engine (VINs F, P, S RPOs L65, L49, L56) This bulletin contains revisions to the "Driveability, Emissions and Electrical Diagnostic" Service Manuals for the following pages: 1994 S/T Truck - 3A-5 1994-1995 G Van - 3A-4 1994-1995 C/K Truck - 3A-4 1994-1995 M/L Truck - 3A-4 1994-1995 PG/P3 Truck - 3A-4 1994-1995 C/K, G, P Truck - 3-17 and Supplement This Text is to be Deleted "The replacement PCM may be faulty - After the PCM is replaced, the system should be rechecked for proper operation. If the Diagnostic Chart again indicates that the PCM is the problem, substitute a known good PCM". Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Page 190 Engine Control Module: Specifications Engine VIN Code ID [1] ....................................................................................................................... .............................................................................. Z Engine Displacement ........................................................................................................................... ........................................................... 4.3L (262 cid) Engine Configuration ........................................................................................................................... ............................................................................ V6 Fuel Control System ...................................................................................................................................................... Throttle Body Fuel Injection (TBI) Ignition System ....................................................................................................... Distributor Ignition W/Ignition Control and Knock Sensor(DI-IC-KS) Control Module Systems S/T Pickup Automatic Transmission ......................................................................................................................... Powertrain Control Module (93PCM6) S/T Utility Manual Transmission .............................................................................................................................. Powertrain Control Module (93PCM6) S/T Pickup Manual Transmission ........................................................................................................................................ Vehicle Control Module (VCM) Remarks: [1] The eighth digit of the VIN denotes engine code. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Page 191 Engine Control Module: Locations Vehicle Speed Sensor Buffer And Electric Shift Transfer Case Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Page 192 Engine Or Powertrain Control Module Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Diagrams > C1 Red (32 Pin) Engine Control Module: Diagrams C1 Red (32 Pin) Manual Transmission (1 Of 2) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Diagrams > C1 Red (32 Pin) > Page 195 Manual Transmission (2 Of 2) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Diagrams > C1 Red (32 Pin) > Page 196 Engine Control Module: Diagrams C2-Blue (32 Pin) Automatic Transmission (1 Of 2) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Diagrams > C1 Red (32 Pin) > Page 197 Automatic Transmission (2 Of 2) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Diagrams > C1 Red (32 Pin) > Page 198 Engine Control Module: Diagrams C210 C210 - PCM C210 - ECM Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Diagrams > C1 Red (32 Pin) > Page 199 Engine Control Module: Diagrams C211 C211 - PCM C211 - ECM Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Diagrams > C1 Red (32 Pin) > Page 200 Engine Control Module: Diagrams With Manual Transmission Pinout Chart Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Diagrams > C1 Red (32 Pin) > Page 201 Pinout Chart Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Diagrams > C1 Red (32 Pin) > Page 202 Pinout Chart Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Diagrams > C1 Red (32 Pin) > Page 203 Pinout Chart Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Diagrams > Page 204 Engine Control Module: Description and Operation Engine Control Module Fig. 5 ECM Unit (Showing PROM & CALPAK Locations) Powertrain Control Module (PCM) PURPOSE The Powertrain Control Module (PCM) is the control center of the fuel injection system. It constantly looks at the information from various sensors (inputs) and controls the systems (outputs) that affect vehicle performance. The PCM also performs the diagnostic function of the system. It can recognize operational problems, alert the driver through the Malfunction Indicator Lamp (MIL) "Service Engine Soon" light on the instrument panel and store a Diagnostic Trouble Code(s) (DTC) in the PCM memory. The DTC identifies the problem areas to aid the technician in performing repairs. OPERATION The PCM is an electronic computer designed to process the various input information, and send the necessary electrical response to control fuel delivery, spark control, and other emission control systems. The PCM can control these devices through the use of Quad Driver Modules (QDM). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Diagrams > Page 205 When the PCM is commanding a device or a component "ON," the voltage potential of the output is "LOW" or near zero volts. When the PCM is commanding a device or component "OFF," the voltage potential of the circuit will be "HIGH," or near 12 volts. The primary function of the QDM is to supply the ground for the component being controlled. The input information has an interrelation between sensor output. If one of the input devices failed, such as the oxygen sensor, this could affect more than one of the systems controlled by the computer. The PCM has two parts for service: Controller which is the PCM (93 PCM6), without the PROM (MEM-CAL). - PROM (Programmable Read Only Memory) which is a separate memory calibrator unit PCM Learning Ability The PCM has a "learning" ability which allows it to make corrections for minor variations in the fuel system to improve driveability. If the battery is disconnected, to clear diagnostic trouble codes or for other repairs. the "learning" process resets and begins again. A change may be noted in the vehicle's performance. To "teach" the vehicle, ensure the engine is at operating temperature. The vehicle should be driven at part throttle, with moderate acceleration and idle conditions until normal performance returns. NOTE The PCM must be maintained at a temperature below 85°C (185°F) at all times. This is most essential if the vehicle is put through a baking process. The PCM will become inoperative if it's temperature exceeds 85°C (185°F). It is recommended that temporary insulation be placed around the PCM during the time the vehicle is in a paint oven or other high temperature processes. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Diagrams > Page 206 Engine Control Module: Service and Repair Figure 1 CAUTION [a] The ignition must be "OFF," when disconnecting or reconnecting the control module connector, to prevent internal damage to the control module. [b] To prevent possible Electrostatic Discharge to the control module, Do NOT touch the connector pins or soldered components on the circuit boards. NOTE When replacing a production control module with a service controller, transfer the broadcast code and production control module part number to the controller label. DO NOT record information on the access cover. REMOVE/DISCONNECT - Negative battery terminal. - Passenger side kick panel. - Hush panel if equipped. - Mounting screw. - Control module from mounting bracket. - VSS buffer connector and rotate control module to ease removal. - Control module harness connectors. - Mounting brackets and modules if equipped. - Remove new control module from its packaging and check the service number to make sure it is the same as the defective control module. - PROM removal. Refer to PROM (MEM-CAL) replacement. NOTE Replacement control module is supplied without a PROM, so care should be used when removing it from the defective control module, because it will be reused in the new control module. INSTALL/CONNECT - Mounting brackets and modules if equipped. - Control module harness connectors. - VSS buffer connector and rotate control module to ease installation. - Control module into mounting bracket. - Mounting screw. - Hush panel if equipped. - Passenger side kick panel. - Negative battery terminal. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > Customer Interest for Fuel Pump Relay: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking Fuel Pump Relay: Customer Interest Engine - Will Not Start Readily Upon Cranking File In Section: 6E - Engine Fuel & Emission Bulletin No.: 56-63-05A Date: January, 1996 Subject: Vehicle Does Not Start Readily Upon Cranking (Replace Fuel Pump Relay) Models: 1993-94 Chevrolet and GMC Truck M/L Vans 1994 Chevrolet and GMC Truck S/T Utility 1994 Oldsmobile Bravada with 4.3L Engine (VIN W, Z - RPOs L35, LB4) This bulletin is being revised to change the correction procedure and parts information and to add the L Van and artwork. Please discard Corporate Bulletin Number 56-63-05 (Section 6E - Engine Fuel & Emission). Condition Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > Customer Interest for Fuel Pump Relay: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking > Page 216 Some owners may experience extended engine crank times on cold start and may set diagnostic trouble code 54 and activate the M/L (Check Engine light). Cause This condition may be due to failure of the fuel pump relay. Correction Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > Customer Interest for Fuel Pump Relay: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking > Page 217 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > Customer Interest for Fuel Pump Relay: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking > Page 218 Verify condition using the normal diagnostic procedure in the service manual. Replace the Fuel Pump Relay (P/N 12077867) following the service manual procedure. Replace the connector (Kit P/N 12166225) following the instructions in Figures 3 and 4. Note that each of the four cavities of the old connector are lettered. The new connector is numbered and it should be wired according to Figure 3 and not the instructions contained within the connector kit. Parts Information P/N Description Qty 12077867 Fuel Pump Relay 1 12166225 Connector 1 12129073 Bracket (S/T Only) 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: Labor Operation Description Labor Time J5460 Relay, Fuel Pump- Use Published Replace Labor Operation Time Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Fuel Pump Relay: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking Fuel Pump Relay: All Technical Service Bulletins Engine - Will Not Start Readily Upon Cranking File In Section: 6E - Engine Fuel & Emission Bulletin No.: 56-63-05A Date: January, 1996 Subject: Vehicle Does Not Start Readily Upon Cranking (Replace Fuel Pump Relay) Models: 1993-94 Chevrolet and GMC Truck M/L Vans 1994 Chevrolet and GMC Truck S/T Utility 1994 Oldsmobile Bravada with 4.3L Engine (VIN W, Z - RPOs L35, LB4) This bulletin is being revised to change the correction procedure and parts information and to add the L Van and artwork. Please discard Corporate Bulletin Number 56-63-05 (Section 6E - Engine Fuel & Emission). Condition Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Fuel Pump Relay: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking > Page 224 Some owners may experience extended engine crank times on cold start and may set diagnostic trouble code 54 and activate the M/L (Check Engine light). Cause This condition may be due to failure of the fuel pump relay. Correction Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Fuel Pump Relay: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking > Page 225 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Fuel Pump Relay: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking > Page 226 Verify condition using the normal diagnostic procedure in the service manual. Replace the Fuel Pump Relay (P/N 12077867) following the service manual procedure. Replace the connector (Kit P/N 12166225) following the instructions in Figures 3 and 4. Note that each of the four cavities of the old connector are lettered. The new connector is numbered and it should be wired according to Figure 3 and not the instructions contained within the connector kit. Parts Information P/N Description Qty 12077867 Fuel Pump Relay 1 12166225 Connector 1 12129073 Bracket (S/T Only) 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: Labor Operation Description Labor Time J5460 Relay, Fuel Pump- Use Published Replace Labor Operation Time Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > Page 227 Fuel Pump Relay: Locations FUEL PUMP RELAY Fuel Pump Relay The Fuel Pump Relay is located on the driver side firewall, near brake booster. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > Page 228 C124 - Fuel Pump Relay Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > Page 229 Fuel Pump Relay: Description and Operation When the ignition key is first turned to the "ON" position, the control module will energize the fuel pump relay as long as the engine is cranking or running, and the control module is receiving distributor reference pulses. If there are no reference pulses, the control module will shut "OFF" the fuel pump relay within two seconds. An inoperative fuel pump relay can result in extended crank times, particularily if the engine is cold. The oil pressure switch will turn "ON" the fuel pump, as soon as oil pressure reaches about 28 kPa (4 psi). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > Page 230 Fuel Pump Relay: Testing and Inspection *** UPDATED BY TSB 893206E, DATED OCTOBER 90 When the key is first turned ON, without the engine running, the ECM will turn the fuel pump relay ON for two seconds. This builds up the fuel pressure to normal operating pressure. If the engine is not started within two seconds, the ECM will shut the fuel pump OFF and wait until ignition reference pulses are present. As soon as the engine is cranked, the ECM turns the relay ON, which powers the fuel pump. The ECM continues to power the fuel pump during engine operation. If the fuel pump relay fails, it is backed up by the oil pressure switch, which continues to operate the fuel pump as long as oil pressure remains above 28.0 kPa (4 psi). RESULTS OF INCORRECT FUEL PUMP SYSTEM OPERATION - A faulty fuel pump relay can result in long cranking times, particularly if the engine is cold. - An inoperative fuel pump would cause a no start condition. - A fuel pump which does not provide enough pressure can result in poor performance. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > Page 231 Fuel Pump Relay: Service and Repair Relay Center 2.5L,2.8L S REMOVE/DISCONNECT 1. Verify that ignition switch is in the "OFF" position. 2. Retainer, if installed. 3. Electrical connector. 4. Fuel pump relay by depressing bracket clip at rear of relay, or removing bolts from retaining bracket. INSTALL/DISCONNECT 1. Fuel pump relay. 2. Electrical connector. 3. Retainer. 4. Verify correct operation to confirm repair. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Ignition System > Ignition Control Module > Component Information > Locations > Ignition Module Typical Distributor Components Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Ignition System > Ignition Control Module > Component Information > Locations > Ignition Module > Page 237 Rear Engine Wiring W/Man Trans Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Ignition System > Ignition Control Module > Component Information > Locations > Page 238 C121 - Ignition Control Module Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Ignition System > Ignition Control Module > Component Information > Locations > Page 239 Ignition Control Module: Service and Repair Typical Distributor Components REMOVE OR DISCONNECT NOTE It is not necessary to remove ignition distributor assembly from engine. - Distributor cap and rotor. - Connectors from module. - Two module attaching screws. - Lift module from housing and remove. INSTALL OR CONNECT NOTE: Do not wipe silicone grease from metal face of module or distributor base (where the module seats), when reinstalling the same module. If new module is to be installed clean distributor module base and spread new silicone grease on base and metal face of ignition module. The purpose of the silicone grease is to cool module. - Module onto housing. - Module attaching screws. Tighten to 2 Nm (18 lb.in.) - Connectors to module. - Rotor and cap. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Restraint Systems > Air Bag Control Module > Component Information > Description and Operation Air Bag Control Module: Description and Operation A function of the DERM is to supply the deployment loop with a 36 volt loop reserve to ensure sufficient energy to deploy the air bag if the ignition feed to the arming sensor is lost during a frontal collision. Another function of the DERM is electrical system diagnostics. The DERM can detect circuit and component malfunctions within the deployment loop. Voltage drops across components within the loop are measured during non-deployment conditions. If the monitored voltages fall outside of the expected limits, the DERM will indicate a malfunction through the storage of a diagnostic trouble code and the illumination of the air bag warning light. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Restraint Systems > Air Bag Control Module > Component Information > Description and Operation > Page 244 Air Bag Control Module: Service and Repair Prior to performing replacement procedures, disarm air bag system. Refer to, Service and Repair/ Air Bag System Disarming & Air Bag System Arming. Refer to, / Specifications/ Mechanical for torque values when installing components. All sensors and mounting bracket bolts must be carefully torqued to assure proper operation. Never power up the air bag system when any sensor is not rigidly attached to the vehicle, since the sensor could be activated when not attached, causing air bag deployment. Do not open DERM case for any reason. Touching connector pins or soldered components may cause electrostatic discharge damage. Repair of a malfunctioning DERM is by replacement only. 1. Remove righthand sound insulator, then the righthand sill plate. 2. Remove righthand cowl side trim plate. 3. Remove DERM from mounting bracket. 4. Remove Connector Position Assurance (CPA) lock, then disconnect DERM electrical connector from DERM. 5. Reverse procedure to install. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Locations Control Module: Locations Mounted on the back of the Electronic Control Module (ECM)/Powertrain Control Module (PCM) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Locations > Page 250 C202A - Transfer Case Control Module Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting Control Module: Description and Operation Electric 4WD Shifting Transfer Case 4WD Selector Switch 4WD Selector Switch Wiring Schematic OPERATION On vehicles equipped with the Model 233 transfer case, there is no transfer case selector lever in the cab. The operator selects 4HI or 4LO by pushing a three-position (4HI, 4LO, 2HI) rocker-type selector switch mounted on the instrument panel. During normal driving the transfer case is in the 2HI mode. The switch is spring-loaded to the center position. When the transfer case is in 2HI both the 4HI and 4L0 switch circuits are open, and both lights are off. When shifting to 4HI or 4LO the rocker switch will still return to the center position and the 4HI or 4LO light will be on. The above image shows the wiring schematic of the transfer case selector switch. Mode Shifts Mode shifts are shifts from: - 2HI to 4HI - 4HI to 2HI A mode shift can be accomplished in any gear position and at any vehicle speed. If the system is in 2HI, the operator can shift into 4HI merely by pressing and releasing the 4HI area of the selector rocker switch. The green 4HI status lamp flashes whenever a 2HI or 4HI shift is initiated and continues to flash until the TCCM completes the shift (or until 30 seconds elapses). After the shift into 4HI is accomplished, the 4HI status lamp remains lit to indicate that the system is in 4HI. The operator can shift from 4HI back to 2HI by again pressing 4HI on the selector switch. Again, the green 4HI status lamp flashes until the shift to 2HI is complete, and then extinguishes once the shift is complete. Both the 4HI and 4LO lamps remain oft when the vehicle is in 2HI. Range Shifts Range shifts are shifts between the HI and LO ranges, from: Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 253 - 2HI to 4LO - 4HI to 4LO - 4LO to 4HI A range shift from 4L0 directly to 2HI cannot be made. The operator must first make range shift from 4LO to 4HI, then a mode shift from 4HI to 2HI. A range shift can only be made with the automatic transmission in neutral or with the manual transmission clutch fully depressed. The vehicle speed must also be below three miles per hour before the shift can occur. Whenever a shift into 4LO is initiated, the amber 4LO status lamp flashes and continues to flash until the TCCM completes the shift (or until 30 seconds elapses). The 4LO status lamp must glow steadily before the vehicle transmission is shifted into gear or before the clutch pedal is released. If a range shift is initiated when the transmission is engaged or when the vehicle speed is above 3 mph, the 4LO status lamp flashes for 30 seconds and no range shift actually occurs; the system returns to the position before the shift was initiated. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 254 Control Module: Description and Operation TCCM Power and Ground Fig. 1, Memory Power, System Power, And Ground Circuit Fig. 2, Fuse Block And Cavity Location Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 255 POWER, CIRCUIT PROTECTION, AND GROUND The Transfer Case Control Module (TCCM) memory power, system power, and the ground circuit are shown in Figure 1. The vehicle fuse block and cavity location for memory power, system power, and motor power are shown in Figure 2. Memory Power Trouble code memory power is protected by a 5-amp TCCM fuse. Memory power is supplied to TCCM connector pin C6 through circuit 140. System Power Operating power is controlled by the ignition switch and is protected by a 15-amp radio fuse. System power is supplied to TCCM connector pin C8 through circuit 141. This fuse also supplies, voltage to pin B of the transfer case switch. The system power will shut down if either the 5-amp TCCM fuse or the 15-amp radio fuse are removed or blown. System Ground System ground is supplied to TCCM connector pin C10 through circuit 150. Circuit 150 is connected to the bus bar ground located on the left side of the steering column support. Refer to Figure 1. Turn/BU Fuse A 15-amp TURN/BU fuse supplies ignition voltage to the park/neutral position switch. This voltage enables the park switch to send a park signal to TCCM connector pin D2. Power Accessory Circuit Breaker The 30-amp power accessory circuit breaker supplies ignition voltage to TCCM connector pins D14 and D15. This voltage is used to control the electric-shift motor circuit. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 256 Control Module: Description and Operation TCCM Inputs and Outputs General Description INPUTS The Transfer Case Control Module (TCCM) receives input signals from the following sources: - Transfer case selector switch on the instrument panel. - Park/neutral position switch on vehicles with automatic transmissions. - Clutch safety switch on vehicles with manual transmissions. - Vehicle speed sensor buffer which supplies vehicle speed signals. - Encoder switch within the electric-shift motor which provides actual mode and range information signals. - Data link connector (DLC) pin J which provides diagnostic enable. OUTPUTS After processing the input information, the Transfer Case Control Module (TCCM) outputs signals to the following: - Electric shift motor to effect mode and range shifts. - Selector switch status lamps to provide transfer case status information. - Diagnostic trouble codes (DTC) which are output via the selector switch status lamps. 2HI to 4HI Selector Switch Input 4WD Selector Switch Wiring Schematic OPERATION When the transfer case is in 2HI and the operator presses the 4HI area of the rocker switch, the 4HI contacts of the selector switch close, connecting circuits 141 and 1564, and furnishing 12-volts to pin C5 of the TCCM connector. The 12-volt signal at pin C5 commands the Transfer Case Control Module (TCCM) to signal the electric-shift motor to shift into 4HI. The contacts return to the open position as soon as the switch is released. 4HI to 2HI Selector Switch Input Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 257 4WD Selector Switch Wiring Schematic OPERATION If the transfer case is in 4HI and the operator presses the 4HI area of the rocker switch, the 4HI contacts of the selector switch close, connecting circuits 141 and 1564 and furnishing 12-volts to pin C5 of the Transfer Case Control Module (TCCM) connector. The 12-volt signal at pin C5 commands the TCCM to signal the electric-shift motor to shift into 4HI. Again, the contacts return to the open position as soon as the switch is released. 2HI to 4HI to 4LO Selector Switch Input 4WD Selector Switch Wiring Schematic OPERATION When the operator presses the 4LO area of the rocker switch while the transfer case is in either 2HI or 4HI, the 4LO contacts of the selector switch close, connecting circuits 141 and 1559, and furnishing 12-volts to pin C3 of the Transfer Case Control Module (TCCM) connector. The 12-volt signal at pin C3 commands the TCCM to signal the electric-shift motor to shift the transfer case into 4LO. Once more, the contacts return to the open position as soon as the switch is released. Park/Neutral Position Switch Inputs Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 258 Automatic Transmission Neutral Start Switch Neutral Start Switch Voltages OPERATION Because range shift should only be made with the automatic transmission in neutral, the park/neutral position switch informs the Transfer Case Control Module (TCCM) that the vehicle automatic transmission is in either: - Park - Neutral - One of the drive positions The park/neutral position switch consists of three switches together in one unit, and it provides three signals: - Park - When the automatic transmission is in park, the contacts of both the park switch and the park neutral switch are closed. When these contacts are closed, a battery voltage signal is sent to TCCM connector pin D2, while connector pin D16 is pulled to ground (0 voltage). The TCCM interprets this signal to mean the automatic transmission is in park. - Neutral - When the automatic transmission is in neutral, the contacts of the park switch are open and the contacts of the park neutral position switch are closed. In this condition, a 0-voltage signal is sent to TCCM connector pin D2, while connector pin D16 is pulled to ground (0 volts). The TCCM interprets this signal to mean the automatic transmission is in neutral. - In gear - When the automatic transmission is in any other gear position, the contacts of both the park switch and park neutral switch are open. In this condition, a 0-voltage signal is sent to TCCM connector pin D16. The TCCM interprets this signal to mean the automatic transmission is neither park or neutral. Important - If the backup switch connector were to be plugged in upside down, the park switch would receive no power. Such a condition would cause a 0-voltage signal at both pin D2 and pin D16 in neutral and in park. The transfer case, accordingly, would perform a range shift in park as well as in neutral. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 259 - An open in circuit 75, or an open in the Turn/BU fuse would also cause this condition. - Additionally, a park/neutral position switch that is out of adjustment may prevent a range shift in park. Clutch Safety Switch Inputs Clutch Safety Switch Schematic Clutch Safety Switch Voltage Signals OPERATION Because range shifts should only be made with the manual transmission clutch fully depressed, the clutch safety switch informs the Transfer Case Control Module (TCCM) that the vehicle clutch pedal is fully depressed or released. The clutch safety switch is connected to TCCM connector pin D16. When the clutch pedal is released, the contacts of the clutch safety switch are open. When these contacts are open, a battery voltage signal is seen at TCCM connector pin D16. The TCCM interprets this signal to mean the clutch is released. When the clutch is fully depressed, the contacts of the clutch safety switch are closed. When the contacts are closed, voltage is pulled low to 0 at TCCM connector pin D16. The TCCM interprets this signal to mean the clutch pedal is fully depressed. Because TCCM connector pin D2 is not connected when the vehicle is equipped with a manual transmission, the TCCM reads a 0-volt signal at pin D2 at all times. All readings are taken while back-probing the TCCM pins with the ignition in the "Run" position. A reading of less than 0.5 volt is considered to be zero. Vehicle Speed Input Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 260 Vehicle Sensor Buffer And TCCM Schematic OPERATION The vehicle speed sensor buffer informs the Transfer Case Control Module (TCCM) about the speed of the vehicle in miles per hour. Such information is essential to inform the TCCM to prohibit range shifts at speeds above 3 mph. The vehicle speed sensor (VSS) is a variable-reluctance magnetic sensing device that converts tone wheel rotation into a frequency and voltage output proportional to the vehicle speed. The frequency and voltage signal is sent to the vehicle speed sensor buffer which converts the speed sensor output into a useful pulse signal. The vehicle speed sensor buffer then, pulses circuit 1567 to ground at a rate of 4000 pulses per mile. Whenever the vehicle speed sensor buffer grounds circuit 1567, the voltage at TCCM connector pin D8 returns to 5 volts. The TCCM reads the 4000 pulses-per-mile (1.11 Hz per mph) signal to determine vehicle speed. Encoder Switch Inputs Fig 1, Electric Shift Encoder Switch Layout Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 261 Fig 2, Electric Shift Encoder Switch Schematic Fig 3, Encoder Switch Channel Signals And Positions OPERATION The four-channel encoder switch indicates the current transfer case mode and range to the Transfer Case Control Module (TCCM). The encoder switch is located inside the encoder itself and is not serviceable. The TCCM reads the status of the four channels to determine the range and mode in which the transfer case is operating or whether the transfer case is shifting between modes and/or ranges. The encoder assembly is composed of an inner ground ring in contact with a three-leg wiper arm. The three legs of the wiper, spaced 120 degrees apart, make contact with the conductive areas of the four channels. When any leg of the wiper arm is in contact with the conductive area of any channel, a path to ground is provided to the inner ground ring. A schematic of the encoder switch is shown in Figure 2. The channel signals in various transfer case operating modes and ranges are shown in Figure 3. Any combination of signals not listed in Figure 3 are considered invalid by the TCCM. Encoder Switch Channel Positions These voltage readings can be obtained by back-probing either the TCCM connector pins or the transfer case connector pins. For TCCM pin numbers and encoder channels, refer to Figure 2. Diagnostic Enable Input Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 262 Wiring Schematic For Enabling The Status Lamps OPERATION When pin J of the Data Link Connector (DLC) is connected either to pin A of the DLC or to a good ground while the ignition is on, the diagnostics routine of the Transfer Case Control Module (TCCM) is activated. When the diagnostics routine is activated, the transfer case selector switch 4HI and 4LO status lamps flash the diagnostic codes. Electric Shift Motor Outputs Electric Shift Motor Schematic OPERATION The Transfer Case Control Module (TCCM) provides the output for the electric shift motor as the schematic shows. - Motor control is achieved by energizing one of the two motor control relays located in the TCCM, by way of the transfer case selector switch. The TCCM operates the motor in one direction by energizing one relay while the second relay is de-energized. The TCCM operates the motor in the reverse direction by energizing the second relay while the first relay is de-energized. - Motor power to actuate the motor drive relays is input at TCCM connector pins D14 and D15. This power is supplied by the ignition through the 30-amp power circuit breaker. - Motor ground is input at TCCM connector pins D12 and D13 to provide the return line for the motor drive relays. 4HI and 4LO Status Lamps Outputs Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 263 Selector Switch Status Lamp Schematic OPERATION The Transfer Case Control Module (TCCM) controls the operation of the 4HI and 4LO status lamps in the transfer case selector switch. The status lamps also show the transfer case mode and range of operation. The status lamps also provide a self-test when the ignition is first turned on. Additionally, the status lamps are used to alert the driver that there is a problem somewhere in the four-wheel drive system, and also to flash diagnostic trouble codes (DTC's). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Page 264 Control Module: Service and Repair TRANSFER CASE MODULE REPLACEMENT REMOVE OR DISCONNECT 1. Negative battery cable. 2. ECM (utility only). 3. Cowl side panel (pickup only). 4. Electrical connection. 5. Module to cowl panel screws (pickup only). 6. Module. INSTALL OR CONNECT 1. Module. 2. Module to cowl panel screws (pickup only). 3. Electrical connection. 4. ECM (utility only). 5. Negative battery cable. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Windows and Glass > Heated Glass Element Relay > Component Information > Locations Rear Window Release And Defogger Forward Wiring - 4-Door Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Windows and Glass > Heated Glass Element Relay > Component Information > Locations > Page 269 C244 - Defogger Timer Relay Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Windows and Glass > Power Window Relay > Component Information > Locations Rear Window Release Forward Wiring Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Relays and Modules > Relays and Modules - Wiper and Washer Systems > Wiper Control Module > Component Information > Locations Wiper/Washer Wiring Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Body and Frame > Power Door Lock Switch > Component Information > Locations > Door Lock Switch, Right Front Power Door Lock Switch: Locations Door Lock Switch, Right Front Power Door Lock Wiring-4-Door Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Body and Frame > Power Door Lock Switch > Component Information > Locations > Door Lock Switch, Right Front > Page 283 Power Window And Door Lock Body Wiring-4-Door Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Body and Frame > Power Door Lock Switch > Component Information > Locations > Door Lock Switch, Right Front > Page 284 RH Door Harness (LH Typical) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Body and Frame > Power Door Lock Switch > Component Information > Diagrams > Left Front Door Lock Switch C504 - Front LH Power Door Lock Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Body and Frame > Power Door Lock Switch > Component Information > Diagrams > Left Front Door Lock Switch > Page 287 C604 - Front RH Power Door Lock Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Body and Frame > Power Mirror Switch > Component Information > Locations Outside Rearview Mirror Switch Wiring Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Body and Frame > Power Mirror Switch > Component Information > Locations > Page 291 C298A - Power Outside Rearview Mirror Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Body and Frame > Power Seat Switch > Component Information > Locations Power Seat And Wiring Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Body and Frame > Power Seat Switch > Component Information > Diagrams > Passenger's C334 - Passenger's Seat Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Body and Frame > Power Seat Switch > Component Information > Diagrams > Passenger's > Page 297 C333 - Driver's Seat Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Body and Frame > Trunk / Liftgate Switch > Component Information > Diagrams > I/P to Liftgate Release Switch C242 - I/P To Liftgate Release Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Body and Frame > Trunk / Liftgate Switch > Component Information > Diagrams > I/P to Liftgate Release Switch > Page 302 C247A - I/P To Liftgate Release/Defogger Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Body and Frame > Trunk / Liftgate Switch > Component Information > Diagrams > I/P to Liftgate Release Switch > Page 303 C242 - Liftgate Release Switch To I/P Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Brakes and Traction Control > 4WD Switch > Component Information > Technical Service Bulletins > Recalls for 4WD Switch: > 99-041 > May > 00 > Recall ABS Front Axle Signal Malfunction Technical Service Bulletin # 99-041 Date: 000501 Recall - ABS Front Axle Signal Malfunction File in: Product Section: Campaigns Bulletin No: 99041 Dates: May, 2000 SUBJECT: 99041 - INCORRECT FRONT AXLE STATUS SIGNAL TO EBC4 ABS MODELS: 1991-1996 CHEVROLET AND GMC 4WD T UTILITIES 1994-1996 CHEVROLET AND GMC 4WD T PICKUP TRUCKS DUE TO THE AVAILABILITY OF PARTS, THIS CAMPAIGN WILL BE ADMINISTERED IN PHASES. YOU WILL RECEIVE A DEALER LISTING AS PHASES ARE RELEASED. CONDITION General Motors has decided that a defect which relates to motor vehicle safety exists in certain 1991-1996 Chevrolet and GMC 4WD T utilities and 1994-1996 Chevrolet and GMC 4WD T pickup trucks. Some of these vehicles exhibit a condition in which a switch that signals the antilock brake system (ABS) module when the vehicle is in four-wheel drive (4WD) may malfunction. The ABS module is designed with two different operating algorithms; one for two-wheel drive (2WD) operation and another for 4WD drive operation. This allows the ABS system to compensate for the braking torque applied tot he rear wheels through the drivetrain when the vehicle is in 4WD drive. When the vehicle is in 2WD, a malfunctioning switch may send an incorrect signal tot he ABS module. If this occurs during an ABS stop, a somewhat longer stopping distance could result. If this occurred when minimum stopping distance was required, it could result a vehicle crash. CORRECTION Dealers are to install a new transfer case selector switch, wiring harness, and an additional switch to ensure that the ABS receives the 4WD signal only when the drivetrain is in 4WD. VEHICLES INVOLVED Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Brakes and Traction Control > 4WD Switch > Component Information > Technical Service Bulletins > Recalls for 4WD Switch: > 99-041 > May > 00 > Recall ABS Front Axle Signal Malfunction > Page 313 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Brakes and Traction Control > 4WD Switch > Component Information > Technical Service Bulletins > Recalls for 4WD Switch: > 99-041 > May > 00 > Recall ABS Front Axle Signal Malfunction > Page 314 Involved are certain 1991-1996 Chevrolet and GMC 4WD T utilities and 1994-1996 Chevrolet and GMC 4WD T pickup truck built within these VIN breakpoints as shown. IMPORTANT Dealers should confirm vehicle eligibility through GMVIS (GM Vehicle Inquiry System) or GM Access Screen (Canada only) or DCS Screen 445 (IPC only) before beginning campaign repairs. [Not all vehicles within the above breakpoints may be involved.] Involved vehicles have been identified by Vehicle Identification Number. Computer listing containing the complete Vehicle Identification, customer name address data have been prepared, and are being furnished to involved dealers with the campaign bulletin. The customer name address data furnished will enable dealers to follow up with the campaign bulletin has no involved vehicles currently assigned. These dealer listings may contain customer names and addresses obtained from Motor Vehicle Registration Records. The use of such motor vehicle registration data for any other purpose is a violation of law in several states/provinces/countries. Accordingly, you are urged to limit the use of this listing to the follow-up necessary to complete this campaign. PARTS INFORMATION Parts required to complete this campaign are to be obtained from General Motors Service Parts Operations (GMSPO). Please refer to your "involved vehicles listing" before ordering parts. Normal orders should be placed on a DRO = Daily Replenishment Order, in an emergency situation, parts should be ordered on a CSO = Customer Special Order. Part Number Description Quantity/Vehicle 88880028 Switch Kit, Elek Brk Cont Frt 1 Drv Axle Vac (1991-94 Utility) 88880029 Switch Kit, Elek Brk Cont Frt 1 Drv Axle Vac (1995-96 Utility, 1994-96 Pickup) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Brakes and Traction Control > 4WD Switch > Component Information > Technical Service Bulletins > Recalls for 4WD Switch: > 99-041 > May > 00 > Recall ABS Front Axle Signal Malfunction > Page 315 CAMPAIGN IDENTIFICATION LABEL - For US IPC Place a Campaign Identification Label on each vehicle corrected in accordance with the instructions outlined in this Product Campaign Bulletin. Each label provides a space to include the campaign number and the five (5) digit dealer code of the dealer performing the campaign service. This Information may be inserted with a typewriter a ball point pen. CAMPAIGN IDENTIFICATION LABEL - For CANADA Place a Campaign Identification Label on each vehicle corrected in accordance with the instruction outlined in this Product Campaign Bulletin. Each label provides a space to include the campaign number and the five (5) digit dealer code of the dealer performing the campaign service. This information may be inserted with a typewriter or a ball point pen. CLAIM INFORMATION Submit a Product Campaign Claim with the information indicated. Refer to the General Motors WINS claims processing Manual for details on Product Campaign Claim Submission. CUSTOMER NOTIFICATION - For US and CANADA Customers will be notified of this campaign on their vehicles by General Motors (see copy of customer letter included with this bulletin. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Brakes and Traction Control > 4WD Switch > Component Information > Technical Service Bulletins > Recalls for 4WD Switch: > 99-041 > May > 00 > Recall ABS Front Axle Signal Malfunction > Page 316 CUSTOMER NOTIFICATION - For IPC Letters will be sent to known owners of record located within areas covered by the US National Traffic and Motor Vehicle Safety Act. For owners outside these areas, dealers should notify customers using the attached suggested dealer letter. DEALER CAMPAIGN RESPONSIBILITY - For US and IPC (US States, Territories, and Possessions) The US National Traffic end Motor Vehicle safety Act provides that each vehicle that is subject to recall campaign of this type must be adequately repaired within a reasonable time after the customer has tendered it for repair. A failure to repair within sixty days after tender of vehicle is prima facie evidence of failure to repair within a reasonable time. If the condition is not adequately repaired within a reasonable time the customer may be entitled to an identical or reasonably equivalent vehicle at no charge or to a refund of the purchase price less a reasonable allowance for depreciation. To avoid having to provide these burdensome remedies, every effort must be made to promptly schedule an appointment with each customer and to repair their vehicle as soon as possible. In the recall campaign notification letters, customers are told how to contact the US National Highway Traffic Safety Administration if the campaign is not completed within a reasonable time. DEALER CAMPAIGN RESPONSIBILITY - ALL All unsold new vehicle in dealers' possession and subject to this campaign must be held an inspected/repaired per the service procedure of this campaign bulletin before customers take possession of these vehicles. Dealers are to service all vehicles subject to this campaign at no charge to customers, regardless of mileage, age of vehicle, or ownership, from this time forward. Customers who have recently purchased vehicles sold from your vehicle inventory, and for which there is no customer information indicated on the dealer listing, are to be contacted by the dealer. Arrangements are to be made to make the required correction according to the instructions contained in this bulletin. This could be done by mailing to such customers, a copy of the customer letter accompanying this bulletin. Campaign follow-up cards should not be used for this purpose, since the customer may not as yet have received the notification letter. In summary, whenever a vehicle subject to this campaign enters your vehicle inventory, or is in your dealership for service in the future, you must take the steps necessary to be sure the campaign correction has been made before selling or releasing the vehicle. Disclaimer 1991-94 T-Utility 1. Disconnect the negative battery cable. 2. Remove the front lower coolant reservoir attaching bolt. 3. Install the new vacuum switch, bracket, and hose assembly at the front lower coolant reservoir attaching location using the bolt removed in the previous step. Important The bracket must be rotated/positioned and held as close to the coolant reservoir as possible during the tightening of the bolt or nut to maintain maximum clearance between the battery and the vacuum switch. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Brakes and Traction Control > 4WD Switch > Component Information > Technical Service Bulletins > Recalls for 4WD Switch: > 99-041 > May > 00 > Recall ABS Front Axle Signal Malfunction > Page 317 4. Position the vacuum switch, bracket, and hose assembly as shown in Figure 1 and tighten the bolt to 8 Nm (71 lb in). 5. Locate the vacuum hose leading from the front axle vacuum actuator, located under the battery tray, to the vacuum switch mounted bon the transfer case. This vacuum hose typically is routed along the right front frame rail rearward up along the wheel well towards the cowl area of the engine compartment. On some vehicle this hose may be covered with a black convoluted protective sleeve. 6. Select a point on the vacuum hose, which was located in the previous step, that will be lower in the vehicle than the new vacuum switch and will not result in the loading or stretching of either the existing or new hoses when they are connected together. Important The location where the vacuum line is tapped into must be lower than the vacuum switch to ensure condensation cannot accumulate in the switch, possibly resulting in a switch malfunction. 7. Cut the existing vacuum hose at me point located in the previous step, and connect the ends of the cut vacuum hose to the tee fitting that is part of the new vacuum switch and hose assembly. 8. Connect the new wiring harness to the vacuum switch and ensure the locking feature of the connector is engaged. Important Ensure that the new harness is routed and secured in such a manner that it will not come in contact with any moving parts or be exposed to any other conitions that may result in damage to the harness. 9. Route the new harness is shown in Figure 1 and secure it to the existing Underhood components at the locations indicated (1) using the tie straps provided in the kit. 10. Locate and disconnect the existing underhood front exle switch wiring harness connector, located in the area above the brake booster assembly, and jumper in the new wiring harness. 11. Raise the vehicle and suitably support. 12. Loate the transfer case selector switch positioned on top of the transfer case. 13. Remove any foreign material from around the transfer case selector switch or vacuum connector. Important Ensure that the O-ring is removed and discarded. 14. Disconnect the vacuum connector, remove and discard the transfer case selector switch and the O-ring. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Brakes and Traction Control > 4WD Switch > Component Information > Technical Service Bulletins > Recalls for 4WD Switch: > 99-041 > May > 00 > Recall ABS Front Axle Signal Malfunction > Page 318 15. Hand start the new transfer case selector switch and tighten to 24 Nm (18 lb ft). 16. Ensure that the alignment feature of the vacuum harness connector is oriented correctly to engage the alignment post/pin of the transfer case selector switch and connect the harness to the switch. 17. Lower the vehicle and connect the negative battery cable. 18. Install the GM Campaign Identification Label. 1994 T-Pickup 1. Disconnect the negative battery cable. 2. Locate the new vacuum switch, bracket, and hose assembly so that the hole in the bracket align with the front inboard nut that is molded into the top of the coolant reservoir as shown in Figure 2. 3. Using the bolt provided in the kit, switch the vacuum switch, bracket, and hose assembly to the coolant reservoir by hand at starting the bolt. 4. With the vacuum switch, bracket and hose assembly positioned as shown in Figure 2, tighten the bolt to 10 Nm (88 lb in). 5. Locate the vacuum hose leading from the front axle vacuum actuator, located under the battery tray, to the vacuum switch mounted on the transfer case. This hose is routed up from the axle vacuum actuator and then rearward towards the cowl area inside the right fender as shown in Figure 2. 6. Select a point on the vacuum hose, which was located in the previous step, that will be lower in the vehicle than the new vacuum switch and will not result in the loading or stretching of either the existing or new hoses when they are connected together. Important The location where the vacuum line is tapped into must be lower than the vacuum switch to ensure condensation cannot accumulate in the switch, possibly resulting in a switch malfunction. 7. Cut the existing vacuum hose at the point located in the previous step, and connect the ends of the cut vacuum hose to the tee fitting that is a part of the new vacuum switch and hose assembly. 8. Connect the new wiring harness to the vacuum switch and ensure the locking feature of the connector is engaged. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Brakes and Traction Control > 4WD Switch > Component Information > Technical Service Bulletins > Recalls for 4WD Switch: > 99-041 > May > 00 > Recall ABS Front Axle Signal Malfunction > Page 319 Important: Ensure that the new harness is routed and secured in such a manner that it will not come in contact with any moving parts or be exposed to any other conditions that may result in damage to the harness. 9. Route the harness as shown in Figure 2 and secure the new harness to the existing underhood components at the locations indicated (1) using the tie straps provided in the kits. 10. Disconnect the existing underhood front axle switch wiring harness connector, located in the area of the left front inner wheel well skirt under the brake master cylinder, and jumper in the new wiring harness. 11. Raise the vehicle and suitably support. 12. Locate the transfer case selector switch positioned on top of the transfer case. 13. Remove any foreign material from around the transfer case selector switch or vacuum connector. Important: Ensure that the O-ring is removed and discarded. 14. Disconnect the vacuum connector, remove and discard the transfer case selector switch and the O-ring. 15. Hand start the new transfer case selector switch and tighten to 24 Nm (18 lb ft). 16. Ensure the alignment feature of the vacuum harness connector is oriented correctly to engage the alignment post/pin of the transfer case selector switch and connect the harness to the switch. 17. Lower the vehicle and connect the negative battery cable. 18. Install the GM Campaign Identification Label. 1995-96 T-Pickup and 1995-96 T-Utility 1. Disconnect the negative battery cable. 2. Remove the front lower coolant reservoir attaching nut and discard. 3. Install the new vacuum switch, bracket, and hose assembly at the front lower coolant reservoir attaching location using the new nut contained in the kit. Important: The bracket must be rotated/positioned and held as close to the coalant reservoir as possible during the tightening of the nut to maintain maximum clearance between the battery and the vacuum switch. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Brakes and Traction Control > 4WD Switch > Component Information > Technical Service Bulletins > Recalls for 4WD Switch: > 99-041 > May > 00 > Recall ABS Front Axle Signal Malfunction > Page 320 4. Position the vacuum switch, bracket, and hose assembly as shown in Figure 3 and tighten the nut to 8 Nm (71 lb in). 5. Locate the vacuum hose leading from the front axle vacuum actuator, located under the battery tray, to the vacuum switch mounted on the transfer case. This vacuum hose typically is route along the right front frame rail rearward up along the wheel welt towards the cowl area of the engine compartment. On come vehicle this hose may be covered with black convoluted protective sleeve. 6. Select a point on the vacuum hose, which was located in the previous step, that Will be lower in the vehicle than the new vacuum switch and will not result in the loading or stretching of either the existing or new hoses when they are connected together. Important The location where the vacuum line le tapped into must be lower than the vacuum switch to ensure condensation cannot accumulate in the switch, possibly resulting in a switch malfunction. 7. Cut the existing vacuum hose at the point located in the previous step, and connect the ends of the cut vacuum hose to the tee fitting that is part of the new vacuum switch and hose assembly. 8. Connect the new wiring harness to the vacuum switch and ensure the looking feature of the connector is engaged. Important: Ensure that the new harness is routed and secured in such a manner that it will not come in contact with any moving parts or be exposed to any other conditions that may result in damage to the harness. 9. Route the new harness as shown in Figure 3 and secure it to the existing underhood components at the locations indicated (1) using the tie straps provided in the kit. 10. Locate and disconnect the existing underhood front axle switch wiring harness connector, located in the area of the left front inner wheel well skirt under the brake master cylinder, and jumper in the new wiring harness. 11. Raise the vehicle and suitably support. 12. Locate the transfer case selector switch positioned on top of the transfer case. 13. Remove any foreign material from around the transfer case selector switch or vacuum connector. Important: Ensure that the O-ring is removed and discarded. 14. Disconnect the vacuum connector, remove and discard the transfer case selector switch and the O-ring. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Brakes and Traction Control > 4WD Switch > Component Information > Technical Service Bulletins > Recalls for 4WD Switch: > 99-041 > May > 00 > Recall ABS Front Axle Signal Malfunction > Page 321 15. Hand start the new transfer case selector switch and tighten to 24 Nm (18 lb ft) 16. Ensure that the alignment feature of the vacuum harness connector is oriented correctly to engage the alignment post/pin of the transfer case selector switch and connect the harness to the switch. 17. Lower the vehicle and connect the negative battery cable. 18. Install the GM Campaign Identification Label. Owner Letter 99041 (Sample Of Notification Used) May, 2000 Dear General Motors Customer: This notice is sent to you in accordance with the requirements of the National Traffic and Motor Vehicle Safety Act. Reason For This Recall: General Motors has decided that a defect which relates to motor vehicle safety exists in certain 1991-1996 4WD wheel drive (4WD) Blazers and Jimmys, and 1994-1996 4WD S-10 and Sonoma pickup trucks. Some of these Vehicles exhibit a condition in which a switch that signals the antilook brake system (ADS) module when the vehicle is in 4WD may malfunction. The ABS module is designed with two different operating algorithms: one for 2-wheel drive (2WD) operation and another for 4WD drive operation. This allows the ABS system to compensate for the braking torque applied to the rear wheels through the drivetrain when the vehicle is in 4WD drive. When the vehicle is in 2WD, a malfunction switch may send an incorrect signal to the ABS module. If this occurs during an ABS stop, a somewhat longer stopping distance could result. If this occurred when minimum stopping distance was required, it could result in a vehicle crash. What Will Be Done: Your dealer will install a new transfer case selector switch, wiring harness, and an additional switch to ensure that the ABS receives the 4WD signal only when the drivetrain is in 4WD. This service will be performed for you at no charge. How Long Will The Repair Take? The length of time required to perform this service correction is approximately 30 minutes. Additional time may be required to schedule and process your vehicle. If your dealer has a large number of vehicles awaiting service, this additional time may be significant. Please ask your dealer if you wish to know how much additional time will be needed to schedule process and repair your vehicle. Contacting Your Dealer: Please contact your Chevrolet/GMC dealer as soon as possible to arrange a service date. Parts are available and instructions for making this correction have been sent to your dealer. Your Chevrolet/GMC dealer is best equipped to obtain parts and provide services to correct you vehicle as promptly as possible. Should your dealer be unable to schedule a service date within a reasonable time, you should contact the appropriate Customer Assistance Center at the listed number below: Division Number Deaf, Hearing Impaired or Speech Chevrolet 1-800-222-1020 1-800-833-2438 GMC 1-800-462-8782 1-800-462-8583 Utilize Telecommunication Devices If, after contacting the appropriate Customer Assistance Center, you are still not satisfied that we have done our best to remedy this condition without charge and within a reasonable time, you may wish to write the Administrator, National Highway Traffic Safety Administration, 400 Seventh Street, SW, Washington, DC 20590 or call 1-800-424-9393 (Washington, DC residents use (202-366-0123). Customer Reply Card: The customer reply card identifies your vehicle. Presentation of this card to your dealer will assist in making necessary correction in the shortest possible time. If you no longer own this vehicle, please let us know by completing the attached and mailing it in the postage paid envelope. We are sorry to cause you this inconvenience; however, we have taken this action in the interest of your safety and continued satisfaction with our products. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Brakes and Traction Control > 4WD Switch > Component Information > Technical Service Bulletins > All Technical Service Bulletins for 4WD Switch: > 99-041 > May > 00 > Recall - ABS Front Axle Signal Malfunction Technical Service Bulletin # 99-041 Date: 000501 Recall - ABS Front Axle Signal Malfunction File in: Product Section: Campaigns Bulletin No: 99041 Dates: May, 2000 SUBJECT: 99041 - INCORRECT FRONT AXLE STATUS SIGNAL TO EBC4 ABS MODELS: 1991-1996 CHEVROLET AND GMC 4WD T UTILITIES 1994-1996 CHEVROLET AND GMC 4WD T PICKUP TRUCKS DUE TO THE AVAILABILITY OF PARTS, THIS CAMPAIGN WILL BE ADMINISTERED IN PHASES. YOU WILL RECEIVE A DEALER LISTING AS PHASES ARE RELEASED. CONDITION General Motors has decided that a defect which relates to motor vehicle safety exists in certain 1991-1996 Chevrolet and GMC 4WD T utilities and 1994-1996 Chevrolet and GMC 4WD T pickup trucks. Some of these vehicles exhibit a condition in which a switch that signals the antilock brake system (ABS) module when the vehicle is in four-wheel drive (4WD) may malfunction. The ABS module is designed with two different operating algorithms; one for two-wheel drive (2WD) operation and another for 4WD drive operation. This allows the ABS system to compensate for the braking torque applied tot he rear wheels through the drivetrain when the vehicle is in 4WD drive. When the vehicle is in 2WD, a malfunctioning switch may send an incorrect signal tot he ABS module. If this occurs during an ABS stop, a somewhat longer stopping distance could result. If this occurred when minimum stopping distance was required, it could result a vehicle crash. CORRECTION Dealers are to install a new transfer case selector switch, wiring harness, and an additional switch to ensure that the ABS receives the 4WD signal only when the drivetrain is in 4WD. VEHICLES INVOLVED Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Brakes and Traction Control > 4WD Switch > Component Information > Technical Service Bulletins > All Technical Service Bulletins for 4WD Switch: > 99-041 > May > 00 > Recall - ABS Front Axle Signal Malfunction > Page 327 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Brakes and Traction Control > 4WD Switch > Component Information > Technical Service Bulletins > All Technical Service Bulletins for 4WD Switch: > 99-041 > May > 00 > Recall - ABS Front Axle Signal Malfunction > Page 328 Involved are certain 1991-1996 Chevrolet and GMC 4WD T utilities and 1994-1996 Chevrolet and GMC 4WD T pickup truck built within these VIN breakpoints as shown. IMPORTANT Dealers should confirm vehicle eligibility through GMVIS (GM Vehicle Inquiry System) or GM Access Screen (Canada only) or DCS Screen 445 (IPC only) before beginning campaign repairs. [Not all vehicles within the above breakpoints may be involved.] Involved vehicles have been identified by Vehicle Identification Number. Computer listing containing the complete Vehicle Identification, customer name address data have been prepared, and are being furnished to involved dealers with the campaign bulletin. The customer name address data furnished will enable dealers to follow up with the campaign bulletin has no involved vehicles currently assigned. These dealer listings may contain customer names and addresses obtained from Motor Vehicle Registration Records. The use of such motor vehicle registration data for any other purpose is a violation of law in several states/provinces/countries. Accordingly, you are urged to limit the use of this listing to the follow-up necessary to complete this campaign. PARTS INFORMATION Parts required to complete this campaign are to be obtained from General Motors Service Parts Operations (GMSPO). Please refer to your "involved vehicles listing" before ordering parts. Normal orders should be placed on a DRO = Daily Replenishment Order, in an emergency situation, parts should be ordered on a CSO = Customer Special Order. Part Number Description Quantity/Vehicle 88880028 Switch Kit, Elek Brk Cont Frt 1 Drv Axle Vac (1991-94 Utility) 88880029 Switch Kit, Elek Brk Cont Frt 1 Drv Axle Vac (1995-96 Utility, 1994-96 Pickup) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Brakes and Traction Control > 4WD Switch > Component Information > Technical Service Bulletins > All Technical Service Bulletins for 4WD Switch: > 99-041 > May > 00 > Recall - ABS Front Axle Signal Malfunction > Page 329 CAMPAIGN IDENTIFICATION LABEL - For US IPC Place a Campaign Identification Label on each vehicle corrected in accordance with the instructions outlined in this Product Campaign Bulletin. Each label provides a space to include the campaign number and the five (5) digit dealer code of the dealer performing the campaign service. This Information may be inserted with a typewriter a ball point pen. CAMPAIGN IDENTIFICATION LABEL - For CANADA Place a Campaign Identification Label on each vehicle corrected in accordance with the instruction outlined in this Product Campaign Bulletin. Each label provides a space to include the campaign number and the five (5) digit dealer code of the dealer performing the campaign service. This information may be inserted with a typewriter or a ball point pen. CLAIM INFORMATION Submit a Product Campaign Claim with the information indicated. Refer to the General Motors WINS claims processing Manual for details on Product Campaign Claim Submission. CUSTOMER NOTIFICATION - For US and CANADA Customers will be notified of this campaign on their vehicles by General Motors (see copy of customer letter included with this bulletin. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Brakes and Traction Control > 4WD Switch > Component Information > Technical Service Bulletins > All Technical Service Bulletins for 4WD Switch: > 99-041 > May > 00 > Recall - ABS Front Axle Signal Malfunction > Page 330 CUSTOMER NOTIFICATION - For IPC Letters will be sent to known owners of record located within areas covered by the US National Traffic and Motor Vehicle Safety Act. For owners outside these areas, dealers should notify customers using the attached suggested dealer letter. DEALER CAMPAIGN RESPONSIBILITY - For US and IPC (US States, Territories, and Possessions) The US National Traffic end Motor Vehicle safety Act provides that each vehicle that is subject to recall campaign of this type must be adequately repaired within a reasonable time after the customer has tendered it for repair. A failure to repair within sixty days after tender of vehicle is prima facie evidence of failure to repair within a reasonable time. If the condition is not adequately repaired within a reasonable time the customer may be entitled to an identical or reasonably equivalent vehicle at no charge or to a refund of the purchase price less a reasonable allowance for depreciation. To avoid having to provide these burdensome remedies, every effort must be made to promptly schedule an appointment with each customer and to repair their vehicle as soon as possible. In the recall campaign notification letters, customers are told how to contact the US National Highway Traffic Safety Administration if the campaign is not completed within a reasonable time. DEALER CAMPAIGN RESPONSIBILITY - ALL All unsold new vehicle in dealers' possession and subject to this campaign must be held an inspected/repaired per the service procedure of this campaign bulletin before customers take possession of these vehicles. Dealers are to service all vehicles subject to this campaign at no charge to customers, regardless of mileage, age of vehicle, or ownership, from this time forward. Customers who have recently purchased vehicles sold from your vehicle inventory, and for which there is no customer information indicated on the dealer listing, are to be contacted by the dealer. Arrangements are to be made to make the required correction according to the instructions contained in this bulletin. This could be done by mailing to such customers, a copy of the customer letter accompanying this bulletin. Campaign follow-up cards should not be used for this purpose, since the customer may not as yet have received the notification letter. In summary, whenever a vehicle subject to this campaign enters your vehicle inventory, or is in your dealership for service in the future, you must take the steps necessary to be sure the campaign correction has been made before selling or releasing the vehicle. Disclaimer 1991-94 T-Utility 1. Disconnect the negative battery cable. 2. Remove the front lower coolant reservoir attaching bolt. 3. Install the new vacuum switch, bracket, and hose assembly at the front lower coolant reservoir attaching location using the bolt removed in the previous step. Important The bracket must be rotated/positioned and held as close to the coolant reservoir as possible during the tightening of the bolt or nut to maintain maximum clearance between the battery and the vacuum switch. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Brakes and Traction Control > 4WD Switch > Component Information > Technical Service Bulletins > All Technical Service Bulletins for 4WD Switch: > 99-041 > May > 00 > Recall - ABS Front Axle Signal Malfunction > Page 331 4. Position the vacuum switch, bracket, and hose assembly as shown in Figure 1 and tighten the bolt to 8 Nm (71 lb in). 5. Locate the vacuum hose leading from the front axle vacuum actuator, located under the battery tray, to the vacuum switch mounted bon the transfer case. This vacuum hose typically is routed along the right front frame rail rearward up along the wheel well towards the cowl area of the engine compartment. On some vehicle this hose may be covered with a black convoluted protective sleeve. 6. Select a point on the vacuum hose, which was located in the previous step, that will be lower in the vehicle than the new vacuum switch and will not result in the loading or stretching of either the existing or new hoses when they are connected together. Important The location where the vacuum line is tapped into must be lower than the vacuum switch to ensure condensation cannot accumulate in the switch, possibly resulting in a switch malfunction. 7. Cut the existing vacuum hose at me point located in the previous step, and connect the ends of the cut vacuum hose to the tee fitting that is part of the new vacuum switch and hose assembly. 8. Connect the new wiring harness to the vacuum switch and ensure the locking feature of the connector is engaged. Important Ensure that the new harness is routed and secured in such a manner that it will not come in contact with any moving parts or be exposed to any other conitions that may result in damage to the harness. 9. Route the new harness is shown in Figure 1 and secure it to the existing Underhood components at the locations indicated (1) using the tie straps provided in the kit. 10. Locate and disconnect the existing underhood front exle switch wiring harness connector, located in the area above the brake booster assembly, and jumper in the new wiring harness. 11. Raise the vehicle and suitably support. 12. Loate the transfer case selector switch positioned on top of the transfer case. 13. Remove any foreign material from around the transfer case selector switch or vacuum connector. Important Ensure that the O-ring is removed and discarded. 14. Disconnect the vacuum connector, remove and discard the transfer case selector switch and the O-ring. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Brakes and Traction Control > 4WD Switch > Component Information > Technical Service Bulletins > All Technical Service Bulletins for 4WD Switch: > 99-041 > May > 00 > Recall - ABS Front Axle Signal Malfunction > Page 332 15. Hand start the new transfer case selector switch and tighten to 24 Nm (18 lb ft). 16. Ensure that the alignment feature of the vacuum harness connector is oriented correctly to engage the alignment post/pin of the transfer case selector switch and connect the harness to the switch. 17. Lower the vehicle and connect the negative battery cable. 18. Install the GM Campaign Identification Label. 1994 T-Pickup 1. Disconnect the negative battery cable. 2. Locate the new vacuum switch, bracket, and hose assembly so that the hole in the bracket align with the front inboard nut that is molded into the top of the coolant reservoir as shown in Figure 2. 3. Using the bolt provided in the kit, switch the vacuum switch, bracket, and hose assembly to the coolant reservoir by hand at starting the bolt. 4. With the vacuum switch, bracket and hose assembly positioned as shown in Figure 2, tighten the bolt to 10 Nm (88 lb in). 5. Locate the vacuum hose leading from the front axle vacuum actuator, located under the battery tray, to the vacuum switch mounted on the transfer case. This hose is routed up from the axle vacuum actuator and then rearward towards the cowl area inside the right fender as shown in Figure 2. 6. Select a point on the vacuum hose, which was located in the previous step, that will be lower in the vehicle than the new vacuum switch and will not result in the loading or stretching of either the existing or new hoses when they are connected together. Important The location where the vacuum line is tapped into must be lower than the vacuum switch to ensure condensation cannot accumulate in the switch, possibly resulting in a switch malfunction. 7. Cut the existing vacuum hose at the point located in the previous step, and connect the ends of the cut vacuum hose to the tee fitting that is a part of the new vacuum switch and hose assembly. 8. Connect the new wiring harness to the vacuum switch and ensure the locking feature of the connector is engaged. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Brakes and Traction Control > 4WD Switch > Component Information > Technical Service Bulletins > All Technical Service Bulletins for 4WD Switch: > 99-041 > May > 00 > Recall - ABS Front Axle Signal Malfunction > Page 333 Important: Ensure that the new harness is routed and secured in such a manner that it will not come in contact with any moving parts or be exposed to any other conditions that may result in damage to the harness. 9. Route the harness as shown in Figure 2 and secure the new harness to the existing underhood components at the locations indicated (1) using the tie straps provided in the kits. 10. Disconnect the existing underhood front axle switch wiring harness connector, located in the area of the left front inner wheel well skirt under the brake master cylinder, and jumper in the new wiring harness. 11. Raise the vehicle and suitably support. 12. Locate the transfer case selector switch positioned on top of the transfer case. 13. Remove any foreign material from around the transfer case selector switch or vacuum connector. Important: Ensure that the O-ring is removed and discarded. 14. Disconnect the vacuum connector, remove and discard the transfer case selector switch and the O-ring. 15. Hand start the new transfer case selector switch and tighten to 24 Nm (18 lb ft). 16. Ensure the alignment feature of the vacuum harness connector is oriented correctly to engage the alignment post/pin of the transfer case selector switch and connect the harness to the switch. 17. Lower the vehicle and connect the negative battery cable. 18. Install the GM Campaign Identification Label. 1995-96 T-Pickup and 1995-96 T-Utility 1. Disconnect the negative battery cable. 2. Remove the front lower coolant reservoir attaching nut and discard. 3. Install the new vacuum switch, bracket, and hose assembly at the front lower coolant reservoir attaching location using the new nut contained in the kit. Important: The bracket must be rotated/positioned and held as close to the coalant reservoir as possible during the tightening of the nut to maintain maximum clearance between the battery and the vacuum switch. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Brakes and Traction Control > 4WD Switch > Component Information > Technical Service Bulletins > All Technical Service Bulletins for 4WD Switch: > 99-041 > May > 00 > Recall - ABS Front Axle Signal Malfunction > Page 334 4. Position the vacuum switch, bracket, and hose assembly as shown in Figure 3 and tighten the nut to 8 Nm (71 lb in). 5. Locate the vacuum hose leading from the front axle vacuum actuator, located under the battery tray, to the vacuum switch mounted on the transfer case. This vacuum hose typically is route along the right front frame rail rearward up along the wheel welt towards the cowl area of the engine compartment. On come vehicle this hose may be covered with black convoluted protective sleeve. 6. Select a point on the vacuum hose, which was located in the previous step, that Will be lower in the vehicle than the new vacuum switch and will not result in the loading or stretching of either the existing or new hoses when they are connected together. Important The location where the vacuum line le tapped into must be lower than the vacuum switch to ensure condensation cannot accumulate in the switch, possibly resulting in a switch malfunction. 7. Cut the existing vacuum hose at the point located in the previous step, and connect the ends of the cut vacuum hose to the tee fitting that is part of the new vacuum switch and hose assembly. 8. Connect the new wiring harness to the vacuum switch and ensure the looking feature of the connector is engaged. Important: Ensure that the new harness is routed and secured in such a manner that it will not come in contact with any moving parts or be exposed to any other conditions that may result in damage to the harness. 9. Route the new harness as shown in Figure 3 and secure it to the existing underhood components at the locations indicated (1) using the tie straps provided in the kit. 10. Locate and disconnect the existing underhood front axle switch wiring harness connector, located in the area of the left front inner wheel well skirt under the brake master cylinder, and jumper in the new wiring harness. 11. Raise the vehicle and suitably support. 12. Locate the transfer case selector switch positioned on top of the transfer case. 13. Remove any foreign material from around the transfer case selector switch or vacuum connector. Important: Ensure that the O-ring is removed and discarded. 14. Disconnect the vacuum connector, remove and discard the transfer case selector switch and the O-ring. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Brakes and Traction Control > 4WD Switch > Component Information > Technical Service Bulletins > All Technical Service Bulletins for 4WD Switch: > 99-041 > May > 00 > Recall - ABS Front Axle Signal Malfunction > Page 335 15. Hand start the new transfer case selector switch and tighten to 24 Nm (18 lb ft) 16. Ensure that the alignment feature of the vacuum harness connector is oriented correctly to engage the alignment post/pin of the transfer case selector switch and connect the harness to the switch. 17. Lower the vehicle and connect the negative battery cable. 18. Install the GM Campaign Identification Label. Owner Letter 99041 (Sample Of Notification Used) May, 2000 Dear General Motors Customer: This notice is sent to you in accordance with the requirements of the National Traffic and Motor Vehicle Safety Act. Reason For This Recall: General Motors has decided that a defect which relates to motor vehicle safety exists in certain 1991-1996 4WD wheel drive (4WD) Blazers and Jimmys, and 1994-1996 4WD S-10 and Sonoma pickup trucks. Some of these Vehicles exhibit a condition in which a switch that signals the antilook brake system (ADS) module when the vehicle is in 4WD may malfunction. The ABS module is designed with two different operating algorithms: one for 2-wheel drive (2WD) operation and another for 4WD drive operation. This allows the ABS system to compensate for the braking torque applied to the rear wheels through the drivetrain when the vehicle is in 4WD drive. When the vehicle is in 2WD, a malfunction switch may send an incorrect signal to the ABS module. If this occurs during an ABS stop, a somewhat longer stopping distance could result. If this occurred when minimum stopping distance was required, it could result in a vehicle crash. What Will Be Done: Your dealer will install a new transfer case selector switch, wiring harness, and an additional switch to ensure that the ABS receives the 4WD signal only when the drivetrain is in 4WD. This service will be performed for you at no charge. How Long Will The Repair Take? The length of time required to perform this service correction is approximately 30 minutes. Additional time may be required to schedule and process your vehicle. If your dealer has a large number of vehicles awaiting service, this additional time may be significant. Please ask your dealer if you wish to know how much additional time will be needed to schedule process and repair your vehicle. Contacting Your Dealer: Please contact your Chevrolet/GMC dealer as soon as possible to arrange a service date. Parts are available and instructions for making this correction have been sent to your dealer. Your Chevrolet/GMC dealer is best equipped to obtain parts and provide services to correct you vehicle as promptly as possible. Should your dealer be unable to schedule a service date within a reasonable time, you should contact the appropriate Customer Assistance Center at the listed number below: Division Number Deaf, Hearing Impaired or Speech Chevrolet 1-800-222-1020 1-800-833-2438 GMC 1-800-462-8782 1-800-462-8583 Utilize Telecommunication Devices If, after contacting the appropriate Customer Assistance Center, you are still not satisfied that we have done our best to remedy this condition without charge and within a reasonable time, you may wish to write the Administrator, National Highway Traffic Safety Administration, 400 Seventh Street, SW, Washington, DC 20590 or call 1-800-424-9393 (Washington, DC residents use (202-366-0123). Customer Reply Card: The customer reply card identifies your vehicle. Presentation of this card to your dealer will assist in making necessary correction in the shortest possible time. If you no longer own this vehicle, please let us know by completing the attached and mailing it in the postage paid envelope. We are sorry to cause you this inconvenience; however, we have taken this action in the interest of your safety and continued satisfaction with our products. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Brakes and Traction Control > Brake Fluid Pressure Sensor/Switch > Component Information > Diagrams C150 - Brake Pressure Warning Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Brakes and Traction Control > Parking Brake Release Switch > Component Information > Locations LH Side Of I/P Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Brakes and Traction Control > Parking Brake Warning Switch > Component Information > Locations Parking Brake Warning Switch: Locations LH I/P Harness Wiring Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Brakes and Traction Control > Parking Brake Warning Switch > Component Information > Locations > Page 345 I/P Harness Wiring, LH Side Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Brakes and Traction Control > Parking Brake Warning Switch > Component Information > Locations > Page 346 C208 - Park Brake Warning Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Brakes and Traction Control > Wheel Speed Sensor > Component Information > Specifications Wheel Speed Sensor: Specifications Wheel Speed Sensor ........................................................................................................................... .......................................................... 900-2000 ohms Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Brakes and Traction Control > Wheel Speed Sensor > Component Information > Specifications > Page 350 Wheel Speed Sensor: Service and Repair 1. Raise and support vehicle, then remove wheel and tire assembly. 2. Disconnect brake caliper assembly and position aside. 3. Remove rotor, then hub and bearing assembly. 4. Disconnect wheel sensor electrical connector 5. Remove sensor wire form upper control arm clip. 6. Remove sensor and splash shield assembly attaching bolts, then remove sensor. 7. Reverse procedure to install. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Specifications Coolant Temperature Sensor/Switch (For Computer): Specifications Resistance 185 ohms at 210 deg F 450 ohms at 160 deg F 1800 ohms at 100 deg F 3400 ohms at 70 deg F 7500 ohms at 40 deg F 13500 ohms at 20 deg F 25000 ohms at 0 deg F 100700 ohms at -40 deg F Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Specifications > Page 356 Coolant Temperature Sensor/Switch (For Computer): Locations Engine Coolant Temperature Sensor Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Specifications > Page 357 Engine Harness, Right Front Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions Coolant Temperature Sensor/Switch (For Computer): Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. Use this page as a reference to determine the meaning of an abbreviation if necessary. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery Bi-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CHMSL Center High Mount Stoplamp CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRO Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 360 F-PUMP Fuel Pump FLASH Flasher FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 361 SIR Supplemental Inflatable Restraint SKT Socket SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature TIL Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 362 example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE (ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: ^ Slide across the vehicle seat. ^ Sit down or stand up. ^ Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: ^ They are bumped or dropped. ^ They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 363 Symbols (Part 1 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 364 Symbols (Part 2 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 365 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 366 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 367 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 368 Coolant Temperature Sensor/Switch (For Computer): Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 369 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 370 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 371 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 372 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 373 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. ^ If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. ^ A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 374 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 375 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 376 Ohmmeter Meter Scales Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 377 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. ^ An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. ^ On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: ^ A range selector switch which permits the selection of different ranges of resistance. ^ A set adjust control which allows the meter to be set at zero for accurate measurements. ^ Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 378 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: ^ Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. ^ Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. ^ Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 379 be less than 10 percent of the total drop. When using a voltmeter: ^ Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. ^ Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. ^ The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: ^ Check the accuracy and completeness of the complaint. ^ Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 380 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. ^ The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 381 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 382 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 383 Twisted/Shielded Wire Repair Twisted Wires Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 384 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 385 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 386 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). ^ Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean ^ Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. ^ Roll crimp (13) and solder the terminal. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 387 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 388 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 389 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. ^ Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean ^ Terminal cavity of the connector body. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 390 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. ^ Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 391 C105 - Engine Coolant Temperature Sensor Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 392 Engine Coolant Temperature (ECT) Circuit Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Page 393 Coolant Temperature Sensor/Switch (For Computer): Description and Operation Engine Coolant Temperature Sensor PURPOSE The Engine Coolant Temperature (ECT) Sensor information is used by the control module to control: Fuel delivery - Torque Converter Clutch (TCC) - Engine Spark Timing (EST) - Controlled Canister Purge (CCP) - Idle Air Control (IAC) - Cooling Fan OPERATION The ECT is a thermistor that is located in the engine coolant flow mounted to the intake manifold. When the coolant temperature is low, the sensor produces a high resistance. When the coolant temperature is high, the sensor produces a low resistance. The PCM sends a 5.0 volt signal to the ECT through a resistor in the computer and measures the voltage. The voltage will be high or low depending on coolant temperature. With the ECT varying its resistance, the PCM can sense engine coolant temperature by reading the varying voltage. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Temperature Sensor (Gauge) > Component Information > Locations Temperature Sensor (Gauge): Locations ENGINE COOLANT TEMPERATURE SENSOR Right Front Engine Harness Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Temperature Sensor (Gauge) > Component Information > Locations > Page 397 Engine Harness, Right Front NOTE: The OEM service manual provides multiple location views for this component. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Temperature Sensor (Gauge) > Component Information > Locations > Page 398 C108 - Eng Coolant Temp Sender Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Brake Switch (Cruise Control) > Component Information > Locations > Manual Transmission Cruise Control Brake Switch And Vacuum Release Valve (W/Man Trans) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Brake Switch (Cruise Control) > Component Information > Locations > Manual Transmission > Page 404 Cruise Control Brake Switch And Vacuum Release Valve (W/Auto Trans) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Brake Switch (Cruise Control) > Component Information > Diagrams > Diagram Information and Instructions Brake Switch (Cruise Control): Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. Use this page as a reference to determine the meaning of an abbreviation if necessary. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery Bi-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CHMSL Center High Mount Stoplamp CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRO Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Brake Switch (Cruise Control) > Component Information > Diagrams > Diagram Information and Instructions > Page 407 F-PUMP Fuel Pump FLASH Flasher FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Brake Switch (Cruise Control) > Component Information > Diagrams > Diagram Information and Instructions > Page 408 SIR Supplemental Inflatable Restraint SKT Socket SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature TIL Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Brake Switch (Cruise Control) > Component Information > Diagrams > Diagram Information and Instructions > Page 409 example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE (ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: ^ Slide across the vehicle seat. ^ Sit down or stand up. ^ Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: ^ They are bumped or dropped. ^ They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Brake Switch (Cruise Control) > Component Information > Diagrams > Diagram Information and Instructions > Page 410 Symbols (Part 1 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Brake Switch (Cruise Control) > Component Information > Diagrams > Diagram Information and Instructions > Page 411 Symbols (Part 2 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Brake Switch (Cruise Control) > Component Information > Diagrams > Diagram Information and Instructions > Page 412 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Brake Switch (Cruise Control) > Component Information > Diagrams > Diagram Information and Instructions > Page 413 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Brake Switch (Cruise Control) > Component Information > Diagrams > Diagram Information and Instructions > Page 414 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Brake Switch (Cruise Control) > Component Information > Diagrams > Diagram Information and Instructions > Page 415 Brake Switch (Cruise Control): Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Brake Switch (Cruise Control) > Component Information > Diagrams > Diagram Information and Instructions > Page 416 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Brake Switch (Cruise Control) > Component Information > Diagrams > Diagram Information and Instructions > Page 417 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Brake Switch (Cruise Control) > Component Information > Diagrams > Diagram Information and Instructions > Page 418 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Brake Switch (Cruise Control) > Component Information > Diagrams > Diagram Information and Instructions > Page 419 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Brake Switch (Cruise Control) > Component Information > Diagrams > Diagram Information and Instructions > Page 420 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. ^ If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. ^ A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Brake Switch (Cruise Control) > Component Information > Diagrams > Diagram Information and Instructions > Page 421 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Brake Switch (Cruise Control) > Component Information > Diagrams > Diagram Information and Instructions > Page 422 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Brake Switch (Cruise Control) > Component Information > Diagrams > Diagram Information and Instructions > Page 423 Ohmmeter Meter Scales Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Brake Switch (Cruise Control) > Component Information > Diagrams > Diagram Information and Instructions > Page 424 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. ^ An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. ^ On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: ^ A range selector switch which permits the selection of different ranges of resistance. ^ A set adjust control which allows the meter to be set at zero for accurate measurements. ^ Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Brake Switch (Cruise Control) > Component Information > Diagrams > Diagram Information and Instructions > Page 425 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: ^ Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. ^ Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. ^ Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Brake Switch (Cruise Control) > Component Information > Diagrams > Diagram Information and Instructions > Page 426 be less than 10 percent of the total drop. When using a voltmeter: ^ Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. ^ Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. ^ The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: ^ Check the accuracy and completeness of the complaint. ^ Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Brake Switch (Cruise Control) > Component Information > Diagrams > Diagram Information and Instructions > Page 427 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. ^ The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Brake Switch (Cruise Control) > Component Information > Diagrams > Diagram Information and Instructions > Page 428 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Brake Switch (Cruise Control) > Component Information > Diagrams > Diagram Information and Instructions > Page 429 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Brake Switch (Cruise Control) > Component Information > Diagrams > Diagram Information and Instructions > Page 430 Twisted/Shielded Wire Repair Twisted Wires Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Brake Switch (Cruise Control) > Component Information > Diagrams > Diagram Information and Instructions > Page 431 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Brake Switch (Cruise Control) > Component Information > Diagrams > Diagram Information and Instructions > Page 432 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Brake Switch (Cruise Control) > Component Information > Diagrams > Diagram Information and Instructions > Page 433 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). ^ Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean ^ Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. ^ Roll crimp (13) and solder the terminal. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Brake Switch (Cruise Control) > Component Information > Diagrams > Diagram Information and Instructions > Page 434 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Brake Switch (Cruise Control) > Component Information > Diagrams > Diagram Information and Instructions > Page 435 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Brake Switch (Cruise Control) > Component Information > Diagrams > Diagram Information and Instructions > Page 436 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. ^ Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean ^ Terminal cavity of the connector body. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Brake Switch (Cruise Control) > Component Information > Diagrams > Diagram Information and Instructions > Page 437 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. ^ Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Brake Switch (Cruise Control) > Component Information > Diagrams > Diagram Information and Instructions > Page 438 C252 - Cruise Control Brake Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Clutch Switch, Cruise Control > Component Information > Locations Clutch Switch: Locations Brake Pedal Switches. On the Clutch Pedal Support bracket. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Clutch Switch, Cruise Control > Component Information > Diagrams > Diagram Information and Instructions Clutch Switch: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. Use this page as a reference to determine the meaning of an abbreviation if necessary. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery Bi-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CHMSL Center High Mount Stoplamp CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRO Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Clutch Switch, Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 444 F-PUMP Fuel Pump FLASH Flasher FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Clutch Switch, Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 445 SIR Supplemental Inflatable Restraint SKT Socket SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature TIL Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Clutch Switch, Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 446 example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE (ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: ^ Slide across the vehicle seat. ^ Sit down or stand up. ^ Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: ^ They are bumped or dropped. ^ They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Clutch Switch, Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 447 Symbols (Part 1 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Clutch Switch, Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 448 Symbols (Part 2 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Clutch Switch, Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 449 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Clutch Switch, Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 450 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Clutch Switch, Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 451 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Clutch Switch, Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 452 Clutch Switch: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Clutch Switch, Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 453 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Clutch Switch, Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 454 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Clutch Switch, Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 455 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Clutch Switch, Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 456 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Clutch Switch, Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 457 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. ^ If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. ^ A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Clutch Switch, Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 458 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Clutch Switch, Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 459 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Clutch Switch, Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 460 Ohmmeter Meter Scales Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Clutch Switch, Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 461 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. ^ An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. ^ On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: ^ A range selector switch which permits the selection of different ranges of resistance. ^ A set adjust control which allows the meter to be set at zero for accurate measurements. ^ Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Clutch Switch, Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 462 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: ^ Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. ^ Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. ^ Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Clutch Switch, Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 463 be less than 10 percent of the total drop. When using a voltmeter: ^ Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. ^ Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. ^ The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: ^ Check the accuracy and completeness of the complaint. ^ Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Clutch Switch, Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 464 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. ^ The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Clutch Switch, Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 465 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Clutch Switch, Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 466 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Clutch Switch, Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 467 Twisted/Shielded Wire Repair Twisted Wires Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Clutch Switch, Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 468 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Clutch Switch, Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 469 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Clutch Switch, Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 470 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). ^ Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean ^ Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. ^ Roll crimp (13) and solder the terminal. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Clutch Switch, Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 471 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Clutch Switch, Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 472 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Clutch Switch, Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 473 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. ^ Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean ^ Terminal cavity of the connector body. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Clutch Switch, Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 474 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. ^ Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Cruise Control Switch > Component Information > Locations Cruise Control Switch: Locations Cruise Control I/P Wiring Part of the multi-function lever. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Cruise Control Switch > Component Information > Diagrams > Diagram Information and Instructions Cruise Control Switch: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. Use this page as a reference to determine the meaning of an abbreviation if necessary. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery Bi-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CHMSL Center High Mount Stoplamp CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRO Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Cruise Control Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 480 F-PUMP Fuel Pump FLASH Flasher FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Cruise Control Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 481 SIR Supplemental Inflatable Restraint SKT Socket SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature TIL Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Cruise Control Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 482 example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE (ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: ^ Slide across the vehicle seat. ^ Sit down or stand up. ^ Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: ^ They are bumped or dropped. ^ They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Cruise Control Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 483 Symbols (Part 1 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Cruise Control Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 484 Symbols (Part 2 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Cruise Control Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 485 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Cruise Control Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 486 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Cruise Control Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 487 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Cruise Control Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 488 Cruise Control Switch: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Cruise Control Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 489 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Cruise Control Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 490 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Cruise Control Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 491 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Cruise Control Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 492 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Cruise Control Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 493 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. ^ If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. ^ A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Cruise Control Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 494 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Cruise Control Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 495 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Cruise Control Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 496 Ohmmeter Meter Scales Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Cruise Control Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 497 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. ^ An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. ^ On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: ^ A range selector switch which permits the selection of different ranges of resistance. ^ A set adjust control which allows the meter to be set at zero for accurate measurements. ^ Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Cruise Control Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 498 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: ^ Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. ^ Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. ^ Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Cruise Control Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 499 be less than 10 percent of the total drop. When using a voltmeter: ^ Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. ^ Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. ^ The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: ^ Check the accuracy and completeness of the complaint. ^ Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Cruise Control Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 500 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. ^ The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Cruise Control Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 501 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Cruise Control Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 502 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Cruise Control Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 503 Twisted/Shielded Wire Repair Twisted Wires Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Cruise Control Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 504 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Cruise Control Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 505 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Cruise Control Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 506 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). ^ Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean ^ Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. ^ Roll crimp (13) and solder the terminal. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Cruise Control Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 507 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Cruise Control Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 508 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Cruise Control Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 509 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. ^ Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean ^ Terminal cavity of the connector body. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Cruise Control Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 510 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. ^ Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Cruise Control Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 511 C251 - Cruise Control Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Cruise Control Switch > Component Information > Diagrams > Page 512 Cruise Control Switch: Service and Repair 1. Remove steering wheel, lower steering column covers and steering lock plate cover, if equipped. 2. Disconnect cruise control connector from main harness connector and attach a suitable length of flexible wire to cruise control harness. Fig. 10 Cruise Control Switch replacement 3. Tape joint between main and control harness to aid removal, then remove control assembly, Fig. 10. 4. Reverse procedure to install. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Vehicle Speed Sensor/Transducer - Cruise Control > Component Information > Locations Vehicle Speed Sensor/Transducer - Cruise Control: Locations Components Behind the right hand side of the I/P near the ECM, PCM. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Vehicle Speed Sensor/Transducer - Cruise Control > Component Information > Diagrams > Diagram Information and Instructions Vehicle Speed Sensor/Transducer - Cruise Control: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. Use this page as a reference to determine the meaning of an abbreviation if necessary. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery Bi-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CHMSL Center High Mount Stoplamp CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRO Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Vehicle Speed Sensor/Transducer - Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 518 F-PUMP Fuel Pump FLASH Flasher FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Vehicle Speed Sensor/Transducer - Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 519 SIR Supplemental Inflatable Restraint SKT Socket SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature TIL Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Vehicle Speed Sensor/Transducer - Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 520 example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE (ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: ^ Slide across the vehicle seat. ^ Sit down or stand up. ^ Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: ^ They are bumped or dropped. ^ They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Vehicle Speed Sensor/Transducer - Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 521 Symbols (Part 1 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Vehicle Speed Sensor/Transducer - Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 522 Symbols (Part 2 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Vehicle Speed Sensor/Transducer - Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 523 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Vehicle Speed Sensor/Transducer - Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 524 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Vehicle Speed Sensor/Transducer - Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 525 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Vehicle Speed Sensor/Transducer - Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 526 Vehicle Speed Sensor/Transducer - Cruise Control: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Vehicle Speed Sensor/Transducer - Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 527 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Vehicle Speed Sensor/Transducer - Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 528 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Vehicle Speed Sensor/Transducer - Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 529 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Vehicle Speed Sensor/Transducer - Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 530 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Vehicle Speed Sensor/Transducer - Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 531 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. ^ If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. ^ A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Vehicle Speed Sensor/Transducer - Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 532 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Vehicle Speed Sensor/Transducer - Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 533 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Vehicle Speed Sensor/Transducer - Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 534 Ohmmeter Meter Scales Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Vehicle Speed Sensor/Transducer - Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 535 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. ^ An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. ^ On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: ^ A range selector switch which permits the selection of different ranges of resistance. ^ A set adjust control which allows the meter to be set at zero for accurate measurements. ^ Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Vehicle Speed Sensor/Transducer - Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 536 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: ^ Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. ^ Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. ^ Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Vehicle Speed Sensor/Transducer - Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 537 be less than 10 percent of the total drop. When using a voltmeter: ^ Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. ^ Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. ^ The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: ^ Check the accuracy and completeness of the complaint. ^ Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Vehicle Speed Sensor/Transducer - Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 538 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. ^ The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Vehicle Speed Sensor/Transducer - Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 539 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Vehicle Speed Sensor/Transducer - Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 540 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Vehicle Speed Sensor/Transducer - Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 541 Twisted/Shielded Wire Repair Twisted Wires Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Vehicle Speed Sensor/Transducer - Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 542 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Vehicle Speed Sensor/Transducer - Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 543 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Vehicle Speed Sensor/Transducer - Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 544 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). ^ Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean ^ Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. ^ Roll crimp (13) and solder the terminal. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Vehicle Speed Sensor/Transducer - Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 545 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Vehicle Speed Sensor/Transducer - Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 546 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Vehicle Speed Sensor/Transducer - Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 547 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. ^ Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean ^ Terminal cavity of the connector body. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Cruise Control > Vehicle Speed Sensor/Transducer - Cruise Control > Component Information > Diagrams > Diagram Information and Instructions > Page 548 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. ^ Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Engine > Oil Pressure Sender > Component Information > Technical Service Bulletins > Customer Interest: > 476149 > Dec > 94 > Oil Pressure Gauge Erratic Reading Concerns Oil Pressure Sender: Customer Interest Oil Pressure Gauge - Erratic Reading Concerns File In Section: 6 - Engine Bulletin No. 47-61-49 Date: December, 1994 Subject: Oil Pressure Gauge Reading Concerns (Replace Oil Pressure Sending Unit) Models: 1991-94 Chevrolet and GMC Truck C/K, S/T, P Models, M/L, G Vans 1991-92 Oldsmobile Bravada with 2.2L, 4.3L, 5.0L, 5.7L, 7.4L Engines (VINs 4, Z, H, K, N - RPOs LN2, LB4, L03, L05, L19) CONDITION Some owners may comment on one or all of the following conditions: ^ High oil pressure when starting engine cold. ^ Low oil pressure when engine is at idle hot. ^ Erratic gauge readings. CAUSE Oil pressure sending unit was not optimally calibrated for all operating conditions. CORRECTION If actual oil pressures are within tolerances listed in Section 6A of the Service Manual, and gauge circuit electrical diagnostics in Section SC of the Service Manual do not uncover the source of the problem, an improved oil pressure sending unit should be installed. Parts Information DESCRIPTION PART NUMBER Oil Pressure Sending Unit 12553175 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: LABOR OPERATION LABOR TIME N222O Use published labor operation and time. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Engine > Oil Pressure Sender > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 476149 > Dec > 94 > Oil Pressure Gauge - Erratic Reading Concerns Oil Pressure Sender: All Technical Service Bulletins Oil Pressure Gauge - Erratic Reading Concerns File In Section: 6 - Engine Bulletin No. 47-61-49 Date: December, 1994 Subject: Oil Pressure Gauge Reading Concerns (Replace Oil Pressure Sending Unit) Models: 1991-94 Chevrolet and GMC Truck C/K, S/T, P Models, M/L, G Vans 1991-92 Oldsmobile Bravada with 2.2L, 4.3L, 5.0L, 5.7L, 7.4L Engines (VINs 4, Z, H, K, N - RPOs LN2, LB4, L03, L05, L19) CONDITION Some owners may comment on one or all of the following conditions: ^ High oil pressure when starting engine cold. ^ Low oil pressure when engine is at idle hot. ^ Erratic gauge readings. CAUSE Oil pressure sending unit was not optimally calibrated for all operating conditions. CORRECTION If actual oil pressures are within tolerances listed in Section 6A of the Service Manual, and gauge circuit electrical diagnostics in Section SC of the Service Manual do not uncover the source of the problem, an improved oil pressure sending unit should be installed. Parts Information DESCRIPTION PART NUMBER Oil Pressure Sending Unit 12553175 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: LABOR OPERATION LABOR TIME N222O Use published labor operation and time. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Engine > Oil Pressure Sender > Component Information > Technical Service Bulletins > All Other Service Bulletins for Oil Pressure Sender: > 668304A > Sep > 96 > Odometer/Speedometer - ACDelco Service Center Locations Speedometer Head: All Technical Service Bulletins Odometer/Speedometer - ACDelco Service Center Locations File In Section: 8 - Chassis/Body Electrical Bulletin No.: 66-83-04A Date: September, 1996 INFORMATION Subject: AC Delco Service Center Locations for Odometer/Speedometer Service Models: 1997 and Prior Passenger Cars and Trucks (excluding Cadillac) This bulletin is being revised to provide the necessary contact information only. Please discard Corporate Bulletin Number 66-83-04 (Section 8 - Chassis/Body Electrical) General Motors provides service for sophisticated electronic products through the authorized AC Delco Service Center Program. This program is designed to provide GM vehicle owners with the highest quality and most technically up-to-date product available. Repair products from unauthorized service outlets are not acceptable as warranty replacements. Currently, there are 25 authorized AC Delco Service Centers who exchange and remanufacture odometer/speedometers (list included). Only these Centers should be contacted for service. Important: W series and 1997 T series Medium Duty truck odometer/speedometers must be ordered directly from GMSPO. The following steps should be taken when utilizing the AC Delco Service Centers: Dealers should contact their local AC Delco Service Center (list included). Any listed facility may be used. The following information must be provided: Part number VIN, Mileage, Vehicle Year, Make and Model Dealer Name and Address Delivery Date of Vehicle Name of the person requesting exchange or service Phone number Repair Order Number P.O. number (if non - warranty) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Engine > Oil Pressure Sender > Component Information > Technical Service Bulletins > All Other Service Bulletins for Oil Pressure Sender: > 668304A > Sep > 96 > Odometer/Speedometer - ACDelco Service Center Locations > Page 568 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Engine > Oil Pressure Sender > Component Information > Technical Service Bulletins > All Other Service Bulletins for Oil Pressure Sender: > 668304A > Sep > 96 > Odometer/Speedometer - ACDelco Service Center Locations > Page 569 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Engine > Oil Pressure Sender > Component Information > Technical Service Bulletins > All Other Service Bulletins for Oil Pressure Sender: > 668304A > Sep > 96 > Odometer/Speedometer - ACDelco Service Center Locations > Page 570 AC Delco Service Centers Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Engine > Oil Pressure Sender > Component Information > Technical Service Bulletins > All Other Service Bulletins for Oil Pressure Sender: > 468304 > Oct > 94 > Speedometer - Momentary Drop With Flashers On Speedometer Head: All Technical Service Bulletins Speedometer - Momentary Drop With Flashers On File In Section: 8 - Chassis/Body Electrical Bulletin No.: 46-83-04 Date: October, 1994 Subject: Speedometer Momentary Drop when Turning on Park Lamps, Turn Signals or Hazard Flashers (Send I/P Cluster to Delco Repair Station) Models: 1993-94 Chevrolet and GMC Truck C/K Models 1994 Chevrolet and GMC Truck S/T Pickup Models Condition Some speedometers in the above vehicles may momentarily drop when the turn signal, park lamp, or hazard flasher is turned on. This condition often occurs at speeds over 60 miles per hour. Cause Slight system voltage drop when the extra load from the lights is added. Correction Remove the instrument cluster and send it to the local Delco Repair Station. Repair stations are aware of the condition and have parts available to repair the cluster. They will add a capacitor to the power circuit to assure a consistent power flow during power up of the above mentioned lamps. Be sure to clearly describe the condition on the Delco Repair Order accompanying the cluster. Warranty Information For vehicles repaired under warranty, use: Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Engine > Oil Pressure Sender > Component Information > Technical Service Bulletins > All Other Service Bulletins for Oil Pressure Sender: > 668304A > Sep > 96 > Odometer/Speedometer - ACDelco Service Center Locations > Page 580 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Engine > Oil Pressure Sender > Component Information > Technical Service Bulletins > All Other Service Bulletins for Oil Pressure Sender: > 668304A > Sep > 96 > Odometer/Speedometer - ACDelco Service Center Locations > Page 581 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Engine > Oil Pressure Sender > Component Information > Technical Service Bulletins > All Other Service Bulletins for Oil Pressure Sender: > 668304A > Sep > 96 > Odometer/Speedometer - ACDelco Service Center Locations > Page 582 AC Delco Service Centers Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Engine > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Automatic Transmission LH Rear Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Engine > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Automatic Transmission > Page 591 Rear Engine Wiring W/Man Trans Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Engine > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Page 592 C120 - Fuel Pump Oil Pressure Sender/Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Engine > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Page 593 Oil Pressure Switch (For Fuel Pump): Service and Repair REMOVE/DISCONNECT - Negative battery cable from battery. - Sensor or switch connectors. - Sensor or switch. INSTALL/CONNECT - Sensor or switch. - Sensor or switch. - Negative battery cable. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - HVAC > Air Conditioning Switch > Component Information > Locations Air Conditioning Switch: Locations A/C And Heater Wiring Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - HVAC > Air Conditioning Switch > Component Information > Locations > Page 598 A/C And Heater Wiring Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - HVAC > Air Conditioning Switch > Component Information > Description and Operation > Pressure Cycling Switch Air Conditioning Switch: Description and Operation Pressure Cycling Switch The refrigeration cycle (on and off operation of the compressor) is controlled by a switch which senses the low-side pressure as an indicator of evaporator temperature. The pressure cycling switch is the freeze protection device in the system and senses refrigerant pressure on the suction side of the system. This switch is mounted on a standard service fitting on the accumulator. This switch also provides compressor cutoff during cold weather. Additional compressor protection results from the operating characteristics of the low-side pressure cycling system. If a massive discharge occurs in the low side of the system, or the orifice tube becomes plugged, low-side pressures could be insufficient to close the contacts of the pressure switch. In the event of a low charge, insufficient cooling accompanied by rapid compressor clutch cycling will be noticed at high outside (ambient) air temperatures. If replacement of the pressure cycling switch is necessary, it is important to note that this may be done without removing the refrigerant charge. During replacement of the pressure switch, a new O-ring seal must be installed and the switch assembled to the specified torque of 4.5 Nm (40 lbs. in.). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - HVAC > Air Conditioning Switch > Component Information > Description and Operation > Pressure Cycling Switch > Page 601 Air Conditioning Switch: Description and Operation High Pressure Cutoff Switch This system is equipped with a high pressure cutoff switch. This switch is normally closed, and opens at 2827-3103 kPa (410-450 psi) to interrupt the voltage to the compressor clutch coil. This will stop the compressor from cycling and prevent the pressure relief valve from discharging refrigerant and oil. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - HVAC > Blower Motor Switch > Component Information > Diagrams > Blower Control Switch C267 - Blower Control Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - HVAC > Blower Motor Switch > Component Information > Diagrams > Blower Control Switch > Page 606 C267 - Heater Blower Control Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - HVAC > Blower Motor Switch > Component Information > Service and Repair > With A/C Blower Motor Switch: Service and Repair With A/C Heater Control Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - HVAC > Blower Motor Switch > Component Information > Service and Repair > With A/C > Page 609 Temperature Control Cable REMOVE OR DISCONNECT 1. Screws (64). 2. Control assembly (63). 3. Electrical connectors, as necessary. 4. Vacuum connectors, as necessary. 5. Temperature cable. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - HVAC > Blower Motor Switch > Component Information > Service and Repair > With A/C > Page 610 6. Blower switch, if necessary. NOTICE: Remove the blower switch knob and spring clip, and remove the blower switch. Inspect - Electrical terminals for corrosion. Remove the corrosion or replace the component as necessary. - Temperature and mode levers for freedom of movement. Lubricate, repair, or replace as necessary. - Temperature control cable for kinks, binding, and other damage. Repair or replace as necessary. INSTALL OR CONNECT 1. Heater blower switch, if removed. - Hold the blower switch in position and install the spring clip. - Install the blower switch knob. 2. Temperature cable. 3. Vacuum connectors, as necessary. 4. Electrical connectors, as necessary. 5. Control assembly (63). NOTICE: Refer to "Fasteners" under "Vehicle Damage Warnings." 6. Screws (64). - Tighten Screws (64) to 1.6 Nm (14 lbs. in.). 7. Check circuit operation. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - HVAC > Blower Motor Switch > Component Information > Service and Repair > With A/C > Page 611 Blower Motor Switch: Service and Repair Without A/C Heater Control Assembly REMOVE OR DISCONNECT 1. Screws (64). 2. Control assembly (63). 3. Electrical connectors, as necessary. 4. Vacuum connectors, as necessary. 5. Temperature cable. 6. Blower switch, if necessary. - Remove the blower switch knob and spring clip, and remove the blower switch. Inspect - Electrical terminals for corrosion. Remove the corrosion or replace the component as necessary. - Temperature and mode levers for freedom of movement. Lubricate, repair, or replace as necessary. - Temperature control cable for kinks, binding, and other damage. Repair or replace as necessary. INSTALL OR CONNECT 1. Heater blower switch, if removed. - Hold the blower switch in position and install the spring clip. - Install the blower switch knob. 2. Temperature cable. 3. Vacuum connectors, as necessary. 4. Electrical connectors, as necessary. 5. Control assembly (63). NOTICE: Refer to "Fasteners" under "Vehicle Damage Warnings." 6. Screws (64). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - HVAC > Blower Motor Switch > Component Information > Service and Repair > With A/C > Page 612 - Tighten screws (64) to 1.6 Nm (14 lbs. in.). 7. Check circuit operation. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - HVAC > Heater Lockout Switch > Component Information > Diagrams Heater Lockout Switch: Diagrams C266 - A/C-Heater Selector Switch C266 - A/C-Heater Selector Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - HVAC > Refrigerant Pressure Sensor / Switch, HVAC > Component Information > Locations A/C Compressor Wiring Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - HVAC > Refrigerant Pressure Sensor / Switch, HVAC > Component Information > Diagrams > A/C High Pressure Cutout Switch C190 - A/C High Pressure Cutout Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - HVAC > Refrigerant Pressure Sensor / Switch, HVAC > Component Information > Diagrams > A/C High Pressure Cutout Switch > Page 621 C138 - A/C Low Pressure Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - HVAC > Refrigerant Pressure Sensor / Switch, HVAC > Component Information > Description and Operation > Compressor Cut-Off/Cycling Switch Refrigerant Pressure Sensor / Switch: Description and Operation Compressor Cut-Off/Cycling Switch The refrigeration cycle (on and off operation of the compressor) is controlled by a switch which senses the low-side pressure as an indicator of evaporator temperature. The pressure cycling switch is the freeze protection device in the system and senses refrigerant pressure on the suction side of the system. This switch is mounted on a standard service fitting on the accumulator. This switch also provides compressor cutoff during cold weather. Additional compressor protection results from the operating characteristics of the low-side pressure cycling system. If a massive discharge occurs in the low side of the system, or the orifice tube becomes plugged, low-side pressures could be insufficient to close the contacts of the pressure switch. In the event of a low charge, insufficient cooling accompanied by rapid compressor clutch cycling will be noticed at high outside (ambient) air temperatures. If replacement of the pressure cycling switch is necessary, it is important to note that this may be done without removing the refrigerant charge. During replacement of the pressure switch, a new O-ring seal must be installed and the switch assembled to the specified torque of 4.5 Nm (40 lbs. in.). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - HVAC > Refrigerant Pressure Sensor / Switch, HVAC > Component Information > Description and Operation > Compressor Cut-Off/Cycling Switch > Page 624 Refrigerant Pressure Sensor / Switch: Description and Operation Compressor High Side Cut-Off Switch This system is equipped with a high pressure cutoff switch. This switch is normally closed, and opens at 2827-3103 kPa (410-450 psi) to interrupt the voltage to the compressor clutch coil. This will stop the compressor from cycling and prevent the pressure relief valve from discharging refrigerant and oil. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Instrument Panel > Dimmer Switch > Component Information > Technical Service Bulletins > IP Dimmer Control - Proper Setting Dimmer Switch: Technical Service Bulletins IP Dimmer Control - Proper Setting File In Section: 08 - Body and Accessories Bulletin No.: 99-08-42-009 Date: November, 1999 INFORMATION Subject: Proper Setting of I/P Dimmer Control to View PRNDL Display with Automatic Headlamp Control Models: 2000 and Prior All Passenger Cars and Trucks With Automatic Headlamp Control and Electronic PRNDL Display Under certain conditions, if the instrument panel dimmer control is turned relatively low, the PRNDL will not be visible until the automatic headlamp control turns the headlamps off and the daytime running lamps (DRL) are turned back on. Such a condition may be if the vehicle is first started in an environment where the headlamp control turns on the headlamps and then the vehicle is driven out into a brighter environment (for example, when a vehicle is backed out of a dark garage into the bright sunlight). This condition is normal and any repair attempt will not be successful. Demonstrate this condition to the customer using the service lane and then turn the instrument panel dimmer control to a higher setting. This will enable the driver to see the PRNDL display Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Instrument Panel > Dimmer Switch > Component Information > Technical Service Bulletins > Page 630 Dimmer Switch: Locations I/P Harness Wiring, LH Side Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Instrument Panel > Dimmer Switch > Component Information > Technical Service Bulletins > Page 631 LH I/P Harness Wiring Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Instrument Panel > Dimmer Switch > Component Information > Technical Service Bulletins > Page 632 C219 - Panel Dimmer Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Instrument Panel > Dimmer Switch > Component Information > Technical Service Bulletins > Page 633 Dimmer Switch: Service and Repair Fig. 5 Lock Plate Compression 1. Disconnect battery ground cable. 2. Remove steering wheel. WARNING: Refer to Air Bags and Seat Belts/ Air Bags (Supplemental Restraint Systems)/ Service and Repair/ Air Bag System Disarming & Arming. 3. Using a screwdriver, pry cover from lock plate. 4. Using lock plate compressing tool No. J-23653, or equivalent, remove lock plate as follows: a. Compress lock plate and pry retaining ring from groove on shaft, Fig. 5. b. Slowly release lock plate compressing tool, then remove tool and lock plate from shaft end. 5. Slide canceling cam and upper bearing preload spring from end of shaft. 6. Remove turn signal (multi-function) lever. 7. Remove hazard warning knob retaining screw, button, spring and knob. 8. Remove pivot arm. 9. Remove switch retaining screws and pull switch up from column, guiding wire harness through column. 10. Reverse procedure to install. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Instrument Panel > Door Switch > Component Information > Locations > Door Jamb Switch Dome Lamp Wiring Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Instrument Panel > Door Switch > Component Information > Locations > Door Jamb Switch > Page 638 Door Switch: Locations Door Jamb Switch, LH Front LH Door Jamb Switch Wiring Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Instrument Panel > Door Switch > Component Information > Locations > Door Jamb Switch > Page 639 Interior Lamp Harness Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Instrument Panel > Door Switch > Component Information > Locations > Door Jamb Switch > Page 640 Power Mirrors Wiring Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Instrument Panel > Door Switch > Component Information > Locations > Door Jamb Switch > Page 641 Door Switch: Locations Door Jamb Switch, RH Front Interior Lamp Harness Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Instrument Panel > Door Switch > Component Information > Locations > Door Jamb Switch > Page 642 Power Mirrors Wiring Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Instrument Panel > Door Switch > Component Information > Locations > Door Jamb Switch > Page 643 Door Switch: Locations Door Jamb Switch, 4-Door Power Door Lock Wiring-4-Door Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Instrument Panel > Door Switch > Component Information > Locations > Door Jamb Switch > Page 644 Power Window And Door Lock Body Wiring-4-Door Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Instrument Panel > Door Switch > Component Information > Locations > Page 645 Door Switch: Diagrams C205 - LH Door Jamb Wiring C205 - LH Door Jamb Wiring Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Instrument Panel > Fuel Gauge Sender > Component Information > Locations > Fuel Pump Sending Unit Fuel Gauge Sender: Locations Fuel Pump Sending Unit Rear Lamps Crossbody Harness W/O Trailer Tow Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Instrument Panel > Fuel Gauge Sender > Component Information > Locations > Fuel Pump Sending Unit > Page 650 Rear Lamps Harness W/Trailer Tow Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Instrument Panel > Fuel Gauge Sender > Component Information > Locations > Fuel Pump Sending Unit > Page 651 Fuel Pump And Sender Assembly (Typical) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Instrument Panel > Fuel Gauge Sender > Component Information > Locations > Page 652 Fuel Gauge Sender: Service and Repair Fuel Pump And Sender Assembly (Typical) REMOVE/DISCONNECT - Negative battery cable. - Raise vehicle. - Fuel tank. - Pump and sending unit assembly by turning cam lock counterclockwise using tool J-36608 or J-24187 or equivalent. Pull fuel pump up into attaching hose while pulling outward from the bottom support. Do not damage rubber insulator or strainer. INSPECT - Inspect fuel pump attaching hose for signs of deterioration. - Inspect rubber sound insulation at bottom of pump for deterioration. INSTALL/CONNECT - Pump assembly into attaching hose. NOTE: Care should be taken not to fold over or twist strainer when installing sending unit as this will restrict fuel flow. Sending unit and fuel pump assembly into fuel tank. (Always use a new O-ring seal). - Cam lock assembly. Turn cam lock clockwise to lock it. - Fuel tank assembly. - Negative battery cable. - START vehicle and check for fuel leaks. - Lower vehicle. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Instrument Panel > Parking Brake Warning Switch > Component Information > Locations Parking Brake Warning Switch: Locations LH I/P Harness Wiring Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Instrument Panel > Parking Brake Warning Switch > Component Information > Locations > Page 656 I/P Harness Wiring, LH Side Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Instrument Panel > Parking Brake Warning Switch > Component Information > Locations > Page 657 C208 - Park Brake Warning Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Backup Lamp Switch > Component Information > Locations > Automatic Transmission Backup Lamp And Park/Neutral Position Switch (Auto Trans) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Backup Lamp Switch > Component Information > Locations > Automatic Transmission > Page 663 Backup Lamp Switch: Locations Manual Transmission Backup Lamp Switch Wiring-Four-Wheel Drive Models Backup Lamp Switch Wiring-Four-Wheel Drive Models Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Locations > Brake Light Switch LH I/P Harness Wiring Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Locations > Brake Light Switch > Page 668 Brake Light Switch: Locations Stop Lamp Switch I/P Harness Wiring, LH Side Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Locations > Brake Light Switch > Page 669 Stoplamp/TCC Brake Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions Brake Light Switch: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. Use this page as a reference to determine the meaning of an abbreviation if necessary. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery Bi-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CHMSL Center High Mount Stoplamp CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRO Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 672 F-PUMP Fuel Pump FLASH Flasher FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 673 SIR Supplemental Inflatable Restraint SKT Socket SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature TIL Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 674 example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE (ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: ^ Slide across the vehicle seat. ^ Sit down or stand up. ^ Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: ^ They are bumped or dropped. ^ They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 675 Symbols (Part 1 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 676 Symbols (Part 2 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 677 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 678 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 679 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 680 Brake Light Switch: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 681 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 682 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 683 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 684 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 685 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. ^ If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. ^ A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 686 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 687 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 688 Ohmmeter Meter Scales Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 689 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. ^ An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. ^ On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: ^ A range selector switch which permits the selection of different ranges of resistance. ^ A set adjust control which allows the meter to be set at zero for accurate measurements. ^ Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 690 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: ^ Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. ^ Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. ^ Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 691 be less than 10 percent of the total drop. When using a voltmeter: ^ Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. ^ Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. ^ The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: ^ Check the accuracy and completeness of the complaint. ^ Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 692 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. ^ The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 693 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 694 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 695 Twisted/Shielded Wire Repair Twisted Wires Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 696 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 697 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 698 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). ^ Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean ^ Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. ^ Roll crimp (13) and solder the terminal. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 699 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 700 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 701 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. ^ Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean ^ Terminal cavity of the connector body. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 702 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. ^ Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 703 Brake Light Switch: Connector Views C264 - Backup Lamp Switch C321 - Backup Lamp Switch C264 - Backup Lamp Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 704 Brake Light Switch: Electrical Diagrams Exterior Lamps: Standard I/P (Part 1 Of 2) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 705 Cruise Control Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 706 Fig. 5 Cruise Control Wiring Diagram. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Page 707 Brake Light Switch: Description and Operation PURPOSE The brake switch signals the control module to turn "OFF" the torque converter clutch when the brakes are applied. OPERATION The brake switch is normally closed. When the brake pedal is applied the switch will open, changing the signal to the control module. The control module uses this signal to de-energize the TCC solenoid when brake pedal is applied. LOCATION The brake switch is located on the brake pedal mounting bracket. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Page 708 Brake Light Switch: Service and Repair Below LH Side Of I/P - Clutch And Brake Pedal Bracket Areas All Except Utility Truck Brake Switch 1. Disconnect battery ground cable. 2. Disconnect wiring connector from brake light switch located on brake pedal bracket. 3. Disconnect retainer from brake pedal pin. 4. Disconnect switch by unsnapping from pushrod. 5. Reverse procedure to install. Fig. 4 Stop Light Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Brake Light Switch > Component Information > Diagrams > Page 709 Utility Truck Brake Switch 1. Disconnect battery ground cable. 2. Disconnect wiring connector from brake light switch located on brake pedal bracket. 3. Pull switch from mounting bracket. 4. Depress brake pedal, then push new switch into clip until shoulder bottoms out, Fig. 4. 5. Pull brake pedal rearward against pedal stop to adjust switch. Switch is properly adjusted when brake lights operate when brake pedal is depressed 0.53 inch from normal position. If further adjustment of switch is necessary, switch can be rotated or pulled in clip. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Door Switch > Component Information > Locations > Door Jamb Switch Dome Lamp Wiring Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Door Switch > Component Information > Locations > Door Jamb Switch > Page 714 Door Switch: Locations Door Jamb Switch, LH Front LH Door Jamb Switch Wiring Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Door Switch > Component Information > Locations > Door Jamb Switch > Page 715 Interior Lamp Harness Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Door Switch > Component Information > Locations > Door Jamb Switch > Page 716 Power Mirrors Wiring Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Door Switch > Component Information > Locations > Door Jamb Switch > Page 717 Door Switch: Locations Door Jamb Switch, RH Front Interior Lamp Harness Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Door Switch > Component Information > Locations > Door Jamb Switch > Page 718 Power Mirrors Wiring Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Door Switch > Component Information > Locations > Door Jamb Switch > Page 719 Door Switch: Locations Door Jamb Switch, 4-Door Power Door Lock Wiring-4-Door Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Door Switch > Component Information > Locations > Door Jamb Switch > Page 720 Power Window And Door Lock Body Wiring-4-Door Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Door Switch > Component Information > Locations > Page 721 Door Switch: Diagrams C205 - LH Door Jamb Wiring C205 - LH Door Jamb Wiring Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Fog/Driving Lamp Switch > Component Information > Locations Fog Lamp Switch And Relay Wiring Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Fog/Driving Lamp Switch > Component Information > Locations > Page 725 Fog/Driving Lamp Switch: Diagrams C225 - Fog Lamp Switch C225 - Fog Lamp Switch C146 - Fog LP Switch Harness C146 - Fog LP Wiring Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Headlamp Dimmer Switch > Component Information > Locations Headlamp Dimmer Switch: Locations Steering Column Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Headlamp Dimmer Switch > Component Information > Locations > Page 729 Steering Column Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Headlamp Dimmer Switch > Component Information > Locations > Page 730 Steering Column Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Headlamp Dimmer Switch > Component Information > Locations > Page 731 Steering Column Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Headlamp Dimmer Switch > Component Information > Locations > Page 732 Steering Column Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Headlamp Dimmer Switch > Component Information > Locations > Page 733 C203 - Headlamp Dimmer Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Locations I/P Harness Wiring, LH Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Locations > Page 737 Headlamp Switch: Description and Operation HEADLAMPS Voltage is supplied to the Light Switch at all times. The Light Switch includes a Self-Resetting Circuit Breaker. The Circuit Breaker opens when the Circuit Breaker opens, it interrupts the current flow. With no current flow, the Circuit Breaker cools off the resets automatically. When the Light Switch is in HEAD, the Headlamps Dimmer Switch directs voltage to either the Low Beams or High Beams. The High Beams Indicator also receives voltage along with the High Beams. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Locations > Page 738 Headlamp Switch: Testing and Inspection HEADLAMPS Voltage is supplied to the Light Switch at all times. The Light Switch includes a Self-Resetting Circuit Breaker. The Circuit Breaker opens when the Circuit Breaker opens, it interrupts the current flow. With no current flow, the Circuit Breaker cools off the resets automatically. When the Light Switch is in HEAD, the Headlamps Dimmer Switch directs voltage to either the Low Beams or High Beams. The High Beams Indicator also receives voltage along with the High Beams. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Headlamp Switch > Component Information > Locations > Page 739 Headlamp Switch: Service and Repair 1. Disconnect battery ground cable. 2. Remove Headlamp switch trim plate and switch assembly attaching screws. 3. Disconnect electrical connectors from Headlamp switch, then remove switch assembly from dash panel. 4. Reverse procedure to install. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Turn Signal Switch > Component Information > Technical Service Bulletins > Turn Signal Switch - Damage During I/P Replacement Turn Signal Switch: Technical Service Bulletins Turn Signal Switch - Damage During I/P Replacement File In Section: 8 - Chassis/Body Electrical Bulletin No.: 56-83-03 Date: September, 1995 INFORMATION Subject: Hazard Button/Multi-Function Signal Switch Damage During I/P or Cluster Removal or Replacement Models: 1994-95 Chevrolet and GMC Truck S/T Models The following is an update on the installation and replacement of the I/P cluster and the procedure necessary to avoid possible damage to the Multi-function Switch (MFS) and especially the hazard button. These hazard buttons which are part of the MFS are common for both S/T and C/K vehicles. The damage to the hazard button is most common when installing an after-market radio or when doing repairs to the I/P. If for any reason the I/P trim bezel needs to be removed, the procedure for instrument cluster replacement (1995 S/T Service Manual, Section 8C-6) must be followed exactly. This includes removing the steering column nuts and lowering the steering column. If not, the possibility of damage of the hazard button is increased. Warranty Information For vehicles repaired under warranty, use: Labor Operation Description Labor Time C2323 Lower I/P Trim Panel R&R; 0.3 hr C2327 Steering Column Lower 0.3 hr Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Turn Signal Switch > Component Information > Technical Service Bulletins > Page 744 Hazard Flasher And Multi-Function Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Turn Signal Switch > Component Information > Technical Service Bulletins > Page 745 Turn Signal Switch: Diagrams C204 - Turn Signal Switch C204 - Turn Signal Switch In-Line Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Lighting and Horns > Turn Signal Switch > Component Information > Technical Service Bulletins > Page 746 Turn Signal Switch: Service and Repair Fig. 5 Lock Plate Compression 1. Disconnect battery ground cable. 2. Remove steering wheel. WARNING: Refer to Air Bags and Seat Belts/ Air Bags (Supplemental Restraint Systems)/ Service and Repair/ Air Bag System Disarming & Arming. 3. Using a screwdriver, pry cover from lock plate. 4. Using lock plate compressing tool No. J-23653, or equivalent, remove lock plate as follows: a. Compress lock plate and pry retaining ring from groove on shaft, Fig. 5. b. Slowly release lock plate compressing tool, then remove tool and lock plate from shaft end. 5. Slide canceling cam and upper bearing preload spring from end of shaft. 6. Remove turn signal (multi-function) lever. 7. Remove hazard warning knob retaining screw, button, spring and knob. 8. Remove pivot arm. 9. Remove switch retaining screws and pull switch up from column, guiding wire harness through column. 10. Reverse procedure to install. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Specifications Coolant Temperature Sensor/Switch (For Computer): Specifications Resistance 185 ohms at 210 deg F 450 ohms at 160 deg F 1800 ohms at 100 deg F 3400 ohms at 70 deg F 7500 ohms at 40 deg F 13500 ohms at 20 deg F 25000 ohms at 0 deg F 100700 ohms at -40 deg F Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Specifications > Page 752 Coolant Temperature Sensor/Switch (For Computer): Locations Engine Coolant Temperature Sensor Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Specifications > Page 753 Engine Harness, Right Front Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions Coolant Temperature Sensor/Switch (For Computer): Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. Use this page as a reference to determine the meaning of an abbreviation if necessary. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery Bi-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CHMSL Center High Mount Stoplamp CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRO Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 756 F-PUMP Fuel Pump FLASH Flasher FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 757 SIR Supplemental Inflatable Restraint SKT Socket SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature TIL Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 758 example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE (ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: ^ Slide across the vehicle seat. ^ Sit down or stand up. ^ Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: ^ They are bumped or dropped. ^ They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 759 Symbols (Part 1 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 760 Symbols (Part 2 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 761 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 762 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 763 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 764 Coolant Temperature Sensor/Switch (For Computer): Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 765 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 766 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 767 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 768 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 769 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. ^ If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. ^ A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 770 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 771 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 772 Ohmmeter Meter Scales Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 773 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. ^ An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. ^ On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: ^ A range selector switch which permits the selection of different ranges of resistance. ^ A set adjust control which allows the meter to be set at zero for accurate measurements. ^ Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 774 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: ^ Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. ^ Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. ^ Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 775 be less than 10 percent of the total drop. When using a voltmeter: ^ Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. ^ Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. ^ The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: ^ Check the accuracy and completeness of the complaint. ^ Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 776 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. ^ The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 777 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 778 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 779 Twisted/Shielded Wire Repair Twisted Wires Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 780 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 781 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 782 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). ^ Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean ^ Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. ^ Roll crimp (13) and solder the terminal. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 783 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 784 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 785 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. ^ Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean ^ Terminal cavity of the connector body. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 786 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. ^ Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 787 C105 - Engine Coolant Temperature Sensor Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 788 Engine Coolant Temperature (ECT) Circuit Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Page 789 Coolant Temperature Sensor/Switch (For Computer): Description and Operation Engine Coolant Temperature Sensor PURPOSE The Engine Coolant Temperature (ECT) Sensor information is used by the control module to control: Fuel delivery - Torque Converter Clutch (TCC) - Engine Spark Timing (EST) - Controlled Canister Purge (CCP) - Idle Air Control (IAC) - Cooling Fan OPERATION The ECT is a thermistor that is located in the engine coolant flow mounted to the intake manifold. When the coolant temperature is low, the sensor produces a high resistance. When the coolant temperature is high, the sensor produces a low resistance. The PCM sends a 5.0 volt signal to the ECT through a resistor in the computer and measures the voltage. The voltage will be high or low depending on coolant temperature. With the ECT varying its resistance, the PCM can sense engine coolant temperature by reading the varying voltage. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Intake Air Temperature Sensor > Component Information > Specifications > Electrical Specifications Intake Air Temperature Sensor: Electrical Specifications Resistance 185 ohms at 210 deg F 450 ohms at 160 deg F 1800 ohms at 100 deg F 3400 ohms at 70 deg F 7500 ohms at 40 deg F 13500 ohms at 20 deg F 25000 ohms at 0 deg F 100700 ohms at -40 deg F Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Intake Air Temperature Sensor > Component Information > Specifications > Electrical Specifications > Page 794 Intake Air Temperature Sensor: Mechanical Specifications Torque Valve Torque Valve Induction Air Sensor 44 in.lb Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Knock Sensor > Component Information > Technical Service Bulletins > Knock Sensor Circuit - DTC 43 Chart Revision Knock Sensor: Technical Service Bulletins Knock Sensor Circuit - DTC 43 Chart Revision File In Section: 6E Engine Fuel & Emission Bulletin No.: 51-65-19 Date: April, 1995 Subject: Section 3A - Control Module System (PCM) Driveability and Emissions - Revised DTC 43 Knock Sensor (KS) Circuit (Dual Knock Sensors) Models: 1994 Chevrolet and GMC Truck S/T; M/L, C/K Models with 4.3L Engine (VINs W, Z RPOs L35, LB4) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Knock Sensor > Component Information > Technical Service Bulletins > Knock Sensor Circuit - DTC 43 Chart Revision > Page 799 This bulletin advises of a revision to the DTC 43 Knock Sensor (KS) Circuit (Dual Knock Sensor System) chart in the following service manuals: 1994 S/T Driveability Emissions and Electrical Diagnosis Manual, page 3A-119 1994 M/L Driveability Emissions and Electrical Diagnosis Manual, page 3A-75 1994 C/K Driveability Emissions and Electrical Diagnosis Manual, page 3A-69 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Knock Sensor > Component Information > Technical Service Bulletins > Page 800 Knock Sensor: Specifications Coil bracket bolt/nut ............................................................................................................................. ................................................. 27 N-m (20 lbs ft) Distributor clamp bolt ........................................................................................................................... ................................................ 27 N-m (20 lbs ft) Knock Sensor ...................................................................................................................................... .................................................. 19 N-m (14 lbs ft) Spark Plugs ......................................................................................................................................... .................................................. 15 N-M (11 lbs ft) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Knock Sensor > Component Information > Locations > Assembly View Knock Sensors Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Knock Sensor > Component Information > Locations > Assembly View > Page 803 Knock Sensor: Locations Harness View LH Rear Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Knock Sensor > Component Information > Locations > Assembly View > Page 804 LH Rear Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Knock Sensor > Component Information > Locations > Page 805 Knock Sensor: Diagrams C119 - Knock Sensor C135 - Knock Sensor Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Knock Sensor > Component Information > Locations > Page 806 Knock Sensor: Description and Operation PURPOSE: The Knock Sensor (KS) is used to detect engine detonation (ping). The control module will retard the electronic spark timing up to 8° based on the signal received. CONSTRUCTION The KS system has two major components: Control Module. - Knock Sensor(s). The two knock sensors are spliced together and go directly to the control module. OPERATION The knock sensor internal circuit causes the control modules 5 volts to be pulled down to about 2.5 volts. The knock sensor produces an A/C signal which rides on the 2.5 volts DC signal. The AC voltage monitor in the control module will detect this AC voltage and provide a signal to begin retarding spark until the knock diminishes. The amplitude and frequency are dependent upon the knock level. LOCATION Engine block. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Knock Sensor > Component Information > Locations > Page 807 Knock Sensor: Testing and Inspection Knock Sensor (KS) System Check Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Knock Sensor > Component Information > Locations > Page 808 Knock Sensor Circuit Circuit Description The Knock Sensor (KS) circuit consists of two knock sensors with one wire that goes directly to the control modules. There are two Knock Sensor (KS) checks performed by the ECM. One check consists of monitoring CKT 496 for a voltage that is more than .63 volt and less than 3.1 volts. If voltage is either too high or too low for 10 or more seconds, DTC 43 will set. The PCM uses this self check only. The next test is used only by the ECM along with the previous test. Once engine temperature reaches 85°C, MAP is over 83 kPa, and engine speed is less than 3200 RPM, the ECM will perform a self check. This self check will advance the timing until it receives a knock signal. If no knock signal is received, DTC 43 will set. Chart Test Description Number(s) below refer to circled number(s) on the diagnostic chart. 1. The first test is to determine if the system is functioning at the present time. 2. Test two determines the state of the 5 volt reference voltage applied to the knock sensor circuit. 3. Test 3 determines the state of the knock sensors and connections themselves. Diagnostic Aids The control module applies 5 volts to CKT 496. A 8200 ohm resistor in the knock sensors reduces the voltage to about 2.5 volts. When knock occurs, the knock sensor produces a small AC voltage that rides on top of the 2.5 volts already applied. An AC voltage monitor, in the control module, is able to read this signal as knock and incrementally retard spark. If the KS system checks OK, but detonation is the complaint, refer to "Detonation/Spark Knock". See: Powertrain Management/Computers and Control Systems/Testing and Inspection/Symptom Related Diagnostic Procedures/Detonation/ Spark Knock Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Knock Sensor > Component Information > Locations > Page 809 Knock Sensor: Service and Repair REMOVE OR DISCONNECT - Negative battery cable. - Drain cooling system. NOTE On knock sensors which are mounted in the end of the cylinder head draining the cooling system will not be necessary. - Wiring harness connector from knock sensor. - Knock sensor. INSTALL OR CONNECT - Knock sensor. If reinstalling original sensor, apply water base caulk to sensor threads. Do NOT use silicone tape as this will insulate sensor from engine. ^ Tighten to 19 Nm (14 lb. ft.). - Wiring harness connector to knock sensor. - Refill cooling system and pressure test for leaks. - Negative battery cable. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Specifications Manifold Pressure/Vacuum Sensor: Specifications Voltage 3.6 to 5.2 V at 1000 to 2000 ft 3.5 to 5.1 V at 2000 to 3000 ft 3.3 to 5.0 V at 3000 to 4000 ft 3.2 to 4.8 V at 4000 to 5000 ft 3.0 to 4.6 V at 5000 to 6000 ft 2.9 to 4.5 V at 6000 to 7000 ft 2.8 to 4.3 V at 7000 to 8000 ft 2.6 to 4.2 V at 8000 to 9000 ft 2.5 to 4.0 V at 9000 to 10000 ft Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Specifications > Page 813 Manifold Pressure/Vacuum Sensor: Locations Engine Harness, Right Front Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Specifications > Page 814 MAP Sensor 4.3Z Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions Manifold Pressure/Vacuum Sensor: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. Use this page as a reference to determine the meaning of an abbreviation if necessary. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery Bi-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CHMSL Center High Mount Stoplamp CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRO Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 817 F-PUMP Fuel Pump FLASH Flasher FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 818 SIR Supplemental Inflatable Restraint SKT Socket SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature TIL Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 819 example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE (ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: ^ Slide across the vehicle seat. ^ Sit down or stand up. ^ Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: ^ They are bumped or dropped. ^ They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 820 Symbols (Part 1 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 821 Symbols (Part 2 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 822 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 823 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 824 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 825 Manifold Pressure/Vacuum Sensor: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 826 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 827 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 828 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 829 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 830 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. ^ If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. ^ A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 831 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 832 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 833 Ohmmeter Meter Scales Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 834 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. ^ An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. ^ On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: ^ A range selector switch which permits the selection of different ranges of resistance. ^ A set adjust control which allows the meter to be set at zero for accurate measurements. ^ Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 835 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: ^ Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. ^ Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. ^ Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 836 be less than 10 percent of the total drop. When using a voltmeter: ^ Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. ^ Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. ^ The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: ^ Check the accuracy and completeness of the complaint. ^ Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 837 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. ^ The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 838 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 839 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 840 Twisted/Shielded Wire Repair Twisted Wires Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 841 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 842 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 843 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). ^ Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean ^ Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. ^ Roll crimp (13) and solder the terminal. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 844 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 845 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 846 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. ^ Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean ^ Terminal cavity of the connector body. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 847 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. ^ Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 848 C109 - MAP Sensor Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 849 MAP Sensor Circuit Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Page 850 Manifold Pressure/Vacuum Sensor: Description and Operation Map Sensor Circuit (GM Generic) Manifold Absolute Pressure (MAP) Sensor PURPOSE The Manifold Absolute Pressure (MAP) sensor measures changes in the intake manifold pressure resulting from engine load and speed changes. As intake manifold pressure increases, the air density in the intake manifold also increases and additional fuel is required. Under certain conditions, the MAP sensor is also used to measure barometric pressure. This allows the control module to automatically adjust for different altitudes. The PCM uses information from the MAP sensor to calculate spark advance and fuel as follows: Low MAP output voltage (low pressure) results in more spark advance. - High MAP output voltage (high pressure) results in less spark advance. - Low MAP output voltage (low pressure) results in less fuel. - High MAP output voltage (high pressure) results in more fuel. OPERATION The control module supplies a 5 volt reference signal to the MAP sensor and the sensor provides a path to ground through its variable resistor. The control module by monitoring the sensor output voltage can determine the manifold pressure. A closed throttle on engine coastdown will produce a relatively low MAP output, while a wide open throttle will produce a high output. At higher pressure or at Wide Open Throttle (WOT) output voltage will be about 4 to 4.8 volts. The higher the MAP voltage output the lower the engine vacuum, which requires more fuel. The lower the MAP voltage output the higher the engine vacuum. At lower pressure output voltage will be about 1 to 2 volts at idle. A failure in the MAP sensor circuit should set Diagnostic Trouble Codes (DTC) 33 or 34 with PCM/ECM systems and DTC P0107 or P0108 with VCM systems. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Page 851 Manifold Pressure/Vacuum Sensor: Testing and Inspection Manifold Absolute Pressure (MAP) Output Check Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Page 852 MAP Sensor Circuit Circuit Description: The Manifold Absolute Pressure (MAP) sensor measures the changes in the intake manifold pressure which result from engine load (intake manifold vacuum) and RPM changes; and converts these into a voltage output. The PCM sends a 5 volt reference voltage to the MAP sensor. As the manifold pressure changes, the output voltage of the sensor also changes. By monitoring the sensor output voltage, the PCM knows the manifold pressure. At lower pressure output voltage will be about 1 to 2 volts at idle. While at higher pressure or at Wide Open Throttle (WOT) output voltage will be about 4 to 4.8 volts. The MAP sensor is also used, under certain conditions, to measure barometric pressure, allowing the PCM to make adjustments for different altitudes. The PCM uses the MAP sensor to control fuel delivery and ignition timing. Chart Test Description Number(s) below refer to circled number(s) on the diagnostic chart. Important ^ Be sure to use the same Diagnostic Test Equipment for all measurements. 1. Checks MAP sensor output voltage to the PCM. This voltage, without engine running, represents a barometer reading to the PCM. ^ When comparing Tech 1 scan readings to a known good vehicle, it is important to compare vehicles that use a MAP sensor having the same color insert or having the same "Hot Stamped" number. Refer to figures on facing page. 2. Applying 34 kPa (10" Hg) vacuum to the MAP sensor should cause the voltage to change. Subtract second reading from the first. Voltage value should be greater than 1.5 volts. Upon applying vacuum to the sensor, the change in voltage should be instantaneous. A slow voltage change indicates a faulty sensor. 3. Check vacuum hose to sensor for leaking or restriction. Be sure that no other vacuum devices are connected to the MAP hose. NOTICE:Make sure electrical connector remains securely fastened. 4. Disconnect sensor from bracket and twist sensor by hand (only) to check for intermittent connection. Output changes greater than .1 volt indicate a bad connector or connection. If OK, replace sensor. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > Customer Interest: > 566501 > Jul > 95 > O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear Oxygen Sensor: Customer Interest O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear FILE IN SECTION: 6E - Engine Fuel & Emission BULLETIN NO.: 56-65-01 DATE: July, 1995 SUBJECT: Rattling Noise on Acceleration/Transmission Starting Out in 3rd Gear (Provide Clearance or Replace Exhaust Crossover) MODELS: 1993-94 Chevrolet and GMC Truck M/L Vans 1994 Chevrolet and GMC Truck T Models 1994 Oldsmobile Bravada with 4.3L Engines (VINs W, Z - RPOs L35, LB4) CONDITION Customers may comment on one or more of the following conditions: A rattling noise on acceleration, transmission starting out in 3rd gear (possible DTC 66, 67, 81, 82) and/or diagnostic trouble codes 13 or 44. CAUSE M/L Vans Oxygen sensor and/or harness pigtail contacting the heat shield due to improper routing of the harness. Sharp edges of the heat shield cuts through the wire insulation. T Trucks The rattle noise may be the oxygen sensor and/or harness pigtail contacting the heat shield due to the mispositioning of the oxygen sensor mounting boss. Starting out in 3rd gear may be due to the pink wire (CKT 39) shorting out against the heat shield causing power to be interrupted to the transmission control circuit putting the transmission into backup mode (3rd Gear Starts). Diagnostic trouble codes 13 or 44 may be set due to the oxygen sensor signal wire shorting to or cut through by the heat shield. CORRECTION M/L Vans Refer to the "1993 M/L Van Electrical Diagrams and Diagnosis" manual or the "1994 Driveability, Emissions and Electrical Diagnosis" manual for circuit 39 schematics. Normal circuit diagnostics should be performed first if the problem is constant. If the problem is intermittent, an inspection of circuit 39 (pink/black) in the area of the exhaust heat shields may lead to the problem. Inspect the oxygen sensor wiring and replace the sensor it the insulation has been damaged. Re-route wiring harness as needed to protect harness. Clear any codes and test drive. T Trucks If the oxygen sensor is contacting the heat shield, this condition can be corrected by replacing the exhaust crossover pipe. If the oxygen sensor wire is damaged, the oxygen sensor must also be replaced. Follow regular Service Manual Procedures in Section 3 of the 1993 or 1994 "S/T Truck Driveability, Emission and Electrical Diagnosis" manual to make above repairs. Clear any diagnostic trouble codes and test drive. PARTS INFORMATION P/N Description Qty 10096129 Sensor, Oxygen (1993) 1 25133503 Sensor, Oxygen (1994) 1 15661132 Pipe, Exhaust Crossover (w/ZR2) 1 15672887 Pipe, Exhaust Crossover (w/o ZR2) 1 Parts are currently available from GMSPO. WARRANTY INFORMATION Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > Customer Interest: > 566501 > Jul > 95 > O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear > Page 861 For vehicles repaired under warranty, use: Labor Operation Description Labor Time J6372 Sensor, Oxygen Replace Use Published L2080 Pipe, Crossover Exhaust Replace Labor Operation Time Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oxygen Sensor: > 566501 > Jul > 95 > O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear Oxygen Sensor: All Technical Service Bulletins O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear FILE IN SECTION: 6E - Engine Fuel & Emission BULLETIN NO.: 56-65-01 DATE: July, 1995 SUBJECT: Rattling Noise on Acceleration/Transmission Starting Out in 3rd Gear (Provide Clearance or Replace Exhaust Crossover) MODELS: 1993-94 Chevrolet and GMC Truck M/L Vans 1994 Chevrolet and GMC Truck T Models 1994 Oldsmobile Bravada with 4.3L Engines (VINs W, Z - RPOs L35, LB4) CONDITION Customers may comment on one or more of the following conditions: A rattling noise on acceleration, transmission starting out in 3rd gear (possible DTC 66, 67, 81, 82) and/or diagnostic trouble codes 13 or 44. CAUSE M/L Vans Oxygen sensor and/or harness pigtail contacting the heat shield due to improper routing of the harness. Sharp edges of the heat shield cuts through the wire insulation. T Trucks The rattle noise may be the oxygen sensor and/or harness pigtail contacting the heat shield due to the mispositioning of the oxygen sensor mounting boss. Starting out in 3rd gear may be due to the pink wire (CKT 39) shorting out against the heat shield causing power to be interrupted to the transmission control circuit putting the transmission into backup mode (3rd Gear Starts). Diagnostic trouble codes 13 or 44 may be set due to the oxygen sensor signal wire shorting to or cut through by the heat shield. CORRECTION M/L Vans Refer to the "1993 M/L Van Electrical Diagrams and Diagnosis" manual or the "1994 Driveability, Emissions and Electrical Diagnosis" manual for circuit 39 schematics. Normal circuit diagnostics should be performed first if the problem is constant. If the problem is intermittent, an inspection of circuit 39 (pink/black) in the area of the exhaust heat shields may lead to the problem. Inspect the oxygen sensor wiring and replace the sensor it the insulation has been damaged. Re-route wiring harness as needed to protect harness. Clear any codes and test drive. T Trucks If the oxygen sensor is contacting the heat shield, this condition can be corrected by replacing the exhaust crossover pipe. If the oxygen sensor wire is damaged, the oxygen sensor must also be replaced. Follow regular Service Manual Procedures in Section 3 of the 1993 or 1994 "S/T Truck Driveability, Emission and Electrical Diagnosis" manual to make above repairs. Clear any diagnostic trouble codes and test drive. PARTS INFORMATION P/N Description Qty 10096129 Sensor, Oxygen (1993) 1 25133503 Sensor, Oxygen (1994) 1 15661132 Pipe, Exhaust Crossover (w/ZR2) 1 15672887 Pipe, Exhaust Crossover (w/o ZR2) 1 Parts are currently available from GMSPO. WARRANTY INFORMATION Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oxygen Sensor: > 566501 > Jul > 95 > O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear > Page 867 For vehicles repaired under warranty, use: Labor Operation Description Labor Time J6372 Sensor, Oxygen Replace Use Published L2080 Pipe, Crossover Exhaust Replace Labor Operation Time Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oxygen Sensor: > 81I37 > Feb > 81 > Oxygen Sensors - Silica Contamination Oxygen Sensor: All Technical Service Bulletins Oxygen Sensors - Silica Contamination Model Year: 1981 Bulletin No: 81-I-37 File In Group: 60 Number: 11 Date: Feb. 81 Subject: Silica Contamination of Oxygen Sensors and Gelation of Oil. Models Affected: All Oxygen sensor performance can deteriorate if certain RTV silicone gasket materials are used. Other RTV's when used with certain oils, may cause gelation of the oil. The degree of performance severity depends on the type of RTV and application of the engine involved. Therefore, when repairing engines where this item is involved, it is important to use either cork composition gaskets or RTV silicone gasket material approved for such use. GMS (General Motors Sealant) or equivalent material can be used. GMS is available through GMPD with the following part numbers: 1052366 3 oz. 1052434 10.14 oz. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > All Other Service Bulletins for Oxygen Sensor: > 81I37 > Feb > 81 > Oxygen Sensors - Silica Contamination Oxygen Sensor: All Technical Service Bulletins Oxygen Sensors - Silica Contamination Model Year: 1981 Bulletin No: 81-I-37 File In Group: 60 Number: 11 Date: Feb. 81 Subject: Silica Contamination of Oxygen Sensors and Gelation of Oil. Models Affected: All Oxygen sensor performance can deteriorate if certain RTV silicone gasket materials are used. Other RTV's when used with certain oils, may cause gelation of the oil. The degree of performance severity depends on the type of RTV and application of the engine involved. Therefore, when repairing engines where this item is involved, it is important to use either cork composition gaskets or RTV silicone gasket material approved for such use. GMS (General Motors Sealant) or equivalent material can be used. GMS is available through GMPD with the following part numbers: 1052366 3 oz. 1052434 10.14 oz. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Specifications > Electrical Specifications Oxygen Sensor: Electrical Specifications Closed Loop 100 - 0.999 mV Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Specifications > Electrical Specifications > Page 879 Oxygen Sensor: Mechanical Specifications Oxygen Sensor 30 ft.lb Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Locations > Heated Oxygen Sensor Engine Harness, Right Front Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Locations > Heated Oxygen Sensor > Page 882 Heated Oxygen Sensor (HO2S) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions Oxygen Sensor: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. Use this page as a reference to determine the meaning of an abbreviation if necessary. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery Bi-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CHMSL Center High Mount Stoplamp CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRO Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 885 F-PUMP Fuel Pump FLASH Flasher FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 886 SIR Supplemental Inflatable Restraint SKT Socket SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature TIL Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 887 example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE (ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: ^ Slide across the vehicle seat. ^ Sit down or stand up. ^ Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: ^ They are bumped or dropped. ^ They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 888 Symbols (Part 1 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 889 Symbols (Part 2 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 890 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 891 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 892 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 893 Oxygen Sensor: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 894 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 895 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 896 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 897 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 898 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. ^ If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. ^ A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 899 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 900 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 901 Ohmmeter Meter Scales Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 902 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. ^ An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. ^ On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: ^ A range selector switch which permits the selection of different ranges of resistance. ^ A set adjust control which allows the meter to be set at zero for accurate measurements. ^ Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 903 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: ^ Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. ^ Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. ^ Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 904 be less than 10 percent of the total drop. When using a voltmeter: ^ Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. ^ Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. ^ The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: ^ Check the accuracy and completeness of the complaint. ^ Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 905 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. ^ The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 906 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 907 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 908 Twisted/Shielded Wire Repair Twisted Wires Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 909 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 910 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 911 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). ^ Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean ^ Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. ^ Roll crimp (13) and solder the terminal. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 912 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 913 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 914 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. ^ Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean ^ Terminal cavity of the connector body. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 915 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. ^ Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 916 C116 - Oxygen Sensor Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 917 Heated Oxygen Sensor (HO2S) Circuit Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Page 918 Oxygen Sensor: Description and Operation Exhaust Oxygen Sensor (02) PURPOSE The Oxygen sensor (O2 Sensor) has the ability to produce a low voltage signal that feeds information on engine exhaust content to the control module. CONSTRUCTION The O2 Sensor is constructed from a zirconia/platinum electrolytic element. Zirconia is an electrolyte that conducts electricity under certain chemical conditions. The element is made of a ceramic material and is an insulator when cold. At operating temperature, 315°C (600°F), the element becomes a semiconductor. A platinum coating on the outer surface of the element stimulates further combustion of the exhaust gases right at the surface and this helps deep the element up to the desired temperature. The O2 Sensor has an inter cavity which is filled with atmospheric (reference) air. The atmosphere has approximately 21% oxygen in it. In the electrical circuit this inter cavity is the positive (+) terminal. The outer surface of the element is exposed to the exhaust gas stream. It is the negative (-) terminal. Oxygen Sensor Output Voltage vs. Air/Fuel Ratio The difference in oxygen concentration in the narrow range of optimum air/fuel ratio causes a large voltage change that is easily measured. OPERATION A rich exhaust (excessive fuel) has almost no oxygen. When there is a large difference in the amount of oxygen touching the inside and outside surfaces, there is more conduction, and the sensor puts out a voltage signal above 0.6 volts (600 mV). With lean exhaust (excessive oxygen) there is about two percent oxygen in the exhaust. This is a smaller difference in oxygen from the outside surfaces which results in less conduction and a voltage signal below 0.3 volts (300 mV). The voltages are monitored and used by the control module to "fine tune" the air/fuel ratio to achieve the ideal mixture desired. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Page 919 The control module puts out a reference signal of 0.45 volts (450 mV). The reference signal serves two purposes. The first is to run the engine when it is in OPEN LOOP mode of operation. When the air/fuel ratio is correct the control module senses 450 mV. When the engine is operating with a rich air/fuel ratio there is a reduction of free oxygen in the exhaust stream and the O2 sensor voltage rises above the reference voltage. When the engine is running lean the voltage drops below the reference voltage due to the excess oxygen in the exhaust stream. The O2 sensor provides the feedback information for the CLOSED LOOP operating mode of the fuel delivery system. The O2 sensor indicates to the control module what is happening in the exhaust. It does not cause things to happen. It is a type of gauge: Low voltage output = lean mixture = high oxygen content in the exhaust; high voltage output = rich mixture = low oxygen content in the exhaust. CONDITIONS THAT CAN SET CODES An open O2 sensor, should set a Diagnostic Trouble Code (DTC) 13. A constant low voltage in the O2 sensor circuit should set a DTC 44. A constant high voltage in the circuit should set a DTC 45. DTC 44 and DTC 45 could be set as a result of fuel system problems. REFER TO COMPUTERS AND CONTROL SYSTEMS/DIAGNOSTIC CHARTS for diagnosis of these codes. HEATED OXYGEN SENSOR TYPE The heated oxygen sensor works in the same manner as the non-heated oxygen sensor. The exception is that B+ is supplied to a heating element that is part of the sensor itself. The heater helps the control module control the fuel injection sooner for better fuel emissions. There are no Diagnostic Trouble Codes (DTC's) to detect if the heater part of the sensor is working. To check the heater, REFER TO COMPUTERS AND CONTROL SYSTEMS/DIAGNOSIS AND TESTING PROCEDURES/OXYGEN SENSOR TESTING. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Page 920 Oxygen Sensor: Testing and Inspection VISUAL INSPECTION - Connectors and wires - Housing and insulator for cracks/damage - Sensor tip for silicone contamination (white powdery coating) CAUTION Do NOT perform the following test for more than 2 minutes, as this may cause damage to the catalytic converter. PERFORMANCE TEST Checks working range and response (speed). Warm engine - Install DVOM between sensor and ground (2 volt D.C. range) - "RUN" engine at steady cruise speed (about 2500 rpm) Voltage should vary at least eight times in ten seconds between 0.2 and 0.8 volts (normal range). - Drive system rich: The use of a properly adjusted propane flow-meter (J-26911) is industry standard. Voltage should increase to at least 0.8 volts within two to three seconds. - Drive system lean: Create a vacuum leak from a source that is not an control module input or output. Voltage should drop to at least 0.3 volts within two to three seconds. NOTE After each test the O2 sensor should return to normal operating range within two to three seconds. - O2 Sensor should be replaced for failure to pass any of the tests above. NOTE A CEC system that is operating excessively rich or lean will drive the 02 sensor to its maximum range and should be repaired first and not diagnosed as a 02 sensor failure. - Reconnect all hoses and electrical connectors. Clear all codes set and retrain idle. HEATING ELEMENT (H20S only) - Turn ignition "OFF". Disconnect electrical connector. - Connect test light between harness terminals "A" and "B". - Turn ignition "ON". Test light should be "ON". If test light is "OFF", connect test light to harness terminal "A" to ground. Light should be "ON" ensuring power circuit is operating correctly. - Turn ignition "OFF". - Using an ohmmeter, measure resistance between terminals A and B. Resistance @ Specified Temperature 3.5 ohms @ 20°C (68°F) 14 ohms @ 350°C (662°F) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Page 921 Oxygen Sensor: Service and Repair NOTE The oxygen sensor has a permanently attached pig-tail and connector. This pig-tail should not be removed, since removal will affect proper operation of the oxygen sensor. REMOVAL - Disconnect electrical connector from oxygen sensor. - Using suitable wrench, carefully remove sensor from exhaust manifold or pipe. Caution The oxygen sensor may be difficult to remove when engine temperature is below 120°F. Excessive force may damage threads in exhaust manifold or pipe. INSTALLATION - If new sensor is being used, install sensor into manifold or pipe. - If old sensor is being reused, coat threads with anti-seize compound, Part No. 5613695 or equivalent, then install into manifold or pipe. - Torque oxygen sensor to 41 N-m (30 lb. ft.), then reconnect electrical connector. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Specifications Throttle Position Sensor: Specifications Idle Normal 0.45 to 0.95 V Maximum 1.25 V Wide Open Throttle 4.0 to 4.5 V Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Specifications > Page 925 Engine Harness, Right Front Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions Throttle Position Sensor: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. Use this page as a reference to determine the meaning of an abbreviation if necessary. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery Bi-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CHMSL Center High Mount Stoplamp CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRO Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 928 F-PUMP Fuel Pump FLASH Flasher FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 929 SIR Supplemental Inflatable Restraint SKT Socket SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature TIL Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 930 example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE (ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: ^ Slide across the vehicle seat. ^ Sit down or stand up. ^ Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: ^ They are bumped or dropped. ^ They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 931 Symbols (Part 1 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 932 Symbols (Part 2 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 933 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 934 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 935 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 936 Throttle Position Sensor: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 937 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 938 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 939 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 940 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 941 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. ^ If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. ^ A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 942 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 943 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 944 Ohmmeter Meter Scales Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 945 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. ^ An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. ^ On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: ^ A range selector switch which permits the selection of different ranges of resistance. ^ A set adjust control which allows the meter to be set at zero for accurate measurements. ^ Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 946 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: ^ Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. ^ Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. ^ Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 947 be less than 10 percent of the total drop. When using a voltmeter: ^ Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. ^ Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. ^ The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: ^ Check the accuracy and completeness of the complaint. ^ Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 948 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. ^ The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 949 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 950 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 951 Twisted/Shielded Wire Repair Twisted Wires Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 952 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 953 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 954 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). ^ Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean ^ Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. ^ Roll crimp (13) and solder the terminal. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 955 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 956 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 957 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. ^ Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean ^ Terminal cavity of the connector body. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 958 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. ^ Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 959 C110 - TP Sensor Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 960 Throttle Position (TP) Circuit Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Page 961 Throttle Position Sensor: Description and Operation Wiring Diagram For Code 21 - Throttle Position Sensor (Signal Voltage High) NOTE Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE The Throttle Position Sensor (TPS) is a potentiometer that senses throttle angle and sends a signal to the PCM. The TP signal is one of the most important inputs used by the control module for fuel control and for most of the control module control outputs. OPERATION The TPS has three internal circuits provided by the control module. One to ground, a second from the control module as a 5.0 volt reference source and a third circuit is used by the control module to measure the output voltage. As the throttle angle changes (pressing down on accelerator pedal) the TPS voltage output varies from about .5 volt at idle to about 4.9 volts at wide open throttle (WOT). Each time the voltage drops below 1.25 volts and stops, the control module assumes this value is 0 throttle from this point on. LOCATION: Side of throttle body opposite of throttle lever. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Page 962 Throttle Position Sensor: Adjustments The TPS is not adjustable. Each time voltage drops below 1.25 volts and stops, the control module assumes that this value is zero throttle angle and measures percent throttle from this point on. Therefore adjustment is not necessary. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Page 963 Throttle Position Sensor: Service and Repair NOTE Since Throttle Position Sensor (TPS) configurations can be mounted interchangeably, be sure to order the correct one for your engine with identical part number of the one being replaced. Throttle Position (TP) Sensor REMOVE/DISCONNECT - Electrical connectors. - TPS attaching screw assemblies and retainer, (if applicable). - TPS from throttle body assembly. NOTE Do NOT immerse in any type of liquid solvent or cleaner, as damage may occur. INSTALL/CONNECT - With throttle valve in normally closed position, install TPS on throttle shaft with seal and rotate counter clockwise to align mounting hole. - Two attaching screw assemblies. Tighten screw assemblies to 2.0 Nm (18.0 lb-in). - Electrical connector to TPS. - Check for TPS output as follows: Connect an ALDL scanner to read TPS output voltage. - With ignition "ON" and engine stopped, TPS voltage should be less than 1.25 volts. If more than 1.25 volts, replace TPS. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Transmission Position Switch/Sensor, A/T > Component Information > Description and Operation Transmission Position Switch/Sensor: Description and Operation Automatic Transmission Electrical Components PURPOSE This device is a set of five presure switches (two normally closed and three normally open), that detect fluid pressure within the valve body passages and signals the PCM which transmission range is selected (PRNDL). OPERATION The five pressure switches are connected to three signal circuits referred to as range signals A, B, C. The combination of pressure switch states determines the voltage signal (B+ or 0) on each range signal to the PCM. LOCATION The transmission range fluid pressure switch assembly is attached to the control valve body within the transmission. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Vehicle Speed Sensor > Component Information > Technical Service Bulletins > Digital Ratio Adapter/Controller (DRAC) - Service Vehicle Speed Sensor: Technical Service Bulletins Digital Ratio Adapter/Controller (DRAC) Service Group Ref.: 8 - Chassis/Body Electrical Bulletin No.: 448301 Date: August, 1994 INFORMATION SUBJECT: NEW PROCEDURE FOR OBTAINING SERVICE DRACS (DIGITAL RATIO ADAPTOR/CONTROLLER) MODELS: 1989-94 CHEVROLET AND GMC TRUCK M/L VANS, S/T MODELS 1990-94 CHEVROLET AND GMC TRUCK G VANS, R/V MODELS 1992-94 CHEVROLET AND GMC TRUCK C/K MODELS 1991-94 OLDSMOBILE BRAVADA If a dealer is contacted about or is in need of a service DRAC (Digital Ratio Adaptor/Controller) for any of the following reasons: 1. Radio interference (EMI). 2. Speedometer fluctuation or flaring. 3. Erratic/surging cruise control operation. 4. Different tire size. 5. Defective part. The dealer must contact an AC-Delco Service Center authorized to repair electronic instrument clusters for a new service DRAC, P/N 16202915. NOTE: This part is a service part and has to be programmed for the vehicle. It cannot be used until this procedure has been done by the authorized Service Center. The dealer will need the P/N and the broadcast code (the 3 bold letters located on the printed label of the old DRAC). The Service Center will program the DRAC according to this information. If the customer is changing the tire size, the Service Center will need the axle ratio and tire sized in order to program the DRAC to the new tire specifications. The AC-Delco Service Center will send the programmed DRAC via common carrier to the dealership. For further information, consult the AC-Delco authorized Service Center Manual WA-2 (September 1990 or later). AC-Delco centers are subject to change. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Vehicle Speed Sensor > Component Information > Locations > Assembly View Vehicle Speed Sensor: Locations Assembly View LOCATION Mounted To Transmisssion Tailshaft. 2WD Automatic Transmission VSS 2WD (A/TRANS.) VEHICLE SPEED SENSOR 2WD Manual Transmission VSS 2WD Manual Transmission 4WD Automatic and Manual Transmission VSS 4WD Or AWD Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Vehicle Speed Sensor > Component Information > Locations > Assembly View > Page 973 Speed Sensor, Backup Lamp Switch & Electric Shift Transfer Case Wiring Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Vehicle Speed Sensor > Component Information > Locations > Page 974 C320 - Vehicle Speed Sensor Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Vehicle Speed Sensor > Component Information > Locations > Page 975 Vehicle Speed Sensor: Description and Operation 2 Wheel Drive (Manual Transmission) VSS 2WD Manual Transmission 2 Wheel Drive (Automatic Transmission) VSS 2WD (A/TRANS.) VEHICLE SPEED SENSOR 4 Wheel Drive VSS 4WD Or AWD PURPOSE The Vehicle Speed Sensor (VSS) provides information to the control module for control of: Transmission Torque Converter Clutch (TCC) - Speedometer - Odometer - Cruise control Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Vehicle Speed Sensor > Component Information > Locations > Page 976 - ANTILOCK brake system. CONSTRUCTION The VSS is made up of: Permanent Magnet (PM) generator (coil), which is mounted on the transmission. - Rotor (tooth), which is mounted on the output shaft in the transmission. - VSS Buffer, which is mounted to the control module bracket. OPERATION The VSS is a Permanent Magnet (PM) generator that produces a pulsing Alternating Current (AC) voltage as each rotor tooth nears the coil. As the vehicle speed increases, the number of AC voltage pulses increase. The VSS buffer processes inputs from the VSS and outputs signal to the speedometer control module and cruise module. The VSS buffer takes the voltage pulses from the VSS and uses them to open and close four solid state output switches to ground at a rate proportional to vehicle speed. The VSS buffer is matched to the vehicle based on final drive ratio and tire size. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Vehicle Speed Sensor > Component Information > Locations > Page 977 Vehicle Speed Sensor: Service and Repair Speed sensor resistance should be 900-2000 ohms. The sensor is not serviceable and should be replaced if defective. The speed sensor is located on the transfer case. 1. Raise and support vehicle, then disconnect electrical connector from speed sensor. 2. Loosen sensor with suitable wrench. 3. Position suitable container under sensor, then remove sensor and O-ring. 4. Coat O-ring with transmission fluid, then install O-ring and speed sensor. 5. Torque sensor to 32 ft. lbs. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Automatic Transmission LH Rear Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Automatic Transmission > Page 983 Rear Engine Wiring W/Man Trans Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Page 984 C120 - Fuel Pump Oil Pressure Sender/Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Page 985 Oil Pressure Switch (For Fuel Pump): Service and Repair REMOVE/DISCONNECT - Negative battery cable from battery. - Sensor or switch connectors. - Sensor or switch. INSTALL/CONNECT - Sensor or switch. - Sensor or switch. - Negative battery cable. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Specifications Throttle Position Sensor: Specifications Idle Normal 0.45 to 0.95 V Maximum 1.25 V Wide Open Throttle 4.0 to 4.5 V Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Specifications > Page 989 Engine Harness, Right Front Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions Throttle Position Sensor: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. Use this page as a reference to determine the meaning of an abbreviation if necessary. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery Bi-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CHMSL Center High Mount Stoplamp CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRO Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 992 F-PUMP Fuel Pump FLASH Flasher FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 993 SIR Supplemental Inflatable Restraint SKT Socket SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature TIL Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 994 example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE (ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: ^ Slide across the vehicle seat. ^ Sit down or stand up. ^ Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: ^ They are bumped or dropped. ^ They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 995 Symbols (Part 1 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 996 Symbols (Part 2 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 997 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 998 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 999 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 1000 Throttle Position Sensor: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 1001 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 1002 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 1003 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 1004 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 1005 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. ^ If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. ^ A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 1006 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 1007 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 1008 Ohmmeter Meter Scales Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 1009 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. ^ An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. ^ On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: ^ A range selector switch which permits the selection of different ranges of resistance. ^ A set adjust control which allows the meter to be set at zero for accurate measurements. ^ Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 1010 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: ^ Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. ^ Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. ^ Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 1011 be less than 10 percent of the total drop. When using a voltmeter: ^ Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. ^ Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. ^ The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: ^ Check the accuracy and completeness of the complaint. ^ Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 1012 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. ^ The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 1013 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 1014 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 1015 Twisted/Shielded Wire Repair Twisted Wires Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 1016 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 1017 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 1018 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). ^ Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean ^ Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. ^ Roll crimp (13) and solder the terminal. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 1019 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 1020 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 1021 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. ^ Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean ^ Terminal cavity of the connector body. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 1022 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. ^ Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 1023 C110 - TP Sensor Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 1024 Throttle Position (TP) Circuit Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Page 1025 Throttle Position Sensor: Description and Operation Wiring Diagram For Code 21 - Throttle Position Sensor (Signal Voltage High) NOTE Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE The Throttle Position Sensor (TPS) is a potentiometer that senses throttle angle and sends a signal to the PCM. The TP signal is one of the most important inputs used by the control module for fuel control and for most of the control module control outputs. OPERATION The TPS has three internal circuits provided by the control module. One to ground, a second from the control module as a 5.0 volt reference source and a third circuit is used by the control module to measure the output voltage. As the throttle angle changes (pressing down on accelerator pedal) the TPS voltage output varies from about .5 volt at idle to about 4.9 volts at wide open throttle (WOT). Each time the voltage drops below 1.25 volts and stops, the control module assumes this value is 0 throttle from this point on. LOCATION: Side of throttle body opposite of throttle lever. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Page 1026 Throttle Position Sensor: Adjustments The TPS is not adjustable. Each time voltage drops below 1.25 volts and stops, the control module assumes that this value is zero throttle angle and measures percent throttle from this point on. Therefore adjustment is not necessary. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Page 1027 Throttle Position Sensor: Service and Repair NOTE Since Throttle Position Sensor (TPS) configurations can be mounted interchangeably, be sure to order the correct one for your engine with identical part number of the one being replaced. Throttle Position (TP) Sensor REMOVE/DISCONNECT - Electrical connectors. - TPS attaching screw assemblies and retainer, (if applicable). - TPS from throttle body assembly. NOTE Do NOT immerse in any type of liquid solvent or cleaner, as damage may occur. INSTALL/CONNECT - With throttle valve in normally closed position, install TPS on throttle shaft with seal and rotate counter clockwise to align mounting hole. - Two attaching screw assemblies. Tighten screw assemblies to 2.0 Nm (18.0 lb-in). - Electrical connector to TPS. - Check for TPS output as follows: Connect an ALDL scanner to read TPS output voltage. - With ignition "ON" and engine stopped, TPS voltage should be less than 1.25 volts. If more than 1.25 volts, replace TPS. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Technical Service Bulletins > Knock Sensor Circuit DTC 43 Chart Revision Knock Sensor: Technical Service Bulletins Knock Sensor Circuit - DTC 43 Chart Revision File In Section: 6E Engine Fuel & Emission Bulletin No.: 51-65-19 Date: April, 1995 Subject: Section 3A - Control Module System (PCM) Driveability and Emissions - Revised DTC 43 Knock Sensor (KS) Circuit (Dual Knock Sensors) Models: 1994 Chevrolet and GMC Truck S/T; M/L, C/K Models with 4.3L Engine (VINs W, Z RPOs L35, LB4) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Technical Service Bulletins > Knock Sensor Circuit DTC 43 Chart Revision > Page 1033 This bulletin advises of a revision to the DTC 43 Knock Sensor (KS) Circuit (Dual Knock Sensor System) chart in the following service manuals: 1994 S/T Driveability Emissions and Electrical Diagnosis Manual, page 3A-119 1994 M/L Driveability Emissions and Electrical Diagnosis Manual, page 3A-75 1994 C/K Driveability Emissions and Electrical Diagnosis Manual, page 3A-69 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Technical Service Bulletins > Page 1034 Knock Sensor: Specifications Coil bracket bolt/nut ............................................................................................................................. ................................................. 27 N-m (20 lbs ft) Distributor clamp bolt ........................................................................................................................... ................................................ 27 N-m (20 lbs ft) Knock Sensor ...................................................................................................................................... .................................................. 19 N-m (14 lbs ft) Spark Plugs ......................................................................................................................................... .................................................. 15 N-M (11 lbs ft) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Locations > Assembly View Knock Sensors Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Locations > Assembly View > Page 1037 Knock Sensor: Locations Harness View LH Rear Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Locations > Assembly View > Page 1038 LH Rear Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Locations > Page 1039 Knock Sensor: Diagrams C119 - Knock Sensor C135 - Knock Sensor Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Locations > Page 1040 Knock Sensor: Description and Operation PURPOSE: The Knock Sensor (KS) is used to detect engine detonation (ping). The control module will retard the electronic spark timing up to 8° based on the signal received. CONSTRUCTION The KS system has two major components: Control Module. - Knock Sensor(s). The two knock sensors are spliced together and go directly to the control module. OPERATION The knock sensor internal circuit causes the control modules 5 volts to be pulled down to about 2.5 volts. The knock sensor produces an A/C signal which rides on the 2.5 volts DC signal. The AC voltage monitor in the control module will detect this AC voltage and provide a signal to begin retarding spark until the knock diminishes. The amplitude and frequency are dependent upon the knock level. LOCATION Engine block. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Locations > Page 1041 Knock Sensor: Testing and Inspection Knock Sensor (KS) System Check Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Locations > Page 1042 Knock Sensor Circuit Circuit Description The Knock Sensor (KS) circuit consists of two knock sensors with one wire that goes directly to the control modules. There are two Knock Sensor (KS) checks performed by the ECM. One check consists of monitoring CKT 496 for a voltage that is more than .63 volt and less than 3.1 volts. If voltage is either too high or too low for 10 or more seconds, DTC 43 will set. The PCM uses this self check only. The next test is used only by the ECM along with the previous test. Once engine temperature reaches 85°C, MAP is over 83 kPa, and engine speed is less than 3200 RPM, the ECM will perform a self check. This self check will advance the timing until it receives a knock signal. If no knock signal is received, DTC 43 will set. Chart Test Description Number(s) below refer to circled number(s) on the diagnostic chart. 1. The first test is to determine if the system is functioning at the present time. 2. Test two determines the state of the 5 volt reference voltage applied to the knock sensor circuit. 3. Test 3 determines the state of the knock sensors and connections themselves. Diagnostic Aids The control module applies 5 volts to CKT 496. A 8200 ohm resistor in the knock sensors reduces the voltage to about 2.5 volts. When knock occurs, the knock sensor produces a small AC voltage that rides on top of the 2.5 volts already applied. An AC voltage monitor, in the control module, is able to read this signal as knock and incrementally retard spark. If the KS system checks OK, but detonation is the complaint, refer to "Detonation/Spark Knock". See: Powertrain Management/Computers and Control Systems/Testing and Inspection/Symptom Related Diagnostic Procedures/Detonation/ Spark Knock Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Powertrain Management > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Locations > Page 1043 Knock Sensor: Service and Repair REMOVE OR DISCONNECT - Negative battery cable. - Drain cooling system. NOTE On knock sensors which are mounted in the end of the cylinder head draining the cooling system will not be necessary. - Wiring harness connector from knock sensor. - Knock sensor. INSTALL OR CONNECT - Knock sensor. If reinstalling original sensor, apply water base caulk to sensor threads. Do NOT use silicone tape as this will insulate sensor from engine. ^ Tighten to 19 Nm (14 lb. ft.). - Wiring harness connector to knock sensor. - Refill cooling system and pressure test for leaks. - Negative battery cable. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Restraint Systems > Impact Sensor > Component Information > Description and Operation > Arming Sensor Impact Sensor: Description and Operation Arming Sensor The arming sensor is a protective switch located in the power side of the deployment loop. It is calibrated to close at low level speed changes. This ensures that the inflator module is connected directly to the 36 Volt Loop Reserve (VLR) output of the DERM when either of the discriminating sensors close. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Restraint Systems > Impact Sensor > Component Information > Description and Operation > Arming Sensor > Page 1049 Impact Sensor: Description and Operation Discriminating Sensors There are two discriminating sensors in the air bag system. They are wired in parallel on the low (ground) side of the deployment loop. These sensors are calibrated to close with speed changes severe enough to warrant deployment. A diagnostic resistor is connected in parallel with the switch contacts within each of the discriminating sensors. These parallel resistors supply the ground path for the current passing through the deployment loop during normal operation. This current flow results in voltage drops across each component in the deployment loop. The DERM monitors these voltage drops to detect malfunctions. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Restraint Systems > Impact Sensor > Component Information > Service and Repair > Arming Sensor Impact Sensor: Service and Repair Arming Sensor Prior to performing replacement procedures, disarm air bag system. Refer to, Service and Repair/ Air Bag System Disarming & Air Bag System Arming. Refer to, / Specifications/ Mechanical for torque values when installing components. All sensors and mounting bracket bolts must be carefully torqued to assure proper operation. Never power up the air bag system when any sensor is not rigidly attached to the vehicle, since the sensor could be activated when not attached, causing air bag deployment. 1. disconnect sensor electrical connector from retainer, remove Connector Position Assurance (CPA) lock from connector, then disconnect connector. 2. Remove sensor mounting bolts and sensor from vehicle. 3. Reverse procedure to install. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Restraint Systems > Impact Sensor > Component Information > Service and Repair > Arming Sensor > Page 1052 Impact Sensor: Service and Repair Forward Discriminating Sensor Prior to performing replacement procedures, disarm air bag system. Refer to, Service and Repair/ Air Bag System Disarming & Air Bag System Arming. Refer to, / Specifications/ Mechanical for torque values when installing components. All sensors and mounting bracket bolts must be carefully torqued to assure proper operation. Never power up the air bag system when any sensor is not rigidly attached to the vehicle, since the sensor could be activated when not attached, causing air bag deployment. 1. Drill out mounting rivets. 2. Remove discriminating sensor electrical connector from retainer, then the Connector Position Assurance (CPA) lock from connector. 3. Disconnect sensor electrical connector. 4. Remove sensor from vehicle. 5. Reverse procedure to install. Ensure arrow on sensor is pointing toward front of vehicle. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Restraint Systems > Seat Belt Buckle Switch > Component Information > Locations > Safety Belt Switch Seat Belt Buckle Switch: Locations Safety Belt Switch Safety Belt Wiring Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Restraint Systems > Seat Belt Buckle Switch > Component Information > Locations > Safety Belt Switch > Page 1057 Safety Belt Wiring Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Restraint Systems > Seat Belt Buckle Switch > Component Information > Locations > Safety Belt Switch > Page 1058 Seat Belt Buckle Switch: Locations Safety Belt Switch Jumper Harness Safety Belt Wiring Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Restraint Systems > Seat Belt Buckle Switch > Component Information > Locations > Safety Belt Switch > Page 1059 Safety Belt Wiring Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Restraint Systems > Seat Occupant Sensor > Component Information > Technical Service Bulletins > Restraints - Passenger Presence System Information Seat Occupant Sensor: Technical Service Bulletins Restraints - Passenger Presence System Information INFORMATION Bulletin No.: 06-08-50-009F Date: December 23, 2010 Subject: Information on Passenger Presence Sensing System (PPS or PSS) Concerns With Custom Upholstery, Accessory Seat Heaters or Other Comfort Enhancing Devices Models: 2011 and Prior GM Passenger Cars and Trucks Equipped with Passenger Presence Sensing System Supercede: This bulletin is being revised to update the model years. Please discard Corporate Bulletin Number 06-08-50-009E (Section 08 - Body and Accessories). Concerns About Safety and Alterations to the Front Passenger Seat Important ON A GM VEHICLE EQUIPPED WITH A PASSENGER SENSING SYSTEM, USE THE SEAT COVERS AND OTHER SEAT-RELATED EQUIPMENT AS RELEASED BY GM FOR THAT VEHICLE. DO NOT ALTER THE SEAT COVERS OR SEAT-RELATED EQUIPMENT. ANY ALTERATIONS TO SEAT COVERS OR GM ACCESSORIES DEFEATS THE INTENDED DESIGN OF THE SYSTEM. GM WILL NOT BE LIABLE FOR ANY PROBLEMS CAUSED BY USE OF SUCH IMPROPER SEAT ALTERATIONS, INCLUDING ANY WARRANTY REPAIRS INCURRED. The front passenger seat in many GM vehicles is equipped with a passenger sensing system that will turn off the right front passenger's frontal airbag under certain conditions, such as when an infant or child seat is present. In some vehicles, the passenger sensing system will also turn off the right front passenger's seat mounted side impact airbag. For the system to function properly, sensors are used in the seat to detect the presence of a properly-seated occupant. The passenger sensing system may not operate properly if the original seat trim is replaced (1) by non-GM covers, upholstery or trim, or (2) by GM covers, upholstery or trim designed for a different vehicle or (3) by GM covers, upholstery or trim that has been altered by a trim shop, or (4) if any object, such as an aftermarket seat heater or a comfort enhancing pad or device is installed under the seat fabric or between the occupant and the seat fabric. Aftermarket Seat Heaters, Custom Upholstery, and Comfort Enhancing Pads or Devices Important ON A GM VEHICLE EQUIPPED WITH A PASSENGER SENSING SYSTEM, USE ONLY SEAT COVERS AND OTHER SEAT-RELATED EQUIPMENT RELEASED AS GM ACCESSORIES FOR THAT VEHICLE. DO NOT USE ANY OTHER TYPE OF SEAT COVERS OR SEAT-RELATED EQUIPMENT, OR GM ACCESSORIES RELEASED FOR OTHER VEHICLE APPLICATIONS. GM WILL NOT BE LIABLE FOR ANY PROBLEMS CAUSED BY USE OF SUCH IMPROPER SEAT ACCESSORIES, INCLUDING ANY WARRANTY REPAIRS MADE NECESSARY BY SUCH USE. Many types of aftermarket accessories are available to customers, upfitting shops, and dealers. Some of these devices sit on top of, or are Velcro(R) strapped to the seat while others such as seat heaters are installed under the seat fabric. Additionally, seat covers made of leather or other materials may have different padding thickness installed that could prevent the Passenger Sensing System from functioning properly. Never alter the vehicle seats. Never add pads or other devices to the seat cushion, as this may interfere with the operation of the Passenger Sensing System and either prevent proper deployment of the passenger airbag or prevent proper suppression of the passenger air bag. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Clutch Switch > Component Information > Locations I/P Wiring, Steering Column Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Clutch Switch > Component Information > Locations > Page 1068 C253 - Clutch Release Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Clutch Switch > Component Information > Locations > Page 1069 Clutch Switch: Service and Repair 1. Remove lower instrument panel trim. 2. Remove clutch start switch electrical connector, Fig. 3. 3. Remove clutch start switch from clutch pedal. 4. Reverse procedure to install. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions Neutral Safety Switch: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. Use this page as a reference to determine the meaning of an abbreviation if necessary. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery Bi-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CHMSL Center High Mount Stoplamp CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRO Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 1074 F-PUMP Fuel Pump FLASH Flasher FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 1075 SIR Supplemental Inflatable Restraint SKT Socket SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature TIL Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 1076 example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE (ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: ^ Slide across the vehicle seat. ^ Sit down or stand up. ^ Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: ^ They are bumped or dropped. ^ They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 1077 Symbols (Part 1 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 1078 Symbols (Part 2 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 1079 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 1080 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 1081 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 1082 Neutral Safety Switch: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 1083 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 1084 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 1085 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 1086 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 1087 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. ^ If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. ^ A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 1088 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 1089 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 1090 Ohmmeter Meter Scales Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 1091 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. ^ An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. ^ On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: ^ A range selector switch which permits the selection of different ranges of resistance. ^ A set adjust control which allows the meter to be set at zero for accurate measurements. ^ Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 1092 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: ^ Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. ^ Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. ^ Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 1093 be less than 10 percent of the total drop. When using a voltmeter: ^ Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. ^ Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. ^ The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: ^ Check the accuracy and completeness of the complaint. ^ Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 1094 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. ^ The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 1095 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 1096 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 1097 Twisted/Shielded Wire Repair Twisted Wires Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 1098 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 1099 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 1100 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). ^ Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean ^ Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. ^ Roll crimp (13) and solder the terminal. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 1101 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 1102 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 1103 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. ^ Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean ^ Terminal cavity of the connector body. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 1104 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. ^ Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Diagram Information and Instructions > Page 1105 Neutral Safety Switch: Connector Views C209 - Park/Neutral Position Switch C247 - Park/Neutral Position Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Starting and Charging > Neutral Safety Switch > Component Information > Diagrams > Page 1106 Neutral Safety Switch: Service and Repair The neutral start switch also incorporates the back-up light switch in these vehicles. AUTOMATIC TRANSMISSION 1. Remove battery ground cable. 2. Remove lower insulator panel. 3. Remove neutral start switch electrical connector. 4. Remove neutral start switch. 5. Reverse procedure to install, noting the following: a. Align actuator on the switch with holes in shift tube. b. Press down on front of switch until tangs snap into rectangular holes in the steering column jacket. c. Adjust switch by moving the gear selector to park. MANUAL TRANSMISSION 1. Disconnect battery ground cable. 2. Disconnect back-up lamp switch electrical connector. 3. Disconnect switch wiring from transmission bracket. 4. Remove switch from transmission. 5. Reverse procedure to install. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Transmission and Drivetrain > Sensors and Switches - A/T > Brake Switch - TCC > Component Information > Locations > Stoplamp/TCC Brake Switch Stoplamp/TCC Brake Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Transmission and Drivetrain > Sensors and Switches - A/T > Brake Switch - TCC > Component Information > Locations > Stoplamp/TCC Brake Switch > Page 1113 I/P Harness Wiring, LH Side Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Transmission and Drivetrain > Sensors and Switches - A/T > Brake Switch - TCC > Component Information > Locations > Page 1114 C217 - Brake Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Transmission and Drivetrain > Sensors and Switches - A/T > Fluid Pressure Sensor/Switch, A/T > Component Information > Specifications Fluid Pressure Sensor/Switch: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Pressure Plugs (1/8 - 27) ..................................................................................................................... ................................................................................. 8 Pressure Plugs (1/4 - 18) ................................ .............................................................................................................................................................. ...... 18 Pressure Switches ................................................................................................................... .............................................................................................. 8 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Transmission and Drivetrain > Sensors and Switches - A/T > Transmission Position Switch/Sensor, A/T > Component Information > Description and Operation Transmission Position Switch/Sensor: Description and Operation Automatic Transmission Electrical Components PURPOSE This device is a set of five presure switches (two normally closed and three normally open), that detect fluid pressure within the valve body passages and signals the PCM which transmission range is selected (PRNDL). OPERATION The five pressure switches are connected to three signal circuits referred to as range signals A, B, C. The combination of pressure switch states determines the voltage signal (B+ or 0) on each range signal to the PCM. LOCATION The transmission range fluid pressure switch assembly is attached to the control valve body within the transmission. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Transmission and Drivetrain > Sensors and Switches - A/T > Transmission Speed Sensor, A/T > Component Information > Specifications Transmission Speed Sensor: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Vehicle Speed Sensor Retainer ........................... .............................................................................................................................................................. ... 8 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Transmission and Drivetrain > Sensors and Switches - A/T > Transmission Temperature Sensor/Switch, A/T > Component Information > Description and Operation Transmission Temperature Sensor/Switch: Description and Operation Automatic Transmission Electrical Components PURPOSE The Transmission Fluid Temperature (TFT) Sensor is used by the control module to control: Torque Converter Clutch (TCC) apply and release schedule. - Hot mode determination. - Shift quality. OPERATION The TFT is a thermistor used to indicate transmission fluid temperature. The control module sends a 5.0 volt signal to the TFT through a resistor in the computer and measures the voltage. High sensor resistance produces high signal input voltage which corresponds to low fluid temperature. Low sensor resistance produces low signal input voltage which corresponds to high fluid temperature. With the TFT varying its resistance, the control module can sense transmission fluid temperature by reading the varying voltage. LOCATION The sensor is part of the transmission range fluid pressure switch assembly and is attached to the control valve body within the transmission. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Transmission and Drivetrain > Sensors and Switches - Transfer Case > Four Wheel Drive Selector Switch > Component Information > Locations > Pickup Transfer Case Select Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Transmission and Drivetrain > Sensors and Switches - Transfer Case > Four Wheel Drive Selector Switch > Component Information > Locations > Pickup > Page 1132 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Transmission and Drivetrain > Sensors and Switches - Transfer Case > Four Wheel Drive Selector Switch > Component Information > Locations > Page 1133 Four Wheel Drive Selector Switch: Service and Repair Fig. 2 Transfer Case Shift Linkage. Except Bravada, Sonoma GT, Syclone & Typhoon Fig. 4 Selector Switch Installation. Except Bravada, Sonoma GT, Syclone & Typhoon 1. Disconnect battery ground cable. 2. Remove console, then disconnect console wiring harness. 3. Remove shifter boot retaining screws and slide boot up shift lever. 4. Remove switch attaching screw, then the switch and harness, Fig. 2. 5. Position new switch on mounting bracket and install attaching screw.Ensure shift lever assembly pawl is on the switch contact carrier. 6. Route wiring as shown in Fig. 4. 7. Place shifter boot in proper position, then install retaining screws. 8. Connect console wiring harness, then install console. 9. Connect battery ground cable. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Transmission and Drivetrain > Sensors and Switches - Transfer Case > Gear Sensor/Switch, Transfer Case > Component Information > Locations > Electric Shift Transfer Case Switch Gear Sensor/Switch: Locations Electric Shift Transfer Case Switch Transfer Case Electric Shift Motor Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Transmission and Drivetrain > Sensors and Switches - Transfer Case > Gear Sensor/Switch, Transfer Case > Component Information > Locations > Electric Shift Transfer Case Switch > Page 1138 Electric Shift Transfer Case Wiring Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Transmission and Drivetrain > Sensors and Switches - Transfer Case > Gear Sensor/Switch, Transfer Case > Component Information > Locations > Electric Shift Transfer Case Switch > Page 1139 4WD Components Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Transmission and Drivetrain > Sensors and Switches - Transfer Case > Speed Sensor, Transfer Case > Component Information > Technical Service Bulletins > Drivetrain - Updated Transfer Case Speed Sensor Conn. Speed Sensor: Technical Service Bulletins Drivetrain - Updated Transfer Case Speed Sensor Conn. Bulletin No.: 06-04-21-001 Date: May 17, 2006 INFORMATION Subject: Updated Transfer Case Connector Service Kit Now Available For Transfer Case Speed Sensor Wire Harness Connector that Comes Loose Or Connector Retainer Clip Breaks Models: 2007 and Prior GM Light Duty Trucks 2007 and Prior HUMMER H2, H3 2005-2007 Saab 9-7X with Four-Wheel Drive or All-Wheel Drive Technicians may find that when the transfer case speed sensor wire harness connector is removed, the connector lock flexes/bends and does not return to the original position. The transfer case speed sensor wire harness connector then has no locking device. On older vehicles, the plastic connector retainer becomes brittle and the clip may break as soon as it is flexed. In the past, the only service fix was to install a wire harness connector service pack, P/N 88987183. This repair procedure involved splicing a new service connector with an integral connector lock. This connector service kit is of the same design and was still prone to failure over time. A new connector service repair kit is now available, P/N 15306187, that is an updated design. This new kit should be used whenever the speed sensor wire harness connector requires replacement. Parts Information Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Windows and Glass > Heated Glass Element Switch > Component Information > Locations Heated Glass Element Switch: Locations Rear Window Release And Defogger Forward Wiring - 4-Door Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Windows and Glass > Heated Glass Element Switch > Component Information > Locations > Page 1148 Rear Window Release Forward Wiring Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Windows and Glass > Power Window Switch > Component Information > Locations Rear Door Power Window-4Door Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Windows and Glass > Power Window Switch > Component Information > Locations > Page 1152 Power Window Switch: Diagrams C503 - Front LH Power Window Switch C503 - Front LH Power Window Switch C512 - Rear LH Power Window Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Windows and Glass > Power Window Switch > Component Information > Locations > Page 1153 C603 - Front RH Power Window Switch C603 - Front RH Power Window Switch C612 - Rear RH Power Window Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Wiper and Washer Systems > Windshield Washer Switch > Component Information > Locations Rear Wiper/Washer Wiring Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Wiper and Washer Systems > Windshield Washer Switch > Component Information > Diagrams > Windshield Wiper/Washer Switch C218 - Wiper/Washer Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Wiper and Washer Systems > Windshield Washer Switch > Component Information > Diagrams > Windshield Wiper/Washer Switch > Page 1160 Windshield Washer Switch: Diagrams Window Wiper/Washer Switch, Rear C211A - Rear Wiper/Washer To Rear Body C207 - Rear Wiper/Washer Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Wiper and Washer Systems > Wiper Switch > Component Information > Locations Rear Wiper/Washer Wiring Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Wiper and Washer Systems > Wiper Switch > Component Information > Diagrams > Wiper/Washer Switch C218 - Wiper/Washer Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Wiper and Washer Systems > Wiper Switch > Component Information > Diagrams > Wiper/Washer Switch > Page 1166 C207 - Rear Wiper/Washer Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Wiper and Washer Systems > Wiper Switch > Component Information > Diagrams > Wiper/Washer Switch > Page 1167 C211A - Rear Wiper/Washer To Rear Body Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Sensors and Switches > Sensors and Switches - Wiper and Washer Systems > Wiper Switch > Component Information > Diagrams > Page 1168 Wiper Switch: Service and Repair WARNING: Refer to Air Bags and Seat Belts/ Air Bags (Supplemental Restraint Systems)/ Service and Repair/ Air Bag System Disarming & Arming. 1. Remove ignition lock. 2. Remove shift lever clevis, then the lever from vehicle. 3. Remove wire harness straps, then disconnect steering column bulkhead connector from vehicle wire harness. 4. Disconnect turn signal switch gray and black connectors from column bulkhead connector. 5. Remove pan head tapping screws, then the turn signal switch assembly from column. 6. Reverse procedure to install. Torque pan head tapping screws to 53 inch lbs. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Alignment > System Information > Technical Service Bulletins > By Symptom Alignment: By Symptom Technical Service Bulletin # 463501 Date: 950401 Alignment - Front Tire Wear/Steering Returnability File in Section: 3 - Steering/Suspension Bulletin No.: 46-35-01 Date: April, 1995 Subject: Front Tire Wear and/or Steering Returnability (Set to New Alignment Specification) Models: 1991-95 Chevrolet and GMC Truck T Models 1991-94 Oldsmobile Bravada CONDITION Some owners may comment on excessive front tire wear and/or steering returnability. PERFORM PRELIMINARY INSPECTION BEFORE ALIGNMENT CORRECTION The following procedures should be used to address customer's concerns about front tire wear and/or steering returnability: 1. Check to be sure the tire pressure is set to GVW Certification/Tire label specifications located on the driver's door lock pillar. Important: It is essential proper tire rotation schedule be followed at proper intervals to minimize tire wear. 2. 4WD ONLY, front suspension "Z" height dimension and setting must be made prior to any other alignment changes. 3. Perform front wheel alignment to the specifications in chart (figure). Notice: Vehicle must be jounced three times before checking alignment to eliminate false geometry readings. a. For 4WD only, front suspension "Z" height dimension 122 ± 6.0 mm (4.8 ± 0.2 inch), left and right side to be equal within 6 mm. b. Left and right side to be equal within 0.5". c. Left and right side to be equal within 1.0". d. Steering wheel must be held in straight ahead position with ± 3.0". Front individual toe must be equalized relative to rear wheel thrust angle. e. GVW alignment is the same for all vehicles. Technical Service Bulletin # 463501 Date: 950401 Alignment - Front Tire Wear/Steering Returnability File in Section: 3 - Steering/Suspension Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Alignment > System Information > Technical Service Bulletins > By Symptom > Page 1174 Bulletin No.: 46-35-01 Date: April, 1995 Subject: Front Tire Wear and/or Steering Returnability (Set to New Alignment Specification) Models: 1991-95 Chevrolet and GMC Truck T Models 1991-94 Oldsmobile Bravada CONDITION Some owners may comment on excessive front tire wear and/or steering returnability. PERFORM PRELIMINARY INSPECTION BEFORE ALIGNMENT CORRECTION The following procedures should be used to address customer's concerns about front tire wear and/or steering returnability: 1. Check to be sure the tire pressure is set to GVW Certification/Tire label specifications located on the driver's door lock pillar. Important: It is essential proper tire rotation schedule be followed at proper intervals to minimize tire wear. 2. 4WD ONLY, front suspension "Z" height dimension and setting must be made prior to any other alignment changes. 3. Perform front wheel alignment to the specifications in chart (figure). Notice: Vehicle must be jounced three times before checking alignment to eliminate false geometry readings. a. For 4WD only, front suspension "Z" height dimension 122 ± 6.0 mm (4.8 ± 0.2 inch), left and right side to be equal within 6 mm. b. Left and right side to be equal within 0.5". c. Left and right side to be equal within 1.0". d. Steering wheel must be held in straight ahead position with ± 3.0". Front individual toe must be equalized relative to rear wheel thrust angle. e. GVW alignment is the same for all vehicles. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Alignment > System Information > Technical Service Bulletins > All Technical Service Bulletins for Alignment: > 05-03-07-009C > Dec > 10 > Steering/Suspension - Wheel Alignment Specifications Alignment: All Technical Service Bulletins Steering/Suspension - Wheel Alignment Specifications WARRANTY ADMINISTRATION Bulletin No.: 05-03-07-009C Date: December 09, 2010 Subject: Wheel Alignment Specifications, Requirements and Recommendations for GM Vehicles Models: 2011 and Prior GM Passenger Cars and Light Duty Trucks Supercede: This bulletin is being extensively revised to provide technicians and warranty administrators with an all inclusive guide for wheel alignments. PLEASE FAMILIARIZE YOURSELF WITH THESE UPDATES BEFORE PERFORMING YOUR NEXT GM WHEEL ALIGNMENT SERVICE. Please discard Corporate Bulletin Number 05-03-07-009B (Section 03 - Suspension). Purpose The purpose of this bulletin is to provide retail, wholesale and fleet personnel with General Motors' warranty service requirements and recommendations for customer concerns related to wheel alignment. For your convenience, this bulletin updates and centralizes all of GM's Standard Wheel Alignment Service Procedures, Policy Guidelines and bulletins on wheel alignment warranty service. Important PLEASE FAMILIARIZE YOURSELF WITH THESE UPDATES BEFORE PERFORMING YOUR NEXT GM WHEEL ALIGNMENT SERVICE. The following five (5) key steps are a summary of this bulletin and are REQUIRED in completing a successful wheel alignment service. 1. Verify the vehicle is in an Original Equipment condition for curb weight, tires, wheels, suspension and steering configurations. Vehicles modified in any of these areas are not covered for wheel alignment warranty. 2. Review the customer concern relative to "Normal Operation" definitions. 3. Verify that vehicle is within the "Mileage Policy" range. 4. Document wheel alignment warranty claims appropriately for labor operations E2000 and E2020. The following information must be documented or attached to the repair order: - Customer concern in detail - What corrected the customer concern? - If a wheel alignment is performed: - Consult SI for proper specifications. - Document the "Before" AND "After" wheel alignment measurements/settings. - Completed "Wheel Alignment Repair Order Questionnaire" (form attached to this bulletin) 5. Use the proper wheel alignment equipment (preferred with print-out capability), process and the appropriate calibration maintenance schedules. Important If it is determined that a wheel alignment is necessary under warranty, use the proper labor code for the repair. E2000 for Steering Wheel Angle and/or Front Toe set or E2020 for Wheel Alignment Check/Adjust includes Caster, Camber and Toe set (Wheel alignment labor time for other component repairs is to be charged to the component that causes a wheel alignment operation.). The following flowchart is to help summarize the information detailed in this bulletin and should be used whenever a wheel alignment is performed. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Alignment > System Information > Technical Service Bulletins > All Technical Service Bulletins for Alignment: > 05-03-07-009C > Dec > 10 > Steering/Suspension - Wheel Alignment Specifications > Page 1180 Verify Original Equipment Condition of the Vehicle - Verify that Original Equipment Tires and Wheels or Official GM Accessory Tires and Wheels are on the vehicle. - Verify that aftermarket suspension "Lift" or "Lowering" Kits or other suspension alterations have NOT been done to the vehicle. - Check for accidental damage to the vehicle; for example, severe pothole or curb impacts, collision damage that may have affected the wheel alignment of the vehicle; e.g., engine cradles, suspension control arms, axles, wheels, wheel covers, tires may show evidence of damage/impact. - Check to be sure vehicle has seen "Normal Use" rather than abuse; e.g., very aggressive driving may show up by looking at the tires and condition of the vehicle. - Check for other additional equipment items that may significantly affect vehicle mass such as large tool boxes, campers, snow plow packages (without the snowplow RPO), etc., especially in trucks and cutaway/incomplete vehicles. Significant additional mass can affect trim height and wheel alignment of the vehicle and may necessitate a customer pay wheel alignment when placed semi-permanently in the vehicle (Upfitter instructions are to realign the vehicle after placement of these types of items. (This typically applies to trucks and incomplete vehicles that can be upfit with equipment such as the above.) Customer Concerns, "Normal Operation" Conditions and "Mileage Policy" Possible Concerns The following are typical conditions that may require wheel alignment warranty service: 1. Lead/Pull: defined as "at a constant highway speed on a typical straight road, the amount of effort required at the steering wheel to maintain the vehicle's straight heading." Important Please evaluate for the condition with hands-on the steering wheel. Follow the "Vehicle Leads/Pulls" diagnostic tree located in SI to determine the cause of a lead/pull concern. Lead/Pull concerns can be due to road crown or road slope, tires, wheel alignment or even in rare circumstances a steering gear issue. Lead/pull concerns due to road crown are considered "Normal Operation" and are NOT a warrantable condition -- the customer should be advised that this is "Normal Operation." Important Some customers may comment on a "Lead/Pull" when they hold the steering wheel in a level condition. If so, this is more likely a "steering wheel angle" concern because the customer is "steering" the vehicle to obtain a "level" steering wheel. 2. Steering wheel angle to the left or right (counter-clockwise or clockwise, respectively): Defined as the steering wheel angle (clocking) deviation from "level" while maintaining a straight heading on a typical straight road. 3. Irregular or Premature tire wear: Slight to very slight "feathering" or "edge" wear on the shoulders of tires is NOT considered unusual and should even out with a tire rotation; if the customer is concerned about a "feathering" condition of the tires, the customer could be advised to rotate the tires earlier than the next scheduled mileage/maintenance interval (but no later than the next interval). Be sure to understand the customer's driving habits as this will also heavily influence the tire wear performance; tire wear from aggressive or abusive driving habits is NOT a warrantable condition. Important Slight or mild feathering, cupping, edge or heel/toe wear of tire tread shoulders is "normal" and can show up very early in a tire/vehicle service mileage; in fact, some new tires can show evidence of feathering from the factory. These issues do NOT affect the overall performance and tread life of the tire. Dealer personnel should always check the customer's maintenance records to ensure that tire inflation pressure is being maintained to placard and that the tires are being rotated (modified-X pattern) at the proper mileage intervals. Wheel alignments are NOT to be performed for the types of "Normal" Tire Feathering shown in Figures 1-4 below. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Alignment > System Information > Technical Service Bulletins > All Technical Service Bulletins for Alignment: > 05-03-07-009C > Dec > 10 > Steering/Suspension - Wheel Alignment Specifications > Page 1181 Figure 1: Full Tread View - "NORMAL" Tire "Feathering" Wear on the Shoulder/Adjacent/Center Ribs Figure 2: Tire Shoulder View Example 1 - "NORMAL" Tire "Feathering" Wear on the Shoulder Figure 3: Tire Shoulder View Example 2 - "NORMAL" Tire "Feathering" Wear Figure 4: Detail Side View of Tire Shoulder Area - "NORMAL" Tire "Feathering" Wear Important When a wheel alignment is deemed necessary for tire wear, be sure to document on the repair order, in as much detail as possible, the severity and type of tire wear (e.g., severe center wear or severe inside or outside shoulder wear) and the position of the tire on the vehicle (RF, LF, LR, RR). Please note the customer's concern with the wear such as, noise, appearance, wear life, etc. A field product report with pictures of the tire wear condition is recommended. Refer to Corporate Bulletin Number 02-00-89-002J and #07-00-89-036C. 4. Other repairs that affect wheel alignment; e.g., certain component replacement such as suspension control arm replacement, engine cradle adjustment/replace, steering gear replacement, steering tie rod replace, suspension strut/shock, steering knuckle, etc. may require a wheel alignment. Important If other components or repairs are identified as affecting the wheel alignment, policy calls for the wheel alignment labor time to be charged to the replaced/repaired component's labor operation time rather than the wheel alignment labor operations. Important Vibration type customer concerns are generally NOT due to wheel alignment except in the rare cases; e.g., extreme diagonal wear across the tread. In general, wheel alignments are NOT to be performed as an investigation/correction for vibration concerns. "Normal Operation" Conditions Vehicle Lead/Pull Due to Road Crown or Slope: As part of "Normal Operation," vehicles will follow side-to-side or left to right road crown or slope. Be sure to verify from the customer the types of roads they are driving as they may not recognize the influence of road crown on vehicle lead/pull and steering wheel angle. If a vehicle requires significant steering effort to prevent it from "climbing" the road crown there may be an issue to be looked into further. Important Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Alignment > System Information > Technical Service Bulletins > All Technical Service Bulletins for Alignment: > 05-03-07-009C > Dec > 10 > Steering/Suspension - Wheel Alignment Specifications > Page 1182 A wheel alignment will generally NOT correct vehicles that follow the road crown since this is within "Normal Operation." Mileage Policy The following mileage policy applies for E2020 and E2000 labor operations: Note Wheel Alignment is NOT covered under the New Vehicle Limited Warranty for Express and Savana Cutaway vehicles as these vehicles require Upfitters to set the wheel alignment after completing the vehicles. - 0-800 km (0-500 mi): E2000/E2020 claims ONLY allowed with Call Center Authorization. Due to the tie down during shipping, the vehicle's suspension requires some time to reach normal operating position. For this reason, new vehicles are generally NOT to be aligned until they have accumulated at least 800 km (500 mi). A field product report should accompany any claim within this mileage range. - 801-12,000 km (501-7,500 mi): - If a vehicle came from the factory with incorrect alignment settings, any resulting off-angle steering wheel, lead/pull characteristics or the rare occurrence of excessive tire wear would be apparent early in the life of the vehicle. The following policy applies: - Vehicles 100% Factory Set/Measured for Caster/Camber/Toe - Escalade/ESV/EXT, Tahoe/Suburban, Yukon/XL/Denali, Silverado/Sierra, Express/Savana, Corvette and Colorado/Canyon: E2000/E2020 Claims: Call Center Authorization Required - All Vehicles NOT 100% Factory Set/Measured for Caster/Camber/Toe as noted above: E2000/E2020 Claims: Dealer Service Manager Authorization Required - 12,001 km and beyond (7,501 miles and beyond): During this period, customers are responsible for the wheel alignment expense or dealers may provide on a case-by case basis a one-time customer enthusiasm claim up to 16,000 km (10,000 mi). In the event that a defective component required the use of the subject labor operations, the identified defective component labor operation will include the appropriate labor time for a wheel alignment as an add condition to the component repair. Important Only one wheel alignment labor operation claim (E2000 or E2020) may be used per VIN. Warranty Documentation Requirements When a wheel alignment service has been deemed necessary, the following items will need to be clearly documented on/with the repair order: - Customer concern in detail - What corrected the customer concern? - If a wheel alignment is performed: - Consult SI for proper specifications. - Document the "Before" AND "After" wheel alignment measurements/settings. - Completed "Wheel Alignment Repair Order Questionnaire" (form attached to this bulletin) 1. Document the customer concern in as much detail as possible on the repair order and in the warranty administration system. Preferred examples: - Steering wheel is off angle in the counterclockwise direction by approximately x degrees or clocking position. - Vehicle lead/pulls to the right at approximately x-y mph. Vehicle will climb the road crown. Severe, Moderate or Slight. - RF and LF tires are wearing on the outside shoulders with severe feathering. Important In the event of a lead/pull or steering wheel angle concern, please note the direction of lead/pull (left or right) or direction of steering wheel angle (clockwise or counterclockwise) on the repair order and within the warranty claim verbatim. Important In the event of a tire wear concern, please note the position on the vehicle and where the wear is occurring on the tire; i.e., the RF tire is wearing on the inside shoulder. 2. Document the technician's findings on cause and correction of the issue. Examples: - Reset LF toe from 0.45 degrees to 0.10 degrees and RF toe from -0.25 degrees to 0.10 degrees to correct the steering wheel angle from 5 degrees counterclockwise to 0 degrees. - Reset LF camber from 0.25 degrees to -0.05 degrees to correct the cross-camber condition of +0.30 degrees to 0.00 degrees on the vehicle. - Front Sum toe was found to be 0.50 degrees, reset to 0.20 degrees. 3. Print-out the "Before" and "After" wheel alignment measurements/settings and attach them to the Repair Order or if print-out capability is not Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Alignment > System Information > Technical Service Bulletins > All Technical Service Bulletins for Alignment: > 05-03-07-009C > Dec > 10 > Steering/Suspension - Wheel Alignment Specifications > Page 1183 available, measurements may also be clearly and legibly handwritten into the Wheel Alignment Repair Order Questionnaire attached to this bulletin. 4. Attach the Wheel Alignment Repair Order Questionnaire below along with the print-out of "Before" and "After" wheel alignment measurements to the Repair Order and retain for use by GM. Wheel Alignment Equipment and Process Wheel alignments must be performed with a quality machine that will give accurate results when performing checks. "External Reference" (image-based camera technology) is preferred. Please refer to Corporate Bulletin Number 05-00-89-029B: General Motors Dealership Critical Equipment Requirements and Recommendations. Requirements: - Computerized four wheel alignment system. - Computer capable of printing before and after alignment reports. - Computer capable of time and date stamp printout. - Racking system must have jacking capability - Racking system must be capable of level to 1.6 mm (1/16 in) - Appropriate wheel stops and safety certification - Built-in turn plates and slip plates - Wheel clamps capable of attaching to 20" or larger wheels - Racking capable of accepting any GM passenger car or light duty truck - Operator properly trained and ASE-certified (U.S. only) in wheel alignment Recommendations: Racking should have front and rear jacking capability. Equipment Maintenance and Calibration: Alignment machines must be regularly calibrated in order to give correct information. Most manufacturers recommend the following: - Alignment machines with "internal reference" sensors should be checked (and calibrated, if necessary) every six months. - Alignment machines with "external reference" (image-based camera technology) should be checked (and calibrated, if necessary) once a year. - Racks must be kept level to within 1.6 mm (1/16 in). - If any instrument that is part of the alignment machine is dropped or damaged in some way, check the calibration immediately. Check with the manufacturer of your specific equipment for their recommended service/calibration schedule. Wheel Alignment Process When performing wheel alignment measurement and/or adjustment, the following steps should be taken: Preliminary Steps: 1. Verify that the vehicle has a full tank of fuel (compensate as necessary). 2. Inspect the wheels and the tires for damage. 3. Inspect the tires for the proper inflation and irregular tire wear. 4. Inspect the wheel bearings for excessive play. 5. Inspect all suspension and steering parts for looseness, wear, or damage. 6. Inspect the steering wheel for excessive drag or poor return due to stiff or rusted linkage or suspension components. 7. Inspect the vehicle trim height. 8. Compensate for frame angle on targeted vehicles (refer to Wheel Alignment Specifications in SI). Satisfactory vehicle operation may occur over a wide range of alignment angles. However, if the wheel alignment angles are not within the range of specifications, adjust the wheel alignment to the specifications. Refer to Wheel Alignment Specifications in SI. Give consideration to excess loads, such as tool boxes, sample cases, etc. Follow the wheel alignment equipment manufacturer's instructions. Measure/Adjust: Important Prior to making any adjustments to wheel alignment on a vehicle, technicians must verify that the wheel alignment specifications loaded into their wheel alignment machine are up-to-date by comparing these to the wheel alignment specifications for the appropriate model and model year in SI. Using incorrect and/or outdated specifications may result in unnecessary adjustments, irregular and/or premature tire wear and repeat customer concerns Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Alignment > System Information > Technical Service Bulletins > All Technical Service Bulletins for Alignment: > 05-03-07-009C > Dec > 10 > Steering/Suspension - Wheel Alignment Specifications > Page 1184 Important When performing adjustments to vehicles requiring a 4-wheel alignment, set the rear wheel alignment angles first in order to obtain proper front wheel alignment angles. Perform the following steps in order to measure the front and rear alignment angles: 1. Install the alignment equipment according to the manufacturer's instructions. 2. Jounce the front and the rear bumpers 3 times prior to checking the wheel alignment. 3. Measure the alignment angles and record the readings. If necessary, adjust the wheel alignment to vehicle specification and record the before and after measurements. Refer to Wheel Alignment Specifications in SI. Important Technicians must refer to SI for the correct wheel alignment specifications. SI is the only source of GM wheel alignment specifications that is kept up-to-date throughout the year. Test drive vehicle to ensure proper repair. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Alignment > System Information > Technical Service Bulletins > All Technical Service Bulletins for Alignment: > 05-03-07-009C > Dec > 10 > Steering/Suspension - Wheel Alignment Specifications > Page 1185 Frame Angle Measurement (Express / Savana Only) ........ Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Alignment > System Information > Technical Service Bulletins > All Technical Service Bulletins for Alignment: > 05-03-07-009C > Dec > 10 > Steering/Suspension - Wheel Alignment Specifications > Page 1186 What corrected the customer concern and was the repair verified? Please Explain: ............. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Alignment > System Information > Technical Service Bulletins > All Technical Service Bulletins for Alignment: > 463501 > Apr > 95 > Alignment - Front Tire Wear/Steering Returnability Alignment: All Technical Service Bulletins Alignment - Front Tire Wear/Steering Returnability File in Section: 3 - Steering/Suspension Bulletin No.: 46-35-01 Date: April, 1995 Subject: Front Tire Wear and/or Steering Returnability (Set to New Alignment Specification) Models: 1991-95 Chevrolet and GMC Truck T Models 1991-94 Oldsmobile Bravada CONDITION Some owners may comment on excessive front tire wear and/or steering returnability. PERFORM PRELIMINARY INSPECTION BEFORE ALIGNMENT CORRECTION The following procedures should be used to address customer's concerns about front tire wear and/or steering returnability: 1. Check to be sure the tire pressure is set to GVW Certification/Tire label specifications located on the driver's door lock pillar. Important: It is essential proper tire rotation schedule be followed at proper intervals to minimize tire wear. 2. 4WD ONLY, front suspension "Z" height dimension and setting must be made prior to any other alignment changes. 3. Perform front wheel alignment to the specifications in chart (figure). Notice: Vehicle must be jounced three times before checking alignment to eliminate false geometry readings. a. For 4WD only, front suspension "Z" height dimension 122 ± 6.0 mm (4.8 ± 0.2 inch), left and right side to be equal within 6 mm. b. Left and right side to be equal within 0.5". c. Left and right side to be equal within 1.0". d. Steering wheel must be held in straight ahead position with ± 3.0". Front individual toe must be equalized relative to rear wheel thrust angle. e. GVW alignment is the same for all vehicles. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Alignment > System Information > Specifications > Vehicle Ride (Trim) Height Specifications Alignment: Specifications Vehicle Ride (Trim) Height Specifications Fig. 4 Vehicle Ride Height Measurement Locations And Specifications Refer to Fig. 4 for ride height measurements and specifications. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Alignment > System Information > Specifications > Vehicle Ride (Trim) Height Specifications > Page 1193 Alignment: Specifications Alignment Specifications Caster, Deg. ........................................................................................................................................ ................................................................ +1.0 to +3.0 Camber, Deg. ................................................. ..................................................................................................................................................... +0.0 to +1.6 Toe-In, Deg. ............................................................................................................................ ....................................................................... +0.05 to +0.25 Ball Joint Wear, Inches ........................ .............................................................................................................................................................. ............. [01] [01] Refer to Steering & Suspension/ Suspension/ Ball Joint/ Testing and Inspection. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Fuel Pressure > Diagnostic Connector - Fuel Pump > Component Information > Locations Component Location - "S/T" 4.3Z Utility - Manual Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Idle Speed > System Information > Technical Service Bulletins > Idle Speed - Specification Revised Idle Speed: Technical Service Bulletins Idle Speed - Specification Revised File In Section: 6E - Engine Fuel & Emission Bulletin No.: 41-65-22 Date: September, 1994 SERVICE MANUAL UPDATE Subject: Section 4 - Revised Controlled Idle Speed Specification Models: 1994 Chevrolet and GMC Truck Light Duty Models 1994 Oldsmobile Bravada with Gasoline Engines Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Idle Speed > System Information > Technical Service Bulletins > Idle Speed - Specification Revised > Page 1203 This service bulletin supersedes Service Manual information for the Controlled Idle Speed Specification on Page 4-3 of the Driveability, Emissions, and Electrical Diagnosis Manual. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Idle Speed > System Information > Technical Service Bulletins > Page 1204 Idle Speed: Specifications Refer to Adjustment Procedures Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > Customer Interest for Air Filter Element: > 04-07-30-013B > Feb > 07 > Engine, A/T - Shift/Driveability Concerns/MIL ON Air Filter Element: Customer Interest Engine, A/T - Shift/Driveability Concerns/MIL ON Bulletin No.: 04-07-30-013B Date: February 01, 2007 INFORMATION Subject: Automatic Transmission Shift, Engine Driveability Concerns or Service Engine Soon (SES) Light On as a Result of the Use of an Excessively/Over-Oiled Aftermarket, Reusable Air Filter Models: 2007 and Prior GM Cars and Light Duty Trucks 2007 and Prior Saturn Models 2003-2007 HUMMER H2 2006-2007 HUMMER H3 2005-2007 Saab 9-7X Supercede: This bulletin is being revised to add models and model years. Please discard Corporate Bulletin Number 04-07-30-013A (Section 07 - Transmission/Transaxle). The use of an excessively/over-oiled aftermarket, reusable air filter may result in: Service Engine Soon (SES) light on Transmission shift concerns, slipping and damaged clutch(es) or band(s) Engine driveability concerns, poor acceleration from a stop, limited engine RPM range The oil that is used on these air filter elements may be transferred onto the Mass Air Flow (MAF) sensor causing contamination of the sensor. As a result, the Grams per Second (GPS) signal from the MAF may be low and any or all of the concerns listed above may occur. When servicing a vehicle with any of these concerns, be sure to check for the presence of an aftermarket reusable, excessively/over-oiled air filter. The MAF, GPS reading should be compared to a like vehicle with an OEM air box and filter under the same driving conditions to verify the concern. The use of an aftermarket reusable air filter DOES NOT void the vehicle's warranty. If an aftermarket reusable air filter is used, technicians should inspect the MAF sensor element and the air induction hose for contamination of oil prior to making warranty repairs. Transmission or engine driveability concerns (related to the MAF sensor being contaminated with oil) that are the result of the use of an aftermarket reusable, excessively/over-oiled air filter are not considered to be warrantable repair items. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > Customer Interest for Air Filter Element: > 04-07-30-013B > Feb > 07 > Engine, A/T - Shift/Driveability Concerns/MIL ON > Page 1214 Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Air Filter Element: > 04-07-30-013B > Feb > 07 > Engine, A/T - Shift/Driveability Concerns/MIL ON Air Filter Element: All Technical Service Bulletins Engine, A/T - Shift/Driveability Concerns/MIL ON Bulletin No.: 04-07-30-013B Date: February 01, 2007 INFORMATION Subject: Automatic Transmission Shift, Engine Driveability Concerns or Service Engine Soon (SES) Light On as a Result of the Use of an Excessively/Over-Oiled Aftermarket, Reusable Air Filter Models: 2007 and Prior GM Cars and Light Duty Trucks 2007 and Prior Saturn Models 2003-2007 HUMMER H2 2006-2007 HUMMER H3 2005-2007 Saab 9-7X Supercede: This bulletin is being revised to add models and model years. Please discard Corporate Bulletin Number 04-07-30-013A (Section 07 - Transmission/Transaxle). The use of an excessively/over-oiled aftermarket, reusable air filter may result in: Service Engine Soon (SES) light on Transmission shift concerns, slipping and damaged clutch(es) or band(s) Engine driveability concerns, poor acceleration from a stop, limited engine RPM range The oil that is used on these air filter elements may be transferred onto the Mass Air Flow (MAF) sensor causing contamination of the sensor. As a result, the Grams per Second (GPS) signal from the MAF may be low and any or all of the concerns listed above may occur. When servicing a vehicle with any of these concerns, be sure to check for the presence of an aftermarket reusable, excessively/over-oiled air filter. The MAF, GPS reading should be compared to a like vehicle with an OEM air box and filter under the same driving conditions to verify the concern. The use of an aftermarket reusable air filter DOES NOT void the vehicle's warranty. If an aftermarket reusable air filter is used, technicians should inspect the MAF sensor element and the air induction hose for contamination of oil prior to making warranty repairs. Transmission or engine driveability concerns (related to the MAF sensor being contaminated with oil) that are the result of the use of an aftermarket reusable, excessively/over-oiled air filter are not considered to be warrantable repair items. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Air Filter Element: > 04-07-30-013B > Feb > 07 > Engine, A/T - Shift/Driveability Concerns/MIL ON > Page 1220 Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Fuel Filter > Fuel Pressure Release > System Information > Service and Repair Fuel Pressure Release: Service and Repair WARNING To reduce the risk of fire and personal injury, it is necessary to relieve fuel system pressure before servicing fuel system components. A small amount of fuel may be released when servicing fuel lines or connections. In order to reduce the chance of personal injury, cover fuel line fittings with a shop towel before disconnecting to catch any fuel that may leak out. Place the towel in an approved container when disconnect is complete. PROCEDURE - Disconnect negative battery terminal to avoid possible fuel discharge if an accidental attempt is made to start the engine. - Loosen fuel filler cap to relieve tank vapor pressure. (Do not tighten until service has been completed.) - The TBI model 220 contains a constant bleed feature in the pressure regulator that relieves pressure. Therefore, no further action is required. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Firing Order > Component Information > Specifications > Ignition Firing Order Firing Order: Specifications Ignition Firing Order Firing Order ......................................................................................................................................... ............................................................... 1-6-5-4-3-2 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Ignition Timing > Ignition Timing Connector > Component Information > Technical Service Bulletins > Ignition Set Timing Connector - Location Correction Ignition Timing Connector: Technical Service Bulletins Ignition Set Timing Connector - Location Correction File in Section: Engine Fuel & Emission Bulletin No.: 41-65-41 Date: January, 1995 SERVICE MANUAL UPDATE Subject: Section 6A - Ignition Set Timing Connector Location Models: 1994 Chevrolet and GMC Truck S/T Models 1994 Oldsmobile Bravada with 4.3L Engine (VINs W, Z - RPOs L35, LB4) The location of the Set Timing Connector is incorrectly called out in "Section 6A" (Page 6A-8) of the "Driveability, Emissions and Electrical Diagnosis", Service Manual and in the 1994 Oldsmobile Bravada Service Manual Supplement (Page 6E3-C4-8). The correct location of the Set Timing Connector is inside the cab where the Heater Box and the carpet meet on the passenger side floor. Pull carpet back to expose the single wire and connectors on the outside of the control module harness. The wire colors are tan with a black stripe. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Ignition Timing > Ignition Timing Connector > Component Information > Technical Service Bulletins > Page 1234 Timing Connector-In Pass Comp Behind Carpet, Below Heater Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Ignition Timing > Number One Cylinder > Component Information > Locations > Number 1 Cylinder Location Number One Cylinder: Locations Number 1 Cylinder Location NUMBER ONE CYLINDER LOCATION Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Ignition Timing > Timing Marks and Indicators > System Information > Locations Timing Mark Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Ignition Cable > Component Information > Specifications Ignition Cable: Specifications RESISTANCE VALUES 0-15 inch cable .................................................................................................................................... ................................................. 3,000 - 10,000 ohms. 15-25 inch cable .................................................................................................................................. ................................................. 4,000 - 15,000 ohms. 25-35 inch cable .................................................................................................................................. ................................................. 6,000 - 20,000 ohms. NOTE: Longer wires should measure about 5,000 to 10,000 ohms per foot. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Ignition Cable > Component Information > Specifications > Page 1245 Ignition Cable: Locations Spark Plug Wire Routing Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Distributor, Ignition > Component Information > Specifications Distributor: Specifications Coil bracket bolt/nut ............................................................................................................................. ................................................. 27 N-m (20 lbs ft) Distributor clamp bolt ........................................................................................................................... ................................................ 27 N-m (20 lbs ft) Knock Sensor ...................................................................................................................................... .................................................. 19 N-m (14 lbs ft) Spark Plugs ......................................................................................................................................... .................................................. 15 N-M (11 lbs ft) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Distributor, Ignition > Component Information > Specifications > Page 1249 LH Rear Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Distributor, Ignition > Component Information > Specifications > Page 1250 Distributor: Description and Operation PURPOSE The distributor reference signal provides the ECM with both engine RPM and crankshaft position information. This enables the ECM to operate the fuel pump relay and energize the fuel injector. OPERATION When the engine is cranking or running the ECM receives Distributor Ignition (DI) reference pulses from the ignition module. If the wire becomes open or grounded the engine will not run, as the ECM will not operate the injector. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Distributor, Ignition > Component Information > Specifications > Page 1251 Distributor: Service and Repair Distributor Remove or Disconnect Figure 8 - Spark Plug Wire Routing - Left Side (2.2L) Figure 9 - Spark Plug Wire Routing - Right Side (2.2L) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Distributor, Ignition > Component Information > Specifications > Page 1252 Figure 10 - Distributor And Coil (4.3L VIN Z) Figure 11 - Distributor And Coil (4.3L VIN W) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Distributor, Ignition > Component Information > Specifications > Page 1253 Figure 12 - Spark Plug Wire Routing - Left Side (4.3L VIN Z) Figure 13 - Spark Plug Wire Routing - Right Side - Pickup Models (4.3L VIN Z) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Distributor, Ignition > Component Information > Specifications > Page 1254 Figure 14 - Spark Plug Wire Routing - Right Side - Utility Models (4.3L VIN Z) Figure 15 - Spark Plug Wire Routing (4.3L VIN W) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Distributor, Ignition > Component Information > Specifications > Page 1255 - Make sure the ignition switch is "OFF." 1. Air cleaner and hoses (4.3L VIN Z). 2. Wiring harness connectors at the side of the distributor cap. 3. Two screws on the sides of the distributor cap. 4. Coil wire and spark plug wires on either the left or right side of the distributor. 5. Distributor cap and move it aside. A. Use chalk to note the position of the rotor in relation to the engine. B. Use chalk to note the position of the distributor housing in relation to the engine. 6. Distributor bolt and hold-down clamp. 7. Distributor and gasket, when present. Install or Connect Figure 8 - Spark Plug Wire Routing - Left Side (2.2L) Figure 9 - Spark Plug Wire Routing - Right Side (2.2L) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Distributor, Ignition > Component Information > Specifications > Page 1256 Figure 10 - Distributor And Coil (4.3L VIN Z) Figure 11 - Distributor And Coil (4.3L VIN W) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Distributor, Ignition > Component Information > Specifications > Page 1257 Figure 12 - Spark Plug Wire Routing - Left Side (4.3L VIN Z) Figure 13 - Spark Plug Wire Routing - Right Side - Pickup Models (4.3L VIN Z) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Distributor, Ignition > Component Information > Specifications > Page 1258 Figure 14 - Spark Plug Wire Routing - Right Side - Utility Models (4.3L VIN Z) Figure 15 - Spark Plug Wire Routing (4.3L VIN W) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Distributor, Ignition > Component Information > Specifications > Page 1259 A. To ensure correct timing of the distributor, it must be installed with the rotor correctly positioned as noted in step 5 of the removal procedure. Line up the rotor to the mark on the engine, and the mark on the housing to the engine. B. If the distributor shaft won't drop into the engine, remove the distributor, insert a screwdriver into the hole for the distributor and rotate the oil pump driveshaft so that it lines up with the distributor driver gear. 1. Distributor and gasket, where present. 2. Hold-down clamp and bolt. - Bolt on the 4.3L to 27 Nm (20 lbs. ft.). 3. Distributor cap. 4. Wiring harness connectors at the side of the distributor. 5. Spark plug wires and coil wire. 6. Air Cleaner and hoses. - Check the engine timing. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Spark Plug > Component Information > Specifications Spark Plug: Specifications Spark Plug Gap ................................................................................................................................... ........................................ N/A see NOTE following. Spark Plug Torque ............................................................................................................................... ...................................................... 15 N-m (11 lb.ft.) Spark Plug Type .................................................................................................................................. .......................................................... AC CR43TSM NOTE Check the gap specifications given on the Emissions Control Label. If the gap is different from what is listed here, use the information on the label. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Compression Check > System Information > Specifications Compression Check: Specifications Minimum, 698 kPa (100 psi) @ 200 rpm. The lowest cylinder reading should not be less than 80% of the highest. Perform compression test with engine at normal operating temperature, spark plugs removed and throttle wide open. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Valve Clearance > System Information > Specifications > Valve Clearance Specifications Valve Clearance: Specifications Valve Clearance Specifications VALVE ADJUSTMENT (VIN Z) WITH SCREW-IN ROCKER ARM STUDS AND POSITIVE STOP SHOULDERS Valve Rocker Arm Nuts ....................................................................................................................... .......................................... 27 Nm (20 lb. ft.). WITH PRESSED-IN ROCKER ARM STUDS Refer to Rocker Arm / Adjustments. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Valve Clearance > System Information > Specifications > Valve Clearance Specifications > Page 1270 Valve Clearance: Specifications Valve Arrangement FRONT TO REAR 4.3L/V6-262 Left Side........................................................................................................................... .................................................................................. E-I-E-I-I-E Right Side......................................... .............................................................................................................................................................. .... E-I-I-E-I-E Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Valve Clearance > System Information > Specifications > Page 1271 Valve Clearance: Adjustments VALVE ADJUSTMENT Fig. 10 Valve Adjustment The 4.3L VIN Z engine can be equipped with two different rocker arm stud configurations that require different valve lash procedures. TYPE 1 - VIN Z If you have a 4.3L VIN Z engine that has screw-in rocker arm studs with positive stop shoulders, no valve adjustment is necessary. When the valve train requires service, you simply tighten the rocker arm nuts to 27 Nm (20 ft lb). TYPE 2 - VIN Z If you have a 4.3L VIN Z engine that has pressed-in rocker arm studs, you must follow the valve adjustment procedure outlined below. 1. Remove rocker arm cover. 2. Rotate engine until mark on torsional damper is aligned with "0" mark on timing tab fastened to crankcase front cover. To ensure engine is at No. 1 cylinder firing position, place fingers on No. 1 cylinder valves as the mark on damper approaches the "0" mark on timing tab. If valves are not moving, engine is in the No. 1 cylinder firing position. If valves are moving, engine is in the No. 4 cylinder firing position and should be rotated one revolution. 3. With engine in No. 1 cylinder firing position, adjust the following valves: ^ Exhaust valves 1, 5 and 6. ^ Intake valves 1, 2 and 3. NOTE: Even numbered cylinders are in the left bank and odd numbered cylinders are in the right bank, when viewed from front of the engine. 4. Back off adjusting nut until lash is felt at pushrod, then tighten nut until all lash is removed. This can be determined by rotating pushrod while turning adjusting nut. When all lash is removed, tighten adjusting nut 1 and 3/4 turns to center lifter plunger. 5. Crank engine one full revolution until mark on torsional damper and "0" mark on timing tab are again in alignment. This is the No. 4 cylinder firing position. With engine in this position, adjust the following valves: ^ Exhaust valves 2, 3 and 4. ^ Intake valves 4, 5 and 6. 6. Install valve covers and related components, then start engine and check timing and idle speed. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Tune-up and Engine Performance Checks > Valve Clearance > System Information > Specifications > Page 1272 Valve Clearance: Service and Repair For Valve Adjustment, Refer to Valve Clearance / Adjustments. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Drive Belt > Component Information > Technical Service Bulletins > Engine - Drive Belt Misalignment Diagnostics Drive Belt: Technical Service Bulletins Engine - Drive Belt Misalignment Diagnostics INFORMATION Bulletin No.: 08-06-01-008A Date: July 27, 2009 Subject: Diagnosing Accessory Drive Belt / Serpentine Belt Noise and Availability and Use of Kent-Moore EN-49228 Laser Alignment Tool - Drive Belt Models: 2010 and Prior GM Passenger Cars and Trucks (Including Saturn) 2010 and Prior HUMMER H2, H3 Vehicles 2009 and Prior Saab 9-7X Supercede: This bulletin is being revised to add a model year and update the Tool Information. Please discard Corporate Bulletin Number 08-06-01-008 (Section 06 - Engine). Background Several aftermarket companies offer laser alignment tools for accessory drive systems that can be very helpful in eliminating drive belt noise as a result of misaligned pulleys. Typically pricing ranges from $160 - $200. EN-49228 Laser Alignment Tool - Drive Belt The GM Tool program has now made available a competitive, simple to use and time-saving laser tool to assist in achieving precise alignment of the drive belt pulleys. This optional tool removes the guesswork from proper pulley alignment and may serve to reduce comebacks from: - Drive Belt Noise - Accelerated Drive Belt Wear - Drive Belt Slippage Instructions The instructions below are specific only to the truck Gen IV V-8 family of engines. These instructions are only for illustrative purposes to show how the tool may be used. Universal instructions are included in the box with the Laser Alignment Tool - Drive Belt. Caution - Do not look directly into the beam projected from the laser. - Use caution when shining the laser on highly polished or reflective surfaces. Laser safety glasses help reduce laser beam glare in many circumstances. - Always use laser safety glasses when using the laser. Laser safety glasses are not designed to protect eyes from direct laser exposure. 1. Observe and mark the serpentine belt orientation. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Drive Belt > Component Information > Technical Service Bulletins > Engine - Drive Belt Misalignment Diagnostics > Page 1277 2. Remove the serpentine belt from the accessory drive system. 3. Install the tool onto the power steering pulley. Position the legs of the tool into the outer grooves of the pulley, farthest from the front of the engine. 4. Install the retaining cord around the pulley and to the legs of the tool. 5. Put on the laser safety glasses provided with the tool. 6. Depress the switch on the rear of the tool to activate the light beam. 7. Rotate the power steering pulley as required to project the light beam onto the crankshaft balancer pulley grooves. 8. Inspect for proper power steering pulley alignment. - If the laser beam projects onto the second rib or raised area (1), the pulleys are aligned properly. - If the laser beam projects more than one-quarter rib 0.9 mm (0.035 in) mis-alignment, adjust the position of the power steering pulley as required. - Refer to SI for Power Steering Pulley Removal and Installation procedures. 9. Install the serpentine belt to the accessory drive system in the original orientation. 10. Operate the vehicle and verify that the belt noise concern is no longer present. Tool Information Please visit the GM service tool website for pricing information or to place your order for this tool. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Drive Belt > Component Information > Technical Service Bulletins > Engine - Drive Belt Misalignment Diagnostics > Page 1278 Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Drive Belt > Component Information > Technical Service Bulletins > Engine - Drive Belt Misalignment Diagnostics > Page 1279 Drive Belt: Technical Service Bulletins Engine - Serpentine Drive Belt Wear Information Bulletin No.: 04-06-01-013 Date: April 29, 2004 INFORMATION Subject: Information on Serpentine Belt Wear Models: 2004 and Prior Passenger Cars and Trucks 2003-2004 and Prior HUMMER H2 All current GM vehicles designed and manufactured in North America were assembled with serpentine belts that are made with an EPDM material and should last the life of the vehicle. It is extremely rare to observe any cracks in EPDM belts and it is not expected that they will require maintenance before 10 years or 240,000 km (150,000 mi) of use. Older style belts, which were manufactured with a chloroprene compound, may exhibit cracks depending on age. However, the onset of cracking typically signals that the belt is only about halfway through its usable life. A good rule of thumb for chloroprene-based belts is that if cracks are observed 3 mm (1/8 in) apart, ALL AROUND THE BELT, the belt may be reaching the end of its serviceable life and should be considered a candidate for changing. Small cracks spaced at greater intervals should not be considered as indicative that the belt needs changing. Any belt that exhibits chunking should be replaced. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Drive Belt > Component Information > Technical Service Bulletins > Page 1280 Drive Belt: Service and Repair Serpentine Drive Belt Routing Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Drive Belt > Component Information > Technical Service Bulletins > Page 1281 Serpentine Belt Routing REMOVE OR DISCONNECT 1. Use a 1/2 inch breaker bar with a socket placed on the tensioner pulley axis bolt and rotate the tensioner to the left (counterclockwise). CAUTION: Do NOT allow the drive belt tensioner to snap into the "free" position as this may damage the tensioner. 2. Remove belt. INSTALL OR CONNECT 1. Route belt over pulleys except the belt tensioner. 2. Use a 1/2 inch breaker bar with a socket placed on the tensioner pulley axis bolt and rotate the tensioner to the left (counterclockwise). 3. Belt over the tensioner pulley. 4. Check the belt for correct "V" groove tracking around each pulley. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > Customer Interest for Air Filter Element: > 04-07-30-013B > Feb > 07 > Engine, A/T Shift/Driveability Concerns/MIL ON Air Filter Element: Customer Interest Engine, A/T - Shift/Driveability Concerns/MIL ON Bulletin No.: 04-07-30-013B Date: February 01, 2007 INFORMATION Subject: Automatic Transmission Shift, Engine Driveability Concerns or Service Engine Soon (SES) Light On as a Result of the Use of an Excessively/Over-Oiled Aftermarket, Reusable Air Filter Models: 2007 and Prior GM Cars and Light Duty Trucks 2007 and Prior Saturn Models 2003-2007 HUMMER H2 2006-2007 HUMMER H3 2005-2007 Saab 9-7X Supercede: This bulletin is being revised to add models and model years. Please discard Corporate Bulletin Number 04-07-30-013A (Section 07 - Transmission/Transaxle). The use of an excessively/over-oiled aftermarket, reusable air filter may result in: Service Engine Soon (SES) light on Transmission shift concerns, slipping and damaged clutch(es) or band(s) Engine driveability concerns, poor acceleration from a stop, limited engine RPM range The oil that is used on these air filter elements may be transferred onto the Mass Air Flow (MAF) sensor causing contamination of the sensor. As a result, the Grams per Second (GPS) signal from the MAF may be low and any or all of the concerns listed above may occur. When servicing a vehicle with any of these concerns, be sure to check for the presence of an aftermarket reusable, excessively/over-oiled air filter. The MAF, GPS reading should be compared to a like vehicle with an OEM air box and filter under the same driving conditions to verify the concern. The use of an aftermarket reusable air filter DOES NOT void the vehicle's warranty. If an aftermarket reusable air filter is used, technicians should inspect the MAF sensor element and the air induction hose for contamination of oil prior to making warranty repairs. Transmission or engine driveability concerns (related to the MAF sensor being contaminated with oil) that are the result of the use of an aftermarket reusable, excessively/over-oiled air filter are not considered to be warrantable repair items. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > Customer Interest for Air Filter Element: > 04-07-30-013B > Feb > 07 > Engine, A/T Shift/Driveability Concerns/MIL ON > Page 1292 Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Air Filter Element: > 04-07-30-013B > Feb > 07 > Engine, A/T - Shift/Driveability Concerns/MIL ON Air Filter Element: All Technical Service Bulletins Engine, A/T - Shift/Driveability Concerns/MIL ON Bulletin No.: 04-07-30-013B Date: February 01, 2007 INFORMATION Subject: Automatic Transmission Shift, Engine Driveability Concerns or Service Engine Soon (SES) Light On as a Result of the Use of an Excessively/Over-Oiled Aftermarket, Reusable Air Filter Models: 2007 and Prior GM Cars and Light Duty Trucks 2007 and Prior Saturn Models 2003-2007 HUMMER H2 2006-2007 HUMMER H3 2005-2007 Saab 9-7X Supercede: This bulletin is being revised to add models and model years. Please discard Corporate Bulletin Number 04-07-30-013A (Section 07 - Transmission/Transaxle). The use of an excessively/over-oiled aftermarket, reusable air filter may result in: Service Engine Soon (SES) light on Transmission shift concerns, slipping and damaged clutch(es) or band(s) Engine driveability concerns, poor acceleration from a stop, limited engine RPM range The oil that is used on these air filter elements may be transferred onto the Mass Air Flow (MAF) sensor causing contamination of the sensor. As a result, the Grams per Second (GPS) signal from the MAF may be low and any or all of the concerns listed above may occur. When servicing a vehicle with any of these concerns, be sure to check for the presence of an aftermarket reusable, excessively/over-oiled air filter. The MAF, GPS reading should be compared to a like vehicle with an OEM air box and filter under the same driving conditions to verify the concern. The use of an aftermarket reusable air filter DOES NOT void the vehicle's warranty. If an aftermarket reusable air filter is used, technicians should inspect the MAF sensor element and the air induction hose for contamination of oil prior to making warranty repairs. Transmission or engine driveability concerns (related to the MAF sensor being contaminated with oil) that are the result of the use of an aftermarket reusable, excessively/over-oiled air filter are not considered to be warrantable repair items. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Air Filter Element: > 04-07-30-013B > Feb > 07 > Engine, A/T - Shift/Driveability Concerns/MIL ON > Page 1298 Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Crankcase Filter > Component Information > Service and Repair Crankcase Filter: Service and Repair Inspection The crankcase ventilation system should be checked every 30,000 miles and also during regular engine tune-ups. If the crankcase ventilation system includes a breather filter, located in the air cleaner housing, this filter should be replaced whenever the crankcase ventilation valve or air cleaner is replaced. When a periodic inspection indicates the crankcase ventilation is not functioning properly, it should be serviced by replacement only. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > EGR Filter > Component Information > Service and Repair EGR Filter: Service and Repair EVRV Filter Replacment REMOVE AND INSTALL - Grasp and pull the filter OFF with a rocking motion. - Push the new filter on making sure that the cut-out for the wires is properly aligned. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Evaporative Canister Filter > Component Information > Locations Vapor Canister 2.5;2.8;4.3;5.0;5.7;7.4L Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Evaporative Canister Filter > Component Information > Service and Repair > Fuel Evaporative Canister Filter Replacement Evaporative Canister Filter: Service and Repair Fuel Evaporative Canister Filter Replacement PROCEDURE At intervals recommended, usually every 24 months or 30,000 miles, the filter on an open bottom canister should be replaced, - Remove all hoses from the top of the canister and mark. Remove the canister. - Remove the filter element by squeezing it out from under the lip surface at bottom of canister and from under retainer bar, where used. - Squeeze the new element under retainer bar, where used, and position it evenly around the entire bottom of the canister. Tuck the edges under the lip of canister. - Reinstall the canister to its original position on the vehicle, following normal service procedures. - Reconnect the hoses to the top of the canister, according to the labeling on top of canister. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Evaporative Canister Filter > Component Information > Service and Repair > Fuel Evaporative Canister Filter Replacement > Page 1310 Evaporative Canister Filter: Service and Repair EVRV Filter Replacement EVRV Filter Replacment Removal and Installation - Grasp and pull the filter OFF with a rocking motion. - Push the new filter on making sure that the cut-out for the wires is properly aligned. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Fluid Filter - A/T > Component Information > Technical Service Bulletins > A/T - Updated Design Oil Filter Assembly & Seal Fluid Filter - A/T: Technical Service Bulletins A/T - Updated Design Oil Filter Assembly & Seal Group Ref.: Transmission Bulletin No.: 377142A Date: February, 1994 INFORMATION SUBJECT: NEW TRANSMISSION OIL FILTER ASSEMBLY MODELS: 1994 BUICK ROADMASTER 1994 CADILLAC FLEETWOOD 1994 CHEVROLET CAPRICE, CAMARO, CORVETTE 1994 PONTIAC FIREBIRD 1994 CHEVROLET AND GMC C/K AND S/T TRUCKS 1994 CHEVROLET AND GMC M/L AND G VANS 1994 OLDSMOBILE BRAVADA TRANSMISSION APPLICATIONS: 1994 HYDRA-MATIC 4L60-E (M30) THIS BULLETIN IS BEING REVISED TO CLARIFY TRANSMISSION USAGE. PLEASE DISCARD BULLETIN 377142. BULLETIN COVERS: New product information for 1994 HYDRA-MATIC 4L60-E transmissions. Be certain to familiarize yourself with these updates to properly repair the 1994 HYDRA-MATIC 4L60-E transmission. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Fluid Filter - A/T > Component Information > Technical Service Bulletins > A/T - Updated Design Oil Filter Assembly & Seal > Page 1315 DATE OF PRODUCTION CHANGE: (Figure 1 and 2) On August 10, 1993 (Julian Date 222), HYDRA-MATIC 4L60-E transmissions were built with a new filter seal (ill. 71) and transmission oil filter assembly (ill. 72). The previous transmission oil filter assembly and filter seal had an assembly method of installing the seal on the filter neck and then installing the filter in the transmission. When using the new filter seal and transmission oil filter assembly, the filter seal must be installed in the transmission first and then install the transmission oil filter assembly into the transmission. NOTE: The new filter seal and transmission oil filter assembly can be used on all HYDRA-MATIC 4L60-E transmissions 1993-1994. The new filter seal and transmission oil filter assembly cannot be used on any HYDRA-MATIC 4L60 transmission. The new filter seal cannot be used with the old transmission oil filter assembly and the new transmission oil filter assembly cannot be used with the old filter seal. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Fuel Filter > Fuel Pressure Release > System Information > Service and Repair Fuel Pressure Release: Service and Repair WARNING To reduce the risk of fire and personal injury, it is necessary to relieve fuel system pressure before servicing fuel system components. A small amount of fuel may be released when servicing fuel lines or connections. In order to reduce the chance of personal injury, cover fuel line fittings with a shop towel before disconnecting to catch any fuel that may leak out. Place the towel in an approved container when disconnect is complete. PROCEDURE - Disconnect negative battery terminal to avoid possible fuel discharge if an accidental attempt is made to start the engine. - Loosen fuel filler cap to relieve tank vapor pressure. (Do not tighten until service has been completed.) - The TBI model 220 contains a constant bleed feature in the pressure regulator that relieves pressure. Therefore, no further action is required. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Oil Filter, Engine > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM Oil Filter: Customer Interest Engine - Cold Knock, Replace Oil Filter/Bearings/PROM File In Section: 6 - Engine Bulletin No.: 37-61-05A Date: October, 1995 Subject: Cold Engine Knock (Replace Oil Filter/Bearings/PROM) Models: 1990-95 Chevrolet and GMC Truck C/K, R/V, S/T, M/L, G, P Models 1991-92 Oldsmobile Bravada with 4.3L (VIN Z - RPO LB4), 5.7L (VIN K - RPO L05), 7.4 (VIN N - RPO L19) Engine This bulletin is being revised to add the 1995 model year information. Please discard Corporate Bulletin Number 37-61-05 (Section 6 - Engine). Condition Some late model truck engines have been reported to exhibit "cold knock" on start up. "Cold Knock" usually occurs after the vehicle has been completely warmed up, then parked for 8 or more hours in ambient temperatures of 35° F or less. "Cold knock" can be separated into three distinct categories. 1. Short Duration - Harsh, deep metallic knock that usually lasts from 1 to 10 seconds. Generally classified as a bearing or rod knock. 2. Valve Train - Light clatter, tick or click that may last up to 1 minute. 3. Piston Slap - Metallic knock that occurs only under load. Piston slap may last as long as 5 minutes. Correction Category A: Short Duration Knock This matrix describes the repair for each affected model year and engine. Specific information for each affected model year and engine is supplied. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Oil Filter, Engine > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1328 1992 LB4 VIN Z with "cold knock" only 1992-93 LB4 VIN Z with "cold knock" and installed field fix PROM OR with "cold knock" and detonation 1990-95 LB4 VIN Z Install check valve oil filter P/N 12555891 (FRAM PH3980). If the filter does not cure the condition, install the appropriate calibration from the tables (calibrations are available for all 1992 and some 1993 LB4 applications). If a calibration is not offered or does not cure the short duration cold knock Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Oil Filter, Engine > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1329 condition, install the appropriate main bearings as determined by the following procedure. Calibration Information - 1992-93 LB4 VIN Z The revised PROMs reduce spark advance after the engine is started. The reduction in spark lowers the cylinder pressure and eliminates the knock. The revised PROMs will NOT eliminate a piston slap (Category C) or valve train noise (Category B) concern. The base cold knock PROM contains the previously released calibration updates. For 1992 LB4, the previous field release is included for torque converter clutch (TCC) lock up (see Bulletin 137107 - Chevrolet 92-75-7A; GMC Truck 92-7A-40; Oldsmobile 92-T-34; Canada 9274L60100) for automatic transmissions, or neutral gear rattle for manual transmissions (see Bulletin 267201R - Chevrolet 92-187B-7B; GMC Truck 92-7B-149A; Canada 93-7B-105). If a vehicle has had a detonation fix PROM installed previously, select the combined detonation and cold knock fix PROM for the application. See Bulletin 376508 for more information on field fix PROM for the application and detonation. Important: Use of a detonation fix PROM in a non-detonating vehicle may result in degraded driveability. GMSPO currently stocks three (3) PROMs for each light duty 1992 model year LB4 application. Base Cold Knock Fix Combination Cold Knock and Detonation Fix GMSPO Service Parts Assistance Center (SPAC 1-800-433-6961) will have information available on each PROM part number. Select the PROM from the table. Old Broadcast Code (Old B/C Code) and Scan I.D. information has been supplied to help installed previously. Use a TECH-1 to determine the Scan I.D. of the PROM in the vehicle or remove the PROM and read the Broadcast Code (B/C Code). If the B/C Code/Scan I.D. can be found in the first table, a detonation fix has not been installed. PROMs are currently available GMSPO. 1990-95 L05 VIN K Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Oil Filter, Engine > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1330 1993 to 1995 L05 VIN K Install the appropriate check valve oil filter P/N 25160561 (PF1218 for two-wheel C-series and P/N 12555891 (FRAM PH3980) for four-wheel drive K-series). If the oil filter does not cure the condition, install the appropriate calibration from the table (calibrations are available for some 1993 and 1994 L05 applications). All calibrations are for light duty vehicles equipped with 4L60-E (M30) transmissions (no heavy duty emission/4L80-E calibrations are available). If a calibration is not offered or does not cure the short duration cold knock condition, install the appropriate main bearings as determined by the procedure. 1990-94 L19 VIN N Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Oil Filter, Engine > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1331 Install a check valve oil filter; no other recommended actions at this time. Important: The previous actions are only applicable to short duration cold knock. These actions will not eliminate a knock occurring under load or a knock lasting for more than 10 seconds. Two main bearing procedures are recommended: 1. For main bearing replacement with the engine IN the vehicle: C, G, P, M and L vehicles 2. For main bearing replacement with the engine OUT OF the vehicle: K, S and T THE FOLLOWING PROCEDURE IS TO BE USED FOR VEHICLES REQUIRING MAIN BEARING REPLACEMENT WITH THE ENGINE IN THE VEHICLE Recommended for C, G, P, M and L vehicles. Important: A OEM training video has been produced for in-vehicle main bearing replacement procedure. One copy of the video will be sent to each dealer. If the video has not been received, contact XPRESS 1 Distribution Center at 1-800-783-3034. Main Bearing Clearance Determination and Installation Procedure 1. REMOVE THE SERPENTINE BELT, dipstick, dipstick tube and disconnect the negative battery cable. 2. Raise the vehicle and remove (or set aside) any parts restricting access to the oil pan bolts (i.e., starter motor, oil cooler lines, oil filter adapter, flywheel inspection cover). 3. Remove the oil pan, oil pump, and shield. 4. Remove # 5 (flange) bearing cap. Wipe the oil from the crankshaft journal and the lower main bearing insert. 5. Place a screw jack under an accessible part of the crankshaft, carefully apply pressure to the crankshaft to force it solidly against the top bearing insert. The reason for this is to remove any clearance between the top bearing insert and the crankshaft. If this step is not performed, a smaller than actual clearance will be measured. Important: This should be done as close as possible to the bearing being measured. This step is only required for on-vehicle service where the engine cannot be turned upside down as on an engine stand. 6. Place a piece of plastigage across the width of the lower bearing insert (parallel to the centerline of the crankshaft). 7. Reinstall # 5 main bearing cap. Torque to 110 N.m (80 lb ft). Do not allow crankshaft to turn. 8. Carefully remove the # 5 main bearing cap and bearing insert. The flattened plastigage will adhere to either the bearing insert or the crank journal. Do not remove the plastigage from the insert or journal. 9. On the edge of the plastigage envelope, there is a graduated scale. Without removing the flattened plastigage, measure its width at the widest point using the graduated scale on the plastigage envelope. 10. The desired main bearing clearance is 0.0008" - 0.0028". If the clearance measured with the plastigage is greater than 0.0028", write down the clearance. Next, read the back of the bearing insert to determine what size bearing was originally installed (usual STD, 0.0006", 0.0010" or 0.0012"). The size stamped on the bearing is the effective undersize when both inserts are installed. For example, a 0.0006" undersize bearing set consists of two (2) 0.0003" thicker bearing inserts, both stamped 0.0006". 11. Remove the top bearing insert using tool J 8080 and read the back to determine what size upper bearing insert was originally installed. The top insert may be different size than the bottom. 12. Calculate the original bearing undersize by dividing the size on each insert by 2, then add the values together. EXAMPLE 1: The lower insert is stamped 0.0006" and the upper is stamped 0.0010". Divide 0.0006" by two to get 0.0003". Divide 0.0010" by 2 to get 0.0005". Add 0.0003" and 0.0005" together to calculate the bearing undersize, which is 0.0008" in this case. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Oil Filter, Engine > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1332 EXAMPLE 2: The lower insert is stamped STD (standard) and the upper is stamped 0.0010". The undersize for a STD bearing is 0. Divide 0 by 2 to get 0. Divide 0.0010" by 2 to get 0.0005". Add 0 and 0.0005" together to calculate the bearing undersize, which is 0.0005" in this case. 13. Add the original bearing undersize calculated in step 12 to the clearance measured and written down in step 9. For example, if a clearance of 0.0030" was measured with plastigage in step 9 and the calculated bearing undersize from step 12 was 0.0005", the bearing clearance for that particular main journal is equal to 0.0030" plus 0.0005". The bearing clearance would be 0.0035" in this case. 14. Determine which of the combinations of two sizes of replacement bearings will produce the desired clearance. The two sizes available are 0.001" and 0.002". One insert of each size may be combined to produce an intermediate undersize of 0.0015". Subtract the replacement bearing size from the actual clearance to determine which bearing should be used. The bearing that should be used is the one which gives a clearance closer to 0.0008" than to 0.0028". The clearance must not be less than 0.0008". Using the example from step 11, the actual clearance is 0.0035". Subtracting 0.001" from 0.0035" will give a clearance of 0.0025", just barely within the required range. Subtracting 0.002" from 0.0035" will give a clearance of 0.0015". The 0.002" undersize bearing set would be the one to use in this case since it gives a clearance closer to 0.0008", but not less. 15. Install the replacement upper main bearing insert using tool J 8080. 16. Install the replacement lower main bearing insert in the main bearing cap. Lay a piece of plastigage across the width of the lower main bearing insert (same as step 5). 17. Repeat steps 7, 8 and 9. 18. Measuring the plastigage with the scale on the envelope, verify the clearance of the replacement bearings is within the range of 0.001" to 0.003". 19. Repeat steps 4 through 16 for each main bearing. 20. Thrust the crankshaft forward and backward several times to seat the thrust bearing. 21. Reinstall oil pump; torque to 88 N.m (65 lb ft). 22. Reinstall the oil pan and other hardware. 23. Before starting the engine, remove the fuel pump fuse and crank the engine until oil pressure registers on the gauge. Stop cranking, let the starter cool down, then crank for another 15 seconds. 24. Install fuel pump fuse, start engine, check for leaks or unusual noises. 25. Road test vehicle, check for leaks or unusual noises. THE FOLLOWING PROCEDURE IS TO BE USED FOR VEHICLES REQUIRING MAIN BEARING REPLACEMENT WITH THE ENGINE OUT OF THE VEHICLE Recommended for K, S and T vehicles. 1. Remove the engine from the vehicle using the appropriate service manual procedure. 2. Mount the engine on an engine stand, flip the engine so the oil pan is facing up. 3. Remove the oil pan. 4. Remove the oil pump and shield. 5. Remove the dipstick tube. 6. Remove one (1) main bearing cap (must do one at a time). 7. Plasti-gage bearing. 8. If the bearing clearance is out of specification (clearance greater than 0.003 inches), remove upper main bearing from the block. 9. Check the size of the original bearing. 10. Determine what combination of new bearings are required to get the clearance in the acceptable range of 0.0008 inches to 0.0028 inches. See steps Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Oil Filter, Engine > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1333 12 through 14 in the "in-vehicle" service outlined above. 11. Reinstall the upper main bearing. 12. Reinstall the main cap and lower bearing; torque to 110 N.m (80 lb ft). 13. Repeat for each main bearing. 14. Reinstall oil pump and shield; torque to 88 N.m (65 lb ft). 15. Reinstall dipstick tube. 16. Reinstall oil pan. 17. Reinstall engine in vehicle. 18. Before starting the engine, remove the fuel pump fuse and crank the engine until oil pressure registers on the gauge. Stop cranking, let the starter cool down, then crank for another 15 seconds. 19. Install fuel pump fuse, start engine, check for leaks or unusual noises. 20. Road test vehicle, check for leaks or unusual noises. Correction Category B: Valve Train Clatter, Tick or Click For 1992-94 vehicles equipped with a 4.3L V6 (LB4 VIN Z or L35 VIN W) engine see Corporate Bulletin 376006 for information on converting from net lash to adjustable lash and/or re-lashing the valves on an adjustable lash system. Investigation of "cold knock" is continuing. Updates will continue to be provided when available. Parts Information Check-Valve Filters Description Part Number V6, V8 (Four-Wheel Drive) FRAM PH3980 12555891 V8 (Two-Wheel Drive), Mark V8 PF1218 25160561 The FRAM PH3980 is to be used in place of the PF52. The PH3980 provides superior anti-drainback performance, a key factor in reducing cold knock. FRAM filters are to be procured locally until 08-15-95. After this date the filters may be ordered from GMSPO using the supplied part number. Orders placed to GMSPO prior to this date will not be placed on backorder. Bearings Description Part Number 0.001" Main Bearing Kit, Positions 1-4 on V8, 1-3 on V6 10120992 0.001" Main Bearing Kit, Flange # 5 on V8, # 4 on V6 10120994 0.002" Main Bearing Kit, Positions 1-4 on V8, 1-3 on V6 12329758 0.002" Main Bearing Kit, Flange # 5 on V8, # 4 on V6 12329792 Main bearing kits are currently available from GMSPO. All calibrations are currently available from GMSPO. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Oil Filter, Engine > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1334 Warranty Information Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oil Filter: > 07-06-01-016B > Jul > 09 > Engine - Noise/Damage Oil Filter Application Importance Oil Filter: All Technical Service Bulletins Engine - Noise/Damage Oil Filter Application Importance INFORMATION Bulletin No.: 07-06-01-016B Date: July 27, 2009 Subject: Information on Internal Engine Noise or Damage After Oil Filter Replacement Models: 2010 and Prior Passenger Cars and Trucks (Including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X Supercede: This bulletin is being updated to add model years. Please discard Corporate Bulletin Number 07-06-01-016A (Section 06 - Engine/Propulsion System). Important Engine damage that is the result of an incorrect or improperly installed engine oil filter is not a warrantable claim. The best way to avoid oil filter quality concerns is to purchase ACDelco(R) oil filters directly from GMSPO. Oil filter misapplication may cause abnormal engine noise or internal damage. Always utilize the most recent parts information to ensure the correct part number filter is installed when replacing oil filters. Do not rely on physical dimensions alone. Counterfeit copies of name brand parts have been discovered in some aftermarket parts systems. Always ensure the parts you install are from a trusted source. Improper oil filter installation may result in catastrophic engine damage. Refer to the appropriate Service Information (SI) installation instructions when replacing any oil filter and pay particular attention to procedures for proper cartridge filter element alignment. If the diagnostics in SI (Engine Mechanical) lead to the oil filter as the cause of the internal engine noise or damage, dealers should submit a field product report. Refer to Corporate Bulletin Number 02-00-89-002I (Information for Dealers on How to Submit a Field Product Report). Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oil Filter: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM Oil Filter: All Technical Service Bulletins Engine - Cold Knock, Replace Oil Filter/Bearings/PROM File In Section: 6 - Engine Bulletin No.: 37-61-05A Date: October, 1995 Subject: Cold Engine Knock (Replace Oil Filter/Bearings/PROM) Models: 1990-95 Chevrolet and GMC Truck C/K, R/V, S/T, M/L, G, P Models 1991-92 Oldsmobile Bravada with 4.3L (VIN Z - RPO LB4), 5.7L (VIN K - RPO L05), 7.4 (VIN N - RPO L19) Engine This bulletin is being revised to add the 1995 model year information. Please discard Corporate Bulletin Number 37-61-05 (Section 6 - Engine). Condition Some late model truck engines have been reported to exhibit "cold knock" on start up. "Cold Knock" usually occurs after the vehicle has been completely warmed up, then parked for 8 or more hours in ambient temperatures of 35° F or less. "Cold knock" can be separated into three distinct categories. 1. Short Duration - Harsh, deep metallic knock that usually lasts from 1 to 10 seconds. Generally classified as a bearing or rod knock. 2. Valve Train - Light clatter, tick or click that may last up to 1 minute. 3. Piston Slap - Metallic knock that occurs only under load. Piston slap may last as long as 5 minutes. Correction Category A: Short Duration Knock This matrix describes the repair for each affected model year and engine. Specific information for each affected model year and engine is supplied. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oil Filter: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1344 1992 LB4 VIN Z with "cold knock" only 1992-93 LB4 VIN Z with "cold knock" and installed field fix PROM OR with "cold knock" and detonation 1990-95 LB4 VIN Z Install check valve oil filter P/N 12555891 (FRAM PH3980). If the filter does not cure the condition, install the appropriate calibration from the tables (calibrations are available for all 1992 and some 1993 LB4 applications). If a calibration is not offered or does not cure the short duration cold knock Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oil Filter: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1345 condition, install the appropriate main bearings as determined by the following procedure. Calibration Information - 1992-93 LB4 VIN Z The revised PROMs reduce spark advance after the engine is started. The reduction in spark lowers the cylinder pressure and eliminates the knock. The revised PROMs will NOT eliminate a piston slap (Category C) or valve train noise (Category B) concern. The base cold knock PROM contains the previously released calibration updates. For 1992 LB4, the previous field release is included for torque converter clutch (TCC) lock up (see Bulletin 137107 - Chevrolet 92-75-7A; GMC Truck 92-7A-40; Oldsmobile 92-T-34; Canada 9274L60100) for automatic transmissions, or neutral gear rattle for manual transmissions (see Bulletin 267201R - Chevrolet 92-187B-7B; GMC Truck 92-7B-149A; Canada 93-7B-105). If a vehicle has had a detonation fix PROM installed previously, select the combined detonation and cold knock fix PROM for the application. See Bulletin 376508 for more information on field fix PROM for the application and detonation. Important: Use of a detonation fix PROM in a non-detonating vehicle may result in degraded driveability. GMSPO currently stocks three (3) PROMs for each light duty 1992 model year LB4 application. Base Cold Knock Fix Combination Cold Knock and Detonation Fix GMSPO Service Parts Assistance Center (SPAC 1-800-433-6961) will have information available on each PROM part number. Select the PROM from the table. Old Broadcast Code (Old B/C Code) and Scan I.D. information has been supplied to help installed previously. Use a TECH-1 to determine the Scan I.D. of the PROM in the vehicle or remove the PROM and read the Broadcast Code (B/C Code). If the B/C Code/Scan I.D. can be found in the first table, a detonation fix has not been installed. PROMs are currently available GMSPO. 1990-95 L05 VIN K Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oil Filter: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1346 1993 to 1995 L05 VIN K Install the appropriate check valve oil filter P/N 25160561 (PF1218 for two-wheel C-series and P/N 12555891 (FRAM PH3980) for four-wheel drive K-series). If the oil filter does not cure the condition, install the appropriate calibration from the table (calibrations are available for some 1993 and 1994 L05 applications). All calibrations are for light duty vehicles equipped with 4L60-E (M30) transmissions (no heavy duty emission/4L80-E calibrations are available). If a calibration is not offered or does not cure the short duration cold knock condition, install the appropriate main bearings as determined by the procedure. 1990-94 L19 VIN N Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oil Filter: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1347 Install a check valve oil filter; no other recommended actions at this time. Important: The previous actions are only applicable to short duration cold knock. These actions will not eliminate a knock occurring under load or a knock lasting for more than 10 seconds. Two main bearing procedures are recommended: 1. For main bearing replacement with the engine IN the vehicle: C, G, P, M and L vehicles 2. For main bearing replacement with the engine OUT OF the vehicle: K, S and T THE FOLLOWING PROCEDURE IS TO BE USED FOR VEHICLES REQUIRING MAIN BEARING REPLACEMENT WITH THE ENGINE IN THE VEHICLE Recommended for C, G, P, M and L vehicles. Important: A OEM training video has been produced for in-vehicle main bearing replacement procedure. One copy of the video will be sent to each dealer. If the video has not been received, contact XPRESS 1 Distribution Center at 1-800-783-3034. Main Bearing Clearance Determination and Installation Procedure 1. REMOVE THE SERPENTINE BELT, dipstick, dipstick tube and disconnect the negative battery cable. 2. Raise the vehicle and remove (or set aside) any parts restricting access to the oil pan bolts (i.e., starter motor, oil cooler lines, oil filter adapter, flywheel inspection cover). 3. Remove the oil pan, oil pump, and shield. 4. Remove # 5 (flange) bearing cap. Wipe the oil from the crankshaft journal and the lower main bearing insert. 5. Place a screw jack under an accessible part of the crankshaft, carefully apply pressure to the crankshaft to force it solidly against the top bearing insert. The reason for this is to remove any clearance between the top bearing insert and the crankshaft. If this step is not performed, a smaller than actual clearance will be measured. Important: This should be done as close as possible to the bearing being measured. This step is only required for on-vehicle service where the engine cannot be turned upside down as on an engine stand. 6. Place a piece of plastigage across the width of the lower bearing insert (parallel to the centerline of the crankshaft). 7. Reinstall # 5 main bearing cap. Torque to 110 N.m (80 lb ft). Do not allow crankshaft to turn. 8. Carefully remove the # 5 main bearing cap and bearing insert. The flattened plastigage will adhere to either the bearing insert or the crank journal. Do not remove the plastigage from the insert or journal. 9. On the edge of the plastigage envelope, there is a graduated scale. Without removing the flattened plastigage, measure its width at the widest point using the graduated scale on the plastigage envelope. 10. The desired main bearing clearance is 0.0008" - 0.0028". If the clearance measured with the plastigage is greater than 0.0028", write down the clearance. Next, read the back of the bearing insert to determine what size bearing was originally installed (usual STD, 0.0006", 0.0010" or 0.0012"). The size stamped on the bearing is the effective undersize when both inserts are installed. For example, a 0.0006" undersize bearing set consists of two (2) 0.0003" thicker bearing inserts, both stamped 0.0006". 11. Remove the top bearing insert using tool J 8080 and read the back to determine what size upper bearing insert was originally installed. The top insert may be different size than the bottom. 12. Calculate the original bearing undersize by dividing the size on each insert by 2, then add the values together. EXAMPLE 1: The lower insert is stamped 0.0006" and the upper is stamped 0.0010". Divide 0.0006" by two to get 0.0003". Divide 0.0010" by 2 to get 0.0005". Add 0.0003" and 0.0005" together to calculate the bearing undersize, which is 0.0008" in this case. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oil Filter: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1348 EXAMPLE 2: The lower insert is stamped STD (standard) and the upper is stamped 0.0010". The undersize for a STD bearing is 0. Divide 0 by 2 to get 0. Divide 0.0010" by 2 to get 0.0005". Add 0 and 0.0005" together to calculate the bearing undersize, which is 0.0005" in this case. 13. Add the original bearing undersize calculated in step 12 to the clearance measured and written down in step 9. For example, if a clearance of 0.0030" was measured with plastigage in step 9 and the calculated bearing undersize from step 12 was 0.0005", the bearing clearance for that particular main journal is equal to 0.0030" plus 0.0005". The bearing clearance would be 0.0035" in this case. 14. Determine which of the combinations of two sizes of replacement bearings will produce the desired clearance. The two sizes available are 0.001" and 0.002". One insert of each size may be combined to produce an intermediate undersize of 0.0015". Subtract the replacement bearing size from the actual clearance to determine which bearing should be used. The bearing that should be used is the one which gives a clearance closer to 0.0008" than to 0.0028". The clearance must not be less than 0.0008". Using the example from step 11, the actual clearance is 0.0035". Subtracting 0.001" from 0.0035" will give a clearance of 0.0025", just barely within the required range. Subtracting 0.002" from 0.0035" will give a clearance of 0.0015". The 0.002" undersize bearing set would be the one to use in this case since it gives a clearance closer to 0.0008", but not less. 15. Install the replacement upper main bearing insert using tool J 8080. 16. Install the replacement lower main bearing insert in the main bearing cap. Lay a piece of plastigage across the width of the lower main bearing insert (same as step 5). 17. Repeat steps 7, 8 and 9. 18. Measuring the plastigage with the scale on the envelope, verify the clearance of the replacement bearings is within the range of 0.001" to 0.003". 19. Repeat steps 4 through 16 for each main bearing. 20. Thrust the crankshaft forward and backward several times to seat the thrust bearing. 21. Reinstall oil pump; torque to 88 N.m (65 lb ft). 22. Reinstall the oil pan and other hardware. 23. Before starting the engine, remove the fuel pump fuse and crank the engine until oil pressure registers on the gauge. Stop cranking, let the starter cool down, then crank for another 15 seconds. 24. Install fuel pump fuse, start engine, check for leaks or unusual noises. 25. Road test vehicle, check for leaks or unusual noises. THE FOLLOWING PROCEDURE IS TO BE USED FOR VEHICLES REQUIRING MAIN BEARING REPLACEMENT WITH THE ENGINE OUT OF THE VEHICLE Recommended for K, S and T vehicles. 1. Remove the engine from the vehicle using the appropriate service manual procedure. 2. Mount the engine on an engine stand, flip the engine so the oil pan is facing up. 3. Remove the oil pan. 4. Remove the oil pump and shield. 5. Remove the dipstick tube. 6. Remove one (1) main bearing cap (must do one at a time). 7. Plasti-gage bearing. 8. If the bearing clearance is out of specification (clearance greater than 0.003 inches), remove upper main bearing from the block. 9. Check the size of the original bearing. 10. Determine what combination of new bearings are required to get the clearance in the acceptable range of 0.0008 inches to 0.0028 inches. See steps Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oil Filter: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1349 12 through 14 in the "in-vehicle" service outlined above. 11. Reinstall the upper main bearing. 12. Reinstall the main cap and lower bearing; torque to 110 N.m (80 lb ft). 13. Repeat for each main bearing. 14. Reinstall oil pump and shield; torque to 88 N.m (65 lb ft). 15. Reinstall dipstick tube. 16. Reinstall oil pan. 17. Reinstall engine in vehicle. 18. Before starting the engine, remove the fuel pump fuse and crank the engine until oil pressure registers on the gauge. Stop cranking, let the starter cool down, then crank for another 15 seconds. 19. Install fuel pump fuse, start engine, check for leaks or unusual noises. 20. Road test vehicle, check for leaks or unusual noises. Correction Category B: Valve Train Clatter, Tick or Click For 1992-94 vehicles equipped with a 4.3L V6 (LB4 VIN Z or L35 VIN W) engine see Corporate Bulletin 376006 for information on converting from net lash to adjustable lash and/or re-lashing the valves on an adjustable lash system. Investigation of "cold knock" is continuing. Updates will continue to be provided when available. Parts Information Check-Valve Filters Description Part Number V6, V8 (Four-Wheel Drive) FRAM PH3980 12555891 V8 (Two-Wheel Drive), Mark V8 PF1218 25160561 The FRAM PH3980 is to be used in place of the PF52. The PH3980 provides superior anti-drainback performance, a key factor in reducing cold knock. FRAM filters are to be procured locally until 08-15-95. After this date the filters may be ordered from GMSPO using the supplied part number. Orders placed to GMSPO prior to this date will not be placed on backorder. Bearings Description Part Number 0.001" Main Bearing Kit, Positions 1-4 on V8, 1-3 on V6 10120992 0.001" Main Bearing Kit, Flange # 5 on V8, # 4 on V6 10120994 0.002" Main Bearing Kit, Positions 1-4 on V8, 1-3 on V6 12329758 0.002" Main Bearing Kit, Flange # 5 on V8, # 4 on V6 12329792 Main bearing kits are currently available from GMSPO. All calibrations are currently available from GMSPO. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oil Filter: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 1350 Warranty Information Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oil Filter: > 476118 > Jun > 94 > Oil Filters - Enhanced Anti-Drainback Valves Oil Filter: All Technical Service Bulletins Oil Filters - Enhanced Anti-Drainback Valves GROUP REF.: 6 - Engine BULLETIN NO.: 476118 DATE: June, 1994 SUBJECT: ENHANCED PF52 AND PF1218 OIL FILTERS MODELS: 1986-94 CHEVROLET AND GMC C/K, S/T, M/L, R/V, AND G MODELS 1991-94 OLDSMOBILE BRAVADA THIS BULLETIN CANCELS AND SUPERSEDES BULLETIN 476502 TO CORRECT THE CATEGORY IDENTIFIER/GROUP REFERENCE. PLEASE DISCARD BULLETIN 476502 (GROUP REFERENCE 6E- ENGINE FUEL & EMISSION). AC Rochester will be supplying a limited number of new oil filters with enhanced anti-drainback valves to GMSPO. Oil filters with effective anti-drainback valves may reduce or eliminate short duration cold knock. Due to limited production capacity, the new filters are only to be used on the following special cases. 1. Trucks or vans with short duration cold knock. 2. Routine maintenance of 1994 trucks or vans. Use the existing PF52 (P/N 25012760) and PF1218 (P/N 25013977) oil filters for applications other than the special cases listed above. PART INFORMATION: For "cold knock" vehicles or 1994 vehicle maintenance: DESCRIPTION PART NUMBER REPLACES PF52 25160560 PF51 PF1218 25160561 PF35 Parts are currently available from GMSPO. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oil Filter: > 420502 > May > 94 > Parts - OE and Aftermarket Oil Filters Revised Oil Filter: All Technical Service Bulletins Parts - OE and Aftermarket Oil Filters Revised Group Ref.: Warranty Administration Bulletin No.: 420502 Date: May, 1994 WARRANTY ADMINISTRATION SUBJECT: AC ROCHESTER ENGINE OIL FILTER IDENTIFICATION MODELS: 1994 PASSENGER CARS AND TRUCKS ATTENTION: DEALER SERVICE MANAGER/WARRANTY ADMINISTRATOR The purpose of this bulletin is to notify retail/wholesale service personnel of a running change to the AC Rochester Original Equipment engine oil filters. Due to an agreement to decrease the number of GMSPO part numbers, AC Rochester will phase in a decision to make all Original Equipment engine oil filters blue; same color used on AC aftermarket engine oil filters. This means that eventually the use of black Original Equipment engine oil filters will be discontinued. For the purpose of Warranty/Policy administration, the following will assist retail/wholesale service personnel in identifying the difference between blue Original Equipment and aftermarket engine oil filters: ^ AFTERMARKET FILTER: will continue to use "AC DURAGUARD OIL FILTER" label. ^ OE FILTER: will have a black bar code, Julian date code and the letters "OE" printed on the dome of the filter. At this time, it is anticipated that all OE engine oil filters will be changed by May 1994. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Other Service Bulletins for Oil Filter: > 07-06-01-016B > Jul > 09 > Engine - Noise/Damage Oil Filter Application Importance Oil Filter: All Technical Service Bulletins Engine - Noise/Damage Oil Filter Application Importance INFORMATION Bulletin No.: 07-06-01-016B Date: July 27, 2009 Subject: Information on Internal Engine Noise or Damage After Oil Filter Replacement Models: 2010 and Prior Passenger Cars and Trucks (Including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X Supercede: This bulletin is being updated to add model years. Please discard Corporate Bulletin Number 07-06-01-016A (Section 06 - Engine/Propulsion System). Important Engine damage that is the result of an incorrect or improperly installed engine oil filter is not a warrantable claim. The best way to avoid oil filter quality concerns is to purchase ACDelco(R) oil filters directly from GMSPO. Oil filter misapplication may cause abnormal engine noise or internal damage. Always utilize the most recent parts information to ensure the correct part number filter is installed when replacing oil filters. Do not rely on physical dimensions alone. Counterfeit copies of name brand parts have been discovered in some aftermarket parts systems. Always ensure the parts you install are from a trusted source. Improper oil filter installation may result in catastrophic engine damage. Refer to the appropriate Service Information (SI) installation instructions when replacing any oil filter and pay particular attention to procedures for proper cartridge filter element alignment. If the diagnostics in SI (Engine Mechanical) lead to the oil filter as the cause of the internal engine noise or damage, dealers should submit a field product report. Refer to Corporate Bulletin Number 02-00-89-002I (Information for Dealers on How to Submit a Field Product Report). Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Other Service Bulletins for Oil Filter: > 476118 > Jun > 94 > Oil Filters - Enhanced Anti-Drainback Valves Oil Filter: All Technical Service Bulletins Oil Filters - Enhanced Anti-Drainback Valves GROUP REF.: 6 - Engine BULLETIN NO.: 476118 DATE: June, 1994 SUBJECT: ENHANCED PF52 AND PF1218 OIL FILTERS MODELS: 1986-94 CHEVROLET AND GMC C/K, S/T, M/L, R/V, AND G MODELS 1991-94 OLDSMOBILE BRAVADA THIS BULLETIN CANCELS AND SUPERSEDES BULLETIN 476502 TO CORRECT THE CATEGORY IDENTIFIER/GROUP REFERENCE. PLEASE DISCARD BULLETIN 476502 (GROUP REFERENCE 6E- ENGINE FUEL & EMISSION). AC Rochester will be supplying a limited number of new oil filters with enhanced anti-drainback valves to GMSPO. Oil filters with effective anti-drainback valves may reduce or eliminate short duration cold knock. Due to limited production capacity, the new filters are only to be used on the following special cases. 1. Trucks or vans with short duration cold knock. 2. Routine maintenance of 1994 trucks or vans. Use the existing PF52 (P/N 25012760) and PF1218 (P/N 25013977) oil filters for applications other than the special cases listed above. PART INFORMATION: For "cold knock" vehicles or 1994 vehicle maintenance: DESCRIPTION PART NUMBER REPLACES PF52 25160560 PF51 PF1218 25160561 PF35 Parts are currently available from GMSPO. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Filters > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Other Service Bulletins for Oil Filter: > 420502 > May > 94 > Parts - OE and Aftermarket Oil Filters Revised Oil Filter: All Technical Service Bulletins Parts - OE and Aftermarket Oil Filters Revised Group Ref.: Warranty Administration Bulletin No.: 420502 Date: May, 1994 WARRANTY ADMINISTRATION SUBJECT: AC ROCHESTER ENGINE OIL FILTER IDENTIFICATION MODELS: 1994 PASSENGER CARS AND TRUCKS ATTENTION: DEALER SERVICE MANAGER/WARRANTY ADMINISTRATOR The purpose of this bulletin is to notify retail/wholesale service personnel of a running change to the AC Rochester Original Equipment engine oil filters. Due to an agreement to decrease the number of GMSPO part numbers, AC Rochester will phase in a decision to make all Original Equipment engine oil filters blue; same color used on AC aftermarket engine oil filters. This means that eventually the use of black Original Equipment engine oil filters will be discontinued. For the purpose of Warranty/Policy administration, the following will assist retail/wholesale service personnel in identifying the difference between blue Original Equipment and aftermarket engine oil filters: ^ AFTERMARKET FILTER: will continue to use "AC DURAGUARD OIL FILTER" label. ^ OE FILTER: will have a black bar code, Julian date code and the letters "OE" printed on the dome of the filter. At this time, it is anticipated that all OE engine oil filters will be changed by May 1994. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Hoses > Heater Hose > Component Information > Specifications Heater Hose: Specifications Heater Inlet Hose Mounting Screw ....................................................................................................................................................... 1.4 Nm (12 lbs. in.) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Hoses > Heater Hose > Component Information > Service and Repair > Heater Inlet Hose Heater Hose: Service and Repair Heater Inlet Hose With A/C Heater Hose Routing-With A/C REMOVE OR DISCONNECT Tool Required: - J 38723 Heater Line Quick Connect Separator or Equivalent 1. Air cleaner. 2. Engine coolant. 3. Inlet hose mounting screw. 4. Inlet hose clamp at heater core. NOTE: Loosen the clamp enough to slide away from the fitting on the inlet hose (72). 5. Inlet hose (72) from heater core. 6. Push inlet hose (72) into connector and insert J 38723 or equivalent into connector to release locking tabs. 7. Pull retainer and hose (72) from heater inlet connector. Inspect Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Hoses > Heater Hose > Component Information > Service and Repair > Heater Inlet Hose > Page 1378 - O-ring sealing surface on hose/pipe. Adjust - If replacing heater inlet connector remove retainer from hose and discard as new connector is equipped with retainer. - If replacing hose, remove retainer from hose and reinsert in connector. - If reusing hose and connector, retainer can remain in place on hose. INSTALL OR CONNECT 1. Push hose (72) into connector until retainer tabs lock. NOTE: Pull back on hose to check for proper engagement. 2. Inlet hose (72) to heater core. 3. Inlet hose clamp. NOTICE: Refer to "Fasteners" under "Vehicle Damage Warnings." 4. Inlet hose mounting screw. - Tighten screw to 1.4 Nm (12 lbs. in.). 5. Engine coolant. 6. Air cleaner. - Check the system for leaks. Without A/C Heater Hose Routing W/out A/C REMOVE OR DISCONNECT Tool Required: Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Hoses > Heater Hose > Component Information > Service and Repair > Heater Inlet Hose > Page 1379 - J 38723 Heater Line Quick Connect Separator or Equivalent 1. Air cleaner. 2. Engine coolant. 3. Inlet hose mounting screw. 4. Inlet hose clamp at heater core. NOTE: Loosen the clamp enough to slide away from the fitting on the inlet hose (72). 5. Inlet hose (72) from heater core. 6. Push inlet hose (72) into connector and insert J 38723 or equivalent into connector to release locking tabs. 7. Pull retainer and hose (72) from heater inlet connector. Inspect - O-ring sealing surface on hose/pipe. Adjust - If replacing heater inlet connector remove retainer from hose and discard as new connector is equipped with retainer. - If replacing hose, remove retainer from hose and reinsert in connector. - If reusing hose and connector, retainer can remain in place on hose. INSTALL OR CONNECT 1. Push hose (72) into connector until retainer tabs lock. NOTE: Pull back on hose to check for proper engagement. 2. Inlet hose (72) to heater core. 3. Inlet hose clamp. NOTICE: Refer to "Fasteners" under "Vehicle Damage Warnings." 4. Inlet hose mounting screw. - Tighten screw to 1.4 Nm (12 lbs. in.). 5. Engine coolant. 6. Air cleaner. - Check the system for leaks. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Hoses > Heater Hose > Component Information > Service and Repair > Heater Inlet Hose > Page 1380 Heater Hose: Service and Repair Heater Outlet Hose With A/C Heater Hose Routing-With A/C REMOVE OR DISCONNECT 1. Engine coolant. 2. Hose clamps. 3. Outlet hose (70) from heater core. 4. Outlet hose (70) from radiator. INSTALL OR CONNECT 1. Outlet hose (70) to radiator. 2. Outlet hose (70) to heater core. 3. Hose clamps. 4. Engine coolant. - Check the system for leaks. Without A/C Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Hoses > Heater Hose > Component Information > Service and Repair > Heater Inlet Hose > Page 1381 Heater Hose Routing W/out A/C REMOVE OR DISCONNECT 1. Engine coolant. 2. Hose clamps. 3. Outlet hose (70) from heater core. 4. Outlet hose (70) from radiator. INSTALL OR CONNECT 1. Outlet hose (70) to radiator. 2. Outlet hose (70) to heater core. 3. Hose clamps. 4. Engine coolant. - Check the system for leaks. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Hoses > Heater Hose > Component Information > Service and Repair > Page 1382 Special Tool Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Hoses > Hose/Line HVAC > Component Information > Service Precautions Hose/Line HVAC: Service Precautions The life and efficient operation of the air conditioning system depends upon the chemical stability of the refrigerant system. When foreign materials, such as dirt, air, or moisture, contaminate the refrigeration system, they change the stability of the Refrigerant-12 or Refrigerant-134a and 525 viscosity or polyalkaline glycol (PAG) refrigerant oil. They will also affect the pressure-temperature relationship, reduce efficiency, and could cause internal corrosion and abnormal wear of moving parts. The following general practices should be followed to ensure chemical stability in the system: 1. Whenever it becomes necessary to disconnect a hose connection, wipe away any dirt or oil at or near the connection to eliminate the possibility of dirt entering the system. Both sides of the connection should be capped, plugged, or taped as soon as possible to prevent the entrance of dirt and moisture. (Remember that all air contains moisture. Air that enters any part of the refrigeration system will carry moisture with it, and the exposed surfaces will collect the moisture quickly.) 2. Keep tools clean and dry. This includes the Manifold Gage Set and all replacement parts. 3. When adding 525 viscosity or polyalkaline glycol (PAG) refrigerant oil, the container/transfer tube through which the oil will flow should be exceptionally clean and dry. Refrigerant oil must be as moisture-free as possible. 4. When it is necessary to "open" an air conditioning system, have everything needed ready so that as little time as possible will be required to perform the operation. Do not leave the air conditioning system open any longer than necessary. 5. Anytime the air conditioning system has been "opened," it should be properly evacuated before recharging. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Hoses > Hose/Line HVAC > Component Information > Service Precautions > Page 1386 Hose/Line HVAC: Service and Repair Compressor And Condenser Hose Routing-Utility REMOVE OR DISCONNECT 1. Negative battery cable. 2. Discharge and recover refrigerant from the system. 3. Bolt (7) and washer (8). 4. Hose assembly (3) from compressor (1). 5. Sealing washers. Refer to "Compressor Sealing Washers." 6. Hose assembly (3) from accumulator (6). 7. O-ring seal. 8. Hose assembly (3) from condenser (4). 9. O-ring seal. - Cap or plug all open connections. INSTALL OR CONNECT NOTICE: For steps 2, 4, and 7, refer to "Fasteners" under "Vehicle Damage Warnings." 1. New O-ring seal. - Coat O-ring seal with 525 viscosity refrigerant oil. 2. Hose assembly (3) to condenser (4). - Tighten hose assembly (3) to 24 Nm (18 lbs. ft.). 3. New O-ring seal. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Hoses > Hose/Line HVAC > Component Information > Service Precautions > Page 1387 - Coat O-ring seal with 525 viscosity refrigerant oil. 4. Hose assembly (3) to accumulator (6). - Tighten hose assembly (3) to 41 Nm (30 lbs. ft.). 5. Sealing washers. 6. Hose assembly (3) to compressor (1). 7. Washer (8) and bolt (7). - Tighten bolt (7) to 34 Nm (25 lbs. ft.). 8. Negative battery cable. 9. Refrigerant to the system. - Check the system for leaks. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Hoses > Power Steering Line/Hose > Component Information > Service and Repair Power Steering Line/Hose: Service and Repair Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Hoses > Power Steering Line/Hose > Component Information > Service and Repair > Page 1391 When either a hose is reinstalled or replaced, the following points are essential: - Route return and feed hoses in the same position they were in before removal. - Route return and feed hoses smoothly, avoid sharp bends and chinking. - After return and feed hoses are installed, check for leaks while the system is being bled. Refer to "Bleeding The Power Steering System." NOTICE: Do not start the engine with any power steering hose disconnected, or damage to the components could occur. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Brake Fluid > Component Information > Technical Service Bulletins > Brake Fluid - Level & Filling Recommendations Brake Fluid: Technical Service Bulletins Brake Fluid - Level & Filling Recommendations File In Section: 05 - Brakes Bulletin No.: 00-05-22-004 Date: May, 2000 INFORMATION Subject: Brake Fluid Level and Filling Recommendations Models: 2001 and Prior Passenger Cars and Trucks Many dealers and after-market repair shops advertise multi-point fluid "top-ups" in conjunction with oil changes or regular maintenance packages. These offers often include adding brake fluid to the master cylinder reservoir. There are only two reasons why the brake fluid level in the brake reservoir might go down. The first is that the brake fluid level goes down an acceptable level during normal brake lining wear. When the linings are replaced, the fluid will return to it's original level. The second possible reason for a low fluid level is that fluid is leaking out of the brake system. If fluid is leaking, the brake system requires repair and adding additional fluid will not correct the leak. If the system was properly filled during delivery of the vehicle, no additional fluid should be required under most circumstances between brake pad and/or shoe replacements. This information can be reinforced with the customer by referring them to the Brake Fluid section of their vehicle's Owner's Manual. Guidelines GM vehicles have incorporated a variety of brake fluid reservoir styles. The following guidelines are restricted to the plastic bodied fluid reservoirs and do not affect the original service recommendations for the older style metal bodied units. You may encounter both black plastic and translucent style reservoirs. You may have reservoirs with: ^ A MAX fill mark only ^ A MIN fill mark only ^ Both MAX and MIN marks The translucent style reservoirs do not have to have the covers removed in order to view the fluid level. It is a good practice not to remove the reservoir cover unless necessary to reduce the possibility of contaminating the system. Use the following guidelines to assist in determining the proper fluid level. Important: When adding brake fluid, use Delco Supreme II(R) Brake Fluid, GM P/N 12377967 or equivalent brand bearing the DOT-3 rating only. Important: At no time should the fluid level be allowed to remain in an overfilled condition. Overfilling the brake reservoir may put unnecessary stress on the seals and cover of the reservoir. Use the following guidelines to properly maintain the fluid level. If the reservoir is overfilled, siphon out the additional fluid to comply with the guidelines below. Important: If under any circumstance the brake fluid level is extremely low in the reservoir or the BRAKE warning indicator is illuminated, the brake system should be checked for leaks and the system repaired in addition to bringing the fluid level up to the recommended guidelines outlined below. A leaking brake system will have reduced braking performance and will eventually not work at all. Important: Some vehicles have reservoirs that are very sensitive to brake fluid levels and may cause the BRAKE indicator to flicker on turns as the fluid approaches the minimum required level. If you encounter a vehicle with this concern, increase the fluid level staying within the guidelines outlined below. ^ If the reservoir has a MAX level indicator, the reservoir should be returned to the MAX marking only at the time new brake pads and/or shoes are installed. If the reservoir fluid level is at the half-way point or above do not attempt to add additional brake fluid during routine fluid checks. ^ If the reservoir has both MAX and MIN indicators, the fluid level should be maintained above the MIN indicator during routine fluid checks and returned to the MAX indication only after new brake pads and/or shoes are installed. ^ For reservoirs with only a MIN indication, the fluid level should be maintained above the MIN indicator during routine fluid checks. Return the Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Brake Fluid > Component Information > Technical Service Bulletins > Brake Fluid - Level & Filling Recommendations > Page 1397 reservoir fluid level to full only after installing new brake pads and/or shoes. A full reservoir is indicated on translucent, snap cover reservoirs by a fluid level even with the top level of the view window imprinted into the side of the reservoir. On screw top models in black or translucent plastic, the full level is just below the bottom of the filler neck. Parts Information Part Number Description 12377967 Brake Fluid Parts are currently available from GMSPO. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Brake Fluid > Component Information > Technical Service Bulletins > Page 1398 Brake Fluid: Specifications Brake System DOT 3 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Clutch Fluid > Component Information > Specifications > Capacity Specifications Clutch Fluid: Capacity Specifications Fill the clutch master cylinder to the "Full" or "MAX" mark on the reservoir. Do not overfill. Caution: Should accidental spillage occur, rinse the area thoroughly with water. Pay special attention to any electrical wires, parts, harnesses, rubber or painted surfaces. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Clutch Fluid > Component Information > Specifications > Capacity Specifications > Page 1403 Clutch Fluid: Fluid Type Specifications Hydraulic Clutch Fluid ........................................................................................................................................................... DOT 3 or DOT 4 Brake Fluid Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Coolant > Component Information > Technical Service Bulletins > Cooling System - Coolant Recycling Information Coolant: Technical Service Bulletins Cooling System - Coolant Recycling Information Bulletin No.: 00-06-02-006D Date: August 15, 2006 INFORMATION Subject: Engine Coolant Recycling and Warranty Information Models: 2007 and Prior GM Passenger Cars and Trucks (Including Saturn) 2007 and Prior HUMMER Vehicles 2005-2007 Saab 9-7X Attention: Please address this bulletin to the Warranty Claims Administrator and the Service Manager. Supercede: This bulletin is being revised to adjust the title and Include Warranty Information. Please discard Corporate Bulletin Number 00-06-02-006C (Section 06 - Engine/Propulsion System). Coolant Reimbursement Policy General Motors supports the use of recycled engine coolant for warranty repairs/service, providing a GM approved engine coolant recycling system is used. Recycled coolant will be reimbursed at the GMSPO dealer price for new coolant plus the appropriate mark-up. When coolant replacement is required during a warranty repair, it is crucial that only the relative amount of engine coolant concentrate be charged, not the total diluted volume. In other words: if you are using two gallons of pre-diluted (50:50) recycled engine coolant to service a vehicle, you may request reimbursement for one gallon of GM Goodwrench engine coolant concentrate at the dealer price plus the appropriate warranty parts handling allowance. Licensed Approved DEX-COOL(R) Providers Important: USE OF NON-APPROVED VIRGIN OR RECYCLED DEX-COOL(R) OR DEVIATIONS IN THE FORM OF ALTERNATE CHEMICALS OR ALTERATION OF EQUIPMENT, WILL VOID THE GM ENDORSEMENT, MAY DEGRADE COOLANT SYSTEM INTEGRITY AND PLACE THE COOLING SYSTEM WARRANTY UNDER JEOPARDY. Shown in Table 1 are the only current licensed and approved providers of DEX-COOL(R). Products that are advertised as "COMPATIBLE" or "RECOMMENDED" for use with DEX-COOL(R) have not been tested or approved by General Motors. Non-approved coolants may degrade the Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Coolant > Component Information > Technical Service Bulletins > Cooling System - Coolant Recycling Information > Page 1408 coolant system integrity and will no longer be considered a 5 yr/150,000 mile (240,000 km) coolant. Coolant Removal Services/Recycling The tables include all coolant recycling processes currently approved by GM. Also included is a primary phone number and demographic information. Used DEX-COOL(R) can be combined with used conventional coolant (green) for recycling. Depending on the recycling service and/or equipment, it is then designated as a conventional 2 yr/30,000 mile (50,000 km) coolant or DEX-COOL(R) 5 yr/150,000 mile (240,000 km) coolant. Recycled coolants as designated in this bulletin may be used during the vehicle(s) warranty period. DEX-COOL(R) Recycling The DEX-COOL(R) recycling service listed in Table 2 has been approved for recycling waste engine coolants (DEX-COOL) or conventional) to DEX-COOL(R) with 5 yr/150,000 mile (240,000 km) usability. Recycling Fluid Technologies is the only licensed provider of Recycled DEX-COOL(R) meeting GM6277M specifications and utilizes GM approved inhibitor packages. This is currently a limited program being monitored by GM Service Operations which will be expanded as demand increases. Conventional (Green) Recycling Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Coolant > Component Information > Technical Service Bulletins > Cooling System - Coolant Recycling Information > Page 1409 Processes shown in the Table 3 are capable of recycling waste engine coolants (DEX-COOL(R) or conventional) to a conventional (green) coolant. Recycling conventional coolant can be accomplished at your facility by a technician using approved EQUIPMENT (listed by model number in Table 3), or by an approved coolant recycling SERVICE which may recycle the coolant at your facility or at an offsite operation. Refer to the table for GM approved coolant recyclers in either of these two categories. Should you decide to recycle the coolant yourself, strict adherence to the operating procedures is imperative. Use ONLY the inhibitor chemicals supplied by the respective (GM approved) recycling equipment manufacturer. Sealing Tablets Cooling System Sealing Tablets (Seal Tabs) should not be used as a regular maintenance item after servicing an engine cooling system. Discoloration of coolant can occur if too many seal tabs have been inserted into the cooling system. This can occur if seal tabs are repeatedly used over the service life of a vehicle. Where appropriate, seal tabs may be used if diagnostics fail to repair a small leak in the cooling system. When a condition appears in which seal tabs may be recommended, a specific bulletin will be released describing their proper usage. Water Quality The integrity of the coolant is dependent upon the quality of DEX-COOL(R) and water. DEX-COOL(R) is a product that has enhanced protection capability as well as an extended service interval. These enhanced properties may be jeopardized by combining DEX-COOL(R) with poor quality water. If you suspect the water in your area of being poor quality, it is recommended you use distilled or de-ionized water with DEX-COOL(R). "Pink" DEX-COOL(R) DEX-COOL(R) is orange in color to distinguish it from other coolants. Due to inconsistencies in the mixing of the dyes used with DEX-COOL(R), some batches may appear pink after time. The color shift from orange to pink does not affect the integrity of the coolant, and still maintains the 5 yr/150,000 mile (240,000 km) service interval. Back Service Only use DEX-COOL(R) if the vehicle was originally equipped with DEX-COOL(R). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Coolant > Component Information > Technical Service Bulletins > Cooling System - Coolant Recycling Information > Page 1410 Contamination Mixing conventional green coolant with DEX-COOL(R) will degrade the service interval from 5 yrs./150,000 miles (240,000 km) to 2 yrs./30,000 miles (50,000 km) if left in the contaminated condition. If contamination occurs, the cooling system must be flushed twice immediately and re-filled with a 50/50 mixture of DEX-COOL(R) and clean water in order to preserve the enhanced properties and extended service interval of DEX-COOL(R). After 5 years/150,000 miles (240,000 km) After 5 yrs/150,000 miles (240,000 km), the coolant should be changed, preferably using a coolant exchanger. If the vehicle was originally equipped with DEX-COOL(R) and has not had problems with contamination from non-DEX-COOL(R) coolants, then the service interval remains the same, and the coolant does not need to be changed for another 5 yrs/150,000 miles (240,000 km) Equipment (Coolant Exchangers) The preferred method of performing coolant replacement is to use a coolant exchanger. A coolant exchanger can replace virtually all of the old coolant with new coolant. Coolant exchangers can be used to perform coolant replacement without spillage, and facilitate easy waste collection. They can also be used to lower the coolant level in a vehicle to allow for less messy servicing of cooling system components. It is recommended that you use a coolant exchanger with a vacuum feature facilitates removing trapped air from the cooling system. This is a substantial time savings over repeatedly thermo cycling the vehicle and topping-off the radiator. The vacuum feature also allows venting of a hot system to relieve system pressure. Approved coolant exchangers are available through the GMDE (General Motors Dealer Equipment) program. For refilling a cooling system that has been partially or fully drained for repairs other than coolant replacement, the Vac-N-Fill Coolant Refill Tool (GE-47716) is recommended to facilitate removal of trapped air from the cooling system during refill. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Coolant > Component Information > Technical Service Bulletins > Cooling System - Coolant Recycling Information > Page 1411 Coolant: Technical Service Bulletins Engine Coolant - Information on Back Service File In Section: 6 - Engine Bulletin No: 53-62-02 Date: November, 1995 Subject: DEX-COOL(TM) Engine Coolant - Information on Back service Models: 1994-95 Passenger Cars and Trucks A new extended-life engine coolant called DEX-COOL(TM) is currently being used in all General Motors' vehicles (excluding Chevrolet Geo and Saturn). Refer to bulletin 53-62-01 for general service information. Backservice DEX-COOL(TM) may be used in General Motors vehicles originally built with conventional (green) coolant with the following considerations: ^ Vehicles eligible for back service are 1994 and 1995 models (excluding 1994 J Body with 4 cylinder engines). ^ The service interval for DEX-COOL(TM) introduced into an older model vehicle originally built with "green" coolant will be 2 years/30,000 miles (50,000 Km) (not 5 years/100,000 miles (160,000 Km)). ^ All the "green" coolant must be removed from the cooling system by means of a system flush. This may be accomplished with a water flushing device or a GMDE waterless coolant changer (use a unit dedicated to "green" coolant, not DEX-COOL TM). Important: When using a GMDE waterless coolant changer, conduct the procedure twice, once with water, and once with DEX-COOL(TM) Backservice with DEX-COOL(TM) is advocated because of enhanced water pump seal durability experienced with this coolant. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Coolant > Component Information > Technical Service Bulletins > Cooling System - Coolant Recycling Information > Page 1412 Coolant: Technical Service Bulletins Warranty - Recycled Engine Coolant Policy Group Ref.: Warranty Administration Bulletin No.: 310504 Date: February, 1994 WARRANTY ADMINISTRATION SUBJECT: RECYCLED ENGINE COOLANT POLICY MODELS: 1994 AND PRIOR PASSENGER CARS AND TRUCKS ATTENTION: WARRANTY CLAIMS ADMINISTRATOR AND SERVICE MANAGER General Motors supports the use of recycled engine coolant for warranty repairs/service, providing a GM approved engine coolant recycling system is used. For detailed information on GM approved engine coolant recycling equipment guidelines refer to the following bulletins: Cadillac 93-1-18, GMC Truck 93-6B-34, Chevrolet 93-73-6B, Pontiac 93-6-18, Oldsmobile 1-93-43, Buick 93-6B-1 (Corporate Number 236203). Recycled coolant will be reimbursed at the GMSPO dealer price for new coolant plus the appropriate mark-up. When coolant replacement is required during a warranty repair, it is crucial to assure that only the relative amount of engine coolant concentrate be charged, not the total diluted volume. In other words, if you are using two gallons of pre-diluted (50:50) recycled engine coolant to service a vehicle, you may request reimbursement for one gallon of Goodwrench engine coolant concentrate at the dealer price plus the appropriate warranty parts handling allowance. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Coolant > Component Information > Technical Service Bulletins > Cooling System - Coolant Recycling Information > Page 1413 Coolant: Technical Service Bulletins Coolant - Information on Propylene Glycol Usage File In Section: 6 - Engine Bulletin No.: 43-62-01B Date: April, 1995 Subject: Propylene Glycol Engine Coolant Models: 1994 and Prior Passenger Cars and Trucks This bulletin is being revised to reflect most current information on propylene glycol engine coolant. Please discard Corporate Bulletin Number 4362O1A (Group Reference 6 - Engine). General Motors has been reviewing data supplied on the performance of propylene glycol engine coolant in GM vehicles. It is our conclusion that propylene glycol engine coolant will perform adequately under most vehicle operating conditions. As a result, propylene glycol engine coolant (meeting performance specification GM 1825M) may be used in GM vehicles and will not affect the warranty coverage. Prior to adding propylene glycol engine coolant to the cooling system, all the existing (ethylene glycol) coolant must be removed. This can be accomplished either by utilizing water-based coolant flushing equipment or "waterless quick change" equipment available in the GMDE program. As with any coolant change procedure, be sure to thoroughly purge the heater core and block as well as the radiator before attempting to convert the system to propylene glycol coolant. Freeze/Boil point levels are different for propylene glycol than for ethylene glycol engine coolant. To accurately determine freeze/boil protection level, it is imperative that coolants not be mixed. Removing all the used coolant as previously discussed resolves this concern. Freeze protection of propylene glycol cannot be determined using a standard hydrometer. Rather, a refractometer or test strip must be used. Propylene glycol engine coolants may be recycled in the same manner as conventional ethylene glycol coolant. No adverse effects will be encountered if these coolants are mixed prior to recycling, however, the ratio of propylene glycol coolant to ethylene glycol coolant should be kept low to minimize the effects on freeze point measurements. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Coolant > Component Information > Technical Service Bulletins > Page 1414 Coolant: Specifications Coolant Capacity, Qts. Less A/C .............................................................................................................................................. ........................................................................ 12.1 With A/C ............................................................. ........................................................................................................................................................ 12.1 Radiator Cap Relief Pressure, Lbs. ..................................................................................................... ............................................................................... 15 Thermo. Opening Temp., deg.F ..................... .............................................................................................................................................................. .... 195 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Fluid - A/T > Component Information > Technical Service Bulletins > A/T - DEXRON(R)-VI Fluid Information Fluid - A/T: Technical Service Bulletins A/T - DEXRON(R)-VI Fluid Information INFORMATION Bulletin No.: 04-07-30-037E Date: April 07, 2011 Subject: Release of DEXRON(R)-VI Automatic Transmission Fluid (ATF) Models: 2008 and Prior GM Passenger Cars and Light Duty Trucks 2003-2008 HUMMER H2 2006-2008 HUMMER H3 2005-2007 Saturn Relay 2005 and Prior Saturn L-Series 2005-2007 Saturn ION 2005-2008 Saturn VUE with 4T45-E 2005-2008 Saab 9-7X Except 2008 and Prior Chevrolet Aveo, Equinox Except 2006 and Prior Chevrolet Epica Except 2007 and Prior Chevrolet Optra Except 2008 and Prior Pontiac Torrent, Vibe, Wave Except 2003-2005 Saturn ION with CVT or AF23 Only Except 1991-2002 Saturn S-Series Except 2008 and Prior Saturn VUE with CVT, AF33 or 5AT (MJ7/MJ8) Transmission Only Except 2008 Saturn Astra Attention: DEXRON(R)-VI Automatic Transmission Fluid (ATF) is the only approved fluid for warranty repairs for General Motors transmissions/transaxles requiring DEXRON(R)-III and/or prior DEXRON(R) transmission fluids. Supercede: This bulletin is being revised to update information. Please discard Corporate Bulletin Number 04-07-30-037D (Section 07 - Transmission/Transaxle). MANUAL TRANSMISSIONS / TRANSFER CASES and POWER STEERING The content of this bulletin does not apply to manual transmissions or transfer cases. Any vehicle that previously required DEXRON(R)-III for a manual transmission or transfer case should now use P/N 88861800. This fluid is labeled Manual Transmission and Transfer Case Fluid. Some manual transmissions and transfer cases require a different fluid. Appropriate references should be checked when servicing any of these components. Power Steering Systems should now use P/N 9985010 labeled Power Steering Fluid. Consult the Parts Catalog, Owner's Manual, or Service Information (SI) for fluid recommendations. Some of our customers and/or General Motors dealerships/Saturn Retailers may have some concerns with DEXRON(R)-VI and DEXRON(R)-III Automatic Transmission Fluid (ATF) and transmission warranty claims. DEXRON(R)-VI is the only approved fluid for warranty repairs for General Motors transmissions/transaxles requiring DEXRON(R)-III and/or prior DEXRON(R) transmission fluids (except as noted above). Please remember that the clean oil reservoirs of the J-45096 - Flushing and Flow Tester machine should be purged of DEXRON(R)-III and filled with DEXRON(R)-VI for testing, flushing or filling General Motors transmissions/transaxles (except as noted above). DEXRON(R)-VI can be used in any proportion in past model vehicles equipped with an automatic transmission/transaxle in place of DEXRON(R)-III (i.e. topping off the fluid in the event of a repair or fluid change). DEXRON(R)-VI is also compatible with any former version of DEXRON(R) for use in automatic transmissions/transaxles. DEXRON(R)-VI ATF General Motors Powertrain has upgraded to DEXRON(R)-VI ATF with the start of 2006 vehicle production. Current and prior automatic transmission models that had used DEXRON(R)-III must now only use DEXRON(R)-VI. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Fluid - A/T > Component Information > Technical Service Bulletins > A/T - DEXRON(R)-VI Fluid Information > Page 1419 All 2006 and future model transmissions that use DEXRON(R)-VI are to be serviced ONLY with DEXRON(R)-VI fluid. DEXRON(R)-VI is an improvement over DEXRON(R)-III in the following areas: * These ATF change intervals remain the same as DEXRON(R)-III for the time being. 2006-2008 Transmission Fill and Cooler Flushing Some new applications of the 6L80 six speed transmission will require the use of the J 45096 Flushing and Flow Tester to accomplish transmission fluid fill. The clean oil reservoir of the machine should be purged of DEXRON(R)-III and filled with DEXRON(R)-VI. Parts Information Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Fluid - A/T > Component Information > Technical Service Bulletins > A/T - DEXRON(R)-VI Fluid Information > Page 1420 Fluid - A/T: Technical Service Bulletins A/T - Water Or Coolant Contamination Information INFORMATION Bulletin No.: 08-07-30-035B Date: November 01, 2010 Subject: Information on Water or Ethylene Glycol in Transmission Fluid Models: 2011 and Prior GM Passenger Cars and Light Duty Trucks with Automatic Transmission Supercede: This bulletin is being revised to update model years. Please discard Corporate Bulletin Number 08-07-30-035A (Section 07 - Transmission/Transaxle). Water or ethylene glycol in automatic transmission fluid (ATF) is harmful to internal transmission components and will have a negative effect on reliability and durability of these parts. Water or ethylene glycol in ATF will also change the friction of the clutches, frequently resulting in shudder during engagement or gear changes, especially during torque converter clutch engagement. Indications of water in the ATF may include: - ATF blowing out of the transmission vent tube. - ATF may appear cloudy or, in cases of extreme contamination, have the appearance of a strawberry milkshake. - Visible water in the oil pan. - A milky white substance inside the pan area. - Spacer plate gaskets that appear to be glued to the valve body face or case. - Spacer plate gaskets that appear to be swollen or wrinkled in areas where they are not compressed. - Rust on internal transmission iron/steel components. If water in the ATF has been found and the source of the water entry has not been identified, or if a leaking in-radiator transmission oil cooler is suspected (with no evidence of cross-contamination in the coolant recovery reservoir), a simple and quick test kit is available that detects the presence of ethylene glycol in ATF. The "Gly-Tek" test kit, available from the Nelco Company, should be obtained and the ATF tested to make an accurate decision on the need for radiator replacement. This can help to prevent customer comebacks if the in-radiator transmission oil cooler is leaking and reduce repair expenses by avoiding radiator replacement if the cooler is not leaking. These test kits can be obtained from: Nelco Company Test kits can be ordered by phone or through the website listed above. Orders are shipped standard delivery time but can be shipped on a next day delivery basis for an extra charge. One test kit will complete 10 individual fluid sample tests. For vehicles repaired under warranty, the cost of the complete test kit plus shipping charges should be divided by 10 and submitted on the warranty claim as a net item. The transmission should be repaired or replaced based on the normal cost comparison procedure. Important If water or coolant is found in the transmission, the following components MUST be replaced. - Replace all of the rubber-type seals. - Replace all of the composition-faced clutch plates and/or bands. - Replace all of the nylon parts. - Replace the torque converter. - Thoroughly clean and rebuild the transmission, using new gaskets and oil filter. Important The following steps must be completed when repairing or replacing. Flush and flow check the transmission oil cooler using J 45096. Refer to Corporate Bulletin Number 02-07-30-052F- Automatic Transmission Oil Cooler Flush and Flow Test Essential Tool J 45096 TransFlow. - Thoroughly inspect the engine cooling system and hoses and clean/repair as necessary. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Fluid - A/T > Component Information > Technical Service Bulletins > A/T - DEXRON(R)-VI Fluid Information > Page 1421 Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Fluid - A/T > Component Information > Technical Service Bulletins > A/T - DEXRON(R)-VI Fluid Information > Page 1422 Fluid - A/T: Technical Service Bulletins A/T - Dexron IIE Preferred Fluid for All Hydra-matic BULLETIN No.: 9274T60-E-02 CORP. REF. NO.: 177125 DATE: October 1991 TRANSMISSION APPLICATIONS: All TRANSMISSION MODELS: All SUBJECT: Dexron(R)-IIE Automatic Transmission/Transaxle Fluid VEHICLE APPLICATIONS: All Hydra-matic Automatic Transmissions/Transaxles BULLETIN COVERS: General Motors has developed a new service fill automatic transmission/transaxle fluid which is designated DEXRON(R)-IIE. This fluid is the preferred fluid for all HYDRA-MATIC automatic transmissions/transaxles and will eventually replace DEXRON(R)-II. DEXRON(R)-IIE is acceptable for use whenever DEXRON(R)-II was previously specified. DEXRON(R)-II is acceptable for use when DEXRON(R)-IIE is not available. DEXRON(R)-II and DEXRON(R)-IIE can be used in both electronically and hydraulically controlled transmissions/ transaxles. DEXRON(R)-IIE Advantages Over DEXRON(R)-II: ^ Has better anti-foaming characteristic. ^ Improved high temperature oxidation stability and improved low temperature flow characteristics (low temperature viscosity). ^ DEXRON(R)-IIE and DEXRON(R)-II can be mixed in any ratio. No draining or flushing of system is required. ^ DEXRON(R)-IIE is back serviceable to 1949 for all General Motors automatic transmissions/transaxles. ^ No change in transmission/transaxle calibration or reduction in transmission/transaxle durability will occur as a result of using DEXRON(R)-IIE. SERVICE PART INFORMATION: PART NUMBER DESCRIPTION 12345881 1 quart container 12345882 1 gallon container 12345883 55 gallon drum Parts are currently available from GMSPO. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Fluid - A/T > Component Information > Technical Service Bulletins > A/T - DEXRON(R)-VI Fluid Information > Page 1423 Fluid - A/T: Technical Service Bulletins A/T - DEXRON III Fluid Introduction File In Section: 0 - General Information Bulletin No.: 57-02-01 Date: March, 1995 SERVICE MANUAL UPDATE Subject: Section 0 - General Information - DEXRON(R)-III Transmission Fluid Introduction Models: 1995 and Prior Passenger Cars and Trucks General Motors has phased in a new automatic transmission fluid, DEXRON(R)-III, that does not need replacing under normal service. DEXRON(R)-III is designed to help the transmission deliver the best possible performance under all conditions. Refer to Figure 1. The improvements in DEXRON(R)-III include better friction stability, more high temperature oxidation stability and better material compatibility. DEXRON(R)-III has the same low temperature fluidity as DEXRON(R)-IIE, for better transmission performance in cold weather. DEXRON(R)-IIE and DEXRON(R)-III are fully compatible. DEXRON(R)-III is fully compatible with any General Motors passenger vehicle or light truck with automatic transmission and built since 1949. Dealers should require their supplier to include the DEXRON(R)-III license number on all automatic transmission fluid invoices. Starting February 1, 1994 DEXRON(R)-III was phased into all North American assembly plants. DEXRON(R)-III fluid is available from GMSPO (see fluid numbers below): U.S. 1 Quart 12346143 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Fluid - A/T > Component Information > Technical Service Bulletins > A/T - DEXRON(R)-VI Fluid Information > Page 1424 1 Gallon 12346144 55 Gallon 12346145 In Canada 1 Liter 10952622 4 Liter 10952623 200 Liter 10952624 The 1995 Automatic Transmission/Transaxle fluid change intervals are the following: (1994 and prior should use the schedules as written in the Owner's Manual.) If the vehicle is mainly driven under one or more of these conditions: In heavy city traffic where the outside temperature regularly reaches 90°F (32°C) or higher. In hilly or mountainous terrain. When doing frequent trailer towing. Uses such as found in taxi, police car or delivery service. Change the fluid and filter every 50,000 miles (63,000 km). If the vehicle is not used mainly under any of these conditions, the fluid and filter do not require periodic changing for vehicles under 8,600 GVWR. Vehicles over 8,600 GVWR change the fluid and filter every 50,000 miles (83,000 km) regardless of driving conditions. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Fluid - A/T > Component Information > Specifications > Capacity Specifications Fluid - A/T: Capacity Specifications CAPACITIES ....................................................................................................................................... ................................................................ QUARTS Pan Capacity ....................................................................................................................................... .............................................................................. 5.0 Total (Overhaul) Capacity ............................... .............................................................................................................................................................. .. 11.2 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Fluid - A/T > Component Information > Specifications > Capacity Specifications > Page 1427 Fluid - A/T: Fluid Type Specifications Fluid Type ............................................................................................................................................ ............................................................... Dexron IIE Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Fluid - A/T > Component Information > Specifications > Page 1428 Fluid - A/T: Testing and Inspection Fluid level should be checked at every engine oil change. Frequency of change for transmission fluid is dependent on the type of driving conditions in which the vehicle is used. If the transmission is subjected to severe service such as: use in heavy city traffic when the outside temperature regularly reaches 90°F, use in very hilly or mountainous areas, commercial use such as taxi or delivery service, the fluid should be changed every 15,000 miles when using Dexron II and 50,000 miles when using Dexron III or equivalent. Otherwise, change the fluid every 100,000 miles, using Dexron II, III or equivalent automatic transmission fluid. When checking fluid, ensure vehicle is at operating temperature (190°-200°F), which can be obtained by 15 miles of highway-type driving. After transmission fluid is at operating temperature, use the following procedure to check fluid level: 1. Ensure vehicle is on a level surface, then move gear selector to the Park position. 2. Apply parking brake and block wheels, then allow engine to run at idle speed for three minutes with accessories off. 3. Check fluid level, color and condition. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Fluid - A/T > Component Information > Service and Repair > Changing Fluid Fluid - A/T: Service and Repair Changing Fluid 1. Raise and support vehicle. 2. Loosen two bolts attaching right side of transmission support to frame rail. 3. Remove two bolts attaching left side transmission support to frame rail. 4. Using suitable transmission jack, support and slightly raise transmission. 5. Slide transmission support rearward enough to access rear oil pan attaching bolts. 6. Place drain pan under transmission oil pan, loosen pan bolts on front of pan, pry carefully with screwdriver to loosen oil pan, and allow fluid to drain. 7. Remove remaining oil pan bolts, oil pan, and gasket. 8. Drain fluid from pan, then clean pan and dry thoroughly with compressed air. 9. Remove oil filter to valve body bolt, then remove filter and gasket, replace with new filter and gasket. 10. Install new gasket on oil pan, then oil pan and attaching bolts. Tighten attaching bolts to specification. 11. Lower vehicle and add five quarts of automatic transmission fluid through filler tube. 12. With selector lever in Park and parking brake applied, start engine and let idle. Do not race engine. 13. Move selector lever through each gear range, then return lever to park. 14. Check fluid, then add additional fluid to bring level between dimples on dipstick. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Fluid - A/T > Component Information > Service and Repair > Changing Fluid > Page 1431 Fluid - A/T: Service and Repair Adding Fluid to A DRY Transmission 1. Add transmission fluid through filler tube until oil level is between the "ADD" and "HOT" marks on dipstick. 2. Place selector lever in park, depress accelerator to place carburetor on fast idle cam, and move selector lever through each range. Do not race engine. 3. With selector lever in park, engine running at idle (1-3 minutes), and vehicle on level surface, check fluid level and add additional fluid to bring level between dimples on dipstick. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Fluid - M/T > Component Information > Specifications > Capacity Specifications Fluid - M/T: Capacity Specifications Fluid Capacity ...................................................................................................................................... ...................................................................... 6.0 Pts. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Fluid - M/T > Component Information > Specifications > Capacity Specifications > Page 1436 Fluid - M/T: Fluid Type Specifications Transmission Manual ................................................................................................................................................. ........................................................................ [01] [01] New Venture Gear 3500; synchromesh transmission fluid, G.M. P/N 12345349 or equivalent. Borg Warner T5; DEXRON IIE automatic transmission fluid, G.M. P/N 12345881 or equivalent. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Fluid - Differential > Component Information > Technical Service Bulletins > Drivetrain - Recommended Axle Lubricant Fluid - Differential: Technical Service Bulletins Drivetrain - Recommended Axle Lubricant File In Section: 0 - General Information Bulletin No.: 76-02-02A Date: October, 1998 INFORMATION Subject: Recommended Axle Lubricant Models: 1999 and Prior Rear Wheel Drive Passenger Cars, Light and Medium Duty Trucks, and Four Wheel Drive Vehicles This bulletin is being revised to add the 1998 and 1999 Model Years and add Vehicle Line and Recommended Axle Lubricant Information. Please discard Corporate Bulletin Number 76-02-02 (Section 0 - General Information). The following tables provide the latest information on recommended axle lubricant. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Fluid - Differential > Component Information > Technical Service Bulletins > Drivetrain - Recommended Axle Lubricant > Page 1441 Parts Information Parts are currently available from GMSPO. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Fluid - Differential > Component Information > Specifications > Capacity Specifications Fluid - Differential: Capacity Specifications Rear Axle Oil, Pints [05] ...................................................................................................................... ............................................................................. 3.9 [05] Front drive axle, 2.6 pts. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Fluid - Differential > Component Information > Specifications > Capacity Specifications > Page 1444 Fluid - Differential: Fluid Type Specifications Front Axle SAE 80W-90 GL5 Gear Lubricant. GM P/N 1052271 Locking Differential (G80) This Article has been updated by TSB # 76-02-02A. SAE 80W-90 GL5 Gear Lubricant, GM P/N 1052271. Do not use limited slip additive. Non-Locking Differential Rear Axle with Non Limited Slip or Non Locking Differentials HD-3500 Trucks (Dana 11.0 axles) Recommended Lubricant - GM P/N 12346140, SAE 75W-140 Synthetic Gear Lubricant. 1999 GMT 800 Trucks Recommended Lubricant - GM P/N 12378261, SAE 75W-90 Synthetic Axle Lubricant. All other non limited-slip or non locking differentials including B and D cars, S/T, M/L, G, P, and C/K trucks except GMT 800 trucks, and as noted above. Recommended Lubricant - GM P/N 1052271 or an SAE 80W90 GL-5 Gear Lubricant. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Fluid - Transfer Case > Component Information > Specifications > Capacity Specifications Fluid - Transfer Case: Capacity Specifications Fluid Capacity ...................................................................................................................................... ...................................................................... 2.5 Pts. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Fluid - Transfer Case > Component Information > Specifications > Capacity Specifications > Page 1449 Fluid - Transfer Case: Fluid Type Specifications Lubricant Type ..................................................................................................................................... .................................................... Dexron II E ATF * * 1996 Models, Dexron III ATF Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Engine Oil > Component Information > Technical Service Bulletins > Engine - GM dexos 1 and dexos 2(R) Oil Specifications Engine Oil: Technical Service Bulletins Engine - GM dexos 1 and dexos 2(R) Oil Specifications INFORMATION Bulletin No.: 11-00-90-001 Date: March 14, 2011 Subject: Global Information for GM dexos1(TM) and GM dexos2(TM) Engine Oil Specifications for Spark Ignited and Diesel Engines, Available Licensed Brands, and Service Fill for Adding or Complete Oil Change Models: 2012 and Prior GM Passenger Cars and Trucks Excluding All Vehicles Equipped with Duramax(TM) Diesel Engines GM dexos 1(TM) Information Center Website Refer to the following General Motors website for dexos 1(TM) information about the different licensed brands that are currently available: http://www.gmdexos.com GM dexos 1(TM) Engine Oil Trademark and Icons The dexos(TM) specification and trademarks are exclusive to General Motors, LLC. Only those oils displaying the dexos‹›(TM) trademark and icon on the front label meet the demanding performance requirements and stringent quality standards set forth in the dexos‹›(TM) specification. Look on the front label for any of the logos shown above to identify an authorized, licensed dexos 1(TM) engine oil. GM dexos 1(TM) Engine Oil Specification Important General Motors dexos 1(TM) engine oil specification replaces the previous General Motors specifications GM6094M, GM4718M and GM-LL-A-025 for most GM gasoline engines. The oil specified for use in GM passenger cars and trucks, PRIOR to the 2011 model year remains acceptable for those previous vehicles. However, dexos 1(TM) is backward compatible and can be used in those older vehicles. In North America, starting with the 2011 model year, GM introduced dexos 1(TM) certified engine oil as a factory fill and service fill for gasoline engines. The reasons for the new engine oil specification are as follows: - To meet environmental goals such as increasing fuel efficiency and reducing engine emissions. - To promote long engine life. - To minimize the number of engine oil changes in order to help meet the goal of lessening the industry's overall dependence on crude oil. dexos 1(TM) is a GM-developed engine oil specification that has been designed to provide the following benefits: - Further improve fuel economy, to meet future corporate average fuel economy (CAFE) requirements and fuel economy retention by allowing the oil to maintain its fuel economy benefits throughout the life of the oil. - More robust formulations for added engine protection and aeration performance. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Engine Oil > Component Information > Technical Service Bulletins > Engine - GM dexos 1 and dexos 2(R) Oil Specifications > Page 1454 - Support the GM Oil Life System, thereby minimizing the replacement of engine oil, before its life has been depleted. - Reduce the duplication of requirements for a large number of internal GM engine oil specifications. International Lubricants Standardization and Approval Committee (ILSAC) GF-5 Standard In addition to GM dexos 1(TM), a new International Lubricants Standardization and Approval Committee (ILSAC) standard called GF-5, was introduced in October 2010. - There will be a corresponding API category, called: SN Resource Conserving. The current GF-4 standard was put in place in 2004 and will become obsolete in October 2011. Similar to dexos 1(TM), the GF-5 standard will use a new fuel economy test, Sequence VID, which demands a statistically significant increase in fuel economy versus the Sequence VIB test that was used for GF-4. - It is expected that all dexos 1(TM) approved oils will be capable of meeting the GF-5 standard. However, not all GF-5 engine oils will be capable of meeting the dexos 1(TM) specification. - Like dexos(TM), the new ILSAC GF-5 standard will call for more sophisticated additives. The API will begin licensing marketers during October 2010, to produce and distribute GF-5 certified products, which are expected to include SAE 0W-20, 0W-30, 5W-20, 5W-30 and 10W-30 oils. Corporate Average Fuel Economy (CAFE) Requirements Effect on Fuel Economy Since CAFE standards were first introduced in 1974, the fuel economy of cars has more than doubled, while the fuel economy of light trucks has increased by more than 50 percent. Proposed CAFE standards call for a continuation of increased fuel economy in new cars and trucks. To meet these future requirements, all aspects of vehicle operation are being looked at more critically than ever before. New technology being introduced in GM vehicles designed to increase vehicle efficiency and fuel economy include direct injection, cam phasing, turbocharging and active fuel management (AFM). The demands of these new technologies on engine oil also are taken into consideration when determining new oil specifications. AFM for example can help to achieve improved fuel economy. However alternately deactivating and activating the cylinders by not allowing the intake and exhaust valves to open contributes to additional stress on the engine oil. Another industry trend for meeting tough fuel economy mandates has been a shift toward lower viscosity oils. dexos 1(TM) will eventually be offered in several viscosity grades in accordance with engine needs: SAE 0W-20, 5W-20, 0W-30 and 5W-30. Using the right viscosity grade oil is critical for proper engine performance. Always refer to the Maintenance section of a vehicle Owner Manual for the proper viscosity grade for the engine being serviced. GM Oil Life System in Conjunction With dexos (TM) Supports Extended Oil Change Intervals To help conserve oil while maintaining engine protection, many GM vehicles are equipped with the GM Oil Life System. This system can provide oil change intervals that exceed the traditional 3,000 mile (4,830 km) recommendation. The dexos (TM) specification, with its requirements for improved oil robustness, compliments the GM Oil Life System by supporting extended oil change intervals over the lifetime of a vehicle. If all GM customers with GM Oil Life System equipped vehicles would use the system as intended, GM estimates that more than 100 million gallons of oil could be saved annually. GM dexos 2(TM) Information Center Website Refer to the following General Motors website for dexos 2(TM) information about the different licensed brands that are currently available: http://www.gmdexos.com GM dexos 2(TM) Engine Oil Trademark and Icons Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Engine Oil > Component Information > Technical Service Bulletins > Engine - GM dexos 1 and dexos 2(R) Oil Specifications > Page 1455 The dexos (TM) specification and trademarks are exclusive to General Motors, LLC. Only those oils displaying the dexos (TM) trademark and icon on the front label meet the demanding performance requirements and stringent quality standards set forth in the dexos (TM)specification. Look on the front label for any of the logos shown above to identify an authorized, licensed dexos 2(TM) engine oil. GM dexos 2(TM) Engine Oil Specification - dexos 2(TM) is approved and recommended by GM for use in Europe starting in model year 2010 vehicles, regardless of where the vehicle was manufactured. - dexos 2(TM) is the recommended service fill oil for European gasoline engines. Important The Duramax(TM) diesel engine is the exception and requires lubricants meeting specification CJ-4. - dexos 2(TM) is the recommended service fill oil for European light-duty diesel engines and replaces GM-LL-B-025 and GM-LL-A-025. - dexos 2(TM) protects diesel engines from harmful soot deposits and is designed with limits on certain chemical components to prolong catalyst life and protect expensive emission reduction systems. It is a robust oil, resisting degradation between oil changes and maintaining optimum performance longer. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Engine Oil > Component Information > Specifications > Capacity Specifications Engine Oil: Capacity Specifications TYPE.................................................................................................................................................... .......................................................................SG, SH Note: 1992-93 Syclone, and Typhoon engine oil must be Mobile 1 synthetic or equivalent CAPACITY, Refill: 4-cyl. 2.5L............................................................................................................... ..............................................................................2.8 Liters 3.0 Quarts Others................................... .............................................................................................................................................................. ...3.8 Liters 4.0 Quarts Capacity shown is without filter. When replacing filter, additional oil may be needed 1987-88 4.3L: Above 40°F (4°C).......................................................................................................... .....................................................................................................30‡ Above 0°F to (-18°C)................ .............................................................................................................................................................. ...................10W-30* Below 60°F (16°C).............................................................................................. ..........................................................................................................5W-30 1987-88 others, 1988-94 except Syclone & Typhoon: Above 40°F (4°C)............................................ .............................................................................................................................................................. .....30‡ Above 0°F to (-18°C)................................................................................................................ ...................................................................................10W-30 All temperatures................................... .............................................................................................................................................................. ..........5W-30* 1992-93 Syclone, Typhoon: All temperatures...................................................................................... .....................................................................................................................10W-30 *Preferred, except V6 4.3L ‡May be used when other recommended viscosities are unavailable Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Power Steering Fluid > Component Information > Technical Service Bulletins > Customer Interest: > 033206 > Mar > 94 > P/S - Reduced Assist When Cold Power Steering Fluid: Customer Interest P/S - Reduced Assist When Cold Group Ref.: Steering/Suspension Bulletin No.: 033206 Date: March 1994 SUBJECT: REDUCED POWER STEERING ASSIST AT LOW AMBIENT TEMPERATURES (NEW POWER STEERING FLUID) MODELS: 1994 AND PRIOR PASSENGER CARS AND LIGHT DUTY TRUCKS Applications: Appropriate for all passenger vehicles, but particularly beneficial in 1980 and later FWD Models equipped with Power Rack and Pinion Steering. CONDITION: Comments of reduced power steering assist at low ambient temperatures (approximately 10°F and lower) may be noted by some vehicle operators when turning the steering wheel in BOTH the right and left direction during warm-up after cold start. All vehicles with power steering exhibit this condition to varying degrees, but condition may be more noticeable with power rack and pinion steering systems that typically have longer hoses and cooler lines. Note: This condition, which is related to power steering fluid viscosity, should not, however, be confused with conditions having similar symptoms such as that described divisional Special Policy numbers listed: CAUSE: In cold weather, power steering fluid thickens in the same manner as any other petroleum-based oil or fluid. Upon cold starting, the fluid resists movement through the system and the driver senses reduced power assist (sometimes referred to as "stiff steer"). As the vehicle operates and fluid circulates through the power steering system, the fluid warms and thins to its normal operating viscosity. CORRECTION: Saginaw Division has developed a new Low Temperature Climate Service Fluid for use in cold climates. Compared with conventional power steering fluid, this new fluid flows better at low temperatures and resists the thickening which contributes to reduced power assist upon start up. RACK AND PINION STEERING SYSTEMS Reduced power assist upon cold weather starting may be more noticeable in Power Rack and Pinion steering systems that may contain six or more feet of Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Power Steering Fluid > Component Information > Technical Service Bulletins > Customer Interest: > 033206 > Mar > 94 > P/S - Reduced Assist When Cold > Page 1466 pressure and return hose along with long cooler lines. Such long systems contain greater volumes of fluid and vehicles so equipped tend to have longer periods of reduced power assist. The new fluid performs particularly well with current designed Rack and Pinion steering systems and special remanufactured Rack and Pinion Steering Assemblies. PARTS INFORMATION: Low Temperature Climate Service Fluid is available from GMSPO. Order as: Parts are currently available from GMSPO. SERVICE PROCEDURE: The power steering fluid replacement procedure is a two-stage process: first, flushing the old fluid from the system with new fluid; and second, bleeding the system to remove any trapped air. The two sequences outline the steps in each procedure. FLUSHING THE POWER STEERING SYSTEM 1. Raise the front end of the vehicle off the ground until the wheels are free to turn. 2. Remove the fluid return line at the pump reservoir inlet connector. 3. Plug the inlet connector port on the pump reservoir. 4. Position the fluid return line toward a large container in order to catch the draining fluid. 5. While a second person fills the reservoir with new Low Temperature Climate Service Fluid, start and run the engine at idle. 6. Turn the steering wheel from stop to stop. NOTICE: Do not hold the wheel against stops while flushing the system, Holding steering wheel against wheel stops will cause high system pressure, overheating, and damage to the pump and/or gear. 7. Continue draining until all of the old fluid is cleared from the power steering system. Addition of approximately 1 quart of new fluid will be required to flush system. 8. Unplug pump reservoir inlet and reconnect return line. 9. Turn engine off, and fill reservoir to the "Full Cold" mark. 10. Continue with following procedure "Bleeding the Power Steering System". Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Power Steering Fluid > Component Information > Technical Service Bulletins > Customer Interest: > 033206 > Mar > 94 > P/S - Reduced Assist When Cold > Page 1467 BLEEDING THE POWER STEERING SYSTEM After replacing the fluid or servicing the power steering hydraulic system, you must bleed air from the system. Air in the system prevents an accurate fluid level reading, causes pump cavitation noise and over time could damage the pump. To bleed the power steering system proceed as follows: 1. Begin with the engine off, front wheels off the ground, and wheels turned all the way to the left. 2. Add Low Temperature Climate Service Fluid to the "FULL COLD" mark on the fluid level indicator. 3. Bleed the system by turning the wheels from side to side without hitting stops. Important: Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Power Steering Fluid > Component Information > Technical Service Bulletins > Customer Interest: > 033206 > Mar > 94 > P/S - Reduced Assist When Cold > Page 1468 This may require turning the wheels from side to side twenty times. On systems with long return lines or fluid coolers, turning steering wheel lock-to-lock forty times may be required. Keep the fluid level at the "FULL COLD" mark. Fluid with air In it has a light tan appearance. This air must be eliminated from the fluid before normal steering action can be obtained. 4. Start the engine. With the engine idling, recheck the fluid level. If necessary, add fluid to bring the level to the "FULL COLD" mark. 5. Return the wheels to the center position. Lower front wheels to the ground. Continue running the engine for two or three minutes. 6. Test the vehicle to be sure the steering functions normally and is free from noise. Important: Inspect for fluid leakage at connection points along the power steering system. 7. Recheck the fluid level as described in Steps 3 and 4 except that the fluid level should now be up to the "FULL HOT" mark after the system has stabilized at its normal operating temperature. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Power Steering Fluid > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 033206 > Mar > 94 > P/S - Reduced Assist When Cold Power Steering Fluid: All Technical Service Bulletins P/S - Reduced Assist When Cold Group Ref.: Steering/Suspension Bulletin No.: 033206 Date: March 1994 SUBJECT: REDUCED POWER STEERING ASSIST AT LOW AMBIENT TEMPERATURES (NEW POWER STEERING FLUID) MODELS: 1994 AND PRIOR PASSENGER CARS AND LIGHT DUTY TRUCKS Applications: Appropriate for all passenger vehicles, but particularly beneficial in 1980 and later FWD Models equipped with Power Rack and Pinion Steering. CONDITION: Comments of reduced power steering assist at low ambient temperatures (approximately 10°F and lower) may be noted by some vehicle operators when turning the steering wheel in BOTH the right and left direction during warm-up after cold start. All vehicles with power steering exhibit this condition to varying degrees, but condition may be more noticeable with power rack and pinion steering systems that typically have longer hoses and cooler lines. Note: This condition, which is related to power steering fluid viscosity, should not, however, be confused with conditions having similar symptoms such as that described divisional Special Policy numbers listed: CAUSE: In cold weather, power steering fluid thickens in the same manner as any other petroleum-based oil or fluid. Upon cold starting, the fluid resists movement through the system and the driver senses reduced power assist (sometimes referred to as "stiff steer"). As the vehicle operates and fluid circulates through the power steering system, the fluid warms and thins to its normal operating viscosity. CORRECTION: Saginaw Division has developed a new Low Temperature Climate Service Fluid for use in cold climates. Compared with conventional power steering fluid, this new fluid flows better at low temperatures and resists the thickening which contributes to reduced power assist upon start up. RACK AND PINION STEERING SYSTEMS Reduced power assist upon cold weather starting may be more noticeable in Power Rack and Pinion steering systems that may contain six or more feet of Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Power Steering Fluid > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 033206 > Mar > 94 > P/S - Reduced Assist When Cold > Page 1474 pressure and return hose along with long cooler lines. Such long systems contain greater volumes of fluid and vehicles so equipped tend to have longer periods of reduced power assist. The new fluid performs particularly well with current designed Rack and Pinion steering systems and special remanufactured Rack and Pinion Steering Assemblies. PARTS INFORMATION: Low Temperature Climate Service Fluid is available from GMSPO. Order as: Parts are currently available from GMSPO. SERVICE PROCEDURE: The power steering fluid replacement procedure is a two-stage process: first, flushing the old fluid from the system with new fluid; and second, bleeding the system to remove any trapped air. The two sequences outline the steps in each procedure. FLUSHING THE POWER STEERING SYSTEM 1. Raise the front end of the vehicle off the ground until the wheels are free to turn. 2. Remove the fluid return line at the pump reservoir inlet connector. 3. Plug the inlet connector port on the pump reservoir. 4. Position the fluid return line toward a large container in order to catch the draining fluid. 5. While a second person fills the reservoir with new Low Temperature Climate Service Fluid, start and run the engine at idle. 6. Turn the steering wheel from stop to stop. NOTICE: Do not hold the wheel against stops while flushing the system, Holding steering wheel against wheel stops will cause high system pressure, overheating, and damage to the pump and/or gear. 7. Continue draining until all of the old fluid is cleared from the power steering system. Addition of approximately 1 quart of new fluid will be required to flush system. 8. Unplug pump reservoir inlet and reconnect return line. 9. Turn engine off, and fill reservoir to the "Full Cold" mark. 10. Continue with following procedure "Bleeding the Power Steering System". Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Power Steering Fluid > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 033206 > Mar > 94 > P/S - Reduced Assist When Cold > Page 1475 BLEEDING THE POWER STEERING SYSTEM After replacing the fluid or servicing the power steering hydraulic system, you must bleed air from the system. Air in the system prevents an accurate fluid level reading, causes pump cavitation noise and over time could damage the pump. To bleed the power steering system proceed as follows: 1. Begin with the engine off, front wheels off the ground, and wheels turned all the way to the left. 2. Add Low Temperature Climate Service Fluid to the "FULL COLD" mark on the fluid level indicator. 3. Bleed the system by turning the wheels from side to side without hitting stops. Important: Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Power Steering Fluid > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 033206 > Mar > 94 > P/S - Reduced Assist When Cold > Page 1476 This may require turning the wheels from side to side twenty times. On systems with long return lines or fluid coolers, turning steering wheel lock-to-lock forty times may be required. Keep the fluid level at the "FULL COLD" mark. Fluid with air In it has a light tan appearance. This air must be eliminated from the fluid before normal steering action can be obtained. 4. Start the engine. With the engine idling, recheck the fluid level. If necessary, add fluid to bring the level to the "FULL COLD" mark. 5. Return the wheels to the center position. Lower front wheels to the ground. Continue running the engine for two or three minutes. 6. Test the vehicle to be sure the steering functions normally and is free from noise. Important: Inspect for fluid leakage at connection points along the power steering system. 7. Recheck the fluid level as described in Steps 3 and 4 except that the fluid level should now be up to the "FULL HOT" mark after the system has stabilized at its normal operating temperature. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Power Steering Fluid > Component Information > Technical Service Bulletins > All Other Service Bulletins for Power Steering Fluid: > 668304A > Sep > 96 > Odometer/Speedometer - ACDelco Service Center Locations Speedometer Head: All Technical Service Bulletins Odometer/Speedometer - ACDelco Service Center Locations File In Section: 8 - Chassis/Body Electrical Bulletin No.: 66-83-04A Date: September, 1996 INFORMATION Subject: AC Delco Service Center Locations for Odometer/Speedometer Service Models: 1997 and Prior Passenger Cars and Trucks (excluding Cadillac) This bulletin is being revised to provide the necessary contact information only. Please discard Corporate Bulletin Number 66-83-04 (Section 8 - Chassis/Body Electrical) General Motors provides service for sophisticated electronic products through the authorized AC Delco Service Center Program. This program is designed to provide GM vehicle owners with the highest quality and most technically up-to-date product available. Repair products from unauthorized service outlets are not acceptable as warranty replacements. Currently, there are 25 authorized AC Delco Service Centers who exchange and remanufacture odometer/speedometers (list included). Only these Centers should be contacted for service. Important: W series and 1997 T series Medium Duty truck odometer/speedometers must be ordered directly from GMSPO. The following steps should be taken when utilizing the AC Delco Service Centers: Dealers should contact their local AC Delco Service Center (list included). Any listed facility may be used. The following information must be provided: Part number VIN, Mileage, Vehicle Year, Make and Model Dealer Name and Address Delivery Date of Vehicle Name of the person requesting exchange or service Phone number Repair Order Number P.O. number (if non - warranty) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Power Steering Fluid > Component Information > Technical Service Bulletins > All Other Service Bulletins for Power Steering Fluid: > 668304A > Sep > 96 > Odometer/Speedometer - ACDelco Service Center Locations > Page 1482 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Power Steering Fluid > Component Information > Technical Service Bulletins > All Other Service Bulletins for Power Steering Fluid: > 668304A > Sep > 96 > Odometer/Speedometer - ACDelco Service Center Locations > Page 1483 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Power Steering Fluid > Component Information > Technical Service Bulletins > All Other Service Bulletins for Power Steering Fluid: > 668304A > Sep > 96 > Odometer/Speedometer - ACDelco Service Center Locations > Page 1484 AC Delco Service Centers Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Power Steering Fluid > Component Information > Technical Service Bulletins > All Other Service Bulletins for Power Steering Fluid: > 468304 > Oct > 94 > Speedometer - Momentary Drop With Flashers On Speedometer Head: All Technical Service Bulletins Speedometer - Momentary Drop With Flashers On File In Section: 8 - Chassis/Body Electrical Bulletin No.: 46-83-04 Date: October, 1994 Subject: Speedometer Momentary Drop when Turning on Park Lamps, Turn Signals or Hazard Flashers (Send I/P Cluster to Delco Repair Station) Models: 1993-94 Chevrolet and GMC Truck C/K Models 1994 Chevrolet and GMC Truck S/T Pickup Models Condition Some speedometers in the above vehicles may momentarily drop when the turn signal, park lamp, or hazard flasher is turned on. This condition often occurs at speeds over 60 miles per hour. Cause Slight system voltage drop when the extra load from the lights is added. Correction Remove the instrument cluster and send it to the local Delco Repair Station. Repair stations are aware of the condition and have parts available to repair the cluster. They will add a capacitor to the power circuit to assure a consistent power flow during power up of the above mentioned lamps. Be sure to clearly describe the condition on the Delco Repair Order accompanying the cluster. Warranty Information For vehicles repaired under warranty, use: Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Power Steering Fluid > Component Information > Technical Service Bulletins > All Other Service Bulletins for Power Steering Fluid: > 668304A > Sep > 96 > Odometer/Speedometer - ACDelco Service Center Locations > Page 1494 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Power Steering Fluid > Component Information > Technical Service Bulletins > All Other Service Bulletins for Power Steering Fluid: > 668304A > Sep > 96 > Odometer/Speedometer - ACDelco Service Center Locations > Page 1495 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Power Steering Fluid > Component Information > Technical Service Bulletins > All Other Service Bulletins for Power Steering Fluid: > 668304A > Sep > 96 > Odometer/Speedometer - ACDelco Service Center Locations > Page 1496 AC Delco Service Centers Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > A/C - Refrigerant Recovery/Recycling/Equipment Refrigerant: Technical Service Bulletins A/C - Refrigerant Recovery/Recycling/Equipment Bulletin No.: 08-01-38-001 Date: January 25, 2008 INFORMATION Subject: Information On New GE-48800 CoolTech Refrigerant Recovery/Recharge Equipment Models: 2008 and Prior GM Passenger Cars and Light Duty Trucks (Including Saturn) 2008 and Prior HUMMER H2, H3 2005-2008 Saab 9-7X Attention: This bulletin is being issued to announce the release of GM approved Air Conditioning (A/C) Refrigerant Recovery and Recharging Equipment that meets the new Society of Automotive Engineers (SAE) J2788 Refrigerant Recovery Standards. The ACR2000 (J-43600) cannot be manufactured in its current state after December 2007 and will be superseded by GE-48800. The new J2788 standard does not require that GM Dealers replace their ACR2000 units. ACR2000's currently in use are very capable of servicing today's refrigerant systems when used correctly and can continue to be used. Details regarding the new SAE J2788 standard are outlined in GM Bulletin 07-01-38-004. Effective February 1 2008, new A/C Refrigerant Recovery/Recharging equipment (P/N GE-48800) will be released as a required replacement for the previously essential ACR2000 (J-43600). This equipment is SAE J2788 compliant and meets GM requirements for A/C Refrigerant System Repairs on all General Motors vehicles, including Hybrid systems with Polyolester (POE) refrigerant oil. This equipment will not be shipped as an essential tool to GM Dealerships. In addition, this equipment is Hybrid compliant and designed to prevent oil cross contamination when servicing Hybrid vehicles with Electric A/C Compressors that use POE refrigerant oil. The ACR2000 (J-43600) will need to be retrofitted with a J-43600-50 (Hose - ACR2000 Oil Flush Loop) to be able to perform Hybrid A/C service work. All Hybrid dealers will receive the J-43600-50, with installation instructions, as a component of the Hybrid essential tool package. Dealerships that do not sell Hybrids, but may need to service Hybrids, can obtain J-43600-50 from SPX Kent Moore. Refer to GM Bulletin 08-01-39-001 for the ACR2000 Hose Flush procedure. The High Voltage (HV) electric A/C compressor used on Two Mode Hybrid vehicles uses a Polyolester (POE) refrigerant oil instead of a Polyalkylene Glycol (PAG) synthetic refrigerant oil. This is due to the better electrical resistance of the POE oil and its ability to provide HV isolation. Failure to flush the hoses before adding refrigerant to a Hybrid vehicle with an electric A/C compressor may result in an unacceptable amount of PAG oil entering the refrigerant system. It may cause a Battery Energy Control Module Hybrid Battery Voltage System Isolation Lost Diagnostic Trouble Code (DTC P1AE7) to be set. Additionally, the A/C system warranty will be voided. Warranty Submission Requirements The Electronically Generated Repair Data (snapshot summary) and printer functions have been eliminated from the GE-48800. The VGA display and temperature probes were eliminated to reduce equipment costs. As a result, effective immediately the 18 digit "Snapshot/Charge Summary" code is no longer required for Air Conditioning (A/C) refrigerant system repairs that are submitted for warranty reimbursement. The charge summary data from before and after system repairs will continue to required, but documented on the repair order only. Both high and low pressures and the recovery and charge amounts should be noted during the repair and entered on the repair order. If using ACR2000 (J-43600), the "Snapshot/Charge Summary" printouts should continue to be attached to the shops copy of the repair order. The labor codes that are affected by this requirement are D3000 through D4500. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 08-01-38-001 > Jan > 08 > A/C - Refrigerant Recovery/Recycling/Equipment Refrigerant: Technical Service Bulletins A/C - Refrigerant Recovery/Recycling/Equipment Bulletin No.: 08-01-38-001 Date: January 25, 2008 INFORMATION Subject: Information On New GE-48800 CoolTech Refrigerant Recovery/Recharge Equipment Models: 2008 and Prior GM Passenger Cars and Light Duty Trucks (Including Saturn) 2008 and Prior HUMMER H2, H3 2005-2008 Saab 9-7X Attention: This bulletin is being issued to announce the release of GM approved Air Conditioning (A/C) Refrigerant Recovery and Recharging Equipment that meets the new Society of Automotive Engineers (SAE) J2788 Refrigerant Recovery Standards. The ACR2000 (J-43600) cannot be manufactured in its current state after December 2007 and will be superseded by GE-48800. The new J2788 standard does not require that GM Dealers replace their ACR2000 units. ACR2000's currently in use are very capable of servicing today's refrigerant systems when used correctly and can continue to be used. Details regarding the new SAE J2788 standard are outlined in GM Bulletin 07-01-38-004. Effective February 1 2008, new A/C Refrigerant Recovery/Recharging equipment (P/N GE-48800) will be released as a required replacement for the previously essential ACR2000 (J-43600). This equipment is SAE J2788 compliant and meets GM requirements for A/C Refrigerant System Repairs on all General Motors vehicles, including Hybrid systems with Polyolester (POE) refrigerant oil. This equipment will not be shipped as an essential tool to GM Dealerships. In addition, this equipment is Hybrid compliant and designed to prevent oil cross contamination when servicing Hybrid vehicles with Electric A/C Compressors that use POE refrigerant oil. The ACR2000 (J-43600) will need to be retrofitted with a J-43600-50 (Hose - ACR2000 Oil Flush Loop) to be able to perform Hybrid A/C service work. All Hybrid dealers will receive the J-43600-50, with installation instructions, as a component of the Hybrid essential tool package. Dealerships that do not sell Hybrids, but may need to service Hybrids, can obtain J-43600-50 from SPX Kent Moore. Refer to GM Bulletin 08-01-39-001 for the ACR2000 Hose Flush procedure. The High Voltage (HV) electric A/C compressor used on Two Mode Hybrid vehicles uses a Polyolester (POE) refrigerant oil instead of a Polyalkylene Glycol (PAG) synthetic refrigerant oil. This is due to the better electrical resistance of the POE oil and its ability to provide HV isolation. Failure to flush the hoses before adding refrigerant to a Hybrid vehicle with an electric A/C compressor may result in an unacceptable amount of PAG oil entering the refrigerant system. It may cause a Battery Energy Control Module Hybrid Battery Voltage System Isolation Lost Diagnostic Trouble Code (DTC P1AE7) to be set. Additionally, the A/C system warranty will be voided. Warranty Submission Requirements The Electronically Generated Repair Data (snapshot summary) and printer functions have been eliminated from the GE-48800. The VGA display and temperature probes were eliminated to reduce equipment costs. As a result, effective immediately the 18 digit "Snapshot/Charge Summary" code is no longer required for Air Conditioning (A/C) refrigerant system repairs that are submitted for warranty reimbursement. The charge summary data from before and after system repairs will continue to required, but documented on the repair order only. Both high and low pressures and the recovery and charge amounts should be noted during the repair and entered on the repair order. If using ACR2000 (J-43600), the "Snapshot/Charge Summary" printouts should continue to be attached to the shops copy of the repair order. The labor codes that are affected by this requirement are D3000 through D4500. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 06-01-39-007 > Jul > 06 > A/C - Contaminated R134A Refrigerant Refrigerant: Technical Service Bulletins A/C - Contaminated R134A Refrigerant Bulletin No.: 06-01-39-007 Date: July 25, 2006 INFORMATION Subject: Contaminated R134a Refrigerant Found on Market for Automotive Air-Conditioning Systems Models: 2007 and Prior GM Passenger Cars and Trucks (including Saturn) 2007 and Prior HUMMER H2, H3 2007 and Prior Saab 9-7X Attention: This bulletin should be directed to the Service Manager as well as the Parts Manager. Commercially Available Contaminated R134a Refrigerant Impurities have been found in new commercially available containers of R134a. High levels of contaminates may cause decreased performance, and be detrimental to some air-conditioning components. Accompanying these contaminates has been high levels of moisture. Tip: Excessive moisture may cause system concerns such as orifice tube freeze-up and reduced performance. Industry Reaction: New Industry Purity Standards Due to the potential availability of these lower quality refrigerants, the Society of Automotive Engineers (SAE), and the Air Conditioning and Refrigeration Industry (ARI) are in the process of instituting reliable standards that will be carried on the labels of future R134a refrigerant containers. This identifying symbol will be your assurance of a product that conforms to the minimum standard for OEM Automotive Air-Conditioning use. How Can You Protect Yourself Today? It is recommended to use GM or ACDelco(R) sourced refrigerants for all A/C repair work. These refrigerants meet General Motors own internal standards for quality and purity, insuring that your completed repairs are as good as the way it left the factory. Parts Information The part numbers shown are available through GMSPO or ACDelco(R). The nearest ACDelco(R) distributor in your area can be found by calling 1-800-223-3526 (U.S. Only). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 06-01-39-007 > Jul > 06 > A/C - Contaminated R134A Refrigerant > Page 1514 Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 99-01-38-006A > May > 00 > A/C - Refrigerant Recovery/Recharge Equipment Refrigerant: Technical Service Bulletins A/C - Refrigerant Recovery/Recharge Equipment File In Section: 01 - HVAC Bulletin No.: 99-01-38-006A Date: May, 2000 WARRANTY ADMINISTRATION Subject: J-43600 ACR 2000 Essential Refrigerant Recovery/Recharge Equipment Models: 1993-2000 Passenger Cars and Light Duty Trucks with R-134a Refrigerant This bulletin is being revised to change the effective date and to update the text. Please discard Corporate Bulletin Number 99-01-38-006 (Section 01 - HVAC). Effective June 1, 2000, the use of J-43600 ACR 2000 will be required on all repairs that require A/C system recovery and are reimbursable by GM. Additionally, GM highly recommends that J-43600 ACR 2000 be used on all GM cars and trucks for customer paid A/C repairs. Important: Also effective June 1, 2000, the "Add" time for all air conditioning recovery is revised to 0.5 hours for front systems and 0.7 hours for front/rear dual systems (RPO C69 or C34). After June 1, 2000, all air conditioning claims submitted with the 0.9 hours "Add" time will be rejected for "labor hours excessive". After the completion of repairs (charging), the ACR 2000 will prompt the user to perform a snapshot of the air conditioning system operating data. The snapshot includes: ^ Maximum high side pressure. ^ Minimum low side pressure. ^ Duct outlet temperatures (2). ^ Refrigerant purity information. This information is captured on a paper printout and in a warranty code. For all GM paid repairs, the paper printout should be attached to the shop copy of the repair order. The warranty code must be submitted in the warranty claim information in the comments field. The code enables the reporting of valuable information about the repair to GM for product quality improvement. Claims submitted without this information may be subject to review and subsequent debit. The required use of J-43600 ACR 2000 raises the question of the acceptable uses for any existing recovery/recycle equipment that GM dealers are currently using. GM recognizes that many of the previously essential ACR4's are reaching the end of their useful life. There are several alternatives for existing equipment that may be considered: ^ Use the existing equipment as customer paid recovery only equipment. Example: Collision repair area. ^ Use the existing equipment as a scavenger unit for contaminated A/C systems. ^ Sell the existing units to repair facilities outside the GM dealer network. ^ Discontinue the use of the existing units if the repair/maintenance costs exceed the value of the equipment. ^ Donate the existing equipment to local technical schools. ^ Dedicate the ACR4 to A/C system flushing, using the J-42939 Flush Adapter. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 99-01-38-006A > May > 00 > A/C - Refrigerant Recovery/Recharge Equipment > Page 1519 Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a Technical Service Bulletin # 431207E Date: 970101 A/C - Retrofitting R-12 to R-134a File In Section: 1 - HVAC Bulletin No.: 43-12-07E Date: January, 1997 INFORMATION Subject: Guidelines for Retrofitting R-12 Vehicles to R-134a Models: 1984-94 Passenger Cars and Trucks (See List Below) This bulletin is being revised with the following changes: 1. Addition of all remaining GM vehicles, as listed. 2. Format rearranged for easier use. Please discard Corporate Bulletin Number 43-12-07D (Section 1 - HVAC). Car/Truck Platform Coverage Starts: 1984 - A, B, D, E, F, J, K, P, Y Carlines 1985 - C, M, N, R, S Carlines 1986 - H Carline 1987 - L, V (Allante) Car lines; M/L, G, R/V, S/T, P Truck lines 1988 - T (LeMans), E (Reatta), W Car lines; C/k, MED. Duty Truck lines 1989 - Tracker 1990 - U Van Vehicles Not Covered: T (Chevette and T1000), G RWD, C RWD, and X Car If a vehicle is not covered in the list above, GM's recommendation is that the vehicle continue to be serviced with R-12. This bulletin outlines the detailed retrofit procedures, as well as providing background information on many components and procedures. It is important to follow the bulletin, since each car and truck line has unique parts and procedures. However, the basic procedure is simple, and will become easier as you complete more retrofits. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1524 Retrofit Requirements The customer should be reminded that there is NO requirement in the U.S. to retrofit any vehicle produced with R-12. Vehicles built with R-12 can be serviced with R-12 as long as it is available (except in certain Canadian Provinces). GM has taken steps to extend the supply of R-12 and recommends that all R-12 vehicles continue to be serviced with R-12 as long as it is available. Training Video Before doing a retrofit the first time, it is recommended that you view the Certified Plus Training Video, Program number 51010.15, "R-134a Retrofit for GM Cars and Trucks". Table of Contents A. Retrofit Procedure 1. Inspect Condition of Vehicle 2. Recover the R-12 (new method) 3. Install the service port conversion fittings 4. Install any additional parts needed 5. Evacuate and recharge with new PAG or V5 retrofit oil and R-134a 6. Install the retrofit label Platform Details Compressor Replacement Chart B. General Information 1. Performance 2. Leakage 3. Desiccant 4. Improved Cooling Performance 5. PAG or V5 Oil Compatibility 6. Refrigerant Oil Level Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1525 C. Parts Information D. Warranty Information 1. Vehicle Still in Warranty 2. Customer Paid' Retrofitting Costs 3. Labor Time Information Notes on Retrofit Important: Before proceeding with any retrofit, make sure you have all component Parts required on hand to perform a proper and complete repair with Minimal downtime. R-12 Removal Prior to Retrofit To prepare a system for retrofitting, the R-12 must be recovered and the system must be completely evacuated. Evacuation is necessary to insure that small amounts of R-12 and air remaining in the system are removed. This will prevent cross contamination of the two refrigerants, which could lead to reduced A/C system reliability and performance. It is very important that the specified times for waiting after recovery and evacuation not be reduced. This time is required to sufficiently remove residual R-12 from the oil in the system. A considerable amount of testing has determined that the following procedure is required to achieve satisfactory results and conform to SAE J 1661: 1. Inspect Condition of Vehicle Install the gauge set on the high and low side ports. Use normal diagnostic procedures to find the cause of the vehicle's reported condition. One of three conditions will exist with the refrigerant system: a. System pressure correct, no leaks - proceed to Step 2 (Recovery). This would normally apply when: 1. The system must be recovered/recharged for a repair to a system other than the A/C system, or 2. Where the A/C system condition did not involve leaks, but requires recovery/recharge to replace a component. b. Compressor not operating, but some charge. Leak test to find the leak, complete Step 2 (Recovery), then correct the leak before proceeding with Step 3 (Conversion port installation). c. No charge in system - proceed with the Conversion port installation in Step 3. Use the ACR4 to evacuate for 5 minutes. If the leak can be heard, repair the leak. If the leak cannot be heard, charge with 1/2 pound of R-134a. Leak test with the J 39400 Leak Detector, recover the R-134a, repair any additional leaks found, and proceed with the evacuation in Step 5. 2. Recover the R-12 from the System Notice: THIS PROCEDURE IS DIFFERENT THAN THE NORMAL (NON-RETROFIT) RECOVERY PROCEDURE. R-12 will be recovered through the HIGH SIDE SERVICE PORT ONLY, WITH THE ENGINE RUNNING. Recovery through the low side will not effectively remove the R-12 from the accumulator, resulting in possible damage to the retrofitted system. Important: Vehicle must be above 50° F (10° C) to allow for complete recovery of the R-12. If it is not, either allow it to warm up in the shop overnight, or increase the evacuation time in Step 5.a to 30 minutes. a. Connect the recovery hose from the R-12 recovery cart (ACR3) to the middle port of the A/C gauge set. Open the oil drain valve on the ACR3 cart long enough to drain the oil. Failure to do so could cause excessive amounts of oil to build up in the separator, resulting in damage to the recovery cart compressor. b. Start the engine. Leave the hood up, and the windows open. On vehicles with manual A/C controls, set the A/C controls to normal A/C mode, high blower, and temperature control to full cold. On cars with automatic A/C controls, set the temperature to 75° F, "AUTO" mode, and manually select high blower. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1526 Make sure the vehicle compressor is engaged. Turn the cart on and start the recovery cycle. OPEN ONLY THE HIGH SIDE VALVE ON THE GAUGE SET. The vehicle system should eventually shut the compressor off. If the low side pressure drops below 15 psi, and the compressor does not turn off, turn it off now (go to "VENT" or "ECON" mode), but leave the engine running and the blower on "high". c. After the recovery cart shuts off the first time, wait 5 minutes. If the pressure on either the high or the low side rises above 0 psi, restart the recovery process. After the second shutoff, wait 2 minutes. If the pressure again rises above 0 psi, restart, and after shutoff, again wait 2 minutes. The process can be stopped when the pressure does not rise above 0 psi after 2 minutes. The engine can be shut off at this time. d. Remove the R-12 reclaim hose and the gauge set from the vehicle. Any repairs needed should be done at this time. If any components other than the compressor are replaced, they should be installed dry, and no extra oil should be added. 3. Install the Service Port Conversion Fittings Important: For GEO vehicles, skip to Step 4. Fitting installation is covered in that step. For vehicles that require a HPCOS, see Step 4. Some of these vehicles use a specific combination fitting to mount the HPCOS, which includes the high side service port fitting and the HPCOS port. The low side fitting is installed as detailed below. See "Platform Details" for further information. Important: A new tool kit, P/N J 39500-250, has been released. This kit contains the following items: ^ J 39500-71 Oil Injection Bottle Conversion Kit (includes 3 12 oz bottles, an extender tube, caps, and fittings) ^ J 39500-275 Tool kit, including the following: (See Figure 2) - J 34611-A Double ended valve core remover - J 25498-A High side adapter fitting - J 38702 Deep valve core adapter fitting Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1527 - J 41265 Thread cleaning wire brush - J 41266 Low side port thread restorer - J 41267 High side port thread restorer - J 39037 High side octagon socket - J 41256 Low side octagon socket New low profile, quick connect couplers, J 39500-20A (High side), and J 39500-24A (Low side), have been released as essential tools, to attach to the ACR4 (see Figure 3). These are much smaller couplers than the existing ones, and will allow attachment to the port fittings in much tighter quarters. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1528 Select and install the proper R-134a fittings (shown in Figure 4) from the chart below, based on how the ACR4 couplers will attach. Also, remember to check for proper hood clearance with the conversion fittings. Try the straight fittings first. The two-piece high side fitting is used when the existing fitting is screwed into the pipe fitting (some 1992, and nearly all 1993 models, use these fittings). Use the 90° elbow if the straight fitting does not allow the ACR4 couplers to connect. Fitting Type High Side Low Side Straight 52467941 52467943 Straight Two-piece 52467324 N/A 90° Elbow 52469054 52469055 The fittings should be installed as follows: a. Remove the caps from the R-12 fittings. Remove any dirt or grease from the port threads using the thread cleaning wire brush, J 41265. Inspect the fittings for thread damage. If any damage is found, use the port thread restorer (J 41266 low side, J 41267 high side) to repair the thread. For the two-piece fitting, remove the existing R-12 fitting and discard it. Use tool J 38704A (previously released, not part of the above kit) to remove the fitting. Make sure to hold the line securely to prevent damage when removing the existing fitting. If the fitting cannot be removed easily, use the saddle clamp valve listed below and seal the R-12 port and cap permanently. b. Install the selected fitting onto the existing R-12 fitting. Leave the valve core in the straight fittings, and remove the valve core when using the 90° fittings. If the valve cores need to be removed at a later time, they can be removed with the straight conversion fittings in place. On the low side straight fitting, use the J 34611-A tool to remove the core pin in the conversion fitting, then remove the core valve from the original R-12 fitting. Always recover the charge before valve core removal. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1529 Use the octagon sockets on the straight fittings (J 39037 high side, and J 41256 low side). Torque the new fitting until it seats. The fitting should seat fully BEFORE reaching 11 N.m (8 lb ft). If 11 N.m (8 lb ft) of torque is reached and the fitting has not seated, it is probable that the threads have been damaged. In this case, remove the fitting and use the thread restorer listed above. Reinstall the fitting, adding one drop of a thread locking compound such as Loctite(R) 242. The fittings (except the two-piece) have a thread locking compound applied to the threads. This compound will set up enough to restrict removal of the fitting in about 15 minutes. The fittings can now be used to evacuate the system (see Step 5). An additional type of conversion port fitting has been developed. This fitting is called a saddle clamp valve (see Figure 5). It can be clamped directly on a metal refrigerant line, and will be used if the existing fitting is damaged or is inaccessible. A drop of a thread locking compound, such as Loctite(R) 242, should be used on each bolt to prevent the threads from loosening. The R134a saddle clamp valve part numbers are: If an existing R-12 service port is not used, it must be rendered inoperative. Place several drops of a thread locking compound, such as Loctite(R) 243, in the valve core, and onto the cap threads. Secure the cap and let it set for 15 minutes. 4. Install Any Additional Parts Needed See "Platform Details" after Step 6. If a vehicle is listed as a "Basic Retrofit", no additional parts are required (except for compressors, see the Compressor Replacement Chart at the beginning of Platform Details). If no parts are required, PROCEED TO STEP 5. Compressors Compressors do not need to be replaced as part of a normal retrofit, unless indicated in the Compressor Replacement Chart. An R-12 compressor that is operating properly can, in most cases, be left in the vehicle when it is retrofitted to R134a. However, if a compressor failure is the reason the vehicle is in for service, and the vehicle will be retrofitted, OR if a vehicle has already been retrofitted with R-134a and the compressor fails at some time in the future, new compressors for use with R-134a are available. See the GMSPO Parts Catalog for specific part numbers. DO NOT use a replacement R-12 compressor for any vehicle retrofitted to R-134a (unless it is the new "oil-less" design). See "Compressor Availability" at the end of the Compressor Replacement Chart. Accumulator /Dryer If the vehicle is more than 5 years old, the Accumulator/Dryer (A/D) should be replaced to ensure that moisture is removed from the system. See the instructions for proper A/D identification in General Information. High Pressure Cut-Off Switch (HPCOS) Most trucks, and some 1984-93 B and D cars, require that a HPCOS be added to protect the refrigerant system during long idles at high temperature. The HPCOS kit (P/N 15981985) contains the switch, wire harness, heat sealing splice connectors, switch "0" ring, and installation instructions. A saddle clamp adapter (P/N 15985307), or a special dual fitting, is mounted to the high pressure line, and provides the port to mount the switch. A drop of a Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1530 thread locking compound, such as Loctite(R) 242, should be used on each bolt of the saddle clamp to prevent the threads from loosening. Some vehicles produced during the second half of the 1993 model year will already have a factory installed HPCOS. Check the back of the compressor for this switch. If present, the above switch will not have to be added. 5. Evacuate the System, and Recharge with PAG or V5 Retrofit Oil and R-134a Newly designed low profile quick connect couplers for the ACR4, J 39500-20A and J 39500-24A, have been released. These should be installed before proceeding with the evacuation. See Step 3, and Figure 3. a. Connect the R-134a cart (ACR4) to the system. Open the coupler valves on the hoses so that the pressures can be read on the gauges. On the cart, open the HIGH SIDE VALVE ONLY. DO NOT OPEN THE LOW SIDE VALVE! Program the cart for a 15 minute evacuation. Important: If the vehicle has been at outside temperatures of less than 50° F (10° C), or at high altitudes (above 3000 ft), use a 30 minute evacuation to insure complete removal of the R-12. If the vacuum pump will not start and a "H-P" reading is indicated on the ACR4 display, loosen the fitting at the high side line connection to the ACR4 to relieve pressure in the line. Tighten the fitting after pressure has been relieved. DO NOT USE THE RECOVERY MODE TO RELIEVE LINE PRESSURE. b. Start the evacuation. For a proper evacuation, the cart must pull down to 28-29 in. Hg. at sea level (reduce by 1 in. for each 1000 ft above sea level). Check the low side gauge for proper vacuum level, to make sure the new fittings are operating properly. While the evacuation is being done, the Retrofit label can be filled out and installed (see Step 6). Important: If the compressor was replaced at the same time as this retrofit, and the new compressor was shipped with the correct amount of PAG oil already in it, DO NOT add any additional oil to the system! Go to Step D. If an "oil-less" compressor was installed, add oil in Step C. A new retrofit oil for use with V5 compressor vehicles has been released. This oil will be used ONLY for retrofitted vehicles in which the original V5 compressor is retained. IT WILL NOT BE USED IF A COMPRESSOR IS REPLACED AT THE TIME OF THE RETROFIT. Failure to use this oil may significantly shorten the useful life of the compressor. Important: If the V5 Retrofit oil is not available from GMSPO, the compressor MUST BE REPLACED! To summarize the correct retrofit oil usage: ^ Compressor replaced during retrofit - NO OIL ADDED if new compressor shipped with oil - 8 oz. of PAG oil (9 oz of PAG oil with V5 compressor) added if compressor shipped without oil ("oil-less" design) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1531 ^ PAG oil used for future service if needed (mark PAG on box on label, Figure 6). ^ HR6 or R4 original compressor RETAINED - add 8 oz FAG oil to system ^ V5 original compressor RETAINED - add 9 oz V5 Retrofit oil to system. If V5 Retrofit oil is not available from GMSPO, REPLACE THE COMPRESSOR. c. Based on the above chart, add oil if needed. Use the new oil bottle and the extended tube kit, J 39500-71. Fill the bottle with at least 10 oz of oil. Attach the new bottle to the back of the ACR4, and open the oil fill valve. Allow the correct amount of oil to be drawn into the system. DO NOT allow the oil level to drop below the end of the pickup tube. This will prevent any air from being drawn into the system. If any oil was removed during the R-12 recovery evacuation steps, DO NOT add additional oil to replace it. d. Determine the correct amount of R-134a to use. Check the existing label of the vehicle for the R-12 charge amount. Use the formula {(R12 x .9) - .25 lb = R-134a} to determine the correct charge. This can also be stated as: Take 90% of the R12 charge, and subtract 1/4 lb. Follow the directions for the ACR4 cart to recharge the system. At the end of the process, "CPL" will be displayed. Close the high side valve. e. Start the vehicle, turn on the A/C system, and confirm that pressures are within normal operating ranges, as shown in the 1994 Service Manual. The 1994 Service Manuals can be used as a reference for diagnosis and specification of retrofitted systems. On some vehicles with automatic A/C controls or low charge diagnostics, the A/C compressor may not engage if any diagnostic codes were set during the retrofit. Check to see if any codes were set in either the HVAC or Engine Control systems. If they were, clear the codes following the directions in the Service Manual. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1532 f. TO INSURE AN ACCURATE CHARGE AMOUNT, IT IS IMPORTANT TO CLEAR THE ACR4 OF ANY REMAINING REFRIGERANT. Close the high side coupler valve and remove the high side hose from the vehicle. Then, open both the high and low side valves on the ACR4. After the pressures on both gages are at low side pressure, close the low side coupler valve. See Step G below, then remove the low side hose from the vehicle. Shut off the engine. Install the service port caps on the new fittings. These serve as a seal and can prevent system leaks. g. In the unlikely event that the low side fitting leaks when the coupler is removed, use the following procedure: 1. Immediately reinstall the coupler on the fitting. 2. Find the valve core remover J 34611-A. 3. Remove the coupler. 4. Use the double-ended valve core remover to turn the valve core pin counter-clockwise until the leak stops. 5. Install the cap. If the leak was substantial or continued for an extended period of time, it is highly recommended to evacuate and recharge the system to insure proper performance. If there is any question, the system can be rechecked by repeating Step F. h. Leak test any new port fittings, adapters, or valves that were installed, and any joints that were opened or repaired during the retrofit process, using tool J 39400. 6. Install the Retrofit Label The retrofit label (P/N 21030857, roll of 250) has been developed following SAF specifications to insure a smooth transition from R-12 to R-134a, and to insure a professional approach to the retrofit and a quality repair. Following the instructions in this bulletin will insure that the retrofit meets the SAE standards. Fill in the new label using a typewriter or a ball-point pen (see Figure 6). Select a location for the label that will be easily visible. Some suggested areas are the radiator support panel, an area near the existing R-12 charge label, or a flat surface near the high or low side service ports. The area selected should be a clean, underhood, painted sheet metal surface, and should be degreased and wiped down with a non-petroleum based cleaner. Do not install the label on a rubber surface. Apply the label, then apply the clear overlay to the label. Do not remove, cover, or render unreadable the existing R-12 charge label. DO cover the R-12 refrigerant charge amount on the existing label with an indelible, preferably black, marker. Platform Details Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1533 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1534 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1535 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1536 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1537 FOR ALL VEHICLES EXCEPT GEO, see the "Compressor Replacement Chart" at the end of this section. Compressor replacement requirements ARE NOT LISTED in the platform details (except for application details), except as noted below for Y car and P and Medium Duty truck. Compressor Replacement Chart Important: It is important to check the date code on the compressor. Any vehicle may have had a compressor replaced either during or after the warranty period. The date code will determine whether or not the compressor must be replaced. Compressor Availability A new compressor for use with R-134a systems will be shipped with the correct amount of PAG oil installed (see "IMPORTANT" below). Do not add any additional oil in Step 5 of the retrofit procedure if a compressor is to be replaced with a new R-134a compressor at the same time the initial retrofit is Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1538 being done. Important: During 1996, "oil-less" compressors began to be serviced with NO added oil. New part numbers will be issued, and both the box and the compressor will be clearly marked to indicate that no oil is present. If you receive one of these newer compressors, simply add the normal amount of oil to the system in Step 5 of the retrofit procedure (8 oz of PAG oil, or 9 oz of PAG oil with V5 compressor). These "oil-less" compressors are compatible with EITHER R12 or R-134a. Geo Models Compressors DO NOT HAVE TO BE REPLACED as part of the retrofit. New compressors are shipped with enough oil to accommodate the entire A/C system. Do not add additional PAG oil to the system it the compressor is being replaced. 1985-88 Nova, 1989-93 Prizm (S) 1. Using the Service Manual, remove the following components in the order given: a. Receiver/dryer. b. Loosen evaporator to compressor (suction) pipe (to be reinstalled) c. 1985-92 only: Loosen compressor to condenser (compressor discharge) pipe (to be reinstalled). d. 1985-88 only: Service Valve & Extension Housing on compressor (to be installed). e. Compressor (only if being replaced). 2. Using the Service Manual, install the following components in the order given. Be sure to use new 0-rings whenever a refrigerant connection has been disconnected. a. Compressor (if being replaced). b. High and low side adapter fittings (see Step 3 of the retrofit procedure for detailed installation instructions). c. 1985-88 only: Service Valve & Extension Housing on compressor using new 0-rings. Six small 0-rings and one large 0-ring are required. d. Evaporator to compressor (suction) pipe 0-ring. e. 1985-92 Compressor to condenser (discharge) hose 0-ring. f. Receiver/dryer and 0-rings. R-134a amount: 85-92 - 650 grams (1.43 lb) 93 - 700 grams (1.54 lb) PAG oil amount: 100 cc (3.0 oz) Parts Required: Receiver/dryer: 85-88 - 94855761 89-93 - 94855762 Adapter Fittings: Low Side - 94855760 High Side - 94855759 0-Rings: 85-88 Compressor - Small 0-rings (6 required) - 94857336 - Large 0-ring - 94857337 85-93 Receiver/Dryer (2) - 94845949 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1539 85-93 Suction hose - 94855765 85-92 Discharge hose - 94845943 1985-88 Sprint, 1989-93 Metro (M) 1. Using the Service Manual, remove the following components in the order given: a. Receiver/dryer. b. Evaporator to compressor (suction) pipe. c. Compressor to condenser (compressor discharge) pipe. d. Joint service connector on compressor (to be reinstalled). e. Compressor (only if being replaced). 2. Using the Service Manual, install the following components in the the order given. Be sure to use new 0-rings whenever a refrigerant connection has been disconnected. a. Compressor (if being replaced). b. High and low side adapter fittings (see Step 3 of the retrofit procedure for detailed installation instructions). c. Joint service connector to compressor. Use new 0-rings. Six small 0-rings and one large 0-ring are required. d. Evaporator to compressor (suction) pipe, and new 0-ring. e. Compressor to condenser (discharge) hose and new 0-ring. f. Receiver/dryer and 0-ring. R-134a amount: 500 grams (1.10 lb) PAG oil amount: 100 cc (3.0 oz) Parts Required: Receiver/dryer: 85-86 - 91172081 87-88 - 91172079 89-93 - 96068480 Adapter Fittings: Low Side - 91172092 85-88 - High Side - 91172094 89-93 - High Side - 52467941 0-Rings: Compressor - Small 0-rings (6 required) - 91172095 - Large 0-ring - 96068915 Receiver/Dryer (2) - 96068488 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1540 89-93 - Suction hose - 96068490 89-93 - Discharge hose - 96068489 Suction hose: 85-86 - 91172086 85-86 Dealer installed: 91172087 87-88 - 91172088 89-93 - w/turbo - 96069121 - w/o turbo - 91172089 Discharge hose: 85-86 - 91172082 85-86 Dealer installed: 91172083 87-88 - 91172084 89-93 - 96069024 1989-93 Tracker 1. Using the Service Manual, remove the following components in the order given: a. Receiver/dryer. b. Evaporator to compressor (suction) pipe. c. Compressor to condenser (compressor discharge) pipe. d. Joint service connector on compressor (to be reinstalled). e. Compressor (only if being replaced). 2. Using the Service Manual, install the following components in the order given. Be sure to use new 0-rings whenever a refrigerant connection has been disconnected. a. Compressor (if being replaced). b. High and low side adapter fittings (see Step 3 of the Retrofit procedure for detailed installation instructions). c. Joint service connector to compressor. Use new 0-rings. Six small 0-rings and one large 0-ring are required. d. Evaporator to compressor (suction) pipe, and new 0-ring. e. Compressor to condenser (discharge) hose and new 0-ring. f. Receiver/dryer and 0-ring. R-134a amount: 550 grams (1.21 lb) PAG oil amount: 100 cc (3.0 oz) Parts Required: Receiver/dryer - 91172080 Adapter, Low Side - 91172092 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1541 Adapter, High Side - 91172093 0-Rings: Compressor - Small (6) - 91172095 Large - 96068915 Receiver/dryer (2) - 96068488 Suction hose - 96068490 Discharge hose - 96068489 Suction hose - 91172091 Discharge hose - 91172085 1985-89 Spectrum and 1990-93 Storm (R) 1. Using the Service Manual, remove the following components in the order given: a. Condenser (Storm) or radiator grille (Spectrum) (to be reinstalled). b. Triple switch (Storm) or dual pressure switch (Spectrum) (to be reinstalled). c. Receiver/dryer. d. Evaporator to compressor (suction) pipe. e. Check valve from high side service valve (discard). f. Compressor (only if being replaced). 2. Using the Service Manual, install the following components in the order given. Be sure to use new 0-rings whenever a refrigerant connection has been disconnected. a. Compressor (if being replaced). b. High side adapter fitting (see Step 3 of the retrofit procedure for detailed installation instructions). Low Side - Part of suction hose c. Evaporator to compressor (suction) pipe, and new 0-rings. d. Receiver/dryer and 0-rings. e. Triple switch or dual switch, and new 0-ring. f. Condenser or radiator grille. R-134a amount: 91 - 500 grams (1.10 lb) 92-93 - 600 grams (1.32 lb) PAG oil amount: 150 cc (4.50 oz) Parts Required: Receiver/dryer: 85-89 - 97104795 90-91 - 97104797 92-93 - 97104798 Adapter, High Side: Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1542 85-89 - 97104794 90-93 - 97104793 Adapter, Low Side: Part of Hose Asm. 0-rings: Receiver/dryer 85-91 - 94154048 92-93 - 94461700 Switch/pipe - 94461902 Suction hose: 85-86: 1.5L - 97104799; 1.6L - 97104800 90-93: 1.6L - 97104801; 1.8L - 97104803 B. General Information Several items affecting the performance and durability of the system should be considered: 1. Performance When performed properly, the retrofit from R-12 to R-134a will have minimal effect on the system's performance in most climatic conditions found in the United States and Canada. 2. Leakage Experience has shown that most leakage in an A/C system is due to leaks at the joints, or through a small leak in a hose, usually at the coupling. The R-134a molecules are smaller than R-12, and a small leak may result in a faster loss of refrigerant with R-134a. Because of this, it is very important to leak check all vehicles using the J 39400 leak detector, BEFORE the retrofit is performed, and repair any leaks found. "0" rings and hoses used in most GM vehicles are compatible with R-134a and do not need replacement during a retrofit. "0" rings or hoses installed in previous repairs may have been of non-compatible materials if GM parts were not used and will be more likely to deteriorate and leak than the original equipment materials. All "0" rings and hoses available through GMSP0 are compatible with R-134a. Remember that the normal policy is to replace the "0" rings whenever a joint is opened for any reason. 3. Desiccant You may have heard that the currently used desiccant in the accumulator is not compatible with R-134a. Extensive testing has shown that it is, in fact, suitable for use with R-134a, once it has been in service in an R-12 system. The accumulator in these models will not have to be changed during the retrofit procedure, unless the vehicle is more than 5 years old. Vehicles more than 5 years old should have the A/D replaced to add new desiccant for proper system drying. In the event that an accumulator/dryer (A/D) needs to be replaced on a retrofitted system in the future, only A/D's with XH-7 desiccant should be used. The service parts for the 1993 vehicles contain only XH-7 desiccant. The parts for the 1992 and older vehicles may contain either XH-5 or XH-7. Parts containing XH-7 can be identified (see Figure 1) by 1) an "A" printed on the top of the A/D; or 2) if there is a label on top of the A/D, there will be a square with an "A" inside; or 3) if there is a time code and date printed on top of the A/D just under the "Harrison" logo, the A/D contains XH-7. A/D's containing XH-5 can still be used on R-12 vehicles. 4. Improved Cooling Performance There have been service bulletins issued in the past with information improving the cooling performance of existing R-12 systems. These bulletins can also be used to improve the performance of retrofitted vehicles in high ambient temperature climates. 5. PAG or V5 Oil Compatibility Contrary to information published to date outside of General Motors, mineral oil and PAG or V5 oil ARE chemically compatible. The mineral oil left in the system after reclaiming the R-12 can remain in the system with no harmful effects. However, the mineral oil will not mix with the R-134a, and so will not circulate and perform its lubricating function. Testing has shown that most of the mineral oil will eventually collect in the Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1543 accumulator. The system will operate properly as long as refrigerant charge amounts are strictly adhered to. 6. Refrigerant Charge Level The retrofit R-134a charge level is more critical than with R-12 systems. Overcharging may push the mineral oil out of the AID, and cause it to circulate as a liquid. This is more likely to result in compressor damage. Undercharging may lead to loss of performance. It is very important to clear the hoses during the charging operation, to insure that all the refrigerant is delivered to the vehicle A/C system. This is covered in Step 6D of the Retrofit Procedure. C. Parts Information Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1544 Important: All of the following parts are NOT NEEDED for a normal retrofit. Follow the bulletin procedures to determine which parts you need! Individual vehicle kits are not necessary, since most of the parts are generic and only a few parts are needed for most vehicles. GEO Parts are listed in "Platform Details." Parts are currently available from GMSPO. D. Warranty Information 1. Vehicle Still Within the Original New Vehicle Limited Warranty Period When GM models for the years listed in the bulletin require repairs to the refrigerant system and the vehicles are still covered under the New Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 431207E > Jan > 97 > A/C - Retrofitting R-12 to R-134a > Page 1545 Vehicle Limited Warranty, dealers are instructed to proceed as follows: Important: On vehicles equipped with A/C systems NOT produced by GM (i.e., rear A/C systems in van conversions), consult the manufacturer of that A/C system for retrofit guidelines. ^ Offer the customer the option of repairing and recharging the system with R12, or retrofitting after repair and recharging with R-134a at no additional charge. ^ Provide the owner with, and review the information contained in, the "Converting Your Auto Air Conditioning System to Use the New Refrigerant" brochure. (Brochure, Form GM-0011, can be ordered free of charge from GM Fulfillment HQ, Phone 1-800-269-5100). ^ Record the customer's choice on the repair order and, as with all properly completed repair orders, ask the customer to sign on the appropriate line acknowledging the repairs requested. ^ Under no circumstances should the retrofit to R-134a be performed unless the customer has had the option explained prior to repair. Once the vehicle has been retrofitted to R-134a, a significant expenditure would be incurred to go back to R-12, in the event the customer has changed his/her mind. THIS OFFER APPLIES ONLY TO VEHICLES REQUIRING A/C REFRIGERANT SYSTEM REPAIRS UNDER THE TERMS OF THE NEW VEHICLE LIMITED WARRANTY. It is not a special policy, and any existing deductibles still apply. This is simply an option being offered to the customer during the warranty period at this time. GM reserves the right to terminate this offer at any time. If the R-12 refrigerant system does not require discharging for a warranty repair, but the customer requests a retrofit to R-134a, the retrofit WOULD BE PERFORMED AT THE CUSTOMER'S EXPENSE, EVEN DURING THE WARRANTY PERIOD. 2. Customer Paid Retrofitting Costs If the customer requests a retrofit to R-134a, for a specific vehicle whose retrofit parts and procedures have been released in this bulletin, the customer would be expected to pay the costs to retrofit under the following conditions: ^ The vehicle is no longer covered by the terms of the New Vehicle Limited Warranty. ^ The vehicle is covered by warranty, but the repair covered under the warranty does not require evacuating and recharging the refrigerant system. 3. Labor Time Information For Vehicles Repaired Under Warranty: Use existing labor operations for correcting the original condition. The quantity of R-134a used should be charged to the normal labor operation (not D4500), just as if it were R-12. Use D4500, 0.3 HR., to charge for parts and labor, for all of the following items: ^ Additional time for recovery of R-12 to meet SAE standards; ^ Install high and low side service port converter fittings; ^ Add PAG or V5 retrofit oil; ^ Complete label information and install. Add 0.2 hours to D4500 for installation of the HPCOS. Use T5321, 0.3 HR., for the Pontiac Bonneville hood seal installation. ANY PARTS OR LABOR TIME OTHER THAN THOSE LISTED ABOVE SHOULD BE CHARGED TO THE REGULAR LABOR OPERATION CORRESPONDING TO THE ORIGINAL CONDITION THAT 1S BEING REPAIRED. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 631209 > May > 96 > A/C - R12 or R134a Service Recommendations Technical Service Bulletin # 631209 Date: 960501 A/C - R12 or R134a Service Recommendations File In Section: 1 - HVAC Bulletin No.: 63-12-09 Date: May, 1996 INFORMATION Subject: Service Issues for Vehicles with R12 or R134a Air Conditioning Systems Models: 1988-96 Passenger Cars and Trucks R12 Service Recommendations As you know, production of R12 refrigerant ceased on December 31, 1995. Although R12 will no longer be manufactured, there is a reserve supply of R12 available. This reserve, along with strict A/C repair service adherence to proper refrigerant recycling procedures, should assure continued availability to meet consumers' needs. R12 can and should continue to be used to service vehicles built with R12 A/C systems as long as it is available. If R12 is no longer available or affordable, a system retrofit utilizing R134a is recommended. R134a IS THE ONLY SUBSTITUTE REFRIGERANT RECOMMENDED BY GM FOR USE IN GM VEHICLE A/C SYSTEMS, AND THEN ONLY AFTER FOLLOWING THE PROPER RETROFIT PROCEDURES FOR THE SPECIFIC MODEL. All new vehicle manufacturers have chosen R134a for retrofit. One of the key reasons is to protect both the service industry and consumers from the high costs that would result from purchasing equipment necessary to service multiple refrigerants. This position also reduces the threat of recycled refrigerant contamination. GM currently offers a simple, low cost R12 to R134a retrofit on many of its late model, front wheel drive passenger cars. Dealers should discuss this capability with owners of these specific models, listed in Retrofit Corporate Bulletin # 43-12-07D, whenever a repair to the A/C refrigerant system is required. Early retrofit of these specific models will aid in prolonging availability of the R12 supply and provide dealer service technicians the opportunity to become more familiar with the proper procedures for performing a retrofit. Remember - R12 and R134a refrigerant are not interchangeable! They cannot be mixed together. In fact, despite the claims of some refrigerant manufacturers, no proposed R12 refrigerant substitute can be added to, mixed with or used to "top off" an R12 system. Under provisions of law covering the service of refrigerants, mixing dissimilar refrigerant products during service is prohibited. To Summarize GM R12 Service Policy 1. Service R12 vehicles with good quality new or recycled R12 as long as it is available. 2. Purchase R12 from a reliable supplier. GMSPO has a supply of high quality R12 available. Dealers are requested to use only R12 supplied by GMSPO for warranty repairs. This high quality refrigerant will insure system performance and avoid the possibility of introducing contaminated material into the customer's A/C system. 3. Carefully test recovered R12 using the PureGuard monitor. On recovery equipment not protected by the PureGuard, always test the recovery cylinder prior to recharging a vehicle A/C system. 4. Discuss the R12 to R134a retrofit option with owners of GM vehicles listed in Retrofit Corporate Bulletin # 43-12-07D. Provide owner with a copy of the pamphlet "Converting Your Auto Air Conditioning System to Use the New Refrigerant". 5. Become familiar with retrofit procedures and exercise care in the handling of dissimilar refrigerants to prevent contamination. R134A Service Recommendations When servicing a previously retrofitted vehicle, there is concern that if all of the R12 is not completely removed prior to the retrofit procedure, it could contaminate your R134a equipment and recovery tank when a subsequent A/C repair is performed. Although the number of retrofits being performed today is minimal, the volume will increase as R12 prices rise. GM Service Technology Group is in the process of field testing a new R134a refrigerant purity tester similar to the PureGuard R12 refrigerant tester you now use. This new tool will mount to your ACR4 R134a Recovery Recycle and Recharge cart and sample all R134a refrigerant prior to recovery. It is expected that testing of this tool will be completed this year. This new tool, the Pureguard 2, will also test vehicles and your recycle tank for air contamination, which is threatening A/C system performance. High levels of air have been found in the recovery tanks on a number of R12 and R134a recovery carts. Air contamination is caused by improper recovery Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 631209 > May > 96 > A/C - R12 or R134a Service Recommendations > Page 1550 procedures and short-cutting refrigerant recycling times. Use the following procedure for testing and correcting air contamination in your A/C service equipment. 1. Make certain that the ACR4 equipment has not been used for at least 12 hours. It is recommended that the equipment be left in an area where the temperature will remain constant overnight to allow the temperature of the refrigerant in the tank to stabilize. 2. Record the surrounding air temperature next to the ACR4 refrigerant tank. Important: A major assumption is that the ambient air temperature next to the tank represents the refrigerant temperature in the tank. Failure to take care in measuring the temperature could result in unnecessary work. 3. Close both liquid (blue) and vapor (red) valves on the ACR4 tank. 4. Disconnect low side (blue) service hose from the back of the ACR4. 5. Slowly disconnect the tank vapor hose (red) from the back of the ACR4 and connect it to the low side service port. 6. Open the vapor (red) valve on the tank and record the tank pressure on the low side gage. 7. Restore hoses to the original position. 8. Referring to the Table, find the ambient temperature measured in Step 2. Compare the pressure reading from Step 6 to the "maximum allowable pressure". If the pressure reading from Step 6 is less than the "maximum allowable pressure", no further action is necessary. Important: The closer the tank pressure is to the desired tank pressure, the better the A/C system will perform. 9. If the pressure reading from Step 6 exceeds the maximum allowable pressure from the Table, open both tank valves and operate the ACR4 through 4 or 5 evacuation cycles. This will activate the automatic air purge to lower the tank pressure. Important: Station should not be connected to vehicle. 10. Repeat the tank pressure checking procedure the next day to determine if the pressure has been reduced to acceptable levels. If the tank pressure has been reduced but is not acceptable, cycle with ACR4 through more evacuation cycles and recheck the next day. Continue process until acceptable pressure is obtained. If the tank pressure is not reduced through the evacuation cycling, then Kent-Moore should be contacted at 1-800-345-2233. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 531205 > May > 95 > Contaminated R12 Refrigerant - Testing & Handling Refrigerant: Technical Service Bulletins Contaminated R12 Refrigerant - Testing & Handling FILE IN SECTION: 1 - HVAC BULLETIN NO.: 53-12-05 DATE: May, 1995 SUBJECT: Contaminated R12 Refrigerant Testing and Handling MODELS: 1994 and Prior Passenger Cars and Trucks with R12 A/C Systems The J 39851 "PureGuard" R12 refrigerant monitor was recently shipped to all GM dealers as an essential tool to test R12 refrigerant. Dealers are strongly urged to install this protective device on their ACR3 or other R12 recovery equipment immediately. The PureGuard is easily installed on any recovery cart (20 minutes), requires no recovery cart modifications, is fully automatic (no training required) and does not increase the time required to perform normal A/C service procedures. Proper use of this tool can: ^ Prevent damage to your R12 recovery/recycling equipment. ^ Prevent contamination of previously recovered R12 in the recovery tank. ^ Prevent loss of your recovered R12 as contaminated refrigerant will activate automatic air purge system. ^ Prevent the spread of contaminated R12 to other vehicles you service. If your dealership has multiple R12 recovery stations which are not protected, use the PureGuard to check the refrigerant in these recovery tanks for contamination at least once each week. Simply connect the PureGuard blue service hose (that would normally be connected to the vehicle low side service port) to the red or vapor side of any recovery cart tank and run the test. It is also important to check a tank containing recovered/recycled material for purity before installation on your charging equipment. Even new R12 refrigerant purchased from sources other than GM should be tested for contamination prior to use. Sources of Contaminated R12 Refrigerant Since refrigerant testing has not been a standard practice in the mobile A/C repair industry, the amount of R12 refrigerant contamination is unknown. As R12 prices rise and supplies are depleted, it is anticipated that contaminated R12 refrigerant may become more prevalent from the following as well as other sources: ^ The use of R12 refrigerant substitutes without installation of unique service fittings and proper identification labeling. ^ Improper use of R12 substitutes, such as topping off R12 systems with R134a or other refrigerants available to "do-it-yourselfers". ^ Poor quality or contaminated new or reprocessed R12 refrigerant. R12 can and should continue to be used to service vehicles built with R12 as long as it is available. Combining any refrigerant with R12 results in a refrigerant mixture which cannot be used in an A/C system. R134a is the only substitute refrigerant approved by GM and should only be used when the appropriate retrofit service bulletin procedures are explicitly followed. Use of any other substitute refrigerant requires the purchase of additional dedicated recovery, recycling (if applicable) and charging equipment to service each substitute refrigerant used. However, you should know that the Environmental Protection Agency (EPA) has listed several products as acceptable replacements for R12 mobile A/C systems under the Significant New Alternatives Policy (SNAP). Some of these products are: R134a, R401c (a DuPont refrigerant blend) and FRIGC (another refrigerant blend). It is important to understand that the SNAP program only considers the health, safety and environmental characteristics of a chemical. It does not test for A/C system cooling performance or durability. That judgment is deferred to the vehicle manufacturer. Use of any R12 refrigerant substitute without dedicated service equipment, unique fittings, labels and refrigerant testing prior to recovery, could result in contamination of the R12 supply and the loss of the R12 recycling program. What To Do When Contamination is Detected Repeat the test to verify contaminated refrigerant is present. Clear the PureGuard following the instructions listed on the face panel, then perform a second test to verify that the vehicle A/C system contains contaminated or mixed refrigerant. Contact the vehicle owner to advise that previous A/C system repairs were apparently performed with an R12 refrigerant substitute. Suggest the owner Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 531205 > May > 95 > Contaminated R12 Refrigerant - Testing & Handling > Page 1555 contact or return to the previous repair facility. Explain that environmental regulations prohibit repair facilities from discharging ozone depleting A/C refrigerants into the atmosphere. Explain that recovery of this unknown refrigerant could damage your service equipment. If the customer wishes to pursue repairs through your facility, it is recommended that the proper A/C service equipment be purchased. General Motors recommends the Kent-Moore J 41428 "Scavenger", an air operated refrigerant recovery station, be used to remove unknown refrigerants. The air operated feature reduces the hazard of recovering potentially flammable refrigerants. Dealers should evaluate the need to purchase the equipment based on the number of contaminated vehicles they encounter. As an alternative to the initial purchase of a recovery only station, dealers should check locally for A/C specialty shops which may have the equipment to service substitute or contaminated refrigerants. They may be able to provide contaminated refrigerant recovery service to the dealer. The GM Service Technology Group has tested a recovery procedure where a 15 or 30 pound DOT approved refillable tank is fully evacuated then connected to a vehicle A/C system to recover the charge. Testing has shown that even when the recovery tank is cooled down in dry ice, the procedure does not guarantee the entire charge will be recovered. Since EPA regulations require full recovery of ozone depleting substances, GM does not recommend this procedure. Contaminated Refrigerant Disposal Although A/C refrigerant testing and disposal have not been a service practice in the mobile A/C industry, It has been common in the stationary A/C service industry for many years. Listed at the end of this bulletin are companies that provide refrigerant disposal service for the stationary A/C industry. Please be advised that GM has not independently evaluated these companies and is not in any way endorsing or promoting the use of these companies. Each of these companies has expressed an interest in providing refrigerant disposal service to GM dealers. In working with the stationary A/C industry, these companies typically receive large volumes of different refrigerants that have been mixed together. Unfortunately, because the volume of material returned by the mobile A/C industry will be in much smaller quantities, the cost of handling will be greater. To arrange for return of the refrigerant, simply call the company nearest you using the phone number listed below. The company will advise you on billing and shipping procedures. Disposal cost will vary between $3.00 and $5.00 per pound plus freight and handling. Shipping charges will vary by distance and location. In general, a 7 to 10 day turn-around time on the tank can be expected. The tank can be shipped via common carrier. Documents that your refrigerant has been properly disposed of will be sent to you with the return of your tank. As an alternative, many dealerships already have contracts in place with a disposal company who manages their hazardous wastes. In these cases, the disposal service may agree to handle containers of mixed refrigerants. Initially, the local disposal companies may be surprised by this inquiry. They may want to evaluate how much material will be collected before deciding whether to provide this service. As we move forward with the practice of testing R12 refrigerant, it will take time for all the questions to be answered. STG will provide additional information as soon as it is available. Understanding The PureGuard The PureGuard is a highly sensitive instrument capable of detecting R12 with 3% or less cross-contamination with other refrigerants. Any refrigerant mixture in excess of this amount poses a threat to both your refrigerant supply and recovery equipment. The PureGuard uses a pass/fail approach when monitoring the refrigerant and is precisely calibrated to cut power to the recovery machine if it encounters R12 mixed with any substitute refrigerants. The PureGuard ignores the presence of the air, dyes or oils in the refrigerant sampled. At least 20 psi must be present in the vehicle's A/C system for the PureGuard to function. Otherwise, refrigerant cannot be introduced to the PureGuard's test chamber. If a vehicle's A/C system contains less than 20 psi, it is an indication that the vehicle's system is nearly depleted of refrigerant. Occasionally, erratic PureGuard operation or service code 002 display will be encountered when A/C system pressure is exactly 20 psi. If this occurs, simply cycle the on/off switch to reset the PureGuard. After the 30 second PureGuard warm-up cycle, proceed immediately with vehicle recovery operation. Feedback from the field has indicated PureGuard service code 002 will also be displayed if the oil drain port is not sealed. Make sure the "0" ring seal in the cap is in place and that the cap is tight. If the PureGuard fails to clear or if you experience any other problems operating the PureGuard, contact Kent-Moore Technical Service at 1-800-345-2233. The unit should not be returned without first contacting Kent-Moore to obtain return authorization. Refrigerant Disposal Locations: United States Refrigerant Reclamation Inc. 12420 North Green River Rd. Evansville, IN 47711 800-207-5931, FAX - 812-867-1463 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 531205 > May > 95 > Contaminated R12 Refrigerant - Testing & Handling > Page 1556 Omega Refrigerant Reclamation 5263 North Fourth St. Irwindale, CA 91706 310-698-0991, FAX 310-696-1908 Refrigerant Management Svcs of Georgia 216 F. Atlanta Hwy. Cumming, GA 30130 Ph/FAX 800-347-5872 Refrigerant Reclaim Inc. 122 Old Stage Coach Rd. Dumfries, VA 22026 800-238-5902, FAX 703-441-0393 Gartech Refrigerant Reclamation Ctr. 2002 Platinum Garland, TX 75042 214-272-4070, FAX 214-272-8548 National Refrigerants, Inc. 11401 Roosevelt Blvd. Philadelphia, PA 19154 215-698-6620, FAX 215-602-8205 CFC Reclamation 1321 Swift North Kansas City, MO 64116 816-471-2511 Full Cycle-Global 550 James Street Lakewood, NJ 08701 908-370-3400, FAX - 908-370-3088 Refrigerant Reclaim Svcs, Inc. dba Full Cycle-Global 121 S. Norwood Drive Ft. Worth, TX 76053-7807 817-282-0022, FAX - 800-831-6182 Full Cycle-Global 2055 Silber, Ste. 109 Houston, TX 77055 713-681-7370, FAX - 713-681-9947 Full Cycle-Global 343 South Airline Hwy. Gonzales, LA 70737 504-644-5303, FAX - 504-644-1809 Full Cycle-Global 2966 Wireton Blue Island, IL 60406 708-388-8551, FAX - 708-388-8550 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 431215 > Nov > 94 > A/C - R134a Leak Detection With Tracer Dye Refrigerant: Technical Service Bulletins A/C - R134a Leak Detection With Tracer Dye File In Section: 1 - HVAC Bulletin No.: 43-12-15 Date: November, 1994 Subject: R134a Leak Detection with Tracer Dye Models: All 1993-95 Vehicles with OEM R134a Systems All R12 Vehicles Retrofitted to R134a Systems R134a refrigerant is uniquely different from R12 refrigerant and requires some changes in the repair methods, tools and materials used in A/C service. Two important differences between R134a and R12 which affect the technicians ability to locate refrigerant leaks are: 1. The R134a molecule is smaller than the R12 molecule and therefore will leak through smaller openings. For the same size opening the smaller R134a molecule will leak out faster than the R12. 2. R134a refrigerant does not contain chlorine which the older R12 electronic leak detectors found very easy to identify. Many of today's electronic leak detectors have difficulty locating small R134a refrigerant leaks. In order to insure the highest quality in A/C system service, the J 39400 electronic leak detector was released as an essential tool for all GM dealers. This is the only refrigerant leak detector approved by GM for service on R134a vehicles. If maintained properly (Reference Bulletin No. 431218) and used in accordance with Service Manual procedures, the J 39400 will provide the most accurate and efficient method of locating R134a refrigerant leaks under most conditions. If the technician cannot find the leak with the J 39400 and the system is known to have lost charge, a new fluorescent leak tracer dye Kent-Moore* P/N J 41447, has been released that mixes with the R134a PAG oil. This dye is detectable through the use of an ultraviolet (black) light and glows yellow/green at the leak location (similar to using dye in engine leak detection). J 41447 IS THE ONLY APPROVED DYE BY GENERAL MOTORS. Not all R134a dyes are compatible with GM's PAG oil. Some dyes decrease the oil viscosity or chemically react with the oil. Use of alternate products may affect system reliability and cause premature compressor failure. Note: THIS DYE IS NOT TO BE USED IN R-12 SYSTEMS. Unlike mineral oil, the R134a PAG oil has special properties the technician should keep in mind. 1. PAG oil is water soluble and traces of PAG oil found at leaking joints are subject to "washing out". Condensation on refrigerant lines or the evaporator core may wash the PAG oil and leak dye off the line or off the core and out the condensate drain. This can make some leaks harder to find using the dye detector. Fluorescence at the drain opening would indicate a core leak. 2. Use of the R134a tracer dye requires time. Depending upon the leak rate, it may take between 15 minutes and 7 days for the leak to become visible. 3. The dye, mixed with the PAG oil, is retained in the system and is detectable for 2+ years. Do not double or triple charge the system with dye as this may cause reliability concerns. Use only the 1/4 oz. charge. The dye has a refrigerant leak detection notice sticker included with the package. Complete the sticker information and place near the charge label. Dye Injection R-134a dye can be injected two ways: 1. With the A/C system charged, use the instructions provided with the new R134a leak dye injection tool, J 41436. 2. With A/C system discharged, add dye into the newly replaced component assembly. It is important to note that it is normal to find oil traces at the compressor shaft seal during compressor operation, some oil will hydraulically seep past the shaft seal. This does not mean that the shaft seal is defective or that the refrigerant has leaked. Refrigerant leaks at the shaft seal should be verified with the electronic leak detector (J 39400) following the procedure detailed in the Service Manual. If, however, the amount of oil is excessive, the shaft seal is suspect and should be replaced. (For example, refrigerant oil has coated the clutch plate edge at gap between clutch and pulley, or oil slinging has occurred-oil line shows on underside of hood, etc.). Also, after working on A/C components with dye, it is important to wipe the joint and/or access ports clean of any residual dye with GM solvent (GM Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 431215 > Nov > 94 > A/C - R134a Leak Detection With Tracer Dye > Page 1561 P/N 1050436) to prevent false diagnosis at a later point. * We believe this source and their equipment to be reliable. There may be additional manufacturers of such equipment. General Motors does not endorse, indicate any preference for or assume any responsibility for the products or equipment from these firms or for any such items which may be available from other sources. Parts Information GM solvent, P/N 1050436, is currently available from GMSPO. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 431223 > Sep > 94 > A/C Refrigerant - Contamination Refrigerant: Technical Service Bulletins A/C Refrigerant - Contamination File In Section: 1 - HVAC Bulletin No.: 43-12-23 Date: September, 1994 Subject: Contaminated A/C Refrigerant Models: 1994 and Prior Passenger Cars and Trucks with R12 Air Conditioning Systems Government regulations limit the production of R12 refrigerant, commonly referred to as Freon, during 1994/1995 and restrict manufacture of new R12 material effective January 1, 1996. As R12 prices rise and supplies are depleted, it is anticipated non-approved substitute refrigerants and/or poor quality R12 material sold as new or reprocessed may become more prevalent. The Mobile Air Conditioning Society (MACS) recently expressed concern over reports of the sale of R12 refrigerant containing as high as 15% contamination by R22, a refrigerant commonly used in stationary home systems but unsuitable for use in mobile units. GM dealers should be careful to protect against contaminating their existing supplies of R12 or the A/C systems in customers' vehicles they service by dealing with reputable suppliers. All R12 refrigerant purchased for warranty repairs should be purchased through GM SPO to ensure GM quality standards are met. The use of non-approved R12 refrigerant substitutes, some of which contain flammable materials, has also been reported by MACS. These products are available to "do-it-yourselfers" who, in many cases, believe they are harmless replacements for the small cans of R12 used so commonly in the past. Once added to the A/C system, the vehicle can no longer be serviced using R12 recovery/recycling equipment without: - Risking permanent damage to recovery/recycling equipment - Contaminating the previously recovered R12 material in the recovery tank - Spreading the contamination when the recovered material is used to charge other vehicles or - Possible loss of the recovered material if the contaminated level is high enough to activate the air purge system Contaminated refrigerant also impacts customer satisfaction through poor vehicle A/C performance and loss of A/C system compressor/component durability. System or component failure resulting from the use of refrigerant which does not meet GM specification is not covered by the "New Vehicle Warranty". Unfortunately, there is no simple method to identify if a "do-it-yourselfer" or repair shop has added to or recharged a system with a non-approved refrigerant. The inability to protect against the spread of contaminated refrigerant threatens the recycling program and the industry's desire to maximize use of the remaining R12 supply. Beginning in 1993, General Motors STG, Harrison Division, Research Labs and Kent-Moore worked in conjunction with suppliers of various technologies to develop a tester to identify contaminated refrigerant in vehicle A/C systems before recovery. During development of the technology, several dealer service manager focus group studies were conducted to identify design features to best suit dealership needs. The discussions and surveys clearly indicated the desire for a dedicated instrument, permanently mounted to the refrigerant recovery cart to ensure ALL vehicles are automatically tested prior to recovering refrigerant. Testing ALL refrigerant for contamination prior to recovery is the ONLY means to ensure customer satisfaction, protect recovery equipment and avoid unintentional venting of refrigerant by your dealership. General Motors has evaluated all available technology for this project and only the J 39851 R12 "Pureguard" meets General Motors' specifications. The J 39851 R12 Pureguard Refrigerant Monitor has been classified as an essential tool and will be shipped by Kent-Moore to your dealership beginning in September of 1994. The essential price of the R12 "Pureguard" is $561 (for Canadian dealers the price is $800 Canadian). If your dealership has multiple R12 recovery equipment, additional units may be ordered from Kent-Moore for $561 at 1-800-345-2233. Features of the R12 "Pureguard" include: - Universally mounts to R12 Recovery Equipment - Automatically interrupts power to the Recovery Equipment when contaminated refrigerant is identified - Fully automatic design does not require technician action, training or interpretation - LCD displays Pureguard functions Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 431223 > Sep > 94 > A/C Refrigerant - Contamination > Page 1566 - Meets GM contamination sensitivity requirements - Self calibrating - Micro-processor controlled - Audio alarm alerts technician Other Refrigerant Identifiers are being advertised which may be available this A/C season. However, ONLY the Kent-Moore J 39851 R12 "Pureguard" meets General Motors' current specifications which ensure recovered refrigerant is compatible with General Motors vehicles and General Motors approved recovery systems. An R134a Pureguard Refrigerant Identifier is currently under development and is anticipated to be available in early 1995. The contamination of R134a refrigerant is not expected to be a concern until the program to retrofit R12 vehicles to R134a becomes more widely used. Future bulletins will be issued to address the recovery and disposal of contaminated refrigerant. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 331226 > Jan > 94 > A/C - Retrofitting R-12 Vehicles to R-134A Refrigerant: Technical Service Bulletins A/C - Retrofitting R-12 Vehicles to R-134A Group Ref.: HVAC Bulletin No.: 331226 Date: January, 1994 INFORMATION SUBJECT: RETROFITTING R-12 VEHICLES TO R-134a MODELS: 1994 AND PRIOR YEARS, PASSENGER CARS AND TRUCKS WITH R-12 A/C SYSTEMS There has been a great deal of information presented by the media regarding the need to retrofit vehicles produced with R-12, to a substitute refrigerant. This bulletin will outline GM's position and future plans on this subject. Most important, there is currently NO requirement to retrofit any R-12 vehicle. Vehicles built with R-12 can be serviced with R-12, as long as the refrigerant is available. At some point in time, R-12 may become either too scarce or too expensive to economically justify service on some vehicles with R-12. By that time, GM will provide you with instructions on retrofitting those vehicles from R-12 to R-134a. GM vehicle divisions, platforms, and component suppliers have been actively working on the details of retrofitting R-12 vehicles. An enormous amount of work is required to determine how hundreds of vehicle models can be satisfactorily retrofitted. Additional information will be provided as it becomes available. The following items contain important technical information that should answer many of the questions, and correct some misconceptions reported in the media. SUBSTITUTE REFRIGERANTS R-134a is the only approved substitute refrigerant that GM recommends and it should only be used if a complete retrofit procedure has been performed. None of the other refrigerants currently being marketed as replacement or drop-in substitutes for R-12 are approved for use in GM vehicles. R-12 and R-134a are not interchangeable. R-134a cannot be added to fill a low R-12 system. The combination of the two materials can cause high system pressures, which could cause damage to the system. Retrofitting an R-12 vehicle to R-134a requires careful preparation to insure that neither the vehicle nor the A/C service equipment has become contaminated. RESIDUAL MINERAL OIL The concern that mineral oil is chemically incompatible with R-134a and/or PAG lubricant has been proven to be untrue. A normal charge of mineral oil left in the A/C system after a retrofit to R-134a will not damage the system. Mineral oil, however, does not mix well with R-134a, and will not provide adequate lubrication. Tests on both the orifice tube and TXV systems show that the mineral oil parks in places such as the accumulator, and does not appreciably affect performance or damage the system. The retrofit service bulletin will specify the correct oil to be used. It is important that this oil recommendation be followed carefully. RESIDUAL R-12 Residual R-12 left in a system, due to improper retrofit service procedures, may result in system damage unless the residual R-12 is kept below the 2 percent limit specified by the Society of Automotive Engineers' Specification J-1661. New service methods are being developed to minimize the level of R-12 remaining in the A/C system after the retrofit procedure is completed. Following these new procedures will be critical to insure that the above limits are met. SYSTEM FLUSHING R-11, a material commonly used as an A/C system flushing solvent, has been found to be chemically incompatible with PAG lubricant. Technicians should be aware that residual R-11 remaining in an R-12 system will be very damaging if the vehicle is retrofitted to R-134a later in its life. For many years GM has recommended the use of in-line filters as an alternative to system flushing. SYSTEM FLUSHING, USING EITHER R-11 OR ANY OTHER FLUSHING MATERIAL, IS NOT APPROVED BY GM FOR ANY A/C SYSTEM. DESICCANT PROTECTION Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 331226 > Jan > 94 > A/C - Retrofitting R-12 Vehicles to R-134A > Page 1571 It has been reported that the desiccant (moisture absorption material) used in 1992 and older R-12 A/C systems is incompatible with R-134a and PAG oil. The older desiccant was designed specifically for R-12 systems, but testing has shown that it is NOT necessary to replace the older desiccant just because the vehicle is being retrofitted to R-134a. 1993 and newer GM vehicles use desiccant designed to be compatible with both R-12 and R-134a systems. The amount of desiccant used in most GM vehicles is designed to last for at least seven years. To help maintain adequate protection for vehicles that must be retrofitted, it is recommended that the accumulator/dryer, which contains the desiccant, be replaced if the vehicle is more than five years old. "O" RINGS While continuing to service with R-12, be sure to use "O" rings and seal materials which are compatible with R-134a and PAG oil. This practice will eliminate concern in case the vehicle requires retrofitting later in its life. All "O" rings and seal materials available from GMSPO are compatible with R-134a systems. RETROFITTED SYSTEM PERFORMANCE Currently, it appears that for most GM vehicles, the retrofit procedure will require minimal changes to the existing system. Some vehicles may need additional parts and/or procedures to provide acceptable performance and/or durability. Our testing has shown that vehicles that have undergone recommended retrofit procedures will, in most climatic conditions, be minimally affected in terms of A/C performance. SERVICE POLICY Basic service policy is as follows: During Warranty - If an R-12 produced vehicle A/C system must be repaired or recharged under warranty, repairs will be completed using R-12. If R-12 is unavailable or unaffordable, GM will notify the dealer body and will pay for the warranty repair and the retrofit to R-134a. NOTE: It a customer requests that an in-warranty vehicle be converted to R-134a, and the R-12 system is functioning properly, the customer will be expected to pay for the retrofit. Out of Warranty - The cost of the conversion will be the responsibility of the customer. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > 922501A > Aug > 92 > A/C - Use of Alternate Refrigerants In CFC 12 Refrigerant: Technical Service Bulletins A/C - Use of Alternate Refrigerants In CFC 12 Number: 92-250-1A Section: 0A Date: AUGUST 1992 Corporate Bulletin No.: 231205 ASE No.: A7 Subject: USE OF ALTERNATE REFRIGERANTS IN CFC 12 REFRIGERANT MOBILE AIR CONDITIONERS Model and Year: GALL MODEL YEARS - ALL PASSENGER CARS AND TRUCKS INCLUDING GEO A number of inquiries have been received concerning the use of "alternate refrigerants" as a replacement for R-12 refrigerant in General Motors air conditioning systems. Regardless of any advertised claims, there are currently no substitutes for refrigerant R-12 approved by General Motors. At the present time, only new or recycled R-12 is approved for use in General Motors R-12 air conditioning systems. Based on studies performed to date, the use of "alternate refrigerants" in General Motors R-12 air conditioning systems may result in higher system pressures, higher leak rates or incompatibility with drying and sealing materials. System performance and reliability may also be affected. Service equipment manufacturers have indicated that cross-contaminating R-12 recovery/recycling equipment with "alternate refrigerants" may damage the equipment. General Motors supports the Society of Automotive Engineers recommended service procedures for recovery and recycling of R-12. The use of known "alternate refrigerants" without proper service practices for identifying vehicle systems containing these "alternate refrigerants" and dedicated recovery equipment to service those vehicles will contaminate the recycled supply of R-12 refrigerant. Contamination of the recycled R-12 refrigerant makes the refrigerant unusable for recharging air conditioning systems and could jeopardize the recycling program. At the present time, General Motors has not approved any "alternate refrigerant" for R-12 in R-12 air conditioning systems. Therefore, R-12 systems should continue to be serviced with new or recycled R-12 only. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > Page 1576 Refrigerant: Technical Service Bulletins A/C - Contaminated R134A Refrigerant Bulletin No.: 06-01-39-007 Date: July 25, 2006 INFORMATION Subject: Contaminated R134a Refrigerant Found on Market for Automotive Air-Conditioning Systems Models: 2007 and Prior GM Passenger Cars and Trucks (including Saturn) 2007 and Prior HUMMER H2, H3 2007 and Prior Saab 9-7X Attention: This bulletin should be directed to the Service Manager as well as the Parts Manager. Commercially Available Contaminated R134a Refrigerant Impurities have been found in new commercially available containers of R134a. High levels of contaminates may cause decreased performance, and be detrimental to some air-conditioning components. Accompanying these contaminates has been high levels of moisture. Tip: Excessive moisture may cause system concerns such as orifice tube freeze-up and reduced performance. Industry Reaction: New Industry Purity Standards Due to the potential availability of these lower quality refrigerants, the Society of Automotive Engineers (SAE), and the Air Conditioning and Refrigeration Industry (ARI) are in the process of instituting reliable standards that will be carried on the labels of future R134a refrigerant containers. This identifying symbol will be your assurance of a product that conforms to the minimum standard for OEM Automotive Air-Conditioning use. How Can You Protect Yourself Today? It is recommended to use GM or ACDelco(R) sourced refrigerants for all A/C repair work. These refrigerants meet General Motors own internal standards for quality and purity, insuring that your completed repairs are as good as the way it left the factory. Parts Information The part numbers shown are available through GMSPO or ACDelco(R). The nearest ACDelco(R) distributor in your area can be found by calling 1-800-223-3526 (U.S. Only). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > Page 1577 Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > Page 1578 Refrigerant: Technical Service Bulletins A/C - Refrigerant Recovery/Recharge Equipment File In Section: 01 - HVAC Bulletin No.: 99-01-38-006A Date: May, 2000 WARRANTY ADMINISTRATION Subject: J-43600 ACR 2000 Essential Refrigerant Recovery/Recharge Equipment Models: 1993-2000 Passenger Cars and Light Duty Trucks with R-134a Refrigerant This bulletin is being revised to change the effective date and to update the text. Please discard Corporate Bulletin Number 99-01-38-006 (Section 01 - HVAC). Effective June 1, 2000, the use of J-43600 ACR 2000 will be required on all repairs that require A/C system recovery and are reimbursable by GM. Additionally, GM highly recommends that J-43600 ACR 2000 be used on all GM cars and trucks for customer paid A/C repairs. Important: Also effective June 1, 2000, the "Add" time for all air conditioning recovery is revised to 0.5 hours for front systems and 0.7 hours for front/rear dual systems (RPO C69 or C34). After June 1, 2000, all air conditioning claims submitted with the 0.9 hours "Add" time will be rejected for "labor hours excessive". After the completion of repairs (charging), the ACR 2000 will prompt the user to perform a snapshot of the air conditioning system operating data. The snapshot includes: ^ Maximum high side pressure. ^ Minimum low side pressure. ^ Duct outlet temperatures (2). ^ Refrigerant purity information. This information is captured on a paper printout and in a warranty code. For all GM paid repairs, the paper printout should be attached to the shop copy of the repair order. The warranty code must be submitted in the warranty claim information in the comments field. The code enables the reporting of valuable information about the repair to GM for product quality improvement. Claims submitted without this information may be subject to review and subsequent debit. The required use of J-43600 ACR 2000 raises the question of the acceptable uses for any existing recovery/recycle equipment that GM dealers are currently using. GM recognizes that many of the previously essential ACR4's are reaching the end of their useful life. There are several alternatives for existing equipment that may be considered: ^ Use the existing equipment as customer paid recovery only equipment. Example: Collision repair area. ^ Use the existing equipment as a scavenger unit for contaminated A/C systems. ^ Sell the existing units to repair facilities outside the GM dealer network. ^ Discontinue the use of the existing units if the repair/maintenance costs exceed the value of the equipment. ^ Donate the existing equipment to local technical schools. ^ Dedicate the ACR4 to A/C system flushing, using the J-42939 Flush Adapter. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > Page 1579 Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > Page 1580 Refrigerant: Technical Service Bulletins A/C - Retrofitting R-12 Vehicles to R-134A Group Ref.: HVAC Bulletin No.: 331226 Date: January, 1994 INFORMATION SUBJECT: RETROFITTING R-12 VEHICLES TO R-134a MODELS: 1994 AND PRIOR YEARS, PASSENGER CARS AND TRUCKS WITH R-12 A/C SYSTEMS There has been a great deal of information presented by the media regarding the need to retrofit vehicles produced with R-12, to a substitute refrigerant. This bulletin will outline GM's position and future plans on this subject. Most important, there is currently NO requirement to retrofit any R-12 vehicle. Vehicles built with R-12 can be serviced with R-12, as long as the refrigerant is available. At some point in time, R-12 may become either too scarce or too expensive to economically justify service on some vehicles with R-12. By that time, GM will provide you with instructions on retrofitting those vehicles from R-12 to R-134a. GM vehicle divisions, platforms, and component suppliers have been actively working on the details of retrofitting R-12 vehicles. An enormous amount of work is required to determine how hundreds of vehicle models can be satisfactorily retrofitted. Additional information will be provided as it becomes available. The following items contain important technical information that should answer many of the questions, and correct some misconceptions reported in the media. SUBSTITUTE REFRIGERANTS R-134a is the only approved substitute refrigerant that GM recommends and it should only be used if a complete retrofit procedure has been performed. None of the other refrigerants currently being marketed as replacement or drop-in substitutes for R-12 are approved for use in GM vehicles. R-12 and R-134a are not interchangeable. R-134a cannot be added to fill a low R-12 system. The combination of the two materials can cause high system pressures, which could cause damage to the system. Retrofitting an R-12 vehicle to R-134a requires careful preparation to insure that neither the vehicle nor the A/C service equipment has become contaminated. RESIDUAL MINERAL OIL The concern that mineral oil is chemically incompatible with R-134a and/or PAG lubricant has been proven to be untrue. A normal charge of mineral oil left in the A/C system after a retrofit to R-134a will not damage the system. Mineral oil, however, does not mix well with R-134a, and will not provide adequate lubrication. Tests on both the orifice tube and TXV systems show that the mineral oil parks in places such as the accumulator, and does not appreciably affect performance or damage the system. The retrofit service bulletin will specify the correct oil to be used. It is important that this oil recommendation be followed carefully. RESIDUAL R-12 Residual R-12 left in a system, due to improper retrofit service procedures, may result in system damage unless the residual R-12 is kept below the 2 percent limit specified by the Society of Automotive Engineers' Specification J-1661. New service methods are being developed to minimize the level of R-12 remaining in the A/C system after the retrofit procedure is completed. Following these new procedures will be critical to insure that the above limits are met. SYSTEM FLUSHING R-11, a material commonly used as an A/C system flushing solvent, has been found to be chemically incompatible with PAG lubricant. Technicians should be aware that residual R-11 remaining in an R-12 system will be very damaging if the vehicle is retrofitted to R-134a later in its life. For many years GM has recommended the use of in-line filters as an alternative to system flushing. SYSTEM FLUSHING, USING EITHER R-11 OR ANY OTHER FLUSHING MATERIAL, IS NOT APPROVED BY GM FOR ANY A/C SYSTEM. DESICCANT PROTECTION Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Technical Service Bulletins for Refrigerant: > Page 1581 It has been reported that the desiccant (moisture absorption material) used in 1992 and older R-12 A/C systems is incompatible with R-134a and PAG oil. The older desiccant was designed specifically for R-12 systems, but testing has shown that it is NOT necessary to replace the older desiccant just because the vehicle is being retrofitted to R-134a. 1993 and newer GM vehicles use desiccant designed to be compatible with both R-12 and R-134a systems. The amount of desiccant used in most GM vehicles is designed to last for at least seven years. To help maintain adequate protection for vehicles that must be retrofitted, it is recommended that the accumulator/dryer, which contains the desiccant, be replaced if the vehicle is more than five years old. "O" RINGS While continuing to service with R-12, be sure to use "O" rings and seal materials which are compatible with R-134a and PAG oil. This practice will eliminate concern in case the vehicle requires retrofitting later in its life. All "O" rings and seal materials available from GMSPO are compatible with R-134a systems. RETROFITTED SYSTEM PERFORMANCE Currently, it appears that for most GM vehicles, the retrofit procedure will require minimal changes to the existing system. Some vehicles may need additional parts and/or procedures to provide acceptable performance and/or durability. Our testing has shown that vehicles that have undergone recommended retrofit procedures will, in most climatic conditions, be minimally affected in terms of A/C performance. SERVICE POLICY Basic service policy is as follows: During Warranty - If an R-12 produced vehicle A/C system must be repaired or recharged under warranty, repairs will be completed using R-12. If R-12 is unavailable or unaffordable, GM will notify the dealer body and will pay for the warranty repair and the retrofit to R-134a. NOTE: It a customer requests that an in-warranty vehicle be converted to R-134a, and the R-12 system is functioning properly, the customer will be expected to pay for the retrofit. Out of Warranty - The cost of the conversion will be the responsibility of the customer. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Page 1582 Refrigerant: Specifications REFRIGERANT AND OIL CAPACITY The refrigerant system requires refrigerant and oil in quantities listed: Refrigerant Refrigerant-12 ...................................................................................................................................... ................................................. 1.134 kg (2.5 lbs.) Refrigerant Oil 525 Viscosity Refrigerant Oil ............................................................................................................... .................................................. 240 ml (8 fl. oz.) CAUTION: Overcharging a system may allow liquid Refrigerant-12 or Refrigerant-134a to get into the compressor, causing compressor noise and damage. Undercharging will cause insufficient cooling. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Technical Service Bulletins > Page 1583 Refrigerant: Description and Operation Like the coolant in an engine cooling system, the refrigerant is the substance in the air conditioning system that absorbs, carries, and then releases heat. Although various substances are used as refrigerants in other types of refrigeration systems, most automotive air conditioning systems use the Refrigerant-12. This compound is not explosive, not flammable, not corrosive except when in contact with water, and not poisonous except when in contact with an open flame or hot metal. It is soluble in oil. Refrigerant-12 carries a charge of a special lubricating oil, normally 525 viscosity refrigerant oil. Since the refrigerant has an affinity for oil, the two compounds mix easily and completely. Even the refrigerant vapor carries small particles of oil. As the liquid or vapor moves through the system, it keeps the moving parts of the compressor lubricated. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Service and Repair > Proper Flushing Procedures Refrigerant: Service and Repair Proper Flushing Procedures General Information This article has been updated with bulletin No. 01-01-38-006A. CONTAMINATED R-134A A/C SYSTEMS - AIR CONDITIONING SYSTEM FLUSHING PROCEDURES AND GUIDELINES A/C system flushing should NOT be routinely performed when a system failure is encountered. System flushing takes a considerable amount of time to perform and is NOT necessary on most system failures and should be performed only when any one of the following conditions is found. - Desiccant bag failure - Gross overcharge of PAG oil - Refrigerant contamination - Contaminated PAG oil - Catastrophic compressor failure causing oil contamination A/C system flushing will remove some of the metal particles during a flush, but flushing is not completely effective in removing all metallic debris. System flushing should not be considered if removal of metallic debris is the only objective. GM Service Operations continues to recommend the use of LIQUID LINE FILTERS and SUCTION SCREENS to control this type of system contamination and avoid repeat failures. A/C System Flushing Procedure A/C SYSTEM FLUSHING PROCEDURE TOOLS REQUIRED: - J 43600 ACR 2000 - J 45263 Flush Adapter Kit - J 41447 Leak Detection Dye or equivalent - J 41459 Leak Detection Dye Injector or equivalent - J 42220 Universal 12V Leak Detection Lamp or equivalent - J 39400-A Leak Detector - J 44551 A/C Suction Screen Kit A warm engine compartment or higher ambient temperatures speed the refrigerant recovery time during the A/C flush procedure. Whenever possible, warm the engine prior to system flushing. The use of an external fan blowing across the condenser may also be helpful to speed recovery. FRONT ONLY A/C SYSTEMS 1. Recover system refrigerant. 2. Remove the expansion device (orifice tube or TXV). 3. Connect the A/C lines with the orifice tube removed or install the appropriate TXV Adapter from kit J 45268. 4. Remove the A/C compressor. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Service and Repair > Proper Flushing Procedures > Page 1586 5. Inspect the end of the suction hose for a suction screen. Remove the suction screen using the J 44551 A/C suction screen kit, if installed. 6. Install the appropriate A/C compressor hose assembly flush adapter(s) from kit J 45268. 7. Configure the flush adapter and hose for either a forward flush or reverse flush. Refer to the Flushing Configuration section of this bulletin. FRONT/REAR (DUAL CIRCUIT) A/C SYSTEMS Each circuit of a front/rear A/C system must be flushed separately. Flow to one circuit must be blocked with the use of a blocked orifice tube or blocked TXV. The front circuit should always be flushed first. FRONT CIRCUIT 1. Recover system refrigerant. 2. Remove the expansion device (TXV or orifice tube) from the front circuit. 3. Reconnect the A/C lines with the orifice tube removed or install the appropriate non-blocked (open) TXV Adapter from kit J 45268. IMPORTANT: A blocked orifice tube is not supplied with the J 45268 Adapter kit. A blocked orifice can be made as follows: Cut the orifice tube frame and screen. Remove enough of the frame and screen to access the end of the orifice tube. Seal the tube by pinching oft the end of the orifice tube. 4. Remove the expansion device (TXV or orifice tube) from the rear circuit and install a plugged expansion device (TXV or orifice tube) into the rear circuit. 5. Remove the A/C compressor. 6. Inspect the end of the suction hose for a suction screen. Remove the suction screen using the J 44551 A/C suction screen kit, if installed. 7. Install the appropriate A/C compressor hose assembly flush adapter(s) from kit J 45268. 8. Configure the flush adapter and hose for either a forward flush or reverse flush. Refer to the Flushing Configuration section of this bulletin. 9. Perform the flush of the front system by following the instructions supplied with the J 43600 ACR 2000. 10. Replace the plugged expansion device (TXV or orifice tube) in the rear circuit with an open expansion device (TXV or orifice tube). 11. Replace the open expansion device (TXV or orifice tube) in the front circuit with a plugged expansion device (TXV or orifice tube). 12. Flush the rear system by following the instructions supplied with the J 43600 ACR 2000. Flushing Configuration - Forward Flush FORWARD FLUSH Forward flushing (the same flow as normal system operation) is recommended for contaminated refrigerant or RAG oil. IMPORTANT: Install a new filter inside the J 45268-1 for every flush. Service the filter with GM P/N 5651802 (in Canada, use P/N 729832). Remove and discard the check valve filter from the filter. IMPORTANT: Always close the valve on the J 43600 ACR 2000 external refrigerant tank before starting the flush process. To perform the forward flush, follow these steps: 1. Connect the flush filter adapter J 45268-1 to the suction port of the A/C compressor hose assembly flush adapter. 2. Connect the blue hose from the J 43600 ACR 2000 to the J 45268-1 flush filter adapter. 3. Connect the red hose from the J 43600 ACR 2000 to the discharge port of the A/C compressor hose assembly flush adapter. 4. Follow the instructions supplied with the J 43600 ACR 2000 and flush the A/C system. Flushing Configuration - Reverse Flush REVERSE FLUSH Reverse flushing (the opposite flow of normal operation) is recommended for desiccant bag failure. Always replace the accumulator after the reverse flushing procedure is complete. IMPORTANT: Install a new filter inside the J 45268-1 for every flush. Service the filter with GM P/N 5651802 (in Canada, use P/N 729832). Remove and discard the check valve from the filter. IMPORTANT: Always close the valve on the J 43600 external refrigerant tank before starting the flush process. To perform the reverse flush, follow these steps: 1. Connect the J 45268-1 flush filter adapter to the discharge port of the A/C compressor hose assembly flush adapter. 2. Connect the blue hose from the J 45268-1 flush filter adapter. 3. Connect the red hose to the suction port of the A/C compressor hose assembly flush adapter. 4. Follow the instructions supplied with the J 43600 ACR 2000 and flush the A/C system. After Flushing Is Complete AFTER FLUSHING IS COMPLETE IMPORTANT: Flushing will remove all the PAG oil and leak detection dye from the A/C system. After a catastrophic compressor failure, it is extremely important to eliminate and/or contain debris that cause repeat repairs. The debris generated from a catastrophic compressor failure is discharged into the compressor suction line, discharge line, condenser and liquid line. The use of the J 44551 Suction Screen kit DOES NOT replace the need for liquid line filters as described in the vehicle specific Service Information. Liquid line filters Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Service and Repair > Proper Flushing Procedures > Page 1587 should be used whenever possible (after a catastrophic compressor failure) to protect the expansion device (orifice tube or TXV) from debris. Delphi V5 and V7 compressors already have this screen installed in the suction port of the compressor and do not need an additional screen installed. The J 44551 Suction Screen kit contains three different screen sizes. It is important to select the correct size screen that will press fit into the suction port of the compressor hose assembly. The screen should not be installed loose inside the hose assembly. 1. Insert the J 44551-6 sizing tool into the suction hose to select the correct size suction screen. 2. Insert the suction screen into the compressor end of the suction hose. 3. Select and install the correct mandrel to the J 44551-5. 4. Install the J 44551-5 screen installation tool over the end of the suction hose and the suction screen. IMPORTANT: Correct placement of the J 44551 is critical. 5. Tighten the forcing screw of the J 44551-5. The suction screen is fully installed when the screen is flush with the end of the suction hose fitting. 6. Remove the J 44551-5 suction screen tool from the suction hose. 7. Install the J 44551-1 Suction Screen Notification Label. 8. Remove the A/C compressor drain plug, if equipped. Drain the PAG oil from the A/C compressor. Rotate the compressor input shaft to assist in draining the PAG oil from the A/C compressor. 9. Install the A/C compressor drain plug, if equipped. 10. Install the A/C compressor. 11. Remove the blocked orifice tube or TXV adapter (front/rear systems only). 12. Install a new orifice tube or remove the TXV adapter. - Inspect the original TXV for debris. - Clean or replace the original TXV as needed. - For front/rear systems, be sure both expansion devices (orifices or TXVs) are installed. IMPORTANT: - Install the in-line filter on front A/C systems before the orifice tube. - Install the in-line filter on front/rear A/C systems before the "Y" in the evaporator tube. - Do not allow metal burrs to enter the evaporator tube during cuffing or when removing the burrs. Because of limited space in the engine compartment, it may be necessary to remove the system's existing orifice tube and install a filter with an orifice. 13. Follow these steps for in-line filter installation: 13.1. Using a tubing cutter, cut the marked section of the evaporator tube. 13.2. Remove the burrs from the evaporator tube. 13.3. Remove the nuts (4), the ferrules (3) and the O-rings (2) from the A/C refrigerant filter (1). IMPORTANT: Do not install the O-rings (2)in this step. 13.4. Push the nuts (4) and the ferrules (3) over each of the evaporator tube halves. Install the ferrules (3) with the small end toward the nut (4). 13.5. Install the A/C refrigerant filter (3) to the evaporator tube (2) with the flow arrow pointing towards the evaporator. 13.6. While holding the evaporator tube in the A/C refrigerant filter (1), tighten the nuts (4) to the A/C refrigerant filter (1). TIGHTEN Nuts to 15 Nm (11 lb ft). 13.7. Remove the nuts (4) from the A/C refrigerant filter (1). 13.8. Coat the O-rings (2) with 525 viscosity refrigerant PAG oil 13.9. Install the O-rings (2) to the evaporator tube halves. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant > Component Information > Service and Repair > Proper Flushing Procedures > Page 1588 13.10. Install the nuts (4) to the A/C refrigerant filter (1). TIGHTEN Nuts to 15 Nm (11 lb ft). 14. Add the total system capacity of PAG oil to the A/C system. Refer to the System Capacities table in the appropriate Service Manual. 15. Add one bottle of J 41447 dye, GM P/N 12346303 (in Canada, use 10953458), or the equivalent using the J 41459 dye injector (or the equivalent). 16. Recharge the A/C system. 17. Leak test all connections using the J 44220 Universal 12V Leak Detection Lamp or the J 39400-A Leak Detector. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant Oil > Component Information > Technical Service Bulletins > A/C - New PAG Oil Refrigerant Oil: Technical Service Bulletins A/C - New PAG Oil Bulletin No.: 02-01-39-004B Date: November 16, 2005 INFORMATION Subject: New PAG Oil Released Models: 2006 and Prior GM Passenger Cars and Trucks (Including Saturn) 2003-2006 HUMMER H2 2006 HUMMER H3 2005-2006 Saab 9-7X Built With R-134a Refrigeration System All Air Conditioning Compressor Types (Excluding R4 and A6 Type Compressors) Supercede: This bulletin is being revised to change the PAG oil part number used for R4 and A6 compressors with R-134a refrigerant systems. Please discard Corporate Bulletin Number 02-01-39-004A (Section 01 - HVAC). All General Motors vehicles built with R-134a refrigerant systems shall now be serviced with GM Universal PAG Oil (excluding vehicles equipped with an R4 or A6 compressor). R4 and A6 compressors with R-134a refrigerant systems shall use PAG OIL, GM P/N 12356151 (A/C Delco part number 15-118) (in Canada, use P/N 10953486). Important: The PAG oil referenced in this bulletin is formulated with specific additive packages that meet General Motors specifications and use of another oil may void the A/C systems warranty. Use this new PAG oil when servicing the A/C system on the vehicles listed above. Oil packaged in an 8 oz tube should be installed using A/C Oil Injector, J 45037. Refer to the HVAC Section of Service Information for detailed information on Oil Balancing and Capacities. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant Oil > Component Information > Specifications > Capacity Specifications Refrigerant Oil: Capacity Specifications REFRIGERANT OIL DISTRIBUTION The Harrison HR1OOT, HR11OMD (CCOT), and V-5 (VDOT) compressor systems used on S/T models require 525 viscosity or polyalkaline glycol (PAG) refrigerant oil in the quantities listed below. - CCOT System-240 ml (8 fl. oz.) - VDOT System-265 ml (9 fl. oz.) New oil quantities must be added to the system during component replacement and conditions stated as follows: - With no signs of excessive oil leakage, add: A. All Compressors (drain and measure the oil). - If less than 30 ml (1 fl. oz.) is drained-add 60 ml (2 fl. oz.) to the new compressor. - If more than 30 ml (1 fl. oz.) is drained-add same amount that was drained to the new compressor. B. Accumulator-Add 105 ml (3.5 fl. oz.) of new oil to the replacement accumulator to compensate for oil retained by original accumulator desiccant and bag assemblies. The accumulator should only be replaced if leaking due to a perforation, damaged O-ring seal seat, or damaged threads. C. Evaporator-Add 90 ml (3 fl. oz.) of new refrigerant oil. D. Condenser-Add 30 ml (1 fl. oz.) of new refrigerant oil. REFRIGERANT OIL LOSS DUE TO A LARGE LEAK If the refrigerant charge is abruptly lost due to a large refrigerant leak, approximately 90 ml (3 fl. oz.) of refrigerant oil will be carried out of the system suspended in the refrigerant. Any malfunction that caused an abrupt refrigerant discharge will experience this oil loss. Malfunctions that allow the refrigerant to seep or bleed off over time do not experience this oil loss. After replacing a component which caused a large refrigerant leak, add 90 ml (3 fl. oz.) of new 525 viscosity or polyalkaline glycol (PAG) refrigerant oil plus the desired amount of oil for the particular component. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant Oil > Component Information > Specifications > Capacity Specifications > Page 1595 Refrigerant Oil: Fluid Type Specifications Polyalkaline Glycol (PAG) Refrigerant Oil Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fluids > Refrigerant Oil > Component Information > Specifications > Page 1596 Refrigerant Oil: Service and Repair Refrigerant Oil The PAG lubricant may be poured into the suction port. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Brake Bleeding > System Information > Service and Repair > General Information Brake Bleeding: Service and Repair General Information BLEEDING BRAKE HYDRAULIC SYSTEM Bleeding is necessary if air has entered the hydraulic brake system. It may be necessary to bleed the system at all four wheels if a low fluid level allowed air to enter the system, or the brake pipes have been disconnected at the master cylinder or combination valve. If a pipe is disconnected at one wheel, then only bleed that wheel. The time required to bleed the hydraulic system when the master cylinder is removed can be reduced by bleeding the master cylinder before installing it on the vehicle. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Brake Bleeding > System Information > Service and Repair > General Information > Page 1601 Brake Bleeding: Service and Repair With Four Wheel Antilock Brake System FOUR WHEEL ANTILOCK BRAKE BLEEDING The 4WAL brake pressure modulator valve (BPMV) should be bled after replacement or if air is trapped in it. Bleeding should not be necessary if the fluid is not contaminated or no air is in the BPMV. There are internal bleed valves on each side of the BPMV that open internal channels. Open the internal bleed valves 1/4 to 1/2 turn before bleeding. Should the module need bleeding, it must be bled after the master cylinder and before the wheel cylinders and calipers. NOTICE: The ignition switch must be in the "OFF" position or false trouble codes could be set to memory. Tools Required: - J 39177 Combination Valve Pressure Bleeding Tool - TK 00000 Tech-1 Scan Tool - TK 02650 RWAL/4WAL Cartridge Kit or 3000003 Mass Storage Cartridge - A modified J 35856 Combination Valve Pressure Bleeding Tool can be used in place of J 39177 provided that the dimple is removed from it first. Important: Expect to use two quarts of brake fluid to thoroughly bleed the system. Fig. 59 EHCU/BPMV Module Bleeding 1. Open the internal bleed valves on the sides of the BPMV 1/4 to 1/2 turn each (A). 2. Install J 39177 on the left high pressure accumulator bleed stem (C) of the BPMV. 3. Install J 39177 on the right high pressure accumulator bleed stem (C) of the BPMV. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Brake Bleeding > System Information > Service and Repair > General Information > Page 1602 Combination Valve Pressure Bleeding Tool 4. Install J 39177 on the combination valve. 5. Check the master cylinder reservoir fluid level and fill if needed. 6. Bleed the brakes as described under Pressure Bleeding. NOTICE: Always use the correct fastener in the proper location. When you replace a fastener, use ONLY the exact part number for that application. General Motors will call out those fasteners that require a replacement after removal. General Motors will also call out the fasteners that require thread lockers or thread sealant. UNLESS OTHERWISE SPECIFIED, do not use supplemental coatings (paints, greases, or other corrosion inhibitors) on threaded fasteners or fastener joint interfaces. Generally, such coatings adversely affect the fastener torque and the joint clamping force, and may damage the fastener. When you install fasteners, use the correct tightening sequence and specifications. Following these instructions can help you avoid damage to parts and systems. 7. Close the internal bleed valves. Tighten Internal bleed valves (A) to 7 Nm (60 lbs. in.). 8. Remove the three J 39177 tools. 9. Check the master cylinder reservoir fluid level and fill if needed. 10. With the ignition switch "ON" and the engine off, do six function tests with the Tech-1 scan tool. 11. Repeat the wheel cylinder and caliper bleed procedure to remove the air that purged from the BPMV during the function tests. 12. Apply firm pressure to the brake pedal and evaluate brake pedal feel. 13. Repeat the bleed procedure if needed. - Make sure you have a good, hard brake pedal before starting the engine and moving the vehicle. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Brake Bleeding > System Information > Service and Repair > General Information > Page 1603 Brake Bleeding: Service and Repair With VCM/Four Wheel Antilock Brake System VCM/FOUR WHEEL ANTILOCK BRAKE SYSTEM BLEEDING The brake pressure modulator valve (BPMV) should be bled after replacement or if air is trapped in it. Bleeding should not be necessary if the fluid is not contaminated or no air is in the BPMV. There are internal bleed valves on each side of the BPMV that open internal channels. Open the internal bleed valves 1/4 to 1/2 turn before bleeding. Should the module need bleeding, it must be bled after the master cylinder and before the wheel cylinders and calipers. NOTICE: The ignition switch must be in the "OFF" position or false trouble codes could be set to memory. Tools Required: - J 39177 Combination Valve Pressure Bleeding Tool (Three required) - TK 00000 Tech-1 Scan Tool - TK 02650 RWAL/4WAL Cartridge Kit or 3000003 Mass Storage Cartridge - A modified J 35856 Combination Valve Pressure Bleeding Tool can be used in place of J 39177 providing you remove the dimple from it first. Important: Expect to use two quarts of brake fluid to thoroughly bleed the system. Fig. 59 EHCU/BPMV Module Bleeding 1. Open the internal bleed valves on the sides of the BPMV 1/4 to 1/2 turn each (A). 2. Install J 39177 on the left high pressure accumulator bleed stem (C) of the BPMV. 3. Install J 39177 on the right high pressure accumulator bleed stem (C) of the BPMV. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Brake Bleeding > System Information > Service and Repair > General Information > Page 1604 Combination Valve Pressure Bleeding Tool 4. Install J 39177 on the combination valve. 5. Check the master cylinder reservoir fluid level and fill if needed. 6. Bleed the brakes as described under Pressure Bleeding. NOTICE: Always use the correct fastener in the proper location. When you replace a fastener, use ONLY the exact part number for that application. General Motors will call out those fasteners that require a replacement after removal. General Motors will also call out the fasteners that require thread lockers or thread sealant. UNLESS OTHERWISE SPECIFIED, do not use supplemental coatings (paints, greases, or other corrosion inhibitors) on threaded fasteners or fastener joint interfaces. Generally, such coatings adversely affect the fastener torque and the joint clamping force, and may damage the fastener. When you install fasteners, use the correct tightening sequence and specifications. Following these instructions can help you avoid damage to parts and systems. 7. Close the internal bleed valves. Tighten Internal bleed valves (A) to 7 Nm (60 lbs. in.). 8. Remove the three J 39177 tools. 9. Check the master cylinder reservoir fluid level and fill if needed. 10. With the ignition switch "ON" and the engine off, do six function tests with the Tech-1 scan tool. 11. Repeat the wheel cylinder and caliper bleed procedure to remove the air that purged from the BPMV during the tunction tests. 12. Apply firm pressure to the brake pedal and evaluate brake pedal feel. 13. Repeat the bleed procedure if needed. - Make sure you have a good, hard brake pedal before starting the engine and moving the vehicle. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Brake Bleeding > System Information > Service and Repair > General Information > Page 1605 Brake Bleeding: Service and Repair With Rear Wheel Antilock Brake System REAR WHEEL ANTILOCK BRAKE SYSTEM BLEEDING NOTICE: The ignition switch must be in the "OFF" position or false DTCs could be set to memory. Tools Required: - J 39177 Combination Valve Pressure Bleeding Tool - TK 00000 Tech-1 Scan Tool - TK 02650 RWALI4WAL Cartridge Kit or 7000001 Mass Storage Cartridge 1. Install J 39177 on the combination valve. 2. Check the master cylinder reservoir fluid level and fill it needed. 3. Bleed wheel cylinders and calipers. 4. Turn ignition switch "ON" and do three function tests with the Tech-1 scan tool. 5. Re-bleed the rear brakes as described under Pressure Bleeding. 6. Evaluate brake pedal feel. 7. Repeat the bleed procedure if needed. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Brake Bleeding > System Information > Service and Repair > General Information > Page 1606 Brake Bleeding: Service and Repair General Information BLEEDING BRAKE HYDRAULIC SYSTEM Bleeding is necessary if air has entered the hydraulic brake system. It may be necessary to bleed the system at all four wheels if a low fluid level allowed air to enter the system, or the brake pipes have been disconnected at the master cylinder or combination valve. If a pipe is disconnected at one wheel, then only bleed that wheel. The time required to bleed the hydraulic system when the master cylinder is removed can be reduced by bleeding the master cylinder before installing it on the vehicle. With Four Wheel Antilock Brake System FOUR WHEEL ANTILOCK BRAKE BLEEDING The 4WAL brake pressure modulator valve (BPMV) should be bled after replacement or if air is trapped in it. Bleeding should not be necessary if the fluid is not contaminated or no air is in the BPMV. There are internal bleed valves on each side of the BPMV that open internal channels. Open the internal bleed valves 1/4 to 1/2 turn before bleeding. Should the module need bleeding, it must be bled after the master cylinder and before the wheel cylinders and calipers. NOTICE: The ignition switch must be in the "OFF" position or false trouble codes could be set to memory. Tools Required: - J 39177 Combination Valve Pressure Bleeding Tool - TK 00000 Tech-1 Scan Tool - TK 02650 RWAL/4WAL Cartridge Kit or 3000003 Mass Storage Cartridge - A modified J 35856 Combination Valve Pressure Bleeding Tool can be used in place of J 39177 provided that the dimple is removed from it first. Important: Expect to use two quarts of brake fluid to thoroughly bleed the system. Fig. 59 EHCU/BPMV Module Bleeding 1. Open the internal bleed valves on the sides of the BPMV 1/4 to 1/2 turn each (A). 2. Install J 39177 on the left high pressure accumulator bleed stem (C) of the BPMV. 3. Install J 39177 on the right high pressure accumulator bleed stem (C) of the BPMV. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Brake Bleeding > System Information > Service and Repair > General Information > Page 1607 Combination Valve Pressure Bleeding Tool 4. Install J 39177 on the combination valve. 5. Check the master cylinder reservoir fluid level and fill if needed. 6. Bleed the brakes as described under Pressure Bleeding. NOTICE: Always use the correct fastener in the proper location. When you replace a fastener, use ONLY the exact part number for that application. General Motors will call out those fasteners that require a replacement after removal. General Motors will also call out the fasteners that require thread lockers or thread sealant. UNLESS OTHERWISE SPECIFIED, do not use supplemental coatings (paints, greases, or other corrosion inhibitors) on threaded fasteners or fastener joint interfaces. Generally, such coatings adversely affect the fastener torque and the joint clamping force, and may damage the fastener. When you install fasteners, use the correct tightening sequence and specifications. Following these instructions can help you avoid damage to parts and systems. 7. Close the internal bleed valves. Tighten Internal bleed valves (A) to 7 Nm (60 lbs. in.). 8. Remove the three J 39177 tools. 9. Check the master cylinder reservoir fluid level and fill if needed. 10. With the ignition switch "ON" and the engine off, do six function tests with the Tech-1 scan tool. 11. Repeat the wheel cylinder and caliper bleed procedure to remove the air that purged from the BPMV during the function tests. 12. Apply firm pressure to the brake pedal and evaluate brake pedal feel. 13. Repeat the bleed procedure if needed. - Make sure you have a good, hard brake pedal before starting the engine and moving the vehicle. With VCM/Four Wheel Antilock Brake System VCM/FOUR WHEEL ANTILOCK BRAKE SYSTEM BLEEDING The brake pressure modulator valve (BPMV) should be bled after replacement or if air is trapped in it. Bleeding should not be necessary if the fluid is not contaminated or no air is in the BPMV. There are internal bleed valves on each side of the BPMV that open internal channels. Open the internal bleed valves 1/4 to 1/2 turn before bleeding. Should the module need bleeding, it must be bled after the master cylinder and before the wheel cylinders and calipers. NOTICE: The ignition switch must be in the "OFF" position or false trouble codes could be set to memory. Tools Required: - J 39177 Combination Valve Pressure Bleeding Tool (Three required) - TK 00000 Tech-1 Scan Tool - TK 02650 RWAL/4WAL Cartridge Kit or 3000003 Mass Storage Cartridge - A modified J 35856 Combination Valve Pressure Bleeding Tool can be used in place of J 39177 providing you remove the dimple from it first. Important: Expect to use two quarts of brake fluid to thoroughly bleed the system. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Brake Bleeding > System Information > Service and Repair > General Information > Page 1608 Fig. 59 EHCU/BPMV Module Bleeding 1. Open the internal bleed valves on the sides of the BPMV 1/4 to 1/2 turn each (A). 2. Install J 39177 on the left high pressure accumulator bleed stem (C) of the BPMV. 3. Install J 39177 on the right high pressure accumulator bleed stem (C) of the BPMV. Combination Valve Pressure Bleeding Tool 4. Install J 39177 on the combination valve. 5. Check the master cylinder reservoir fluid level and fill if needed. 6. Bleed the brakes as described under Pressure Bleeding. NOTICE: Always use the correct fastener in the proper location. When you replace a fastener, use ONLY the exact part number for that application. General Motors will call out those fasteners that require a replacement after removal. General Motors will also call out the fasteners that require thread lockers or thread sealant. UNLESS OTHERWISE SPECIFIED, do not use supplemental coatings (paints, greases, or other corrosion inhibitors) on threaded fasteners or fastener joint interfaces. Generally, such coatings adversely affect the fastener torque and the joint clamping force, and may damage the fastener. When you install fasteners, use the correct tightening sequence and specifications. Following these instructions can help you avoid damage to parts and systems. 7. Close the internal bleed valves. Tighten Internal bleed valves (A) to 7 Nm (60 lbs. in.). 8. Remove the three J 39177 tools. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Brake Bleeding > System Information > Service and Repair > General Information > Page 1609 9. Check the master cylinder reservoir fluid level and fill if needed. 10. With the ignition switch "ON" and the engine off, do six function tests with the Tech-1 scan tool. 11. Repeat the wheel cylinder and caliper bleed procedure to remove the air that purged from the BPMV during the tunction tests. 12. Apply firm pressure to the brake pedal and evaluate brake pedal feel. 13. Repeat the bleed procedure if needed. - Make sure you have a good, hard brake pedal before starting the engine and moving the vehicle. With Rear Wheel Antilock Brake System REAR WHEEL ANTILOCK BRAKE SYSTEM BLEEDING NOTICE: The ignition switch must be in the "OFF" position or false DTCs could be set to memory. Tools Required: - J 39177 Combination Valve Pressure Bleeding Tool - TK 00000 Tech-1 Scan Tool - TK 02650 RWALI4WAL Cartridge Kit or 7000001 Mass Storage Cartridge 1. Install J 39177 on the combination valve. 2. Check the master cylinder reservoir fluid level and fill it needed. 3. Bleed wheel cylinders and calipers. 4. Turn ignition switch "ON" and do three function tests with the Tech-1 scan tool. 5. Re-bleed the rear brakes as described under Pressure Bleeding. 6. Evaluate brake pedal feel. 7. Repeat the bleed procedure if needed. Hydraulic System Flushing HYDRAULIC SYSTEM FLUSHING Flushing is done at each bleeder valve similar to the bleeding procedure. The difference-is that the bleeder valve is opened 1 1/2 turns and fluid is forced through the pipes, hoses, and bleeder valves until it comes out clear in color. Refer to Hydraulic System, Service and Repair. Check the master cylinder fluid level after flushing at each bleeder valve and refill as required. After flushing, make sure the master cylinder reservoir is filled to the correct level. Manual Bleeding MANUAL BLEEDING NOTICE: Brake fluid will damage electrical connections and painted surfaces. Use shop cloths, suitable containers, and tender covers to prevent brake fluid from contacting these areas. Always re-seal and wipe off brake fluid containers to prevent spills. Tool Required: J 28434 Wheel Cylinder Bleeder Wrench - Relieve the vacuum reserve by applying the brakes several times with the ignition "OFF" 1. Fill the master cylinder reservoirs with Delco Supreme No. 11 Hydraulic Brake Fluid (GM P/N 1052535) or an equivalent DOT 3 motor vehicle brake fluid. - Maintain the fluid level during bleeding. 2. If the master cylinder is suspected to have air in the bore, bleed it before any wheel cylinder or caliper. A. Disconnect the forward brake pipe connection at the master cylinder. B. Allow the brake fluid to flow from the connector port. C. Connect the brake pipe but do not tighten. D. Slowly apply the brake pedal and allow the air to bleed from the loose fitting. E. Tighten the fitting before releasing the pedal. F. Wait 15 seconds. G. Repeat this sequence, including the 15-second wait, until all air is purged from the bore. H. After all air has been removed from the forward connection, repeat this procedure for the rear pipe. 3. If the BPMV of the 4WAL system is replaced or suspected to have air trapped inside, it must be bled next. Refer to With ABS. 4. Bleed each wheel in the following sequence: Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Brake Bleeding > System Information > Service and Repair > General Information > Page 1610 A. Right rear B. Left rear C. Right front D. Left front 5. Attach J 28434 to the wheel cylinder/caliper bleeder valve. - Immerse the opposite end of the hose into a container partially filled with clean brake fluid. 6. Slowly apply the brake pedal one time and hold. 7. Loosen the bleeder valve to purge the air from the wheel cylinder/caliper. 8. Tighten the bleeder valve and slowly release the pedal. 9. Wait 15 seconds. 10. Repeat this sequence, including the 15-second wait, until all air is purged from the wheel cylinder/caliper. 11. Tighten the bleeder valve to 7 N.m (62 lbs. in.). 12. Continue steps 5 through 11 at each wheel until the system is bled. 13. Check the brake pedal for "sponginess" and the brake warning lamp for an indication of unbalanced pressure. Repeat the bleeding procedure to correct either of these conditions. Pressure Bleeding PRESSURE BLEEDING A diaphragm-type pressure bleeder must be used. It must have a rubber diaphragm between the air supply and brake fluid to prevent air, moisture, oil, and other contaminants from entering the hydraulic system. NOTICE: Brake fluid will damage electrical connections and painted surfaces. Use shop cloths, suitable containers, and fender covers to prevent brake fluid from contacting these areas. Always reseal and wipe off brake fluid containers to prevent spills. Tools Required: - J 29567 Brake Bleeder Adapter - J 39177 Combination Valve Pressure Bleeding Tool - J 28434 Wheel Cylinder Bleeder Wrench 1. Fill the pressure tank at least 2/3 full of brake fluid. The bleeder must be bled each time fluid is added. 2. Charge the bleeder to 140-170 kPa (20-25 psi). Combination Valve Pressure Bleeding Tool 3. Use J 39177 to depress and hold the valve stem on the combination valve. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Brake Bleeding > System Information > Service and Repair > General Information > Page 1611 4. Install the bleeder adapter. 5. If the BPMV of the 4WAL system is replaced or suspected to air trapped inside, it must be bled next. 6. Bleed each wheel in the following sequence: A. Right rear B. Left rear C. Right front D. Left front 7. Connect the hose from the bleeder to the adapter at the master cylinder. 8. Open the tank valve. 9. Attach J 28434 to a bleeder valve. 10. Immerse the opposite end of the hose into a contamer partially filled with clean brake fluid. 11. Open the bleeder valve at least 3/4 of a turn and allow the fluid to flow until no air is seen in the fluid. 12. Tighten the bleeder valve to 7 Nm (62 lbs. in.). 13. Repeat steps 9 through 12 at all the wheels. 14. Check the brake pedal for "sponginess". - Repeat the bleeding procedure if this condition is found. 15. Remove J 39177. 16. Disconnect the hose from the bleeder adapter. 17. Remove the bleeder adapter. 18. Fill the master cylinder to the proper level. Master Cylinder Bench Bleeding MASTER CYLINDER BENCH BLEEDING Bench bleed the master cylinder to remove the air from it prior to installation. This reduces the amount of bleeding needed after it is installed on the vehicle. 1. Plug the outlet ports and mount the master cylinder in a vise with the front end tilted slightly down. 2. Fill the reservoir with clean brake fluid. 3. Using a tool with a smooth rounded end, stroke the primary piston about 25 mm (1 inch) several times. - As air is bled from the master cylinder, the primary piston will not travel the full 25-mm (1-inch) stroke. 4. Reposition the master cylinder in the vise with the front end tilted slightly up. 5. Again stroke the primary piston about 25 mm (1 inch) several times. 6. Reposition the master cylinder in the vise to the level position. 7. Loosen the plugs one at a time and push the piston into the bore to force the air from the cylinder. - To prevent air from being sucked back into the cylinder, tighten the plug(s) before allowing the piston to return to its original position. 8. Fill the reservoir. - Normal bleeding procedures should be followed after the master cylinder is installed. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Circuit Breaker > Component Information > Diagrams > Diagram Information and Instructions Circuit Breaker: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. Use this page as a reference to determine the meaning of an abbreviation if necessary. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery Bi-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CHMSL Center High Mount Stoplamp CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRO Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Circuit Breaker > Component Information > Diagrams > Diagram Information and Instructions > Page 1617 F-PUMP Fuel Pump FLASH Flasher FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Circuit Breaker > Component Information > Diagrams > Diagram Information and Instructions > Page 1618 SIR Supplemental Inflatable Restraint SKT Socket SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature TIL Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Circuit Breaker > Component Information > Diagrams > Diagram Information and Instructions > Page 1619 example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE (ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: ^ Slide across the vehicle seat. ^ Sit down or stand up. ^ Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: ^ They are bumped or dropped. ^ They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Circuit Breaker > Component Information > Diagrams > Diagram Information and Instructions > Page 1620 Symbols (Part 1 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Circuit Breaker > Component Information > Diagrams > Diagram Information and Instructions > Page 1621 Symbols (Part 2 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Circuit Breaker > Component Information > Diagrams > Diagram Information and Instructions > Page 1622 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Circuit Breaker > Component Information > Diagrams > Diagram Information and Instructions > Page 1623 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Circuit Breaker > Component Information > Diagrams > Diagram Information and Instructions > Page 1624 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Circuit Breaker > Component Information > Diagrams > Diagram Information and Instructions > Page 1625 Circuit Breaker: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Circuit Breaker > Component Information > Diagrams > Diagram Information and Instructions > Page 1626 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Circuit Breaker > Component Information > Diagrams > Diagram Information and Instructions > Page 1627 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Circuit Breaker > Component Information > Diagrams > Diagram Information and Instructions > Page 1628 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Circuit Breaker > Component Information > Diagrams > Diagram Information and Instructions > Page 1629 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Circuit Breaker > Component Information > Diagrams > Diagram Information and Instructions > Page 1630 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. ^ If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. ^ A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Circuit Breaker > Component Information > Diagrams > Diagram Information and Instructions > Page 1631 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Circuit Breaker > Component Information > Diagrams > Diagram Information and Instructions > Page 1632 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Circuit Breaker > Component Information > Diagrams > Diagram Information and Instructions > Page 1633 Ohmmeter Meter Scales Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Circuit Breaker > Component Information > Diagrams > Diagram Information and Instructions > Page 1634 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. ^ An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. ^ On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: ^ A range selector switch which permits the selection of different ranges of resistance. ^ A set adjust control which allows the meter to be set at zero for accurate measurements. ^ Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Circuit Breaker > Component Information > Diagrams > Diagram Information and Instructions > Page 1635 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: ^ Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. ^ Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. ^ Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Circuit Breaker > Component Information > Diagrams > Diagram Information and Instructions > Page 1636 be less than 10 percent of the total drop. When using a voltmeter: ^ Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. ^ Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. ^ The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: ^ Check the accuracy and completeness of the complaint. ^ Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Circuit Breaker > Component Information > Diagrams > Diagram Information and Instructions > Page 1637 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. ^ The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Circuit Breaker > Component Information > Diagrams > Diagram Information and Instructions > Page 1638 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Circuit Breaker > Component Information > Diagrams > Diagram Information and Instructions > Page 1639 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Circuit Breaker > Component Information > Diagrams > Diagram Information and Instructions > Page 1640 Twisted/Shielded Wire Repair Twisted Wires Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Circuit Breaker > Component Information > Diagrams > Diagram Information and Instructions > Page 1641 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Circuit Breaker > Component Information > Diagrams > Diagram Information and Instructions > Page 1642 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Circuit Breaker > Component Information > Diagrams > Diagram Information and Instructions > Page 1643 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). ^ Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean ^ Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. ^ Roll crimp (13) and solder the terminal. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Circuit Breaker > Component Information > Diagrams > Diagram Information and Instructions > Page 1644 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Circuit Breaker > Component Information > Diagrams > Diagram Information and Instructions > Page 1645 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Circuit Breaker > Component Information > Diagrams > Diagram Information and Instructions > Page 1646 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. ^ Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean ^ Terminal cavity of the connector body. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Circuit Breaker > Component Information > Diagrams > Diagram Information and Instructions > Page 1647 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. ^ Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Circuit Breaker > Component Information > Diagrams > Diagram Information and Instructions > Page 1648 Circuit Breaker: Connector Views Fuse Block Details Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Circuit Breaker > Component Information > Diagrams > Diagram Information and Instructions > Page 1649 Fuse Block Details Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Circuit Breaker > Component Information > Diagrams > Diagram Information and Instructions > Page 1650 Circuit Breaker: Electrical Diagrams Fuse Block Details (Part 1 Of 4) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Circuit Breaker > Component Information > Diagrams > Diagram Information and Instructions > Page 1651 Fuse Block Details (Part 4 Of 4) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Circuit Breaker > Component Information > Diagrams > Diagram Information and Instructions > Page 1652 Fuse Block Details (Part 3 Of 4) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Circuit Breaker > Component Information > Diagrams > Diagram Information and Instructions > Page 1653 Fuse Block Details (Part 4 Of 4) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Circuit Breaker > Component Information > Diagrams > Diagram Information and Instructions > Page 1654 Fuse Block Details (Part 2 Of 4) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Circuit Breaker > Component Information > Diagrams > Diagram Information and Instructions > Page 1655 Fuse Block Details Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Circuit Breaker > Component Information > Diagrams > Page 1656 Fuse And Circuit Breaker Identification Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse > Component Information > Technical Service Bulletins > Customer Interest: > 361102 > Feb > 94 > A/C - Erratic HVAC Operation & Self Diagnostic Blinks Fuse: Customer Interest A/C - Erratic HVAC Operation & Self Diagnostic Blinks Group Ref.: HVAC Bulletin No.: 361102 Date: February, 1994 SUBJECT: BLOWN FUSE, ERRATIC HVAC OPERATION, AND SELF DIAGNOSTIC FEATURE BLINKS (INSULATE WIRES) MODELS: 1994 AND PRIOR CHEVROLET AND GMC C/K TRUCKS CONDITION: Some owners may experience a blown fuse, erratic HVAC operation, or a blinking HVAC control head self diagnostic indicator. CAUSE: Two possible hard to find causes have been discovered for the above symptoms: - Six way I/P to HVAC connector terminals may short to the ashtray. The connector has slots to accommodate the terminal positive attachment locks that allow metal to metal contact between the exposed terminals and the ashtray (Figure 1). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse > Component Information > Technical Service Bulletins > Customer Interest: > 361102 > Feb > 94 > A/C - Erratic HVAC Operation & Self Diagnostic Blinks > Page 1665 - The HVAC Harness from the control head to the blower and mode door motors, running across the vehicle just under the dash panel, may chafe against the cassette deck support bracket (Figure 2). CORRECTION: Both conditions can be corrected by taping or otherwise shielding the wires from contact with the respective metal edges. If the second condition has caused significant wire damage, repair according to guidelines found in the wire repair section of the appropriate service manual. WARRANTY INFORMATION: For vehicles repaired under warranty, use: Labor Op Description Labor Time N6030 Wiring and/or Use Published connector repair, A/C Labor Operation Time Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Fuse: > 07-08-45-002 > Sep > 07 > Electrical - Aftermarket Fuse Warning Fuse: All Technical Service Bulletins Electrical - Aftermarket Fuse Warning Bulletin No.: 07-08-45-002 Date: September 05, 2007 ADVANCED SERVICE INFORMATION Subject: Service Alert: Concerns With Aftermarket Fuses in GM Vehicles Models: 2008 and Prior GM Passenger Cars and Light Duty Trucks (including Saturn) 2008 and Prior HUMMER H2, H3 2008 and Prior Saab 9-7X Concerns with Harbor Freight Tools "Storehouse" Branded Blade Type Fuses General Motors has become aware of a fuse recall by Harbor Freight Tools/Storehouse for a variety of aftermarket fuses. In two cases, these fuses have not provided protection for the wiring system of the vehicles they were customer installed in. Upon testing the 15 amp version, it was found that the fuse still would not "open" when shorted directly across the battery terminals. How to Identify These Fuses Packed in a 120 piece set, the fuse has a translucent, hard plastic, blue body with the amperage stamped into the top. There are no white painted numbers on the fuse to indicate amperage. There are no identifying marks on the fuse to tell who is making it. The fuses are known to be distributed by Harbor Freight Tools but there may be other marketers, and packaging of this style of fuse. It would be prudent to replace these fuses if found in a customers vehicle. Likewise, if wiring overheating is found you should check the fuse panel for the presence of this style of fuse. All GM dealers should use genuine GM fuses on the vehicles they service. You should also encourage the use of GM fuses to your customers to assure they are getting the required electrical system protection. GM has no knowledge of any concerns with other aftermarket fuses. If additional information becomes available, this bulletin will be updated. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Fuse: > 361102 > Feb > 94 > A/C - Erratic HVAC Operation & Self Diagnostic Blinks Fuse: All Technical Service Bulletins A/C - Erratic HVAC Operation & Self Diagnostic Blinks Group Ref.: HVAC Bulletin No.: 361102 Date: February, 1994 SUBJECT: BLOWN FUSE, ERRATIC HVAC OPERATION, AND SELF DIAGNOSTIC FEATURE BLINKS (INSULATE WIRES) MODELS: 1994 AND PRIOR CHEVROLET AND GMC C/K TRUCKS CONDITION: Some owners may experience a blown fuse, erratic HVAC operation, or a blinking HVAC control head self diagnostic indicator. CAUSE: Two possible hard to find causes have been discovered for the above symptoms: - Six way I/P to HVAC connector terminals may short to the ashtray. The connector has slots to accommodate the terminal positive attachment locks that allow metal to metal contact between the exposed terminals and the ashtray (Figure 1). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Fuse: > 361102 > Feb > 94 > A/C - Erratic HVAC Operation & Self Diagnostic Blinks > Page 1675 - The HVAC Harness from the control head to the blower and mode door motors, running across the vehicle just under the dash panel, may chafe against the cassette deck support bracket (Figure 2). CORRECTION: Both conditions can be corrected by taping or otherwise shielding the wires from contact with the respective metal edges. If the second condition has caused significant wire damage, repair according to guidelines found in the wire repair section of the appropriate service manual. WARRANTY INFORMATION: For vehicles repaired under warranty, use: Labor Op Description Labor Time N6030 Wiring and/or Use Published connector repair, A/C Labor Operation Time Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse > Component Information > Technical Service Bulletins > All Other Service Bulletins for Fuse: > 07-08-45-002 > Sep > 07 > Electrical - Aftermarket Fuse Warning Fuse: All Technical Service Bulletins Electrical - Aftermarket Fuse Warning Bulletin No.: 07-08-45-002 Date: September 05, 2007 ADVANCED SERVICE INFORMATION Subject: Service Alert: Concerns With Aftermarket Fuses in GM Vehicles Models: 2008 and Prior GM Passenger Cars and Light Duty Trucks (including Saturn) 2008 and Prior HUMMER H2, H3 2008 and Prior Saab 9-7X Concerns with Harbor Freight Tools "Storehouse" Branded Blade Type Fuses General Motors has become aware of a fuse recall by Harbor Freight Tools/Storehouse for a variety of aftermarket fuses. In two cases, these fuses have not provided protection for the wiring system of the vehicles they were customer installed in. Upon testing the 15 amp version, it was found that the fuse still would not "open" when shorted directly across the battery terminals. How to Identify These Fuses Packed in a 120 piece set, the fuse has a translucent, hard plastic, blue body with the amperage stamped into the top. There are no white painted numbers on the fuse to indicate amperage. There are no identifying marks on the fuse to tell who is making it. The fuses are known to be distributed by Harbor Freight Tools but there may be other marketers, and packaging of this style of fuse. It would be prudent to replace these fuses if found in a customers vehicle. Likewise, if wiring overheating is found you should check the fuse panel for the presence of this style of fuse. All GM dealers should use genuine GM fuses on the vehicles they service. You should also encourage the use of GM fuses to your customers to assure they are getting the required electrical system protection. GM has no knowledge of any concerns with other aftermarket fuses. If additional information becomes available, this bulletin will be updated. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse > Component Information > Locations > In-Line Fuse Trailer Tow Harness Engine Compartment Wiring Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse > Component Information > Locations > In-Line Fuse > Page 1683 Fuse: Locations In-Line Fuse Holder Underhood Lamp Floor Parcel Tray Harness Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse > Component Information > Locations > In-Line Fuse > Page 1684 Underhood Lamp Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Locations Fuse Block: Locations Steering Column Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Locations > Page 1688 I/P Harness Wiring, LH Side Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Locations > Page 1689 Turn Signal And Hazard Flashers Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Locations > Page 1690 Safety Belt Wiring Bus Bar Ground Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions Fuse Block: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. Use this page as a reference to determine the meaning of an abbreviation if necessary. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery Bi-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CHMSL Center High Mount Stoplamp CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRO Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1693 F-PUMP Fuel Pump FLASH Flasher FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1694 SIR Supplemental Inflatable Restraint SKT Socket SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature TIL Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1695 example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE (ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: ^ Slide across the vehicle seat. ^ Sit down or stand up. ^ Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: ^ They are bumped or dropped. ^ They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1696 Symbols (Part 1 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1697 Symbols (Part 2 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1698 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1699 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1700 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1701 Fuse Block: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1702 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1703 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1704 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1705 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1706 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. ^ If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. ^ A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1707 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1708 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1709 Ohmmeter Meter Scales Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1710 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. ^ An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. ^ On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: ^ A range selector switch which permits the selection of different ranges of resistance. ^ A set adjust control which allows the meter to be set at zero for accurate measurements. ^ Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1711 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: ^ Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. ^ Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. ^ Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1712 be less than 10 percent of the total drop. When using a voltmeter: ^ Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. ^ Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. ^ The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: ^ Check the accuracy and completeness of the complaint. ^ Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1713 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. ^ The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1714 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1715 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1716 Twisted/Shielded Wire Repair Twisted Wires Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1717 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1718 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1719 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). ^ Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean ^ Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. ^ Roll crimp (13) and solder the terminal. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1720 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1721 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1722 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. ^ Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean ^ Terminal cavity of the connector body. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1723 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. ^ Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1724 Fuse Block: Connector Views Fuse Block Details Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1725 Fuse Block Details Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1726 Fuse Block: Electrical Diagrams Fuse Block Details (Part 1 Of 4) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1727 Fuse Block Details (Part 2 Of 4) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1728 Fuse Block Details (Part 3 Of 4) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1729 Fuse Block Details (Part 4 Of 4) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1730 Fuse Block Details (Part 4 Of 4) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Diagram Information and Instructions > Page 1731 Fuse Block Details Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fuse Block > Component Information > Diagrams > Page 1732 Fuse And Circuit Breaker Identification Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Fusible Link > Component Information > Locations Forward Lamps Harness - RH Side Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Relay Box > Component Information > Locations Relay Box: Locations I/P Harness Wiring, LH Side Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Relay Box > Component Information > Locations > Page 1739 Turn Signal And Hazard Flashers Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Relay Box > Component Information > Locations > Page 1740 Horn Relay Installation Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Relay Box > Component Information > Diagrams > Diagram Information and Instructions Relay Box: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. Use this page as a reference to determine the meaning of an abbreviation if necessary. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery Bi-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CHMSL Center High Mount Stoplamp CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRO Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 1743 F-PUMP Fuel Pump FLASH Flasher FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 1744 SIR Supplemental Inflatable Restraint SKT Socket SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature TIL Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 1745 example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE (ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: ^ Slide across the vehicle seat. ^ Sit down or stand up. ^ Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: ^ They are bumped or dropped. ^ They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 1746 Symbols (Part 1 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 1747 Symbols (Part 2 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 1748 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 1749 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 1750 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 1751 Relay Box: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 1752 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 1753 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 1754 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 1755 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 1756 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. ^ If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. ^ A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 1757 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 1758 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 1759 Ohmmeter Meter Scales Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 1760 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. ^ An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. ^ On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: ^ A range selector switch which permits the selection of different ranges of resistance. ^ A set adjust control which allows the meter to be set at zero for accurate measurements. ^ Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 1761 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: ^ Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. ^ Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. ^ Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 1762 be less than 10 percent of the total drop. When using a voltmeter: ^ Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. ^ Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. ^ The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: ^ Check the accuracy and completeness of the complaint. ^ Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 1763 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. ^ The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 1764 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 1765 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 1766 Twisted/Shielded Wire Repair Twisted Wires Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 1767 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 1768 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 1769 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). ^ Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean ^ Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. ^ Roll crimp (13) and solder the terminal. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 1770 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 1771 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 1772 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. ^ Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean ^ Terminal cavity of the connector body. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 1773 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. ^ Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 1774 Relay Box: Electrical Diagrams Convenience Center Details (Part 1 Of 2) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Fuses and Circuit Breakers > Relay Box > Component Information > Diagrams > Diagram Information and Instructions > Page 1775 Convenience Center Details (Part 2 Of 2) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Service Reminder Indicators > Coolant Level Indicator Lamp > Component Information > Description and Operation Coolant Level Indicator Lamp: Description and Operation This system uses a sensor mounted on the radiator and an indicator light mounted in the instrument panel to warn the driver if coolant level is too low. This light is wired in series with the ignition switch, ECM and the sensor. When the ignition switch is turned to the crank position, the circuit is energized and the indicator light will illuminate. When the ignition switch is turned to the ON position and coolant level is sufficient, the sensor will indicate this to the ECM and the light will turn off. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Service Reminder Indicators > Coolant Level Indicator Lamp > Component Information > Testing and Inspection > Indicator Lamp Remains Illuminated Coolant Level Indicator Lamp: Testing and Inspection Indicator Lamp Remains Illuminated 1. Turn ignition switch to the On position, then check coolant level and add coolant as necessary. If lamp remains illuminated, proceed to step 2. 2. Disconnect electrical connector at the sensor. If lamp does not illuminate replace the sensor. If lamp remains illuminated, proceed to step 3. 3. Connect electrical lead to the sensor and check for an open circuit between the sensor and the module. Repair or replace as necessary. If circuit is satisfactory, replace the ECM. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Service Reminder Indicators > Coolant Level Indicator Lamp > Component Information > Testing and Inspection > Indicator Lamp Remains Illuminated > Page 1782 Coolant Level Indicator Lamp: Testing and Inspection Indicator Lamp Will Not Illuminate 1. Turn ignition switch to the crank position, and proceed as follows: a. If lamp illuminates, lamp is satisfactory and connector is properly installed. Proceed to step 2. b. If lamp does not illuminate, check bulb, socket and wiring between socket and module connector. Replace or repair as necessary. 2. Turn ignition switch to the On position and disconnect electrical lead at coolant level sensor mounted on the radiator. If lamp fails to illuminate, check wiring between coolant level sensor connector and ECM for a short circuit to ground. If circuit is satisfactory, replace the ECM. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Service Reminder Indicators > Malfunction Indicator Lamp > Component Information > Locations Malfunction Indicator Lamp: Locations Instrument cluster. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Service Reminder Indicators > Malfunction Indicator Lamp > Component Information > Locations > Page 1786 Malfunction Indicator Lamp: Description and Operation PURPOSE The Malfunction Indicator Lamp (MIL), "Service Engine Soon" light has the following purposes: Inform the driver that a problem has occurred, and that the vehicle should be taken for service as soon as reasonably possible. - Displays Diagnostic Trouble Codes (DTC) stored by the ECM helping the technician diagnose system faults. - Indicates "Open Loop" or "Closed Loop" operation. OPERATION The MIL will come "ON" with the key "ON" and the engine not running. When the engine is started, the light will turn "OFF.". This is a bulb and system check. If the light remains "ON," the self-diagnostic system has detected a problem. If the problem goes away, the light will go out in most cases after 10 seconds, but a DTC will remain stored in the ECM. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Service Reminder Indicators > Malfunction Indicator Lamp > Component Information > Locations > Page 1787 Malfunction Indicator Lamp: Service and Repair The CHECK ENGINE LAMP will be illuminated when the ignition switch is placed in the "ON" position. When the engine is started, the lamp should turn "OFF". If the lamp remains "ON" for 10 seconds or constantly after the engine is started, the self diagnosis system has detected a problem and has stored a code in the system Control Module. After diagnosis and repair, the ECM memory can be cleared of codes by removing the Control Module fuse or disconnecting the battery ground cable for approximately 30 seconds, with ignition switch in the "OFF" position. NOTE If battery ground cable is disconnected to clear codes, components such as clocks, electronically tuned radios etc., will have to be reset. - It is a good idea to record preset radio stations before disconnecting the negative battery cable. This will allow the stations to be reset as to not inconvenience the customer. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Tires > Component Information > Technical Service Bulletins > Customer Interest: > 662003 > Nov > 96 > Front Tire Tread - Contacts Inner Fender Bolts Tires: Customer Interest Front Tire Tread - Contacts Inner Fender Bolts File In Section: 10 - Body Bulletin No.: 66-20-03 Date: November, 1996 Subject: Front Tire Tread Contacts Lower Inner Fender Bolts (Replace Lower Bolts) Models: 1994-96 Chevrolet and GMC T Models with High Wider Option (RPO ZR2) Condition Some owners may comment that when turning, the front tire tread rubs against the inner fender lower bolts and damages the tread. Cause The installation of non-OEM wheels and/or tires may contribute to tire to inner fender bolt contact. Also, if the steering alignment, including suspension "Z" height is not within the specifications in Section 3A of the S/T Truck Service Manual, tire tread to inner fender bolt contact can occur. Correction Replace the two lower rear inner fender Hex Head Bolts with Pan Head Bolts. These bolts provide additional tire to bolt head clearance and reduce the possibility of tread damage. Service Procedure Notice: Always use the correct fastener in the proper location. When you replace a fastener, use ONLY the exact part number for that application General Motors will call out the fasteners that require thread lockers or thread sealant. Unless otherwise specified, do not use supplemental coatings (paints, greases, or other corrosion inhibitors) on threaded fasteners or fastener joint interfaces. Generally, such coatings adversely affect the fastener torque and joint clamping force, and may damage the fastener. When you install fasteners, use the correct tightening sequence and specifications. Following these instructions can help you avoid damage to parts and systems. 1. Remove the two rear lower inner fender to wheel house panel bolts. 2. Install new bolts (P/N 15715627) and torque to 29 N.m (21 lb ft). Parts Information P/N Description Qty 15715627 Pan Head Bolt 4/vehicle Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use as shown. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Tires > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Tires: > 04-03-10-001F > Apr > 10 > Tires/Wheels - Tire Puncture Repair Procedures Tires: All Technical Service Bulletins Tires/Wheels - Tire Puncture Repair Procedures INFORMATION Bulletin No.: 04-03-10-001F Date: April 27, 2010 Subject: Tire Puncture Repair Procedures For All Cars and Light Duty Trucks Models: 2011 and Prior GM Passenger Cars and Light Duty Trucks (including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 04-03-10-001E (Section 03 - Suspension). This bulletin covers puncture repair procedures for passenger car and light duty truck radial tires in the tread area only. The tire manufacturer must be contacted for its individual repair policy and whether or not the speed rating is retained after repair. Caution - Tire changing can be dangerous and should be done by trained professionals using proper tools and procedures. Always read and understand any manufacturer's warnings contained in their customers literature or molded into the tire sidewall. - Serious eye and ear injury may result from not wearing adequate eye and ear protection while repairing tires. - NEVER inflate beyond 275 kPa (40 pounds) pressure to seat beads. Some run flat tires, such as the Goodyear Extended Mobility Tire (EMT) used on the Corvette, may require more than 275 kPa (40 psi) to seat the bead. In such a case, a tire safety cage must be used. Consult the tire manufacturer for its individual repair policy. - NEVER stand, lean or reach over the assembly during inflation. Repairable area on a radial tire. Important - NEVER repair tires worn to the tread indicators 1.59 mm (2/32") remaining depth). - NEVER repair tires with a tread puncture larger than 6.35 mm (1/4"). - NEVER substitute an inner tube for a permissible or non-permissible repair. - NEVER perform an outside-in tire repair (plug only, on the wheel). - Every tire must be removed from the wheel for proper inspection and repair. - Regardless of the type of repair used, the repair must seal the inner liner and fill the injury. - Consult with repair material supplier/manufacturer for repair unit application procedures and repair tools/repair material recommendations. Three basic steps for tire puncture repair: 1. Remove the tire from the wheel for inspection and repair. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Tires > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Tires: > 04-03-10-001F > Apr > 10 > Tires/Wheels - Tire Puncture Repair Procedures > Page 1802 2. Fill the injury (puncture) to keep moisture out. 3. Seal the inner liner with a repair unit to prevent air loss. External Inspection 1. Prior to demounting, inspect the tire surface, the valve and the wheel for the source of the leak by using a water and soap solution. Mark the injured area and totally deflate the tire by removing the valve core. 2. Demount the tire from the wheel and place the tire on a well-lighted spreader. Internal Inspection 1. Spread the beads and mark the puncture with a tire crayon. 2. Inspect the inner tire for any signs of internal damage. 3. Remove the puncturing object, noting the direction of the penetration. 4. Probe the injury with a blunt awl in order to determine the extent and direction of the injury. 5. Remove any loose foreign material from the injury. 6. Punctures exceeding 6.35 mm (1/4") should not be repaired. Cleaning 1. Clean the area around the puncture thoroughly with a proper liner cleaner, clean cloth and a scraper. This step serves to remove dirt and mold lubricants to insure proper adhesion and non-contamination of the buffing tool. 2. Refer to information on the product or manufacturer's Material Safety Data Sheet and follow guidelines for handling and disposal. Clean the Injury Channel Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Tires > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Tires: > 04-03-10-001F > Apr > 10 > Tires/Wheels - Tire Puncture Repair Procedures > Page 1803 1. Use a proper hand reamer, carbide cutter or drill bit to ream the puncture channel from the inside of the tire in order to clean the injury. 2. Remove steel wires protruding above the liner surface to prevent damage to the repair unit. 3. Consult your repair material supplier for recommended reaming tool(s). Fill the Injury 1. It is necessary to fill the injury channel to provide back up for the repair unit and to prevent moisture from entering the tire fabric and steel wires. 2. (For combination repair/plug units skip this step.) Cement the injured channel and fill the injury from the inside of the tire with the repair plug per repair material manufacturer's recommendations. Without stretching the plug, cut the plug off just above the inside tire surface. 3. Consult your repair material supplier for proper repair material selection. Repair Unit Selection Important Do not install the repair unit in this step. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Tires > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Tires: > 04-03-10-001F > Apr > 10 > Tires/Wheels - Tire Puncture Repair Procedures > Page 1804 1. Center the repair unit over the injury as a reference and outline an area larger than the unit so that buffing will not remove the crayon marks. 2. Remove the repair unit. 3. DO NOT overlap previous or multiple repair units. 4. Consult your repair material supplier for proper repair unit selection. Buffing 1. To prevent contamination and preserve the outline, buff within the marked area thoroughly and evenly with a low speed buffing tool using a fine wire brush or gritted rasp. 2. Buff to a smooth velvet surface (RMA #1 or #2 buffed texture). 3. Use caution not to gouge the inner liner or expose casing fabric. 4. Remove any buffing dust with a vacuum cleaner. 5. Consult your repair material supplier for a proper buffing tool. Cementing Apply chemical cement according to the repair material manufacturer's procedures. Repair Unit Application Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Tires > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Tires: > 04-03-10-001F > Apr > 10 > Tires/Wheels - Tire Puncture Repair Procedures > Page 1805 1. The tire must be in the relaxed position when the repair unit is installed (Do not spread the beads excessively). Two-Piece Plug and Repair Units 1. If applicable, install the repair unit so that the alignment is correct. 2. Center the repair unit over the injury and stitch down thoroughly with the stitching tool, working from the center out. 3. Being careful not to stretch the plug material, cut the plug flush with the outer tread. Combination Repair/Plug Units 1. Pull the plug through the injury until the repair just reaches the liner. Stitch down thoroughly. 2. Follow the repair material manufacturer's recommendations for further installation instructions. 2. Consult your repair material supplier for the proper stitching tool. Safety Cage Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Tires > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Tires: > 04-03-10-001F > Apr > 10 > Tires/Wheels - Tire Puncture Repair Procedures > Page 1806 Some run flat tires, such as the Goodyear Extended Mobility Tire (EMT) used on the Corvette, may require more than 275 kPa (40 psi) to seat the bead. In such a case, a tire safety cage must be used. Consult the tire manufacturer for its individual repair policy. Final Inspection 1. After remounting and inflating the tire, check both beads, the repair and the valve with a water and soap solution in order to detect leaks. 2. If the tire continues to lose air, the tire must be demounted and reinspected. 3. Balance the tire and wheel assembly. Refer to Tire and Wheel Assembly Balancing - OFF Vehicle. For additional tire puncture repair information, contact: Rubber Manufacturers Association (RMA) Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Tires > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Tires: > 05-03-10-020C > Apr > 10 > Wheels/Tires - Use of Nitrogen Gas in Tires Tires: All Technical Service Bulletins Wheels/Tires - Use of Nitrogen Gas in Tires INFORMATION Bulletin No.: 05-03-10-020C Date: April 27, 2010 Subject: Use of Nitrogen Gas in Tires Models: 2011 and Prior GM Passenger Cars and Trucks (including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 05-03-10-020B (Section 03 - Suspension). GM's Position on the Use of Nitrogen Gas in Tires General Motors does not oppose the use of purified nitrogen as an inflation gas for tires. We expect the theoretical benefits to be reduced in practical use due to the lack of an existing infrastructure to continuously facilitate inflating tires with nearly pure nitrogen. Even occasional inflation with compressed atmospheric air will negate many of the theoretical benefits. Given those theoretical benefits, practical limitations, and the robust design of GM original equipment TPC tires, the realized benefits to our customer of inflating their tires with purified nitrogen are expected to be minimal. The Promise of Nitrogen: Under Controlled Conditions Recently, nitrogen gas (for use in inflating tires) has become available to the general consumer through some retailers. The use of nitrogen gas to inflate tires is a technology used in automobile racing. The following benefits under controlled conditions are attributed to nitrogen gas and its unique properties: - A reduction in the expected loss of Tire Pressure over time. - A reduction in the variance of Tire Pressures with temperature changes due to reduction of water vapor concentration. - A reduction of long term rubber degradation due to a decrease in oxygen concentrations. Important These are obtainable performance improvements when relatively pure nitrogen gas is used to inflate tires under controlled conditions. The Promise of Nitrogen: Real World Use Nitrogen inflation can provide some benefit by reducing gas migration (pressure loss) at the molecular level through the tire structure. NHTSA (National Highway Traffic Safety Administration) has stated that the inflation pressure loss of tires can be up to 5% a month. Nitrogen molecules are larger than oxygen molecules and, therefore, are less prone to "seeping" through the tire casing. The actual obtainable benefits of nitrogen vary, based on the physical construction and the materials used in the manufacturing of the tire being inflated. Another potential benefit of nitrogen is the reduced oxidation of tire components. Research has demonstrated that oxygen consumed in the oxidation process of the tire primarily comes from the inflation media. Therefore, it is reasonable to assume that oxidation of tire components can be reduced if the tire is inflated with pure nitrogen. However, only very small amounts of oxygen are required to begin the normal oxidation process. Even slight contamination of the tire inflation gas with compressed atmospheric air during normal inflation pressure maintenance, may negate the benefits of using nitrogen. GM Tire Quality, Technology and Focus of Importance Since 1972, General Motors has designed tires under the TPC (Tire Performance Criteria) specification system, which includes specific requirements that ensure robust tire performance under normal usage. General Motors works with tire suppliers to design and manufacture original equipment tires for GM vehicles. The GM TPC addresses required performance with respect to both inflation pressure retention, and endurance properties for original equipment tires. The inflation pressure retention requirements address availability of oxygen and oxidation concerns, while endurance requirements ensure the mechanical structure of the tire has sufficient strength. This combination has provided our customers with tires that maintain their structural integrity throughout their useful treadlife under normal operating conditions. Regardless of the inflation media for tires (atmospheric air or nitrogen), inflation pressure maintenance of tires is critical for overall tire, and ultimately, vehicle performance. Maintaining the correct inflation pressure allows the tire to perform as intended by the vehicle manufacturer in many areas, including comfort, fuel economy, stopping distance, cornering, traction, treadwear, and noise. Since the load carrying capability of a tire is related to inflation pressure, proper inflation pressure maintenance is necessary for the tire to support the load imposed by the vehicle without excessive structural Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Tires > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Tires: > 05-03-10-020C > Apr > 10 > Wheels/Tires - Use of Nitrogen Gas in Tires > Page 1811 degradation. Important Regardless of the inflation media for tires (atmospheric air or nitrogen), inflation pressure maintenance of tires is critical for overall tire, and ultimately, vehicle performance. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Tires > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Tires: > 00-00-90-002J > Jan > 09 > Tires - Correct Inflation Pressure Information Tires: All Technical Service Bulletins Tires - Correct Inflation Pressure Information INFORMATION Bulletin No.: 00-00-90-002J Date: January 28, 2009 Subject: Information on Proper Tire Pressure Models: 2010 and Prior GM Passenger Cars and Light Duty Trucks (including Saturn) 2009 and Prior HUMMER H2, H3, H3T 2005-2009 Saab 9-7X Supercede: This bulletin is being revised to add model years and clarify additional information. Please discard Corporate Bulletin Number 00-00-90-002I (Section 00 - General Information). Important: ^ Adjustment of tire pressure for a customer with a Low Tire Pressure Monitor (TPM) light on and no codes in the TPM system is NOT a warrantable repair. Claims to simply adjust the tire pressure will be rejected. ^ ALL tires (including the spare tire) MUST be set to the recommended inflation pressure stated on the vehicle's tire placard (on driver's door) during the PRE-DELIVERY INSPECTION (PDI). Recommended inflation pressure is not the pressure printed on tire sidewall. ^ Tires may be over-inflated from the assembly plant due to the mounting process. ^ Generally a 5.6°C (10°F) temperature change will result in (is equivalent to) a 6.9 kPa (1 psi) tire pressure change. ^ 2008-2009 HUMMER H2 Only - The H2 comes standard with Light Truck "D" Load Range tires with a recommended cold inflation pressure of 289 kPa (42 psi). These tires will alert the driver to a low pressure situation at roughly 262 kPa (38 psi) due to a requirement in FMVSS 138 which specifies a Minimum Activation Pressure for each tire type. This creates a relatively narrow window of "usable" pressure values and the warning will be more sensitive to outside temperature changes during the colder months. As with other cold temperature/tire pressure issues, there is nothing wrong with the system itself. If a vehicle is brought in with this concern, check for tire damage and set all tires to the Recommended Cold Inflation Pressure shown on the vehicle placard. Accurate tire pressures ensure the safe handling and appropriate ride characteristics of GM cars and trucks. It is critical that the tire pressure be adjusted to the specifications on the vehicle¡C■s tire placard during PDI. Ride, handling and road noise concerns may be caused by improperly adjusted tire pressure. The first step in the diagnosis of these concerns is to verify that the tires are inflated to the correct pressures. The recommended tire inflation pressure is listed on the vehicle¡C■s tire placard. The tire placard is located on the driver¡C■s side front or rear door edge, center pillar, or the rear compartment lid. Tip ^ Generally a 5.6°C (10°F) temperature increase will result in (is equivalent to) a 6.9 kPa (1 psi) tire pressure increase. ^ The definition of a "cold" tire is one that has been sitting for at least 3 hours, or driven no more than 1.6 km (1 mi). ^ On extremely cold days, if the vehicle has been indoors, it may be necessary to compensate for the low external temperature by adding additional air to the tire during PDI. ^ During cold weather, the Tire Pressure Monitor (TPM) indicator light (a yellow horseshoe with an exclamation point) may illuminate. If this indicator turns off after the tires warm up (reach operating temperature), the tire pressure should be reset to placard pressure at the cold temperature. ^ The TPM system will work correctly with nitrogen in tires. ^ The TPM system is compatible with the GM Vehicle Care Tire Sealant but may not be with other commercially available sealants. Important: ^ Do not use the tire pressure indicated on the tire itself as a guide. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Tires > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Tires: > 00-00-90-002J > Jan > 09 > Tires - Correct Inflation Pressure Information > Page 1816 ^ Always inspect and adjust the pressure when the tires are cold. ^ Vehicles that have different pressures for the front and the rear need to be adjusted after tire rotation. Improper tire inflation may result in any or all of the following conditions: ^ Premature tire wear ^ Harsh ride ^ Excessive road noise ^ Poor handling ^ Reduced fuel economy ^ Low Tire Pressure Monitor (TPM) Light ON ^ Low Tire Pressure Message on the Drivers Information Center (DIC) Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Tires > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Tires: > 662003 > Nov > 96 > Front Tire Tread - Contacts Inner Fender Bolts Tires: All Technical Service Bulletins Front Tire Tread - Contacts Inner Fender Bolts File In Section: 10 - Body Bulletin No.: 66-20-03 Date: November, 1996 Subject: Front Tire Tread Contacts Lower Inner Fender Bolts (Replace Lower Bolts) Models: 1994-96 Chevrolet and GMC T Models with High Wider Option (RPO ZR2) Condition Some owners may comment that when turning, the front tire tread rubs against the inner fender lower bolts and damages the tread. Cause The installation of non-OEM wheels and/or tires may contribute to tire to inner fender bolt contact. Also, if the steering alignment, including suspension "Z" height is not within the specifications in Section 3A of the S/T Truck Service Manual, tire tread to inner fender bolt contact can occur. Correction Replace the two lower rear inner fender Hex Head Bolts with Pan Head Bolts. These bolts provide additional tire to bolt head clearance and reduce the possibility of tread damage. Service Procedure Notice: Always use the correct fastener in the proper location. When you replace a fastener, use ONLY the exact part number for that application General Motors will call out the fasteners that require thread lockers or thread sealant. Unless otherwise specified, do not use supplemental coatings (paints, greases, or other corrosion inhibitors) on threaded fasteners or fastener joint interfaces. Generally, such coatings adversely affect the fastener torque and joint clamping force, and may damage the fastener. When you install fasteners, use the correct tightening sequence and specifications. Following these instructions can help you avoid damage to parts and systems. 1. Remove the two rear lower inner fender to wheel house panel bolts. 2. Install new bolts (P/N 15715627) and torque to 29 N.m (21 lb ft). Parts Information P/N Description Qty 15715627 Pan Head Bolt 4/vehicle Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use as shown. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Tires > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Tires: > 463501 > Apr > 95 > Alignment - Front Tire Wear/Steering Returnability Tires: All Technical Service Bulletins Alignment - Front Tire Wear/Steering Returnability File in Section: 3 - Steering/Suspension Bulletin No.: 46-35-01 Date: April, 1995 Subject: Front Tire Wear and/or Steering Returnability (Set to New Alignment Specification) Models: 1991-95 Chevrolet and GMC Truck T Models 1991-94 Oldsmobile Bravada CONDITION Some owners may comment on excessive front tire wear and/or steering returnability. PERFORM PRELIMINARY INSPECTION BEFORE ALIGNMENT CORRECTION The following procedures should be used to address customer's concerns about front tire wear and/or steering returnability: 1. Check to be sure the tire pressure is set to GVW Certification/Tire label specifications located on the driver's door lock pillar. Important: It is essential proper tire rotation schedule be followed at proper intervals to minimize tire wear. 2. 4WD ONLY, front suspension "Z" height dimension and setting must be made prior to any other alignment changes. 3. Perform front wheel alignment to the specifications in chart (figure). Notice: Vehicle must be jounced three times before checking alignment to eliminate false geometry readings. a. For 4WD only, front suspension "Z" height dimension 122 ± 6.0 mm (4.8 ± 0.2 inch), left and right side to be equal within 6 mm. b. Left and right side to be equal within 0.5". c. Left and right side to be equal within 1.0". d. Steering wheel must be held in straight ahead position with ± 3.0". Front individual toe must be equalized relative to rear wheel thrust angle. e. GVW alignment is the same for all vehicles. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Tires > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Tires: > 433502 > Jul > 94 > Tires - Speed Rated Information Tires: All Technical Service Bulletins Tires - Speed Rated Information Group Ref.: 3 - Steering/Suspension Bulletin No.: 433502 Date: July, 1994 INFORMATION SUBJECT: SPEED RATED TIRES MODELS: 1995 AND PRIOR YEAR PASSENGER CARS AND LIGHT DUTY TRUCKS All original equipment passenger car and light duty truck tires used by General Motors have a speed rating symbol molded on their sidewall. This speed symbol, along with the tire's load index, make up the service description that follows the tire's size. The original equipment tire size, speed rating, and recommended inflation pressure are listed on the tire placard usually located on the driver's door edge. WHEN REPLACING TIRES, NEVER INSTALL A TIRE THAT IS A SMALLER SIZE OR LESSER SPEED RATING THAN THAT USED AS ORIGINAL EQUIPMENT. As in the past, it is recommended that replacement tires have a TPC (Tire Performance Criteria) number on the sidewall that is identical to that on the original tires. Common speed rating on tires used by General Motors are as follows: (see illustration) IMPORTANT: Most base all season tires and touring tires used by GM are S rated. Performance tires will usually have a higher speed rating. High performance tires are usually Z rated. Z rated tires carry the Z symbol within the tire size, rather than after the size in the service description. These speeds apply only at the tire's full pressure. An underinflated tire will not meet its speed rating capability. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Tires > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Tires: > 323501 > Dec > 93 > Tires - Manufacturers' Assistance Tires: All Technical Service Bulletins Tires - Manufacturers' Assistance Group Ref.: Steering/ Suspension Bulletin No.: 323501 Date: December, 1993 INFORMATION SUBJECT: TIRE MANUFACTURERS' CONTACTS FOR ASSISTANCE MODELS: 1991-94 PASSENGER CARS AND TRUCKS General Tire has established a "Tire Fix" Department to assist you with anything from a tire adjustment to the location of the nearest General Tire dealer. "Tire Fix" representatives are available Monday through Friday from 8:00 A.M. to 6:00 P.M. Eastern Time at 1-800-847-3349. A General Tire Brochure is provided for review with all appropriate dealer personnel. A single contact point at General Tire can assist you with most aspects of their product to satisfy your customers' needs. Other tire manufacturers can be contacted for assistance at the Toll Free Numbers listed in illustration: Please retain this information for future reference. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Tires > Component Information > Technical Service Bulletins > All Other Service Bulletins for Tires: > 04-03-10-001F > Apr > 10 > Tires/Wheels - Tire Puncture Repair Procedures Tires: All Technical Service Bulletins Tires/Wheels - Tire Puncture Repair Procedures INFORMATION Bulletin No.: 04-03-10-001F Date: April 27, 2010 Subject: Tire Puncture Repair Procedures For All Cars and Light Duty Trucks Models: 2011 and Prior GM Passenger Cars and Light Duty Trucks (including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 04-03-10-001E (Section 03 - Suspension). This bulletin covers puncture repair procedures for passenger car and light duty truck radial tires in the tread area only. The tire manufacturer must be contacted for its individual repair policy and whether or not the speed rating is retained after repair. Caution - Tire changing can be dangerous and should be done by trained professionals using proper tools and procedures. Always read and understand any manufacturer's warnings contained in their customers literature or molded into the tire sidewall. - Serious eye and ear injury may result from not wearing adequate eye and ear protection while repairing tires. - NEVER inflate beyond 275 kPa (40 pounds) pressure to seat beads. Some run flat tires, such as the Goodyear Extended Mobility Tire (EMT) used on the Corvette, may require more than 275 kPa (40 psi) to seat the bead. In such a case, a tire safety cage must be used. Consult the tire manufacturer for its individual repair policy. - NEVER stand, lean or reach over the assembly during inflation. Repairable area on a radial tire. Important - NEVER repair tires worn to the tread indicators 1.59 mm (2/32") remaining depth). - NEVER repair tires with a tread puncture larger than 6.35 mm (1/4"). - NEVER substitute an inner tube for a permissible or non-permissible repair. - NEVER perform an outside-in tire repair (plug only, on the wheel). - Every tire must be removed from the wheel for proper inspection and repair. - Regardless of the type of repair used, the repair must seal the inner liner and fill the injury. - Consult with repair material supplier/manufacturer for repair unit application procedures and repair tools/repair material recommendations. Three basic steps for tire puncture repair: 1. Remove the tire from the wheel for inspection and repair. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Tires > Component Information > Technical Service Bulletins > All Other Service Bulletins for Tires: > 04-03-10-001F > Apr > 10 > Tires/Wheels - Tire Puncture Repair Procedures > Page 1838 2. Fill the injury (puncture) to keep moisture out. 3. Seal the inner liner with a repair unit to prevent air loss. External Inspection 1. Prior to demounting, inspect the tire surface, the valve and the wheel for the source of the leak by using a water and soap solution. Mark the injured area and totally deflate the tire by removing the valve core. 2. Demount the tire from the wheel and place the tire on a well-lighted spreader. Internal Inspection 1. Spread the beads and mark the puncture with a tire crayon. 2. Inspect the inner tire for any signs of internal damage. 3. Remove the puncturing object, noting the direction of the penetration. 4. Probe the injury with a blunt awl in order to determine the extent and direction of the injury. 5. Remove any loose foreign material from the injury. 6. Punctures exceeding 6.35 mm (1/4") should not be repaired. Cleaning 1. Clean the area around the puncture thoroughly with a proper liner cleaner, clean cloth and a scraper. This step serves to remove dirt and mold lubricants to insure proper adhesion and non-contamination of the buffing tool. 2. Refer to information on the product or manufacturer's Material Safety Data Sheet and follow guidelines for handling and disposal. Clean the Injury Channel Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Tires > Component Information > Technical Service Bulletins > All Other Service Bulletins for Tires: > 04-03-10-001F > Apr > 10 > Tires/Wheels - Tire Puncture Repair Procedures > Page 1839 1. Use a proper hand reamer, carbide cutter or drill bit to ream the puncture channel from the inside of the tire in order to clean the injury. 2. Remove steel wires protruding above the liner surface to prevent damage to the repair unit. 3. Consult your repair material supplier for recommended reaming tool(s). Fill the Injury 1. It is necessary to fill the injury channel to provide back up for the repair unit and to prevent moisture from entering the tire fabric and steel wires. 2. (For combination repair/plug units skip this step.) Cement the injured channel and fill the injury from the inside of the tire with the repair plug per repair material manufacturer's recommendations. Without stretching the plug, cut the plug off just above the inside tire surface. 3. Consult your repair material supplier for proper repair material selection. Repair Unit Selection Important Do not install the repair unit in this step. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Tires > Component Information > Technical Service Bulletins > All Other Service Bulletins for Tires: > 04-03-10-001F > Apr > 10 > Tires/Wheels - Tire Puncture Repair Procedures > Page 1840 1. Center the repair unit over the injury as a reference and outline an area larger than the unit so that buffing will not remove the crayon marks. 2. Remove the repair unit. 3. DO NOT overlap previous or multiple repair units. 4. Consult your repair material supplier for proper repair unit selection. Buffing 1. To prevent contamination and preserve the outline, buff within the marked area thoroughly and evenly with a low speed buffing tool using a fine wire brush or gritted rasp. 2. Buff to a smooth velvet surface (RMA #1 or #2 buffed texture). 3. Use caution not to gouge the inner liner or expose casing fabric. 4. Remove any buffing dust with a vacuum cleaner. 5. Consult your repair material supplier for a proper buffing tool. Cementing Apply chemical cement according to the repair material manufacturer's procedures. Repair Unit Application Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Tires > Component Information > Technical Service Bulletins > All Other Service Bulletins for Tires: > 04-03-10-001F > Apr > 10 > Tires/Wheels - Tire Puncture Repair Procedures > Page 1841 1. The tire must be in the relaxed position when the repair unit is installed (Do not spread the beads excessively). Two-Piece Plug and Repair Units 1. If applicable, install the repair unit so that the alignment is correct. 2. Center the repair unit over the injury and stitch down thoroughly with the stitching tool, working from the center out. 3. Being careful not to stretch the plug material, cut the plug flush with the outer tread. Combination Repair/Plug Units 1. Pull the plug through the injury until the repair just reaches the liner. Stitch down thoroughly. 2. Follow the repair material manufacturer's recommendations for further installation instructions. 2. Consult your repair material supplier for the proper stitching tool. Safety Cage Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Tires > Component Information > Technical Service Bulletins > All Other Service Bulletins for Tires: > 04-03-10-001F > Apr > 10 > Tires/Wheels - Tire Puncture Repair Procedures > Page 1842 Some run flat tires, such as the Goodyear Extended Mobility Tire (EMT) used on the Corvette, may require more than 275 kPa (40 psi) to seat the bead. In such a case, a tire safety cage must be used. Consult the tire manufacturer for its individual repair policy. Final Inspection 1. After remounting and inflating the tire, check both beads, the repair and the valve with a water and soap solution in order to detect leaks. 2. If the tire continues to lose air, the tire must be demounted and reinspected. 3. Balance the tire and wheel assembly. Refer to Tire and Wheel Assembly Balancing - OFF Vehicle. For additional tire puncture repair information, contact: Rubber Manufacturers Association (RMA) Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Tires > Component Information > Technical Service Bulletins > All Other Service Bulletins for Tires: > 05-03-10-020C > Apr > 10 > Wheels/Tires - Use of Nitrogen Gas in Tires Tires: All Technical Service Bulletins Wheels/Tires - Use of Nitrogen Gas in Tires INFORMATION Bulletin No.: 05-03-10-020C Date: April 27, 2010 Subject: Use of Nitrogen Gas in Tires Models: 2011 and Prior GM Passenger Cars and Trucks (including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 05-03-10-020B (Section 03 - Suspension). GM's Position on the Use of Nitrogen Gas in Tires General Motors does not oppose the use of purified nitrogen as an inflation gas for tires. We expect the theoretical benefits to be reduced in practical use due to the lack of an existing infrastructure to continuously facilitate inflating tires with nearly pure nitrogen. Even occasional inflation with compressed atmospheric air will negate many of the theoretical benefits. Given those theoretical benefits, practical limitations, and the robust design of GM original equipment TPC tires, the realized benefits to our customer of inflating their tires with purified nitrogen are expected to be minimal. The Promise of Nitrogen: Under Controlled Conditions Recently, nitrogen gas (for use in inflating tires) has become available to the general consumer through some retailers. The use of nitrogen gas to inflate tires is a technology used in automobile racing. The following benefits under controlled conditions are attributed to nitrogen gas and its unique properties: - A reduction in the expected loss of Tire Pressure over time. - A reduction in the variance of Tire Pressures with temperature changes due to reduction of water vapor concentration. - A reduction of long term rubber degradation due to a decrease in oxygen concentrations. Important These are obtainable performance improvements when relatively pure nitrogen gas is used to inflate tires under controlled conditions. The Promise of Nitrogen: Real World Use Nitrogen inflation can provide some benefit by reducing gas migration (pressure loss) at the molecular level through the tire structure. NHTSA (National Highway Traffic Safety Administration) has stated that the inflation pressure loss of tires can be up to 5% a month. Nitrogen molecules are larger than oxygen molecules and, therefore, are less prone to "seeping" through the tire casing. The actual obtainable benefits of nitrogen vary, based on the physical construction and the materials used in the manufacturing of the tire being inflated. Another potential benefit of nitrogen is the reduced oxidation of tire components. Research has demonstrated that oxygen consumed in the oxidation process of the tire primarily comes from the inflation media. Therefore, it is reasonable to assume that oxidation of tire components can be reduced if the tire is inflated with pure nitrogen. However, only very small amounts of oxygen are required to begin the normal oxidation process. Even slight contamination of the tire inflation gas with compressed atmospheric air during normal inflation pressure maintenance, may negate the benefits of using nitrogen. GM Tire Quality, Technology and Focus of Importance Since 1972, General Motors has designed tires under the TPC (Tire Performance Criteria) specification system, which includes specific requirements that ensure robust tire performance under normal usage. General Motors works with tire suppliers to design and manufacture original equipment tires for GM vehicles. The GM TPC addresses required performance with respect to both inflation pressure retention, and endurance properties for original equipment tires. The inflation pressure retention requirements address availability of oxygen and oxidation concerns, while endurance requirements ensure the mechanical structure of the tire has sufficient strength. This combination has provided our customers with tires that maintain their structural integrity throughout their useful treadlife under normal operating conditions. Regardless of the inflation media for tires (atmospheric air or nitrogen), inflation pressure maintenance of tires is critical for overall tire, and ultimately, vehicle performance. Maintaining the correct inflation pressure allows the tire to perform as intended by the vehicle manufacturer in many areas, including comfort, fuel economy, stopping distance, cornering, traction, treadwear, and noise. Since the load carrying capability of a tire is related to inflation pressure, proper inflation pressure maintenance is necessary for the tire to support the load imposed by the vehicle without excessive structural Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Tires > Component Information > Technical Service Bulletins > All Other Service Bulletins for Tires: > 05-03-10-020C > Apr > 10 > Wheels/Tires - Use of Nitrogen Gas in Tires > Page 1847 degradation. Important Regardless of the inflation media for tires (atmospheric air or nitrogen), inflation pressure maintenance of tires is critical for overall tire, and ultimately, vehicle performance. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Tires > Component Information > Technical Service Bulletins > All Other Service Bulletins for Tires: > 00-00-90-002J > Jan > 09 > Tires - Correct Inflation Pressure Information Tires: All Technical Service Bulletins Tires - Correct Inflation Pressure Information INFORMATION Bulletin No.: 00-00-90-002J Date: January 28, 2009 Subject: Information on Proper Tire Pressure Models: 2010 and Prior GM Passenger Cars and Light Duty Trucks (including Saturn) 2009 and Prior HUMMER H2, H3, H3T 2005-2009 Saab 9-7X Supercede: This bulletin is being revised to add model years and clarify additional information. Please discard Corporate Bulletin Number 00-00-90-002I (Section 00 - General Information). Important: ^ Adjustment of tire pressure for a customer with a Low Tire Pressure Monitor (TPM) light on and no codes in the TPM system is NOT a warrantable repair. Claims to simply adjust the tire pressure will be rejected. ^ ALL tires (including the spare tire) MUST be set to the recommended inflation pressure stated on the vehicle's tire placard (on driver's door) during the PRE-DELIVERY INSPECTION (PDI). Recommended inflation pressure is not the pressure printed on tire sidewall. ^ Tires may be over-inflated from the assembly plant due to the mounting process. ^ Generally a 5.6°C (10°F) temperature change will result in (is equivalent to) a 6.9 kPa (1 psi) tire pressure change. ^ 2008-2009 HUMMER H2 Only - The H2 comes standard with Light Truck "D" Load Range tires with a recommended cold inflation pressure of 289 kPa (42 psi). These tires will alert the driver to a low pressure situation at roughly 262 kPa (38 psi) due to a requirement in FMVSS 138 which specifies a Minimum Activation Pressure for each tire type. This creates a relatively narrow window of "usable" pressure values and the warning will be more sensitive to outside temperature changes during the colder months. As with other cold temperature/tire pressure issues, there is nothing wrong with the system itself. If a vehicle is brought in with this concern, check for tire damage and set all tires to the Recommended Cold Inflation Pressure shown on the vehicle placard. Accurate tire pressures ensure the safe handling and appropriate ride characteristics of GM cars and trucks. It is critical that the tire pressure be adjusted to the specifications on the vehicle¡C■s tire placard during PDI. Ride, handling and road noise concerns may be caused by improperly adjusted tire pressure. The first step in the diagnosis of these concerns is to verify that the tires are inflated to the correct pressures. The recommended tire inflation pressure is listed on the vehicle¡C■s tire placard. The tire placard is located on the driver¡C■s side front or rear door edge, center pillar, or the rear compartment lid. Tip ^ Generally a 5.6°C (10°F) temperature increase will result in (is equivalent to) a 6.9 kPa (1 psi) tire pressure increase. ^ The definition of a "cold" tire is one that has been sitting for at least 3 hours, or driven no more than 1.6 km (1 mi). ^ On extremely cold days, if the vehicle has been indoors, it may be necessary to compensate for the low external temperature by adding additional air to the tire during PDI. ^ During cold weather, the Tire Pressure Monitor (TPM) indicator light (a yellow horseshoe with an exclamation point) may illuminate. If this indicator turns off after the tires warm up (reach operating temperature), the tire pressure should be reset to placard pressure at the cold temperature. ^ The TPM system will work correctly with nitrogen in tires. ^ The TPM system is compatible with the GM Vehicle Care Tire Sealant but may not be with other commercially available sealants. Important: ^ Do not use the tire pressure indicated on the tire itself as a guide. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Tires > Component Information > Technical Service Bulletins > All Other Service Bulletins for Tires: > 00-00-90-002J > Jan > 09 > Tires - Correct Inflation Pressure Information > Page 1852 ^ Always inspect and adjust the pressure when the tires are cold. ^ Vehicles that have different pressures for the front and the rear need to be adjusted after tire rotation. Improper tire inflation may result in any or all of the following conditions: ^ Premature tire wear ^ Harsh ride ^ Excessive road noise ^ Poor handling ^ Reduced fuel economy ^ Low Tire Pressure Monitor (TPM) Light ON ^ Low Tire Pressure Message on the Drivers Information Center (DIC) Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Tires > Component Information > Technical Service Bulletins > All Other Service Bulletins for Tires: > 463501 > Apr > 95 > Alignment - Front Tire Wear/Steering Returnability Tires: All Technical Service Bulletins Alignment - Front Tire Wear/Steering Returnability File in Section: 3 - Steering/Suspension Bulletin No.: 46-35-01 Date: April, 1995 Subject: Front Tire Wear and/or Steering Returnability (Set to New Alignment Specification) Models: 1991-95 Chevrolet and GMC Truck T Models 1991-94 Oldsmobile Bravada CONDITION Some owners may comment on excessive front tire wear and/or steering returnability. PERFORM PRELIMINARY INSPECTION BEFORE ALIGNMENT CORRECTION The following procedures should be used to address customer's concerns about front tire wear and/or steering returnability: 1. Check to be sure the tire pressure is set to GVW Certification/Tire label specifications located on the driver's door lock pillar. Important: It is essential proper tire rotation schedule be followed at proper intervals to minimize tire wear. 2. 4WD ONLY, front suspension "Z" height dimension and setting must be made prior to any other alignment changes. 3. Perform front wheel alignment to the specifications in chart (figure). Notice: Vehicle must be jounced three times before checking alignment to eliminate false geometry readings. a. For 4WD only, front suspension "Z" height dimension 122 ± 6.0 mm (4.8 ± 0.2 inch), left and right side to be equal within 6 mm. b. Left and right side to be equal within 0.5". c. Left and right side to be equal within 1.0". d. Steering wheel must be held in straight ahead position with ± 3.0". Front individual toe must be equalized relative to rear wheel thrust angle. e. GVW alignment is the same for all vehicles. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Tires > Component Information > Technical Service Bulletins > All Other Service Bulletins for Tires: > 433502 > Jul > 94 > Tires - Speed Rated Information Tires: All Technical Service Bulletins Tires - Speed Rated Information Group Ref.: 3 - Steering/Suspension Bulletin No.: 433502 Date: July, 1994 INFORMATION SUBJECT: SPEED RATED TIRES MODELS: 1995 AND PRIOR YEAR PASSENGER CARS AND LIGHT DUTY TRUCKS All original equipment passenger car and light duty truck tires used by General Motors have a speed rating symbol molded on their sidewall. This speed symbol, along with the tire's load index, make up the service description that follows the tire's size. The original equipment tire size, speed rating, and recommended inflation pressure are listed on the tire placard usually located on the driver's door edge. WHEN REPLACING TIRES, NEVER INSTALL A TIRE THAT IS A SMALLER SIZE OR LESSER SPEED RATING THAN THAT USED AS ORIGINAL EQUIPMENT. As in the past, it is recommended that replacement tires have a TPC (Tire Performance Criteria) number on the sidewall that is identical to that on the original tires. Common speed rating on tires used by General Motors are as follows: (see illustration) IMPORTANT: Most base all season tires and touring tires used by GM are S rated. Performance tires will usually have a higher speed rating. High performance tires are usually Z rated. Z rated tires carry the Z symbol within the tire size, rather than after the size in the service description. These speeds apply only at the tire's full pressure. An underinflated tire will not meet its speed rating capability. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Tires > Component Information > Technical Service Bulletins > All Other Service Bulletins for Tires: > 323501 > Dec > 93 > Tires - Manufacturers' Assistance Tires: All Technical Service Bulletins Tires - Manufacturers' Assistance Group Ref.: Steering/ Suspension Bulletin No.: 323501 Date: December, 1993 INFORMATION SUBJECT: TIRE MANUFACTURERS' CONTACTS FOR ASSISTANCE MODELS: 1991-94 PASSENGER CARS AND TRUCKS General Tire has established a "Tire Fix" Department to assist you with anything from a tire adjustment to the location of the nearest General Tire dealer. "Tire Fix" representatives are available Monday through Friday from 8:00 A.M. to 6:00 P.M. Eastern Time at 1-800-847-3349. A General Tire Brochure is provided for review with all appropriate dealer personnel. A single contact point at General Tire can assist you with most aspects of their product to satisfy your customers' needs. Other tire manufacturers can be contacted for assistance at the Toll Free Numbers listed in illustration: Please retain this information for future reference. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > Customer Interest: > 00-03-10-006F > May > 10 > Wheels/Tires - Tire Radial Force Variation (RFV) Wheels: Customer Interest Wheels/Tires - Tire Radial Force Variation (RFV) INFORMATION Bulletin No.: 00-03-10-006F Date: May 04, 2010 Subject: Information on Tire Radial Force Variation (RFV) Models: 2011 and Prior GM Passenger Cars and Light Duty Trucks 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X 2000-2005 Saturn L Series 2003-2007 Saturn ION Supercede: This bulletin is being revised to considerably expand the available information on Radial Force Variation (RFV) and should be reviewed in whole. Please discard Corporate Bulletin Number 00-03-10-006E (Section 03 - Suspension). Important - Before measuring tires on equipment such as the Hunter GSP9700, the vehicle MUST be driven a minimum of 16 km (10 mi) to ensure removal of any flat-spotting. Refer to Corporate Bulletin Number 03-03-10-007E - Tire/Wheel Characteristics of GM Original Equipment Tires. - Equipment such as the Hunter GSP9700 MUST be calibrated prior to measuring tire/wheel assemblies for each vehicle. The purpose of this bulletin is to provide guidance to GM dealers when using tire force variation measurement equipment, such as the Hunter GSP9700. This type of equipment can be a valuable tool in diagnosing vehicle ride concerns. The most common ride concern involving tire radial force variation is highway speed shake on smooth roads. Tire related smooth road highway speed shake can be caused by three conditions: imbalance, out of round and tire force variation. These three conditions are not necessarily related. All three conditions must be addressed. Imbalance is normally addressed first, because it is the simpler of the three to correct. Off-vehicle, two plane dynamic wheel balancers are readily available and can accurately correct any imbalance. Balancer calibration and maintenance, proper attachment of the wheel to the balancer, and proper balance weights, are all factors required for a quality balance. However, a perfectly balanced tire/wheel assembly can still be "oval shaped" and cause a vibration. Before balancing, perform the following procedures. Tire and Wheel Diagnosis 1. Set the tire pressure to the placard values. 2. With the vehicle raised, ensure the wheels are centered on the hub by loosening all wheel nuts and hand-tightening all nuts first by hand while shaking the wheel, then torque to specifications using a torque wrench, NOT a torque stick. 3. Visually inspect the tires and the wheels. Inspect for evidence of the following conditions and correct as necessary: - Missing balance weights - Bent rim flange - Irregular tire wear - Incomplete bead seating - Tire irregularities (including pressure settings) - Mud/ice build-up in wheel - Stones in the tire tread - Remove any aftermarket wheels and/or tires and restore vehicle to original condition prior to diagnosing a smooth road shake condition. 4. Road test the vehicle using the Electronic Vibration Analyzer (EVA) essential tool. Drive for a sufficient distance on a known, smooth road surface to duplicate the condition. Determine if the vehicle is sensitive to brake apply. If the brakes are applied lightly and the pulsation felt in the steering wheel increases, refer to the Brakes section of the service manual that deals with brake-induced pulsation. If you can start to hear the vibration as a low boom noise (in addition to feeling it), but cannot see it, the vehicle likely has a first order (one pulse per propshaft revolution) driveline vibration. Driveline first order vibrations are high enough in frequency that most humans can start to hear them at highway speeds, but are too high to be able to be easily seen. These issues can be caused by driveline imbalance or misalignment. If the vehicle exhibits this low boom and the booming pulses in-and-out on a regular basis (like a throbbing), chances are good that the vehicle could have driveline vibration. This type Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > Customer Interest: > 00-03-10-006F > May > 10 > Wheels/Tires - Tire Radial Force Variation (RFV) > Page 1873 of vibration is normally felt more in the "seat of the pants" than the steering wheel. 5. Next, record the Hertz (Hz) reading as displayed by the EVA onto the tire data worksheet found at the end of this bulletin. This should be done after a tire break-in period of at least 16 km (10 mi) at 72 km/h (45 mph) or greater, in order to eliminate any possible tire flat-spotting. This reading confirms what the vehicle vibration frequency is prior to vehicle service and documents the amount of improvement occurring as the result of the various steps taken to repair. Completing the Steering Wheel Shake Worksheet below is required. A copy of the completed worksheet must be saved with the R.O. and a copy included with any parts returned to the Warranty Parts Center for analysis. A reading of 35 to 50 Hz typically indicates a first order propshaft vibration. If this is the situation, refer to Corporate Bulletin Number 08-07-30-044D. Generally, a reading between 10 and 20 Hz indicates a tire/wheel vibration and if this is the reading obtained, continue using this bulletin. If the tire 1st order vibration goes away and stays away during this evaluation, the cause is likely tire flat-spotting. Tire flat-spotting vibration may come and go at any speed over 72 km/h (45 mph) during the first 10 minutes of operation, if vibration continues after 10 minutes of driving at speeds greater than 72 km/h (45 mph), tire flat-spotting can be ruled out as the cause for vibration. 6. If flat-spotting is the cause, provide the explanation that this has occurred due to the vehicle being parked for long periods of time and that the nature of the tire is to take a set. Refer to Corporate Bulletin Number 03-03-10-007E: Information on Tire/Wheel Characteristics (Vibration, Balance, Shake, Flat Spotting) of GM Original Equipment Tires. 7. If the road test indicates a shake/vibration exists, check the imbalance of each tire/wheel assembly on a known, calibrated, off-car dynamic balancer.Make sure the mounting surface of the wheel and the surface of the balancer are absolutely clean and free of debris. Be sure to chose the proper cone/collet for the wheel, and always use the pilot bore for centering. Never center the wheel using the hub-cap bore since it is not a precision machined surface. If any assembly calls for more than 1/4 ounce on either rim flange, remove all balance weights and rebalance to as close to zero as possible. If you can see the vibration (along with feeling it) in the steering wheel (driving straight without your hands on the wheel), it is very likely to be a tire/wheel first order (one pulse per revolution) disturbance. First order disturbances can be caused by imbalance as well as non-uniformities in tires, wheels or hubs. This first order frequency is too low for a human to hear, but if the amplitude is high enough, it can be seen. If a vibration or shake still exists after balancing, any out of round conditions, of the wheel, and force variation conditions of the tire, must be addressed. Equipment such as the Hunter GSP9700 can address both (it is also a wheel balancer). Tire radial force vibration (RFV) can be defined as the amount of stiffness variation the tire will produce in one revolution under a constant load. Radial force variation is what the vehicle feels because the load (weight) of the vehicle is always on the tires. Although free runout of tires (not under load) is not always a good indicator of a smooth ride, it is critical that total tire/wheel assembly runout be within specification. Equipment such as the Hunter GSP9700 loads the tire, similar to on the vehicle, and measures radial force variation of the tire/wheel assembly. Note that the wheel is affecting the tire's RFV measurement at this point. To isolate the wheel, its runout must be measured. This can be easily done on the Hunter, without the need to set up dial indicators. If the wheel meets the runout specification, the tire's RFV can then be addressed. After measuring the tire/wheel assembly under load, and the wheel alone, the machine then calculates (predicts) the radial force variation of the tire. However, because this is a prediction that can include mounting inaccuracies, and the load wheel is much smaller in diameter than used in tire production, this type of service equipment should NOT be used to audit new tires. Rather, it should be used as a service diagnostic tool to minimize radial force variation of the tire/wheel assembly. Equipment such as the Hunter GSP9700 does an excellent job of measuring wheel runout, and of finding the low point of the wheel (for runout) and the high point of the tire (for radial force variation). This allows the tire to be matched mounted to the wheel for lowest tire/wheel assembly force variation. The machine will simplify this process into easy steps. The following assembly radial force variation numbers should be used as a guide: When measuring RFV and match mounting tires perform the following steps. Measuring Wheel Runout and Assembly Radial Force Variation Important The completed worksheet at the end of this bulletin must be attached to the hard copy of the repair order. - Measure radial force variation and radial runout. - If a road force/balancing machine is used, record the radial force variation (RFV) on the worksheet at the end of this bulletin. It may be of benefit to have the lowest RFV assembly to the front left corner. If the machine is not available and the EVA data suggests there is an issue, swap the tire and wheel assemblies from the front to the back. Re-check on the EVA and if the problem still exists, test another vehicle to find tires that do not exhibit the same frequency and swap those tires onto the subject vehicle. - If a runout/balancing machine is used, record the radial runout of the tire/wheel assemblies on the worksheet at the end of this bulletin. If one or more of the tire/wheel assemblies are more than.040 in (1.02 mm), match mount the tire to the wheel to get below.040 in (1.02 mm). For sensitive customers, readings of 0.030 inch (0.76 mm) or less are preferable, it may also be of benefit to have the lowest runout assembly to the front left corner. If the machine is not available and the EVA data suggests there is an issue, swap the tire and wheel assemblies from the front to the back. Re-check on the EVA and if the problem still exists, test another vehicle to find tires that do not exhibit the same frequency and swap those tires Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > Customer Interest: > 00-03-10-006F > May > 10 > Wheels/Tires - Tire Radial Force Variation (RFV) > Page 1874 onto the subject vehicle. - After match mounting, the tire/wheel assembly must be rebalanced. If match mounting tires to in-spec wheels produces assembly values higher than these, tire replacement may be necessary. Replacing tires at lower values will probably mean good tires are being condemned. Because tires can sometimes become temporarily flat-spotted, which will affect force variation, it is important that the vehicle be driven at least 16 km (10 mi) prior to measuring. Tire pressure must also be adjusted to the usage pressure on the vehicle's tire placard prior to measuring. Most GM vehicles will tolerate radial force variation up to these levels. However, some vehicles are more sensitive, and may require lower levels. Also, there are other tire parameters that equipment such as the Hunter GSP9700 cannot measure that may be a factor. In such cases, TAC should be contacted for further instructions. Important - When mounting a GM wheel to a wheel balancer/force variation machine, always use the wheel's center pilot hole. This is the primary centering mechanism on all GM wheels; the bolt holes are secondary. Usually a back cone method to the machine should be used. For added accuracy and repeatability, a flange plate should be used to clamp the wheel onto the cone and machine. This system is offered by all balancer manufacturers in GM's dealer program. - Any type of service equipment that removes tread rubber by grinding, buffing or truing is NOT recommended, and may void the tire warranty. However, tires may have been ground by the tire company as part of their tire manufacturing process. This is a legitimate procedure. Steering Wheel Shake Worksheet When diagnosing vibration concerns, use the following worksheet in conjunction with the appropriate Vibration Analysis-Road testing procedure in the Vibration Correction sub-section in SI. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > Customer Interest: > 00-03-10-006F > May > 10 > Wheels/Tires - Tire Radial Force Variation (RFV) > Page 1875 Refer to the appropriate section of SI for specifications and repair procedures that are related to the vibration concern. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > Customer Interest: > 05-03-10-003F > Apr > 10 > Tires/Wheels - Low Tire/Leaking Cast Aluminum Wheels Wheels: Customer Interest Tires/Wheels - Low Tire/Leaking Cast Aluminum Wheels TECHNICAL Bulletin No.: 05-03-10-003F Date: April 27, 2010 Subject: Low Tire Pressure, Leaking Cast Aluminum Wheels (Repair with Adhesive Sealant) Models: 2011 and Prior GM Passenger Cars and Light Duty Trucks (Including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X with Cast Aluminum Wheels Supercede: This bulletin is being revised to update the model years and the bulletin reference information. Please discard Corporate Bulletin Number 05-03-10-003E (Section 03 - Suspension). Condition Some customers may comment on a low tire pressure condition. Diagnosis of the low tire pressure condition indicates an air leak through the cast aluminum wheel. Cause Porosity in the cast aluminum wheel may be the cause. Notice This bulletin specifically addresses issues related to the wheel casting that may result in an air leak. For issues related to corrosion of the wheel in service, please refer to Corporate Bulletin Number 08-03-10-006C - Tire Slowly Goes Flat, Tire Air Loss, Low Tire Pressure Warning Light Illuminated, Aluminum Wheel Bead Seat Corrosion (Clean and Resurface Wheel Bead Seat). Correction 1. Remove the tire and wheel assembly from the vehicle. Refer to the appropriate service procedure in SI. 2. Locate the leaking area by inflating the tire to 276 kPa (40 psi) and dipping the tire/wheel assembly in a water bath, or use a spray bottle with soap and water to locate the specific leak location. Important - If the porosity leak is located in the bead area of the aluminum rim (where the tire meets the rim), the wheel should be replaced. - If two or more leaks are located on one wheel, the wheel should be replaced. 3. If air bubbles are observed, mark the location. - If the leak location is on the tire/rubber area, refer to Corporate Bulletin Number 04-03-10-001F Tire Puncture Repair Procedures for All Cars and Light Duty Trucks. - If the leak is located on the aluminum wheel area, continue with the next step. 4. Inscribe a mark on the tire at the valve stem in order to indicate the orientation of the tire to the wheel. 5. Dismount the tire from the wheel. Refer to Tire Mounting and Dismounting. 6. Remove the tire pressure sensor. Refer to Tire Pressure Sensor removal procedure in SI. 7. Scuff the INSIDE rim surface at the leak area with #80 grit paper and clean the area with general purpose cleaner, such as 3M(R) General Purpose Adhesive Cleaner, P/N 08984, or equivalent. 8. Apply a 3 mm (0.12 in) thick layer of Silicone - Adhesive/Sealant, P/N 12378478 (in Canada, use 88900041), or equivalent, to the leak area. 9. Allow for the adhesive/sealant to dry. Notice Caution must be used when mounting the tire so as not to damage the sealer. Damaging the repair area may result in an air leak. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > Customer Interest: > 05-03-10-003F > Apr > 10 > Tires/Wheels - Low Tire/Leaking Cast Aluminum Wheels > Page 1880 10. Align the inscribed mark on the tire with the valve stem on the wheel. 11. Reinstall the Tire Pressure Sensor. Refer to Tire Pressure Sensor installation procedure in SI. 12. Mount the tire on the wheel. Refer to Tire Mounting and Dismounting. 13. Pressurize the tire to 276 kPa (40 psi) and inspect for leaks. 14. Adjust tire pressure to meet the placard specification. 15. Balance the tire/wheel assembly. Refer to Tire and Wheel Assembly Balancing - Off-Vehicle. 16. Install the tire and wheel assembly onto the vehicle. Refer to the appropriate service procedure in SI. Parts Information Warranty Information (excluding Saab U.S. Models) Important The Silicone - Adhesive/Sealant comes in a case quantity of six. ONLY charge warranty one tube of adhesive/sealant per wheel repair. For vehicles repaired under warranty, use: One leak repair per wheel. Warranty Information (Saab U.S. Models) For vehicles repaired under warranty, use the table above. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 00-03-10-002F > Apr > 11 > Wheels - Chrome Wheel Staining/Pitting/Corrosion Wheels: All Technical Service Bulletins Wheels - Chrome Wheel Staining/Pitting/Corrosion INFORMATION Bulletin No.: 00-03-10-002F Date: April 21, 2011 Subject: Chemical Staining, Pitting, Corrosion and/or Spotted Appearance of Chromed Aluminum Wheels Models: 2012 and Prior GM Cars and Trucks Supercede: This bulletin is being revised to update model years, suggest additional restorative products and add additional corrosion information. Please discard Corporate Bulletin Number 00-03-10-002E (Section 03 - Suspension). Important You may give a copy of this bulletin to the customer. What is Chemical Staining of Chrome Wheels? Figure 1 Chemical staining in most cases results from acid based cleaners (refer to Figure 1 for an example). These stains are frequently milky, black, or greenish in appearance. They result from using cleaning solutions that contain acids on chrome wheels. Soap and water is usually sufficient to clean wheels. If the customer insists on using a wheel cleaner they should only use one that specifically states that it is safe for chromed wheels and does not contain anything in the following list. (Dealers should also survey any products they use during prep or normal cleaning of stock units for these chemicals.) - Ammonium Bifluoride (fluoride source for dissolution of chrome) - Hydrofluoric Acid (directly dissolves chrome) - Hydrochloric Acid (directly dissolves chrome) - Sodium Dodecylbenzenesulfonic Acid - Sulfamic Acid - Phosphoric Acid - Hydroxyacetic Acid Notice Many wheel cleaner instructions advise to take care to avoid contact with painted surfaces. Most customers think of painted surfaces as the fenders, quarter panels and other exterior sheet metal. Many vehicles have painted brake calipers. Acidic wheel cleaners may craze, crack, or discolor the paint on the brake calipers. Damage from wheel cleaners is not covered under the vehicle new car warranty. Soap and water applied with a soft brush is usually all that is required to clean the calipers. Whenever any wheel cleaner is used, it must be THOROUGHLY rinsed off of the wheel with clean, clear water. Special care must be taken to rinse under the hub cap, balance weights, wheel nuts, lug nut caps, between the wheel cladding and off the back side of the wheel. Wheels returned to the Warranty Parts Center (WPC) that exhibit damage from wheel cleaners most often have the damage around and under the wheel weight where the cleaner was incompletely flushed away. Notice Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 00-03-10-002F > Apr > 11 > Wheels - Chrome Wheel Staining/Pitting/Corrosion > Page 1886 Do not use cleaning solutions that contain hydrofluoric, oxalic and most other acids on chrome wheels (or any wheels). If the customer is unsure of the chemical make-up of a particular wheel cleaner, it should be avoided. For wheels showing signs of milky staining from acidic cleaners, refer to Customer Assistance and Instructions below. Warranty of Stained Chrome Wheels Stained wheels are not warrantable. Most acid based cleaners will permanently stain chrome wheels. Follow-up with dealers has confirmed that such cleaners were used on wheels that were returned to the Warranty Parts Center (WPC). Any stained wheels received by the WPC will be charged back to the dealership. To assist the customer, refer to Customer Assistance and Instructions below. Pitting or Spotted Appearance of Chrome Wheels Figure 2 A second type or staining or finish disturbance may result from road chemicals, such as calcium chloride used for dust control of unpaved roads. The staining will look like small pitting (refer to Figure 2). This staining will usually be on the leading edges of each wheel spoke, but may be uniformly distributed. If a vehicle must be operated under such conditions, the chrome wheels should be washed with mild soap and water and thoroughly rinsed as soon as conveniently possible. Important Road chemicals, such as calcium chloride used for dust control of unpaved roads, can also stain chrome wheels. The staining will look like small pitting. This staining will usually be on the leading edges of each wheel spoke. This is explained by the vehicle traveling in the forward direction while being splashed by the road chemical. If a vehicle must be operated under such conditions, the chrome wheels should be washed with mild soap and water and thoroughly rinsed as soon as conveniently possible. Warranty of Pitted or Spotted Chrome Wheels Wheels returned with pitting or spotting as a result of road chemicals may be replaced one time. Damage resulting from contact with these applied road chemicals is corrosive to the wheels finish and may cause damage if the wheels are not kept clean. Important Notify the customer that this is a one time replacement. Please stress to the customer the vital importance of keeping the wheels clean if they are operating the vehicle in an area that applies calcium chloride or other dust controlling chemicals! "GM of Canada" dealers require prior approval by the District Manager - Customer Care and Service Process (DM-CCSP). "Stardust" Corrosion of Chrome Wheels Figure 3 A third type of finish disturbance results from prolonged exposure to brake dust and resultant penetration of brake dust through the chrome. As brakes are applied hot particles of brake material are thrown off and tend to be forced through the leading edge of the wheel spoke windows by airflow. These Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 00-03-10-002F > Apr > 11 > Wheels - Chrome Wheel Staining/Pitting/Corrosion > Page 1887 hot particles embed themselves in the chrome layer and create a small pit. If the material is allowed to sit on the wheel while it is exposed to moisture or salt, it will corrode the wheel beneath the chrome leaving a pit or small blister in the chrome. Heavy brake dust build-up should be removed from wheels by using GM Chrome Cleaner and Polish, P/N 1050173 (in Canada use 10953013). For moderate cleaning, light brake dust build-up or water spots use GM Swirl Remover Polish, P/N 12377965 (in Canada, use Meguiars Plast-X(TM) Clear Plastic Cleaner and Polish #G12310C**). After cleaning, the wheel should be waxed using GM Cleaner Wax, P/N 12377966 (in Canada, use Meguiars Cleaner Wax #M0616C**), which will help protect the wheel from brake dust and reduce adhesion of any brake dust that gets on the wheel surface. For general maintenance cleaning, PEEK Metal Polish† may be used. It will clean and shine the chrome and leave behind a wax coating that may help protect the finish. Warranty of Stardust Corroded Chrome Wheels Wheels returned with pitting or spotting as a result of neglect and brake dust build-up may be replaced one time. Important Notify the customer that this is a one time replacement. Please stress to the customer the vital importance of keeping the wheels clean and free of prolonged exposure to brake dust build-up. "GM of Canada" dealers require prior approval by the District Manager - Customer Care and Service Process (DM-CCSP). Customer Assistance and Instructions GM has looked for ways customers may improve the appearance of wheels damaged by acidic cleaners. The following product and procedure has been found to dramatically improve the appearance of stained wheels. For wheels that have milky stains caused by acidic cleaners try the following: Notice THE 3M CHROME AND METAL POLISH REQUIRED FOR THIS PROCEDURE IS AN EXTREMELY AGGRESSIVE POLISH/CLEANER. THE WHEELS MUST BE CLEANED BEFORE APPLICATION TO AVOID SCRATCHING THE WHEEL SURFACE. THIS PRODUCT WILL REDUCE THE THICKNESS OF THE CHROME PLATING ON THE WHEEL AND IF USED INCORRECTLY OR EXCESSIVELY MAY REMOVE THE CHROME PLATING ALL TOGETHER, EXPOSING A LESS BRIGHT AND BRASSY COLORED SUB-LAYER. FOLLOW INSTRUCTIONS EXACTLY. 1. Wash the wheels with vigorously with soap and water. This step will clean and may reduce wheel staining. Flood all areas of the wheel with water to rinse. 2. Dry the wheels completely. Notice Begin with a small section of the wheel and with light pressure buff off polish and examine results. ONLY apply and rub with sufficient force and time to remove enough staining that you are satisfied with the results. Some wheels may be stained to the extent that you may only achieve a 50% improvement while others may be able to be restored to the original lustre. IN ALL CASES, only apply until the results are satisfactory. 3. Apply 3M Chrome and Metal Polish #39527* with a clean terry cloth towel. As you apply the polish, the staining will be diminished. 4. When dry, buff off the polish with a clean portion of the towel. 5. Repeat application of the 3M Chrome and Metal Polish until satisfied with the results. If continued applications fail to improve the appearance further discontinue use. This procedure will improve the appearance of the wheels and may, with repeated applications, restore the finish dramatically. For wheels that exhibit spotting from road chemicals the above procedure may marginally improve the condition but will not restore the finish or remove the pitting. In this type of staining the wheel finish has actually been removed in spots and no manner of cleaning will restore the finish. †*We believe this source and their products to be reliable. There may be additional manufacturers of such products/materials. General Motors does not endorse, indicate any preference for or assume any responsibility for the products or material from this firm or for any such items that may be available from other sources. Parts Information Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 00-03-10-002F > Apr > 11 > Wheels - Chrome Wheel Staining/Pitting/Corrosion > Page 1888 *This product is currently available from 3M. To obtain information for your local retail location please call 3M at 1-888-364-3577. **This product is currently available from Meguiars (Canada). To obtain information for your local retail location please call Meguiars at 1-800-347-5700 or at www.meguiarscanada.com. ^ This product is currently available from Tri-Peek International. To obtain information for your local retail location please call Tri-Peek at 1-877-615-4272 or at www.tripeek.com. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 99-08-51-007E > Mar > 11 > Wheels/Tires - Refinishing Aluminum Wheels Wheels: All Technical Service Bulletins Wheels/Tires - Refinishing Aluminum Wheels INFORMATION Bulletin No.: 99-08-51-007E Date: March 17, 2011 Subject: Refinishing Aluminum Wheels Models: 2012 and Prior GM Passenger Cars and Trucks Supercede: This bulletin is being revised to add additional model years. Please discard Corporate Bulletin Number 99-08-51-007D (Section 08 - Body and Accessories). This bulletin updates General Motor's position on refinishing aluminum wheels. GM does not endorse any repairs that involve welding, bending, straightening or re-machining. Only cosmetic refinishing of the wheel's coatings, using recommended procedures, is allowed. Evaluating Damage In evaluating damage, it is the GM Dealer's responsibility to inspect the wheel for corrosion, scrapes, gouges, etc. The Dealer must insure that such damage is not deeper than what can be sanded or polished off. The wheel must be inspected for cracks. If cracks are found, discard the wheel. Any wheels with bent rim flanges must not be repaired or refinished. Wheels that have been refinished by an outside company must be returned to the same vehicle. The Dealer must record the wheel ID stamp or the cast date on the wheel in order to assure this requirement. Refer to Refinisher's Responsibility - Outside Company later in this bulletin. Aluminum Wheel Refinishing Recommendations - Chrome-plated aluminum wheels Re-plating these wheels is not recommended. - Polished aluminum wheels These wheels have a polyester or acrylic clearcoat on them. If the clearcoat is damaged, refinishing is possible. However, the required refinishing process cannot be performed in the dealer environment. Refer to Refinisher's Responsibility - Outside Company later in this bulletin. - Painted aluminum wheels These wheels are painted using a primer, color coat, and clearcoat procedure. If the paint is damaged, refinishing is possible. As with polished wheels, all original coatings must be removed first. Media blasting is recommended. Refer to GM Aluminum Refinishing Bulletin #53-17-03A for the re-painting of this type of wheel. - Bright, machined aluminum wheels These wheels have a polyester or acrylic clearcoat on them. In some cases, the recessed "pocket" areas of the wheel may be painted. Surface refinishing is possible. The wheel must be totally stripped by media blasting or other suitable means. The wheel should be resurfaced by using a sanding process rather than a machining process. This allows the least amount of material to be removed. Important Do not use any re-machining process that removes aluminum. This could affect the dimensions and function of the wheel. Painting is an option to re-clearcoating polished and bright machined aluminum wheels. Paint will better mask any surface imperfections and is somewhat more durable than clearcoat alone. GM recommends using Corsican SILVER WAEQ9283 for a fine "aluminum-like" look or Sparkle SILVER WA9967 for a very bright look. As an option, the body color may also be used. When using any of the painting options, it is recommended that all four wheels be refinished in order to maintain color uniformity. Refer to GM Aluminum Refinishing Bulletin #53-17-03A for specific procedures and product recommendations. Refinisher's Responsibility - Outside Company Important Some outside companies are offering wheel refinishing services. Such refinished wheels will be permanently marked by the refinisher and are warranted by the refinisher. Any process that re-machines or otherwise re-manufactures the wheel should not be used. A refinisher's responsibility includes inspecting for cracks using the Zyglo system or the equivalent. Any cracked wheels must not be refinished. No welding, hammering or reforming of any kind is allowed. The wheel ID must be recorded and follow the wheel throughout the process in order to assure that the same wheel is returned. A plastic media blast may be used for clean up of the wheel. Hand and/or lathe sanding of the machined surface and the wheel window is allowed. Material removal, though, must be kept to a minimum. Re-machining of the wheel is not allowed. Paint and/or clear coat must not be present on the following surfaces: the nut chamfers, the wheel mounting surfaces and the wheel pilot hole. The refinisher must permanently ID stamp the wheel and warrant the painted/clearcoated surfaces for a minimum of one year or the remainder of the new vehicle warranty, whichever is Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 99-08-51-007E > Mar > 11 > Wheels/Tires - Refinishing Aluminum Wheels > Page 1893 longer. Important Whenever a wheel is refinished, the mounting surface and the wheel nut contact surfaces must not be painted or clearcoated. Coating these surfaces could affect the wheel nut torque. When re-mounting a tire on an aluminum wheel, coated balance weights must be used in order to reduce the chance of future cosmetic damage. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 06-03-10-010A > Jun > 10 > Wheels - Changing Procedures/Precautions Wheels: All Technical Service Bulletins Wheels - Changing Procedures/Precautions INFORMATION Bulletin No.: 06-03-10-010A Date: June 09, 2010 Subject: Information on Proper Wheel Changing Procedures and Cautions Models: 2011 and Prior GM Passenger Cars and Trucks 2010 and Prior HUMMER Models 2005-2009 Saab 9-7X 2005-2009 Saturn Vehicles Attention: Complete wheel changing instructions for each vehicle line can be found under Tire and Wheel Removal and Installation in Service Information (SI). This bulletin is intended to quickly review and reinforce simple but vital procedures to reduce the possibility of achieving low torque during wheel installation. Always refer to SI for wheel lug nut torque specifications and complete jacking instructions for safe wheel changing. Supercede: This bulletin is being revised to include the 2011 model year and update the available special tool list. Please discard Corporate Bulletin Number 06-03-10-010 (Section 03 Suspension). Frequency of Wheel Changes - Marketplace Driven Just a few years ago, the increasing longevity of tires along with greater resistance to punctures had greatly reduced the number of times wheels were removed to basically required tire rotation intervals. Today with the booming business in accessory wheels/special application tires (such as winter tires), consumers are having tire/wheel assemblies removed - replaced - or installed more than ever. With this increased activity, it opens up more of a chance for error on the part of the technician. This bulletin will review a few of the common concerns and mistakes to make yourself aware of. Proper Servicing Starts With the Right Tools The following tools have been made available to assist in proper wheel and tire removal and installation. - J 41013 Rotor Resurfacing Kit (or equivalent) - J 42450-A Wheel Hub Resurfacing Kit (or equivalent) Corroded Surfaces One area of concern is corrosion on the mating surfaces of the wheel to the hub on the vehicle. Excessive corrosion, dirt, rust or debris built up on these surfaces can mimic a properly tightened wheel in the service stall. Once the vehicle is driven, the debris may loosen, grind up or be washed away from water splash. This action may result in clearance at the mating surface of the wheel and an under-torqued condition. Caution Before installing a wheel, remove any buildup on the wheel mounting surface and brake drum or brake disc mounting surface. Installing wheels with poor metal-to-metal contact at the mounting surfaces can cause wheel nuts to loosen. This may cause a wheel to come off when the vehicle is moving, possibly resulting in a loss of control or personal injury. Whenever you remove the tire/wheel assemblies, you must inspect the mating surfaces. If corrosion is found, you should remove the debris with a die grinder equipped with a fine sanding pad, wire brush or cleaning disc. Just remove enough material to assure a clean, smooth mating surface. The J 41013 (or equivalent) can be used to clean the following surfaces: - The hub mounting surface - The brake rotor mounting surface - The wheel mounting surface Use the J 42450-A (or equivalent) to clean around the base of the studs and the hub. Lubricants, Grease and Fluids Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 06-03-10-010A > Jun > 10 > Wheels - Changing Procedures/Precautions > Page 1898 Some customers may use penetrating oils, grease or other lubricants on wheel studs to aid in removal or installation. Always use a suitable cleaner/solvent to remove these lubricants prior to installing the wheel and tire assemblies. Lubricants left on the wheel studs may cause improper readings of wheel nut torque. Always install wheels to clean, dry wheel studs ONLY. Notice Lubricants left on the wheel studs or vertical mounting surfaces between the wheel and the rotor or drum may cause the wheel to work itself loose after the vehicle is driven. Always install wheels to clean, dry wheel studs and surfaces ONLY. Beginning with 2011 model year vehicles, put a light coating of grease, GM P/N 1051344 (in Canada, P/N 9930370), on the inner surface of the wheel pilot hole to prevent wheel seizure to the axle or bearing hub. Wheel Stud and Lug Nut Damage Always inspect the wheel studs and lug nuts for signs of damage from crossthreading or abuse. You should never have to force wheel nuts down the stud. Lug nuts that are damaged may not retain properly, yet give the impression of fully tightening. Always inspect and replace any component suspected of damage. Tip Always start wheel nuts by hand! Be certain that all wheel nut threads have been engaged BEFORE tightening the nut. Important If the vehicle has directional tread tires, verify the directional arrow on the outboard side of the tire is pointing in the direction of forward rotation. Wheel Nut Tightening and Torque Improper wheel nut tightening can lead to brake pulsation and rotor damage. In order to avoid additional brake repairs, evenly tighten the wheel nuts to the proper torque specification as shown for each vehicle in SI. Always observe the proper wheel nut tightening sequence as shown below in order to avoid trapping the wheel on the wheel stud threads or clamping the wheel slightly off center resulting in vibration. The Most Important Service You Provide While the above information is well known, and wheel removal so common, technicians run the risk of becoming complacent on this very important Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 06-03-10-010A > Jun > 10 > Wheels - Changing Procedures/Precautions > Page 1899 service operation. A simple distraction or time constraint that rushes the job may result in personal injury if the greatest of care is not exercised. Make it a habit to double check your work and to always side with caution when installing wheels. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 00-03-10-006F > May > 10 > Wheels/Tires - Tire Radial Force Variation (RFV) Wheels: All Technical Service Bulletins Wheels/Tires - Tire Radial Force Variation (RFV) INFORMATION Bulletin No.: 00-03-10-006F Date: May 04, 2010 Subject: Information on Tire Radial Force Variation (RFV) Models: 2011 and Prior GM Passenger Cars and Light Duty Trucks 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X 2000-2005 Saturn L Series 2003-2007 Saturn ION Supercede: This bulletin is being revised to considerably expand the available information on Radial Force Variation (RFV) and should be reviewed in whole. Please discard Corporate Bulletin Number 00-03-10-006E (Section 03 - Suspension). Important - Before measuring tires on equipment such as the Hunter GSP9700, the vehicle MUST be driven a minimum of 16 km (10 mi) to ensure removal of any flat-spotting. Refer to Corporate Bulletin Number 03-03-10-007E - Tire/Wheel Characteristics of GM Original Equipment Tires. - Equipment such as the Hunter GSP9700 MUST be calibrated prior to measuring tire/wheel assemblies for each vehicle. The purpose of this bulletin is to provide guidance to GM dealers when using tire force variation measurement equipment, such as the Hunter GSP9700. This type of equipment can be a valuable tool in diagnosing vehicle ride concerns. The most common ride concern involving tire radial force variation is highway speed shake on smooth roads. Tire related smooth road highway speed shake can be caused by three conditions: imbalance, out of round and tire force variation. These three conditions are not necessarily related. All three conditions must be addressed. Imbalance is normally addressed first, because it is the simpler of the three to correct. Off-vehicle, two plane dynamic wheel balancers are readily available and can accurately correct any imbalance. Balancer calibration and maintenance, proper attachment of the wheel to the balancer, and proper balance weights, are all factors required for a quality balance. However, a perfectly balanced tire/wheel assembly can still be "oval shaped" and cause a vibration. Before balancing, perform the following procedures. Tire and Wheel Diagnosis 1. Set the tire pressure to the placard values. 2. With the vehicle raised, ensure the wheels are centered on the hub by loosening all wheel nuts and hand-tightening all nuts first by hand while shaking the wheel, then torque to specifications using a torque wrench, NOT a torque stick. 3. Visually inspect the tires and the wheels. Inspect for evidence of the following conditions and correct as necessary: - Missing balance weights - Bent rim flange - Irregular tire wear - Incomplete bead seating - Tire irregularities (including pressure settings) - Mud/ice build-up in wheel - Stones in the tire tread - Remove any aftermarket wheels and/or tires and restore vehicle to original condition prior to diagnosing a smooth road shake condition. 4. Road test the vehicle using the Electronic Vibration Analyzer (EVA) essential tool. Drive for a sufficient distance on a known, smooth road surface to duplicate the condition. Determine if the vehicle is sensitive to brake apply. If the brakes are applied lightly and the pulsation felt in the steering wheel increases, refer to the Brakes section of the service manual that deals with brake-induced pulsation. If you can start to hear the vibration as a low boom noise (in addition to feeling it), but cannot see it, the vehicle likely has a first order (one pulse per propshaft revolution) driveline vibration. Driveline first order vibrations are high enough in frequency that most humans can start to hear them at highway speeds, but are too high to be able to be easily seen. These issues can be caused by driveline imbalance or misalignment. If the vehicle exhibits this low boom and the booming pulses in-and-out on a regular basis (like a throbbing), chances are good that the vehicle could have driveline vibration. This type Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 00-03-10-006F > May > 10 > Wheels/Tires - Tire Radial Force Variation (RFV) > Page 1904 of vibration is normally felt more in the "seat of the pants" than the steering wheel. 5. Next, record the Hertz (Hz) reading as displayed by the EVA onto the tire data worksheet found at the end of this bulletin. This should be done after a tire break-in period of at least 16 km (10 mi) at 72 km/h (45 mph) or greater, in order to eliminate any possible tire flat-spotting. This reading confirms what the vehicle vibration frequency is prior to vehicle service and documents the amount of improvement occurring as the result of the various steps taken to repair. Completing the Steering Wheel Shake Worksheet below is required. A copy of the completed worksheet must be saved with the R.O. and a copy included with any parts returned to the Warranty Parts Center for analysis. A reading of 35 to 50 Hz typically indicates a first order propshaft vibration. If this is the situation, refer to Corporate Bulletin Number 08-07-30-044D. Generally, a reading between 10 and 20 Hz indicates a tire/wheel vibration and if this is the reading obtained, continue using this bulletin. If the tire 1st order vibration goes away and stays away during this evaluation, the cause is likely tire flat-spotting. Tire flat-spotting vibration may come and go at any speed over 72 km/h (45 mph) during the first 10 minutes of operation, if vibration continues after 10 minutes of driving at speeds greater than 72 km/h (45 mph), tire flat-spotting can be ruled out as the cause for vibration. 6. If flat-spotting is the cause, provide the explanation that this has occurred due to the vehicle being parked for long periods of time and that the nature of the tire is to take a set. Refer to Corporate Bulletin Number 03-03-10-007E: Information on Tire/Wheel Characteristics (Vibration, Balance, Shake, Flat Spotting) of GM Original Equipment Tires. 7. If the road test indicates a shake/vibration exists, check the imbalance of each tire/wheel assembly on a known, calibrated, off-car dynamic balancer.Make sure the mounting surface of the wheel and the surface of the balancer are absolutely clean and free of debris. Be sure to chose the proper cone/collet for the wheel, and always use the pilot bore for centering. Never center the wheel using the hub-cap bore since it is not a precision machined surface. If any assembly calls for more than 1/4 ounce on either rim flange, remove all balance weights and rebalance to as close to zero as possible. If you can see the vibration (along with feeling it) in the steering wheel (driving straight without your hands on the wheel), it is very likely to be a tire/wheel first order (one pulse per revolution) disturbance. First order disturbances can be caused by imbalance as well as non-uniformities in tires, wheels or hubs. This first order frequency is too low for a human to hear, but if the amplitude is high enough, it can be seen. If a vibration or shake still exists after balancing, any out of round conditions, of the wheel, and force variation conditions of the tire, must be addressed. Equipment such as the Hunter GSP9700 can address both (it is also a wheel balancer). Tire radial force vibration (RFV) can be defined as the amount of stiffness variation the tire will produce in one revolution under a constant load. Radial force variation is what the vehicle feels because the load (weight) of the vehicle is always on the tires. Although free runout of tires (not under load) is not always a good indicator of a smooth ride, it is critical that total tire/wheel assembly runout be within specification. Equipment such as the Hunter GSP9700 loads the tire, similar to on the vehicle, and measures radial force variation of the tire/wheel assembly. Note that the wheel is affecting the tire's RFV measurement at this point. To isolate the wheel, its runout must be measured. This can be easily done on the Hunter, without the need to set up dial indicators. If the wheel meets the runout specification, the tire's RFV can then be addressed. After measuring the tire/wheel assembly under load, and the wheel alone, the machine then calculates (predicts) the radial force variation of the tire. However, because this is a prediction that can include mounting inaccuracies, and the load wheel is much smaller in diameter than used in tire production, this type of service equipment should NOT be used to audit new tires. Rather, it should be used as a service diagnostic tool to minimize radial force variation of the tire/wheel assembly. Equipment such as the Hunter GSP9700 does an excellent job of measuring wheel runout, and of finding the low point of the wheel (for runout) and the high point of the tire (for radial force variation). This allows the tire to be matched mounted to the wheel for lowest tire/wheel assembly force variation. The machine will simplify this process into easy steps. The following assembly radial force variation numbers should be used as a guide: When measuring RFV and match mounting tires perform the following steps. Measuring Wheel Runout and Assembly Radial Force Variation Important The completed worksheet at the end of this bulletin must be attached to the hard copy of the repair order. - Measure radial force variation and radial runout. - If a road force/balancing machine is used, record the radial force variation (RFV) on the worksheet at the end of this bulletin. It may be of benefit to have the lowest RFV assembly to the front left corner. If the machine is not available and the EVA data suggests there is an issue, swap the tire and wheel assemblies from the front to the back. Re-check on the EVA and if the problem still exists, test another vehicle to find tires that do not exhibit the same frequency and swap those tires onto the subject vehicle. - If a runout/balancing machine is used, record the radial runout of the tire/wheel assemblies on the worksheet at the end of this bulletin. If one or more of the tire/wheel assemblies are more than.040 in (1.02 mm), match mount the tire to the wheel to get below.040 in (1.02 mm). For sensitive customers, readings of 0.030 inch (0.76 mm) or less are preferable, it may also be of benefit to have the lowest runout assembly to the front left corner. If the machine is not available and the EVA data suggests there is an issue, swap the tire and wheel assemblies from the front to the back. Re-check on the EVA and if the problem still exists, test another vehicle to find tires that do not exhibit the same frequency and swap those tires Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 00-03-10-006F > May > 10 > Wheels/Tires - Tire Radial Force Variation (RFV) > Page 1905 onto the subject vehicle. - After match mounting, the tire/wheel assembly must be rebalanced. If match mounting tires to in-spec wheels produces assembly values higher than these, tire replacement may be necessary. Replacing tires at lower values will probably mean good tires are being condemned. Because tires can sometimes become temporarily flat-spotted, which will affect force variation, it is important that the vehicle be driven at least 16 km (10 mi) prior to measuring. Tire pressure must also be adjusted to the usage pressure on the vehicle's tire placard prior to measuring. Most GM vehicles will tolerate radial force variation up to these levels. However, some vehicles are more sensitive, and may require lower levels. Also, there are other tire parameters that equipment such as the Hunter GSP9700 cannot measure that may be a factor. In such cases, TAC should be contacted for further instructions. Important - When mounting a GM wheel to a wheel balancer/force variation machine, always use the wheel's center pilot hole. This is the primary centering mechanism on all GM wheels; the bolt holes are secondary. Usually a back cone method to the machine should be used. For added accuracy and repeatability, a flange plate should be used to clamp the wheel onto the cone and machine. This system is offered by all balancer manufacturers in GM's dealer program. - Any type of service equipment that removes tread rubber by grinding, buffing or truing is NOT recommended, and may void the tire warranty. However, tires may have been ground by the tire company as part of their tire manufacturing process. This is a legitimate procedure. Steering Wheel Shake Worksheet When diagnosing vibration concerns, use the following worksheet in conjunction with the appropriate Vibration Analysis-Road testing procedure in the Vibration Correction sub-section in SI. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 00-03-10-006F > May > 10 > Wheels/Tires - Tire Radial Force Variation (RFV) > Page 1906 Refer to the appropriate section of SI for specifications and repair procedures that are related to the vibration concern. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 05-03-10-003F > Apr > 10 > Tires/Wheels - Low Tire/Leaking Cast Aluminum Wheels Wheels: All Technical Service Bulletins Tires/Wheels - Low Tire/Leaking Cast Aluminum Wheels TECHNICAL Bulletin No.: 05-03-10-003F Date: April 27, 2010 Subject: Low Tire Pressure, Leaking Cast Aluminum Wheels (Repair with Adhesive Sealant) Models: 2011 and Prior GM Passenger Cars and Light Duty Trucks (Including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X with Cast Aluminum Wheels Supercede: This bulletin is being revised to update the model years and the bulletin reference information. Please discard Corporate Bulletin Number 05-03-10-003E (Section 03 - Suspension). Condition Some customers may comment on a low tire pressure condition. Diagnosis of the low tire pressure condition indicates an air leak through the cast aluminum wheel. Cause Porosity in the cast aluminum wheel may be the cause. Notice This bulletin specifically addresses issues related to the wheel casting that may result in an air leak. For issues related to corrosion of the wheel in service, please refer to Corporate Bulletin Number 08-03-10-006C - Tire Slowly Goes Flat, Tire Air Loss, Low Tire Pressure Warning Light Illuminated, Aluminum Wheel Bead Seat Corrosion (Clean and Resurface Wheel Bead Seat). Correction 1. Remove the tire and wheel assembly from the vehicle. Refer to the appropriate service procedure in SI. 2. Locate the leaking area by inflating the tire to 276 kPa (40 psi) and dipping the tire/wheel assembly in a water bath, or use a spray bottle with soap and water to locate the specific leak location. Important - If the porosity leak is located in the bead area of the aluminum rim (where the tire meets the rim), the wheel should be replaced. - If two or more leaks are located on one wheel, the wheel should be replaced. 3. If air bubbles are observed, mark the location. - If the leak location is on the tire/rubber area, refer to Corporate Bulletin Number 04-03-10-001F Tire Puncture Repair Procedures for All Cars and Light Duty Trucks. - If the leak is located on the aluminum wheel area, continue with the next step. 4. Inscribe a mark on the tire at the valve stem in order to indicate the orientation of the tire to the wheel. 5. Dismount the tire from the wheel. Refer to Tire Mounting and Dismounting. 6. Remove the tire pressure sensor. Refer to Tire Pressure Sensor removal procedure in SI. 7. Scuff the INSIDE rim surface at the leak area with #80 grit paper and clean the area with general purpose cleaner, such as 3M(R) General Purpose Adhesive Cleaner, P/N 08984, or equivalent. 8. Apply a 3 mm (0.12 in) thick layer of Silicone - Adhesive/Sealant, P/N 12378478 (in Canada, use 88900041), or equivalent, to the leak area. 9. Allow for the adhesive/sealant to dry. Notice Caution must be used when mounting the tire so as not to damage the sealer. Damaging the repair area may result in an air leak. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 05-03-10-003F > Apr > 10 > Tires/Wheels - Low Tire/Leaking Cast Aluminum Wheels > Page 1911 10. Align the inscribed mark on the tire with the valve stem on the wheel. 11. Reinstall the Tire Pressure Sensor. Refer to Tire Pressure Sensor installation procedure in SI. 12. Mount the tire on the wheel. Refer to Tire Mounting and Dismounting. 13. Pressurize the tire to 276 kPa (40 psi) and inspect for leaks. 14. Adjust tire pressure to meet the placard specification. 15. Balance the tire/wheel assembly. Refer to Tire and Wheel Assembly Balancing - Off-Vehicle. 16. Install the tire and wheel assembly onto the vehicle. Refer to the appropriate service procedure in SI. Parts Information Warranty Information (excluding Saab U.S. Models) Important The Silicone - Adhesive/Sealant comes in a case quantity of six. ONLY charge warranty one tube of adhesive/sealant per wheel repair. For vehicles repaired under warranty, use: One leak repair per wheel. Warranty Information (Saab U.S. Models) For vehicles repaired under warranty, use the table above. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 04-03-10-012B > Feb > 08 > Wheels - Chrome Wheel Brake Dust Accumulation/Pitting Wheels: All Technical Service Bulletins Wheels - Chrome Wheel Brake Dust Accumulation/Pitting Bulletin No.: 04-03-10-012B Date: February 01, 2008 INFORMATION Subject: Pitting and Brake Dust on Chrome wheels Models: 2008 and Prior GM Passenger Cars and Trucks (including Saturn) 2008 and Prior HUMMER H2, H3 2005-2008 Saab 9-7X Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 04-03-10-012A (Section 03 - Suspension). Analysis of Returned Wheels Chrome wheels returned under the New Vehicle Limited Warranty for pitting concerns have recently been evaluated. This condition is usually most severe in the vent (or window) area of the front wheels. This "pitting" may actually be brake dust that has been allowed to accumulate on the wheel. The longer this accumulation builds up, the more difficult it is to remove. Cleaning the Wheels In all cases, the returned wheels could be cleaned to their original condition using GM Vehicle Care Cleaner Wax, P/N 12377966 (in Canada, P/N 10952905). When using this product, you should confine your treatment to the areas of the wheel that show evidence of the brake dust build-up. This product is only for use on chromed steel or chromed aluminum wheels. Parts Information Warranty Information Wheel replacement for this condition is NOT applicable under the terms of the New Vehicle Limited Warranty. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 99-03-10-102 > Jun > 99 > Warranty - OE Chrome Plated Aluminum Wheel ID Wheels: All Technical Service Bulletins Warranty - OE Chrome Plated Aluminum Wheel ID File In Section: 03 - Suspension Bulletin No.: 99-03-10-102 Date: June, 1999 INFORMATION Subject: Original Equipment Chrome Plated Aluminum Wheel Identification Models: 1999 and Prior Passenger Cars and Light Duty Trucks Chrome plated aluminum wheels have been returned to the Warranty Parts Center that are not the original equipment (OE) components. Original equipment chrome plated aluminum wheels can be identified by either a balance weight clip retention groove (1) or a step (2) that is machined around both of the wheel's rim flanges. The rim flanges (3) of painted original equipment aluminum wheels do not have a groove or a step. Chrome plated aluminum wheels that do not have the wheel rim flange groove or step are aftermarket chrome plated components and are NOT warrantable. Any aftermarket chrome wheels received by the Warranty Parts Center will be charged back to the dealership. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 72-05-05 > Aug > 97 > Warranty - Guidelines for Using E0420 Wheel Replace Wheels: All Technical Service Bulletins Warranty - Guidelines for Using E0420 Wheel Replace File In Section: Warranty Administration Bulletin No.: 72-05-05 Date: August, 1997 WARRANTY ADMINISTRATION Subject: Guidelines for Using EO42O Wheel Replace Models: 1989-98 Passenger Cars and Light Duty Trucks The purpose of this bulletin is to provide service personnel with guidelines for using the above subject labor operation. Effective with repair orders dated on or after September 1, 1997, dealers are to be guided by the following: ^ Aluminum Wheels (including chrome plated) with Porosity - Wheels that exhibit porosity should be repaired as described in the vehicle service manual. Wheels should not be replaced without wholesale approval. ^ Aluminum Wheels (except chrome plated) with a "Finish Defect" - Wheels that exhibit a defect in the finish, (i.e., discoloration or surface degradation) should be refinished as described in the Corporate Service Bulletin Number 53-17-03A released in May, 1996. ^ Chrome Wheels - Wheels that are chromed and found to have a finish defect can only be replaced. ^ Aluminum and chrome wheels replaced under warranty will be subject to random part review and inspection. Those wheels inspected and found not to be defective and/or should have been repaired, will be subject to charge back. Wheels damaged by normal wear, road hazards, car wash brushes, or other physical or chemical damage are not eligible for warranty coverage. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 531703A > May > 96 > Aluminum Wheels - Refinishing Technical Service Bulletin # 531703A Date: 960501 Aluminum Wheels - Refinishing File In Section: 10 - Body Bulletin No.: 53-17-03A Date: May, 1996 INFORMATION Subject: Aluminum Wheel Refinishing Models: 1991-96 Passenger Cars and Trucks This bulletin is being revised to delete the 1990 model year and add the 1996 model year. Please discard Corporate Bulletin Number 53-17-03 (Section 10 - Body). This bulletin supersedes and cancels all previous service bulletins concerning the refinishing of aluminum wheels. The purpose of this service bulletin is to assist dealerships in repairing the discoloration or surface degradation that has occurred on styled aluminum wheels. This bulletin provides NEW PROCEDURES AND SPECIFIC MATERIALS for the refinishing of painted aluminum wheels or aluminum wheels with discoloration or surface degradation. Important: THE RE-MACHINING OF ALUMINUM WHEELS IS NOT RECOMMENDED. THE RE-CLEAR COATING OF ALUMINUM WHEELS IS NO LONGER RECOMMENDED DUE TO CONCERNS OF REPAIR DURABILITY The new procedure requires the wheel surface be plastic media blasted to remove old paint or clear coat. CHEMICAL STRIPPERS ARE NOT RECOMMENDED. Material Required System 1: DuPont Products 3939-S Cleaning Solvent 615/616 Etching Primer URO 5000 Primer Surfacer IMRON 6000 Basecoat 3440-S IMRON Clear System 2: PPG Products DX533 Aluminum Cleaner DX503 Aluminum Conditioner DP Epoxy Primer Deltron Basecoat (DBC) Concept 2001 Clear Acrylic Urethane System 3: Spies Hecker Permahyd Silicone Remover 7090 Permahyd 1:1 Primer 4070 Permahyd 2:1 Surfacer 5080 Permahyd Base Coat Series 280/285 Permahyd H.S. Clearcoat 8060 Color Selection If the wheels being painted were previously clearcoated aluminum, we would recommend using Corsican SILVER WAEQ9283 for a fine "aluminum-like" look or Sparkle SILVER WA9967 for a very bright look. As an option to the customer, you may also use body color. For color Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 531703A > May > 96 > Aluminum Wheels - Refinishing > Page 1928 selection and verification, refer to your paint manufacturer's color book. On wheels that were previous clearcoated aluminum it is recommended that all four wheels and their center caps be refinished to maintain color uniformity. Important: THE PRODUCTS LISTED MUST BE USED AS A SYSTEM. DO NOT MIX OTHER MANUFACTURERS' PRODUCT LINES WITH THE REQUIRED MATERIALS. PRODUCTS LISTED IN THIS BULLETIN HAVE SHOWN THE REQUIRED REPAIR DURABILITY, AND CURRENTLY ARE THE ONLY PAINT SYSTEMS THAT MEET GM SPECIFICATION 4350M-A336. Procedures 1. Remove wheels from vehicle. Tires may remain mounted on wheels. 2. Remove balance weights and mark their location on tire. 3. Wipe excess grease, etc. from wheels with wax and grease remover. 4. Have wheels plastic media blasted to remove clearcoat. FOR FURTHER INFORMATION ON MEDIA BLASTING IN YOUR AREA, CALL US TECHNOLOGIES INC., CONTACT DAVE ROSENBURG AT 1-800-634-9185. Caution: IT IS MANDATORY THAT ADEQUATE RESPIRATORY PROTECTION BE WORN. EXAMPLES OF SUCH PROTECTION ARE: AIR LINE RESPIRATORS WITH FULL HOOD OR HALF MASK. IF NOT AVAILABLE, USE A VAPOR/PARTICULATE RESPIRATOR THAT RESPIRATOR MANUFACTURER RECOMMENDS AS EFFECTIVE FOR ISOCYANATE VAPOR AND MISTS (UNLESS LOCAL REGULATIONS PREVAIL). 5. Painting Process a. Refer to Attachments 1-3 for each System's individual formula and process. b. After following the specific System's individual formula and process, follow these steps: 6. Unmask wheels. 7. Clean all wheel mounting surface of any corrosion, overspray, or dirt. 8. Install new coated balance weights, at marked locations. 9. Replace wheels on vehicle. 10. USE A TORQUE STICK ON AN IMPACT WRENCH, OR A TORQUE WRENCH TO CONSISTENTLY AND UNIFORMLY FASTEN THE WHEEL TO THE SPECIFIED TORQUE FOR THE VEHICLE. THE STAR PATTERN MUST BE FOLLOWED. Important: TORQUE STICKS MUST BE USED ANY TIME AN IMPACT WRENCH IS USED TO TIGHTEN WHEEL NUTS. Warranty Information For vehicles repaired under warranty, use as shown. Attachment 1 - DuPont Products Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 531703A > May > 96 > Aluminum Wheels - Refinishing > Page 1929 Painting Process System: Dupont Products Paint Color Information: Corsican Silver WA EQ9283 Dupont # C9143, Sparkle Silver WA9967 Dupont # C9339 1. Wipe wheel with cleaning solvent: 3939-S, 3949-S or 3900-S. 2. Mask off tires. Important: 3. Mask off all wheel mounting surfaces and wheel mount surfaces. 4. Apply two coats of 615/616-S etching primer to wheel allowing 10 minutes flash between coats. Allow to dry for 30 minutes before applying primer coat. 5. Apply URO 5000 primer 1220/193-S + accelerator 389-S using two coats at 65-70 PSI at the gun. Allow 12-15 minutes between coats. Force bake 30 minutes at 140°F (60°C). 6. Scuff sand using green Scotch-Brite pad. 7. Solvent wipe before top coating. 8. Apply IMRON 6000 base coat to wheel. 2-3 coats to hiding at 60-70 PSI allowing to flash between coats. Base coat needs to dry 20-30 minutes before clearcoat is applied. 9. Apply 3440-S clearcoat to wheel using two coats at 60-70 PSI. Flash 10-15 minutes between coats. 389-S can be used in basecoat and clearcoat to give faster set up times. 10. Allow overnight dry before reassemble. Can be baked for 30 minutes at 140°F (60°C). Attachment 2 - PPG Products Painting Process: PPG System Paint Color Information: Corsican Silver WAEQ9283; PPG # DBC-3531, Sparkle Silver WA9967; PPG # 35367 1. Wash entire wheel with aluminum cleaner DX533, mix 1:3 with water. Allow to react 2-3 minutes and rinse thoroughly. 2. Wash entire wheel with aluminum conditioner DX5O3 straight from the container. Allow to react 2-3 minutes until pale gold or tan color develops. Rinse thoroughly and dry. 3. Mask off tires. Important: 4. Mask off all wheel nut mounting surfaces and wheel mounting surfaces. 5. Apply 1-2 coats of DP Primer and allow to flash for 15-20 minutes. 6. Apply 2-3 coats of Deltron Basecoat (DBC) and allow to flash 20 minutes after the final coat. 7. Apply two (2) wet coats of Concept 2001 Acrylic urethane. 8. Flash 20 minutes and bake 140°F (60°C) for 30 minutes. For more information contact your PPG Jobber. Attachment 3 - Spies Hecker Painting Process: Spies Hecker System Paint Color Information: Corsican Silver AWEQ9283; SH-72913, Sparkle Silver WA9967; SH-71912 1. Clean with Permahyd Silicone Remover 7090. 2. Mask off tires. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheels: > 531703A > May > 96 > Aluminum Wheels - Refinishing > Page 1930 Important: 3. Mask off all wheel nut mounting surfaces and wheel mounting surfaces. 4. Apply 1-1/2 coats of Permahyd 1:1 Primer 4070. Mix 1:1 with Permahyd Hardener 3070 as per TDS. 5. Allow to flash for 30 minutes. 6. Apply two (2) coats of Permahyd 2:1 Surfacer 5080. Mix 2:1 with Permahyd Hardener 3071 as per TDS. 7. Bake for 60 minutes at 140°F (60°C) or allow to flash for 3 hours at 68°F (20°C). 8. Apply Permahyd Base Coat Series 280/285 as per TDS. 9. Allow to flash 10 to 15 minutes. 10. Apply 1 to 2 coats of Permacron High Solid Clear Coat 8060 as per TDS. 11. Allow to flash 10 minutes. Then bake at 140°F (60°C) for 40 minutes. For more information, contact your SPIES HECKER Jobber. We believe these sources and their products to be reliable. There may be additional manufacturers of such products. General Motors does not endorse, indicate any preference for or assume any responsibility for the products or equipment from these firms or for any such items which may be available from other sources. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wheels: > 00-03-10-002F > Apr > 11 > Wheels - Chrome Wheel Staining/Pitting/Corrosion Wheels: All Technical Service Bulletins Wheels - Chrome Wheel Staining/Pitting/Corrosion INFORMATION Bulletin No.: 00-03-10-002F Date: April 21, 2011 Subject: Chemical Staining, Pitting, Corrosion and/or Spotted Appearance of Chromed Aluminum Wheels Models: 2012 and Prior GM Cars and Trucks Supercede: This bulletin is being revised to update model years, suggest additional restorative products and add additional corrosion information. Please discard Corporate Bulletin Number 00-03-10-002E (Section 03 - Suspension). Important You may give a copy of this bulletin to the customer. What is Chemical Staining of Chrome Wheels? Figure 1 Chemical staining in most cases results from acid based cleaners (refer to Figure 1 for an example). These stains are frequently milky, black, or greenish in appearance. They result from using cleaning solutions that contain acids on chrome wheels. Soap and water is usually sufficient to clean wheels. If the customer insists on using a wheel cleaner they should only use one that specifically states that it is safe for chromed wheels and does not contain anything in the following list. (Dealers should also survey any products they use during prep or normal cleaning of stock units for these chemicals.) - Ammonium Bifluoride (fluoride source for dissolution of chrome) - Hydrofluoric Acid (directly dissolves chrome) - Hydrochloric Acid (directly dissolves chrome) - Sodium Dodecylbenzenesulfonic Acid - Sulfamic Acid - Phosphoric Acid - Hydroxyacetic Acid Notice Many wheel cleaner instructions advise to take care to avoid contact with painted surfaces. Most customers think of painted surfaces as the fenders, quarter panels and other exterior sheet metal. Many vehicles have painted brake calipers. Acidic wheel cleaners may craze, crack, or discolor the paint on the brake calipers. Damage from wheel cleaners is not covered under the vehicle new car warranty. Soap and water applied with a soft brush is usually all that is required to clean the calipers. Whenever any wheel cleaner is used, it must be THOROUGHLY rinsed off of the wheel with clean, clear water. Special care must be taken to rinse under the hub cap, balance weights, wheel nuts, lug nut caps, between the wheel cladding and off the back side of the wheel. Wheels returned to the Warranty Parts Center (WPC) that exhibit damage from wheel cleaners most often have the damage around and under the wheel weight where the cleaner was incompletely flushed away. Notice Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wheels: > 00-03-10-002F > Apr > 11 > Wheels - Chrome Wheel Staining/Pitting/Corrosion > Page 1936 Do not use cleaning solutions that contain hydrofluoric, oxalic and most other acids on chrome wheels (or any wheels). If the customer is unsure of the chemical make-up of a particular wheel cleaner, it should be avoided. For wheels showing signs of milky staining from acidic cleaners, refer to Customer Assistance and Instructions below. Warranty of Stained Chrome Wheels Stained wheels are not warrantable. Most acid based cleaners will permanently stain chrome wheels. Follow-up with dealers has confirmed that such cleaners were used on wheels that were returned to the Warranty Parts Center (WPC). Any stained wheels received by the WPC will be charged back to the dealership. To assist the customer, refer to Customer Assistance and Instructions below. Pitting or Spotted Appearance of Chrome Wheels Figure 2 A second type or staining or finish disturbance may result from road chemicals, such as calcium chloride used for dust control of unpaved roads. The staining will look like small pitting (refer to Figure 2). This staining will usually be on the leading edges of each wheel spoke, but may be uniformly distributed. If a vehicle must be operated under such conditions, the chrome wheels should be washed with mild soap and water and thoroughly rinsed as soon as conveniently possible. Important Road chemicals, such as calcium chloride used for dust control of unpaved roads, can also stain chrome wheels. The staining will look like small pitting. This staining will usually be on the leading edges of each wheel spoke. This is explained by the vehicle traveling in the forward direction while being splashed by the road chemical. If a vehicle must be operated under such conditions, the chrome wheels should be washed with mild soap and water and thoroughly rinsed as soon as conveniently possible. Warranty of Pitted or Spotted Chrome Wheels Wheels returned with pitting or spotting as a result of road chemicals may be replaced one time. Damage resulting from contact with these applied road chemicals is corrosive to the wheels finish and may cause damage if the wheels are not kept clean. Important Notify the customer that this is a one time replacement. Please stress to the customer the vital importance of keeping the wheels clean if they are operating the vehicle in an area that applies calcium chloride or other dust controlling chemicals! "GM of Canada" dealers require prior approval by the District Manager - Customer Care and Service Process (DM-CCSP). "Stardust" Corrosion of Chrome Wheels Figure 3 A third type of finish disturbance results from prolonged exposure to brake dust and resultant penetration of brake dust through the chrome. As brakes are applied hot particles of brake material are thrown off and tend to be forced through the leading edge of the wheel spoke windows by airflow. These Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wheels: > 00-03-10-002F > Apr > 11 > Wheels - Chrome Wheel Staining/Pitting/Corrosion > Page 1937 hot particles embed themselves in the chrome layer and create a small pit. If the material is allowed to sit on the wheel while it is exposed to moisture or salt, it will corrode the wheel beneath the chrome leaving a pit or small blister in the chrome. Heavy brake dust build-up should be removed from wheels by using GM Chrome Cleaner and Polish, P/N 1050173 (in Canada use 10953013). For moderate cleaning, light brake dust build-up or water spots use GM Swirl Remover Polish, P/N 12377965 (in Canada, use Meguiars Plast-X(TM) Clear Plastic Cleaner and Polish #G12310C**). After cleaning, the wheel should be waxed using GM Cleaner Wax, P/N 12377966 (in Canada, use Meguiars Cleaner Wax #M0616C**), which will help protect the wheel from brake dust and reduce adhesion of any brake dust that gets on the wheel surface. For general maintenance cleaning, PEEK Metal Polish† may be used. It will clean and shine the chrome and leave behind a wax coating that may help protect the finish. Warranty of Stardust Corroded Chrome Wheels Wheels returned with pitting or spotting as a result of neglect and brake dust build-up may be replaced one time. Important Notify the customer that this is a one time replacement. Please stress to the customer the vital importance of keeping the wheels clean and free of prolonged exposure to brake dust build-up. "GM of Canada" dealers require prior approval by the District Manager - Customer Care and Service Process (DM-CCSP). Customer Assistance and Instructions GM has looked for ways customers may improve the appearance of wheels damaged by acidic cleaners. The following product and procedure has been found to dramatically improve the appearance of stained wheels. For wheels that have milky stains caused by acidic cleaners try the following: Notice THE 3M CHROME AND METAL POLISH REQUIRED FOR THIS PROCEDURE IS AN EXTREMELY AGGRESSIVE POLISH/CLEANER. THE WHEELS MUST BE CLEANED BEFORE APPLICATION TO AVOID SCRATCHING THE WHEEL SURFACE. THIS PRODUCT WILL REDUCE THE THICKNESS OF THE CHROME PLATING ON THE WHEEL AND IF USED INCORRECTLY OR EXCESSIVELY MAY REMOVE THE CHROME PLATING ALL TOGETHER, EXPOSING A LESS BRIGHT AND BRASSY COLORED SUB-LAYER. FOLLOW INSTRUCTIONS EXACTLY. 1. Wash the wheels with vigorously with soap and water. This step will clean and may reduce wheel staining. Flood all areas of the wheel with water to rinse. 2. Dry the wheels completely. Notice Begin with a small section of the wheel and with light pressure buff off polish and examine results. ONLY apply and rub with sufficient force and time to remove enough staining that you are satisfied with the results. Some wheels may be stained to the extent that you may only achieve a 50% improvement while others may be able to be restored to the original lustre. IN ALL CASES, only apply until the results are satisfactory. 3. Apply 3M Chrome and Metal Polish #39527* with a clean terry cloth towel. As you apply the polish, the staining will be diminished. 4. When dry, buff off the polish with a clean portion of the towel. 5. Repeat application of the 3M Chrome and Metal Polish until satisfied with the results. If continued applications fail to improve the appearance further discontinue use. This procedure will improve the appearance of the wheels and may, with repeated applications, restore the finish dramatically. For wheels that exhibit spotting from road chemicals the above procedure may marginally improve the condition but will not restore the finish or remove the pitting. In this type of staining the wheel finish has actually been removed in spots and no manner of cleaning will restore the finish. †*We believe this source and their products to be reliable. There may be additional manufacturers of such products/materials. General Motors does not endorse, indicate any preference for or assume any responsibility for the products or material from this firm or for any such items that may be available from other sources. Parts Information Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wheels: > 00-03-10-002F > Apr > 11 > Wheels - Chrome Wheel Staining/Pitting/Corrosion > Page 1938 *This product is currently available from 3M. To obtain information for your local retail location please call 3M at 1-888-364-3577. **This product is currently available from Meguiars (Canada). To obtain information for your local retail location please call Meguiars at 1-800-347-5700 or at www.meguiarscanada.com. ^ This product is currently available from Tri-Peek International. To obtain information for your local retail location please call Tri-Peek at 1-877-615-4272 or at www.tripeek.com. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wheels: > 99-08-51-007E > Mar > 11 > Wheels/Tires - Refinishing Aluminum Wheels Wheels: All Technical Service Bulletins Wheels/Tires - Refinishing Aluminum Wheels INFORMATION Bulletin No.: 99-08-51-007E Date: March 17, 2011 Subject: Refinishing Aluminum Wheels Models: 2012 and Prior GM Passenger Cars and Trucks Supercede: This bulletin is being revised to add additional model years. Please discard Corporate Bulletin Number 99-08-51-007D (Section 08 - Body and Accessories). This bulletin updates General Motor's position on refinishing aluminum wheels. GM does not endorse any repairs that involve welding, bending, straightening or re-machining. Only cosmetic refinishing of the wheel's coatings, using recommended procedures, is allowed. Evaluating Damage In evaluating damage, it is the GM Dealer's responsibility to inspect the wheel for corrosion, scrapes, gouges, etc. The Dealer must insure that such damage is not deeper than what can be sanded or polished off. The wheel must be inspected for cracks. If cracks are found, discard the wheel. Any wheels with bent rim flanges must not be repaired or refinished. Wheels that have been refinished by an outside company must be returned to the same vehicle. The Dealer must record the wheel ID stamp or the cast date on the wheel in order to assure this requirement. Refer to Refinisher's Responsibility - Outside Company later in this bulletin. Aluminum Wheel Refinishing Recommendations - Chrome-plated aluminum wheels Re-plating these wheels is not recommended. - Polished aluminum wheels These wheels have a polyester or acrylic clearcoat on them. If the clearcoat is damaged, refinishing is possible. However, the required refinishing process cannot be performed in the dealer environment. Refer to Refinisher's Responsibility - Outside Company later in this bulletin. - Painted aluminum wheels These wheels are painted using a primer, color coat, and clearcoat procedure. If the paint is damaged, refinishing is possible. As with polished wheels, all original coatings must be removed first. Media blasting is recommended. Refer to GM Aluminum Refinishing Bulletin #53-17-03A for the re-painting of this type of wheel. - Bright, machined aluminum wheels These wheels have a polyester or acrylic clearcoat on them. In some cases, the recessed "pocket" areas of the wheel may be painted. Surface refinishing is possible. The wheel must be totally stripped by media blasting or other suitable means. The wheel should be resurfaced by using a sanding process rather than a machining process. This allows the least amount of material to be removed. Important Do not use any re-machining process that removes aluminum. This could affect the dimensions and function of the wheel. Painting is an option to re-clearcoating polished and bright machined aluminum wheels. Paint will better mask any surface imperfections and is somewhat more durable than clearcoat alone. GM recommends using Corsican SILVER WAEQ9283 for a fine "aluminum-like" look or Sparkle SILVER WA9967 for a very bright look. As an option, the body color may also be used. When using any of the painting options, it is recommended that all four wheels be refinished in order to maintain color uniformity. Refer to GM Aluminum Refinishing Bulletin #53-17-03A for specific procedures and product recommendations. Refinisher's Responsibility - Outside Company Important Some outside companies are offering wheel refinishing services. Such refinished wheels will be permanently marked by the refinisher and are warranted by the refinisher. Any process that re-machines or otherwise re-manufactures the wheel should not be used. A refinisher's responsibility includes inspecting for cracks using the Zyglo system or the equivalent. Any cracked wheels must not be refinished. No welding, hammering or reforming of any kind is allowed. The wheel ID must be recorded and follow the wheel throughout the process in order to assure that the same wheel is returned. A plastic media blast may be used for clean up of the wheel. Hand and/or lathe sanding of the machined surface and the wheel window is allowed. Material removal, though, must be kept to a minimum. Re-machining of the wheel is not allowed. Paint and/or clear coat must not be present on the following surfaces: the nut chamfers, the wheel mounting surfaces and the wheel pilot hole. The refinisher must permanently ID stamp the wheel and warrant the painted/clearcoated surfaces for a minimum of one year or the remainder of the new vehicle warranty, whichever is Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wheels: > 99-08-51-007E > Mar > 11 > Wheels/Tires - Refinishing Aluminum Wheels > Page 1943 longer. Important Whenever a wheel is refinished, the mounting surface and the wheel nut contact surfaces must not be painted or clearcoated. Coating these surfaces could affect the wheel nut torque. When re-mounting a tire on an aluminum wheel, coated balance weights must be used in order to reduce the chance of future cosmetic damage. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wheels: > 06-03-10-010A > Jun > 10 > Wheels - Changing Procedures/Precautions Wheels: All Technical Service Bulletins Wheels - Changing Procedures/Precautions INFORMATION Bulletin No.: 06-03-10-010A Date: June 09, 2010 Subject: Information on Proper Wheel Changing Procedures and Cautions Models: 2011 and Prior GM Passenger Cars and Trucks 2010 and Prior HUMMER Models 2005-2009 Saab 9-7X 2005-2009 Saturn Vehicles Attention: Complete wheel changing instructions for each vehicle line can be found under Tire and Wheel Removal and Installation in Service Information (SI). This bulletin is intended to quickly review and reinforce simple but vital procedures to reduce the possibility of achieving low torque during wheel installation. Always refer to SI for wheel lug nut torque specifications and complete jacking instructions for safe wheel changing. Supercede: This bulletin is being revised to include the 2011 model year and update the available special tool list. Please discard Corporate Bulletin Number 06-03-10-010 (Section 03 Suspension). Frequency of Wheel Changes - Marketplace Driven Just a few years ago, the increasing longevity of tires along with greater resistance to punctures had greatly reduced the number of times wheels were removed to basically required tire rotation intervals. Today with the booming business in accessory wheels/special application tires (such as winter tires), consumers are having tire/wheel assemblies removed - replaced - or installed more than ever. With this increased activity, it opens up more of a chance for error on the part of the technician. This bulletin will review a few of the common concerns and mistakes to make yourself aware of. Proper Servicing Starts With the Right Tools The following tools have been made available to assist in proper wheel and tire removal and installation. - J 41013 Rotor Resurfacing Kit (or equivalent) - J 42450-A Wheel Hub Resurfacing Kit (or equivalent) Corroded Surfaces One area of concern is corrosion on the mating surfaces of the wheel to the hub on the vehicle. Excessive corrosion, dirt, rust or debris built up on these surfaces can mimic a properly tightened wheel in the service stall. Once the vehicle is driven, the debris may loosen, grind up or be washed away from water splash. This action may result in clearance at the mating surface of the wheel and an under-torqued condition. Caution Before installing a wheel, remove any buildup on the wheel mounting surface and brake drum or brake disc mounting surface. Installing wheels with poor metal-to-metal contact at the mounting surfaces can cause wheel nuts to loosen. This may cause a wheel to come off when the vehicle is moving, possibly resulting in a loss of control or personal injury. Whenever you remove the tire/wheel assemblies, you must inspect the mating surfaces. If corrosion is found, you should remove the debris with a die grinder equipped with a fine sanding pad, wire brush or cleaning disc. Just remove enough material to assure a clean, smooth mating surface. The J 41013 (or equivalent) can be used to clean the following surfaces: - The hub mounting surface - The brake rotor mounting surface - The wheel mounting surface Use the J 42450-A (or equivalent) to clean around the base of the studs and the hub. Lubricants, Grease and Fluids Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wheels: > 06-03-10-010A > Jun > 10 > Wheels - Changing Procedures/Precautions > Page 1948 Some customers may use penetrating oils, grease or other lubricants on wheel studs to aid in removal or installation. Always use a suitable cleaner/solvent to remove these lubricants prior to installing the wheel and tire assemblies. Lubricants left on the wheel studs may cause improper readings of wheel nut torque. Always install wheels to clean, dry wheel studs ONLY. Notice Lubricants left on the wheel studs or vertical mounting surfaces between the wheel and the rotor or drum may cause the wheel to work itself loose after the vehicle is driven. Always install wheels to clean, dry wheel studs and surfaces ONLY. Beginning with 2011 model year vehicles, put a light coating of grease, GM P/N 1051344 (in Canada, P/N 9930370), on the inner surface of the wheel pilot hole to prevent wheel seizure to the axle or bearing hub. Wheel Stud and Lug Nut Damage Always inspect the wheel studs and lug nuts for signs of damage from crossthreading or abuse. You should never have to force wheel nuts down the stud. Lug nuts that are damaged may not retain properly, yet give the impression of fully tightening. Always inspect and replace any component suspected of damage. Tip Always start wheel nuts by hand! Be certain that all wheel nut threads have been engaged BEFORE tightening the nut. Important If the vehicle has directional tread tires, verify the directional arrow on the outboard side of the tire is pointing in the direction of forward rotation. Wheel Nut Tightening and Torque Improper wheel nut tightening can lead to brake pulsation and rotor damage. In order to avoid additional brake repairs, evenly tighten the wheel nuts to the proper torque specification as shown for each vehicle in SI. Always observe the proper wheel nut tightening sequence as shown below in order to avoid trapping the wheel on the wheel stud threads or clamping the wheel slightly off center resulting in vibration. The Most Important Service You Provide While the above information is well known, and wheel removal so common, technicians run the risk of becoming complacent on this very important Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wheels: > 06-03-10-010A > Jun > 10 > Wheels - Changing Procedures/Precautions > Page 1949 service operation. A simple distraction or time constraint that rushes the job may result in personal injury if the greatest of care is not exercised. Make it a habit to double check your work and to always side with caution when installing wheels. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wheels: > 04-03-10-012B > Feb > 08 > Wheels - Chrome Wheel Brake Dust Accumulation/Pitting Wheels: All Technical Service Bulletins Wheels - Chrome Wheel Brake Dust Accumulation/Pitting Bulletin No.: 04-03-10-012B Date: February 01, 2008 INFORMATION Subject: Pitting and Brake Dust on Chrome wheels Models: 2008 and Prior GM Passenger Cars and Trucks (including Saturn) 2008 and Prior HUMMER H2, H3 2005-2008 Saab 9-7X Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 04-03-10-012A (Section 03 - Suspension). Analysis of Returned Wheels Chrome wheels returned under the New Vehicle Limited Warranty for pitting concerns have recently been evaluated. This condition is usually most severe in the vent (or window) area of the front wheels. This "pitting" may actually be brake dust that has been allowed to accumulate on the wheel. The longer this accumulation builds up, the more difficult it is to remove. Cleaning the Wheels In all cases, the returned wheels could be cleaned to their original condition using GM Vehicle Care Cleaner Wax, P/N 12377966 (in Canada, P/N 10952905). When using this product, you should confine your treatment to the areas of the wheel that show evidence of the brake dust build-up. This product is only for use on chromed steel or chromed aluminum wheels. Parts Information Warranty Information Wheel replacement for this condition is NOT applicable under the terms of the New Vehicle Limited Warranty. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wheels: > 99-03-10-102 > Jun > 99 > Warranty - OE Chrome Plated Aluminum Wheel ID Wheels: All Technical Service Bulletins Warranty - OE Chrome Plated Aluminum Wheel ID File In Section: 03 - Suspension Bulletin No.: 99-03-10-102 Date: June, 1999 INFORMATION Subject: Original Equipment Chrome Plated Aluminum Wheel Identification Models: 1999 and Prior Passenger Cars and Light Duty Trucks Chrome plated aluminum wheels have been returned to the Warranty Parts Center that are not the original equipment (OE) components. Original equipment chrome plated aluminum wheels can be identified by either a balance weight clip retention groove (1) or a step (2) that is machined around both of the wheel's rim flanges. The rim flanges (3) of painted original equipment aluminum wheels do not have a groove or a step. Chrome plated aluminum wheels that do not have the wheel rim flange groove or step are aftermarket chrome plated components and are NOT warrantable. Any aftermarket chrome wheels received by the Warranty Parts Center will be charged back to the dealership. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wheels: > 72-05-05 > Aug > 97 > Warranty - Guidelines for Using E0420 Wheel Replace Wheels: All Technical Service Bulletins Warranty - Guidelines for Using E0420 Wheel Replace File In Section: Warranty Administration Bulletin No.: 72-05-05 Date: August, 1997 WARRANTY ADMINISTRATION Subject: Guidelines for Using EO42O Wheel Replace Models: 1989-98 Passenger Cars and Light Duty Trucks The purpose of this bulletin is to provide service personnel with guidelines for using the above subject labor operation. Effective with repair orders dated on or after September 1, 1997, dealers are to be guided by the following: ^ Aluminum Wheels (including chrome plated) with Porosity - Wheels that exhibit porosity should be repaired as described in the vehicle service manual. Wheels should not be replaced without wholesale approval. ^ Aluminum Wheels (except chrome plated) with a "Finish Defect" - Wheels that exhibit a defect in the finish, (i.e., discoloration or surface degradation) should be refinished as described in the Corporate Service Bulletin Number 53-17-03A released in May, 1996. ^ Chrome Wheels - Wheels that are chromed and found to have a finish defect can only be replaced. ^ Aluminum and chrome wheels replaced under warranty will be subject to random part review and inspection. Those wheels inspected and found not to be defective and/or should have been repaired, will be subject to charge back. Wheels damaged by normal wear, road hazards, car wash brushes, or other physical or chemical damage are not eligible for warranty coverage. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wheels: > 531703A > May > 96 > Aluminum Wheels - Refinishing Technical Service Bulletin # 531703A Date: 960501 Aluminum Wheels - Refinishing File In Section: 10 - Body Bulletin No.: 53-17-03A Date: May, 1996 INFORMATION Subject: Aluminum Wheel Refinishing Models: 1991-96 Passenger Cars and Trucks This bulletin is being revised to delete the 1990 model year and add the 1996 model year. Please discard Corporate Bulletin Number 53-17-03 (Section 10 - Body). This bulletin supersedes and cancels all previous service bulletins concerning the refinishing of aluminum wheels. The purpose of this service bulletin is to assist dealerships in repairing the discoloration or surface degradation that has occurred on styled aluminum wheels. This bulletin provides NEW PROCEDURES AND SPECIFIC MATERIALS for the refinishing of painted aluminum wheels or aluminum wheels with discoloration or surface degradation. Important: THE RE-MACHINING OF ALUMINUM WHEELS IS NOT RECOMMENDED. THE RE-CLEAR COATING OF ALUMINUM WHEELS IS NO LONGER RECOMMENDED DUE TO CONCERNS OF REPAIR DURABILITY The new procedure requires the wheel surface be plastic media blasted to remove old paint or clear coat. CHEMICAL STRIPPERS ARE NOT RECOMMENDED. Material Required System 1: DuPont Products 3939-S Cleaning Solvent 615/616 Etching Primer URO 5000 Primer Surfacer IMRON 6000 Basecoat 3440-S IMRON Clear System 2: PPG Products DX533 Aluminum Cleaner DX503 Aluminum Conditioner DP Epoxy Primer Deltron Basecoat (DBC) Concept 2001 Clear Acrylic Urethane System 3: Spies Hecker Permahyd Silicone Remover 7090 Permahyd 1:1 Primer 4070 Permahyd 2:1 Surfacer 5080 Permahyd Base Coat Series 280/285 Permahyd H.S. Clearcoat 8060 Color Selection If the wheels being painted were previously clearcoated aluminum, we would recommend using Corsican SILVER WAEQ9283 for a fine "aluminum-like" look or Sparkle SILVER WA9967 for a very bright look. As an option to the customer, you may also use body color. For color Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wheels: > 531703A > May > 96 > Aluminum Wheels - Refinishing > Page 1966 selection and verification, refer to your paint manufacturer's color book. On wheels that were previous clearcoated aluminum it is recommended that all four wheels and their center caps be refinished to maintain color uniformity. Important: THE PRODUCTS LISTED MUST BE USED AS A SYSTEM. DO NOT MIX OTHER MANUFACTURERS' PRODUCT LINES WITH THE REQUIRED MATERIALS. PRODUCTS LISTED IN THIS BULLETIN HAVE SHOWN THE REQUIRED REPAIR DURABILITY, AND CURRENTLY ARE THE ONLY PAINT SYSTEMS THAT MEET GM SPECIFICATION 4350M-A336. Procedures 1. Remove wheels from vehicle. Tires may remain mounted on wheels. 2. Remove balance weights and mark their location on tire. 3. Wipe excess grease, etc. from wheels with wax and grease remover. 4. Have wheels plastic media blasted to remove clearcoat. FOR FURTHER INFORMATION ON MEDIA BLASTING IN YOUR AREA, CALL US TECHNOLOGIES INC., CONTACT DAVE ROSENBURG AT 1-800-634-9185. Caution: IT IS MANDATORY THAT ADEQUATE RESPIRATORY PROTECTION BE WORN. EXAMPLES OF SUCH PROTECTION ARE: AIR LINE RESPIRATORS WITH FULL HOOD OR HALF MASK. IF NOT AVAILABLE, USE A VAPOR/PARTICULATE RESPIRATOR THAT RESPIRATOR MANUFACTURER RECOMMENDS AS EFFECTIVE FOR ISOCYANATE VAPOR AND MISTS (UNLESS LOCAL REGULATIONS PREVAIL). 5. Painting Process a. Refer to Attachments 1-3 for each System's individual formula and process. b. After following the specific System's individual formula and process, follow these steps: 6. Unmask wheels. 7. Clean all wheel mounting surface of any corrosion, overspray, or dirt. 8. Install new coated balance weights, at marked locations. 9. Replace wheels on vehicle. 10. USE A TORQUE STICK ON AN IMPACT WRENCH, OR A TORQUE WRENCH TO CONSISTENTLY AND UNIFORMLY FASTEN THE WHEEL TO THE SPECIFIED TORQUE FOR THE VEHICLE. THE STAR PATTERN MUST BE FOLLOWED. Important: TORQUE STICKS MUST BE USED ANY TIME AN IMPACT WRENCH IS USED TO TIGHTEN WHEEL NUTS. Warranty Information For vehicles repaired under warranty, use as shown. Attachment 1 - DuPont Products Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wheels: > 531703A > May > 96 > Aluminum Wheels - Refinishing > Page 1967 Painting Process System: Dupont Products Paint Color Information: Corsican Silver WA EQ9283 Dupont # C9143, Sparkle Silver WA9967 Dupont # C9339 1. Wipe wheel with cleaning solvent: 3939-S, 3949-S or 3900-S. 2. Mask off tires. Important: 3. Mask off all wheel mounting surfaces and wheel mount surfaces. 4. Apply two coats of 615/616-S etching primer to wheel allowing 10 minutes flash between coats. Allow to dry for 30 minutes before applying primer coat. 5. Apply URO 5000 primer 1220/193-S + accelerator 389-S using two coats at 65-70 PSI at the gun. Allow 12-15 minutes between coats. Force bake 30 minutes at 140°F (60°C). 6. Scuff sand using green Scotch-Brite pad. 7. Solvent wipe before top coating. 8. Apply IMRON 6000 base coat to wheel. 2-3 coats to hiding at 60-70 PSI allowing to flash between coats. Base coat needs to dry 20-30 minutes before clearcoat is applied. 9. Apply 3440-S clearcoat to wheel using two coats at 60-70 PSI. Flash 10-15 minutes between coats. 389-S can be used in basecoat and clearcoat to give faster set up times. 10. Allow overnight dry before reassemble. Can be baked for 30 minutes at 140°F (60°C). Attachment 2 - PPG Products Painting Process: PPG System Paint Color Information: Corsican Silver WAEQ9283; PPG # DBC-3531, Sparkle Silver WA9967; PPG # 35367 1. Wash entire wheel with aluminum cleaner DX533, mix 1:3 with water. Allow to react 2-3 minutes and rinse thoroughly. 2. Wash entire wheel with aluminum conditioner DX5O3 straight from the container. Allow to react 2-3 minutes until pale gold or tan color develops. Rinse thoroughly and dry. 3. Mask off tires. Important: 4. Mask off all wheel nut mounting surfaces and wheel mounting surfaces. 5. Apply 1-2 coats of DP Primer and allow to flash for 15-20 minutes. 6. Apply 2-3 coats of Deltron Basecoat (DBC) and allow to flash 20 minutes after the final coat. 7. Apply two (2) wet coats of Concept 2001 Acrylic urethane. 8. Flash 20 minutes and bake 140°F (60°C) for 30 minutes. For more information contact your PPG Jobber. Attachment 3 - Spies Hecker Painting Process: Spies Hecker System Paint Color Information: Corsican Silver AWEQ9283; SH-72913, Sparkle Silver WA9967; SH-71912 1. Clean with Permahyd Silicone Remover 7090. 2. Mask off tires. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheels > Component Information > Technical Service Bulletins > All Other Service Bulletins for Wheels: > 531703A > May > 96 > Aluminum Wheels - Refinishing > Page 1968 Important: 3. Mask off all wheel nut mounting surfaces and wheel mounting surfaces. 4. Apply 1-1/2 coats of Permahyd 1:1 Primer 4070. Mix 1:1 with Permahyd Hardener 3070 as per TDS. 5. Allow to flash for 30 minutes. 6. Apply two (2) coats of Permahyd 2:1 Surfacer 5080. Mix 2:1 with Permahyd Hardener 3071 as per TDS. 7. Bake for 60 minutes at 140°F (60°C) or allow to flash for 3 hours at 68°F (20°C). 8. Apply Permahyd Base Coat Series 280/285 as per TDS. 9. Allow to flash 10 to 15 minutes. 10. Apply 1 to 2 coats of Permacron High Solid Clear Coat 8060 as per TDS. 11. Allow to flash 10 minutes. Then bake at 140°F (60°C) for 40 minutes. For more information, contact your SPIES HECKER Jobber. We believe these sources and their products to be reliable. There may be additional manufacturers of such products. General Motors does not endorse, indicate any preference for or assume any responsibility for the products or equipment from these firms or for any such items which may be available from other sources. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheel Bearing > Component Information > Adjustments Wheel Bearing: Adjustments These vehicles use sealed front wheel bearings which require no lubrication or adjustment. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheel Bearing > Component Information > Service and Repair > Front Wheel Bearing: Service and Repair Front FRONT WHEEL BEARINGS AND/OR HUB Remove or Disconnect Tools Required: J 28733-A Front Hub Spindle Remover J 24319-01 Universal Steering Linkage Puller J 28712 Axle Shaft Boot Seal Protector J 36607 Ball Joint Separator Raise the vehicle and support with safety stands. Unload the torsion bar. 1. Tire and wheel. Note: Install J 28712 to the tripot axle joint (fig. 44). 2. Cotter pin (122). 3. Retainer (121). 4. Nut (120). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheel Bearing > Component Information > Service and Repair > Front > Page 1974 Note: Insert a drift or large screwdriver through brake caliper into rotor vanes to prevent from turning (fig. 45). 5. Washer (119). 6. Brake Caliper. Note: Support the caliper with a piece of wire to prevent damage to the brake hose. 7. Rotor. 8. Bolts (116). 9. Hub and bearing assembly (114) from axle joint splined shaft using J 28733-A (fig. 46). Note: Lay the hub and bearing assembly on the hub bolt (outboard) side. This will prevent damage or contamination of the bearing seal (fig. 47). 10. Splash shield (118). 11. Cotter pin (123). 12. Nut (124). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheel Bearing > Component Information > Service and Repair > Front > Page 1975 13. Tie rod end (125) from the knuckle (117) using J 24319-01 (fig. 48). 14. Cotter pins (130). 15. Ball joints (115 and 127) from the knuckle (117) using J 36607 (fig 49). Note: Locate J 36607 on the ball joint and back off the nut (129, 131) until the ball stud is forced out of the knuckle. 16. Nuts (129 and 131). 17. Knuckle (117) from the ball joints. 18. Spacer (128) from the knuckle (117). 19. Seal (126) from the knuckle (117). Install or Connect 1. New seal (126) to the knuckle (117) using J 28574 (fig. 50). 2. Spacer (128) to the knuckle (117). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheel Bearing > Component Information > Service and Repair > Front > Page 1976 3. Knuckle (117) to the upper and lower ball joints (115 and 127). 4. Nuts (129 and 131). Tighten Nuts (129) to 83 N.m (61 lbs. ft.). Tighten Nut (131) to 113 N.m (83 lbs. ft.). Important: Tighten the nuts to align the cotter pin. Do not tighten more than 1/6 turn. 5. New cotter pins (130). Bend the pin ends against the nut flats. 6. Splash shield(118) aligned to the knuckle (117). 7. Hub and bearing assembly (114) (fig. 43). Align the threaded holes. 8. Bolts (116). Tighten Bolts (116) to 105 N.m (77 lbs. ft.). 9. Tie rod end (125) to the knuckle (117). 10. Nut (124). Tighten to 48 N.m (35 lbs. ft.). 11. New cotter pin. Bend the pin ends against the nut flats. 12. Rotor (113). 13. Brake caliper. 14. Washer (119). 15. Nut (120). Tighten to 245 N.m (181 lbs. ft.). Note: Insert a drift or large screwdriver through brake caliper into rotor vanes to prevent from turning (fig. 45). 16. Retainer (121). 17. New cotter pin (122). Note: Remove J 28712. 18. Tire and wheel. A. Lower the vehicle. B. Apply the brake pedal. C. Check vehicle trim height and align the front end. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheel Bearing > Component Information > Service and Repair > Front > Page 1977 Wheel Bearing: Service and Repair Rear REAR WHEEL BEARINGS AND/OR HUB Fig. 3 Axle Shaft Bearing Removal Fig. 4 Axle Shaft Bearing Installation Fig. 5 Axle Shaft Seal Installation 1. Remove axle shaft as described under "Rear Axle Shaft, Replace." 2. Remove axle seal by prying behind seal steel case with a pry bar. Use caution to avoid damaging axle housing. 3. Using a puller and slide hammer, remove axle bearing, Fig. 3. 4. Lubricate new bearing with gear lubricant, then install bearing in axle housing with axle shaft bearing installer tool No. J-23765, or equivalent, until bearing is seated in housing, Fig. 4. 5. Lubricate seal lips with gear lubricant, then position seal on axle shaft seal installer tool No. J-23771, or equivalent, and install in axle housing, tapping into place until seal is flush with axle housing, Fig. 5. 6. Install axle shaft. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheel Hub > Axle Nut > Component Information > Specifications Axle Nut: Specifications Component .......................................................................................................................................... ....................................................... Torque/Ft. Lbs. Axle Nut ............................................................................................................................................... ............................................................................ 180 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheel Fastener > Component Information > Technical Service Bulletins > Customer Interest for Wheel Fastener: > 01-03-10-009A > Jul > 04 > Wheels - Plastic Wheel Nut Covers Loose/Missing Wheel Fastener: Customer Interest Wheels - Plastic Wheel Nut Covers Loose/Missing Bulletin No.: 01-03-10-009A Date: July 27, 2004 TECHNICAL Subject: Plastic Wheel Nut Covers Missing and/or Loose (Replace Missing Covers and Add Sealant to All Covers) Models: 2005 and All Prior Passenger Cars (Except All Cadillac Models and Pontiac GTO) with Plastic Wheel Nut Covers Supercede: This bulletin is being revised to add additional models years. Please discard Corporate Bulletin Number 01-03-10-009. Condition Some customers may comment that the plastic wheel nut covers are missing and/or loose. Correction Important: ^ DO NOT USE a silicone-based adhesive. ^ Do not apply the *permatex(R) around the threads in a circular pattern. ^ Apply a single bead across the threads approximately 10 mm (0.4 in) in length, 5 mm (0.2 in) in height and 5 mm (0.2 in) in width. Replace any missing plastic wheel nut covers with the appropriate covers and apply Permatex(R) # 2 Form A Gasket Sealant(R) to the threads of all the plastic wheel nut covers. Tighten finger tight plus a 1/4 turn with a hand wrench. *We believe this source and their products to be reliable. There may be additional manufacturers of such material. General Motors does not endorse, indicate any preference for or assume any responsibility for the products from this firm or for any other such items which may be available from other sources. Permatex(R) # 2 Form A Gasket Sealant(R) part numbers (available at your local parts supplier) ^ P/N 80009 (2A/2AR) - 44 ml (1.5 oz) tube boxed ^ P/N 80015 (2AR) - 44 ml (1.5 oz) tube carded ^ P/N 80010 (2B/2BR) - 89 ml (3 oz) tube boxed ^ P/N 80016 (2BR) - 89 ml (3 oz) tube carded ^ P/N 80011 (2C) - 325 ml (11 oz) tube boxed Warranty Information For vehicles repaired under warranty, use the table. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheel Fastener > Component Information > Technical Service Bulletins > Customer Interest for Wheel Fastener: > 01-03-10-009A > Jul > 04 > Wheels - Plastic Wheel Nut Covers Loose/Missing > Page 1990 Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheel Fastener > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheel Fastener: > 01-03-10-009A > Jul > 04 > Wheels - Plastic Wheel Nut Covers Loose/Missing Wheel Fastener: All Technical Service Bulletins Wheels - Plastic Wheel Nut Covers Loose/Missing Bulletin No.: 01-03-10-009A Date: July 27, 2004 TECHNICAL Subject: Plastic Wheel Nut Covers Missing and/or Loose (Replace Missing Covers and Add Sealant to All Covers) Models: 2005 and All Prior Passenger Cars (Except All Cadillac Models and Pontiac GTO) with Plastic Wheel Nut Covers Supercede: This bulletin is being revised to add additional models years. Please discard Corporate Bulletin Number 01-03-10-009. Condition Some customers may comment that the plastic wheel nut covers are missing and/or loose. Correction Important: ^ DO NOT USE a silicone-based adhesive. ^ Do not apply the *permatex(R) around the threads in a circular pattern. ^ Apply a single bead across the threads approximately 10 mm (0.4 in) in length, 5 mm (0.2 in) in height and 5 mm (0.2 in) in width. Replace any missing plastic wheel nut covers with the appropriate covers and apply Permatex(R) # 2 Form A Gasket Sealant(R) to the threads of all the plastic wheel nut covers. Tighten finger tight plus a 1/4 turn with a hand wrench. *We believe this source and their products to be reliable. There may be additional manufacturers of such material. General Motors does not endorse, indicate any preference for or assume any responsibility for the products from this firm or for any other such items which may be available from other sources. Permatex(R) # 2 Form A Gasket Sealant(R) part numbers (available at your local parts supplier) ^ P/N 80009 (2A/2AR) - 44 ml (1.5 oz) tube boxed ^ P/N 80015 (2AR) - 44 ml (1.5 oz) tube carded ^ P/N 80010 (2B/2BR) - 89 ml (3 oz) tube boxed ^ P/N 80016 (2BR) - 89 ml (3 oz) tube carded ^ P/N 80011 (2C) - 325 ml (11 oz) tube boxed Warranty Information For vehicles repaired under warranty, use the table. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheel Fastener > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Wheel Fastener: > 01-03-10-009A > Jul > 04 > Wheels - Plastic Wheel Nut Covers Loose/Missing > Page 1996 Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Maintenance > Wheels and Tires > Wheel Fastener > Component Information > Technical Service Bulletins > Page 1997 Wheel Fastener: Specifications Wheel Lug Nuts 95 ft.lb Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Compression Check > System Information > Specifications Compression Check: Specifications Minimum, 698 kPa (100 psi) @ 200 rpm. The lowest cylinder reading should not be less than 80% of the highest. Perform compression test with engine at normal operating temperature, spark plugs removed and throttle wide open. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Camshaft, Lifters and Push Rods > Camshaft, Engine > Component Information > Specifications > Camshaft Lift Specs Camshaft: Specifications Camshaft Lift Specs Camshaft lift should measure .357 inch at intake valves and .390 inch at exhaust valves. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Camshaft, Lifters and Push Rods > Camshaft, Engine > Component Information > Specifications > Camshaft Lift Specs > Page 2008 Camshaft: Specifications Camshaft Engine Liter/CID [04] ........................................................................................................................... ............................................................ 4.3L/V6-262 All specifications given in inches. Camshaft Journal Diameter ................................................................................................................. ............................................................ 1.8682-1.8692 Camshaft Endplay .......................................... ................................................................................................................................................. 0.0040-0.0120 Camshaft Runout (Max.) ............................................................................................. .................................................................................................. 0.001 Lifter Diameter ........................ .............................................................................................................................................................. ......... 0.8420-0.8427 Lifter To Bore Clearance ................................................................................... ............................................................................................. 0.0008-0.0025 [04] VIN Z. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Camshaft, Lifters and Push Rods > Camshaft, Engine > Component Information > Specifications > Page 2009 Camshaft: Service and Repair Fig. 15 Timing Mark Alignment 1. Disconnect battery ground cable. 2. Remove air cleaner assembly and drain cooling system. 3. Remove rocker arm covers and pushrods. 4. Remove distributor. 5. Remove intake manifold. 6. Remove valve lifters. 7. Remove radiator, fan and pulley. 8. Remove water pump and torsional damper. 9. Remove timing cover. 10. Remove camshaft sprocket bolts, then the sprocket and timing chain. 11. Remove thrust plate attaching bolts, then the thrust plate. 12. Remove camshaft. 13. Reverse procedure to install. Ensure timing marks are properly aligned after installation of sprockets and chain, Fig. 15. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Camshaft, Lifters and Push Rods > Lifter / Lash Adjuster, Valve > Component Information > Service and Repair Lifter / Lash Adjuster: Service and Repair Fig. 10 Hydraulic Lifters And Retainer REMOVAL/INSTALLATION 1. Remove rocker arm cover and pushrods. 2. Remove intake manifold. 3. Remove retainer-to-engine attaching bolts, retainer and restrictors, Fig. 10. 4. Remove lifters. Note lifter location when removing. Lifters must be installed in same bore. DISASSEMBLY 1. Depress pushrod seat with pushrod, remove seat retainer, then slowly release spring tension. 2. Remove pushrod seat and metering valve. 3. Invert lifter and tap on flat surface to remove plunger and plunger spring. 4. Remove check ball retainer by prying from plunger with small screwdriver. 5. Remove check ball spring and check ball. 6. Clean lifter components in solvent, keeping components for each lifter separate INSPECTION 1. Inspect lifter body for internal and external wear. Also inspect bottom for wear grooves and flat spots. 2. Inspect roller for free operation, flat spots and pitting. Replace lifter if roller is worn, pitted or cannot be freed up. 3. Inspect pushrod seat and replace lifter and pushrod if seat is scored or excessively worn. 4. Inspect check ball and replace lifter if ball is pitted or scored. Do not attempt to recondition lifter assembly by interchanging components from other lifters. If components are damaged or worn, lifter assembly should be replaced. ASSEMBLY Ensure lifter components are kept clean during assembly, as small particles of dirt or lint can cause lifter to fail. 1. Install check ball to the small hole in bottom of plunger. 2. Install check ball spring and retainer, over check ball, then press retainer into position in plunger with small screwdriver. 3. Install plunger spring to check ball retainer. 4. Align oil feed holes in lifter body and plunger, then install plunger into lifter body. 5. Fill lifter with SAE 10.0 oil and proceed as follows: a. Insert a 1/8 inch punch into plunger and press down solidly, then using a 1/16 inch punch, insert punch through oil holes to retain plunger down against plunger spring tension. b. Remove 1/8 inch punch and fill lifter with SAE 10.0 oil. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Camshaft, Lifters and Push Rods > Lifter / Lash Adjuster, Valve > Component Information > Service and Repair > Page 2013 6. Install metering valve, pushrod seat and seat retainer. 7. Depress pushrod seat with pushrod and remove 1/16 inch punch from lifter body. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Camshaft, Lifters and Push Rods > Rocker Arm Assembly > Component Information > Specifications > Rocker Arm Rocker Arm Assembly: Specifications Rocker Arm VALVE ADJUSTMENT (VIN Z) WITH SCREW-IN ROCKER ARM STUDS AND POSITIVE STOP SHOULDERS Valve Rocker Arm Nuts ....................................................................................................................... .......................................... 27 Nm (20 lb. ft.). WITH PRESSED-IN ROCKER ARM STUDS Refer to Rocker Arm / Adjustments. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Camshaft, Lifters and Push Rods > Rocker Arm Assembly > Component Information > Specifications > Rocker Arm > Page 2018 Rocker Arm Assembly: Specifications Rocker Arm Stud ROCKER ARM STUD TORQUE ^ Rocker Arm Stud to Cylinder Head ................................................................................................................................................ 47 Nm (35 lb. ft.). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Camshaft, Lifters and Push Rods > Rocker Arm Assembly > Component Information > Specifications > Page 2019 Rocker Arm Assembly: Adjustments VALVE ADJUSTMENT Fig. 10 Valve Adjustment The 4.3L VIN Z engine can be equipped with two different rocker arm stud configurations that require different valve lash procedures. TYPE 1 - VIN Z If you have a 4.3L VIN Z engine that has screw-in rocker arm studs with positive stop shoulders, no valve adjustment is necessary. When the valve train requires service, you simply tighten the rocker arm nuts to 27 Nm (20 ft lb). TYPE 2 - VIN Z If you have a 4.3L VIN Z engine that has pressed-in rocker arm studs, you must follow the valve adjustment procedure outlined below. 1. Remove rocker arm cover. 2. Rotate engine until mark on torsional damper is aligned with "0" mark on timing tab fastened to crankcase front cover. To ensure engine is at No. 1 cylinder firing position, place fingers on No. 1 cylinder valves as the mark on damper approaches the "0" mark on timing tab. If valves are not moving, engine is in the No. 1 cylinder firing position. If valves are moving, engine is in the No. 4 cylinder firing position and should be rotated one revolution. 3. With engine in No. 1 cylinder firing position, adjust the following valves: ^ Exhaust valves 1, 5 and 6. ^ Intake valves 1, 2 and 3. NOTE: Even numbered cylinders are in the left bank and odd numbered cylinders are in the right bank, when viewed from front of the engine. 4. Back off adjusting nut until lash is felt at pushrod, then tighten nut until all lash is removed. This can be determined by rotating pushrod while turning adjusting nut. When all lash is removed, tighten adjusting nut 1 and 3/4 turns to center lifter plunger. 5. Crank engine one full revolution until mark on torsional damper and "0" mark on timing tab are again in alignment. This is the No. 4 cylinder firing position. With engine in this position, adjust the following valves: ^ Exhaust valves 2, 3 and 4. ^ Intake valves 4, 5 and 6. 6. Install valve covers and related components, then start engine and check timing and idle speed. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Camshaft, Lifters and Push Rods > Rocker Arm Assembly > Component Information > Service and Repair > Rocker Arm Studs Replace Rocker Arm Assembly: Service and Repair Rocker Arm Studs Replace Fig. 12 Rocker Arm Stud Removal Fig. 13 Rocker Arm Stud Bore Reaming Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Camshaft, Lifters and Push Rods > Rocker Arm Assembly > Component Information > Service and Repair > Rocker Arm Studs Replace > Page 2022 Fig. 14 Rocker Arm Stud Installation Rocker arm studs that have damaged threads or are loose should be replaced with oversize studs. Oversize studs are available in 0.003 and 0.013 inch and can be installed after properly reaming the holes as follows: 1. Remove stud using stud reamer tool No. J-5802-01, or equivalent, Fig. 12, with a nut and flat washer placed over tool. 2. Ream hole to proper size using reamer tool No. J-5715, or equivalent, Fig. 13, for 0.003 inch oversize or reamer tool No. J-6036, or equivalent, for 0.013 inch oversize. Do not install oversize stud without reaming hole since cylinder head damage could occur. 3. Apply axle lubricant to press fit area of stud and install using stud installer tool No. J-6880, or equivalent, Fig. 14. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Camshaft, Lifters and Push Rods > Rocker Arm Assembly > Component Information > Service and Repair > Rocker Arm Studs Replace > Page 2023 Rocker Arm Assembly: Service and Repair Rocker Arms Replace 1. Disconnect battery ground cable. 2. Remove air cleaner assembly, then the emission relays and bracket. 3. Remove wiring harnesses and spark plug wires from clips and position aside. 4. Disconnect dipstick tube from cylinder head and position tube aside. 5. Remove rocker arm cover. 6. Remove rocker arm nut, then rocker arm and ball. 7. Remove pushrod. 8. Reverse procedure to install. Adjust valves if adjustable. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Block Assembly > Balance Shaft > Component Information > Specifications Balance Shaft: Specifications Engine Liter/CID .................................................................................................................................. ........................................................... 4.3L/V6-262 All specifications given in inches. Journal Bearing Diameter Front .................................................................................................................................................... ...................................................... 2.1648-2.1654 Rear ...................................................................... ...................................................................................................................................... 1.4994-1.5000 Rear Bearing Journal Clearance ......................................................................................................... ........................................................ 0.0010-0.0036 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Block Assembly > Balance Shaft > Component Information > Specifications > Page 2028 Balance Shaft: Service and Repair BALANCE SHAFT REMOVAL TOOLS REQUIRED: J 38834 Balance Shaft Bearing Service Kit J 26941 Bearing Remover Installing Balance Shaft And Components REMOVE OR DISCONNECT 1. Bolt (49). 2. Driven gear (42). 3. Retainer bolts (48). 4. Retainer (43). 5. Balance shaft (47) using a soft faced hammer. 6. Balance shaft rear bearing (45) using J 38834 and J 26941. IMPORTANT ^ The balance shaft with front bearing are serviced as an assembly. ^ Use only the correct tools for bearing and shaft installation. ^ inspect the balance shaft driven gear and the drive gear for nicks and burrs. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Block Assembly > Balance Shaft > Component Information > Specifications > Page 2029 BALANCE SHAFT INSTALLATION TOOLS REQUIRED: J 38834 Balance Shaft Bearing Service Kit J 36998 Balance Shaft Installer J 8092 Driver Handle J 36660 Torque/Angel Meter INSTALL OR CONNECT 1. Balance shaft rear bearing (45) using J 38834. Dip bearing in clean engine oil before installation. 2. Balance shaft (47) into block using J 36996 and J 8092. A. Dip the front balance shaft bearing into clean engine oil before assembly. B. Retaining ring on balance shaft front bearing must be seated on case. 3. Install balance shaft bearing retainer (43) and bolts (48). TIGHTEN ^ Balance shaft retainer bolts (48) to 14 Nm (124 lbs in.). 4. Balance shaft driven gear (42) and bolt (49). TIGHTEN ^ Balance shaft driven gear bolt (49) to 20 Nm (15 lbs. ft.) plus an additional turn of 35 degrees using J 36660. ^ Rotate balance shaft (47) by hand to make sure there is clearance between the balance shaft (47) and retainer (43). If balance shaft does not rotate freely, check to be sure retaining ring on front bearing is seated on case. Balance Shaft Drive Gear To Driven Gear Timing Marks ^ Turn the camshaft so, with the balance shaft drive gear temporarily installed, the timing mark on the drive gear is straight up. ^ With the balance shaft drive gear removed, turn the balance shaft so the timing mark on the driven gear (42) points straight down. 5. Balance shaft drive gear (37) onto camshaft. IMPORTANT ^ Make sure the timing marks on the balance shaft drive gear and driven gear line up. 6. Balance shaft drive gear bolts. TIGHTEN ^ Bolt to 16 Nm (12 lbs. ft.). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Block Assembly > Connecting Rod Bearing > Component Information > Specifications Connecting Rod Bearing: Specifications Connecting rod bearings are available in standard size and 0.001 and 0.002 inch undersize for use with new and used standard size crankshafts and 0.010 and 0.020 inch undersize for use with reconditioned crankshafts. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Block Assembly > Connecting Rod, Engine > Component Information > Specifications Connecting Rod: Specifications Torque Specifications 45 ft.lb Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Block Assembly > Crankshaft Main Bearing > Component Information > Technical Service Bulletins > Customer Interest for Crankshaft Main Bearing: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM Crankshaft Main Bearing: Customer Interest Engine - Cold Knock, Replace Oil Filter/Bearings/PROM File In Section: 6 - Engine Bulletin No.: 37-61-05A Date: October, 1995 Subject: Cold Engine Knock (Replace Oil Filter/Bearings/PROM) Models: 1990-95 Chevrolet and GMC Truck C/K, R/V, S/T, M/L, G, P Models 1991-92 Oldsmobile Bravada with 4.3L (VIN Z - RPO LB4), 5.7L (VIN K - RPO L05), 7.4 (VIN N - RPO L19) Engine This bulletin is being revised to add the 1995 model year information. Please discard Corporate Bulletin Number 37-61-05 (Section 6 - Engine). Condition Some late model truck engines have been reported to exhibit "cold knock" on start up. "Cold Knock" usually occurs after the vehicle has been completely warmed up, then parked for 8 or more hours in ambient temperatures of 35° F or less. "Cold knock" can be separated into three distinct categories. 1. Short Duration - Harsh, deep metallic knock that usually lasts from 1 to 10 seconds. Generally classified as a bearing or rod knock. 2. Valve Train - Light clatter, tick or click that may last up to 1 minute. 3. Piston Slap - Metallic knock that occurs only under load. Piston slap may last as long as 5 minutes. Correction Category A: Short Duration Knock This matrix describes the repair for each affected model year and engine. Specific information for each affected model year and engine is supplied. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Block Assembly > Crankshaft Main Bearing > Component Information > Technical Service Bulletins > Customer Interest for Crankshaft Main Bearing: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 2044 1992 LB4 VIN Z with "cold knock" only 1992-93 LB4 VIN Z with "cold knock" and installed field fix PROM OR with "cold knock" and detonation 1990-95 LB4 VIN Z Install check valve oil filter P/N 12555891 (FRAM PH3980). If the filter does not cure the condition, install the appropriate calibration from the tables (calibrations are available for all 1992 and some 1993 LB4 applications). If a calibration is not offered or does not cure the short duration cold knock Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Block Assembly > Crankshaft Main Bearing > Component Information > Technical Service Bulletins > Customer Interest for Crankshaft Main Bearing: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 2045 condition, install the appropriate main bearings as determined by the following procedure. Calibration Information - 1992-93 LB4 VIN Z The revised PROMs reduce spark advance after the engine is started. The reduction in spark lowers the cylinder pressure and eliminates the knock. The revised PROMs will NOT eliminate a piston slap (Category C) or valve train noise (Category B) concern. The base cold knock PROM contains the previously released calibration updates. For 1992 LB4, the previous field release is included for torque converter clutch (TCC) lock up (see Bulletin 137107 - Chevrolet 92-75-7A; GMC Truck 92-7A-40; Oldsmobile 92-T-34; Canada 9274L60100) for automatic transmissions, or neutral gear rattle for manual transmissions (see Bulletin 267201R - Chevrolet 92-187B-7B; GMC Truck 92-7B-149A; Canada 93-7B-105). If a vehicle has had a detonation fix PROM installed previously, select the combined detonation and cold knock fix PROM for the application. See Bulletin 376508 for more information on field fix PROM for the application and detonation. Important: Use of a detonation fix PROM in a non-detonating vehicle may result in degraded driveability. GMSPO currently stocks three (3) PROMs for each light duty 1992 model year LB4 application. Base Cold Knock Fix Combination Cold Knock and Detonation Fix GMSPO Service Parts Assistance Center (SPAC 1-800-433-6961) will have information available on each PROM part number. Select the PROM from the table. Old Broadcast Code (Old B/C Code) and Scan I.D. information has been supplied to help installed previously. Use a TECH-1 to determine the Scan I.D. of the PROM in the vehicle or remove the PROM and read the Broadcast Code (B/C Code). If the B/C Code/Scan I.D. can be found in the first table, a detonation fix has not been installed. PROMs are currently available GMSPO. 1990-95 L05 VIN K Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Block Assembly > Crankshaft Main Bearing > Component Information > Technical Service Bulletins > Customer Interest for Crankshaft Main Bearing: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 2046 1993 to 1995 L05 VIN K Install the appropriate check valve oil filter P/N 25160561 (PF1218 for two-wheel C-series and P/N 12555891 (FRAM PH3980) for four-wheel drive K-series). If the oil filter does not cure the condition, install the appropriate calibration from the table (calibrations are available for some 1993 and 1994 L05 applications). All calibrations are for light duty vehicles equipped with 4L60-E (M30) transmissions (no heavy duty emission/4L80-E calibrations are available). If a calibration is not offered or does not cure the short duration cold knock condition, install the appropriate main bearings as determined by the procedure. 1990-94 L19 VIN N Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Block Assembly > Crankshaft Main Bearing > Component Information > Technical Service Bulletins > Customer Interest for Crankshaft Main Bearing: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 2047 Install a check valve oil filter; no other recommended actions at this time. Important: The previous actions are only applicable to short duration cold knock. These actions will not eliminate a knock occurring under load or a knock lasting for more than 10 seconds. Two main bearing procedures are recommended: 1. For main bearing replacement with the engine IN the vehicle: C, G, P, M and L vehicles 2. For main bearing replacement with the engine OUT OF the vehicle: K, S and T THE FOLLOWING PROCEDURE IS TO BE USED FOR VEHICLES REQUIRING MAIN BEARING REPLACEMENT WITH THE ENGINE IN THE VEHICLE Recommended for C, G, P, M and L vehicles. Important: A OEM training video has been produced for in-vehicle main bearing replacement procedure. One copy of the video will be sent to each dealer. If the video has not been received, contact XPRESS 1 Distribution Center at 1-800-783-3034. Main Bearing Clearance Determination and Installation Procedure 1. REMOVE THE SERPENTINE BELT, dipstick, dipstick tube and disconnect the negative battery cable. 2. Raise the vehicle and remove (or set aside) any parts restricting access to the oil pan bolts (i.e., starter motor, oil cooler lines, oil filter adapter, flywheel inspection cover). 3. Remove the oil pan, oil pump, and shield. 4. Remove # 5 (flange) bearing cap. Wipe the oil from the crankshaft journal and the lower main bearing insert. 5. Place a screw jack under an accessible part of the crankshaft, carefully apply pressure to the crankshaft to force it solidly against the top bearing insert. The reason for this is to remove any clearance between the top bearing insert and the crankshaft. If this step is not performed, a smaller than actual clearance will be measured. Important: This should be done as close as possible to the bearing being measured. This step is only required for on-vehicle service where the engine cannot be turned upside down as on an engine stand. 6. Place a piece of plastigage across the width of the lower bearing insert (parallel to the centerline of the crankshaft). 7. Reinstall # 5 main bearing cap. Torque to 110 N.m (80 lb ft). Do not allow crankshaft to turn. 8. Carefully remove the # 5 main bearing cap and bearing insert. The flattened plastigage will adhere to either the bearing insert or the crank journal. Do not remove the plastigage from the insert or journal. 9. On the edge of the plastigage envelope, there is a graduated scale. Without removing the flattened plastigage, measure its width at the widest point using the graduated scale on the plastigage envelope. 10. The desired main bearing clearance is 0.0008" - 0.0028". If the clearance measured with the plastigage is greater than 0.0028", write down the clearance. Next, read the back of the bearing insert to determine what size bearing was originally installed (usual STD, 0.0006", 0.0010" or 0.0012"). The size stamped on the bearing is the effective undersize when both inserts are installed. For example, a 0.0006" undersize bearing set consists of two (2) 0.0003" thicker bearing inserts, both stamped 0.0006". 11. Remove the top bearing insert using tool J 8080 and read the back to determine what size upper bearing insert was originally installed. The top insert may be different size than the bottom. 12. Calculate the original bearing undersize by dividing the size on each insert by 2, then add the values together. EXAMPLE 1: The lower insert is stamped 0.0006" and the upper is stamped 0.0010". Divide 0.0006" by two to get 0.0003". Divide 0.0010" by 2 to get 0.0005". Add 0.0003" and 0.0005" together to calculate the bearing undersize, which is 0.0008" in this case. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Block Assembly > Crankshaft Main Bearing > Component Information > Technical Service Bulletins > Customer Interest for Crankshaft Main Bearing: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 2048 EXAMPLE 2: The lower insert is stamped STD (standard) and the upper is stamped 0.0010". The undersize for a STD bearing is 0. Divide 0 by 2 to get 0. Divide 0.0010" by 2 to get 0.0005". Add 0 and 0.0005" together to calculate the bearing undersize, which is 0.0005" in this case. 13. Add the original bearing undersize calculated in step 12 to the clearance measured and written down in step 9. For example, if a clearance of 0.0030" was measured with plastigage in step 9 and the calculated bearing undersize from step 12 was 0.0005", the bearing clearance for that particular main journal is equal to 0.0030" plus 0.0005". The bearing clearance would be 0.0035" in this case. 14. Determine which of the combinations of two sizes of replacement bearings will produce the desired clearance. The two sizes available are 0.001" and 0.002". One insert of each size may be combined to produce an intermediate undersize of 0.0015". Subtract the replacement bearing size from the actual clearance to determine which bearing should be used. The bearing that should be used is the one which gives a clearance closer to 0.0008" than to 0.0028". The clearance must not be less than 0.0008". Using the example from step 11, the actual clearance is 0.0035". Subtracting 0.001" from 0.0035" will give a clearance of 0.0025", just barely within the required range. Subtracting 0.002" from 0.0035" will give a clearance of 0.0015". The 0.002" undersize bearing set would be the one to use in this case since it gives a clearance closer to 0.0008", but not less. 15. Install the replacement upper main bearing insert using tool J 8080. 16. Install the replacement lower main bearing insert in the main bearing cap. Lay a piece of plastigage across the width of the lower main bearing insert (same as step 5). 17. Repeat steps 7, 8 and 9. 18. Measuring the plastigage with the scale on the envelope, verify the clearance of the replacement bearings is within the range of 0.001" to 0.003". 19. Repeat steps 4 through 16 for each main bearing. 20. Thrust the crankshaft forward and backward several times to seat the thrust bearing. 21. Reinstall oil pump; torque to 88 N.m (65 lb ft). 22. Reinstall the oil pan and other hardware. 23. Before starting the engine, remove the fuel pump fuse and crank the engine until oil pressure registers on the gauge. Stop cranking, let the starter cool down, then crank for another 15 seconds. 24. Install fuel pump fuse, start engine, check for leaks or unusual noises. 25. Road test vehicle, check for leaks or unusual noises. THE FOLLOWING PROCEDURE IS TO BE USED FOR VEHICLES REQUIRING MAIN BEARING REPLACEMENT WITH THE ENGINE OUT OF THE VEHICLE Recommended for K, S and T vehicles. 1. Remove the engine from the vehicle using the appropriate service manual procedure. 2. Mount the engine on an engine stand, flip the engine so the oil pan is facing up. 3. Remove the oil pan. 4. Remove the oil pump and shield. 5. Remove the dipstick tube. 6. Remove one (1) main bearing cap (must do one at a time). 7. Plasti-gage bearing. 8. If the bearing clearance is out of specification (clearance greater than 0.003 inches), remove upper main bearing from the block. 9. Check the size of the original bearing. 10. Determine what combination of new bearings are required to get the clearance in the acceptable range of 0.0008 inches to 0.0028 inches. See steps Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Block Assembly > Crankshaft Main Bearing > Component Information > Technical Service Bulletins > Customer Interest for Crankshaft Main Bearing: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 2049 12 through 14 in the "in-vehicle" service outlined above. 11. Reinstall the upper main bearing. 12. Reinstall the main cap and lower bearing; torque to 110 N.m (80 lb ft). 13. Repeat for each main bearing. 14. Reinstall oil pump and shield; torque to 88 N.m (65 lb ft). 15. Reinstall dipstick tube. 16. Reinstall oil pan. 17. Reinstall engine in vehicle. 18. Before starting the engine, remove the fuel pump fuse and crank the engine until oil pressure registers on the gauge. Stop cranking, let the starter cool down, then crank for another 15 seconds. 19. Install fuel pump fuse, start engine, check for leaks or unusual noises. 20. Road test vehicle, check for leaks or unusual noises. Correction Category B: Valve Train Clatter, Tick or Click For 1992-94 vehicles equipped with a 4.3L V6 (LB4 VIN Z or L35 VIN W) engine see Corporate Bulletin 376006 for information on converting from net lash to adjustable lash and/or re-lashing the valves on an adjustable lash system. Investigation of "cold knock" is continuing. Updates will continue to be provided when available. Parts Information Check-Valve Filters Description Part Number V6, V8 (Four-Wheel Drive) FRAM PH3980 12555891 V8 (Two-Wheel Drive), Mark V8 PF1218 25160561 The FRAM PH3980 is to be used in place of the PF52. The PH3980 provides superior anti-drainback performance, a key factor in reducing cold knock. FRAM filters are to be procured locally until 08-15-95. After this date the filters may be ordered from GMSPO using the supplied part number. Orders placed to GMSPO prior to this date will not be placed on backorder. Bearings Description Part Number 0.001" Main Bearing Kit, Positions 1-4 on V8, 1-3 on V6 10120992 0.001" Main Bearing Kit, Flange # 5 on V8, # 4 on V6 10120994 0.002" Main Bearing Kit, Positions 1-4 on V8, 1-3 on V6 12329758 0.002" Main Bearing Kit, Flange # 5 on V8, # 4 on V6 12329792 Main bearing kits are currently available from GMSPO. All calibrations are currently available from GMSPO. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Block Assembly > Crankshaft Main Bearing > Component Information > Technical Service Bulletins > Customer Interest for Crankshaft Main Bearing: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 2050 Warranty Information Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Block Assembly > Crankshaft Main Bearing > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Crankshaft Main Bearing: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM Crankshaft Main Bearing: All Technical Service Bulletins Engine - Cold Knock, Replace Oil Filter/Bearings/PROM File In Section: 6 - Engine Bulletin No.: 37-61-05A Date: October, 1995 Subject: Cold Engine Knock (Replace Oil Filter/Bearings/PROM) Models: 1990-95 Chevrolet and GMC Truck C/K, R/V, S/T, M/L, G, P Models 1991-92 Oldsmobile Bravada with 4.3L (VIN Z - RPO LB4), 5.7L (VIN K - RPO L05), 7.4 (VIN N - RPO L19) Engine This bulletin is being revised to add the 1995 model year information. Please discard Corporate Bulletin Number 37-61-05 (Section 6 - Engine). Condition Some late model truck engines have been reported to exhibit "cold knock" on start up. "Cold Knock" usually occurs after the vehicle has been completely warmed up, then parked for 8 or more hours in ambient temperatures of 35° F or less. "Cold knock" can be separated into three distinct categories. 1. Short Duration - Harsh, deep metallic knock that usually lasts from 1 to 10 seconds. Generally classified as a bearing or rod knock. 2. Valve Train - Light clatter, tick or click that may last up to 1 minute. 3. Piston Slap - Metallic knock that occurs only under load. Piston slap may last as long as 5 minutes. Correction Category A: Short Duration Knock This matrix describes the repair for each affected model year and engine. Specific information for each affected model year and engine is supplied. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Block Assembly > Crankshaft Main Bearing > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Crankshaft Main Bearing: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 2056 1992 LB4 VIN Z with "cold knock" only 1992-93 LB4 VIN Z with "cold knock" and installed field fix PROM OR with "cold knock" and detonation 1990-95 LB4 VIN Z Install check valve oil filter P/N 12555891 (FRAM PH3980). If the filter does not cure the condition, install the appropriate calibration from the tables (calibrations are available for all 1992 and some 1993 LB4 applications). If a calibration is not offered or does not cure the short duration cold knock Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Block Assembly > Crankshaft Main Bearing > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Crankshaft Main Bearing: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 2057 condition, install the appropriate main bearings as determined by the following procedure. Calibration Information - 1992-93 LB4 VIN Z The revised PROMs reduce spark advance after the engine is started. The reduction in spark lowers the cylinder pressure and eliminates the knock. The revised PROMs will NOT eliminate a piston slap (Category C) or valve train noise (Category B) concern. The base cold knock PROM contains the previously released calibration updates. For 1992 LB4, the previous field release is included for torque converter clutch (TCC) lock up (see Bulletin 137107 - Chevrolet 92-75-7A; GMC Truck 92-7A-40; Oldsmobile 92-T-34; Canada 9274L60100) for automatic transmissions, or neutral gear rattle for manual transmissions (see Bulletin 267201R - Chevrolet 92-187B-7B; GMC Truck 92-7B-149A; Canada 93-7B-105). If a vehicle has had a detonation fix PROM installed previously, select the combined detonation and cold knock fix PROM for the application. See Bulletin 376508 for more information on field fix PROM for the application and detonation. Important: Use of a detonation fix PROM in a non-detonating vehicle may result in degraded driveability. GMSPO currently stocks three (3) PROMs for each light duty 1992 model year LB4 application. Base Cold Knock Fix Combination Cold Knock and Detonation Fix GMSPO Service Parts Assistance Center (SPAC 1-800-433-6961) will have information available on each PROM part number. Select the PROM from the table. Old Broadcast Code (Old B/C Code) and Scan I.D. information has been supplied to help installed previously. Use a TECH-1 to determine the Scan I.D. of the PROM in the vehicle or remove the PROM and read the Broadcast Code (B/C Code). If the B/C Code/Scan I.D. can be found in the first table, a detonation fix has not been installed. PROMs are currently available GMSPO. 1990-95 L05 VIN K Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Block Assembly > Crankshaft Main Bearing > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Crankshaft Main Bearing: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 2058 1993 to 1995 L05 VIN K Install the appropriate check valve oil filter P/N 25160561 (PF1218 for two-wheel C-series and P/N 12555891 (FRAM PH3980) for four-wheel drive K-series). If the oil filter does not cure the condition, install the appropriate calibration from the table (calibrations are available for some 1993 and 1994 L05 applications). All calibrations are for light duty vehicles equipped with 4L60-E (M30) transmissions (no heavy duty emission/4L80-E calibrations are available). If a calibration is not offered or does not cure the short duration cold knock condition, install the appropriate main bearings as determined by the procedure. 1990-94 L19 VIN N Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Block Assembly > Crankshaft Main Bearing > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Crankshaft Main Bearing: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 2059 Install a check valve oil filter; no other recommended actions at this time. Important: The previous actions are only applicable to short duration cold knock. These actions will not eliminate a knock occurring under load or a knock lasting for more than 10 seconds. Two main bearing procedures are recommended: 1. For main bearing replacement with the engine IN the vehicle: C, G, P, M and L vehicles 2. For main bearing replacement with the engine OUT OF the vehicle: K, S and T THE FOLLOWING PROCEDURE IS TO BE USED FOR VEHICLES REQUIRING MAIN BEARING REPLACEMENT WITH THE ENGINE IN THE VEHICLE Recommended for C, G, P, M and L vehicles. Important: A OEM training video has been produced for in-vehicle main bearing replacement procedure. One copy of the video will be sent to each dealer. If the video has not been received, contact XPRESS 1 Distribution Center at 1-800-783-3034. Main Bearing Clearance Determination and Installation Procedure 1. REMOVE THE SERPENTINE BELT, dipstick, dipstick tube and disconnect the negative battery cable. 2. Raise the vehicle and remove (or set aside) any parts restricting access to the oil pan bolts (i.e., starter motor, oil cooler lines, oil filter adapter, flywheel inspection cover). 3. Remove the oil pan, oil pump, and shield. 4. Remove # 5 (flange) bearing cap. Wipe the oil from the crankshaft journal and the lower main bearing insert. 5. Place a screw jack under an accessible part of the crankshaft, carefully apply pressure to the crankshaft to force it solidly against the top bearing insert. The reason for this is to remove any clearance between the top bearing insert and the crankshaft. If this step is not performed, a smaller than actual clearance will be measured. Important: This should be done as close as possible to the bearing being measured. This step is only required for on-vehicle service where the engine cannot be turned upside down as on an engine stand. 6. Place a piece of plastigage across the width of the lower bearing insert (parallel to the centerline of the crankshaft). 7. Reinstall # 5 main bearing cap. Torque to 110 N.m (80 lb ft). Do not allow crankshaft to turn. 8. Carefully remove the # 5 main bearing cap and bearing insert. The flattened plastigage will adhere to either the bearing insert or the crank journal. Do not remove the plastigage from the insert or journal. 9. On the edge of the plastigage envelope, there is a graduated scale. Without removing the flattened plastigage, measure its width at the widest point using the graduated scale on the plastigage envelope. 10. The desired main bearing clearance is 0.0008" - 0.0028". If the clearance measured with the plastigage is greater than 0.0028", write down the clearance. Next, read the back of the bearing insert to determine what size bearing was originally installed (usual STD, 0.0006", 0.0010" or 0.0012"). The size stamped on the bearing is the effective undersize when both inserts are installed. For example, a 0.0006" undersize bearing set consists of two (2) 0.0003" thicker bearing inserts, both stamped 0.0006". 11. Remove the top bearing insert using tool J 8080 and read the back to determine what size upper bearing insert was originally installed. The top insert may be different size than the bottom. 12. Calculate the original bearing undersize by dividing the size on each insert by 2, then add the values together. EXAMPLE 1: The lower insert is stamped 0.0006" and the upper is stamped 0.0010". Divide 0.0006" by two to get 0.0003". Divide 0.0010" by 2 to get 0.0005". Add 0.0003" and 0.0005" together to calculate the bearing undersize, which is 0.0008" in this case. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Block Assembly > Crankshaft Main Bearing > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Crankshaft Main Bearing: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 2060 EXAMPLE 2: The lower insert is stamped STD (standard) and the upper is stamped 0.0010". The undersize for a STD bearing is 0. Divide 0 by 2 to get 0. Divide 0.0010" by 2 to get 0.0005". Add 0 and 0.0005" together to calculate the bearing undersize, which is 0.0005" in this case. 13. Add the original bearing undersize calculated in step 12 to the clearance measured and written down in step 9. For example, if a clearance of 0.0030" was measured with plastigage in step 9 and the calculated bearing undersize from step 12 was 0.0005", the bearing clearance for that particular main journal is equal to 0.0030" plus 0.0005". The bearing clearance would be 0.0035" in this case. 14. Determine which of the combinations of two sizes of replacement bearings will produce the desired clearance. The two sizes available are 0.001" and 0.002". One insert of each size may be combined to produce an intermediate undersize of 0.0015". Subtract the replacement bearing size from the actual clearance to determine which bearing should be used. The bearing that should be used is the one which gives a clearance closer to 0.0008" than to 0.0028". The clearance must not be less than 0.0008". Using the example from step 11, the actual clearance is 0.0035". Subtracting 0.001" from 0.0035" will give a clearance of 0.0025", just barely within the required range. Subtracting 0.002" from 0.0035" will give a clearance of 0.0015". The 0.002" undersize bearing set would be the one to use in this case since it gives a clearance closer to 0.0008", but not less. 15. Install the replacement upper main bearing insert using tool J 8080. 16. Install the replacement lower main bearing insert in the main bearing cap. Lay a piece of plastigage across the width of the lower main bearing insert (same as step 5). 17. Repeat steps 7, 8 and 9. 18. Measuring the plastigage with the scale on the envelope, verify the clearance of the replacement bearings is within the range of 0.001" to 0.003". 19. Repeat steps 4 through 16 for each main bearing. 20. Thrust the crankshaft forward and backward several times to seat the thrust bearing. 21. Reinstall oil pump; torque to 88 N.m (65 lb ft). 22. Reinstall the oil pan and other hardware. 23. Before starting the engine, remove the fuel pump fuse and crank the engine until oil pressure registers on the gauge. Stop cranking, let the starter cool down, then crank for another 15 seconds. 24. Install fuel pump fuse, start engine, check for leaks or unusual noises. 25. Road test vehicle, check for leaks or unusual noises. THE FOLLOWING PROCEDURE IS TO BE USED FOR VEHICLES REQUIRING MAIN BEARING REPLACEMENT WITH THE ENGINE OUT OF THE VEHICLE Recommended for K, S and T vehicles. 1. Remove the engine from the vehicle using the appropriate service manual procedure. 2. Mount the engine on an engine stand, flip the engine so the oil pan is facing up. 3. Remove the oil pan. 4. Remove the oil pump and shield. 5. Remove the dipstick tube. 6. Remove one (1) main bearing cap (must do one at a time). 7. Plasti-gage bearing. 8. If the bearing clearance is out of specification (clearance greater than 0.003 inches), remove upper main bearing from the block. 9. Check the size of the original bearing. 10. Determine what combination of new bearings are required to get the clearance in the acceptable range of 0.0008 inches to 0.0028 inches. See steps Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Block Assembly > Crankshaft Main Bearing > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Crankshaft Main Bearing: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 2061 12 through 14 in the "in-vehicle" service outlined above. 11. Reinstall the upper main bearing. 12. Reinstall the main cap and lower bearing; torque to 110 N.m (80 lb ft). 13. Repeat for each main bearing. 14. Reinstall oil pump and shield; torque to 88 N.m (65 lb ft). 15. Reinstall dipstick tube. 16. Reinstall oil pan. 17. Reinstall engine in vehicle. 18. Before starting the engine, remove the fuel pump fuse and crank the engine until oil pressure registers on the gauge. Stop cranking, let the starter cool down, then crank for another 15 seconds. 19. Install fuel pump fuse, start engine, check for leaks or unusual noises. 20. Road test vehicle, check for leaks or unusual noises. Correction Category B: Valve Train Clatter, Tick or Click For 1992-94 vehicles equipped with a 4.3L V6 (LB4 VIN Z or L35 VIN W) engine see Corporate Bulletin 376006 for information on converting from net lash to adjustable lash and/or re-lashing the valves on an adjustable lash system. Investigation of "cold knock" is continuing. Updates will continue to be provided when available. Parts Information Check-Valve Filters Description Part Number V6, V8 (Four-Wheel Drive) FRAM PH3980 12555891 V8 (Two-Wheel Drive), Mark V8 PF1218 25160561 The FRAM PH3980 is to be used in place of the PF52. The PH3980 provides superior anti-drainback performance, a key factor in reducing cold knock. FRAM filters are to be procured locally until 08-15-95. After this date the filters may be ordered from GMSPO using the supplied part number. Orders placed to GMSPO prior to this date will not be placed on backorder. Bearings Description Part Number 0.001" Main Bearing Kit, Positions 1-4 on V8, 1-3 on V6 10120992 0.001" Main Bearing Kit, Flange # 5 on V8, # 4 on V6 10120994 0.002" Main Bearing Kit, Positions 1-4 on V8, 1-3 on V6 12329758 0.002" Main Bearing Kit, Flange # 5 on V8, # 4 on V6 12329792 Main bearing kits are currently available from GMSPO. All calibrations are currently available from GMSPO. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Block Assembly > Crankshaft Main Bearing > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Crankshaft Main Bearing: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 2062 Warranty Information Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Block Assembly > Crankshaft Main Bearing > Component Information > Specifications > Bearing Undersize Availability Crankshaft Main Bearing: Specifications Bearing Undersize Availability Main bearings are available in standard size and undersizes of 0.001, 0.002, 0.009, 0.010 and 0.020 inch. Connecting rod bearings are available in standard size and 0.001 and 0.002 inch undersize for use with new and used standard size crankshafts and 0.010 and 0.020 inch undersize for use with reconditioned crankshafts. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Block Assembly > Crankshaft, Engine > Component Information > Specifications > Main Bearing Torque Specifications Crankshaft: Specifications Main Bearing Cap Main Bearing Cap Torque Specifications 80 ft.lb Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Block Assembly > Crankshaft, Engine > Component Information > Specifications > Main Bearing Torque Specifications > Page 2069 Crankshaft: Specifications Crankshaft Dimensions Engine Liter/CID .................................................................................................................................. ........................................................... 4.3L/V6-262 All specifications given in inches. Crankshaft Journals Main Bearing Journal Diameter ........................................................................................................... ..................................................................... [6] Connecting Rod Journal Diameter .......................................................................................................................................................... 2.2487-2.2497 Maximum Out Of Round All ......................................................................................... ...................................................................................... 0.0010 Runout Service Limit ........................ .............................................................................................................................................................. .......... [02] Bearing Clearance Main Bearings ...................................................................................................................................... ...................................................................... [07] Connecting Rod Bearings ...................................... ................................................................................................................................................... [08] Thrust Bearing ..................................................................................................................................... ..................................................... 0.0020-0.0070 Connecting Rods Pin Clearance ...................................................................................................................................... ....................................................................... [03] Side Clearance ..................................................... ...................................................................................................................................... 0.0060-0.0140 [02] If main journals are misaligned, crankshaft is bent & must be replaced. [03] 0.0008-0.0016 inch interference fit. [06] Front No. 1 journal, 2.4484-2.4493 inches; Nos. 2, 3, & 4 journals, 2.4481-2.4490 inches; No. 5 journal, 2.4479-2.4488 inches. [07] Production: Front, .0008-.0020 inch; intermediate, .0011-.0023 inch; rear, .0017-.0032 inch. Service: Front, .0010-.0015 inch; intermediate, .0010-.0025 inch; rear, .0025-.0035 inch. [08] Production, .0013-.0035 inch; service, .0020-.0030 inch. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Block Assembly > Harmonic Balancer Crankshaft Pulley > Component Information > Technical Service Bulletins > Crankshaft Balancer - Removal/Installation Tool Harmonic Balancer - Crankshaft Pulley: Technical Service Bulletins Crankshaft Balancer Removal/Installation Tool File In Section: 6 - Engine Bulletin No.: 57-61-38 Date: January, 1996 SERVICE MANUAL UPDATE Subject: Section 6A - Engine Mechanical - Crankshaft Balancer Remover/Installer Tool Incorrectly Referenced Models: 1990-96 Chevrolet and GMC Truck S/T; M/L, C/K, P, G Models 1991-94 Oldsmobile Bravada 1996 Oldsmobile Bravada The crankshaft balancer remover/installer tool J 39046 listed in some 1990-96 service information sections 6A2, 6A3, 6A4, 6A5, 6A6, 6A7, 6A2B, 6A3B, 6A4B, 6A5B, and 6A6B is incorrectly referenced. The correct tool number for the truck models listed above is J 23523-F or equivalent. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Block Assembly > Piston, Engine > Component Information > Specifications Piston: Specifications Engine Liter/CID .................................................................................................................................. ........................................................... 4.3L/V6-262 All specifications given in inches. Piston Diameter (Std.) [01] .................................................................................................................. ......................................................... 3.9988-4.0008 Piston Clearance ............................................... ..................................................................................................................................... 0.0007-0.0017 [07] Piston Pin Diameter (Std.) ............................................................................................................ .............................................................. 0.9270-0.09273 Pin To Piston Bore Clearance [05] ............. ............................................................................................................................................................. 0.0010 Piston Rings End Gap [02] Comp. .................................................................................................................................................. .................................................................. [21] Oil .............................................................................. ......................................................................................................................................... 0.015 Side Clearance Comp. .................................................................................................................................................. ................................................. 0.0014-0.0032 Oil .............................................................................. ........................................................................................................................... 0.0014-0.0032 [01] Measured at 90 deg. angle to piston pin. [02] Minimum. [05] Maximum. [07] Service limit, 0.0027 inch. [21] Top ring, 0.010 inch; second ring, 0.018 inch. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Block Assembly > Piston, Engine > Component Information > Specifications > Page 2077 Piston: Service and Repair Piston & rod assembly Assemble pistons to connecting rods as shown in Fig 16 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Head Assembly > Valve Clearance > System Information > Specifications > Valve Clearance Specifications Valve Clearance: Specifications Valve Clearance Specifications VALVE ADJUSTMENT (VIN Z) WITH SCREW-IN ROCKER ARM STUDS AND POSITIVE STOP SHOULDERS Valve Rocker Arm Nuts ....................................................................................................................... .......................................... 27 Nm (20 lb. ft.). WITH PRESSED-IN ROCKER ARM STUDS Refer to Rocker Arm / Adjustments. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Head Assembly > Valve Clearance > System Information > Specifications > Valve Clearance Specifications > Page 2083 Valve Clearance: Specifications Valve Arrangement FRONT TO REAR 4.3L/V6-262 Left Side........................................................................................................................... .................................................................................. E-I-E-I-I-E Right Side......................................... .............................................................................................................................................................. .... E-I-I-E-I-E Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Head Assembly > Valve Clearance > System Information > Specifications > Page 2084 Valve Clearance: Adjustments VALVE ADJUSTMENT Fig. 10 Valve Adjustment The 4.3L VIN Z engine can be equipped with two different rocker arm stud configurations that require different valve lash procedures. TYPE 1 - VIN Z If you have a 4.3L VIN Z engine that has screw-in rocker arm studs with positive stop shoulders, no valve adjustment is necessary. When the valve train requires service, you simply tighten the rocker arm nuts to 27 Nm (20 ft lb). TYPE 2 - VIN Z If you have a 4.3L VIN Z engine that has pressed-in rocker arm studs, you must follow the valve adjustment procedure outlined below. 1. Remove rocker arm cover. 2. Rotate engine until mark on torsional damper is aligned with "0" mark on timing tab fastened to crankcase front cover. To ensure engine is at No. 1 cylinder firing position, place fingers on No. 1 cylinder valves as the mark on damper approaches the "0" mark on timing tab. If valves are not moving, engine is in the No. 1 cylinder firing position. If valves are moving, engine is in the No. 4 cylinder firing position and should be rotated one revolution. 3. With engine in No. 1 cylinder firing position, adjust the following valves: ^ Exhaust valves 1, 5 and 6. ^ Intake valves 1, 2 and 3. NOTE: Even numbered cylinders are in the left bank and odd numbered cylinders are in the right bank, when viewed from front of the engine. 4. Back off adjusting nut until lash is felt at pushrod, then tighten nut until all lash is removed. This can be determined by rotating pushrod while turning adjusting nut. When all lash is removed, tighten adjusting nut 1 and 3/4 turns to center lifter plunger. 5. Crank engine one full revolution until mark on torsional damper and "0" mark on timing tab are again in alignment. This is the No. 4 cylinder firing position. With engine in this position, adjust the following valves: ^ Exhaust valves 2, 3 and 4. ^ Intake valves 4, 5 and 6. 6. Install valve covers and related components, then start engine and check timing and idle speed. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Head Assembly > Valve Clearance > System Information > Specifications > Page 2085 Valve Clearance: Service and Repair For Valve Adjustment, Refer to Valve Clearance / Adjustments. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Head Assembly > Fuel Pressure Release > System Information > Service and Repair Fuel Pressure Release: Service and Repair WARNING To reduce the risk of fire and personal injury, it is necessary to relieve fuel system pressure before servicing fuel system components. A small amount of fuel may be released when servicing fuel lines or connections. In order to reduce the chance of personal injury, cover fuel line fittings with a shop towel before disconnecting to catch any fuel that may leak out. Place the towel in an approved container when disconnect is complete. PROCEDURE - Disconnect negative battery terminal to avoid possible fuel discharge if an accidental attempt is made to start the engine. - Loosen fuel filler cap to relieve tank vapor pressure. (Do not tighten until service has been completed.) - The TBI model 220 contains a constant bleed feature in the pressure regulator that relieves pressure. Therefore, no further action is required. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Head Assembly > Rocker Arm Assembly > Component Information > Specifications > Rocker Arm Rocker Arm Assembly: Specifications Rocker Arm VALVE ADJUSTMENT (VIN Z) WITH SCREW-IN ROCKER ARM STUDS AND POSITIVE STOP SHOULDERS Valve Rocker Arm Nuts ....................................................................................................................... .......................................... 27 Nm (20 lb. ft.). WITH PRESSED-IN ROCKER ARM STUDS Refer to Rocker Arm / Adjustments. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Head Assembly > Rocker Arm Assembly > Component Information > Specifications > Rocker Arm > Page 2093 Rocker Arm Assembly: Specifications Rocker Arm Stud ROCKER ARM STUD TORQUE ^ Rocker Arm Stud to Cylinder Head ................................................................................................................................................ 47 Nm (35 lb. ft.). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Head Assembly > Rocker Arm Assembly > Component Information > Specifications > Page 2094 Rocker Arm Assembly: Adjustments VALVE ADJUSTMENT Fig. 10 Valve Adjustment The 4.3L VIN Z engine can be equipped with two different rocker arm stud configurations that require different valve lash procedures. TYPE 1 - VIN Z If you have a 4.3L VIN Z engine that has screw-in rocker arm studs with positive stop shoulders, no valve adjustment is necessary. When the valve train requires service, you simply tighten the rocker arm nuts to 27 Nm (20 ft lb). TYPE 2 - VIN Z If you have a 4.3L VIN Z engine that has pressed-in rocker arm studs, you must follow the valve adjustment procedure outlined below. 1. Remove rocker arm cover. 2. Rotate engine until mark on torsional damper is aligned with "0" mark on timing tab fastened to crankcase front cover. To ensure engine is at No. 1 cylinder firing position, place fingers on No. 1 cylinder valves as the mark on damper approaches the "0" mark on timing tab. If valves are not moving, engine is in the No. 1 cylinder firing position. If valves are moving, engine is in the No. 4 cylinder firing position and should be rotated one revolution. 3. With engine in No. 1 cylinder firing position, adjust the following valves: ^ Exhaust valves 1, 5 and 6. ^ Intake valves 1, 2 and 3. NOTE: Even numbered cylinders are in the left bank and odd numbered cylinders are in the right bank, when viewed from front of the engine. 4. Back off adjusting nut until lash is felt at pushrod, then tighten nut until all lash is removed. This can be determined by rotating pushrod while turning adjusting nut. When all lash is removed, tighten adjusting nut 1 and 3/4 turns to center lifter plunger. 5. Crank engine one full revolution until mark on torsional damper and "0" mark on timing tab are again in alignment. This is the No. 4 cylinder firing position. With engine in this position, adjust the following valves: ^ Exhaust valves 2, 3 and 4. ^ Intake valves 4, 5 and 6. 6. Install valve covers and related components, then start engine and check timing and idle speed. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Head Assembly > Rocker Arm Assembly > Component Information > Service and Repair > Rocker Arm Studs Replace Rocker Arm Assembly: Service and Repair Rocker Arm Studs Replace Fig. 12 Rocker Arm Stud Removal Fig. 13 Rocker Arm Stud Bore Reaming Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Head Assembly > Rocker Arm Assembly > Component Information > Service and Repair > Rocker Arm Studs Replace > Page 2097 Fig. 14 Rocker Arm Stud Installation Rocker arm studs that have damaged threads or are loose should be replaced with oversize studs. Oversize studs are available in 0.003 and 0.013 inch and can be installed after properly reaming the holes as follows: 1. Remove stud using stud reamer tool No. J-5802-01, or equivalent, Fig. 12, with a nut and flat washer placed over tool. 2. Ream hole to proper size using reamer tool No. J-5715, or equivalent, Fig. 13, for 0.003 inch oversize or reamer tool No. J-6036, or equivalent, for 0.013 inch oversize. Do not install oversize stud without reaming hole since cylinder head damage could occur. 3. Apply axle lubricant to press fit area of stud and install using stud installer tool No. J-6880, or equivalent, Fig. 14. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Head Assembly > Rocker Arm Assembly > Component Information > Service and Repair > Rocker Arm Studs Replace > Page 2098 Rocker Arm Assembly: Service and Repair Rocker Arms Replace 1. Disconnect battery ground cable. 2. Remove air cleaner assembly, then the emission relays and bracket. 3. Remove wiring harnesses and spark plug wires from clips and position aside. 4. Disconnect dipstick tube from cylinder head and position tube aside. 5. Remove rocker arm cover. 6. Remove rocker arm nut, then rocker arm and ball. 7. Remove pushrod. 8. Reverse procedure to install. Adjust valves if adjustable. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Head Assembly > Valve Spring > Component Information > Specifications Valve Spring: Specifications Engine Liter/CID .................................................................................................................................. ........................................................... 4.3L/V6-262 All specifications given in inches. Free Length ......................................................................................................................................... ........................................................................... [04] Out Of Square Limit .......................................... ......................................................................................................................................................... 0.062 Installed Height .......................................................................................................................... ....................................................................... 1.687-1.750 Pressure, Lbs. @ Inches Closed Intake ................................................................................................................................................... ........................................... 76.0-84.0 @ 1.700 Exhaust ..................................................................... ...................................................................................................................... 76.0-84.0 @ 1.700 Open Intake ................................................................................................................................................... ............................................... 194-206 @ 1.25 Exhaust ..................................................................... .......................................................................................................................... 194-206 @ 1.25 [04] Outer spring, 2.030 inches; damper spring, 1.860 inches. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Head Assembly > Valve, Intake/Exhaust > Component Information > Specifications > Valve Specifications Valve: Specifications Valve Specifications Engine Liter/CID .................................................................................................................................. ........................................................... 4.3L/V6-262 All specifications given in inches. Stem Diameter Std. Intake ................................................................................................................................................... ...................................................... 0.3410-0.3417 Exhaust ................................................................ ...................................................................................................................................... 0.3410-0.3417 Maximum Tip Refinish ......................................................................................................................... ........................................................................ [03] Face Angle .......................................................... ....................................................................................................................................................... 45 deg. Margin [01] Intake ................................................................................................................................................... .................................................................. 0.0315 Exhaust ................................................................. .................................................................................................................................................. 0.0315 Valve Lash ........................................................................................................................................... ........................................................................... [07] [01] Minimum. [03] Grind only enough to provide true surface. After grinding valve stems, ensure sufficient clearance remains between rocker arm & valve spring cap or rotator. [07] Torque rocker arm nut to 20 ft. lbs. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Cylinder Head Assembly > Valve, Intake/Exhaust > Component Information > Specifications > Valve Specifications > Page 2106 Valve: Specifications Valve Arrangement FRONT TO REAR 4.3L/V6-262 Left Side........................................................................................................................... .................................................................................. E-I-E-I-I-E Right Side......................................... .............................................................................................................................................................. .... E-I-I-E-I-E Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Drive Belts, Mounts, Brackets and Accessories > Drive Belt > Component Information > Technical Service Bulletins > Engine - Drive Belt Misalignment Diagnostics Drive Belt: Technical Service Bulletins Engine - Drive Belt Misalignment Diagnostics INFORMATION Bulletin No.: 08-06-01-008A Date: July 27, 2009 Subject: Diagnosing Accessory Drive Belt / Serpentine Belt Noise and Availability and Use of Kent-Moore EN-49228 Laser Alignment Tool - Drive Belt Models: 2010 and Prior GM Passenger Cars and Trucks (Including Saturn) 2010 and Prior HUMMER H2, H3 Vehicles 2009 and Prior Saab 9-7X Supercede: This bulletin is being revised to add a model year and update the Tool Information. Please discard Corporate Bulletin Number 08-06-01-008 (Section 06 - Engine). Background Several aftermarket companies offer laser alignment tools for accessory drive systems that can be very helpful in eliminating drive belt noise as a result of misaligned pulleys. Typically pricing ranges from $160 - $200. EN-49228 Laser Alignment Tool - Drive Belt The GM Tool program has now made available a competitive, simple to use and time-saving laser tool to assist in achieving precise alignment of the drive belt pulleys. This optional tool removes the guesswork from proper pulley alignment and may serve to reduce comebacks from: - Drive Belt Noise - Accelerated Drive Belt Wear - Drive Belt Slippage Instructions The instructions below are specific only to the truck Gen IV V-8 family of engines. These instructions are only for illustrative purposes to show how the tool may be used. Universal instructions are included in the box with the Laser Alignment Tool - Drive Belt. Caution - Do not look directly into the beam projected from the laser. - Use caution when shining the laser on highly polished or reflective surfaces. Laser safety glasses help reduce laser beam glare in many circumstances. - Always use laser safety glasses when using the laser. Laser safety glasses are not designed to protect eyes from direct laser exposure. 1. Observe and mark the serpentine belt orientation. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Drive Belts, Mounts, Brackets and Accessories > Drive Belt > Component Information > Technical Service Bulletins > Engine - Drive Belt Misalignment Diagnostics > Page 2112 2. Remove the serpentine belt from the accessory drive system. 3. Install the tool onto the power steering pulley. Position the legs of the tool into the outer grooves of the pulley, farthest from the front of the engine. 4. Install the retaining cord around the pulley and to the legs of the tool. 5. Put on the laser safety glasses provided with the tool. 6. Depress the switch on the rear of the tool to activate the light beam. 7. Rotate the power steering pulley as required to project the light beam onto the crankshaft balancer pulley grooves. 8. Inspect for proper power steering pulley alignment. - If the laser beam projects onto the second rib or raised area (1), the pulleys are aligned properly. - If the laser beam projects more than one-quarter rib 0.9 mm (0.035 in) mis-alignment, adjust the position of the power steering pulley as required. - Refer to SI for Power Steering Pulley Removal and Installation procedures. 9. Install the serpentine belt to the accessory drive system in the original orientation. 10. Operate the vehicle and verify that the belt noise concern is no longer present. Tool Information Please visit the GM service tool website for pricing information or to place your order for this tool. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Drive Belts, Mounts, Brackets and Accessories > Drive Belt > Component Information > Technical Service Bulletins > Engine - Drive Belt Misalignment Diagnostics > Page 2113 Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Drive Belts, Mounts, Brackets and Accessories > Drive Belt > Component Information > Technical Service Bulletins > Engine - Drive Belt Misalignment Diagnostics > Page 2114 Drive Belt: Technical Service Bulletins Engine - Serpentine Drive Belt Wear Information Bulletin No.: 04-06-01-013 Date: April 29, 2004 INFORMATION Subject: Information on Serpentine Belt Wear Models: 2004 and Prior Passenger Cars and Trucks 2003-2004 and Prior HUMMER H2 All current GM vehicles designed and manufactured in North America were assembled with serpentine belts that are made with an EPDM material and should last the life of the vehicle. It is extremely rare to observe any cracks in EPDM belts and it is not expected that they will require maintenance before 10 years or 240,000 km (150,000 mi) of use. Older style belts, which were manufactured with a chloroprene compound, may exhibit cracks depending on age. However, the onset of cracking typically signals that the belt is only about halfway through its usable life. A good rule of thumb for chloroprene-based belts is that if cracks are observed 3 mm (1/8 in) apart, ALL AROUND THE BELT, the belt may be reaching the end of its serviceable life and should be considered a candidate for changing. Small cracks spaced at greater intervals should not be considered as indicative that the belt needs changing. Any belt that exhibits chunking should be replaced. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Drive Belts, Mounts, Brackets and Accessories > Drive Belt > Component Information > Technical Service Bulletins > Page 2115 Drive Belt: Service and Repair Serpentine Drive Belt Routing Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Drive Belts, Mounts, Brackets and Accessories > Drive Belt > Component Information > Technical Service Bulletins > Page 2116 Serpentine Belt Routing REMOVE OR DISCONNECT 1. Use a 1/2 inch breaker bar with a socket placed on the tensioner pulley axis bolt and rotate the tensioner to the left (counterclockwise). CAUTION: Do NOT allow the drive belt tensioner to snap into the "free" position as this may damage the tensioner. 2. Remove belt. INSTALL OR CONNECT 1. Route belt over pulleys except the belt tensioner. 2. Use a 1/2 inch breaker bar with a socket placed on the tensioner pulley axis bolt and rotate the tensioner to the left (counterclockwise). 3. Belt over the tensioner pulley. 4. Check the belt for correct "V" groove tracking around each pulley. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Drive Belts, Mounts, Brackets and Accessories > Engine Mount > Component Information > Service and Repair Engine Mount: Service and Repair Fig. 1 Front Engine Mount Installation Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Drive Belts, Mounts, Brackets and Accessories > Engine Mount > Component Information > Service and Repair > Page 2120 Fig. 2 Rear Engine Mount Installtion FRONT 1. Support engine using lifting equipment. 2. Remove engine mount through bolt and nut. 3. Raise engine and remove mount to engine attaching bolts, Fig. 1. 4. Remove engine mount. 5. Reverse procedure to install Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Drive Belts, Mounts, Brackets and Accessories > Engine Mount > Component Information > Service and Repair > Page 2121 REAR 1. Raise and support vehicle. 2. Support rear of engine using equipment. 3. Remove mount to crossmember attaching nuts and washers. 4. Remove mount to transmission attaching bolts, then the mount. 5. Reverse procedure to install. Tighten bolts to specifications shown in Fig. 2. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Engine Oil Pressure > Component Information > Specifications Engine Oil Pressure: Specifications Normal Oil Pressure, Psi ..................................................................................................................... ................................................. 25-50 @ 1200 RPM. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Engine Oil > Component Information > Technical Service Bulletins > Engine - GM dexos 1 and dexos 2(R) Oil Specifications Engine Oil: Technical Service Bulletins Engine - GM dexos 1 and dexos 2(R) Oil Specifications INFORMATION Bulletin No.: 11-00-90-001 Date: March 14, 2011 Subject: Global Information for GM dexos1(TM) and GM dexos2(TM) Engine Oil Specifications for Spark Ignited and Diesel Engines, Available Licensed Brands, and Service Fill for Adding or Complete Oil Change Models: 2012 and Prior GM Passenger Cars and Trucks Excluding All Vehicles Equipped with Duramax(TM) Diesel Engines GM dexos 1(TM) Information Center Website Refer to the following General Motors website for dexos 1(TM) information about the different licensed brands that are currently available: http://www.gmdexos.com GM dexos 1(TM) Engine Oil Trademark and Icons The dexos(TM) specification and trademarks are exclusive to General Motors, LLC. Only those oils displaying the dexos‹›(TM) trademark and icon on the front label meet the demanding performance requirements and stringent quality standards set forth in the dexos‹›(TM) specification. Look on the front label for any of the logos shown above to identify an authorized, licensed dexos 1(TM) engine oil. GM dexos 1(TM) Engine Oil Specification Important General Motors dexos 1(TM) engine oil specification replaces the previous General Motors specifications GM6094M, GM4718M and GM-LL-A-025 for most GM gasoline engines. The oil specified for use in GM passenger cars and trucks, PRIOR to the 2011 model year remains acceptable for those previous vehicles. However, dexos 1(TM) is backward compatible and can be used in those older vehicles. In North America, starting with the 2011 model year, GM introduced dexos 1(TM) certified engine oil as a factory fill and service fill for gasoline engines. The reasons for the new engine oil specification are as follows: - To meet environmental goals such as increasing fuel efficiency and reducing engine emissions. - To promote long engine life. - To minimize the number of engine oil changes in order to help meet the goal of lessening the industry's overall dependence on crude oil. dexos 1(TM) is a GM-developed engine oil specification that has been designed to provide the following benefits: - Further improve fuel economy, to meet future corporate average fuel economy (CAFE) requirements and fuel economy retention by allowing the oil to maintain its fuel economy benefits throughout the life of the oil. - More robust formulations for added engine protection and aeration performance. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Engine Oil > Component Information > Technical Service Bulletins > Engine - GM dexos 1 and dexos 2(R) Oil Specifications > Page 2130 - Support the GM Oil Life System, thereby minimizing the replacement of engine oil, before its life has been depleted. - Reduce the duplication of requirements for a large number of internal GM engine oil specifications. International Lubricants Standardization and Approval Committee (ILSAC) GF-5 Standard In addition to GM dexos 1(TM), a new International Lubricants Standardization and Approval Committee (ILSAC) standard called GF-5, was introduced in October 2010. - There will be a corresponding API category, called: SN Resource Conserving. The current GF-4 standard was put in place in 2004 and will become obsolete in October 2011. Similar to dexos 1(TM), the GF-5 standard will use a new fuel economy test, Sequence VID, which demands a statistically significant increase in fuel economy versus the Sequence VIB test that was used for GF-4. - It is expected that all dexos 1(TM) approved oils will be capable of meeting the GF-5 standard. However, not all GF-5 engine oils will be capable of meeting the dexos 1(TM) specification. - Like dexos(TM), the new ILSAC GF-5 standard will call for more sophisticated additives. The API will begin licensing marketers during October 2010, to produce and distribute GF-5 certified products, which are expected to include SAE 0W-20, 0W-30, 5W-20, 5W-30 and 10W-30 oils. Corporate Average Fuel Economy (CAFE) Requirements Effect on Fuel Economy Since CAFE standards were first introduced in 1974, the fuel economy of cars has more than doubled, while the fuel economy of light trucks has increased by more than 50 percent. Proposed CAFE standards call for a continuation of increased fuel economy in new cars and trucks. To meet these future requirements, all aspects of vehicle operation are being looked at more critically than ever before. New technology being introduced in GM vehicles designed to increase vehicle efficiency and fuel economy include direct injection, cam phasing, turbocharging and active fuel management (AFM). The demands of these new technologies on engine oil also are taken into consideration when determining new oil specifications. AFM for example can help to achieve improved fuel economy. However alternately deactivating and activating the cylinders by not allowing the intake and exhaust valves to open contributes to additional stress on the engine oil. Another industry trend for meeting tough fuel economy mandates has been a shift toward lower viscosity oils. dexos 1(TM) will eventually be offered in several viscosity grades in accordance with engine needs: SAE 0W-20, 5W-20, 0W-30 and 5W-30. Using the right viscosity grade oil is critical for proper engine performance. Always refer to the Maintenance section of a vehicle Owner Manual for the proper viscosity grade for the engine being serviced. GM Oil Life System in Conjunction With dexos (TM) Supports Extended Oil Change Intervals To help conserve oil while maintaining engine protection, many GM vehicles are equipped with the GM Oil Life System. This system can provide oil change intervals that exceed the traditional 3,000 mile (4,830 km) recommendation. The dexos (TM) specification, with its requirements for improved oil robustness, compliments the GM Oil Life System by supporting extended oil change intervals over the lifetime of a vehicle. If all GM customers with GM Oil Life System equipped vehicles would use the system as intended, GM estimates that more than 100 million gallons of oil could be saved annually. GM dexos 2(TM) Information Center Website Refer to the following General Motors website for dexos 2(TM) information about the different licensed brands that are currently available: http://www.gmdexos.com GM dexos 2(TM) Engine Oil Trademark and Icons Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Engine Oil > Component Information > Technical Service Bulletins > Engine - GM dexos 1 and dexos 2(R) Oil Specifications > Page 2131 The dexos (TM) specification and trademarks are exclusive to General Motors, LLC. Only those oils displaying the dexos (TM) trademark and icon on the front label meet the demanding performance requirements and stringent quality standards set forth in the dexos (TM)specification. Look on the front label for any of the logos shown above to identify an authorized, licensed dexos 2(TM) engine oil. GM dexos 2(TM) Engine Oil Specification - dexos 2(TM) is approved and recommended by GM for use in Europe starting in model year 2010 vehicles, regardless of where the vehicle was manufactured. - dexos 2(TM) is the recommended service fill oil for European gasoline engines. Important The Duramax(TM) diesel engine is the exception and requires lubricants meeting specification CJ-4. - dexos 2(TM) is the recommended service fill oil for European light-duty diesel engines and replaces GM-LL-B-025 and GM-LL-A-025. - dexos 2(TM) protects diesel engines from harmful soot deposits and is designed with limits on certain chemical components to prolong catalyst life and protect expensive emission reduction systems. It is a robust oil, resisting degradation between oil changes and maintaining optimum performance longer. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Engine Oil > Component Information > Specifications > Capacity Specifications Engine Oil: Capacity Specifications TYPE.................................................................................................................................................... .......................................................................SG, SH Note: 1992-93 Syclone, and Typhoon engine oil must be Mobile 1 synthetic or equivalent CAPACITY, Refill: 4-cyl. 2.5L............................................................................................................... ..............................................................................2.8 Liters 3.0 Quarts Others................................... .............................................................................................................................................................. ...3.8 Liters 4.0 Quarts Capacity shown is without filter. When replacing filter, additional oil may be needed 1987-88 4.3L: Above 40°F (4°C).......................................................................................................... .....................................................................................................30‡ Above 0°F to (-18°C)................ .............................................................................................................................................................. ...................10W-30* Below 60°F (16°C).............................................................................................. ..........................................................................................................5W-30 1987-88 others, 1988-94 except Syclone & Typhoon: Above 40°F (4°C)............................................ .............................................................................................................................................................. .....30‡ Above 0°F to (-18°C)................................................................................................................ ...................................................................................10W-30 All temperatures................................... .............................................................................................................................................................. ..........5W-30* 1992-93 Syclone, Typhoon: All temperatures...................................................................................... .....................................................................................................................10W-30 *Preferred, except V6 4.3L ‡May be used when other recommended viscosities are unavailable Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Filter, Engine > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM Oil Filter: Customer Interest Engine - Cold Knock, Replace Oil Filter/Bearings/PROM File In Section: 6 - Engine Bulletin No.: 37-61-05A Date: October, 1995 Subject: Cold Engine Knock (Replace Oil Filter/Bearings/PROM) Models: 1990-95 Chevrolet and GMC Truck C/K, R/V, S/T, M/L, G, P Models 1991-92 Oldsmobile Bravada with 4.3L (VIN Z - RPO LB4), 5.7L (VIN K - RPO L05), 7.4 (VIN N - RPO L19) Engine This bulletin is being revised to add the 1995 model year information. Please discard Corporate Bulletin Number 37-61-05 (Section 6 - Engine). Condition Some late model truck engines have been reported to exhibit "cold knock" on start up. "Cold Knock" usually occurs after the vehicle has been completely warmed up, then parked for 8 or more hours in ambient temperatures of 35° F or less. "Cold knock" can be separated into three distinct categories. 1. Short Duration - Harsh, deep metallic knock that usually lasts from 1 to 10 seconds. Generally classified as a bearing or rod knock. 2. Valve Train - Light clatter, tick or click that may last up to 1 minute. 3. Piston Slap - Metallic knock that occurs only under load. Piston slap may last as long as 5 minutes. Correction Category A: Short Duration Knock This matrix describes the repair for each affected model year and engine. Specific information for each affected model year and engine is supplied. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Filter, Engine > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 2142 1992 LB4 VIN Z with "cold knock" only 1992-93 LB4 VIN Z with "cold knock" and installed field fix PROM OR with "cold knock" and detonation 1990-95 LB4 VIN Z Install check valve oil filter P/N 12555891 (FRAM PH3980). If the filter does not cure the condition, install the appropriate calibration from the tables (calibrations are available for all 1992 and some 1993 LB4 applications). If a calibration is not offered or does not cure the short duration cold knock Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Filter, Engine > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 2143 condition, install the appropriate main bearings as determined by the following procedure. Calibration Information - 1992-93 LB4 VIN Z The revised PROMs reduce spark advance after the engine is started. The reduction in spark lowers the cylinder pressure and eliminates the knock. The revised PROMs will NOT eliminate a piston slap (Category C) or valve train noise (Category B) concern. The base cold knock PROM contains the previously released calibration updates. For 1992 LB4, the previous field release is included for torque converter clutch (TCC) lock up (see Bulletin 137107 - Chevrolet 92-75-7A; GMC Truck 92-7A-40; Oldsmobile 92-T-34; Canada 9274L60100) for automatic transmissions, or neutral gear rattle for manual transmissions (see Bulletin 267201R - Chevrolet 92-187B-7B; GMC Truck 92-7B-149A; Canada 93-7B-105). If a vehicle has had a detonation fix PROM installed previously, select the combined detonation and cold knock fix PROM for the application. See Bulletin 376508 for more information on field fix PROM for the application and detonation. Important: Use of a detonation fix PROM in a non-detonating vehicle may result in degraded driveability. GMSPO currently stocks three (3) PROMs for each light duty 1992 model year LB4 application. Base Cold Knock Fix Combination Cold Knock and Detonation Fix GMSPO Service Parts Assistance Center (SPAC 1-800-433-6961) will have information available on each PROM part number. Select the PROM from the table. Old Broadcast Code (Old B/C Code) and Scan I.D. information has been supplied to help installed previously. Use a TECH-1 to determine the Scan I.D. of the PROM in the vehicle or remove the PROM and read the Broadcast Code (B/C Code). If the B/C Code/Scan I.D. can be found in the first table, a detonation fix has not been installed. PROMs are currently available GMSPO. 1990-95 L05 VIN K Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Filter, Engine > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 2144 1993 to 1995 L05 VIN K Install the appropriate check valve oil filter P/N 25160561 (PF1218 for two-wheel C-series and P/N 12555891 (FRAM PH3980) for four-wheel drive K-series). If the oil filter does not cure the condition, install the appropriate calibration from the table (calibrations are available for some 1993 and 1994 L05 applications). All calibrations are for light duty vehicles equipped with 4L60-E (M30) transmissions (no heavy duty emission/4L80-E calibrations are available). If a calibration is not offered or does not cure the short duration cold knock condition, install the appropriate main bearings as determined by the procedure. 1990-94 L19 VIN N Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Filter, Engine > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 2145 Install a check valve oil filter; no other recommended actions at this time. Important: The previous actions are only applicable to short duration cold knock. These actions will not eliminate a knock occurring under load or a knock lasting for more than 10 seconds. Two main bearing procedures are recommended: 1. For main bearing replacement with the engine IN the vehicle: C, G, P, M and L vehicles 2. For main bearing replacement with the engine OUT OF the vehicle: K, S and T THE FOLLOWING PROCEDURE IS TO BE USED FOR VEHICLES REQUIRING MAIN BEARING REPLACEMENT WITH THE ENGINE IN THE VEHICLE Recommended for C, G, P, M and L vehicles. Important: A OEM training video has been produced for in-vehicle main bearing replacement procedure. One copy of the video will be sent to each dealer. If the video has not been received, contact XPRESS 1 Distribution Center at 1-800-783-3034. Main Bearing Clearance Determination and Installation Procedure 1. REMOVE THE SERPENTINE BELT, dipstick, dipstick tube and disconnect the negative battery cable. 2. Raise the vehicle and remove (or set aside) any parts restricting access to the oil pan bolts (i.e., starter motor, oil cooler lines, oil filter adapter, flywheel inspection cover). 3. Remove the oil pan, oil pump, and shield. 4. Remove # 5 (flange) bearing cap. Wipe the oil from the crankshaft journal and the lower main bearing insert. 5. Place a screw jack under an accessible part of the crankshaft, carefully apply pressure to the crankshaft to force it solidly against the top bearing insert. The reason for this is to remove any clearance between the top bearing insert and the crankshaft. If this step is not performed, a smaller than actual clearance will be measured. Important: This should be done as close as possible to the bearing being measured. This step is only required for on-vehicle service where the engine cannot be turned upside down as on an engine stand. 6. Place a piece of plastigage across the width of the lower bearing insert (parallel to the centerline of the crankshaft). 7. Reinstall # 5 main bearing cap. Torque to 110 N.m (80 lb ft). Do not allow crankshaft to turn. 8. Carefully remove the # 5 main bearing cap and bearing insert. The flattened plastigage will adhere to either the bearing insert or the crank journal. Do not remove the plastigage from the insert or journal. 9. On the edge of the plastigage envelope, there is a graduated scale. Without removing the flattened plastigage, measure its width at the widest point using the graduated scale on the plastigage envelope. 10. The desired main bearing clearance is 0.0008" - 0.0028". If the clearance measured with the plastigage is greater than 0.0028", write down the clearance. Next, read the back of the bearing insert to determine what size bearing was originally installed (usual STD, 0.0006", 0.0010" or 0.0012"). The size stamped on the bearing is the effective undersize when both inserts are installed. For example, a 0.0006" undersize bearing set consists of two (2) 0.0003" thicker bearing inserts, both stamped 0.0006". 11. Remove the top bearing insert using tool J 8080 and read the back to determine what size upper bearing insert was originally installed. The top insert may be different size than the bottom. 12. Calculate the original bearing undersize by dividing the size on each insert by 2, then add the values together. EXAMPLE 1: The lower insert is stamped 0.0006" and the upper is stamped 0.0010". Divide 0.0006" by two to get 0.0003". Divide 0.0010" by 2 to get 0.0005". Add 0.0003" and 0.0005" together to calculate the bearing undersize, which is 0.0008" in this case. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Filter, Engine > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 2146 EXAMPLE 2: The lower insert is stamped STD (standard) and the upper is stamped 0.0010". The undersize for a STD bearing is 0. Divide 0 by 2 to get 0. Divide 0.0010" by 2 to get 0.0005". Add 0 and 0.0005" together to calculate the bearing undersize, which is 0.0005" in this case. 13. Add the original bearing undersize calculated in step 12 to the clearance measured and written down in step 9. For example, if a clearance of 0.0030" was measured with plastigage in step 9 and the calculated bearing undersize from step 12 was 0.0005", the bearing clearance for that particular main journal is equal to 0.0030" plus 0.0005". The bearing clearance would be 0.0035" in this case. 14. Determine which of the combinations of two sizes of replacement bearings will produce the desired clearance. The two sizes available are 0.001" and 0.002". One insert of each size may be combined to produce an intermediate undersize of 0.0015". Subtract the replacement bearing size from the actual clearance to determine which bearing should be used. The bearing that should be used is the one which gives a clearance closer to 0.0008" than to 0.0028". The clearance must not be less than 0.0008". Using the example from step 11, the actual clearance is 0.0035". Subtracting 0.001" from 0.0035" will give a clearance of 0.0025", just barely within the required range. Subtracting 0.002" from 0.0035" will give a clearance of 0.0015". The 0.002" undersize bearing set would be the one to use in this case since it gives a clearance closer to 0.0008", but not less. 15. Install the replacement upper main bearing insert using tool J 8080. 16. Install the replacement lower main bearing insert in the main bearing cap. Lay a piece of plastigage across the width of the lower main bearing insert (same as step 5). 17. Repeat steps 7, 8 and 9. 18. Measuring the plastigage with the scale on the envelope, verify the clearance of the replacement bearings is within the range of 0.001" to 0.003". 19. Repeat steps 4 through 16 for each main bearing. 20. Thrust the crankshaft forward and backward several times to seat the thrust bearing. 21. Reinstall oil pump; torque to 88 N.m (65 lb ft). 22. Reinstall the oil pan and other hardware. 23. Before starting the engine, remove the fuel pump fuse and crank the engine until oil pressure registers on the gauge. Stop cranking, let the starter cool down, then crank for another 15 seconds. 24. Install fuel pump fuse, start engine, check for leaks or unusual noises. 25. Road test vehicle, check for leaks or unusual noises. THE FOLLOWING PROCEDURE IS TO BE USED FOR VEHICLES REQUIRING MAIN BEARING REPLACEMENT WITH THE ENGINE OUT OF THE VEHICLE Recommended for K, S and T vehicles. 1. Remove the engine from the vehicle using the appropriate service manual procedure. 2. Mount the engine on an engine stand, flip the engine so the oil pan is facing up. 3. Remove the oil pan. 4. Remove the oil pump and shield. 5. Remove the dipstick tube. 6. Remove one (1) main bearing cap (must do one at a time). 7. Plasti-gage bearing. 8. If the bearing clearance is out of specification (clearance greater than 0.003 inches), remove upper main bearing from the block. 9. Check the size of the original bearing. 10. Determine what combination of new bearings are required to get the clearance in the acceptable range of 0.0008 inches to 0.0028 inches. See steps Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Filter, Engine > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 2147 12 through 14 in the "in-vehicle" service outlined above. 11. Reinstall the upper main bearing. 12. Reinstall the main cap and lower bearing; torque to 110 N.m (80 lb ft). 13. Repeat for each main bearing. 14. Reinstall oil pump and shield; torque to 88 N.m (65 lb ft). 15. Reinstall dipstick tube. 16. Reinstall oil pan. 17. Reinstall engine in vehicle. 18. Before starting the engine, remove the fuel pump fuse and crank the engine until oil pressure registers on the gauge. Stop cranking, let the starter cool down, then crank for another 15 seconds. 19. Install fuel pump fuse, start engine, check for leaks or unusual noises. 20. Road test vehicle, check for leaks or unusual noises. Correction Category B: Valve Train Clatter, Tick or Click For 1992-94 vehicles equipped with a 4.3L V6 (LB4 VIN Z or L35 VIN W) engine see Corporate Bulletin 376006 for information on converting from net lash to adjustable lash and/or re-lashing the valves on an adjustable lash system. Investigation of "cold knock" is continuing. Updates will continue to be provided when available. Parts Information Check-Valve Filters Description Part Number V6, V8 (Four-Wheel Drive) FRAM PH3980 12555891 V8 (Two-Wheel Drive), Mark V8 PF1218 25160561 The FRAM PH3980 is to be used in place of the PF52. The PH3980 provides superior anti-drainback performance, a key factor in reducing cold knock. FRAM filters are to be procured locally until 08-15-95. After this date the filters may be ordered from GMSPO using the supplied part number. Orders placed to GMSPO prior to this date will not be placed on backorder. Bearings Description Part Number 0.001" Main Bearing Kit, Positions 1-4 on V8, 1-3 on V6 10120992 0.001" Main Bearing Kit, Flange # 5 on V8, # 4 on V6 10120994 0.002" Main Bearing Kit, Positions 1-4 on V8, 1-3 on V6 12329758 0.002" Main Bearing Kit, Flange # 5 on V8, # 4 on V6 12329792 Main bearing kits are currently available from GMSPO. All calibrations are currently available from GMSPO. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Filter, Engine > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 2148 Warranty Information Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oil Filter: > 07-06-01-016B > Jul > 09 > Engine - Noise/Damage Oil Filter Application Importance Oil Filter: All Technical Service Bulletins Engine - Noise/Damage Oil Filter Application Importance INFORMATION Bulletin No.: 07-06-01-016B Date: July 27, 2009 Subject: Information on Internal Engine Noise or Damage After Oil Filter Replacement Models: 2010 and Prior Passenger Cars and Trucks (Including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X Supercede: This bulletin is being updated to add model years. Please discard Corporate Bulletin Number 07-06-01-016A (Section 06 - Engine/Propulsion System). Important Engine damage that is the result of an incorrect or improperly installed engine oil filter is not a warrantable claim. The best way to avoid oil filter quality concerns is to purchase ACDelco(R) oil filters directly from GMSPO. Oil filter misapplication may cause abnormal engine noise or internal damage. Always utilize the most recent parts information to ensure the correct part number filter is installed when replacing oil filters. Do not rely on physical dimensions alone. Counterfeit copies of name brand parts have been discovered in some aftermarket parts systems. Always ensure the parts you install are from a trusted source. Improper oil filter installation may result in catastrophic engine damage. Refer to the appropriate Service Information (SI) installation instructions when replacing any oil filter and pay particular attention to procedures for proper cartridge filter element alignment. If the diagnostics in SI (Engine Mechanical) lead to the oil filter as the cause of the internal engine noise or damage, dealers should submit a field product report. Refer to Corporate Bulletin Number 02-00-89-002I (Information for Dealers on How to Submit a Field Product Report). Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oil Filter: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM Oil Filter: All Technical Service Bulletins Engine - Cold Knock, Replace Oil Filter/Bearings/PROM File In Section: 6 - Engine Bulletin No.: 37-61-05A Date: October, 1995 Subject: Cold Engine Knock (Replace Oil Filter/Bearings/PROM) Models: 1990-95 Chevrolet and GMC Truck C/K, R/V, S/T, M/L, G, P Models 1991-92 Oldsmobile Bravada with 4.3L (VIN Z - RPO LB4), 5.7L (VIN K - RPO L05), 7.4 (VIN N - RPO L19) Engine This bulletin is being revised to add the 1995 model year information. Please discard Corporate Bulletin Number 37-61-05 (Section 6 - Engine). Condition Some late model truck engines have been reported to exhibit "cold knock" on start up. "Cold Knock" usually occurs after the vehicle has been completely warmed up, then parked for 8 or more hours in ambient temperatures of 35° F or less. "Cold knock" can be separated into three distinct categories. 1. Short Duration - Harsh, deep metallic knock that usually lasts from 1 to 10 seconds. Generally classified as a bearing or rod knock. 2. Valve Train - Light clatter, tick or click that may last up to 1 minute. 3. Piston Slap - Metallic knock that occurs only under load. Piston slap may last as long as 5 minutes. Correction Category A: Short Duration Knock This matrix describes the repair for each affected model year and engine. Specific information for each affected model year and engine is supplied. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oil Filter: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 2158 1992 LB4 VIN Z with "cold knock" only 1992-93 LB4 VIN Z with "cold knock" and installed field fix PROM OR with "cold knock" and detonation 1990-95 LB4 VIN Z Install check valve oil filter P/N 12555891 (FRAM PH3980). If the filter does not cure the condition, install the appropriate calibration from the tables (calibrations are available for all 1992 and some 1993 LB4 applications). If a calibration is not offered or does not cure the short duration cold knock Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oil Filter: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 2159 condition, install the appropriate main bearings as determined by the following procedure. Calibration Information - 1992-93 LB4 VIN Z The revised PROMs reduce spark advance after the engine is started. The reduction in spark lowers the cylinder pressure and eliminates the knock. The revised PROMs will NOT eliminate a piston slap (Category C) or valve train noise (Category B) concern. The base cold knock PROM contains the previously released calibration updates. For 1992 LB4, the previous field release is included for torque converter clutch (TCC) lock up (see Bulletin 137107 - Chevrolet 92-75-7A; GMC Truck 92-7A-40; Oldsmobile 92-T-34; Canada 9274L60100) for automatic transmissions, or neutral gear rattle for manual transmissions (see Bulletin 267201R - Chevrolet 92-187B-7B; GMC Truck 92-7B-149A; Canada 93-7B-105). If a vehicle has had a detonation fix PROM installed previously, select the combined detonation and cold knock fix PROM for the application. See Bulletin 376508 for more information on field fix PROM for the application and detonation. Important: Use of a detonation fix PROM in a non-detonating vehicle may result in degraded driveability. GMSPO currently stocks three (3) PROMs for each light duty 1992 model year LB4 application. Base Cold Knock Fix Combination Cold Knock and Detonation Fix GMSPO Service Parts Assistance Center (SPAC 1-800-433-6961) will have information available on each PROM part number. Select the PROM from the table. Old Broadcast Code (Old B/C Code) and Scan I.D. information has been supplied to help installed previously. Use a TECH-1 to determine the Scan I.D. of the PROM in the vehicle or remove the PROM and read the Broadcast Code (B/C Code). If the B/C Code/Scan I.D. can be found in the first table, a detonation fix has not been installed. PROMs are currently available GMSPO. 1990-95 L05 VIN K Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oil Filter: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 2160 1993 to 1995 L05 VIN K Install the appropriate check valve oil filter P/N 25160561 (PF1218 for two-wheel C-series and P/N 12555891 (FRAM PH3980) for four-wheel drive K-series). If the oil filter does not cure the condition, install the appropriate calibration from the table (calibrations are available for some 1993 and 1994 L05 applications). All calibrations are for light duty vehicles equipped with 4L60-E (M30) transmissions (no heavy duty emission/4L80-E calibrations are available). If a calibration is not offered or does not cure the short duration cold knock condition, install the appropriate main bearings as determined by the procedure. 1990-94 L19 VIN N Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oil Filter: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 2161 Install a check valve oil filter; no other recommended actions at this time. Important: The previous actions are only applicable to short duration cold knock. These actions will not eliminate a knock occurring under load or a knock lasting for more than 10 seconds. Two main bearing procedures are recommended: 1. For main bearing replacement with the engine IN the vehicle: C, G, P, M and L vehicles 2. For main bearing replacement with the engine OUT OF the vehicle: K, S and T THE FOLLOWING PROCEDURE IS TO BE USED FOR VEHICLES REQUIRING MAIN BEARING REPLACEMENT WITH THE ENGINE IN THE VEHICLE Recommended for C, G, P, M and L vehicles. Important: A OEM training video has been produced for in-vehicle main bearing replacement procedure. One copy of the video will be sent to each dealer. If the video has not been received, contact XPRESS 1 Distribution Center at 1-800-783-3034. Main Bearing Clearance Determination and Installation Procedure 1. REMOVE THE SERPENTINE BELT, dipstick, dipstick tube and disconnect the negative battery cable. 2. Raise the vehicle and remove (or set aside) any parts restricting access to the oil pan bolts (i.e., starter motor, oil cooler lines, oil filter adapter, flywheel inspection cover). 3. Remove the oil pan, oil pump, and shield. 4. Remove # 5 (flange) bearing cap. Wipe the oil from the crankshaft journal and the lower main bearing insert. 5. Place a screw jack under an accessible part of the crankshaft, carefully apply pressure to the crankshaft to force it solidly against the top bearing insert. The reason for this is to remove any clearance between the top bearing insert and the crankshaft. If this step is not performed, a smaller than actual clearance will be measured. Important: This should be done as close as possible to the bearing being measured. This step is only required for on-vehicle service where the engine cannot be turned upside down as on an engine stand. 6. Place a piece of plastigage across the width of the lower bearing insert (parallel to the centerline of the crankshaft). 7. Reinstall # 5 main bearing cap. Torque to 110 N.m (80 lb ft). Do not allow crankshaft to turn. 8. Carefully remove the # 5 main bearing cap and bearing insert. The flattened plastigage will adhere to either the bearing insert or the crank journal. Do not remove the plastigage from the insert or journal. 9. On the edge of the plastigage envelope, there is a graduated scale. Without removing the flattened plastigage, measure its width at the widest point using the graduated scale on the plastigage envelope. 10. The desired main bearing clearance is 0.0008" - 0.0028". If the clearance measured with the plastigage is greater than 0.0028", write down the clearance. Next, read the back of the bearing insert to determine what size bearing was originally installed (usual STD, 0.0006", 0.0010" or 0.0012"). The size stamped on the bearing is the effective undersize when both inserts are installed. For example, a 0.0006" undersize bearing set consists of two (2) 0.0003" thicker bearing inserts, both stamped 0.0006". 11. Remove the top bearing insert using tool J 8080 and read the back to determine what size upper bearing insert was originally installed. The top insert may be different size than the bottom. 12. Calculate the original bearing undersize by dividing the size on each insert by 2, then add the values together. EXAMPLE 1: The lower insert is stamped 0.0006" and the upper is stamped 0.0010". Divide 0.0006" by two to get 0.0003". Divide 0.0010" by 2 to get 0.0005". Add 0.0003" and 0.0005" together to calculate the bearing undersize, which is 0.0008" in this case. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oil Filter: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 2162 EXAMPLE 2: The lower insert is stamped STD (standard) and the upper is stamped 0.0010". The undersize for a STD bearing is 0. Divide 0 by 2 to get 0. Divide 0.0010" by 2 to get 0.0005". Add 0 and 0.0005" together to calculate the bearing undersize, which is 0.0005" in this case. 13. Add the original bearing undersize calculated in step 12 to the clearance measured and written down in step 9. For example, if a clearance of 0.0030" was measured with plastigage in step 9 and the calculated bearing undersize from step 12 was 0.0005", the bearing clearance for that particular main journal is equal to 0.0030" plus 0.0005". The bearing clearance would be 0.0035" in this case. 14. Determine which of the combinations of two sizes of replacement bearings will produce the desired clearance. The two sizes available are 0.001" and 0.002". One insert of each size may be combined to produce an intermediate undersize of 0.0015". Subtract the replacement bearing size from the actual clearance to determine which bearing should be used. The bearing that should be used is the one which gives a clearance closer to 0.0008" than to 0.0028". The clearance must not be less than 0.0008". Using the example from step 11, the actual clearance is 0.0035". Subtracting 0.001" from 0.0035" will give a clearance of 0.0025", just barely within the required range. Subtracting 0.002" from 0.0035" will give a clearance of 0.0015". The 0.002" undersize bearing set would be the one to use in this case since it gives a clearance closer to 0.0008", but not less. 15. Install the replacement upper main bearing insert using tool J 8080. 16. Install the replacement lower main bearing insert in the main bearing cap. Lay a piece of plastigage across the width of the lower main bearing insert (same as step 5). 17. Repeat steps 7, 8 and 9. 18. Measuring the plastigage with the scale on the envelope, verify the clearance of the replacement bearings is within the range of 0.001" to 0.003". 19. Repeat steps 4 through 16 for each main bearing. 20. Thrust the crankshaft forward and backward several times to seat the thrust bearing. 21. Reinstall oil pump; torque to 88 N.m (65 lb ft). 22. Reinstall the oil pan and other hardware. 23. Before starting the engine, remove the fuel pump fuse and crank the engine until oil pressure registers on the gauge. Stop cranking, let the starter cool down, then crank for another 15 seconds. 24. Install fuel pump fuse, start engine, check for leaks or unusual noises. 25. Road test vehicle, check for leaks or unusual noises. THE FOLLOWING PROCEDURE IS TO BE USED FOR VEHICLES REQUIRING MAIN BEARING REPLACEMENT WITH THE ENGINE OUT OF THE VEHICLE Recommended for K, S and T vehicles. 1. Remove the engine from the vehicle using the appropriate service manual procedure. 2. Mount the engine on an engine stand, flip the engine so the oil pan is facing up. 3. Remove the oil pan. 4. Remove the oil pump and shield. 5. Remove the dipstick tube. 6. Remove one (1) main bearing cap (must do one at a time). 7. Plasti-gage bearing. 8. If the bearing clearance is out of specification (clearance greater than 0.003 inches), remove upper main bearing from the block. 9. Check the size of the original bearing. 10. Determine what combination of new bearings are required to get the clearance in the acceptable range of 0.0008 inches to 0.0028 inches. See steps Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oil Filter: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 2163 12 through 14 in the "in-vehicle" service outlined above. 11. Reinstall the upper main bearing. 12. Reinstall the main cap and lower bearing; torque to 110 N.m (80 lb ft). 13. Repeat for each main bearing. 14. Reinstall oil pump and shield; torque to 88 N.m (65 lb ft). 15. Reinstall dipstick tube. 16. Reinstall oil pan. 17. Reinstall engine in vehicle. 18. Before starting the engine, remove the fuel pump fuse and crank the engine until oil pressure registers on the gauge. Stop cranking, let the starter cool down, then crank for another 15 seconds. 19. Install fuel pump fuse, start engine, check for leaks or unusual noises. 20. Road test vehicle, check for leaks or unusual noises. Correction Category B: Valve Train Clatter, Tick or Click For 1992-94 vehicles equipped with a 4.3L V6 (LB4 VIN Z or L35 VIN W) engine see Corporate Bulletin 376006 for information on converting from net lash to adjustable lash and/or re-lashing the valves on an adjustable lash system. Investigation of "cold knock" is continuing. Updates will continue to be provided when available. Parts Information Check-Valve Filters Description Part Number V6, V8 (Four-Wheel Drive) FRAM PH3980 12555891 V8 (Two-Wheel Drive), Mark V8 PF1218 25160561 The FRAM PH3980 is to be used in place of the PF52. The PH3980 provides superior anti-drainback performance, a key factor in reducing cold knock. FRAM filters are to be procured locally until 08-15-95. After this date the filters may be ordered from GMSPO using the supplied part number. Orders placed to GMSPO prior to this date will not be placed on backorder. Bearings Description Part Number 0.001" Main Bearing Kit, Positions 1-4 on V8, 1-3 on V6 10120992 0.001" Main Bearing Kit, Flange # 5 on V8, # 4 on V6 10120994 0.002" Main Bearing Kit, Positions 1-4 on V8, 1-3 on V6 12329758 0.002" Main Bearing Kit, Flange # 5 on V8, # 4 on V6 12329792 Main bearing kits are currently available from GMSPO. All calibrations are currently available from GMSPO. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oil Filter: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 2164 Warranty Information Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oil Filter: > 476118 > Jun > 94 > Oil Filters - Enhanced Anti-Drainback Valves Oil Filter: All Technical Service Bulletins Oil Filters - Enhanced Anti-Drainback Valves GROUP REF.: 6 - Engine BULLETIN NO.: 476118 DATE: June, 1994 SUBJECT: ENHANCED PF52 AND PF1218 OIL FILTERS MODELS: 1986-94 CHEVROLET AND GMC C/K, S/T, M/L, R/V, AND G MODELS 1991-94 OLDSMOBILE BRAVADA THIS BULLETIN CANCELS AND SUPERSEDES BULLETIN 476502 TO CORRECT THE CATEGORY IDENTIFIER/GROUP REFERENCE. PLEASE DISCARD BULLETIN 476502 (GROUP REFERENCE 6E- ENGINE FUEL & EMISSION). AC Rochester will be supplying a limited number of new oil filters with enhanced anti-drainback valves to GMSPO. Oil filters with effective anti-drainback valves may reduce or eliminate short duration cold knock. Due to limited production capacity, the new filters are only to be used on the following special cases. 1. Trucks or vans with short duration cold knock. 2. Routine maintenance of 1994 trucks or vans. Use the existing PF52 (P/N 25012760) and PF1218 (P/N 25013977) oil filters for applications other than the special cases listed above. PART INFORMATION: For "cold knock" vehicles or 1994 vehicle maintenance: DESCRIPTION PART NUMBER REPLACES PF52 25160560 PF51 PF1218 25160561 PF35 Parts are currently available from GMSPO. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oil Filter: > 420502 > May > 94 > Parts - OE and Aftermarket Oil Filters Revised Oil Filter: All Technical Service Bulletins Parts - OE and Aftermarket Oil Filters Revised Group Ref.: Warranty Administration Bulletin No.: 420502 Date: May, 1994 WARRANTY ADMINISTRATION SUBJECT: AC ROCHESTER ENGINE OIL FILTER IDENTIFICATION MODELS: 1994 PASSENGER CARS AND TRUCKS ATTENTION: DEALER SERVICE MANAGER/WARRANTY ADMINISTRATOR The purpose of this bulletin is to notify retail/wholesale service personnel of a running change to the AC Rochester Original Equipment engine oil filters. Due to an agreement to decrease the number of GMSPO part numbers, AC Rochester will phase in a decision to make all Original Equipment engine oil filters blue; same color used on AC aftermarket engine oil filters. This means that eventually the use of black Original Equipment engine oil filters will be discontinued. For the purpose of Warranty/Policy administration, the following will assist retail/wholesale service personnel in identifying the difference between blue Original Equipment and aftermarket engine oil filters: ^ AFTERMARKET FILTER: will continue to use "AC DURAGUARD OIL FILTER" label. ^ OE FILTER: will have a black bar code, Julian date code and the letters "OE" printed on the dome of the filter. At this time, it is anticipated that all OE engine oil filters will be changed by May 1994. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Other Service Bulletins for Oil Filter: > 07-06-01-016B > Jul > 09 > Engine - Noise/Damage Oil Filter Application Importance Oil Filter: All Technical Service Bulletins Engine - Noise/Damage Oil Filter Application Importance INFORMATION Bulletin No.: 07-06-01-016B Date: July 27, 2009 Subject: Information on Internal Engine Noise or Damage After Oil Filter Replacement Models: 2010 and Prior Passenger Cars and Trucks (Including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X Supercede: This bulletin is being updated to add model years. Please discard Corporate Bulletin Number 07-06-01-016A (Section 06 - Engine/Propulsion System). Important Engine damage that is the result of an incorrect or improperly installed engine oil filter is not a warrantable claim. The best way to avoid oil filter quality concerns is to purchase ACDelco(R) oil filters directly from GMSPO. Oil filter misapplication may cause abnormal engine noise or internal damage. Always utilize the most recent parts information to ensure the correct part number filter is installed when replacing oil filters. Do not rely on physical dimensions alone. Counterfeit copies of name brand parts have been discovered in some aftermarket parts systems. Always ensure the parts you install are from a trusted source. Improper oil filter installation may result in catastrophic engine damage. Refer to the appropriate Service Information (SI) installation instructions when replacing any oil filter and pay particular attention to procedures for proper cartridge filter element alignment. If the diagnostics in SI (Engine Mechanical) lead to the oil filter as the cause of the internal engine noise or damage, dealers should submit a field product report. Refer to Corporate Bulletin Number 02-00-89-002I (Information for Dealers on How to Submit a Field Product Report). Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Other Service Bulletins for Oil Filter: > 476118 > Jun > 94 > Oil Filters - Enhanced Anti-Drainback Valves Oil Filter: All Technical Service Bulletins Oil Filters - Enhanced Anti-Drainback Valves GROUP REF.: 6 - Engine BULLETIN NO.: 476118 DATE: June, 1994 SUBJECT: ENHANCED PF52 AND PF1218 OIL FILTERS MODELS: 1986-94 CHEVROLET AND GMC C/K, S/T, M/L, R/V, AND G MODELS 1991-94 OLDSMOBILE BRAVADA THIS BULLETIN CANCELS AND SUPERSEDES BULLETIN 476502 TO CORRECT THE CATEGORY IDENTIFIER/GROUP REFERENCE. PLEASE DISCARD BULLETIN 476502 (GROUP REFERENCE 6E- ENGINE FUEL & EMISSION). AC Rochester will be supplying a limited number of new oil filters with enhanced anti-drainback valves to GMSPO. Oil filters with effective anti-drainback valves may reduce or eliminate short duration cold knock. Due to limited production capacity, the new filters are only to be used on the following special cases. 1. Trucks or vans with short duration cold knock. 2. Routine maintenance of 1994 trucks or vans. Use the existing PF52 (P/N 25012760) and PF1218 (P/N 25013977) oil filters for applications other than the special cases listed above. PART INFORMATION: For "cold knock" vehicles or 1994 vehicle maintenance: DESCRIPTION PART NUMBER REPLACES PF52 25160560 PF51 PF1218 25160561 PF35 Parts are currently available from GMSPO. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Filter, Engine > Component Information > Technical Service Bulletins > All Other Service Bulletins for Oil Filter: > 420502 > May > 94 > Parts - OE and Aftermarket Oil Filters Revised Oil Filter: All Technical Service Bulletins Parts - OE and Aftermarket Oil Filters Revised Group Ref.: Warranty Administration Bulletin No.: 420502 Date: May, 1994 WARRANTY ADMINISTRATION SUBJECT: AC ROCHESTER ENGINE OIL FILTER IDENTIFICATION MODELS: 1994 PASSENGER CARS AND TRUCKS ATTENTION: DEALER SERVICE MANAGER/WARRANTY ADMINISTRATOR The purpose of this bulletin is to notify retail/wholesale service personnel of a running change to the AC Rochester Original Equipment engine oil filters. Due to an agreement to decrease the number of GMSPO part numbers, AC Rochester will phase in a decision to make all Original Equipment engine oil filters blue; same color used on AC aftermarket engine oil filters. This means that eventually the use of black Original Equipment engine oil filters will be discontinued. For the purpose of Warranty/Policy administration, the following will assist retail/wholesale service personnel in identifying the difference between blue Original Equipment and aftermarket engine oil filters: ^ AFTERMARKET FILTER: will continue to use "AC DURAGUARD OIL FILTER" label. ^ OE FILTER: will have a black bar code, Julian date code and the letters "OE" printed on the dome of the filter. At this time, it is anticipated that all OE engine oil filters will be changed by May 1994. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Pan, Engine > Component Information > Service and Repair Oil Pan: Service and Repair 4X2 Remove or Disconnect 1. Drain the engine oil. 2. Engine from the vehicle. 3. Oil pan bolts, nuts, and reinforcements. 4. Oil pan. 5. Gasket. 6. Clean sealing surfaces on the oil pan and engine block. 7. Inspect oil pan gasket. Replace if necessary. Install or Connect 1. Apply sealant to the front cover to block joint and to the crankshaft rear seal retainer to block joint. Apply the sealant for about 25 mm (1 inch) in both directions from each of the four corners. 2. Oil pan gasket to the oil pan. 3. Oil pan to the engine. 4. Oil pan bolts, nuts, and reinforcements. 5. Tighten Oil pan bolts to 11 N.m (100 in. lbs.). 6. Oil pan nuts at comers to 23 N.m (17 ft. 11 lbs.). 7. Engine to the vehicle. 8. Proper quantity and grade of engine oil. 4X4 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Pan, Engine > Component Information > Service and Repair > Page 2189 Remove or Disconnect 1. Negative battery cable. 2. Dipstick. 3. Raise the vehicle and support with safety stands. 4. Drive belt splash shield. 5. Front axle shield. 6. Front skid plate. 7. Drain engine oil. 8. Flywheel cover. 9. Left motor mount through bolts. 10. Right motor mount through bolts. 11. Raise the engine. Block in position. 12. Oil cooler line. 13. Oil filter adapter. 14 Pitman arm bolt. 15. Pitman arm. 16. Idler arm bolts. 17. Idler arm. 18. Front differential through bolts. 19. Front propeller shaft 20. Roll differential forward. 21. Starter bolts. 22. Starter motor and lay aside. 23. Oil pan bolts, nuts, and reinforcements. 24. Oil pan and gasket. 25. Clean sealing surfaces on the engine and oil pan. 26. Inspect pan gasket. Replace if necessary. Install or Connect 1. Apply sealant to the front cover to block joint and to the crankshaft rear seal to block joint. Apply the sealant for about 25 mm (1 inch) in both Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Pan, Engine > Component Information > Service and Repair > Page 2190 directions from each of the four corners. 2. Oil pan gasket to the oil pan. 3. Oil pan to the engine. 4. Oil pan bolts, nuts, and reinforcements. 5. Tighten pan bolts to 11 N.m (100 in. lbs.). 6. pan nuts at corners to 23 N.m (17 ft. lbs.). 7. Starter motor. 8. Starter motor bolts. 9. Align differential into position. 10. Front propeller shaft. 11. Front differential through bolts. 12. Idler arm. 13. Idler arm bolts. 14. Pitman arm. 15. Pitman arm bolt. 16. Transfer case shield. 17. Flywheel cover. 18. Front skid plate. 19. Front axle shield. 20. Drive belt splash shield. 21. Lower the vehicle. 22. Dipstick. 23. Proper quantity and grade of crankcase oil. 24. Negative battery cable. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Pressure Gauge > Component Information > Testing and Inspection > Gauge Readings Are Inaccurate Oil Pressure Gauge: Testing and Inspection Gauge Readings Are Inaccurate 1. Remove lead from sensor, then connect tester J 33431-A or equivalent to sensor lead and ground. 2. If gauge responds accurately to tester, replace sensor. 3. If gauge does not respond accurately to tester, replace cluster. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Pressure Gauge > Component Information > Testing and Inspection > Gauge Readings Are Inaccurate > Page 2195 Oil Pressure Gauge: Testing and Inspection Gauge Reads High 1. Disconnect lead from sensor, then turn ignition switch to the ON position and ground lead. 2. If gauge reads low, replace sensor. 3. If gauge reads high, locate and repair open circuit between sensor and gauge. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Pressure Gauge > Component Information > Testing and Inspection > Gauge Readings Are Inaccurate > Page 2196 Oil Pressure Gauge: Testing and Inspection Gauge Reads Low 1. Check oil level, add if necessary. 2. Turn ignition switch to the On position. 3. Remove oil pressure sensor lead at sensor, gauge should read high. 4. If gauge stays low, remove sensor lead at gauge. Gauge should read high. If gauge reads high, locate and repair short to ground between gauge and sensor. 5. If gauge still reads low, replace cluster. 6. With lead removed at sensor, connect an ohmmeter to sensor. With engine stopped resistance should be one ohm, and approximately 44 ohms with engine running. 7. If sensor reads significantly lower than 44 ohms with engine running, replace sensor. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Pressure Sender > Component Information > Technical Service Bulletins > Customer Interest for Oil Pressure Sender: > 476149 > Dec > 94 > Oil Pressure Gauge - Erratic Reading Concerns Oil Pressure Sender: Customer Interest Oil Pressure Gauge - Erratic Reading Concerns File In Section: 6 - Engine Bulletin No. 47-61-49 Date: December, 1994 Subject: Oil Pressure Gauge Reading Concerns (Replace Oil Pressure Sending Unit) Models: 1991-94 Chevrolet and GMC Truck C/K, S/T, P Models, M/L, G Vans 1991-92 Oldsmobile Bravada with 2.2L, 4.3L, 5.0L, 5.7L, 7.4L Engines (VINs 4, Z, H, K, N - RPOs LN2, LB4, L03, L05, L19) CONDITION Some owners may comment on one or all of the following conditions: ^ High oil pressure when starting engine cold. ^ Low oil pressure when engine is at idle hot. ^ Erratic gauge readings. CAUSE Oil pressure sending unit was not optimally calibrated for all operating conditions. CORRECTION If actual oil pressures are within tolerances listed in Section 6A of the Service Manual, and gauge circuit electrical diagnostics in Section SC of the Service Manual do not uncover the source of the problem, an improved oil pressure sending unit should be installed. Parts Information DESCRIPTION PART NUMBER Oil Pressure Sending Unit 12553175 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: LABOR OPERATION LABOR TIME N222O Use published labor operation and time. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Pressure Sender > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oil Pressure Sender: > 476149 > Dec > 94 > Oil Pressure Gauge - Erratic Reading Concerns Oil Pressure Sender: All Technical Service Bulletins Oil Pressure Gauge - Erratic Reading Concerns File In Section: 6 - Engine Bulletin No. 47-61-49 Date: December, 1994 Subject: Oil Pressure Gauge Reading Concerns (Replace Oil Pressure Sending Unit) Models: 1991-94 Chevrolet and GMC Truck C/K, S/T, P Models, M/L, G Vans 1991-92 Oldsmobile Bravada with 2.2L, 4.3L, 5.0L, 5.7L, 7.4L Engines (VINs 4, Z, H, K, N - RPOs LN2, LB4, L03, L05, L19) CONDITION Some owners may comment on one or all of the following conditions: ^ High oil pressure when starting engine cold. ^ Low oil pressure when engine is at idle hot. ^ Erratic gauge readings. CAUSE Oil pressure sending unit was not optimally calibrated for all operating conditions. CORRECTION If actual oil pressures are within tolerances listed in Section 6A of the Service Manual, and gauge circuit electrical diagnostics in Section SC of the Service Manual do not uncover the source of the problem, an improved oil pressure sending unit should be installed. Parts Information DESCRIPTION PART NUMBER Oil Pressure Sending Unit 12553175 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: LABOR OPERATION LABOR TIME N222O Use published labor operation and time. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Automatic Transmission LH Rear Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Automatic Transmission > Page 2214 Rear Engine Wiring W/Man Trans Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Page 2215 C120 - Fuel Pump Oil Pressure Sender/Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Page 2216 Oil Pressure Switch (For Fuel Pump): Service and Repair REMOVE/DISCONNECT - Negative battery cable from battery. - Sensor or switch connectors. - Sensor or switch. INSTALL/CONNECT - Sensor or switch. - Sensor or switch. - Negative battery cable. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Pressure Warning Lamp/Indicator > Component Information > Description and Operation Oil Pressure Warning Lamp/Indicator: Description and Operation Many trucks use a warning light on the instrument panel in place of the conventional dash indicating gauge to warn the driver when the oil pressure is dangerously low. The warning light is wired in series with the ignition switch and the engine unit--which is an oil pressure switch. The oil pressure switch contains a diaphragm and a set of contacts. When the ignition switch is turned on, the warning light circuit is energized and the circuit is completed through the closed contacts in the pressure switch. When the engine is started, build-up of oil pressure compresses the diaphragm, opening the contacts, thereby breaking the circuit causing the light to go out. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Pressure Warning Lamp/Indicator > Component Information > Description and Operation > Page 2220 Oil Pressure Warning Lamp/Indicator: Testing and Inspection The oil pressure warning light should go on when the ignition is turned on. If it does not light, disconnect the wire from the engine unit and ground the wire to the frame or cylinder block. Then if the warning light still does not go on, replace the bulb. If the warning light goes on when the wire is grounded, check the engine unit for a poor ground, or improper installation. (The presence of sealing compound on the threads of the engine unit will cause a poor ground.) If the unit is found to be properly grounded and installed, replace the unit. If the warning light remains lit when it normally should be out, replace the engine unit before proceeding to determine the cause for low pressure indication. The warning light will sometimes light or flicker when the engine is idling, even if oil pressure is adequate. However, the light should go out when the engine speed is increased. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Engine Lubrication > Oil Pump, Engine > Engine Oil Pressure > Component Information > Specifications Engine Oil Pressure: Specifications Normal Oil Pressure, Psi ..................................................................................................................... ................................................. 25-50 @ 1200 RPM. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Intake Manifold > Component Information > Technical Service Bulletins > Engine - Intake Manifold Inspection/Replacement Intake Manifold: Technical Service Bulletins Engine - Intake Manifold Inspection/Replacement INFORMATION Bulletin No.: 00-06-01-026C Date: February 03, 2010 Subject: Intake Manifold Inspection/Replacement After Severe Internal Engine Damage Models: 2010 and Prior Passenger Cars and Trucks (Including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X Supercede: This bulletin is being revised to include additional model years. Please discard Corporate Bulletin Number 00-06-01-026B (Section 06 - Engine). When replacing an engine due to internal damage, extreme care should be taken when transferring the intake manifold to the new Goodwrench service engine long block. Internal damage may result in the potential discharge of internal engine component debris in the intake manifold via broken pistons and/or bent, broken, or missing intake valves. After removing the intake manifold from the engine, the technician should carefully inspect all of the cylinder head intake ports to see if the valve heads are still present and not bent. Usually when the valve heads are missing or sufficiently bent, internal engine component debris will be present to varying degrees in the intake port of the cylinder head. If this debris is present in any of the cylinder head intake ports, the intake manifold should be replaced. This replacement is required due to the complex inlet runner and plenum configuration of most of the intake manifolds, making thorough and complete component cleaning difficult and nearly impossible to verify complete removal of debris. Re-installation of an intake manifold removed from an engine with deposits of internal engine component debris may result in the ingestion of any remaining debris into the new Goodwrench service engine. This may cause damage or potential failure of the new service engine. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Intake Manifold > Component Information > Technical Service Bulletins > Engine - Intake Manifold Inspection/Replacement > Page 2229 Intake Manifold: Technical Service Bulletins Engine - Use of Wacker RTV Sealant for Intake Manifold File In Section: 6 - Engine Bulletin No.: 67-61-17A Date: August, 1996 Subject: Use of Wacker T-330 RTV Sealant (Pronounced Vaucker T) Models: 1990-96 Buick Road master, Estate Wagon 1990-96 Cadillac Fleetwood 1990-96 Chevrolet Camaro, Caprice, Corvette, Impala SS 1990-92 Oldsmobile Custom Cruiser 1990-96 Pontiac Firebird with 4.3L, 5.7L Engine (VINs W, P, 5, 8 - RPOs L99, L98, LT1, LT4) 1990-96 Chevrolet and GMC Light and Medium Duty Trucks with 4.3L, 5.0L, 5.7L, 6.0L, 7.0L, 7.4L Engines (VINs W, Z, E H, K, M, N, P, R - RPOs L35, LB4, L03, L05, LS0, LR0, L19, L30, L31) This bulletin is being revised to add further Chevrolet models. Please discard Corporate Bulletin Number 67-61-17 (Section 6 - Engine). When installing the intake manifold, use a 5 mm (1/4 in.) thick bead of Wacker T-330 RTV, P/N 12346192, on the front and rear sealing areas between Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Intake Manifold > Component Information > Technical Service Bulletins > Engine - Intake Manifold Inspection/Replacement > Page 2230 the engine block and intake manifold. See Figures 1 and 2. Wacker T-330 RTV has improved adhesive abilities, is oxygen sensor safe, and is noncorrosive to ferrous metals. Wacker T-330 RW cannot be used in coolant sealing surface areas. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Intake Manifold > Component Information > Technical Service Bulletins > Page 2231 Intake Manifold: Service and Repair Fig. 5 Intake Manifold Sealant Application Fig. 6 Intake Manifold Tightening Sequence. 1. Disconnect battery ground cable. 2. Remove air cleaner and heat stove tube. 3. Remove two braces from rear of fan belt tensioner. 4. Drain cooling system, then remove upper radiator hose. 5. Remove emission relays and bracket. 6. Remove wiring harnesses from retainers and position aside. 7. Remove power brake vacuum pipe, then ground cable from manifold stud. 8. Disconnect heater hose pipe from manifold. 9. Disconnect fuel pipes from throttle body. 10. Remove electrical connectors from sensors on manifold, then the ignition coil. 11. Remove distributor. 12. Remove electrical connectors and hoses from throttle body. 13. Remove throttle, TVS and cruise control cables, as equipped. 14. Remove EGR hose, then the manifold bolts. 15. Remove intake manifold. 16. Reverse procedure to install, noting the following: a. Ensure gaskets are installed with port blocking plates facing the rear. b. Apply a 3/16 bead of sealer to front and rear of block, Fig. 5. Extend bead 1/2 inch up each cylinder head to seal gaskets. c. Install manifold retaining bolts and torque to specification in proper sequence shown in Fig. 6. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Lamps and Indicators - Engine > Oil Pressure Gauge > Component Information > Testing and Inspection > Gauge Readings Are Inaccurate Oil Pressure Gauge: Testing and Inspection Gauge Readings Are Inaccurate 1. Remove lead from sensor, then connect tester J 33431-A or equivalent to sensor lead and ground. 2. If gauge responds accurately to tester, replace sensor. 3. If gauge does not respond accurately to tester, replace cluster. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Lamps and Indicators - Engine > Oil Pressure Gauge > Component Information > Testing and Inspection > Gauge Readings Are Inaccurate > Page 2237 Oil Pressure Gauge: Testing and Inspection Gauge Reads High 1. Disconnect lead from sensor, then turn ignition switch to the ON position and ground lead. 2. If gauge reads low, replace sensor. 3. If gauge reads high, locate and repair open circuit between sensor and gauge. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Lamps and Indicators - Engine > Oil Pressure Gauge > Component Information > Testing and Inspection > Gauge Readings Are Inaccurate > Page 2238 Oil Pressure Gauge: Testing and Inspection Gauge Reads Low 1. Check oil level, add if necessary. 2. Turn ignition switch to the On position. 3. Remove oil pressure sensor lead at sensor, gauge should read high. 4. If gauge stays low, remove sensor lead at gauge. Gauge should read high. If gauge reads high, locate and repair short to ground between gauge and sensor. 5. If gauge still reads low, replace cluster. 6. With lead removed at sensor, connect an ohmmeter to sensor. With engine stopped resistance should be one ohm, and approximately 44 ohms with engine running. 7. If sensor reads significantly lower than 44 ohms with engine running, replace sensor. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Lamps and Indicators - Engine > Oil Pressure Warning Lamp/Indicator > Component Information > Description and Operation Oil Pressure Warning Lamp/Indicator: Description and Operation Many trucks use a warning light on the instrument panel in place of the conventional dash indicating gauge to warn the driver when the oil pressure is dangerously low. The warning light is wired in series with the ignition switch and the engine unit--which is an oil pressure switch. The oil pressure switch contains a diaphragm and a set of contacts. When the ignition switch is turned on, the warning light circuit is energized and the circuit is completed through the closed contacts in the pressure switch. When the engine is started, build-up of oil pressure compresses the diaphragm, opening the contacts, thereby breaking the circuit causing the light to go out. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Lamps and Indicators - Engine > Oil Pressure Warning Lamp/Indicator > Component Information > Description and Operation > Page 2242 Oil Pressure Warning Lamp/Indicator: Testing and Inspection The oil pressure warning light should go on when the ignition is turned on. If it does not light, disconnect the wire from the engine unit and ground the wire to the frame or cylinder block. Then if the warning light still does not go on, replace the bulb. If the warning light goes on when the wire is grounded, check the engine unit for a poor ground, or improper installation. (The presence of sealing compound on the threads of the engine unit will cause a poor ground.) If the unit is found to be properly grounded and installed, replace the unit. If the warning light remains lit when it normally should be out, replace the engine unit before proceeding to determine the cause for low pressure indication. The warning light will sometimes light or flicker when the engine is idling, even if oil pressure is adequate. However, the light should go out when the engine speed is increased. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Seals and Gaskets, Engine > Crankshaft Main Bearing Seal > Component Information > Service and Repair Crankshaft Main Bearing Seal: Service and Repair Rear oil seal installation 1. Remove transmission. Refer to Transmision and Drivetrain / Manual Transmission/Transaxle / Service and Repair. Refer to Transmision and Drivetrain / Automatic Transmission/Transaxle / Service and Repair. 2. Remove clutch and flywheel, if equipped. 3. Remove rear crankshaft oil seal by placing screwdriver in notches provided and pry the seal out. 4. After cleaning groove, apply a thin even coat of adhesive, part No. 1052621, Loctite 414 or equivalent over entire surface of seal groove. 5. Within one minute install seal using seal installer J-35621 or equivalent, Fig. 17. 6. Reverse steps 1 and 2 to complete installation. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Seals and Gaskets, Engine > Front Crankshaft Seal > Component Information > Service and Repair Front Crankshaft Seal: Service and Repair Fig. 16 Front Oil Seal Installation 1. Disconnect battery ground cable. 2. Remove fan belt, fan and pulley. 3. Remove fan shroud, then the accessory drive pulley. 4. Remove torsional damper. 5. Remove front crankshaft seal by prying out with large screwdriver. Use care to not distort front cover. 6. Remove crankshaft key, if necessary. 7. Coat seal lips with engine oil and install using crankshaft seal installer tool No. J-35468, or equivalent, Fig. 16. 8. Reverse steps 1 through 6 to complete installation. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Sensors and Switches - Engine > Oil Pressure Sender > Component Information > Technical Service Bulletins > Customer Interest: > 476149 > Dec > 94 > Oil Pressure Gauge - Erratic Reading Concerns Oil Pressure Sender: Customer Interest Oil Pressure Gauge - Erratic Reading Concerns File In Section: 6 - Engine Bulletin No. 47-61-49 Date: December, 1994 Subject: Oil Pressure Gauge Reading Concerns (Replace Oil Pressure Sending Unit) Models: 1991-94 Chevrolet and GMC Truck C/K, S/T, P Models, M/L, G Vans 1991-92 Oldsmobile Bravada with 2.2L, 4.3L, 5.0L, 5.7L, 7.4L Engines (VINs 4, Z, H, K, N - RPOs LN2, LB4, L03, L05, L19) CONDITION Some owners may comment on one or all of the following conditions: ^ High oil pressure when starting engine cold. ^ Low oil pressure when engine is at idle hot. ^ Erratic gauge readings. CAUSE Oil pressure sending unit was not optimally calibrated for all operating conditions. CORRECTION If actual oil pressures are within tolerances listed in Section 6A of the Service Manual, and gauge circuit electrical diagnostics in Section SC of the Service Manual do not uncover the source of the problem, an improved oil pressure sending unit should be installed. Parts Information DESCRIPTION PART NUMBER Oil Pressure Sending Unit 12553175 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: LABOR OPERATION LABOR TIME N222O Use published labor operation and time. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Sensors and Switches - Engine > Oil Pressure Sender > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 476149 > Dec > 94 > Oil Pressure Gauge - Erratic Reading Concerns Oil Pressure Sender: All Technical Service Bulletins Oil Pressure Gauge - Erratic Reading Concerns File In Section: 6 - Engine Bulletin No. 47-61-49 Date: December, 1994 Subject: Oil Pressure Gauge Reading Concerns (Replace Oil Pressure Sending Unit) Models: 1991-94 Chevrolet and GMC Truck C/K, S/T, P Models, M/L, G Vans 1991-92 Oldsmobile Bravada with 2.2L, 4.3L, 5.0L, 5.7L, 7.4L Engines (VINs 4, Z, H, K, N - RPOs LN2, LB4, L03, L05, L19) CONDITION Some owners may comment on one or all of the following conditions: ^ High oil pressure when starting engine cold. ^ Low oil pressure when engine is at idle hot. ^ Erratic gauge readings. CAUSE Oil pressure sending unit was not optimally calibrated for all operating conditions. CORRECTION If actual oil pressures are within tolerances listed in Section 6A of the Service Manual, and gauge circuit electrical diagnostics in Section SC of the Service Manual do not uncover the source of the problem, an improved oil pressure sending unit should be installed. Parts Information DESCRIPTION PART NUMBER Oil Pressure Sending Unit 12553175 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: LABOR OPERATION LABOR TIME N222O Use published labor operation and time. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Sensors and Switches - Engine > Oil Pressure Sender > Component Information > Technical Service Bulletins > All Other Service Bulletins for Oil Pressure Sender: > 07-08-45-002 > Sep > 07 > Electrical - Aftermarket Fuse Warning Fuse: All Technical Service Bulletins Electrical - Aftermarket Fuse Warning Bulletin No.: 07-08-45-002 Date: September 05, 2007 ADVANCED SERVICE INFORMATION Subject: Service Alert: Concerns With Aftermarket Fuses in GM Vehicles Models: 2008 and Prior GM Passenger Cars and Light Duty Trucks (including Saturn) 2008 and Prior HUMMER H2, H3 2008 and Prior Saab 9-7X Concerns with Harbor Freight Tools "Storehouse" Branded Blade Type Fuses General Motors has become aware of a fuse recall by Harbor Freight Tools/Storehouse for a variety of aftermarket fuses. In two cases, these fuses have not provided protection for the wiring system of the vehicles they were customer installed in. Upon testing the 15 amp version, it was found that the fuse still would not "open" when shorted directly across the battery terminals. How to Identify These Fuses Packed in a 120 piece set, the fuse has a translucent, hard plastic, blue body with the amperage stamped into the top. There are no white painted numbers on the fuse to indicate amperage. There are no identifying marks on the fuse to tell who is making it. The fuses are known to be distributed by Harbor Freight Tools but there may be other marketers, and packaging of this style of fuse. It would be prudent to replace these fuses if found in a customers vehicle. Likewise, if wiring overheating is found you should check the fuse panel for the presence of this style of fuse. All GM dealers should use genuine GM fuses on the vehicles they service. You should also encourage the use of GM fuses to your customers to assure they are getting the required electrical system protection. GM has no knowledge of any concerns with other aftermarket fuses. If additional information becomes available, this bulletin will be updated. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Sensors and Switches - Engine > Oil Pressure Sender > Component Information > Technical Service Bulletins > All Other Service Bulletins for Oil Pressure Sender: > 361102 > Feb > 94 > A/C - Erratic HVAC Operation & Self Diagnostic Blinks Fuse: All Technical Service Bulletins A/C - Erratic HVAC Operation & Self Diagnostic Blinks Group Ref.: HVAC Bulletin No.: 361102 Date: February, 1994 SUBJECT: BLOWN FUSE, ERRATIC HVAC OPERATION, AND SELF DIAGNOSTIC FEATURE BLINKS (INSULATE WIRES) MODELS: 1994 AND PRIOR CHEVROLET AND GMC C/K TRUCKS CONDITION: Some owners may experience a blown fuse, erratic HVAC operation, or a blinking HVAC control head self diagnostic indicator. CAUSE: Two possible hard to find causes have been discovered for the above symptoms: - Six way I/P to HVAC connector terminals may short to the ashtray. The connector has slots to accommodate the terminal positive attachment locks that allow metal to metal contact between the exposed terminals and the ashtray (Figure 1). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Sensors and Switches - Engine > Oil Pressure Sender > Component Information > Technical Service Bulletins > All Other Service Bulletins for Oil Pressure Sender: > 361102 > Feb > 94 > A/C - Erratic HVAC Operation & Self Diagnostic Blinks > Page 2273 - The HVAC Harness from the control head to the blower and mode door motors, running across the vehicle just under the dash panel, may chafe against the cassette deck support bracket (Figure 2). CORRECTION: Both conditions can be corrected by taping or otherwise shielding the wires from contact with the respective metal edges. If the second condition has caused significant wire damage, repair according to guidelines found in the wire repair section of the appropriate service manual. WARRANTY INFORMATION: For vehicles repaired under warranty, use: Labor Op Description Labor Time N6030 Wiring and/or Use Published connector repair, A/C Labor Operation Time Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Sensors and Switches - Engine > Oil Pressure Sender > Component Information > Technical Service Bulletins > All Other Service Bulletins for Oil Pressure Sender: > 361102 > Feb > 94 > A/C - Erratic HVAC Operation & Self Diagnostic Blinks > Page 2283 - The HVAC Harness from the control head to the blower and mode door motors, running across the vehicle just under the dash panel, may chafe against the cassette deck support bracket (Figure 2). CORRECTION: Both conditions can be corrected by taping or otherwise shielding the wires from contact with the respective metal edges. If the second condition has caused significant wire damage, repair according to guidelines found in the wire repair section of the appropriate service manual. WARRANTY INFORMATION: For vehicles repaired under warranty, use: Labor Op Description Labor Time N6030 Wiring and/or Use Published connector repair, A/C Labor Operation Time Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Timing Components > Balance Shaft > Component Information > Specifications Balance Shaft: Specifications Engine Liter/CID .................................................................................................................................. ........................................................... 4.3L/V6-262 All specifications given in inches. Journal Bearing Diameter Front .................................................................................................................................................... ...................................................... 2.1648-2.1654 Rear ...................................................................... ...................................................................................................................................... 1.4994-1.5000 Rear Bearing Journal Clearance ......................................................................................................... ........................................................ 0.0010-0.0036 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Timing Components > Balance Shaft > Component Information > Specifications > Page 2288 Balance Shaft: Service and Repair BALANCE SHAFT REMOVAL TOOLS REQUIRED: J 38834 Balance Shaft Bearing Service Kit J 26941 Bearing Remover Installing Balance Shaft And Components REMOVE OR DISCONNECT 1. Bolt (49). 2. Driven gear (42). 3. Retainer bolts (48). 4. Retainer (43). 5. Balance shaft (47) using a soft faced hammer. 6. Balance shaft rear bearing (45) using J 38834 and J 26941. IMPORTANT ^ The balance shaft with front bearing are serviced as an assembly. ^ Use only the correct tools for bearing and shaft installation. ^ inspect the balance shaft driven gear and the drive gear for nicks and burrs. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Timing Components > Balance Shaft > Component Information > Specifications > Page 2289 BALANCE SHAFT INSTALLATION TOOLS REQUIRED: J 38834 Balance Shaft Bearing Service Kit J 36998 Balance Shaft Installer J 8092 Driver Handle J 36660 Torque/Angel Meter INSTALL OR CONNECT 1. Balance shaft rear bearing (45) using J 38834. Dip bearing in clean engine oil before installation. 2. Balance shaft (47) into block using J 36996 and J 8092. A. Dip the front balance shaft bearing into clean engine oil before assembly. B. Retaining ring on balance shaft front bearing must be seated on case. 3. Install balance shaft bearing retainer (43) and bolts (48). TIGHTEN ^ Balance shaft retainer bolts (48) to 14 Nm (124 lbs in.). 4. Balance shaft driven gear (42) and bolt (49). TIGHTEN ^ Balance shaft driven gear bolt (49) to 20 Nm (15 lbs. ft.) plus an additional turn of 35 degrees using J 36660. ^ Rotate balance shaft (47) by hand to make sure there is clearance between the balance shaft (47) and retainer (43). If balance shaft does not rotate freely, check to be sure retaining ring on front bearing is seated on case. Balance Shaft Drive Gear To Driven Gear Timing Marks ^ Turn the camshaft so, with the balance shaft drive gear temporarily installed, the timing mark on the drive gear is straight up. ^ With the balance shaft drive gear removed, turn the balance shaft so the timing mark on the driven gear (42) points straight down. 5. Balance shaft drive gear (37) onto camshaft. IMPORTANT ^ Make sure the timing marks on the balance shaft drive gear and driven gear line up. 6. Balance shaft drive gear bolts. TIGHTEN ^ Bolt to 16 Nm (12 lbs. ft.). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Timing Components > Timing Chain > Component Information > Service and Repair Timing Chain: Service and Repair REMOVAL ^ Tools Required J 5825-A Crankshaft Sprocket Puller 1. Remove the timing cover. 2. Remove the crankshaft position sensor reluctor ring. 3. Remove the camshaft sprocket bolts. 4. Remove camshaft sprocket. 5. Remove timing chain. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Timing Components > Timing Chain > Component Information > Service and Repair > Page 2293 6. Remove the crankshaft sprocket. 7. Remove crankshaft sprocket key. INSTALLATION 1. Install the key into the crankshaft keyway. 2. Use the crankshaft balancer installer to install the crankshaft sprocket. 3. Install the camshaft sprocket and timing chain. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Timing Components > Timing Chain > Component Information > Service and Repair > Page 2294 NOTE: The gears must mesh in order to prevent damage to the camshaft retainer. 4. Install camshaft sprocket bolts. CAUTION Be sure to align the camshaft and the crankshaft sprocket marks. Timing marks (Number 4 Firing). ^ Tighten bolts to 28 Nm (21 ft. lbs.) 5. Align the keyway on the reluctor ring with the key in the crankshaft. 6. Install the reluctor ring onto the crankshaft until the ring is completely seated against the crankshaft sprocket. 7. Install the timing cover. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Timing Components > Timing Cover > Component Information > Service and Repair Timing Cover: Service and Repair 1. Disconnect battery ground cable. 2. Remove torsional damper. 3. Remove water pump, then the upper radiator hose. 4. Remove oil pan. 5. Remove A/C compressor and position aside. 6. Remove right side engine accessory bracket. 7. Remove front cover attaching bolts and reinforcements. 8. Remove front cover. 9. Reverse procedure to install, tightening cover bolts to specification. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Fuel Pressure > Diagnostic Connector - Fuel Pump > Component Information > Locations Component Location - "S/T" 4.3Z Utility - Manual Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Idle Speed > System Information > Technical Service Bulletins > Idle Speed - Specification Revised Idle Speed: Technical Service Bulletins Idle Speed - Specification Revised File In Section: 6E - Engine Fuel & Emission Bulletin No.: 41-65-22 Date: September, 1994 SERVICE MANUAL UPDATE Subject: Section 4 - Revised Controlled Idle Speed Specification Models: 1994 Chevrolet and GMC Truck Light Duty Models 1994 Oldsmobile Bravada with Gasoline Engines Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Idle Speed > System Information > Technical Service Bulletins > Idle Speed - Specification Revised > Page 2307 This service bulletin supersedes Service Manual information for the Controlled Idle Speed Specification on Page 4-3 of the Driveability, Emissions, and Electrical Diagnosis Manual. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Idle Speed > System Information > Technical Service Bulletins > Page 2308 Idle Speed: Specifications Refer to Adjustment Procedures Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > Customer Interest for Air Filter Element: > 04-07-30-013B > Feb > 07 > Engine, A/T - Shift/Driveability Concerns/MIL ON Air Filter Element: Customer Interest Engine, A/T - Shift/Driveability Concerns/MIL ON Bulletin No.: 04-07-30-013B Date: February 01, 2007 INFORMATION Subject: Automatic Transmission Shift, Engine Driveability Concerns or Service Engine Soon (SES) Light On as a Result of the Use of an Excessively/Over-Oiled Aftermarket, Reusable Air Filter Models: 2007 and Prior GM Cars and Light Duty Trucks 2007 and Prior Saturn Models 2003-2007 HUMMER H2 2006-2007 HUMMER H3 2005-2007 Saab 9-7X Supercede: This bulletin is being revised to add models and model years. Please discard Corporate Bulletin Number 04-07-30-013A (Section 07 - Transmission/Transaxle). The use of an excessively/over-oiled aftermarket, reusable air filter may result in: Service Engine Soon (SES) light on Transmission shift concerns, slipping and damaged clutch(es) or band(s) Engine driveability concerns, poor acceleration from a stop, limited engine RPM range The oil that is used on these air filter elements may be transferred onto the Mass Air Flow (MAF) sensor causing contamination of the sensor. As a result, the Grams per Second (GPS) signal from the MAF may be low and any or all of the concerns listed above may occur. When servicing a vehicle with any of these concerns, be sure to check for the presence of an aftermarket reusable, excessively/over-oiled air filter. The MAF, GPS reading should be compared to a like vehicle with an OEM air box and filter under the same driving conditions to verify the concern. The use of an aftermarket reusable air filter DOES NOT void the vehicle's warranty. If an aftermarket reusable air filter is used, technicians should inspect the MAF sensor element and the air induction hose for contamination of oil prior to making warranty repairs. Transmission or engine driveability concerns (related to the MAF sensor being contaminated with oil) that are the result of the use of an aftermarket reusable, excessively/over-oiled air filter are not considered to be warrantable repair items. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > Customer Interest for Air Filter Element: > 04-07-30-013B > Feb > 07 > Engine, A/T - Shift/Driveability Concerns/MIL ON > Page 2318 Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Air Filter Element: > 04-07-30-013B > Feb > 07 > Engine, A/T - Shift/Driveability Concerns/MIL ON Air Filter Element: All Technical Service Bulletins Engine, A/T - Shift/Driveability Concerns/MIL ON Bulletin No.: 04-07-30-013B Date: February 01, 2007 INFORMATION Subject: Automatic Transmission Shift, Engine Driveability Concerns or Service Engine Soon (SES) Light On as a Result of the Use of an Excessively/Over-Oiled Aftermarket, Reusable Air Filter Models: 2007 and Prior GM Cars and Light Duty Trucks 2007 and Prior Saturn Models 2003-2007 HUMMER H2 2006-2007 HUMMER H3 2005-2007 Saab 9-7X Supercede: This bulletin is being revised to add models and model years. Please discard Corporate Bulletin Number 04-07-30-013A (Section 07 - Transmission/Transaxle). The use of an excessively/over-oiled aftermarket, reusable air filter may result in: Service Engine Soon (SES) light on Transmission shift concerns, slipping and damaged clutch(es) or band(s) Engine driveability concerns, poor acceleration from a stop, limited engine RPM range The oil that is used on these air filter elements may be transferred onto the Mass Air Flow (MAF) sensor causing contamination of the sensor. As a result, the Grams per Second (GPS) signal from the MAF may be low and any or all of the concerns listed above may occur. When servicing a vehicle with any of these concerns, be sure to check for the presence of an aftermarket reusable, excessively/over-oiled air filter. The MAF, GPS reading should be compared to a like vehicle with an OEM air box and filter under the same driving conditions to verify the concern. The use of an aftermarket reusable air filter DOES NOT void the vehicle's warranty. If an aftermarket reusable air filter is used, technicians should inspect the MAF sensor element and the air induction hose for contamination of oil prior to making warranty repairs. Transmission or engine driveability concerns (related to the MAF sensor being contaminated with oil) that are the result of the use of an aftermarket reusable, excessively/over-oiled air filter are not considered to be warrantable repair items. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Air Filter Element: > 04-07-30-013B > Feb > 07 > Engine, A/T - Shift/Driveability Concerns/MIL ON > Page 2324 Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Fuel Filter > Fuel Pressure Release > System Information > Service and Repair Fuel Pressure Release: Service and Repair WARNING To reduce the risk of fire and personal injury, it is necessary to relieve fuel system pressure before servicing fuel system components. A small amount of fuel may be released when servicing fuel lines or connections. In order to reduce the chance of personal injury, cover fuel line fittings with a shop towel before disconnecting to catch any fuel that may leak out. Place the towel in an approved container when disconnect is complete. PROCEDURE - Disconnect negative battery terminal to avoid possible fuel discharge if an accidental attempt is made to start the engine. - Loosen fuel filler cap to relieve tank vapor pressure. (Do not tighten until service has been completed.) - The TBI model 220 contains a constant bleed feature in the pressure regulator that relieves pressure. Therefore, no further action is required. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Firing Order > Component Information > Specifications > Ignition Firing Order Firing Order: Specifications Ignition Firing Order Firing Order ......................................................................................................................................... ............................................................... 1-6-5-4-3-2 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Ignition Timing > Ignition Timing Connector > Component Information > Technical Service Bulletins > Ignition Set Timing Connector - Location Correction Ignition Timing Connector: Technical Service Bulletins Ignition Set Timing Connector - Location Correction File in Section: Engine Fuel & Emission Bulletin No.: 41-65-41 Date: January, 1995 SERVICE MANUAL UPDATE Subject: Section 6A - Ignition Set Timing Connector Location Models: 1994 Chevrolet and GMC Truck S/T Models 1994 Oldsmobile Bravada with 4.3L Engine (VINs W, Z - RPOs L35, LB4) The location of the Set Timing Connector is incorrectly called out in "Section 6A" (Page 6A-8) of the "Driveability, Emissions and Electrical Diagnosis", Service Manual and in the 1994 Oldsmobile Bravada Service Manual Supplement (Page 6E3-C4-8). The correct location of the Set Timing Connector is inside the cab where the Heater Box and the carpet meet on the passenger side floor. Pull carpet back to expose the single wire and connectors on the outside of the control module harness. The wire colors are tan with a black stripe. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Ignition Timing > Ignition Timing Connector > Component Information > Technical Service Bulletins > Page 2338 Timing Connector-In Pass Comp Behind Carpet, Below Heater Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Ignition Timing > Number One Cylinder > Component Information > Locations > Number 1 Cylinder Location Number One Cylinder: Locations Number 1 Cylinder Location NUMBER ONE CYLINDER LOCATION Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Ignition Timing > Timing Marks and Indicators > System Information > Locations Timing Mark Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Ignition Cable > Component Information > Specifications Ignition Cable: Specifications RESISTANCE VALUES 0-15 inch cable .................................................................................................................................... ................................................. 3,000 - 10,000 ohms. 15-25 inch cable .................................................................................................................................. ................................................. 4,000 - 15,000 ohms. 25-35 inch cable .................................................................................................................................. ................................................. 6,000 - 20,000 ohms. NOTE: Longer wires should measure about 5,000 to 10,000 ohms per foot. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Ignition Cable > Component Information > Specifications > Page 2349 Ignition Cable: Locations Spark Plug Wire Routing Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Distributor, Ignition > Component Information > Specifications Distributor: Specifications Coil bracket bolt/nut ............................................................................................................................. ................................................. 27 N-m (20 lbs ft) Distributor clamp bolt ........................................................................................................................... ................................................ 27 N-m (20 lbs ft) Knock Sensor ...................................................................................................................................... .................................................. 19 N-m (14 lbs ft) Spark Plugs ......................................................................................................................................... .................................................. 15 N-M (11 lbs ft) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Distributor, Ignition > Component Information > Specifications > Page 2353 LH Rear Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Distributor, Ignition > Component Information > Specifications > Page 2354 Distributor: Description and Operation PURPOSE The distributor reference signal provides the ECM with both engine RPM and crankshaft position information. This enables the ECM to operate the fuel pump relay and energize the fuel injector. OPERATION When the engine is cranking or running the ECM receives Distributor Ignition (DI) reference pulses from the ignition module. If the wire becomes open or grounded the engine will not run, as the ECM will not operate the injector. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Distributor, Ignition > Component Information > Specifications > Page 2355 Distributor: Service and Repair Distributor Remove or Disconnect Figure 8 - Spark Plug Wire Routing - Left Side (2.2L) Figure 9 - Spark Plug Wire Routing - Right Side (2.2L) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Distributor, Ignition > Component Information > Specifications > Page 2356 Figure 10 - Distributor And Coil (4.3L VIN Z) Figure 11 - Distributor And Coil (4.3L VIN W) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Distributor, Ignition > Component Information > Specifications > Page 2357 Figure 12 - Spark Plug Wire Routing - Left Side (4.3L VIN Z) Figure 13 - Spark Plug Wire Routing - Right Side - Pickup Models (4.3L VIN Z) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Distributor, Ignition > Component Information > Specifications > Page 2358 Figure 14 - Spark Plug Wire Routing - Right Side - Utility Models (4.3L VIN Z) Figure 15 - Spark Plug Wire Routing (4.3L VIN W) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Distributor, Ignition > Component Information > Specifications > Page 2359 - Make sure the ignition switch is "OFF." 1. Air cleaner and hoses (4.3L VIN Z). 2. Wiring harness connectors at the side of the distributor cap. 3. Two screws on the sides of the distributor cap. 4. Coil wire and spark plug wires on either the left or right side of the distributor. 5. Distributor cap and move it aside. A. Use chalk to note the position of the rotor in relation to the engine. B. Use chalk to note the position of the distributor housing in relation to the engine. 6. Distributor bolt and hold-down clamp. 7. Distributor and gasket, when present. Install or Connect Figure 8 - Spark Plug Wire Routing - Left Side (2.2L) Figure 9 - Spark Plug Wire Routing - Right Side (2.2L) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Distributor, Ignition > Component Information > Specifications > Page 2360 Figure 10 - Distributor And Coil (4.3L VIN Z) Figure 11 - Distributor And Coil (4.3L VIN W) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Distributor, Ignition > Component Information > Specifications > Page 2361 Figure 12 - Spark Plug Wire Routing - Left Side (4.3L VIN Z) Figure 13 - Spark Plug Wire Routing - Right Side - Pickup Models (4.3L VIN Z) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Distributor, Ignition > Component Information > Specifications > Page 2362 Figure 14 - Spark Plug Wire Routing - Right Side - Utility Models (4.3L VIN Z) Figure 15 - Spark Plug Wire Routing (4.3L VIN W) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Distributor, Ignition > Component Information > Specifications > Page 2363 A. To ensure correct timing of the distributor, it must be installed with the rotor correctly positioned as noted in step 5 of the removal procedure. Line up the rotor to the mark on the engine, and the mark on the housing to the engine. B. If the distributor shaft won't drop into the engine, remove the distributor, insert a screwdriver into the hole for the distributor and rotate the oil pump driveshaft so that it lines up with the distributor driver gear. 1. Distributor and gasket, where present. 2. Hold-down clamp and bolt. - Bolt on the 4.3L to 27 Nm (20 lbs. ft.). 3. Distributor cap. 4. Wiring harness connectors at the side of the distributor. 5. Spark plug wires and coil wire. 6. Air Cleaner and hoses. - Check the engine timing. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Spark Plug > Component Information > Specifications Spark Plug: Specifications Spark Plug Gap ................................................................................................................................... ........................................ N/A see NOTE following. Spark Plug Torque ............................................................................................................................... ...................................................... 15 N-m (11 lb.ft.) Spark Plug Type .................................................................................................................................. .......................................................... AC CR43TSM NOTE Check the gap specifications given on the Emissions Control Label. If the gap is different from what is listed here, use the information on the label. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Compression Check > System Information > Specifications Compression Check: Specifications Minimum, 698 kPa (100 psi) @ 200 rpm. The lowest cylinder reading should not be less than 80% of the highest. Perform compression test with engine at normal operating temperature, spark plugs removed and throttle wide open. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Valve Clearance > System Information > Specifications > Valve Clearance Specifications Valve Clearance: Specifications Valve Clearance Specifications VALVE ADJUSTMENT (VIN Z) WITH SCREW-IN ROCKER ARM STUDS AND POSITIVE STOP SHOULDERS Valve Rocker Arm Nuts ....................................................................................................................... .......................................... 27 Nm (20 lb. ft.). WITH PRESSED-IN ROCKER ARM STUDS Refer to Rocker Arm / Adjustments. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Valve Clearance > System Information > Specifications > Valve Clearance Specifications > Page 2374 Valve Clearance: Specifications Valve Arrangement FRONT TO REAR 4.3L/V6-262 Left Side........................................................................................................................... .................................................................................. E-I-E-I-I-E Right Side......................................... .............................................................................................................................................................. .... E-I-I-E-I-E Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Valve Clearance > System Information > Specifications > Page 2375 Valve Clearance: Adjustments VALVE ADJUSTMENT Fig. 10 Valve Adjustment The 4.3L VIN Z engine can be equipped with two different rocker arm stud configurations that require different valve lash procedures. TYPE 1 - VIN Z If you have a 4.3L VIN Z engine that has screw-in rocker arm studs with positive stop shoulders, no valve adjustment is necessary. When the valve train requires service, you simply tighten the rocker arm nuts to 27 Nm (20 ft lb). TYPE 2 - VIN Z If you have a 4.3L VIN Z engine that has pressed-in rocker arm studs, you must follow the valve adjustment procedure outlined below. 1. Remove rocker arm cover. 2. Rotate engine until mark on torsional damper is aligned with "0" mark on timing tab fastened to crankcase front cover. To ensure engine is at No. 1 cylinder firing position, place fingers on No. 1 cylinder valves as the mark on damper approaches the "0" mark on timing tab. If valves are not moving, engine is in the No. 1 cylinder firing position. If valves are moving, engine is in the No. 4 cylinder firing position and should be rotated one revolution. 3. With engine in No. 1 cylinder firing position, adjust the following valves: ^ Exhaust valves 1, 5 and 6. ^ Intake valves 1, 2 and 3. NOTE: Even numbered cylinders are in the left bank and odd numbered cylinders are in the right bank, when viewed from front of the engine. 4. Back off adjusting nut until lash is felt at pushrod, then tighten nut until all lash is removed. This can be determined by rotating pushrod while turning adjusting nut. When all lash is removed, tighten adjusting nut 1 and 3/4 turns to center lifter plunger. 5. Crank engine one full revolution until mark on torsional damper and "0" mark on timing tab are again in alignment. This is the No. 4 cylinder firing position. With engine in this position, adjust the following valves: ^ Exhaust valves 2, 3 and 4. ^ Intake valves 4, 5 and 6. 6. Install valve covers and related components, then start engine and check timing and idle speed. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Valve Clearance > System Information > Specifications > Page 2376 Valve Clearance: Service and Repair For Valve Adjustment, Refer to Valve Clearance / Adjustments. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Engine > Water Pump > Component Information > Service and Repair Water Pump: Service and Repair Water pump replacement. 4.3L/V6-262 1. Drain cooling system. 2. Remove serpentine drive belt, then the upper fan shroud. 3. Remove fan,then fan clutch assembly and water pump pulley. 4. Remove hoses from pump. 5. Remove water pump attaching bolts, then pump Fig. 20. 6. Reverse procedure to install. Torque bolts to specification. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Coolant > Component Information > Technical Service Bulletins > Cooling System - Coolant Recycling Information Coolant: Technical Service Bulletins Cooling System - Coolant Recycling Information Bulletin No.: 00-06-02-006D Date: August 15, 2006 INFORMATION Subject: Engine Coolant Recycling and Warranty Information Models: 2007 and Prior GM Passenger Cars and Trucks (Including Saturn) 2007 and Prior HUMMER Vehicles 2005-2007 Saab 9-7X Attention: Please address this bulletin to the Warranty Claims Administrator and the Service Manager. Supercede: This bulletin is being revised to adjust the title and Include Warranty Information. Please discard Corporate Bulletin Number 00-06-02-006C (Section 06 - Engine/Propulsion System). Coolant Reimbursement Policy General Motors supports the use of recycled engine coolant for warranty repairs/service, providing a GM approved engine coolant recycling system is used. Recycled coolant will be reimbursed at the GMSPO dealer price for new coolant plus the appropriate mark-up. When coolant replacement is required during a warranty repair, it is crucial that only the relative amount of engine coolant concentrate be charged, not the total diluted volume. In other words: if you are using two gallons of pre-diluted (50:50) recycled engine coolant to service a vehicle, you may request reimbursement for one gallon of GM Goodwrench engine coolant concentrate at the dealer price plus the appropriate warranty parts handling allowance. Licensed Approved DEX-COOL(R) Providers Important: USE OF NON-APPROVED VIRGIN OR RECYCLED DEX-COOL(R) OR DEVIATIONS IN THE FORM OF ALTERNATE CHEMICALS OR ALTERATION OF EQUIPMENT, WILL VOID THE GM ENDORSEMENT, MAY DEGRADE COOLANT SYSTEM INTEGRITY AND PLACE THE COOLING SYSTEM WARRANTY UNDER JEOPARDY. Shown in Table 1 are the only current licensed and approved providers of DEX-COOL(R). Products that are advertised as "COMPATIBLE" or "RECOMMENDED" for use with DEX-COOL(R) have not been tested or approved by General Motors. Non-approved coolants may degrade the Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Coolant > Component Information > Technical Service Bulletins > Cooling System - Coolant Recycling Information > Page 2385 coolant system integrity and will no longer be considered a 5 yr/150,000 mile (240,000 km) coolant. Coolant Removal Services/Recycling The tables include all coolant recycling processes currently approved by GM. Also included is a primary phone number and demographic information. Used DEX-COOL(R) can be combined with used conventional coolant (green) for recycling. Depending on the recycling service and/or equipment, it is then designated as a conventional 2 yr/30,000 mile (50,000 km) coolant or DEX-COOL(R) 5 yr/150,000 mile (240,000 km) coolant. Recycled coolants as designated in this bulletin may be used during the vehicle(s) warranty period. DEX-COOL(R) Recycling The DEX-COOL(R) recycling service listed in Table 2 has been approved for recycling waste engine coolants (DEX-COOL) or conventional) to DEX-COOL(R) with 5 yr/150,000 mile (240,000 km) usability. Recycling Fluid Technologies is the only licensed provider of Recycled DEX-COOL(R) meeting GM6277M specifications and utilizes GM approved inhibitor packages. This is currently a limited program being monitored by GM Service Operations which will be expanded as demand increases. Conventional (Green) Recycling Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Coolant > Component Information > Technical Service Bulletins > Cooling System - Coolant Recycling Information > Page 2386 Processes shown in the Table 3 are capable of recycling waste engine coolants (DEX-COOL(R) or conventional) to a conventional (green) coolant. Recycling conventional coolant can be accomplished at your facility by a technician using approved EQUIPMENT (listed by model number in Table 3), or by an approved coolant recycling SERVICE which may recycle the coolant at your facility or at an offsite operation. Refer to the table for GM approved coolant recyclers in either of these two categories. Should you decide to recycle the coolant yourself, strict adherence to the operating procedures is imperative. Use ONLY the inhibitor chemicals supplied by the respective (GM approved) recycling equipment manufacturer. Sealing Tablets Cooling System Sealing Tablets (Seal Tabs) should not be used as a regular maintenance item after servicing an engine cooling system. Discoloration of coolant can occur if too many seal tabs have been inserted into the cooling system. This can occur if seal tabs are repeatedly used over the service life of a vehicle. Where appropriate, seal tabs may be used if diagnostics fail to repair a small leak in the cooling system. When a condition appears in which seal tabs may be recommended, a specific bulletin will be released describing their proper usage. Water Quality The integrity of the coolant is dependent upon the quality of DEX-COOL(R) and water. DEX-COOL(R) is a product that has enhanced protection capability as well as an extended service interval. These enhanced properties may be jeopardized by combining DEX-COOL(R) with poor quality water. If you suspect the water in your area of being poor quality, it is recommended you use distilled or de-ionized water with DEX-COOL(R). "Pink" DEX-COOL(R) DEX-COOL(R) is orange in color to distinguish it from other coolants. Due to inconsistencies in the mixing of the dyes used with DEX-COOL(R), some batches may appear pink after time. The color shift from orange to pink does not affect the integrity of the coolant, and still maintains the 5 yr/150,000 mile (240,000 km) service interval. Back Service Only use DEX-COOL(R) if the vehicle was originally equipped with DEX-COOL(R). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Coolant > Component Information > Technical Service Bulletins > Cooling System - Coolant Recycling Information > Page 2387 Contamination Mixing conventional green coolant with DEX-COOL(R) will degrade the service interval from 5 yrs./150,000 miles (240,000 km) to 2 yrs./30,000 miles (50,000 km) if left in the contaminated condition. If contamination occurs, the cooling system must be flushed twice immediately and re-filled with a 50/50 mixture of DEX-COOL(R) and clean water in order to preserve the enhanced properties and extended service interval of DEX-COOL(R). After 5 years/150,000 miles (240,000 km) After 5 yrs/150,000 miles (240,000 km), the coolant should be changed, preferably using a coolant exchanger. If the vehicle was originally equipped with DEX-COOL(R) and has not had problems with contamination from non-DEX-COOL(R) coolants, then the service interval remains the same, and the coolant does not need to be changed for another 5 yrs/150,000 miles (240,000 km) Equipment (Coolant Exchangers) The preferred method of performing coolant replacement is to use a coolant exchanger. A coolant exchanger can replace virtually all of the old coolant with new coolant. Coolant exchangers can be used to perform coolant replacement without spillage, and facilitate easy waste collection. They can also be used to lower the coolant level in a vehicle to allow for less messy servicing of cooling system components. It is recommended that you use a coolant exchanger with a vacuum feature facilitates removing trapped air from the cooling system. This is a substantial time savings over repeatedly thermo cycling the vehicle and topping-off the radiator. The vacuum feature also allows venting of a hot system to relieve system pressure. Approved coolant exchangers are available through the GMDE (General Motors Dealer Equipment) program. For refilling a cooling system that has been partially or fully drained for repairs other than coolant replacement, the Vac-N-Fill Coolant Refill Tool (GE-47716) is recommended to facilitate removal of trapped air from the cooling system during refill. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Coolant > Component Information > Technical Service Bulletins > Cooling System - Coolant Recycling Information > Page 2388 Coolant: Technical Service Bulletins Engine Coolant - Information on Back Service File In Section: 6 - Engine Bulletin No: 53-62-02 Date: November, 1995 Subject: DEX-COOL(TM) Engine Coolant - Information on Back service Models: 1994-95 Passenger Cars and Trucks A new extended-life engine coolant called DEX-COOL(TM) is currently being used in all General Motors' vehicles (excluding Chevrolet Geo and Saturn). Refer to bulletin 53-62-01 for general service information. Backservice DEX-COOL(TM) may be used in General Motors vehicles originally built with conventional (green) coolant with the following considerations: ^ Vehicles eligible for back service are 1994 and 1995 models (excluding 1994 J Body with 4 cylinder engines). ^ The service interval for DEX-COOL(TM) introduced into an older model vehicle originally built with "green" coolant will be 2 years/30,000 miles (50,000 Km) (not 5 years/100,000 miles (160,000 Km)). ^ All the "green" coolant must be removed from the cooling system by means of a system flush. This may be accomplished with a water flushing device or a GMDE waterless coolant changer (use a unit dedicated to "green" coolant, not DEX-COOL TM). Important: When using a GMDE waterless coolant changer, conduct the procedure twice, once with water, and once with DEX-COOL(TM) Backservice with DEX-COOL(TM) is advocated because of enhanced water pump seal durability experienced with this coolant. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Coolant > Component Information > Technical Service Bulletins > Cooling System - Coolant Recycling Information > Page 2389 Coolant: Technical Service Bulletins Warranty - Recycled Engine Coolant Policy Group Ref.: Warranty Administration Bulletin No.: 310504 Date: February, 1994 WARRANTY ADMINISTRATION SUBJECT: RECYCLED ENGINE COOLANT POLICY MODELS: 1994 AND PRIOR PASSENGER CARS AND TRUCKS ATTENTION: WARRANTY CLAIMS ADMINISTRATOR AND SERVICE MANAGER General Motors supports the use of recycled engine coolant for warranty repairs/service, providing a GM approved engine coolant recycling system is used. For detailed information on GM approved engine coolant recycling equipment guidelines refer to the following bulletins: Cadillac 93-1-18, GMC Truck 93-6B-34, Chevrolet 93-73-6B, Pontiac 93-6-18, Oldsmobile 1-93-43, Buick 93-6B-1 (Corporate Number 236203). Recycled coolant will be reimbursed at the GMSPO dealer price for new coolant plus the appropriate mark-up. When coolant replacement is required during a warranty repair, it is crucial to assure that only the relative amount of engine coolant concentrate be charged, not the total diluted volume. In other words, if you are using two gallons of pre-diluted (50:50) recycled engine coolant to service a vehicle, you may request reimbursement for one gallon of Goodwrench engine coolant concentrate at the dealer price plus the appropriate warranty parts handling allowance. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Coolant > Component Information > Technical Service Bulletins > Cooling System - Coolant Recycling Information > Page 2390 Coolant: Technical Service Bulletins Coolant - Information on Propylene Glycol Usage File In Section: 6 - Engine Bulletin No.: 43-62-01B Date: April, 1995 Subject: Propylene Glycol Engine Coolant Models: 1994 and Prior Passenger Cars and Trucks This bulletin is being revised to reflect most current information on propylene glycol engine coolant. Please discard Corporate Bulletin Number 4362O1A (Group Reference 6 - Engine). General Motors has been reviewing data supplied on the performance of propylene glycol engine coolant in GM vehicles. It is our conclusion that propylene glycol engine coolant will perform adequately under most vehicle operating conditions. As a result, propylene glycol engine coolant (meeting performance specification GM 1825M) may be used in GM vehicles and will not affect the warranty coverage. Prior to adding propylene glycol engine coolant to the cooling system, all the existing (ethylene glycol) coolant must be removed. This can be accomplished either by utilizing water-based coolant flushing equipment or "waterless quick change" equipment available in the GMDE program. As with any coolant change procedure, be sure to thoroughly purge the heater core and block as well as the radiator before attempting to convert the system to propylene glycol coolant. Freeze/Boil point levels are different for propylene glycol than for ethylene glycol engine coolant. To accurately determine freeze/boil protection level, it is imperative that coolants not be mixed. Removing all the used coolant as previously discussed resolves this concern. Freeze protection of propylene glycol cannot be determined using a standard hydrometer. Rather, a refractometer or test strip must be used. Propylene glycol engine coolants may be recycled in the same manner as conventional ethylene glycol coolant. No adverse effects will be encountered if these coolants are mixed prior to recycling, however, the ratio of propylene glycol coolant to ethylene glycol coolant should be kept low to minimize the effects on freeze point measurements. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Coolant > Component Information > Technical Service Bulletins > Page 2391 Coolant: Specifications Coolant Capacity, Qts. Less A/C .............................................................................................................................................. ........................................................................ 12.1 With A/C ............................................................. ........................................................................................................................................................ 12.1 Radiator Cap Relief Pressure, Lbs. ..................................................................................................... ............................................................................... 15 Thermo. Opening Temp., deg.F ..................... .............................................................................................................................................................. .... 195 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Coolant Level Indicator Lamp > Component Information > Description and Operation Coolant Level Indicator Lamp: Description and Operation This system uses a sensor mounted on the radiator and an indicator light mounted in the instrument panel to warn the driver if coolant level is too low. This light is wired in series with the ignition switch, ECM and the sensor. When the ignition switch is turned to the crank position, the circuit is energized and the indicator light will illuminate. When the ignition switch is turned to the ON position and coolant level is sufficient, the sensor will indicate this to the ECM and the light will turn off. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Coolant Level Indicator Lamp > Component Information > Testing and Inspection > Indicator Lamp Remains Illuminated Coolant Level Indicator Lamp: Testing and Inspection Indicator Lamp Remains Illuminated 1. Turn ignition switch to the On position, then check coolant level and add coolant as necessary. If lamp remains illuminated, proceed to step 2. 2. Disconnect electrical connector at the sensor. If lamp does not illuminate replace the sensor. If lamp remains illuminated, proceed to step 3. 3. Connect electrical lead to the sensor and check for an open circuit between the sensor and the module. Repair or replace as necessary. If circuit is satisfactory, replace the ECM. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Coolant Level Indicator Lamp > Component Information > Testing and Inspection > Indicator Lamp Remains Illuminated > Page 2397 Coolant Level Indicator Lamp: Testing and Inspection Indicator Lamp Will Not Illuminate 1. Turn ignition switch to the crank position, and proceed as follows: a. If lamp illuminates, lamp is satisfactory and connector is properly installed. Proceed to step 2. b. If lamp does not illuminate, check bulb, socket and wiring between socket and module connector. Replace or repair as necessary. 2. Turn ignition switch to the On position and disconnect electrical lead at coolant level sensor mounted on the radiator. If lamp fails to illuminate, check wiring between coolant level sensor connector and ECM for a short circuit to ground. If circuit is satisfactory, replace the ECM. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Radiator Cooling Fan > Fan Blade > Component Information > Service Precautions > Technician Safety Information Fan Blade: Technician Safety Information WARNING: Do not operate engine until fan has first been inspected for cracks and/or separations. If a fan blade is found to be bent or damaged in any way, do not attempt to repair or reuse damaged part. Proper balance is essential in fan assembly operation. Balance cannot be assured once a fan assembly has been found to be bent or damaged and failure may occur during operation, creating an extremely dangerous condition. Always replace damaged fan assembly. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Radiator Cooling Fan > Fan Blade > Component Information > Service Precautions > Technician Safety Information > Page 2403 Fan Blade: Vehicle Damage Warnings WARNING: Do not operate engine until fan has first been inspected for cracks and/or separations. If a fan blade is found to be bent or damaged in any way, do not attempt to repair or reuse damaged part. Proper balance is essential in fan assembly operation. Balance cannot be assured once a fan assembly has been found to be bent or damaged and failure may occur during operation, creating an extremely dangerous condition. Always replace damaged fan assembly. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Radiator Cooling Fan > Fan Clutch > Component Information > Technical Service Bulletins > A/T - Intermittent Downshift/Slip/Cycling Diagnosis Fan Clutch: Technical Service Bulletins A/T - Intermittent Downshift/Slip/Cycling Diagnosis File In Section: 07 Transmission/Transaxle Bulletin No.: 99-07-30-016B Date: October, 2002 INFORMATION Subject: Diagnostic Information For Intermittent Transmission Downshift, Slip, Busy/cycling TCC or Noisy Cooling Fan Models: 1999-2000 Cadillac Escalade 2002-2003 Cadillac Escalade, Escalade EXT 1988-2003 Chevrolet Astro, Blazer, S-10, Silverado, Suburban 1989-2003 Chevrolet/Geo Tracker 1995-2003 Chevrolet Tahoe 1996-2003 Chevrolet Express 1988-1994 GMC S-15 1988-1999 GMC Suburban 1988-2003 GMC Safari, Sierra 1995-2003 GMC Sonoma, Yukon, Yukon XL 1996-2003 GMC Savana 1999-2001 GMC Envoy 1991-2001 Oldsmobile Bravada 2003 HUMMER H2 with Air Conditioning This bulletin is being revised to change the Model information and text. Please discard Corporate Bulletin Number 99-07-30-016A (Section 07 - Transmission/Transaxle) Some customers may comment that at times the transmission seems to slip, or that there is a loud roar from the engine with slow acceleration. This condition is most noticeable after the vehicle has sat idle for 12 or more hours, or on hot days when the A/C is on and the vehicle moves slowly with traffic. Typical comments from customers may include the following conditions: ^ Intermittent slipping ^ Intermittent downshift followed by an upshift, both with no apparent reason ^ Busyness or cycling of the TCC (torque converter clutch) at steady throttle conditions and on a level roadway ^ Noisy cooling fan The type of concern described above requires further definition. The customer should be asked the following questions: ^ Is the situation more pronounced with higher vehicle loads such as when pulling a trailer? ^ Do warmer ambient temperatures make the situation more pronounced? ^ When the condition occurred, did you have the A/C on, and were you driving in stop and go city traffic? ^ Does the condition exhibit itself on the first start-up after sitting more than eight hours? If the customer indicates that these conditions apply, and your observation confirms that the vehicle is operating properly, provide the customer with the vehicle operating description included at the end of this bulletin. Further action may not be necessary. A service procedure follows if further definition is required. Diagnostic Aids Cooling fan operation or the resulting sound varies. The cooling fan clutch may be described as a continuously variable clutch. If the vehicle engine is running, the fan blade is always turning unless the fan clutch is non-functional. The speed of the fan in relation to engine speed is temperature dependent. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Radiator Cooling Fan > Fan Clutch > Component Information > Technical Service Bulletins > A/T - Intermittent Downshift/Slip/Cycling Diagnosis > Page 2408 Maximum fan speed (air flow and related fan noise) through the engine compartment is experienced under two conditions. 1. When the vehicle sits in an unused condition for several hours, the viscous fluid within the thermostatic fan clutch assembly migrates and fully engages the clutch of the fan. After a short drive, the viscous fluid will migrate to the storage area in the fan clutch and the fan clutch will slip, reducing the noise (roar of the fan). This is normal thermostatic fan clutch operation. 2. When the engine is running, and the air being drawn by the fan or pushed through the radiator from the vehicle movement reaches a high enough temperature, the fan clutch will fully engage the fan clutch, drawing additional air through the radiator to lower the engine coolant temperature and A/C refrigerant temperature. When the cooling fan clutch fully engages, fan noise increases (for example; this is the same as switching an electric household fan from low to high speed). Some customers have interpreted this sound increase to be an increase in the engine RPM due to transmission downshift, transmission slipping, or TCC cycling. As the engine coolant temperature decreases, the fan clutch will begin to slip, lowering the actual speed of the fan blade and the resultant sound. Service Procedure When diagnosing an intermittent transmission downshift, slip, or busy/cycling TCC, follow these steps: 1. Verify the transmission fluid level and the fluid condition. Refer to the Automatic Transmission sub-section of the appropriate Service Manual. 2. Test drive the vehicle under the conditions described by the customer (ambient temperature, engine coolant temperature, trailering, etc.). It may be necessary to partially restrict airflow to the radiator in order to raise the engine coolant temperature to match the customer's conditions. 3. Monitor the engine RPM and the engine coolant temperature using a scan tool. 4. Listen for an actual increase in the engine RPM. Use either the vehicle tachometer (if equipped), the Tech 2 RPM or transmission slip speed as an indicator, rather than just the sound. If the engine RPM display on the tachometer or the Tech 2 increases, verify the scan tool RPM and coolant temperature readings. If the noise increase is due to the engagement of the fan, the engine RPM will not increase and the engine coolant temperature will begin to decrease after the fan engages. As the fan runs, the engine coolant temperature will drop and the fan will disengage, reducing noise levels. The engine RPM will not decrease. This cycle will repeat as the engine coolant temperature rises again. If the above procedure shows the condition to be cooling fan-related, no further action is necessary. The vehicle should be returned to the customer and the condition explained. If the above procedure shows the condition to be other than cooling fan-related, refer to the Automatic Transmission sub-section of the appropriate Service Manual for transmission diagnosis information. The following information regarding the operation of the engine cooling fan should be photocopied and given to the customer. Intermittent Transmission Downshift All light duty trucks are equipped with a thermostatic engine cooling fan. This fan is designed to provide greater fuel efficiency and quieter operation than a standard fan. These benefits are possible through the addition of a thermostatic clutch to the fan drive. When the engine is cool (it the engine has been run in the last few hours), the clutch allows the fan to "slip" or turn at a speed slower than the engine. By turning at a slower speed, the fan uses less horsepower, which saves fuel, and is quieter. When the engine temperature reaches a preset temperature or if the engine has not been run for several hours, the fan "engages" and turns at the same speed as the engine. "Engagement" of the fan provides increased airflow through the radiator to cool the engine. As the airflow increases, fan operation becomes clearly audible. This increase in noise can easily be mistaken for an increase in engine RPM and may be incorrectly blamed on the automatic transmission. When operating an unloaded vehicle in cooler ambient temperatures, the thermostatic clutch usually won't fully engage. However, if the vehicle is pulling a trailer, is heavily loaded or is operated at high ambient temperatures, the thermostatic fan clutch may cycle on and off as the engine coolant temperature rises and falls. The sound of fan operation under the conditions described above is a sign that the cooling system on your vehicle is working correctly. Replacement or modification of the cooling system or the transmission parts will not change or reduce the noise level. Attempts to reduce this noise may cause you, the customer, to believe that your vehicle is not reliable and will inconvenience you by causing your vehicle to be out of service. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Radiator Cooling Fan > Fan Clutch > Component Information > Technical Service Bulletins > A/T - Intermittent Downshift/Slip/Cycling Diagnosis > Page 2409 DISCLAIMER Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Radiator Cooling Fan > Fan Clutch > Component Information > Technical Service Bulletins > Page 2410 Fan Clutch: Description and Operation Fan Drive Clutch Assembly Variable Speed Fan W/Bi-Metallic Coiled Thermostatic Spring The fan drive clutch, Fig. 1, is a fluid coupling containing silicone oil. Fan speed is regulated by the torque-carrying capacity of the silicone oil. The more silicone oil in the coupling, the greater the fan speed, and the less silicone oil, the slower the fan speed. The type of fan drive clutch in use is a coiled bimetallic thermostatic spring, Fig. 2. The fan drive clutch uses a heat-sensitive, coiled bimetallic spring connected to an opening plate which regulates the flow of silicone oil into the coupling from a reserve chamber. The silicone oil is returned to the reserve chamber through a bleed hole when the valve is closed. This unit causes the fan speed to increase with a rise in temperature and to decrease as temperature decreases. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Radiator Cooling Fan > Fan Clutch > Component Information > Testing and Inspection > Clutch Fluid Leak Fan Clutch: Testing and Inspection Clutch Fluid Leak Small fluid leaks do not generally affect the operation of the unit. These leaks generally occur around the area of the bearing assembly, but if the leaks appear to be excessive, engine overheating may occur. Clutch and fan free-wheeling can cause overheating. To check for clutch and fan free-wheeling, turn the motor "OFF." Spin the fan and clutch assembly by hand. If the fan spins five or more times before it stops, replace the clutch. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Radiator Cooling Fan > Fan Clutch > Component Information > Testing and Inspection > Clutch Fluid Leak > Page 2413 Fan Clutch: Testing and Inspection Engine Overheating 1. Start with cool engine to ensure complete fan clutch disengagement. 2. If fan and clutch assembly free wheels with no drag (revolves more than five times when spun by hand), replace clutch. If clutch performs properly with slight drag, proceed to following step. 3. Position thermometer so it is located between fan blades and radiator, noting the following: a. Insert thermometer sensor through one of existing holes in fan shroud or place between radiator and shroud. It may be necessary to drill a 3/16 inch hole in fan shroud to insert thermometer. b. Check for adequate clearance between fan blades and thermometer sensor before starting engine, as damage could occur. 4. With thermometer in position, cover radiator grill sufficiently to induce high engine temperature. 5. Start engine, then turn on air conditioning and operate at 2000 RPM. 6. Observe thermometer reading when clutch disengages, noting the following: a. It will take approximately five to ten minutes for temperature to become high enough to allow engagement of fan clutch. This will be indicated by a 5-15 degrees F drop in thermometer reading. b. If clutch did not engage between 150-195 degrees F, unit should be replaced. Ensure fan clutch was disengaged at beginning of test. c. If no sharp increase in fan noise or temperature drop was observed and fan noise level was constantly high from start of test to 190 degrees F, unit should be replaced. Do not continue this test past thermometer reading of 190 degrees F to prevent engine overheating. 7. As soon as clutch engages, remove radiator grill cover and turn A/C off to assist in engine cooling. Run engine at approximately 1500 RPM. 8. After several minutes, fan clutch should disengage as indicated by reduction in fan speed and roar. If fan clutch fails to function as described, replace it. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Radiator Cooling Fan > Fan Clutch > Component Information > Testing and Inspection > Clutch Fluid Leak > Page 2414 Fan Clutch: Testing and Inspection Fan Clutch Noise Fan clutch noise can sometimes be noticed when clutch is engaged for maximum cooling. Clutch noise is also noticeable within the first few minutes after starting engine while clutch is redistributing the silicone fluid back to its normal, disengaged operating condition after settling for long periods of time (overnight). However, continuous fan noise or an excessive roar indicates the clutch assembly is locked-up due to internal failure. This condition can be checked by attempting to manually rotate fan. If fan cannot be rotated manually or there is a rough, abrasive feel as fan is rotated, the clutch should be replaced. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Radiator Cooling Fan > Fan Clutch > Component Information > Testing and Inspection > Clutch Fluid Leak > Page 2415 Fan Clutch: Testing and Inspection Fan Looseness Lateral movement can be observed at the fan blade tip under various temperature conditions because of the type bearing used. This movement should not exceed 1/4 inch (6.5 mm) as measured at the fan tip. If this lateral movement does not exceed specifications, there is no cause for replacement. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Radiator Cooling Fan > Fan Clutch > Component Information > Testing and Inspection > Page 2416 Fan Clutch: Service and Repair To prevent silicone fluid from draining into fan drive bearing, do not store or place drive unit on bench with rear of shaft pointing downward. The coil spring type fan clutch cannot be disassembled, serviced or repaired. If it does not function properly, it must be replaced with a new unit. To replace the fan clutch, use the following procedure: 1. Remove the radiator fan shroud. 2. Unfasten the unit from the water pump, then remove the assembly from vehicle. 3. Separate fan from fan clutch. 4. Reverse procedure to install, noting the following: a. Ensure mating surfaces of water pump hub and fan clutch hub are smooth and free of any burrs. b. Align yellow reference marks on water pump hub and fan clutch hub. c. Torque nuts to 18 ft. lbs. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Specifications Coolant Temperature Sensor/Switch (For Computer): Specifications Resistance 185 ohms at 210 deg F 450 ohms at 160 deg F 1800 ohms at 100 deg F 3400 ohms at 70 deg F 7500 ohms at 40 deg F 13500 ohms at 20 deg F 25000 ohms at 0 deg F 100700 ohms at -40 deg F Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Specifications > Page 2421 Coolant Temperature Sensor/Switch (For Computer): Locations Engine Coolant Temperature Sensor Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Specifications > Page 2422 Engine Harness, Right Front Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions Coolant Temperature Sensor/Switch (For Computer): Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. Use this page as a reference to determine the meaning of an abbreviation if necessary. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery Bi-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CHMSL Center High Mount Stoplamp CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRO Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2425 F-PUMP Fuel Pump FLASH Flasher FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2426 SIR Supplemental Inflatable Restraint SKT Socket SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature TIL Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2427 example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE (ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: ^ Slide across the vehicle seat. ^ Sit down or stand up. ^ Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: ^ They are bumped or dropped. ^ They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2428 Symbols (Part 1 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2429 Symbols (Part 2 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2430 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2431 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2432 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2433 Coolant Temperature Sensor/Switch (For Computer): Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2434 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2435 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2436 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2437 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2438 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. ^ If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. ^ A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2439 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2440 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2441 Ohmmeter Meter Scales Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2442 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. ^ An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. ^ On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: ^ A range selector switch which permits the selection of different ranges of resistance. ^ A set adjust control which allows the meter to be set at zero for accurate measurements. ^ Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2443 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: ^ Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. ^ Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. ^ Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2444 be less than 10 percent of the total drop. When using a voltmeter: ^ Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. ^ Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. ^ The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: ^ Check the accuracy and completeness of the complaint. ^ Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2445 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. ^ The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2446 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2447 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2448 Twisted/Shielded Wire Repair Twisted Wires Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2449 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2450 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2451 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). ^ Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean ^ Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. ^ Roll crimp (13) and solder the terminal. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2452 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2453 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2454 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. ^ Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean ^ Terminal cavity of the connector body. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2455 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. ^ Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2456 C105 - Engine Coolant Temperature Sensor Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2457 Engine Coolant Temperature (ECT) Circuit Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Page 2458 Coolant Temperature Sensor/Switch (For Computer): Description and Operation Engine Coolant Temperature Sensor PURPOSE The Engine Coolant Temperature (ECT) Sensor information is used by the control module to control: Fuel delivery - Torque Converter Clutch (TCC) - Engine Spark Timing (EST) - Controlled Canister Purge (CCP) - Idle Air Control (IAC) - Cooling Fan OPERATION The ECT is a thermistor that is located in the engine coolant flow mounted to the intake manifold. When the coolant temperature is low, the sensor produces a high resistance. When the coolant temperature is high, the sensor produces a low resistance. The PCM sends a 5.0 volt signal to the ECT through a resistor in the computer and measures the voltage. The voltage will be high or low depending on coolant temperature. With the ECT varying its resistance, the PCM can sense engine coolant temperature by reading the varying voltage. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Temperature Sensor (Gauge) > Component Information > Locations Temperature Sensor (Gauge): Locations ENGINE COOLANT TEMPERATURE SENSOR Right Front Engine Harness Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Temperature Sensor (Gauge) > Component Information > Locations > Page 2462 Engine Harness, Right Front NOTE: The OEM service manual provides multiple location views for this component. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Engine - Coolant Temperature Sensor/Switch > Temperature Sensor (Gauge) > Component Information > Locations > Page 2463 C108 - Eng Coolant Temp Sender Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Heater Core > Component Information > Technical Service Bulletins > Cooling System, A/C - Aluminum Heater Cores/Radiators Heater Core: Technical Service Bulletins Cooling System, A/C - Aluminum Heater Cores/Radiators INFORMATION Bulletin No.: 05-06-02-001A Date: July 16, 2008 Subject: Information On Aluminum Heater Core and/or Radiator Replacement Models: 2005 and Prior GM Passenger Cars and Light Duty Trucks (including Saturn) 2003-2005 HUMMER H2 Supercede: This bulletin is being revised to update the Warranty Information. Please discard Corporate Bulletin Number 05-06-02-001 (Section 06 - Engine/Propulsion System). Important: 2004-05 Chevrolet Aveo (Pontiac Wave, Canada Only) does not use DEX-COOL(R). Refer to the flushing procedure explained later in this bulletin. The following information should be utilized when servicing aluminum heater core and/or radiators on repeat visits. A replacement may be necessary because erosion, corrosion, or insufficient inhibitor levels may cause damage to the heater core, radiator or water pump. A coolant check should be performed whenever a heater core, radiator, or water pump is replaced. The following procedures/ inspections should be done to verify proper coolant effectiveness. Caution: To avoid being burned, do not remove the radiator cap or surge tank cap while the engine is hot. The cooling system will release scalding fluid and steam under pressure if the radiator cap or surge tank cap is removed while the engine and radiator are still hot. Important: If the vehicle's coolant is low, drained out, or the customer has repeatedly added coolant or water to the system, then the system should be completely flushed using the procedure explained later in this bulletin. Technician Diagnosis ^ Verify coolant concentration. A 50% coolant/water solution ensures proper freeze and corrosion protection. Inhibitor levels cannot be easily measured in the field, but can be indirectly done by the measurement of coolant concentration. This must be done by using a Refractometer J 23688 (Fahrenheit scale) or J 26568 (centigrade scale), or equivalent, coolant tester. The Refractometer uses a minimal amount of coolant that can be taken from the coolant recovery reservoir, radiator or the engine block. Inexpensive gravity float testers (floating balls) will not completely analyze the coolant concentration fully and should not be used. The concentration levels should be between 50% and 65% coolant concentrate. This mixture will have a freeze point protection of -34 degrees Fahrenheit (-37 degrees Celsius). If the concentration is below 50%, the cooling system must be flushed. ^ Inspect the coolant flow restrictor if the vehicle is equipped with one. Refer to Service Information (SI) and/or the appropriate Service Manual for component location and condition for operation. ^ Verify that no electrolysis is present in the cooling system. This electrolysis test can be performed before or after the system has been repaired. Use a digital voltmeter set to 12 volts. Attach one test lead to the negative battery post and insert the other test lead into the radiator coolant, making sure the lead does not touch the filler neck or core. Any voltage reading over 0.3 volts indicates that stray current is finding its way into the coolant. Electrolysis is often an intermittent condition that occurs when a device or accessory that is mounted to the radiator is energized. This type of current could be caused from a poorly grounded cooling fan or some other accessory and can be verified by watching the volt meter and turning on and off various accessories or engage the starter motor. Before using one of the following flush procedures, the coolant recovery reservoir must be removed, drained, cleaned and reinstalled before refilling the system. Notice: ^ Using coolant other than DEX‐COOL(R) may cause premature engine, heater core or radiator corrosion. In addition, the engine coolant may require changing sooner, at 30,000 miles (50,000 km) or 24 months, whichever occurs first. Any repairs would not be covered by your warranty. Always use DEX‐COOL(R) (silicate free) coolant in your vehicle. ^ If you use an improper coolant mixture, your engine could overheat and be badly damaged. The repair cost would not be covered by your warranty. Too much water in the mixture can freeze and crack the engine, radiator, heater core and other parts. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Heater Core > Component Information > Technical Service Bulletins > Cooling System, A/C - Aluminum Heater Cores/Radiators > Page 2468 Flushing Procedures using DEX-COOL(R) Important: The following procedure recommends refilling the system with DEX-COOL(R), P/N 12346290 (in Canada, use P/N 10953464), GM specification 6277M. This coolant is orange in color and has a service interval of 5 years or 240,000 km (150,000 mi). However, when used on vehicles built prior to the introduction of DEX-COOL(R), maintenance intervals will remain the same as specified in the Owner's Manual. ^ If available, use the approved cooling system flush and fill machine (available through the GM Dealer Equipment Program) following the manufacturer's operating instructions. ^ If approved cooling system flush and fill machine is not available, drain the coolant and dispose of properly following the draining procedures in the appropriate Service Manual. Refill the system using clear, drinkable water and run the vehicle until the thermostat opens. Repeat and run the vehicle three (3) times to totally remove the old coolant or until the drained coolant is almost clear. Once the system is completely flushed, refill the cooling system to a 50%-60% concentration with DEX‐COOL(R), P/N 12346290 (in Canada, use P/N 10953464), GM specification 6277M, following the refill procedures in the appropriate Service Manual. If a Service Manual is not available, fill half the capacity of the system with 100% DEX-COOL(R), P/N 12346290 (in Canada, use P/N 10953464), GM specification 6277M. Then slowly add clear, drinkable water (preferably distilled) to the system until the level of the coolant mixture has reached the base of the radiator neck. Wait two (2) minutes and reverify the coolant level. If necessary, add clean water to restore the coolant to the appropriate level. Once the system is refilled, reverify the coolant concentration using a Refractometer J 23688 (Fahrenheit scale) or J 26568 (centigrade scale) coolant tester, or equivalent. The concentration levels should be between 50% and 65%. Flushing Procedures using Conventional Silicated (Green Colored) Coolant Important: 2004-2005 Chevrolet Aveo (Pontiac Wave, Canada Only) does not use DEX‐COOL(R). The Aveo and Wave are filled with conventional, silicated engine coolant that is blue in color. Silicated coolants are typically green in color and are required to be drained, flushed and refilled every 30,000 miles (48,000 km). The Aveo and Wave are to be serviced with conventional, silicated coolant. Use P/N 12378560 (1 gal) (in Canada, use P/N 88862159 (1 L). Refer to the Owner's Manual or Service Information (SI) for further information on OEM coolant. Important: Do not mix the OEM orange colored DEX-COOL(R) coolant with green colored coolant when adding coolant to the system or when servicing the vehicle's cooling system. Mixing the orange and green colored coolants will produce a brown coolant which may be a customer dissatisfier and will not extend the service interval to that of DEX-COOL(R). Conventional silicated coolants offered by GM Service and Parts Operations are green in color. ^ If available, use the approved cooling system flush and fill machine (available through the GM Dealer Equipment Program) following the manufacturer's operating instructions. ^ If approved cooling systems flush and fill machine is not available, drain coolant and dispose of properly following the draining procedures in appropriate Service Manual. Refill the system using clear, drinkable water and run vehicle until thermostat opens. Repeat and run vehicle three (3) times to totally remove old coolant or until drained coolant is almost clear. Once the system is completely flushed, refill the cooling system to a 50%-60% concentration with a good quality ethylene glycol base engine coolant, P/N 12378560, 1 gal (in Canada, use P/N 88862159 1 L), conforming to GM specification 1825M, or recycled coolant conforming to GM specification 1825M, following the refill procedures in the appropriate Service Manual. If a Service Manual is not available, fill half the capacity of the system with 100% good quality ethylene glycol base (green colored) engine coolant, P/N 12378560 1 gal., (in Canada, use P/N 88862159 1 L) conforming to GM specification 1825M. Then slowly add clear, drinkable water (preferably distilled) to system until the level of the coolant mixture has reached the base of the radiator neck. Wait two (2) minutes and recheck coolant level. If necessary, add clean water to restore coolant to the appropriate level. Once the system is refilled, recheck the coolant concentration using a Refractometer J 23688 (Fahrenheit scale) or J 26568 (centigrade scale) coolant tester, or equivalent. Concentration levels should be between 50% and 65%. Parts Information Warranty Information Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Heater Core > Component Information > Technical Service Bulletins > Cooling System, A/C - Aluminum Heater Cores/Radiators > Page 2469 For vehicles repaired under warranty, use the table. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Heater Core > Component Information > Technical Service Bulletins > Page 2470 Heater Core: Description and Operation In any air conditioning mode, the heater core can be used to heat the cool dehumidified air to achieve the desired air temperature. The position of the control assembly temperature selector will determine how much heat will be added to the incoming air. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Heater Core > Component Information > Service and Repair > Heater Core Replacement Heater Core: Service and Repair Heater Core Replacement Figure 41: Heater Assembly Component View HEATER CORE REPLACEMENT Remove Or Disconnect 1. Engine coolant. 2. Heater hoses. - Refer to "Heater Hose". See: Heater Hose Replacement 3. Instrument panel. - Refer to "Dash Board" under Body and Frame / Interior Trim. See: Body and Frame/Interior Moulding / Trim/Dash Board / Instrument Panel 4. Rear case screws. (88) 5. Rear case. (96) 6. Screws. (94) 7. Straps. (93) 8. Heater core. (92) 9. Seals. (89 & 90) Install Or Connect 1. Seals. (89 & 90) 2. Heater core. (92) 3. Straps. (93) 4. Screws. (94) 5. Rear case. (96) 6. Rear case screws. (88) 7. Instrument panel. 8. Heater hoses. 9. Engine coolant. - Check the system for leaks. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Heater Core > Component Information > Service and Repair > Heater Core Replacement > Page 2473 Heater Core: Service and Repair Heater Hose Replacement HEATER HOSE REPLACEMENT Heater Hose Routing To Heater Heater Hose Routing To The Engine Heater Hose Routing To Heater Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Heater Core > Component Information > Service and Repair > Heater Core Replacement > Page 2474 Heater Hose Routing Through The Retainer Heater Hose Routing Through The Thermostat Housing Bracket Retainer REMOVE OR DISCONNECT 1. Engine coolant. 2. Heater inlet hose clamps. 3. Heater inlet hose from heater hose fitting. 4. Heater inlet hose from heater core. 5. Heater outlet hose clamps. 6. Heater outlet hose from heater hose fitting. 7. Heater outlet hose from heater core. INSTALL OR CONNECT 1. Heater outlet hose to heater core. 2. Heater outlet hose to heater hose fitting. 3. Heater outlet hose clamps. 4. Heater inlet hose to heater core. 5. Heater inlet hose to heater hose fitting. 6. Heater inlet hose clamps. 7. Engine coolant. ^ Check the system for leaks. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Heater Hose > Component Information > Specifications Heater Hose: Specifications Heater Inlet Hose Mounting Screw ....................................................................................................................................................... 1.4 Nm (12 lbs. in.) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Heater Hose > Component Information > Service and Repair > Heater Inlet Hose Heater Hose: Service and Repair Heater Inlet Hose With A/C Heater Hose Routing-With A/C REMOVE OR DISCONNECT Tool Required: - J 38723 Heater Line Quick Connect Separator or Equivalent 1. Air cleaner. 2. Engine coolant. 3. Inlet hose mounting screw. 4. Inlet hose clamp at heater core. NOTE: Loosen the clamp enough to slide away from the fitting on the inlet hose (72). 5. Inlet hose (72) from heater core. 6. Push inlet hose (72) into connector and insert J 38723 or equivalent into connector to release locking tabs. 7. Pull retainer and hose (72) from heater inlet connector. Inspect Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Heater Hose > Component Information > Service and Repair > Heater Inlet Hose > Page 2480 - O-ring sealing surface on hose/pipe. Adjust - If replacing heater inlet connector remove retainer from hose and discard as new connector is equipped with retainer. - If replacing hose, remove retainer from hose and reinsert in connector. - If reusing hose and connector, retainer can remain in place on hose. INSTALL OR CONNECT 1. Push hose (72) into connector until retainer tabs lock. NOTE: Pull back on hose to check for proper engagement. 2. Inlet hose (72) to heater core. 3. Inlet hose clamp. NOTICE: Refer to "Fasteners" under "Vehicle Damage Warnings." 4. Inlet hose mounting screw. - Tighten screw to 1.4 Nm (12 lbs. in.). 5. Engine coolant. 6. Air cleaner. - Check the system for leaks. Without A/C Heater Hose Routing W/out A/C REMOVE OR DISCONNECT Tool Required: Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Heater Hose > Component Information > Service and Repair > Heater Inlet Hose > Page 2481 - J 38723 Heater Line Quick Connect Separator or Equivalent 1. Air cleaner. 2. Engine coolant. 3. Inlet hose mounting screw. 4. Inlet hose clamp at heater core. NOTE: Loosen the clamp enough to slide away from the fitting on the inlet hose (72). 5. Inlet hose (72) from heater core. 6. Push inlet hose (72) into connector and insert J 38723 or equivalent into connector to release locking tabs. 7. Pull retainer and hose (72) from heater inlet connector. Inspect - O-ring sealing surface on hose/pipe. Adjust - If replacing heater inlet connector remove retainer from hose and discard as new connector is equipped with retainer. - If replacing hose, remove retainer from hose and reinsert in connector. - If reusing hose and connector, retainer can remain in place on hose. INSTALL OR CONNECT 1. Push hose (72) into connector until retainer tabs lock. NOTE: Pull back on hose to check for proper engagement. 2. Inlet hose (72) to heater core. 3. Inlet hose clamp. NOTICE: Refer to "Fasteners" under "Vehicle Damage Warnings." 4. Inlet hose mounting screw. - Tighten screw to 1.4 Nm (12 lbs. in.). 5. Engine coolant. 6. Air cleaner. - Check the system for leaks. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Heater Hose > Component Information > Service and Repair > Heater Inlet Hose > Page 2482 Heater Hose: Service and Repair Heater Outlet Hose With A/C Heater Hose Routing-With A/C REMOVE OR DISCONNECT 1. Engine coolant. 2. Hose clamps. 3. Outlet hose (70) from heater core. 4. Outlet hose (70) from radiator. INSTALL OR CONNECT 1. Outlet hose (70) to radiator. 2. Outlet hose (70) to heater core. 3. Hose clamps. 4. Engine coolant. - Check the system for leaks. Without A/C Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Heater Hose > Component Information > Service and Repair > Heater Inlet Hose > Page 2483 Heater Hose Routing W/out A/C REMOVE OR DISCONNECT 1. Engine coolant. 2. Hose clamps. 3. Outlet hose (70) from heater core. 4. Outlet hose (70) from radiator. INSTALL OR CONNECT 1. Outlet hose (70) to radiator. 2. Outlet hose (70) to heater core. 3. Hose clamps. 4. Engine coolant. - Check the system for leaks. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Heater Hose > Component Information > Service and Repair > Page 2484 Special Tool Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Lamps and Indicators - Cooling System > Coolant Level Indicator Lamp > Component Information > Description and Operation Coolant Level Indicator Lamp: Description and Operation This system uses a sensor mounted on the radiator and an indicator light mounted in the instrument panel to warn the driver if coolant level is too low. This light is wired in series with the ignition switch, ECM and the sensor. When the ignition switch is turned to the crank position, the circuit is energized and the indicator light will illuminate. When the ignition switch is turned to the ON position and coolant level is sufficient, the sensor will indicate this to the ECM and the light will turn off. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Lamps and Indicators - Cooling System > Coolant Level Indicator Lamp > Component Information > Testing and Inspection > Indicator Lamp Remains Illuminated Coolant Level Indicator Lamp: Testing and Inspection Indicator Lamp Remains Illuminated 1. Turn ignition switch to the On position, then check coolant level and add coolant as necessary. If lamp remains illuminated, proceed to step 2. 2. Disconnect electrical connector at the sensor. If lamp does not illuminate replace the sensor. If lamp remains illuminated, proceed to step 3. 3. Connect electrical lead to the sensor and check for an open circuit between the sensor and the module. Repair or replace as necessary. If circuit is satisfactory, replace the ECM. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Lamps and Indicators - Cooling System > Coolant Level Indicator Lamp > Component Information > Testing and Inspection > Indicator Lamp Remains Illuminated > Page 2491 Coolant Level Indicator Lamp: Testing and Inspection Indicator Lamp Will Not Illuminate 1. Turn ignition switch to the crank position, and proceed as follows: a. If lamp illuminates, lamp is satisfactory and connector is properly installed. Proceed to step 2. b. If lamp does not illuminate, check bulb, socket and wiring between socket and module connector. Replace or repair as necessary. 2. Turn ignition switch to the On position and disconnect electrical lead at coolant level sensor mounted on the radiator. If lamp fails to illuminate, check wiring between coolant level sensor connector and ECM for a short circuit to ground. If circuit is satisfactory, replace the ECM. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Lamps and Indicators - Cooling System > Temperature Gauge > Component Information > Technical Service Bulletins > Customer Interest: > 468306 > Dec > 94 > Temperature Gauge - Erratic Temperature Gauge: Customer Interest Temperature Gauge - Erratic File In Section: 8 - Chassis/Body Electrical Bulletin No.: 46-83-06 Date: December, 1994 Subject: Erratic Temperature Gauge (Exchange Instrument Panel Cluster) Models: 1994 Chevrolet and GMC Truck S/T Models with Standard Analog Instrument Panel Cluster Condition Some temperature gauges in the above vehicles may give erratic readings. Cause Improper nut on back of temperature gauge inside the I/P cluster, resulting in erratic voltage feed to gauge. Correction Remove the instrument cluster and send it to your nearest Delco Repair Station. Repair stations are aware of the condition and have pans available to repair the cluster. They will add a capacitor to the power circuit to assure a consistent power flow to the temperature gauge. Be certain to clearly describe the condition on the Delco Repair Order accompanying the cluster. Warranty Information For vehicles repaired under warranty. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Lamps and Indicators - Cooling System > Temperature Gauge > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 468306 > Dec > 94 > Temperature Gauge - Erratic Temperature Gauge: All Technical Service Bulletins Temperature Gauge - Erratic File In Section: 8 - Chassis/Body Electrical Bulletin No.: 46-83-06 Date: December, 1994 Subject: Erratic Temperature Gauge (Exchange Instrument Panel Cluster) Models: 1994 Chevrolet and GMC Truck S/T Models with Standard Analog Instrument Panel Cluster Condition Some temperature gauges in the above vehicles may give erratic readings. Cause Improper nut on back of temperature gauge inside the I/P cluster, resulting in erratic voltage feed to gauge. Correction Remove the instrument cluster and send it to your nearest Delco Repair Station. Repair stations are aware of the condition and have pans available to repair the cluster. They will add a capacitor to the power circuit to assure a consistent power flow to the temperature gauge. Be certain to clearly describe the condition on the Delco Repair Order accompanying the cluster. Warranty Information For vehicles repaired under warranty. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Lamps and Indicators - Cooling System > Temperature Gauge > Component Information > Technical Service Bulletins > All Other Service Bulletins for Temperature Gauge: > 449601 > Apr > 94 > Radio - Buzzing Noise in AM Band With Engine Running Radio/Stereo Noise Filter: All Technical Service Bulletins Radio - Buzzing Noise in AM Band With Engine Running Group Ref.: Accessories Bulletin No.: 449601 Date: April, 1994 SUBJECT: BUZZING NOISE IN AM BAND OF RADIO (INSTALL FILTER ON PCM/TCM) MODELS: 1992-94 CHEVROLET AND GMC TRUCK C/K, S/T TRUCKS AND M/L, G VANS 1992-94 OLDSMOBILE BRAVADA WITH 4L60-E AND 4L80-E TRANSMISSIONS CONDITION: Some owners may comment of a buzzing noise in the low end of the AM radio band with the engine running. CAUSE: The switching of the force motor in the electronic transmission emits an RFI signal through the PCM/TCM. The AM band of the radio is receiving this interference through the antenna. CORRECTION; To determine if this is the cause of the owner's comments. first duplicate the condition and then disconnect the electrical connector at the transmission (this will disable the force motor). If the condition improves. install an in-line filter (P/N 1224205) to the ignition lead (ckt 439) of the PCM/TCM. Some applications may have two (439 ckt), in which case, a filter will be required for each lead. NOTE: Disconnecting the electrical connector at the transmission will set the transmission diagnostic codes. It will be necessary to remove these codes after the corrective action has been performed. IMPORTANT: Discard the instructions in the filter package. This filter Is an in-line filter with a single lead on one end and two leads on the other end (one lead being black (ground). Install this filter as close to the PCM/TCM connector as possible. It Is important to Install the filter with the single lead end going toward the PCM/TCM and then take the black (ground) lead back and attach it to the case of the PCM/TCM. If this filter is installed incorrectly, the condition will become worse. SERVICE PARTS INFORMATION: Parts are currently available from GMSPO. WARRANTY INFORMATION: For vehicles repaired under warranty use: Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Lamps and Indicators - Cooling System > Temperature Gauge > Component Information > Testing and Inspection > Gauge Does Not Move From Cold When Engine Is Hot Temperature Gauge: Testing and Inspection Gauge Does Not Move From Cold When Engine Is Hot This condition is generally caused by a blown fuse, open circuit or faulty sensor. 1. Check fuse, replace if necessary. 2. Turn ignition switch to On position, then remove lead at sensor unit. 3. Connect test lamp from sensor lead to ground, lamp should glow. Short sensor lead to ground, gauge should indicate "Hot." 4. If gauge indicated HOT, check lead on sensor. If satisfactory, replace sensor. If gauge indicates COLD, replace cluster. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Lamps and Indicators - Cooling System > Temperature Gauge > Component Information > Testing and Inspection > Gauge Does Not Move From Cold When Engine Is Hot > Page 2517 Temperature Gauge: Testing and Inspection Gauge Indicates Hot When Engine Is Cold This condition is generally caused by a shorted or grounded circuit. 1. Remove sensor lead at sensor unit. Gauge should move to COLD position, if not check unit for a external short. If no external short is found, replace sensor. 2. If gauge stays HOT, check for a short circuit in gauge to sensor wiring. If circuit is satisfactory, replace cluster. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Lamps and Indicators - Cooling System > Temperature Gauge > Component Information > Testing and Inspection > Gauge Does Not Move From Cold When Engine Is Hot > Page 2518 Temperature Gauge: Testing and Inspection Gauge Reads High 1. Remove lead at sensor, measure resistance using an ohmmeter. 2. At 104 degrees F resistance should be approximately 1200-1350 ohms, and at 125 degrees F resistance should be approximately 53-55 ohms. 3. If resistance is not within specifications, replace sensor. 4. Disconnect lead at sensor and gauge, check for a high resistance using an ohmmeter. Repair wiring if necessary. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Lamps and Indicators - Cooling System > Temperature Gauge > Component Information > Testing and Inspection > Gauge Does Not Move From Cold When Engine Is Hot > Page 2519 Temperature Gauge: Testing and Inspection Gauge Reads Low 1. Ensure terminals are clean and connections are tight. 2. Remove lead at sensor, measure resistance using an ohmmeter. 3. At 104 degrees F resistance should be approximately 1200-1350 ohms, and at 125 degrees F resistance should be approximately 53-55 ohms. 4. If resistance is not within specifications, replace sensor. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Lamps and Indicators - Cooling System > Temperature Warning Lamp/Indicator, Engine Cooling > Component Information > Description and Operation Temperature Warning Lamp/Indicator: Description and Operation A bi-metal temperature switch located in the cylinder head controls the operation of a temperature indicator light. If the engine cooling system is not functioning properly and/or coolant temperature exceeds a predetermined value, the warning light will illuminate. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Lamps and Indicators - Cooling System > Temperature Warning Lamp/Indicator, Engine Cooling > Component Information > Description and Operation > Page 2523 Temperature Warning Lamp/Indicator: Testing and Inspection If the light is not lit when the engine is being cranked, check for a burned out bulb, an open in the light circuit, or a defective ignition switch. If the light is lit when the engine is running, check the wiring between light and switch for a ground, defective temperature switch, or overheated cooling system. As a test circuit to check whether the bulb is functioning properly, connect a wire from the ground terminal of the ignition switch to the temperature indicator light circuit. When the ignition is in the START (engine cranking) position, the ground terminal is grounded inside the switch and the bulb will be lit. When the engine is started and the ignition switch is in the ON position, the test circuit is opened and the bulb is then controlled by the temperature switch. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Radiator > Component Information > Technical Service Bulletins > Cooling System, A/C - Aluminum Heater Cores/Radiators Radiator: Technical Service Bulletins Cooling System, A/C - Aluminum Heater Cores/Radiators INFORMATION Bulletin No.: 05-06-02-001A Date: July 16, 2008 Subject: Information On Aluminum Heater Core and/or Radiator Replacement Models: 2005 and Prior GM Passenger Cars and Light Duty Trucks (including Saturn) 2003-2005 HUMMER H2 Supercede: This bulletin is being revised to update the Warranty Information. Please discard Corporate Bulletin Number 05-06-02-001 (Section 06 - Engine/Propulsion System). Important: 2004-05 Chevrolet Aveo (Pontiac Wave, Canada Only) does not use DEX-COOL(R). Refer to the flushing procedure explained later in this bulletin. The following information should be utilized when servicing aluminum heater core and/or radiators on repeat visits. A replacement may be necessary because erosion, corrosion, or insufficient inhibitor levels may cause damage to the heater core, radiator or water pump. A coolant check should be performed whenever a heater core, radiator, or water pump is replaced. The following procedures/ inspections should be done to verify proper coolant effectiveness. Caution: To avoid being burned, do not remove the radiator cap or surge tank cap while the engine is hot. The cooling system will release scalding fluid and steam under pressure if the radiator cap or surge tank cap is removed while the engine and radiator are still hot. Important: If the vehicle's coolant is low, drained out, or the customer has repeatedly added coolant or water to the system, then the system should be completely flushed using the procedure explained later in this bulletin. Technician Diagnosis ^ Verify coolant concentration. A 50% coolant/water solution ensures proper freeze and corrosion protection. Inhibitor levels cannot be easily measured in the field, but can be indirectly done by the measurement of coolant concentration. This must be done by using a Refractometer J 23688 (Fahrenheit scale) or J 26568 (centigrade scale), or equivalent, coolant tester. The Refractometer uses a minimal amount of coolant that can be taken from the coolant recovery reservoir, radiator or the engine block. Inexpensive gravity float testers (floating balls) will not completely analyze the coolant concentration fully and should not be used. The concentration levels should be between 50% and 65% coolant concentrate. This mixture will have a freeze point protection of -34 degrees Fahrenheit (-37 degrees Celsius). If the concentration is below 50%, the cooling system must be flushed. ^ Inspect the coolant flow restrictor if the vehicle is equipped with one. Refer to Service Information (SI) and/or the appropriate Service Manual for component location and condition for operation. ^ Verify that no electrolysis is present in the cooling system. This electrolysis test can be performed before or after the system has been repaired. Use a digital voltmeter set to 12 volts. Attach one test lead to the negative battery post and insert the other test lead into the radiator coolant, making sure the lead does not touch the filler neck or core. Any voltage reading over 0.3 volts indicates that stray current is finding its way into the coolant. Electrolysis is often an intermittent condition that occurs when a device or accessory that is mounted to the radiator is energized. This type of current could be caused from a poorly grounded cooling fan or some other accessory and can be verified by watching the volt meter and turning on and off various accessories or engage the starter motor. Before using one of the following flush procedures, the coolant recovery reservoir must be removed, drained, cleaned and reinstalled before refilling the system. Notice: ^ Using coolant other than DEX‐COOL(R) may cause premature engine, heater core or radiator corrosion. In addition, the engine coolant may require changing sooner, at 30,000 miles (50,000 km) or 24 months, whichever occurs first. Any repairs would not be covered by your warranty. Always use DEX‐COOL(R) (silicate free) coolant in your vehicle. ^ If you use an improper coolant mixture, your engine could overheat and be badly damaged. The repair cost would not be covered by your warranty. Too much water in the mixture can freeze and crack the engine, radiator, heater core and other parts. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Radiator > Component Information > Technical Service Bulletins > Cooling System, A/C - Aluminum Heater Cores/Radiators > Page 2528 Flushing Procedures using DEX-COOL(R) Important: The following procedure recommends refilling the system with DEX-COOL(R), P/N 12346290 (in Canada, use P/N 10953464), GM specification 6277M. This coolant is orange in color and has a service interval of 5 years or 240,000 km (150,000 mi). However, when used on vehicles built prior to the introduction of DEX-COOL(R), maintenance intervals will remain the same as specified in the Owner's Manual. ^ If available, use the approved cooling system flush and fill machine (available through the GM Dealer Equipment Program) following the manufacturer's operating instructions. ^ If approved cooling system flush and fill machine is not available, drain the coolant and dispose of properly following the draining procedures in the appropriate Service Manual. Refill the system using clear, drinkable water and run the vehicle until the thermostat opens. Repeat and run the vehicle three (3) times to totally remove the old coolant or until the drained coolant is almost clear. Once the system is completely flushed, refill the cooling system to a 50%-60% concentration with DEX‐COOL(R), P/N 12346290 (in Canada, use P/N 10953464), GM specification 6277M, following the refill procedures in the appropriate Service Manual. If a Service Manual is not available, fill half the capacity of the system with 100% DEX-COOL(R), P/N 12346290 (in Canada, use P/N 10953464), GM specification 6277M. Then slowly add clear, drinkable water (preferably distilled) to the system until the level of the coolant mixture has reached the base of the radiator neck. Wait two (2) minutes and reverify the coolant level. If necessary, add clean water to restore the coolant to the appropriate level. Once the system is refilled, reverify the coolant concentration using a Refractometer J 23688 (Fahrenheit scale) or J 26568 (centigrade scale) coolant tester, or equivalent. The concentration levels should be between 50% and 65%. Flushing Procedures using Conventional Silicated (Green Colored) Coolant Important: 2004-2005 Chevrolet Aveo (Pontiac Wave, Canada Only) does not use DEX‐COOL(R). The Aveo and Wave are filled with conventional, silicated engine coolant that is blue in color. Silicated coolants are typically green in color and are required to be drained, flushed and refilled every 30,000 miles (48,000 km). The Aveo and Wave are to be serviced with conventional, silicated coolant. Use P/N 12378560 (1 gal) (in Canada, use P/N 88862159 (1 L). Refer to the Owner's Manual or Service Information (SI) for further information on OEM coolant. Important: Do not mix the OEM orange colored DEX-COOL(R) coolant with green colored coolant when adding coolant to the system or when servicing the vehicle's cooling system. Mixing the orange and green colored coolants will produce a brown coolant which may be a customer dissatisfier and will not extend the service interval to that of DEX-COOL(R). Conventional silicated coolants offered by GM Service and Parts Operations are green in color. ^ If available, use the approved cooling system flush and fill machine (available through the GM Dealer Equipment Program) following the manufacturer's operating instructions. ^ If approved cooling systems flush and fill machine is not available, drain coolant and dispose of properly following the draining procedures in appropriate Service Manual. Refill the system using clear, drinkable water and run vehicle until thermostat opens. Repeat and run vehicle three (3) times to totally remove old coolant or until drained coolant is almost clear. Once the system is completely flushed, refill the cooling system to a 50%-60% concentration with a good quality ethylene glycol base engine coolant, P/N 12378560, 1 gal (in Canada, use P/N 88862159 1 L), conforming to GM specification 1825M, or recycled coolant conforming to GM specification 1825M, following the refill procedures in the appropriate Service Manual. If a Service Manual is not available, fill half the capacity of the system with 100% good quality ethylene glycol base (green colored) engine coolant, P/N 12378560 1 gal., (in Canada, use P/N 88862159 1 L) conforming to GM specification 1825M. Then slowly add clear, drinkable water (preferably distilled) to system until the level of the coolant mixture has reached the base of the radiator neck. Wait two (2) minutes and recheck coolant level. If necessary, add clean water to restore coolant to the appropriate level. Once the system is refilled, recheck the coolant concentration using a Refractometer J 23688 (Fahrenheit scale) or J 26568 (centigrade scale) coolant tester, or equivalent. Concentration levels should be between 50% and 65%. Parts Information Warranty Information Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Radiator > Component Information > Technical Service Bulletins > Cooling System, A/C - Aluminum Heater Cores/Radiators > Page 2529 For vehicles repaired under warranty, use the table. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Radiator > Component Information > Technical Service Bulletins > Cooling System, A/C - Aluminum Heater Cores/Radiators > Page 2530 Radiator: Technical Service Bulletins Cooling - Radiator Repair/Replacement Guidelines File In Section: 06 - Engine/Propulsion System Bulletin No.: 99-06-02-017 Date: October, 1999 INFORMATION Subject: Radiator Repair/Replacement Guidelines Models: 2000 and Prior Passenger Cars and Trucks If repair of an aluminum/plastic radiator is required, it is recommended that the following guidelines be followed: For Vehicles Under Warranty For aluminum/plastic radiators that have damage to the face of the core including bent fins, punctures, cuts, leaking tubes or header tubes, the aluminum radiator core section should be replaced with a new one. In these cases, if both of the plastic tanks are not damaged, they can be reused with the new core. If one or both of the plastic tanks are damaged along with the core, it is recommended that a complete new radiator assembly be installed. Warranty repairs for leaks at the tank to header (gasket leaks), broken/cracked plastic tanks, cross threaded or leaking oil coolers should be repaired without replacing the complete radiator. This type of repair should be handled by the radiator repair facility in your area. Many of these radiator repair facilities are members of the National Automotive Radiator Service Association (NARSA) who follow industry and General Motors guidelines when repairing radiators. These facilities have the special tools, tanks and pressurizing equipment needed to properly test the repaired radiator prior to returning it to the dealership. Many of these facilities receive the repair components directly from General Motors. The sublet expense for a new radiator or the repair of the radiator under warranty should be handled following normal procedures. For Vehicles No Longer Under Warranty The GM released epoxy repair kit referenced in previous publications is no longer available. Repairs to the radiator, rather than replacement, is strictly at the owner's discretion. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Radiator > Component Information > Service and Repair > Radiator Replacement Radiator: Service and Repair Radiator Replacement Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Radiator > Component Information > Service and Repair > Radiator Replacement > Page 2533 Remove or Disconnect 1. Coolant from the radiator. 2. Coolant reservoir hose. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Radiator > Component Information > Service and Repair > Radiator Replacement > Page 2534 3. Upper fan shroud. 4. Hoses. 5. Transmission fluid cooler pipes. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Radiator > Component Information > Service and Repair > Radiator Replacement > Page 2535 6. Engine oil cooler pipes. 7. Radiator. Install or Connect 1. Radiator. 2. Engine oil cooler line fittings. Tighten Fittings to 35 N.m (25 ft. lbs.). 3. Transmission fluid cooler line fittings. Tighten Fittings to 27 N.m (20 ft. lbs.). 4. Hoses. 5. Upper fan shroud. 6. Coolant reservoir hose. 7. Coolant to the radiator. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Radiator > Component Information > Service and Repair > Radiator Replacement > Page 2536 Radiator: Service and Repair Cooling System 1. Drain coolant from radiator, then disconnect upper coolant reservoir hose. 2. Remove upper fan shroud bolts, then the shroud. 3. Disconnect and plug transmission fluid cooler lines. 4. Disconnect and plug engine oil cooler lines. 5. Raise and support vehicle, then disconnect lower radiator hose. 6. Disconnect heater hose and coolant overflow hose from radiator. 7. Remove radiator. 8. Reverse procedure to install. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Radiator Cap > Component Information > Specifications Radiator Cap: Specifications Radiator Cap Relief Pressure, Lbs. ..................................................................................................... ............................................................................... 15 Thermo. Opening Temp., deg.F ..................... .............................................................................................................................................................. .... 195 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Specifications Coolant Temperature Sensor/Switch (For Computer): Specifications Resistance 185 ohms at 210 deg F 450 ohms at 160 deg F 1800 ohms at 100 deg F 3400 ohms at 70 deg F 7500 ohms at 40 deg F 13500 ohms at 20 deg F 25000 ohms at 0 deg F 100700 ohms at -40 deg F Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Specifications > Page 2545 Coolant Temperature Sensor/Switch (For Computer): Locations Engine Coolant Temperature Sensor Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Specifications > Page 2546 Engine Harness, Right Front Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions Coolant Temperature Sensor/Switch (For Computer): Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. Use this page as a reference to determine the meaning of an abbreviation if necessary. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery Bi-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CHMSL Center High Mount Stoplamp CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRO Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2549 F-PUMP Fuel Pump FLASH Flasher FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2550 SIR Supplemental Inflatable Restraint SKT Socket SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature TIL Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2551 example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE (ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: ^ Slide across the vehicle seat. ^ Sit down or stand up. ^ Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: ^ They are bumped or dropped. ^ They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2552 Symbols (Part 1 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2553 Symbols (Part 2 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2554 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2555 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2556 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2557 Coolant Temperature Sensor/Switch (For Computer): Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2558 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2559 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2560 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2561 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2562 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. ^ If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. ^ A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2563 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2564 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2565 Ohmmeter Meter Scales Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2566 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. ^ An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. ^ On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: ^ A range selector switch which permits the selection of different ranges of resistance. ^ A set adjust control which allows the meter to be set at zero for accurate measurements. ^ Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2567 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: ^ Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. ^ Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. ^ Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2568 be less than 10 percent of the total drop. When using a voltmeter: ^ Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. ^ Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. ^ The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: ^ Check the accuracy and completeness of the complaint. ^ Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2569 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. ^ The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2570 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2571 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2572 Twisted/Shielded Wire Repair Twisted Wires Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2573 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2574 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2575 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). ^ Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean ^ Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. ^ Roll crimp (13) and solder the terminal. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2576 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2577 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2578 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. ^ Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean ^ Terminal cavity of the connector body. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2579 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. ^ Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2580 C105 - Engine Coolant Temperature Sensor Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2581 Engine Coolant Temperature (ECT) Circuit Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Page 2582 Coolant Temperature Sensor/Switch (For Computer): Description and Operation Engine Coolant Temperature Sensor PURPOSE The Engine Coolant Temperature (ECT) Sensor information is used by the control module to control: Fuel delivery - Torque Converter Clutch (TCC) - Engine Spark Timing (EST) - Controlled Canister Purge (CCP) - Idle Air Control (IAC) - Cooling Fan OPERATION The ECT is a thermistor that is located in the engine coolant flow mounted to the intake manifold. When the coolant temperature is low, the sensor produces a high resistance. When the coolant temperature is high, the sensor produces a low resistance. The PCM sends a 5.0 volt signal to the ECT through a resistor in the computer and measures the voltage. The voltage will be high or low depending on coolant temperature. With the ECT varying its resistance, the PCM can sense engine coolant temperature by reading the varying voltage. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Temperature Sensor (Gauge) > Component Information > Locations Temperature Sensor (Gauge): Locations ENGINE COOLANT TEMPERATURE SENSOR Right Front Engine Harness Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Temperature Sensor (Gauge) > Component Information > Locations > Page 2586 Engine Harness, Right Front NOTE: The OEM service manual provides multiple location views for this component. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Sensors and Switches - Cooling System > Engine - Coolant Temperature Sensor/Switch > Temperature Sensor (Gauge) > Component Information > Locations > Page 2587 C108 - Eng Coolant Temp Sender Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Temperature Gauge > Component Information > Technical Service Bulletins > Customer Interest: > 468306 > Dec > 94 > Temperature Gauge - Erratic Temperature Gauge: Customer Interest Temperature Gauge - Erratic File In Section: 8 - Chassis/Body Electrical Bulletin No.: 46-83-06 Date: December, 1994 Subject: Erratic Temperature Gauge (Exchange Instrument Panel Cluster) Models: 1994 Chevrolet and GMC Truck S/T Models with Standard Analog Instrument Panel Cluster Condition Some temperature gauges in the above vehicles may give erratic readings. Cause Improper nut on back of temperature gauge inside the I/P cluster, resulting in erratic voltage feed to gauge. Correction Remove the instrument cluster and send it to your nearest Delco Repair Station. Repair stations are aware of the condition and have pans available to repair the cluster. They will add a capacitor to the power circuit to assure a consistent power flow to the temperature gauge. Be certain to clearly describe the condition on the Delco Repair Order accompanying the cluster. Warranty Information For vehicles repaired under warranty. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Temperature Gauge > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 468306 > Dec > 94 > Temperature Gauge Erratic Temperature Gauge: All Technical Service Bulletins Temperature Gauge - Erratic File In Section: 8 - Chassis/Body Electrical Bulletin No.: 46-83-06 Date: December, 1994 Subject: Erratic Temperature Gauge (Exchange Instrument Panel Cluster) Models: 1994 Chevrolet and GMC Truck S/T Models with Standard Analog Instrument Panel Cluster Condition Some temperature gauges in the above vehicles may give erratic readings. Cause Improper nut on back of temperature gauge inside the I/P cluster, resulting in erratic voltage feed to gauge. Correction Remove the instrument cluster and send it to your nearest Delco Repair Station. Repair stations are aware of the condition and have pans available to repair the cluster. They will add a capacitor to the power circuit to assure a consistent power flow to the temperature gauge. Be certain to clearly describe the condition on the Delco Repair Order accompanying the cluster. Warranty Information For vehicles repaired under warranty. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Temperature Gauge > Component Information > Technical Service Bulletins > All Other Service Bulletins for Temperature Gauge: > NHTSA94V114000 > Jun > 94 > Recall 94V114000: Trailer Hitch Attaching Bolts Defect Trailer Hitch: All Technical Service Bulletins Recall 94V114000: Trailer Hitch Attaching Bolts Defect THE TRAILER HITCH ATTACHING BOLTS WERE NOT TIGHTENED TO THE SPECIFIED TORQUE. THIS CAN LEAD TO LOOSENING AND SUBSEQUENT BREAKAGE OF THE FASTENERS. IF THIS WERE TO OCCUR WHILE THE TRAILER WAS BEING PULLED, THE HITCH AND TRAILER CAN SEPARATE FROM THE VEHICLE. DEALERS WILL TORQUE ALL EIGHT TRAILER HITCH BOLTS TO THE CORRECT TORQUE. SYSTEM: EQUIPMENT; OTHER PIECES; TRAILER HITCHES AND ATTACHMENTS. VEHICLE DESCRIPTION: LIGHT DUTY 4 DOOR MULTI-PURPOSE VEHICLES EQUIPPED WITH A WEIGHT DISTRIBUTION TRAILER HITCH (VR4) OPTION. NOTE: IF YOUR VEHICLE IS PRESENTED TO AN AUTHORIZED DEALER ON AN AGREED UPON SERVICE DATE AND THE REMEDY IS NOT PROVIDED WITHIN A REASONABLE TIME AND FREE OF CHARGE OR THE REMEDY DOES NOT CORRECT THE DEFECT OR NON-COMPLIANCE, PLEASE CONTACT CHEVROLET SERVICE CENTER AT 1-800-222-1020 OR GMC AT 1-313-456-4547. ALSO, CONTACT THE NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION'S AUTO SAFETY HOTLINE AT 1-800-424-9393. 1994 CHEVROLET TRUCK BLAZER 1994 GMC JIMMY Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Temperature Gauge > Component Information > Testing and Inspection > Gauge Does Not Move From Cold When Engine Is Hot Temperature Gauge: Testing and Inspection Gauge Does Not Move From Cold When Engine Is Hot This condition is generally caused by a blown fuse, open circuit or faulty sensor. 1. Check fuse, replace if necessary. 2. Turn ignition switch to On position, then remove lead at sensor unit. 3. Connect test lamp from sensor lead to ground, lamp should glow. Short sensor lead to ground, gauge should indicate "Hot." 4. If gauge indicated HOT, check lead on sensor. If satisfactory, replace sensor. If gauge indicates COLD, replace cluster. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Temperature Gauge > Component Information > Testing and Inspection > Gauge Does Not Move From Cold When Engine Is Hot > Page 2613 Temperature Gauge: Testing and Inspection Gauge Indicates Hot When Engine Is Cold This condition is generally caused by a shorted or grounded circuit. 1. Remove sensor lead at sensor unit. Gauge should move to COLD position, if not check unit for a external short. If no external short is found, replace sensor. 2. If gauge stays HOT, check for a short circuit in gauge to sensor wiring. If circuit is satisfactory, replace cluster. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Temperature Gauge > Component Information > Testing and Inspection > Gauge Does Not Move From Cold When Engine Is Hot > Page 2614 Temperature Gauge: Testing and Inspection Gauge Reads High 1. Remove lead at sensor, measure resistance using an ohmmeter. 2. At 104 degrees F resistance should be approximately 1200-1350 ohms, and at 125 degrees F resistance should be approximately 53-55 ohms. 3. If resistance is not within specifications, replace sensor. 4. Disconnect lead at sensor and gauge, check for a high resistance using an ohmmeter. Repair wiring if necessary. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Temperature Gauge > Component Information > Testing and Inspection > Gauge Does Not Move From Cold When Engine Is Hot > Page 2615 Temperature Gauge: Testing and Inspection Gauge Reads Low 1. Ensure terminals are clean and connections are tight. 2. Remove lead at sensor, measure resistance using an ohmmeter. 3. At 104 degrees F resistance should be approximately 1200-1350 ohms, and at 125 degrees F resistance should be approximately 53-55 ohms. 4. If resistance is not within specifications, replace sensor. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Temperature Warning Lamp/Indicator, Engine Cooling > Component Information > Description and Operation Temperature Warning Lamp/Indicator: Description and Operation A bi-metal temperature switch located in the cylinder head controls the operation of a temperature indicator light. If the engine cooling system is not functioning properly and/or coolant temperature exceeds a predetermined value, the warning light will illuminate. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Temperature Warning Lamp/Indicator, Engine Cooling > Component Information > Description and Operation > Page 2619 Temperature Warning Lamp/Indicator: Testing and Inspection If the light is not lit when the engine is being cranked, check for a burned out bulb, an open in the light circuit, or a defective ignition switch. If the light is lit when the engine is running, check the wiring between light and switch for a ground, defective temperature switch, or overheated cooling system. As a test circuit to check whether the bulb is functioning properly, connect a wire from the ground terminal of the ignition switch to the temperature indicator light circuit. When the ignition is in the START (engine cranking) position, the ground terminal is grounded inside the switch and the bulb will be lit. When the engine is started and the ignition switch is in the ON position, the test circuit is opened and the bulb is then controlled by the temperature switch. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Thermostat, Engine Cooling > Component Information > Specifications Thermostat: Specifications Radiator Cap Relief Pressure, Lbs. ..................................................................................................... ............................................................................... 15 Thermo. Opening Temp., deg.F ..................... .............................................................................................................................................................. .... 195 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Thermostat, Engine Cooling > Component Information > Specifications > Page 2623 Thermostat: Service and Repair 1. Disconnect battery ground cable. 2. Drain coolant from radiator, then remove water outlet retaining bolts. 3. Remove outlet and gasket, then the thermostat from the outlet. 4. Reverse procedure to install. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Cooling System > Water Pump > Component Information > Service and Repair Water Pump: Service and Repair Water pump replacement. 4.3L/V6-262 1. Drain cooling system. 2. Remove serpentine drive belt, then the upper fan shroud. 3. Remove fan,then fan clutch assembly and water pump pulley. 4. Remove hoses from pump. 5. Remove water pump attaching bolts, then pump Fig. 20. 6. Reverse procedure to install. Torque bolts to specification. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Exhaust System > Catalytic Converter > Component Information > Locations Exhaust Layout S/T 2WD PUP 4.3L Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Exhaust System > Catalytic Converter > Component Information > Locations > Page 2631 Catalytic Converter: Description and Operation CAUTION Prolonged operation with a misfiring or flooded engine may cause the converter to overheat. This could cause damage either to the catalyst itself or the operating vehicle and possible personal injury. NOTE When jacking or lifting vehicle from frame side rails, be certain lift pads DO NOT contact catalytic converter or damage to converter may result. Catalytic Converters Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Exhaust System > Catalytic Converter > Component Information > Locations > Page 2632 PURPOSE The catalytic converter is an emission control device added to the exhaust system to effectively reduce the levels of carbon monoxide, hydrocarbons, and in some cases oxides of nitrogen, entering the atmosphere. The converter serves two purposes: it permits a faster chemical reaction to take place and although it enters into the chemical reaction, it remains unchanged, ready to repeat the process. CONSTRUCTION AND OPERATION General Motors uses four different converter designs in conjunction with two types of catalysts. The four converter designs, are: single bed monolith, dual bed monolith, single bed pellet and dual bed pellet. The two types of catalysts used are an oxidation catalyst and a three-way (reduction) catalyst. The oxidation catalyst is coated with material containing platinum and palladium which lowers levels of carbon monoxide and hydrocarbons. The three-way (reduction) catalyst is coated with platinum and rhodium which lowers levels of oxides of nitrogen (NOx), as well as carbon monoxide and hydrocarbons. All dual bed converters, whether monolith or pellet type, contain both oxidation and three-way catalysts. Due to its high operating temperatures, the catalytic converter usually requires the use of heat shields. Heat shields are necessary to protect chassis components, passenger compartment and other areas from heat related damage. A fill pipe restrictor is used on catalytic converter equipped vehicles, to prevent the larger service station pump nozzle, used for leaded fuels, being inserted into the filler tube. Since the use of leaded fuels contaminates the catalysts, rendering them ineffective, the use of unleaded fuels is mandatory in catalytic converter equipped vehicles. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Exhaust System > Catalytic Converter > Component Information > Locations > Page 2633 Restricted Exhaust System Check Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Exhaust System > Exhaust Crossover Pipe > Component Information > Technical Service Bulletins > Customer Interest for Exhaust Crossover Pipe: > 566501 > Jul > 95 > O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear Exhaust Crossover Pipe: Customer Interest O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear FILE IN SECTION: 6E - Engine Fuel & Emission BULLETIN NO.: 56-65-01 DATE: July, 1995 SUBJECT: Rattling Noise on Acceleration/Transmission Starting Out in 3rd Gear (Provide Clearance or Replace Exhaust Crossover) MODELS: 1993-94 Chevrolet and GMC Truck M/L Vans 1994 Chevrolet and GMC Truck T Models 1994 Oldsmobile Bravada with 4.3L Engines (VINs W, Z - RPOs L35, LB4) CONDITION Customers may comment on one or more of the following conditions: A rattling noise on acceleration, transmission starting out in 3rd gear (possible DTC 66, 67, 81, 82) and/or diagnostic trouble codes 13 or 44. CAUSE M/L Vans Oxygen sensor and/or harness pigtail contacting the heat shield due to improper routing of the harness. Sharp edges of the heat shield cuts through the wire insulation. T Trucks The rattle noise may be the oxygen sensor and/or harness pigtail contacting the heat shield due to the mispositioning of the oxygen sensor mounting boss. Starting out in 3rd gear may be due to the pink wire (CKT 39) shorting out against the heat shield causing power to be interrupted to the transmission control circuit putting the transmission into backup mode (3rd Gear Starts). Diagnostic trouble codes 13 or 44 may be set due to the oxygen sensor signal wire shorting to or cut through by the heat shield. CORRECTION M/L Vans Refer to the "1993 M/L Van Electrical Diagrams and Diagnosis" manual or the "1994 Driveability, Emissions and Electrical Diagnosis" manual for circuit 39 schematics. Normal circuit diagnostics should be performed first if the problem is constant. If the problem is intermittent, an inspection of circuit 39 (pink/black) in the area of the exhaust heat shields may lead to the problem. Inspect the oxygen sensor wiring and replace the sensor it the insulation has been damaged. Re-route wiring harness as needed to protect harness. Clear any codes and test drive. T Trucks If the oxygen sensor is contacting the heat shield, this condition can be corrected by replacing the exhaust crossover pipe. If the oxygen sensor wire is damaged, the oxygen sensor must also be replaced. Follow regular Service Manual Procedures in Section 3 of the 1993 or 1994 "S/T Truck Driveability, Emission and Electrical Diagnosis" manual to make above repairs. Clear any diagnostic trouble codes and test drive. PARTS INFORMATION P/N Description Qty 10096129 Sensor, Oxygen (1993) 1 25133503 Sensor, Oxygen (1994) 1 15661132 Pipe, Exhaust Crossover (w/ZR2) 1 15672887 Pipe, Exhaust Crossover (w/o ZR2) 1 Parts are currently available from GMSPO. WARRANTY INFORMATION Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Exhaust System > Exhaust Crossover Pipe > Component Information > Technical Service Bulletins > Customer Interest for Exhaust Crossover Pipe: > 566501 > Jul > 95 > O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear > Page 2642 For vehicles repaired under warranty, use: Labor Operation Description Labor Time J6372 Sensor, Oxygen Replace Use Published L2080 Pipe, Crossover Exhaust Replace Labor Operation Time Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Exhaust System > Exhaust Crossover Pipe > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Exhaust Crossover Pipe: > 566501 > Jul > 95 > O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear Exhaust Crossover Pipe: All Technical Service Bulletins O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear FILE IN SECTION: 6E - Engine Fuel & Emission BULLETIN NO.: 56-65-01 DATE: July, 1995 SUBJECT: Rattling Noise on Acceleration/Transmission Starting Out in 3rd Gear (Provide Clearance or Replace Exhaust Crossover) MODELS: 1993-94 Chevrolet and GMC Truck M/L Vans 1994 Chevrolet and GMC Truck T Models 1994 Oldsmobile Bravada with 4.3L Engines (VINs W, Z - RPOs L35, LB4) CONDITION Customers may comment on one or more of the following conditions: A rattling noise on acceleration, transmission starting out in 3rd gear (possible DTC 66, 67, 81, 82) and/or diagnostic trouble codes 13 or 44. CAUSE M/L Vans Oxygen sensor and/or harness pigtail contacting the heat shield due to improper routing of the harness. Sharp edges of the heat shield cuts through the wire insulation. T Trucks The rattle noise may be the oxygen sensor and/or harness pigtail contacting the heat shield due to the mispositioning of the oxygen sensor mounting boss. Starting out in 3rd gear may be due to the pink wire (CKT 39) shorting out against the heat shield causing power to be interrupted to the transmission control circuit putting the transmission into backup mode (3rd Gear Starts). Diagnostic trouble codes 13 or 44 may be set due to the oxygen sensor signal wire shorting to or cut through by the heat shield. CORRECTION M/L Vans Refer to the "1993 M/L Van Electrical Diagrams and Diagnosis" manual or the "1994 Driveability, Emissions and Electrical Diagnosis" manual for circuit 39 schematics. Normal circuit diagnostics should be performed first if the problem is constant. If the problem is intermittent, an inspection of circuit 39 (pink/black) in the area of the exhaust heat shields may lead to the problem. Inspect the oxygen sensor wiring and replace the sensor it the insulation has been damaged. Re-route wiring harness as needed to protect harness. Clear any codes and test drive. T Trucks If the oxygen sensor is contacting the heat shield, this condition can be corrected by replacing the exhaust crossover pipe. If the oxygen sensor wire is damaged, the oxygen sensor must also be replaced. Follow regular Service Manual Procedures in Section 3 of the 1993 or 1994 "S/T Truck Driveability, Emission and Electrical Diagnosis" manual to make above repairs. Clear any diagnostic trouble codes and test drive. PARTS INFORMATION P/N Description Qty 10096129 Sensor, Oxygen (1993) 1 25133503 Sensor, Oxygen (1994) 1 15661132 Pipe, Exhaust Crossover (w/ZR2) 1 15672887 Pipe, Exhaust Crossover (w/o ZR2) 1 Parts are currently available from GMSPO. WARRANTY INFORMATION Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Exhaust System > Exhaust Crossover Pipe > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Exhaust Crossover Pipe: > 566501 > Jul > 95 > O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear > Page 2648 For vehicles repaired under warranty, use: Labor Operation Description Labor Time J6372 Sensor, Oxygen Replace Use Published L2080 Pipe, Crossover Exhaust Replace Labor Operation Time Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Engine, Cooling and Exhaust > Exhaust System > Exhaust Manifold > Component Information > Service and Repair Exhaust Manifold: Service and Repair 1. Disconnect battery ground cable. 2. Raise and support vehicle. 3. Disconnect exhaust pipe from manifold. 4. Lower vehicle, then remove spark plug wires from spark plugs. 5. Remove power steering and alternator rear bracket from left manifold. 6. Remove air cleaner with heat stove pipe and cold air intake pipe. 7. Remove exhaust manifold bolts and washers, then the manifold. 8. Reverse procedure to install. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Air Flow Meter/Sensor Relay > Component Information > Technical Service Bulletins > Shift Indicator Light Application and Operation Air Flow Meter/Sensor Relay: Technical Service Bulletins Shift Indicator Light Application and Operation File In Section: 7 - Transmission Bulletin No.: 36-72-07A Date: February, 1995 Subject: Manual Transmission Shift Indicator Light Application and Operation Models: 1993-95 Chevrolet and GMC Truck C/K and S/T Models with Manual Transmission This bulletin is being revised to add the 1995 model year. Please discard bulletin number 367207 (Group Reference - Transmission). Certain trucks are not equipped with a shift indicator light. The shift light is commonly used to achieve improved fuel economy by prompting the driver when to upshift. Depending on the engine/transmission installed in the vehicle, the shift light can have the following characteristics: ^ Indicates proper shift point for maximum fuel economy. ^ Indicates engine over-speed. ^ Shift light is inoperative. The following charts detail normal shift light operation: 1993 Models: Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Air Flow Meter/Sensor Relay > Component Information > Technical Service Bulletins > Shift Indicator Light Application and Operation > Page 2659 1994 Models: 1995 Models: Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage Engine Control Module: Technical Service Bulletins Engine Controls - Aftermarket Accessory Usage INFORMATION Bulletin No.: 04-06-04-054B Date: November 18, 2010 Subject: Info - Non-GM Parts and Accessories (Aftermarket) Models: 2011 and Prior GM Passenger Cars and Trucks Supercede: This bulletin is being revised to add model years and update to the new U.S. Fixed Operation Manager (FOM) and Canada Warranty Manager (WM) names. Please discard Corporate Bulletin Number 04-06-04-054A (Section 06 - Engine/Propulsion System). The recent rise and expansion of companies selling non-GM parts and accessories has made it necessary to issue this reminder to dealers regarding GM's policy on the use and installation of these aftermarket components. When a dealer is performing a repair under the New Vehicle Limited Warranty, they are required to use only genuine GM or GM-approved parts and accessories. This applies to all warranty repairs, special policy repairs or any repairs paid for by GM. Parts and accessories advertised as being "the same" as parts manufactured by GM, but not sold through GM, do not qualify for use in warranty repairs, special policy repairs or any repairs paid for by GM. During a warranty repair, if a GM original equipment part is not available through GM Customer Care and Aftersales (GM CC&A;), ACDelco(R) distributors, other GM dealers or approved sources, the dealer is to obtain comparable, non-GM parts and clearly indicate, in detail, on the repair order the circumstances surrounding why non-GM parts were used. The dealer must give customers written notice, prior to the sale or service, that such parts or accessories are not marketed or warranted by General Motors. It should also be noted that dealers modifying new vehicles and installing equipment, parts and accessories obtained from sources not authorized by GM are responsible for complying with the National Traffic and Motor Vehicle Safety Act. Certain non-approved parts or assemblies, installed by the dealer or its agent not authorized by GM, may result in a change to the vehicle's design characteristics and may affect the vehicle's ability to conform to federal law. Dealers must fully understand that non-GM approved parts may not have been validated, tested or certified for use. This puts the dealer at risk for potential liability in the event of a part or vehicle failure. If a GM part failure occurs as the result of the installation or use of a non-GM approved part, the warranty will not be honored. A good example of non-authorized modification of vehicles is the result of an ever increasing supply of aftermarket devices available to the customer, which claim to increase the horsepower and torque of the Duramax(TM) Diesel Engines. These include the addition of, but are not limited to one or more of the following modifications: - Propane injection - Nitrous oxide injection - Additional modules (black boxes) that connect to the vehicle wiring systems - Revised engine calibrations downloaded for the engine control module - Calibration modules which connect to the vehicle diagnostic connector - Modification to the engine turbocharger waste gate Although the installation of these devices, or modification of vehicle components, can increase engine horsepower and torque, they may also negatively affect the engine emissions, reliability and/or durability. In addition, other powertrain components, such as transmissions, universal joints, drive shafts, and front/rear axle components, can be stressed beyond design safety limits by the installation of these devices. General Motors does not support or endorse the use of devices or modifications that, when installed, increase the engine horsepower and torque. It is because of these unknown stresses, and the potential to alter reliability, durability and emissions performance, that GM has adopted a policy that prevents any UNAUTHORIZED dealer warranty claim submissions to any remaining warranty coverage, to the powertrain and driveline components whenever the presence of a non-GM (aftermarket) calibration is confirmed - even if the non-GM control module calibration is subsequently removed. Refer to the latest version of Bulletin 09-06-04-026 (V8 Gas Engines) or 06-06-01-007 (Duramax(TM) Diesel Engines) for more information on dealer requirements for calibration verification. These same policies apply as they relate to the use of non-GM accessories. Damage or failure from the use or installation of a non-GM accessory will not be covered under warranty. Failure resulting from the alteration or modification of the vehicle, including the cutting, welding or disconnecting of the vehicle's original equipment parts and components will void the warranty. Additionally, dealers will NOT be reimbursed or compensated by GM in the event of any legal inquiry at either the local, state or federal level that Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 2664 results from the alteration or modification of a vehicle using non-GM approved parts or accessories. Dealers should be especially cautious of accessory companies that claim the installation of their product will not void the factory warranty. Many times these companies have even given direction on how to quickly disassemble the accessory in an attempt to preclude the manufacturer from finding out that is has been installed. Any suspect repairs should be reviewed by the Fixed Operations Manager (FOM), and in Canada by the Warranty Manager (WM) for appropriate repair direction. If it is decided that a goodwill repair is to be made on the vehicle, even with the installation of such non-GM approved components, the customer is to be made aware of General Motors position on this issue and is to sign the appropriate goodwill documentation required by General Motors. It is imperative for dealers to understand that by installing such devices, they are jeopardizing not only the warranty coverage, but also the performance and reliability of the customer's vehicle. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 2665 Engine Control Module: Technical Service Bulletins PROM - Reprogram Using Off Board Program Adapter File In Section: 6E - Engine Fuel & Emission Bulletin No.: 73-65-13 Date: March, 1997 INFORMATION Subject: Reprogramming Capability using the Off Board Programming Adapter Models: 1993-97 Passenger Cars and Trucks (Applicable Reprogrammable Vehicles) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 2666 The General Motors vehicles contain Electronically Reprogrammable Devices (i.e. PCM, VCM, ECM). These vehicles cannot be programmed through PROM replacement, however service programming capability is available through the Tech 1/1A, Tech 2 and Techline terminals via direct or remote programming. The Environmental Protection Agency (EPA) has requested that all new vehicle manufacturers ensure their dealers/retailers are aware that they are responsible for providing customers access to reprogramming services at a reasonable cost and in a timely manner. Although programming of controllers has become a common service practice at GM dealers/retailers, the EPA has received reports from consumers and the aftermarket repair industry that they were unable to purchase a new (programmed) Electronically Reprogrammable Device (ERD) over-the-counter. As a result, on August 1, 1995, the Federal Government issued a regulation requiring all manufacturers to make available reprogramming to the independent aftermarket by December 1, 1997. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 2667 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 2668 Today, the Off Board Programming Adapter (OBPA) is used to reprogram ERD's sold over-the-counter. For all practical purposes, the OBPA takes the place of the vehicle when the vehicle is not available. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 2669 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 2670 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 2671 The list of dealerships/retailers currently own the OBPA (see Attachments 1 - 3). These locations are equipped to provide over-the-counter preprogrammed ERD's. The hardware required to perform reprogramming in addition to the OBPA is a Techline terminal, Tech 1/1A and associated cables and adapters. THE TECH 2 SHOULD NOT BE USED WITH THE OBPA AT THIS TIME BECAUSE OF INADEQUATE OBPA GROUNDING. The current OBPA can support reprogramming on all late model General Motor's vehicles except: ^ Premium V-8's ^ 1996 Diesel Truck ^ Cadillac Catera Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 2672 ^ All 1997 programmable vehicles (requires use of the Tech 2) A modification to the OBPA is being offered by Kent-Moore to support these additional vehicles and to allow reprogramming using the Tech 2. The revisions to the OBPA for the Tech 2 is very important as the Tech 2 is the only tool used for service programming for 1997 and future vehicles. To have the modifications performed, contact Kent-Moore at (800) 345-2233. The revisions (part number J 41207 REV-C) are free of charge for GM dealerships/retailers. A dealership/retailer can purchase the OBPA by contacting Kent-Moore (part number J 41207-C). Support on how to use the OBPA is provided by the Techline Customer Support Center (TCSC) at (800) 828-6860 (English) or (800) 503-3222 (French). If you need to purchase an OBPA and/or cable, contact Kent-Moore at (800) 345-2233. The OBPA retails for $695.00 (includes all revisions 1-4) under part number J 41207-C. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 2673 Engine Control Module: Technical Service Bulletins PCM - Replacement Component Text Deletion File in Section: 6E - Engine Fuel & Emission Bulletin No.: 41-65-33 Date: October, 1994 SERVICE MANUAL UPDATE Subject: Section 3A - Driveability, Emissions and Electrical Diagnosis - Text Deletion Models: 1994 Chevrolet and GMC Truck & T Models with 2.2L Gasoline Engine (VIN 4 - RPO LN2) or 4.3L Engine (VINs Z, W - RPOs LB4, L35) 1994-95 Chevrolet and GMC Truck C/K, M/L, G, P3, PG Models with 4.3L Engine (VIN Z - RPO LB4), 5.0L Engine (VIN H - RPO L03), 5.7L Engine VIN K - RPO L05) or 7.4L Engine (VIN N - RPO L19) 1994-95 Chevrolet and GMC Truck C/K, G, P3 Models with 6.5L Diesel Engine (VINs F, P, S RPOs L65, L49, L56) This bulletin contains revisions to the "Driveability, Emissions and Electrical Diagnostic" Service Manuals for the following pages: 1994 S/T Truck - 3A-5 1994-1995 G Van - 3A-4 1994-1995 C/K Truck - 3A-4 1994-1995 M/L Truck - 3A-4 1994-1995 PG/P3 Truck - 3A-4 1994-1995 C/K, G, P Truck - 3-17 and Supplement This Text is to be Deleted "The replacement PCM may be faulty - After the PCM is replaced, the system should be rechecked for proper operation. If the Diagnostic Chart again indicates that the PCM is the problem, substitute a known good PCM". Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Page 2674 Engine Control Module: Specifications Engine VIN Code ID [1] ....................................................................................................................... .............................................................................. Z Engine Displacement ........................................................................................................................... ........................................................... 4.3L (262 cid) Engine Configuration ........................................................................................................................... ............................................................................ V6 Fuel Control System ...................................................................................................................................................... Throttle Body Fuel Injection (TBI) Ignition System ....................................................................................................... Distributor Ignition W/Ignition Control and Knock Sensor(DI-IC-KS) Control Module Systems S/T Pickup Automatic Transmission ......................................................................................................................... Powertrain Control Module (93PCM6) S/T Utility Manual Transmission .............................................................................................................................. Powertrain Control Module (93PCM6) S/T Pickup Manual Transmission ........................................................................................................................................ Vehicle Control Module (VCM) Remarks: [1] The eighth digit of the VIN denotes engine code. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Page 2675 Engine Control Module: Locations Vehicle Speed Sensor Buffer And Electric Shift Transfer Case Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Page 2676 Engine Or Powertrain Control Module Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Diagrams > C1 Red (32 Pin) Engine Control Module: Diagrams C1 Red (32 Pin) Manual Transmission (1 Of 2) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Diagrams > C1 Red (32 Pin) > Page 2679 Manual Transmission (2 Of 2) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Diagrams > C1 Red (32 Pin) > Page 2680 Engine Control Module: Diagrams C2-Blue (32 Pin) Automatic Transmission (1 Of 2) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Diagrams > C1 Red (32 Pin) > Page 2681 Automatic Transmission (2 Of 2) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Diagrams > C1 Red (32 Pin) > Page 2682 Engine Control Module: Diagrams C210 C210 - PCM C210 - ECM Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Diagrams > C1 Red (32 Pin) > Page 2683 Engine Control Module: Diagrams C211 C211 - PCM C211 - ECM Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Diagrams > C1 Red (32 Pin) > Page 2684 Engine Control Module: Diagrams With Manual Transmission Pinout Chart Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Diagrams > C1 Red (32 Pin) > Page 2685 Pinout Chart Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Diagrams > C1 Red (32 Pin) > Page 2686 Pinout Chart Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Diagrams > C1 Red (32 Pin) > Page 2687 Pinout Chart Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Diagrams > Page 2688 Engine Control Module: Description and Operation Engine Control Module Fig. 5 ECM Unit (Showing PROM & CALPAK Locations) Powertrain Control Module (PCM) PURPOSE The Powertrain Control Module (PCM) is the control center of the fuel injection system. It constantly looks at the information from various sensors (inputs) and controls the systems (outputs) that affect vehicle performance. The PCM also performs the diagnostic function of the system. It can recognize operational problems, alert the driver through the Malfunction Indicator Lamp (MIL) "Service Engine Soon" light on the instrument panel and store a Diagnostic Trouble Code(s) (DTC) in the PCM memory. The DTC identifies the problem areas to aid the technician in performing repairs. OPERATION The PCM is an electronic computer designed to process the various input information, and send the necessary electrical response to control fuel delivery, spark control, and other emission control systems. The PCM can control these devices through the use of Quad Driver Modules (QDM). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Diagrams > Page 2689 When the PCM is commanding a device or a component "ON," the voltage potential of the output is "LOW" or near zero volts. When the PCM is commanding a device or component "OFF," the voltage potential of the circuit will be "HIGH," or near 12 volts. The primary function of the QDM is to supply the ground for the component being controlled. The input information has an interrelation between sensor output. If one of the input devices failed, such as the oxygen sensor, this could affect more than one of the systems controlled by the computer. The PCM has two parts for service: Controller which is the PCM (93 PCM6), without the PROM (MEM-CAL). - PROM (Programmable Read Only Memory) which is a separate memory calibrator unit PCM Learning Ability The PCM has a "learning" ability which allows it to make corrections for minor variations in the fuel system to improve driveability. If the battery is disconnected, to clear diagnostic trouble codes or for other repairs. the "learning" process resets and begins again. A change may be noted in the vehicle's performance. To "teach" the vehicle, ensure the engine is at operating temperature. The vehicle should be driven at part throttle, with moderate acceleration and idle conditions until normal performance returns. NOTE The PCM must be maintained at a temperature below 85°C (185°F) at all times. This is most essential if the vehicle is put through a baking process. The PCM will become inoperative if it's temperature exceeds 85°C (185°F). It is recommended that temporary insulation be placed around the PCM during the time the vehicle is in a paint oven or other high temperature processes. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Engine Control Module > Component Information > Diagrams > Page 2690 Engine Control Module: Service and Repair Figure 1 CAUTION [a] The ignition must be "OFF," when disconnecting or reconnecting the control module connector, to prevent internal damage to the control module. [b] To prevent possible Electrostatic Discharge to the control module, Do NOT touch the connector pins or soldered components on the circuit boards. NOTE When replacing a production control module with a service controller, transfer the broadcast code and production control module part number to the controller label. DO NOT record information on the access cover. REMOVE/DISCONNECT - Negative battery terminal. - Passenger side kick panel. - Hush panel if equipped. - Mounting screw. - Control module from mounting bracket. - VSS buffer connector and rotate control module to ease removal. - Control module harness connectors. - Mounting brackets and modules if equipped. - Remove new control module from its packaging and check the service number to make sure it is the same as the defective control module. - PROM removal. Refer to PROM (MEM-CAL) replacement. NOTE Replacement control module is supplied without a PROM, so care should be used when removing it from the defective control module, because it will be reused in the new control module. INSTALL/CONNECT - Mounting brackets and modules if equipped. - Control module harness connectors. - VSS buffer connector and rotate control module to ease installation. - Control module into mounting bracket. - Mounting screw. - Hush panel if equipped. - Passenger side kick panel. - Negative battery terminal. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > Customer Interest for Fuel Pump Relay: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking Fuel Pump Relay: Customer Interest Engine - Will Not Start Readily Upon Cranking File In Section: 6E - Engine Fuel & Emission Bulletin No.: 56-63-05A Date: January, 1996 Subject: Vehicle Does Not Start Readily Upon Cranking (Replace Fuel Pump Relay) Models: 1993-94 Chevrolet and GMC Truck M/L Vans 1994 Chevrolet and GMC Truck S/T Utility 1994 Oldsmobile Bravada with 4.3L Engine (VIN W, Z - RPOs L35, LB4) This bulletin is being revised to change the correction procedure and parts information and to add the L Van and artwork. Please discard Corporate Bulletin Number 56-63-05 (Section 6E - Engine Fuel & Emission). Condition Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > Customer Interest for Fuel Pump Relay: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking > Page 2700 Some owners may experience extended engine crank times on cold start and may set diagnostic trouble code 54 and activate the M/L (Check Engine light). Cause This condition may be due to failure of the fuel pump relay. Correction Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > Customer Interest for Fuel Pump Relay: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking > Page 2701 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > Customer Interest for Fuel Pump Relay: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking > Page 2702 Verify condition using the normal diagnostic procedure in the service manual. Replace the Fuel Pump Relay (P/N 12077867) following the service manual procedure. Replace the connector (Kit P/N 12166225) following the instructions in Figures 3 and 4. Note that each of the four cavities of the old connector are lettered. The new connector is numbered and it should be wired according to Figure 3 and not the instructions contained within the connector kit. Parts Information P/N Description Qty 12077867 Fuel Pump Relay 1 12166225 Connector 1 12129073 Bracket (S/T Only) 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: Labor Operation Description Labor Time J5460 Relay, Fuel Pump- Use Published Replace Labor Operation Time Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Fuel Pump Relay: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking Fuel Pump Relay: All Technical Service Bulletins Engine - Will Not Start Readily Upon Cranking File In Section: 6E - Engine Fuel & Emission Bulletin No.: 56-63-05A Date: January, 1996 Subject: Vehicle Does Not Start Readily Upon Cranking (Replace Fuel Pump Relay) Models: 1993-94 Chevrolet and GMC Truck M/L Vans 1994 Chevrolet and GMC Truck S/T Utility 1994 Oldsmobile Bravada with 4.3L Engine (VIN W, Z - RPOs L35, LB4) This bulletin is being revised to change the correction procedure and parts information and to add the L Van and artwork. Please discard Corporate Bulletin Number 56-63-05 (Section 6E - Engine Fuel & Emission). Condition Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Fuel Pump Relay: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking > Page 2708 Some owners may experience extended engine crank times on cold start and may set diagnostic trouble code 54 and activate the M/L (Check Engine light). Cause This condition may be due to failure of the fuel pump relay. Correction Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Fuel Pump Relay: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking > Page 2709 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Fuel Pump Relay: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking > Page 2710 Verify condition using the normal diagnostic procedure in the service manual. Replace the Fuel Pump Relay (P/N 12077867) following the service manual procedure. Replace the connector (Kit P/N 12166225) following the instructions in Figures 3 and 4. Note that each of the four cavities of the old connector are lettered. The new connector is numbered and it should be wired according to Figure 3 and not the instructions contained within the connector kit. Parts Information P/N Description Qty 12077867 Fuel Pump Relay 1 12166225 Connector 1 12129073 Bracket (S/T Only) 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: Labor Operation Description Labor Time J5460 Relay, Fuel Pump- Use Published Replace Labor Operation Time Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > Page 2711 Fuel Pump Relay: Locations FUEL PUMP RELAY Fuel Pump Relay The Fuel Pump Relay is located on the driver side firewall, near brake booster. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > Page 2712 C124 - Fuel Pump Relay Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > Page 2713 Fuel Pump Relay: Description and Operation When the ignition key is first turned to the "ON" position, the control module will energize the fuel pump relay as long as the engine is cranking or running, and the control module is receiving distributor reference pulses. If there are no reference pulses, the control module will shut "OFF" the fuel pump relay within two seconds. An inoperative fuel pump relay can result in extended crank times, particularily if the engine is cold. The oil pressure switch will turn "ON" the fuel pump, as soon as oil pressure reaches about 28 kPa (4 psi). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > Page 2714 Fuel Pump Relay: Testing and Inspection *** UPDATED BY TSB 893206E, DATED OCTOBER 90 When the key is first turned ON, without the engine running, the ECM will turn the fuel pump relay ON for two seconds. This builds up the fuel pressure to normal operating pressure. If the engine is not started within two seconds, the ECM will shut the fuel pump OFF and wait until ignition reference pulses are present. As soon as the engine is cranked, the ECM turns the relay ON, which powers the fuel pump. The ECM continues to power the fuel pump during engine operation. If the fuel pump relay fails, it is backed up by the oil pressure switch, which continues to operate the fuel pump as long as oil pressure remains above 28.0 kPa (4 psi). RESULTS OF INCORRECT FUEL PUMP SYSTEM OPERATION - A faulty fuel pump relay can result in long cranking times, particularly if the engine is cold. - An inoperative fuel pump would cause a no start condition. - A fuel pump which does not provide enough pressure can result in poor performance. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > Page 2715 Fuel Pump Relay: Service and Repair Relay Center 2.5L,2.8L S REMOVE/DISCONNECT 1. Verify that ignition switch is in the "OFF" position. 2. Retainer, if installed. 3. Electrical connector. 4. Fuel pump relay by depressing bracket clip at rear of relay, or removing bolts from retaining bracket. INSTALL/DISCONNECT 1. Fuel pump relay. 2. Electrical connector. 3. Retainer. 4. Verify correct operation to confirm repair. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Ignition System > Ignition Control Module > Component Information > Locations > Ignition Module Typical Distributor Components Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Ignition System > Ignition Control Module > Component Information > Locations > Ignition Module > Page 2721 Rear Engine Wiring W/Man Trans Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Ignition System > Ignition Control Module > Component Information > Locations > Page 2722 C121 - Ignition Control Module Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Relays and Modules - Powertrain Management > Relays and Modules - Ignition System > Ignition Control Module > Component Information > Locations > Page 2723 Ignition Control Module: Service and Repair Typical Distributor Components REMOVE OR DISCONNECT NOTE It is not necessary to remove ignition distributor assembly from engine. - Distributor cap and rotor. - Connectors from module. - Two module attaching screws. - Lift module from housing and remove. INSTALL OR CONNECT NOTE: Do not wipe silicone grease from metal face of module or distributor base (where the module seats), when reinstalling the same module. If new module is to be installed clean distributor module base and spread new silicone grease on base and metal face of ignition module. The purpose of the silicone grease is to cool module. - Module onto housing. - Module attaching screws. Tighten to 2 Nm (18 lb.in.) - Connectors to module. - Rotor and cap. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Specifications Coolant Temperature Sensor/Switch (For Computer): Specifications Resistance 185 ohms at 210 deg F 450 ohms at 160 deg F 1800 ohms at 100 deg F 3400 ohms at 70 deg F 7500 ohms at 40 deg F 13500 ohms at 20 deg F 25000 ohms at 0 deg F 100700 ohms at -40 deg F Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Specifications > Page 2729 Coolant Temperature Sensor/Switch (For Computer): Locations Engine Coolant Temperature Sensor Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Specifications > Page 2730 Engine Harness, Right Front Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions Coolant Temperature Sensor/Switch (For Computer): Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. Use this page as a reference to determine the meaning of an abbreviation if necessary. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery Bi-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CHMSL Center High Mount Stoplamp CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRO Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2733 F-PUMP Fuel Pump FLASH Flasher FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2734 SIR Supplemental Inflatable Restraint SKT Socket SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature TIL Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2735 example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE (ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: ^ Slide across the vehicle seat. ^ Sit down or stand up. ^ Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: ^ They are bumped or dropped. ^ They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2736 Symbols (Part 1 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2737 Symbols (Part 2 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2738 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2739 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2740 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2741 Coolant Temperature Sensor/Switch (For Computer): Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2742 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2743 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2744 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2745 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2746 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. ^ If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. ^ A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2747 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2748 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2749 Ohmmeter Meter Scales Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2750 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. ^ An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. ^ On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: ^ A range selector switch which permits the selection of different ranges of resistance. ^ A set adjust control which allows the meter to be set at zero for accurate measurements. ^ Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2751 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: ^ Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. ^ Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. ^ Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2752 be less than 10 percent of the total drop. When using a voltmeter: ^ Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. ^ Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. ^ The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: ^ Check the accuracy and completeness of the complaint. ^ Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2753 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. ^ The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2754 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2755 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2756 Twisted/Shielded Wire Repair Twisted Wires Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2757 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2758 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2759 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). ^ Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean ^ Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. ^ Roll crimp (13) and solder the terminal. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2760 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2761 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2762 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. ^ Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean ^ Terminal cavity of the connector body. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2763 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. ^ Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2764 C105 - Engine Coolant Temperature Sensor Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 2765 Engine Coolant Temperature (ECT) Circuit Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Page 2766 Coolant Temperature Sensor/Switch (For Computer): Description and Operation Engine Coolant Temperature Sensor PURPOSE The Engine Coolant Temperature (ECT) Sensor information is used by the control module to control: Fuel delivery - Torque Converter Clutch (TCC) - Engine Spark Timing (EST) - Controlled Canister Purge (CCP) - Idle Air Control (IAC) - Cooling Fan OPERATION The ECT is a thermistor that is located in the engine coolant flow mounted to the intake manifold. When the coolant temperature is low, the sensor produces a high resistance. When the coolant temperature is high, the sensor produces a low resistance. The PCM sends a 5.0 volt signal to the ECT through a resistor in the computer and measures the voltage. The voltage will be high or low depending on coolant temperature. With the ECT varying its resistance, the PCM can sense engine coolant temperature by reading the varying voltage. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Intake Air Temperature Sensor > Component Information > Specifications > Electrical Specifications Intake Air Temperature Sensor: Electrical Specifications Resistance 185 ohms at 210 deg F 450 ohms at 160 deg F 1800 ohms at 100 deg F 3400 ohms at 70 deg F 7500 ohms at 40 deg F 13500 ohms at 20 deg F 25000 ohms at 0 deg F 100700 ohms at -40 deg F Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Intake Air Temperature Sensor > Component Information > Specifications > Electrical Specifications > Page 2771 Intake Air Temperature Sensor: Mechanical Specifications Torque Valve Torque Valve Induction Air Sensor 44 in.lb Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Knock Sensor > Component Information > Technical Service Bulletins > Knock Sensor Circuit - DTC 43 Chart Revision Knock Sensor: Technical Service Bulletins Knock Sensor Circuit - DTC 43 Chart Revision File In Section: 6E Engine Fuel & Emission Bulletin No.: 51-65-19 Date: April, 1995 Subject: Section 3A - Control Module System (PCM) Driveability and Emissions - Revised DTC 43 Knock Sensor (KS) Circuit (Dual Knock Sensors) Models: 1994 Chevrolet and GMC Truck S/T; M/L, C/K Models with 4.3L Engine (VINs W, Z RPOs L35, LB4) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Knock Sensor > Component Information > Technical Service Bulletins > Knock Sensor Circuit - DTC 43 Chart Revision > Page 2776 This bulletin advises of a revision to the DTC 43 Knock Sensor (KS) Circuit (Dual Knock Sensor System) chart in the following service manuals: 1994 S/T Driveability Emissions and Electrical Diagnosis Manual, page 3A-119 1994 M/L Driveability Emissions and Electrical Diagnosis Manual, page 3A-75 1994 C/K Driveability Emissions and Electrical Diagnosis Manual, page 3A-69 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Knock Sensor > Component Information > Technical Service Bulletins > Page 2777 Knock Sensor: Specifications Coil bracket bolt/nut ............................................................................................................................. ................................................. 27 N-m (20 lbs ft) Distributor clamp bolt ........................................................................................................................... ................................................ 27 N-m (20 lbs ft) Knock Sensor ...................................................................................................................................... .................................................. 19 N-m (14 lbs ft) Spark Plugs ......................................................................................................................................... .................................................. 15 N-M (11 lbs ft) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Knock Sensor > Component Information > Locations > Assembly View Knock Sensors Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Knock Sensor > Component Information > Locations > Assembly View > Page 2780 Knock Sensor: Locations Harness View LH Rear Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Knock Sensor > Component Information > Locations > Assembly View > Page 2781 LH Rear Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Knock Sensor > Component Information > Locations > Page 2782 Knock Sensor: Diagrams C119 - Knock Sensor C135 - Knock Sensor Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Knock Sensor > Component Information > Locations > Page 2783 Knock Sensor: Description and Operation PURPOSE: The Knock Sensor (KS) is used to detect engine detonation (ping). The control module will retard the electronic spark timing up to 8° based on the signal received. CONSTRUCTION The KS system has two major components: Control Module. - Knock Sensor(s). The two knock sensors are spliced together and go directly to the control module. OPERATION The knock sensor internal circuit causes the control modules 5 volts to be pulled down to about 2.5 volts. The knock sensor produces an A/C signal which rides on the 2.5 volts DC signal. The AC voltage monitor in the control module will detect this AC voltage and provide a signal to begin retarding spark until the knock diminishes. The amplitude and frequency are dependent upon the knock level. LOCATION Engine block. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Knock Sensor > Component Information > Locations > Page 2784 Knock Sensor: Testing and Inspection Knock Sensor (KS) System Check Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Knock Sensor > Component Information > Locations > Page 2785 Knock Sensor Circuit Circuit Description The Knock Sensor (KS) circuit consists of two knock sensors with one wire that goes directly to the control modules. There are two Knock Sensor (KS) checks performed by the ECM. One check consists of monitoring CKT 496 for a voltage that is more than .63 volt and less than 3.1 volts. If voltage is either too high or too low for 10 or more seconds, DTC 43 will set. The PCM uses this self check only. The next test is used only by the ECM along with the previous test. Once engine temperature reaches 85°C, MAP is over 83 kPa, and engine speed is less than 3200 RPM, the ECM will perform a self check. This self check will advance the timing until it receives a knock signal. If no knock signal is received, DTC 43 will set. Chart Test Description Number(s) below refer to circled number(s) on the diagnostic chart. 1. The first test is to determine if the system is functioning at the present time. 2. Test two determines the state of the 5 volt reference voltage applied to the knock sensor circuit. 3. Test 3 determines the state of the knock sensors and connections themselves. Diagnostic Aids The control module applies 5 volts to CKT 496. A 8200 ohm resistor in the knock sensors reduces the voltage to about 2.5 volts. When knock occurs, the knock sensor produces a small AC voltage that rides on top of the 2.5 volts already applied. An AC voltage monitor, in the control module, is able to read this signal as knock and incrementally retard spark. If the KS system checks OK, but detonation is the complaint, refer to "Detonation/Spark Knock". See: Computers and Control Systems/Testing and Inspection/Symptom Related Diagnostic Procedures/Detonation/ Spark Knock Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Knock Sensor > Component Information > Locations > Page 2786 Knock Sensor: Service and Repair REMOVE OR DISCONNECT - Negative battery cable. - Drain cooling system. NOTE On knock sensors which are mounted in the end of the cylinder head draining the cooling system will not be necessary. - Wiring harness connector from knock sensor. - Knock sensor. INSTALL OR CONNECT - Knock sensor. If reinstalling original sensor, apply water base caulk to sensor threads. Do NOT use silicone tape as this will insulate sensor from engine. ^ Tighten to 19 Nm (14 lb. ft.). - Wiring harness connector to knock sensor. - Refill cooling system and pressure test for leaks. - Negative battery cable. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Specifications Manifold Pressure/Vacuum Sensor: Specifications Voltage 3.6 to 5.2 V at 1000 to 2000 ft 3.5 to 5.1 V at 2000 to 3000 ft 3.3 to 5.0 V at 3000 to 4000 ft 3.2 to 4.8 V at 4000 to 5000 ft 3.0 to 4.6 V at 5000 to 6000 ft 2.9 to 4.5 V at 6000 to 7000 ft 2.8 to 4.3 V at 7000 to 8000 ft 2.6 to 4.2 V at 8000 to 9000 ft 2.5 to 4.0 V at 9000 to 10000 ft Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Specifications > Page 2790 Manifold Pressure/Vacuum Sensor: Locations Engine Harness, Right Front Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Specifications > Page 2791 MAP Sensor 4.3Z Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions Manifold Pressure/Vacuum Sensor: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. Use this page as a reference to determine the meaning of an abbreviation if necessary. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery Bi-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CHMSL Center High Mount Stoplamp CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRO Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2794 F-PUMP Fuel Pump FLASH Flasher FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2795 SIR Supplemental Inflatable Restraint SKT Socket SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature TIL Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2796 example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE (ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: ^ Slide across the vehicle seat. ^ Sit down or stand up. ^ Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: ^ They are bumped or dropped. ^ They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2797 Symbols (Part 1 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2798 Symbols (Part 2 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2799 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2800 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2801 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2802 Manifold Pressure/Vacuum Sensor: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2803 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2804 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2805 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2806 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2807 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. ^ If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. ^ A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2808 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2809 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2810 Ohmmeter Meter Scales Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2811 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. ^ An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. ^ On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: ^ A range selector switch which permits the selection of different ranges of resistance. ^ A set adjust control which allows the meter to be set at zero for accurate measurements. ^ Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2812 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: ^ Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. ^ Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. ^ Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2813 be less than 10 percent of the total drop. When using a voltmeter: ^ Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. ^ Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. ^ The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: ^ Check the accuracy and completeness of the complaint. ^ Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2814 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. ^ The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2815 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2816 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2817 Twisted/Shielded Wire Repair Twisted Wires Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2818 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2819 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2820 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). ^ Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean ^ Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. ^ Roll crimp (13) and solder the terminal. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2821 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2822 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2823 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. ^ Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean ^ Terminal cavity of the connector body. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2824 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. ^ Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2825 C109 - MAP Sensor Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2826 MAP Sensor Circuit Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Page 2827 Manifold Pressure/Vacuum Sensor: Description and Operation Map Sensor Circuit (GM Generic) Manifold Absolute Pressure (MAP) Sensor PURPOSE The Manifold Absolute Pressure (MAP) sensor measures changes in the intake manifold pressure resulting from engine load and speed changes. As intake manifold pressure increases, the air density in the intake manifold also increases and additional fuel is required. Under certain conditions, the MAP sensor is also used to measure barometric pressure. This allows the control module to automatically adjust for different altitudes. The PCM uses information from the MAP sensor to calculate spark advance and fuel as follows: Low MAP output voltage (low pressure) results in more spark advance. - High MAP output voltage (high pressure) results in less spark advance. - Low MAP output voltage (low pressure) results in less fuel. - High MAP output voltage (high pressure) results in more fuel. OPERATION The control module supplies a 5 volt reference signal to the MAP sensor and the sensor provides a path to ground through its variable resistor. The control module by monitoring the sensor output voltage can determine the manifold pressure. A closed throttle on engine coastdown will produce a relatively low MAP output, while a wide open throttle will produce a high output. At higher pressure or at Wide Open Throttle (WOT) output voltage will be about 4 to 4.8 volts. The higher the MAP voltage output the lower the engine vacuum, which requires more fuel. The lower the MAP voltage output the higher the engine vacuum. At lower pressure output voltage will be about 1 to 2 volts at idle. A failure in the MAP sensor circuit should set Diagnostic Trouble Codes (DTC) 33 or 34 with PCM/ECM systems and DTC P0107 or P0108 with VCM systems. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Page 2828 Manifold Pressure/Vacuum Sensor: Testing and Inspection Manifold Absolute Pressure (MAP) Output Check Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Page 2829 MAP Sensor Circuit Circuit Description: The Manifold Absolute Pressure (MAP) sensor measures the changes in the intake manifold pressure which result from engine load (intake manifold vacuum) and RPM changes; and converts these into a voltage output. The PCM sends a 5 volt reference voltage to the MAP sensor. As the manifold pressure changes, the output voltage of the sensor also changes. By monitoring the sensor output voltage, the PCM knows the manifold pressure. At lower pressure output voltage will be about 1 to 2 volts at idle. While at higher pressure or at Wide Open Throttle (WOT) output voltage will be about 4 to 4.8 volts. The MAP sensor is also used, under certain conditions, to measure barometric pressure, allowing the PCM to make adjustments for different altitudes. The PCM uses the MAP sensor to control fuel delivery and ignition timing. Chart Test Description Number(s) below refer to circled number(s) on the diagnostic chart. Important ^ Be sure to use the same Diagnostic Test Equipment for all measurements. 1. Checks MAP sensor output voltage to the PCM. This voltage, without engine running, represents a barometer reading to the PCM. ^ When comparing Tech 1 scan readings to a known good vehicle, it is important to compare vehicles that use a MAP sensor having the same color insert or having the same "Hot Stamped" number. Refer to figures on facing page. 2. Applying 34 kPa (10" Hg) vacuum to the MAP sensor should cause the voltage to change. Subtract second reading from the first. Voltage value should be greater than 1.5 volts. Upon applying vacuum to the sensor, the change in voltage should be instantaneous. A slow voltage change indicates a faulty sensor. 3. Check vacuum hose to sensor for leaking or restriction. Be sure that no other vacuum devices are connected to the MAP hose. NOTICE:Make sure electrical connector remains securely fastened. 4. Disconnect sensor from bracket and twist sensor by hand (only) to check for intermittent connection. Output changes greater than .1 volt indicate a bad connector or connection. If OK, replace sensor. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > Customer Interest: > 566501 > Jul > 95 > O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear Oxygen Sensor: Customer Interest O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear FILE IN SECTION: 6E - Engine Fuel & Emission BULLETIN NO.: 56-65-01 DATE: July, 1995 SUBJECT: Rattling Noise on Acceleration/Transmission Starting Out in 3rd Gear (Provide Clearance or Replace Exhaust Crossover) MODELS: 1993-94 Chevrolet and GMC Truck M/L Vans 1994 Chevrolet and GMC Truck T Models 1994 Oldsmobile Bravada with 4.3L Engines (VINs W, Z - RPOs L35, LB4) CONDITION Customers may comment on one or more of the following conditions: A rattling noise on acceleration, transmission starting out in 3rd gear (possible DTC 66, 67, 81, 82) and/or diagnostic trouble codes 13 or 44. CAUSE M/L Vans Oxygen sensor and/or harness pigtail contacting the heat shield due to improper routing of the harness. Sharp edges of the heat shield cuts through the wire insulation. T Trucks The rattle noise may be the oxygen sensor and/or harness pigtail contacting the heat shield due to the mispositioning of the oxygen sensor mounting boss. Starting out in 3rd gear may be due to the pink wire (CKT 39) shorting out against the heat shield causing power to be interrupted to the transmission control circuit putting the transmission into backup mode (3rd Gear Starts). Diagnostic trouble codes 13 or 44 may be set due to the oxygen sensor signal wire shorting to or cut through by the heat shield. CORRECTION M/L Vans Refer to the "1993 M/L Van Electrical Diagrams and Diagnosis" manual or the "1994 Driveability, Emissions and Electrical Diagnosis" manual for circuit 39 schematics. Normal circuit diagnostics should be performed first if the problem is constant. If the problem is intermittent, an inspection of circuit 39 (pink/black) in the area of the exhaust heat shields may lead to the problem. Inspect the oxygen sensor wiring and replace the sensor it the insulation has been damaged. Re-route wiring harness as needed to protect harness. Clear any codes and test drive. T Trucks If the oxygen sensor is contacting the heat shield, this condition can be corrected by replacing the exhaust crossover pipe. If the oxygen sensor wire is damaged, the oxygen sensor must also be replaced. Follow regular Service Manual Procedures in Section 3 of the 1993 or 1994 "S/T Truck Driveability, Emission and Electrical Diagnosis" manual to make above repairs. Clear any diagnostic trouble codes and test drive. PARTS INFORMATION P/N Description Qty 10096129 Sensor, Oxygen (1993) 1 25133503 Sensor, Oxygen (1994) 1 15661132 Pipe, Exhaust Crossover (w/ZR2) 1 15672887 Pipe, Exhaust Crossover (w/o ZR2) 1 Parts are currently available from GMSPO. WARRANTY INFORMATION Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > Customer Interest: > 566501 > Jul > 95 > O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear > Page 2838 For vehicles repaired under warranty, use: Labor Operation Description Labor Time J6372 Sensor, Oxygen Replace Use Published L2080 Pipe, Crossover Exhaust Replace Labor Operation Time Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oxygen Sensor: > 566501 > Jul > 95 > O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear Oxygen Sensor: All Technical Service Bulletins O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear FILE IN SECTION: 6E - Engine Fuel & Emission BULLETIN NO.: 56-65-01 DATE: July, 1995 SUBJECT: Rattling Noise on Acceleration/Transmission Starting Out in 3rd Gear (Provide Clearance or Replace Exhaust Crossover) MODELS: 1993-94 Chevrolet and GMC Truck M/L Vans 1994 Chevrolet and GMC Truck T Models 1994 Oldsmobile Bravada with 4.3L Engines (VINs W, Z - RPOs L35, LB4) CONDITION Customers may comment on one or more of the following conditions: A rattling noise on acceleration, transmission starting out in 3rd gear (possible DTC 66, 67, 81, 82) and/or diagnostic trouble codes 13 or 44. CAUSE M/L Vans Oxygen sensor and/or harness pigtail contacting the heat shield due to improper routing of the harness. Sharp edges of the heat shield cuts through the wire insulation. T Trucks The rattle noise may be the oxygen sensor and/or harness pigtail contacting the heat shield due to the mispositioning of the oxygen sensor mounting boss. Starting out in 3rd gear may be due to the pink wire (CKT 39) shorting out against the heat shield causing power to be interrupted to the transmission control circuit putting the transmission into backup mode (3rd Gear Starts). Diagnostic trouble codes 13 or 44 may be set due to the oxygen sensor signal wire shorting to or cut through by the heat shield. CORRECTION M/L Vans Refer to the "1993 M/L Van Electrical Diagrams and Diagnosis" manual or the "1994 Driveability, Emissions and Electrical Diagnosis" manual for circuit 39 schematics. Normal circuit diagnostics should be performed first if the problem is constant. If the problem is intermittent, an inspection of circuit 39 (pink/black) in the area of the exhaust heat shields may lead to the problem. Inspect the oxygen sensor wiring and replace the sensor it the insulation has been damaged. Re-route wiring harness as needed to protect harness. Clear any codes and test drive. T Trucks If the oxygen sensor is contacting the heat shield, this condition can be corrected by replacing the exhaust crossover pipe. If the oxygen sensor wire is damaged, the oxygen sensor must also be replaced. Follow regular Service Manual Procedures in Section 3 of the 1993 or 1994 "S/T Truck Driveability, Emission and Electrical Diagnosis" manual to make above repairs. Clear any diagnostic trouble codes and test drive. PARTS INFORMATION P/N Description Qty 10096129 Sensor, Oxygen (1993) 1 25133503 Sensor, Oxygen (1994) 1 15661132 Pipe, Exhaust Crossover (w/ZR2) 1 15672887 Pipe, Exhaust Crossover (w/o ZR2) 1 Parts are currently available from GMSPO. WARRANTY INFORMATION Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oxygen Sensor: > 566501 > Jul > 95 > O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear > Page 2844 For vehicles repaired under warranty, use: Labor Operation Description Labor Time J6372 Sensor, Oxygen Replace Use Published L2080 Pipe, Crossover Exhaust Replace Labor Operation Time Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oxygen Sensor: > 81I37 > Feb > 81 > Oxygen Sensors - Silica Contamination Oxygen Sensor: All Technical Service Bulletins Oxygen Sensors - Silica Contamination Model Year: 1981 Bulletin No: 81-I-37 File In Group: 60 Number: 11 Date: Feb. 81 Subject: Silica Contamination of Oxygen Sensors and Gelation of Oil. Models Affected: All Oxygen sensor performance can deteriorate if certain RTV silicone gasket materials are used. Other RTV's when used with certain oils, may cause gelation of the oil. The degree of performance severity depends on the type of RTV and application of the engine involved. Therefore, when repairing engines where this item is involved, it is important to use either cork composition gaskets or RTV silicone gasket material approved for such use. GMS (General Motors Sealant) or equivalent material can be used. GMS is available through GMPD with the following part numbers: 1052366 3 oz. 1052434 10.14 oz. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > All Other Service Bulletins for Oxygen Sensor: > 81I37 > Feb > 81 > Oxygen Sensors - Silica Contamination Oxygen Sensor: All Technical Service Bulletins Oxygen Sensors - Silica Contamination Model Year: 1981 Bulletin No: 81-I-37 File In Group: 60 Number: 11 Date: Feb. 81 Subject: Silica Contamination of Oxygen Sensors and Gelation of Oil. Models Affected: All Oxygen sensor performance can deteriorate if certain RTV silicone gasket materials are used. Other RTV's when used with certain oils, may cause gelation of the oil. The degree of performance severity depends on the type of RTV and application of the engine involved. Therefore, when repairing engines where this item is involved, it is important to use either cork composition gaskets or RTV silicone gasket material approved for such use. GMS (General Motors Sealant) or equivalent material can be used. GMS is available through GMPD with the following part numbers: 1052366 3 oz. 1052434 10.14 oz. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Specifications > Electrical Specifications Oxygen Sensor: Electrical Specifications Closed Loop 100 - 0.999 mV Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Specifications > Electrical Specifications > Page 2856 Oxygen Sensor: Mechanical Specifications Oxygen Sensor 30 ft.lb Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Locations > Heated Oxygen Sensor Engine Harness, Right Front Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Locations > Heated Oxygen Sensor > Page 2859 Heated Oxygen Sensor (HO2S) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions Oxygen Sensor: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. Use this page as a reference to determine the meaning of an abbreviation if necessary. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery Bi-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CHMSL Center High Mount Stoplamp CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRO Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2862 F-PUMP Fuel Pump FLASH Flasher FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2863 SIR Supplemental Inflatable Restraint SKT Socket SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature TIL Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2864 example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE (ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: ^ Slide across the vehicle seat. ^ Sit down or stand up. ^ Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: ^ They are bumped or dropped. ^ They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2865 Symbols (Part 1 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2866 Symbols (Part 2 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2867 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2868 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2869 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2870 Oxygen Sensor: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2871 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2872 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2873 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2874 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2875 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. ^ If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. ^ A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2876 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2877 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2878 Ohmmeter Meter Scales Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2879 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. ^ An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. ^ On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: ^ A range selector switch which permits the selection of different ranges of resistance. ^ A set adjust control which allows the meter to be set at zero for accurate measurements. ^ Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2880 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: ^ Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. ^ Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. ^ Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2881 be less than 10 percent of the total drop. When using a voltmeter: ^ Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. ^ Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. ^ The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: ^ Check the accuracy and completeness of the complaint. ^ Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2882 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. ^ The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2883 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2884 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2885 Twisted/Shielded Wire Repair Twisted Wires Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2886 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2887 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2888 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). ^ Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean ^ Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. ^ Roll crimp (13) and solder the terminal. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2889 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2890 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2891 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. ^ Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean ^ Terminal cavity of the connector body. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2892 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. ^ Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2893 C116 - Oxygen Sensor Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2894 Heated Oxygen Sensor (HO2S) Circuit Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Page 2895 Oxygen Sensor: Description and Operation Exhaust Oxygen Sensor (02) PURPOSE The Oxygen sensor (O2 Sensor) has the ability to produce a low voltage signal that feeds information on engine exhaust content to the control module. CONSTRUCTION The O2 Sensor is constructed from a zirconia/platinum electrolytic element. Zirconia is an electrolyte that conducts electricity under certain chemical conditions. The element is made of a ceramic material and is an insulator when cold. At operating temperature, 315°C (600°F), the element becomes a semiconductor. A platinum coating on the outer surface of the element stimulates further combustion of the exhaust gases right at the surface and this helps deep the element up to the desired temperature. The O2 Sensor has an inter cavity which is filled with atmospheric (reference) air. The atmosphere has approximately 21% oxygen in it. In the electrical circuit this inter cavity is the positive (+) terminal. The outer surface of the element is exposed to the exhaust gas stream. It is the negative (-) terminal. Oxygen Sensor Output Voltage vs. Air/Fuel Ratio The difference in oxygen concentration in the narrow range of optimum air/fuel ratio causes a large voltage change that is easily measured. OPERATION A rich exhaust (excessive fuel) has almost no oxygen. When there is a large difference in the amount of oxygen touching the inside and outside surfaces, there is more conduction, and the sensor puts out a voltage signal above 0.6 volts (600 mV). With lean exhaust (excessive oxygen) there is about two percent oxygen in the exhaust. This is a smaller difference in oxygen from the outside surfaces which results in less conduction and a voltage signal below 0.3 volts (300 mV). The voltages are monitored and used by the control module to "fine tune" the air/fuel ratio to achieve the ideal mixture desired. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Page 2896 The control module puts out a reference signal of 0.45 volts (450 mV). The reference signal serves two purposes. The first is to run the engine when it is in OPEN LOOP mode of operation. When the air/fuel ratio is correct the control module senses 450 mV. When the engine is operating with a rich air/fuel ratio there is a reduction of free oxygen in the exhaust stream and the O2 sensor voltage rises above the reference voltage. When the engine is running lean the voltage drops below the reference voltage due to the excess oxygen in the exhaust stream. The O2 sensor provides the feedback information for the CLOSED LOOP operating mode of the fuel delivery system. The O2 sensor indicates to the control module what is happening in the exhaust. It does not cause things to happen. It is a type of gauge: Low voltage output = lean mixture = high oxygen content in the exhaust; high voltage output = rich mixture = low oxygen content in the exhaust. CONDITIONS THAT CAN SET CODES An open O2 sensor, should set a Diagnostic Trouble Code (DTC) 13. A constant low voltage in the O2 sensor circuit should set a DTC 44. A constant high voltage in the circuit should set a DTC 45. DTC 44 and DTC 45 could be set as a result of fuel system problems. REFER TO COMPUTERS AND CONTROL SYSTEMS/DIAGNOSTIC CHARTS for diagnosis of these codes. HEATED OXYGEN SENSOR TYPE The heated oxygen sensor works in the same manner as the non-heated oxygen sensor. The exception is that B+ is supplied to a heating element that is part of the sensor itself. The heater helps the control module control the fuel injection sooner for better fuel emissions. There are no Diagnostic Trouble Codes (DTC's) to detect if the heater part of the sensor is working. To check the heater, REFER TO COMPUTERS AND CONTROL SYSTEMS/DIAGNOSIS AND TESTING PROCEDURES/OXYGEN SENSOR TESTING. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Page 2897 Oxygen Sensor: Testing and Inspection VISUAL INSPECTION - Connectors and wires - Housing and insulator for cracks/damage - Sensor tip for silicone contamination (white powdery coating) CAUTION Do NOT perform the following test for more than 2 minutes, as this may cause damage to the catalytic converter. PERFORMANCE TEST Checks working range and response (speed). Warm engine - Install DVOM between sensor and ground (2 volt D.C. range) - "RUN" engine at steady cruise speed (about 2500 rpm) Voltage should vary at least eight times in ten seconds between 0.2 and 0.8 volts (normal range). - Drive system rich: The use of a properly adjusted propane flow-meter (J-26911) is industry standard. Voltage should increase to at least 0.8 volts within two to three seconds. - Drive system lean: Create a vacuum leak from a source that is not an control module input or output. Voltage should drop to at least 0.3 volts within two to three seconds. NOTE After each test the O2 sensor should return to normal operating range within two to three seconds. - O2 Sensor should be replaced for failure to pass any of the tests above. NOTE A CEC system that is operating excessively rich or lean will drive the 02 sensor to its maximum range and should be repaired first and not diagnosed as a 02 sensor failure. - Reconnect all hoses and electrical connectors. Clear all codes set and retrain idle. HEATING ELEMENT (H20S only) - Turn ignition "OFF". Disconnect electrical connector. - Connect test light between harness terminals "A" and "B". - Turn ignition "ON". Test light should be "ON". If test light is "OFF", connect test light to harness terminal "A" to ground. Light should be "ON" ensuring power circuit is operating correctly. - Turn ignition "OFF". - Using an ohmmeter, measure resistance between terminals A and B. Resistance @ Specified Temperature 3.5 ohms @ 20°C (68°F) 14 ohms @ 350°C (662°F) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Page 2898 Oxygen Sensor: Service and Repair NOTE The oxygen sensor has a permanently attached pig-tail and connector. This pig-tail should not be removed, since removal will affect proper operation of the oxygen sensor. REMOVAL - Disconnect electrical connector from oxygen sensor. - Using suitable wrench, carefully remove sensor from exhaust manifold or pipe. Caution The oxygen sensor may be difficult to remove when engine temperature is below 120°F. Excessive force may damage threads in exhaust manifold or pipe. INSTALLATION - If new sensor is being used, install sensor into manifold or pipe. - If old sensor is being reused, coat threads with anti-seize compound, Part No. 5613695 or equivalent, then install into manifold or pipe. - Torque oxygen sensor to 41 N-m (30 lb. ft.), then reconnect electrical connector. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Specifications Throttle Position Sensor: Specifications Idle Normal 0.45 to 0.95 V Maximum 1.25 V Wide Open Throttle 4.0 to 4.5 V Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Specifications > Page 2902 Engine Harness, Right Front Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions Throttle Position Sensor: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. Use this page as a reference to determine the meaning of an abbreviation if necessary. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery Bi-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CHMSL Center High Mount Stoplamp CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRO Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2905 F-PUMP Fuel Pump FLASH Flasher FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2906 SIR Supplemental Inflatable Restraint SKT Socket SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature TIL Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2907 example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE (ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: ^ Slide across the vehicle seat. ^ Sit down or stand up. ^ Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: ^ They are bumped or dropped. ^ They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2908 Symbols (Part 1 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2909 Symbols (Part 2 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2910 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2911 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2912 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2913 Throttle Position Sensor: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2914 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2915 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2916 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2917 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2918 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. ^ If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. ^ A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2919 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2920 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2921 Ohmmeter Meter Scales Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2922 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. ^ An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. ^ On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: ^ A range selector switch which permits the selection of different ranges of resistance. ^ A set adjust control which allows the meter to be set at zero for accurate measurements. ^ Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2923 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: ^ Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. ^ Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. ^ Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2924 be less than 10 percent of the total drop. When using a voltmeter: ^ Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. ^ Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. ^ The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: ^ Check the accuracy and completeness of the complaint. ^ Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2925 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. ^ The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2926 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2927 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2928 Twisted/Shielded Wire Repair Twisted Wires Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2929 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2930 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2931 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). ^ Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean ^ Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. ^ Roll crimp (13) and solder the terminal. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2932 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2933 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2934 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. ^ Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean ^ Terminal cavity of the connector body. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2935 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. ^ Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2936 C110 - TP Sensor Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2937 Throttle Position (TP) Circuit Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Page 2938 Throttle Position Sensor: Description and Operation Wiring Diagram For Code 21 - Throttle Position Sensor (Signal Voltage High) NOTE Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE The Throttle Position Sensor (TPS) is a potentiometer that senses throttle angle and sends a signal to the PCM. The TP signal is one of the most important inputs used by the control module for fuel control and for most of the control module control outputs. OPERATION The TPS has three internal circuits provided by the control module. One to ground, a second from the control module as a 5.0 volt reference source and a third circuit is used by the control module to measure the output voltage. As the throttle angle changes (pressing down on accelerator pedal) the TPS voltage output varies from about .5 volt at idle to about 4.9 volts at wide open throttle (WOT). Each time the voltage drops below 1.25 volts and stops, the control module assumes this value is 0 throttle from this point on. LOCATION: Side of throttle body opposite of throttle lever. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Page 2939 Throttle Position Sensor: Adjustments The TPS is not adjustable. Each time voltage drops below 1.25 volts and stops, the control module assumes that this value is zero throttle angle and measures percent throttle from this point on. Therefore adjustment is not necessary. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Page 2940 Throttle Position Sensor: Service and Repair NOTE Since Throttle Position Sensor (TPS) configurations can be mounted interchangeably, be sure to order the correct one for your engine with identical part number of the one being replaced. Throttle Position (TP) Sensor REMOVE/DISCONNECT - Electrical connectors. - TPS attaching screw assemblies and retainer, (if applicable). - TPS from throttle body assembly. NOTE Do NOT immerse in any type of liquid solvent or cleaner, as damage may occur. INSTALL/CONNECT - With throttle valve in normally closed position, install TPS on throttle shaft with seal and rotate counter clockwise to align mounting hole. - Two attaching screw assemblies. Tighten screw assemblies to 2.0 Nm (18.0 lb-in). - Electrical connector to TPS. - Check for TPS output as follows: Connect an ALDL scanner to read TPS output voltage. - With ignition "ON" and engine stopped, TPS voltage should be less than 1.25 volts. If more than 1.25 volts, replace TPS. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Transmission Position Switch/Sensor, A/T > Component Information > Description and Operation Transmission Position Switch/Sensor: Description and Operation Automatic Transmission Electrical Components PURPOSE This device is a set of five presure switches (two normally closed and three normally open), that detect fluid pressure within the valve body passages and signals the PCM which transmission range is selected (PRNDL). OPERATION The five pressure switches are connected to three signal circuits referred to as range signals A, B, C. The combination of pressure switch states determines the voltage signal (B+ or 0) on each range signal to the PCM. LOCATION The transmission range fluid pressure switch assembly is attached to the control valve body within the transmission. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Vehicle Speed Sensor > Component Information > Technical Service Bulletins > Digital Ratio Adapter/Controller (DRAC) - Service Vehicle Speed Sensor: Technical Service Bulletins Digital Ratio Adapter/Controller (DRAC) Service Group Ref.: 8 - Chassis/Body Electrical Bulletin No.: 448301 Date: August, 1994 INFORMATION SUBJECT: NEW PROCEDURE FOR OBTAINING SERVICE DRACS (DIGITAL RATIO ADAPTOR/CONTROLLER) MODELS: 1989-94 CHEVROLET AND GMC TRUCK M/L VANS, S/T MODELS 1990-94 CHEVROLET AND GMC TRUCK G VANS, R/V MODELS 1992-94 CHEVROLET AND GMC TRUCK C/K MODELS 1991-94 OLDSMOBILE BRAVADA If a dealer is contacted about or is in need of a service DRAC (Digital Ratio Adaptor/Controller) for any of the following reasons: 1. Radio interference (EMI). 2. Speedometer fluctuation or flaring. 3. Erratic/surging cruise control operation. 4. Different tire size. 5. Defective part. The dealer must contact an AC-Delco Service Center authorized to repair electronic instrument clusters for a new service DRAC, P/N 16202915. NOTE: This part is a service part and has to be programmed for the vehicle. It cannot be used until this procedure has been done by the authorized Service Center. The dealer will need the P/N and the broadcast code (the 3 bold letters located on the printed label of the old DRAC). The Service Center will program the DRAC according to this information. If the customer is changing the tire size, the Service Center will need the axle ratio and tire sized in order to program the DRAC to the new tire specifications. The AC-Delco Service Center will send the programmed DRAC via common carrier to the dealership. For further information, consult the AC-Delco authorized Service Center Manual WA-2 (September 1990 or later). AC-Delco centers are subject to change. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Vehicle Speed Sensor > Component Information > Locations > Assembly View Vehicle Speed Sensor: Locations Assembly View LOCATION Mounted To Transmisssion Tailshaft. 2WD Automatic Transmission VSS 2WD (A/TRANS.) VEHICLE SPEED SENSOR 2WD Manual Transmission VSS 2WD Manual Transmission 4WD Automatic and Manual Transmission VSS 4WD Or AWD Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Vehicle Speed Sensor > Component Information > Locations > Assembly View > Page 2950 Speed Sensor, Backup Lamp Switch & Electric Shift Transfer Case Wiring Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Vehicle Speed Sensor > Component Information > Locations > Page 2951 C320 - Vehicle Speed Sensor Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Vehicle Speed Sensor > Component Information > Locations > Page 2952 Vehicle Speed Sensor: Description and Operation 2 Wheel Drive (Manual Transmission) VSS 2WD Manual Transmission 2 Wheel Drive (Automatic Transmission) VSS 2WD (A/TRANS.) VEHICLE SPEED SENSOR 4 Wheel Drive VSS 4WD Or AWD PURPOSE The Vehicle Speed Sensor (VSS) provides information to the control module for control of: Transmission Torque Converter Clutch (TCC) - Speedometer - Odometer - Cruise control Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Vehicle Speed Sensor > Component Information > Locations > Page 2953 - ANTILOCK brake system. CONSTRUCTION The VSS is made up of: Permanent Magnet (PM) generator (coil), which is mounted on the transmission. - Rotor (tooth), which is mounted on the output shaft in the transmission. - VSS Buffer, which is mounted to the control module bracket. OPERATION The VSS is a Permanent Magnet (PM) generator that produces a pulsing Alternating Current (AC) voltage as each rotor tooth nears the coil. As the vehicle speed increases, the number of AC voltage pulses increase. The VSS buffer processes inputs from the VSS and outputs signal to the speedometer control module and cruise module. The VSS buffer takes the voltage pulses from the VSS and uses them to open and close four solid state output switches to ground at a rate proportional to vehicle speed. The VSS buffer is matched to the vehicle based on final drive ratio and tire size. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Computers and Control Systems > Vehicle Speed Sensor > Component Information > Locations > Page 2954 Vehicle Speed Sensor: Service and Repair Speed sensor resistance should be 900-2000 ohms. The sensor is not serviceable and should be replaced if defective. The speed sensor is located on the transfer case. 1. Raise and support vehicle, then disconnect electrical connector from speed sensor. 2. Loosen sensor with suitable wrench. 3. Position suitable container under sensor, then remove sensor and O-ring. 4. Coat O-ring with transmission fluid, then install O-ring and speed sensor. 5. Torque sensor to 32 ft. lbs. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Automatic Transmission LH Rear Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Automatic Transmission > Page 2960 Rear Engine Wiring W/Man Trans Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Page 2961 C120 - Fuel Pump Oil Pressure Sender/Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Page 2962 Oil Pressure Switch (For Fuel Pump): Service and Repair REMOVE/DISCONNECT - Negative battery cable from battery. - Sensor or switch connectors. - Sensor or switch. INSTALL/CONNECT - Sensor or switch. - Sensor or switch. - Negative battery cable. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Specifications Throttle Position Sensor: Specifications Idle Normal 0.45 to 0.95 V Maximum 1.25 V Wide Open Throttle 4.0 to 4.5 V Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Specifications > Page 2966 Engine Harness, Right Front Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions Throttle Position Sensor: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. Use this page as a reference to determine the meaning of an abbreviation if necessary. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery Bi-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CHMSL Center High Mount Stoplamp CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRO Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2969 F-PUMP Fuel Pump FLASH Flasher FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2970 SIR Supplemental Inflatable Restraint SKT Socket SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature TIL Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2971 example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE (ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: ^ Slide across the vehicle seat. ^ Sit down or stand up. ^ Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: ^ They are bumped or dropped. ^ They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2972 Symbols (Part 1 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2973 Symbols (Part 2 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2974 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2975 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2976 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2977 Throttle Position Sensor: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2978 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2979 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2980 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2981 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2982 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. ^ If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. ^ A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2983 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2984 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2985 Ohmmeter Meter Scales Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2986 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. ^ An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. ^ On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: ^ A range selector switch which permits the selection of different ranges of resistance. ^ A set adjust control which allows the meter to be set at zero for accurate measurements. ^ Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2987 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: ^ Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. ^ Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. ^ Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2988 be less than 10 percent of the total drop. When using a voltmeter: ^ Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. ^ Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. ^ The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: ^ Check the accuracy and completeness of the complaint. ^ Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2989 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. ^ The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2990 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2991 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2992 Twisted/Shielded Wire Repair Twisted Wires Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2993 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2994 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2995 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). ^ Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean ^ Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. ^ Roll crimp (13) and solder the terminal. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2996 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2997 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2998 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. ^ Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean ^ Terminal cavity of the connector body. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 2999 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. ^ Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3000 C110 - TP Sensor Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3001 Throttle Position (TP) Circuit Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Page 3002 Throttle Position Sensor: Description and Operation Wiring Diagram For Code 21 - Throttle Position Sensor (Signal Voltage High) NOTE Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE The Throttle Position Sensor (TPS) is a potentiometer that senses throttle angle and sends a signal to the PCM. The TP signal is one of the most important inputs used by the control module for fuel control and for most of the control module control outputs. OPERATION The TPS has three internal circuits provided by the control module. One to ground, a second from the control module as a 5.0 volt reference source and a third circuit is used by the control module to measure the output voltage. As the throttle angle changes (pressing down on accelerator pedal) the TPS voltage output varies from about .5 volt at idle to about 4.9 volts at wide open throttle (WOT). Each time the voltage drops below 1.25 volts and stops, the control module assumes this value is 0 throttle from this point on. LOCATION: Side of throttle body opposite of throttle lever. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Page 3003 Throttle Position Sensor: Adjustments The TPS is not adjustable. Each time voltage drops below 1.25 volts and stops, the control module assumes that this value is zero throttle angle and measures percent throttle from this point on. Therefore adjustment is not necessary. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Page 3004 Throttle Position Sensor: Service and Repair NOTE Since Throttle Position Sensor (TPS) configurations can be mounted interchangeably, be sure to order the correct one for your engine with identical part number of the one being replaced. Throttle Position (TP) Sensor REMOVE/DISCONNECT - Electrical connectors. - TPS attaching screw assemblies and retainer, (if applicable). - TPS from throttle body assembly. NOTE Do NOT immerse in any type of liquid solvent or cleaner, as damage may occur. INSTALL/CONNECT - With throttle valve in normally closed position, install TPS on throttle shaft with seal and rotate counter clockwise to align mounting hole. - Two attaching screw assemblies. Tighten screw assemblies to 2.0 Nm (18.0 lb-in). - Electrical connector to TPS. - Check for TPS output as follows: Connect an ALDL scanner to read TPS output voltage. - With ignition "ON" and engine stopped, TPS voltage should be less than 1.25 volts. If more than 1.25 volts, replace TPS. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Technical Service Bulletins > Knock Sensor Circuit DTC 43 Chart Revision Knock Sensor: Technical Service Bulletins Knock Sensor Circuit - DTC 43 Chart Revision File In Section: 6E Engine Fuel & Emission Bulletin No.: 51-65-19 Date: April, 1995 Subject: Section 3A - Control Module System (PCM) Driveability and Emissions - Revised DTC 43 Knock Sensor (KS) Circuit (Dual Knock Sensors) Models: 1994 Chevrolet and GMC Truck S/T; M/L, C/K Models with 4.3L Engine (VINs W, Z RPOs L35, LB4) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Technical Service Bulletins > Knock Sensor Circuit DTC 43 Chart Revision > Page 3010 This bulletin advises of a revision to the DTC 43 Knock Sensor (KS) Circuit (Dual Knock Sensor System) chart in the following service manuals: 1994 S/T Driveability Emissions and Electrical Diagnosis Manual, page 3A-119 1994 M/L Driveability Emissions and Electrical Diagnosis Manual, page 3A-75 1994 C/K Driveability Emissions and Electrical Diagnosis Manual, page 3A-69 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Technical Service Bulletins > Page 3011 Knock Sensor: Specifications Coil bracket bolt/nut ............................................................................................................................. ................................................. 27 N-m (20 lbs ft) Distributor clamp bolt ........................................................................................................................... ................................................ 27 N-m (20 lbs ft) Knock Sensor ...................................................................................................................................... .................................................. 19 N-m (14 lbs ft) Spark Plugs ......................................................................................................................................... .................................................. 15 N-M (11 lbs ft) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Locations > Assembly View Knock Sensors Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Locations > Assembly View > Page 3014 Knock Sensor: Locations Harness View LH Rear Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Locations > Assembly View > Page 3015 LH Rear Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Locations > Page 3016 Knock Sensor: Diagrams C119 - Knock Sensor C135 - Knock Sensor Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Locations > Page 3017 Knock Sensor: Description and Operation PURPOSE: The Knock Sensor (KS) is used to detect engine detonation (ping). The control module will retard the electronic spark timing up to 8° based on the signal received. CONSTRUCTION The KS system has two major components: Control Module. - Knock Sensor(s). The two knock sensors are spliced together and go directly to the control module. OPERATION The knock sensor internal circuit causes the control modules 5 volts to be pulled down to about 2.5 volts. The knock sensor produces an A/C signal which rides on the 2.5 volts DC signal. The AC voltage monitor in the control module will detect this AC voltage and provide a signal to begin retarding spark until the knock diminishes. The amplitude and frequency are dependent upon the knock level. LOCATION Engine block. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Locations > Page 3018 Knock Sensor: Testing and Inspection Knock Sensor (KS) System Check Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Locations > Page 3019 Knock Sensor Circuit Circuit Description The Knock Sensor (KS) circuit consists of two knock sensors with one wire that goes directly to the control modules. There are two Knock Sensor (KS) checks performed by the ECM. One check consists of monitoring CKT 496 for a voltage that is more than .63 volt and less than 3.1 volts. If voltage is either too high or too low for 10 or more seconds, DTC 43 will set. The PCM uses this self check only. The next test is used only by the ECM along with the previous test. Once engine temperature reaches 85°C, MAP is over 83 kPa, and engine speed is less than 3200 RPM, the ECM will perform a self check. This self check will advance the timing until it receives a knock signal. If no knock signal is received, DTC 43 will set. Chart Test Description Number(s) below refer to circled number(s) on the diagnostic chart. 1. The first test is to determine if the system is functioning at the present time. 2. Test two determines the state of the 5 volt reference voltage applied to the knock sensor circuit. 3. Test 3 determines the state of the knock sensors and connections themselves. Diagnostic Aids The control module applies 5 volts to CKT 496. A 8200 ohm resistor in the knock sensors reduces the voltage to about 2.5 volts. When knock occurs, the knock sensor produces a small AC voltage that rides on top of the 2.5 volts already applied. An AC voltage monitor, in the control module, is able to read this signal as knock and incrementally retard spark. If the KS system checks OK, but detonation is the complaint, refer to "Detonation/Spark Knock". See: Computers and Control Systems/Testing and Inspection/Symptom Related Diagnostic Procedures/Detonation/ Spark Knock Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Sensors and Switches - Powertrain Management > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Locations > Page 3020 Knock Sensor: Service and Repair REMOVE OR DISCONNECT - Negative battery cable. - Drain cooling system. NOTE On knock sensors which are mounted in the end of the cylinder head draining the cooling system will not be necessary. - Wiring harness connector from knock sensor. - Knock sensor. INSTALL OR CONNECT - Knock sensor. If reinstalling original sensor, apply water base caulk to sensor threads. Do NOT use silicone tape as this will insulate sensor from engine. ^ Tighten to 19 Nm (14 lb. ft.). - Wiring harness connector to knock sensor. - Refill cooling system and pressure test for leaks. - Negative battery cable. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Fuel Pressure > Diagnostic Connector - Fuel Pump > Component Information > Locations Component Location - "S/T" 4.3Z Utility - Manual Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Idle Speed > System Information > Technical Service Bulletins > Idle Speed - Specification Revised Idle Speed: Technical Service Bulletins Idle Speed - Specification Revised File In Section: 6E - Engine Fuel & Emission Bulletin No.: 41-65-22 Date: September, 1994 SERVICE MANUAL UPDATE Subject: Section 4 - Revised Controlled Idle Speed Specification Models: 1994 Chevrolet and GMC Truck Light Duty Models 1994 Oldsmobile Bravada with Gasoline Engines Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Idle Speed > System Information > Technical Service Bulletins > Idle Speed - Specification Revised > Page 3030 This service bulletin supersedes Service Manual information for the Controlled Idle Speed Specification on Page 4-3 of the Driveability, Emissions, and Electrical Diagnosis Manual. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Idle Speed > System Information > Technical Service Bulletins > Page 3031 Idle Speed: Specifications Refer to Adjustment Procedures Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > Customer Interest for Air Filter Element: > 04-07-30-013B > Feb > 07 > Engine, A/T - Shift/Driveability Concerns/MIL ON Air Filter Element: Customer Interest Engine, A/T - Shift/Driveability Concerns/MIL ON Bulletin No.: 04-07-30-013B Date: February 01, 2007 INFORMATION Subject: Automatic Transmission Shift, Engine Driveability Concerns or Service Engine Soon (SES) Light On as a Result of the Use of an Excessively/Over-Oiled Aftermarket, Reusable Air Filter Models: 2007 and Prior GM Cars and Light Duty Trucks 2007 and Prior Saturn Models 2003-2007 HUMMER H2 2006-2007 HUMMER H3 2005-2007 Saab 9-7X Supercede: This bulletin is being revised to add models and model years. Please discard Corporate Bulletin Number 04-07-30-013A (Section 07 - Transmission/Transaxle). The use of an excessively/over-oiled aftermarket, reusable air filter may result in: Service Engine Soon (SES) light on Transmission shift concerns, slipping and damaged clutch(es) or band(s) Engine driveability concerns, poor acceleration from a stop, limited engine RPM range The oil that is used on these air filter elements may be transferred onto the Mass Air Flow (MAF) sensor causing contamination of the sensor. As a result, the Grams per Second (GPS) signal from the MAF may be low and any or all of the concerns listed above may occur. When servicing a vehicle with any of these concerns, be sure to check for the presence of an aftermarket reusable, excessively/over-oiled air filter. The MAF, GPS reading should be compared to a like vehicle with an OEM air box and filter under the same driving conditions to verify the concern. The use of an aftermarket reusable air filter DOES NOT void the vehicle's warranty. If an aftermarket reusable air filter is used, technicians should inspect the MAF sensor element and the air induction hose for contamination of oil prior to making warranty repairs. Transmission or engine driveability concerns (related to the MAF sensor being contaminated with oil) that are the result of the use of an aftermarket reusable, excessively/over-oiled air filter are not considered to be warrantable repair items. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > Customer Interest for Air Filter Element: > 04-07-30-013B > Feb > 07 > Engine, A/T - Shift/Driveability Concerns/MIL ON > Page 3041 Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Air Filter Element: > 04-07-30-013B > Feb > 07 > Engine, A/T - Shift/Driveability Concerns/MIL ON Air Filter Element: All Technical Service Bulletins Engine, A/T - Shift/Driveability Concerns/MIL ON Bulletin No.: 04-07-30-013B Date: February 01, 2007 INFORMATION Subject: Automatic Transmission Shift, Engine Driveability Concerns or Service Engine Soon (SES) Light On as a Result of the Use of an Excessively/Over-Oiled Aftermarket, Reusable Air Filter Models: 2007 and Prior GM Cars and Light Duty Trucks 2007 and Prior Saturn Models 2003-2007 HUMMER H2 2006-2007 HUMMER H3 2005-2007 Saab 9-7X Supercede: This bulletin is being revised to add models and model years. Please discard Corporate Bulletin Number 04-07-30-013A (Section 07 - Transmission/Transaxle). The use of an excessively/over-oiled aftermarket, reusable air filter may result in: Service Engine Soon (SES) light on Transmission shift concerns, slipping and damaged clutch(es) or band(s) Engine driveability concerns, poor acceleration from a stop, limited engine RPM range The oil that is used on these air filter elements may be transferred onto the Mass Air Flow (MAF) sensor causing contamination of the sensor. As a result, the Grams per Second (GPS) signal from the MAF may be low and any or all of the concerns listed above may occur. When servicing a vehicle with any of these concerns, be sure to check for the presence of an aftermarket reusable, excessively/over-oiled air filter. The MAF, GPS reading should be compared to a like vehicle with an OEM air box and filter under the same driving conditions to verify the concern. The use of an aftermarket reusable air filter DOES NOT void the vehicle's warranty. If an aftermarket reusable air filter is used, technicians should inspect the MAF sensor element and the air induction hose for contamination of oil prior to making warranty repairs. Transmission or engine driveability concerns (related to the MAF sensor being contaminated with oil) that are the result of the use of an aftermarket reusable, excessively/over-oiled air filter are not considered to be warrantable repair items. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Air Filter Element: > 04-07-30-013B > Feb > 07 > Engine, A/T - Shift/Driveability Concerns/MIL ON > Page 3047 Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Fuel Filter > Fuel Pressure Release > System Information > Service and Repair Fuel Pressure Release: Service and Repair WARNING To reduce the risk of fire and personal injury, it is necessary to relieve fuel system pressure before servicing fuel system components. A small amount of fuel may be released when servicing fuel lines or connections. In order to reduce the chance of personal injury, cover fuel line fittings with a shop towel before disconnecting to catch any fuel that may leak out. Place the towel in an approved container when disconnect is complete. PROCEDURE - Disconnect negative battery terminal to avoid possible fuel discharge if an accidental attempt is made to start the engine. - Loosen fuel filler cap to relieve tank vapor pressure. (Do not tighten until service has been completed.) - The TBI model 220 contains a constant bleed feature in the pressure regulator that relieves pressure. Therefore, no further action is required. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Firing Order > Component Information > Specifications > Ignition Firing Order Firing Order: Specifications Ignition Firing Order Firing Order ......................................................................................................................................... ............................................................... 1-6-5-4-3-2 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Ignition Timing > Ignition Timing Connector > Component Information > Technical Service Bulletins > Ignition Set Timing Connector Location Correction Ignition Timing Connector: Technical Service Bulletins Ignition Set Timing Connector - Location Correction File in Section: Engine Fuel & Emission Bulletin No.: 41-65-41 Date: January, 1995 SERVICE MANUAL UPDATE Subject: Section 6A - Ignition Set Timing Connector Location Models: 1994 Chevrolet and GMC Truck S/T Models 1994 Oldsmobile Bravada with 4.3L Engine (VINs W, Z - RPOs L35, LB4) The location of the Set Timing Connector is incorrectly called out in "Section 6A" (Page 6A-8) of the "Driveability, Emissions and Electrical Diagnosis", Service Manual and in the 1994 Oldsmobile Bravada Service Manual Supplement (Page 6E3-C4-8). The correct location of the Set Timing Connector is inside the cab where the Heater Box and the carpet meet on the passenger side floor. Pull carpet back to expose the single wire and connectors on the outside of the control module harness. The wire colors are tan with a black stripe. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Ignition Timing > Ignition Timing Connector > Component Information > Technical Service Bulletins > Page 3061 Timing Connector-In Pass Comp Behind Carpet, Below Heater Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Ignition Timing > Number One Cylinder > Component Information > Locations > Number 1 Cylinder Location Number One Cylinder: Locations Number 1 Cylinder Location NUMBER ONE CYLINDER LOCATION Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Ignition Timing > Timing Marks and Indicators > System Information > Locations Timing Mark Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Ignition Cable > Component Information > Specifications Ignition Cable: Specifications RESISTANCE VALUES 0-15 inch cable .................................................................................................................................... ................................................. 3,000 - 10,000 ohms. 15-25 inch cable .................................................................................................................................. ................................................. 4,000 - 15,000 ohms. 25-35 inch cable .................................................................................................................................. ................................................. 6,000 - 20,000 ohms. NOTE: Longer wires should measure about 5,000 to 10,000 ohms per foot. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Ignition Cable > Component Information > Specifications > Page 3072 Ignition Cable: Locations Spark Plug Wire Routing Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Distributor, Ignition > Component Information > Specifications Distributor: Specifications Coil bracket bolt/nut ............................................................................................................................. ................................................. 27 N-m (20 lbs ft) Distributor clamp bolt ........................................................................................................................... ................................................ 27 N-m (20 lbs ft) Knock Sensor ...................................................................................................................................... .................................................. 19 N-m (14 lbs ft) Spark Plugs ......................................................................................................................................... .................................................. 15 N-M (11 lbs ft) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Distributor, Ignition > Component Information > Specifications > Page 3076 LH Rear Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Distributor, Ignition > Component Information > Specifications > Page 3077 Distributor: Description and Operation PURPOSE The distributor reference signal provides the ECM with both engine RPM and crankshaft position information. This enables the ECM to operate the fuel pump relay and energize the fuel injector. OPERATION When the engine is cranking or running the ECM receives Distributor Ignition (DI) reference pulses from the ignition module. If the wire becomes open or grounded the engine will not run, as the ECM will not operate the injector. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Distributor, Ignition > Component Information > Specifications > Page 3078 Distributor: Service and Repair Distributor Remove or Disconnect Figure 8 - Spark Plug Wire Routing - Left Side (2.2L) Figure 9 - Spark Plug Wire Routing - Right Side (2.2L) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Distributor, Ignition > Component Information > Specifications > Page 3079 Figure 10 - Distributor And Coil (4.3L VIN Z) Figure 11 - Distributor And Coil (4.3L VIN W) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Distributor, Ignition > Component Information > Specifications > Page 3080 Figure 12 - Spark Plug Wire Routing - Left Side (4.3L VIN Z) Figure 13 - Spark Plug Wire Routing - Right Side - Pickup Models (4.3L VIN Z) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Distributor, Ignition > Component Information > Specifications > Page 3081 Figure 14 - Spark Plug Wire Routing - Right Side - Utility Models (4.3L VIN Z) Figure 15 - Spark Plug Wire Routing (4.3L VIN W) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Distributor, Ignition > Component Information > Specifications > Page 3082 - Make sure the ignition switch is "OFF." 1. Air cleaner and hoses (4.3L VIN Z). 2. Wiring harness connectors at the side of the distributor cap. 3. Two screws on the sides of the distributor cap. 4. Coil wire and spark plug wires on either the left or right side of the distributor. 5. Distributor cap and move it aside. A. Use chalk to note the position of the rotor in relation to the engine. B. Use chalk to note the position of the distributor housing in relation to the engine. 6. Distributor bolt and hold-down clamp. 7. Distributor and gasket, when present. Install or Connect Figure 8 - Spark Plug Wire Routing - Left Side (2.2L) Figure 9 - Spark Plug Wire Routing - Right Side (2.2L) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Distributor, Ignition > Component Information > Specifications > Page 3083 Figure 10 - Distributor And Coil (4.3L VIN Z) Figure 11 - Distributor And Coil (4.3L VIN W) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Distributor, Ignition > Component Information > Specifications > Page 3084 Figure 12 - Spark Plug Wire Routing - Left Side (4.3L VIN Z) Figure 13 - Spark Plug Wire Routing - Right Side - Pickup Models (4.3L VIN Z) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Distributor, Ignition > Component Information > Specifications > Page 3085 Figure 14 - Spark Plug Wire Routing - Right Side - Utility Models (4.3L VIN Z) Figure 15 - Spark Plug Wire Routing (4.3L VIN W) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Distributor, Ignition > Component Information > Specifications > Page 3086 A. To ensure correct timing of the distributor, it must be installed with the rotor correctly positioned as noted in step 5 of the removal procedure. Line up the rotor to the mark on the engine, and the mark on the housing to the engine. B. If the distributor shaft won't drop into the engine, remove the distributor, insert a screwdriver into the hole for the distributor and rotate the oil pump driveshaft so that it lines up with the distributor driver gear. 1. Distributor and gasket, where present. 2. Hold-down clamp and bolt. - Bolt on the 4.3L to 27 Nm (20 lbs. ft.). 3. Distributor cap. 4. Wiring harness connectors at the side of the distributor. 5. Spark plug wires and coil wire. 6. Air Cleaner and hoses. - Check the engine timing. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Spark Plug > Component Information > Specifications Spark Plug: Specifications Spark Plug Gap ................................................................................................................................... ........................................ N/A see NOTE following. Spark Plug Torque ............................................................................................................................... ...................................................... 15 N-m (11 lb.ft.) Spark Plug Type .................................................................................................................................. .......................................................... AC CR43TSM NOTE Check the gap specifications given on the Emissions Control Label. If the gap is different from what is listed here, use the information on the label. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Compression Check > System Information > Specifications Compression Check: Specifications Minimum, 698 kPa (100 psi) @ 200 rpm. The lowest cylinder reading should not be less than 80% of the highest. Perform compression test with engine at normal operating temperature, spark plugs removed and throttle wide open. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Valve Clearance > System Information > Specifications > Valve Clearance Specifications Valve Clearance: Specifications Valve Clearance Specifications VALVE ADJUSTMENT (VIN Z) WITH SCREW-IN ROCKER ARM STUDS AND POSITIVE STOP SHOULDERS Valve Rocker Arm Nuts ....................................................................................................................... .......................................... 27 Nm (20 lb. ft.). WITH PRESSED-IN ROCKER ARM STUDS Refer to Rocker Arm / Adjustments. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Valve Clearance > System Information > Specifications > Valve Clearance Specifications > Page 3097 Valve Clearance: Specifications Valve Arrangement FRONT TO REAR 4.3L/V6-262 Left Side........................................................................................................................... .................................................................................. E-I-E-I-I-E Right Side......................................... .............................................................................................................................................................. .... E-I-I-E-I-E Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Valve Clearance > System Information > Specifications > Page 3098 Valve Clearance: Adjustments VALVE ADJUSTMENT Fig. 10 Valve Adjustment The 4.3L VIN Z engine can be equipped with two different rocker arm stud configurations that require different valve lash procedures. TYPE 1 - VIN Z If you have a 4.3L VIN Z engine that has screw-in rocker arm studs with positive stop shoulders, no valve adjustment is necessary. When the valve train requires service, you simply tighten the rocker arm nuts to 27 Nm (20 ft lb). TYPE 2 - VIN Z If you have a 4.3L VIN Z engine that has pressed-in rocker arm studs, you must follow the valve adjustment procedure outlined below. 1. Remove rocker arm cover. 2. Rotate engine until mark on torsional damper is aligned with "0" mark on timing tab fastened to crankcase front cover. To ensure engine is at No. 1 cylinder firing position, place fingers on No. 1 cylinder valves as the mark on damper approaches the "0" mark on timing tab. If valves are not moving, engine is in the No. 1 cylinder firing position. If valves are moving, engine is in the No. 4 cylinder firing position and should be rotated one revolution. 3. With engine in No. 1 cylinder firing position, adjust the following valves: ^ Exhaust valves 1, 5 and 6. ^ Intake valves 1, 2 and 3. NOTE: Even numbered cylinders are in the left bank and odd numbered cylinders are in the right bank, when viewed from front of the engine. 4. Back off adjusting nut until lash is felt at pushrod, then tighten nut until all lash is removed. This can be determined by rotating pushrod while turning adjusting nut. When all lash is removed, tighten adjusting nut 1 and 3/4 turns to center lifter plunger. 5. Crank engine one full revolution until mark on torsional damper and "0" mark on timing tab are again in alignment. This is the No. 4 cylinder firing position. With engine in this position, adjust the following valves: ^ Exhaust valves 2, 3 and 4. ^ Intake valves 4, 5 and 6. 6. Install valve covers and related components, then start engine and check timing and idle speed. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Tune-up and Engine Performance Checks > Valve Clearance > System Information > Specifications > Page 3099 Valve Clearance: Service and Repair For Valve Adjustment, Refer to Valve Clearance / Adjustments. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > A/C Signal > Component Information > Description and Operation A/C Signal: Description and Operation PURPOSE This signal indicates that the A/C control switch is turned "ON" and the pressure switch is closed. The PCM uses this signal to adjust the idle speed. CONSTRUCTION A/C clutch control circuit system consists of: Heater and A/C control assembly located at the dashboard. - Two A/C pressure switches (LOW and HIGH). - Compressor clutch. - PCM OPERATION Turning "ON" air conditioning supplies battery voltage to the the A/C compressor clutch and terminal "E12" of the PCM connector to increase and maintain idle speed. The PCM does not control the A/C compressor clutch, therefore, if A/C does not function refer to HVAC section for diagnosis of the system. If A/C compressor turns "OFF", check for an open CKT 59 to the PCM. If circuits are OK, it is a faulty PCM connector terminal "E12" or PCM. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > A/C Signal > Component Information > Description and Operation > Page 3104 A/C Signal: Testing and Inspection A/C Clutch Control Diagnosis Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > A/C Signal > Component Information > Description and Operation > Page 3105 A/C Signal Circuit Circuit Description Turning "ON" the air conditioning supplies CKT 59 battery voltage to the A/C compressor clutch and to terminal "E12" of the PCM connector to increase and maintain idle speed. The PCM does not control the A/C compressor clutch, therefore, if A/C does not function, refer to the A/C section of the service manual for diagnosis of the system. If A/C is operating properly and idle speed dips too low when the A/C compressor turns "ON" or flares too high when the A/C compressor turns "OFF," check for an open CKT 59 to the PCM. If circuits are OK, it is a faulty PCM connector terminal "E12" or PCM. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Air Flow Meter/Sensor Relay > Component Information > Technical Service Bulletins > Shift Indicator Light Application and Operation Air Flow Meter/Sensor Relay: Technical Service Bulletins Shift Indicator Light Application and Operation File In Section: 7 - Transmission Bulletin No.: 36-72-07A Date: February, 1995 Subject: Manual Transmission Shift Indicator Light Application and Operation Models: 1993-95 Chevrolet and GMC Truck C/K and S/T Models with Manual Transmission This bulletin is being revised to add the 1995 model year. Please discard bulletin number 367207 (Group Reference - Transmission). Certain trucks are not equipped with a shift indicator light. The shift light is commonly used to achieve improved fuel economy by prompting the driver when to upshift. Depending on the engine/transmission installed in the vehicle, the shift light can have the following characteristics: ^ Indicates proper shift point for maximum fuel economy. ^ Indicates engine over-speed. ^ Shift light is inoperative. The following charts detail normal shift light operation: 1993 Models: Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Air Flow Meter/Sensor Relay > Component Information > Technical Service Bulletins > Shift Indicator Light Application and Operation > Page 3110 1994 Models: 1995 Models: Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Intake Air Temperature Sensor > Component Information > Specifications > Electrical Specifications Intake Air Temperature Sensor: Electrical Specifications Resistance 185 ohms at 210 deg F 450 ohms at 160 deg F 1800 ohms at 100 deg F 3400 ohms at 70 deg F 7500 ohms at 40 deg F 13500 ohms at 20 deg F 25000 ohms at 0 deg F 100700 ohms at -40 deg F Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Intake Air Temperature Sensor > Component Information > Specifications > Electrical Specifications > Page 3115 Intake Air Temperature Sensor: Mechanical Specifications Torque Valve Torque Valve Induction Air Sensor 44 in.lb Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Specifications Coolant Temperature Sensor/Switch (For Computer): Specifications Resistance 185 ohms at 210 deg F 450 ohms at 160 deg F 1800 ohms at 100 deg F 3400 ohms at 70 deg F 7500 ohms at 40 deg F 13500 ohms at 20 deg F 25000 ohms at 0 deg F 100700 ohms at -40 deg F Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Specifications > Page 3119 Coolant Temperature Sensor/Switch (For Computer): Locations Engine Coolant Temperature Sensor Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Specifications > Page 3120 Engine Harness, Right Front Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions Coolant Temperature Sensor/Switch (For Computer): Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. Use this page as a reference to determine the meaning of an abbreviation if necessary. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery Bi-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CHMSL Center High Mount Stoplamp CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRO Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3123 F-PUMP Fuel Pump FLASH Flasher FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3124 SIR Supplemental Inflatable Restraint SKT Socket SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature TIL Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3125 example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE (ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: ^ Slide across the vehicle seat. ^ Sit down or stand up. ^ Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: ^ They are bumped or dropped. ^ They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3126 Symbols (Part 1 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3127 Symbols (Part 2 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3128 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3129 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3130 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3131 Coolant Temperature Sensor/Switch (For Computer): Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3132 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3133 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3134 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3135 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3136 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. ^ If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. ^ A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3137 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3138 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3139 Ohmmeter Meter Scales Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3140 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. ^ An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. ^ On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: ^ A range selector switch which permits the selection of different ranges of resistance. ^ A set adjust control which allows the meter to be set at zero for accurate measurements. ^ Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3141 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: ^ Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. ^ Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. ^ Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3142 be less than 10 percent of the total drop. When using a voltmeter: ^ Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. ^ Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. ^ The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: ^ Check the accuracy and completeness of the complaint. ^ Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3143 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. ^ The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3144 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3145 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3146 Twisted/Shielded Wire Repair Twisted Wires Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3147 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3148 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3149 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). ^ Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean ^ Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. ^ Roll crimp (13) and solder the terminal. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3150 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3151 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3152 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. ^ Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean ^ Terminal cavity of the connector body. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3153 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. ^ Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3154 C105 - Engine Coolant Temperature Sensor Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3155 Engine Coolant Temperature (ECT) Circuit Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Page 3156 Coolant Temperature Sensor/Switch (For Computer): Description and Operation Engine Coolant Temperature Sensor PURPOSE The Engine Coolant Temperature (ECT) Sensor information is used by the control module to control: Fuel delivery - Torque Converter Clutch (TCC) - Engine Spark Timing (EST) - Controlled Canister Purge (CCP) - Idle Air Control (IAC) - Cooling Fan OPERATION The ECT is a thermistor that is located in the engine coolant flow mounted to the intake manifold. When the coolant temperature is low, the sensor produces a high resistance. When the coolant temperature is high, the sensor produces a low resistance. The PCM sends a 5.0 volt signal to the ECT through a resistor in the computer and measures the voltage. The voltage will be high or low depending on coolant temperature. With the ECT varying its resistance, the PCM can sense engine coolant temperature by reading the varying voltage. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Data Link Connector > Component Information > Locations Steering Column Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Data Link Connector > Component Information > Locations > Page 3160 C221 - Data Link Connector Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Data Link Connector > Component Information > Locations > Page 3161 Data Link Connector: Description and Operation ALDL Connector PURPOSE The Data Link Connector (DLC) provides a means of communicating with the PCM concerning engine and transmission operating parameters and accessing Diagnostic Trouble Codes (DTC). OPERATION The PCM communicates a variety of information through the Serial Data Line (DLC terminal "M"). The data is transmitted at a high frequency which requires a Tech 1 diagnostic computer (scan) tool for interpretation. There are several other non-OEM scan tools available for displaying the same information. LOCATION The Data Link Connector is located in the passenger compartment. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage Engine Control Module: Technical Service Bulletins Engine Controls - Aftermarket Accessory Usage INFORMATION Bulletin No.: 04-06-04-054B Date: November 18, 2010 Subject: Info - Non-GM Parts and Accessories (Aftermarket) Models: 2011 and Prior GM Passenger Cars and Trucks Supercede: This bulletin is being revised to add model years and update to the new U.S. Fixed Operation Manager (FOM) and Canada Warranty Manager (WM) names. Please discard Corporate Bulletin Number 04-06-04-054A (Section 06 - Engine/Propulsion System). The recent rise and expansion of companies selling non-GM parts and accessories has made it necessary to issue this reminder to dealers regarding GM's policy on the use and installation of these aftermarket components. When a dealer is performing a repair under the New Vehicle Limited Warranty, they are required to use only genuine GM or GM-approved parts and accessories. This applies to all warranty repairs, special policy repairs or any repairs paid for by GM. Parts and accessories advertised as being "the same" as parts manufactured by GM, but not sold through GM, do not qualify for use in warranty repairs, special policy repairs or any repairs paid for by GM. During a warranty repair, if a GM original equipment part is not available through GM Customer Care and Aftersales (GM CC&A;), ACDelco(R) distributors, other GM dealers or approved sources, the dealer is to obtain comparable, non-GM parts and clearly indicate, in detail, on the repair order the circumstances surrounding why non-GM parts were used. The dealer must give customers written notice, prior to the sale or service, that such parts or accessories are not marketed or warranted by General Motors. It should also be noted that dealers modifying new vehicles and installing equipment, parts and accessories obtained from sources not authorized by GM are responsible for complying with the National Traffic and Motor Vehicle Safety Act. Certain non-approved parts or assemblies, installed by the dealer or its agent not authorized by GM, may result in a change to the vehicle's design characteristics and may affect the vehicle's ability to conform to federal law. Dealers must fully understand that non-GM approved parts may not have been validated, tested or certified for use. This puts the dealer at risk for potential liability in the event of a part or vehicle failure. If a GM part failure occurs as the result of the installation or use of a non-GM approved part, the warranty will not be honored. A good example of non-authorized modification of vehicles is the result of an ever increasing supply of aftermarket devices available to the customer, which claim to increase the horsepower and torque of the Duramax(TM) Diesel Engines. These include the addition of, but are not limited to one or more of the following modifications: - Propane injection - Nitrous oxide injection - Additional modules (black boxes) that connect to the vehicle wiring systems - Revised engine calibrations downloaded for the engine control module - Calibration modules which connect to the vehicle diagnostic connector - Modification to the engine turbocharger waste gate Although the installation of these devices, or modification of vehicle components, can increase engine horsepower and torque, they may also negatively affect the engine emissions, reliability and/or durability. In addition, other powertrain components, such as transmissions, universal joints, drive shafts, and front/rear axle components, can be stressed beyond design safety limits by the installation of these devices. General Motors does not support or endorse the use of devices or modifications that, when installed, increase the engine horsepower and torque. It is because of these unknown stresses, and the potential to alter reliability, durability and emissions performance, that GM has adopted a policy that prevents any UNAUTHORIZED dealer warranty claim submissions to any remaining warranty coverage, to the powertrain and driveline components whenever the presence of a non-GM (aftermarket) calibration is confirmed - even if the non-GM control module calibration is subsequently removed. Refer to the latest version of Bulletin 09-06-04-026 (V8 Gas Engines) or 06-06-01-007 (Duramax(TM) Diesel Engines) for more information on dealer requirements for calibration verification. These same policies apply as they relate to the use of non-GM accessories. Damage or failure from the use or installation of a non-GM accessory will not be covered under warranty. Failure resulting from the alteration or modification of the vehicle, including the cutting, welding or disconnecting of the vehicle's original equipment parts and components will void the warranty. Additionally, dealers will NOT be reimbursed or compensated by GM in the event of any legal inquiry at either the local, state or federal level that Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 3166 results from the alteration or modification of a vehicle using non-GM approved parts or accessories. Dealers should be especially cautious of accessory companies that claim the installation of their product will not void the factory warranty. Many times these companies have even given direction on how to quickly disassemble the accessory in an attempt to preclude the manufacturer from finding out that is has been installed. Any suspect repairs should be reviewed by the Fixed Operations Manager (FOM), and in Canada by the Warranty Manager (WM) for appropriate repair direction. If it is decided that a goodwill repair is to be made on the vehicle, even with the installation of such non-GM approved components, the customer is to be made aware of General Motors position on this issue and is to sign the appropriate goodwill documentation required by General Motors. It is imperative for dealers to understand that by installing such devices, they are jeopardizing not only the warranty coverage, but also the performance and reliability of the customer's vehicle. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 3167 Engine Control Module: Technical Service Bulletins PROM - Reprogram Using Off Board Program Adapter File In Section: 6E - Engine Fuel & Emission Bulletin No.: 73-65-13 Date: March, 1997 INFORMATION Subject: Reprogramming Capability using the Off Board Programming Adapter Models: 1993-97 Passenger Cars and Trucks (Applicable Reprogrammable Vehicles) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 3168 The General Motors vehicles contain Electronically Reprogrammable Devices (i.e. PCM, VCM, ECM). These vehicles cannot be programmed through PROM replacement, however service programming capability is available through the Tech 1/1A, Tech 2 and Techline terminals via direct or remote programming. The Environmental Protection Agency (EPA) has requested that all new vehicle manufacturers ensure their dealers/retailers are aware that they are responsible for providing customers access to reprogramming services at a reasonable cost and in a timely manner. Although programming of controllers has become a common service practice at GM dealers/retailers, the EPA has received reports from consumers and the aftermarket repair industry that they were unable to purchase a new (programmed) Electronically Reprogrammable Device (ERD) over-the-counter. As a result, on August 1, 1995, the Federal Government issued a regulation requiring all manufacturers to make available reprogramming to the independent aftermarket by December 1, 1997. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 3169 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 3170 Today, the Off Board Programming Adapter (OBPA) is used to reprogram ERD's sold over-the-counter. For all practical purposes, the OBPA takes the place of the vehicle when the vehicle is not available. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 3171 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 3172 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 3173 The list of dealerships/retailers currently own the OBPA (see Attachments 1 - 3). These locations are equipped to provide over-the-counter preprogrammed ERD's. The hardware required to perform reprogramming in addition to the OBPA is a Techline terminal, Tech 1/1A and associated cables and adapters. THE TECH 2 SHOULD NOT BE USED WITH THE OBPA AT THIS TIME BECAUSE OF INADEQUATE OBPA GROUNDING. The current OBPA can support reprogramming on all late model General Motor's vehicles except: ^ Premium V-8's ^ 1996 Diesel Truck ^ Cadillac Catera Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 3174 ^ All 1997 programmable vehicles (requires use of the Tech 2) A modification to the OBPA is being offered by Kent-Moore to support these additional vehicles and to allow reprogramming using the Tech 2. The revisions to the OBPA for the Tech 2 is very important as the Tech 2 is the only tool used for service programming for 1997 and future vehicles. To have the modifications performed, contact Kent-Moore at (800) 345-2233. The revisions (part number J 41207 REV-C) are free of charge for GM dealerships/retailers. A dealership/retailer can purchase the OBPA by contacting Kent-Moore (part number J 41207-C). Support on how to use the OBPA is provided by the Techline Customer Support Center (TCSC) at (800) 828-6860 (English) or (800) 503-3222 (French). If you need to purchase an OBPA and/or cable, contact Kent-Moore at (800) 345-2233. The OBPA retails for $695.00 (includes all revisions 1-4) under part number J 41207-C. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 3175 Engine Control Module: Technical Service Bulletins PCM - Replacement Component Text Deletion File in Section: 6E - Engine Fuel & Emission Bulletin No.: 41-65-33 Date: October, 1994 SERVICE MANUAL UPDATE Subject: Section 3A - Driveability, Emissions and Electrical Diagnosis - Text Deletion Models: 1994 Chevrolet and GMC Truck & T Models with 2.2L Gasoline Engine (VIN 4 - RPO LN2) or 4.3L Engine (VINs Z, W - RPOs LB4, L35) 1994-95 Chevrolet and GMC Truck C/K, M/L, G, P3, PG Models with 4.3L Engine (VIN Z - RPO LB4), 5.0L Engine (VIN H - RPO L03), 5.7L Engine VIN K - RPO L05) or 7.4L Engine (VIN N - RPO L19) 1994-95 Chevrolet and GMC Truck C/K, G, P3 Models with 6.5L Diesel Engine (VINs F, P, S RPOs L65, L49, L56) This bulletin contains revisions to the "Driveability, Emissions and Electrical Diagnostic" Service Manuals for the following pages: 1994 S/T Truck - 3A-5 1994-1995 G Van - 3A-4 1994-1995 C/K Truck - 3A-4 1994-1995 M/L Truck - 3A-4 1994-1995 PG/P3 Truck - 3A-4 1994-1995 C/K, G, P Truck - 3-17 and Supplement This Text is to be Deleted "The replacement PCM may be faulty - After the PCM is replaced, the system should be rechecked for proper operation. If the Diagnostic Chart again indicates that the PCM is the problem, substitute a known good PCM". Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Page 3176 Engine Control Module: Specifications Engine VIN Code ID [1] ....................................................................................................................... .............................................................................. Z Engine Displacement ........................................................................................................................... ........................................................... 4.3L (262 cid) Engine Configuration ........................................................................................................................... ............................................................................ V6 Fuel Control System ...................................................................................................................................................... Throttle Body Fuel Injection (TBI) Ignition System ....................................................................................................... Distributor Ignition W/Ignition Control and Knock Sensor(DI-IC-KS) Control Module Systems S/T Pickup Automatic Transmission ......................................................................................................................... Powertrain Control Module (93PCM6) S/T Utility Manual Transmission .............................................................................................................................. Powertrain Control Module (93PCM6) S/T Pickup Manual Transmission ........................................................................................................................................ Vehicle Control Module (VCM) Remarks: [1] The eighth digit of the VIN denotes engine code. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Page 3177 Engine Control Module: Locations Vehicle Speed Sensor Buffer And Electric Shift Transfer Case Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Page 3178 Engine Or Powertrain Control Module Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Engine Control Module > Component Information > Diagrams > C1 Red (32 Pin) Engine Control Module: Diagrams C1 Red (32 Pin) Manual Transmission (1 Of 2) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Engine Control Module > Component Information > Diagrams > C1 Red (32 Pin) > Page 3181 Manual Transmission (2 Of 2) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Engine Control Module > Component Information > Diagrams > C1 Red (32 Pin) > Page 3182 Engine Control Module: Diagrams C2-Blue (32 Pin) Automatic Transmission (1 Of 2) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Engine Control Module > Component Information > Diagrams > C1 Red (32 Pin) > Page 3183 Automatic Transmission (2 Of 2) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Engine Control Module > Component Information > Diagrams > C1 Red (32 Pin) > Page 3184 Engine Control Module: Diagrams C210 C210 - PCM C210 - ECM Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Engine Control Module > Component Information > Diagrams > C1 Red (32 Pin) > Page 3185 Engine Control Module: Diagrams C211 C211 - PCM C211 - ECM Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Engine Control Module > Component Information > Diagrams > C1 Red (32 Pin) > Page 3186 Engine Control Module: Diagrams With Manual Transmission Pinout Chart Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Engine Control Module > Component Information > Diagrams > C1 Red (32 Pin) > Page 3187 Pinout Chart Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Engine Control Module > Component Information > Diagrams > C1 Red (32 Pin) > Page 3188 Pinout Chart Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Engine Control Module > Component Information > Diagrams > C1 Red (32 Pin) > Page 3189 Pinout Chart Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Engine Control Module > Component Information > Diagrams > Page 3190 Engine Control Module: Description and Operation Engine Control Module Fig. 5 ECM Unit (Showing PROM & CALPAK Locations) Powertrain Control Module (PCM) PURPOSE The Powertrain Control Module (PCM) is the control center of the fuel injection system. It constantly looks at the information from various sensors (inputs) and controls the systems (outputs) that affect vehicle performance. The PCM also performs the diagnostic function of the system. It can recognize operational problems, alert the driver through the Malfunction Indicator Lamp (MIL) "Service Engine Soon" light on the instrument panel and store a Diagnostic Trouble Code(s) (DTC) in the PCM memory. The DTC identifies the problem areas to aid the technician in performing repairs. OPERATION The PCM is an electronic computer designed to process the various input information, and send the necessary electrical response to control fuel delivery, spark control, and other emission control systems. The PCM can control these devices through the use of Quad Driver Modules (QDM). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Engine Control Module > Component Information > Diagrams > Page 3191 When the PCM is commanding a device or a component "ON," the voltage potential of the output is "LOW" or near zero volts. When the PCM is commanding a device or component "OFF," the voltage potential of the circuit will be "HIGH," or near 12 volts. The primary function of the QDM is to supply the ground for the component being controlled. The input information has an interrelation between sensor output. If one of the input devices failed, such as the oxygen sensor, this could affect more than one of the systems controlled by the computer. The PCM has two parts for service: Controller which is the PCM (93 PCM6), without the PROM (MEM-CAL). - PROM (Programmable Read Only Memory) which is a separate memory calibrator unit PCM Learning Ability The PCM has a "learning" ability which allows it to make corrections for minor variations in the fuel system to improve driveability. If the battery is disconnected, to clear diagnostic trouble codes or for other repairs. the "learning" process resets and begins again. A change may be noted in the vehicle's performance. To "teach" the vehicle, ensure the engine is at operating temperature. The vehicle should be driven at part throttle, with moderate acceleration and idle conditions until normal performance returns. NOTE The PCM must be maintained at a temperature below 85°C (185°F) at all times. This is most essential if the vehicle is put through a baking process. The PCM will become inoperative if it's temperature exceeds 85°C (185°F). It is recommended that temporary insulation be placed around the PCM during the time the vehicle is in a paint oven or other high temperature processes. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Engine Control Module > Component Information > Diagrams > Page 3192 Engine Control Module: Service and Repair Figure 1 CAUTION [a] The ignition must be "OFF," when disconnecting or reconnecting the control module connector, to prevent internal damage to the control module. [b] To prevent possible Electrostatic Discharge to the control module, Do NOT touch the connector pins or soldered components on the circuit boards. NOTE When replacing a production control module with a service controller, transfer the broadcast code and production control module part number to the controller label. DO NOT record information on the access cover. REMOVE/DISCONNECT - Negative battery terminal. - Passenger side kick panel. - Hush panel if equipped. - Mounting screw. - Control module from mounting bracket. - VSS buffer connector and rotate control module to ease removal. - Control module harness connectors. - Mounting brackets and modules if equipped. - Remove new control module from its packaging and check the service number to make sure it is the same as the defective control module. - PROM removal. Refer to PROM (MEM-CAL) replacement. NOTE Replacement control module is supplied without a PROM, so care should be used when removing it from the defective control module, because it will be reused in the new control module. INSTALL/CONNECT - Mounting brackets and modules if equipped. - Control module harness connectors. - VSS buffer connector and rotate control module to ease installation. - Control module into mounting bracket. - Mounting screw. - Hush panel if equipped. - Passenger side kick panel. - Negative battery terminal. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Idle Speed/Throttle Actuator - Electronic > Component Information > Specifications Idle Speed/Throttle Actuator - Electronic: Specifications Actuator Resistance Values Actuator Resistance Values Terminals "A" To "B" 40 to 80 ohms Terminals "C" to "D" 40 to 80 ohms Terminals "B" to "C" Infinite ohms Terminals "A" to "D" Infinite ohms Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Idle Speed/Throttle Actuator - Electronic > Component Information > Specifications > Page 3196 Engine Harness, Right Front Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Idle Speed/Throttle Actuator - Electronic > Component Information > Diagrams > Exploded Views Throttle Body Assembly (Exploded View) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Idle Speed/Throttle Actuator - Electronic > Component Information > Diagrams > Exploded Views > Page 3199 C111 - IAC Motor Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Idle Speed/Throttle Actuator - Electronic > Component Information > Diagrams > Page 3200 Idle Speed/Throttle Actuator - Electronic: Description and Operation Idle Air Control (IAC) System Idle Air Control Valve IAC System PURPOSE To control engine idle speed and prevent stalling due to changes in engine load. OPERATION All engine idle speeds are controlled by the control module through the Idle Air Control (IAC) valve mounted on the throttle body. The control module sends voltage pulses to the IAC motor windings causing the IAC motor shaft and pintle to move "IN" or "OUT" a given distance (number of Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Idle Speed/Throttle Actuator - Electronic > Component Information > Diagrams > Page 3201 steps) for each pulse (called counts). Inward movement of the pintle = Decreased RPM =Lower Counts. Outward movement of the pintle = Increased RPM = Higher Counts. This movement controls airflow around the throttle plate, which in turn, controls engine idle speed, either cold or hot. IAC valve pintle position counts can be seen using a Tech 1 scan tool. Zero (0) counts correspond to a fully closed passage, while 140 counts or more (depending on the application) corresponds to full flow. - Actual or "controlled" idle speed is obtained by the control module positioning the IAC valve pintle. Resulting idle speed is generated from the total idle air flow (IAC/passage + PCV + throttle valve + vacuum leaks). - Controlled idle speed is always specified for normal operating conditions. Normal operating condition is engine coolant temperature in operating range, the A/C is "OFF," manual transmission is in neutral or automatic transmission in drive with proper Park/Neutral Position (PNP) switch adjustment. A high or low engine coolant temperature, or A/C clutch engagement may signal the control module to change the IAC counts. - The minimum idle speed is set at the factory with a stop screw. This setting allows enough air flow by the throttle valves to cause the IAC valve pintle to be positioned a calibrated number of steps (counts) from the seat during normal controlled idle operation. The IAC counts will be higher than normal on an engine with less than 500 miles, or an engine operating at high altitude or an engine with an accessory load such as the alternator, A/C, power steering or hydra-boost brakes activated. Results of Incorrect Operation If the pintle is stuck open, the idle speed will remain high. If the pintle is stuck closed, the idle speed will be too low, and stalling may occur. If the pintle is stuck partially open, the idle speed will be higher than normal, and there will be no response to changes in engine load such as A/C ("ON") or transmission in ("Drive"). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Idle Speed/Throttle Actuator - Electronic > Component Information > Testing and Inspection > PCM Charts Idle Speed/Throttle Actuator - Electronic: Testing and Inspection PCM Charts Idle Air Control (IAC) System Check Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Idle Speed/Throttle Actuator - Electronic > Component Information > Testing and Inspection > PCM Charts > Page 3204 Circuit Description The control module controls engine idle speed with the IAC valve. To increase idle speed, the control module retracts the IAC valve pintle away from its seat, allowing more air to pass by the throttle bore. To decrease idle speed, it extends the IAC valve pintle towards its seat, reducing bypass air flow. A Tech 1 scan tool will read the control module commands to the IAC valve in counts. Higher the counts indicate more air bypass (higher idle). The lower the counts indicate less air is allowed to bypass (lower idle). Test Description Number(s) below refer to circled number(s) on the diagnostic chart. 1. The IAC tester is used to extend and retract the IAC valve. Valve movement is verified by an engine speed change. If no change in engine speed occurs, the valve can be retested when removed from the throttle body. 2. This step checks the quality of the IAC movement in Step 1. Between 700 RPM and about 1500 RPM the engine speed should change smoothly with each flash of the tester light in both extend and retract. If the IAC valve is retracted beyond the control range (about 1500 RPM), it may take many flashes in the extend position before engine speed will begin to drop. This is normal on certain engines, fully extending IAC may cause engine stall. This may be normal. 3. Steps 1 and 2 verified proper IAC valve operation while this step checks the IAC circuits. Each lamp on the node light should flash red and green while the IAC valve is cycled. While the sequence of color is not important if either light is "OFF" or does not flash red and green, check the circuits for faults beginning with poor terminal contacts. IAC VALVE RESET PROCEDURE ^ Disconnect battery cable at battery for 10 seconds then reconnect cable. ^ Ignition "ON," engine "OFF" for 5 seconds. ^ Ignition "OFF" for 10 seconds. Diagnostic Aids A slow, unstable, or fast idle may be caused by a non-IAC system problem that cannot be overcome by the IAC valve. Out of control range, IAC Tech 1 scan tool counts will be above 60 if idle is too low, and zero counts if idle is too high. The following checks should be made to repair a non-IAC system problem. ^ Vacuum Leak (High Idle) - If idle is too high, stop the engine. Fully extend (low) IAC with tester. Start engine. If idle speed is above 800 RPM, locate and correct vacuum leak including crankcase ventilation system. Also, check for binding of throttle blade or linkage. ^ System Too Rich (Low Air Fuel Ratio) The idle speed will be too low. Tech 1 scan tool IAC counts will usually be above 80. System is obviously rich and may exhibit black smoke in exhaust. Tech 1 scan tool O2 voltage will be fixed above 800 mV (.8 volt). Check for high fuel pressure, leaking or sticking injector. Silicone contaminated 02S scan voltage will be slow to respond. ^ Throttle Body - Remove IAC valve and inspect bore for foreign material. ^ IAC Valve Electrical Connections - IAC valve connections should be carefully checked for proper contact. ^ Crankcase Ventilation Valve - An incorrect or faulty crankcase ventilation valve may result in an incorrect idle speed. Refer to "Rough, Unstable, Incorrect Idle or Stalling". ^ A/C Compressor - Refer to A/C diagnosis if circuit is shorted to ground. If the relay is faulty, an idle problem may exist. Refer to "Rough, Unstable, Incorrect Idle or Stalling". ^ If intermittent poor driveability or idle symptoms are resolved by disconnecting the IAC, carefully recheck connections, valve terminal resistance or replace IAC. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Idle Speed/Throttle Actuator - Electronic > Component Information > Testing and Inspection > PCM Charts > Page 3205 Idle Speed/Throttle Actuator - Electronic: Testing and Inspection VCM Charts Idle Air Control (IAC) System Check Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Idle Speed/Throttle Actuator - Electronic > Component Information > Testing and Inspection > PCM Charts > Page 3206 Circuit Description The control module controls engine idle speed with the IAC valve. To increase idle speed, the control module retracts the IAC valve pintle away from its seat, allowing more air to pass by the throttle bore. To decrease idle speed, it extends the IAC valve pintle towards its seat, reducing bypass air flow. A Tech 1 scan tool will read the control module commands to the IAC valve in counts. Higher the counts indicate more air bypass (higher idle). The lower the counts indicate less air is allowed to bypass (lower idle). Test Description Number(s) below refer to circled number(s) on the diagnostic chart. 1. The IAC tester is used to extend and retract the IAC valve. Valve movement is verified by an engine speed change. If no change in engine speed occurs, the valve can be retested when removed from the throttle body. 2. This step checks the quality of the IAC movement in Step 1. Between 700 RPM and about 1500 RPM the engine speed should change smoothly with each flash of the tester light in both extend and retract. If the IAC valve is retracted beyond the control range (about 1500 RPM), it may take many flashes in the extend position before engine speed will begin to drop. This is normal on certain engines, fully extending IAC may cause engine stall. This may be normal. 3. Steps 1 and 2 verified proper IAC valve operation while this step checks the IAC circuits. Each lamp on the node light should flash red and green while the IAC valve is cycled. While the sequence of color is not important if either light is "OFF" or does not flash red and green, check the circuits for faults beginning with poor terminal contacts. IAC VALVE RESET PROCEDURE ^ Disconnect battery cable at battery for 10 seconds then reconnect cable. ^ Ignition "ON," engine "OFF" for 5 seconds. ^ Ignition "OFF" for 10 seconds. Diagnostic Aids A slow, unstable, or fast idle may be caused by a non-IAC system problem that cannot be overcome by the IAC valve. Out of control range, IAC Tech 1 scan tool counts will be above 60 if idle is too low, and zero counts if idle is too high. The following checks should be made to repair a non-IAC system problem. ^ Vacuum Leak (High Idle) - If idle is too high, stop the engine. Fully extend (low) IAC with tester. Start engine. If idle speed is above 800 RPM, locate and correct vacuum leak including crankcase ventilation system. Also, check for binding of throttle blade or linkage. ^ System Too Rich (Low Air Fuel Ratio) The idle speed will be too low. Tech 1 scan tool IAC counts will usually be above 80. System is obviously rich and may exhibit black smoke in exhaust. Tech 1 scan tool O2 voltage will be fixed above 800 mV (.8 volt). Check for high fuel pressure, leaking or sticking injector. Silicone contaminated 02S scan voltage will be slow to respond. ^ Throttle Body - Remove IAC valve and inspect bore for foreign material. ^ IAC Valve Electrical Connections - IAC valve connections should be carefully checked for proper contact. ^ Crankcase Ventilation Valve - An incorrect or faulty crankcase ventilation valve may result in an incorrect idle speed. Refer to "Rough, Unstable, Incorrect Idle or Stalling". ^ A/C Compressor - Refer to A/C diagnosis if circuit is shorted to ground. If the relay is faulty, an idle problem may exist. Refer to "Rough, Unstable, Incorrect Idle or Stalling". ^ If intermittent poor driveability or idle symptoms are resolved by disconnecting the IAC, carefully recheck connections, valve terminal resistance or replace IAC. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Idle Speed/Throttle Actuator - Electronic > Component Information > Testing and Inspection > Page 3207 Idle Speed/Throttle Actuator - Electronic: Service and Repair NOTES - The Idle Air Control (IAC) valve is an electrical component and must not be soaked in any liquid cleaner or solvent. Otherwise damage could result. - The IAC valve for this application is thread-mounted and has a dual taper, 10 mm diameter, pintle. Any replacement of the IAC valve must have the correct part number, with the appropriate pintle taper and diameter for proper seating of the valve in the throttle body. IAC Thread Mounted 10mm Pintle REMOVE/DISCONNECT - Electrical connector. - IAC valve, use a 32 mm (1 1/4") wrench. - IAC gasket and discard. CLEAN - Both original and replacement IAC valves have a special factory applied thread-locking compound applied to the screw threads. If the valve removed from throttle body is being reinstalled, DO NOT remove thread-locking that may remain on the threads. - Clean IAC valve seating surfaces on throttle body to assure proper seal of new gasket and IAC valve. Idle Air Control Valve Pintle Retraction (Manually) NOTES - If the IAC valve was removed during service, its operation may be tested electrically with the IAC/ISC Motor Tester (J-37027 or BT-8256K) or equivalent. Before installing IAC valve, measure the distance between the tip of the valve pintle and mounting surface. If the dimension is greater than 28.0 mm (1.10 inches), valve pintle must be retracted to prevent damage to valve. This may be done electrically using an IAC/ISC Motor Tester or manually by exerting firm pressure, as shown in the illustration, with a slight side to side movement on valve pintle to retract it. - No physical adjustment of the IAC valve assembly is required after installation. The IAC valve pintle is reset by turning the ignition "ON" for ten seconds and then OFF. The ECM then resets the pintle to the correct position. Proper idle regulation should result. INSTALL/CONNECT - IAC valve into throttle body with new gasket. NOTE New IAC valves have been reset at the factory and should be installed in throttle body in an "as is" condition, without any adjustment. - Tighten IAC valve assembly to 18.0 Nm (13.0 lb-ft). - Electrical connector to IAC valve. - Reset IAC valve pintle position as follows: - Depress accelerator pedal slightly. - "START" and run engine for five seconds. - Turn ignition "OFF" for ten seconds. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Idle Speed/Throttle Actuator - Electronic > Component Information > Testing and Inspection > Page 3208 - Restart engine and check for proper idle operation. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Knock Sensor > Component Information > Technical Service Bulletins > Knock Sensor Circuit - DTC 43 Chart Revision Knock Sensor: Technical Service Bulletins Knock Sensor Circuit - DTC 43 Chart Revision File In Section: 6E Engine Fuel & Emission Bulletin No.: 51-65-19 Date: April, 1995 Subject: Section 3A - Control Module System (PCM) Driveability and Emissions - Revised DTC 43 Knock Sensor (KS) Circuit (Dual Knock Sensors) Models: 1994 Chevrolet and GMC Truck S/T; M/L, C/K Models with 4.3L Engine (VINs W, Z RPOs L35, LB4) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Knock Sensor > Component Information > Technical Service Bulletins > Knock Sensor Circuit - DTC 43 Chart Revision > Page 3213 This bulletin advises of a revision to the DTC 43 Knock Sensor (KS) Circuit (Dual Knock Sensor System) chart in the following service manuals: 1994 S/T Driveability Emissions and Electrical Diagnosis Manual, page 3A-119 1994 M/L Driveability Emissions and Electrical Diagnosis Manual, page 3A-75 1994 C/K Driveability Emissions and Electrical Diagnosis Manual, page 3A-69 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Knock Sensor > Component Information > Technical Service Bulletins > Page 3214 Knock Sensor: Specifications Coil bracket bolt/nut ............................................................................................................................. ................................................. 27 N-m (20 lbs ft) Distributor clamp bolt ........................................................................................................................... ................................................ 27 N-m (20 lbs ft) Knock Sensor ...................................................................................................................................... .................................................. 19 N-m (14 lbs ft) Spark Plugs ......................................................................................................................................... .................................................. 15 N-M (11 lbs ft) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Knock Sensor > Component Information > Locations > Assembly View Knock Sensors Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Knock Sensor > Component Information > Locations > Assembly View > Page 3217 Knock Sensor: Locations Harness View LH Rear Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Knock Sensor > Component Information > Locations > Assembly View > Page 3218 LH Rear Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Knock Sensor > Component Information > Locations > Page 3219 Knock Sensor: Diagrams C119 - Knock Sensor C135 - Knock Sensor Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Knock Sensor > Component Information > Locations > Page 3220 Knock Sensor: Description and Operation PURPOSE: The Knock Sensor (KS) is used to detect engine detonation (ping). The control module will retard the electronic spark timing up to 8° based on the signal received. CONSTRUCTION The KS system has two major components: Control Module. - Knock Sensor(s). The two knock sensors are spliced together and go directly to the control module. OPERATION The knock sensor internal circuit causes the control modules 5 volts to be pulled down to about 2.5 volts. The knock sensor produces an A/C signal which rides on the 2.5 volts DC signal. The AC voltage monitor in the control module will detect this AC voltage and provide a signal to begin retarding spark until the knock diminishes. The amplitude and frequency are dependent upon the knock level. LOCATION Engine block. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Knock Sensor > Component Information > Locations > Page 3221 Knock Sensor: Testing and Inspection Knock Sensor (KS) System Check Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Knock Sensor > Component Information > Locations > Page 3222 Knock Sensor Circuit Circuit Description The Knock Sensor (KS) circuit consists of two knock sensors with one wire that goes directly to the control modules. There are two Knock Sensor (KS) checks performed by the ECM. One check consists of monitoring CKT 496 for a voltage that is more than .63 volt and less than 3.1 volts. If voltage is either too high or too low for 10 or more seconds, DTC 43 will set. The PCM uses this self check only. The next test is used only by the ECM along with the previous test. Once engine temperature reaches 85°C, MAP is over 83 kPa, and engine speed is less than 3200 RPM, the ECM will perform a self check. This self check will advance the timing until it receives a knock signal. If no knock signal is received, DTC 43 will set. Chart Test Description Number(s) below refer to circled number(s) on the diagnostic chart. 1. The first test is to determine if the system is functioning at the present time. 2. Test two determines the state of the 5 volt reference voltage applied to the knock sensor circuit. 3. Test 3 determines the state of the knock sensors and connections themselves. Diagnostic Aids The control module applies 5 volts to CKT 496. A 8200 ohm resistor in the knock sensors reduces the voltage to about 2.5 volts. When knock occurs, the knock sensor produces a small AC voltage that rides on top of the 2.5 volts already applied. An AC voltage monitor, in the control module, is able to read this signal as knock and incrementally retard spark. If the KS system checks OK, but detonation is the complaint, refer to "Detonation/Spark Knock". See: Testing and Inspection/Symptom Related Diagnostic Procedures/Detonation/ Spark Knock Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Knock Sensor > Component Information > Locations > Page 3223 Knock Sensor: Service and Repair REMOVE OR DISCONNECT - Negative battery cable. - Drain cooling system. NOTE On knock sensors which are mounted in the end of the cylinder head draining the cooling system will not be necessary. - Wiring harness connector from knock sensor. - Knock sensor. INSTALL OR CONNECT - Knock sensor. If reinstalling original sensor, apply water base caulk to sensor threads. Do NOT use silicone tape as this will insulate sensor from engine. ^ Tighten to 19 Nm (14 lb. ft.). - Wiring harness connector to knock sensor. - Refill cooling system and pressure test for leaks. - Negative battery cable. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Malfunction Indicator Lamp > Component Information > Locations Malfunction Indicator Lamp: Locations Instrument cluster. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Malfunction Indicator Lamp > Component Information > Locations > Page 3227 Malfunction Indicator Lamp: Description and Operation PURPOSE The Malfunction Indicator Lamp (MIL), "Service Engine Soon" light has the following purposes: Inform the driver that a problem has occurred, and that the vehicle should be taken for service as soon as reasonably possible. - Displays Diagnostic Trouble Codes (DTC) stored by the ECM helping the technician diagnose system faults. - Indicates "Open Loop" or "Closed Loop" operation. OPERATION The MIL will come "ON" with the key "ON" and the engine not running. When the engine is started, the light will turn "OFF.". This is a bulb and system check. If the light remains "ON," the self-diagnostic system has detected a problem. If the problem goes away, the light will go out in most cases after 10 seconds, but a DTC will remain stored in the ECM. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Malfunction Indicator Lamp > Component Information > Locations > Page 3228 Malfunction Indicator Lamp: Service and Repair The CHECK ENGINE LAMP will be illuminated when the ignition switch is placed in the "ON" position. When the engine is started, the lamp should turn "OFF". If the lamp remains "ON" for 10 seconds or constantly after the engine is started, the self diagnosis system has detected a problem and has stored a code in the system Control Module. After diagnosis and repair, the ECM memory can be cleared of codes by removing the Control Module fuse or disconnecting the battery ground cable for approximately 30 seconds, with ignition switch in the "OFF" position. NOTE If battery ground cable is disconnected to clear codes, components such as clocks, electronically tuned radios etc., will have to be reset. - It is a good idea to record preset radio stations before disconnecting the negative battery cable. This will allow the stations to be reset as to not inconvenience the customer. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Specifications Manifold Pressure/Vacuum Sensor: Specifications Voltage 3.6 to 5.2 V at 1000 to 2000 ft 3.5 to 5.1 V at 2000 to 3000 ft 3.3 to 5.0 V at 3000 to 4000 ft 3.2 to 4.8 V at 4000 to 5000 ft 3.0 to 4.6 V at 5000 to 6000 ft 2.9 to 4.5 V at 6000 to 7000 ft 2.8 to 4.3 V at 7000 to 8000 ft 2.6 to 4.2 V at 8000 to 9000 ft 2.5 to 4.0 V at 9000 to 10000 ft Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Specifications > Page 3232 Manifold Pressure/Vacuum Sensor: Locations Engine Harness, Right Front Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Specifications > Page 3233 MAP Sensor 4.3Z Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions Manifold Pressure/Vacuum Sensor: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. Use this page as a reference to determine the meaning of an abbreviation if necessary. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery Bi-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CHMSL Center High Mount Stoplamp CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRO Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3236 F-PUMP Fuel Pump FLASH Flasher FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3237 SIR Supplemental Inflatable Restraint SKT Socket SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature TIL Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3238 example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE (ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: ^ Slide across the vehicle seat. ^ Sit down or stand up. ^ Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: ^ They are bumped or dropped. ^ They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3239 Symbols (Part 1 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3240 Symbols (Part 2 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3241 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3242 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3243 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3244 Manifold Pressure/Vacuum Sensor: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3245 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3246 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3247 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3248 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3249 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. ^ If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. ^ A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3250 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3251 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3252 Ohmmeter Meter Scales Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3253 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. ^ An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. ^ On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: ^ A range selector switch which permits the selection of different ranges of resistance. ^ A set adjust control which allows the meter to be set at zero for accurate measurements. ^ Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3254 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: ^ Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. ^ Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. ^ Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3255 be less than 10 percent of the total drop. When using a voltmeter: ^ Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. ^ Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. ^ The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: ^ Check the accuracy and completeness of the complaint. ^ Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3256 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. ^ The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3257 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3258 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3259 Twisted/Shielded Wire Repair Twisted Wires Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3260 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3261 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3262 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). ^ Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean ^ Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. ^ Roll crimp (13) and solder the terminal. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3263 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3264 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3265 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. ^ Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean ^ Terminal cavity of the connector body. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3266 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. ^ Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3267 C109 - MAP Sensor Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3268 MAP Sensor Circuit Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Page 3269 Manifold Pressure/Vacuum Sensor: Description and Operation Map Sensor Circuit (GM Generic) Manifold Absolute Pressure (MAP) Sensor PURPOSE The Manifold Absolute Pressure (MAP) sensor measures changes in the intake manifold pressure resulting from engine load and speed changes. As intake manifold pressure increases, the air density in the intake manifold also increases and additional fuel is required. Under certain conditions, the MAP sensor is also used to measure barometric pressure. This allows the control module to automatically adjust for different altitudes. The PCM uses information from the MAP sensor to calculate spark advance and fuel as follows: Low MAP output voltage (low pressure) results in more spark advance. - High MAP output voltage (high pressure) results in less spark advance. - Low MAP output voltage (low pressure) results in less fuel. - High MAP output voltage (high pressure) results in more fuel. OPERATION The control module supplies a 5 volt reference signal to the MAP sensor and the sensor provides a path to ground through its variable resistor. The control module by monitoring the sensor output voltage can determine the manifold pressure. A closed throttle on engine coastdown will produce a relatively low MAP output, while a wide open throttle will produce a high output. At higher pressure or at Wide Open Throttle (WOT) output voltage will be about 4 to 4.8 volts. The higher the MAP voltage output the lower the engine vacuum, which requires more fuel. The lower the MAP voltage output the higher the engine vacuum. At lower pressure output voltage will be about 1 to 2 volts at idle. A failure in the MAP sensor circuit should set Diagnostic Trouble Codes (DTC) 33 or 34 with PCM/ECM systems and DTC P0107 or P0108 with VCM systems. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Page 3270 Manifold Pressure/Vacuum Sensor: Testing and Inspection Manifold Absolute Pressure (MAP) Output Check Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Page 3271 MAP Sensor Circuit Circuit Description: The Manifold Absolute Pressure (MAP) sensor measures the changes in the intake manifold pressure which result from engine load (intake manifold vacuum) and RPM changes; and converts these into a voltage output. The PCM sends a 5 volt reference voltage to the MAP sensor. As the manifold pressure changes, the output voltage of the sensor also changes. By monitoring the sensor output voltage, the PCM knows the manifold pressure. At lower pressure output voltage will be about 1 to 2 volts at idle. While at higher pressure or at Wide Open Throttle (WOT) output voltage will be about 4 to 4.8 volts. The MAP sensor is also used, under certain conditions, to measure barometric pressure, allowing the PCM to make adjustments for different altitudes. The PCM uses the MAP sensor to control fuel delivery and ignition timing. Chart Test Description Number(s) below refer to circled number(s) on the diagnostic chart. Important ^ Be sure to use the same Diagnostic Test Equipment for all measurements. 1. Checks MAP sensor output voltage to the PCM. This voltage, without engine running, represents a barometer reading to the PCM. ^ When comparing Tech 1 scan readings to a known good vehicle, it is important to compare vehicles that use a MAP sensor having the same color insert or having the same "Hot Stamped" number. Refer to figures on facing page. 2. Applying 34 kPa (10" Hg) vacuum to the MAP sensor should cause the voltage to change. Subtract second reading from the first. Voltage value should be greater than 1.5 volts. Upon applying vacuum to the sensor, the change in voltage should be instantaneous. A slow voltage change indicates a faulty sensor. 3. Check vacuum hose to sensor for leaking or restriction. Be sure that no other vacuum devices are connected to the MAP hose. NOTICE:Make sure electrical connector remains securely fastened. 4. Disconnect sensor from bracket and twist sensor by hand (only) to check for intermittent connection. Output changes greater than .1 volt indicate a bad connector or connection. If OK, replace sensor. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Memory Calibration Unit > Component Information > Technical Service Bulletins > PROM/MEMCAL - Identification Marks Memory Calibration Unit: Technical Service Bulletins PROM/MEMCAL - Identification Marks File In Section: 6E - Engine Fuel & Emission Bulletin No.: 44-65-01 Date: October, 1994 Subject: New PROM/MEMCAL Identification Markings Models: 1995 and Prior Passenger Cars and Trucks Note: For the purposes of this document, the terms PROM and MEMCAL will be used interchangeably. To simplify identification of service PROMs. a new external marking format will be implemented. Parts manufactured after Sept. 1994 will feature these new markings. This change will place the full 8-digit service part number on the PROM, in place of the old 4-digit "EXTERNAL ID" number. In the past, parts and service personnel could not identify a PROM without using a cross-reference table that matched external IDs and service numbers. In the future, the cross-reference table will not be required for PROMs; parts will be ordered directly from the number appearing on the PROM. However, the label will retain the broadcast code alpha characters to allow continued use of cross-reference charts, if so desired. Old Marking Format: New Marking Format: ^ Ordering the above PROM from the old marking format would require using a cross-reference chart to determine a service part number, based on the BROAD CAST CODE and EXTERNAL ID NUMBERS. ^ To order from the new format, simply combine the 2nd and 3rd lines to form an 8-digit part number that can be directly ordered from SPO (number 16134624 in the above example). As these changes are phased into the parts inventory, it should be noted that dealers will continue to see parts with both formats for some time in the future. This is because: ^ Millions of vehicles have already been built with the old format. ^ SPO has existing stock of MEMCALs and PROMs with the old format. ^ PROMS with 7-digit part numbers (representing less than 10% of current part numbers) will continue to use the old format. The 7-digit part numbers are easily identified because they always begin with "122xxxx". Due to manufacturing processes, more than one 8-digit part number may appear on a MEMCAL. In this event, service personnel should use the label on the exterior cover of the MEMCAL assembly. To avoid confusion, only the service label will include the BROAD CAST CODE, consisting of letter characters (I.E., ARCL). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Memory Calibration Unit > Component Information > Technical Service Bulletins > PROM/MEMCAL - Identification Marks > Page 3276 CHANGES TO MEMCAL/PROM LABELING FORMATS ^ MEMCALs may use either INK-JET or ADHESIVE labels, as shown. ^ PROMs will always use ADHESIVE labels with the same format as shown for MEMCALs. These changes will become effective on parts manufactured after 10/94. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Quad Driver <--> [Output Driver] > Component Information > Locations Quad Driver: Locations Quad/Output drivers are hard wired onto the ECM/PCM/VCM. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Quad Driver <--> [Output Driver] > Component Information > Locations > Page 3280 Quad Driver: Description and Operation Quad/Output Driver Module The Control Module in this vehicle controls most components with electronic switches which complete a ground circuit when turned on. When the switches are arranged in groups of 4, they can independently control up to 4 outputs and are called Quad Drivers. When the switches are arranged in groups of 7, they can independently control up to 7 outputs and are called Output Drivers. Not all outputs are always used. Shorted solenoid. relay coil. or harness- Solenoids and relays are turned "ON" and "OFF" by the PCM or VCM using internal electronic switches called "drivers." Each driver is part of a group of four called "quad-drivers." Failure of one driver can damage any other driver in the set. A shorted solenoid, relay coil. or harness will not damage the "quad-drivers" in this VCM/PCM, but will cause the circuit and controlled component to be inoperative. When the circuit fault is not present or has been repaired, the "quad-driver" will again operate in a normal manner due to its fault protected design. If a fault has been repaired in a circuit, controlled by a "quad-driver," the original VCM/PCM should be reinstalled and the circuit checked for proper operation. PCM replacement will not be necessary if the repaired circuit or component operates correctly. The J 39200 DVM testers, or equivalent, provide a fast, accurate means of checking for a shorted coil, or a short to battery voltage. The replacement VCM/PCM may be faulty - After the VCM/PCM is replaced, the system should be rechecked for proper operation. If the diagnostic chart again indicates that the VCM/PCM is the problem, substitute a known good VCM/PCM. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Quad Driver <--> [Output Driver] > Component Information > Locations > Page 3281 Quad Driver: Testing and Inspection Little or no quad driver testing was supplied by the manufacturer. The engine module decides when to turn each switch of the driver "ON". Even though some models will set codes, in the end, if you want to check the driver itself, you'll need: 1. To use a scantool to command the suspected driver switch to energize (ground) the circuit, while checking with a test light, 2. To operate the vehicle in a way that should cause the suspected portion of the driver to switch "ON". On the up side, since the early 90's, most driver load circuits utilized circuit breakers. This protected most drivers and engine models from burning up when the circuit was overloaded. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Quad Driver <--> [Output Driver] > Component Information > Locations > Page 3282 Quad Driver: Service and Repair Quad/Output drivers are hard wired onto the ECM/PCM/VCM, and can't be serviced separately. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > Customer Interest: > 566501 > Jul > 95 > O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear Oxygen Sensor: Customer Interest O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear FILE IN SECTION: 6E - Engine Fuel & Emission BULLETIN NO.: 56-65-01 DATE: July, 1995 SUBJECT: Rattling Noise on Acceleration/Transmission Starting Out in 3rd Gear (Provide Clearance or Replace Exhaust Crossover) MODELS: 1993-94 Chevrolet and GMC Truck M/L Vans 1994 Chevrolet and GMC Truck T Models 1994 Oldsmobile Bravada with 4.3L Engines (VINs W, Z - RPOs L35, LB4) CONDITION Customers may comment on one or more of the following conditions: A rattling noise on acceleration, transmission starting out in 3rd gear (possible DTC 66, 67, 81, 82) and/or diagnostic trouble codes 13 or 44. CAUSE M/L Vans Oxygen sensor and/or harness pigtail contacting the heat shield due to improper routing of the harness. Sharp edges of the heat shield cuts through the wire insulation. T Trucks The rattle noise may be the oxygen sensor and/or harness pigtail contacting the heat shield due to the mispositioning of the oxygen sensor mounting boss. Starting out in 3rd gear may be due to the pink wire (CKT 39) shorting out against the heat shield causing power to be interrupted to the transmission control circuit putting the transmission into backup mode (3rd Gear Starts). Diagnostic trouble codes 13 or 44 may be set due to the oxygen sensor signal wire shorting to or cut through by the heat shield. CORRECTION M/L Vans Refer to the "1993 M/L Van Electrical Diagrams and Diagnosis" manual or the "1994 Driveability, Emissions and Electrical Diagnosis" manual for circuit 39 schematics. Normal circuit diagnostics should be performed first if the problem is constant. If the problem is intermittent, an inspection of circuit 39 (pink/black) in the area of the exhaust heat shields may lead to the problem. Inspect the oxygen sensor wiring and replace the sensor it the insulation has been damaged. Re-route wiring harness as needed to protect harness. Clear any codes and test drive. T Trucks If the oxygen sensor is contacting the heat shield, this condition can be corrected by replacing the exhaust crossover pipe. If the oxygen sensor wire is damaged, the oxygen sensor must also be replaced. Follow regular Service Manual Procedures in Section 3 of the 1993 or 1994 "S/T Truck Driveability, Emission and Electrical Diagnosis" manual to make above repairs. Clear any diagnostic trouble codes and test drive. PARTS INFORMATION P/N Description Qty 10096129 Sensor, Oxygen (1993) 1 25133503 Sensor, Oxygen (1994) 1 15661132 Pipe, Exhaust Crossover (w/ZR2) 1 15672887 Pipe, Exhaust Crossover (w/o ZR2) 1 Parts are currently available from GMSPO. WARRANTY INFORMATION Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > Customer Interest: > 566501 > Jul > 95 > O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear > Page 3291 For vehicles repaired under warranty, use: Labor Operation Description Labor Time J6372 Sensor, Oxygen Replace Use Published L2080 Pipe, Crossover Exhaust Replace Labor Operation Time Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oxygen Sensor: > 566501 > Jul > 95 > O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear Oxygen Sensor: All Technical Service Bulletins O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear FILE IN SECTION: 6E - Engine Fuel & Emission BULLETIN NO.: 56-65-01 DATE: July, 1995 SUBJECT: Rattling Noise on Acceleration/Transmission Starting Out in 3rd Gear (Provide Clearance or Replace Exhaust Crossover) MODELS: 1993-94 Chevrolet and GMC Truck M/L Vans 1994 Chevrolet and GMC Truck T Models 1994 Oldsmobile Bravada with 4.3L Engines (VINs W, Z - RPOs L35, LB4) CONDITION Customers may comment on one or more of the following conditions: A rattling noise on acceleration, transmission starting out in 3rd gear (possible DTC 66, 67, 81, 82) and/or diagnostic trouble codes 13 or 44. CAUSE M/L Vans Oxygen sensor and/or harness pigtail contacting the heat shield due to improper routing of the harness. Sharp edges of the heat shield cuts through the wire insulation. T Trucks The rattle noise may be the oxygen sensor and/or harness pigtail contacting the heat shield due to the mispositioning of the oxygen sensor mounting boss. Starting out in 3rd gear may be due to the pink wire (CKT 39) shorting out against the heat shield causing power to be interrupted to the transmission control circuit putting the transmission into backup mode (3rd Gear Starts). Diagnostic trouble codes 13 or 44 may be set due to the oxygen sensor signal wire shorting to or cut through by the heat shield. CORRECTION M/L Vans Refer to the "1993 M/L Van Electrical Diagrams and Diagnosis" manual or the "1994 Driveability, Emissions and Electrical Diagnosis" manual for circuit 39 schematics. Normal circuit diagnostics should be performed first if the problem is constant. If the problem is intermittent, an inspection of circuit 39 (pink/black) in the area of the exhaust heat shields may lead to the problem. Inspect the oxygen sensor wiring and replace the sensor it the insulation has been damaged. Re-route wiring harness as needed to protect harness. Clear any codes and test drive. T Trucks If the oxygen sensor is contacting the heat shield, this condition can be corrected by replacing the exhaust crossover pipe. If the oxygen sensor wire is damaged, the oxygen sensor must also be replaced. Follow regular Service Manual Procedures in Section 3 of the 1993 or 1994 "S/T Truck Driveability, Emission and Electrical Diagnosis" manual to make above repairs. Clear any diagnostic trouble codes and test drive. PARTS INFORMATION P/N Description Qty 10096129 Sensor, Oxygen (1993) 1 25133503 Sensor, Oxygen (1994) 1 15661132 Pipe, Exhaust Crossover (w/ZR2) 1 15672887 Pipe, Exhaust Crossover (w/o ZR2) 1 Parts are currently available from GMSPO. WARRANTY INFORMATION Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oxygen Sensor: > 566501 > Jul > 95 > O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear > Page 3297 For vehicles repaired under warranty, use: Labor Operation Description Labor Time J6372 Sensor, Oxygen Replace Use Published L2080 Pipe, Crossover Exhaust Replace Labor Operation Time Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oxygen Sensor: > 81I37 > Feb > 81 > Oxygen Sensors - Silica Contamination Oxygen Sensor: All Technical Service Bulletins Oxygen Sensors - Silica Contamination Model Year: 1981 Bulletin No: 81-I-37 File In Group: 60 Number: 11 Date: Feb. 81 Subject: Silica Contamination of Oxygen Sensors and Gelation of Oil. Models Affected: All Oxygen sensor performance can deteriorate if certain RTV silicone gasket materials are used. Other RTV's when used with certain oils, may cause gelation of the oil. The degree of performance severity depends on the type of RTV and application of the engine involved. Therefore, when repairing engines where this item is involved, it is important to use either cork composition gaskets or RTV silicone gasket material approved for such use. GMS (General Motors Sealant) or equivalent material can be used. GMS is available through GMPD with the following part numbers: 1052366 3 oz. 1052434 10.14 oz. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > All Other Service Bulletins for Oxygen Sensor: > 81I37 > Feb > 81 > Oxygen Sensors - Silica Contamination Oxygen Sensor: All Technical Service Bulletins Oxygen Sensors - Silica Contamination Model Year: 1981 Bulletin No: 81-I-37 File In Group: 60 Number: 11 Date: Feb. 81 Subject: Silica Contamination of Oxygen Sensors and Gelation of Oil. Models Affected: All Oxygen sensor performance can deteriorate if certain RTV silicone gasket materials are used. Other RTV's when used with certain oils, may cause gelation of the oil. The degree of performance severity depends on the type of RTV and application of the engine involved. Therefore, when repairing engines where this item is involved, it is important to use either cork composition gaskets or RTV silicone gasket material approved for such use. GMS (General Motors Sealant) or equivalent material can be used. GMS is available through GMPD with the following part numbers: 1052366 3 oz. 1052434 10.14 oz. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Specifications > Electrical Specifications Oxygen Sensor: Electrical Specifications Closed Loop 100 - 0.999 mV Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Specifications > Electrical Specifications > Page 3309 Oxygen Sensor: Mechanical Specifications Oxygen Sensor 30 ft.lb Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Locations > Heated Oxygen Sensor Engine Harness, Right Front Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Locations > Heated Oxygen Sensor > Page 3312 Heated Oxygen Sensor (HO2S) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions Oxygen Sensor: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. Use this page as a reference to determine the meaning of an abbreviation if necessary. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery Bi-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CHMSL Center High Mount Stoplamp CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRO Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3315 F-PUMP Fuel Pump FLASH Flasher FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3316 SIR Supplemental Inflatable Restraint SKT Socket SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature TIL Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3317 example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE (ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: ^ Slide across the vehicle seat. ^ Sit down or stand up. ^ Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: ^ They are bumped or dropped. ^ They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3318 Symbols (Part 1 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3319 Symbols (Part 2 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3320 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3321 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3322 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3323 Oxygen Sensor: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3324 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3325 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3326 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3327 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3328 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. ^ If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. ^ A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3329 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3330 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3331 Ohmmeter Meter Scales Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3332 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. ^ An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. ^ On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: ^ A range selector switch which permits the selection of different ranges of resistance. ^ A set adjust control which allows the meter to be set at zero for accurate measurements. ^ Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3333 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: ^ Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. ^ Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. ^ Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3334 be less than 10 percent of the total drop. When using a voltmeter: ^ Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. ^ Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. ^ The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: ^ Check the accuracy and completeness of the complaint. ^ Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3335 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. ^ The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3336 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3337 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3338 Twisted/Shielded Wire Repair Twisted Wires Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3339 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3340 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3341 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). ^ Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean ^ Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. ^ Roll crimp (13) and solder the terminal. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3342 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3343 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3344 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. ^ Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean ^ Terminal cavity of the connector body. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3345 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. ^ Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3346 C116 - Oxygen Sensor Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3347 Heated Oxygen Sensor (HO2S) Circuit Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Page 3348 Oxygen Sensor: Description and Operation Exhaust Oxygen Sensor (02) PURPOSE The Oxygen sensor (O2 Sensor) has the ability to produce a low voltage signal that feeds information on engine exhaust content to the control module. CONSTRUCTION The O2 Sensor is constructed from a zirconia/platinum electrolytic element. Zirconia is an electrolyte that conducts electricity under certain chemical conditions. The element is made of a ceramic material and is an insulator when cold. At operating temperature, 315°C (600°F), the element becomes a semiconductor. A platinum coating on the outer surface of the element stimulates further combustion of the exhaust gases right at the surface and this helps deep the element up to the desired temperature. The O2 Sensor has an inter cavity which is filled with atmospheric (reference) air. The atmosphere has approximately 21% oxygen in it. In the electrical circuit this inter cavity is the positive (+) terminal. The outer surface of the element is exposed to the exhaust gas stream. It is the negative (-) terminal. Oxygen Sensor Output Voltage vs. Air/Fuel Ratio The difference in oxygen concentration in the narrow range of optimum air/fuel ratio causes a large voltage change that is easily measured. OPERATION A rich exhaust (excessive fuel) has almost no oxygen. When there is a large difference in the amount of oxygen touching the inside and outside surfaces, there is more conduction, and the sensor puts out a voltage signal above 0.6 volts (600 mV). With lean exhaust (excessive oxygen) there is about two percent oxygen in the exhaust. This is a smaller difference in oxygen from the outside surfaces which results in less conduction and a voltage signal below 0.3 volts (300 mV). The voltages are monitored and used by the control module to "fine tune" the air/fuel ratio to achieve the ideal mixture desired. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Page 3349 The control module puts out a reference signal of 0.45 volts (450 mV). The reference signal serves two purposes. The first is to run the engine when it is in OPEN LOOP mode of operation. When the air/fuel ratio is correct the control module senses 450 mV. When the engine is operating with a rich air/fuel ratio there is a reduction of free oxygen in the exhaust stream and the O2 sensor voltage rises above the reference voltage. When the engine is running lean the voltage drops below the reference voltage due to the excess oxygen in the exhaust stream. The O2 sensor provides the feedback information for the CLOSED LOOP operating mode of the fuel delivery system. The O2 sensor indicates to the control module what is happening in the exhaust. It does not cause things to happen. It is a type of gauge: Low voltage output = lean mixture = high oxygen content in the exhaust; high voltage output = rich mixture = low oxygen content in the exhaust. CONDITIONS THAT CAN SET CODES An open O2 sensor, should set a Diagnostic Trouble Code (DTC) 13. A constant low voltage in the O2 sensor circuit should set a DTC 44. A constant high voltage in the circuit should set a DTC 45. DTC 44 and DTC 45 could be set as a result of fuel system problems. REFER TO COMPUTERS AND CONTROL SYSTEMS/DIAGNOSTIC CHARTS for diagnosis of these codes. HEATED OXYGEN SENSOR TYPE The heated oxygen sensor works in the same manner as the non-heated oxygen sensor. The exception is that B+ is supplied to a heating element that is part of the sensor itself. The heater helps the control module control the fuel injection sooner for better fuel emissions. There are no Diagnostic Trouble Codes (DTC's) to detect if the heater part of the sensor is working. To check the heater, REFER TO COMPUTERS AND CONTROL SYSTEMS/DIAGNOSIS AND TESTING PROCEDURES/OXYGEN SENSOR TESTING. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Page 3350 Oxygen Sensor: Testing and Inspection VISUAL INSPECTION - Connectors and wires - Housing and insulator for cracks/damage - Sensor tip for silicone contamination (white powdery coating) CAUTION Do NOT perform the following test for more than 2 minutes, as this may cause damage to the catalytic converter. PERFORMANCE TEST Checks working range and response (speed). Warm engine - Install DVOM between sensor and ground (2 volt D.C. range) - "RUN" engine at steady cruise speed (about 2500 rpm) Voltage should vary at least eight times in ten seconds between 0.2 and 0.8 volts (normal range). - Drive system rich: The use of a properly adjusted propane flow-meter (J-26911) is industry standard. Voltage should increase to at least 0.8 volts within two to three seconds. - Drive system lean: Create a vacuum leak from a source that is not an control module input or output. Voltage should drop to at least 0.3 volts within two to three seconds. NOTE After each test the O2 sensor should return to normal operating range within two to three seconds. - O2 Sensor should be replaced for failure to pass any of the tests above. NOTE A CEC system that is operating excessively rich or lean will drive the 02 sensor to its maximum range and should be repaired first and not diagnosed as a 02 sensor failure. - Reconnect all hoses and electrical connectors. Clear all codes set and retrain idle. HEATING ELEMENT (H20S only) - Turn ignition "OFF". Disconnect electrical connector. - Connect test light between harness terminals "A" and "B". - Turn ignition "ON". Test light should be "ON". If test light is "OFF", connect test light to harness terminal "A" to ground. Light should be "ON" ensuring power circuit is operating correctly. - Turn ignition "OFF". - Using an ohmmeter, measure resistance between terminals A and B. Resistance @ Specified Temperature 3.5 ohms @ 20°C (68°F) 14 ohms @ 350°C (662°F) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Page 3351 Oxygen Sensor: Service and Repair NOTE The oxygen sensor has a permanently attached pig-tail and connector. This pig-tail should not be removed, since removal will affect proper operation of the oxygen sensor. REMOVAL - Disconnect electrical connector from oxygen sensor. - Using suitable wrench, carefully remove sensor from exhaust manifold or pipe. Caution The oxygen sensor may be difficult to remove when engine temperature is below 120°F. Excessive force may damage threads in exhaust manifold or pipe. INSTALLATION - If new sensor is being used, install sensor into manifold or pipe. - If old sensor is being reused, coat threads with anti-seize compound, Part No. 5613695 or equivalent, then install into manifold or pipe. - Torque oxygen sensor to 41 N-m (30 lb. ft.), then reconnect electrical connector. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Relays and Modules Computers and Control Systems > Air Flow Meter/Sensor Relay > Component Information > Technical Service Bulletins > Shift Indicator Light Application and Operation Air Flow Meter/Sensor Relay: Technical Service Bulletins Shift Indicator Light Application and Operation File In Section: 7 - Transmission Bulletin No.: 36-72-07A Date: February, 1995 Subject: Manual Transmission Shift Indicator Light Application and Operation Models: 1993-95 Chevrolet and GMC Truck C/K and S/T Models with Manual Transmission This bulletin is being revised to add the 1995 model year. Please discard bulletin number 367207 (Group Reference - Transmission). Certain trucks are not equipped with a shift indicator light. The shift light is commonly used to achieve improved fuel economy by prompting the driver when to upshift. Depending on the engine/transmission installed in the vehicle, the shift light can have the following characteristics: ^ Indicates proper shift point for maximum fuel economy. ^ Indicates engine over-speed. ^ Shift light is inoperative. The following charts detail normal shift light operation: 1993 Models: Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Relays and Modules Computers and Control Systems > Air Flow Meter/Sensor Relay > Component Information > Technical Service Bulletins > Shift Indicator Light Application and Operation > Page 3357 1994 Models: 1995 Models: Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Relays and Modules Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage Engine Control Module: Technical Service Bulletins Engine Controls - Aftermarket Accessory Usage INFORMATION Bulletin No.: 04-06-04-054B Date: November 18, 2010 Subject: Info - Non-GM Parts and Accessories (Aftermarket) Models: 2011 and Prior GM Passenger Cars and Trucks Supercede: This bulletin is being revised to add model years and update to the new U.S. Fixed Operation Manager (FOM) and Canada Warranty Manager (WM) names. Please discard Corporate Bulletin Number 04-06-04-054A (Section 06 - Engine/Propulsion System). The recent rise and expansion of companies selling non-GM parts and accessories has made it necessary to issue this reminder to dealers regarding GM's policy on the use and installation of these aftermarket components. When a dealer is performing a repair under the New Vehicle Limited Warranty, they are required to use only genuine GM or GM-approved parts and accessories. This applies to all warranty repairs, special policy repairs or any repairs paid for by GM. Parts and accessories advertised as being "the same" as parts manufactured by GM, but not sold through GM, do not qualify for use in warranty repairs, special policy repairs or any repairs paid for by GM. During a warranty repair, if a GM original equipment part is not available through GM Customer Care and Aftersales (GM CC&A;), ACDelco(R) distributors, other GM dealers or approved sources, the dealer is to obtain comparable, non-GM parts and clearly indicate, in detail, on the repair order the circumstances surrounding why non-GM parts were used. The dealer must give customers written notice, prior to the sale or service, that such parts or accessories are not marketed or warranted by General Motors. It should also be noted that dealers modifying new vehicles and installing equipment, parts and accessories obtained from sources not authorized by GM are responsible for complying with the National Traffic and Motor Vehicle Safety Act. Certain non-approved parts or assemblies, installed by the dealer or its agent not authorized by GM, may result in a change to the vehicle's design characteristics and may affect the vehicle's ability to conform to federal law. Dealers must fully understand that non-GM approved parts may not have been validated, tested or certified for use. This puts the dealer at risk for potential liability in the event of a part or vehicle failure. If a GM part failure occurs as the result of the installation or use of a non-GM approved part, the warranty will not be honored. A good example of non-authorized modification of vehicles is the result of an ever increasing supply of aftermarket devices available to the customer, which claim to increase the horsepower and torque of the Duramax(TM) Diesel Engines. These include the addition of, but are not limited to one or more of the following modifications: - Propane injection - Nitrous oxide injection - Additional modules (black boxes) that connect to the vehicle wiring systems - Revised engine calibrations downloaded for the engine control module - Calibration modules which connect to the vehicle diagnostic connector - Modification to the engine turbocharger waste gate Although the installation of these devices, or modification of vehicle components, can increase engine horsepower and torque, they may also negatively affect the engine emissions, reliability and/or durability. In addition, other powertrain components, such as transmissions, universal joints, drive shafts, and front/rear axle components, can be stressed beyond design safety limits by the installation of these devices. General Motors does not support or endorse the use of devices or modifications that, when installed, increase the engine horsepower and torque. It is because of these unknown stresses, and the potential to alter reliability, durability and emissions performance, that GM has adopted a policy that prevents any UNAUTHORIZED dealer warranty claim submissions to any remaining warranty coverage, to the powertrain and driveline components whenever the presence of a non-GM (aftermarket) calibration is confirmed - even if the non-GM control module calibration is subsequently removed. Refer to the latest version of Bulletin 09-06-04-026 (V8 Gas Engines) or 06-06-01-007 (Duramax(TM) Diesel Engines) for more information on dealer requirements for calibration verification. These same policies apply as they relate to the use of non-GM accessories. Damage or failure from the use or installation of a non-GM accessory will not be covered under warranty. Failure resulting from the alteration or modification of the vehicle, including the cutting, welding or disconnecting of the vehicle's original equipment parts and components will void the warranty. Additionally, dealers will NOT be reimbursed or compensated by GM in the event of any legal inquiry at either the local, state or federal level that Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Relays and Modules Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 3362 results from the alteration or modification of a vehicle using non-GM approved parts or accessories. Dealers should be especially cautious of accessory companies that claim the installation of their product will not void the factory warranty. Many times these companies have even given direction on how to quickly disassemble the accessory in an attempt to preclude the manufacturer from finding out that is has been installed. Any suspect repairs should be reviewed by the Fixed Operations Manager (FOM), and in Canada by the Warranty Manager (WM) for appropriate repair direction. If it is decided that a goodwill repair is to be made on the vehicle, even with the installation of such non-GM approved components, the customer is to be made aware of General Motors position on this issue and is to sign the appropriate goodwill documentation required by General Motors. It is imperative for dealers to understand that by installing such devices, they are jeopardizing not only the warranty coverage, but also the performance and reliability of the customer's vehicle. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Relays and Modules Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 3363 Engine Control Module: Technical Service Bulletins PROM - Reprogram Using Off Board Program Adapter File In Section: 6E - Engine Fuel & Emission Bulletin No.: 73-65-13 Date: March, 1997 INFORMATION Subject: Reprogramming Capability using the Off Board Programming Adapter Models: 1993-97 Passenger Cars and Trucks (Applicable Reprogrammable Vehicles) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Relays and Modules Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 3364 The General Motors vehicles contain Electronically Reprogrammable Devices (i.e. PCM, VCM, ECM). These vehicles cannot be programmed through PROM replacement, however service programming capability is available through the Tech 1/1A, Tech 2 and Techline terminals via direct or remote programming. The Environmental Protection Agency (EPA) has requested that all new vehicle manufacturers ensure their dealers/retailers are aware that they are responsible for providing customers access to reprogramming services at a reasonable cost and in a timely manner. Although programming of controllers has become a common service practice at GM dealers/retailers, the EPA has received reports from consumers and the aftermarket repair industry that they were unable to purchase a new (programmed) Electronically Reprogrammable Device (ERD) over-the-counter. As a result, on August 1, 1995, the Federal Government issued a regulation requiring all manufacturers to make available reprogramming to the independent aftermarket by December 1, 1997. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Relays and Modules Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 3365 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Relays and Modules Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 3366 Today, the Off Board Programming Adapter (OBPA) is used to reprogram ERD's sold over-the-counter. For all practical purposes, the OBPA takes the place of the vehicle when the vehicle is not available. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Relays and Modules Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 3367 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Relays and Modules Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 3368 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Relays and Modules Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 3369 The list of dealerships/retailers currently own the OBPA (see Attachments 1 - 3). These locations are equipped to provide over-the-counter preprogrammed ERD's. The hardware required to perform reprogramming in addition to the OBPA is a Techline terminal, Tech 1/1A and associated cables and adapters. THE TECH 2 SHOULD NOT BE USED WITH THE OBPA AT THIS TIME BECAUSE OF INADEQUATE OBPA GROUNDING. The current OBPA can support reprogramming on all late model General Motor's vehicles except: ^ Premium V-8's ^ 1996 Diesel Truck ^ Cadillac Catera Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Relays and Modules Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 3370 ^ All 1997 programmable vehicles (requires use of the Tech 2) A modification to the OBPA is being offered by Kent-Moore to support these additional vehicles and to allow reprogramming using the Tech 2. The revisions to the OBPA for the Tech 2 is very important as the Tech 2 is the only tool used for service programming for 1997 and future vehicles. To have the modifications performed, contact Kent-Moore at (800) 345-2233. The revisions (part number J 41207 REV-C) are free of charge for GM dealerships/retailers. A dealership/retailer can purchase the OBPA by contacting Kent-Moore (part number J 41207-C). Support on how to use the OBPA is provided by the Techline Customer Support Center (TCSC) at (800) 828-6860 (English) or (800) 503-3222 (French). If you need to purchase an OBPA and/or cable, contact Kent-Moore at (800) 345-2233. The OBPA retails for $695.00 (includes all revisions 1-4) under part number J 41207-C. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Relays and Modules Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Engine Controls - Aftermarket Accessory Usage > Page 3371 Engine Control Module: Technical Service Bulletins PCM - Replacement Component Text Deletion File in Section: 6E - Engine Fuel & Emission Bulletin No.: 41-65-33 Date: October, 1994 SERVICE MANUAL UPDATE Subject: Section 3A - Driveability, Emissions and Electrical Diagnosis - Text Deletion Models: 1994 Chevrolet and GMC Truck & T Models with 2.2L Gasoline Engine (VIN 4 - RPO LN2) or 4.3L Engine (VINs Z, W - RPOs LB4, L35) 1994-95 Chevrolet and GMC Truck C/K, M/L, G, P3, PG Models with 4.3L Engine (VIN Z - RPO LB4), 5.0L Engine (VIN H - RPO L03), 5.7L Engine VIN K - RPO L05) or 7.4L Engine (VIN N - RPO L19) 1994-95 Chevrolet and GMC Truck C/K, G, P3 Models with 6.5L Diesel Engine (VINs F, P, S RPOs L65, L49, L56) This bulletin contains revisions to the "Driveability, Emissions and Electrical Diagnostic" Service Manuals for the following pages: 1994 S/T Truck - 3A-5 1994-1995 G Van - 3A-4 1994-1995 C/K Truck - 3A-4 1994-1995 M/L Truck - 3A-4 1994-1995 PG/P3 Truck - 3A-4 1994-1995 C/K, G, P Truck - 3-17 and Supplement This Text is to be Deleted "The replacement PCM may be faulty - After the PCM is replaced, the system should be rechecked for proper operation. If the Diagnostic Chart again indicates that the PCM is the problem, substitute a known good PCM". Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Relays and Modules Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Page 3372 Engine Control Module: Specifications Engine VIN Code ID [1] ....................................................................................................................... .............................................................................. Z Engine Displacement ........................................................................................................................... ........................................................... 4.3L (262 cid) Engine Configuration ........................................................................................................................... ............................................................................ V6 Fuel Control System ...................................................................................................................................................... Throttle Body Fuel Injection (TBI) Ignition System ....................................................................................................... Distributor Ignition W/Ignition Control and Knock Sensor(DI-IC-KS) Control Module Systems S/T Pickup Automatic Transmission ......................................................................................................................... Powertrain Control Module (93PCM6) S/T Utility Manual Transmission .............................................................................................................................. Powertrain Control Module (93PCM6) S/T Pickup Manual Transmission ........................................................................................................................................ Vehicle Control Module (VCM) Remarks: [1] The eighth digit of the VIN denotes engine code. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Relays and Modules Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Page 3373 Engine Control Module: Locations Vehicle Speed Sensor Buffer And Electric Shift Transfer Case Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Relays and Modules Computers and Control Systems > Engine Control Module > Component Information > Technical Service Bulletins > Page 3374 Engine Or Powertrain Control Module Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Relays and Modules Computers and Control Systems > Engine Control Module > Component Information > Diagrams > C1 Red (32 Pin) Engine Control Module: Diagrams C1 Red (32 Pin) Manual Transmission (1 Of 2) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Relays and Modules Computers and Control Systems > Engine Control Module > Component Information > Diagrams > C1 Red (32 Pin) > Page 3377 Manual Transmission (2 Of 2) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Relays and Modules Computers and Control Systems > Engine Control Module > Component Information > Diagrams > C1 Red (32 Pin) > Page 3378 Engine Control Module: Diagrams C2-Blue (32 Pin) Automatic Transmission (1 Of 2) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Relays and Modules Computers and Control Systems > Engine Control Module > Component Information > Diagrams > C1 Red (32 Pin) > Page 3379 Automatic Transmission (2 Of 2) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Relays and Modules Computers and Control Systems > Engine Control Module > Component Information > Diagrams > C1 Red (32 Pin) > Page 3380 Engine Control Module: Diagrams C210 C210 - PCM C210 - ECM Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Relays and Modules Computers and Control Systems > Engine Control Module > Component Information > Diagrams > C1 Red (32 Pin) > Page 3381 Engine Control Module: Diagrams C211 C211 - PCM C211 - ECM Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Relays and Modules Computers and Control Systems > Engine Control Module > Component Information > Diagrams > C1 Red (32 Pin) > Page 3382 Engine Control Module: Diagrams With Manual Transmission Pinout Chart Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Relays and Modules Computers and Control Systems > Engine Control Module > Component Information > Diagrams > C1 Red (32 Pin) > Page 3383 Pinout Chart Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Relays and Modules Computers and Control Systems > Engine Control Module > Component Information > Diagrams > C1 Red (32 Pin) > Page 3384 Pinout Chart Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Relays and Modules Computers and Control Systems > Engine Control Module > Component Information > Diagrams > C1 Red (32 Pin) > Page 3385 Pinout Chart Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Relays and Modules Computers and Control Systems > Engine Control Module > Component Information > Diagrams > Page 3386 Engine Control Module: Description and Operation Engine Control Module Fig. 5 ECM Unit (Showing PROM & CALPAK Locations) Powertrain Control Module (PCM) PURPOSE The Powertrain Control Module (PCM) is the control center of the fuel injection system. It constantly looks at the information from various sensors (inputs) and controls the systems (outputs) that affect vehicle performance. The PCM also performs the diagnostic function of the system. It can recognize operational problems, alert the driver through the Malfunction Indicator Lamp (MIL) "Service Engine Soon" light on the instrument panel and store a Diagnostic Trouble Code(s) (DTC) in the PCM memory. The DTC identifies the problem areas to aid the technician in performing repairs. OPERATION The PCM is an electronic computer designed to process the various input information, and send the necessary electrical response to control fuel delivery, spark control, and other emission control systems. The PCM can control these devices through the use of Quad Driver Modules (QDM). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Relays and Modules Computers and Control Systems > Engine Control Module > Component Information > Diagrams > Page 3387 When the PCM is commanding a device or a component "ON," the voltage potential of the output is "LOW" or near zero volts. When the PCM is commanding a device or component "OFF," the voltage potential of the circuit will be "HIGH," or near 12 volts. The primary function of the QDM is to supply the ground for the component being controlled. The input information has an interrelation between sensor output. If one of the input devices failed, such as the oxygen sensor, this could affect more than one of the systems controlled by the computer. The PCM has two parts for service: Controller which is the PCM (93 PCM6), without the PROM (MEM-CAL). - PROM (Programmable Read Only Memory) which is a separate memory calibrator unit PCM Learning Ability The PCM has a "learning" ability which allows it to make corrections for minor variations in the fuel system to improve driveability. If the battery is disconnected, to clear diagnostic trouble codes or for other repairs. the "learning" process resets and begins again. A change may be noted in the vehicle's performance. To "teach" the vehicle, ensure the engine is at operating temperature. The vehicle should be driven at part throttle, with moderate acceleration and idle conditions until normal performance returns. NOTE The PCM must be maintained at a temperature below 85°C (185°F) at all times. This is most essential if the vehicle is put through a baking process. The PCM will become inoperative if it's temperature exceeds 85°C (185°F). It is recommended that temporary insulation be placed around the PCM during the time the vehicle is in a paint oven or other high temperature processes. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Relays and Modules Computers and Control Systems > Engine Control Module > Component Information > Diagrams > Page 3388 Engine Control Module: Service and Repair Figure 1 CAUTION [a] The ignition must be "OFF," when disconnecting or reconnecting the control module connector, to prevent internal damage to the control module. [b] To prevent possible Electrostatic Discharge to the control module, Do NOT touch the connector pins or soldered components on the circuit boards. NOTE When replacing a production control module with a service controller, transfer the broadcast code and production control module part number to the controller label. DO NOT record information on the access cover. REMOVE/DISCONNECT - Negative battery terminal. - Passenger side kick panel. - Hush panel if equipped. - Mounting screw. - Control module from mounting bracket. - VSS buffer connector and rotate control module to ease removal. - Control module harness connectors. - Mounting brackets and modules if equipped. - Remove new control module from its packaging and check the service number to make sure it is the same as the defective control module. - PROM removal. Refer to PROM (MEM-CAL) replacement. NOTE Replacement control module is supplied without a PROM, so care should be used when removing it from the defective control module, because it will be reused in the new control module. INSTALL/CONNECT - Mounting brackets and modules if equipped. - Control module harness connectors. - VSS buffer connector and rotate control module to ease installation. - Control module into mounting bracket. - Mounting screw. - Hush panel if equipped. - Passenger side kick panel. - Negative battery terminal. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Specifications Coolant Temperature Sensor/Switch (For Computer): Specifications Resistance 185 ohms at 210 deg F 450 ohms at 160 deg F 1800 ohms at 100 deg F 3400 ohms at 70 deg F 7500 ohms at 40 deg F 13500 ohms at 20 deg F 25000 ohms at 0 deg F 100700 ohms at -40 deg F Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Specifications > Page 3393 Coolant Temperature Sensor/Switch (For Computer): Locations Engine Coolant Temperature Sensor Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Specifications > Page 3394 Engine Harness, Right Front Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions Coolant Temperature Sensor/Switch (For Computer): Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. Use this page as a reference to determine the meaning of an abbreviation if necessary. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery Bi-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CHMSL Center High Mount Stoplamp CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRO Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3397 F-PUMP Fuel Pump FLASH Flasher FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3398 SIR Supplemental Inflatable Restraint SKT Socket SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature TIL Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3399 example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE (ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: ^ Slide across the vehicle seat. ^ Sit down or stand up. ^ Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: ^ They are bumped or dropped. ^ They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3400 Symbols (Part 1 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3401 Symbols (Part 2 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3402 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3403 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3404 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3405 Coolant Temperature Sensor/Switch (For Computer): Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3406 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3407 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3408 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3409 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3410 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. ^ If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. ^ A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3411 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3412 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3413 Ohmmeter Meter Scales Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3414 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. ^ An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. ^ On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: ^ A range selector switch which permits the selection of different ranges of resistance. ^ A set adjust control which allows the meter to be set at zero for accurate measurements. ^ Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3415 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: ^ Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. ^ Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. ^ Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3416 be less than 10 percent of the total drop. When using a voltmeter: ^ Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. ^ Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. ^ The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: ^ Check the accuracy and completeness of the complaint. ^ Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3417 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. ^ The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3418 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3419 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3420 Twisted/Shielded Wire Repair Twisted Wires Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3421 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3422 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3423 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). ^ Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean ^ Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. ^ Roll crimp (13) and solder the terminal. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3424 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3425 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3426 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. ^ Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean ^ Terminal cavity of the connector body. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3427 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. ^ Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3428 C105 - Engine Coolant Temperature Sensor Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Diagram Information and Instructions > Page 3429 Engine Coolant Temperature (ECT) Circuit Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Coolant Temperature Sensor/Switch (For Computer) > Component Information > Diagrams > Page 3430 Coolant Temperature Sensor/Switch (For Computer): Description and Operation Engine Coolant Temperature Sensor PURPOSE The Engine Coolant Temperature (ECT) Sensor information is used by the control module to control: Fuel delivery - Torque Converter Clutch (TCC) - Engine Spark Timing (EST) - Controlled Canister Purge (CCP) - Idle Air Control (IAC) - Cooling Fan OPERATION The ECT is a thermistor that is located in the engine coolant flow mounted to the intake manifold. When the coolant temperature is low, the sensor produces a high resistance. When the coolant temperature is high, the sensor produces a low resistance. The PCM sends a 5.0 volt signal to the ECT through a resistor in the computer and measures the voltage. The voltage will be high or low depending on coolant temperature. With the ECT varying its resistance, the PCM can sense engine coolant temperature by reading the varying voltage. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Intake Air Temperature Sensor > Component Information > Specifications > Electrical Specifications Intake Air Temperature Sensor: Electrical Specifications Resistance 185 ohms at 210 deg F 450 ohms at 160 deg F 1800 ohms at 100 deg F 3400 ohms at 70 deg F 7500 ohms at 40 deg F 13500 ohms at 20 deg F 25000 ohms at 0 deg F 100700 ohms at -40 deg F Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Intake Air Temperature Sensor > Component Information > Specifications > Electrical Specifications > Page 3435 Intake Air Temperature Sensor: Mechanical Specifications Torque Valve Torque Valve Induction Air Sensor 44 in.lb Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Knock Sensor > Component Information > Technical Service Bulletins > Knock Sensor Circuit - DTC 43 Chart Revision Knock Sensor: Technical Service Bulletins Knock Sensor Circuit - DTC 43 Chart Revision File In Section: 6E Engine Fuel & Emission Bulletin No.: 51-65-19 Date: April, 1995 Subject: Section 3A - Control Module System (PCM) Driveability and Emissions - Revised DTC 43 Knock Sensor (KS) Circuit (Dual Knock Sensors) Models: 1994 Chevrolet and GMC Truck S/T; M/L, C/K Models with 4.3L Engine (VINs W, Z RPOs L35, LB4) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Knock Sensor > Component Information > Technical Service Bulletins > Knock Sensor Circuit - DTC 43 Chart Revision > Page 3440 This bulletin advises of a revision to the DTC 43 Knock Sensor (KS) Circuit (Dual Knock Sensor System) chart in the following service manuals: 1994 S/T Driveability Emissions and Electrical Diagnosis Manual, page 3A-119 1994 M/L Driveability Emissions and Electrical Diagnosis Manual, page 3A-75 1994 C/K Driveability Emissions and Electrical Diagnosis Manual, page 3A-69 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Knock Sensor > Component Information > Technical Service Bulletins > Page 3441 Knock Sensor: Specifications Coil bracket bolt/nut ............................................................................................................................. ................................................. 27 N-m (20 lbs ft) Distributor clamp bolt ........................................................................................................................... ................................................ 27 N-m (20 lbs ft) Knock Sensor ...................................................................................................................................... .................................................. 19 N-m (14 lbs ft) Spark Plugs ......................................................................................................................................... .................................................. 15 N-M (11 lbs ft) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Knock Sensor > Component Information > Locations > Assembly View Knock Sensors Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Knock Sensor > Component Information > Locations > Assembly View > Page 3444 Knock Sensor: Locations Harness View LH Rear Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Knock Sensor > Component Information > Locations > Assembly View > Page 3445 LH Rear Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Knock Sensor > Component Information > Locations > Page 3446 Knock Sensor: Diagrams C119 - Knock Sensor C135 - Knock Sensor Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Knock Sensor > Component Information > Locations > Page 3447 Knock Sensor: Description and Operation PURPOSE: The Knock Sensor (KS) is used to detect engine detonation (ping). The control module will retard the electronic spark timing up to 8° based on the signal received. CONSTRUCTION The KS system has two major components: Control Module. - Knock Sensor(s). The two knock sensors are spliced together and go directly to the control module. OPERATION The knock sensor internal circuit causes the control modules 5 volts to be pulled down to about 2.5 volts. The knock sensor produces an A/C signal which rides on the 2.5 volts DC signal. The AC voltage monitor in the control module will detect this AC voltage and provide a signal to begin retarding spark until the knock diminishes. The amplitude and frequency are dependent upon the knock level. LOCATION Engine block. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Knock Sensor > Component Information > Locations > Page 3448 Knock Sensor: Testing and Inspection Knock Sensor (KS) System Check Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Knock Sensor > Component Information > Locations > Page 3449 Knock Sensor Circuit Circuit Description The Knock Sensor (KS) circuit consists of two knock sensors with one wire that goes directly to the control modules. There are two Knock Sensor (KS) checks performed by the ECM. One check consists of monitoring CKT 496 for a voltage that is more than .63 volt and less than 3.1 volts. If voltage is either too high or too low for 10 or more seconds, DTC 43 will set. The PCM uses this self check only. The next test is used only by the ECM along with the previous test. Once engine temperature reaches 85°C, MAP is over 83 kPa, and engine speed is less than 3200 RPM, the ECM will perform a self check. This self check will advance the timing until it receives a knock signal. If no knock signal is received, DTC 43 will set. Chart Test Description Number(s) below refer to circled number(s) on the diagnostic chart. 1. The first test is to determine if the system is functioning at the present time. 2. Test two determines the state of the 5 volt reference voltage applied to the knock sensor circuit. 3. Test 3 determines the state of the knock sensors and connections themselves. Diagnostic Aids The control module applies 5 volts to CKT 496. A 8200 ohm resistor in the knock sensors reduces the voltage to about 2.5 volts. When knock occurs, the knock sensor produces a small AC voltage that rides on top of the 2.5 volts already applied. An AC voltage monitor, in the control module, is able to read this signal as knock and incrementally retard spark. If the KS system checks OK, but detonation is the complaint, refer to "Detonation/Spark Knock". See: Testing and Inspection/Symptom Related Diagnostic Procedures/Detonation/ Spark Knock Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Knock Sensor > Component Information > Locations > Page 3450 Knock Sensor: Service and Repair REMOVE OR DISCONNECT - Negative battery cable. - Drain cooling system. NOTE On knock sensors which are mounted in the end of the cylinder head draining the cooling system will not be necessary. - Wiring harness connector from knock sensor. - Knock sensor. INSTALL OR CONNECT - Knock sensor. If reinstalling original sensor, apply water base caulk to sensor threads. Do NOT use silicone tape as this will insulate sensor from engine. ^ Tighten to 19 Nm (14 lb. ft.). - Wiring harness connector to knock sensor. - Refill cooling system and pressure test for leaks. - Negative battery cable. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Specifications Manifold Pressure/Vacuum Sensor: Specifications Voltage 3.6 to 5.2 V at 1000 to 2000 ft 3.5 to 5.1 V at 2000 to 3000 ft 3.3 to 5.0 V at 3000 to 4000 ft 3.2 to 4.8 V at 4000 to 5000 ft 3.0 to 4.6 V at 5000 to 6000 ft 2.9 to 4.5 V at 6000 to 7000 ft 2.8 to 4.3 V at 7000 to 8000 ft 2.6 to 4.2 V at 8000 to 9000 ft 2.5 to 4.0 V at 9000 to 10000 ft Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Specifications > Page 3454 Manifold Pressure/Vacuum Sensor: Locations Engine Harness, Right Front Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Specifications > Page 3455 MAP Sensor 4.3Z Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions Manifold Pressure/Vacuum Sensor: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. Use this page as a reference to determine the meaning of an abbreviation if necessary. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery Bi-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CHMSL Center High Mount Stoplamp CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRO Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3458 F-PUMP Fuel Pump FLASH Flasher FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3459 SIR Supplemental Inflatable Restraint SKT Socket SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature TIL Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3460 example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE (ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: ^ Slide across the vehicle seat. ^ Sit down or stand up. ^ Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: ^ They are bumped or dropped. ^ They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3461 Symbols (Part 1 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3462 Symbols (Part 2 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3463 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3464 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3465 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3466 Manifold Pressure/Vacuum Sensor: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3467 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3468 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3469 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3470 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3471 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. ^ If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. ^ A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3472 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3473 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3474 Ohmmeter Meter Scales Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3475 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. ^ An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. ^ On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: ^ A range selector switch which permits the selection of different ranges of resistance. ^ A set adjust control which allows the meter to be set at zero for accurate measurements. ^ Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3476 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: ^ Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. ^ Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. ^ Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3477 be less than 10 percent of the total drop. When using a voltmeter: ^ Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. ^ Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. ^ The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: ^ Check the accuracy and completeness of the complaint. ^ Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3478 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. ^ The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3479 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3480 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3481 Twisted/Shielded Wire Repair Twisted Wires Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3482 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3483 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3484 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). ^ Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean ^ Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. ^ Roll crimp (13) and solder the terminal. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3485 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3486 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3487 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. ^ Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean ^ Terminal cavity of the connector body. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3488 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. ^ Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3489 C109 - MAP Sensor Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3490 MAP Sensor Circuit Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Page 3491 Manifold Pressure/Vacuum Sensor: Description and Operation Map Sensor Circuit (GM Generic) Manifold Absolute Pressure (MAP) Sensor PURPOSE The Manifold Absolute Pressure (MAP) sensor measures changes in the intake manifold pressure resulting from engine load and speed changes. As intake manifold pressure increases, the air density in the intake manifold also increases and additional fuel is required. Under certain conditions, the MAP sensor is also used to measure barometric pressure. This allows the control module to automatically adjust for different altitudes. The PCM uses information from the MAP sensor to calculate spark advance and fuel as follows: Low MAP output voltage (low pressure) results in more spark advance. - High MAP output voltage (high pressure) results in less spark advance. - Low MAP output voltage (low pressure) results in less fuel. - High MAP output voltage (high pressure) results in more fuel. OPERATION The control module supplies a 5 volt reference signal to the MAP sensor and the sensor provides a path to ground through its variable resistor. The control module by monitoring the sensor output voltage can determine the manifold pressure. A closed throttle on engine coastdown will produce a relatively low MAP output, while a wide open throttle will produce a high output. At higher pressure or at Wide Open Throttle (WOT) output voltage will be about 4 to 4.8 volts. The higher the MAP voltage output the lower the engine vacuum, which requires more fuel. The lower the MAP voltage output the higher the engine vacuum. At lower pressure output voltage will be about 1 to 2 volts at idle. A failure in the MAP sensor circuit should set Diagnostic Trouble Codes (DTC) 33 or 34 with PCM/ECM systems and DTC P0107 or P0108 with VCM systems. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Page 3492 Manifold Pressure/Vacuum Sensor: Testing and Inspection Manifold Absolute Pressure (MAP) Output Check Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Manifold Pressure/Vacuum Sensor > Component Information > Diagrams > Page 3493 MAP Sensor Circuit Circuit Description: The Manifold Absolute Pressure (MAP) sensor measures the changes in the intake manifold pressure which result from engine load (intake manifold vacuum) and RPM changes; and converts these into a voltage output. The PCM sends a 5 volt reference voltage to the MAP sensor. As the manifold pressure changes, the output voltage of the sensor also changes. By monitoring the sensor output voltage, the PCM knows the manifold pressure. At lower pressure output voltage will be about 1 to 2 volts at idle. While at higher pressure or at Wide Open Throttle (WOT) output voltage will be about 4 to 4.8 volts. The MAP sensor is also used, under certain conditions, to measure barometric pressure, allowing the PCM to make adjustments for different altitudes. The PCM uses the MAP sensor to control fuel delivery and ignition timing. Chart Test Description Number(s) below refer to circled number(s) on the diagnostic chart. Important ^ Be sure to use the same Diagnostic Test Equipment for all measurements. 1. Checks MAP sensor output voltage to the PCM. This voltage, without engine running, represents a barometer reading to the PCM. ^ When comparing Tech 1 scan readings to a known good vehicle, it is important to compare vehicles that use a MAP sensor having the same color insert or having the same "Hot Stamped" number. Refer to figures on facing page. 2. Applying 34 kPa (10" Hg) vacuum to the MAP sensor should cause the voltage to change. Subtract second reading from the first. Voltage value should be greater than 1.5 volts. Upon applying vacuum to the sensor, the change in voltage should be instantaneous. A slow voltage change indicates a faulty sensor. 3. Check vacuum hose to sensor for leaking or restriction. Be sure that no other vacuum devices are connected to the MAP hose. NOTICE:Make sure electrical connector remains securely fastened. 4. Disconnect sensor from bracket and twist sensor by hand (only) to check for intermittent connection. Output changes greater than .1 volt indicate a bad connector or connection. If OK, replace sensor. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > Customer Interest: > 566501 > Jul > 95 > O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear Oxygen Sensor: Customer Interest O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear FILE IN SECTION: 6E - Engine Fuel & Emission BULLETIN NO.: 56-65-01 DATE: July, 1995 SUBJECT: Rattling Noise on Acceleration/Transmission Starting Out in 3rd Gear (Provide Clearance or Replace Exhaust Crossover) MODELS: 1993-94 Chevrolet and GMC Truck M/L Vans 1994 Chevrolet and GMC Truck T Models 1994 Oldsmobile Bravada with 4.3L Engines (VINs W, Z - RPOs L35, LB4) CONDITION Customers may comment on one or more of the following conditions: A rattling noise on acceleration, transmission starting out in 3rd gear (possible DTC 66, 67, 81, 82) and/or diagnostic trouble codes 13 or 44. CAUSE M/L Vans Oxygen sensor and/or harness pigtail contacting the heat shield due to improper routing of the harness. Sharp edges of the heat shield cuts through the wire insulation. T Trucks The rattle noise may be the oxygen sensor and/or harness pigtail contacting the heat shield due to the mispositioning of the oxygen sensor mounting boss. Starting out in 3rd gear may be due to the pink wire (CKT 39) shorting out against the heat shield causing power to be interrupted to the transmission control circuit putting the transmission into backup mode (3rd Gear Starts). Diagnostic trouble codes 13 or 44 may be set due to the oxygen sensor signal wire shorting to or cut through by the heat shield. CORRECTION M/L Vans Refer to the "1993 M/L Van Electrical Diagrams and Diagnosis" manual or the "1994 Driveability, Emissions and Electrical Diagnosis" manual for circuit 39 schematics. Normal circuit diagnostics should be performed first if the problem is constant. If the problem is intermittent, an inspection of circuit 39 (pink/black) in the area of the exhaust heat shields may lead to the problem. Inspect the oxygen sensor wiring and replace the sensor it the insulation has been damaged. Re-route wiring harness as needed to protect harness. Clear any codes and test drive. T Trucks If the oxygen sensor is contacting the heat shield, this condition can be corrected by replacing the exhaust crossover pipe. If the oxygen sensor wire is damaged, the oxygen sensor must also be replaced. Follow regular Service Manual Procedures in Section 3 of the 1993 or 1994 "S/T Truck Driveability, Emission and Electrical Diagnosis" manual to make above repairs. Clear any diagnostic trouble codes and test drive. PARTS INFORMATION P/N Description Qty 10096129 Sensor, Oxygen (1993) 1 25133503 Sensor, Oxygen (1994) 1 15661132 Pipe, Exhaust Crossover (w/ZR2) 1 15672887 Pipe, Exhaust Crossover (w/o ZR2) 1 Parts are currently available from GMSPO. WARRANTY INFORMATION Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > Customer Interest: > 566501 > Jul > 95 > O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear > Page 3502 For vehicles repaired under warranty, use: Labor Operation Description Labor Time J6372 Sensor, Oxygen Replace Use Published L2080 Pipe, Crossover Exhaust Replace Labor Operation Time Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oxygen Sensor: > 566501 > Jul > 95 > O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear Oxygen Sensor: All Technical Service Bulletins O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear FILE IN SECTION: 6E - Engine Fuel & Emission BULLETIN NO.: 56-65-01 DATE: July, 1995 SUBJECT: Rattling Noise on Acceleration/Transmission Starting Out in 3rd Gear (Provide Clearance or Replace Exhaust Crossover) MODELS: 1993-94 Chevrolet and GMC Truck M/L Vans 1994 Chevrolet and GMC Truck T Models 1994 Oldsmobile Bravada with 4.3L Engines (VINs W, Z - RPOs L35, LB4) CONDITION Customers may comment on one or more of the following conditions: A rattling noise on acceleration, transmission starting out in 3rd gear (possible DTC 66, 67, 81, 82) and/or diagnostic trouble codes 13 or 44. CAUSE M/L Vans Oxygen sensor and/or harness pigtail contacting the heat shield due to improper routing of the harness. Sharp edges of the heat shield cuts through the wire insulation. T Trucks The rattle noise may be the oxygen sensor and/or harness pigtail contacting the heat shield due to the mispositioning of the oxygen sensor mounting boss. Starting out in 3rd gear may be due to the pink wire (CKT 39) shorting out against the heat shield causing power to be interrupted to the transmission control circuit putting the transmission into backup mode (3rd Gear Starts). Diagnostic trouble codes 13 or 44 may be set due to the oxygen sensor signal wire shorting to or cut through by the heat shield. CORRECTION M/L Vans Refer to the "1993 M/L Van Electrical Diagrams and Diagnosis" manual or the "1994 Driveability, Emissions and Electrical Diagnosis" manual for circuit 39 schematics. Normal circuit diagnostics should be performed first if the problem is constant. If the problem is intermittent, an inspection of circuit 39 (pink/black) in the area of the exhaust heat shields may lead to the problem. Inspect the oxygen sensor wiring and replace the sensor it the insulation has been damaged. Re-route wiring harness as needed to protect harness. Clear any codes and test drive. T Trucks If the oxygen sensor is contacting the heat shield, this condition can be corrected by replacing the exhaust crossover pipe. If the oxygen sensor wire is damaged, the oxygen sensor must also be replaced. Follow regular Service Manual Procedures in Section 3 of the 1993 or 1994 "S/T Truck Driveability, Emission and Electrical Diagnosis" manual to make above repairs. Clear any diagnostic trouble codes and test drive. PARTS INFORMATION P/N Description Qty 10096129 Sensor, Oxygen (1993) 1 25133503 Sensor, Oxygen (1994) 1 15661132 Pipe, Exhaust Crossover (w/ZR2) 1 15672887 Pipe, Exhaust Crossover (w/o ZR2) 1 Parts are currently available from GMSPO. WARRANTY INFORMATION Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oxygen Sensor: > 566501 > Jul > 95 > O2 Sensor - Rattling Noise/A/T Starts In 3rd Gear > Page 3508 For vehicles repaired under warranty, use: Labor Operation Description Labor Time J6372 Sensor, Oxygen Replace Use Published L2080 Pipe, Crossover Exhaust Replace Labor Operation Time Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Oxygen Sensor: > 81I37 > Feb > 81 > Oxygen Sensors - Silica Contamination Oxygen Sensor: All Technical Service Bulletins Oxygen Sensors - Silica Contamination Model Year: 1981 Bulletin No: 81-I-37 File In Group: 60 Number: 11 Date: Feb. 81 Subject: Silica Contamination of Oxygen Sensors and Gelation of Oil. Models Affected: All Oxygen sensor performance can deteriorate if certain RTV silicone gasket materials are used. Other RTV's when used with certain oils, may cause gelation of the oil. The degree of performance severity depends on the type of RTV and application of the engine involved. Therefore, when repairing engines where this item is involved, it is important to use either cork composition gaskets or RTV silicone gasket material approved for such use. GMS (General Motors Sealant) or equivalent material can be used. GMS is available through GMPD with the following part numbers: 1052366 3 oz. 1052434 10.14 oz. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Technical Service Bulletins > All Other Service Bulletins for Oxygen Sensor: > 81I37 > Feb > 81 > Oxygen Sensors - Silica Contamination Oxygen Sensor: All Technical Service Bulletins Oxygen Sensors - Silica Contamination Model Year: 1981 Bulletin No: 81-I-37 File In Group: 60 Number: 11 Date: Feb. 81 Subject: Silica Contamination of Oxygen Sensors and Gelation of Oil. Models Affected: All Oxygen sensor performance can deteriorate if certain RTV silicone gasket materials are used. Other RTV's when used with certain oils, may cause gelation of the oil. The degree of performance severity depends on the type of RTV and application of the engine involved. Therefore, when repairing engines where this item is involved, it is important to use either cork composition gaskets or RTV silicone gasket material approved for such use. GMS (General Motors Sealant) or equivalent material can be used. GMS is available through GMPD with the following part numbers: 1052366 3 oz. 1052434 10.14 oz. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Specifications > Electrical Specifications Oxygen Sensor: Electrical Specifications Closed Loop 100 - 0.999 mV Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Specifications > Electrical Specifications > Page 3520 Oxygen Sensor: Mechanical Specifications Oxygen Sensor 30 ft.lb Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Locations > Heated Oxygen Sensor Engine Harness, Right Front Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Locations > Heated Oxygen Sensor > Page 3523 Heated Oxygen Sensor (HO2S) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions Oxygen Sensor: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. Use this page as a reference to determine the meaning of an abbreviation if necessary. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery Bi-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CHMSL Center High Mount Stoplamp CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRO Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3526 F-PUMP Fuel Pump FLASH Flasher FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3527 SIR Supplemental Inflatable Restraint SKT Socket SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature TIL Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3528 example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE (ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: ^ Slide across the vehicle seat. ^ Sit down or stand up. ^ Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: ^ They are bumped or dropped. ^ They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3529 Symbols (Part 1 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3530 Symbols (Part 2 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3531 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3532 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3533 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3534 Oxygen Sensor: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3535 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3536 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3537 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3538 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3539 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. ^ If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. ^ A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3540 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3541 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3542 Ohmmeter Meter Scales Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3543 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. ^ An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. ^ On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: ^ A range selector switch which permits the selection of different ranges of resistance. ^ A set adjust control which allows the meter to be set at zero for accurate measurements. ^ Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3544 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: ^ Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. ^ Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. ^ Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3545 be less than 10 percent of the total drop. When using a voltmeter: ^ Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. ^ Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. ^ The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: ^ Check the accuracy and completeness of the complaint. ^ Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3546 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. ^ The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3547 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3548 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3549 Twisted/Shielded Wire Repair Twisted Wires Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3550 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3551 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3552 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). ^ Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean ^ Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. ^ Roll crimp (13) and solder the terminal. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3553 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3554 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3555 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. ^ Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean ^ Terminal cavity of the connector body. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3556 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. ^ Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3557 C116 - Oxygen Sensor Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3558 Heated Oxygen Sensor (HO2S) Circuit Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Page 3559 Oxygen Sensor: Description and Operation Exhaust Oxygen Sensor (02) PURPOSE The Oxygen sensor (O2 Sensor) has the ability to produce a low voltage signal that feeds information on engine exhaust content to the control module. CONSTRUCTION The O2 Sensor is constructed from a zirconia/platinum electrolytic element. Zirconia is an electrolyte that conducts electricity under certain chemical conditions. The element is made of a ceramic material and is an insulator when cold. At operating temperature, 315°C (600°F), the element becomes a semiconductor. A platinum coating on the outer surface of the element stimulates further combustion of the exhaust gases right at the surface and this helps deep the element up to the desired temperature. The O2 Sensor has an inter cavity which is filled with atmospheric (reference) air. The atmosphere has approximately 21% oxygen in it. In the electrical circuit this inter cavity is the positive (+) terminal. The outer surface of the element is exposed to the exhaust gas stream. It is the negative (-) terminal. Oxygen Sensor Output Voltage vs. Air/Fuel Ratio The difference in oxygen concentration in the narrow range of optimum air/fuel ratio causes a large voltage change that is easily measured. OPERATION A rich exhaust (excessive fuel) has almost no oxygen. When there is a large difference in the amount of oxygen touching the inside and outside surfaces, there is more conduction, and the sensor puts out a voltage signal above 0.6 volts (600 mV). With lean exhaust (excessive oxygen) there is about two percent oxygen in the exhaust. This is a smaller difference in oxygen from the outside surfaces which results in less conduction and a voltage signal below 0.3 volts (300 mV). The voltages are monitored and used by the control module to "fine tune" the air/fuel ratio to achieve the ideal mixture desired. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Page 3560 The control module puts out a reference signal of 0.45 volts (450 mV). The reference signal serves two purposes. The first is to run the engine when it is in OPEN LOOP mode of operation. When the air/fuel ratio is correct the control module senses 450 mV. When the engine is operating with a rich air/fuel ratio there is a reduction of free oxygen in the exhaust stream and the O2 sensor voltage rises above the reference voltage. When the engine is running lean the voltage drops below the reference voltage due to the excess oxygen in the exhaust stream. The O2 sensor provides the feedback information for the CLOSED LOOP operating mode of the fuel delivery system. The O2 sensor indicates to the control module what is happening in the exhaust. It does not cause things to happen. It is a type of gauge: Low voltage output = lean mixture = high oxygen content in the exhaust; high voltage output = rich mixture = low oxygen content in the exhaust. CONDITIONS THAT CAN SET CODES An open O2 sensor, should set a Diagnostic Trouble Code (DTC) 13. A constant low voltage in the O2 sensor circuit should set a DTC 44. A constant high voltage in the circuit should set a DTC 45. DTC 44 and DTC 45 could be set as a result of fuel system problems. REFER TO COMPUTERS AND CONTROL SYSTEMS/DIAGNOSTIC CHARTS for diagnosis of these codes. HEATED OXYGEN SENSOR TYPE The heated oxygen sensor works in the same manner as the non-heated oxygen sensor. The exception is that B+ is supplied to a heating element that is part of the sensor itself. The heater helps the control module control the fuel injection sooner for better fuel emissions. There are no Diagnostic Trouble Codes (DTC's) to detect if the heater part of the sensor is working. To check the heater, REFER TO COMPUTERS AND CONTROL SYSTEMS/DIAGNOSIS AND TESTING PROCEDURES/OXYGEN SENSOR TESTING. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Page 3561 Oxygen Sensor: Testing and Inspection VISUAL INSPECTION - Connectors and wires - Housing and insulator for cracks/damage - Sensor tip for silicone contamination (white powdery coating) CAUTION Do NOT perform the following test for more than 2 minutes, as this may cause damage to the catalytic converter. PERFORMANCE TEST Checks working range and response (speed). Warm engine - Install DVOM between sensor and ground (2 volt D.C. range) - "RUN" engine at steady cruise speed (about 2500 rpm) Voltage should vary at least eight times in ten seconds between 0.2 and 0.8 volts (normal range). - Drive system rich: The use of a properly adjusted propane flow-meter (J-26911) is industry standard. Voltage should increase to at least 0.8 volts within two to three seconds. - Drive system lean: Create a vacuum leak from a source that is not an control module input or output. Voltage should drop to at least 0.3 volts within two to three seconds. NOTE After each test the O2 sensor should return to normal operating range within two to three seconds. - O2 Sensor should be replaced for failure to pass any of the tests above. NOTE A CEC system that is operating excessively rich or lean will drive the 02 sensor to its maximum range and should be repaired first and not diagnosed as a 02 sensor failure. - Reconnect all hoses and electrical connectors. Clear all codes set and retrain idle. HEATING ELEMENT (H20S only) - Turn ignition "OFF". Disconnect electrical connector. - Connect test light between harness terminals "A" and "B". - Turn ignition "ON". Test light should be "ON". If test light is "OFF", connect test light to harness terminal "A" to ground. Light should be "ON" ensuring power circuit is operating correctly. - Turn ignition "OFF". - Using an ohmmeter, measure resistance between terminals A and B. Resistance @ Specified Temperature 3.5 ohms @ 20°C (68°F) 14 ohms @ 350°C (662°F) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Oxygen Sensor > Component Information > Diagrams > Page 3562 Oxygen Sensor: Service and Repair NOTE The oxygen sensor has a permanently attached pig-tail and connector. This pig-tail should not be removed, since removal will affect proper operation of the oxygen sensor. REMOVAL - Disconnect electrical connector from oxygen sensor. - Using suitable wrench, carefully remove sensor from exhaust manifold or pipe. Caution The oxygen sensor may be difficult to remove when engine temperature is below 120°F. Excessive force may damage threads in exhaust manifold or pipe. INSTALLATION - If new sensor is being used, install sensor into manifold or pipe. - If old sensor is being reused, coat threads with anti-seize compound, Part No. 5613695 or equivalent, then install into manifold or pipe. - Torque oxygen sensor to 41 N-m (30 lb. ft.), then reconnect electrical connector. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Specifications Throttle Position Sensor: Specifications Idle Normal 0.45 to 0.95 V Maximum 1.25 V Wide Open Throttle 4.0 to 4.5 V Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Specifications > Page 3566 Engine Harness, Right Front Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions Throttle Position Sensor: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. Use this page as a reference to determine the meaning of an abbreviation if necessary. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery Bi-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CHMSL Center High Mount Stoplamp CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRO Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3569 F-PUMP Fuel Pump FLASH Flasher FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3570 SIR Supplemental Inflatable Restraint SKT Socket SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature TIL Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3571 example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE (ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: ^ Slide across the vehicle seat. ^ Sit down or stand up. ^ Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: ^ They are bumped or dropped. ^ They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3572 Symbols (Part 1 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3573 Symbols (Part 2 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3574 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3575 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3576 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3577 Throttle Position Sensor: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3578 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3579 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3580 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3581 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3582 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. ^ If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. ^ A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3583 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3584 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3585 Ohmmeter Meter Scales Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3586 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. ^ An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. ^ On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: ^ A range selector switch which permits the selection of different ranges of resistance. ^ A set adjust control which allows the meter to be set at zero for accurate measurements. ^ Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3587 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: ^ Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. ^ Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. ^ Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3588 be less than 10 percent of the total drop. When using a voltmeter: ^ Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. ^ Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. ^ The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: ^ Check the accuracy and completeness of the complaint. ^ Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3589 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. ^ The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3590 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3591 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3592 Twisted/Shielded Wire Repair Twisted Wires Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3593 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3594 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3595 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). ^ Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean ^ Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. ^ Roll crimp (13) and solder the terminal. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3596 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3597 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3598 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. ^ Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean ^ Terminal cavity of the connector body. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3599 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. ^ Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3600 C110 - TP Sensor Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3601 Throttle Position (TP) Circuit Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Page 3602 Throttle Position Sensor: Description and Operation Wiring Diagram For Code 21 - Throttle Position Sensor (Signal Voltage High) NOTE Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE The Throttle Position Sensor (TPS) is a potentiometer that senses throttle angle and sends a signal to the PCM. The TP signal is one of the most important inputs used by the control module for fuel control and for most of the control module control outputs. OPERATION The TPS has three internal circuits provided by the control module. One to ground, a second from the control module as a 5.0 volt reference source and a third circuit is used by the control module to measure the output voltage. As the throttle angle changes (pressing down on accelerator pedal) the TPS voltage output varies from about .5 volt at idle to about 4.9 volts at wide open throttle (WOT). Each time the voltage drops below 1.25 volts and stops, the control module assumes this value is 0 throttle from this point on. LOCATION: Side of throttle body opposite of throttle lever. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Page 3603 Throttle Position Sensor: Adjustments The TPS is not adjustable. Each time voltage drops below 1.25 volts and stops, the control module assumes that this value is zero throttle angle and measures percent throttle from this point on. Therefore adjustment is not necessary. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Page 3604 Throttle Position Sensor: Service and Repair NOTE Since Throttle Position Sensor (TPS) configurations can be mounted interchangeably, be sure to order the correct one for your engine with identical part number of the one being replaced. Throttle Position (TP) Sensor REMOVE/DISCONNECT - Electrical connectors. - TPS attaching screw assemblies and retainer, (if applicable). - TPS from throttle body assembly. NOTE Do NOT immerse in any type of liquid solvent or cleaner, as damage may occur. INSTALL/CONNECT - With throttle valve in normally closed position, install TPS on throttle shaft with seal and rotate counter clockwise to align mounting hole. - Two attaching screw assemblies. Tighten screw assemblies to 2.0 Nm (18.0 lb-in). - Electrical connector to TPS. - Check for TPS output as follows: Connect an ALDL scanner to read TPS output voltage. - With ignition "ON" and engine stopped, TPS voltage should be less than 1.25 volts. If more than 1.25 volts, replace TPS. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Transmission Position Switch/Sensor, A/T > Component Information > Description and Operation Transmission Position Switch/Sensor: Description and Operation Automatic Transmission Electrical Components PURPOSE This device is a set of five presure switches (two normally closed and three normally open), that detect fluid pressure within the valve body passages and signals the PCM which transmission range is selected (PRNDL). OPERATION The five pressure switches are connected to three signal circuits referred to as range signals A, B, C. The combination of pressure switch states determines the voltage signal (B+ or 0) on each range signal to the PCM. LOCATION The transmission range fluid pressure switch assembly is attached to the control valve body within the transmission. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Vehicle Speed Sensor > Component Information > Technical Service Bulletins > Digital Ratio Adapter/Controller (DRAC) - Service Vehicle Speed Sensor: Technical Service Bulletins Digital Ratio Adapter/Controller (DRAC) Service Group Ref.: 8 - Chassis/Body Electrical Bulletin No.: 448301 Date: August, 1994 INFORMATION SUBJECT: NEW PROCEDURE FOR OBTAINING SERVICE DRACS (DIGITAL RATIO ADAPTOR/CONTROLLER) MODELS: 1989-94 CHEVROLET AND GMC TRUCK M/L VANS, S/T MODELS 1990-94 CHEVROLET AND GMC TRUCK G VANS, R/V MODELS 1992-94 CHEVROLET AND GMC TRUCK C/K MODELS 1991-94 OLDSMOBILE BRAVADA If a dealer is contacted about or is in need of a service DRAC (Digital Ratio Adaptor/Controller) for any of the following reasons: 1. Radio interference (EMI). 2. Speedometer fluctuation or flaring. 3. Erratic/surging cruise control operation. 4. Different tire size. 5. Defective part. The dealer must contact an AC-Delco Service Center authorized to repair electronic instrument clusters for a new service DRAC, P/N 16202915. NOTE: This part is a service part and has to be programmed for the vehicle. It cannot be used until this procedure has been done by the authorized Service Center. The dealer will need the P/N and the broadcast code (the 3 bold letters located on the printed label of the old DRAC). The Service Center will program the DRAC according to this information. If the customer is changing the tire size, the Service Center will need the axle ratio and tire sized in order to program the DRAC to the new tire specifications. The AC-Delco Service Center will send the programmed DRAC via common carrier to the dealership. For further information, consult the AC-Delco authorized Service Center Manual WA-2 (September 1990 or later). AC-Delco centers are subject to change. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Vehicle Speed Sensor > Component Information > Locations > Assembly View Vehicle Speed Sensor: Locations Assembly View LOCATION Mounted To Transmisssion Tailshaft. 2WD Automatic Transmission VSS 2WD (A/TRANS.) VEHICLE SPEED SENSOR 2WD Manual Transmission VSS 2WD Manual Transmission 4WD Automatic and Manual Transmission VSS 4WD Or AWD Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Vehicle Speed Sensor > Component Information > Locations > Assembly View > Page 3614 Speed Sensor, Backup Lamp Switch & Electric Shift Transfer Case Wiring Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Vehicle Speed Sensor > Component Information > Locations > Page 3615 C320 - Vehicle Speed Sensor Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Vehicle Speed Sensor > Component Information > Locations > Page 3616 Vehicle Speed Sensor: Description and Operation 2 Wheel Drive (Manual Transmission) VSS 2WD Manual Transmission 2 Wheel Drive (Automatic Transmission) VSS 2WD (A/TRANS.) VEHICLE SPEED SENSOR 4 Wheel Drive VSS 4WD Or AWD PURPOSE The Vehicle Speed Sensor (VSS) provides information to the control module for control of: Transmission Torque Converter Clutch (TCC) - Speedometer - Odometer - Cruise control Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Vehicle Speed Sensor > Component Information > Locations > Page 3617 - ANTILOCK brake system. CONSTRUCTION The VSS is made up of: Permanent Magnet (PM) generator (coil), which is mounted on the transmission. - Rotor (tooth), which is mounted on the output shaft in the transmission. - VSS Buffer, which is mounted to the control module bracket. OPERATION The VSS is a Permanent Magnet (PM) generator that produces a pulsing Alternating Current (AC) voltage as each rotor tooth nears the coil. As the vehicle speed increases, the number of AC voltage pulses increase. The VSS buffer processes inputs from the VSS and outputs signal to the speedometer control module and cruise module. The VSS buffer takes the voltage pulses from the VSS and uses them to open and close four solid state output switches to ground at a rate proportional to vehicle speed. The VSS buffer is matched to the vehicle based on final drive ratio and tire size. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Sensors and Switches Computers and Control Systems > Vehicle Speed Sensor > Component Information > Locations > Page 3618 Vehicle Speed Sensor: Service and Repair Speed sensor resistance should be 900-2000 ohms. The sensor is not serviceable and should be replaced if defective. The speed sensor is located on the transfer case. 1. Raise and support vehicle, then disconnect electrical connector from speed sensor. 2. Loosen sensor with suitable wrench. 3. Position suitable container under sensor, then remove sensor and O-ring. 4. Coat O-ring with transmission fluid, then install O-ring and speed sensor. 5. Torque sensor to 32 ft. lbs. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Shift Light > Component Information > Technical Service Bulletins > Shift Indicator Light Application and Operation Shift Light: Technical Service Bulletins Shift Indicator Light Application and Operation File In Section: 7 - Transmission Bulletin No.: 36-72-07A Date: February, 1995 Subject: Manual Transmission Shift Indicator Light Application and Operation Models: 1993-95 Chevrolet and GMC Truck C/K and S/T Models with Manual Transmission This bulletin is being revised to add the 1995 model year. Please discard bulletin number 367207 (Group Reference - Transmission). Certain trucks are not equipped with a shift indicator light. The shift light is commonly used to achieve improved fuel economy by prompting the driver when to upshift. Depending on the engine/transmission installed in the vehicle, the shift light can have the following characteristics: ^ Indicates proper shift point for maximum fuel economy. ^ Indicates engine over-speed. ^ Shift light is inoperative. The following charts detail normal shift light operation: 1993 Models: Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Shift Light > Component Information > Technical Service Bulletins > Shift Indicator Light Application and Operation > Page 3623 1994 Models: 1995 Models: Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Shift Light > Component Information > Technical Service Bulletins > Page 3624 Shift Light: Description and Operation Manual Transmission Shift Light Circuit PURPOSE The Manual Transmission Shift Light provides a display which indicates to the driver the optimum fuel economy point for upshifting the manual transmission based on engine speed and load. OPERATION Activation of the control module driver turns the lamp "ON". The Shift Light will stay "ON" for up to 5 seconds, so as to urge the driver to shift-up. The control module uses information from the following inputs to control the shift light: Engine Coolant Temperature (ECT) sensor. - Throttle Position (TP) sensor. - Vehicle Speed Sensor (VSS). - Engine RPM. The Shift Light will dim slightly when the headlights and/or parking lights are turned "ON". This is to give better driver visibility through the windshield. LOCATION The display lamp is on instrument panel. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Specifications Throttle Position Sensor: Specifications Idle Normal 0.45 to 0.95 V Maximum 1.25 V Wide Open Throttle 4.0 to 4.5 V Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Specifications > Page 3628 Engine Harness, Right Front Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions Throttle Position Sensor: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. Use this page as a reference to determine the meaning of an abbreviation if necessary. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery Bi-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CHMSL Center High Mount Stoplamp CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRO Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3631 F-PUMP Fuel Pump FLASH Flasher FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3632 SIR Supplemental Inflatable Restraint SKT Socket SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature TIL Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3633 example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE (ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: ^ Slide across the vehicle seat. ^ Sit down or stand up. ^ Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: ^ They are bumped or dropped. ^ They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3634 Symbols (Part 1 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3635 Symbols (Part 2 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3636 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3637 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3638 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3639 Throttle Position Sensor: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3640 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3641 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3642 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3643 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3644 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. ^ If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. ^ A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3645 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3646 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3647 Ohmmeter Meter Scales Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3648 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. ^ An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. ^ On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: ^ A range selector switch which permits the selection of different ranges of resistance. ^ A set adjust control which allows the meter to be set at zero for accurate measurements. ^ Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3649 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: ^ Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. ^ Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. ^ Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3650 be less than 10 percent of the total drop. When using a voltmeter: ^ Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. ^ Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. ^ The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: ^ Check the accuracy and completeness of the complaint. ^ Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3651 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. ^ The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3652 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3653 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3654 Twisted/Shielded Wire Repair Twisted Wires Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3655 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3656 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3657 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). ^ Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean ^ Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. ^ Roll crimp (13) and solder the terminal. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3658 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3659 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3660 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. ^ Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean ^ Terminal cavity of the connector body. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3661 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. ^ Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3662 C110 - TP Sensor Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 3663 Throttle Position (TP) Circuit Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Page 3664 Throttle Position Sensor: Description and Operation Wiring Diagram For Code 21 - Throttle Position Sensor (Signal Voltage High) NOTE Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE The Throttle Position Sensor (TPS) is a potentiometer that senses throttle angle and sends a signal to the PCM. The TP signal is one of the most important inputs used by the control module for fuel control and for most of the control module control outputs. OPERATION The TPS has three internal circuits provided by the control module. One to ground, a second from the control module as a 5.0 volt reference source and a third circuit is used by the control module to measure the output voltage. As the throttle angle changes (pressing down on accelerator pedal) the TPS voltage output varies from about .5 volt at idle to about 4.9 volts at wide open throttle (WOT). Each time the voltage drops below 1.25 volts and stops, the control module assumes this value is 0 throttle from this point on. LOCATION: Side of throttle body opposite of throttle lever. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Page 3665 Throttle Position Sensor: Adjustments The TPS is not adjustable. Each time voltage drops below 1.25 volts and stops, the control module assumes that this value is zero throttle angle and measures percent throttle from this point on. Therefore adjustment is not necessary. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Throttle Position Sensor > Component Information > Diagrams > Page 3666 Throttle Position Sensor: Service and Repair NOTE Since Throttle Position Sensor (TPS) configurations can be mounted interchangeably, be sure to order the correct one for your engine with identical part number of the one being replaced. Throttle Position (TP) Sensor REMOVE/DISCONNECT - Electrical connectors. - TPS attaching screw assemblies and retainer, (if applicable). - TPS from throttle body assembly. NOTE Do NOT immerse in any type of liquid solvent or cleaner, as damage may occur. INSTALL/CONNECT - With throttle valve in normally closed position, install TPS on throttle shaft with seal and rotate counter clockwise to align mounting hole. - Two attaching screw assemblies. Tighten screw assemblies to 2.0 Nm (18.0 lb-in). - Electrical connector to TPS. - Check for TPS output as follows: Connect an ALDL scanner to read TPS output voltage. - With ignition "ON" and engine stopped, TPS voltage should be less than 1.25 volts. If more than 1.25 volts, replace TPS. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Transmission Position Switch/Sensor, A/T > Component Information > Description and Operation Transmission Position Switch/Sensor: Description and Operation Automatic Transmission Electrical Components PURPOSE This device is a set of five presure switches (two normally closed and three normally open), that detect fluid pressure within the valve body passages and signals the PCM which transmission range is selected (PRNDL). OPERATION The five pressure switches are connected to three signal circuits referred to as range signals A, B, C. The combination of pressure switch states determines the voltage signal (B+ or 0) on each range signal to the PCM. LOCATION The transmission range fluid pressure switch assembly is attached to the control valve body within the transmission. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Vehicle Speed Sensor > Component Information > Technical Service Bulletins > Digital Ratio Adapter/Controller (DRAC) - Service Vehicle Speed Sensor: Technical Service Bulletins Digital Ratio Adapter/Controller (DRAC) Service Group Ref.: 8 - Chassis/Body Electrical Bulletin No.: 448301 Date: August, 1994 INFORMATION SUBJECT: NEW PROCEDURE FOR OBTAINING SERVICE DRACS (DIGITAL RATIO ADAPTOR/CONTROLLER) MODELS: 1989-94 CHEVROLET AND GMC TRUCK M/L VANS, S/T MODELS 1990-94 CHEVROLET AND GMC TRUCK G VANS, R/V MODELS 1992-94 CHEVROLET AND GMC TRUCK C/K MODELS 1991-94 OLDSMOBILE BRAVADA If a dealer is contacted about or is in need of a service DRAC (Digital Ratio Adaptor/Controller) for any of the following reasons: 1. Radio interference (EMI). 2. Speedometer fluctuation or flaring. 3. Erratic/surging cruise control operation. 4. Different tire size. 5. Defective part. The dealer must contact an AC-Delco Service Center authorized to repair electronic instrument clusters for a new service DRAC, P/N 16202915. NOTE: This part is a service part and has to be programmed for the vehicle. It cannot be used until this procedure has been done by the authorized Service Center. The dealer will need the P/N and the broadcast code (the 3 bold letters located on the printed label of the old DRAC). The Service Center will program the DRAC according to this information. If the customer is changing the tire size, the Service Center will need the axle ratio and tire sized in order to program the DRAC to the new tire specifications. The AC-Delco Service Center will send the programmed DRAC via common carrier to the dealership. For further information, consult the AC-Delco authorized Service Center Manual WA-2 (September 1990 or later). AC-Delco centers are subject to change. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Vehicle Speed Sensor > Component Information > Locations > Assembly View Vehicle Speed Sensor: Locations Assembly View LOCATION Mounted To Transmisssion Tailshaft. 2WD Automatic Transmission VSS 2WD (A/TRANS.) VEHICLE SPEED SENSOR 2WD Manual Transmission VSS 2WD Manual Transmission 4WD Automatic and Manual Transmission VSS 4WD Or AWD Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Vehicle Speed Sensor > Component Information > Locations > Assembly View > Page 3676 Speed Sensor, Backup Lamp Switch & Electric Shift Transfer Case Wiring Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Vehicle Speed Sensor > Component Information > Locations > Page 3677 C320 - Vehicle Speed Sensor Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Vehicle Speed Sensor > Component Information > Locations > Page 3678 Vehicle Speed Sensor: Description and Operation 2 Wheel Drive (Manual Transmission) VSS 2WD Manual Transmission 2 Wheel Drive (Automatic Transmission) VSS 2WD (A/TRANS.) VEHICLE SPEED SENSOR 4 Wheel Drive VSS 4WD Or AWD PURPOSE The Vehicle Speed Sensor (VSS) provides information to the control module for control of: Transmission Torque Converter Clutch (TCC) - Speedometer - Odometer - Cruise control Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Vehicle Speed Sensor > Component Information > Locations > Page 3679 - ANTILOCK brake system. CONSTRUCTION The VSS is made up of: Permanent Magnet (PM) generator (coil), which is mounted on the transmission. - Rotor (tooth), which is mounted on the output shaft in the transmission. - VSS Buffer, which is mounted to the control module bracket. OPERATION The VSS is a Permanent Magnet (PM) generator that produces a pulsing Alternating Current (AC) voltage as each rotor tooth nears the coil. As the vehicle speed increases, the number of AC voltage pulses increase. The VSS buffer processes inputs from the VSS and outputs signal to the speedometer control module and cruise module. The VSS buffer takes the voltage pulses from the VSS and uses them to open and close four solid state output switches to ground at a rate proportional to vehicle speed. The VSS buffer is matched to the vehicle based on final drive ratio and tire size. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Vehicle Speed Sensor > Component Information > Locations > Page 3680 Vehicle Speed Sensor: Service and Repair Speed sensor resistance should be 900-2000 ohms. The sensor is not serviceable and should be replaced if defective. The speed sensor is located on the transfer case. 1. Raise and support vehicle, then disconnect electrical connector from speed sensor. 2. Loosen sensor with suitable wrench. 3. Position suitable container under sensor, then remove sensor and O-ring. 4. Coat O-ring with transmission fluid, then install O-ring and speed sensor. 5. Torque sensor to 32 ft. lbs. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Vehicle Speed Sensor Signal Buffer > Component Information > Locations Vehicle Speed Sensor Signal Buffer: Locations Vehicle Speed Sensor Buffer And Electric Shift Transfer Case Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Vehicle Speed Sensor Signal Buffer > Component Information > Locations > Page 3684 Electric Shift Transfer Case Wiring Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Vehicle Speed Sensor Signal Buffer > Component Information > Locations > Page 3685 Vehicle Speed Sensor Signal Buffer: Diagrams C255 - Vehicle Speed Sensor Buffer C249 - Vehicle Speed Sensor Buffer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Vehicle Speed Sensor Signal Buffer > Component Information > Locations > Page 3686 Vehicle Speed Sensor Signal Buffer: Description and Operation The Vehicle Speed Sensor Buffer processes inputs from the Vehicle Speed Sensor (VSS) and outputs signals to the Speedometer, Powertrain Control Module (PCM) Cruise Control Module and the Four-Wheel Antilock Brake (4WAL) Module. The VSS is made up of a 4O-tooth rotor and a coil mounted on the transmission. As each rotor tooth nears the coil, the coil produces an AC voltage pulse. Each revolution of the rotor produces 40 AC voltage pulses. As the vehicle speed increases, the number of AC voltage pulses per second increases. The Vehicle Speed Sensor Buffer takes the voltage pulses from the VSS and uses them to open and close four Solid-State output switches to ground at a rate proportional to vehicle speed. The Speedometer switch opens and closes at the same rate as the VSS pulses. The PCM and Cruise Control switches open and close at half the rate of the VSS pulses. The 4WAL switch opens and closes at a rate seven times the VSS pulses. The Vehicle Speed Sensor Buffer is matched to the vehicle based on transmission, final drive ratio and tire size. It is important to ensure that the correct Vehicle Speed Sensor Buffer is installed in the vehicle if replacement is necessary. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Vehicle Speed Sensor Signal Buffer > Component Information > Testing and Inspection > Symptom Related Diagnostic Procedures Vehicle Speed Sensor Signal Buffer: Symptom Related Diagnostic Procedures Cruise Control Does Not Operate Properly (Part 1 Of 2) Cruise Control Does Not Operate Properly (Part 2 Of 2) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Vehicle Speed Sensor Signal Buffer > Component Information > Testing and Inspection > Symptom Related Diagnostic Procedures > Page 3689 Speed Sensor Components Do Not Operate Properly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Vehicle Speed Sensor Signal Buffer > Component Information > Testing and Inspection > Symptom Related Diagnostic Procedures > Page 3690 Vehicle Speed Sensor Signal Buffer: Component Tests and General Diagnostics The Vehicle Speed Sensor Buffer processes inputs from the Vehicle Speed Sensor (VSS) and outputs signals to the Speedometer, Powertrain Control Module (PCM) Cruise Control Module and the Four-Wheel Antilock Brake (4WAL) Module. The VSS is made up of a 4O-tooth rotor and a coil mounted on the transmission. As each rotor tooth nears the coil, the coil produces an AC voltage pulse. Each revolution of the rotor produces 40 AC voltage pulses. As the vehicle speed increases, the number of AC voltage pulses per second increases. The Vehicle Speed Sensor Buffer takes the voltage pulses from the VSS and uses them to open and close four Solid-State output switches to ground at a rate proportional to vehicle speed. The Speedometer switch opens and closes at the same rate as the VSS pulses. The PCM and Cruise Control switches open and close at half the rate of the VSS pulses. The 4WAL switch opens and closes at a rate seven times the VSS pulses. The Vehicle Speed Sensor Buffer is matched to the vehicle based on transmission, final drive ratio and tire size. It is important to ensure that the correct Vehicle Speed Sensor Buffer is installed in the vehicle if replacement is necessary. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Computers and Control Systems > Voltage Signal > Component Information > Description and Operation Voltage Signal: Description and Operation PURPOSE Inform the control module that there is a basic generator over voltage problem. OPERATION PCM/ECM If voltage is greater than 19.5 volts for 2 seconds at PCM terminal "E16" (ECM is "C16"), the control module sets Diagnostic Trouble Code 53, the automatic transmission pressure control solenoid is turned "OFF", the automatic transmission shifts immediately to third gear, and TCC operation is inhibited. (the setting of additional DTC's may result.) VCM If voltage is greater than 17.1 volts at VCM terminal "GR2" sets Diagnostic Fault Code P1632. For 2 seconds after the fault is detected, the VCM will disengage its outputs. This may result in additional DTC's being set. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Air Injection > Air Injection Vacuum Control Solenoid Valve > Component Information > Diagrams C180 - Air Switching Solenoid Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Catalytic Converter > Component Information > Locations Exhaust Layout S/T 2WD PUP 4.3L Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Catalytic Converter > Component Information > Locations > Page 3702 Catalytic Converter: Description and Operation CAUTION Prolonged operation with a misfiring or flooded engine may cause the converter to overheat. This could cause damage either to the catalyst itself or the operating vehicle and possible personal injury. NOTE When jacking or lifting vehicle from frame side rails, be certain lift pads DO NOT contact catalytic converter or damage to converter may result. Catalytic Converters Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Catalytic Converter > Component Information > Locations > Page 3703 PURPOSE The catalytic converter is an emission control device added to the exhaust system to effectively reduce the levels of carbon monoxide, hydrocarbons, and in some cases oxides of nitrogen, entering the atmosphere. The converter serves two purposes: it permits a faster chemical reaction to take place and although it enters into the chemical reaction, it remains unchanged, ready to repeat the process. CONSTRUCTION AND OPERATION General Motors uses four different converter designs in conjunction with two types of catalysts. The four converter designs, are: single bed monolith, dual bed monolith, single bed pellet and dual bed pellet. The two types of catalysts used are an oxidation catalyst and a three-way (reduction) catalyst. The oxidation catalyst is coated with material containing platinum and palladium which lowers levels of carbon monoxide and hydrocarbons. The three-way (reduction) catalyst is coated with platinum and rhodium which lowers levels of oxides of nitrogen (NOx), as well as carbon monoxide and hydrocarbons. All dual bed converters, whether monolith or pellet type, contain both oxidation and three-way catalysts. Due to its high operating temperatures, the catalytic converter usually requires the use of heat shields. Heat shields are necessary to protect chassis components, passenger compartment and other areas from heat related damage. A fill pipe restrictor is used on catalytic converter equipped vehicles, to prevent the larger service station pump nozzle, used for leaded fuels, being inserted into the filler tube. Since the use of leaded fuels contaminates the catalysts, rendering them ineffective, the use of unleaded fuels is mandatory in catalytic converter equipped vehicles. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Catalytic Converter > Component Information > Locations > Page 3704 Restricted Exhaust System Check Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Evaporative Emissions System > Evaporative Canister Filter > Component Information > Locations Vapor Canister 2.5;2.8;4.3;5.0;5.7;7.4L Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Evaporative Emissions System > Evaporative Canister Filter > Component Information > Service and Repair > Fuel Evaporative Canister Filter Replacement Evaporative Canister Filter: Service and Repair Fuel Evaporative Canister Filter Replacement PROCEDURE At intervals recommended, usually every 24 months or 30,000 miles, the filter on an open bottom canister should be replaced, - Remove all hoses from the top of the canister and mark. Remove the canister. - Remove the filter element by squeezing it out from under the lip surface at bottom of canister and from under retainer bar, where used. - Squeeze the new element under retainer bar, where used, and position it evenly around the entire bottom of the canister. Tuck the edges under the lip of canister. - Reinstall the canister to its original position on the vehicle, following normal service procedures. - Reconnect the hoses to the top of the canister, according to the labeling on top of canister. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Evaporative Emissions System > Evaporative Canister Filter > Component Information > Service and Repair > Fuel Evaporative Canister Filter Replacement > Page 3711 Evaporative Canister Filter: Service and Repair EVRV Filter Replacement EVRV Filter Replacment Removal and Installation - Grasp and pull the filter OFF with a rocking motion. - Push the new filter on making sure that the cut-out for the wires is properly aligned. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Evaporative Emissions System > Evaporative Emission Control Canister > Component Information > Specifications Evaporative Emission Control Canister: Specifications Canister Torque Values Canister Torque Values Vapor Canister Bracket Bolt 19 ft.lb Vapor Canister Clamp Bolt 7 ft.lb Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Evaporative Emissions System > Evaporative Emission Control Canister > Component Information > Service and Repair > Vapor Canister Replacement Evaporative Emission Control Canister: Service and Repair Vapor Canister Replacement Removal - Remove hoses from canister. Mark hoses for installation of new canister. - Remove screw from bracket and canister. Installation - Install new canister and secure to bracket with screw. - Connect hoses to canister making sure hoses are connected to the correct ports. - Check operation of new canister. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Evaporative Emissions System > Evaporative Emission Control Canister > Component Information > Service and Repair > Vapor Canister Replacement > Page 3717 Evaporative Emission Control Canister: Service and Repair Vapor Canister Hose Replacement Refer to "Vehicle Emission Control Information" underhood label for proper routing of the canister hoses. When replacing hoses, only use hose that is identified with the word "Flouroelastomer". Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Exhaust Gas Recirculation > EGR Control Solenoid > Component Information > Specifications EGR Control Solenoid: Specifications Solenoid To Bracket Torque Solenoid To Bracket Torque EVRV Solenoid to Bracket 18 in.lb Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Exhaust Gas Recirculation > EGR Control Solenoid > Component Information > Locations > EGR Solenoid EGR Solenoid 4.3Z Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Exhaust Gas Recirculation > EGR Control Solenoid > Component Information > Locations > EGR Solenoid > Page 3724 EGR Solenoid 4.3Z Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Exhaust Gas Recirculation > EGR Control Solenoid > Component Information > Locations > Page 3725 EGR Control Solenoid: Service and Repair Top Of Engine REMOVE/DISCONNECT - Negative battery cable. - Air cleaner, if necessary. - Electrical connector at solenoid. - Vacuum hoses. - Bolts and solenoid. - Filter, if required. INSTALL/CONNECT - Filter, if required. - Solenoid. Tighten bolts to 24 N-m (17 lb.ft.). - Vacuum hoses. - Electrical connector to solenoid. - Air cleaner, if removed. - Negative battery cable. - Check system to ensure proper operation. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Exhaust Gas Recirculation > EGR Electronic Vacuum Regulator Solenoid > Component Information > Locations Engine Harness, Right Front Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Exhaust Gas Recirculation > EGR Filter > Component Information > Service and Repair EGR Filter: Service and Repair EVRV Filter Replacment REMOVE AND INSTALL - Grasp and pull the filter OFF with a rocking motion. - Push the new filter on making sure that the cut-out for the wires is properly aligned. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Exhaust Gas Recirculation > EGR Valve > Component Information > Technical Service Bulletins > Linear EGR - Installation Procedure Revision EGR Valve: Technical Service Bulletins Linear EGR - Installation Procedure Revision FILE IN SECTION: 6E - Engine Fuel & Emission BULLETIN NO.: 51-65-32 DATE: May, 1995 SUBJECT: Section 6E3, 9, 9C, 9A - Driveability and Emissions - Revised Linear EGR installation Procedure MODELS: 1992-95 Chevrolet and GMC Truck M/L Vans 1992-95 Chevrolet and GMC Truck S/T Models 1993-95 Chevrolet and GMC Truck C/K Models 1994-95 Chevrolet and GMC Truck G Vans 1994-95 Chevrolet and GMC Truck P3, P/G Chassis 1992-93 Oldsmobile Bravada with 4.3L, 7.4L Engines (VINs W, N - RPOs L35, L19) and (VIN Z - RPO LB4 - with California Emissions) This service bulletin revises the Linear EGR installation Procedure, in the following service manuals: 1992-93 Oldsmobile Bravada Service Manual, page 6E3-C7-6. 1992-93 Light Duty Truck, Fuel and Emissions Service Manual, pages 9-19 and 90-6. 1994-95 S/T Driveability Emissions and Electrical Diagnosis Service Manual and the 1994 S/T Truck Supplement with RPO CTF, page 9A-8. 1994-95 C/K, M/L, G Van and P/G and P3 Chassis Driveability Emissions and Electrical Diagnosis Service Manuals, page 9A-6. The revised procedure is as follows: Install or Connect 1. EGR valve and new gasket. 2. Valve to flange bolts. Tighten Tighten bolts in two steps. a. The first step to 10 Nm (89 lb.in.). b. The second step to 25 Nm (18 lb.ft.). 3. Electrical connector. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Exhaust Gas Recirculation > EGR Valve > Component Information > Technical Service Bulletins > Page 3736 EGR Valve: Specifications Valve To Intake Manifold Torque Valve To Intake Manifold Torque EGR Valve to Intake Manifold 17 ft.lb Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Exhaust Gas Recirculation > EGR Valve > Component Information > Technical Service Bulletins > Page 3737 EGR Valve Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Exhaust Gas Recirculation > EGR Valve > Component Information > Technical Service Bulletins > Page 3738 EGR Valve: Description and Operation PURPOSE The Exhaust Gas Recirculation (EGR) system is designed to lower NOx (oxides of nitrogen) emission levels created by high combustion temperatures. EGR System OPERATION The EGR system routes exhaust gases from the exhaust manifold to the intake manifold at specified engine operating conditions. The EGR valve is opened by ECM/PCM controlled vacuum and engine exhaust backpressure which allows exhaust gas to flow into the intake manifold. The exhaust gas then moves with the air/fuel mixture into the combustion chamber. Since there is less air/fuel mixture to burn in the combustion chamber during EGR operation, the temperature is reduced enough to limit NOx formation. If too much exhaust gas enters, combustion will NOT occur. Because of this, very little exhaust gas is allowed to pass through the valve, especially at idle. The valve should only open when the engine is at operating temperature and above idle speed. Variations in vacuum and exhaust backpressure, control the amount of exhaust gas recirculation. EGR Valve The port EGR valve is controlled by a flexible diaphragm which is spring loaded to hold the valve closed. Vacuum applied to the top side of the diaphragm overcomes the spring pressure and opens the valve in the exhaust gas port. This allows the exhaust gas to be pulled into the intake manifold and enter the engine cylinders. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Exhaust Gas Recirculation > EGR Valve > Component Information > Technical Service Bulletins > Page 3739 IDENTIFICATION EGR Valve Identification The ported EGR valve is identified by having NO identification number or letter stamped after the part number. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Exhaust Gas Recirculation > EGR Valve > Component Information > Service and Repair > EGR Intake Manifold Cleaning EGR Valve: Service and Repair EGR Intake Manifold Cleaning PROCEDURE WARNING Appropriate eye protection should be worn when cleaning the EGR system to prevent injury to eyes. CAUTION When cleaning intake manifold EGR passages, care should be taken to ensure that all loose particles are completely removed to prevent them from clogging the EGR valve or from being ingested into the engine, as damage to system or engine may occur. - Remove throttle body. - Disconnect vacuum hose or electrical connector from EGR valve, then remove EGR valve to manifold retaining bolts and valve. - Remove deposits from EGR ports by hand using a suitable drill bit and screwdriver. - Brush small deposits down EGR port into passages, then using compressed air, blow ports clean. Solvents should not be used to clean EGR valve or passages, since damage to system may result. - Install EGR valve, using new gasket. - Install throttle body. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Exhaust Gas Recirculation > EGR Valve > Component Information > Service and Repair > EGR Intake Manifold Cleaning > Page 3742 EGR Valve: Service and Repair EGR Valve Cleaning PROCEDURE WARNING Appropriate eye protection should be worn when cleaning the EGR system to prevent injury to eyes. CAUTION DO NOT wash the EGR valve in solvents or degreaser as permanent damage to the valve diaphragm or electrical connection may result. Also, sand blasting of the valve is not recommended since this can affect the operation of the valve. - With a wire wheel, buff the exhaust deposits from the mounting surface and around the valve. - Look for exhaust deposits in the valve outlet. Remove deposit build up with a screwdriver. - Clean the mounting surfaces of the intake manifold and valve assembly. - Install valve assembly using new gasket. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Exhaust Gas Recirculation > EGR Valve > Component Information > Service and Repair > EGR Intake Manifold Cleaning > Page 3743 EGR Valve: Service and Repair Port EGR Valve Replacement EGR Valve REMOVE - Air cleaner. - EGR valve vacuum tube at valve. - Bolts or nuts. - EGR valve and gasket from manifold. Discard gasket. INSPECT If the EGR passage indicates excessive build up of deposits, the passage should be cleaned Care should be taken to ensure that all loose particles are completely removed to prevent them from clogging the EGR valve of from being ingested into the engine. CLEAN CAUTION Do NOT wash the EGR valve in solvents or degreaser as permanent damage to the valve diaphragm may result. Sand blasting of the valve is not recommended since this can affect the operation of the valve. - With a wire wheel, buff exhaust deposits from mounting surface around valve - Look for exhaust deposits in the valve outlet Remove deposit build up with a screwdriver - Clean mounting surfaces of intake manifold and valve assembly INSTALL - New EGR gasket. - EGR valve onto manifold. - Bolts or nuts. Torque to 24 Nm (17 ft.lb). - Vacuum tube to EGR valve. - Air cleaner assembly. - Check operation of EGR system to ensure correct operation. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Fillpipe Restrictor > Component Information > Description and Operation Fillpipe Restrictor: Description and Operation Fuel Filler Neck Fuel Door And Restrictor (Typical) Purpose To prevent refueling with leaded fuel, the fuel filter neck has a built-in restrictor and deflector. The opening in the restrictor will accept only the smaller unleaded gasoline fuel nozzle which must be fully inserted to bypass the deflector. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Fillpipe Restrictor > Component Information > Description and Operation > Page 3747 Fillpipe Restrictor: Testing and Inspection Fuel Door And Restrictor (Typical) Fuel Filler Neck The fillpipe restrictor should prevent insertion of special dowel with a diameter same as that of leaded fuel pump nozzles (0.950"). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Positive Crankcase Ventilation > Crankcase Filter > Component Information > Service and Repair Crankcase Filter: Service and Repair Inspection The crankcase ventilation system should be checked every 30,000 miles and also during regular engine tune-ups. If the crankcase ventilation system includes a breather filter, located in the air cleaner housing, this filter should be replaced whenever the crankcase ventilation valve or air cleaner is replaced. When a periodic inspection indicates the crankcase ventilation is not functioning properly, it should be serviced by replacement only. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Positive Crankcase Ventilation > Positive Crankcase Ventilation Valve > Component Information > Locations Crankcase Ventilation 4.3Z Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Positive Crankcase Ventilation > Positive Crankcase Ventilation Valve > Component Information > Locations > Page 3755 Positive Crankcase Ventilation Valve: Service and Repair Inspection The crankcase ventilation system should be checked every 30,000 miles and also during regular engine tune-ups. If the crankcase ventilation system includes a breather filter, located in the air cleaner housing, this filter should be replaced whenever the crankcase ventilation valve or air cleaner is replaced. When a periodic inspection indicates the crankcase ventilation is not functioning properly, it should be serviced by replacement only. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Thermostatic Air Cleaner > Component Information > Description and Operation Thermostatic Air Cleaner: Description and Operation Air Cleaner With Heated Air Intake System Thermac Operation DESCRIPTION A heated intake air system is used for good driveability under varying climatic conditions. Having a uniform inlet air temperature improves fuel vaporization. OPERATION The THERMAC system regulates in incoming air temperature without the use of vacuum. The air regulating damper is controlled by means of a self contained, wax pellet actuated assembly mounted in the air cleaner. When incoming air is cold, the wax material sealed in the actuator is in a solid phase and the damper closes off the cold air inlet. This causes all incoming air to be heated by the exhaust manifold. As the incoming air warms, the wax material expands changing to a liquid phase which forces out a piston to reposition the damper allowing a cold and hot air mix or all cold air to enter the engine. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Emission Control Systems > Thermostatic Air Cleaner > Component Information > Description and Operation > Page 3759 Thermostatic Air Cleaner: Testing and Inspection Results of Incorrect Operation Hesitation during warm up can be caused by: Heat stove tube disconnected. - Missing or damaged air cleaner to TBI gasket. - Loose air cleaner cover and air cleaner. - Missing air cleaner cover seal. - Stuck open damper door. Lack of power, sluggish, pinging or spongy, on a hot engine check for: Stuck closed damper door. Air Cleaner Functional Check - Remove air cleaner assembly and cool to below 4°C (40°F). The damper should be closed to outside air (cold air). - Check condition of air cleaner to throttle body gasket. - Reinstall air cleaner and connect heat stove tube at air cleaner snorkel and exhaust manifold. - Start engine. Watch damper door in air cleaner snorkel. As air cleaner warms up, damper door should open slowly to outside air (cold air). - If air cleaner fails to operate as described, be sure calibrated spring is properly installed and damper door is not binding. - If still inoperative after last step, replace wax pellet actuator assembly and recheck Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Pressure > Diagnostic Connector - Fuel Pump > Component Information > Locations Component Location - "S/T" 4.3Z Utility - Manual Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Pressure Release > System Information > Service and Repair Fuel Pressure Release: Service and Repair WARNING To reduce the risk of fire and personal injury, it is necessary to relieve fuel system pressure before servicing fuel system components. A small amount of fuel may be released when servicing fuel lines or connections. In order to reduce the chance of personal injury, cover fuel line fittings with a shop towel before disconnecting to catch any fuel that may leak out. Place the towel in an approved container when disconnect is complete. PROCEDURE - Disconnect negative battery terminal to avoid possible fuel discharge if an accidental attempt is made to start the engine. - Loosen fuel filler cap to relieve tank vapor pressure. (Do not tighten until service has been completed.) - The TBI model 220 contains a constant bleed feature in the pressure regulator that relieves pressure. Therefore, no further action is required. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Idle Speed > System Information > Technical Service Bulletins > Idle Speed - Specification Revised Idle Speed: Technical Service Bulletins Idle Speed - Specification Revised File In Section: 6E - Engine Fuel & Emission Bulletin No.: 41-65-22 Date: September, 1994 SERVICE MANUAL UPDATE Subject: Section 4 - Revised Controlled Idle Speed Specification Models: 1994 Chevrolet and GMC Truck Light Duty Models 1994 Oldsmobile Bravada with Gasoline Engines Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Idle Speed > System Information > Technical Service Bulletins > Idle Speed - Specification Revised > Page 3772 This service bulletin supersedes Service Manual information for the Controlled Idle Speed Specification on Page 4-3 of the Driveability, Emissions, and Electrical Diagnosis Manual. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Idle Speed > System Information > Technical Service Bulletins > Page 3773 Idle Speed: Specifications Refer to Adjustment Procedures Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Accelerator Pedal > Component Information > Locations Accelerator Pedal: Locations Control Cable And Linkage Accelerator Pedal Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Accelerator Pedal > Component Information > Locations > Page 3777 Accelerator Pedal: Service and Repair Accelerator Pedal Assembly ACCELERATOR PEDAL When performing service on the accelerator pedal, observe the following: The mounting surface between the support and dash panel must be free of insulation. The carpet and padding in the pedal and tunnel area must be positioned to lay flat and be free of wrinkles and bunches. - Slip the accelerator control cable through the slot in the rod and then install the retainer in the rod, makeing sure it is seated. Use care when pressing the retainer into the hole in the rod to ensure that the cable is not kinked or damaged in any way. - After securing all components of the accelerator linkage, the linkage must operate freely without binding between full closed throttle and full wide open throttle. - Wires, hoses, cables or other obstructions must not be placed within 13 mm (1/2 inch) of the cable or the rod at any point in their travel. Control Cable And Linkage ACCELERATOR CONTROL CABLE Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Accelerator Pedal > Component Information > Locations > Page 3778 When performing service on the accelerator control cable, observe the following: The retainer must be installed with the tangs secured overhead of the stud. - The conduit fitting at both ends of the cable must have the locking tangs expanded and locked in the attaching holes. - The braided portion of the accelerator cable assembly must not come in contact with the front of the dash sealer during assembly, repair, or replacement of the assembly. - The flexible components (hoses, wires, conduits, etc.) must not be routed within 50 mm (2 inches) of the moving parts of the accelerator linkage outboard of the support unless the routing is positively controlled. REMOVE/DISCONNECT - Retainer from throttle lever stud - Retainer locking tangs from support bracket - Retainer from accelerator pedal rod or release cable from rod. - Retainer locking tangs from dash panel INSTALL/CONNECT - Retainer to dash panel. - Retainer to accelerator pedal rod or connect cable in rod slot. - Retainer to support bracket. - Retainer to throttle lever stud or connect cable to pulley. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > Customer Interest: > 04-07-30-013B > Feb > 07 > Engine, A/T - Shift/Driveability Concerns/MIL ON Air Filter Element: Customer Interest Engine, A/T - Shift/Driveability Concerns/MIL ON Bulletin No.: 04-07-30-013B Date: February 01, 2007 INFORMATION Subject: Automatic Transmission Shift, Engine Driveability Concerns or Service Engine Soon (SES) Light On as a Result of the Use of an Excessively/Over-Oiled Aftermarket, Reusable Air Filter Models: 2007 and Prior GM Cars and Light Duty Trucks 2007 and Prior Saturn Models 2003-2007 HUMMER H2 2006-2007 HUMMER H3 2005-2007 Saab 9-7X Supercede: This bulletin is being revised to add models and model years. Please discard Corporate Bulletin Number 04-07-30-013A (Section 07 - Transmission/Transaxle). The use of an excessively/over-oiled aftermarket, reusable air filter may result in: Service Engine Soon (SES) light on Transmission shift concerns, slipping and damaged clutch(es) or band(s) Engine driveability concerns, poor acceleration from a stop, limited engine RPM range The oil that is used on these air filter elements may be transferred onto the Mass Air Flow (MAF) sensor causing contamination of the sensor. As a result, the Grams per Second (GPS) signal from the MAF may be low and any or all of the concerns listed above may occur. When servicing a vehicle with any of these concerns, be sure to check for the presence of an aftermarket reusable, excessively/over-oiled air filter. The MAF, GPS reading should be compared to a like vehicle with an OEM air box and filter under the same driving conditions to verify the concern. The use of an aftermarket reusable air filter DOES NOT void the vehicle's warranty. If an aftermarket reusable air filter is used, technicians should inspect the MAF sensor element and the air induction hose for contamination of oil prior to making warranty repairs. Transmission or engine driveability concerns (related to the MAF sensor being contaminated with oil) that are the result of the use of an aftermarket reusable, excessively/over-oiled air filter are not considered to be warrantable repair items. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > Customer Interest: > 04-07-30-013B > Feb > 07 > Engine, A/T - Shift/Driveability Concerns/MIL ON > Page 3788 Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 04-07-30-013B > Feb > 07 > Engine, A/T - Shift/Driveability Concerns/MIL ON Air Filter Element: All Technical Service Bulletins Engine, A/T - Shift/Driveability Concerns/MIL ON Bulletin No.: 04-07-30-013B Date: February 01, 2007 INFORMATION Subject: Automatic Transmission Shift, Engine Driveability Concerns or Service Engine Soon (SES) Light On as a Result of the Use of an Excessively/Over-Oiled Aftermarket, Reusable Air Filter Models: 2007 and Prior GM Cars and Light Duty Trucks 2007 and Prior Saturn Models 2003-2007 HUMMER H2 2006-2007 HUMMER H3 2005-2007 Saab 9-7X Supercede: This bulletin is being revised to add models and model years. Please discard Corporate Bulletin Number 04-07-30-013A (Section 07 - Transmission/Transaxle). The use of an excessively/over-oiled aftermarket, reusable air filter may result in: Service Engine Soon (SES) light on Transmission shift concerns, slipping and damaged clutch(es) or band(s) Engine driveability concerns, poor acceleration from a stop, limited engine RPM range The oil that is used on these air filter elements may be transferred onto the Mass Air Flow (MAF) sensor causing contamination of the sensor. As a result, the Grams per Second (GPS) signal from the MAF may be low and any or all of the concerns listed above may occur. When servicing a vehicle with any of these concerns, be sure to check for the presence of an aftermarket reusable, excessively/over-oiled air filter. The MAF, GPS reading should be compared to a like vehicle with an OEM air box and filter under the same driving conditions to verify the concern. The use of an aftermarket reusable air filter DOES NOT void the vehicle's warranty. If an aftermarket reusable air filter is used, technicians should inspect the MAF sensor element and the air induction hose for contamination of oil prior to making warranty repairs. Transmission or engine driveability concerns (related to the MAF sensor being contaminated with oil) that are the result of the use of an aftermarket reusable, excessively/over-oiled air filter are not considered to be warrantable repair items. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 04-07-30-013B > Feb > 07 > Engine, A/T - Shift/Driveability Concerns/MIL ON > Page 3794 Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Other Service Bulletins for Air Filter Element: > 99-01-39-004C > Jun > 09 > A/C - Musty Odors Emitted From (HVAC) System Evaporator Core: All Technical Service Bulletins A/C - Musty Odors Emitted From (HVAC) System TECHNICAL Bulletin No.: 99-01-39-004C Date: June 12, 2009 Subject: Air Conditioning Odor (Install Evaporator Core Dryer Kit and Apply Cooling Coil Coating) Models: 1993-2010 GM Passenger Cars and Trucks (Including Saturn) 2010 and Prior HUMMER H2, H3 All Equipped with Air Conditioning Supercede: This bulletin is being revised to add the 2009 and 2010 model years. Please discard Corporate Bulletin Number 99-01-39-004B (Section 01 - HVAC). Condition Some customers may comment about musty odors emitted from the Heating, Ventilation and Air Conditioning (HVAC) system at vehicle start-up in hot, humid conditions. Cause This condition may be caused by condensate build-up on the evaporator core, which does not evaporate by itself in high humidity conditions. The odor may be the result of microbial growth on the evaporator core. When the blower motor fan is turned on, the microbial growth may release an unpleasant musty odor into the passenger compartment. There are several other possible sources of a musty odor in a vehicle. A common source is a water leak into the interior of the vehicle or foreign material in the HVAC air distribution system. Follow the procedures in SI for identifying and correcting water leaks and air inlet inspection. The procedure contained in this bulletin is only applicable if the odor source has been determined to be microbial growth on the evaporator core inside the HVAC module. Correction Many vehicles currently incorporate an afterblow function within the HVAC control module software. The afterblow feature, when enabled, employs the HVAC blower fan to dry the evaporator after vehicle shut down and this function will inhibit microbial growth. Technicians are to confirm that the customer concern is evaporator core odor and that the vehicle has the imbedded afterblow feature, as defined in the SI document for that specific vehicle model, model year and specific HVAC option. Refer to SI for enabling the afterblow function. Vehicles being delivered in areas prone to high humidity conditions may benefit from having the afterblow enabled calibration installed prior to any customer comment. Important If the vehicle is not factory equipped with the imbedded afterblow enable feature, it may be added with the Electronic Evaporator Dryer Module Kit (P/N 12497910 or AC Delco 15-5876). Important When installing the Electronic Evaporator Dryer Module, you MUST use the included electrical splice connectors to ensure a proper splice. Complete detailed installation instructions and self testing procedures are supplied with the kit. If necessary, the Electronic Evaporator Dryer Module may be installed underhood if it is protected from extreme heat and water splash areas. To immediately remove the evaporator core odor on all suspect vehicles, it is necessary to eliminate the microbial growth and prevent its re-occurrence. To accomplish this, perform the following procedure: Vehicle and Applicator Tool Preparation 1. The evaporator core must be dry. This may be accomplished by disabling the compressor and running the blower fan on the recirc heat setting for an extended period of time. Note Compressor engagement will cause the evaporator core to remain wet and will prevent full adherence of the Coiling Coil Coating to the evaporator core surfaces. 2. Verify that the air conditioning drain hose is not clogged and place a drain pan beneath the vehicle. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Other Service Bulletins for Air Filter Element: > 99-01-39-004C > Jun > 09 > A/C - Musty Odors Emitted From (HVAC) System > Page 3800 3. Place a protective cover over the carpet below the evaporator core. 4. Remove the cabin air filter, if equipped, and cover the opening prior to applying the Cooling Coil Coating, as the product may clog the filter. If the cabin air filter appears to have little or no remaining life, suggest a replacement to your customer. 5. If the HVAC module has a blower motor cooling tube, be careful NOT TO SPRAY THE COOLING COIL COATING INTO THE BLOWER MOTOR COOLING TUBE. 6. Attach the Flexible Applicator Pressure Spray Tool (J-43810-20A) to a compressed air line operating at 586 kPa (85 psi) to 793 kPa (115 psi). 7. Shake the bottle of Cooling Coil Coating well. Screw the bottle onto the cap on the applicator tool's pick-up tube. Note The pick-up tube is designed for 120 ml (4 oz) and 240 ml (8 oz) bottles and should coil slightly in the bottom of a 120 ml (4 oz) bottle. 8. Use one of the following three methods to apply the Cooling Coil Coating. Important If the Pressure Applicator Spray Tool (J-43810-20A) is not available, the Cooling Coil Coating is also available in an aerosol can (P/N 12377951 (in Canada, 10953503)). Application Through Blower Motor Control Module Opening - Remove the blower motor control module (blower motor resistor). Refer to the applicable procedure in SI. - Clean any debris or foreign material from inside the HVAC module and on the evaporator core surface. - Apply the Cooling Coil Coating directly to the evaporator core through the blower motor blower motor control module (blower motor resistor) opening. - Use the flexible wand to direct the Cooling Coil Coating over the entire evaporator core and surrounding gasket surfaces. - When the application is complete, install the blower motor blower motor control module (blower motor control module). Application Through Blower Motor Opening - Remove the blower motor. Refer to the applicable blower motor removal procedure in SI. - Clean any debris or foreign material from inside the HVAC module and on the evaporator core surface. - Apply the Cooling Coil Coating directly to the evaporator core through the blower motor opening. - Use the flexible wand to direct the Cooling Coil Coating over the entire evaporator core and surrounding gasket surfaces. - When the application is complete, install the blower motor. Application Through a Hole in the HVAC Module - If neither of the two previous application methods are available, it may be necessary to drill a hole in the HVAC module. - Locate an area of the HVAC module between the blower motor and the evaporator core. Drill a 10 mm (3/8 in) hole in the HVAC module. Use caution to keep the drill clear of the evaporator core and the blower motor fan. - With the air distribution vents closed and the blower motor fan speed on HIGH, insert the applicator tool into the hole and spray the Cooling Coil Coating into the airstream toward the evaporator core. - Use a GM approved RTV sealant to plug the hole in the HVAC module. 9. After the Cooling Coil Coating application is complete, start and run the vehicle for approximately 10 minutes, with the compressor disabled, HVAC mode set to Recirculate/Max, heat set to full warm, blower motor fan speed on high, and one window open approximately 12 mm (1/2 in). This cures the Cooling Coil Coating onto the evaporator core surface. 10. While the engine is running, rinse the applicator tool with warm water to prolong the life of the tool. Be sure to spray warm water through the nozzle to rinse out any residual Cooling Coil Coating still in the capillary pick up tube, otherwise it will dry and clog the applicator tool. Also remove the small green valve from the bottle cap and rinse it thoroughly while rolling it between two fingers and then reinstall it. If this valve is clogged , the Cooling Coil Coating will not flow through the applicator tool. 11. Shut off the engine and enable the compressor again. 12. Verify proper HVAC system operation. 13. Remove the protective cover from inside the vehicle. 14. Remove the drain pan from underneath the vehicle. 15. Reinstall the cabin air filter if necessary. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Other Service Bulletins for Air Filter Element: > 99-01-39-004C > Jun > 09 > A/C - Musty Odors Emitted From (HVAC) System > Page 3801 Parts Information Important The Cooling Coil Coating listed below is the only GM approved product for use under warranty as an evaporator core disinfectant and for the long term control of evaporator core microbial growth. Warranty Information For vehicles repaired under warranty, use the table above. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Other Service Bulletins for Air Filter Element: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates Evaporator Core: All Technical Service Bulletins A/C - Odor at Start up in Humid Climates File In Section: 1 - HVAC Bulletin No.: 53-12-12A Date: December, 1996 Subject: Air Conditioning Odor at Start Up in Humid Climates (Disinfect Evaporator Core, Install Delayed Blower Control Package) Models: 1993-96 Passenger Cars (Except GEO) 1993-96 Light Duty Models (Except Tracker) This bulletin is being revised to update the wiring diagrams, add the Corvette (with RPO C60) and delete medium/heavy duty trucks. Please discard Corporate Bulletin Number 53-12-12 (Section 1 HVAC). Condition Some owners may comment on odors emitted from the air conditioning system, primarily at start up in hot, humid climates. Cause This odor may be the result of microbial growth on the evaporator core. When the blower motor fan is turned on, the microbial growth may release an unpleasant musty odor into the passenger compartment. Correction To remove odors of this type, it is necessary to eliminate the microbial growth and prevent its recurrence. To accomplish this, these two procedures must be completed. ^ Deodorize the evaporator core using Deodorizing Aerosol Kit, P/N 12377951 (AC Delco 15-102). ^ Install the new A/C Delayed Blower Control Package, P/N 12370470, (AC Delco 15-8632). The blower control package will enable the blower to run at high speed for five (5) minutes. It will do so approximately fifty (50) minutes after the ignition has been turned off if the compressor had been engaged for four (4) or more minutes prior to shutting off engine. By doing so, the evaporator case and core are dried out, reducing the chances of a recurring A/C odor. Procedure 1. Visually inspect the air conditioning evaporator drain hose for obstructions or working condition. 2. Apply deodorizing aerosol as described in the instructions supplied with the kit. Once the deodorizer has been applied, some of the mixture may overflow from the drain hose. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Other Service Bulletins for Air Filter Element: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 3806 3. The chart identifies specific instructions for each vehicle. This chart will identify the proper deodorizing procedure, template and wiring diagram. Deodorizing the evaporator case can easily be done by removing the blower motor resistor and tape off opening. The nozzle can now be inserted through a pierced hole in the tape to deodorize the evaporator case. For some of the vehicles specified below, a drilling procedure is identified in the deodorizing instructions. This type of alternative procedure and others can be done by using the referenced templates in the chart. 4. Complete detailed installation instructions are supplied with the blower control package. Important: A. 1996 ONLY (Use blower resistor location for drilling procedure) B. 1994-1996 ONLY Refer to appropriate Service Manual for enabling afterblow feature through on-board diagnostics. Parts Information Parts are currently available from GMSPO. Warranty Information Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Other Service Bulletins for Air Filter Element: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 3807 For vehicles repaired under warranty, use as shown. Figure 1 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Other Service Bulletins for Air Filter Element: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 3808 Figure 2 Figure 3 Figure 4 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Other Service Bulletins for Air Filter Element: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 3809 Figure 5 Figure 6 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Other Service Bulletins for Air Filter Element: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 3810 Figure 7 Figure 8 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Other Service Bulletins for Air Filter Element: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 3811 Figure 9 Figure 10 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Other Service Bulletins for Air Filter Element: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 3812 Figure 11 Figure 12 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Other Service Bulletins for Air Filter Element: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 3813 Figure 13 Figure 14 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Other Service Bulletins for Air Filter Element: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 3814 Figure 15 Figure 16 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Other Service Bulletins for Air Filter Element: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 3815 Figure 17 Figure 18 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Other Service Bulletins for Air Filter Element: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 3816 Figure 19 Figure 20 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Other Service Bulletins for Air Filter Element: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 3817 Figure 21 Figure 22 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Other Service Bulletins for Air Filter Element: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 3818 Figure 23 Figure 24 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Other Service Bulletins for Air Filter Element: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 3819 Figure 25 Figure 26 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Other Service Bulletins for Air Filter Element: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 3820 Figure 27 Figure 28 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Other Service Bulletins for Air Filter Element: > 99-01-39-004C > Jun > 09 > A/C - Musty Odors Emitted From (HVAC) System > Page 3826 3. Place a protective cover over the carpet below the evaporator core. 4. Remove the cabin air filter, if equipped, and cover the opening prior to applying the Cooling Coil Coating, as the product may clog the filter. If the cabin air filter appears to have little or no remaining life, suggest a replacement to your customer. 5. If the HVAC module has a blower motor cooling tube, be careful NOT TO SPRAY THE COOLING COIL COATING INTO THE BLOWER MOTOR COOLING TUBE. 6. Attach the Flexible Applicator Pressure Spray Tool (J-43810-20A) to a compressed air line operating at 586 kPa (85 psi) to 793 kPa (115 psi). 7. Shake the bottle of Cooling Coil Coating well. Screw the bottle onto the cap on the applicator tool's pick-up tube. Note The pick-up tube is designed for 120 ml (4 oz) and 240 ml (8 oz) bottles and should coil slightly in the bottom of a 120 ml (4 oz) bottle. 8. Use one of the following three methods to apply the Cooling Coil Coating. Important If the Pressure Applicator Spray Tool (J-43810-20A) is not available, the Cooling Coil Coating is also available in an aerosol can (P/N 12377951 (in Canada, 10953503)). Application Through Blower Motor Control Module Opening - Remove the blower motor control module (blower motor resistor). Refer to the applicable procedure in SI. - Clean any debris or foreign material from inside the HVAC module and on the evaporator core surface. - Apply the Cooling Coil Coating directly to the evaporator core through the blower motor blower motor control module (blower motor resistor) opening. - Use the flexible wand to direct the Cooling Coil Coating over the entire evaporator core and surrounding gasket surfaces. - When the application is complete, install the blower motor blower motor control module (blower motor control module). Application Through Blower Motor Opening - Remove the blower motor. Refer to the applicable blower motor removal procedure in SI. - Clean any debris or foreign material from inside the HVAC module and on the evaporator core surface. - Apply the Cooling Coil Coating directly to the evaporator core through the blower motor opening. - Use the flexible wand to direct the Cooling Coil Coating over the entire evaporator core and surrounding gasket surfaces. - When the application is complete, install the blower motor. Application Through a Hole in the HVAC Module - If neither of the two previous application methods are available, it may be necessary to drill a hole in the HVAC module. - Locate an area of the HVAC module between the blower motor and the evaporator core. Drill a 10 mm (3/8 in) hole in the HVAC module. Use caution to keep the drill clear of the evaporator core and the blower motor fan. - With the air distribution vents closed and the blower motor fan speed on HIGH, insert the applicator tool into the hole and spray the Cooling Coil Coating into the airstream toward the evaporator core. - Use a GM approved RTV sealant to plug the hole in the HVAC module. 9. After the Cooling Coil Coating application is complete, start and run the vehicle for approximately 10 minutes, with the compressor disabled, HVAC mode set to Recirculate/Max, heat set to full warm, blower motor fan speed on high, and one window open approximately 12 mm (1/2 in). This cures the Cooling Coil Coating onto the evaporator core surface. 10. While the engine is running, rinse the applicator tool with warm water to prolong the life of the tool. Be sure to spray warm water through the nozzle to rinse out any residual Cooling Coil Coating still in the capillary pick up tube, otherwise it will dry and clog the applicator tool. Also remove the small green valve from the bottle cap and rinse it thoroughly while rolling it between two fingers and then reinstall it. If this valve is clogged , the Cooling Coil Coating will not flow through the applicator tool. 11. Shut off the engine and enable the compressor again. 12. Verify proper HVAC system operation. 13. Remove the protective cover from inside the vehicle. 14. Remove the drain pan from underneath the vehicle. 15. Reinstall the cabin air filter if necessary. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Other Service Bulletins for Air Filter Element: > 99-01-39-004C > Jun > 09 > A/C - Musty Odors Emitted From (HVAC) System > Page 3827 Parts Information Important The Cooling Coil Coating listed below is the only GM approved product for use under warranty as an evaporator core disinfectant and for the long term control of evaporator core microbial growth. Warranty Information For vehicles repaired under warranty, use the table above. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Other Service Bulletins for Air Filter Element: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 3832 3. The chart identifies specific instructions for each vehicle. This chart will identify the proper deodorizing procedure, template and wiring diagram. Deodorizing the evaporator case can easily be done by removing the blower motor resistor and tape off opening. The nozzle can now be inserted through a pierced hole in the tape to deodorize the evaporator case. For some of the vehicles specified below, a drilling procedure is identified in the deodorizing instructions. This type of alternative procedure and others can be done by using the referenced templates in the chart. 4. Complete detailed installation instructions are supplied with the blower control package. Important: A. 1996 ONLY (Use blower resistor location for drilling procedure) B. 1994-1996 ONLY Refer to appropriate Service Manual for enabling afterblow feature through on-board diagnostics. Parts Information Parts are currently available from GMSPO. Warranty Information Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Other Service Bulletins for Air Filter Element: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 3833 For vehicles repaired under warranty, use as shown. Figure 1 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Other Service Bulletins for Air Filter Element: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 3834 Figure 2 Figure 3 Figure 4 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Other Service Bulletins for Air Filter Element: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 3835 Figure 5 Figure 6 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Other Service Bulletins for Air Filter Element: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 3836 Figure 7 Figure 8 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Other Service Bulletins for Air Filter Element: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 3837 Figure 9 Figure 10 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Other Service Bulletins for Air Filter Element: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 3838 Figure 11 Figure 12 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Other Service Bulletins for Air Filter Element: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 3839 Figure 13 Figure 14 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Other Service Bulletins for Air Filter Element: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 3840 Figure 15 Figure 16 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Other Service Bulletins for Air Filter Element: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 3841 Figure 17 Figure 18 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Other Service Bulletins for Air Filter Element: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 3842 Figure 19 Figure 20 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Other Service Bulletins for Air Filter Element: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 3843 Figure 21 Figure 22 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Other Service Bulletins for Air Filter Element: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 3844 Figure 23 Figure 24 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Other Service Bulletins for Air Filter Element: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 3845 Figure 25 Figure 26 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Air Cleaner Housing > Air Filter Element > Component Information > Technical Service Bulletins > All Other Service Bulletins for Air Filter Element: > 531212A > Dec > 96 > A/C - Odor at Start up in Humid Climates > Page 3846 Figure 27 Figure 28 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Diagnostic Connector - Fuel Pump > Component Information > Locations Component Location - "S/T" 4.3Z Utility - Manual Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fillpipe Restrictor > Component Information > Description and Operation Fillpipe Restrictor: Description and Operation Fuel Filler Neck Fuel Door And Restrictor (Typical) Purpose To prevent refueling with leaded fuel, the fuel filter neck has a built-in restrictor and deflector. The opening in the restrictor will accept only the smaller unleaded gasoline fuel nozzle which must be fully inserted to bypass the deflector. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fillpipe Restrictor > Component Information > Description and Operation > Page 3853 Fillpipe Restrictor: Testing and Inspection Fuel Door And Restrictor (Typical) Fuel Filler Neck The fillpipe restrictor should prevent insertion of special dowel with a diameter same as that of leaded fuel pump nozzles (0.950"). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel > Component Information > Technical Service Bulletins > Customer Interest: > 93966C > Feb > 93 > Fuel System - Factors That Affect Economy/Mileage Fuel: Customer Interest Fuel System - Factors That Affect Economy/Mileage Number: 93-96-6C Section: 6C Date: FEB. 1993 Corporate Bulletin No.: 306502 ASE No.: A1, A8 Subject: FACTORS THAT AFFECT FUEL ECONOMY Model and Year: ALL YEARS ALL MODELS BACKGROUND INFORMATION: EPA fuel economy estimates are posted on the fuel economy label of all new vehicles. The only intended use of these values is for comparison among the different vehicles. Fuel economy estimates are generated from data taken during a laboratory test using pre-production prototype vehicles under extremely controlled conditions using a professional driver, with the vehicle operating on an instrument similar to a treadmill. The comparisons of current vehicle fuel economy to the EPA fuel economy estimates is a misuse of the information and should be discouraged. The EPA GAS MILEAGE GUIDE, available at each dealership, points out that the actual mileage when driving a vehicle may differ considerably from the estimated mileage. The guide also describes how vehicles are tested under identical conditions to insure the results can be compared with confidence. The EPA GAS MILEAGE GUIDE also points out that city fuel economy estimate simulates a 7.5 mile, stop-and-go trip with an average speed of 20 mph. The trip takes 23 minutes and has 18 stops. About 18 percent of the time is spent idling, as in waiting at traffic lights or in rush hour traffic. Two kinds of engine starts are used - the cold start, which is similar to starting a car in the morning after it has been parked all night - and the hot start, similar to restarting a vehicle after it has been warmed up, driven and stopped for a short time. The test to determine the highway fuel economy estimate represents a mixture of "non-city" driving. Segments corresponding to different kinds of rural roads and interstate highways are included. The test simulates a 10 mile trip and averages 48 mph. The test is run from a hot start and has little idling time and no stops. The EPA GAS MILEAGE GUIDE explains that the actual test results are adjusted downward to arrive at the estimates used in the booklet and on the labels. City estimates are lowered by 10 percent and the highway estimate by 22 percent from the laboratory test results. The guide also points out that traveling at higher speeds lowers fuel economy and traveling at 65 mph instead of 55 mph lowers fuel economy over 15 percent. FACTORS THAT AFFECT FUEL ECONOMY: Axle Ratio Numerically lower axle ratios generally produce better highway fuel economy. The exception to this is if the engine is "working" exceptionally hard, (heavy vehicle loads pulling a trailer, small engine in a large vehicle ... ). In these cases a numerically higher axle may provide better fuel economy. Numerically higher axle ratios will also tend to provide more fuel economy in congested city traffic and stop and go conditions. Brakes Brake drag (even a minimal amount undetectable by coasting), can have a significant negative impact on fuel economy. Pull upward on the brake pedal to assure that the stoplight switch and cruise switch at the brake pedal are full and properly adjusted. A "click" sound when the pedal is pulled upward indicates that the switch was improperly adjusted. This causes the front brake pads to lightly rub the rotors, causing a fuel economy loss, without generating excessive heat or brake pad wear. Driving Habits Frequent short trips (less than 5 miles), especially in cooler ambient temperatures (less than 65 degrees), will necessitate fuel enrichment on start-ups, especially after "soaks" with the engine off for approximately a half hour or more. Frequent accelerator pedal movement while driving will reduce fuel economy because of fuel enrichment during the periods of acceleration. Under such driving conditions the torque converter clutch (TCC) also disengages, contributing to fuel economy losses. Prolonged idle periods reduce fuel economy especially in cold ambients when vehicle is allowed to "Warm up". Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel > Component Information > Technical Service Bulletins > Customer Interest: > 93966C > Feb > 93 > Fuel System - Factors That Affect Economy/Mileage > Page 3862 Fuels Oxygenated fuels, with methanol and/or ethanol blended into the gasoline have lower energy and thus reduce fuel economy. Typically there is about a 1 MPG penalty for a vehicle which gets 25 to 30 MPG on 100 percent gasoline. Using fuels of a lower octane than the vehicle was calibrated to will cause increased "KS" Knock Sensor system activity. This will result in a net decrease in spark advance and thus poorer fuel economy. Using fuel of a higher octane than the vehicle was calibrated for WILL NOT increase fuel economy. Variations in how much fuel is added to the fuel tank during re-fueling can greatly affect calculated fuel economy. These effects decrease as the distance traveled and the number of tank fillups increase. Green Engine New vehicles have not yet had an opportunity for the engine to break in, (rings to seat ... ). A typical engine will take 3 to 5 thousand miles to break in and during this time period a gradual increase in fuel economy can be expected. Parasitic Loads Air conditioning and/or electrical loads, (headlights, heated backglass ... ) also result in lower fuel economy, (typically less than 1 MPG difference, each 10 AMPs takes approximately .4 MPG). Road Conditions Road surface condition impacts fuel economy. Gravel and/or pot holed roads decrease fuel economy. Hills (vs. level terrain) also negatively impact fuel economy. Even gradual unperceptible increases in elevation result in real measurable decreases in fuel economy. Similarly, driving in the rain or snow decreases fuel economy. Suspension Vehicle suspension misalignment can cause poor fuel economy. Check all four tires for abnormal and/or premature tire wear. New tires, tire rotation, and/or front end alignment may be required to correct fuel economy. Tires Performance tires and/or tires with larger "contact areas," (like 60 series aspect ratio), can cause as much as 3 MPG lower fuel economy when compared to hard "thin" tires. Find out if the tire size currently on the car is the same as original equipment. Replacement tires tailor than original equipment tires cause the odometer to read LESS THAN actual distance traveled. This will result in lower calculated fuel economy than actual fuel economy. Tire Pressure Harder tires, (more air pressure, or different tire compositions) result in better fuel economy. Do not exceed maximum pressure as labeled on the tire, typically 30-35 psi. The disadvantage of this is that the greater the tire pressure, the harsher the vehicle ride. Transmission On 4-Speed automatics, it is possible to drive the vehicle in 3rd gear rather than "overdrive" and not perceive it. Typically this condition occurs when the shift indicator, or the shift linkage/detent is misadjusted. Misadjusted shift linkage can also result in improper signals to the ECM, which can result in less spark advance, and results in a drop in fuel economy. Driving a vehicle in 3rd gear rather than overdrive at highway speeds typically results in a 3 to 5 MPG penalty. Torque Converter Clutch operation is essential for good fuel economy. A non-locking torque converter typically results in a 1 to 2 MPG penalty at highway speeds. Vehicle Weight Each 125 lbs. of additional weight results in a .3 MPG loss of fuel economy. Thus, additional passengers, luggage ... will decrease fuel economy. Vehicle Wind Resistance More wind "DRAG" means less fuel economy. Thus, hang-on luggage carders, cat toppers, open windows and/or open trunk... mean less fuel economy. (See "Driving Habits"). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Fuel: > 05-06-04-022G > Oct > 10 > Fuel System - TOP TIER Detergent Gasoline (Canada) Fuel: All Technical Service Bulletins Fuel System - TOP TIER Detergent Gasoline (Canada) INFORMATION Bulletin No.: 05-06-04-022G Date: October 27, 2010 Subject: TOP TIER Detergent Gasoline Information and Available Brands (Deposits, Fuel Economy, No Start, Power, Performance, Stall Concerns) - Canada ONLY Models: 2011 and Prior GM Passenger Cars and Trucks (Canada Only) Supercede: This bulletin is being revised to update the model years and include an additional gasoline brand as a TOP TIER source. Please discard Corporate Bulletin Number 05-06-04-022F (Section 06 - Engine/Propulsion System). In the U.S., refer to the latest version of Corporate Bulletin Number 04-06-04-047I. A new class of fuel called TOP TIER Detergent Gasoline is appearing at retail stations of some fuel marketers. This gasoline meets detergency standards developed by six automotive companies. All vehicles will benefit from using TOP TIER Detergent Gasoline over gasoline containing the "Lowest Additive Concentration" recommended by the Canadian General Standards Board (CGSB). Those vehicles that have experienced deposit related concerns may especially benefit from use of TOP TIER Detergent Gasoline. Intake valve: 16,093 km (10,000 mi) with TOP TIER Detergent Gasoline Intake valve: 16,093 km (10,000 mi) with Minimum Additive recommended by the CGSB Top Tier Fuel Availability Chevron was the first to offer TOP TIER Detergent Gasoline in Canada. Shell became the first national gasoline retailer to offer TOP TIER Detergent Gasoline across Canada. Petro-Canada began offering TOP TIER Detergent Gasoline nationally as of October 1, 2006. Sunoco began offering TOP TIER Detergent Gasoline in March of 2007. Esso began offering TOP TIER Detergent Gasoline in May of 2010. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Fuel: > 05-06-04-022G > Oct > 10 > Fuel System - TOP TIER Detergent Gasoline (Canada) > Page 3868 Gasoline Brands That Currently Meet TOP TIER Detergent Gasoline Standards The following gasoline brands meet the TOP TIER Detergent Gasoline Standards in all octane grades : Chevron Canada (markets in British Columbia and western Alberta) - Shell Canada (nationally) - Petro-Canada (nationally) - Sunoco-Canada (Ontario) - Esso-Canada (nationally) What is TOP TIER Detergent Gasoline? TOP TIER Detergent Gasoline is a new class of gasoline with enhanced detergency and no metallic additives. It meets new, voluntary deposit control standards developed by six automotive companies that exceed the detergent recommendations of Canadian standards and does not contain metallic additives, which can damage vehicle emission control components. Where Can TOP TIER Detergent Gasoline Be Purchased? The TOP TIER program began in the U.S. and Canada on May 3, 2004. Some fuel marketers have already joined and introduced TOP TIER Detergent Gasoline. This is a voluntary program and not all fuel marketers will offer this product. Once fuel marketers make public announcements, they will appear on a list of brands that meet the TOP TIER standards. Who developed TOP TIER Detergent Gasoline standards? TOP TIER Detergent Gasoline standards were developed by six automotive companies: BMW, General Motors, Honda, Toyota, Volkswagen and Audi. Why was TOP TIER Detergent Gasoline developed? TOP TIER Detergent Gasoline was developed to increase the level of detergent additive in gasoline. In the U.S., government regulations require that all gasoline sold in the U.S. contain a detergent additive. However, the requirement is minimal and in many cases, is not sufficient to keep engines clean. In Canada, gasoline standards recommend adherence to U.S. detergency requirements but do not require it. In fact, many brands of gasoline in Canada do not contain any detergent additive. In order to meet TOP TIER Detergent Gasoline standards, a higher level of detergent is needed than what is required or recommended, and no metallic additives are allowed. Also, TOP TIER was developed to give fuel marketers the opportunity to differentiate their product. Why did the six automotive companies join together to develop TOP TIER? All six corporations recognized the benefits to both the vehicle and the consumer. Also, joining together emphasized that low detergency and the intentional addition of metallic additives is an issue of concern to several automotive companies. What are the benefits of TOP TIER Detergent Gasoline? TOP TIER Detergent Gasoline will help keep engines cleaner than gasoline containing the "Lowest Additive Concentration" recommended by Canadian standards. Clean engines help provide optimal fuel economy and engine performance, and also provide reduced emissions. Also, the use of TOP TIER Detergent Gasoline will help reduce deposit related concerns. Who should use TOP TIER Detergent Gasoline? All vehicles will benefit from using TOP TIER Detergent Gasoline over gasoline containing the "Lowest Additive Concentration" recommended by Canadian standards. Those vehicles that have experienced deposit related concerns may especially benefit from use of TOP TIER Detergent Gasoline. More information on TOP TIER Detergent Gasoline can be found at this website, http://www.toptiergas.com/. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Fuel: > 05-06-04-022G > Oct > 10 > Fuel System - TOP TIER Detergent Gasoline (Canada) > Page 3869 Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Fuel: > 04-06-04-047I > Aug > 09 > Fuel System - 'TOP TIER' Detergent Gasoline Information Fuel: All Technical Service Bulletins Fuel System - 'TOP TIER' Detergent Gasoline Information INFORMATION Bulletin No.: 04-06-04-047I Date: August 17, 2009 Subject: TOP TIER Detergent Gasoline (Deposits, Fuel Economy, No Start, Power, Performance, Stall Concerns) - U.S. Only Models: 2010 and Prior GM Passenger Cars and Trucks (including Saturn) (U.S. Only) 2003-2010 HUMMER H2 (U.S. Only) 2006-2010 HUMMER H3 (U.S. Only) 2005-2009 Saab 9-7X (U.S. Only) Supercede: This bulletin is being revised to add model years and additional sources to the Top Tier Fuel Retailers list. Please discard Corporate Bulletin Number 04-06-04-047H (Section 06 Engine/Propulsion System). In Canada, refer to Corporate Bulletin Number 05-06-04-022F. A new class of fuel called TOP TIER Detergent Gasoline is appearing at retail stations of some fuel marketers. This gasoline meets detergency standards developed by six automotive companies. All vehicles will benefit from using TOP TIER Detergent Gasoline over gasoline containing the "Lowest Additive Concentration" set by the EPA. Those vehicles that have experienced deposit related concerns may especially benefit from the use of TOP TIER Detergent Gasoline. Intake valve: - 10,000 miles with TOP TIER Detergent Gasoline Intake valve: - 10,000 miles with Legal Minimum additive Gasoline Brands That Currently Meet TOP TIER Detergent Gasoline Standards As of August 1, 2009, all grades of the following gasoline brands meet the TOP TIER Detergent Gasoline Standards: - Chevron - Chevron-Canada - QuikTrip - Conoco Phillips 66 - 76 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Fuel: > 04-06-04-047I > Aug > 09 > Fuel System - 'TOP TIER' Detergent Gasoline Information > Page 3874 - Shell - Shell-Canada - Entec Stations located in the greater Montgomery, Alabama area. - MFA Oil Company located throughout Missouri. - Kwik Trip, Inc. in Minnesota and Wisconsin and Kwik Star convenience stores in Iowa. The Somerset Refinery, Inc. at Somerset Oil stations in Kentucky. Aloha Petroleum - Tri-Par Oil Company - Turkey Hill Minit Markets - Texaco - Petro-Canada - Sunoco-Canada - Road Ranger located in Illinois, Indiana, Iowa, Kentucky, Missouri, Ohio and Wisconsin What is TOP TIER Detergent Gasoline? TOP TIER Detergent Gasoline is a new class of gasoline with enhanced detergency. It meets new, voluntary deposit control standards developed by six automotive companies that exceed the detergent requirements imposed by the EPA. Where Can TOP TIER Detergent Gasoline Be Purchased? The TOP TIER program began on May 3, 2004 and many fuel marketers have joined the program and have introduced TOP TIER Detergent Gasoline. This is a voluntary program and not all fuel marketers will offer this product. Once fuel marketers make public announcements, they will appear on a list of brands that meet the TOP TIER standards. Where Can I find the Latest Information on TOP TIER Fuel and Retailers? On the web, please visit www.toptiergas.com for additional information and updated retailer lists. Who developed TOP TIER Detergent Gasoline standards? TOP TIER Detergent Gasoline standards were developed by six automotive companies: Audi, BMW, General Motors, Honda, Toyota and Volkswagen. Why was TOP TIER Detergent Gasoline developed? TOP TIER Detergent Gasoline was developed to increase the level of detergent additive in gasoline. The EPA requires that all gasoline sold in the U.S. contain a detergent additive. However, the requirement is minimal and in many cases, is not sufficient to keep engines clean. In order to meet TOP TIER Detergent Gasoline standards, a higher level of detergent is needed than what is required by the EPA. Also, TOP TIER was developed to give fuel marketers the opportunity to differentiate their product. Why did the six automotive companies join together to develop TOP TIER? All six corporations recognized the benefits to both the vehicle and the consumer. Also, joining together emphasized that low detergency is an issue of concern to several automotive companies. What are the benefits of TOP TIER Detergent Gasoline? TOP TIER Detergent Gasoline will help keep engines cleaner than gasoline containing the "Lowest Additive Concentration" set by the EPA. Clean engines help provide optimal fuel economy and performance and reduced emissions. Also, use of TOP TIER Detergent Gasoline will help reduce deposit related concerns. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Fuel: > 04-06-00-047 > Jun > 04 > Fuel - Top Tier Detergent Gasoline Information Fuel: All Technical Service Bulletins Fuel - Top Tier Detergent Gasoline Information Bulletin No.: 04-06-00-047 Date: June 24, 2004 ADVANCED SERVICE INFORMATION Subject: Top Tier Detergent Gasoline (Deposits, Fuel Economy, No Start, Power, Performance, Stall Concerns) Models: 2005 and Prior All General Motors Passenger Cars and Trucks (U.S. Only) A new class of gasoline, called Top Tier Detergent Gasoline, will be appearing at retail stations of some fuel marketers. This gasoline meets detergency standards developed by four automotive companies. A description of the concept and benefits of Top Tier is provided in the following question and answer section. What is Top Tier Detergent Gasoline? Top Tier Detergent Gasoline is a new class of gasoline with enhanced detergency. It meets new, voluntary deposit control standards developed by four automotive companies that exceed the detergent requirements imposed by the EPA. Who developed Top Tier Detergent Gasoline standards? Top Tier Detergent Gasoline standards were developed by four automotive companies: BMW, General Motors, Honda and Toyota. Why was Top Tier Detergent Gasoline developed? Top Tier Detergent Gasoline was developed to increase the level of detergent additive in gasoline. The EPA requires that all gasoline sold in the U.S. contain a detergent additive. However, the requirement is minimal and in many cases, is not sufficient to keep engines clean. In order to meet Top Tier Detergent Gasoline standards, a higher level of detergent is needed than what is required by the EPA. Also, Top Tier was developed to give fuel marketers the opportunity to differentiate their product. Why did the four automotive companies join together to develop Top Tier? All four corporations recognized the benefits to both the vehicle and the consumer. Also, joining together emphasized that low detergency is an issue of concern to several automotive companies. What are the benefits of Top Tier Detergent Gasoline? Top Tier Detergent Gasoline will help keep engines cleaner than gasoline containing the "Lowest Additive Concentration" set by the EPA. Clean engines help provide optimal fuel economy and performance and reduced emissions. Also, use of Top Tier Detergent Gasoline will help reduce deposit related concerns. Who should use Top Tier Detergent Gasoline? All vehicles will benefit from using Top Tier Detergent Gasoline over gasoline containing the "Lowest Additive Concentration" set by the EPA. Those vehicles that have experienced deposit related concerns may especially benefit from use of Top Tier Detergent Gasoline. Where can Top Tier Detergent Gasoline be purchased? The Top Tier program began on May 3, 2004. Some fuel marketers have already joined and are making plans to introduce Top Tier Detergent Gasoline. This is a voluntary program and not all fuel marketers will offer this product. Once fuel marketers make public announcements, a list of all fuel marketers meeting Top Tier standards will be made available. For now, look for the "Top Tier" designation at the gas pump. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Fuel: > 570102 > Jun > 95 > Fuel Reformulated/Oxygenated Gasolines Fuel: All Technical Service Bulletins Fuel - Reformulated/Oxygenated Gasolines FILE IN SECTION: 0 - General Information BULLETIN NO.: 57-01-02 DATE: June, 1995 SUBJECT: Reformulated Gasoline (RFG), Oxygenated Gasoline and California Phase 2 RFG MODELS: 1995 and Prior Passenger Cars and Trucks General Motors customers will be potentially exposed to a variety of different fuel types. Besides the conventional gasoline available, new types such as Reformulated Gasoline (RFG), oxygenated gasoline, and starting in 1996, California Phase 2 RFG. Reformulated Gasoline (RFG) is blended to burn more cleanly and not to evaporate as readily. RFG must contain a minimum of 2 percent oxygen, which is usually achieved with ethanol or EPA-approved ethers such as methyl tertiary-butyl ether (MTBE). This type of fuel is required by the Clean Air Act in the nine worst ozone non-attainment areas of the country, and may also be required in other areas designated ozone non-attainment, at the option of the states. RFG is intended to produce approximately 15 percent less pollution than conventional gasoline. Using RFG should reduce the total health risk to the public by reducing exposure to ozone and air toxins. General Motors supports the use of RFG as a cost effective means of providing air quality benefits. Oxygenated gasolines are prevalent in the wintertime for Carbon Monoxide (CO) non-attainment areas. These fuels contain oxygen components similar to RFG. Approximately 50 percent of the fuel sold in the U.S. in the wintertime contains an oxygenate component. Vehicle fuel economy may be slightly reduced, if at all, by the use of gasoline containing oxygenates. Fuel economy is most affected by engine and vehicle type, driving habits, weather conditions, and vehicle maintenance. Properly blended RFG, oxygenated gasoline, and California Phase 2 RFG will have no adverse effect on vehicle performance or to the durability of engine and fuel system components. In fact, the General Motors Owner's Manual fuel statements have consistently permitted the use of properly blended fuels containing up to 10 percent ethanol (since 1980) and up to 15 percent methyl tertiary-butyl ether (MTBE) for current and all past model year vehicles. These statements continue to be valid. The use of oxygenate-containing fuels will not invalidate the GM vehicle warranty. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Fuel: > 93966C > Feb > 93 > Fuel System - Factors That Affect Economy/Mileage Fuel: All Technical Service Bulletins Fuel System - Factors That Affect Economy/Mileage Number: 93-96-6C Section: 6C Date: FEB. 1993 Corporate Bulletin No.: 306502 ASE No.: A1, A8 Subject: FACTORS THAT AFFECT FUEL ECONOMY Model and Year: ALL YEARS ALL MODELS BACKGROUND INFORMATION: EPA fuel economy estimates are posted on the fuel economy label of all new vehicles. The only intended use of these values is for comparison among the different vehicles. Fuel economy estimates are generated from data taken during a laboratory test using pre-production prototype vehicles under extremely controlled conditions using a professional driver, with the vehicle operating on an instrument similar to a treadmill. The comparisons of current vehicle fuel economy to the EPA fuel economy estimates is a misuse of the information and should be discouraged. The EPA GAS MILEAGE GUIDE, available at each dealership, points out that the actual mileage when driving a vehicle may differ considerably from the estimated mileage. The guide also describes how vehicles are tested under identical conditions to insure the results can be compared with confidence. The EPA GAS MILEAGE GUIDE also points out that city fuel economy estimate simulates a 7.5 mile, stop-and-go trip with an average speed of 20 mph. The trip takes 23 minutes and has 18 stops. About 18 percent of the time is spent idling, as in waiting at traffic lights or in rush hour traffic. Two kinds of engine starts are used - the cold start, which is similar to starting a car in the morning after it has been parked all night - and the hot start, similar to restarting a vehicle after it has been warmed up, driven and stopped for a short time. The test to determine the highway fuel economy estimate represents a mixture of "non-city" driving. Segments corresponding to different kinds of rural roads and interstate highways are included. The test simulates a 10 mile trip and averages 48 mph. The test is run from a hot start and has little idling time and no stops. The EPA GAS MILEAGE GUIDE explains that the actual test results are adjusted downward to arrive at the estimates used in the booklet and on the labels. City estimates are lowered by 10 percent and the highway estimate by 22 percent from the laboratory test results. The guide also points out that traveling at higher speeds lowers fuel economy and traveling at 65 mph instead of 55 mph lowers fuel economy over 15 percent. FACTORS THAT AFFECT FUEL ECONOMY: Axle Ratio Numerically lower axle ratios generally produce better highway fuel economy. The exception to this is if the engine is "working" exceptionally hard, (heavy vehicle loads pulling a trailer, small engine in a large vehicle ... ). In these cases a numerically higher axle may provide better fuel economy. Numerically higher axle ratios will also tend to provide more fuel economy in congested city traffic and stop and go conditions. Brakes Brake drag (even a minimal amount undetectable by coasting), can have a significant negative impact on fuel economy. Pull upward on the brake pedal to assure that the stoplight switch and cruise switch at the brake pedal are full and properly adjusted. A "click" sound when the pedal is pulled upward indicates that the switch was improperly adjusted. This causes the front brake pads to lightly rub the rotors, causing a fuel economy loss, without generating excessive heat or brake pad wear. Driving Habits Frequent short trips (less than 5 miles), especially in cooler ambient temperatures (less than 65 degrees), will necessitate fuel enrichment on start-ups, especially after "soaks" with the engine off for approximately a half hour or more. Frequent accelerator pedal movement while driving will reduce fuel economy because of fuel enrichment during the periods of acceleration. Under such driving conditions the torque converter clutch (TCC) also disengages, contributing to fuel economy losses. Prolonged idle periods reduce fuel economy especially in cold ambients when vehicle is allowed to "Warm up". Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Fuel: > 93966C > Feb > 93 > Fuel System - Factors That Affect Economy/Mileage > Page 3887 Fuels Oxygenated fuels, with methanol and/or ethanol blended into the gasoline have lower energy and thus reduce fuel economy. Typically there is about a 1 MPG penalty for a vehicle which gets 25 to 30 MPG on 100 percent gasoline. Using fuels of a lower octane than the vehicle was calibrated to will cause increased "KS" Knock Sensor system activity. This will result in a net decrease in spark advance and thus poorer fuel economy. Using fuel of a higher octane than the vehicle was calibrated for WILL NOT increase fuel economy. Variations in how much fuel is added to the fuel tank during re-fueling can greatly affect calculated fuel economy. These effects decrease as the distance traveled and the number of tank fillups increase. Green Engine New vehicles have not yet had an opportunity for the engine to break in, (rings to seat ... ). A typical engine will take 3 to 5 thousand miles to break in and during this time period a gradual increase in fuel economy can be expected. Parasitic Loads Air conditioning and/or electrical loads, (headlights, heated backglass ... ) also result in lower fuel economy, (typically less than 1 MPG difference, each 10 AMPs takes approximately .4 MPG). Road Conditions Road surface condition impacts fuel economy. Gravel and/or pot holed roads decrease fuel economy. Hills (vs. level terrain) also negatively impact fuel economy. Even gradual unperceptible increases in elevation result in real measurable decreases in fuel economy. Similarly, driving in the rain or snow decreases fuel economy. Suspension Vehicle suspension misalignment can cause poor fuel economy. Check all four tires for abnormal and/or premature tire wear. New tires, tire rotation, and/or front end alignment may be required to correct fuel economy. Tires Performance tires and/or tires with larger "contact areas," (like 60 series aspect ratio), can cause as much as 3 MPG lower fuel economy when compared to hard "thin" tires. Find out if the tire size currently on the car is the same as original equipment. Replacement tires tailor than original equipment tires cause the odometer to read LESS THAN actual distance traveled. This will result in lower calculated fuel economy than actual fuel economy. Tire Pressure Harder tires, (more air pressure, or different tire compositions) result in better fuel economy. Do not exceed maximum pressure as labeled on the tire, typically 30-35 psi. The disadvantage of this is that the greater the tire pressure, the harsher the vehicle ride. Transmission On 4-Speed automatics, it is possible to drive the vehicle in 3rd gear rather than "overdrive" and not perceive it. Typically this condition occurs when the shift indicator, or the shift linkage/detent is misadjusted. Misadjusted shift linkage can also result in improper signals to the ECM, which can result in less spark advance, and results in a drop in fuel economy. Driving a vehicle in 3rd gear rather than overdrive at highway speeds typically results in a 3 to 5 MPG penalty. Torque Converter Clutch operation is essential for good fuel economy. A non-locking torque converter typically results in a 1 to 2 MPG penalty at highway speeds. Vehicle Weight Each 125 lbs. of additional weight results in a .3 MPG loss of fuel economy. Thus, additional passengers, luggage ... will decrease fuel economy. Vehicle Wind Resistance More wind "DRAG" means less fuel economy. Thus, hang-on luggage carders, cat toppers, open windows and/or open trunk... mean less fuel economy. (See "Driving Habits"). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel > Component Information > Technical Service Bulletins > All Other Service Bulletins for Fuel: > 05-06-04-022G > Oct > 10 > Fuel System - TOP TIER Detergent Gasoline (Canada) Fuel: All Technical Service Bulletins Fuel System - TOP TIER Detergent Gasoline (Canada) INFORMATION Bulletin No.: 05-06-04-022G Date: October 27, 2010 Subject: TOP TIER Detergent Gasoline Information and Available Brands (Deposits, Fuel Economy, No Start, Power, Performance, Stall Concerns) - Canada ONLY Models: 2011 and Prior GM Passenger Cars and Trucks (Canada Only) Supercede: This bulletin is being revised to update the model years and include an additional gasoline brand as a TOP TIER source. Please discard Corporate Bulletin Number 05-06-04-022F (Section 06 - Engine/Propulsion System). In the U.S., refer to the latest version of Corporate Bulletin Number 04-06-04-047I. A new class of fuel called TOP TIER Detergent Gasoline is appearing at retail stations of some fuel marketers. This gasoline meets detergency standards developed by six automotive companies. All vehicles will benefit from using TOP TIER Detergent Gasoline over gasoline containing the "Lowest Additive Concentration" recommended by the Canadian General Standards Board (CGSB). Those vehicles that have experienced deposit related concerns may especially benefit from use of TOP TIER Detergent Gasoline. Intake valve: 16,093 km (10,000 mi) with TOP TIER Detergent Gasoline Intake valve: 16,093 km (10,000 mi) with Minimum Additive recommended by the CGSB Top Tier Fuel Availability Chevron was the first to offer TOP TIER Detergent Gasoline in Canada. Shell became the first national gasoline retailer to offer TOP TIER Detergent Gasoline across Canada. Petro-Canada began offering TOP TIER Detergent Gasoline nationally as of October 1, 2006. Sunoco began offering TOP TIER Detergent Gasoline in March of 2007. Esso began offering TOP TIER Detergent Gasoline in May of 2010. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel > Component Information > Technical Service Bulletins > All Other Service Bulletins for Fuel: > 05-06-04-022G > Oct > 10 > Fuel System - TOP TIER Detergent Gasoline (Canada) > Page 3893 Gasoline Brands That Currently Meet TOP TIER Detergent Gasoline Standards The following gasoline brands meet the TOP TIER Detergent Gasoline Standards in all octane grades : Chevron Canada (markets in British Columbia and western Alberta) - Shell Canada (nationally) - Petro-Canada (nationally) - Sunoco-Canada (Ontario) - Esso-Canada (nationally) What is TOP TIER Detergent Gasoline? TOP TIER Detergent Gasoline is a new class of gasoline with enhanced detergency and no metallic additives. It meets new, voluntary deposit control standards developed by six automotive companies that exceed the detergent recommendations of Canadian standards and does not contain metallic additives, which can damage vehicle emission control components. Where Can TOP TIER Detergent Gasoline Be Purchased? The TOP TIER program began in the U.S. and Canada on May 3, 2004. Some fuel marketers have already joined and introduced TOP TIER Detergent Gasoline. This is a voluntary program and not all fuel marketers will offer this product. Once fuel marketers make public announcements, they will appear on a list of brands that meet the TOP TIER standards. Who developed TOP TIER Detergent Gasoline standards? TOP TIER Detergent Gasoline standards were developed by six automotive companies: BMW, General Motors, Honda, Toyota, Volkswagen and Audi. Why was TOP TIER Detergent Gasoline developed? TOP TIER Detergent Gasoline was developed to increase the level of detergent additive in gasoline. In the U.S., government regulations require that all gasoline sold in the U.S. contain a detergent additive. However, the requirement is minimal and in many cases, is not sufficient to keep engines clean. In Canada, gasoline standards recommend adherence to U.S. detergency requirements but do not require it. In fact, many brands of gasoline in Canada do not contain any detergent additive. In order to meet TOP TIER Detergent Gasoline standards, a higher level of detergent is needed than what is required or recommended, and no metallic additives are allowed. Also, TOP TIER was developed to give fuel marketers the opportunity to differentiate their product. Why did the six automotive companies join together to develop TOP TIER? All six corporations recognized the benefits to both the vehicle and the consumer. Also, joining together emphasized that low detergency and the intentional addition of metallic additives is an issue of concern to several automotive companies. What are the benefits of TOP TIER Detergent Gasoline? TOP TIER Detergent Gasoline will help keep engines cleaner than gasoline containing the "Lowest Additive Concentration" recommended by Canadian standards. Clean engines help provide optimal fuel economy and engine performance, and also provide reduced emissions. Also, the use of TOP TIER Detergent Gasoline will help reduce deposit related concerns. Who should use TOP TIER Detergent Gasoline? All vehicles will benefit from using TOP TIER Detergent Gasoline over gasoline containing the "Lowest Additive Concentration" recommended by Canadian standards. Those vehicles that have experienced deposit related concerns may especially benefit from use of TOP TIER Detergent Gasoline. More information on TOP TIER Detergent Gasoline can be found at this website, http://www.toptiergas.com/. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel > Component Information > Technical Service Bulletins > All Other Service Bulletins for Fuel: > 05-06-04-022G > Oct > 10 > Fuel System - TOP TIER Detergent Gasoline (Canada) > Page 3894 Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel > Component Information > Technical Service Bulletins > All Other Service Bulletins for Fuel: > 04-06-04-047I > Aug > 09 > Fuel System - 'TOP TIER' Detergent Gasoline Information Fuel: All Technical Service Bulletins Fuel System - 'TOP TIER' Detergent Gasoline Information INFORMATION Bulletin No.: 04-06-04-047I Date: August 17, 2009 Subject: TOP TIER Detergent Gasoline (Deposits, Fuel Economy, No Start, Power, Performance, Stall Concerns) - U.S. Only Models: 2010 and Prior GM Passenger Cars and Trucks (including Saturn) (U.S. Only) 2003-2010 HUMMER H2 (U.S. Only) 2006-2010 HUMMER H3 (U.S. Only) 2005-2009 Saab 9-7X (U.S. Only) Supercede: This bulletin is being revised to add model years and additional sources to the Top Tier Fuel Retailers list. Please discard Corporate Bulletin Number 04-06-04-047H (Section 06 Engine/Propulsion System). In Canada, refer to Corporate Bulletin Number 05-06-04-022F. A new class of fuel called TOP TIER Detergent Gasoline is appearing at retail stations of some fuel marketers. This gasoline meets detergency standards developed by six automotive companies. All vehicles will benefit from using TOP TIER Detergent Gasoline over gasoline containing the "Lowest Additive Concentration" set by the EPA. Those vehicles that have experienced deposit related concerns may especially benefit from the use of TOP TIER Detergent Gasoline. Intake valve: - 10,000 miles with TOP TIER Detergent Gasoline Intake valve: - 10,000 miles with Legal Minimum additive Gasoline Brands That Currently Meet TOP TIER Detergent Gasoline Standards As of August 1, 2009, all grades of the following gasoline brands meet the TOP TIER Detergent Gasoline Standards: - Chevron - Chevron-Canada - QuikTrip - Conoco Phillips 66 - 76 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel > Component Information > Technical Service Bulletins > All Other Service Bulletins for Fuel: > 04-06-04-047I > Aug > 09 > Fuel System - 'TOP TIER' Detergent Gasoline Information > Page 3899 - Shell - Shell-Canada - Entec Stations located in the greater Montgomery, Alabama area. - MFA Oil Company located throughout Missouri. - Kwik Trip, Inc. in Minnesota and Wisconsin and Kwik Star convenience stores in Iowa. The Somerset Refinery, Inc. at Somerset Oil stations in Kentucky. Aloha Petroleum - Tri-Par Oil Company - Turkey Hill Minit Markets - Texaco - Petro-Canada - Sunoco-Canada - Road Ranger located in Illinois, Indiana, Iowa, Kentucky, Missouri, Ohio and Wisconsin What is TOP TIER Detergent Gasoline? TOP TIER Detergent Gasoline is a new class of gasoline with enhanced detergency. It meets new, voluntary deposit control standards developed by six automotive companies that exceed the detergent requirements imposed by the EPA. Where Can TOP TIER Detergent Gasoline Be Purchased? The TOP TIER program began on May 3, 2004 and many fuel marketers have joined the program and have introduced TOP TIER Detergent Gasoline. This is a voluntary program and not all fuel marketers will offer this product. Once fuel marketers make public announcements, they will appear on a list of brands that meet the TOP TIER standards. Where Can I find the Latest Information on TOP TIER Fuel and Retailers? On the web, please visit www.toptiergas.com for additional information and updated retailer lists. Who developed TOP TIER Detergent Gasoline standards? TOP TIER Detergent Gasoline standards were developed by six automotive companies: Audi, BMW, General Motors, Honda, Toyota and Volkswagen. Why was TOP TIER Detergent Gasoline developed? TOP TIER Detergent Gasoline was developed to increase the level of detergent additive in gasoline. The EPA requires that all gasoline sold in the U.S. contain a detergent additive. However, the requirement is minimal and in many cases, is not sufficient to keep engines clean. In order to meet TOP TIER Detergent Gasoline standards, a higher level of detergent is needed than what is required by the EPA. Also, TOP TIER was developed to give fuel marketers the opportunity to differentiate their product. Why did the six automotive companies join together to develop TOP TIER? All six corporations recognized the benefits to both the vehicle and the consumer. Also, joining together emphasized that low detergency is an issue of concern to several automotive companies. What are the benefits of TOP TIER Detergent Gasoline? TOP TIER Detergent Gasoline will help keep engines cleaner than gasoline containing the "Lowest Additive Concentration" set by the EPA. Clean engines help provide optimal fuel economy and performance and reduced emissions. Also, use of TOP TIER Detergent Gasoline will help reduce deposit related concerns. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel > Component Information > Technical Service Bulletins > All Other Service Bulletins for Fuel: > 04-06-00-047 > Jun > 04 > Fuel - Top Tier Detergent Gasoline Information Fuel: All Technical Service Bulletins Fuel - Top Tier Detergent Gasoline Information Bulletin No.: 04-06-00-047 Date: June 24, 2004 ADVANCED SERVICE INFORMATION Subject: Top Tier Detergent Gasoline (Deposits, Fuel Economy, No Start, Power, Performance, Stall Concerns) Models: 2005 and Prior All General Motors Passenger Cars and Trucks (U.S. Only) A new class of gasoline, called Top Tier Detergent Gasoline, will be appearing at retail stations of some fuel marketers. This gasoline meets detergency standards developed by four automotive companies. A description of the concept and benefits of Top Tier is provided in the following question and answer section. What is Top Tier Detergent Gasoline? Top Tier Detergent Gasoline is a new class of gasoline with enhanced detergency. It meets new, voluntary deposit control standards developed by four automotive companies that exceed the detergent requirements imposed by the EPA. Who developed Top Tier Detergent Gasoline standards? Top Tier Detergent Gasoline standards were developed by four automotive companies: BMW, General Motors, Honda and Toyota. Why was Top Tier Detergent Gasoline developed? Top Tier Detergent Gasoline was developed to increase the level of detergent additive in gasoline. The EPA requires that all gasoline sold in the U.S. contain a detergent additive. However, the requirement is minimal and in many cases, is not sufficient to keep engines clean. In order to meet Top Tier Detergent Gasoline standards, a higher level of detergent is needed than what is required by the EPA. Also, Top Tier was developed to give fuel marketers the opportunity to differentiate their product. Why did the four automotive companies join together to develop Top Tier? All four corporations recognized the benefits to both the vehicle and the consumer. Also, joining together emphasized that low detergency is an issue of concern to several automotive companies. What are the benefits of Top Tier Detergent Gasoline? Top Tier Detergent Gasoline will help keep engines cleaner than gasoline containing the "Lowest Additive Concentration" set by the EPA. Clean engines help provide optimal fuel economy and performance and reduced emissions. Also, use of Top Tier Detergent Gasoline will help reduce deposit related concerns. Who should use Top Tier Detergent Gasoline? All vehicles will benefit from using Top Tier Detergent Gasoline over gasoline containing the "Lowest Additive Concentration" set by the EPA. Those vehicles that have experienced deposit related concerns may especially benefit from use of Top Tier Detergent Gasoline. Where can Top Tier Detergent Gasoline be purchased? The Top Tier program began on May 3, 2004. Some fuel marketers have already joined and are making plans to introduce Top Tier Detergent Gasoline. This is a voluntary program and not all fuel marketers will offer this product. Once fuel marketers make public announcements, a list of all fuel marketers meeting Top Tier standards will be made available. For now, look for the "Top Tier" designation at the gas pump. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel > Component Information > Technical Service Bulletins > All Other Service Bulletins for Fuel: > 570102 > Jun > 95 > Fuel - Reformulated/Oxygenated Gasolines Fuel: All Technical Service Bulletins Fuel - Reformulated/Oxygenated Gasolines FILE IN SECTION: 0 - General Information BULLETIN NO.: 57-01-02 DATE: June, 1995 SUBJECT: Reformulated Gasoline (RFG), Oxygenated Gasoline and California Phase 2 RFG MODELS: 1995 and Prior Passenger Cars and Trucks General Motors customers will be potentially exposed to a variety of different fuel types. Besides the conventional gasoline available, new types such as Reformulated Gasoline (RFG), oxygenated gasoline, and starting in 1996, California Phase 2 RFG. Reformulated Gasoline (RFG) is blended to burn more cleanly and not to evaporate as readily. RFG must contain a minimum of 2 percent oxygen, which is usually achieved with ethanol or EPA-approved ethers such as methyl tertiary-butyl ether (MTBE). This type of fuel is required by the Clean Air Act in the nine worst ozone non-attainment areas of the country, and may also be required in other areas designated ozone non-attainment, at the option of the states. RFG is intended to produce approximately 15 percent less pollution than conventional gasoline. Using RFG should reduce the total health risk to the public by reducing exposure to ozone and air toxins. General Motors supports the use of RFG as a cost effective means of providing air quality benefits. Oxygenated gasolines are prevalent in the wintertime for Carbon Monoxide (CO) non-attainment areas. These fuels contain oxygen components similar to RFG. Approximately 50 percent of the fuel sold in the U.S. in the wintertime contains an oxygenate component. Vehicle fuel economy may be slightly reduced, if at all, by the use of gasoline containing oxygenates. Fuel economy is most affected by engine and vehicle type, driving habits, weather conditions, and vehicle maintenance. Properly blended RFG, oxygenated gasoline, and California Phase 2 RFG will have no adverse effect on vehicle performance or to the durability of engine and fuel system components. In fact, the General Motors Owner's Manual fuel statements have consistently permitted the use of properly blended fuels containing up to 10 percent ethanol (since 1980) and up to 15 percent methyl tertiary-butyl ether (MTBE) for current and all past model year vehicles. These statements continue to be valid. The use of oxygenate-containing fuels will not invalidate the GM vehicle warranty. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Filler Cap > Component Information > Locations Fuel Filler Neck Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Filler Cap > Component Information > Locations > Page 3911 Fuel Filler Cap: Service and Repair If a fuel tank filler cap requires replacement, use only a cap with the same features. Failure to use the correct cap can result in a malfunctioning of the evaporative system. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Filter > Fuel Pressure Release > System Information > Service and Repair Fuel Pressure Release: Service and Repair WARNING To reduce the risk of fire and personal injury, it is necessary to relieve fuel system pressure before servicing fuel system components. A small amount of fuel may be released when servicing fuel lines or connections. In order to reduce the chance of personal injury, cover fuel line fittings with a shop towel before disconnecting to catch any fuel that may leak out. Place the towel in an approved container when disconnect is complete. PROCEDURE - Disconnect negative battery terminal to avoid possible fuel discharge if an accidental attempt is made to start the engine. - Loosen fuel filler cap to relieve tank vapor pressure. (Do not tighten until service has been completed.) - The TBI model 220 contains a constant bleed feature in the pressure regulator that relieves pressure. Therefore, no further action is required. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Injector > Component Information > Technical Service Bulletins > Fuel System - Fuel Injector Maintenance Cleaning Fuel Injector: Technical Service Bulletins Fuel System - Fuel Injector Maintenance Cleaning Bulletin No.: 04-06-04-051B Date: January 04, 2006 INFORMATION Subject: Maintenance Cleaning of Fuel Injectors Models: 2006 and Prior All General Motors Passenger Cars and Trucks 2003-2006 HUMMER H2 2006 HUMMER H3 Supercede: This bulletin is being revised to add models and model years and update the name and part number of GM Fuel System Treatment. Please discard Corporate Bulletin Number 04-06-04-051A (Section 06 - Engine/Propulsion System). General Motors is aware that some companies are marketing tools, equipment and programs to support fuel injector cleaning as a preventative maintenance procedure. General Motors does not endorse, support or acknowledge the need for fuel injector cleaning as a preventative maintenance procedure. Fuel injector cleaning is approved only when performed as directed by a published GM driveability or DTC diagnostic service procedure. Due to variation in fuel quality in different areas of the country, the only preventative maintenance currently endorsed by GM regarding its gasoline engine fuel systems is the addition of GM Fuel System Treatment PLUS, P/N 88861011 (for U.S. ACDelco(R), use P/N 88861013) (in Canada, P/N 88861012), added to a tank of fuel at each oil change. Refer to Corporate Bulletin Number 03-06-04-030A for proper cleaning instructions. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Injector > Component Information > Technical Service Bulletins > Fuel System - Fuel Injector Maintenance Cleaning > Page 3920 Fuel Injector: Technical Service Bulletins Tools - Introduction Of The Fuel Injector Tester NO.: 93-I-39 DATE: June, 1993 GROUP: 6 CORP. NO.: 316501R SUBJECT: INFORMATION ON THE INTRODUCTION OF THE FUEL INJECTOR TESTER TOOL J - 39021 This bulletin is being revised to add information about the coil test and a list of driveability problems. In February, 1993, Kent-Moore shipped a new Fuel Injector Tester, tool J-39021, as part of the Essential Tool Program. This tool has the capability of performing injector balance and coil tests on all GM and many non-GM fuel injection systems. The injector balance test is one familiar to most technicians where fuel pressure drop is measured as an injector is energized for a set period of time. This fuel pressure drop is compared to that of the other injectors in the vehicle or a published standard. The injector coil test is a new test whereby the injector's resistance is measured during normal gperation by feeding a fixed current through the injector and measuring the voltage across the injector. Injector coil failures are more accurately detected using this method than by simply measuring the injectors resistance with an ohmmeter. Refer to the instructions included with the tool for testing procedures. This tool, and the injector coil test specifically, were developed to detect deterioration of injector coils due to the introduction of injector cleaners and fuel blends containing high levels of alcohol. Alcohol and water carried by the alcohol may attack and corrode injector coils resulting in a change in coil resistance and one or more of the following driveability symptoms: ^ rough idle ^ engine miss/surge ^ stall after start/hard start ^ fails emission test ^ poor fuel economy ^ exhaust odor The injector coil test procedure also requires the use of the Digital Voltmeter, J-39200, to measure the voltage across the injector during the test. The Fuel Injector Tester, J-39021, supplies one of three fixed current values throughout the duration of the test. Selection of the supply current value (0.5, 2.5, or 4.0 amps) is based on the injector's specified resistance. When the push-to-start-test button is pressed, the tool energizes the injector coil for five seconds. The condition of the injector coil (pass/fail) is determined by the voltage reading displayed on the voltmeter while the injector is energized. Instructions and specifications for most GM fuel injectors are included with the tool. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Injector > Component Information > Technical Service Bulletins > Page 3921 Engine Harness, Right Front Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Injector > Component Information > Diagrams > Exploded Views Throttle Body Assembly (Exploded View) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Injector > Component Information > Diagrams > Exploded Views > Page 3924 Fuel Injector: Connector Views C104 - Injector B C103 - Injector A Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Injector > Component Information > Diagrams > Page 3925 Fuel Injector: Testing and Inspection PROCEDURE - Connect fuel pressure gauge. - Block off (pinch) return line. - Power up fuel pump (engine "OFF") by applying 12 volts to fuel pump "test" terminal. - Verify fuel pressure is stabile and remains constant. - Visually inspect injectors for evidence of fuel dribbling. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Injector > Component Information > Service and Repair > Fuel Injector Cleaning Procedure Fuel Injector: Service and Repair Fuel Injector Cleaning Procedure PROCEDURE: 1. Relieve the system pressure, refer to FUEL SYSTEM PRESSURE RELIEF. 2. Disconnect the fuel supply line from the inlet of the fuel rail. 3. Attach the fuel supply line to the return line. 4. Plug the fuel return fitting at the fuel rail or connect to tester/cleaner depending on configuration. 5. Connect the fuel supply hose from the tester/cleaner to the fuel supply manifold. 6. Turn the tester/cleaner "ON." Tester/cleaner should run 10 minutes. 7. START the engine and check the fuel lines for leakage. If there is any sign of leakage, turn the vehicle and the tester/cleaner "OFF" and repair the location where fuel is leaking. Then return to Step 6. 8. When the engine speed has stabilized, set the idle speed at 2000 rpm. Run the remainder of the 10 minute cycle to eliminate all the air in the fuel supply hose and fuel rail. 9. Turn power switch "OFF" and disconnect power lines. 10. Disconnect cleaner supply hose from the fuel supply manifold. 11. Connect vehicle fuel lines. START engine and check for leaks. Lubricate O-rings prior to installation and ensure fuel lines are securely connected. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Injector > Component Information > Service and Repair > Fuel Injector Cleaning Procedure > Page 3928 Fuel Injector: Service and Repair Fuel Injector(S) Replacement CAUTION - Each fuel injector is serviced as a complete assembly only. - Use care in removing the fuel injectors to prevent damage to the electrical connector terminals, the injector filter, and the fuel nozzle. The fuel injector is serviced as a complete assembly only. Also, since the injectors are electrical components, they should not be immersed in any type of liquid solvent or cleaner as damage could occur. Fuel Injector Removal REMOVE/DISCONNECT - Electrical connectors to fuel injectors. (Squeeze plastic tabs and pull straight up.) - Fuel meter cover assembly. See: Throttle Body/Service and Repair/Fuel Meter Cover Assembly - With fuel meter cover gasket in place to prevent damage to casting, use a screwdriver and fulcrum to carefully lift out each injector. - Lower (small) O-rings from nozzle of injectors and discard. - Fuel meter cover gasket and discard. - Upper (large) O-rings and steel backup washers from top of fuel injector cavity and discard. INSPECT Fuel injector filter for evidence of dirt and contamination. If present, check for presence of dirt in fuel lines and fuel tank. If dirt is present refer to FUEL SYSTEM CLEANING. Fuel Injector Part Number Location NOTE Be sure to replace the injector with an identical part. Different injectors with different flow rates will fit this unit, but are calibrated for different flow rates. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Injector > Component Information > Service and Repair > Fuel Injector Cleaning Procedure > Page 3929 Fuel Injector Installation INSTALL/CONNECT - Lubricate new lower (small) O-rings with clean engine oil and push on nozzle end of injector until it presses against injector fuel filter. - Steel injector back up washer in counterbore of fuel meter body. - Lubricate new upper (large) O-rings with clean engine oil and install directly over the back up washer. Be sure the O-ring is seated properly and is flush with top of fuel meter body surface. NOTE Backup washers and O-rings must be installed before injectors or improper seating of large O-rings could cause fuel to leak. - Injector, aligning raised lug on each injector base with notch in fuel meter body cavity. Push down on injector until it is fully seated in the fuel meter body. (Electrical terminals of the injector should be parallel with throttle shaft). - Fuel meter cover gasket. - Fuel meter cover. - Electrical connectors to fuel injectors. INSPECT Turn ignition switch to "ON" position for two seconds, then turn to "OFF" position for ten seconds. Again turn ignition switch to "ON" position and check for leaks around gaskets and fuel line couplings. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Pressure Regulator > Component Information > Locations Fuel Pressure Regulator: Locations Fuel Pressure Regulator Throttle Body Assembly (Exploded View) The fuel pressure regulator assembly is located on the top of the engine, inside the throttle body. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Pressure Regulator > Component Information > Locations > Page 3933 Fuel Pressure Regulator: Service and Repair Fuel Pressure Regulator The fuel pressure regulator assembly is located on the top of the engine, inside the throttle body. Please refer to Powertrain Management/Fuel Delivery and Air Induction/Throttle Body/Service and Repair/Procedures. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Pressure Pulsation Damper > Component Information > Technical Service Bulletins > Customer Interest: > 66-63-09 > Apr > 97 > Engine Hard Start or No Start Fuel Pressure Pulsation Damper: Customer Interest Engine - Hard Start or No Start File In Section: 6E - Engine Fuel & Emission Bulletin No.: 66-63-09 Date: April, 1997 Subject: Engine Hard Start or No Start (Replace Fuel Pump Pulsator) Models: 1992-96 Chevrolet and GMC Trucks 1992-96 Oldsmobile Bravada with Gasoline Engines Condition Some owners may report their engine is hard to start or will not start. Cause The fuel delivery system may have low or no pressure due to a ruptured fuel pump pulsator The pulsator is the flexible connector between the fuel pump and the metal fuel line in the tank. This rupture appears as a tear in the pulsator openings and is the result of exposure to gasoline containing a high percentage of ethanol. Correction Follow the Strategy Based Diagnostic Steps for the reported symptoms. If diagnosis reveals low or no fuel system pressure, and the fuel pump is identified as a possible cause, follow the service procedure for, On-Vehicle Service, Fuel Pump, in the appropriate Truck Service Manual. Before replacing the fuel pump, inspect the pulsator for signs of tears or leaks It the pulsator is damaged, replace it with P/N 25175836 and re-test the fuel system for normal pressure. This pulsator is made of Viton which is resistant to Ethanol content fuels. P/N 25175836 replaces P/N 25094266 for trucks. This change will appear in GMSPO parts catalogs as they are revised. Part Information P/N Description QTY 25175836 Damper Asm - Fuel Pulsator 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use the table. Labor Op Description Labor Time J 5590 Pump, Fuel R&R; Use Published Labor Time Important: Labor operation is coded to base vehicle coverage in the warranty system. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Pressure Pulsation Damper > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Fuel Pressure Pulsation Damper: > 66-63-09 > Apr > 97 > Engine - Hard Start or No Start Fuel Pressure Pulsation Damper: All Technical Service Bulletins Engine - Hard Start or No Start File In Section: 6E - Engine Fuel & Emission Bulletin No.: 66-63-09 Date: April, 1997 Subject: Engine Hard Start or No Start (Replace Fuel Pump Pulsator) Models: 1992-96 Chevrolet and GMC Trucks 1992-96 Oldsmobile Bravada with Gasoline Engines Condition Some owners may report their engine is hard to start or will not start. Cause The fuel delivery system may have low or no pressure due to a ruptured fuel pump pulsator The pulsator is the flexible connector between the fuel pump and the metal fuel line in the tank. This rupture appears as a tear in the pulsator openings and is the result of exposure to gasoline containing a high percentage of ethanol. Correction Follow the Strategy Based Diagnostic Steps for the reported symptoms. If diagnosis reveals low or no fuel system pressure, and the fuel pump is identified as a possible cause, follow the service procedure for, On-Vehicle Service, Fuel Pump, in the appropriate Truck Service Manual. Before replacing the fuel pump, inspect the pulsator for signs of tears or leaks It the pulsator is damaged, replace it with P/N 25175836 and re-test the fuel system for normal pressure. This pulsator is made of Viton which is resistant to Ethanol content fuels. P/N 25175836 replaces P/N 25094266 for trucks. This change will appear in GMSPO parts catalogs as they are revised. Part Information P/N Description QTY 25175836 Damper Asm - Fuel Pulsator 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use the table. Labor Op Description Labor Time J 5590 Pump, Fuel R&R; Use Published Labor Time Important: Labor operation is coded to base vehicle coverage in the warranty system. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Pressure Pulsation Damper > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Fuel Pressure Pulsation Damper: > 666309 > Apr > 97 > Engine - Hard Start Or No Start Fuel Pressure Pulsation Damper: All Technical Service Bulletins Engine - Hard Start Or No Start File In Section: 6E Engine Fuel & Emission Bulletin No.: 66-63-09 Date: April, 1997 Subject: Engine Hard Start or No Start (Replace Fuel Pump Pulsator) Models: 1992-96 Chevrolet and GMC Trucks 1992-96 Oldsmobile Bravada with Gasoline Engines Condition Some owners may report their engine is hard to start or will not start. Cause The fuel delivery system may have low or no pressure due to a ruptured fuel pump pulsator. The pulsator is the flexible connector between the fuel pump and the metal fuel line in the tank. This rupture appears as a tear in the pulsator openings and is the result of exposure to gasoline containing a high percentage of ethanol. Correction Follow the Strategy Based Diagnostic Steps for the reported symptoms. If diagnosis reveals low or no fuel system pressure, and the fuel pump is identified as a possible cause, follow the service procedure for, On-Vehicle Service, Fuel Pump, in the appropriate Truck Service Manual. Before replacing the fuel pump, inspect the pulsator for signs of tears or leaks. If the pulsator is damaged, replace it with P/N 25175836 and re-test the fuel system for normal pressure. This pulsator is made of Viton which is resistant to Ethanol content fuels. P/N 25175836 replaces P/N 25094266 for trucks. This change will appear in GMSPO parts catalogs as they are revised. Part Information P/N Description Qty 25175836 Damper Asm - Fuel Pulsator 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty. use: Labor Op Description Labor Time Use Published Labor J 5590 Pump, Fuel R&R; Operation Time Important: Labor operation is coded to base vehicle coverage in the warranty system. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Pressure Pulsation Damper > Component Information > Technical Service Bulletins > All Other Service Bulletins for Fuel Pressure Pulsation Damper: > 666309 > Apr > 97 > Engine - Hard Start Or No Start Fuel Pressure Pulsation Damper: All Technical Service Bulletins Engine - Hard Start Or No Start File In Section: 6E Engine Fuel & Emission Bulletin No.: 66-63-09 Date: April, 1997 Subject: Engine Hard Start or No Start (Replace Fuel Pump Pulsator) Models: 1992-96 Chevrolet and GMC Trucks 1992-96 Oldsmobile Bravada with Gasoline Engines Condition Some owners may report their engine is hard to start or will not start. Cause The fuel delivery system may have low or no pressure due to a ruptured fuel pump pulsator. The pulsator is the flexible connector between the fuel pump and the metal fuel line in the tank. This rupture appears as a tear in the pulsator openings and is the result of exposure to gasoline containing a high percentage of ethanol. Correction Follow the Strategy Based Diagnostic Steps for the reported symptoms. If diagnosis reveals low or no fuel system pressure, and the fuel pump is identified as a possible cause, follow the service procedure for, On-Vehicle Service, Fuel Pump, in the appropriate Truck Service Manual. Before replacing the fuel pump, inspect the pulsator for signs of tears or leaks. If the pulsator is damaged, replace it with P/N 25175836 and re-test the fuel system for normal pressure. This pulsator is made of Viton which is resistant to Ethanol content fuels. P/N 25175836 replaces P/N 25094266 for trucks. This change will appear in GMSPO parts catalogs as they are revised. Part Information P/N Description Qty 25175836 Damper Asm - Fuel Pulsator 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty. use: Labor Op Description Labor Time Use Published Labor J 5590 Pump, Fuel R&R; Operation Time Important: Labor operation is coded to base vehicle coverage in the warranty system. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Pump > Fuel Pressure > Diagnostic Connector - Fuel Pump > Component Information > Locations Component Location - "S/T" 4.3Z Utility - Manual Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Pump > Fuel Pump Relay > Component Information > Technical Service Bulletins > Customer Interest for Fuel Pump Relay: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking Fuel Pump Relay: Customer Interest Engine - Will Not Start Readily Upon Cranking File In Section: 6E - Engine Fuel & Emission Bulletin No.: 56-63-05A Date: January, 1996 Subject: Vehicle Does Not Start Readily Upon Cranking (Replace Fuel Pump Relay) Models: 1993-94 Chevrolet and GMC Truck M/L Vans 1994 Chevrolet and GMC Truck S/T Utility 1994 Oldsmobile Bravada with 4.3L Engine (VIN W, Z - RPOs L35, LB4) This bulletin is being revised to change the correction procedure and parts information and to add the L Van and artwork. Please discard Corporate Bulletin Number 56-63-05 (Section 6E - Engine Fuel & Emission). Condition Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Pump > Fuel Pump Relay > Component Information > Technical Service Bulletins > Customer Interest for Fuel Pump Relay: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking > Page 3969 Some owners may experience extended engine crank times on cold start and may set diagnostic trouble code 54 and activate the M/L (Check Engine light). Cause This condition may be due to failure of the fuel pump relay. Correction Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Pump > Fuel Pump Relay > Component Information > Technical Service Bulletins > Customer Interest for Fuel Pump Relay: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking > Page 3970 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Pump > Fuel Pump Relay > Component Information > Technical Service Bulletins > Customer Interest for Fuel Pump Relay: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking > Page 3971 Verify condition using the normal diagnostic procedure in the service manual. Replace the Fuel Pump Relay (P/N 12077867) following the service manual procedure. Replace the connector (Kit P/N 12166225) following the instructions in Figures 3 and 4. Note that each of the four cavities of the old connector are lettered. The new connector is numbered and it should be wired according to Figure 3 and not the instructions contained within the connector kit. Parts Information P/N Description Qty 12077867 Fuel Pump Relay 1 12166225 Connector 1 12129073 Bracket (S/T Only) 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: Labor Operation Description Labor Time J5460 Relay, Fuel Pump- Use Published Replace Labor Operation Time Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Pump > Fuel Pump Relay > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Fuel Pump Relay: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking Fuel Pump Relay: All Technical Service Bulletins Engine - Will Not Start Readily Upon Cranking File In Section: 6E - Engine Fuel & Emission Bulletin No.: 56-63-05A Date: January, 1996 Subject: Vehicle Does Not Start Readily Upon Cranking (Replace Fuel Pump Relay) Models: 1993-94 Chevrolet and GMC Truck M/L Vans 1994 Chevrolet and GMC Truck S/T Utility 1994 Oldsmobile Bravada with 4.3L Engine (VIN W, Z - RPOs L35, LB4) This bulletin is being revised to change the correction procedure and parts information and to add the L Van and artwork. Please discard Corporate Bulletin Number 56-63-05 (Section 6E - Engine Fuel & Emission). Condition Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Pump > Fuel Pump Relay > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Fuel Pump Relay: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking > Page 3977 Some owners may experience extended engine crank times on cold start and may set diagnostic trouble code 54 and activate the M/L (Check Engine light). Cause This condition may be due to failure of the fuel pump relay. Correction Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Pump > Fuel Pump Relay > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Fuel Pump Relay: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking > Page 3978 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Pump > Fuel Pump Relay > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Fuel Pump Relay: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking > Page 3979 Verify condition using the normal diagnostic procedure in the service manual. Replace the Fuel Pump Relay (P/N 12077867) following the service manual procedure. Replace the connector (Kit P/N 12166225) following the instructions in Figures 3 and 4. Note that each of the four cavities of the old connector are lettered. The new connector is numbered and it should be wired according to Figure 3 and not the instructions contained within the connector kit. Parts Information P/N Description Qty 12077867 Fuel Pump Relay 1 12166225 Connector 1 12129073 Bracket (S/T Only) 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: Labor Operation Description Labor Time J5460 Relay, Fuel Pump- Use Published Replace Labor Operation Time Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Pump > Fuel Pump Relay > Component Information > Technical Service Bulletins > Page 3980 Fuel Pump Relay: Locations FUEL PUMP RELAY Fuel Pump Relay The Fuel Pump Relay is located on the driver side firewall, near brake booster. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Pump > Fuel Pump Relay > Component Information > Technical Service Bulletins > Page 3981 C124 - Fuel Pump Relay Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Pump > Fuel Pump Relay > Component Information > Technical Service Bulletins > Page 3982 Fuel Pump Relay: Description and Operation When the ignition key is first turned to the "ON" position, the control module will energize the fuel pump relay as long as the engine is cranking or running, and the control module is receiving distributor reference pulses. If there are no reference pulses, the control module will shut "OFF" the fuel pump relay within two seconds. An inoperative fuel pump relay can result in extended crank times, particularily if the engine is cold. The oil pressure switch will turn "ON" the fuel pump, as soon as oil pressure reaches about 28 kPa (4 psi). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Pump > Fuel Pump Relay > Component Information > Technical Service Bulletins > Page 3983 Fuel Pump Relay: Testing and Inspection *** UPDATED BY TSB 893206E, DATED OCTOBER 90 When the key is first turned ON, without the engine running, the ECM will turn the fuel pump relay ON for two seconds. This builds up the fuel pressure to normal operating pressure. If the engine is not started within two seconds, the ECM will shut the fuel pump OFF and wait until ignition reference pulses are present. As soon as the engine is cranked, the ECM turns the relay ON, which powers the fuel pump. The ECM continues to power the fuel pump during engine operation. If the fuel pump relay fails, it is backed up by the oil pressure switch, which continues to operate the fuel pump as long as oil pressure remains above 28.0 kPa (4 psi). RESULTS OF INCORRECT FUEL PUMP SYSTEM OPERATION - A faulty fuel pump relay can result in long cranking times, particularly if the engine is cold. - An inoperative fuel pump would cause a no start condition. - A fuel pump which does not provide enough pressure can result in poor performance. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Pump > Fuel Pump Relay > Component Information > Technical Service Bulletins > Page 3984 Fuel Pump Relay: Service and Repair Relay Center 2.5L,2.8L S REMOVE/DISCONNECT 1. Verify that ignition switch is in the "OFF" position. 2. Retainer, if installed. 3. Electrical connector. 4. Fuel pump relay by depressing bracket clip at rear of relay, or removing bolts from retaining bracket. INSTALL/DISCONNECT 1. Fuel pump relay. 2. Electrical connector. 3. Retainer. 4. Verify correct operation to confirm repair. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Return Line > Component Information > Service and Repair Fuel Return Line: Service and Repair NOTES When replacing fuel feed and return pipes, always replace them with original equipment or parts that meet GM specifications for those parts. The replacement pipe must have the same type fittings as the original pipes to ensure the integrity of the connection. Do NOT use copper or aluminum tubing to replace steel tubing. Only tubing meeting the 124M specification or its equivalent is capable of meeting all pressure and vibration characteristics necessary to ensure the durability standard required. Many of the feed and return pipes use screw couplings with O-rings. Any time these fittings are loosened to service or to replace components, ensure that: A back-up wrench is used to loosen and tighten fittings. - Check all O-rings at these locations (if applicable) for cuts or any damage and replace as necessary. - Use correct torque when tightening these fittings. - Inspect all pipes for kinks, leaks or dents. - Pipes must be properly secured to the frame to prevent chafing. A minimum of 6 mm (1/4 inch) clearance must be maintained around a pipe to prevent contact or chafing. - Fuel feed and return pipes are secured to the underbody with clamps and screw assemblies. - Follow the same routing as the original pipe. - Fuel pipes must not contact the fuel tank or underbody at any point. FUEL AND VAPOR PIPE REPAIR When it is impractical to replace an entire fuel line to repair localized damage, use the following procedure: When rubber hose is used to replace pipe, use only reinforced fuel-resistant hose which is identified with the word "Fluoroelastomer" on the hose. The inside diameter of the hose must match the outside pipe diameter. - Do NOT use rubber hose within 100 mm (4 inches) of any part of the exhaust system, or within 254 mm (10 inches) of the catalytic converter. - In repairable areas, cut a piece of hose 100 mm (4 inches) longer than the portion of line removed. If more than a 6 inch length of pipe is removed, use a combination of steel pipe and hose so that hose lengths will not be more than 254 mm (10 inches). - Follow the same routing as the original pipe. - Cut the ends of the pipe, remaining on the car, square with a tubing cutter. Using the first step of a double flaring tool, form a bead on the end of each pipe section. If the pipe is too corroded to withstand the beading operation without damage, the pipe should be replaced. If a new section of pipe is used, form a bead on both ends of it also. - Use a screw type hose clamp NO. #2494772, or equivalent. Slide the clamps onto the pipe and push hoses 51 mm (2 inches) onto each portion of the fuel pipe. Tighten the clamps on each side of the repair. - Pipes must be properly secured to the frame to prevent chafing. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Supply Line > Component Information > Service and Repair Fuel Supply Line: Service and Repair NOTES When replacing fuel feed and return pipes, always replace them with original equipment or parts that meet GM specifications for those parts. The replacement pipe must have the same type fittings as the original pipes to ensure the integrity of the connection. Do NOT use copper or aluminum tubing to replace steel tubing. Only tubing meeting the 124M specification or its equivalent is capable of meeting all pressure and vibration characteristics necessary to ensure the durability standard required. Many of the feed and return pipes use screw couplings with O-rings. Any time these fittings are loosened to service or to replace components, ensure that: A back-up wrench is used to loosen and tighten fittings. - Check all O-rings at these locations (if applicable) for cuts or any damage and replace as necessary. - Use correct torque when tightening these fittings. - Inspect all pipes for kinks, leaks or dents. - Pipes must be properly secured to the frame to prevent chafing. A minimum of 6 mm (1/4 inch) clearance must be maintained around a pipe to prevent contact or chafing. - Fuel feed and return pipes are secured to the underbody with clamps and screw assemblies. - Follow the same routing as the original pipe. - Fuel pipes must not contact the fuel tank or underbody at any point. FUEL AND VAPOR PIPE REPAIR When it is impractical to replace an entire fuel line to repair localized damage, use the following procedure: When rubber hose is used to replace pipe, use only reinforced fuel-resistant hose which is identified with the word "Fluoroelastomer" on the hose. The inside diameter of the hose must match the outside pipe diameter. - Do NOT use rubber hose within 100 mm (4 inches) of any part of the exhaust system, or within 254 mm (10 inches) of the catalytic converter. - In repairable areas, cut a piece of hose 100 mm (4 inches) longer than the portion of line removed. If more than a 6 inch length of pipe is removed, use a combination of steel pipe and hose so that hose lengths will not be more than 254 mm (10 inches). - Follow the same routing as the original pipe. - Cut the ends of the pipe, remaining on the car, square with a tubing cutter. Using the first step of a double flaring tool, form a bead on the end of each pipe section. If the pipe is too corroded to withstand the beading operation without damage, the pipe should be replaced. If a new section of pipe is used, form a bead on both ends of it also. - Use a screw type hose clamp NO. #2494772, or equivalent. Slide the clamps onto the pipe and push hoses 51 mm (2 inches) onto each portion of the fuel pipe. Tighten the clamps on each side of the repair. - Pipes must be properly secured to the frame to prevent chafing. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Tank > Fuel Filler Hose > Component Information > Locations Fuel Filler Neck Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Tank > Fuel Gauge Sender > Component Information > Locations > Fuel Pump Sending Unit Fuel Gauge Sender: Locations Fuel Pump Sending Unit Rear Lamps Crossbody Harness W/O Trailer Tow Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Tank > Fuel Gauge Sender > Component Information > Locations > Fuel Pump Sending Unit > Page 3999 Rear Lamps Harness W/Trailer Tow Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Tank > Fuel Gauge Sender > Component Information > Locations > Fuel Pump Sending Unit > Page 4000 Fuel Pump And Sender Assembly (Typical) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Tank > Fuel Gauge Sender > Component Information > Locations > Page 4001 Fuel Gauge Sender: Service and Repair Fuel Pump And Sender Assembly (Typical) REMOVE/DISCONNECT - Negative battery cable. - Raise vehicle. - Fuel tank. - Pump and sending unit assembly by turning cam lock counterclockwise using tool J-36608 or J-24187 or equivalent. Pull fuel pump up into attaching hose while pulling outward from the bottom support. Do not damage rubber insulator or strainer. INSPECT - Inspect fuel pump attaching hose for signs of deterioration. - Inspect rubber sound insulation at bottom of pump for deterioration. INSTALL/CONNECT - Pump assembly into attaching hose. NOTE: Care should be taken not to fold over or twist strainer when installing sending unit as this will restrict fuel flow. Sending unit and fuel pump assembly into fuel tank. (Always use a new O-ring seal). - Cam lock assembly. Turn cam lock clockwise to lock it. - Fuel tank assembly. - Negative battery cable. - START vehicle and check for fuel leaks. - Lower vehicle. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Fuel Tank Unit > Component Information > Service and Repair Fuel Tank Unit: Service and Repair Fuel Pump And Sender Assembly (Typical) REMOVE/DISCONNECT - Negative battery cable. - Raise vehicle. - Fuel tank. - Pump and sending unit assembly by turning cam lock counterclockwise using tool J-36608 or J-24187 or equivalent. Pull fuel pump up into attaching hose while pulling outward from the bottom support. Do not damage rubber insulator or strainer. INSPECT - Inspect fuel pump attaching hose for signs of deterioration. - Inspect rubber sound insulation at bottom of pump for deterioration. INSTALL/CONNECT - Pump assembly into attaching hose. NOTE: Care should be taken not to fold over or twist strainer when installing sending unit as this will restrict fuel flow. Sending unit and fuel pump assembly into fuel tank. (Always use a new O-ring seal). - Cam lock assembly. Turn cam lock clockwise to lock it. - Fuel tank assembly. - Negative battery cable. - START vehicle and check for fuel leaks. - Lower vehicle. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Idle Speed/Throttle Actuator Electronic > Component Information > Specifications Idle Speed/Throttle Actuator - Electronic: Specifications Actuator Resistance Values Actuator Resistance Values Terminals "A" To "B" 40 to 80 ohms Terminals "C" to "D" 40 to 80 ohms Terminals "B" to "C" Infinite ohms Terminals "A" to "D" Infinite ohms Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Idle Speed/Throttle Actuator Electronic > Component Information > Specifications > Page 4008 Engine Harness, Right Front Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Idle Speed/Throttle Actuator Electronic > Component Information > Diagrams > Exploded Views Throttle Body Assembly (Exploded View) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Idle Speed/Throttle Actuator Electronic > Component Information > Diagrams > Exploded Views > Page 4011 C111 - IAC Motor Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Idle Speed/Throttle Actuator Electronic > Component Information > Diagrams > Page 4012 Idle Speed/Throttle Actuator - Electronic: Description and Operation Idle Air Control (IAC) System Idle Air Control Valve IAC System PURPOSE To control engine idle speed and prevent stalling due to changes in engine load. OPERATION All engine idle speeds are controlled by the control module through the Idle Air Control (IAC) valve mounted on the throttle body. The control module sends voltage pulses to the IAC motor windings causing the IAC motor shaft and pintle to move "IN" or "OUT" a given distance (number of Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Idle Speed/Throttle Actuator Electronic > Component Information > Diagrams > Page 4013 steps) for each pulse (called counts). Inward movement of the pintle = Decreased RPM =Lower Counts. Outward movement of the pintle = Increased RPM = Higher Counts. This movement controls airflow around the throttle plate, which in turn, controls engine idle speed, either cold or hot. IAC valve pintle position counts can be seen using a Tech 1 scan tool. Zero (0) counts correspond to a fully closed passage, while 140 counts or more (depending on the application) corresponds to full flow. - Actual or "controlled" idle speed is obtained by the control module positioning the IAC valve pintle. Resulting idle speed is generated from the total idle air flow (IAC/passage + PCV + throttle valve + vacuum leaks). - Controlled idle speed is always specified for normal operating conditions. Normal operating condition is engine coolant temperature in operating range, the A/C is "OFF," manual transmission is in neutral or automatic transmission in drive with proper Park/Neutral Position (PNP) switch adjustment. A high or low engine coolant temperature, or A/C clutch engagement may signal the control module to change the IAC counts. - The minimum idle speed is set at the factory with a stop screw. This setting allows enough air flow by the throttle valves to cause the IAC valve pintle to be positioned a calibrated number of steps (counts) from the seat during normal controlled idle operation. The IAC counts will be higher than normal on an engine with less than 500 miles, or an engine operating at high altitude or an engine with an accessory load such as the alternator, A/C, power steering or hydra-boost brakes activated. Results of Incorrect Operation If the pintle is stuck open, the idle speed will remain high. If the pintle is stuck closed, the idle speed will be too low, and stalling may occur. If the pintle is stuck partially open, the idle speed will be higher than normal, and there will be no response to changes in engine load such as A/C ("ON") or transmission in ("Drive"). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Idle Speed/Throttle Actuator Electronic > Component Information > Testing and Inspection > PCM Charts Idle Speed/Throttle Actuator - Electronic: Testing and Inspection PCM Charts Idle Air Control (IAC) System Check Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Idle Speed/Throttle Actuator Electronic > Component Information > Testing and Inspection > PCM Charts > Page 4016 Circuit Description The control module controls engine idle speed with the IAC valve. To increase idle speed, the control module retracts the IAC valve pintle away from its seat, allowing more air to pass by the throttle bore. To decrease idle speed, it extends the IAC valve pintle towards its seat, reducing bypass air flow. A Tech 1 scan tool will read the control module commands to the IAC valve in counts. Higher the counts indicate more air bypass (higher idle). The lower the counts indicate less air is allowed to bypass (lower idle). Test Description Number(s) below refer to circled number(s) on the diagnostic chart. 1. The IAC tester is used to extend and retract the IAC valve. Valve movement is verified by an engine speed change. If no change in engine speed occurs, the valve can be retested when removed from the throttle body. 2. This step checks the quality of the IAC movement in Step 1. Between 700 RPM and about 1500 RPM the engine speed should change smoothly with each flash of the tester light in both extend and retract. If the IAC valve is retracted beyond the control range (about 1500 RPM), it may take many flashes in the extend position before engine speed will begin to drop. This is normal on certain engines, fully extending IAC may cause engine stall. This may be normal. 3. Steps 1 and 2 verified proper IAC valve operation while this step checks the IAC circuits. Each lamp on the node light should flash red and green while the IAC valve is cycled. While the sequence of color is not important if either light is "OFF" or does not flash red and green, check the circuits for faults beginning with poor terminal contacts. IAC VALVE RESET PROCEDURE ^ Disconnect battery cable at battery for 10 seconds then reconnect cable. ^ Ignition "ON," engine "OFF" for 5 seconds. ^ Ignition "OFF" for 10 seconds. Diagnostic Aids A slow, unstable, or fast idle may be caused by a non-IAC system problem that cannot be overcome by the IAC valve. Out of control range, IAC Tech 1 scan tool counts will be above 60 if idle is too low, and zero counts if idle is too high. The following checks should be made to repair a non-IAC system problem. ^ Vacuum Leak (High Idle) - If idle is too high, stop the engine. Fully extend (low) IAC with tester. Start engine. If idle speed is above 800 RPM, locate and correct vacuum leak including crankcase ventilation system. Also, check for binding of throttle blade or linkage. ^ System Too Rich (Low Air Fuel Ratio) The idle speed will be too low. Tech 1 scan tool IAC counts will usually be above 80. System is obviously rich and may exhibit black smoke in exhaust. Tech 1 scan tool O2 voltage will be fixed above 800 mV (.8 volt). Check for high fuel pressure, leaking or sticking injector. Silicone contaminated 02S scan voltage will be slow to respond. ^ Throttle Body - Remove IAC valve and inspect bore for foreign material. ^ IAC Valve Electrical Connections - IAC valve connections should be carefully checked for proper contact. ^ Crankcase Ventilation Valve - An incorrect or faulty crankcase ventilation valve may result in an incorrect idle speed. Refer to "Rough, Unstable, Incorrect Idle or Stalling". ^ A/C Compressor - Refer to A/C diagnosis if circuit is shorted to ground. If the relay is faulty, an idle problem may exist. Refer to "Rough, Unstable, Incorrect Idle or Stalling". ^ If intermittent poor driveability or idle symptoms are resolved by disconnecting the IAC, carefully recheck connections, valve terminal resistance or replace IAC. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Idle Speed/Throttle Actuator Electronic > Component Information > Testing and Inspection > PCM Charts > Page 4017 Idle Speed/Throttle Actuator - Electronic: Testing and Inspection VCM Charts Idle Air Control (IAC) System Check Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Idle Speed/Throttle Actuator Electronic > Component Information > Testing and Inspection > PCM Charts > Page 4018 Circuit Description The control module controls engine idle speed with the IAC valve. To increase idle speed, the control module retracts the IAC valve pintle away from its seat, allowing more air to pass by the throttle bore. To decrease idle speed, it extends the IAC valve pintle towards its seat, reducing bypass air flow. A Tech 1 scan tool will read the control module commands to the IAC valve in counts. Higher the counts indicate more air bypass (higher idle). The lower the counts indicate less air is allowed to bypass (lower idle). Test Description Number(s) below refer to circled number(s) on the diagnostic chart. 1. The IAC tester is used to extend and retract the IAC valve. Valve movement is verified by an engine speed change. If no change in engine speed occurs, the valve can be retested when removed from the throttle body. 2. This step checks the quality of the IAC movement in Step 1. Between 700 RPM and about 1500 RPM the engine speed should change smoothly with each flash of the tester light in both extend and retract. If the IAC valve is retracted beyond the control range (about 1500 RPM), it may take many flashes in the extend position before engine speed will begin to drop. This is normal on certain engines, fully extending IAC may cause engine stall. This may be normal. 3. Steps 1 and 2 verified proper IAC valve operation while this step checks the IAC circuits. Each lamp on the node light should flash red and green while the IAC valve is cycled. While the sequence of color is not important if either light is "OFF" or does not flash red and green, check the circuits for faults beginning with poor terminal contacts. IAC VALVE RESET PROCEDURE ^ Disconnect battery cable at battery for 10 seconds then reconnect cable. ^ Ignition "ON," engine "OFF" for 5 seconds. ^ Ignition "OFF" for 10 seconds. Diagnostic Aids A slow, unstable, or fast idle may be caused by a non-IAC system problem that cannot be overcome by the IAC valve. Out of control range, IAC Tech 1 scan tool counts will be above 60 if idle is too low, and zero counts if idle is too high. The following checks should be made to repair a non-IAC system problem. ^ Vacuum Leak (High Idle) - If idle is too high, stop the engine. Fully extend (low) IAC with tester. Start engine. If idle speed is above 800 RPM, locate and correct vacuum leak including crankcase ventilation system. Also, check for binding of throttle blade or linkage. ^ System Too Rich (Low Air Fuel Ratio) The idle speed will be too low. Tech 1 scan tool IAC counts will usually be above 80. System is obviously rich and may exhibit black smoke in exhaust. Tech 1 scan tool O2 voltage will be fixed above 800 mV (.8 volt). Check for high fuel pressure, leaking or sticking injector. Silicone contaminated 02S scan voltage will be slow to respond. ^ Throttle Body - Remove IAC valve and inspect bore for foreign material. ^ IAC Valve Electrical Connections - IAC valve connections should be carefully checked for proper contact. ^ Crankcase Ventilation Valve - An incorrect or faulty crankcase ventilation valve may result in an incorrect idle speed. Refer to "Rough, Unstable, Incorrect Idle or Stalling". ^ A/C Compressor - Refer to A/C diagnosis if circuit is shorted to ground. If the relay is faulty, an idle problem may exist. Refer to "Rough, Unstable, Incorrect Idle or Stalling". ^ If intermittent poor driveability or idle symptoms are resolved by disconnecting the IAC, carefully recheck connections, valve terminal resistance or replace IAC. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Idle Speed/Throttle Actuator Electronic > Component Information > Testing and Inspection > Page 4019 Idle Speed/Throttle Actuator - Electronic: Service and Repair NOTES - The Idle Air Control (IAC) valve is an electrical component and must not be soaked in any liquid cleaner or solvent. Otherwise damage could result. - The IAC valve for this application is thread-mounted and has a dual taper, 10 mm diameter, pintle. Any replacement of the IAC valve must have the correct part number, with the appropriate pintle taper and diameter for proper seating of the valve in the throttle body. IAC Thread Mounted 10mm Pintle REMOVE/DISCONNECT - Electrical connector. - IAC valve, use a 32 mm (1 1/4") wrench. - IAC gasket and discard. CLEAN - Both original and replacement IAC valves have a special factory applied thread-locking compound applied to the screw threads. If the valve removed from throttle body is being reinstalled, DO NOT remove thread-locking that may remain on the threads. - Clean IAC valve seating surfaces on throttle body to assure proper seal of new gasket and IAC valve. Idle Air Control Valve Pintle Retraction (Manually) NOTES - If the IAC valve was removed during service, its operation may be tested electrically with the IAC/ISC Motor Tester (J-37027 or BT-8256K) or equivalent. Before installing IAC valve, measure the distance between the tip of the valve pintle and mounting surface. If the dimension is greater than 28.0 mm (1.10 inches), valve pintle must be retracted to prevent damage to valve. This may be done electrically using an IAC/ISC Motor Tester or manually by exerting firm pressure, as shown in the illustration, with a slight side to side movement on valve pintle to retract it. - No physical adjustment of the IAC valve assembly is required after installation. The IAC valve pintle is reset by turning the ignition "ON" for ten seconds and then OFF. The ECM then resets the pintle to the correct position. Proper idle regulation should result. INSTALL/CONNECT - IAC valve into throttle body with new gasket. NOTE New IAC valves have been reset at the factory and should be installed in throttle body in an "as is" condition, without any adjustment. - Tighten IAC valve assembly to 18.0 Nm (13.0 lb-ft). - Electrical connector to IAC valve. - Reset IAC valve pintle position as follows: - Depress accelerator pedal slightly. - "START" and run engine for five seconds. - Turn ignition "OFF" for ten seconds. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Idle Speed/Throttle Actuator Electronic > Component Information > Testing and Inspection > Page 4020 - Restart engine and check for proper idle operation. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Intake Air Duct > Component Information > Locations Air Intake Ducts S/T PUP TBI Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Automatic Transmission LH Rear Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Automatic Transmission > Page 4028 Rear Engine Wiring W/Man Trans Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Page 4029 C120 - Fuel Pump Oil Pressure Sender/Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Page 4030 Oil Pressure Switch (For Fuel Pump): Service and Repair REMOVE/DISCONNECT - Negative battery cable from battery. - Sensor or switch connectors. - Sensor or switch. INSTALL/CONNECT - Sensor or switch. - Sensor or switch. - Negative battery cable. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > Customer Interest for Fuel Pump Relay: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking Fuel Pump Relay: Customer Interest Engine - Will Not Start Readily Upon Cranking File In Section: 6E - Engine Fuel & Emission Bulletin No.: 56-63-05A Date: January, 1996 Subject: Vehicle Does Not Start Readily Upon Cranking (Replace Fuel Pump Relay) Models: 1993-94 Chevrolet and GMC Truck M/L Vans 1994 Chevrolet and GMC Truck S/T Utility 1994 Oldsmobile Bravada with 4.3L Engine (VIN W, Z - RPOs L35, LB4) This bulletin is being revised to change the correction procedure and parts information and to add the L Van and artwork. Please discard Corporate Bulletin Number 56-63-05 (Section 6E - Engine Fuel & Emission). Condition Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > Customer Interest for Fuel Pump Relay: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking > Page 4040 Some owners may experience extended engine crank times on cold start and may set diagnostic trouble code 54 and activate the M/L (Check Engine light). Cause This condition may be due to failure of the fuel pump relay. Correction Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > Customer Interest for Fuel Pump Relay: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking > Page 4041 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > Customer Interest for Fuel Pump Relay: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking > Page 4042 Verify condition using the normal diagnostic procedure in the service manual. Replace the Fuel Pump Relay (P/N 12077867) following the service manual procedure. Replace the connector (Kit P/N 12166225) following the instructions in Figures 3 and 4. Note that each of the four cavities of the old connector are lettered. The new connector is numbered and it should be wired according to Figure 3 and not the instructions contained within the connector kit. Parts Information P/N Description Qty 12077867 Fuel Pump Relay 1 12166225 Connector 1 12129073 Bracket (S/T Only) 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: Labor Operation Description Labor Time J5460 Relay, Fuel Pump- Use Published Replace Labor Operation Time Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Fuel Pump Relay: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking Fuel Pump Relay: All Technical Service Bulletins Engine - Will Not Start Readily Upon Cranking File In Section: 6E - Engine Fuel & Emission Bulletin No.: 56-63-05A Date: January, 1996 Subject: Vehicle Does Not Start Readily Upon Cranking (Replace Fuel Pump Relay) Models: 1993-94 Chevrolet and GMC Truck M/L Vans 1994 Chevrolet and GMC Truck S/T Utility 1994 Oldsmobile Bravada with 4.3L Engine (VIN W, Z - RPOs L35, LB4) This bulletin is being revised to change the correction procedure and parts information and to add the L Van and artwork. Please discard Corporate Bulletin Number 56-63-05 (Section 6E - Engine Fuel & Emission). Condition Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Fuel Pump Relay: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking > Page 4048 Some owners may experience extended engine crank times on cold start and may set diagnostic trouble code 54 and activate the M/L (Check Engine light). Cause This condition may be due to failure of the fuel pump relay. Correction Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Fuel Pump Relay: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking > Page 4049 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Fuel Pump Relay: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking > Page 4050 Verify condition using the normal diagnostic procedure in the service manual. Replace the Fuel Pump Relay (P/N 12077867) following the service manual procedure. Replace the connector (Kit P/N 12166225) following the instructions in Figures 3 and 4. Note that each of the four cavities of the old connector are lettered. The new connector is numbered and it should be wired according to Figure 3 and not the instructions contained within the connector kit. Parts Information P/N Description Qty 12077867 Fuel Pump Relay 1 12166225 Connector 1 12129073 Bracket (S/T Only) 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: Labor Operation Description Labor Time J5460 Relay, Fuel Pump- Use Published Replace Labor Operation Time Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > Page 4051 Fuel Pump Relay: Locations FUEL PUMP RELAY Fuel Pump Relay The Fuel Pump Relay is located on the driver side firewall, near brake booster. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > Page 4052 C124 - Fuel Pump Relay Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > Page 4053 Fuel Pump Relay: Description and Operation When the ignition key is first turned to the "ON" position, the control module will energize the fuel pump relay as long as the engine is cranking or running, and the control module is receiving distributor reference pulses. If there are no reference pulses, the control module will shut "OFF" the fuel pump relay within two seconds. An inoperative fuel pump relay can result in extended crank times, particularily if the engine is cold. The oil pressure switch will turn "ON" the fuel pump, as soon as oil pressure reaches about 28 kPa (4 psi). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > Page 4054 Fuel Pump Relay: Testing and Inspection *** UPDATED BY TSB 893206E, DATED OCTOBER 90 When the key is first turned ON, without the engine running, the ECM will turn the fuel pump relay ON for two seconds. This builds up the fuel pressure to normal operating pressure. If the engine is not started within two seconds, the ECM will shut the fuel pump OFF and wait until ignition reference pulses are present. As soon as the engine is cranked, the ECM turns the relay ON, which powers the fuel pump. The ECM continues to power the fuel pump during engine operation. If the fuel pump relay fails, it is backed up by the oil pressure switch, which continues to operate the fuel pump as long as oil pressure remains above 28.0 kPa (4 psi). RESULTS OF INCORRECT FUEL PUMP SYSTEM OPERATION - A faulty fuel pump relay can result in long cranking times, particularly if the engine is cold. - An inoperative fuel pump would cause a no start condition. - A fuel pump which does not provide enough pressure can result in poor performance. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Relays and Modules - Fuel Delivery and Air Induction > Fuel Pump Relay > Component Information > Technical Service Bulletins > Page 4055 Fuel Pump Relay: Service and Repair Relay Center 2.5L,2.8L S REMOVE/DISCONNECT 1. Verify that ignition switch is in the "OFF" position. 2. Retainer, if installed. 3. Electrical connector. 4. Fuel pump relay by depressing bracket clip at rear of relay, or removing bolts from retaining bracket. INSTALL/DISCONNECT 1. Fuel pump relay. 2. Electrical connector. 3. Retainer. 4. Verify correct operation to confirm repair. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Automatic Transmission LH Rear Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Automatic Transmission > Page 4061 Rear Engine Wiring W/Man Trans Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Page 4062 C120 - Fuel Pump Oil Pressure Sender/Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Oil Pressure Switch (For Fuel Pump) > Component Information > Locations > Page 4063 Oil Pressure Switch (For Fuel Pump): Service and Repair REMOVE/DISCONNECT - Negative battery cable from battery. - Sensor or switch connectors. - Sensor or switch. INSTALL/CONNECT - Sensor or switch. - Sensor or switch. - Negative battery cable. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Specifications Throttle Position Sensor: Specifications Idle Normal 0.45 to 0.95 V Maximum 1.25 V Wide Open Throttle 4.0 to 4.5 V Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Specifications > Page 4067 Engine Harness, Right Front Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions Throttle Position Sensor: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. Use this page as a reference to determine the meaning of an abbreviation if necessary. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery Bi-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CHMSL Center High Mount Stoplamp CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRO Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4070 F-PUMP Fuel Pump FLASH Flasher FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4071 SIR Supplemental Inflatable Restraint SKT Socket SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature TIL Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4072 example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE (ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: ^ Slide across the vehicle seat. ^ Sit down or stand up. ^ Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: ^ They are bumped or dropped. ^ They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4073 Symbols (Part 1 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4074 Symbols (Part 2 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4075 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4076 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4077 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4078 Throttle Position Sensor: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4079 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4080 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4081 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4082 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4083 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. ^ If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. ^ A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4084 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4085 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4086 Ohmmeter Meter Scales Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4087 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. ^ An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. ^ On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: ^ A range selector switch which permits the selection of different ranges of resistance. ^ A set adjust control which allows the meter to be set at zero for accurate measurements. ^ Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4088 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: ^ Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. ^ Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. ^ Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4089 be less than 10 percent of the total drop. When using a voltmeter: ^ Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. ^ Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. ^ The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: ^ Check the accuracy and completeness of the complaint. ^ Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4090 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. ^ The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4091 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4092 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4093 Twisted/Shielded Wire Repair Twisted Wires Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4094 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4095 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4096 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). ^ Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean ^ Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. ^ Roll crimp (13) and solder the terminal. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4097 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4098 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4099 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. ^ Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean ^ Terminal cavity of the connector body. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4100 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. ^ Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4101 C110 - TP Sensor Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4102 Throttle Position (TP) Circuit Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Page 4103 Throttle Position Sensor: Description and Operation Wiring Diagram For Code 21 - Throttle Position Sensor (Signal Voltage High) NOTE Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE The Throttle Position Sensor (TPS) is a potentiometer that senses throttle angle and sends a signal to the PCM. The TP signal is one of the most important inputs used by the control module for fuel control and for most of the control module control outputs. OPERATION The TPS has three internal circuits provided by the control module. One to ground, a second from the control module as a 5.0 volt reference source and a third circuit is used by the control module to measure the output voltage. As the throttle angle changes (pressing down on accelerator pedal) the TPS voltage output varies from about .5 volt at idle to about 4.9 volts at wide open throttle (WOT). Each time the voltage drops below 1.25 volts and stops, the control module assumes this value is 0 throttle from this point on. LOCATION: Side of throttle body opposite of throttle lever. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Page 4104 Throttle Position Sensor: Adjustments The TPS is not adjustable. Each time voltage drops below 1.25 volts and stops, the control module assumes that this value is zero throttle angle and measures percent throttle from this point on. Therefore adjustment is not necessary. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Sensors and Switches - Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Page 4105 Throttle Position Sensor: Service and Repair NOTE Since Throttle Position Sensor (TPS) configurations can be mounted interchangeably, be sure to order the correct one for your engine with identical part number of the one being replaced. Throttle Position (TP) Sensor REMOVE/DISCONNECT - Electrical connectors. - TPS attaching screw assemblies and retainer, (if applicable). - TPS from throttle body assembly. NOTE Do NOT immerse in any type of liquid solvent or cleaner, as damage may occur. INSTALL/CONNECT - With throttle valve in normally closed position, install TPS on throttle shaft with seal and rotate counter clockwise to align mounting hole. - Two attaching screw assemblies. Tighten screw assemblies to 2.0 Nm (18.0 lb-in). - Electrical connector to TPS. - Check for TPS output as follows: Connect an ALDL scanner to read TPS output voltage. - With ignition "ON" and engine stopped, TPS voltage should be less than 1.25 volts. If more than 1.25 volts, replace TPS. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Body > Component Information > Service and Repair > Throttle Body Assembly Removal and Replacement Throttle Body: Service and Repair Throttle Body Assembly Removal and Replacement Throttle Body Assembly (Exploded View) REMOVAL/DISCONNECT - TBI assembly from vehicle. See: Throttle Body Unit - Fuel meter body attaching screw assemblies. - Fuel meter body assembly. - Fuel meter body to throttle body attaching screws. - Fuel meter body assembly and gasket. Discard gasket. - Throttle body to fuel meter body gasket and discard gasket. DISASSEMBLE Remove TPS from old throttle body, for use on new throttle body. (IAC valve does not have to be removed, since a new one comes with replacement throttle body.) ASSEMBLE Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Body > Component Information > Service and Repair > Throttle Body Assembly Removal and Replacement > Page 4110 Install TPS onto replacement throttle body assembly.See: Sensors and Switches - Fuel Delivery and Air Induction/Throttle Position Sensor/Service and Repair INSTALL/CONNECT - New throttle body to fuel meter body gasket. - Fuel meter body assembly on throttle body assembly. - Fuel meter body to throttle body attaching screws that have been coated with locking compound. Tighten the attaching screw assemblies to 4.0 Nm (3.50 lb-in). - TBI unit onto intake manifold. Tighten mounting bolts to 25.0 Nm (18.0 lb-ft). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Body > Component Information > Service and Repair > Throttle Body Assembly Removal and Replacement > Page 4111 Throttle Body: Service and Repair Fuel Meter Body Assembly Fuel Meter Body Assembly REMOVE/DISCONNECT - Electrical connections to fuel injectors. (Squeeze plastic tabs and pull straight up.) - Fuel meter cover assembly. See: Fuel Meter Cover Assembly - Fuel injectors. See: Fuel Injector/Service and Repair/Fuel Injector(S) Replacement - Fuel inlet and outlet lines. Discard O-rings. - Fuel inlet and outlet nuts and gaskets from fuel meter body assembly. Discard gaskets. NOTE Note locations of nuts, for proper reassembly later. Inlet nut has a larger passage than outlet nut. - Fuel meter body to throttle body attaching screw assemblies. - Fuel meter body assembly from throttle body assembly. - Throttle body to fuel meter body gasket and discard. INSTALL/CONNECT - New throttle body to fuel meter gasket. Match cut-out portions in gasket with openings in throttle body. - Fuel meter body assembly on throttle body assembly. - Fuel meter body-to-throttle body attaching screw assemblies, precoated with appropriate locking compound. Tighten screw assemblies to 4.0 Nm (35.0 lb-in). - Fuel inlet and outlet nuts with new gaskets to fuel body assembly. Tighten inlet nut to 40.0 Nm (30.0 lb-ft) and outlet nut to 29.0 Nm (21.0 lb-ft). - Fuel inlet and return lines and new O-rings. (Use back-up wrench to keep TBI nuts from turning. Tighten fuel lines to 27.0 Nm (20.0 lb-ft). - Injectors with new upper and lower O-rings in fuel meter body assembly. - Fuel meter cover gasket, fuel meter outlet gasket, and pressure regulator seal. - Fuel meter cover assembly. - Long and short fuel meter cover attaching screw assemblies, coated with appropriate compound. Tighten screw assemblies to 3.0 Nm (27.0 lb-in). - Electrical connectors to fuel injectors. INSPECT Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Body > Component Information > Service and Repair > Throttle Body Assembly Removal and Replacement > Page 4112 Turn ignition switch to "ON" position for two seconds, then turn to "OFF" position for ten seconds. Again turn ignition switch to "ON" position and check for leaks around gaskets and fuel line couplings. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Body > Component Information > Service and Repair > Throttle Body Assembly Removal and Replacement > Page 4113 Throttle Body: Service and Repair Fuel Meter Cover Assembly Fuel Meter Cover Assembly The fuel meter cover assembly contains the fuel pressure regulator assembly. The regulator has been adjusted at the factory and should only be serviced as a complete preset assembly. CAUTION: DO NOT remove the four screws securing the pressure regulator to the fuel meter cover. The fuel pressure regulator includes a large spring under heavy compression which, if accidentally released, could cause personal injury. Disassembly might also result in a fuel leak between the diaphragm and the regulator container. Fuel Meter Cover Replacement (TBI 220) Remove or Disconnect 1. Electrical connectors to fuel injectors. (Squeeze plastic tabs and pull straight up.) 2. Long and short fuel meter cover screw assemblies. 3. Fuel meter cover assembly. NOTICE: DO NOT immerse the fuel meter cover (with pressure regulator) in cleaner, as damage to the regulator diaphragm and gasket could occur. 4. Fuel meter outlet gasket and pressure regulator seal. Discard gaskets and seal. INSPECT: ^ For dirt, foreign material and casting warpage. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Body > Component Information > Service and Repair > Throttle Body Assembly Removal and Replacement > Page 4114 Fuel Meter Cover Replacement (TBI 220) Install or Connect 1. New pressure regulator seal, fuel meter outlet passage gasket, and cover gasket. 2. Fuel meter cover assembly. 3. Attaching screw assemblies, precoated with appropriate locking compound to threads. (Short screws are next to injectors.) TIGHTEN: ^ Screw assemblies to 3.0 Nm (28.0 lb. in.). 4. Electrical connectors to fuel injectors. 5. With engine "OFF," and ignition "ON," check for leaks around gasket and fuel line couplings. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Body > Component Information > Service and Repair > Throttle Body Assembly Removal and Replacement > Page 4115 Throttle Body: Service and Repair Throttle Body Unit REMOVE/DISCONNECT - Air cleaner assembly and discard gasket. - Electrical connectors from idle air control valve (IAC), throttle position sensor (TPS), and fuel injectors (squeeze plastic tabs on injector connector and pull straight up). - Grommet with injector wires and lay aside. - Throttle linkage, return spring(s), transmission control cable, and cruise control (wherever applicable). - Cable support bracket attaching screws and bracket. - Vacuum hoses, noting position of hoses. - Inlet and outlet fuel lines. NOTE Relieve fuel pressure before disconnecting fuel lines and use a back-up wrench on inlet and outlet nuts. - Fuel line O-rings from fuel nuts and discard. - TBI unit mounting hardware. - TBI unit. NOTE To prevent damage to the throttle valve, it is essential that the unit be placed on a holding fixture, before performing service. - TBI flange (manifold mounting) gasket. NOTE Before removing old gasket from surface of intake manifold, stuff the manifold opening with a clean rag to prevent material from entering the engine. INSPECT - Manifold bore for loose parts and foreign material. - Intake manifold sealing surface for cleanliness. INSTALL/CONNECT - New TBI flange (manifold mounting) gasket. - TBI unit with mounting hardware. Tighten to 25.0 Nm (18.0 lb.ft.) - New O-rings on fuel line nuts and coat with new engine oil. Use a back-up wrench and tighten to 27.0 Nm (20 lb.ft.). - Vacuum hoses. - Cable support bracket attaching screws and bracket. Tighten to 10.0 Nm (88 lb.in.) - Throttle linkage, return spring(s), transmission control cable, and cruise control (wherever applicable). - Grommet, with injector harness, to throttle body. - Electrical connectors. Ensure connectors are fully seated and latched. - Check to see if accelerator pedal is free, by depressing pedal to the floor and releasing, while engine is "OFF". - Check for fuel leaks around fuel line nuts. Apply fuel pressure by turning ignition "ON" with engine "OFF". - Air cleaner assembly with new gasket. NOTE: Ensure injectors wires are not pinched between TBI and air cleaner assembly. - Start engine check again for fuel leaks. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Cable/Linkage > Component Information > Locations Throttle Cable/Linkage: Locations Control Cable And Linkage Accelerator Pedal Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Cable/Linkage > Component Information > Locations > Page 4119 Throttle Cable/Linkage: Service and Repair Accelerator Pedal Assembly ACCELERATOR PEDAL When performing service on the accelerator pedal, observe the following: The mounting surface between the support and dash panel must be free of insulation. The carpet and padding in the pedal and tunnel area must be positioned to lay flat and be free of wrinkles and bunches. - Slip the accelerator control cable through the slot in the rod and then install the retainer in the rod, makeing sure it is seated. Use care when pressing the retainer into the hole in the rod to ensure that the cable is not kinked or damaged in any way. - After securing all components of the accelerator linkage, the linkage must operate freely without binding between full closed throttle and full wide open throttle. - Wires, hoses, cables or other obstructions must not be placed within 13 mm (1/2 inch) of the cable or the rod at any point in their travel. Control Cable And Linkage ACCELERATOR CONTROL CABLE Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Cable/Linkage > Component Information > Locations > Page 4120 When performing service on the accelerator control cable, observe the following: The retainer must be installed with the tangs secured overhead of the stud. - The conduit fitting at both ends of the cable must have the locking tangs expanded and locked in the attaching holes. - The braided portion of the accelerator cable assembly must not come in contact with the front of the dash sealer during assembly, repair, or replacement of the assembly. - The flexible components (hoses, wires, conduits, etc.) must not be routed within 50 mm (2 inches) of the moving parts of the accelerator linkage outboard of the support unless the routing is positively controlled. REMOVE/DISCONNECT - Retainer from throttle lever stud - Retainer locking tangs from support bracket - Retainer from accelerator pedal rod or release cable from rod. - Retainer locking tangs from dash panel INSTALL/CONNECT - Retainer to dash panel. - Retainer to accelerator pedal rod or connect cable in rod slot. - Retainer to support bracket. - Retainer to throttle lever stud or connect cable to pulley. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Specifications Throttle Position Sensor: Specifications Idle Normal 0.45 to 0.95 V Maximum 1.25 V Wide Open Throttle 4.0 to 4.5 V Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Specifications > Page 4124 Engine Harness, Right Front Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions Throttle Position Sensor: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. Use this page as a reference to determine the meaning of an abbreviation if necessary. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery Bi-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CHMSL Center High Mount Stoplamp CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRO Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4127 F-PUMP Fuel Pump FLASH Flasher FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4128 SIR Supplemental Inflatable Restraint SKT Socket SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature TIL Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4129 example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE (ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: ^ Slide across the vehicle seat. ^ Sit down or stand up. ^ Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: ^ They are bumped or dropped. ^ They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4130 Symbols (Part 1 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4131 Symbols (Part 2 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4132 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4133 Output Outputs The Solid-State Switches are used to turn on a circuit outside the module. When the switch closes, the voltage or ground shown will be applied to the connected circuit. Additional information about what makes the switch close is often provided. The voltage controlled by the switch may be measured just as if it were a mechanical switch. Pulsed Output These symbols are similar to the Solid-State Switch. The pulses represent the rate at which the switch is turned on and off. Data Output These two symbols are special versions of the Solid-State Switch. They represent serial data inputs and outputs. Serial data consists of coded groups of voltage pulses transmitted at high speed. These pulses cannot usually be measured with a Digital Voltmeter. There are cases, however, where procedures in System Diagnosis may describe such measurements. The Scan tool can often read and display this data. Input Inputs These symbols represent the equivalent circuit at the input terminals of electronic modules. You should not attempt to measure the resistance of these terminals unless instructed to do so by a service procedure. These inputs can be used to check wiring to electronic modules. Wire Color Code Identification Black: BLK Blue: BLU Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4134 Brown: BRN Grey: GR Or GRY Green: GRN Natural: NAT Orange: ORN Pink: PNK Purple: PPL Red: RED Tan: TAN White: WHT Yellow: YEL Dark: DK (example: DK GRN same as Dark Green) Light: LT (example: LT BLU same as Light Blue) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4135 Throttle Position Sensor: Diagnostic Aids Basic Electricity Electrical power flows from the power source to a load device and then back to the source of power. The electrical circuit should contain a device to open or close the circuit, such as a switch or relay, and a protective device (in case of an overload), such as a circuit breaker or a fusible link. Electrical circuits can be set up as series circuits, parallel circuits, or series/parallel circuits. The circuits in this vehicle are normally parallel circuits. CIRCUITS Series Circuit Series Circuits In a series circuit, the electrical devices are connected to form one current path to and from the power source. In a series circuit the voltage is shared equally by all the devices in the circuit. Parallel Circuit Parallel Circuits In a parallel circuit, the electrical devices are connected to form more than one current path to and from the power source. In a parallel circuit the voltage is constant and equal for each current path. Series/Parallel Circuit Series/Parallel Circuits A series/parallel circuit consists of a single current path and a circuit with more than one current path to and from the power source. Circuit Components Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4136 Circuit Components Circuit components include power sources, circuit protection devices, circuit controllers, and circuit loads. Power sources are the battery or generator which provide the power for the circuit. Circuit protection devices are components such as fuses, circuit breakers and fusible links and provide overload protection for the circuit. Circuit controllers are used to control the power flow within a circuit and are usually switches and relays. Circuit loads are the actual component that provides a specific function. Circuit loads can be lights, motors, and solenoids. Relayless Circuit Relay Circuit Relays Battery and load location may require that a switch be placed some distance from either component. This means a longer wire and a higher voltage drop. The installation of a relay between the battery and the load reduces the voltage drop, because the switch controls the relay, the switch can be compact. Refer to Fuse, Circuit Breaker, Lamp Bulb, and Relay Data for a listing of relays used in this vehicle. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4137 Diode Specifications And Configurations Diode Markings Diodes Many of the electrical systems in this vehicle use diodes to isolate certain circuits and protect them from voltage surges. Diode specifications and replacement part numbers are listed. To identify the Peak Inverse Voltage (PIV) rating of the diode that will be replaced. Replacement procedures are as follows: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to the direction of current flow, remove the faulty diode from the harness with a suitable soldering tool. If the diode is located next to a connector terminal, remove the terminal(s) from the connector to prevent damage from the soldering tool. 3. Carefully strip away a section of insulation next to the old soldered portion of the wire(s). Do not remove any more than is necessary to attach the new diode. 4. Check the current flow direction of the new diode, being sure to install the diode with the correct bias. Attach the new diode to the wire(s) using 60/40 rosin core solder. Use a heat sink (aluminum alligator clip) attached across the diode leads to protect it from excessive heat. Follow the manufacturer's instructions for the soldering equipment you are using. 5. Install terminal(s) into the connector body, if removed in step 2. 6. Tape the diode to the harness or connector using electrical tape. To prevent shorts to ground and water intrusion, completely cover all exposed wire and diode attachment points. Circuit Malfunctions There are three electrical conditions that can cause a non-working circuit: an "Open Circuit," a "Short Circuit" or a "Grounded Circuit." These conditions can also be caused by intermittent or poor connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4138 Open Circuit Open Circuit An open circuit occurs whenever there is a break in the circuit. The break can be corrosion at the connector, a wire broken off in a component, a wire that burned open from too much current or a component not operating as it should. Short Circuit Short Circuit A short circuit happens when the current bypasses part of the normal circuit. This bypassing is usually caused by wires touching, salt water in or on a component such as a switch or a connector, or solder melting and bridging conductors in a component. Grounded Circuit Grounded Circuit A grounded circuit is like a short circuit but the current flows directly into a ground circuit that is not part of the original circuit. This may be caused by a wire rubbing against the frame or body. Sometimes a wire will break and fall against metal that is connected electrically to the ground side of the voltage supply. A grounded circuit may also be caused by deposits of oil, dirt, or moisture around connections or terminals, which provide a good path to ground. Intermittents And Poor Connections Most intermittents are usually caused by faulty electrical connections or wiring, although occasionally a sticking relay, solenoid, or loose ground point can be a problem. General When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4 for terminal identification), it is important to check terminal contact between a connector and component, or between in-line connectors, before replacing a suspect component. Frequently, a diagnostic chart leads to a step that reads: "Check for poor connection." Mating terminals must be inspected to assure good terminal Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4139 contact. A poor connection between the male and female terminal at a connector may be the result of contamination or deformation. Contamination is caused by the connector halves being improperly connected, a missing or damaged connector seal, or damage to the connector itself, exposing the terminals to moisture and dirt. Contamination, usually in underhood or underbody connectors, leads to terminal corrosion, causing an open circuit or intermittently open circuit. Deformation is caused by probing the mating side of a connector terminal without the proper adapter, improperly joining the connector halves or repeatedly separating and joining the connector halves. Deformation, usually to the female terminal contact tang, can result in poor terminal contact, causing an open or intermittently open circuit. Follow the procedure below to check terminal contact. 1. Separate the connector halves. Refer to Terminal Repair Kit, J 38125-A, instruction manual, J 38125-4. 2. Inspect the connector halves for contamination. Contamination will result in a white or green build-up within the connector body or between terminals, causing high terminal resistance, intermittent contact or an open circuit. An underhood or underbody connector that shows signs of contamination should be replaced in its entirety: terminals, seals and connector body. 3. Using an equivalent male terminal from the Terminal Repair Kit, J 38125-A, check the retention force of the female terminal in question by inserting and removing the male terminal to the female terminal in the connector body. Good terminal contact will require a certain amount of force to separate the terminals. 4. Using an equivalent female terminal from the Terminal Repair Kit, J 38125-A, compare the retention force of this terminal to the female terminal in question by joining and separating the male terminal to the good female terminal, and then joining and separating the male terminal to the female terminal in question. If the retention force is significantly different between the two female terminals, replace the female terminal in question, refer to Terminal Repair Kit, J 38125-A. If a visual (physical) check does not reveal the cause of the problem, the vehicle may be able to be driven with a (DVM) Digital Voltmeter connected to the suspected circuit. An abnormal voltage reading when the problem occurs indicates the problem may be in that circuit. Wiring Connector Terminal Replacement Twin Lock Connector Terminal Wiring Connector Terminal Replacement (Twin Lock-Type) Remove or Disconnect Tool Required: J 22727 Terminal Remover 1. Connector lock tangs. 2. Terminal locks using J 22727 (3). 3. Wire terminal (1). Install or Connect 1. Pry out the tangs. 2. Terminal (1) into the connector (2). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4140 Removing The Terminals From The Connector Wiring Connector Terminal Replacement (Blade-Type) Remove or Disconnect 1. Terminal lock tang. 2. Terminal (1). Resetting The Terminal Lock Tang Install or Connect 1. Pry up on the terminal lock tang (1). 2. Terminal into the connector. General The following test equipment comes in a variety of styles and are adequate for simple tests. However, when accuracy becomes important, the value of a reading obtained using a meter is critical to the diagnosis procedure. Make sure any electrical test meter used is of sufficient quality and accuracy to make the measurements required in the electrical testing. Jumper Wires Jumper wires allow "jumping" across a suspected open or break in a circuit. ^ If the circuit works properly with the jumper wire in place, but does not work when the jumper wire is removed, the circuit has an open spot. ^ A circuit without any opens or breaks has continuity and needs no further testing. The jumper is usually a long wire with alligator clips. A version of the jumper has a fuse holder in it with a 10-amp fuse. This will prevent damaging the circuit if the jumper is connected in the wrong way. The jumper is used to locate opens in a circuit. One end of the jumper is attached to a voltage source and the other end is attached to the load in the circuit, i.e. lamps or motors. If the load works, try "jumping" to circuit points that are progressively closer to the voltage supply. When the circuit load stops working, the open has been located. The jumper is also used to test components in the circuit such as connectors, switches and suspected high resistance points. Unpowered Test Lamp This tool consists of a 12-volt lamp with leads. The ends of the leads usually have alligator clips, but various kinds of probes, terminal spades and special connectors also are used. The 12-volt test lamp continuity tester uses the vehicle's battery to provide voltage to the circuit being tested. 12-volt testers are manufactured with a Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4141 variety of tips to permit touching them to connectors, bare wires, insulated wires, or even wires within wiring harnesses. To check the tester before use, briefly touch the clip to one side of the battery and the probe to the other. 12-volt testers are NOT sensitive to polarity in a circuit and can be connected either way. The 12-volt test lamp generally has a sharp probe tip so it can be inserted into connector terminals or through the wire insulation for testing. It is important to keep the probe tip sharp to minimize damage to wire insulation. When the test is complete at a particular point, be sure to tape any holes made in wire insulation. The unpowered test lamp is used on an open circuit. One lead of the test lamp is grounded and the other lead is moved around the circuit to find the open. Depending on the physical layout of the circuit, sometimes it is easier to start at the voltage supply, and other times it is easier to start at the circuit load or ground circuit. Once one becomes familiar with the test lamp and the brilliance of the bulb in a normal circuit, high-resistance circuits can be recognized by the effect they have on the bulb. As the current drops in a high-resistance circuit, the bulb in the test lamp glows less brightly. Although the 12-volt test lamp cannot be used as a foolproof test for high resistance, a less than normal brilliance of the lamp is an indication of circuit high resistance. Further testing will verify the condition and locate the cause. NOTE: Test lamps are to be used only on circuits that do not contain solid-state devices. If a test lamp is used in a circuit containing a solid-state device, the current that the test lamp would draw would be above the current that the solid-state device would be able to handle. Using a test lamp on a solid-state device may damage the device. Self-Powered Test Lamp This lamp is a pencil-shaped unit with a self-contained battery, a 1.5-volt lamp bulb, a sharp probe, and a ground lead fitted with an alligator clip. This test is used mainly for testing components that are disconnected from the vehicle voltage supply. The powered test lamp is also useful for testing suspected high resistance points in a circuit such as connectors and ground circuits that are corroded or loose. General The following three types of meters are generally used for diagnosis: ammeter, ohmmeter, and voltmeter. These meters are available in two designs: analog (needle-type) and digital (electronic display-type). NOTE: The correct type of meter must be used when diagnosing circuits containing solid-state devices. Incorrect use of the meters will result in damage to the solid-state device. Analog meters may be used for any circuit not containing a solid-state device, while a digital meter MUST be used to diagnose any circuit with a solid-state device. Circuits which contain a solid-state device, such as the engine control module, should be tested only with a 10-megohm or higher impedance digital multimeter (J 39200 or equivalent). Ammeter Ammeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4142 Meter Scales An ammeter is used to measure current flow (amperage) in a circuit. Amperes are units of electron flow which indicate how many electrons are passing through the circuit. Current flow in a circuit is equal to the circuit voltage divided by total circuit resistance. At normal operating voltage, most circuits have a characteristic amount of current flow, referred to as normal current draw. Current draw is measured in amperes (amps) with an ammeter. Comparing measured current draw with the specified current draw rating provides useful diagnostic information. Disconnect the circuit from the voltage source before connecting the ammeter. The ammeter must be placed in series with the circuit being tested. Be sure that the ammeter's positive terminal is connected to the positive (battery) side of the circuit and its negative terminal to the negative (ground) side of the circuit. NOTE: Never connect an ammeter across a circuit like a voltmeter. The ammeter could be damaged by the vehicle electrical system. Excessive current draw is responsible for blowing fuses and, in some cases, draining the battery. An ammeter helps diagnose these conditions by locating the cause of the excessive current draw. On the other hand, there are times when a reduced current draw at a component (a power window motor for example) causes unsatisfactory performance of an electrical system. Ohmmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4143 Ohmmeter Meter Scales Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4144 The ohmmeter is used to read resistance (ohms) or to check for opens or shorts in a circuit or component. There are both analog-type and digital-type ohmmeters. ^ An analog ohmmeter shows the actual resistance on a scale by the movement of a needle. ^ On a digital ohmmeter, the resistance measured is converted inside the meter to a numerical output which is shown on a display panel. Ohmmeters use a small battery to supply the voltage and current which flow through the circuit being tested. The current flows through the circuit, positions the needle on analog-type ohmmeters or converts to a digital readout on digital-type ohmmeters. Although there are several different styles of analog ohmmeters, all usually have the following features in addition to the meter movement: ^ A range selector switch which permits the selection of different ranges of resistance. ^ A set adjust control which allows the meter to be set at zero for accurate measurements. ^ Some model ohmmeters also have a built-in feature that allows the ohmmeter to be used as a self-powered test lamp. Digital meters do not have to be zeroed. They have various ranges just like the analog meters. NOTE: Like a self-powered test lamp, the ohmmeter can only be used on circuits where voltage has been removed. It is designed to be operated on its own voltage and current levels for the meter to make resistance measurements. The 12-volt electrical system voltage in the vehicles circuits could damage the meter. Electrical circuits can be checked for opens using basically the same procedure as previously described for the self-powered test lamp. The circuit must be separated from all voltage sources. The ohmmeter is connected across the two open ends of the circuit to be checked. A high reading (infinity) is an indication of an open circuit. A low reading (near zero) is an indication of a continuous circuit. Checks for short circuits are made in a similar manner to that used for open circuits, except that the circuit being checked must be isolated from both voltage and normal ground. Connecting the ohmmeter between an isolated circuit and a good ground point allows checking the circuit for shorts to ground. A short to ground in the circuit is indicated on the meter by a near zero reading. A good circuit (no short to ground) shows up as infinity (very high resistance) indicated on the meter. To measure the resistance of a component or a circuit, the component or circuit must be isolated from all other components (or circuits). The ohmmeter leads are then placed across the component or circuit and the resistance is read on the ohmmeter. Voltmeter Voltmeter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4145 Meter Scales The voltmeter (properly observed) will give the technician more information than the ammeter, ohmmeter, and test lamp combined. Its application for diagnosis here is to measure the electrical pressure (voltage) drop in a resistance circuit. Voltage drop is a reduction or "using up" of the voltage to push electricity through a resistance. It can be compared to the pressure of water flowing through a metering valve. Low voltage to a lamp makes the lamp glow dimly. This can be caused by low source voltage (battery discharge or low alternator output) or by high resistance in the circuit due to a poor connection. Before making any meter measurements, it is important to review the relationship between current, voltage and resistance. Determining voltage drop is important because it provides the following information: ^ Too high of a voltage drop indicates excessive resistance. If, for instance, a blower motor runs too slowly or a lamp glows too dimly, one can be sure there is excessive resistance in the circuit. By taking voltage drop readings in various parts of the circuit, the problem (corroded terminals, for example) can be isolated. ^ Too low of a voltage drop indicates low resistance. If, for instance, a blower motor runs too fast, the problem could be isolated to a low resistance in a resistor pack by taking voltage drop readings. ^ Maximum allowable voltage drop under a load is critical, especially if there is more than one high resistance problem in a circuit. It is important because, like all resistances, all voltage drops are cumulative. Corroded terminals, loose connections, and similar problems reduce the voltage available across the key circuit components. The current flow is reduced in the circuit, and all of the affected components operate at less than peak efficiency. A small drop across wires (conductors), switches, connectors, etc., is normal. This is due to the resistance of the conductors but should Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4146 be less than 10 percent of the total drop. When using a voltmeter: ^ Be sure to connect the positive lead to the battery side and the negative lead to the ground side of the component being checked. ^ Voltage drop occurs when electricity (current) flows through a resistance. Make sure the voltage drop being measured is only through the component being checked, not through the component and a poor connection. ^ The circuit must be operating (lamp ON or motor running, for example) to measure voltage drop. The instrument panel voltmeter in the vehicle should also be observed for monitoring proper operation of the generator, battery, cranking motor, and cranking circuit. In this application, battery voltage drop can be monitored while the engine is cranking; after the engine is running, generator output voltage can be monitored. This can be a valuable first step before diagnosing other electrical problems. General SIX STEP PROCESS OF ELECTRICAL DIAGNOSIS: To correctly isolate and repair electrical problems, view the video Electrical Diagnosis (T-9067-1) and follow these six electrical diagnosis steps: Step 1: Verify the Problem Review the work order, operate the system, and list symptoms in order to: ^ Check the accuracy and completeness of the complaint. ^ Re-create the problem. Step 2: Narrow the Choice of Possible Causes of Failure Refer to the circuit diagram for clues to the problem. Location and identification of circuit components may give some idea of where the problem is. The circuit diagrams are designed to make it easy to identify common points in circuits. This knowledge can help narrow the problem to a specific area. For example, if several circuits fail at the same time, check for a common power or ground connection. If part of a circuit fails, check the connections between the part that works and the part that does not work. For example, if the low beam headlamps work, but the high beams and the indicator lamps do not, then voltage and ground paths are good. Since the headlamp dimmer switch is the component which switches this voltage, it is most likely the cause of the failure. Step 3: Identify the Failed Circuit Read the circuit operation for the problem circuit identified in the previous step. By studying the circuit diagram and circuit operation, enough information should be learned to narrow the cause to one component or one portion of the circuit. Step 4: Locate the Failed Component or Element The diagnosis charts are a step-by-step approach to diagnose a symptom. Each chart covers one symptom. For example, "HORN(S) WILL NOT OPERATE." The charts are divided into three columns: Test, Result, and Action. The test procedures are listed in numerical sequence and must be followed in that order. Each test step describes what must be done to the circuit, what test equipment to use and where to connect the test equipment. After the test procedure has been performed, refer to the result column. This lists possible results of the test. Once the result has been found, follow it directly over to the action column. The action column instructs what must be done to correct the problem or lists the next test step to be performed. It is important to remember that a problem in one system could result in a symptom in another system. Step 5: Make the Repair Repair the problem circuit as directed in the diagnosis charts. Step 6: Verify that the Repair is Complete Operate the system, and check that the repair has removed all symptoms and has not caused any new symptoms. Finding A Short Circuit or Ground Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4147 Short And Grounded Circuit a. Remove the blown fuse and disconnect all loads of the fuse. b. Connect a test light in place of the fuse. c. Establish conditions in which the test light comes on. Example: A - Ignition SW ON B - Ignition SW and SW 1 ON C - Ignition SW, SW 1 and Relay on (Connect the Relay) and SW 2 OFF (or Disconnect SW 2) d. Disconnect and reconnect the connectors while watching the test light. The short lies between the connector where the test light stays light and the connector where the light goes out. e. Find the exact location of the short by lightly shaking the problem wire along the body. Intermittents and Poor Connections Most intermittents are caused by faulty electrical connections or wiring, although occasionally a sticking relay or solenoid can be a problem. Some items to check are: ^ Poor mating or connector halves, or terminals not fully seated in the connector body (backed out). ^ Dirt or corrosion on the terminals. The terminals must be clean and free of any foreign material which could impede proper terminal contact. ^ Damaged connector body, exposing the terminals to moisture and dirt, as well as not maintaining proper terminal orientation with the component or mating connector. ^ Improperly formed or damaged terminals. All connector terminals in problem circuits should be checked carefully to ensure good contact tension. Use a corresponding mating terminal to check for proper tension. Refer to "Checking Terminal Contact" for the specific procedure. ^ The J 35616-A Connector Test Adapter Kit must be used whenever a diagnostic procedure requests checking or probing a terminal. Using the adapter will ensure that no damage to the terminal will occur, as well as giving an idea of whether contact tension is sufficient. If contact tension seems incorrect, Refer to "Checking Terminal Contact" for specifics. See: General Troubleshooting Procedures/Checking Terminal Contacts Wiring Problems ^ Poor terminal-to-wire connection. Some conditions which fall under this description are poor crimps, poor solder joints, crimping over wire insulation rather than the wire itself, corrosion in the wire-to-terminal contact area, etc. ^ Wire insulation which is rubbed through, causing an intermittent short as the bare area touches other wiring or parts of the vehicle. ^ Wiring broken inside the insulation. This condition could cause a continuity check to show a good circuit, but if only 1 or 2 strands of a multi-strand-type wire are intact, resistance could be far too high. To avoid any of the above problems when making wiring or terminal repairs, always follow the instructions for wiring and terminal repair outlined in the following procedure. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4148 Special Tools General All electrical connections must be kept clean and tight. Loose or corroded connections may cause a discharged battery, difficult starting, dim lamps and possible damage to the generator and regulator. Wires must be replaced it insulation becomes burned, cracked, or deteriorated. Always use rosin flux solder to splice a wire or repair one that is frayed or broken, and use insulating tape to cover all splices or bare wires. When replacing wire, it is important that the correct size wire be used as shown on applicable wiring diagrams or in parts books. Each harness or wire must be held securely in place to prevent chafing or damage to the insulation due to vibration. Wire size in a circuit is determined by the amount of current, the length of the circuit, and the voltage drop allowed. Wire size is specified using the metric gage. The metric gage describes the wire size directly in a cross section area measured in square millimeters. Wire Repair The wire is very important for the continued reliable operation of the vehicle. This repair must be done as described in the following procedures. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4149 Twisted Wire Repair Twisted Wires Remove or Disconnect 1. Jacket (1). 2. Twisted wires (2). 3. Insulation from the wire. Install or Connect 1. Splice clip (3). 2. Crimp and solder the splice clips (4). 3. Electrical tape wrap (5) on the splices. 4. Outer jacket electrical tape wrap (6). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4150 Twisted/Shielded Wire Repair Twisted Wires Shielded Cable Remove or Disconnect 1. Jacket (1). 2. Unwrap aluminum/Mylar tape (2). 3. Drain wire (3). 4. Leads. 5. Insulation on the leads. Install or Connect 1. Splice clips (4). 2. Crimp and solder the splice clips (5). 3. Electrical tape wrap (6) on the splices. 4. Aluminum/Mylar tape by wrapping and taping. 5. Drain wire with a splice clip (7). Crimp and solder the splice clip. 6. Outer jacket electrical tape wrap (8). Solderless Wiring Repair Solderless wiring repair can be accomplished by the use of crimp and seal splice sleeves. Crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial to form a one-to-one splice. They are to be used where there are special requirements such as moisture sealing. Crimp and seal splice sleeves are included in the J 38125 Terminal Repair Kit. Use the following procedure for solderless wiring repair: 1. Open the Harness If the harness is taped, remove the tape. To avoid wire insulation damage, use a sewing "seam ripper" to cut open the harness (available from sewing supply stores). The crimp and seal splice sleeves may be used on all types of insulation except tefzel and coaxial and may only be used to form a one-to-one splice. 2. Cut the Wire Begin cutting as little wire off the harness as possible. You may need the extra length of wire later if you decide to cut more wire to change the location of the splice. You may have to adjust splice locations to make certain that each splice is 40 mm (1.5 in) away from other splices, harness Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4151 branches, or connectors. This will help prevent moisture from bridging adjacent splices and causing damage. 3. Strip the Insulation If it is necessary to add length of wire to the existing harness, be certain to use the same size as the original wire. To find the correct wire size either find the wire on the schematic page and convert the metric size to the equivalent AWG size or use an AWG wire gage. If unsure about the wire size, begin with the largest opening in your wire stripper and work down until you get a clean strip of the insulation. Strip approximately 7.5 mm (5/16 in) of insulation from each wire to be splices. Be careful to avoid nicking or cutting any of the wires. Check the stripped wire for nicks or cut strands. If the wire is damaged, repeat this procedure after removing the damaged section. Crimp And Seal Splice Sleeve Chart 4. Select and Position the Splice Sleeve Select the proper splice sleeve according to wire size. The splice sleeves and tool nests are color coded. Refer above to determine the correct splice sleeve. Hand Crimp Tool Using the J 38125-8 splice crimp tool, position the splice sleeve in the proper color nest of the hand crimp tool. Place the splice sleeve in the nest so that the crimp falls midway between the end of the barrel and the stop. Seal Splice Sequence The splice sleeve has a stop in the middle of the barrel to prevent the wire from going further. Close the handles slightly to hold the splice sleeve firmly in the proper nest. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4152 Seal Splice Sequence 5. Insert the Wires into the Splice Sleeve and Crimp Insert the wire into the splice sleeve until it hits the barrel stop and close the handles of the crimp tool tightly until the crimper handles open when released. The crimper handles will not open until the proper amount of pressure has been applied to the splice sleeve. Repeat steps 4 and 5 for the opposite end of the splice. Figure shows the condition of the splice sleeve after crimping. Seal Splice Sequence 6. Shrink the Insulation Around the Splice Using a heat torch, apply heat to the center of the splice sleeve. Gradually move the heat to the open end of the tubing, shrinking the tubing as the heat is moved along the insulation. A small amount of sealant will come out of the end of the tubing when sufficient shrinking has been achieved. Figure shows the condition of the splice when the tubing is completely shrunk. General Special connectors known as Weather-Pack connectors require special tool J 28742 for servicing. This special tool is required to remove the pin and sleeve terminals. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Unlike standard blade-type terminals, these terminals cannot be straightened once they are bent. Make sure that the connectors are properly seated and all of the sealing rings (1) are in place when connecting the leads. The hinge-type flap (4) provides a back-up, or secondary locking feature for terminals. They are used to improve the connector reliability by retaining the terminals if the small terminal lock tangs are not positioned properly. Molded-on connectors require complete replacement of the connection. This means splicing a new connector assembly into the harness. Environmental connections cannot be replaced with standard connections. Instructions are provided with the Weather-Pack connector and terminal packages. With the low current and voltage levels found in some circuits, it is important that the best possible bond at all wire splices be made by soldering the splices. Use care when probing the connections or replacing terminals in them. It is possible to short between two terminals. If this happens, damage may be done to certain components. Always use jumper wires between connectors for circuit checking. Never probe through the Weather-Pack seals. When diagnosing for possible open circuits, it is often difficult to locate them by sight because oxidation or terminal misalignment is hidden by the connectors. Merely wiggling a connector on a sensor or in the wiring harness may pinpoint the open circuit condition. This should always be considered when an open circuit is indicated while diagnosing.Intermittent problems may also be caused by oxidized or loose connections. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4153 Weather-Pack Connector Replacement Weather Pack Connector Remove or Disconnect Tool Required: J 28742 Terminal Remover 1. Primary lock (2) by lifting. 2. Connector section. 3. Secondary lock (6) by spreading the sides of the hasp, thus clearing the staples and rotating the hasp (8). 4. Terminal (12) by using J 28742 (9). ^ Snip off the old terminal assembly. 5. 5mm (0.2 inch) of the wire insulation (11). Clean ^ Terminal barrel (5). Install or Connect 1. Terminal insulator (15) on the wire. Slide the insulator back on the wire about 8 cm (3 inches). 2. Terminal (12) on the wire. ^ Roll crimp (13) and solder the terminal. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4154 3. Terminal insulator (15) and the roll crimp (14). 4. Terminal into the connector. 5. Secondary lock (6). 6. Connector sections until the primary lock (2) engages. General Metri-pack Connector Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4155 Contact Tang And Amount Of Deformation The Metri-Pack connectors use a pull-to-seat type terminal. The special tool required to remove the terminal is J 35689-A terminal remover. If removal is attempted with an ordinary pick, there is a good chance that the terminal will be bent or deformed. Metri-Pack Connector Replacement Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4156 Metri-pack Connector Remove or Disconnect Tool Required: J 35689-A Terminal Remover 1. Primary lock (2) by lifting. 2. Connector body (17). 3. Connector seal (1) by pulling the seal back onto the wires away from the connector body (17). 4. Terminal (16) by inserting J 35689-A (19) into the connector body (17) to depress the locking tang (18), then push the wire and terminal through the connector body. ^ Snip off the old terminal unless the terminal is to be reused; reshape the locking tang. 5. 5mm (0.2 inch) of the wire insulation. Clean ^ Terminal cavity of the connector body. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4157 Metri-pack Connector Install or Connect 1. Terminal (16) on the wire. ^ Crimp and solder the terminal. 2. Terminal (16) into the connector cavity by pulling the wire on the seal side of the connector until the locking tang (18) is fully seated. 3. Seal (1) by pressing the seal into the connector body(17) until it is fully seated. 4. Connector sections until the primary lock (2) engages. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4158 C110 - TP Sensor Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Diagram Information and Instructions > Page 4159 Throttle Position (TP) Circuit Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Page 4160 Throttle Position Sensor: Description and Operation Wiring Diagram For Code 21 - Throttle Position Sensor (Signal Voltage High) NOTE Because different models and engine applications vary in wire colors, circuit numbers, and pin numbers, the above image is a typical example. Refer to COMPUTERS AND CONTROL SYSTEMS/SCHEMATIC AND ROUTING DIAGRAMS for specific schematic applications. PURPOSE The Throttle Position Sensor (TPS) is a potentiometer that senses throttle angle and sends a signal to the PCM. The TP signal is one of the most important inputs used by the control module for fuel control and for most of the control module control outputs. OPERATION The TPS has three internal circuits provided by the control module. One to ground, a second from the control module as a 5.0 volt reference source and a third circuit is used by the control module to measure the output voltage. As the throttle angle changes (pressing down on accelerator pedal) the TPS voltage output varies from about .5 volt at idle to about 4.9 volts at wide open throttle (WOT). Each time the voltage drops below 1.25 volts and stops, the control module assumes this value is 0 throttle from this point on. LOCATION: Side of throttle body opposite of throttle lever. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Page 4161 Throttle Position Sensor: Adjustments The TPS is not adjustable. Each time voltage drops below 1.25 volts and stops, the control module assumes that this value is zero throttle angle and measures percent throttle from this point on. Therefore adjustment is not necessary. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Fuel Delivery and Air Induction > Throttle Position Sensor > Component Information > Diagrams > Page 4162 Throttle Position Sensor: Service and Repair NOTE Since Throttle Position Sensor (TPS) configurations can be mounted interchangeably, be sure to order the correct one for your engine with identical part number of the one being replaced. Throttle Position (TP) Sensor REMOVE/DISCONNECT - Electrical connectors. - TPS attaching screw assemblies and retainer, (if applicable). - TPS from throttle body assembly. NOTE Do NOT immerse in any type of liquid solvent or cleaner, as damage may occur. INSTALL/CONNECT - With throttle valve in normally closed position, install TPS on throttle shaft with seal and rotate counter clockwise to align mounting hole. - Two attaching screw assemblies. Tighten screw assemblies to 2.0 Nm (18.0 lb-in). - Electrical connector to TPS. - Check for TPS output as follows: Connect an ALDL scanner to read TPS output voltage. - With ignition "ON" and engine stopped, TPS voltage should be less than 1.25 volts. If more than 1.25 volts, replace TPS. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Firing Order > Component Information > Specifications > Ignition Firing Order Firing Order: Specifications Ignition Firing Order Firing Order ......................................................................................................................................... ............................................................... 1-6-5-4-3-2 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Ignition Timing > Ignition Timing Connector > Component Information > Technical Service Bulletins > Ignition Set Timing Connector - Location Correction Ignition Timing Connector: Technical Service Bulletins Ignition Set Timing Connector - Location Correction File in Section: Engine Fuel & Emission Bulletin No.: 41-65-41 Date: January, 1995 SERVICE MANUAL UPDATE Subject: Section 6A - Ignition Set Timing Connector Location Models: 1994 Chevrolet and GMC Truck S/T Models 1994 Oldsmobile Bravada with 4.3L Engine (VINs W, Z - RPOs L35, LB4) The location of the Set Timing Connector is incorrectly called out in "Section 6A" (Page 6A-8) of the "Driveability, Emissions and Electrical Diagnosis", Service Manual and in the 1994 Oldsmobile Bravada Service Manual Supplement (Page 6E3-C4-8). The correct location of the Set Timing Connector is inside the cab where the Heater Box and the carpet meet on the passenger side floor. Pull carpet back to expose the single wire and connectors on the outside of the control module harness. The wire colors are tan with a black stripe. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Ignition Timing > Ignition Timing Connector > Component Information > Technical Service Bulletins > Page 4173 Timing Connector-In Pass Comp Behind Carpet, Below Heater Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Ignition Timing > Number One Cylinder > Component Information > Locations > Number 1 Cylinder Location Number One Cylinder: Locations Number 1 Cylinder Location NUMBER ONE CYLINDER LOCATION Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Ignition Timing > Timing Marks and Indicators > System Information > Locations Timing Mark Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Distributor, Ignition > Component Information > Specifications Distributor: Specifications Coil bracket bolt/nut ............................................................................................................................. ................................................. 27 N-m (20 lbs ft) Distributor clamp bolt ........................................................................................................................... ................................................ 27 N-m (20 lbs ft) Knock Sensor ...................................................................................................................................... .................................................. 19 N-m (14 lbs ft) Spark Plugs ......................................................................................................................................... .................................................. 15 N-M (11 lbs ft) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Distributor, Ignition > Component Information > Specifications > Page 4184 LH Rear Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Distributor, Ignition > Component Information > Specifications > Page 4185 Distributor: Description and Operation PURPOSE The distributor reference signal provides the ECM with both engine RPM and crankshaft position information. This enables the ECM to operate the fuel pump relay and energize the fuel injector. OPERATION When the engine is cranking or running the ECM receives Distributor Ignition (DI) reference pulses from the ignition module. If the wire becomes open or grounded the engine will not run, as the ECM will not operate the injector. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Distributor, Ignition > Component Information > Specifications > Page 4186 Distributor: Service and Repair Distributor Remove or Disconnect Figure 8 - Spark Plug Wire Routing - Left Side (2.2L) Figure 9 - Spark Plug Wire Routing - Right Side (2.2L) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Distributor, Ignition > Component Information > Specifications > Page 4187 Figure 10 - Distributor And Coil (4.3L VIN Z) Figure 11 - Distributor And Coil (4.3L VIN W) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Distributor, Ignition > Component Information > Specifications > Page 4188 Figure 12 - Spark Plug Wire Routing - Left Side (4.3L VIN Z) Figure 13 - Spark Plug Wire Routing - Right Side - Pickup Models (4.3L VIN Z) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Distributor, Ignition > Component Information > Specifications > Page 4189 Figure 14 - Spark Plug Wire Routing - Right Side - Utility Models (4.3L VIN Z) Figure 15 - Spark Plug Wire Routing (4.3L VIN W) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Distributor, Ignition > Component Information > Specifications > Page 4190 - Make sure the ignition switch is "OFF." 1. Air cleaner and hoses (4.3L VIN Z). 2. Wiring harness connectors at the side of the distributor cap. 3. Two screws on the sides of the distributor cap. 4. Coil wire and spark plug wires on either the left or right side of the distributor. 5. Distributor cap and move it aside. A. Use chalk to note the position of the rotor in relation to the engine. B. Use chalk to note the position of the distributor housing in relation to the engine. 6. Distributor bolt and hold-down clamp. 7. Distributor and gasket, when present. Install or Connect Figure 8 - Spark Plug Wire Routing - Left Side (2.2L) Figure 9 - Spark Plug Wire Routing - Right Side (2.2L) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Distributor, Ignition > Component Information > Specifications > Page 4191 Figure 10 - Distributor And Coil (4.3L VIN Z) Figure 11 - Distributor And Coil (4.3L VIN W) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Distributor, Ignition > Component Information > Specifications > Page 4192 Figure 12 - Spark Plug Wire Routing - Left Side (4.3L VIN Z) Figure 13 - Spark Plug Wire Routing - Right Side - Pickup Models (4.3L VIN Z) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Distributor, Ignition > Component Information > Specifications > Page 4193 Figure 14 - Spark Plug Wire Routing - Right Side - Utility Models (4.3L VIN Z) Figure 15 - Spark Plug Wire Routing (4.3L VIN W) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Distributor, Ignition > Component Information > Specifications > Page 4194 A. To ensure correct timing of the distributor, it must be installed with the rotor correctly positioned as noted in step 5 of the removal procedure. Line up the rotor to the mark on the engine, and the mark on the housing to the engine. B. If the distributor shaft won't drop into the engine, remove the distributor, insert a screwdriver into the hole for the distributor and rotate the oil pump driveshaft so that it lines up with the distributor driver gear. 1. Distributor and gasket, where present. 2. Hold-down clamp and bolt. - Bolt on the 4.3L to 27 Nm (20 lbs. ft.). 3. Distributor cap. 4. Wiring harness connectors at the side of the distributor. 5. Spark plug wires and coil wire. 6. Air Cleaner and hoses. - Check the engine timing. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Ignition Cable > Component Information > Specifications Ignition Cable: Specifications RESISTANCE VALUES 0-15 inch cable .................................................................................................................................... ................................................. 3,000 - 10,000 ohms. 15-25 inch cable .................................................................................................................................. ................................................. 4,000 - 15,000 ohms. 25-35 inch cable .................................................................................................................................. ................................................. 6,000 - 20,000 ohms. NOTE: Longer wires should measure about 5,000 to 10,000 ohms per foot. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Ignition Cable > Component Information > Specifications > Page 4198 Ignition Cable: Locations Spark Plug Wire Routing Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Ignition Coil > Component Information > Specifications Ignition Coil: Specifications COIL PACK RESISTANCE SPECIFICATIONS: ^ The OEM service manual does not give a specification for coil resistance and recommends to test all other ignition components first and then switch affected coil with a good known coil and retest. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Ignition Coil > Component Information > Specifications > Page 4202 Engine Harness, Right Front Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Ignition Coil > Component Information > Specifications > Page 4203 C112 - Ignition Coil Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Ignition Coil > Component Information > Specifications > Page 4204 Ignition Coil: Testing and Inspection Ignition Coil Testing TOOL REQUIRED J 39200 Digital Multimeter. Make sure the ignition switch is "OFF." 1. Disconnect the connector and coil wire from the ignition coil. NOTE: Do not insert the J 39200 probe into the ignition coil connectors. The female terminals could be spread and deformed, resulting in intermittent operation of the coil. Be sure to make contact with only the front edge of the terminals. 2. Connect J 39200 as shown in image, (1). Measure resistance using the high scale. The reading should be OL (infinite). If not, replace the coil. 3. Connect J 39200 as shown in (2). Measure resistance using the low scale. The reading should be 0.2 - 1.5 ohms. If not, replace the coil. 4. Connect J 39200 as shown in (3). Measure resistance using the high scale. The meter should read 5k - 25k ohms. If it does, replace the coil. 5. Reconnect the distributor lead and wiring to the coil. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Ignition Coil > Component Information > Specifications > Page 4205 Ignition Coil: Service and Repair Distributor And Coil 4.3L Engine REMOVE OR DISCONNECT - Coil to distributor lead at coil. NOTE Make sure ignition switch is "OFF". - Wiring connectors at side of the coil. - Nuts or screws holding coil bracket and coil to engine. - Coil bracket and coil. ^ Drill and punch out rivets holding coil to coil bracket. - Coil from coil bracket. INSTALL OR CONNECT - Coil to coil bracket with screws. - Coil and coil bracket to engine. Tighten screws to 10 N-m (89 lb. in.). - Wiring connectors to the coil. Assure connectors are fully seated and latched. - Distributor lead to coil. Assure lead is fully seated on coil tower. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Ignition Control Module > Component Information > Locations > Ignition Module Typical Distributor Components Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Ignition Control Module > Component Information > Locations > Ignition Module > Page 4210 Rear Engine Wiring W/Man Trans Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Ignition Control Module > Component Information > Locations > Page 4211 C121 - Ignition Control Module Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Ignition Control Module > Component Information > Locations > Page 4212 Ignition Control Module: Service and Repair Typical Distributor Components REMOVE OR DISCONNECT NOTE It is not necessary to remove ignition distributor assembly from engine. - Distributor cap and rotor. - Connectors from module. - Two module attaching screws. - Lift module from housing and remove. INSTALL OR CONNECT NOTE: Do not wipe silicone grease from metal face of module or distributor base (where the module seats), when reinstalling the same module. If new module is to be installed clean distributor module base and spread new silicone grease on base and metal face of ignition module. The purpose of the silicone grease is to cool module. - Module onto housing. - Module attaching screws. Tighten to 2 Nm (18 lb.in.) - Connectors to module. - Rotor and cap. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Ignition Timing Connector > Component Information > Technical Service Bulletins > Ignition Set Timing Connector - Location Correction Ignition Timing Connector: Technical Service Bulletins Ignition Set Timing Connector - Location Correction File in Section: Engine Fuel & Emission Bulletin No.: 41-65-41 Date: January, 1995 SERVICE MANUAL UPDATE Subject: Section 6A - Ignition Set Timing Connector Location Models: 1994 Chevrolet and GMC Truck S/T Models 1994 Oldsmobile Bravada with 4.3L Engine (VINs W, Z - RPOs L35, LB4) The location of the Set Timing Connector is incorrectly called out in "Section 6A" (Page 6A-8) of the "Driveability, Emissions and Electrical Diagnosis", Service Manual and in the 1994 Oldsmobile Bravada Service Manual Supplement (Page 6E3-C4-8). The correct location of the Set Timing Connector is inside the cab where the Heater Box and the carpet meet on the passenger side floor. Pull carpet back to expose the single wire and connectors on the outside of the control module harness. The wire colors are tan with a black stripe. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Ignition Timing Connector > Component Information > Technical Service Bulletins > Page 4217 Timing Connector-In Pass Comp Behind Carpet, Below Heater Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Knock Sensor > Component Information > Technical Service Bulletins > Knock Sensor Circuit - DTC 43 Chart Revision Knock Sensor: Technical Service Bulletins Knock Sensor Circuit - DTC 43 Chart Revision File In Section: 6E Engine Fuel & Emission Bulletin No.: 51-65-19 Date: April, 1995 Subject: Section 3A - Control Module System (PCM) Driveability and Emissions - Revised DTC 43 Knock Sensor (KS) Circuit (Dual Knock Sensors) Models: 1994 Chevrolet and GMC Truck S/T; M/L, C/K Models with 4.3L Engine (VINs W, Z RPOs L35, LB4) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Knock Sensor > Component Information > Technical Service Bulletins > Knock Sensor Circuit - DTC 43 Chart Revision > Page 4222 This bulletin advises of a revision to the DTC 43 Knock Sensor (KS) Circuit (Dual Knock Sensor System) chart in the following service manuals: 1994 S/T Driveability Emissions and Electrical Diagnosis Manual, page 3A-119 1994 M/L Driveability Emissions and Electrical Diagnosis Manual, page 3A-75 1994 C/K Driveability Emissions and Electrical Diagnosis Manual, page 3A-69 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Knock Sensor > Component Information > Technical Service Bulletins > Page 4223 Knock Sensor: Specifications Coil bracket bolt/nut ............................................................................................................................. ................................................. 27 N-m (20 lbs ft) Distributor clamp bolt ........................................................................................................................... ................................................ 27 N-m (20 lbs ft) Knock Sensor ...................................................................................................................................... .................................................. 19 N-m (14 lbs ft) Spark Plugs ......................................................................................................................................... .................................................. 15 N-M (11 lbs ft) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Knock Sensor > Component Information > Locations > Assembly View Knock Sensors Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Knock Sensor > Component Information > Locations > Assembly View > Page 4226 Knock Sensor: Locations Harness View LH Rear Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Knock Sensor > Component Information > Locations > Assembly View > Page 4227 LH Rear Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Knock Sensor > Component Information > Locations > Page 4228 Knock Sensor: Diagrams C119 - Knock Sensor C135 - Knock Sensor Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Knock Sensor > Component Information > Locations > Page 4229 Knock Sensor: Description and Operation PURPOSE: The Knock Sensor (KS) is used to detect engine detonation (ping). The control module will retard the electronic spark timing up to 8° based on the signal received. CONSTRUCTION The KS system has two major components: Control Module. - Knock Sensor(s). The two knock sensors are spliced together and go directly to the control module. OPERATION The knock sensor internal circuit causes the control modules 5 volts to be pulled down to about 2.5 volts. The knock sensor produces an A/C signal which rides on the 2.5 volts DC signal. The AC voltage monitor in the control module will detect this AC voltage and provide a signal to begin retarding spark until the knock diminishes. The amplitude and frequency are dependent upon the knock level. LOCATION Engine block. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Knock Sensor > Component Information > Locations > Page 4230 Knock Sensor: Testing and Inspection Knock Sensor (KS) System Check Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Knock Sensor > Component Information > Locations > Page 4231 Knock Sensor Circuit Circuit Description The Knock Sensor (KS) circuit consists of two knock sensors with one wire that goes directly to the control modules. There are two Knock Sensor (KS) checks performed by the ECM. One check consists of monitoring CKT 496 for a voltage that is more than .63 volt and less than 3.1 volts. If voltage is either too high or too low for 10 or more seconds, DTC 43 will set. The PCM uses this self check only. The next test is used only by the ECM along with the previous test. Once engine temperature reaches 85°C, MAP is over 83 kPa, and engine speed is less than 3200 RPM, the ECM will perform a self check. This self check will advance the timing until it receives a knock signal. If no knock signal is received, DTC 43 will set. Chart Test Description Number(s) below refer to circled number(s) on the diagnostic chart. 1. The first test is to determine if the system is functioning at the present time. 2. Test two determines the state of the 5 volt reference voltage applied to the knock sensor circuit. 3. Test 3 determines the state of the knock sensors and connections themselves. Diagnostic Aids The control module applies 5 volts to CKT 496. A 8200 ohm resistor in the knock sensors reduces the voltage to about 2.5 volts. When knock occurs, the knock sensor produces a small AC voltage that rides on top of the 2.5 volts already applied. An AC voltage monitor, in the control module, is able to read this signal as knock and incrementally retard spark. If the KS system checks OK, but detonation is the complaint, refer to "Detonation/Spark Knock". See: Computers and Control Systems/Testing and Inspection/Symptom Related Diagnostic Procedures/Detonation/ Spark Knock Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Knock Sensor > Component Information > Locations > Page 4232 Knock Sensor: Service and Repair REMOVE OR DISCONNECT - Negative battery cable. - Drain cooling system. NOTE On knock sensors which are mounted in the end of the cylinder head draining the cooling system will not be necessary. - Wiring harness connector from knock sensor. - Knock sensor. INSTALL OR CONNECT - Knock sensor. If reinstalling original sensor, apply water base caulk to sensor threads. Do NOT use silicone tape as this will insulate sensor from engine. ^ Tighten to 19 Nm (14 lb. ft.). - Wiring harness connector to knock sensor. - Refill cooling system and pressure test for leaks. - Negative battery cable. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Pick-Up Coil, Ignition > Component Information > Service and Repair Pick-Up Coil: Service and Repair Typical Distributor Components REMOVE/DISCONNECT 1. With distributor removed, disconnect wires at module terminals 2. Roll pin from drive gear by driving out with 1/8 inch diameter drift punch. Mark shaft and driven gear so they can be aligned for assembly. 3. Gear, shim and tanged washer from distributor shaft. Remove any burrs that may have been caused by removal of pin. 4. Distributor shaft from housing. Bushings in housing are not serviceable. 5. Remove retainer from inside pickup coil assembly. 6. Remove pickup coil assembly from housing. INSTALL/CONNECT 1. Install pickup coil. ^ Fit tab on the bottom of coil into anchor hole in housing. 2. Connect pickup coil wiring connector to module. ^ Make sure locking tab is in place. 3. Install shield onto coil. 4. Install retainer onto shield. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Pick-Up Coil, Ignition > Component Information > Service and Repair > Page 4236 Installing Pick-up Coil Retainer NOTE: Use a new round retainer if center bushing in distributor base has no groove around the outside. Use a new square retainer when there is a groove in center bushing. a. Place retainer over center bushing with teeth pointing upward. b. Place a 15 mm (5/8 in.) socket head onto edge of retainer. Keep socket centered on retainer so the teeth are not damaged. Use a small hammer to tap retainer evenly down on center bushing. When installing square retainer, make sure both teeth are seated in groove on bushing. NOTE: The retainer should hold shield, pickup coil, and pole piece firmly. 5. Install shaft assembly into housing. 6. Install tanged washer, shim and drive gear (teeth up) to bottom of shaft. Align drive gear and shaft assembly. 7. Install new roll pin and spin shaft to make sure teeth on shaft assembly do not touch pole piece. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Pole Piece / Reluctor Wheel, Ignition > Component Information > Service and Repair Pole Piece / Reluctor Wheel: Service and Repair Typical Distributor Components REMOVE/DISCONNECT 1. With distributor removed, disconnect wires at module terminals 2. Roll pin from drive gear by driving out with 1/8 inch diameter drift punch. Mark shaft and driven gear so they can be aligned for assembly. 3. Gear, shim and tanged washer from distributor shaft. Remove any burrs that may have been caused by removal of pin. 4. Distributor shaft from housing. Bushings in housing are not serviceable. 5. Remove retainer from inside pickup coil assembly. 6. Remove pickup coil assembly from housing. INSTALL/CONNECT 1. Install pickup coil. ^ Fit tab on the bottom of coil into anchor hole in housing. 2. Connect pickup coil wiring connector to module. ^ Make sure locking tab is in place. 3. Install shield onto coil. 4. Install retainer onto shield. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Pole Piece / Reluctor Wheel, Ignition > Component Information > Service and Repair > Page 4240 Installing Pick-up Coil Retainer NOTE: Use a new round retainer if center bushing in distributor base has no groove around the outside. Use a new square retainer when there is a groove in center bushing. a. Place retainer over center bushing with teeth pointing upward. b. Place a 15 mm (5/8 in.) socket head onto edge of retainer. Keep socket centered on retainer so the teeth are not damaged. Use a small hammer to tap retainer evenly down on center bushing. When installing square retainer, make sure both teeth are seated in groove on bushing. NOTE: The retainer should hold shield, pickup coil, and pole piece firmly. 5. Install shaft assembly into housing. 6. Install tanged washer, shim and drive gear (teeth up) to bottom of shaft. Align drive gear and shaft assembly. 7. Install new roll pin and spin shaft to make sure teeth on shaft assembly do not touch pole piece. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Relays and Modules - Ignition System > Ignition Control Module > Component Information > Locations > Ignition Module Typical Distributor Components Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Relays and Modules - Ignition System > Ignition Control Module > Component Information > Locations > Ignition Module > Page 4246 Rear Engine Wiring W/Man Trans Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Relays and Modules - Ignition System > Ignition Control Module > Component Information > Locations > Page 4247 C121 - Ignition Control Module Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Relays and Modules - Ignition System > Ignition Control Module > Component Information > Locations > Page 4248 Ignition Control Module: Service and Repair Typical Distributor Components REMOVE OR DISCONNECT NOTE It is not necessary to remove ignition distributor assembly from engine. - Distributor cap and rotor. - Connectors from module. - Two module attaching screws. - Lift module from housing and remove. INSTALL OR CONNECT NOTE: Do not wipe silicone grease from metal face of module or distributor base (where the module seats), when reinstalling the same module. If new module is to be installed clean distributor module base and spread new silicone grease on base and metal face of ignition module. The purpose of the silicone grease is to cool module. - Module onto housing. - Module attaching screws. Tighten to 2 Nm (18 lb.in.) - Connectors to module. - Rotor and cap. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Technical Service Bulletins > Knock Sensor Circuit - DTC 43 Chart Revision Knock Sensor: Technical Service Bulletins Knock Sensor Circuit - DTC 43 Chart Revision File In Section: 6E Engine Fuel & Emission Bulletin No.: 51-65-19 Date: April, 1995 Subject: Section 3A - Control Module System (PCM) Driveability and Emissions - Revised DTC 43 Knock Sensor (KS) Circuit (Dual Knock Sensors) Models: 1994 Chevrolet and GMC Truck S/T; M/L, C/K Models with 4.3L Engine (VINs W, Z RPOs L35, LB4) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Technical Service Bulletins > Knock Sensor Circuit - DTC 43 Chart Revision > Page 4254 This bulletin advises of a revision to the DTC 43 Knock Sensor (KS) Circuit (Dual Knock Sensor System) chart in the following service manuals: 1994 S/T Driveability Emissions and Electrical Diagnosis Manual, page 3A-119 1994 M/L Driveability Emissions and Electrical Diagnosis Manual, page 3A-75 1994 C/K Driveability Emissions and Electrical Diagnosis Manual, page 3A-69 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Technical Service Bulletins > Page 4255 Knock Sensor: Specifications Coil bracket bolt/nut ............................................................................................................................. ................................................. 27 N-m (20 lbs ft) Distributor clamp bolt ........................................................................................................................... ................................................ 27 N-m (20 lbs ft) Knock Sensor ...................................................................................................................................... .................................................. 19 N-m (14 lbs ft) Spark Plugs ......................................................................................................................................... .................................................. 15 N-M (11 lbs ft) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Locations > Assembly View Knock Sensors Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Locations > Assembly View > Page 4258 Knock Sensor: Locations Harness View LH Rear Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Locations > Assembly View > Page 4259 LH Rear Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Locations > Page 4260 Knock Sensor: Diagrams C119 - Knock Sensor C135 - Knock Sensor Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Locations > Page 4261 Knock Sensor: Description and Operation PURPOSE: The Knock Sensor (KS) is used to detect engine detonation (ping). The control module will retard the electronic spark timing up to 8° based on the signal received. CONSTRUCTION The KS system has two major components: Control Module. - Knock Sensor(s). The two knock sensors are spliced together and go directly to the control module. OPERATION The knock sensor internal circuit causes the control modules 5 volts to be pulled down to about 2.5 volts. The knock sensor produces an A/C signal which rides on the 2.5 volts DC signal. The AC voltage monitor in the control module will detect this AC voltage and provide a signal to begin retarding spark until the knock diminishes. The amplitude and frequency are dependent upon the knock level. LOCATION Engine block. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Locations > Page 4262 Knock Sensor: Testing and Inspection Knock Sensor (KS) System Check Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Locations > Page 4263 Knock Sensor Circuit Circuit Description The Knock Sensor (KS) circuit consists of two knock sensors with one wire that goes directly to the control modules. There are two Knock Sensor (KS) checks performed by the ECM. One check consists of monitoring CKT 496 for a voltage that is more than .63 volt and less than 3.1 volts. If voltage is either too high or too low for 10 or more seconds, DTC 43 will set. The PCM uses this self check only. The next test is used only by the ECM along with the previous test. Once engine temperature reaches 85°C, MAP is over 83 kPa, and engine speed is less than 3200 RPM, the ECM will perform a self check. This self check will advance the timing until it receives a knock signal. If no knock signal is received, DTC 43 will set. Chart Test Description Number(s) below refer to circled number(s) on the diagnostic chart. 1. The first test is to determine if the system is functioning at the present time. 2. Test two determines the state of the 5 volt reference voltage applied to the knock sensor circuit. 3. Test 3 determines the state of the knock sensors and connections themselves. Diagnostic Aids The control module applies 5 volts to CKT 496. A 8200 ohm resistor in the knock sensors reduces the voltage to about 2.5 volts. When knock occurs, the knock sensor produces a small AC voltage that rides on top of the 2.5 volts already applied. An AC voltage monitor, in the control module, is able to read this signal as knock and incrementally retard spark. If the KS system checks OK, but detonation is the complaint, refer to "Detonation/Spark Knock". See: Computers and Control Systems/Testing and Inspection/Symptom Related Diagnostic Procedures/Detonation/ Spark Knock Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Sensors and Switches - Ignition System > Knock Sensor > Component Information > Locations > Page 4264 Knock Sensor: Service and Repair REMOVE OR DISCONNECT - Negative battery cable. - Drain cooling system. NOTE On knock sensors which are mounted in the end of the cylinder head draining the cooling system will not be necessary. - Wiring harness connector from knock sensor. - Knock sensor. INSTALL OR CONNECT - Knock sensor. If reinstalling original sensor, apply water base caulk to sensor threads. Do NOT use silicone tape as this will insulate sensor from engine. ^ Tighten to 19 Nm (14 lb. ft.). - Wiring harness connector to knock sensor. - Refill cooling system and pressure test for leaks. - Negative battery cable. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Ignition System > Spark Plug > Component Information > Specifications Spark Plug: Specifications Spark Plug Gap ................................................................................................................................... ........................................ N/A see NOTE following. Spark Plug Torque ............................................................................................................................... ...................................................... 15 N-m (11 lb.ft.) Spark Plug Type .................................................................................................................................. .......................................................... AC CR43TSM NOTE Check the gap specifications given on the Emissions Control Label. If the gap is different from what is listed here, use the information on the label. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Pressure Regulating Solenoid, A/T > Component Information > Description and Operation Pressure Regulating Solenoid: Description and Operation PURPOSE This electrical device, controlled by the PCM, is used to control fluid line pressure. OPERATION The solenoid controls line pressure by controlling actuator feed limit fluid flow acting on internal spool valve and spring pressure. The solenoid is a normally closed solenoid valve that controls fluid pressure when operating on a duty cycle. LOCATION The solenoid is attached to the control valve body within the transmission. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Specifications > Electrical Specifications Shift Solenoid: Electrical Specifications Component Resistance Chart Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Specifications > Electrical Specifications > Page 4278 Shift Solenoid: Mechanical Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Pressure Control Solenoid To Valve Body .......................................................................................... ................................................................................ 8 Solenoid Assembly To Pump .......................... .............................................................................................................................................................. ....... 8 Solenoid Assembly To Case .................................................................................................... ........................................................................................... 18 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Locations > 4L60-E Automatic Transmission Electronic Component Location Views Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Locations > 4L60-E Automatic Transmission > Page 4281 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Description and Operation > 1 -2 Shift Solenoid Shift Solenoid: Description and Operation 1 -2 Shift Solenoid PURPOSE This electrical device, controlled by the PCM, is used to control fluid flow acting on the 1-2 and 3-4 shift valves. OPERATION The solenoid is a normally open exhaust valve that is used with the 2-3 shift solenoid to allow four different shifting combinations. LOCATION The solenoid is attached to the control valve body within the transmission. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Description and Operation > 1 -2 Shift Solenoid > Page 4284 Shift Solenoid: Description and Operation 2-3 Shift Solenoid PURPOSE This electrical device, controlled by the PCM, is used to control fluid flow acting on the 2-3 shift valves. OPERATION The solenoid is a normally open exhaust valve that is used with the 1-2 shift solenoid to allow four different shifting combinations. LOCATION The solenoid is attached to the control valve body within the transmission. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Description and Operation > 1 -2 Shift Solenoid > Page 4285 Shift Solenoid: Description and Operation 3-2 Control Solenoid PURPOSE This electrical device, controlled by the PCM, is used to control fluid flow acting on the 3-2 shift valve, which then controls the 2-4 band apply rate and 3-4 clutch release rate. The solenoid also controls the 3-2 downshift feel. OPERATION The solenoid is a pulse width modulated solenoid that operates on a negative duty cycle. LOCATION The solenoid is attached to the control valve body within the transmission. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission Shift Solenoid: Service and Repair 4L60-E Automatic Transmission Pan and Filter Assembly PAN AND FILTER ASSEMBLY Pan, Filter And Seal Removal CLEAN - Exposed ends of bottom pan screws and spray with penetrating oil. REMOVE OR DISCONNECT 1. Screws (76), oil pan (75) and gasket (73). 2. Oil filter (72) and filter seal (71). - Filter seal may be stuck in the pump. INSPECT - Filter (72), open filter by prying the metal crimping away from the top of the filter (black) and pull apart. The filter may contain evidence for root cause diagnosis. Clutch material. - Bronze slivers indicating bushing wear. - Steel particles. Valve Body and Wiring Harness VALVE BODY AND WIRING HARNESS Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4288 Valve Body Bolt Location Control Valve And Pressure Switch Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4289 Manual Valve Link Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4290 Valve Body Checkballs Case Checkballs And Filters REMOVE OR DISCONNECT 1. Electrical connections from components. 2. TCC PWM Solenoid Retainer Clip (379) and Solenoid (396). 3. TCC Solenoid bolts (68) and solenoid assembly (66) with O-ring seal (65) and wiring harness. 4. Pressure switch assembly bolts (70) and pressure switch assembly (69). 5. Accumulator cover bolts (58 and 59) and 1-2 accumulator cover and pin assembly (57). 6. 1-2 accumulator piston (56) and seal (55). 7. Spring (54). 8. Dipstick stop bracket (93). REMOVE OR DISCONNECT 1. Bolt (64) and manual detent spring assembly (63). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4291 2. Wiring harness retaining bolts. REMOVE OR DISCONNECT 1. Remaining valve body bolts (62). 2. Manual valve link (89). 3. Control valve assembly (60). 4. Bolts (58 and 59), accumulator cover (57), piston (56, spring (54) and spring (54A). 5. Bolts (77) and plate (53). 6. Spacer plate (48) and spacer plate gaskets (47 and 52). 7. Spring (46), piston (44), and pin (43). - Seven checkballs are located under the valve body and one is located in the case. The large copper flash colored ball is # 1A checkball (91). Valve Body and Associated Parts VALVE BODY AND ASSOCIATED PARTS Accumulator Assembly, Spacer Plate And Gaskets Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4292 Case Checkballs And Filters TOOL REQUIRED: - J 25025-5 Guide Pins NOTICE: The use of a honing stone, fine sandpaper or crocus cloth is not recommended for servicing stuck valves. All valve lands have sharply machined corners that are necessary for "cleaning" the bore. If these corners are rounded, foreign material could wedge between the valve and bore causing the valve to stick. If it is found necessary to clean a valve, "micro fine" lapping compound 900 grit or finer should be used. Too much "lapping" of a valve will cause excessive clearances and increase the chance of a valve not operating. INSTALL OR CONNECT 1. The wiring harness pass-thru connector into the case. 2. The 3-4 accumulator pin (43) into the case. 3. The 3-4 accumulator piston seal (45) onto the 3-4 accumulator piston. 4. The 3-4 accumulator piston (44) onto the pin. - The end with three legs must face the valve body. 5. The 3-4 accumulator piston spring (46). INSTALL OR CONNECT 1. Checkball (91) into case as shown. - Retain with Transjel TM J 36850 or equivalent. 2. J 25025-5 into the case. 3. Screens onto spacer plate as shown. 4. Spacer plate to case gasket (47) and spacer plate to valve body gasket (52) onto the spacer plate (48). - Gasket (47) identified by a "C". Gasket (52) identified by a "V". - Retain with Transjel TM J 36850 or equivalent. 5. Spacer plate and gaskets onto the case. IMPORTANT - Be careful not to damage screens when installing the spacer plate and gaskets. 6. Spacer plate support (53) and bolts (77). TIGHTEN - Bolts to 11 Nm (8 lb. ft.) Control Valve Body CONTROL VALVE BODY Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4293 Case Checkballs And Filters Filter Screen - Locations Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4294 Control Valve Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4295 Control Valve Assembly - Legend Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4296 Valve Body Checkball Locations Valve Body Bolt Locations Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4297 Manual Valve Link Outside Electrical Connector CLEAN - Control valve assembly thoroughly in clean solvent. A. Move the valves with a pick or small screwdriver to dislodge any dirt or debris that may have accumulated. B. Air dry. REMOVE OR DISCONNECT IMPORTANT - Some valves are under pressure - cover the bores while removing roll pins and retainer clips. - Valves, springs and bushings must be laid out on a clean surface in the exact sequence they are removed. 1. Pressure control solenoid retainer bolt (364) retainer (378) and solenoid. 2. Bore plug retainer clip (395), bore plug (376) and valve train (374 and 375). 3. 2-3 shift solenoid retainer (379), solenoid (367) and valve train (368 and 369). 4. 1-2 shift solenoid retainer (379), solenoid (367) and valve train (365 and 366). 5. Accumulator valve train retainer pin (360), bore plug (373) and valve train (370 and 371). 6. Forward accumulator cover bolts (364) and cover (363). 7. Forward accumulator spring (356), piston (354) and pin (355). 8. Lo overrun valve spring (362) and valve (361). 9. Retainer pin (360), bore plug (359) and forward abuse valve train (357 and 358). 10. Manual valve (340). 11. 3-2 control solenoid retainer clip (379) and solenoid (394). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4298 12. Bore plug retainer (395), bore plug (381) and 3-2 control valve train (391 - 393). 13. 3-2 downshift bore plug retainer (395), bore plug (381) and valve train (389 - 390). 14. Reverse abuse bore plug retainer pin (360), bore plug (359) and valve train (387 - 388). 15. 3-4 shift valve bore plug retainer (395), bore plug (381) and valve train (385 - 386). 16. 3-4 relay bore plug retainer (395), bore plug (381) and valve train (382 - 384). 17. Torque converter clutch signal valve bore plug retainer (395), bore plug (381) and valve (380). CLEAN - All valves, springs, bushings and control valve body in clean solvent. - Dry using compressed air. INSPECT - All valves and bushings for: Porosity - Scoring - Nicks - Scratches - Springs for damaged or distorted coils. - Valve body casting for: Porosity - Cracks - Inter connected oil passages - Damaged machined surfaces ASSEMBLE - Control valve assembly (350) exactly as shown. Notice the position of the valve lands and bushing passages. - Position the pressure control solenoid so the connector tabs face outward. NOTICE: TCC PWM solenoid (396) cannot be installed until TCC solenoid has been installed and torqued to proper specifications. INSTALL OR CONNECT 1. Checkballs into the valve body assembly (350). - Retain with Transjell TM J 36850 or equivalent. 2. Valve body assembly (350). - Connect the manual valve link (89) to the inside detent lever (88). - Be careful not to damage screens when installing the valve body assembly. 3. Wiring harness (66), manual spring assembly (63), pressure switch assembly(69), dipstick, stop bracket (93) and all remaining valve body bolts. NOTICE: Torque valve body bolts in a spiral pattern starting from the center. If bolts are torqued at random, valve bores may be distorted and inhibit valve operation. 4. TCC solenoid (66) and bolts (68). TIGHTEN - Bolts to 11 Nm (8 lb. ft.). 5. TCC PWM solenoid (396), and retainer clip (379). INSTALL OR CONNECT - Wiring harness connections to electrical components. - To correctly hook up the wires, see the wiring diagrams. - The pressure control solenoid (377) has two different colored connectors. The black connector should be installed on the tab farthest from the valve body. INSTALL OR CONNECT 1. Parking bracket (86). TIGHTEN - Bolts to 31 Nm (23 lb. ft.). 2. The 1-2 accumulator piston seal (55) onto the 1-2 accumulator piston (56). 3. The 1-2 accumulator spring (54) and 1-2 accumulator inner spring (54A) onto the piston (56). 4. The 1-2 accumulator piston (56) into the 1-2 accumulator cover and pin assembly (57). - The three legs on the piston must face away from the case when installed. 5. The 1-2 accumulator cover and pin assembly (57) onto the case. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4299 TIGHTEN - Torque to 11 Nm (8 lb. ft.). Pan and Filter Assembly PAN AND FILTER ASSEMBLY Case, Pan And Filter Assembly INSTALL OR CONNECT 1. Filter seal (71) into the pump. 2. Oil filter (72). 3. Oil pan gasket (73). 4. Chip magnet (74) onto oil pan (75). 5. Oil pan (75) and bolts (76). TIGHTEN - Torque to 12 Nm (9 lb. ft.). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4300 Shift Solenoid: Service and Repair 4L80-E Automatic Transmission Pan and Filter Assembly PAN AND FILTER ASSEMBLY Pan, Filter And Seal Removal REMOVE OR DISCONNECT 1. Drain the transmission fluid Out case extension by rotating transmission to a vertical position. 2. Seventeen bolts (27), using 10 mm socket, drain transmission fluid. 3. Pan (28), seal (29) and magnet (30). IMPORTANT - Seal (29) is reusable. 4. Filter assembly (31). INSPECT - Filter neck seal (32), replace if necessary. Wire Harness Assembly WIRE HARNESS ASSEMBLY Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4301 Pan, Filter And Seal Removal REMOVE OR DISCONNECT 1. Wire harness connectors from electrical components. NOTICE: Excessive force on the case pass through connector may damage the connector. IMPORTANT - If the wire harness assembly does not need servicing, it is not necessary to remove it from the case. 2. Wire harness assembly (34) from case using a 1-5/16" 12 point socket to release the connector retaining clips. Control Valve Assembly CONTROL VALVE ASSEMBLY Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4302 REMOVE OR DISCONNECT 1. Rotate transmission bottom pan surface up and lock in place. 2. Wire harness assembly (34) connectors from components. IMPORTANT - If the wire harness assembly does not need servicing, it is not necessary to remove it from the case. - Use a cap to cover electrical pin at case connection. 3. Six bolts (76) using 8 mm socket, and transmission fluid pressure switch assembly (40). NOTICE: Be sure five O-rings are attached to transmission fluid pressure switch assembly. 4. Twenty-one bolts (35) using 10 mm socket, from valve body assembly, manual detent spring and roller assembly (41). 5. Three wiring clamps (33), fluid level indicator stop (43), one bolt (36) using 10 mm socket, lube pipe (39), lube pipe retainer (37) and clamp (38). 6. Control valve assembly (44) including the accumulator housing assembly (51), valve body gaskets (45 and 48), spacer plate (46) and accumulator gasket (47). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4303 7. Manual valve (319) from control valve assembly (44) to prevent any damage. 8. Checkballs (54) from case passages. NOTICE: Do not use a magnet. It could cause checkball(s) to be magnetized causing metal particles to stick to the ball. 9. Pulse Width Modulated (PWM) solenoid screen (75). INSPECT - Screen PWM solenoid (75), replace if necessary. DISASSEMBLE Control Valve Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4304 - Control valve assembly. A. Position as shown on a clean surface. B. Remove blind hole retainer pins with a drill bit. CAUTION: Some valves are under pressure - cover the bores while removing the retaining pins or personal injury could result. C. Remove valve trains, shift solenoids (311 and 313), PCS (320), PWM solenoid (323), PCS screen (302) and shift solenoid filter (317). D. Valves, springs, bushings and pistons must be laid out on a clean surface. CLEAN - All valves, springs, bushings, pistons, control valve body and accumulator housing in clean solvent. - Dry using compressed air. INSPECT 1. All valves, pistons and bushings for: - Porosity. - Scoring. - Nicks. - Scratches. 2. Pistons for: - Seal damage. 3. Springs for: - Damaged or distorted coils. 4. Valve body casting and accumulator housing for: - Porosity. - Cracks. - Interconnected passages. - Damaged machined surfaces. 5. Solenoid connectors and filter (317). 6. PCS (Pressure Control Solenoid) screen (302). Control Valve Assembly/Accumulator Housing CONTROL VALVE ASSEMBLY/ACCUMULATOR HOUSING Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4305 Control Valve Assembly/Accumulator Housing Accumulator Housing Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4306 Control Valve Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4307 Torque Sequence And Guide Pin Location Fig. 11 Check Ball Location. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4308 Fig. 10 Control Valve Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4309 Torque Sequence, Control Valve And Switch Assembly NOTICE: The use of a honing stone, fine sandpaper or crocus cloth is not recommended for servicing stuck valves. All valve lands have sharply machined comers that are necessary for cleaning the bore. If these corners are rounded, foreign material could wedge between the valve and the bore causing the valve to stick. If it is found necessary to clean a valve, micro fine lapping compound 900 grit (J 38459) or finer should be used. Too much lapping of the valve will cause excessive clearances and increase the chance of a valve not operating. CLEAN - Control valve assembly and accumulator housing (51) thoroughly in clean solvent. - Air dry. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4310 Accumulator Housing Assembly ACCUMULATOR HOUSING ASSEMBLY Control Valve Assembly/Accumulator Housing Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4311 Accumulator Housing Assembly DISASSEMBLE 1. Six bolts (53), using 8 mm socket. 2. Accumulator housing assembly. 3. Gasket accumulator housing (47). 4. Spacer plate (46). 5. Gasket (45) valve body spacer. 6. Snap ring (402) from outside housing, pin (408), snap ring (402), piston (407) and spring (49). 7. 3rd clutch piston (405) and spring (50). 8. Seals (404 and 406). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4312 CLEAN - All components. INSPECT - All valves, pistons, springs and seals for: - Porosity. - Scoring. - Nicks. - Scratches. Accumulator Housing Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4313 ASSEMBLE - Accumulator housing assembly components exactly as shown. Notice the positions of the pistons. Control Valve Assembly CONTROL VALVE ASSEMBLY Control Valve Assembly ASSEMBLE - Control valve assembly components exactly as shown. Notice the position of the valve lands and bushing passages. Control Valve Assembly/Accumulator Housing Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4314 CONTROL VALVE ASSEMBLY AND ACCUMULATOR HOUSING Control Valve Assembly/Accumulator Housing Torque Sequence And Guide Pin Location TOOL REQUIRED: - Guide Pin J 25025-5 ASSEMBLE 1. Guide pin J 25025-5 into valve body. Located at back bolt hole of detent spring and roller assembly bolt bole. 2. Gasket (45) valve body to spacer plate. 3. Spacer plate (46). 4. Gasket (47) accumulator housing to spacer plate. 5. Accumulator housing assembly (51) onto valve body assembly (44). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4315 6. Six bolts (53) using (8 mm) socket through accumulator housing into valve body assembly. Torque Sequence And Guide Pin Location NOTE: Start accumulator housing bolts finger tight and work towards opposite end. TIGHTEN - Bolt (53) to 11 Nm (97 lb. in.). 7. Remove guide pin J 25025-5. Fig. 11 Check Ball Location. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4316 Fig. 10 Control Valve Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4317 Torque Sequence, Control Valve And Switch Assembly INSTALL OR CONNECT 1. Install checkballs (54) in proper location into case fluid passages. Use TRANSJEL TM J 36850 or equivalent to hold in place. NOTICE: Do not use any type of grease to retain parts during assembly of this unit. Greases other than the recommended assembly lube will change transmission fluid characteristics and cause undesirable shift conditions and/or filter clogging. - # 2 checkball is used only on RCP RDP, ZJP and ZLP models. 2. PWM solenoid screen (75). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4318 3. Gasket (48) spacer plate to case. 4. Manual valve (319) into valve body. 5. Complete valve body assembly (44) onto case (7). Use 1 25025-5 guide pin set. IMPORTANT - Attach manual valve to detent lever. 6. Transmission fluid pressure switch assembly (40) onto valve body assembly (44). 7. Spring and roller assembly (41) into place. 8. Three wiring clamps (33), fluid indicator stop (43) and lube pipe clamp (38). 9. Twenty-one bolts (35). Using 10 mm socket. 10. Six bolts (76) using 8 mm socket into transmission fluid pressure switch assembly (40). 11. Lube pipe (39) long end into case, short end into valve body. 12. Lube pipe retainer (37) with short bolt (36). TIGHTEN - Bolts (35, 36 and 76) to 11 Nm (97 lb. in.). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4319 Torque Sequence, Control Valve And Switch Assembly NOTICE: Torque valve body bolts in a spiral pattern starting from the center. If bolts are torqued at random, valve bores may be distorted and inhibit valve operation. 13. Attach wiring harness (34) to 5 connectors. - Put large end into case first, pressure switch hook up, 1-2 shift solenoid (purple) and 2-3 shift solenoid (tan), PWM (Pulse Width Modulated) solenoid and PCS (Pressure Control Solenoid). Pan and Filter Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4320 PAN AND FILTER ASSEMBLY Installing Pan And Filter INSTALL OR CONNECT 1. Seal (32) inside of case (7). 2. Filter assembly (31). 3. Bottom pan seal (29). 4. Magnet (30) into bottom pan. 5. Pan (29). 6. Seventeen bolts (27) using 10 mm socket. TIGHTEN - Bolts (27) to 24 Nm (18 lb. ft.). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Torque Converter Clutch Solenoid, A/T > Component Information > Technical Service Bulletins > A/T - 2-4 Band, TCC Solenoid, 3-4 Clutch Friction/Plates Torque Converter Clutch Solenoid: Technical Service Bulletins A/T - 2-4 Band, TCC Solenoid, 3-4 Clutch Friction/Plates File In Section: 7 - Transmission Bulletin No.: 47-71-41 Date: January, 1995 Subject: New 2-4 Band Assembly, 3-4 Clutch Friction and Steel Plates and Torque Clutch PWM Solenoid Models: 1995 Buick Roadmaster 1995 Cadillac Fleetwood 1995 Chevrolet Camaro, Caprice, Corvette 1995 Pontiac Firebird 1995 Chevrolet and GMC Truck C/K Models and M/L, G Vans 1994-95 Chevrolet and GMC Truck S/T Models 1994 Oldsmobile Bravada (1994 Models with RPO +CTF Package) Transmission Applications: 1995 Hydra-Matic 4L60-E (RPO M30) A new 2-4 Band Assembly was introduced at the start of production for the 1995 Model Year and 1994 Bravadas and S/T trucks. The 2-4 Band friction material has changed appearance from a brown material to a gray/black material. This change was made to enhance durability. When servicing a 1995 Hydra-Matic 4L60-E transmission, do NOT assume that the 2-4 Band is burned/damaged due to its dark color. This dark color is normal. Before replacing the 2-4 Band inspect it for scoring, chunking or heavily worn friction material. Before Replacing the Reverse Input Housing and Drum Assembly inspect for scoring or signs of excessive heat. The 2-4 Band and/or Reverse Input Housing and Drum Assembly should be replaced ONLY if the above listed damage is found. Note: The new 2-4 Band Assembly will NOT service past model Hydra-Matic 4L60-E or 4L60 transmissions. A new 3-4 clutch friction plate was introduced at the start of production for the 1995 Model Year and 1994 Bravadas and S/T Trucks. The 3-4 clutch plate friction material has changed appearance from a brown material to a green/black material. This change was made to enhance durability. When servicing a 1995 Hydra-Matic 4L60-E transmission, do NOT assume that the 3-4 clutch friction plates are burned/damaged due to their dark color. This dark color is normal. Before replacing the 3-4 clutch friction plates inspect for scoring, chunking or heavily worn friction material. Before replacing the 3-4 clutch steel plates inspect for scoring or signs of excessive heat. The 3-4 clutch friction plates and/or 3-4 clutch steel plates should be replaced ONLY if the above listed damage is found. Note: The new 3-4 friction plates will NOT service past model Hydra-Matic 4L60-E or 4L60 transmissions. A new Torque Converter Clutch PWM Solenoid was introduced at the start of production for the 1995 Model Year and 1994 Bravadas and S/T trucks. The new torque converter clutch PWM solenoid is used to control fluid acting on the converter clutch valve, which then controls TCC apply and release. The solenoid is attached to the control valve body assembly within the transmission. The TCC PWM solenoid is used to provide smooth engagement of the torque converter by operating on a negative duty cycle percent of "ON" time. It a fault is detected in the TCC PWM circuit, DTC 83 will set. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Torque Converter Clutch Solenoid, A/T > Component Information > Technical Service Bulletins > A/T - 2-4 Band, TCC Solenoid, 3-4 Clutch Friction/Plates > Page 4325 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Torque Converter Clutch Solenoid, A/T > Component Information > Technical Service Bulletins > A/T - 2-4 Band, TCC Solenoid, 3-4 Clutch Friction/Plates > Page 4326 Included is a Service Manual update for the 1-2 and 3-4 accumulator spring color chart. Replace these pages in your 1995 Service Manual. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Torque Converter Clutch Solenoid, A/T > Component Information > Technical Service Bulletins > Page 4327 Torque Converter Clutch Solenoid: Locations Inside automatic transmission attached to valve body. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Torque Converter Clutch Solenoid, A/T > Component Information > Technical Service Bulletins > Page 4328 C216 - TCC Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Torque Converter Clutch Solenoid, A/T > Component Information > Technical Service Bulletins > Page 4329 Torque Converter Clutch Solenoid: Description and Operation Torque Converter Clutch Solenoid PURPOSE The Transmission Converter Clutch (TCC) feature eliminates the power loss of the torque converter stage when the vehicle is in a cruise mode. OPERATION The TCC system uses a solenoid operated valve in the automatic transmission to couple the engine flexplate to the output shaft of the transmission through the torque converter. This reduces the slippage losses in the converter, which increases fuel economy. For the converter clutch to apply, two hydraulic conditions must be met: Internal transmission fluid pressure must be correct. - The control module completes a ground circuit to energize the TCC solenoid in the transmission, which moves a check ball in the fluid line. Control module control is based on the input of these sensors: Vehicle Speed Sensor (VSS): Vehicle equipped with A/C will allow TCC engagement at about 35 mph when the A/C is selected "ON". Engagement will occur at a vehicle speed of about 30 mph (25 mph for 92) when A/C is selected "OFF". - Engine Coolant Temperature (ECT) Sensor: Engine at normal operating temperature (above 65°C/149°F). - Throttle Position Sensor (TPS): Output not changing, indicating a steady road speed. - Transmission Fluid (TFT) sensor. Control module is also controlled by these switches: Brake switch closed: 12 volts supplied when brake is depressed. - Transmission Range (TR) pressure switch assembly. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - Transfer Case > Transfer Case Actuator > Component Information > Locations > Electronic Shift Transfer Case Position Switch Transfer Case Actuator: Locations Electronic Shift Transfer Case Position Switch Transfer Case Electric Shift Motor The Electronic Shift Transfer Case Position Switch (Encoder Switch) is located in the in the shift motor on the transfer case. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - Transfer Case > Transfer Case Actuator > Component Information > Locations > Electronic Shift Transfer Case Position Switch > Page 4335 Four-Wheel Drive Indicator Wiring Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - Transfer Case > Transfer Case Actuator > Component Information > Locations > Page 4336 Transfer Case Actuator: Diagrams C154 - Front Axle Switch C155 - Front Axle Switch In-Line C154 - Front Axle Switch C155 - Front Axle Switch In-Line Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - Transfer Case > Transfer Case Actuator > Component Information > Locations > Page 4337 Transfer Case Actuator: Service and Repair ELECTRIC SHIFT MOTOR REPLACEMENT Transfer Case Electric Shift Motor REMOVE OR DISCONNECT 1. Negative battery cable. - Raise vehicle and support with safety stands. 2. Transfer case shield. 3. Motor electrical connection. 4. Front propeller shaft. 5. Front output shaft yoke. 6. Motor to transfer case bolts. 7. Motor from the transfer case. INSTALL OR CONNECT 1. Motor to the transfer case. 2. Bolts. TIGHTEN - Bolts to 18 Nm (13 lbs. ft.). 3. Front output shaft yoke. 4. Front propeller shaft. 5. Motor electrical connection. 6. Transfer case shield. 7. Negative battery cable. - Lower Vehicle Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Lamps and Indicators Transmission and Drivetrain > Lamps and Indicators - A/T > Shift Indicator > Component Information > Locations Shift Indicator: Locations Instrument cluster. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Lamps and Indicators Transmission and Drivetrain > Lamps and Indicators - Transfer Case > Four Wheel Drive Indicator Lamp > Component Information > Locations Four-Wheel Drive Indicator Lamp Wiring I/P Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Lamps and Indicators Transmission and Drivetrain > Lamps and Indicators - Transfer Case > Four Wheel Drive Indicator Lamp > Component Information > Locations > Page 4347 C274 - 4WD Indicator Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Lamps and Indicators Transmission and Drivetrain > Lamps and Indicators - Transfer Case > Four Wheel Drive Indicator Lamp > Component Information > Locations > Page 4348 Four Wheel Drive Indicator Lamp: Description and Operation The Four-Wheel Drive (4WD) Indicator Assembly provides visual information about the operating mode and gear range of the driveline. Voltage is supplied to the IGN/GAU Fuse and Indicator Assembly with the Ignition Switch in START or RUN. The circuit is completed through the Selector Quadrant Switch, which provides a ground path to light various Indicator Assembly Lamps. With the Selector Quadrant Switch in detent position 1, the "2WHL" Indicator Assembly Lamp is lit. With the Selector Quadrant Switch in detent position 2, the "4 HIGH" Indicator Assembly Lamp is lit. At this time, the Front Axle Switch is closed and the Indicator Assembly Front and Rear Axle Display is lit. With the Selector Quadrant Switch in detent position 4, the "4 LOW" Indicator Lamp is lit. At this time, the Front Axle Switch is closed, and the Indicator Assembly Front and Rear Axle Display is lit. A signal is sent to the Four-Wheel Antilock Brake Module (4WAL) whenever the 4WD is engaged. This signal turns off the 4WAL systems to prevent operation during 4WD operation. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Lamps and Indicators Transmission and Drivetrain > Lamps and Indicators - Transfer Case > Four Wheel Drive Indicator Lamp > Component Information > Testing and Inspection > Initial Inspection and Diagnostic Overview Four Wheel Drive Indicator Lamp: Initial Inspection and Diagnostic Overview Circuit Operation - Four-Wheel Drive Indicator The Four-Wheel Drive (4WD) Indicator Assembly provides visual information about the operating mode and gear range of the driveline. Voltage is supplied to the IGN/GAU Fuse and Indicator Assembly with the Ignition Switch in START or RUN. The circuit is completed through the Selector Quadrant Switch, which provides a ground path to light various Indicator Assembly Lamps. With the Selector Quadrant Switch in detent position 1, the "2WHL" Indicator Assembly Lamp is lit. With the Selector Quadrant Switch in detent position 2, the "4 HIGH" Indicator Assembly Lamp is lit. At this time, the Front Axle Switch is closed and the Indicator Assembly Front and Rear Axle Display is lit. With the Selector Quadrant Switch in detent position 4, the "4 LOW" Indicator Lamp is lit. At this time, the Front Axle Switch is closed, and the Indicator Assembly Front and Rear Axle Display is lit. A signal is sent to the Four-Wheel Antilock Brake Module (4WAL) whenever the 4WD is engaged. This signal turns off the 4WAL systems to prevent operation during 4WD operation. Preliminary Checks - Four-Wheel Drive Indicator 1. Check condition of IGN/GAU Fuse. If fuse is Blown, locate and repair overload. Replace fuse. 2. If fuse is not blown, proceed with the Diagnostics. See: Symptom Related Diagnostic Procedures Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Lamps and Indicators Transmission and Drivetrain > Lamps and Indicators - Transfer Case > Four Wheel Drive Indicator Lamp > Component Information > Testing and Inspection > Initial Inspection and Diagnostic Overview > Page 4351 Four Wheel Drive Indicator Lamp: Symptom Related Diagnostic Procedures Indicator Assembly Illumination Lamp Does Not Light One Or More Indicator Assembly Lamps Do Not Light Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Relays and Modules Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Locations Control Module: Locations Mounted on the back of the Electronic Control Module (ECM)/Powertrain Control Module (PCM) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Relays and Modules Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Locations > Page 4357 C202A - Transfer Case Control Module Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Relays and Modules Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting Control Module: Description and Operation Electric 4WD Shifting Transfer Case 4WD Selector Switch 4WD Selector Switch Wiring Schematic OPERATION On vehicles equipped with the Model 233 transfer case, there is no transfer case selector lever in the cab. The operator selects 4HI or 4LO by pushing a three-position (4HI, 4LO, 2HI) rocker-type selector switch mounted on the instrument panel. During normal driving the transfer case is in the 2HI mode. The switch is spring-loaded to the center position. When the transfer case is in 2HI both the 4HI and 4L0 switch circuits are open, and both lights are off. When shifting to 4HI or 4LO the rocker switch will still return to the center position and the 4HI or 4LO light will be on. The above image shows the wiring schematic of the transfer case selector switch. Mode Shifts Mode shifts are shifts from: - 2HI to 4HI - 4HI to 2HI A mode shift can be accomplished in any gear position and at any vehicle speed. If the system is in 2HI, the operator can shift into 4HI merely by pressing and releasing the 4HI area of the selector rocker switch. The green 4HI status lamp flashes whenever a 2HI or 4HI shift is initiated and continues to flash until the TCCM completes the shift (or until 30 seconds elapses). After the shift into 4HI is accomplished, the 4HI status lamp remains lit to indicate that the system is in 4HI. The operator can shift from 4HI back to 2HI by again pressing 4HI on the selector switch. Again, the green 4HI status lamp flashes until the shift to 2HI is complete, and then extinguishes once the shift is complete. Both the 4HI and 4LO lamps remain oft when the vehicle is in 2HI. Range Shifts Range shifts are shifts between the HI and LO ranges, from: Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Relays and Modules Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 4360 - 2HI to 4LO - 4HI to 4LO - 4LO to 4HI A range shift from 4L0 directly to 2HI cannot be made. The operator must first make range shift from 4LO to 4HI, then a mode shift from 4HI to 2HI. A range shift can only be made with the automatic transmission in neutral or with the manual transmission clutch fully depressed. The vehicle speed must also be below three miles per hour before the shift can occur. Whenever a shift into 4LO is initiated, the amber 4LO status lamp flashes and continues to flash until the TCCM completes the shift (or until 30 seconds elapses). The 4LO status lamp must glow steadily before the vehicle transmission is shifted into gear or before the clutch pedal is released. If a range shift is initiated when the transmission is engaged or when the vehicle speed is above 3 mph, the 4LO status lamp flashes for 30 seconds and no range shift actually occurs; the system returns to the position before the shift was initiated. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Relays and Modules Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 4361 Control Module: Description and Operation TCCM Power and Ground Fig. 1, Memory Power, System Power, And Ground Circuit Fig. 2, Fuse Block And Cavity Location Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Relays and Modules Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 4362 POWER, CIRCUIT PROTECTION, AND GROUND The Transfer Case Control Module (TCCM) memory power, system power, and the ground circuit are shown in Figure 1. The vehicle fuse block and cavity location for memory power, system power, and motor power are shown in Figure 2. Memory Power Trouble code memory power is protected by a 5-amp TCCM fuse. Memory power is supplied to TCCM connector pin C6 through circuit 140. System Power Operating power is controlled by the ignition switch and is protected by a 15-amp radio fuse. System power is supplied to TCCM connector pin C8 through circuit 141. This fuse also supplies, voltage to pin B of the transfer case switch. The system power will shut down if either the 5-amp TCCM fuse or the 15-amp radio fuse are removed or blown. System Ground System ground is supplied to TCCM connector pin C10 through circuit 150. Circuit 150 is connected to the bus bar ground located on the left side of the steering column support. Refer to Figure 1. Turn/BU Fuse A 15-amp TURN/BU fuse supplies ignition voltage to the park/neutral position switch. This voltage enables the park switch to send a park signal to TCCM connector pin D2. Power Accessory Circuit Breaker The 30-amp power accessory circuit breaker supplies ignition voltage to TCCM connector pins D14 and D15. This voltage is used to control the electric-shift motor circuit. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Relays and Modules Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 4363 Control Module: Description and Operation TCCM Inputs and Outputs General Description INPUTS The Transfer Case Control Module (TCCM) receives input signals from the following sources: - Transfer case selector switch on the instrument panel. - Park/neutral position switch on vehicles with automatic transmissions. - Clutch safety switch on vehicles with manual transmissions. - Vehicle speed sensor buffer which supplies vehicle speed signals. - Encoder switch within the electric-shift motor which provides actual mode and range information signals. - Data link connector (DLC) pin J which provides diagnostic enable. OUTPUTS After processing the input information, the Transfer Case Control Module (TCCM) outputs signals to the following: - Electric shift motor to effect mode and range shifts. - Selector switch status lamps to provide transfer case status information. - Diagnostic trouble codes (DTC) which are output via the selector switch status lamps. 2HI to 4HI Selector Switch Input 4WD Selector Switch Wiring Schematic OPERATION When the transfer case is in 2HI and the operator presses the 4HI area of the rocker switch, the 4HI contacts of the selector switch close, connecting circuits 141 and 1564, and furnishing 12-volts to pin C5 of the TCCM connector. The 12-volt signal at pin C5 commands the Transfer Case Control Module (TCCM) to signal the electric-shift motor to shift into 4HI. The contacts return to the open position as soon as the switch is released. 4HI to 2HI Selector Switch Input Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Relays and Modules Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 4364 4WD Selector Switch Wiring Schematic OPERATION If the transfer case is in 4HI and the operator presses the 4HI area of the rocker switch, the 4HI contacts of the selector switch close, connecting circuits 141 and 1564 and furnishing 12-volts to pin C5 of the Transfer Case Control Module (TCCM) connector. The 12-volt signal at pin C5 commands the TCCM to signal the electric-shift motor to shift into 4HI. Again, the contacts return to the open position as soon as the switch is released. 2HI to 4HI to 4LO Selector Switch Input 4WD Selector Switch Wiring Schematic OPERATION When the operator presses the 4LO area of the rocker switch while the transfer case is in either 2HI or 4HI, the 4LO contacts of the selector switch close, connecting circuits 141 and 1559, and furnishing 12-volts to pin C3 of the Transfer Case Control Module (TCCM) connector. The 12-volt signal at pin C3 commands the TCCM to signal the electric-shift motor to shift the transfer case into 4LO. Once more, the contacts return to the open position as soon as the switch is released. Park/Neutral Position Switch Inputs Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Relays and Modules Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 4365 Automatic Transmission Neutral Start Switch Neutral Start Switch Voltages OPERATION Because range shift should only be made with the automatic transmission in neutral, the park/neutral position switch informs the Transfer Case Control Module (TCCM) that the vehicle automatic transmission is in either: - Park - Neutral - One of the drive positions The park/neutral position switch consists of three switches together in one unit, and it provides three signals: - Park - When the automatic transmission is in park, the contacts of both the park switch and the park neutral switch are closed. When these contacts are closed, a battery voltage signal is sent to TCCM connector pin D2, while connector pin D16 is pulled to ground (0 voltage). The TCCM interprets this signal to mean the automatic transmission is in park. - Neutral - When the automatic transmission is in neutral, the contacts of the park switch are open and the contacts of the park neutral position switch are closed. In this condition, a 0-voltage signal is sent to TCCM connector pin D2, while connector pin D16 is pulled to ground (0 volts). The TCCM interprets this signal to mean the automatic transmission is in neutral. - In gear - When the automatic transmission is in any other gear position, the contacts of both the park switch and park neutral switch are open. In this condition, a 0-voltage signal is sent to TCCM connector pin D16. The TCCM interprets this signal to mean the automatic transmission is neither park or neutral. Important - If the backup switch connector were to be plugged in upside down, the park switch would receive no power. Such a condition would cause a 0-voltage signal at both pin D2 and pin D16 in neutral and in park. The transfer case, accordingly, would perform a range shift in park as well as in neutral. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Relays and Modules Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 4366 - An open in circuit 75, or an open in the Turn/BU fuse would also cause this condition. - Additionally, a park/neutral position switch that is out of adjustment may prevent a range shift in park. Clutch Safety Switch Inputs Clutch Safety Switch Schematic Clutch Safety Switch Voltage Signals OPERATION Because range shifts should only be made with the manual transmission clutch fully depressed, the clutch safety switch informs the Transfer Case Control Module (TCCM) that the vehicle clutch pedal is fully depressed or released. The clutch safety switch is connected to TCCM connector pin D16. When the clutch pedal is released, the contacts of the clutch safety switch are open. When these contacts are open, a battery voltage signal is seen at TCCM connector pin D16. The TCCM interprets this signal to mean the clutch is released. When the clutch is fully depressed, the contacts of the clutch safety switch are closed. When the contacts are closed, voltage is pulled low to 0 at TCCM connector pin D16. The TCCM interprets this signal to mean the clutch pedal is fully depressed. Because TCCM connector pin D2 is not connected when the vehicle is equipped with a manual transmission, the TCCM reads a 0-volt signal at pin D2 at all times. All readings are taken while back-probing the TCCM pins with the ignition in the "Run" position. A reading of less than 0.5 volt is considered to be zero. Vehicle Speed Input Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Relays and Modules Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 4367 Vehicle Sensor Buffer And TCCM Schematic OPERATION The vehicle speed sensor buffer informs the Transfer Case Control Module (TCCM) about the speed of the vehicle in miles per hour. Such information is essential to inform the TCCM to prohibit range shifts at speeds above 3 mph. The vehicle speed sensor (VSS) is a variable-reluctance magnetic sensing device that converts tone wheel rotation into a frequency and voltage output proportional to the vehicle speed. The frequency and voltage signal is sent to the vehicle speed sensor buffer which converts the speed sensor output into a useful pulse signal. The vehicle speed sensor buffer then, pulses circuit 1567 to ground at a rate of 4000 pulses per mile. Whenever the vehicle speed sensor buffer grounds circuit 1567, the voltage at TCCM connector pin D8 returns to 5 volts. The TCCM reads the 4000 pulses-per-mile (1.11 Hz per mph) signal to determine vehicle speed. Encoder Switch Inputs Fig 1, Electric Shift Encoder Switch Layout Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Relays and Modules Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 4368 Fig 2, Electric Shift Encoder Switch Schematic Fig 3, Encoder Switch Channel Signals And Positions OPERATION The four-channel encoder switch indicates the current transfer case mode and range to the Transfer Case Control Module (TCCM). The encoder switch is located inside the encoder itself and is not serviceable. The TCCM reads the status of the four channels to determine the range and mode in which the transfer case is operating or whether the transfer case is shifting between modes and/or ranges. The encoder assembly is composed of an inner ground ring in contact with a three-leg wiper arm. The three legs of the wiper, spaced 120 degrees apart, make contact with the conductive areas of the four channels. When any leg of the wiper arm is in contact with the conductive area of any channel, a path to ground is provided to the inner ground ring. A schematic of the encoder switch is shown in Figure 2. The channel signals in various transfer case operating modes and ranges are shown in Figure 3. Any combination of signals not listed in Figure 3 are considered invalid by the TCCM. Encoder Switch Channel Positions These voltage readings can be obtained by back-probing either the TCCM connector pins or the transfer case connector pins. For TCCM pin numbers and encoder channels, refer to Figure 2. Diagnostic Enable Input Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Relays and Modules Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 4369 Wiring Schematic For Enabling The Status Lamps OPERATION When pin J of the Data Link Connector (DLC) is connected either to pin A of the DLC or to a good ground while the ignition is on, the diagnostics routine of the Transfer Case Control Module (TCCM) is activated. When the diagnostics routine is activated, the transfer case selector switch 4HI and 4LO status lamps flash the diagnostic codes. Electric Shift Motor Outputs Electric Shift Motor Schematic OPERATION The Transfer Case Control Module (TCCM) provides the output for the electric shift motor as the schematic shows. - Motor control is achieved by energizing one of the two motor control relays located in the TCCM, by way of the transfer case selector switch. The TCCM operates the motor in one direction by energizing one relay while the second relay is de-energized. The TCCM operates the motor in the reverse direction by energizing the second relay while the first relay is de-energized. - Motor power to actuate the motor drive relays is input at TCCM connector pins D14 and D15. This power is supplied by the ignition through the 30-amp power circuit breaker. - Motor ground is input at TCCM connector pins D12 and D13 to provide the return line for the motor drive relays. 4HI and 4LO Status Lamps Outputs Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Relays and Modules Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 4370 Selector Switch Status Lamp Schematic OPERATION The Transfer Case Control Module (TCCM) controls the operation of the 4HI and 4LO status lamps in the transfer case selector switch. The status lamps also show the transfer case mode and range of operation. The status lamps also provide a self-test when the ignition is first turned on. Additionally, the status lamps are used to alert the driver that there is a problem somewhere in the four-wheel drive system, and also to flash diagnostic trouble codes (DTC's). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Relays and Modules Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Page 4371 Control Module: Service and Repair TRANSFER CASE MODULE REPLACEMENT REMOVE OR DISCONNECT 1. Negative battery cable. 2. ECM (utility only). 3. Cowl side panel (pickup only). 4. Electrical connection. 5. Module to cowl panel screws (pickup only). 6. Module. INSTALL OR CONNECT 1. Module. 2. Module to cowl panel screws (pickup only). 3. Electrical connection. 4. ECM (utility only). 5. Negative battery cable. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Sensors and Switches Transmission and Drivetrain > Sensors and Switches - A/T > Brake Switch - TCC > Component Information > Locations > Stoplamp/TCC Brake Switch Stoplamp/TCC Brake Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Sensors and Switches Transmission and Drivetrain > Sensors and Switches - A/T > Brake Switch - TCC > Component Information > Locations > Stoplamp/TCC Brake Switch > Page 4378 I/P Harness Wiring, LH Side Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Sensors and Switches Transmission and Drivetrain > Sensors and Switches - A/T > Brake Switch - TCC > Component Information > Locations > Page 4379 C217 - Brake Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Sensors and Switches Transmission and Drivetrain > Sensors and Switches - A/T > Fluid Pressure Sensor/Switch, A/T > Component Information > Specifications Fluid Pressure Sensor/Switch: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Pressure Plugs (1/8 - 27) ..................................................................................................................... ................................................................................. 8 Pressure Plugs (1/4 - 18) ................................ .............................................................................................................................................................. ...... 18 Pressure Switches ................................................................................................................... .............................................................................................. 8 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Sensors and Switches Transmission and Drivetrain > Sensors and Switches - A/T > Transmission Position Switch/Sensor, A/T > Component Information > Description and Operation Transmission Position Switch/Sensor: Description and Operation Automatic Transmission Electrical Components PURPOSE This device is a set of five presure switches (two normally closed and three normally open), that detect fluid pressure within the valve body passages and signals the PCM which transmission range is selected (PRNDL). OPERATION The five pressure switches are connected to three signal circuits referred to as range signals A, B, C. The combination of pressure switch states determines the voltage signal (B+ or 0) on each range signal to the PCM. LOCATION The transmission range fluid pressure switch assembly is attached to the control valve body within the transmission. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Sensors and Switches Transmission and Drivetrain > Sensors and Switches - A/T > Transmission Speed Sensor, A/T > Component Information > Specifications Transmission Speed Sensor: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Vehicle Speed Sensor Retainer ........................... .............................................................................................................................................................. ... 8 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Sensors and Switches Transmission and Drivetrain > Sensors and Switches - A/T > Transmission Temperature Sensor/Switch, A/T > Component Information > Description and Operation Transmission Temperature Sensor/Switch: Description and Operation Automatic Transmission Electrical Components PURPOSE The Transmission Fluid Temperature (TFT) Sensor is used by the control module to control: Torque Converter Clutch (TCC) apply and release schedule. - Hot mode determination. - Shift quality. OPERATION The TFT is a thermistor used to indicate transmission fluid temperature. The control module sends a 5.0 volt signal to the TFT through a resistor in the computer and measures the voltage. High sensor resistance produces high signal input voltage which corresponds to low fluid temperature. Low sensor resistance produces low signal input voltage which corresponds to high fluid temperature. With the TFT varying its resistance, the control module can sense transmission fluid temperature by reading the varying voltage. LOCATION The sensor is part of the transmission range fluid pressure switch assembly and is attached to the control valve body within the transmission. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Sensors and Switches Transmission and Drivetrain > Sensors and Switches - Transfer Case > Four Wheel Drive Selector Switch > Component Information > Locations > Pickup Transfer Case Select Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Sensors and Switches Transmission and Drivetrain > Sensors and Switches - Transfer Case > Four Wheel Drive Selector Switch > Component Information > Locations > Pickup > Page 4397 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Sensors and Switches Transmission and Drivetrain > Sensors and Switches - Transfer Case > Four Wheel Drive Selector Switch > Component Information > Locations > Page 4398 Four Wheel Drive Selector Switch: Service and Repair Fig. 2 Transfer Case Shift Linkage. Except Bravada, Sonoma GT, Syclone & Typhoon Fig. 4 Selector Switch Installation. Except Bravada, Sonoma GT, Syclone & Typhoon 1. Disconnect battery ground cable. 2. Remove console, then disconnect console wiring harness. 3. Remove shifter boot retaining screws and slide boot up shift lever. 4. Remove switch attaching screw, then the switch and harness, Fig. 2. 5. Position new switch on mounting bracket and install attaching screw.Ensure shift lever assembly pawl is on the switch contact carrier. 6. Route wiring as shown in Fig. 4. 7. Place shifter boot in proper position, then install retaining screws. 8. Connect console wiring harness, then install console. 9. Connect battery ground cable. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Sensors and Switches Transmission and Drivetrain > Sensors and Switches - Transfer Case > Gear Sensor/Switch, Transfer Case > Component Information > Locations > Electric Shift Transfer Case Switch Gear Sensor/Switch: Locations Electric Shift Transfer Case Switch Transfer Case Electric Shift Motor Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Sensors and Switches Transmission and Drivetrain > Sensors and Switches - Transfer Case > Gear Sensor/Switch, Transfer Case > Component Information > Locations > Electric Shift Transfer Case Switch > Page 4403 Electric Shift Transfer Case Wiring Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Sensors and Switches Transmission and Drivetrain > Sensors and Switches - Transfer Case > Gear Sensor/Switch, Transfer Case > Component Information > Locations > Electric Shift Transfer Case Switch > Page 4404 4WD Components Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > Transmission Control Systems > Sensors and Switches Transmission and Drivetrain > Sensors and Switches - Transfer Case > Speed Sensor, Transfer Case > Component Information > Technical Service Bulletins > Drivetrain - Updated Transfer Case Speed Sensor Conn. Speed Sensor: Technical Service Bulletins Drivetrain - Updated Transfer Case Speed Sensor Conn. Bulletin No.: 06-04-21-001 Date: May 17, 2006 INFORMATION Subject: Updated Transfer Case Connector Service Kit Now Available For Transfer Case Speed Sensor Wire Harness Connector that Comes Loose Or Connector Retainer Clip Breaks Models: 2007 and Prior GM Light Duty Trucks 2007 and Prior HUMMER H2, H3 2005-2007 Saab 9-7X with Four-Wheel Drive or All-Wheel Drive Technicians may find that when the transfer case speed sensor wire harness connector is removed, the connector lock flexes/bends and does not return to the original position. The transfer case speed sensor wire harness connector then has no locking device. On older vehicles, the plastic connector retainer becomes brittle and the clip may break as soon as it is flexed. In the past, the only service fix was to install a wire harness connector service pack, P/N 88987183. This repair procedure involved splicing a new service connector with an integral connector lock. This connector service kit is of the same design and was still prone to failure over time. A new connector service repair kit is now available, P/N 15306187, that is an updated design. This new kit should be used whenever the speed sensor wire harness connector requires replacement. Parts Information Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > Recalls: > 99046 > Dec > 99 > Recall - High/Low/High ABS Brake Anomaly Technical Service Bulletin # 99046 Date: 991201 Recall - High/Low/High ABS Brake Anomaly File in Section: Special Prices Bulletin No.: 99046 Date: December, 1999 SPECIAL POLICY SUBJECT: 99046 - SPECIAL POLICY - HIGH/LOW/HIGH ABS BRAKE ANOMALY MODELS: 1993-1996 CHEVROLET, GMC, AND OLDSMOBILE S/T UTILITY 1994-1996 CHEVROLET AND GMC S/T PICKUP EQUIPPED WITH A V6 ENGINE 1993-1995 CHEVROLET AND GMC M/L VAN 1993-1996 CHEVROLET AND GMC G VAN THIS SPECIAL POLICY IS IN EFFECT UNTIL DECEMBER 1, 2002 DUE TO THE AVAILABILITY OF PARTS, THIS SPECIAL POLICY WILL BE ADMINISTERED IN PHASES. THIS FIRST PHASE WILL BE THE REPROGRAMMING OF THE VCM IN 2WD AND 4WD 1994-1996 S/T PICKUPS AND 1995-1996 S/T UTILITIES EQUIPPED WITH A VCM. VEHICLES INVOLVED IN PHASE 1 ARE SHADED IN THE TABLE. YOU WILL BE NOTIFIED OF THE NEXT PHASE VIA DCS MESSAGE. Condition The federal government's highway safety agency, the National Highway Traffic Safety Administration (NHTSA) has identified, and General Motors Corporation has confirmed, the existence of a condition in the antilock braking system of some Chevrolet, GMC, and Oldsmobile S/T utilities. 1994-1996 Chevrolet and GMC S/T pickups equipped with a V6 engine, 1993-1995 Chevrolet and GMC M/L vans, and 1993-1996 Chevrolet and GMC G vans, all equipped with the Lucas Varity three-sensor ABS system. On rare occasions, this condition can result in longer stopping distances during certain antilock brake applications, as explained below. If the customer is driving on a road surface that supports good traction and they begin to stop by applying the brake pedal firmly, and both front wheels of their vehicle then pass onto a slippery surface (such as an ice-covered or wet patched asphalt part of the road), the antilock brake system will adjust the brakes at each of the wheels to take advantage of the available traction. This will allow the customer to steer and maintain stability, which is normal ABS operation1 as their owner's manual explains in more detail. However, if the customer is still braking while the vehicle leaves the slippery surface and both front wheels get back on a higher-traction surface, the ABS may perform as if the vehicle were still on the slippery surface and the vehicle may not stop as quickly. However, this will not happen every time these conditions are encountered. It depends on several additional factors, such as vehicle speed and the length of the slippery surface. The ABS system was designed with increased sensitivity to wheel slip in order to improve vehicle steerability while braking on very slippery surfaces. This improvement for steerability, however, made it possible for reduced front braking effectiveness to occur as described above. SPECIAL POLICY ADJUSTMENT (Phase I) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > Recalls: > 99046 > Dec > 99 > Recall - High/Low/High ABS Brake Anomaly > Page 4417 This special policy adjustment covers the condition described above- until December 1, 2002, regardless of vehicle mileage or ownership. Dealers are to reprogram the VCM. Use the following Service Procedure. This will be performed at no charge to the customer during this time. Other conditions that may cause similar or different brake complaints that are not a result of the condition listed above are not covered by this special policy. The customer should be informed that any further service that is not covered by this special policy would be their responsibility, if they elect to have the service performed. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > Recalls: > 99046 > Dec > 99 > Recall - High/Low/High ABS Brake Anomaly > Page 4418 VEHICLES INVOLVED Involved are 1993-1998 S/T utilities, 1994-1996 S/T pickups equipped with a V6 engine, 1993-1995 M/L van, and 1993-1996 G vans built within the VIN breakpoints. PARTS INFORMATION This phase requires no parts. Calibrations are available in October, 1999 on TIS 2000 CD, # 21 or Techline CD # 20/21 or later versions. CUSTOMER NOTIFICATION Customers will be notified of this special policy on their vehicles, in phases, by General Motors (see copy of typical customer letter included with this bulletin - actual divisional letter may vary slightly). SERVICE PROCEDURE VCM Programming Important: For 1995 S/T utilities with L35, check the Service Parts Identification (SPID) label on the inside of the glovebox to determine if the vehicle has a VCM. If there is an RPO of "K29", the vehicle has a PCM and is programmable. The new calibration,will be available in October, 1999 on TIS 2000 CD # 21 or Techline CD # 20/21 and later versions. The calibration is programmed into the vehicle's VCM via a Techline TOOL. Use a Techline Terminal or scan tool to perform the learn procedure and program the VCM. Important: Use the calibration file "Special Policy 99046" on TIS 2000 CD # 21 or Techline CD # 20/21 or later versions. 1. To ensure VCM programming/RPO configuration, confirm that the following conditions exist in order to prepare for VCM programming: ^ The battery is fully charged ^ The ignition switch is in the "RUN" position ^ The Data Link Connector (DLC) is accessible 2. Refer to the latest Techline Terminal and equipment user's instructions. 3. Clear the diagnostic trouble codes (DTCs) after the programming is complete. CLAIM INFORMATION For vehicles repaired under warranty submit a claim with the information indicated. Owner Letter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > Recalls: > 99046 > Dec > 99 > Recall - High/Low/High ABS Brake Anomaly > Page 4419 December, 1999 Dear Chevrolet/GMC Customer: As the owner of a General Motors truck equipped with the Lucas Varity three-sensor antilock brake system (ABS), your satisfaction with our product is of utmost concern to us. Condition: The federal government's highway safety agency. the National Highway Traffic Safety Administration (NHTSA) has identifled1 and General Motors Corporation has confirmed the existence of a condition in the antilock braking system of some Chevrolet and GMC 1994-1996 S/T pickups equipped with a V6 engine and 1995-1996 S/T utility vehicles. On rare occasions, this condition can result in longer stopping distances during certain antilock brake applications, as explained below. If you're driving on a road surface that supports good traction and you begin to stop by applying your brake pedal firmly, and both front wheels of your vehicle then pass, onto a slippery surface (such as an ice-covered or wet patched asphalt part of the road), your antilock brake system will adjust the brakes at each of the wheels to take advantage of the available traction. This will allow you to steer and maintain stability, which is normal ABS operation, as your owner's manual explains in more detail. However, if you are still braking while the vehicle leaves the slippery surface and both front wheels get back on a higher-traction surface, the ABS may perform as if the vehicle were still on the slippery surface and the vehicle may not stop as quickly. However, this will not happen every time these conditions are encountered. It depends on several additional factors, such as vehicle speed and the length of the slippery surface. Your ABS system was designed with increased sensitivity to wheel slip in order to improve vehicle steerability while braking on very slippery surfaces. This improvement for steerability, however, made it possible for reduced front braking effectiveness to occur as described above. Therefore, GM has developed a software change that will make your vehicle less Sensitive to wheel slip under the circumstances described above. What Will Be Done: Upon your request, your Chevrolet/GMC dealer will make a change to your antilock braking system software to prevent this phenomenon from occurring. This software change will have only a slight effect on vehicle steerablity during braking on very slippery surfaces and is designed to have no effect on normal ABS or other braking operations. This change should not affect how your brakes feel or create any perceptible difference in the steerability or stability of your vehicle while braking. This modification will be performed for you at no charge at anytime until December 1, 2002. How Long Will The Repair Take: Your Chevrolet/GMC dealer will modify your vehicle's ABS software. We estimate that it will take your dealer 45 minutes to perform this modification. Additional time may be required to schedule and process your vehicle. If your dealer has a large number of vehicles awaiting service, this additional time may be significant. Please ask your dealer if you wish to know how much additional time will be needed. Contacting Your Dealer: Repairs and adjustments qualifying under this special coverage must be performed by a Chevrolet/GMC dealer. You may want to call the service department to arrange a convenient appointment. Should your dealer be unable to schedule a service date within a reasonable time, you should contact the appropriate Customer Assistance Center at the number listed below: Deaf, Hearing Impaired Division Number or Speech Impaired* Chevrolet 1-800-222-1020 1-800-833-2438 GMC 1-800-462-8782 1-800-462-8583 * Utilizes Telecommunication Devices for the Deaf/Text Telephones (TDD/TTY) 1-800-462-8782. The deaf, hearing impaired, or speech impaired should call 1-800-462-8583 (utilizes Telecommunication Devices for the Deaf/Text Telephones, TDD/TTY). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM PROM - Programmable Read Only Memory: Customer Interest Engine - Cold Knock, Replace Oil Filter/Bearings/PROM File In Section: 6 - Engine Bulletin No.: 37-61-05A Date: October, 1995 Subject: Cold Engine Knock (Replace Oil Filter/Bearings/PROM) Models: 1990-95 Chevrolet and GMC Truck C/K, R/V, S/T, M/L, G, P Models 1991-92 Oldsmobile Bravada with 4.3L (VIN Z - RPO LB4), 5.7L (VIN K - RPO L05), 7.4 (VIN N - RPO L19) Engine This bulletin is being revised to add the 1995 model year information. Please discard Corporate Bulletin Number 37-61-05 (Section 6 - Engine). Condition Some late model truck engines have been reported to exhibit "cold knock" on start up. "Cold Knock" usually occurs after the vehicle has been completely warmed up, then parked for 8 or more hours in ambient temperatures of 35° F or less. "Cold knock" can be separated into three distinct categories. 1. Short Duration - Harsh, deep metallic knock that usually lasts from 1 to 10 seconds. Generally classified as a bearing or rod knock. 2. Valve Train - Light clatter, tick or click that may last up to 1 minute. 3. Piston Slap - Metallic knock that occurs only under load. Piston slap may last as long as 5 minutes. Correction Category A: Short Duration Knock This matrix describes the repair for each affected model year and engine. Specific information for each affected model year and engine is supplied. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 4425 1992 LB4 VIN Z with "cold knock" only 1992-93 LB4 VIN Z with "cold knock" and installed field fix PROM OR with "cold knock" and detonation 1990-95 LB4 VIN Z Install check valve oil filter P/N 12555891 (FRAM PH3980). If the filter does not cure the condition, install the appropriate calibration from the tables (calibrations are available for all 1992 and some 1993 LB4 applications). If a calibration is not offered or does not cure the short duration cold knock Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 4426 condition, install the appropriate main bearings as determined by the following procedure. Calibration Information - 1992-93 LB4 VIN Z The revised PROMs reduce spark advance after the engine is started. The reduction in spark lowers the cylinder pressure and eliminates the knock. The revised PROMs will NOT eliminate a piston slap (Category C) or valve train noise (Category B) concern. The base cold knock PROM contains the previously released calibration updates. For 1992 LB4, the previous field release is included for torque converter clutch (TCC) lock up (see Bulletin 137107 - Chevrolet 92-75-7A; GMC Truck 92-7A-40; Oldsmobile 92-T-34; Canada 9274L60100) for automatic transmissions, or neutral gear rattle for manual transmissions (see Bulletin 267201R - Chevrolet 92-187B-7B; GMC Truck 92-7B-149A; Canada 93-7B-105). If a vehicle has had a detonation fix PROM installed previously, select the combined detonation and cold knock fix PROM for the application. See Bulletin 376508 for more information on field fix PROM for the application and detonation. Important: Use of a detonation fix PROM in a non-detonating vehicle may result in degraded driveability. GMSPO currently stocks three (3) PROMs for each light duty 1992 model year LB4 application. Base Cold Knock Fix Combination Cold Knock and Detonation Fix GMSPO Service Parts Assistance Center (SPAC 1-800-433-6961) will have information available on each PROM part number. Select the PROM from the table. Old Broadcast Code (Old B/C Code) and Scan I.D. information has been supplied to help installed previously. Use a TECH-1 to determine the Scan I.D. of the PROM in the vehicle or remove the PROM and read the Broadcast Code (B/C Code). If the B/C Code/Scan I.D. can be found in the first table, a detonation fix has not been installed. PROMs are currently available GMSPO. 1990-95 L05 VIN K Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 4427 1993 to 1995 L05 VIN K Install the appropriate check valve oil filter P/N 25160561 (PF1218 for two-wheel C-series and P/N 12555891 (FRAM PH3980) for four-wheel drive K-series). If the oil filter does not cure the condition, install the appropriate calibration from the table (calibrations are available for some 1993 and 1994 L05 applications). All calibrations are for light duty vehicles equipped with 4L60-E (M30) transmissions (no heavy duty emission/4L80-E calibrations are available). If a calibration is not offered or does not cure the short duration cold knock condition, install the appropriate main bearings as determined by the procedure. 1990-94 L19 VIN N Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 4428 Install a check valve oil filter; no other recommended actions at this time. Important: The previous actions are only applicable to short duration cold knock. These actions will not eliminate a knock occurring under load or a knock lasting for more than 10 seconds. Two main bearing procedures are recommended: 1. For main bearing replacement with the engine IN the vehicle: C, G, P, M and L vehicles 2. For main bearing replacement with the engine OUT OF the vehicle: K, S and T THE FOLLOWING PROCEDURE IS TO BE USED FOR VEHICLES REQUIRING MAIN BEARING REPLACEMENT WITH THE ENGINE IN THE VEHICLE Recommended for C, G, P, M and L vehicles. Important: A OEM training video has been produced for in-vehicle main bearing replacement procedure. One copy of the video will be sent to each dealer. If the video has not been received, contact XPRESS 1 Distribution Center at 1-800-783-3034. Main Bearing Clearance Determination and Installation Procedure 1. REMOVE THE SERPENTINE BELT, dipstick, dipstick tube and disconnect the negative battery cable. 2. Raise the vehicle and remove (or set aside) any parts restricting access to the oil pan bolts (i.e., starter motor, oil cooler lines, oil filter adapter, flywheel inspection cover). 3. Remove the oil pan, oil pump, and shield. 4. Remove # 5 (flange) bearing cap. Wipe the oil from the crankshaft journal and the lower main bearing insert. 5. Place a screw jack under an accessible part of the crankshaft, carefully apply pressure to the crankshaft to force it solidly against the top bearing insert. The reason for this is to remove any clearance between the top bearing insert and the crankshaft. If this step is not performed, a smaller than actual clearance will be measured. Important: This should be done as close as possible to the bearing being measured. This step is only required for on-vehicle service where the engine cannot be turned upside down as on an engine stand. 6. Place a piece of plastigage across the width of the lower bearing insert (parallel to the centerline of the crankshaft). 7. Reinstall # 5 main bearing cap. Torque to 110 N.m (80 lb ft). Do not allow crankshaft to turn. 8. Carefully remove the # 5 main bearing cap and bearing insert. The flattened plastigage will adhere to either the bearing insert or the crank journal. Do not remove the plastigage from the insert or journal. 9. On the edge of the plastigage envelope, there is a graduated scale. Without removing the flattened plastigage, measure its width at the widest point using the graduated scale on the plastigage envelope. 10. The desired main bearing clearance is 0.0008" - 0.0028". If the clearance measured with the plastigage is greater than 0.0028", write down the clearance. Next, read the back of the bearing insert to determine what size bearing was originally installed (usual STD, 0.0006", 0.0010" or 0.0012"). The size stamped on the bearing is the effective undersize when both inserts are installed. For example, a 0.0006" undersize bearing set consists of two (2) 0.0003" thicker bearing inserts, both stamped 0.0006". 11. Remove the top bearing insert using tool J 8080 and read the back to determine what size upper bearing insert was originally installed. The top insert may be different size than the bottom. 12. Calculate the original bearing undersize by dividing the size on each insert by 2, then add the values together. EXAMPLE 1: The lower insert is stamped 0.0006" and the upper is stamped 0.0010". Divide 0.0006" by two to get 0.0003". Divide 0.0010" by 2 to get 0.0005". Add 0.0003" and 0.0005" together to calculate the bearing undersize, which is 0.0008" in this case. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 4429 EXAMPLE 2: The lower insert is stamped STD (standard) and the upper is stamped 0.0010". The undersize for a STD bearing is 0. Divide 0 by 2 to get 0. Divide 0.0010" by 2 to get 0.0005". Add 0 and 0.0005" together to calculate the bearing undersize, which is 0.0005" in this case. 13. Add the original bearing undersize calculated in step 12 to the clearance measured and written down in step 9. For example, if a clearance of 0.0030" was measured with plastigage in step 9 and the calculated bearing undersize from step 12 was 0.0005", the bearing clearance for that particular main journal is equal to 0.0030" plus 0.0005". The bearing clearance would be 0.0035" in this case. 14. Determine which of the combinations of two sizes of replacement bearings will produce the desired clearance. The two sizes available are 0.001" and 0.002". One insert of each size may be combined to produce an intermediate undersize of 0.0015". Subtract the replacement bearing size from the actual clearance to determine which bearing should be used. The bearing that should be used is the one which gives a clearance closer to 0.0008" than to 0.0028". The clearance must not be less than 0.0008". Using the example from step 11, the actual clearance is 0.0035". Subtracting 0.001" from 0.0035" will give a clearance of 0.0025", just barely within the required range. Subtracting 0.002" from 0.0035" will give a clearance of 0.0015". The 0.002" undersize bearing set would be the one to use in this case since it gives a clearance closer to 0.0008", but not less. 15. Install the replacement upper main bearing insert using tool J 8080. 16. Install the replacement lower main bearing insert in the main bearing cap. Lay a piece of plastigage across the width of the lower main bearing insert (same as step 5). 17. Repeat steps 7, 8 and 9. 18. Measuring the plastigage with the scale on the envelope, verify the clearance of the replacement bearings is within the range of 0.001" to 0.003". 19. Repeat steps 4 through 16 for each main bearing. 20. Thrust the crankshaft forward and backward several times to seat the thrust bearing. 21. Reinstall oil pump; torque to 88 N.m (65 lb ft). 22. Reinstall the oil pan and other hardware. 23. Before starting the engine, remove the fuel pump fuse and crank the engine until oil pressure registers on the gauge. Stop cranking, let the starter cool down, then crank for another 15 seconds. 24. Install fuel pump fuse, start engine, check for leaks or unusual noises. 25. Road test vehicle, check for leaks or unusual noises. THE FOLLOWING PROCEDURE IS TO BE USED FOR VEHICLES REQUIRING MAIN BEARING REPLACEMENT WITH THE ENGINE OUT OF THE VEHICLE Recommended for K, S and T vehicles. 1. Remove the engine from the vehicle using the appropriate service manual procedure. 2. Mount the engine on an engine stand, flip the engine so the oil pan is facing up. 3. Remove the oil pan. 4. Remove the oil pump and shield. 5. Remove the dipstick tube. 6. Remove one (1) main bearing cap (must do one at a time). 7. Plasti-gage bearing. 8. If the bearing clearance is out of specification (clearance greater than 0.003 inches), remove upper main bearing from the block. 9. Check the size of the original bearing. 10. Determine what combination of new bearings are required to get the clearance in the acceptable range of 0.0008 inches to 0.0028 inches. See steps Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 4430 12 through 14 in the "in-vehicle" service outlined above. 11. Reinstall the upper main bearing. 12. Reinstall the main cap and lower bearing; torque to 110 N.m (80 lb ft). 13. Repeat for each main bearing. 14. Reinstall oil pump and shield; torque to 88 N.m (65 lb ft). 15. Reinstall dipstick tube. 16. Reinstall oil pan. 17. Reinstall engine in vehicle. 18. Before starting the engine, remove the fuel pump fuse and crank the engine until oil pressure registers on the gauge. Stop cranking, let the starter cool down, then crank for another 15 seconds. 19. Install fuel pump fuse, start engine, check for leaks or unusual noises. 20. Road test vehicle, check for leaks or unusual noises. Correction Category B: Valve Train Clatter, Tick or Click For 1992-94 vehicles equipped with a 4.3L V6 (LB4 VIN Z or L35 VIN W) engine see Corporate Bulletin 376006 for information on converting from net lash to adjustable lash and/or re-lashing the valves on an adjustable lash system. Investigation of "cold knock" is continuing. Updates will continue to be provided when available. Parts Information Check-Valve Filters Description Part Number V6, V8 (Four-Wheel Drive) FRAM PH3980 12555891 V8 (Two-Wheel Drive), Mark V8 PF1218 25160561 The FRAM PH3980 is to be used in place of the PF52. The PH3980 provides superior anti-drainback performance, a key factor in reducing cold knock. FRAM filters are to be procured locally until 08-15-95. After this date the filters may be ordered from GMSPO using the supplied part number. Orders placed to GMSPO prior to this date will not be placed on backorder. Bearings Description Part Number 0.001" Main Bearing Kit, Positions 1-4 on V8, 1-3 on V6 10120992 0.001" Main Bearing Kit, Flange # 5 on V8, # 4 on V6 10120994 0.002" Main Bearing Kit, Positions 1-4 on V8, 1-3 on V6 12329758 0.002" Main Bearing Kit, Flange # 5 on V8, # 4 on V6 12329792 Main bearing kits are currently available from GMSPO. All calibrations are currently available from GMSPO. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > Customer Interest: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 4431 Warranty Information Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > Customer Interest: > 476522 > Jan > 95 > Engine - Backfire Upon Acceleration PROM - Programmable Read Only Memory: Customer Interest Engine - Backfire Upon Acceleration File in Section: 6E - Engine Fuel & Emission Bulletin No.: 47-65-22 Date: January, 1995 Subject: Backfire on Acceleration (Correct Calibration) Models: 1994 Chevrolet and GMC Truck S/T Models with 4.3L Engine (VIN Z - RPO LB4) and Manual Transmission (RPO MY2) Condition Some owners may experience a backfire condition upon acceleration. Cause Insufficient ignition timing advance in the spark calibration under some driving conditions. Correction More robust calibrations have been released to address this concern. THIS CALIBRATION WILL NOT CORRECT ANY OTHER DRIVEABILITY CONCERN. Important: These service calibrations should ONLY be used if a backfire concern still exists in a vehicle WHICH HAS HAD THE BASE TIMING CHECKED AND SET TO SPECIFICATION. LAUNCH DETONATION MAY OCCUR IN VEHICLES SERVICED WITH THESE CALIBRATIONS; particularly in vehicles which are heavily loaded or towing trailers. Parts Information Service "FLASH" calibrations are available starting with the December, 1994 CD ROM. Warranty Information Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Technical Service Bulletins for PROM - Programmable Read Only Memory: > 99046 > Dec > 99 > Recall - High/Low/High ABS Brake Anomaly Technical Service Bulletin # 99046 Date: 991201 Recall - High/Low/High ABS Brake Anomaly File in Section: Special Prices Bulletin No.: 99046 Date: December, 1999 SPECIAL POLICY SUBJECT: 99046 - SPECIAL POLICY - HIGH/LOW/HIGH ABS BRAKE ANOMALY MODELS: 1993-1996 CHEVROLET, GMC, AND OLDSMOBILE S/T UTILITY 1994-1996 CHEVROLET AND GMC S/T PICKUP EQUIPPED WITH A V6 ENGINE 1993-1995 CHEVROLET AND GMC M/L VAN 1993-1996 CHEVROLET AND GMC G VAN THIS SPECIAL POLICY IS IN EFFECT UNTIL DECEMBER 1, 2002 DUE TO THE AVAILABILITY OF PARTS, THIS SPECIAL POLICY WILL BE ADMINISTERED IN PHASES. THIS FIRST PHASE WILL BE THE REPROGRAMMING OF THE VCM IN 2WD AND 4WD 1994-1996 S/T PICKUPS AND 1995-1996 S/T UTILITIES EQUIPPED WITH A VCM. VEHICLES INVOLVED IN PHASE 1 ARE SHADED IN THE TABLE. YOU WILL BE NOTIFIED OF THE NEXT PHASE VIA DCS MESSAGE. Condition The federal government's highway safety agency, the National Highway Traffic Safety Administration (NHTSA) has identified, and General Motors Corporation has confirmed, the existence of a condition in the antilock braking system of some Chevrolet, GMC, and Oldsmobile S/T utilities. 1994-1996 Chevrolet and GMC S/T pickups equipped with a V6 engine, 1993-1995 Chevrolet and GMC M/L vans, and 1993-1996 Chevrolet and GMC G vans, all equipped with the Lucas Varity three-sensor ABS system. On rare occasions, this condition can result in longer stopping distances during certain antilock brake applications, as explained below. If the customer is driving on a road surface that supports good traction and they begin to stop by applying the brake pedal firmly, and both front wheels of their vehicle then pass onto a slippery surface (such as an ice-covered or wet patched asphalt part of the road), the antilock brake system will adjust the brakes at each of the wheels to take advantage of the available traction. This will allow the customer to steer and maintain stability, which is normal ABS operation1 as their owner's manual explains in more detail. However, if the customer is still braking while the vehicle leaves the slippery surface and both front wheels get back on a higher-traction surface, the ABS may perform as if the vehicle were still on the slippery surface and the vehicle may not stop as quickly. However, this will not happen every time these conditions are encountered. It depends on several additional factors, such as vehicle speed and the length of the slippery surface. The ABS system was designed with increased sensitivity to wheel slip in order to improve vehicle steerability while braking on very slippery surfaces. This improvement for steerability, however, made it possible for reduced front braking effectiveness to occur as described above. SPECIAL POLICY ADJUSTMENT (Phase I) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Technical Service Bulletins for PROM - Programmable Read Only Memory: > 99046 > Dec > 99 > Recall - High/Low/High ABS Brake Anomaly > Page 4441 This special policy adjustment covers the condition described above- until December 1, 2002, regardless of vehicle mileage or ownership. Dealers are to reprogram the VCM. Use the following Service Procedure. This will be performed at no charge to the customer during this time. Other conditions that may cause similar or different brake complaints that are not a result of the condition listed above are not covered by this special policy. The customer should be informed that any further service that is not covered by this special policy would be their responsibility, if they elect to have the service performed. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Technical Service Bulletins for PROM - Programmable Read Only Memory: > 99046 > Dec > 99 > Recall - High/Low/High ABS Brake Anomaly > Page 4442 VEHICLES INVOLVED Involved are 1993-1998 S/T utilities, 1994-1996 S/T pickups equipped with a V6 engine, 1993-1995 M/L van, and 1993-1996 G vans built within the VIN breakpoints. PARTS INFORMATION This phase requires no parts. Calibrations are available in October, 1999 on TIS 2000 CD, # 21 or Techline CD # 20/21 or later versions. CUSTOMER NOTIFICATION Customers will be notified of this special policy on their vehicles, in phases, by General Motors (see copy of typical customer letter included with this bulletin - actual divisional letter may vary slightly). SERVICE PROCEDURE VCM Programming Important: For 1995 S/T utilities with L35, check the Service Parts Identification (SPID) label on the inside of the glovebox to determine if the vehicle has a VCM. If there is an RPO of "K29", the vehicle has a PCM and is programmable. The new calibration,will be available in October, 1999 on TIS 2000 CD # 21 or Techline CD # 20/21 and later versions. The calibration is programmed into the vehicle's VCM via a Techline TOOL. Use a Techline Terminal or scan tool to perform the learn procedure and program the VCM. Important: Use the calibration file "Special Policy 99046" on TIS 2000 CD # 21 or Techline CD # 20/21 or later versions. 1. To ensure VCM programming/RPO configuration, confirm that the following conditions exist in order to prepare for VCM programming: ^ The battery is fully charged ^ The ignition switch is in the "RUN" position ^ The Data Link Connector (DLC) is accessible 2. Refer to the latest Techline Terminal and equipment user's instructions. 3. Clear the diagnostic trouble codes (DTCs) after the programming is complete. CLAIM INFORMATION For vehicles repaired under warranty submit a claim with the information indicated. Owner Letter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Technical Service Bulletins for PROM - Programmable Read Only Memory: > 99046 > Dec > 99 > Recall - High/Low/High ABS Brake Anomaly > Page 4443 December, 1999 Dear Chevrolet/GMC Customer: As the owner of a General Motors truck equipped with the Lucas Varity three-sensor antilock brake system (ABS), your satisfaction with our product is of utmost concern to us. Condition: The federal government's highway safety agency. the National Highway Traffic Safety Administration (NHTSA) has identifled1 and General Motors Corporation has confirmed the existence of a condition in the antilock braking system of some Chevrolet and GMC 1994-1996 S/T pickups equipped with a V6 engine and 1995-1996 S/T utility vehicles. On rare occasions, this condition can result in longer stopping distances during certain antilock brake applications, as explained below. If you're driving on a road surface that supports good traction and you begin to stop by applying your brake pedal firmly, and both front wheels of your vehicle then pass, onto a slippery surface (such as an ice-covered or wet patched asphalt part of the road), your antilock brake system will adjust the brakes at each of the wheels to take advantage of the available traction. This will allow you to steer and maintain stability, which is normal ABS operation, as your owner's manual explains in more detail. However, if you are still braking while the vehicle leaves the slippery surface and both front wheels get back on a higher-traction surface, the ABS may perform as if the vehicle were still on the slippery surface and the vehicle may not stop as quickly. However, this will not happen every time these conditions are encountered. It depends on several additional factors, such as vehicle speed and the length of the slippery surface. Your ABS system was designed with increased sensitivity to wheel slip in order to improve vehicle steerability while braking on very slippery surfaces. This improvement for steerability, however, made it possible for reduced front braking effectiveness to occur as described above. Therefore, GM has developed a software change that will make your vehicle less Sensitive to wheel slip under the circumstances described above. What Will Be Done: Upon your request, your Chevrolet/GMC dealer will make a change to your antilock braking system software to prevent this phenomenon from occurring. This software change will have only a slight effect on vehicle steerablity during braking on very slippery surfaces and is designed to have no effect on normal ABS or other braking operations. This change should not affect how your brakes feel or create any perceptible difference in the steerability or stability of your vehicle while braking. This modification will be performed for you at no charge at anytime until December 1, 2002. How Long Will The Repair Take: Your Chevrolet/GMC dealer will modify your vehicle's ABS software. We estimate that it will take your dealer 45 minutes to perform this modification. Additional time may be required to schedule and process your vehicle. If your dealer has a large number of vehicles awaiting service, this additional time may be significant. Please ask your dealer if you wish to know how much additional time will be needed. Contacting Your Dealer: Repairs and adjustments qualifying under this special coverage must be performed by a Chevrolet/GMC dealer. You may want to call the service department to arrange a convenient appointment. Should your dealer be unable to schedule a service date within a reasonable time, you should contact the appropriate Customer Assistance Center at the number listed below: Deaf, Hearing Impaired Division Number or Speech Impaired* Chevrolet 1-800-222-1020 1-800-833-2438 GMC 1-800-462-8782 1-800-462-8583 * Utilizes Telecommunication Devices for the Deaf/Text Telephones (TDD/TTY) 1-800-462-8782. The deaf, hearing impaired, or speech impaired should call 1-800-462-8583 (utilizes Telecommunication Devices for the Deaf/Text Telephones, TDD/TTY). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Technical Service Bulletins for PROM - Programmable Read Only Memory: > 99-06-04-053 > Nov > 99 > PROM - Powertrain Control Module Reprogramming PROM - Programmable Read Only Memory: All Technical Service Bulletins PROM - Powertrain Control Module Reprogramming File In Section: 06 - Engine/Propulsion System Bulletin No.: 99-06-04-053 Date: November, 1999 INFORMATION Subject: Powertrain Control Module (PCM) Reprogramming (Do Not Reprogram Using the Same Download Files as Those Already Present in The Control Module) Models: 1990-2000 Passenger Cars and Trucks with Reprogrammable PCM It is strongly recommended to NOT reinstall the same software and/or calibration download file(s) into the powertrain control module as those that are already present in the PCM. There is no technical reason that the download files inside the PCM would ever become corrupted after the control module had previously been successfully programmed. A P0601 (Control Module Read Only Memory) Diagnostic Trouble Code would set in memory and the MIL would be illuminated if the controller memory became corrupted. The Techline Information System 2000 (TIS 2000) PC, combined with vehicle information gained through the Tech 2, can determine when an attempt to reprogram a PCM using the same download files (as those already in the control module) is being requested. If this is attempted, the TIS 2000 PC currently displays the following message: Notice: THE CALIBRATION SELECTED IS THE CURRENT CALIBRATION IN THE CONTROL MODULE. PROGRAMMING WITH THE SAME DOWNLOAD FILES IS NOT AN EFFECTIVE REPAIR. SELECT ( YES ) TO CONTINUE PROGRAMMING THE CONTROL MODULE,OR ( NO ) TO CANCEL. Effective in the first quarter of 2000, the TIS 2000 PC will indicate: Important: THE CALIBRATION SELECTED IS ALREADY THE CURRENT CALIBRATION IN THE CONTROL MODULE. REPROGRAMMING WITH THE SAME DOWNLOAD FILE IS NOT ALLOWED. Certain learned values, such as: (but not limited to) ^ fuel trim (previously known as block learn memory), ^ IAC learned position in various park/neutral and air conditioning on/off combinations, ^ certain OBDII diagnostic thresholds, ^ automatic transmission shift adapts will revert back to their unlearned starting point values after a reprogramming event occurs. It is feasible that the engine or transmission might temporarily operate differently after a reprogramming event, until these values are re-learned. Relearning occurs while operating the vehicle through normal driving routines. If the same download files are simply reinstalled, any changes noticed in engine operation will likely disappear in a short amount of time and/or driving distance. Reprogramming the control module with the same download files that already exist in the module will only accomplish a warranty claim for a non-effective repair, and a likely comeback. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Technical Service Bulletins for PROM - Programmable Read Only Memory: > 736513 > Mar > 97 > PROM - Reprogram Using Off Board Program Adapter PROM - Programmable Read Only Memory: All Technical Service Bulletins PROM - Reprogram Using Off Board Program Adapter File In Section: 6E - Engine Fuel & Emission Bulletin No.: 73-65-13 Date: March, 1997 INFORMATION Subject: Reprogramming Capability using the Off Board Programming Adapter Models: 1993-97 Passenger Cars and Trucks (Applicable Reprogrammable Vehicles) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Technical Service Bulletins for PROM - Programmable Read Only Memory: > 736513 > Mar > 97 > PROM - Reprogram Using Off Board Program Adapter > Page 4452 The General Motors vehicles contain Electronically Reprogrammable Devices (i.e. PCM, VCM, ECM). These vehicles cannot be programmed through PROM replacement, however service programming capability is available through the Tech 1/1A, Tech 2 and Techline terminals via direct or remote programming. The Environmental Protection Agency (EPA) has requested that all new vehicle manufacturers ensure their dealers/retailers are aware that they are responsible for providing customers access to reprogramming services at a reasonable cost and in a timely manner. Although programming of controllers has become a common service practice at GM dealers/retailers, the EPA has received reports from consumers and the aftermarket repair industry that they were unable to purchase a new (programmed) Electronically Reprogrammable Device (ERD) over-the-counter. As a result, on August 1, 1995, the Federal Government issued a regulation requiring all manufacturers to make available reprogramming to the independent aftermarket by December 1, 1997. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Technical Service Bulletins for PROM - Programmable Read Only Memory: > 736513 > Mar > 97 > PROM - Reprogram Using Off Board Program Adapter > Page 4453 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Technical Service Bulletins for PROM - Programmable Read Only Memory: > 736513 > Mar > 97 > PROM - Reprogram Using Off Board Program Adapter > Page 4454 Today, the Off Board Programming Adapter (OBPA) is used to reprogram ERD's sold over-the-counter. For all practical purposes, the OBPA takes the place of the vehicle when the vehicle is not available. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Technical Service Bulletins for PROM - Programmable Read Only Memory: > 736513 > Mar > 97 > PROM - Reprogram Using Off Board Program Adapter > Page 4455 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Technical Service Bulletins for PROM - Programmable Read Only Memory: > 736513 > Mar > 97 > PROM - Reprogram Using Off Board Program Adapter > Page 4456 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Technical Service Bulletins for PROM - Programmable Read Only Memory: > 736513 > Mar > 97 > PROM - Reprogram Using Off Board Program Adapter > Page 4457 The list of dealerships/retailers currently own the OBPA (see Attachments 1 - 3). These locations are equipped to provide over-the-counter preprogrammed ERD's. The hardware required to perform reprogramming in addition to the OBPA is a Techline terminal, Tech 1/1A and associated cables and adapters. THE TECH 2 SHOULD NOT BE USED WITH THE OBPA AT THIS TIME BECAUSE OF INADEQUATE OBPA GROUNDING. The current OBPA can support reprogramming on all late model General Motor's vehicles except: ^ Premium V-8's ^ 1996 Diesel Truck ^ Cadillac Catera Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Technical Service Bulletins for PROM - Programmable Read Only Memory: > 736513 > Mar > 97 > PROM - Reprogram Using Off Board Program Adapter > Page 4458 ^ All 1997 programmable vehicles (requires use of the Tech 2) A modification to the OBPA is being offered by Kent-Moore to support these additional vehicles and to allow reprogramming using the Tech 2. The revisions to the OBPA for the Tech 2 is very important as the Tech 2 is the only tool used for service programming for 1997 and future vehicles. To have the modifications performed, contact Kent-Moore at (800) 345-2233. The revisions (part number J 41207 REV-C) are free of charge for GM dealerships/retailers. A dealership/retailer can purchase the OBPA by contacting Kent-Moore (part number J 41207-C). Support on how to use the OBPA is provided by the Techline Customer Support Center (TCSC) at (800) 828-6860 (English) or (800) 503-3222 (French). If you need to purchase an OBPA and/or cable, contact Kent-Moore at (800) 345-2233. The OBPA retails for $695.00 (includes all revisions 1-4) under part number J 41207-C. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Technical Service Bulletins for PROM - Programmable Read Only Memory: > 536508 > Jan > 96 > SPS/FLASH EPROM - Programming PROM - Programmable Read Only Memory: All Technical Service Bulletins SPS/FLASH EPROM Programming File In Section: 6E - Engine Fuel & Emission Bulletin No.: 53-65-08 Date: January, 1996 INFORMATION Subject: SPS/FLASH EPROM Programming Models: 1993-96 Passenger Cars and Trucks Applicable Reprogrammable Vehicles This bulletin is being issued to assist technicians in reprogramming vehicles and should be used in conjunction with instructions provided on your Techline Terminal and in your Techline Terminal User's Manual. THE TECHLINE TERMINAL (T-20, T-50, T-60) HAS BEEN ABLE TO DO 1996 VEHICLE PROGRAMMING THROUGH THE DIRECT METHOD SINCE 1996 VEHICLES HAVE BEEN AVAILABLE IN THE DEALERSHIPS/RETAIL FACILITIES. THE TECHLINE CD-ROM TITLED DISC 13 CONTAINS THE SOFTWARE NEEDED TO PROGRAM ALL 1996 VEHICLES WITH A TECH 1 (REMOTE PROGRAMMING METHOD). SPS Tips 1. BATTERY VOLTAGE SHOULD BE CHECKED. A FULLY CHARGED BATTERY IS NECESSARY BEFORE REPROGRAMMING TAKES PLACE. THE VEHICLE BATTERY SHOULD NOT BE CONNECTED TO A BATTERY CHARGER DURING A PROGRAMMING EVENT INCORRECT VOLTAGE COULD CAUSE PROGRAMMING AND/OR CONTROL MODULE FAILURE. During programming, the control module depends on the battery as its sole source of power. Also during programming, the vehicle's components (i.e. blower motor) are set to a default mode which may be turned on, placing additional draw on the vehicle's battery. If the voltage goes outside the specified range (11 to 14 volts) the controllers and the Techline equipment will stop communicating. If this happens, it could cause the control module to become inoperable and require replacement. 2. CHECK THE INTEGRITY OF THE TECH 1 CABLES, MAKE SURE THEY ARE NOT FRAYED, BROKEN OR TWISTED. Loss of communication for any reason will require additional time in completing the reprogramming event. 3. IF USING A TECH 1, YOUR MASS STORAGE CARTRIDGE (MSC) MUST BE UPDATED TO REFLECT THE MOST CURRENT UPDATE OFFERED ON THE TECHLINE CD-ROM. DISC 13, 1995 WAS THE FIRST CD-ROM THAT HAD REMOTE PROGRAMMING SUPPORT If your MSC is not updated to reflect the current software version on the Techline Terminal, in some situations the software will not be capable of interpreting the information that is requested from the vehicle. 4. T-100 TERMINALS (CAMS) ARE NOT CAPABLE OF PROGRAMMING OBD II VEHICLES THROUGH THE DIRECT METHOD. A TECH 1 MUST BE USED (REMOTE METHOD) WHEN REPROGRAMMING WITH A T-100. The T-100 terminals communicate with vehicles through a DLC (ALDL) card and cable found within the T-100's computer. The DLC (ALDL) card is not capable of communicating at the new baud rate used with OBD II. 5. PROGRAMMING IS NOT NEEDED IF THE CURRENT CALIBRATION IS THE SAME AS THE SELECTED CALIBRATION. 6. IF PROGRAMMING A NEW CONTROL MODULE, YOU MUST REQUEST INFORMATION FROM THE NEW CONTROL MODULE. The security information that is needed for a control module to be programmed is stored in the new control module. The security information must be requested from the control module to be programmed. At that point, the control module can be successfully programmed. This requesting of security information takes place in both the direct and remote methods. The request is automatic when using the direct method. Looking at the calibration stored in the old controller may be helpful in selecting the calibration from the CD-ROM for the new controller. 7. WHEN PROGRAMMING OBD II VEHICLES WITH A TECH 1 (REMOTE PROGRAMMING METHOD), A VEHICLE INTERFACE MODULE (VIM) IS REQUIRED. The VIM allows the Tech 1 to communicate with the OBD II vehicles. The VIM is necessary for all other Tech 1 diagnostics on OBD II vehicles. VIMs are no longer on backorder. If you are interested in obtaining additional VIMs, call 1-800-GM-TOOLS and ask for VIM kit part number 7000041. 8. DISCONNECT THE TECH I AND VIM FROM THE VEHICLE BETWEEN RETRIEVING DATA AND PROGRAMMING THE VEHICLE. If the VIM remains powered up after data is requested, a communication problem may result when the reprogramming function is performed. 9. WHEN CONNECTING THE TECH 1 TO A TECHLINE TERMINAL (EXCEPT T-100 CAMS), ALWAYS CONNECT THE FLAT GRAY R5232 CABLE FIRST AND THEN THE POWER ADAPTER. FAILURE TO DO SO COULD RESULT IN A LOSS OF INFORMATION Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Technical Service Bulletins for PROM - Programmable Read Only Memory: > 536508 > Jan > 96 > SPS/FLASH EPROM - Programming > Page 4463 STORED ON THE TECH 1. When power is turned on to the Tech 1, it looks for the RS232 connection. If it does not see the connection, the Tech 1 in some cases, will erase the information stored for download. 10. DO NOT DISCONTINUE OR INTERRUPT THE PROGRAM LOADING PROCESS TO THE VEHICLE. This will result in a programming error and could prevent the Electronic Control Module (ECM) from functioning properly. 11. AFTER PROGRAMMING IS COMPLETE, PRESS "EXIT". MAKE SURE THE KEY IS CYCLED OFF FOR APPROXIMATELY 10 SECONDS THEN BACK ON. Some vehicles will lose component settings (PMC/IAC Valve). Cycling the key off two times (Off for 30 seconds, On for 10 then repeat a second time) will allow for resetting of the components. Start the vehicle to ensure programming was successful. FOR CADILLAC VEHICLES ONLY a. DUE TO OTHER MODULES ON THE DATA LINE TRYING TO COMMUNICATE WITH THE ECM DURING PROGRAMMING, SOME COMMUNICATION CODES MAY BE SET After programming is complete, clear any codes and verify they do not reset. b. TO HELP MINIMIZE BATTERY DRAW DURING ECM PROGRAMMING, DISCONNECT THE BLOWER MOTOR (AT THE CONNECTOR, NOT THE FUSE) PRIOR TO PROGRAMMING. When programming is complete, reconnect the blower motor. 12. 1997 VEHICLES REQUIRE REPROGRAMMING BE DONE USING A TECH 2. OBD II vehicle calibration size and complexity will require more memory than the Tech 1 has available. Tech 2 will be an essential tool in the first quarter of 1996 containing limited 1996 applications and updates. 13. STG HAS ISSUED BULLETINS (# 53-65-04 and # 53-65-05 - (SEE CHART EXCERPTED FROM 53-65-05 FOR USE AS A QUICK REFERENCE GUIDE), DEVELOPED QUICK REFERENCE GUIDES (P/N SPSCARD-1 AVAILABLE THROUGH YOUR LOCAL GM TRAINING CENTER), PRODUCED CPT VIDEOS (CPT # 56010.00-B), HAD PULSAT BROADCASTS, AND OFFERS GM TRAINING CENTER CLASSROOM COURSES. As you work through reprogramming, keep the above-mentioned material in mind as resources to assist you if difficulty is encountered. As always, the Techline Customer Support Center (1-800-828-6860 English, 1-800-503-3222 French) is always available to assist the technician with any situation. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Technical Service Bulletins for PROM - Programmable Read Only Memory: > 536508 > Jan > 96 > SPS/FLASH EPROM - Programming > Page 4464 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Technical Service Bulletins for PROM - Programmable Read Only Memory: > 536508 > Jan > 96 > SPS/FLASH EPROM - Programming > Page 4465 SPS/EEPROM Programming 1993 to current Reprogrammable Vehicles Note: If programming a new control module you must request info from the new control module first. Battery voltage should be checked and at full charge before reprogramming takes place. System to be programmed should NOT be connected to a battery charger. Incorrect voltage could cause programming and/or control module failure. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Technical Service Bulletins for PROM - Programmable Read Only Memory: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM PROM - Programmable Read Only Memory: All Technical Service Bulletins Engine - Cold Knock, Replace Oil Filter/Bearings/PROM File In Section: 6 - Engine Bulletin No.: 37-61-05A Date: October, 1995 Subject: Cold Engine Knock (Replace Oil Filter/Bearings/PROM) Models: 1990-95 Chevrolet and GMC Truck C/K, R/V, S/T, M/L, G, P Models 1991-92 Oldsmobile Bravada with 4.3L (VIN Z - RPO LB4), 5.7L (VIN K - RPO L05), 7.4 (VIN N - RPO L19) Engine This bulletin is being revised to add the 1995 model year information. Please discard Corporate Bulletin Number 37-61-05 (Section 6 - Engine). Condition Some late model truck engines have been reported to exhibit "cold knock" on start up. "Cold Knock" usually occurs after the vehicle has been completely warmed up, then parked for 8 or more hours in ambient temperatures of 35° F or less. "Cold knock" can be separated into three distinct categories. 1. Short Duration - Harsh, deep metallic knock that usually lasts from 1 to 10 seconds. Generally classified as a bearing or rod knock. 2. Valve Train - Light clatter, tick or click that may last up to 1 minute. 3. Piston Slap - Metallic knock that occurs only under load. Piston slap may last as long as 5 minutes. Correction Category A: Short Duration Knock This matrix describes the repair for each affected model year and engine. Specific information for each affected model year and engine is supplied. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Technical Service Bulletins for PROM - Programmable Read Only Memory: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 4470 1992 LB4 VIN Z with "cold knock" only 1992-93 LB4 VIN Z with "cold knock" and installed field fix PROM OR with "cold knock" and detonation 1990-95 LB4 VIN Z Install check valve oil filter P/N 12555891 (FRAM PH3980). If the filter does not cure the condition, install the appropriate calibration from the tables (calibrations are available for all 1992 and some 1993 LB4 applications). If a calibration is not offered or does not cure the short duration cold knock Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Technical Service Bulletins for PROM - Programmable Read Only Memory: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 4471 condition, install the appropriate main bearings as determined by the following procedure. Calibration Information - 1992-93 LB4 VIN Z The revised PROMs reduce spark advance after the engine is started. The reduction in spark lowers the cylinder pressure and eliminates the knock. The revised PROMs will NOT eliminate a piston slap (Category C) or valve train noise (Category B) concern. The base cold knock PROM contains the previously released calibration updates. For 1992 LB4, the previous field release is included for torque converter clutch (TCC) lock up (see Bulletin 137107 - Chevrolet 92-75-7A; GMC Truck 92-7A-40; Oldsmobile 92-T-34; Canada 9274L60100) for automatic transmissions, or neutral gear rattle for manual transmissions (see Bulletin 267201R - Chevrolet 92-187B-7B; GMC Truck 92-7B-149A; Canada 93-7B-105). If a vehicle has had a detonation fix PROM installed previously, select the combined detonation and cold knock fix PROM for the application. See Bulletin 376508 for more information on field fix PROM for the application and detonation. Important: Use of a detonation fix PROM in a non-detonating vehicle may result in degraded driveability. GMSPO currently stocks three (3) PROMs for each light duty 1992 model year LB4 application. Base Cold Knock Fix Combination Cold Knock and Detonation Fix GMSPO Service Parts Assistance Center (SPAC 1-800-433-6961) will have information available on each PROM part number. Select the PROM from the table. Old Broadcast Code (Old B/C Code) and Scan I.D. information has been supplied to help installed previously. Use a TECH-1 to determine the Scan I.D. of the PROM in the vehicle or remove the PROM and read the Broadcast Code (B/C Code). If the B/C Code/Scan I.D. can be found in the first table, a detonation fix has not been installed. PROMs are currently available GMSPO. 1990-95 L05 VIN K Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Technical Service Bulletins for PROM - Programmable Read Only Memory: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 4472 1993 to 1995 L05 VIN K Install the appropriate check valve oil filter P/N 25160561 (PF1218 for two-wheel C-series and P/N 12555891 (FRAM PH3980) for four-wheel drive K-series). If the oil filter does not cure the condition, install the appropriate calibration from the table (calibrations are available for some 1993 and 1994 L05 applications). All calibrations are for light duty vehicles equipped with 4L60-E (M30) transmissions (no heavy duty emission/4L80-E calibrations are available). If a calibration is not offered or does not cure the short duration cold knock condition, install the appropriate main bearings as determined by the procedure. 1990-94 L19 VIN N Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Technical Service Bulletins for PROM - Programmable Read Only Memory: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 4473 Install a check valve oil filter; no other recommended actions at this time. Important: The previous actions are only applicable to short duration cold knock. These actions will not eliminate a knock occurring under load or a knock lasting for more than 10 seconds. Two main bearing procedures are recommended: 1. For main bearing replacement with the engine IN the vehicle: C, G, P, M and L vehicles 2. For main bearing replacement with the engine OUT OF the vehicle: K, S and T THE FOLLOWING PROCEDURE IS TO BE USED FOR VEHICLES REQUIRING MAIN BEARING REPLACEMENT WITH THE ENGINE IN THE VEHICLE Recommended for C, G, P, M and L vehicles. Important: A OEM training video has been produced for in-vehicle main bearing replacement procedure. One copy of the video will be sent to each dealer. If the video has not been received, contact XPRESS 1 Distribution Center at 1-800-783-3034. Main Bearing Clearance Determination and Installation Procedure 1. REMOVE THE SERPENTINE BELT, dipstick, dipstick tube and disconnect the negative battery cable. 2. Raise the vehicle and remove (or set aside) any parts restricting access to the oil pan bolts (i.e., starter motor, oil cooler lines, oil filter adapter, flywheel inspection cover). 3. Remove the oil pan, oil pump, and shield. 4. Remove # 5 (flange) bearing cap. Wipe the oil from the crankshaft journal and the lower main bearing insert. 5. Place a screw jack under an accessible part of the crankshaft, carefully apply pressure to the crankshaft to force it solidly against the top bearing insert. The reason for this is to remove any clearance between the top bearing insert and the crankshaft. If this step is not performed, a smaller than actual clearance will be measured. Important: This should be done as close as possible to the bearing being measured. This step is only required for on-vehicle service where the engine cannot be turned upside down as on an engine stand. 6. Place a piece of plastigage across the width of the lower bearing insert (parallel to the centerline of the crankshaft). 7. Reinstall # 5 main bearing cap. Torque to 110 N.m (80 lb ft). Do not allow crankshaft to turn. 8. Carefully remove the # 5 main bearing cap and bearing insert. The flattened plastigage will adhere to either the bearing insert or the crank journal. Do not remove the plastigage from the insert or journal. 9. On the edge of the plastigage envelope, there is a graduated scale. Without removing the flattened plastigage, measure its width at the widest point using the graduated scale on the plastigage envelope. 10. The desired main bearing clearance is 0.0008" - 0.0028". If the clearance measured with the plastigage is greater than 0.0028", write down the clearance. Next, read the back of the bearing insert to determine what size bearing was originally installed (usual STD, 0.0006", 0.0010" or 0.0012"). The size stamped on the bearing is the effective undersize when both inserts are installed. For example, a 0.0006" undersize bearing set consists of two (2) 0.0003" thicker bearing inserts, both stamped 0.0006". 11. Remove the top bearing insert using tool J 8080 and read the back to determine what size upper bearing insert was originally installed. The top insert may be different size than the bottom. 12. Calculate the original bearing undersize by dividing the size on each insert by 2, then add the values together. EXAMPLE 1: The lower insert is stamped 0.0006" and the upper is stamped 0.0010". Divide 0.0006" by two to get 0.0003". Divide 0.0010" by 2 to get 0.0005". Add 0.0003" and 0.0005" together to calculate the bearing undersize, which is 0.0008" in this case. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Technical Service Bulletins for PROM - Programmable Read Only Memory: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 4474 EXAMPLE 2: The lower insert is stamped STD (standard) and the upper is stamped 0.0010". The undersize for a STD bearing is 0. Divide 0 by 2 to get 0. Divide 0.0010" by 2 to get 0.0005". Add 0 and 0.0005" together to calculate the bearing undersize, which is 0.0005" in this case. 13. Add the original bearing undersize calculated in step 12 to the clearance measured and written down in step 9. For example, if a clearance of 0.0030" was measured with plastigage in step 9 and the calculated bearing undersize from step 12 was 0.0005", the bearing clearance for that particular main journal is equal to 0.0030" plus 0.0005". The bearing clearance would be 0.0035" in this case. 14. Determine which of the combinations of two sizes of replacement bearings will produce the desired clearance. The two sizes available are 0.001" and 0.002". One insert of each size may be combined to produce an intermediate undersize of 0.0015". Subtract the replacement bearing size from the actual clearance to determine which bearing should be used. The bearing that should be used is the one which gives a clearance closer to 0.0008" than to 0.0028". The clearance must not be less than 0.0008". Using the example from step 11, the actual clearance is 0.0035". Subtracting 0.001" from 0.0035" will give a clearance of 0.0025", just barely within the required range. Subtracting 0.002" from 0.0035" will give a clearance of 0.0015". The 0.002" undersize bearing set would be the one to use in this case since it gives a clearance closer to 0.0008", but not less. 15. Install the replacement upper main bearing insert using tool J 8080. 16. Install the replacement lower main bearing insert in the main bearing cap. Lay a piece of plastigage across the width of the lower main bearing insert (same as step 5). 17. Repeat steps 7, 8 and 9. 18. Measuring the plastigage with the scale on the envelope, verify the clearance of the replacement bearings is within the range of 0.001" to 0.003". 19. Repeat steps 4 through 16 for each main bearing. 20. Thrust the crankshaft forward and backward several times to seat the thrust bearing. 21. Reinstall oil pump; torque to 88 N.m (65 lb ft). 22. Reinstall the oil pan and other hardware. 23. Before starting the engine, remove the fuel pump fuse and crank the engine until oil pressure registers on the gauge. Stop cranking, let the starter cool down, then crank for another 15 seconds. 24. Install fuel pump fuse, start engine, check for leaks or unusual noises. 25. Road test vehicle, check for leaks or unusual noises. THE FOLLOWING PROCEDURE IS TO BE USED FOR VEHICLES REQUIRING MAIN BEARING REPLACEMENT WITH THE ENGINE OUT OF THE VEHICLE Recommended for K, S and T vehicles. 1. Remove the engine from the vehicle using the appropriate service manual procedure. 2. Mount the engine on an engine stand, flip the engine so the oil pan is facing up. 3. Remove the oil pan. 4. Remove the oil pump and shield. 5. Remove the dipstick tube. 6. Remove one (1) main bearing cap (must do one at a time). 7. Plasti-gage bearing. 8. If the bearing clearance is out of specification (clearance greater than 0.003 inches), remove upper main bearing from the block. 9. Check the size of the original bearing. 10. Determine what combination of new bearings are required to get the clearance in the acceptable range of 0.0008 inches to 0.0028 inches. See steps Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Technical Service Bulletins for PROM - Programmable Read Only Memory: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 4475 12 through 14 in the "in-vehicle" service outlined above. 11. Reinstall the upper main bearing. 12. Reinstall the main cap and lower bearing; torque to 110 N.m (80 lb ft). 13. Repeat for each main bearing. 14. Reinstall oil pump and shield; torque to 88 N.m (65 lb ft). 15. Reinstall dipstick tube. 16. Reinstall oil pan. 17. Reinstall engine in vehicle. 18. Before starting the engine, remove the fuel pump fuse and crank the engine until oil pressure registers on the gauge. Stop cranking, let the starter cool down, then crank for another 15 seconds. 19. Install fuel pump fuse, start engine, check for leaks or unusual noises. 20. Road test vehicle, check for leaks or unusual noises. Correction Category B: Valve Train Clatter, Tick or Click For 1992-94 vehicles equipped with a 4.3L V6 (LB4 VIN Z or L35 VIN W) engine see Corporate Bulletin 376006 for information on converting from net lash to adjustable lash and/or re-lashing the valves on an adjustable lash system. Investigation of "cold knock" is continuing. Updates will continue to be provided when available. Parts Information Check-Valve Filters Description Part Number V6, V8 (Four-Wheel Drive) FRAM PH3980 12555891 V8 (Two-Wheel Drive), Mark V8 PF1218 25160561 The FRAM PH3980 is to be used in place of the PF52. The PH3980 provides superior anti-drainback performance, a key factor in reducing cold knock. FRAM filters are to be procured locally until 08-15-95. After this date the filters may be ordered from GMSPO using the supplied part number. Orders placed to GMSPO prior to this date will not be placed on backorder. Bearings Description Part Number 0.001" Main Bearing Kit, Positions 1-4 on V8, 1-3 on V6 10120992 0.001" Main Bearing Kit, Flange # 5 on V8, # 4 on V6 10120994 0.002" Main Bearing Kit, Positions 1-4 on V8, 1-3 on V6 12329758 0.002" Main Bearing Kit, Flange # 5 on V8, # 4 on V6 12329792 Main bearing kits are currently available from GMSPO. All calibrations are currently available from GMSPO. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Technical Service Bulletins for PROM - Programmable Read Only Memory: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 4476 Warranty Information Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Technical Service Bulletins for PROM - Programmable Read Only Memory: > 476522 > Jan > 95 > Engine - Backfire Upon Acceleration PROM - Programmable Read Only Memory: All Technical Service Bulletins Engine - Backfire Upon Acceleration File in Section: 6E - Engine Fuel & Emission Bulletin No.: 47-65-22 Date: January, 1995 Subject: Backfire on Acceleration (Correct Calibration) Models: 1994 Chevrolet and GMC Truck S/T Models with 4.3L Engine (VIN Z - RPO LB4) and Manual Transmission (RPO MY2) Condition Some owners may experience a backfire condition upon acceleration. Cause Insufficient ignition timing advance in the spark calibration under some driving conditions. Correction More robust calibrations have been released to address this concern. THIS CALIBRATION WILL NOT CORRECT ANY OTHER DRIVEABILITY CONCERN. Important: These service calibrations should ONLY be used if a backfire concern still exists in a vehicle WHICH HAS HAD THE BASE TIMING CHECKED AND SET TO SPECIFICATION. LAUNCH DETONATION MAY OCCUR IN VEHICLES SERVICED WITH THESE CALIBRATIONS; particularly in vehicles which are heavily loaded or towing trailers. Parts Information Service "FLASH" calibrations are available starting with the December, 1994 CD ROM. Warranty Information Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 99-06-04-053 > Nov > 99 > PROM - Powertrain Control Module Reprogramming PROM - Programmable Read Only Memory: All Technical Service Bulletins PROM - Powertrain Control Module Reprogramming File In Section: 06 - Engine/Propulsion System Bulletin No.: 99-06-04-053 Date: November, 1999 INFORMATION Subject: Powertrain Control Module (PCM) Reprogramming (Do Not Reprogram Using the Same Download Files as Those Already Present in The Control Module) Models: 1990-2000 Passenger Cars and Trucks with Reprogrammable PCM It is strongly recommended to NOT reinstall the same software and/or calibration download file(s) into the powertrain control module as those that are already present in the PCM. There is no technical reason that the download files inside the PCM would ever become corrupted after the control module had previously been successfully programmed. A P0601 (Control Module Read Only Memory) Diagnostic Trouble Code would set in memory and the MIL would be illuminated if the controller memory became corrupted. The Techline Information System 2000 (TIS 2000) PC, combined with vehicle information gained through the Tech 2, can determine when an attempt to reprogram a PCM using the same download files (as those already in the control module) is being requested. If this is attempted, the TIS 2000 PC currently displays the following message: Notice: THE CALIBRATION SELECTED IS THE CURRENT CALIBRATION IN THE CONTROL MODULE. PROGRAMMING WITH THE SAME DOWNLOAD FILES IS NOT AN EFFECTIVE REPAIR. SELECT ( YES ) TO CONTINUE PROGRAMMING THE CONTROL MODULE,OR ( NO ) TO CANCEL. Effective in the first quarter of 2000, the TIS 2000 PC will indicate: Important: THE CALIBRATION SELECTED IS ALREADY THE CURRENT CALIBRATION IN THE CONTROL MODULE. REPROGRAMMING WITH THE SAME DOWNLOAD FILE IS NOT ALLOWED. Certain learned values, such as: (but not limited to) ^ fuel trim (previously known as block learn memory), ^ IAC learned position in various park/neutral and air conditioning on/off combinations, ^ certain OBDII diagnostic thresholds, ^ automatic transmission shift adapts will revert back to their unlearned starting point values after a reprogramming event occurs. It is feasible that the engine or transmission might temporarily operate differently after a reprogramming event, until these values are re-learned. Relearning occurs while operating the vehicle through normal driving routines. If the same download files are simply reinstalled, any changes noticed in engine operation will likely disappear in a short amount of time and/or driving distance. Reprogramming the control module with the same download files that already exist in the module will only accomplish a warranty claim for a non-effective repair, and a likely comeback. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 736513 > Mar > 97 > PROM - Reprogram Using Off Board Program Adapter PROM - Programmable Read Only Memory: All Technical Service Bulletins PROM - Reprogram Using Off Board Program Adapter File In Section: 6E - Engine Fuel & Emission Bulletin No.: 73-65-13 Date: March, 1997 INFORMATION Subject: Reprogramming Capability using the Off Board Programming Adapter Models: 1993-97 Passenger Cars and Trucks (Applicable Reprogrammable Vehicles) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 736513 > Mar > 97 > PROM - Reprogram Using Off Board Program Adapter > Page 4490 The General Motors vehicles contain Electronically Reprogrammable Devices (i.e. PCM, VCM, ECM). These vehicles cannot be programmed through PROM replacement, however service programming capability is available through the Tech 1/1A, Tech 2 and Techline terminals via direct or remote programming. The Environmental Protection Agency (EPA) has requested that all new vehicle manufacturers ensure their dealers/retailers are aware that they are responsible for providing customers access to reprogramming services at a reasonable cost and in a timely manner. Although programming of controllers has become a common service practice at GM dealers/retailers, the EPA has received reports from consumers and the aftermarket repair industry that they were unable to purchase a new (programmed) Electronically Reprogrammable Device (ERD) over-the-counter. As a result, on August 1, 1995, the Federal Government issued a regulation requiring all manufacturers to make available reprogramming to the independent aftermarket by December 1, 1997. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 736513 > Mar > 97 > PROM - Reprogram Using Off Board Program Adapter > Page 4491 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 736513 > Mar > 97 > PROM - Reprogram Using Off Board Program Adapter > Page 4492 Today, the Off Board Programming Adapter (OBPA) is used to reprogram ERD's sold over-the-counter. For all practical purposes, the OBPA takes the place of the vehicle when the vehicle is not available. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 736513 > Mar > 97 > PROM - Reprogram Using Off Board Program Adapter > Page 4493 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 736513 > Mar > 97 > PROM - Reprogram Using Off Board Program Adapter > Page 4494 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 736513 > Mar > 97 > PROM - Reprogram Using Off Board Program Adapter > Page 4495 The list of dealerships/retailers currently own the OBPA (see Attachments 1 - 3). These locations are equipped to provide over-the-counter preprogrammed ERD's. The hardware required to perform reprogramming in addition to the OBPA is a Techline terminal, Tech 1/1A and associated cables and adapters. THE TECH 2 SHOULD NOT BE USED WITH THE OBPA AT THIS TIME BECAUSE OF INADEQUATE OBPA GROUNDING. The current OBPA can support reprogramming on all late model General Motor's vehicles except: ^ Premium V-8's ^ 1996 Diesel Truck ^ Cadillac Catera Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 736513 > Mar > 97 > PROM - Reprogram Using Off Board Program Adapter > Page 4496 ^ All 1997 programmable vehicles (requires use of the Tech 2) A modification to the OBPA is being offered by Kent-Moore to support these additional vehicles and to allow reprogramming using the Tech 2. The revisions to the OBPA for the Tech 2 is very important as the Tech 2 is the only tool used for service programming for 1997 and future vehicles. To have the modifications performed, contact Kent-Moore at (800) 345-2233. The revisions (part number J 41207 REV-C) are free of charge for GM dealerships/retailers. A dealership/retailer can purchase the OBPA by contacting Kent-Moore (part number J 41207-C). Support on how to use the OBPA is provided by the Techline Customer Support Center (TCSC) at (800) 828-6860 (English) or (800) 503-3222 (French). If you need to purchase an OBPA and/or cable, contact Kent-Moore at (800) 345-2233. The OBPA retails for $695.00 (includes all revisions 1-4) under part number J 41207-C. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 536508 > Jan > 96 > SPS/FLASH EPROM - Programming PROM - Programmable Read Only Memory: All Technical Service Bulletins SPS/FLASH EPROM Programming File In Section: 6E - Engine Fuel & Emission Bulletin No.: 53-65-08 Date: January, 1996 INFORMATION Subject: SPS/FLASH EPROM Programming Models: 1993-96 Passenger Cars and Trucks Applicable Reprogrammable Vehicles This bulletin is being issued to assist technicians in reprogramming vehicles and should be used in conjunction with instructions provided on your Techline Terminal and in your Techline Terminal User's Manual. THE TECHLINE TERMINAL (T-20, T-50, T-60) HAS BEEN ABLE TO DO 1996 VEHICLE PROGRAMMING THROUGH THE DIRECT METHOD SINCE 1996 VEHICLES HAVE BEEN AVAILABLE IN THE DEALERSHIPS/RETAIL FACILITIES. THE TECHLINE CD-ROM TITLED DISC 13 CONTAINS THE SOFTWARE NEEDED TO PROGRAM ALL 1996 VEHICLES WITH A TECH 1 (REMOTE PROGRAMMING METHOD). SPS Tips 1. BATTERY VOLTAGE SHOULD BE CHECKED. A FULLY CHARGED BATTERY IS NECESSARY BEFORE REPROGRAMMING TAKES PLACE. THE VEHICLE BATTERY SHOULD NOT BE CONNECTED TO A BATTERY CHARGER DURING A PROGRAMMING EVENT INCORRECT VOLTAGE COULD CAUSE PROGRAMMING AND/OR CONTROL MODULE FAILURE. During programming, the control module depends on the battery as its sole source of power. Also during programming, the vehicle's components (i.e. blower motor) are set to a default mode which may be turned on, placing additional draw on the vehicle's battery. If the voltage goes outside the specified range (11 to 14 volts) the controllers and the Techline equipment will stop communicating. If this happens, it could cause the control module to become inoperable and require replacement. 2. CHECK THE INTEGRITY OF THE TECH 1 CABLES, MAKE SURE THEY ARE NOT FRAYED, BROKEN OR TWISTED. Loss of communication for any reason will require additional time in completing the reprogramming event. 3. IF USING A TECH 1, YOUR MASS STORAGE CARTRIDGE (MSC) MUST BE UPDATED TO REFLECT THE MOST CURRENT UPDATE OFFERED ON THE TECHLINE CD-ROM. DISC 13, 1995 WAS THE FIRST CD-ROM THAT HAD REMOTE PROGRAMMING SUPPORT If your MSC is not updated to reflect the current software version on the Techline Terminal, in some situations the software will not be capable of interpreting the information that is requested from the vehicle. 4. T-100 TERMINALS (CAMS) ARE NOT CAPABLE OF PROGRAMMING OBD II VEHICLES THROUGH THE DIRECT METHOD. A TECH 1 MUST BE USED (REMOTE METHOD) WHEN REPROGRAMMING WITH A T-100. The T-100 terminals communicate with vehicles through a DLC (ALDL) card and cable found within the T-100's computer. The DLC (ALDL) card is not capable of communicating at the new baud rate used with OBD II. 5. PROGRAMMING IS NOT NEEDED IF THE CURRENT CALIBRATION IS THE SAME AS THE SELECTED CALIBRATION. 6. IF PROGRAMMING A NEW CONTROL MODULE, YOU MUST REQUEST INFORMATION FROM THE NEW CONTROL MODULE. The security information that is needed for a control module to be programmed is stored in the new control module. The security information must be requested from the control module to be programmed. At that point, the control module can be successfully programmed. This requesting of security information takes place in both the direct and remote methods. The request is automatic when using the direct method. Looking at the calibration stored in the old controller may be helpful in selecting the calibration from the CD-ROM for the new controller. 7. WHEN PROGRAMMING OBD II VEHICLES WITH A TECH 1 (REMOTE PROGRAMMING METHOD), A VEHICLE INTERFACE MODULE (VIM) IS REQUIRED. The VIM allows the Tech 1 to communicate with the OBD II vehicles. The VIM is necessary for all other Tech 1 diagnostics on OBD II vehicles. VIMs are no longer on backorder. If you are interested in obtaining additional VIMs, call 1-800-GM-TOOLS and ask for VIM kit part number 7000041. 8. DISCONNECT THE TECH I AND VIM FROM THE VEHICLE BETWEEN RETRIEVING DATA AND PROGRAMMING THE VEHICLE. If the VIM remains powered up after data is requested, a communication problem may result when the reprogramming function is performed. 9. WHEN CONNECTING THE TECH 1 TO A TECHLINE TERMINAL (EXCEPT T-100 CAMS), ALWAYS CONNECT THE FLAT GRAY R5232 CABLE FIRST AND THEN THE POWER ADAPTER. FAILURE TO DO SO COULD RESULT IN A LOSS OF INFORMATION Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 536508 > Jan > 96 > SPS/FLASH EPROM - Programming > Page 4501 STORED ON THE TECH 1. When power is turned on to the Tech 1, it looks for the RS232 connection. If it does not see the connection, the Tech 1 in some cases, will erase the information stored for download. 10. DO NOT DISCONTINUE OR INTERRUPT THE PROGRAM LOADING PROCESS TO THE VEHICLE. This will result in a programming error and could prevent the Electronic Control Module (ECM) from functioning properly. 11. AFTER PROGRAMMING IS COMPLETE, PRESS "EXIT". MAKE SURE THE KEY IS CYCLED OFF FOR APPROXIMATELY 10 SECONDS THEN BACK ON. Some vehicles will lose component settings (PMC/IAC Valve). Cycling the key off two times (Off for 30 seconds, On for 10 then repeat a second time) will allow for resetting of the components. Start the vehicle to ensure programming was successful. FOR CADILLAC VEHICLES ONLY a. DUE TO OTHER MODULES ON THE DATA LINE TRYING TO COMMUNICATE WITH THE ECM DURING PROGRAMMING, SOME COMMUNICATION CODES MAY BE SET After programming is complete, clear any codes and verify they do not reset. b. TO HELP MINIMIZE BATTERY DRAW DURING ECM PROGRAMMING, DISCONNECT THE BLOWER MOTOR (AT THE CONNECTOR, NOT THE FUSE) PRIOR TO PROGRAMMING. When programming is complete, reconnect the blower motor. 12. 1997 VEHICLES REQUIRE REPROGRAMMING BE DONE USING A TECH 2. OBD II vehicle calibration size and complexity will require more memory than the Tech 1 has available. Tech 2 will be an essential tool in the first quarter of 1996 containing limited 1996 applications and updates. 13. STG HAS ISSUED BULLETINS (# 53-65-04 and # 53-65-05 - (SEE CHART EXCERPTED FROM 53-65-05 FOR USE AS A QUICK REFERENCE GUIDE), DEVELOPED QUICK REFERENCE GUIDES (P/N SPSCARD-1 AVAILABLE THROUGH YOUR LOCAL GM TRAINING CENTER), PRODUCED CPT VIDEOS (CPT # 56010.00-B), HAD PULSAT BROADCASTS, AND OFFERS GM TRAINING CENTER CLASSROOM COURSES. As you work through reprogramming, keep the above-mentioned material in mind as resources to assist you if difficulty is encountered. As always, the Techline Customer Support Center (1-800-828-6860 English, 1-800-503-3222 French) is always available to assist the technician with any situation. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 536508 > Jan > 96 > SPS/FLASH EPROM - Programming > Page 4502 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 536508 > Jan > 96 > SPS/FLASH EPROM - Programming > Page 4503 SPS/EEPROM Programming 1993 to current Reprogrammable Vehicles Note: If programming a new control module you must request info from the new control module first. Battery voltage should be checked and at full charge before reprogramming takes place. System to be programmed should NOT be connected to a battery charger. Incorrect voltage could cause programming and/or control module failure. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM PROM - Programmable Read Only Memory: All Technical Service Bulletins Engine - Cold Knock, Replace Oil Filter/Bearings/PROM File In Section: 6 - Engine Bulletin No.: 37-61-05A Date: October, 1995 Subject: Cold Engine Knock (Replace Oil Filter/Bearings/PROM) Models: 1990-95 Chevrolet and GMC Truck C/K, R/V, S/T, M/L, G, P Models 1991-92 Oldsmobile Bravada with 4.3L (VIN Z - RPO LB4), 5.7L (VIN K - RPO L05), 7.4 (VIN N - RPO L19) Engine This bulletin is being revised to add the 1995 model year information. Please discard Corporate Bulletin Number 37-61-05 (Section 6 - Engine). Condition Some late model truck engines have been reported to exhibit "cold knock" on start up. "Cold Knock" usually occurs after the vehicle has been completely warmed up, then parked for 8 or more hours in ambient temperatures of 35° F or less. "Cold knock" can be separated into three distinct categories. 1. Short Duration - Harsh, deep metallic knock that usually lasts from 1 to 10 seconds. Generally classified as a bearing or rod knock. 2. Valve Train - Light clatter, tick or click that may last up to 1 minute. 3. Piston Slap - Metallic knock that occurs only under load. Piston slap may last as long as 5 minutes. Correction Category A: Short Duration Knock This matrix describes the repair for each affected model year and engine. Specific information for each affected model year and engine is supplied. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 4508 1992 LB4 VIN Z with "cold knock" only 1992-93 LB4 VIN Z with "cold knock" and installed field fix PROM OR with "cold knock" and detonation 1990-95 LB4 VIN Z Install check valve oil filter P/N 12555891 (FRAM PH3980). If the filter does not cure the condition, install the appropriate calibration from the tables (calibrations are available for all 1992 and some 1993 LB4 applications). If a calibration is not offered or does not cure the short duration cold knock Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 4509 condition, install the appropriate main bearings as determined by the following procedure. Calibration Information - 1992-93 LB4 VIN Z The revised PROMs reduce spark advance after the engine is started. The reduction in spark lowers the cylinder pressure and eliminates the knock. The revised PROMs will NOT eliminate a piston slap (Category C) or valve train noise (Category B) concern. The base cold knock PROM contains the previously released calibration updates. For 1992 LB4, the previous field release is included for torque converter clutch (TCC) lock up (see Bulletin 137107 - Chevrolet 92-75-7A; GMC Truck 92-7A-40; Oldsmobile 92-T-34; Canada 9274L60100) for automatic transmissions, or neutral gear rattle for manual transmissions (see Bulletin 267201R - Chevrolet 92-187B-7B; GMC Truck 92-7B-149A; Canada 93-7B-105). If a vehicle has had a detonation fix PROM installed previously, select the combined detonation and cold knock fix PROM for the application. See Bulletin 376508 for more information on field fix PROM for the application and detonation. Important: Use of a detonation fix PROM in a non-detonating vehicle may result in degraded driveability. GMSPO currently stocks three (3) PROMs for each light duty 1992 model year LB4 application. Base Cold Knock Fix Combination Cold Knock and Detonation Fix GMSPO Service Parts Assistance Center (SPAC 1-800-433-6961) will have information available on each PROM part number. Select the PROM from the table. Old Broadcast Code (Old B/C Code) and Scan I.D. information has been supplied to help installed previously. Use a TECH-1 to determine the Scan I.D. of the PROM in the vehicle or remove the PROM and read the Broadcast Code (B/C Code). If the B/C Code/Scan I.D. can be found in the first table, a detonation fix has not been installed. PROMs are currently available GMSPO. 1990-95 L05 VIN K Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 4510 1993 to 1995 L05 VIN K Install the appropriate check valve oil filter P/N 25160561 (PF1218 for two-wheel C-series and P/N 12555891 (FRAM PH3980) for four-wheel drive K-series). If the oil filter does not cure the condition, install the appropriate calibration from the table (calibrations are available for some 1993 and 1994 L05 applications). All calibrations are for light duty vehicles equipped with 4L60-E (M30) transmissions (no heavy duty emission/4L80-E calibrations are available). If a calibration is not offered or does not cure the short duration cold knock condition, install the appropriate main bearings as determined by the procedure. 1990-94 L19 VIN N Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 4511 Install a check valve oil filter; no other recommended actions at this time. Important: The previous actions are only applicable to short duration cold knock. These actions will not eliminate a knock occurring under load or a knock lasting for more than 10 seconds. Two main bearing procedures are recommended: 1. For main bearing replacement with the engine IN the vehicle: C, G, P, M and L vehicles 2. For main bearing replacement with the engine OUT OF the vehicle: K, S and T THE FOLLOWING PROCEDURE IS TO BE USED FOR VEHICLES REQUIRING MAIN BEARING REPLACEMENT WITH THE ENGINE IN THE VEHICLE Recommended for C, G, P, M and L vehicles. Important: A OEM training video has been produced for in-vehicle main bearing replacement procedure. One copy of the video will be sent to each dealer. If the video has not been received, contact XPRESS 1 Distribution Center at 1-800-783-3034. Main Bearing Clearance Determination and Installation Procedure 1. REMOVE THE SERPENTINE BELT, dipstick, dipstick tube and disconnect the negative battery cable. 2. Raise the vehicle and remove (or set aside) any parts restricting access to the oil pan bolts (i.e., starter motor, oil cooler lines, oil filter adapter, flywheel inspection cover). 3. Remove the oil pan, oil pump, and shield. 4. Remove # 5 (flange) bearing cap. Wipe the oil from the crankshaft journal and the lower main bearing insert. 5. Place a screw jack under an accessible part of the crankshaft, carefully apply pressure to the crankshaft to force it solidly against the top bearing insert. The reason for this is to remove any clearance between the top bearing insert and the crankshaft. If this step is not performed, a smaller than actual clearance will be measured. Important: This should be done as close as possible to the bearing being measured. This step is only required for on-vehicle service where the engine cannot be turned upside down as on an engine stand. 6. Place a piece of plastigage across the width of the lower bearing insert (parallel to the centerline of the crankshaft). 7. Reinstall # 5 main bearing cap. Torque to 110 N.m (80 lb ft). Do not allow crankshaft to turn. 8. Carefully remove the # 5 main bearing cap and bearing insert. The flattened plastigage will adhere to either the bearing insert or the crank journal. Do not remove the plastigage from the insert or journal. 9. On the edge of the plastigage envelope, there is a graduated scale. Without removing the flattened plastigage, measure its width at the widest point using the graduated scale on the plastigage envelope. 10. The desired main bearing clearance is 0.0008" - 0.0028". If the clearance measured with the plastigage is greater than 0.0028", write down the clearance. Next, read the back of the bearing insert to determine what size bearing was originally installed (usual STD, 0.0006", 0.0010" or 0.0012"). The size stamped on the bearing is the effective undersize when both inserts are installed. For example, a 0.0006" undersize bearing set consists of two (2) 0.0003" thicker bearing inserts, both stamped 0.0006". 11. Remove the top bearing insert using tool J 8080 and read the back to determine what size upper bearing insert was originally installed. The top insert may be different size than the bottom. 12. Calculate the original bearing undersize by dividing the size on each insert by 2, then add the values together. EXAMPLE 1: The lower insert is stamped 0.0006" and the upper is stamped 0.0010". Divide 0.0006" by two to get 0.0003". Divide 0.0010" by 2 to get 0.0005". Add 0.0003" and 0.0005" together to calculate the bearing undersize, which is 0.0008" in this case. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 4512 EXAMPLE 2: The lower insert is stamped STD (standard) and the upper is stamped 0.0010". The undersize for a STD bearing is 0. Divide 0 by 2 to get 0. Divide 0.0010" by 2 to get 0.0005". Add 0 and 0.0005" together to calculate the bearing undersize, which is 0.0005" in this case. 13. Add the original bearing undersize calculated in step 12 to the clearance measured and written down in step 9. For example, if a clearance of 0.0030" was measured with plastigage in step 9 and the calculated bearing undersize from step 12 was 0.0005", the bearing clearance for that particular main journal is equal to 0.0030" plus 0.0005". The bearing clearance would be 0.0035" in this case. 14. Determine which of the combinations of two sizes of replacement bearings will produce the desired clearance. The two sizes available are 0.001" and 0.002". One insert of each size may be combined to produce an intermediate undersize of 0.0015". Subtract the replacement bearing size from the actual clearance to determine which bearing should be used. The bearing that should be used is the one which gives a clearance closer to 0.0008" than to 0.0028". The clearance must not be less than 0.0008". Using the example from step 11, the actual clearance is 0.0035". Subtracting 0.001" from 0.0035" will give a clearance of 0.0025", just barely within the required range. Subtracting 0.002" from 0.0035" will give a clearance of 0.0015". The 0.002" undersize bearing set would be the one to use in this case since it gives a clearance closer to 0.0008", but not less. 15. Install the replacement upper main bearing insert using tool J 8080. 16. Install the replacement lower main bearing insert in the main bearing cap. Lay a piece of plastigage across the width of the lower main bearing insert (same as step 5). 17. Repeat steps 7, 8 and 9. 18. Measuring the plastigage with the scale on the envelope, verify the clearance of the replacement bearings is within the range of 0.001" to 0.003". 19. Repeat steps 4 through 16 for each main bearing. 20. Thrust the crankshaft forward and backward several times to seat the thrust bearing. 21. Reinstall oil pump; torque to 88 N.m (65 lb ft). 22. Reinstall the oil pan and other hardware. 23. Before starting the engine, remove the fuel pump fuse and crank the engine until oil pressure registers on the gauge. Stop cranking, let the starter cool down, then crank for another 15 seconds. 24. Install fuel pump fuse, start engine, check for leaks or unusual noises. 25. Road test vehicle, check for leaks or unusual noises. THE FOLLOWING PROCEDURE IS TO BE USED FOR VEHICLES REQUIRING MAIN BEARING REPLACEMENT WITH THE ENGINE OUT OF THE VEHICLE Recommended for K, S and T vehicles. 1. Remove the engine from the vehicle using the appropriate service manual procedure. 2. Mount the engine on an engine stand, flip the engine so the oil pan is facing up. 3. Remove the oil pan. 4. Remove the oil pump and shield. 5. Remove the dipstick tube. 6. Remove one (1) main bearing cap (must do one at a time). 7. Plasti-gage bearing. 8. If the bearing clearance is out of specification (clearance greater than 0.003 inches), remove upper main bearing from the block. 9. Check the size of the original bearing. 10. Determine what combination of new bearings are required to get the clearance in the acceptable range of 0.0008 inches to 0.0028 inches. See steps Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 4513 12 through 14 in the "in-vehicle" service outlined above. 11. Reinstall the upper main bearing. 12. Reinstall the main cap and lower bearing; torque to 110 N.m (80 lb ft). 13. Repeat for each main bearing. 14. Reinstall oil pump and shield; torque to 88 N.m (65 lb ft). 15. Reinstall dipstick tube. 16. Reinstall oil pan. 17. Reinstall engine in vehicle. 18. Before starting the engine, remove the fuel pump fuse and crank the engine until oil pressure registers on the gauge. Stop cranking, let the starter cool down, then crank for another 15 seconds. 19. Install fuel pump fuse, start engine, check for leaks or unusual noises. 20. Road test vehicle, check for leaks or unusual noises. Correction Category B: Valve Train Clatter, Tick or Click For 1992-94 vehicles equipped with a 4.3L V6 (LB4 VIN Z or L35 VIN W) engine see Corporate Bulletin 376006 for information on converting from net lash to adjustable lash and/or re-lashing the valves on an adjustable lash system. Investigation of "cold knock" is continuing. Updates will continue to be provided when available. Parts Information Check-Valve Filters Description Part Number V6, V8 (Four-Wheel Drive) FRAM PH3980 12555891 V8 (Two-Wheel Drive), Mark V8 PF1218 25160561 The FRAM PH3980 is to be used in place of the PF52. The PH3980 provides superior anti-drainback performance, a key factor in reducing cold knock. FRAM filters are to be procured locally until 08-15-95. After this date the filters may be ordered from GMSPO using the supplied part number. Orders placed to GMSPO prior to this date will not be placed on backorder. Bearings Description Part Number 0.001" Main Bearing Kit, Positions 1-4 on V8, 1-3 on V6 10120992 0.001" Main Bearing Kit, Flange # 5 on V8, # 4 on V6 10120994 0.002" Main Bearing Kit, Positions 1-4 on V8, 1-3 on V6 12329758 0.002" Main Bearing Kit, Flange # 5 on V8, # 4 on V6 12329792 Main bearing kits are currently available from GMSPO. All calibrations are currently available from GMSPO. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 376105A > Oct > 95 > Engine - Cold Knock, Replace Oil Filter/Bearings/PROM > Page 4514 Warranty Information Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 476522 > Jan > 95 > Engine - Backfire Upon Acceleration PROM - Programmable Read Only Memory: All Technical Service Bulletins Engine - Backfire Upon Acceleration File in Section: 6E - Engine Fuel & Emission Bulletin No.: 47-65-22 Date: January, 1995 Subject: Backfire on Acceleration (Correct Calibration) Models: 1994 Chevrolet and GMC Truck S/T Models with 4.3L Engine (VIN Z - RPO LB4) and Manual Transmission (RPO MY2) Condition Some owners may experience a backfire condition upon acceleration. Cause Insufficient ignition timing advance in the spark calibration under some driving conditions. Correction More robust calibrations have been released to address this concern. THIS CALIBRATION WILL NOT CORRECT ANY OTHER DRIVEABILITY CONCERN. Important: These service calibrations should ONLY be used if a backfire concern still exists in a vehicle WHICH HAS HAD THE BASE TIMING CHECKED AND SET TO SPECIFICATION. LAUNCH DETONATION MAY OCCUR IN VEHICLES SERVICED WITH THESE CALIBRATIONS; particularly in vehicles which are heavily loaded or towing trailers. Parts Information Service "FLASH" calibrations are available starting with the December, 1994 CD ROM. Warranty Information Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 99046 > Dec > 99 > Recall - High/Low/High ABS Brake Anomaly Technical Service Bulletin # 99046 Date: 991201 Recall - High/Low/High ABS Brake Anomaly File in Section: Special Prices Bulletin No.: 99046 Date: December, 1999 SPECIAL POLICY SUBJECT: 99046 - SPECIAL POLICY - HIGH/LOW/HIGH ABS BRAKE ANOMALY MODELS: 1993-1996 CHEVROLET, GMC, AND OLDSMOBILE S/T UTILITY 1994-1996 CHEVROLET AND GMC S/T PICKUP EQUIPPED WITH A V6 ENGINE 1993-1995 CHEVROLET AND GMC M/L VAN 1993-1996 CHEVROLET AND GMC G VAN THIS SPECIAL POLICY IS IN EFFECT UNTIL DECEMBER 1, 2002 DUE TO THE AVAILABILITY OF PARTS, THIS SPECIAL POLICY WILL BE ADMINISTERED IN PHASES. THIS FIRST PHASE WILL BE THE REPROGRAMMING OF THE VCM IN 2WD AND 4WD 1994-1996 S/T PICKUPS AND 1995-1996 S/T UTILITIES EQUIPPED WITH A VCM. VEHICLES INVOLVED IN PHASE 1 ARE SHADED IN THE TABLE. YOU WILL BE NOTIFIED OF THE NEXT PHASE VIA DCS MESSAGE. Condition The federal government's highway safety agency, the National Highway Traffic Safety Administration (NHTSA) has identified, and General Motors Corporation has confirmed, the existence of a condition in the antilock braking system of some Chevrolet, GMC, and Oldsmobile S/T utilities. 1994-1996 Chevrolet and GMC S/T pickups equipped with a V6 engine, 1993-1995 Chevrolet and GMC M/L vans, and 1993-1996 Chevrolet and GMC G vans, all equipped with the Lucas Varity three-sensor ABS system. On rare occasions, this condition can result in longer stopping distances during certain antilock brake applications, as explained below. If the customer is driving on a road surface that supports good traction and they begin to stop by applying the brake pedal firmly, and both front wheels of their vehicle then pass onto a slippery surface (such as an ice-covered or wet patched asphalt part of the road), the antilock brake system will adjust the brakes at each of the wheels to take advantage of the available traction. This will allow the customer to steer and maintain stability, which is normal ABS operation1 as their owner's manual explains in more detail. However, if the customer is still braking while the vehicle leaves the slippery surface and both front wheels get back on a higher-traction surface, the ABS may perform as if the vehicle were still on the slippery surface and the vehicle may not stop as quickly. However, this will not happen every time these conditions are encountered. It depends on several additional factors, such as vehicle speed and the length of the slippery surface. The ABS system was designed with increased sensitivity to wheel slip in order to improve vehicle steerability while braking on very slippery surfaces. This improvement for steerability, however, made it possible for reduced front braking effectiveness to occur as described above. SPECIAL POLICY ADJUSTMENT (Phase I) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 99046 > Dec > 99 > Recall - High/Low/High ABS Brake Anomaly > Page 4524 This special policy adjustment covers the condition described above- until December 1, 2002, regardless of vehicle mileage or ownership. Dealers are to reprogram the VCM. Use the following Service Procedure. This will be performed at no charge to the customer during this time. Other conditions that may cause similar or different brake complaints that are not a result of the condition listed above are not covered by this special policy. The customer should be informed that any further service that is not covered by this special policy would be their responsibility, if they elect to have the service performed. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 99046 > Dec > 99 > Recall - High/Low/High ABS Brake Anomaly > Page 4525 VEHICLES INVOLVED Involved are 1993-1998 S/T utilities, 1994-1996 S/T pickups equipped with a V6 engine, 1993-1995 M/L van, and 1993-1996 G vans built within the VIN breakpoints. PARTS INFORMATION This phase requires no parts. Calibrations are available in October, 1999 on TIS 2000 CD, # 21 or Techline CD # 20/21 or later versions. CUSTOMER NOTIFICATION Customers will be notified of this special policy on their vehicles, in phases, by General Motors (see copy of typical customer letter included with this bulletin - actual divisional letter may vary slightly). SERVICE PROCEDURE VCM Programming Important: For 1995 S/T utilities with L35, check the Service Parts Identification (SPID) label on the inside of the glovebox to determine if the vehicle has a VCM. If there is an RPO of "K29", the vehicle has a PCM and is programmable. The new calibration,will be available in October, 1999 on TIS 2000 CD # 21 or Techline CD # 20/21 and later versions. The calibration is programmed into the vehicle's VCM via a Techline TOOL. Use a Techline Terminal or scan tool to perform the learn procedure and program the VCM. Important: Use the calibration file "Special Policy 99046" on TIS 2000 CD # 21 or Techline CD # 20/21 or later versions. 1. To ensure VCM programming/RPO configuration, confirm that the following conditions exist in order to prepare for VCM programming: ^ The battery is fully charged ^ The ignition switch is in the "RUN" position ^ The Data Link Connector (DLC) is accessible 2. Refer to the latest Techline Terminal and equipment user's instructions. 3. Clear the diagnostic trouble codes (DTCs) after the programming is complete. CLAIM INFORMATION For vehicles repaired under warranty submit a claim with the information indicated. Owner Letter Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 99046 > Dec > 99 > Recall - High/Low/High ABS Brake Anomaly > Page 4526 December, 1999 Dear Chevrolet/GMC Customer: As the owner of a General Motors truck equipped with the Lucas Varity three-sensor antilock brake system (ABS), your satisfaction with our product is of utmost concern to us. Condition: The federal government's highway safety agency. the National Highway Traffic Safety Administration (NHTSA) has identifled1 and General Motors Corporation has confirmed the existence of a condition in the antilock braking system of some Chevrolet and GMC 1994-1996 S/T pickups equipped with a V6 engine and 1995-1996 S/T utility vehicles. On rare occasions, this condition can result in longer stopping distances during certain antilock brake applications, as explained below. If you're driving on a road surface that supports good traction and you begin to stop by applying your brake pedal firmly, and both front wheels of your vehicle then pass, onto a slippery surface (such as an ice-covered or wet patched asphalt part of the road), your antilock brake system will adjust the brakes at each of the wheels to take advantage of the available traction. This will allow you to steer and maintain stability, which is normal ABS operation, as your owner's manual explains in more detail. However, if you are still braking while the vehicle leaves the slippery surface and both front wheels get back on a higher-traction surface, the ABS may perform as if the vehicle were still on the slippery surface and the vehicle may not stop as quickly. However, this will not happen every time these conditions are encountered. It depends on several additional factors, such as vehicle speed and the length of the slippery surface. Your ABS system was designed with increased sensitivity to wheel slip in order to improve vehicle steerability while braking on very slippery surfaces. This improvement for steerability, however, made it possible for reduced front braking effectiveness to occur as described above. Therefore, GM has developed a software change that will make your vehicle less Sensitive to wheel slip under the circumstances described above. What Will Be Done: Upon your request, your Chevrolet/GMC dealer will make a change to your antilock braking system software to prevent this phenomenon from occurring. This software change will have only a slight effect on vehicle steerablity during braking on very slippery surfaces and is designed to have no effect on normal ABS or other braking operations. This change should not affect how your brakes feel or create any perceptible difference in the steerability or stability of your vehicle while braking. This modification will be performed for you at no charge at anytime until December 1, 2002. How Long Will The Repair Take: Your Chevrolet/GMC dealer will modify your vehicle's ABS software. We estimate that it will take your dealer 45 minutes to perform this modification. Additional time may be required to schedule and process your vehicle. If your dealer has a large number of vehicles awaiting service, this additional time may be significant. Please ask your dealer if you wish to know how much additional time will be needed. Contacting Your Dealer: Repairs and adjustments qualifying under this special coverage must be performed by a Chevrolet/GMC dealer. You may want to call the service department to arrange a convenient appointment. Should your dealer be unable to schedule a service date within a reasonable time, you should contact the appropriate Customer Assistance Center at the number listed below: Deaf, Hearing Impaired Division Number or Speech Impaired* Chevrolet 1-800-222-1020 1-800-833-2438 GMC 1-800-462-8782 1-800-462-8583 * Utilizes Telecommunication Devices for the Deaf/Text Telephones (TDD/TTY) 1-800-462-8782. The deaf, hearing impaired, or speech impaired should call 1-800-462-8583 (utilizes Telecommunication Devices for the Deaf/Text Telephones, TDD/TTY). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 736513 > Mar > 97 > PROM - Reprogram Using Off Board Program Adapter > Page 4535 The General Motors vehicles contain Electronically Reprogrammable Devices (i.e. PCM, VCM, ECM). These vehicles cannot be programmed through PROM replacement, however service programming capability is available through the Tech 1/1A, Tech 2 and Techline terminals via direct or remote programming. The Environmental Protection Agency (EPA) has requested that all new vehicle manufacturers ensure their dealers/retailers are aware that they are responsible for providing customers access to reprogramming services at a reasonable cost and in a timely manner. Although programming of controllers has become a common service practice at GM dealers/retailers, the EPA has received reports from consumers and the aftermarket repair industry that they were unable to purchase a new (programmed) Electronically Reprogrammable Device (ERD) over-the-counter. As a result, on August 1, 1995, the Federal Government issued a regulation requiring all manufacturers to make available reprogramming to the independent aftermarket by December 1, 1997. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 736513 > Mar > 97 > PROM - Reprogram Using Off Board Program Adapter > Page 4536 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 736513 > Mar > 97 > PROM - Reprogram Using Off Board Program Adapter > Page 4537 Today, the Off Board Programming Adapter (OBPA) is used to reprogram ERD's sold over-the-counter. For all practical purposes, the OBPA takes the place of the vehicle when the vehicle is not available. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 736513 > Mar > 97 > PROM - Reprogram Using Off Board Program Adapter > Page 4538 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 736513 > Mar > 97 > PROM - Reprogram Using Off Board Program Adapter > Page 4539 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 736513 > Mar > 97 > PROM - Reprogram Using Off Board Program Adapter > Page 4540 The list of dealerships/retailers currently own the OBPA (see Attachments 1 - 3). These locations are equipped to provide over-the-counter preprogrammed ERD's. The hardware required to perform reprogramming in addition to the OBPA is a Techline terminal, Tech 1/1A and associated cables and adapters. THE TECH 2 SHOULD NOT BE USED WITH THE OBPA AT THIS TIME BECAUSE OF INADEQUATE OBPA GROUNDING. The current OBPA can support reprogramming on all late model General Motor's vehicles except: ^ Premium V-8's ^ 1996 Diesel Truck ^ Cadillac Catera Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 736513 > Mar > 97 > PROM - Reprogram Using Off Board Program Adapter > Page 4541 ^ All 1997 programmable vehicles (requires use of the Tech 2) A modification to the OBPA is being offered by Kent-Moore to support these additional vehicles and to allow reprogramming using the Tech 2. The revisions to the OBPA for the Tech 2 is very important as the Tech 2 is the only tool used for service programming for 1997 and future vehicles. To have the modifications performed, contact Kent-Moore at (800) 345-2233. The revisions (part number J 41207 REV-C) are free of charge for GM dealerships/retailers. A dealership/retailer can purchase the OBPA by contacting Kent-Moore (part number J 41207-C). Support on how to use the OBPA is provided by the Techline Customer Support Center (TCSC) at (800) 828-6860 (English) or (800) 503-3222 (French). If you need to purchase an OBPA and/or cable, contact Kent-Moore at (800) 345-2233. The OBPA retails for $695.00 (includes all revisions 1-4) under part number J 41207-C. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 536508 > Jan > 96 > SPS/FLASH EPROM - Programming > Page 4546 STORED ON THE TECH 1. When power is turned on to the Tech 1, it looks for the RS232 connection. If it does not see the connection, the Tech 1 in some cases, will erase the information stored for download. 10. DO NOT DISCONTINUE OR INTERRUPT THE PROGRAM LOADING PROCESS TO THE VEHICLE. This will result in a programming error and could prevent the Electronic Control Module (ECM) from functioning properly. 11. AFTER PROGRAMMING IS COMPLETE, PRESS "EXIT". MAKE SURE THE KEY IS CYCLED OFF FOR APPROXIMATELY 10 SECONDS THEN BACK ON. Some vehicles will lose component settings (PMC/IAC Valve). Cycling the key off two times (Off for 30 seconds, On for 10 then repeat a second time) will allow for resetting of the components. Start the vehicle to ensure programming was successful. FOR CADILLAC VEHICLES ONLY a. DUE TO OTHER MODULES ON THE DATA LINE TRYING TO COMMUNICATE WITH THE ECM DURING PROGRAMMING, SOME COMMUNICATION CODES MAY BE SET After programming is complete, clear any codes and verify they do not reset. b. TO HELP MINIMIZE BATTERY DRAW DURING ECM PROGRAMMING, DISCONNECT THE BLOWER MOTOR (AT THE CONNECTOR, NOT THE FUSE) PRIOR TO PROGRAMMING. When programming is complete, reconnect the blower motor. 12. 1997 VEHICLES REQUIRE REPROGRAMMING BE DONE USING A TECH 2. OBD II vehicle calibration size and complexity will require more memory than the Tech 1 has available. Tech 2 will be an essential tool in the first quarter of 1996 containing limited 1996 applications and updates. 13. STG HAS ISSUED BULLETINS (# 53-65-04 and # 53-65-05 - (SEE CHART EXCERPTED FROM 53-65-05 FOR USE AS A QUICK REFERENCE GUIDE), DEVELOPED QUICK REFERENCE GUIDES (P/N SPSCARD-1 AVAILABLE THROUGH YOUR LOCAL GM TRAINING CENTER), PRODUCED CPT VIDEOS (CPT # 56010.00-B), HAD PULSAT BROADCASTS, AND OFFERS GM TRAINING CENTER CLASSROOM COURSES. As you work through reprogramming, keep the above-mentioned material in mind as resources to assist you if difficulty is encountered. As always, the Techline Customer Support Center (1-800-828-6860 English, 1-800-503-3222 French) is always available to assist the technician with any situation. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 536508 > Jan > 96 > SPS/FLASH EPROM - Programming > Page 4547 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > All Other Service Bulletins for PROM - Programmable Read Only Memory: > 536508 > Jan > 96 > SPS/FLASH EPROM - Programming > Page 4548 SPS/EEPROM Programming 1993 to current Reprogrammable Vehicles Note: If programming a new control module you must request info from the new control module first. Battery voltage should be checked and at full charge before reprogramming takes place. System to be programmed should NOT be connected to a battery charger. Incorrect voltage could cause programming and/or control module failure. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Technical Service Bulletins > Page 4549 PROM - Programmable Read Only Memory: Service Precautions A PROM is a sensitive electronic part and must be handled with care. If the connector terminals (pins) on the bottom of the PROM are exposed, avoid touching them. Pins can be broken easily, and the PROM can be damaged by static electric discharge. Follow these guidelines when replacing a PROM: ^ Disconnect the battery ground cable before removing a PROM. Reconnect the cable after the new PROM is installed. ^ DO NOT try to remove a PROM from its plastic PROM carrier. ^ Note the direction in which the original PROM and its carrier were installed in the ECM, and install the replacement PROM in the same direction. Most PROM's are marked with a notch at one end for orientation. Many PROM's can be installed in a reversed direction, which will destroy the PROM when power is applied. CAUTION: A PROM can be damaged by static electric discharge. Avoid damage as follows: ^ DO NOT remove a PROM from its packing material until you are ready to install it. DO NOT hold a PROM by its pins. ^ Before entering a vehicle to remove or replace a PROM, touch an exposed metal part of the vehicle to discharge any static charge from your body or use anti-static wrist straps. ^ Avoid sliding across upholstery or carpeting when removing or installing a PROM. If this is not possible, touch an exposed metal part of the vehicle with your free hand before removing a PROM or installing a new one in its socket in the ECM. ^ When available, use an antistatic grounding strap attached to your wrist and clipped to a metal part of the vehicle body to prevent static charges from accumulating. Antistatic, conductive floormats are also available. ^ For some vehicles, it may be desirable to remove the ECM when replacing the PROM. ^ NOTE: See POWERTRAIN MANAGEMENT / SERVICE PRECAUTIONS / VEHICLE DAMAGE WARNINGS / ELECTRICAL PRECAUTIONS Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Introducing the GM PROM Cross Reference Index PROM - Programmable Read Only Memory: Application and ID Introducing the GM PROM Cross Reference Index This PROM cross reference index provides tables that let you use a PROM identification (ID) code to identify the PROM installed in the engine control module (ECM) on most GM vehicles. The code can be either - or both - the internal "scan ID" code or the external PROM code. From the PROM identification, you can find the part number of the PROM and trace the PROM history to determine if any revised PROM's have been issued to supersede the one in the vehicle. The PROM history for a specific vehicle lists a succession of superseding PROM's ending with the most recent PROM released as a service part for the vehicle. PROM's that were released as service parts and explained in a technical service bulletin (TSB) are listed with a description of why the PROM was issued. In most cases, the applicable TSB also is referenced. This index lists ECM PROM's for the 1980-95 vehicles. It does not contain ID codes and part numbers for all PROM's used in all GM vehicles. NOTE: GM flash PROM's (EEPROM's) can only be updated at GM Dealerships with factory-supplied equipment. These cars will not display a PROM ID. By following the steps outlined below, you can use the PROM index to determine if the problem you are diagnosing can possibly be corrected by installing a revised PROM. The PROM index tables are organized by model year, engine displacement, and engine code (the eighth digit of the Vehicle Identification Number). The table columns are arranged as shown below: Example of Table Column Arrangement SCAN PROM PROM PART SUPERSEDING TSB REFERENCE ID CODE (BCC) NUMBER ID PART NUMBER NUMBER (1) (2) (3) (4) (5) .............................................................................................................................................................. ........................................................................ 9461 8958 AMU 16058955R 8290 01228290 86194 Column 1, SCAN ID: The scan ID is the internal PROM identification number transmitted on the ECM data stream and displayed by the scanner as PROM ID. The PROM records for each year and engine are listed numerically by this scan ID. Column 2, PROM CODE: These are the numbers and letters marked on the top of the PROM itself. The numbers are often referred to as the "external PROM ID." The letters are often called the "broadcast code." Together they are the external PROM code. Column 3, PROM P/N: This is the GM part number for the PROM identified by the codes in columns 1 and 2. Column 4, SUPERSEDING ID PROM PART NUMBER: Use the superseding scan ID to locate the newer PROM in the table. If the scan ID for the superseding PROM is not known, the PROM broadcast code is listed here. If the PROM is superseded by a newer PROM, that part number is listed here. Column 5, TSB REFERENCE NUMBER The TSB NUMBER column identifies the original TSB that released this PROM for service. Whenever possible you should refer to the TSB for additional information before changing a PROM. The bulletin may list other parts that must be installed when the PROM is changed, or it may provide additional troubleshooting information. To find a TSB, see Reading Technical Service Bulletins. See: Reading Technical Service Bulletins This will display all the TSB's for that particular vehicle. EXPANDED FOOTNOTES Here you will find SUPERSEDING SCAN ID, PROM PART NUMBERS, symptoms and additional parts that need to be replaced when servicing the PROM. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Introducing the GM PROM Cross Reference Index > Page 4552 PROM - Programmable Read Only Memory: Application and ID Introducing the GM PROM Cross Reference Index This PROM cross reference index provides tables that let you use a PROM identification (ID) code to identify the PROM installed in the engine control module (ECM) on most GM vehicles. The code can be either - or both - the internal "scan ID" code or the external PROM code. From the PROM identification, you can find the part number of the PROM and trace the PROM history to determine if any revised PROM's have been issued to supersede the one in the vehicle. The PROM history for a specific vehicle lists a succession of superseding PROM's ending with the most recent PROM released as a service part for the vehicle. PROM's that were released as service parts and explained in a technical service bulletin (TSB) are listed with a description of why the PROM was issued. In most cases, the applicable TSB also is referenced. This index lists ECM PROM's for the 1980-95 vehicles. It does not contain ID codes and part numbers for all PROM's used in all GM vehicles. NOTE: GM flash PROM's (EEPROM's) can only be updated at GM Dealerships with factory-supplied equipment. These cars will not display a PROM ID. By following the steps outlined below, you can use the PROM index to determine if the problem you are diagnosing can possibly be corrected by installing a revised PROM. The PROM index tables are organized by model year, engine displacement, and engine code (the eighth digit of the Vehicle Identification Number). The table columns are arranged as shown below: Example of Table Column Arrangement SCAN PROM PROM PART SUPERSEDING TSB REFERENCE ID CODE (BCC) NUMBER ID PART NUMBER NUMBER (1) (2) (3) (4) (5) .............................................................................................................................................................. ........................................................................ 9461 8958 AMU 16058955R 8290 01228290 86194 Column 1, SCAN ID: The scan ID is the internal PROM identification number transmitted on the ECM data stream and displayed by the scanner as PROM ID. The PROM records for each year and engine are listed numerically by this scan ID. Column 2, PROM CODE: These are the numbers and letters marked on the top of the PROM itself. The numbers are often referred to as the "external PROM ID." The letters are often called the "broadcast code." Together they are the external PROM code. Column 3, PROM P/N: This is the GM part number for the PROM identified by the codes in columns 1 and 2. Column 4, SUPERSEDING ID PROM PART NUMBER: Use the superseding scan ID to locate the newer PROM in the table. If the scan ID for the superseding PROM is not known, the PROM broadcast code is listed here. If the PROM is superseded by a newer PROM, that part number is listed here. Column 5, TSB REFERENCE NUMBER The TSB NUMBER column identifies the original TSB that released this PROM for service. Whenever possible you should refer to the TSB for additional information before changing a PROM. The bulletin may list other parts that must be installed when the PROM is changed, or it may provide additional troubleshooting information. To find a TSB, see Reading Technical Service Bulletins. See: Reading Technical Service Bulletins This will display all the TSB's for that particular vehicle. EXPANDED FOOTNOTES Here you will find SUPERSEDING SCAN ID, PROM PART NUMBERS, symptoms and additional parts that need to be replaced when servicing the PROM. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Introducing the GM PROM Cross Reference Index > Page 4553 PROM - Programmable Read Only Memory: Application and ID Additional PROM Information New ECM PROMs for GM vehicles may be released for service at any time. The information in this system is accurate to the best of the publisher's knowledge and the publication date of the disk. Before ordering a PROM, consult with a GM parts and service dealer to verify the latest part number information. Scanner PROM ID information for earlier-model vehicles (1980-83) is less complete than for later models. To accurately identify PROM's in earlier vehicles, it may be necessary to check the external PROM code marked on the PROM. General Motors has often recommended that dealership technicians check the PROM history of a vehicle and install the most recent PROM revision before performing other diagnostic operations. Each succeeding PROM revision for a specific vehicle includes all previous revisions. Therefore, whenever you consider changing a PROM, review the entire PROM history to see if any revision covered the current driveability problem. Installing the most recent PROM revision may be impractical however for an independent service facility, particularly if the latest PROM revision does not address the specific driveability problem of the vehicle. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Introducing the GM PROM Cross Reference Index > Page 4554 PROM - Programmable Read Only Memory: Application and ID Additional PROM Information New ECM PROMs for GM vehicles may be released for service at any time. The information in this system is accurate to the best of the publisher's knowledge and the publication date of the disk. Before ordering a PROM, consult with a GM parts and service dealer to verify the latest part number information. Scanner PROM ID information for earlier-model vehicles (1980-83) is less complete than for later models. To accurately identify PROM's in earlier vehicles, it may be necessary to check the external PROM code marked on the PROM. General Motors has often recommended that dealership technicians check the PROM history of a vehicle and install the most recent PROM revision before performing other diagnostic operations. Each succeeding PROM revision for a specific vehicle includes all previous revisions. Therefore, whenever you consider changing a PROM, review the entire PROM history to see if any revision covered the current driveability problem. Installing the most recent PROM revision may be impractical however for an independent service facility, particularly if the latest PROM revision does not address the specific driveability problem of the vehicle. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Introducing the GM PROM Cross Reference Index > Page 4555 PROM - Programmable Read Only Memory: Application and ID PROM/MEMCAL Identification Marks File In Section: 6E - Engine Fuel & Emission Bulletin No.: 44-65-01 Date: October, 1994 Subject: New PROM/MEMCAL Identification Markings Models: 1995 and Prior Passenger Cars and Trucks Note: For the purposes of this document, the terms PROM and MEMCAL will be used interchangeably. To simplify identification of service PROMs. a new external marking format will be implemented. Parts manufactured after Sept. 1994 will feature these new markings. This change will place the full 8-digit service part number on the PROM, in place of the old 4-digit "EXTERNAL ID" number. In the past, parts and service personnel could not identify a PROM without using a cross-reference table that matched external IDs and service numbers. In the future, the cross-reference table will not be required for PROMs; parts will be ordered directly from the number appearing on the PROM. However, the label will retain the broadcast code alpha characters to allow continued use of cross-reference charts, if so desired. Old Marking Format: New Marking Format: ^ Ordering the above PROM from the old marking format would require using a cross-reference chart to determine a service part number, based on the BROAD CAST CODE and EXTERNAL ID NUMBERS. ^ To order from the new format, simply combine the 2nd and 3rd lines to form an 8-digit part number that can be directly ordered from SPO (number 16134624 in the above example). As these changes are phased into the parts inventory, it should be noted that dealers will continue to see parts with both formats for some time in the future. This is because: ^ Millions of vehicles have already been built with the old format. ^ SPO has existing stock of MEMCALs and PROMs with the old format. ^ PROMS with 7-digit part numbers (representing less than 10% of current part numbers) will continue to use the old format. The 7-digit part numbers are easily identified because they always begin with "122xxxx". Due to manufacturing processes, more than one 8-digit part number may appear on a MEMCAL. In this event, service personnel should use the label on the exterior cover of the MEMCAL assembly. To avoid confusion, only the service label will include the BROAD CAST CODE, consisting of letter characters (I.E., ARCL). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Introducing the GM PROM Cross Reference Index > Page 4556 CHANGES TO MEMCAL/PROM LABELING FORMATS ^ MEMCALs may use either INK-JET or ADHESIVE labels, as shown. ^ PROMs will always use ADHESIVE labels with the same format as shown for MEMCALs. These changes will become effective on parts manufactured after 10/94. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Introducing the GM PROM Cross Reference Index > Page 4557 PROM - Programmable Read Only Memory: Application and ID PROM/MEMCAL Identification Marks File In Section: 6E - Engine Fuel & Emission Bulletin No.: 44-65-01 Date: October, 1994 Subject: New PROM/MEMCAL Identification Markings Models: 1995 and Prior Passenger Cars and Trucks Note: For the purposes of this document, the terms PROM and MEMCAL will be used interchangeably. To simplify identification of service PROMs. a new external marking format will be implemented. Parts manufactured after Sept. 1994 will feature these new markings. This change will place the full 8-digit service part number on the PROM, in place of the old 4-digit "EXTERNAL ID" number. In the past, parts and service personnel could not identify a PROM without using a cross-reference table that matched external IDs and service numbers. In the future, the cross-reference table will not be required for PROMs; parts will be ordered directly from the number appearing on the PROM. However, the label will retain the broadcast code alpha characters to allow continued use of cross-reference charts, if so desired. Old Marking Format: New Marking Format: ^ Ordering the above PROM from the old marking format would require using a cross-reference chart to determine a service part number, based on the BROAD CAST CODE and EXTERNAL ID NUMBERS. ^ To order from the new format, simply combine the 2nd and 3rd lines to form an 8-digit part number that can be directly ordered from SPO (number 16134624 in the above example). As these changes are phased into the parts inventory, it should be noted that dealers will continue to see parts with both formats for some time in the future. This is because: ^ Millions of vehicles have already been built with the old format. ^ SPO has existing stock of MEMCALs and PROMs with the old format. ^ PROMS with 7-digit part numbers (representing less than 10% of current part numbers) will continue to use the old format. The 7-digit part numbers are easily identified because they always begin with "122xxxx". Due to manufacturing processes, more than one 8-digit part number may appear on a MEMCAL. In this event, service personnel should use the label on the exterior cover of the MEMCAL assembly. To avoid confusion, only the service label will include the BROAD CAST CODE, consisting of letter characters (I.E., ARCL). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Introducing the GM PROM Cross Reference Index > Page 4558 CHANGES TO MEMCAL/PROM LABELING FORMATS ^ MEMCALs may use either INK-JET or ADHESIVE labels, as shown. ^ PROMs will always use ADHESIVE labels with the same format as shown for MEMCALs. These changes will become effective on parts manufactured after 10/94. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Introducing the GM PROM Cross Reference Index > Page 4559 PROM - Programmable Read Only Memory: Application and ID Reading Technical Service Bulletins Always read any Technical Service Bulletins (TSB's) referenced before replacing a PROM. Service bulletins list parts that must be installed when a PROM is changed, and provide information on trouble codes, troubleshooting and driveability problems for which the PROM was released. To find applicable TSB's: Complete TSB Listing 1. Hold down right mouse button and select "Vehicle" in the "Pull Right Menu". 2. Select the TSB ICON. 3. Select "All Technical Service Bulletins by Number, Date, and Title". 4. Select "Sort by Number", "Sort by Date", or "Sort by Title". 5. Scroll up or down to find the desired TSB. PROM TSB Listing Only 1. Hold down right mouse button and select "Technical Service Bulletins" in the "Pull Right Menu". 2. Select "All Technical Service Bulletins for PROM - Programmable Read Only Memory". 3. Select "Sort by Number", "Sort by Date", or "Sort by Title". 4. Scroll up or down to find the desired TSB. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Introducing the GM PROM Cross Reference Index > Page 4560 PROM - Programmable Read Only Memory: Application and ID Reading Technical Service Bulletins Always read any Technical Service Bulletins (TSB's) referenced before replacing a PROM. Service bulletins list parts that must be installed when a PROM is changed, and provide information on trouble codes, troubleshooting and driveability problems for which the PROM was released. To find applicable TSB's: Complete TSB Listing 1. Hold down right mouse button and select "Vehicle" in the "Pull Right Menu". 2. Select the TSB ICON. 3. Select "All Technical Service Bulletins by Number, Date, and Title". 4. Select "Sort by Number", "Sort by Date", or "Sort by Title". 5. Scroll up or down to find the desired TSB. PROM TSB Listing Only 1. Hold down right mouse button and select "Technical Service Bulletins" in the "Pull Right Menu". 2. Select "All Technical Service Bulletins for PROM - Programmable Read Only Memory". 3. Select "Sort by Number", "Sort by Date", or "Sort by Title". 4. Scroll up or down to find the desired TSB. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Expanded Footnotes > Footnotes 1 Thru 50 PROM - Programmable Read Only Memory: Application and ID Footnotes 1 Thru 50 [1] Also needs EGR P/N 1706739. [2] Also requires EGR P/N 17111295. [3] Requires Throttle Body service P/N 17067142, EGR valve service P/N 17067111, Injector service kit P/N 17067976. [4] Requires Throttle Body service P/N 17067142, EGR valve service P/N 17067107, Injector service kit P/N 17067976. [5] Requires Throttle Body service P/N 17067144, EGR valve service P/N 17067110, Injector service kit P/N 17067976. [6] PROM I.D. 7080 KJ is also acceptable for PROM I.D. 5853 KJ only. Requires Throttle Body service P/N 17067144, EGR valve service P/N 17067108 (FED), 17067144 (CAL), Injector service kit P/N 17067976. [7] Required Throttle Body service P/N 17067142, EGR valve service P/N 17067107 (FED), 17068210 (CAL), Injector service kit P/N 17067976. [8] Requires Throttle Body service P/N 17068019, EGR valve service P/N 17067109, Injector service kit P/N 17067976. [9] For Federal - Use 01226047 (PROM CODE 7654 BKW). For California - Use 01226049 (PROM CODE 7665 BKY). [10] For Federal - Use 01226054. For California - Use 01226056 [11] For Federal - Use 01226055. For California - Use 01226057. [12] For Federal - Use 01226046 (PROM CODE 7648 BKU). For California - Use 01226049 (PROM CODE 7665 BKY). [13] For federal - Use 01226046 (PROM CODE 7648 BKU). For California - Use 01226048 (PROM CODE 7659 BKX). [14] ECM may have been replaced by service ECM P/N 16019710 (1225500). [15] ECM may also be 16018161. ECM may also have been replaced by service ECM P/N 16018000 (1225330). [16] ECM may also be 16018201. ECM may also have been replaced by service ECM P/N 16018000 (1225330). [17] ECM may also be 16018211. ECM may have been replaced by service ECM P/N 16018000 (1225330). [18] ECM may also be 16023761. ECM may have been replaced by service ECM P/N 16018000 (1225330). [19] ECM may also be 16018101. ECM may have been replaced by service ECM P/N 16018000 (1225330). [20] For 2-board ECM only. [21] May need EGR valve P/N 17079563. Original equipment P/N 16029014. [22] Original equipment PROM P/N 16017094, now 16025254 [23] Original equipment PROM P/N 16017224, now 16025264. [24] Also needs EGR valve P/N 17079013. Original equipment PROM P/N 16030034 (PROM ID: BOH). [25] Requires kit P/N 25522748 containing: Wiring harness jumper P/N 12043500, Relay P/N 25522747, Foam P/N 25522723, EGR P/N 17079799. [26] Needs EGR valve P/N 17079818. [27] For (MY7) - Use 01226473 (SCAN I.D. = 3941). For (M19) - Use 01226474 (SCAN I.D. = 3951). [28] For (MY7) or (M19, C60) - Use 01226473 (SCAN I.D. = 3941). For (M19) - Use 01226474 (SCAN I.D. = 3951). [29] ECM may also be 16023561(M5), or 16033061(M4 with A/C). [30] For F62 axle - Use 01226441 (SCAN I.D. = 3622). For F17 axle - Use 01226439 (SCAN I.D. = 3332). [31] For one_board ECM only. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Expanded Footnotes > Footnotes 1 Thru 50 > Page 4563 [32] Requires Thermac Sensor P/N 8997916. [33] For Federal - Use 01227729 (SCAN I.D. = 7729). For California - Use 01227728 (SCAN I.D. = 7728). [34] Use 01227629 (SCAN I.D. = 7629) only to resolve surge or chuggle. [35] Use 01227381 (SCAN I.D. = 7381) only to resolve chuggle. [36] Use 01227386 (SCAN I.D. = 7386) only to resolve chuggle. [37] Retrofit PROM - Does not supersede the regular replacement service PROM. To be used only as required to resolve cases of chuggle. [38] Retrofit PROM - Supersedes all previous service PROM part numbers. To be used as both the regular service replacement (PROM-damaged or defective), and to resolve cases of chuggle. [39] Retrofit PROM - Supersedes all previous service PROM part numbers. To be used as both the regular service replacement (PROM-damaged or defective), and to resolve cases of chuggle, detonation, or flatness. [40] Retrofit PROM - Does not supersede the regular replacement service PROMS. To be used only as required to resolve cases of chuggle, detonation, or flatness. [41] Need EGR valve P/N 17111577 (Federal only). [42] For use with P215/65 tires - use 01228290 (SCAN I.D. = 8290). For use with P235/60, P245/50 tires - use 01228291 (SCAN I.D. = 8291). [43] For use with P215/65 tires - use 01228292 (SCAN I.D. - 8292). For use with P235/60, P245/50 tires - use 01228293 (SCAN I.D. = 8293). [44] Use 16143570 (SCAN I.D. = 3531) for hot hard restart (Requires Fuel Pump P/N 25115764, Fuel Sender P/N 25093526). Use 16143459 (SCAN I.D. = 3571) for Code 42, Spark Knock, High Idle. [45] Use 16143455 (SCAN I.D. = 3511) for hot hard restart (Requires Fuel Pump P/N 25115764, Fuel Sender P/N 25093526). Use 16143453 (SCAN I.D. = 3501) for Code 42, Spark Knock, High Idle. [46] Use 16143575 (SCAN I.D. = 3541) for hot hard restart (Requires Fuel Pump P/N 25115764). Use 16143460 (SCAN I.D. = 3581) for Code 42, Spark Knock, High Idle. [47] Use 16143580 (SCAN I.D. = 3551) for hot hard restart (Requires Fuel Pump P/N 25115764). Use 16143462 (SCAN I.D. = 3591) for Code 42, Spark Knock, High Idle. [48] Use 16143457 (SCAN I.D. = 3521) for hot hard restart (Requires Fuel Pump P/N 25115925, Fuel Sender P/N 25092778). Use 16143466 (SCAN I.D. = 3481) for Code 42, Spark Knock, High Idle. [49] Use 16143452 (SCAN I.D. = 3491) for hot hard restart (Requires Fuel Pump P/N 25115925, Fuel Sender P/N 25092778). Use 16143463 (SCAN I.D. = 3451) for Code 42, Spark Knock, High Idle. [50] Needs air injection service kit (P/N 10115773) and new vehicle emission control label. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Expanded Footnotes > Footnotes 1 Thru 50 > Page 4564 PROM - Programmable Read Only Memory: Application and ID Footnotes 51 Thru 100 [51] Must be ordered with service kit P/N 10115773. [52] With this PROM installed, use 1987-88 2.8L speed density engine driveability and emissions manual. [53] PROM update eliminates MAF sensor, replacing it with a speed density system. With a 1990 or earlier primary cartridge, I.D. vehicle on scanner as a 1989 model (VIN = K-1-W). [54] For 2WD use 16120099 (SCAN I.D. = 9941). For 4WD use 16120109 (SCAN I.D. = 9901). [55] For 2.73 (GU2) Axle use 16120077 (SCAN I.D. = 9891). For 3.08 (GU4) Axle use 16120082 (SCAN I.D. = 9901). For 3.42 (GU6) and 3.73 (GT4) Axles use 16120086 (SCAN I.D. = 9911). [56] For 2WD use 16120042 (SCAN I.D. = 9991). For 4WD use 16120129 (SCAN I.D. = 0011). [57] Needs accelerator pump check ball spring P/N 17069583. [58] For false Code 44 on long coast down, use retrofit service PROM 01228486 AAND 1050. For regular service replacement, use PROM 16062797 AAND 2798. [59] For false Code 44 on long coast down, use retrofit service PROM 01228487 AANF 1052. For regular service replacement, use PROM 16062801 AANF 2802. [60] USE 16143545 (SCAN I.D. = 3461) For hot hard restart (Requires Fuel Pump P/N 25115764, Fuel Sender P/N 25093744). Use 16143465 (SCAN I.D. = 3471) for Code 42, Spark Knock, High Idle. [61] With this PROM installed, use 1987-88 2.8L speed density engine driveability and emissions manual. [62] For use with model C1 Trucks - Use 16121162 (SCAN I.D. = 3511). For use with model C2, K, K2, AND K1000 Trucks - use 16121166 (SCAN I.D. = 3521). [63] Also requires installation of new EGR valve package P/N 17112238 (Contains EGR valve P/N 17090078 and a gasket). [64] Use 16181863 (SCAN I.D. = 0844) for cold start stall. Use 16181859 (SCAN I.D. = 0834) only if required to solve both cold start stall and chuggle. [65] Use 16181871 (SCAN I.D. = 0864) for cold start stall. Use 16181867 (SCAN I.D. = 0854) only if required to solve both cold start stall and chuggle. [66] Use 16165848 (SCAN I.D. = 5614) for cold start stall. Use 16165843 (SCAN I.D. = 5624) only if required to solve both cold start stall and chuggle. [67] Do not rely on the scanner ID to determine which PROM is in a vehicle. Look at the BCC on the PROM to be sure. Do not confuse with some 1991 models with a 2.84 axle ratio and a Federal emissions pkg which used scanner ID 5644 but had a BCC of AWJD. [68] This PROM may have a negative impact on fuel economy. [69] Cannot be used on vehicles that do not have digital EGR valves. [70] Use 16165839 (SCAN I.D. = 5634) for cold start stall. Use 16165829 (SCAN I.D. = 5644) only if required to solve both cold start stall and chuggle. [71] Use 16181883 (SCAN I.D. = 0894) for cold start stall. Use 16181875 (SCAN I.D. = 0874) only if required to solve both cold start stall and chuggle. [72] Use 16181887 (SCAN I.D. = 0904) for cold start stall. Use 16181879 (SCAN I.D. = 0884) only if required to solve both cold start stall and chuggle. [73] This PROM may have a negative impact on fuel economy. [74] PROM can only be used with ECM P/N 16144288. [75] Make certain the vehicle has been updated with previously attempted service fixes as follows: EGR valve P/N 17090156 (stamped on valve) 17112373 (GMSPO kit), PCV valve P/N 25098542, ESC module P/N 16175099 (BCC=BARC). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Expanded Footnotes > Footnotes 1 Thru 50 > Page 4565 [76] For vehicles with sleeve bearing engines. [77] Combination detonation and neutral gear rattle PROM available. [78] Needs ESC P/N 16175099. [79] Model 2DDM Transmissions - Check dealer records to see if the torque converter has already been replaced with P/N 8650935 (Tagged BCC: DGAF). Trans. with torque converters with P/N 8656959 (Tagged BCC: DG5F) need to replace it with P/N 8650935. [80] For dedicated natural gas vehicles. Order with kit P/N 12545589 unless the only problem is idle fluctuation. [81] For chuggle at 40-45 condition, use PROM only. For tip-in hesitation only, use EGR valve only - P/N 17078431. For cold driveability hesitation, use both PROM and EGR. [82] Requires supplementary tune-up label, spark bypass relay kit P/N 14086983, spark plugs P/N 5614009, sun visor starting label P/N 14085150. Also, remove and discard fuse labeled "crank" from fuse BLK #2 position (3 Amp. Fuse). [83] Manual transmission cars should also be updated with the clutch anticipate switch per dealer service bulletin number. 91-472-7C. [84] Cold driveability, use with PROM 0051 AAF (G057). REQUIRES THROTTLE BODY SERVICE P/N 17067142, EGR VALVE SERVICE P/N 17067111, INJECTOR SERVICE KIT P/N 17067976. [85] Cold driveability, use with PROM 0050 AAF (G057). REQUIRES THROTTLE BODY SERVICE P/N 17067142, EGR VALVE SERVICE P/N 17067111, INJECTOR SERVICE KIT P/N 17067976. [86] Exhaust noise (requires catalytic converter), cold driveability, use with PROM 5884 BH (G057). REQUIRES THROTTLE BODY SERVICE P/N 17068019, EGR VALVE SERVICE P/N 17067109, INJECTOR SERVICE KIT P/N 17067976. [87] Exhaust noise (requires catalytic converter), cold driveability, use with PROM 5869 BH (G057). REQUIRES THROTTLE BODY SERVICE P/N 17068019, EGR VALVE SERVICE P/N 17067109, INJECTOR SERVICE KIT P/N 17067976. [88] Exhaust noise (requires catalytic converter), cold driveability, use with PROM 5779 KB (G057). REQUIRES THROTTLE BODY SERVICE P/N 17067144, EGR VALVE SERVICE P/N 17067110, INJECTOR SERVICE KIT P/N 17067976. [89] Exhaust noise (requires catalytic converter), cold driveability, use with PROM 5778 KB (G057). REQUIRES THROTTLE BODY SERVICE P/N 17067144, EGR VALVE SERVICE P/N 17067110, INJECTOR SERVICE KIT P/N 17067976. [90] Cold driveability, use with PROM 5854 KJ (G057). PROM I.D. 7080 KJ IS ALSO ACCEPTABLE FOR PROM I.D. 5853 KJ ONLY. REQUIRES THROTTLE BODY SERVICE P/N 17067144, EGR VALVE SERVICE P/N 17067108 (FED), 17067144 (CAL), INJECTOR SERVICE KIT P/N 17067976. [91] Cold driveability, use with PROM 5853 KJ (G057). PROM I.D. 7080 KJ IS ALSO ACCEPTABLE FOR PROM I.D. 5853 KJ ONLY. REQUIRES THROTTLE BODY SERVICE P/N 17067144, EGR VALVE SERVICE P/N 17067108 (FED), 17067144 (CAL), INJECTOR SERVICE KIT P/N 17067976. [92] Cold driveability, use with PROM 5861 KK (G057). REQUIRED THROTTLE BODY SERVICE P/N 17067142, EGR VALVE SERVICE P/N 17067107 (FED), 17068210 (CAL), INJECTOR SERVICE KIT P/N 17067976. [93] Cold driveability, use with PROM 5860 KK (G057). REQUIRED THROTTLE BODY SERVICE P/N 17067142, EGR VALVE SERVICE P/N 17067107 (FED), 17068210 (CAL), INJECTOR SERVICE KIT P/N 17067976. [94] Exhaust noise (requires catalytic converter), cold driveability, use with PROM 5786 LW (G057). REQUIRES THROTTLE BODY SERVICE P/N 17067142, EGR VALVE SERVICE P/N 17067107, INJECTOR SERVICE KIT P/N 17067976. [95] Exhaust noise (requires catalytic converter), cold driveability, use with PROM 5785 LW (G057). REQUIRES THROTTLE BODY SERVICE P/N 17067142, EGR VALVE SERVICE P/N 17067107, INJECTOR SERVICE KIT P/N 17067976. [96] Cold driveability, use with PROM 7088 LY (G057). REQUIRES THROTTLE BODY SERVICE P/N 17067142, EGR VALVE SERVICE P/N 17067111, INJECTOR SERVICE KIT P/N 17067976. [97] Cold driveability, use with PROM 7087 LY (G057). REQUIRES THROTTLE BODY SERVICE P/N 17067142, EGR VALVE SERVICE P/N 17067111, INJECTOR SERVICE KIT P/N 17067976. [98] Chuggle at 40-45 mph, cold driveability hesitation. FOR CHUGGLE AT 40-45 CONDITION, USE PROM ONLY. FOR TIP-IN HESITATION ONLY, USE EGR VALVE ONLY - P/N 17078431. FOR COLD DRIVEABILITY HESITATION, USE BOTH PROM AND EGR. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Expanded Footnotes > Footnotes 1 Thru 50 > Page 4566 [99] Driveability correction for heavy chuggle. REQUIRES KIT P/N 25522748 CONTAINING: WIRING HARNESS JUMPER P/N 12043500, RELAY P/N 25522747, FOAM P/N 25522723, EGR P/N 17079799. [100] Cold startability adjustment. REQUIRES SUPPLEMENTARY TUNE-UP LABEL, SPARK BYPASS RELAY KIT P/N 14086983, SPARK PLUGS P/N 5614009, SUN VISOR STARTING LABEL P/N 14085150. ALSO, REMOVE AND DISCARD FUSE LABELED "CRANK" FROM FUSE BLK #2 POSITION (3 AMP. FUSE). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Expanded Footnotes > Footnotes 1 Thru 50 > Page 4567 PROM - Programmable Read Only Memory: Application and ID Footnotes 101 Thru 150 [101] Driveability correction for heavy chuggle. REQUIRES KIT P/N 25522748 CONTAINING: WIRING HARNESS JUMPER P/N 12043500, RELAY P/N 25522747, FOAM P/N 25522723, EGR P/N 17079799. [102] Cold startability adjustment. REQUIRES SUPPLEMENTARY TUNE-UP LABEL, SPARK BYPASS RELAY KIT P/N 14086983, SPARK PLUGS P/N 5614009, SUN VISOR STARTING LABEL P/N 14085150. ALSO, REMOVE AND DISCARD FUSE LABELED "CRANK" FROM FUSE BLK #2 POSITION (3 AMP. FUSE). [103] Cold startability adjustment. REQUIRES SUPPLEMENTARY TUNE-UP LABEL, SPARK BYPASS RELAY KIT P/N 14086983, SPARK PLUGS P/N 5614009, SUN VISOR STARTING LABEL P/N 14085150. ALSO, REMOVE AND DISCARD FUSE LABELED "CRANK" FROM FUSE BLK #2 POSITION (3 AMP. FUSE). [104] Cold startability adjustment. REQUIRES SUPPLEMENTARY TUNE-UP LABEL, SPARK BYPASS RELAY KIT P/N 14086983, SPARK PLUGS P/N 5614009, SUN VISOR STARTING LABEL P/N 14085150. ALSO, REMOVE AND DISCARD FUSE LABELED "CRANK" FROM FUSE BLK #2 POSITION (3 AMP. FUSE). [105] Surge. RETROFIT PROM - DOES NOT SUPERSEDE THE REGULAR REPLACEMENT SERVICE PROM. TO BE USED ONLY AS REQUIRED TO RESOLVE CASES OF CHUGGLE. [106] Surge and CODE 51. RETROFIT PROM - SUPERSEDES ALL PREVIOUS SERVICE PROM PART NUMBERS. TO BE USED AS BOTH THE REGULAR SERVICE REPLACEMENT (PROM-DAMAGED OR DEFECTIVE), AND TO RESOLVE CASES OF CHUGGLE. [107] Surge and CODE 51. RETROFIT PROM - SUPERSEDES ALL PREVIOUS SERVICE PROM PART NUMBERS. TO BE USED AS BOTH THE REGULAR SERVICE REPLACEMENT (PROM-DAMAGED OR DEFECTIVE), AND TO RESOLVE CASES OF CHUGGLE. [108] Surge and CODE 51. RETROFIT PROM - SUPERSEDES ALL PREVIOUS SERVICE PROM PART NUMBERS. TO BE USED AS BOTH THE REGULAR SERVICE REPLACEMENT (PROM-DAMAGED OR DEFECTIVE), AND TO RESOLVE CASES OF CHUGGLE. [109] Surge and CODE 51. RETROFIT PROM - SUPERSEDES ALL PREVIOUS SERVICE PROM PART NUMBERS. TO BE USED AS BOTH THE REGULAR SERVICE REPLACEMENT (PROM-DAMAGED OR DEFECTIVE), AND TO RESOLVE CASES OF CHUGGLE. [110] Surge. RETROFIT PROM - SUPERSEDES ALL PREVIOUS SERVICE PROM PART NUMBERS. TO BE USED AS BOTH THE REGULAR SERVICE REPLACEMENT (PROM-DAMAGED OR DEFECTIVE), AND TO RESOLVE CASES OF CHUGGLE. [111] Surge and CODE 51. RETROFIT PROM - SUPERSEDES ALL PREVIOUS SERVICE PROM PART NUMBERS. TO BE USED AS BOTH THE REGULAR SERVICE REPLACEMENT (PROM-DAMAGED OR DEFECTIVE), AND TO RESOLVE CASES OF CHUGGLE. [112] Surge and CODE 51. RETROFIT PROM - SUPERSEDES ALL PREVIOUS SERVICE PROM PART NUMBERS. TO BE USED AS BOTH THE REGULAR SERVICE REPLACEMENT (PROM-DAMAGED OR DEFECTIVE), AND TO RESOLVE CASES OF CHUGGLE, DETONATION, OR FLATNESS. [113] Surge and CODE 51. RETROFIT PROM - SUPERSEDES ALL PREVIOUS SERVICE PROM PART NUMBERS. TO BE USED AS BOTH THE REGULAR SERVICE REPLACEMENT (PROM-DAMAGED OR DEFECTIVE), AND TO RESOLVE CASES OF CHUGGLE, DETONATION, OR FLATNESS. [114] Surge, flatness or tip-in hesitation. RETROFIT PROM - DOES NOT SUPERSEDE THE REGULAR REPLACEMENT SERVICE PROMS. TO BE USED ONLY AS REQUIRED TO RESOLVE CASES OF CHUGGLE, DETONATION, OR FLATNESS. [115] FOR USE WITH P215/65 TIRES - USE 01228290 (SCAN I.D. = 8290). FOR USE WITH P235/60, P245/50 TIRES - USE 01228291 (SCAN I.D. = 8291). [116] FOR USE WITH P215/65 TIRES - USE 01228290 (SCAN I.D. = 8290). FOR USE WITH P235/60, P245/50 TIRES - USE 01228291 (SCAN I.D. = 8291). [117] Spark knock only. USE 16143570 (SCAN I.D. = 3531) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093526). USE 16143459 (SCAN I.D. = 3571) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [118] Spark knock only. USE 16143455 (SCAN I.D. = 3511) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093526). USE 16143453 (SCAN I.D. = 3501) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [119] Spark knock. USE 16143575 (SCAN I.D. = 3541) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764). USE 16143460 (SCAN I.D. = 3581) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [120] Detonation. USE 16143580 (SCAN I.D. = 3551) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764). USE 16143462 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Expanded Footnotes > Footnotes 1 Thru 50 > Page 4568 (SCAN I.D. = 3591) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [121] Stall, sags, hesitation. USE 16143575 (SCAN I.D. = 3541) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764). USE 16143460 (SCAN I.D. = 3581) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [122] USE 16143575 (SCAN I.D. = 3541) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764). USE 16143460 (SCAN I.D. = 3581) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [123] USE 16143570 (SCAN I.D. = 3531) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093526). USE 16143459 (SCAN I.D. = 3571) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [124] USE 16143455 (SCAN I.D. = 3511) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093526). USE 16143453 (SCAN I.D. = 3501) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [125] USE 16143457 (SCAN I.D. = 3521) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115925, FUEL SENDER P/N 25092778). USE 16143466 (SCAN I.D. = 3481) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [126] USE 16143452 (SCAN I.D. = 3491) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115925, FUEL SENDER P/N 25092778). USE 16143463 (SCAN I.D. = 3451) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [127] USE 16143457 (SCAN I.D. = 3521) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115925, FUEL SENDER P/N 25092778). USE 16143466 (SCAN I.D. = 3481) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [128] USE 16143452 (SCAN I.D. = 3491) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115925, FUEL SENDER P/N 25092778). USE 16143463 (SCAN I.D. = 3451) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [129] Engine stall and/or hesitation after cold start. NEEDS AIR INJECTION SERVICE KIT (P/N 10115773) AND NEW VEHICLE EMISSION CONTROL LABEL. [130] Engine stall and/or hesitation after cold start. NEEDS AIR INJECTION SERVICE KIT (P/N 10115773) AND NEW VEHICLE EMISSION CONTROL LABEL. [131] Driveability conditions and/or stored engine codes. WITH THIS PROM INSTALLED, USE 1987-88 2.8L SPEED DENSITY ENGINE DRIVEABILITY AND EMISSIONS MANUAL. [132] Cold stall and chuggle. DO NOT RELY ON THE SCANNER ID TO DETERMINE WHICH PROM IS IN A VEHICLE. LOOK AT THE BCC ON THE PROM TO BE SURE. DO NOT CONFUSE WITH SOME 1991 MODELS WITH A 2.84 AXLE RATIO AND A FEDERAL EMISSIONS PKG. WITH USED SCANNER ID 5644 BUT HAD A BCC OF AWJD. [133] Driveability conditions and/or stored engine codes. WITH THIS PROM INSTALLED, USE 1987-88 2.8L SPEED DENSITY ENGINE DRIVEABILITY AND EMISSIONS MANUAL. [134] Tip-in hesitation on acceleration; engine stall or sag on cold start; engine stall on deceleration; check engine light with CODES 23,25,33, or 34; or engine speed flare on clutch operation, with manual transmission equipped vehicle. WITH THIS PROM INSTALLED, USE 1987-88 2.8L SPEED DENSITY ENGINE DRIVEABILITY AND EMISSIONS MANUAL. [135] Tip-in hesitation on acceleration; engine stall or sag on cold start; engine stall on deceleration; check engine light with CODES 23,25,33, or 34; or engine speed flare on declutch operation with manual transmission equipped vehicle. WITH THIS PROM INSTALLED, USE 1987-88 2.8L SPEED DENSITY ENGINE DRIVEABILITY AND EMISSIONS MANUAL. [136] Driveability conditions, and/or CODES 23,25,33,34. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [137] Driveability conditions, and/or CODES 23,25,33,34. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [138] Driveability conditions, and/or CODES 23,25,33,34. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [139] Driveability conditions, and/or CODES 23,25,33,34. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Expanded Footnotes > Footnotes 1 Thru 50 > Page 4569 [140] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [141] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [142] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [143] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [144] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [145] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [146] PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [147] PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [148] PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [149] Tip-in hesitation on acceleration; engine stall or sag on cold start; engine stall on deceleration; check engine light with CODES 23,25,33, or 34; or engine speed flare on declutch operation with manual transmission equipped vehicle. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [150] Tip-in hesitation on acceleration; engine stall or sag on cold start; engine stall on deceleration; check engine light with CODES 23,25,33, or 34; or engine speed flare on declutch operation with manual transmission equipped vehicle. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Expanded Footnotes > Footnotes 1 Thru 50 > Page 4570 PROM - Programmable Read Only Memory: Application and ID Footnotes 151 Thru 200 [151] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [152] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [153] Driveability improvement and eliminate FALSE "Service Engine Soon" lights. FOR 2WD USE 16120099 (SCAN I.D. = 9941). FOR 4WD USE 16120109 (SCAN I.D. = 9901). [154] Driveability improvement and eliminate FALSE "Service Engine Soon" lights. FOR 2.73 (GU2) AXLE USE 16120077 (SCAN I.D. = 9891). FOR 3.08 (GU4) AXLE USE 16120082 (SCAN I.D. = 9901). FOR 3.42 (GU6) AND 3.73 (GT4) AXLES USE 16120086 (SCAN I.D. = 9911). [155] Driveability improvement and eliminate FALSE "Service Engine Soon" lights. FOR 2WD USE 16120042 (SCAN I.D. = 9991). FOR 4WD USE 16120129 (SCAN I.D. = 0011). [156] Prom calibration. FOR FALSE CODE 44 ON LONG COAST DOWN, USE RETROFIT SERVICE PROM 01228486 AAND 1050. FOR REGULAR SERVICE REPLACEMENT, USE PROM 16062797 AAND 2798. [157] FOR FALSE CODE 44 ON LONG COAST DOWN, USE RETROFIT SERVICE PROM 01228487 AANF 1052. FOR REGULAR SERVICE REPLACEMENT, USE PROM 16062801 AANF 2802. [158] Spark knock only. USE 16143570 (SCAN I.D. = 3531) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093526). USE 16143459 (SCAN I.D. = 3571) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [159] Spark knock only. USE 16143455 (SCAN I.D. = 3511) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093526). USE 16143453 (SCAN I.D. = 3501) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [160] Detonation. USE 16143580 (SCAN I.D. = 3551) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764). USE 16143462 (SCAN I.D. = 3591) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [161] USE 16143545 (SCAN I.D. = 3461) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093744). USE 16143465 (SCAN I.D. = 3471) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [162] USE 16143570 (SCAN I.D. = 3531) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093526). USE 16143459 (SCAN I.D. = 3571) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [163] USE 16143545 (SCAN I.D. = 3461) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093744). USE 16143465 (SCAN I.D. = 3471) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [164] USE 16143570 (SCAN I.D. = 3531) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093526). USE 16143459 (SCAN I.D. = 3571) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [165] USE 16143455 (SCAN I.D. = 3511) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093526). USE 16143453 (SCAN I.D. = 3501) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [166] Hard start when hot and detonation. USE 16143457 (SCAN I.D. = 3521) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115925, FUEL SENDER P/N 25092778). USE 16143466 (SCAN I.D. = 3481) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [167] Hard start when hot and detonation. USE 16143452 (SCAN I.D. = 3491) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115925, FUEL SENDER P/N 25092778). USE 16143463 (SCAN I.D. = 3451) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [168] Engine stall and/or hesitation after cold start. NEEDS AIR INJECTION SERVICE KIT (P/N 10115773) AND NEW VEHICLE EMISSION CONTROL LABEL. [169] Cold stall and chuggle. DO NOT RELY ON THE SCANNER ID TO DETERMINE WHICH PROM IS IN A VEHICLE. LOOK AT THE BCC ON THE PROM TO BE SURE. DO NOT CONFUSE WITH SOME 1991 MODELS WITH A 2.84 AXLE RATIO AND A FEDERAL EMISSIONS PKG. WHICH USED SCANNER ID 5644 BUT HAD A BCC OF AWJD. [170] Engine stall and/or hesitation after cold start. NEEDS AIR INJECTION SERVICE KIT (P/N 10115773) AND NEW VEHICLE EMISSION CONTROL LABEL. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Expanded Footnotes > Footnotes 1 Thru 50 > Page 4571 [171] Engine stall and/or hesitation after cold start. MUST BE ORDERED WITH SERVICE KIT P/N 10115773. [172] Driveability conditions and/or stored engine codes. WITH THIS PROM INSTALLED, USE 1987-88 2.8L SPEED DENSITY ENGINE DRIVEABILITY AND EMISSIONS MANUAL. [173] Driveability conditions and/or stored engine codes. WITH THIS PROM INSTALLED, USE 1987-88 2.8L SPEED DENSITY ENGINE DRIVEABILITY AND EMISSIONS MANUAL. [174] Driveability conditions, and/or CODES 23,25,33,34. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [175] Driveability conditions, and/or CODES 23,25,33,34. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [176] Driveability conditions, and/or CODES 23,25,33,34. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [177] Driveability conditions, and/or CODES 23,25,33,34. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [178] Driveability conditions, and/or CODES 23,25,33,34. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [179] Driveability conditions, and/or CODES 23,25,33,34. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [180] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [181] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [182] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [183] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [184] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [185] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [186] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [187] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [188] Driveability conditions, and/or CODES 23,25,33,34. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Expanded Footnotes > Footnotes 1 Thru 50 > Page 4572 DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [189] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [190] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [191] Information on PROM calibrations. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [192] Information on PROM calibrations. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [193] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [194] Driveability conditions and/or stored engine codes. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [195] FOR USE WITH MODEL C1 TRUCKS - USE 16121162 (SCAN I.D. = 3511). FOR USE WITH MODEL C2, K, K2, AND K1000 TRUCKS USE 16121166 (SCAN I.D. = 3521). [196] Engine surge. ALSO REQUIRES INSTALLATION OF NEW EGR VALVE PACKAGE P/N 17112238 (CONTAINS EGR VALVE P/N 17090078 AND A GASKET). [197] Engine stall and/or hesitation after cold start. NEEDS AIR INJECTION SERVICE KIT (P/N 10115773) AND NEW VEHICLE EMISSION CONTROL LABEL. [198] Engine stall and/or hesitation after cold start. NEEDS AIR INJECTION SERVICE KIT (P/N 10115773) AND NEW VEHICLE EMISSION CONTROL LABEL. [199] Cold stall and chuggle. DO NOT RELY ON THE SCANNER ID TO DETERMINE WHICH PROM IS IN A VEHICLE. LOOK AT THE BCC ON THE PROM TO BE SURE. DO NOT CONFUSE WITH SOME 1991 MODELS WITH A 2.84 AXLE RATIO AND A FEDERAL EMISSIONS PKG. WHICH USED SCANNER ID 5644 BUT HAD A BCC OF AWJD. [200] Cold stall and chuggle. DO NOT RELY ON THE SCANNER ID TO DETERMINE WHICH PROM IS IN A VEHICLE. LOOK AT THE BCC ON THE PROM TO BE SURE. DO NOT CONFUSE WITH SOME 1991 MODELS WITH A 2.84 AXLE RATIO AND A FEDERAL EMISSIONS PKG. WHICH USED SCANNER ID 5644 BUT HAD A BCC OF AWJD. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Expanded Footnotes > Footnotes 1 Thru 50 > Page 4573 PROM - Programmable Read Only Memory: Application and ID Footnotes 201 Thru 250 [201] Cold engine extended crank. USE 16181863 (SCAN I.D. = 0844) FOR COLD START STALL. USE 16181859 (SCAN I.D. = 0834) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [202] Cold engine extended crank. USE 16181863 (SCAN I.D. = 0844) FOR COLD START STALL. USE 16181859 (SCAN I.D. = 0834) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [203] Cold engine extended crank. USE 16181863 (SCAN I.D. = 0844) FOR COLD START STALL. USE 16181859 (SCAN I.D. = 0834) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [204] Cold engine extended crank. USE 16181871 (SCAN I.D. = 0864) FOR COLD START STALL. USE 16181867 (SCAN I.D. = 0854) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [205] Cold engine extended crank. USE 16181871 (SCAN I.D. = 0864) FOR COLD START STALL. USE 16181867 (SCAN I.D. = 0854) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [206] Cold stall and chuggle. DO NOT RELY ON THE SCANNER ID TO DETERMINE WHICH PROM IS IN A VEHICLE. LOOK AT THE BCC ON THE PROM TO BE SURE. DO NOT CONFUSE WITH SOME 1991 MODELS WITH A 2.84 AXLE RATIO AND A FEDERAL EMISSIONS PKG. WHICH USED SCANNER ID 5644 BUT HAD A BCC OF AWJD. [207] Cold engine extended crank. USE 16165848 (SCAN I.D. = 5614) FOR COLD START STALL. USE 16165843 (SCAN I.D. = 5624) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [208] Cold engine extended crank. USE 16165839 (SCAN I.D. = 5634) FOR COLD START STALL. USE 16165829 (SCAN I.D. = 5644) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [209] Cold engine extended crank. USE 16165839 (SCAN I.D. = 5634) FOR COLD START STALL. USE 16165829 (SCAN I.D. = 5644) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [210] Cold engine extended crank. USE 16165848 (SCAN I.D. = 5614) FOR COLD START STALL. USE 16165843 (SCAN I.D. = 5624) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [211] Engine stall, long cranks/idle/decel/surge. CANNOT BE USED ON VEHICLES THAT DO NOT HAVE DIGITAL EGR VALVES. [212] Cold stall and chuggle. DO NOT RELY ON THE SCANNER ID TO DETERMINE WHICH PROM IS IN A VEHICLE. LOOK AT THE BCC ON THE PROM TO BE SURE. DO NOT CONFUSE WITH SOME 1991 MODELS WITH A 2.84 AXLE RATIO AND A FEDERAL EMISSIONS PKG. WHICH USED SCANNER ID 5644 BUT HAD A BCC OF AWJD. [213] Cold engine extended crank. USE 16165848 (SCAN I.D. = 5614) FOR COLD START STALL. USE 16165843 (SCAN I.D. = 5624) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [214] Cold engine extended crank. USE 16165839 (SCAN I.D. = 5634) FOR COLD START STALL. USE 16165829 (SCAN I.D. = 5644) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [215] Cold engine extended crank. USE 16165839 (SCAN I.D. = 5634) FOR COLD START STALL. USE 16165829 (SCAN I.D. = 5644) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [216] Cold start extended crank. Engine starts with ignition key cycled. USE 16181883 (SCAN I.D. = 0894) FOR COLD START STALL. USE 16181875 (SCAN I.D. = 0874) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [217] Cold start extended crank, engine starts with ignition key cycled. USE 16181883 (SCAN I.D. = 0894) FOR COLD START STALL. USE 16181875 (SCAN I.D. = 0874) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [218] Cold engine extended crank. USE 16181887 (SCAN I.D. = 0904) FOR COLD START STALL. USE 16181879 (SCAN I.D. = 0884) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [219] Cold engine extended crank. USE 16181887 (SCAN I.D. = 0904) FOR COLD START STALL. USE 16181879 (SCAN I.D. = 0884) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [220] Cold engine extended crank. USE 16165848 (SCAN I.D. = 5614) FOR COLD START STALL. USE 16165843 (SCAN I.D. = 5624) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [221] Surge or chuggle on decel and/or rough idle. PROM CAN ONLY BE USED WITH ECM P/N 16144288. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Expanded Footnotes > Footnotes 1 Thru 50 > Page 4574 [222] Surge or chuggle on decel and/or rough idle. PROM CAN ONLY BE USED WITH ECM P/N 16144288. [223] Engine stall. MANUAL TRANSMISSION CARS SHOULD ALSO BE UPDATED WITH THE CLUTCH ANTICIPATE SWITCH PER DEALER SERVICE BULLETIN NO. 91-472-7C. [224] USE 16165848 (SCAN I.D. = 5614) FOR COLD START STALL. USE 16165843 (SCAN I.D. = 5624) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [225] USE 16165839 (SCAN I.D. = 5634) FOR COLD START STALL. USE 16165829 (SCAN I.D. = 5644) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [226] USE 16165839 (SCAN I.D. = 5634) FOR COLD START STALL. USE 16165829 (SCAN I.D. = 5644) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [227] Cold engine extended crank. USE 16165848 (SCAN I.D. = 5614) FOR COLD START STALL. USE 16165843 (SCAN I.D. = 5624) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [228] Cold engine extended crank. USE 16165839 (SCAN I.D. = 5634) FOR COLD START STALL. USE 16165829 (SCAN I.D. = 5644) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [229] Cold engine extended crank. USE 16165839 (SCAN I.D. = 5634) FOR COLD START STALL. USE 16165829 (SCAN I.D. = 5644) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [230] Surge or chuggle on decel and/or rough idle. PROM CAN ONLY BE USED WITH ECM P/N 16144288. [231] MAKE CERTAIN THE VEHICLE HAS BEEN UPDATED WITH PREVIOUSLY ATTEMPTED SERVICE FIXES AS FOLLOWS: EGR VALVE P/N 17090156 (STAMPED ON VALVE) 17112373 (GMSPO KIT), PCV VALVE P/N 25098542, ESC MODULE P/N 16175099 (BCC=BARC). [232] Driveability improvements. MAKE CERTAIN THE VEHICLE HAS BEEN UPDATED WITH PREVIOUSLY ATTEMPTED SERVICE FIXES AS FOLLOWS: EGR VALVE P/N 17090156 (STAMPED ON VALVE) 17112373 (GMSPO KIT), PCV VALVE P/N 25098542, ESC MODULE P/N 16175099 (BCC=BARC). [233] Driveability improvements. MAKE CERTAIN THE VEHICLE HAS BEEN UPDATED WITH PREVIOUSLY ATTEMPTED SERVICE FIXES AS FOLLOWS: EGR VALVE P/N 17090156 (STAMPED ON VALVE) 17112373 (GMSPO KIT), PCV VALVE P/N 25098542, ESC MODULE P/N 16175099 (BCC=BARC). [234] Driveablity improvements. MAKE CERTAIN THE VEHICLE HAS BEEN UPDATED WITH PREVIOUSLY ATTEMPTED SERVICE FIXES AS FOLLOWS: EGR VALVE P/N 17090156 (STAMPED ON VALVE) 17112373 (GMSPO KIT), PCV VALVE P/N 25098542, ESC MODULE P/N 16175099 (BCC=BARC). [235] Driveability improvements. MAKE CERTAIN THE VEHICLE HAS BEEN UPDATED WITH PREVIOUSLY ATTEMPTED SERVICE FIXES AS FOLLOWS: EGR VALVE P/N 17090156 (STAMPED ON VALVE) 17112373 (GMSPO KIT), PCV VALVE P/N 25098542, ESC MODULE P/N 16175099 (BCC=BARC). [236] Center Port Fuel Injection noise. FOR VEHICLES WITH SLEEVE BEARING ENGINES. [237] Neutral gear rattle only. COMBINATION DETONATION AND NEUTRAL GEAR RATTLE PROM AVAILABLE. [238] Driveability improvements. MAKE CERTAIN THE VEHICLE HAS BEEN UPDATED WITH PREVIOUSLY ATTEMPTED SERVICE FIXES AS FOLLOWS: EGR VALVE P/N 17090156 (STAMPED ON VALVE) 17112373 (GMSPO KIT), PCV VALVE P/N 25098542, ESC MODULE P/N 16175099 (BCC=BARC). [239] TCC chuggle. MODEL 2DDM TRANSMISSIONS - CHECK DEALER RECORDS TO SEE IF THE TORQUE CONVERTER HAS ALREADY BEEN REPLACED WITH P/N 8650935 (TAGGED BCC: DGAF). TRANS. WITH TORQUE CONVERTERS WITH P/N 8656959 (TAGGED BCC: DG5F) NEED TO REPLACE IT WITH P/N 8650935. [240] Unstable idle in park or neutral/poor driveability. FOR DEDICATED NATURAL GAS VEHICLES. ORDER WITH KIT P/N 12545589 UNLESS THE ONLY PROBLEM IS IDLE FLUCTUATION. [241] Driveability improvements. MAKE CERTAIN THE VEHICLE HAS BEEN UPDATED WITH PREVIOUSLY ATTEMPTED SERVICE FIXES AS FOLLOWS: EGR VALVE P/N 17090156 (STAMPED ON VALVE) 17112373 (GMSPO KIT), PCV VALVE P/N 25098542, ESC MODULE P/N 16175099 (BCC=BARC). [242] Information on PROM calibrations. CANNOT BE USED ON VEHICLES THAT DO NOT HAVE DIGITAL EGR VALVES. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Expanded Footnotes > Footnotes 1 Thru 50 > Page 4575 [243] TCC chuggle. MODEL 2DDM TRANSMISSIONS - CHECK DEALER RECORDS TO SEE IF THE TORQUE CONVERTER HAS ALREADY BEEN REPLACED WITH P/N 8650935 (TAGGED BCC: DGAF). TRANS. WITH TORQUE CONVERTERS WITH P/N 8656959 (TAGGED BCC: DG5F) NEED TO REPLACE IT WITH P/N 8650935. [244] TCC chuggle. MODEL 2DDM TRANSMISSIONS - CHECK DEALER RECORDS TO SEE IF THE TORQUE CONVERTER HAS ALREADY BEEN REPLACED WITH P/N 8650935 (TAGGED BCC: DGAF). TRANS. WITH TORQUE CONVERTERS WITH P/N 8656959 (TAGGED BCC: DG5F) NEED TO REPLACE IT WITH P/N 8650935. [245] Tip-in hesitation on acceleration; engine stall or sag on cold start; engine stall on deceleration; check engine light with CODES 23,25,33, or 34; or engine speed flare on declutch operation with manual transmission equipped vehicle. [246] Tip-in hesitation on acceleration; engine stall or sag on cold start; engine stall on deceleration; check engine light with CODES 23,25,33, or 34; or engine speed flare on declutch operation with manual transmission equipped vehicle. [247] Check engine light comes on while idling on vehicles equipped with Computer Controlled Emission System (C.C.E.S.), driven in altitudes above 3000 feet. [248] Engine may stop running during parking maneuver or during coast down at low speeds during ambient temperature above 85°F. [249] Tip-in hesitation on acceleration; engine stall or sag on cold start; engine stall on deceleration; check engine light with CODES 23,25,33, or 34; or engine speed flare on declutch operation with manual transmission equipped vehicle. [250] Surge on acceleration and/or at road load speeds, false "Service Engine Soon" light (CODE 32), poor driveability during warm up, Detonation under load. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Expanded Footnotes > Footnotes 1 Thru 50 > Page 4576 PROM - Programmable Read Only Memory: Application and ID Footnotes 251 Thru 300 [251] Hesitation or sag during the first two minutes of cold operation while vehicle is under moderate to heavy throttle drive away, or TCC chuggle. [252] Cold start-stall, hesitation, or sag when the engine coolant is between 36°F to 111°F (2°C to 44°C); or Inadequate AC performance when driving at a steady speed and throttle position, between 24 to 64 MPH, when the cruise control is not being used. [253] Lack of throttle response on trucks equipped with governors; or hot restart driveaway sag, both governor and non-governor trucks. [254] Intermittent stall after cold start; engine stalling on coast down; hesitation cold; or ECM CODES E22,E26,E32,E55,E70, and/or E85 [255] PROM I.D. 7080 KJ is also acceptable for PROM I.D. 5853 KJ only. Requires Throttle body service P/N 17067144, EGR valve] service P/N 17067108 (FED), 17067144 (CAL), Injector service kit P/N 17067976. [256] Requires Throttle body service P/N 17067142, EGR valve service P/N 17067107 (FED), 17068210 (CAL), Injector service kit P/N 17067976. [257] FOR CHUGGLE AT 40-45 CONDITION, USE PROM ONLY. FOR TIP-IN HESITATION ONLY, USE EGR VALVE ONLY - P/N 17078431. FOR COLD DRIVEABILITY HESITATION, USE BOTH PROM AND EGR. [258] REQUIRES SUPPLEMENTARY TUNE-UP LABEL, SPARK BYPASS RELAY KIT P/N 015 14086983, SPARK PLUGS P/N 5614009, SUN VISOR STARTING LABEL P/N 015 14085150. ALSO, REMOVE AND DISCARD FUSE LABELED "CRANK" FROM FUSE BLK #2 POSITION (3 AMP. FUSE). [259] DO NOT RELY ON THE SCANNER ID TO DETERMINE WHICH PROM IS IN A VEHICLE. LOOK AT THE BCC ON THE PROM TO BE SURE. DO NOT CONFUSE WITH SOME 1991 MODELS WITH A 2.84 AXLE RATIO AND A FEDERAL EMISSIONS PACKAGE WITH USED SCANNER ID 5644 BUT HAD A [260] DO NOT RELY ON THE SCANNER ID TO DETERMINE WHICH PROM IS IN A VEHICLE. LOOK AT THE BCC ON THE PROM TO BE SURE. DO NOT CONFUSE WITH SOME 1991 MODELS WITH A 2.84 AXLE RATIO AND A FEDERAL EMISSIONS PACKAGE WITH USED SCANNER ID 5644 BUT HAD A [261] DO NOT RELY ON THE SCANNER ID TO DETERMINE WHICH PROM IS IN A VEHICLE. LOOK AT THE BCC ON THE PROM TO BE SURE. DO NOT CONFUSE WITH SOME 1991 MODELS WITH A 2.84 AXLE RATIO AND A FEDERAL EMISSIONS PACKAGE WITH USED SCANNER ID 5644 BUT HAD A [262] MAKE CERTAIN THE VEHICLE HAS BEEN UPDATED WITH PREVIOUSLY AT TEMPTED SERVICE FIXES AS FOLLOWS: EGR VALVE P/N 17090156 (STAMPED ON VALVE) 17112373 (GMSPO KIT), PCV VALVE P/N 25098542, ESC MODULE P/N 16175099 (BCC=BARC). [263] MAKE CERTAIN THE VEHICLE HAS BEEN UPDATED WITH PREVIOUSLY ATTEMPTED SERVICE FIXES AS FOLLOWS: EGR VALVE P/N 17090156 (STAMPED ON VALVE) 17112373 (GMSPO KIT), PCV VALVE P/N 25098542, ESC MODULE P/N 16175099 (BCC=BARC). [264] MODEL 2DDM TRANS. CARS - CHECK DLR. RECORDS TO SEE IF THE TORQUE CONVERTER HAS ALREADY BEEN REPLACED WITH PN 8650935 (BCC: DGAF). TRANSMISSIONS WITH TORQUE CONVERTERS WITH PN 8656959 (BCC: DG5F) NEED TO HAVE THE TORQUE CONVERTER REPLACED W [265] MODEL 2DDM TRANS. CARS - CHECK DLR. RECORDS TO SEE IF THE TORQUE CONVERTER HAS ALREADY BEEN REPLACED WITH PN 8650935 (BCC: DGAF). TRANSMISSIONS WITH TORQUE CONVERTERS WITH PN 8656959 (BCC: DG5F) NEED TO HAVE THE TORQUE CONVERTER REPLACED W [266] Vehicles equipped with Computer Controlled Emission System (C.C.E.S) experience a Check Engine Light coming on while idling, usually when idling time exceeds 2 minutes with transmission in gear in altitudes above 3000 feet. [267] Cold driveability, use with PROM 5854 KJ (G057). PROM I.D. 7080 KJ IS ALSO ACCEPTABLE FOR PROM I.D. 5853 KJ ONLY. REQUIRES THROTTLE BODY SERVICE P/N 17067144, EGR VALVE SERVICE P/N 17067108 (FED), 17067144 (CAL), INJECTOR SERVICE KIT P/N 17067976. [268] Cold driveability, use with PROM 5853 KJ (G057). PROM I.D. 7079 KJ IS ALSO ACCEPTABLE FOR PROM I.D. 5854 KJ ONLY. REQUIRES THROTTLE BODY SERVICE P/N 17067144, EGR VALVE SERVICE P/N 17067108 (FED), 17067144 (CAL), INJECTOR SERVICE KIT P/N 17067976. [269] Cold driveability, use with PROM 5861 KK (G057). REQUIRES THROTTLE BODY SERVICE P/N 17067142, EGR VALVE SERVICE P/N 17067107 (FED), 17068210 (CAL), INJECTOR SERVICE KIT P/N 17067976. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Expanded Footnotes > Footnotes 1 Thru 50 > Page 4577 [270] Cold driveability, use with PROM 5860 KK (G057). REQUIRES THROTTLE BODY SERVICE P/N 17067142, EGR VALVE SERVICE P/N 17067107 (FED), 17068210 (CAL), INJECTOR SERVICE KIT P/N 17067976. [271] Tip-in hesitation, lack low speed performance. Used with Manual transaxle vehicles with A/C only. Requires EGR TVS P/N 373510, and A.I.R. valve P/N 17082701. [272] Weak drive-away after cold start, requires EGR TVS P/N 373510. Also, for CALIFORNIA emissions, manual transaxle, replace A.I.R. management valve with PN 17082701. [273] Level road surge, tip-in hesitation, lack of low speed performance - for automatic transaxles only. (Requires EGR valve P/N 17068212). FOR FEDERAL - USE 01226055. FOR CALIFORNIA - USE 01226057. [274] Stall in coast down with clutch disengaged and A/C on, weak drive away after cold start , requires EGR TVS P/N 373510. Also, for CALIFORNIA emissions, manual transaxle, replace A.I.R. management valve with PN 17082701. [275] Idle shake, detonation (G043). FOR 2.5L EFI, AUTOMATIC TRANSAXLE, AND FIRST DESIGN (3-BOARD) ECM. THE SECOND DESIGN (2-BOARD) ECM HAS THE SPARK REVISION ALREADY INCORPORATED IN ITS PROM. [276] Chuggle/surge at 40-45 MPH, tip-in hesitation/sag, spark knock, requires EGR valve (G032). FOR CHUGGLE AT 40-45 CONDITION, USE PROM ONLY. FOR TIP-IN HESITATION ONLY, USE EGR VALVE ONLY - P/N 17078431. FOR COLD DRIVEABILITY HESITATION, USE BOTH PROM AND EGR. [277] Chuggle and surge at 35-55 MPH, requires EGR kit. REQUIRES KIT P/N 25522748 CONTAINING: WIRING HARNESS JUMPER P/N 12043500, RELAY P/N 25522747, FOAM P/N 25522723, EGR P/N 17079799. [278] CODE 42, spark knock, cold startability, plug fouling (G040). REQUIRES SUPPLEMENTARY TUNE-UP LABEL, SPARK BYPASS RELAY KIT P/N 14086983, SPARK PLUGS P/N 5614009, SUN VISOR STARTING LABEL P/N 14085150. ALSO, REMOVE AND DISCARD FUSE LABELED "CRANK" FROM FUSE BLK #2 POSITION (3 AMP. FUSE). [279] Chuggle and surge at 35-55 MPH, requires EGR kit (G040). REQUIRES KIT P/N 25522748 CONTAINING: WIRING HARNESS JUMPER P/N 12043500, RELAY P/N 25522747, FOAM P/N 25522723, EGR P/N 17079799. [280] Cold hesitation/sag, warm surge (G082). RETROFIT PROM SUPERSEDES ALL PREVIOUS SERVICE PROM PART NUMBERS. TO BE USED AS BOTH THE REGULAR SERVICE REPLACEMENT (PROM-DAMAGED OF DEFECTIVE), AND TO RESOLVE CASES OF CHUGGLE, DETONATION, OR FLATNESS. [281] TCC chuggle or surge (G043). WHEN INSTALLING PROM IN A CANADIAN 1985 NB, A CODE 13 WILL OCCUR AS THE VEHICLE WAS NOT EQUIPPED WITH AN O2 SENSOR. TO ELIMINATE THE CODE 13, NEED TO INSTALL O2 SENSOR # 8990741 AND CONNECT TO THE EXISTING PURPLE WIRE AND CONNECTOR IN THE [282] Surge or chuggle at 52-60 MPH (G071). RETROFIT PROM - DOES NOT SUPERSEDE THE REGULAR REPLACEMENT SERVICE PROM. TO BE USED ONLY AS REQUIRED TO RESOLVE CASES OF CHUGGLE. [283] Surge or chuggle at 52-60 MPH (G071). RETROFIT PROM - SUPERSEDES ALL PREVIOUS SERVICE PROM PART NUMBERS. TO BE USED AS BOTH THE REGULAR SERVICE REPLACEMENT (PROM-DAMAGED OR DEFECTIVE), AND TO RESOLVE CASES OF CHUGGLE. [284] Chuggle, hesitation, tip-in spark knock. RETROFIT PROM - SUPERSEDES ALL PREVIOUS SERVICE PROM PART NUMBERS. TO BE USED AS BOTH THE REGULAR SERVICE REPLACEMENT (PROM-DAMAGED OR DEFECTIVE), AND TO RESOLVE CASES OF CHUGGLE, DETONATION, OR FLATNESS. [285] Chuggle, hesitation, tip-in spark knock. RETROFIT PROM - DOES NOT SUPERSEDE THE REGULAR REPLACEMENT SERVICE PROMS. TO BE USED ONLY AS REQUIRED TO RESOLVE CASES OF CHUGGLE, DETONATION, OR FLATNESS. [286] FOR USE WITH P215/65 TIRES - USE 01228290 (SCAN I.D. = 8290). FOR USE WITH P235/60, P245/50 TIRES - USE 01228291 (SCAN I.D. = 8291). [287] FOR USE WITH P215/65 TIRES - USE 01228292 (SCAN I.D. = 8292). FOR USE WITH P235/60, P245/50 TIRES - USE 01228293 (SCAN I.D. = 8293). [288] FALSE CODES 33, 34, 43, rough idle, chuggle, hesitation (G006,G007). USED WITH VIN #119016 OR LATER ALUMINUM HEAD CORVETTES AND ALL CONVERTIBLE MODELS WITH AUTOMATIC TRANSMISSION, 2.59 (GM1) AXLE ONLY. [289] FALSE CODES 33, 34, 43, rough idle, chuggle, hesitation (G006,G007). USED FOR VIN #119016 OR LATER ALUMINUM HAED CORVETTES AND ALL CONVERTIBLE MODELS WITH AUTOMATIC TRANSMISSION, 2.73 (GU2)/3.07 (G44) AXLE ONLY. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Expanded Footnotes > Footnotes 1 Thru 50 > Page 4578 [290] Spark knock. USE 16143570 (SCAN I.D. = 3531) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093526). USE 16143459 (SCAN I.D. = 3571) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [291] Spark knock. USE 16143455 (SCAN I.D. = 3511) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093526). USE 16143453 (SCAN I.D. = 3501) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [292] Spark knock (G055). USE 16143575 (SCAN I.D. = 3541) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764). USE 16143460 (SCAN I.D. = 3581) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [293] Spark knock (G043). USE 16143580 (SCAN I.D. = 3551) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764). USE 16143462 (SCAN I.D. = 3591) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [294] Stalling, tip-in hesitation/sag, rough idle, cold driveability. USE 16143575 (SCAN I.D. = 3541) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764). USE 16143460 (SCAN I.D. = 3581) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [295] Hard hot restart (requires rubber bumper pkg PN 25004553, and a pulsator package PN 25094266), or CODE 42, intermittent high idle, spark knock (G055). [296] USE 16143575 (SCAN I.D. = 3541) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764). USE 16143460 (SCAN I.D. = 3581) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [297] USE 16143570 (SCAN I.D. = 3531) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093526). USE 16143459 (SCAN I.D. = 3571) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [298] USE 16143455 (SCAN I.D. = 3511) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093526). USE 16143453 (SCAN I.D. = 3501) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [299] USE 16143455 (SCAN I.D. = 3511) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093526). USE 16143453 (SCAN I.D. = 3501) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [300] Spark knock. USE 16143457 (SCAN I.D. = 3521) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115925, FUEL SENDER P/N 25092778). USE 16143466 (SCAN I.D. = 3481) FOR CODE 42, SPARK KNOCK, HIGH IDLE. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Expanded Footnotes > Footnotes 1 Thru 50 > Page 4579 PROM - Programmable Read Only Memory: Application and ID Footnotes 301 Thru 350 [301] Spark knock. USE 16143452 (SCAN I.D. = 3491) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115925, FUEL SENDER P/N 25092778). USE 16143463 (SCAN I.D. = 3451) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [302] Hard start hot (requires installation of a rubber bumper pkg PN 25004553, and a pulsator pkg PN 25094266) or CODE 42, high idle, spark knock (G055). [303] USE 16143457 (SCAN I.D. = 3521) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115925, FUEL SENDER P/N 25092778). USE 16143466 (SCAN I.D. = 3481) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [304] Hard hot restart (requires rubber bumper pkg PN 25004553, and a pulsator package PN 25094266), or CODE 42, intermittent high idle, spark knock (G055). [305] USE 16143452 (SCAN I.D. = 3491) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115925, FUEL SENDER P/N 25092778). USE 16143463 (SCAN I.D. = 3451) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [306] Tip-in hesitation,stall,CODES 23,25,33,or 34, or speed flare on declutch op. w/man. trans. (CODE 23 or 25 require MAT sensor model year diagnostics) (G027). WITH THIS PROM INSTALLED, USE 1987-88 2.8L SPEED DENSITY ENGINE DRIVEABILITY AND EMISSIONS MANUAL. [307] CODES 23, 25, 33, 34, driveability and stalling (G027). PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [308] Tip-in hesitation,stall,CODES 23,25,33,or 34, or speed flare on declutch op. w/man. trans. (CODE 23 or 25 require MAT sensor model year diagnostics). PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [309] Code 23, 25, 33, 34, driveability and stalling. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [310] Tip-in hesitation,stall,CODES 23,25,33,or 34, or speed flare on declutch op. w/man. trans. (CODE 23 or 25 require MAT sensor model year diagnostics) (G027). PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [311] High emissions, exhaust odor, starting and driveability problems (G046). Requires Connector Bleed Assembly P/N 10105820 [312] FALSE CODES 43, 54, unstable idle. FOR 2.73 (GU2) AXLE USE 16120077 (SCAN I.D. = 9891). FOR 3.08 (GU4) AXLE USE 16120082 (SCAN I.D. = 9901). FOR 3.42 (GU6) AND 3.73 (GT4) AXLES USE 16120086 (SCAN I.D. = 9911). [313] Running change. FOR FALSE CODE 44 ON LONG COAST DOWN, USE RETROFIT SERVICE PROM 01228486 SCAN I.D. 8486, AAND 1050. FOR REGULAR SERVICE REPLACEMENT, USE PROM 16062797 SCAN I.D. 2223, AAND 2798. [314] Running change. FOR FALSE CODE 44 ON LONG COAST DOWN, USE RETROFIT SERVICE PROM 01228487 SCAN I.D. 8487, AANF 1052. FOR REGULAR SERVICE REPLACEMENT, USE PROM 16062801 SCAN I.D. 2233, AANF 2802. [315] Surge on acceleration and/or at road load speeds, false "Service Engine Soon" light (CODE 32), poor driveability during warm up, Detonation under load (G052). [316] Spark knock. USE 16143570 (SCAN I.D. = 3531) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093526). USE 16143459 (SCAN I.D. = 3571) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [317] Spark knock. USE 16143455 (SCAN I.D. = 3511) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093526). USE 16143453 (SCAN I.D. = 3501) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [318] Spark knock (G043). USE 16143580 (SCAN I.D. = 3551) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764). USE 16143462 (SCAN I.D. = 3591) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [319] Spark knock (G055). USE 16143545 (SCAN I.D. = 3461) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093744). USE 16143465 (SCAN I.D. = 3471) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [320] CODE 42, spark knock, intermittent high idle. IF MAJOR CONDITION IS HARD HOT ENGINE RESTART, PROM ALSO REQUIRES INSTALLATION OF A RUBBER BUMPER PKG PN 25004553, AND PULSATOR PKG PN 25094266. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Expanded Footnotes > Footnotes 1 Thru 50 > Page 4580 [321] USE 16143545 (SCAN I.D. = 3461) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093744). USE 16143465 (SCAN I.D. = 3471) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [322] USE 16143570 (SCAN I.D. = 3531) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093526). USE 16143459 (SCAN I.D. = 3571) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [323] USE 16143455 (SCAN I.D. = 3511) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115764, FUEL SENDER P/N 25093526). USE 16143453 (SCAN I.D. = 3501) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [324] Spark knock. USE 16143457 (SCAN I.D. = 3521) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115925, FUEL SENDER P/N 25092778). USE 16143466 (SCAN I.D. = 3481) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [325] Spark knock. USE 16143452 (SCAN I.D. = 3491) FOR HOT HARD RESTART (REQUIRES FUEL PUMP P/N 25115925, FUEL SENDER P/N 25092778). USE 16143463 (SCAN I.D. = 3451) FOR CODE 42, SPARK KNOCK, HIGH IDLE. [326] Tip-in hesitation, stall, CODES 23, 25, 33, or 34, or speed flare on declutch op. w/man. trans. (CODE 23 or 25 require MAT sensor model year diagnostics) (G027). WITH THIS PROM INSTALLED, USE 1987-88 2.8L SPEED DENSITY ENGINE DRIVEABILITY AND EMISSIONS MANUAL. [327] CODES 23, 25, 33, 34. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [328] Tip-in hesitation,stall,CODES 23,25,33,or 34, or speed flare on declutch op. w/ man. trans. (CODE 23 or 25 require MAT sensor model year diagnostics). PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [329] Tip-in hesitation,stall,CODES 23,25,33,or 34, or speed flare on declutch op. w/ man. trans. (CODE 23 or 25 require MAT sensor model year diagnostics) (G027). PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [330] CODES 23, 25, 33, 34, driveability and stalling (G027). PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [331] Code 23, 25, 33, 34, driveability and stalling. PROM UPDATE ELIMINATES MAF SENSOR, REPLACING IT WITH A SPEED DENSITY SYSTEM. WITH A 1990 OR EARLIER PRIMARY CARTRIDGE, I.D. VEHICLE ON SCANNER AS A 1989 MODEL (VIN = K-1-W). [332] FOR USE WITH MODEL C1 TRUCKS - USE 16121162 (SCAN I.D. = 3511). FOR USE WITH MODEL C2, K, K2, AND K1000 TRUCKS USE 16121166 (SCAN I.D. = 3521). [333] Surge on acceleration and/or at road load speeds, false "Service Engine Soon" light (CODE 32), poor driveability during warm up, Detonation under load (G052). [334] Cold engine extended crank. USE 16181863 (SCAN I.D. = 0844) FOR COLD START STALL. USE 16181859 (SCAN I.D. = 0834) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [335] [Cold engine extended crank. USE 16181871 (SCAN I.D. = 0864) FOR COLD START STALL. USE 16181867 (SCAN I.D. = 0854) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [336] Engine does not stay running on initial cold start and chuggle at 35-45 MPH with TCC engaged. New MEM-CAL may affect fuel economy. DO NOT RELY ON THE SCANNER ID TO DETERMINE WHICH PROM IS IN A VEHICLE. LOOK AT THE BCC ON THE PROM TO BE SURE. DO NOT CONFUSE WITH SOME 1991 MODELS WITH A 2.84 AXLE RATIO AND A FEDERAL EMISSIONS PACKAGE WITH SCANNER ID 5644 BUT A BCC OF A] [337] Cold engine extended crank. USE 16165848 (SCAN I.D. = 5614) FOR COLD START STALL. USE 16165843 (SCAN I.D. = 5624) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [338] Cold engine extended crank. USE 16165839 (SCAN I.D. = 5634) FOR COLD START STALL. USE 16165829 (SCAN I.D. = 5644) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [339] Cold engine extended crank. USE 16165839 (SCAN I.D. = 5634) FOR COLD START STALL. USE 16165829 (SCAN I.D. = 5644) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [340] Cold engine extended crank. USE 16165848 (SCAN I.D. = 5614) FOR COLD START STALL. USE 16165843 (SCAN I.D. = 5624) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Expanded Footnotes > Footnotes 1 Thru 50 > Page 4581 [341] Hesitation or sag during the first two minutes of cold operation while vehicle is under moderate to heavy throttle driveaway, or TCC chuggle. [342] Cold start-stall, hesitation, or sag when the engine coolant is between 36°F - 111°F (2°C 44°C); or Inadequate A/C performance when driving at steady speed and throttle position, between 24 - 64 MPH, when the cruise control is not being used. [343] Engine does not stay running on initial cold start and chuggle at 35-45 MPH with TCC engaged. New MEM-CAL may affect fuel economy. DO NOT RELY ON THE SCANNER ID TO DETERMINE WHICH PROM IS IN A VEHICLE. LOOK AT THE BCC ON THE PROM TO BE SURE. DO NOT CONFUSE WITH SOME 1991 MODELS WITH A 2.84 AXLE RATIO AND A FEDERAL EMISSIONS PACKAGE WITH SCANNER ID 5644 BUT A BCC OF A [344] Cold engine extended crank. USE 16165848 (SCAN I.D. = 5614) FOR COLD START STALL. USE 16165843 (SCAN I.D. = 5624) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [345] Cold engine extended crank. USE 16165839 (SCAN I.D. = 5634) FOR COLD START STALL. USE 16165829 (SCAN I.D. = 5644) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [346] Cold engine extended crank. USE 16181883 (SCAN I.D. = 0894) FOR COLD START STALL. USE 16181875 (SCAN I.D. = 0874) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [347] Cold engine extended crank. USE 16181887 (SCAN I.D. = 0904) FOR COLD START STALL. USE 16181879 (SCAN I.D. = 0884) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [348] Service Engine Soon light (SES) with a code 43 or tip-in sag, tip-in hesitation, surge at WOT, or spark detonation when cold. [349] Engine stall. MANUAL TRANSMISSION CARS SHOULD ALSO BE UPDATED WITH THE CLUTCH ANTICIPATE SWITCH PER DEALER SERVICE BULLETIN NO. 91-472-7C. [350] Engine does not stay running on initial cold start and chuggle at 35-45 MPH with TCC engaged. New MEM-CAL may affect fuel economy. DO NOT RELY ON THE SCANNER ID TO DETERMINE WHICH PROM IS IN A VEHICLE. LOOK AT THE BCC ON THE PROM TO BE SURE. DO NOT CONFUSE WITH SOME 1991 MODELS WITH A 2.84 AXLE RATIO AND A FEDERAL EMISSIONS PACKAGE WITH SCANNER ID 5644 BUT A BCC OF A. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Expanded Footnotes > Footnotes 1 Thru 50 > Page 4582 PROM - Programmable Read Only Memory: Application and ID Footnotes 351 Thru 400 [351] USE 16165848 (SCAN I.D. = 5614) FOR COLD START STALL. USE 16165843 (SCAN I.D. = 5624) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [352] USE 16165839 (SCAN I.D. = 5634) FOR COLD START STALL. USE 16165829 (SCAN I.D. = 5644) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [353] Cold engine extended crank. USE 16165839 (SCAN I.D. = 5634) FOR COLD START STALL. USE 16165829 (SCAN I.D. = 5644) ONLY IF REQUIRED TO SOLVE BOTH COLD START STALL AND CHUGGLE. [354] Lack of throttle response on trucks equipped with governors; or hot restart driveaway sag, both governor and non-governor trucks. [355] Low speed driveability or detonation. MAKE CERTAIN THE VEHICLE HAS BEEN UPDATED WITH PREVIOUSLY ATTEMPTED SERVICE FIXES AS FOLLOWS: EGR VALVE P/N 17090156 (STAMPED ON VALVE) 17112373 (GMSPO KIT), PCV VALVE P/N 25098542, ESC MODULE P/N 16175099 (BCC=BARC). [356] Tip-in hesitation, sag, backfire, spark knock. MAKE CERTAIN THE VEHICLE HAS BEEN UPDATED WITH PREVIOUSLY ATTEMPTED SERVICE FIXES AS FOLLOWS: EGR VALVE P/N 17090156 (STAMPED ON VALVE) 17112373 (GMSPO KIT), PCV VALVE P/N 25098542, ESC MODULE P/N 16175099 (BCC=BARC). [357] Hesitation or sag during the first two minutes of cold operation while vehicle is under moderate to heavy throttle driveaway, or TCC chuggle. [358] Sustained detonation/knock. AUTOMATIC TRANSMISSIONS REQUIRE TORQUE CONVERTER CLUTCH (TCC) CALIBRATION. USE OF THIS PROM IN A NON-DETONATING ENGINE MAY RESULT IN DEGRADED DRIVEABILITY. [359] High emissions, exhaust odor, starting and driveability problems (G046). Requires Connector Bleed Assembly P/N 10105820 [360] Neutral gear rattle. MAY ALSO REQUIRE CLUTCH DRIVEN PLATE P/N 15961141, AND CLUTCH PILOT BEARING P/N 14061685. COMBINATION DETONATION AND NEUTRAL GEAR RATTLE PROM AVAILABLE. [361] Malfunction Indicator Lamp (check engine light) illuminates and may set a DTC 24 (VSS Circuit Fault) during a California State Emissions Test. [362] Higher than normal hydrocarbon emissions during the idle portion of the inspection and maintenance test. Also, may exhibit a slight detonation during a light throttle acceleration [363] TCC chuggle. MODEL 2DDM TRANS. - CHECK DEALER RECORDS TO SEE IF THE TORQUE CONVERTER HAS BEEN REPLACED WITH P/N 8650935 (BCC: DGAF). TRANS. WITH TORQUE CONVERTERS WITH P/N 8656959 (BCC: DG5F) NEED TO HAVE THE TORQUE CONVERTER REPLACED WITH P/N 8650935. [364] Cold start stall, cold tip in hesitation and/or a cold rough idle after extended idling. Additionally, in 40-50°F ambient temp., fogging on the inside of the front windshield which does not clear with the defroster on occurs. [365] Poor throttle response, stall, misfire, poor cold or hot start, extended crank of the starter with a hot engine, and/or vehicle will start and then stall when the engine is hot. MT vehicles may also experience decel. stall and poor accel. performance. [366] Poor throttle response, stalling, misfire, poor cold or hot starting, extended cranking of the starter with a hot engine, and/or vehicle will start and then stall when the engine is hot. USED WITH MANUAL TRANSMISSION ONLY. [367] MIL illuminates and/or store a DTC 32 (EGR error) with no noticeable driveability concern, usually occurring while climbing a grade. [368] MIL illuminates and/or store a DTC 32 (EGR error) with no noticeable driveability concern, usually occurring while climbing a grade, towing a trailer or driving into a strong head wind. [369] High emissions, exhaust odor, starting and driveability problems (G046). Requires Connector Bleed Assembly P/N 10105820 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Expanded Footnotes > Page 4583 Prom Information Scan Prom Prom Prom Superseding ID Code Bcc Part # ID Part # TSB Reference # 0375 0369 BMTA 16210369 0825 0820 BKFK 16200819 Running change. 4005 4008 BKZM 16204004 Chevrolet 476501 DTC 32. GMC Truck 476501 4565 4570 BHCN 16194569 4575 4573 BHCP 16194572 6605 6533 BHYZ 16196532 Running change. 6905 6856 BJAY 16196854 6985 6887 BJBB 16196884 6995 6892 BJBC 16196890 7465 7466 BJFC 16197464 Running change. 7475 7469 BJFD 16197468 7735 7737 BJHW 16197736 8085 8053 BJLA 16198052 8095 8057 BJLB 16198056 8105 8060 BJLC 16198059 0825 16200819 8371 9367 AYXY 16169366 8465 8494 BDSD 16188493 8475 8511 BDSF 16188510 8535 8642 BDSN 16188640 6605 16196532 8561 9452 AYYX 16169450 8581 9460 AYYZ 16169459 9295 9308 BDWZ 16189307 9305 9312 BDXA 16189310 9335 9324 BDXD 16189323 9365 9336 BDXJ 16189334 9375 9339 BDXK 16189338 9425 9358 BDXR 16189357 9435 9362 BDXS 16189360 7465 16197464 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Application and ID > Expanded Footnotes > Page 4584 9525 9527 BDYT 16189526 9545 9537 BDYW 16189536 9555 9540 BDYX 16189539 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Description and Operation > CALPAK PROM - Programmable Read Only Memory: Description and Operation CALPAK CAUTION: If the computer is found to be defective and needs replacement, remove the old CALPAK and PROM, then place both into the replacement computer. When replacing the COMPUTER always transfer the BROADCAST CODE and PRODUCTION ECM/PCM NUMBER to the service label on the replacement computer. DESCRIPTION: The resistor network calibration called a CALPAK is located inside the computer. Its appearance and service is similar to the PROM. The CALPAK allows fuel to be delivered if other parts of the computer fail. The CALPAK provides the computer with calibrations for: ^ Cold Start Cranking. ^ Limp home fuel (fuel backup mode). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Description and Operation > CALPAK > Page 4587 PROM - Programmable Read Only Memory: Description and Operation EEPROM CAUTION: The EEPROM is soldered to the COMPUTER and cannot be serviced separately. Reprogramming of EEPROM information is necessary when replacing a COMPUTER, or when changing the engine and/or transaxle calibrations. Failure to do this will cause the vehicle to have a no start or poor running condition. It is essential that a replacement COMPUTER be reprogrammed with the correct VIN, option content, tire size, and calibration information. Reprogramming of the EEPROM is only possible with the Service Stall System (SSS) hardware available at authorized dealer locations. Check with a dealer before performing COMPUTER replacement or EEPROM reprogramming. DESCRIPTION: The term EEPROM is defined as Electronically Erasable Programmable Read Only Memory (EEPROM) in the COMPUTER. The EEPROM stores vehicle information such as engine and transaxle calibrations, vehicle identification number, programmable vehicle option content and MALF history. Vehicle information stored on the EEPROM has a major effect on how the vehicle will operate. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Description and Operation > CALPAK > Page 4588 PROM - Programmable Read Only Memory: Description and Operation EPROM CAUTION: The EPROM is serviceable in some applications and can be removed for replacement. If the COMPUTER is found to be defective and needs replacement, remove the old EPROM if applicable and place into the new computer. When replacing the COMPUTER always transfer the BROADCAST CODE and PRODUCTION ECM/PCM NUMBER to the service label on the replacement computer. DESCRIPTION: The term EPROM means Erasable Programmable Read Only Memory (EPROM). The EPROM functions in the same manner as a regular PROM and is programmed with data pertaining to the vehicles weight, engine, transmission, axle ratio etc. Automotive technicians do not ERASE or PROGRAM the EPROM in the field. Instead, the EPROM is serviced in one of two manners. Some applications are soldered to the circuit board and require both the computer and EPROM to be replaced as a complete unit. Other applications allow for the EPROM only to replaced. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Description and Operation > CALPAK > Page 4589 PROM - Programmable Read Only Memory: Description and Operation MEMCAL CAUTION: If the COMPUTER is found to be defective and needs replacement, remove the old MEMCAL and place it into the replacement computer. When replacing the COMPUTER always transfer the BROADCAST CODE and PRODUCTION ECM/PCM NUMBER to the service label on the replacement computer. DESCRIPTION: The MEMCAL assembly contains both the functions of the PROM and the CALPAK. Like the PROM, it contains the calibrations needed for a specific vehicle. It also is the fuel back up control for the computer should it become damaged or faulty. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Description and Operation > CALPAK > Page 4590 PROM - Programmable Read Only Memory: Description and Operation PROM CAUTION: If the computer is found to be defective and needs replacement, remove the old PROM and place it into the replacement computer. Some ECM's are equipped with another chip called a CALPAK. If the computer is equipped with a CALPAK chip, it will be located next to the PROM and must be transferred along with the PROM. When replacing the computer always transfer the BROADCAST CODE and PRODUCTION ECM/PCM NUMBER to the service label on the replacement computer. DESCRIPTION: To allow one type of computer to be used for many different vehicles, a device called a Programable Read Only Memory (PROM) unit is used. The PROM is located inside the computer and has system calibration information based upon the vehicle's axle ratio, engine, transmission, weight, and other specific configurations of the vehicle. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Description and Operation > Page 4591 PROM - Programmable Read Only Memory: Testing and Inspection Some control modules may have problems due to cracked solder joints on the circuit board. These internal control module problems can cause the following symptoms: ^ Failure to start or vehicle is stalling. ^ The "CHECK ENGINE" "SERVICE ENGINE SOON" or "MALFUNCTION INDICATOR" light will flash or light up, but no trouble codes will be present. ^ Vehicle instrument panel displays may be inoperative. ^ The control module may or may not communicate with the scanner. ^ Other intermittent driveability problems. Incorrect PROM or MEMCAL removal and replacement can create solder joint problems or aggravate an existing condition. See PROM or MEMCAL INSTALLATION for proper procedures. If a solder joint problem results in a "hard" failure, normal test procedures will usually pinpoint a faulty control module. Many symptoms caused by poor solder joints in the control module result in intermittent problems, but they may be hard to duplicate during troubleshooting. Control modules with solder joint problems are sensitive to heat and vibration. You can check for these internal control module problems in either, or both, of the following ways: ^ Remove the control module from its mounting bracket and extend it on the harness so that you can expose it to the vehicle heater ducts. Alternatively, use the flexible duct to route air from the heater to the control module location. Then run the engine and operate the heater at the "MAX HEAT" position. This exposes the control module to approximately 140°F. ^ With the engine running, tap on the control module several times with your hand or finger tips to simulate vehicle vibration. If the engine stumbles or stalls, the "CHECK ENGINE" "SERVICE ENGINE SOON" or "MALFUNCTION INDICATOR" light flashes, or any of the previous symptoms occur, the control module may have bad solder joints on the circuit board. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Service and Repair > CALPAK PROM - Programmable Read Only Memory: Service and Repair CALPAK 1. Remove ECM from vehicle. 2. Remove ECM access cover. 3. Remove Calibration Pack (CALPAK) using removal tool shown. Grasp the CALPAK carrier on the narrow ends only. Gently rock the carrier from end to end while applying a firm upward force. 4. Inspect the reference end of the CALPAK carrier and carefully set aside. Do not remove the CALPAK from the carrier to confirm CALPAK correctness. The notch in the CALPAK is referenced to the small notch in the carrier. The small notch of the carrier must be aligned with the small notch in the socket. CAUTION: ANY TIME THE CALPAK IS INSTALLED BACKWARDS AND THE IGNITION SWITCH IS TURNED ON, THE CALPAK IS DESTROYED. 5. Install the CALPACK by pressing on the CALPAK carrier until it is firmly seated in the socket. Do not press on the CALPAK, only the carrier. 6. Install ECM access cover. 7. Install ECM and perform a DIAGNOSTIC CIRCUIT CHECK to confirm proper installation. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Service and Repair > CALPAK > Page 4594 PROM - Programmable Read Only Memory: Service and Repair EEPROM CAUTION: The Erasable Programmable Read Only Memory (EEPROM) is a permanent memory that is physically soldered to the circuit boards within the computer. It is not serviceable and should not be removed for replacement. If COMPUTER replacement is performed, reprogramming of the EEPROM will be necessary. Failure to do this will cause the vehicle to have a no start or poor running condition. Reprogramming of the EEPROM is only possible with the Service Stall System (SSS) hardware available at authorized dealer locations. Check with a dealer before performing COMPUTER replacement or EEPROM reprogramming. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Service and Repair > CALPAK > Page 4595 PROM - Programmable Read Only Memory: Service and Repair EPROM REMOVAL: ^ DO NOT remove an EPROM from its packing material until you are ready to install it. DO NOT hold an EPROM by its pins. ^ Before entering a vehicle to remove or replace an EPROM, touch an exposed metal part of the vehicle to discharge any static charge from your body or use anti-static wrist straps. Avoid sliding across upholstery or carpeting when removing or installing an EPROM. If this is not possible, touch an exposed metal part of the vehicle with your free hand before removing or replacing an EPROM. ^ When available, use an antistatic grounding strap attached to your wrist and clipped to a metal part of the vehicle body to prevent static charges from accumulating. Antistatic conductive floormats are also available. ^ It may be desirable to remove the computer for EPROM replacement. ^ Remove computer access cover. ^ Unlock the locking levers by pressing outward toward the sides of the EPROM. ^ Remove EPROM from its socket INSTALLATION: EPROM/MEM-CAL Unit Installation ^ Install the replacement EPROM in the same direction. ^ VERY GENTLY PRESS down on the ends of the EPROM until the locking levers are rotated toward the sides of the EPROM. ^ NOTE: To avoid Computer damage, do not press on the ends of the EPROM until the levers snap into place. Do not use any vertical force beyond the minimum required to engage the EPROM into its socket. ^ While continuing light pressure on the ends of the EPROM, use your index fingers to press the locking levers inward until they are snapped into place. Listen for the click. ^ Install the access cover on the computer. ^ Perform FUNCTIONAL CHECK Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Service and Repair > CALPAK > Page 4596 PROM - Programmable Read Only Memory: Service and Repair MEMCAL CONDITION: When installing a service replacement computer, the use of incorrect MEMCAL installation procedures may cause the computer to fail before it can be installed in the vehicle. This condition may appear as if the computer were defective when shipped to the dealership, when in fact it was damaged while being installed. In addition this condition may also occur when installing an updated MEMCAL into the vehicles original equipment computer. CAUSE: Excessive vertical force may be applied to the MEMCAL resulting in flexing of the circuit board and damage to the connections between the circuit board and attached components. Excessive vertical force may be generated in two ways. ^ Incorrect MEMCAL installation procedures. ^ Interference between MEMCAL and cover. IMPORTANT CORRECTION: This procedure supersedes any instructions regarding MEMCAL installation dated prior to September 1990. 1. Inspect the MEMCAL to determine if a cork spacer is glued to the top side of the MEMCAL assembly. If so, remove it prior to installation. 2. Align small notches with matching notches in Computer MEMCAL socket. 3. VERY GENTLY PRESS down on the ends of the MEMCAL until the locking levers are rotated toward the sides of the MEMCAL. NOTE: To avoid computer damage, do not press on the ends of the MEMCAL until the levers snap into place. Do not use any vertical force beyond the minimum required to engage the MEMCAL into its socket. 4. While continuing light pressure on the ends of the MEMCAL, use your index fingers to press the locking levers inward until they are snapped into place. Listen for the click. 5. Install MEMCAL cover and install computer cover. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Powertrain Management > PROM - Programmable Read Only Memory > Component Information > Service and Repair > CALPAK > Page 4597 PROM - Programmable Read Only Memory: Service and Repair PROM 1. Remove ECM from vehicle. 2. Remove ECM access cover. PROM Removal 3. Remove PROM using the rocker-type PROM removal tool shown. Engage one end of the PROM carrier with the hook end of the tool. Press on the vertical bar end of the tool and rock the engaged end of the PROM carrier up as far as possible. Engage the opposite end of the PROM carrier in the same manner and rock this end up as far as possible. Repeat this process until the PROM carrier and PROM are free of the PROM socket. The PROM carrier with the PROM in it should lift off of the PROM socket easily. 4. Inspect the reference end of the PROM carrier and carefully set aside. Do not remove the PROM from the carrier to confirm PROM correctness. The notch in the PROM is referenced to the small notch in the carrier. The small notch of the carrier must be aligned with the small notch in the socket. CAUTION: ANY TIME THE PROM IS INSTALLED BACKWARDS AND THE IGNITION SWITCH IS TURNED ON, THE PROM IS DESTROYED. 5. Install PROM by pressing on the PROM carrier until it is firmly seated in the socket. Do not press on the PROM, only the carrier. 6. Install ECM access cover. 7. Install ECM and perform a DIAGNOSTIC CIRCUIT CHECK to confirm proper installation. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Pressure Regulating Solenoid, A/T > Component Information > Description and Operation Pressure Regulating Solenoid: Description and Operation PURPOSE This electrical device, controlled by the PCM, is used to control fluid line pressure. OPERATION The solenoid controls line pressure by controlling actuator feed limit fluid flow acting on internal spool valve and spring pressure. The solenoid is a normally closed solenoid valve that controls fluid pressure when operating on a duty cycle. LOCATION The solenoid is attached to the control valve body within the transmission. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Specifications > Electrical Specifications Shift Solenoid: Electrical Specifications Component Resistance Chart Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Specifications > Electrical Specifications > Page 4608 Shift Solenoid: Mechanical Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Pressure Control Solenoid To Valve Body .......................................................................................... ................................................................................ 8 Solenoid Assembly To Pump .......................... .............................................................................................................................................................. ....... 8 Solenoid Assembly To Case .................................................................................................... ........................................................................................... 18 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Locations > 4L60-E Automatic Transmission Electronic Component Location Views Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Locations > 4L60-E Automatic Transmission > Page 4611 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Description and Operation > 1 -2 Shift Solenoid Shift Solenoid: Description and Operation 1 -2 Shift Solenoid PURPOSE This electrical device, controlled by the PCM, is used to control fluid flow acting on the 1-2 and 3-4 shift valves. OPERATION The solenoid is a normally open exhaust valve that is used with the 2-3 shift solenoid to allow four different shifting combinations. LOCATION The solenoid is attached to the control valve body within the transmission. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Description and Operation > 1 -2 Shift Solenoid > Page 4614 Shift Solenoid: Description and Operation 2-3 Shift Solenoid PURPOSE This electrical device, controlled by the PCM, is used to control fluid flow acting on the 2-3 shift valves. OPERATION The solenoid is a normally open exhaust valve that is used with the 1-2 shift solenoid to allow four different shifting combinations. LOCATION The solenoid is attached to the control valve body within the transmission. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Description and Operation > 1 -2 Shift Solenoid > Page 4615 Shift Solenoid: Description and Operation 3-2 Control Solenoid PURPOSE This electrical device, controlled by the PCM, is used to control fluid flow acting on the 3-2 shift valve, which then controls the 2-4 band apply rate and 3-4 clutch release rate. The solenoid also controls the 3-2 downshift feel. OPERATION The solenoid is a pulse width modulated solenoid that operates on a negative duty cycle. LOCATION The solenoid is attached to the control valve body within the transmission. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission Shift Solenoid: Service and Repair 4L60-E Automatic Transmission Pan and Filter Assembly PAN AND FILTER ASSEMBLY Pan, Filter And Seal Removal CLEAN - Exposed ends of bottom pan screws and spray with penetrating oil. REMOVE OR DISCONNECT 1. Screws (76), oil pan (75) and gasket (73). 2. Oil filter (72) and filter seal (71). - Filter seal may be stuck in the pump. INSPECT - Filter (72), open filter by prying the metal crimping away from the top of the filter (black) and pull apart. The filter may contain evidence for root cause diagnosis. Clutch material. - Bronze slivers indicating bushing wear. - Steel particles. Valve Body and Wiring Harness VALVE BODY AND WIRING HARNESS Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4618 Valve Body Bolt Location Control Valve And Pressure Switch Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4619 Manual Valve Link Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4620 Valve Body Checkballs Case Checkballs And Filters REMOVE OR DISCONNECT 1. Electrical connections from components. 2. TCC PWM Solenoid Retainer Clip (379) and Solenoid (396). 3. TCC Solenoid bolts (68) and solenoid assembly (66) with O-ring seal (65) and wiring harness. 4. Pressure switch assembly bolts (70) and pressure switch assembly (69). 5. Accumulator cover bolts (58 and 59) and 1-2 accumulator cover and pin assembly (57). 6. 1-2 accumulator piston (56) and seal (55). 7. Spring (54). 8. Dipstick stop bracket (93). REMOVE OR DISCONNECT 1. Bolt (64) and manual detent spring assembly (63). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4621 2. Wiring harness retaining bolts. REMOVE OR DISCONNECT 1. Remaining valve body bolts (62). 2. Manual valve link (89). 3. Control valve assembly (60). 4. Bolts (58 and 59), accumulator cover (57), piston (56, spring (54) and spring (54A). 5. Bolts (77) and plate (53). 6. Spacer plate (48) and spacer plate gaskets (47 and 52). 7. Spring (46), piston (44), and pin (43). - Seven checkballs are located under the valve body and one is located in the case. The large copper flash colored ball is # 1A checkball (91). Valve Body and Associated Parts VALVE BODY AND ASSOCIATED PARTS Accumulator Assembly, Spacer Plate And Gaskets Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4622 Case Checkballs And Filters TOOL REQUIRED: - J 25025-5 Guide Pins NOTICE: The use of a honing stone, fine sandpaper or crocus cloth is not recommended for servicing stuck valves. All valve lands have sharply machined corners that are necessary for "cleaning" the bore. If these corners are rounded, foreign material could wedge between the valve and bore causing the valve to stick. If it is found necessary to clean a valve, "micro fine" lapping compound 900 grit or finer should be used. Too much "lapping" of a valve will cause excessive clearances and increase the chance of a valve not operating. INSTALL OR CONNECT 1. The wiring harness pass-thru connector into the case. 2. The 3-4 accumulator pin (43) into the case. 3. The 3-4 accumulator piston seal (45) onto the 3-4 accumulator piston. 4. The 3-4 accumulator piston (44) onto the pin. - The end with three legs must face the valve body. 5. The 3-4 accumulator piston spring (46). INSTALL OR CONNECT 1. Checkball (91) into case as shown. - Retain with Transjel TM J 36850 or equivalent. 2. J 25025-5 into the case. 3. Screens onto spacer plate as shown. 4. Spacer plate to case gasket (47) and spacer plate to valve body gasket (52) onto the spacer plate (48). - Gasket (47) identified by a "C". Gasket (52) identified by a "V". - Retain with Transjel TM J 36850 or equivalent. 5. Spacer plate and gaskets onto the case. IMPORTANT - Be careful not to damage screens when installing the spacer plate and gaskets. 6. Spacer plate support (53) and bolts (77). TIGHTEN - Bolts to 11 Nm (8 lb. ft.) Control Valve Body CONTROL VALVE BODY Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4623 Case Checkballs And Filters Filter Screen - Locations Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4624 Control Valve Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4625 Control Valve Assembly - Legend Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4626 Valve Body Checkball Locations Valve Body Bolt Locations Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4627 Manual Valve Link Outside Electrical Connector CLEAN - Control valve assembly thoroughly in clean solvent. A. Move the valves with a pick or small screwdriver to dislodge any dirt or debris that may have accumulated. B. Air dry. REMOVE OR DISCONNECT IMPORTANT - Some valves are under pressure - cover the bores while removing roll pins and retainer clips. - Valves, springs and bushings must be laid out on a clean surface in the exact sequence they are removed. 1. Pressure control solenoid retainer bolt (364) retainer (378) and solenoid. 2. Bore plug retainer clip (395), bore plug (376) and valve train (374 and 375). 3. 2-3 shift solenoid retainer (379), solenoid (367) and valve train (368 and 369). 4. 1-2 shift solenoid retainer (379), solenoid (367) and valve train (365 and 366). 5. Accumulator valve train retainer pin (360), bore plug (373) and valve train (370 and 371). 6. Forward accumulator cover bolts (364) and cover (363). 7. Forward accumulator spring (356), piston (354) and pin (355). 8. Lo overrun valve spring (362) and valve (361). 9. Retainer pin (360), bore plug (359) and forward abuse valve train (357 and 358). 10. Manual valve (340). 11. 3-2 control solenoid retainer clip (379) and solenoid (394). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4628 12. Bore plug retainer (395), bore plug (381) and 3-2 control valve train (391 - 393). 13. 3-2 downshift bore plug retainer (395), bore plug (381) and valve train (389 - 390). 14. Reverse abuse bore plug retainer pin (360), bore plug (359) and valve train (387 - 388). 15. 3-4 shift valve bore plug retainer (395), bore plug (381) and valve train (385 - 386). 16. 3-4 relay bore plug retainer (395), bore plug (381) and valve train (382 - 384). 17. Torque converter clutch signal valve bore plug retainer (395), bore plug (381) and valve (380). CLEAN - All valves, springs, bushings and control valve body in clean solvent. - Dry using compressed air. INSPECT - All valves and bushings for: Porosity - Scoring - Nicks - Scratches - Springs for damaged or distorted coils. - Valve body casting for: Porosity - Cracks - Inter connected oil passages - Damaged machined surfaces ASSEMBLE - Control valve assembly (350) exactly as shown. Notice the position of the valve lands and bushing passages. - Position the pressure control solenoid so the connector tabs face outward. NOTICE: TCC PWM solenoid (396) cannot be installed until TCC solenoid has been installed and torqued to proper specifications. INSTALL OR CONNECT 1. Checkballs into the valve body assembly (350). - Retain with Transjell TM J 36850 or equivalent. 2. Valve body assembly (350). - Connect the manual valve link (89) to the inside detent lever (88). - Be careful not to damage screens when installing the valve body assembly. 3. Wiring harness (66), manual spring assembly (63), pressure switch assembly(69), dipstick, stop bracket (93) and all remaining valve body bolts. NOTICE: Torque valve body bolts in a spiral pattern starting from the center. If bolts are torqued at random, valve bores may be distorted and inhibit valve operation. 4. TCC solenoid (66) and bolts (68). TIGHTEN - Bolts to 11 Nm (8 lb. ft.). 5. TCC PWM solenoid (396), and retainer clip (379). INSTALL OR CONNECT - Wiring harness connections to electrical components. - To correctly hook up the wires, see the wiring diagrams. - The pressure control solenoid (377) has two different colored connectors. The black connector should be installed on the tab farthest from the valve body. INSTALL OR CONNECT 1. Parking bracket (86). TIGHTEN - Bolts to 31 Nm (23 lb. ft.). 2. The 1-2 accumulator piston seal (55) onto the 1-2 accumulator piston (56). 3. The 1-2 accumulator spring (54) and 1-2 accumulator inner spring (54A) onto the piston (56). 4. The 1-2 accumulator piston (56) into the 1-2 accumulator cover and pin assembly (57). - The three legs on the piston must face away from the case when installed. 5. The 1-2 accumulator cover and pin assembly (57) onto the case. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4629 TIGHTEN - Torque to 11 Nm (8 lb. ft.). Pan and Filter Assembly PAN AND FILTER ASSEMBLY Case, Pan And Filter Assembly INSTALL OR CONNECT 1. Filter seal (71) into the pump. 2. Oil filter (72). 3. Oil pan gasket (73). 4. Chip magnet (74) onto oil pan (75). 5. Oil pan (75) and bolts (76). TIGHTEN - Torque to 12 Nm (9 lb. ft.). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4630 Shift Solenoid: Service and Repair 4L80-E Automatic Transmission Pan and Filter Assembly PAN AND FILTER ASSEMBLY Pan, Filter And Seal Removal REMOVE OR DISCONNECT 1. Drain the transmission fluid Out case extension by rotating transmission to a vertical position. 2. Seventeen bolts (27), using 10 mm socket, drain transmission fluid. 3. Pan (28), seal (29) and magnet (30). IMPORTANT - Seal (29) is reusable. 4. Filter assembly (31). INSPECT - Filter neck seal (32), replace if necessary. Wire Harness Assembly WIRE HARNESS ASSEMBLY Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4631 Pan, Filter And Seal Removal REMOVE OR DISCONNECT 1. Wire harness connectors from electrical components. NOTICE: Excessive force on the case pass through connector may damage the connector. IMPORTANT - If the wire harness assembly does not need servicing, it is not necessary to remove it from the case. 2. Wire harness assembly (34) from case using a 1-5/16" 12 point socket to release the connector retaining clips. Control Valve Assembly CONTROL VALVE ASSEMBLY Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4632 REMOVE OR DISCONNECT 1. Rotate transmission bottom pan surface up and lock in place. 2. Wire harness assembly (34) connectors from components. IMPORTANT - If the wire harness assembly does not need servicing, it is not necessary to remove it from the case. - Use a cap to cover electrical pin at case connection. 3. Six bolts (76) using 8 mm socket, and transmission fluid pressure switch assembly (40). NOTICE: Be sure five O-rings are attached to transmission fluid pressure switch assembly. 4. Twenty-one bolts (35) using 10 mm socket, from valve body assembly, manual detent spring and roller assembly (41). 5. Three wiring clamps (33), fluid level indicator stop (43), one bolt (36) using 10 mm socket, lube pipe (39), lube pipe retainer (37) and clamp (38). 6. Control valve assembly (44) including the accumulator housing assembly (51), valve body gaskets (45 and 48), spacer plate (46) and accumulator gasket (47). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4633 7. Manual valve (319) from control valve assembly (44) to prevent any damage. 8. Checkballs (54) from case passages. NOTICE: Do not use a magnet. It could cause checkball(s) to be magnetized causing metal particles to stick to the ball. 9. Pulse Width Modulated (PWM) solenoid screen (75). INSPECT - Screen PWM solenoid (75), replace if necessary. DISASSEMBLE Control Valve Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4634 - Control valve assembly. A. Position as shown on a clean surface. B. Remove blind hole retainer pins with a drill bit. CAUTION: Some valves are under pressure - cover the bores while removing the retaining pins or personal injury could result. C. Remove valve trains, shift solenoids (311 and 313), PCS (320), PWM solenoid (323), PCS screen (302) and shift solenoid filter (317). D. Valves, springs, bushings and pistons must be laid out on a clean surface. CLEAN - All valves, springs, bushings, pistons, control valve body and accumulator housing in clean solvent. - Dry using compressed air. INSPECT 1. All valves, pistons and bushings for: - Porosity. - Scoring. - Nicks. - Scratches. 2. Pistons for: - Seal damage. 3. Springs for: - Damaged or distorted coils. 4. Valve body casting and accumulator housing for: - Porosity. - Cracks. - Interconnected passages. - Damaged machined surfaces. 5. Solenoid connectors and filter (317). 6. PCS (Pressure Control Solenoid) screen (302). Control Valve Assembly/Accumulator Housing CONTROL VALVE ASSEMBLY/ACCUMULATOR HOUSING Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4635 Control Valve Assembly/Accumulator Housing Accumulator Housing Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4636 Control Valve Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4637 Torque Sequence And Guide Pin Location Fig. 11 Check Ball Location. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4638 Fig. 10 Control Valve Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4639 Torque Sequence, Control Valve And Switch Assembly NOTICE: The use of a honing stone, fine sandpaper or crocus cloth is not recommended for servicing stuck valves. All valve lands have sharply machined comers that are necessary for cleaning the bore. If these corners are rounded, foreign material could wedge between the valve and the bore causing the valve to stick. If it is found necessary to clean a valve, micro fine lapping compound 900 grit (J 38459) or finer should be used. Too much lapping of the valve will cause excessive clearances and increase the chance of a valve not operating. CLEAN - Control valve assembly and accumulator housing (51) thoroughly in clean solvent. - Air dry. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4640 Accumulator Housing Assembly ACCUMULATOR HOUSING ASSEMBLY Control Valve Assembly/Accumulator Housing Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4641 Accumulator Housing Assembly DISASSEMBLE 1. Six bolts (53), using 8 mm socket. 2. Accumulator housing assembly. 3. Gasket accumulator housing (47). 4. Spacer plate (46). 5. Gasket (45) valve body spacer. 6. Snap ring (402) from outside housing, pin (408), snap ring (402), piston (407) and spring (49). 7. 3rd clutch piston (405) and spring (50). 8. Seals (404 and 406). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4642 CLEAN - All components. INSPECT - All valves, pistons, springs and seals for: - Porosity. - Scoring. - Nicks. - Scratches. Accumulator Housing Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4643 ASSEMBLE - Accumulator housing assembly components exactly as shown. Notice the positions of the pistons. Control Valve Assembly CONTROL VALVE ASSEMBLY Control Valve Assembly ASSEMBLE - Control valve assembly components exactly as shown. Notice the position of the valve lands and bushing passages. Control Valve Assembly/Accumulator Housing Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4644 CONTROL VALVE ASSEMBLY AND ACCUMULATOR HOUSING Control Valve Assembly/Accumulator Housing Torque Sequence And Guide Pin Location TOOL REQUIRED: - Guide Pin J 25025-5 ASSEMBLE 1. Guide pin J 25025-5 into valve body. Located at back bolt hole of detent spring and roller assembly bolt bole. 2. Gasket (45) valve body to spacer plate. 3. Spacer plate (46). 4. Gasket (47) accumulator housing to spacer plate. 5. Accumulator housing assembly (51) onto valve body assembly (44). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4645 6. Six bolts (53) using (8 mm) socket through accumulator housing into valve body assembly. Torque Sequence And Guide Pin Location NOTE: Start accumulator housing bolts finger tight and work towards opposite end. TIGHTEN - Bolt (53) to 11 Nm (97 lb. in.). 7. Remove guide pin J 25025-5. Fig. 11 Check Ball Location. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4646 Fig. 10 Control Valve Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4647 Torque Sequence, Control Valve And Switch Assembly INSTALL OR CONNECT 1. Install checkballs (54) in proper location into case fluid passages. Use TRANSJEL TM J 36850 or equivalent to hold in place. NOTICE: Do not use any type of grease to retain parts during assembly of this unit. Greases other than the recommended assembly lube will change transmission fluid characteristics and cause undesirable shift conditions and/or filter clogging. - # 2 checkball is used only on RCP RDP, ZJP and ZLP models. 2. PWM solenoid screen (75). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4648 3. Gasket (48) spacer plate to case. 4. Manual valve (319) into valve body. 5. Complete valve body assembly (44) onto case (7). Use 1 25025-5 guide pin set. IMPORTANT - Attach manual valve to detent lever. 6. Transmission fluid pressure switch assembly (40) onto valve body assembly (44). 7. Spring and roller assembly (41) into place. 8. Three wiring clamps (33), fluid indicator stop (43) and lube pipe clamp (38). 9. Twenty-one bolts (35). Using 10 mm socket. 10. Six bolts (76) using 8 mm socket into transmission fluid pressure switch assembly (40). 11. Lube pipe (39) long end into case, short end into valve body. 12. Lube pipe retainer (37) with short bolt (36). TIGHTEN - Bolts (35, 36 and 76) to 11 Nm (97 lb. in.). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4649 Torque Sequence, Control Valve And Switch Assembly NOTICE: Torque valve body bolts in a spiral pattern starting from the center. If bolts are torqued at random, valve bores may be distorted and inhibit valve operation. 13. Attach wiring harness (34) to 5 connectors. - Put large end into case first, pressure switch hook up, 1-2 shift solenoid (purple) and 2-3 shift solenoid (tan), PWM (Pulse Width Modulated) solenoid and PCS (Pressure Control Solenoid). Pan and Filter Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4650 PAN AND FILTER ASSEMBLY Installing Pan And Filter INSTALL OR CONNECT 1. Seal (32) inside of case (7). 2. Filter assembly (31). 3. Bottom pan seal (29). 4. Magnet (30) into bottom pan. 5. Pan (29). 6. Seventeen bolts (27) using 10 mm socket. TIGHTEN - Bolts (27) to 24 Nm (18 lb. ft.). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Torque Converter Clutch Solenoid, A/T > Component Information > Technical Service Bulletins > A/T - 2-4 Band, TCC Solenoid, 3-4 Clutch Friction/Plates Torque Converter Clutch Solenoid: Technical Service Bulletins A/T - 2-4 Band, TCC Solenoid, 3-4 Clutch Friction/Plates File In Section: 7 - Transmission Bulletin No.: 47-71-41 Date: January, 1995 Subject: New 2-4 Band Assembly, 3-4 Clutch Friction and Steel Plates and Torque Clutch PWM Solenoid Models: 1995 Buick Roadmaster 1995 Cadillac Fleetwood 1995 Chevrolet Camaro, Caprice, Corvette 1995 Pontiac Firebird 1995 Chevrolet and GMC Truck C/K Models and M/L, G Vans 1994-95 Chevrolet and GMC Truck S/T Models 1994 Oldsmobile Bravada (1994 Models with RPO +CTF Package) Transmission Applications: 1995 Hydra-Matic 4L60-E (RPO M30) A new 2-4 Band Assembly was introduced at the start of production for the 1995 Model Year and 1994 Bravadas and S/T trucks. The 2-4 Band friction material has changed appearance from a brown material to a gray/black material. This change was made to enhance durability. When servicing a 1995 Hydra-Matic 4L60-E transmission, do NOT assume that the 2-4 Band is burned/damaged due to its dark color. This dark color is normal. Before replacing the 2-4 Band inspect it for scoring, chunking or heavily worn friction material. Before Replacing the Reverse Input Housing and Drum Assembly inspect for scoring or signs of excessive heat. The 2-4 Band and/or Reverse Input Housing and Drum Assembly should be replaced ONLY if the above listed damage is found. Note: The new 2-4 Band Assembly will NOT service past model Hydra-Matic 4L60-E or 4L60 transmissions. A new 3-4 clutch friction plate was introduced at the start of production for the 1995 Model Year and 1994 Bravadas and S/T Trucks. The 3-4 clutch plate friction material has changed appearance from a brown material to a green/black material. This change was made to enhance durability. When servicing a 1995 Hydra-Matic 4L60-E transmission, do NOT assume that the 3-4 clutch friction plates are burned/damaged due to their dark color. This dark color is normal. Before replacing the 3-4 clutch friction plates inspect for scoring, chunking or heavily worn friction material. Before replacing the 3-4 clutch steel plates inspect for scoring or signs of excessive heat. The 3-4 clutch friction plates and/or 3-4 clutch steel plates should be replaced ONLY if the above listed damage is found. Note: The new 3-4 friction plates will NOT service past model Hydra-Matic 4L60-E or 4L60 transmissions. A new Torque Converter Clutch PWM Solenoid was introduced at the start of production for the 1995 Model Year and 1994 Bravadas and S/T trucks. The new torque converter clutch PWM solenoid is used to control fluid acting on the converter clutch valve, which then controls TCC apply and release. The solenoid is attached to the control valve body assembly within the transmission. The TCC PWM solenoid is used to provide smooth engagement of the torque converter by operating on a negative duty cycle percent of "ON" time. It a fault is detected in the TCC PWM circuit, DTC 83 will set. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Torque Converter Clutch Solenoid, A/T > Component Information > Technical Service Bulletins > A/T - 2-4 Band, TCC Solenoid, 3-4 Clutch Friction/Plates > Page 4655 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Torque Converter Clutch Solenoid, A/T > Component Information > Technical Service Bulletins > A/T - 2-4 Band, TCC Solenoid, 3-4 Clutch Friction/Plates > Page 4656 Included is a Service Manual update for the 1-2 and 3-4 accumulator spring color chart. Replace these pages in your 1995 Service Manual. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Torque Converter Clutch Solenoid, A/T > Component Information > Technical Service Bulletins > Page 4657 Torque Converter Clutch Solenoid: Locations Inside automatic transmission attached to valve body. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Torque Converter Clutch Solenoid, A/T > Component Information > Technical Service Bulletins > Page 4658 C216 - TCC Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - A/T > Torque Converter Clutch Solenoid, A/T > Component Information > Technical Service Bulletins > Page 4659 Torque Converter Clutch Solenoid: Description and Operation Torque Converter Clutch Solenoid PURPOSE The Transmission Converter Clutch (TCC) feature eliminates the power loss of the torque converter stage when the vehicle is in a cruise mode. OPERATION The TCC system uses a solenoid operated valve in the automatic transmission to couple the engine flexplate to the output shaft of the transmission through the torque converter. This reduces the slippage losses in the converter, which increases fuel economy. For the converter clutch to apply, two hydraulic conditions must be met: Internal transmission fluid pressure must be correct. - The control module completes a ground circuit to energize the TCC solenoid in the transmission, which moves a check ball in the fluid line. Control module control is based on the input of these sensors: Vehicle Speed Sensor (VSS): Vehicle equipped with A/C will allow TCC engagement at about 35 mph when the A/C is selected "ON". Engagement will occur at a vehicle speed of about 30 mph (25 mph for 92) when A/C is selected "OFF". - Engine Coolant Temperature (ECT) Sensor: Engine at normal operating temperature (above 65°C/149°F). - Throttle Position Sensor (TPS): Output not changing, indicating a steady road speed. - Transmission Fluid (TFT) sensor. Control module is also controlled by these switches: Brake switch closed: 12 volts supplied when brake is depressed. - Transmission Range (TR) pressure switch assembly. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - Transfer Case > Transfer Case Actuator > Component Information > Locations > Electronic Shift Transfer Case Position Switch Transfer Case Actuator: Locations Electronic Shift Transfer Case Position Switch Transfer Case Electric Shift Motor The Electronic Shift Transfer Case Position Switch (Encoder Switch) is located in the in the shift motor on the transfer case. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - Transfer Case > Transfer Case Actuator > Component Information > Locations > Electronic Shift Transfer Case Position Switch > Page 4665 Four-Wheel Drive Indicator Wiring Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - Transfer Case > Transfer Case Actuator > Component Information > Locations > Page 4666 Transfer Case Actuator: Diagrams C154 - Front Axle Switch C155 - Front Axle Switch In-Line C154 - Front Axle Switch C155 - Front Axle Switch In-Line Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Actuators and Solenoids - Transmission and Drivetrain > Actuators and Solenoids - Transfer Case > Transfer Case Actuator > Component Information > Locations > Page 4667 Transfer Case Actuator: Service and Repair ELECTRIC SHIFT MOTOR REPLACEMENT Transfer Case Electric Shift Motor REMOVE OR DISCONNECT 1. Negative battery cable. - Raise vehicle and support with safety stands. 2. Transfer case shield. 3. Motor electrical connection. 4. Front propeller shaft. 5. Front output shaft yoke. 6. Motor to transfer case bolts. 7. Motor from the transfer case. INSTALL OR CONNECT 1. Motor to the transfer case. 2. Bolts. TIGHTEN - Bolts to 18 Nm (13 lbs. ft.). 3. Front output shaft yoke. 4. Front propeller shaft. 5. Motor electrical connection. 6. Transfer case shield. 7. Negative battery cable. - Lower Vehicle Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Pressure Regulating Solenoid, A/T > Component Information > Description and Operation Pressure Regulating Solenoid: Description and Operation PURPOSE This electrical device, controlled by the PCM, is used to control fluid line pressure. OPERATION The solenoid controls line pressure by controlling actuator feed limit fluid flow acting on internal spool valve and spring pressure. The solenoid is a normally closed solenoid valve that controls fluid pressure when operating on a duty cycle. LOCATION The solenoid is attached to the control valve body within the transmission. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Specifications > Electrical Specifications Shift Solenoid: Electrical Specifications Component Resistance Chart Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Specifications > Electrical Specifications > Page 4677 Shift Solenoid: Mechanical Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Pressure Control Solenoid To Valve Body .......................................................................................... ................................................................................ 8 Solenoid Assembly To Pump .......................... .............................................................................................................................................................. ....... 8 Solenoid Assembly To Case .................................................................................................... ........................................................................................... 18 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Locations > 4L60-E Automatic Transmission Electronic Component Location Views Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Locations > 4L60-E Automatic Transmission > Page 4680 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Description and Operation > 1 -2 Shift Solenoid Shift Solenoid: Description and Operation 1 -2 Shift Solenoid PURPOSE This electrical device, controlled by the PCM, is used to control fluid flow acting on the 1-2 and 3-4 shift valves. OPERATION The solenoid is a normally open exhaust valve that is used with the 2-3 shift solenoid to allow four different shifting combinations. LOCATION The solenoid is attached to the control valve body within the transmission. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Description and Operation > 1 -2 Shift Solenoid > Page 4683 Shift Solenoid: Description and Operation 2-3 Shift Solenoid PURPOSE This electrical device, controlled by the PCM, is used to control fluid flow acting on the 2-3 shift valves. OPERATION The solenoid is a normally open exhaust valve that is used with the 1-2 shift solenoid to allow four different shifting combinations. LOCATION The solenoid is attached to the control valve body within the transmission. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Description and Operation > 1 -2 Shift Solenoid > Page 4684 Shift Solenoid: Description and Operation 3-2 Control Solenoid PURPOSE This electrical device, controlled by the PCM, is used to control fluid flow acting on the 3-2 shift valve, which then controls the 2-4 band apply rate and 3-4 clutch release rate. The solenoid also controls the 3-2 downshift feel. OPERATION The solenoid is a pulse width modulated solenoid that operates on a negative duty cycle. LOCATION The solenoid is attached to the control valve body within the transmission. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission Shift Solenoid: Service and Repair 4L60-E Automatic Transmission Pan and Filter Assembly PAN AND FILTER ASSEMBLY Pan, Filter And Seal Removal CLEAN - Exposed ends of bottom pan screws and spray with penetrating oil. REMOVE OR DISCONNECT 1. Screws (76), oil pan (75) and gasket (73). 2. Oil filter (72) and filter seal (71). - Filter seal may be stuck in the pump. INSPECT - Filter (72), open filter by prying the metal crimping away from the top of the filter (black) and pull apart. The filter may contain evidence for root cause diagnosis. Clutch material. - Bronze slivers indicating bushing wear. - Steel particles. Valve Body and Wiring Harness VALVE BODY AND WIRING HARNESS Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4687 Valve Body Bolt Location Control Valve And Pressure Switch Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4688 Manual Valve Link Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4689 Valve Body Checkballs Case Checkballs And Filters REMOVE OR DISCONNECT 1. Electrical connections from components. 2. TCC PWM Solenoid Retainer Clip (379) and Solenoid (396). 3. TCC Solenoid bolts (68) and solenoid assembly (66) with O-ring seal (65) and wiring harness. 4. Pressure switch assembly bolts (70) and pressure switch assembly (69). 5. Accumulator cover bolts (58 and 59) and 1-2 accumulator cover and pin assembly (57). 6. 1-2 accumulator piston (56) and seal (55). 7. Spring (54). 8. Dipstick stop bracket (93). REMOVE OR DISCONNECT 1. Bolt (64) and manual detent spring assembly (63). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4690 2. Wiring harness retaining bolts. REMOVE OR DISCONNECT 1. Remaining valve body bolts (62). 2. Manual valve link (89). 3. Control valve assembly (60). 4. Bolts (58 and 59), accumulator cover (57), piston (56, spring (54) and spring (54A). 5. Bolts (77) and plate (53). 6. Spacer plate (48) and spacer plate gaskets (47 and 52). 7. Spring (46), piston (44), and pin (43). - Seven checkballs are located under the valve body and one is located in the case. The large copper flash colored ball is # 1A checkball (91). Valve Body and Associated Parts VALVE BODY AND ASSOCIATED PARTS Accumulator Assembly, Spacer Plate And Gaskets Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4691 Case Checkballs And Filters TOOL REQUIRED: - J 25025-5 Guide Pins NOTICE: The use of a honing stone, fine sandpaper or crocus cloth is not recommended for servicing stuck valves. All valve lands have sharply machined corners that are necessary for "cleaning" the bore. If these corners are rounded, foreign material could wedge between the valve and bore causing the valve to stick. If it is found necessary to clean a valve, "micro fine" lapping compound 900 grit or finer should be used. Too much "lapping" of a valve will cause excessive clearances and increase the chance of a valve not operating. INSTALL OR CONNECT 1. The wiring harness pass-thru connector into the case. 2. The 3-4 accumulator pin (43) into the case. 3. The 3-4 accumulator piston seal (45) onto the 3-4 accumulator piston. 4. The 3-4 accumulator piston (44) onto the pin. - The end with three legs must face the valve body. 5. The 3-4 accumulator piston spring (46). INSTALL OR CONNECT 1. Checkball (91) into case as shown. - Retain with Transjel TM J 36850 or equivalent. 2. J 25025-5 into the case. 3. Screens onto spacer plate as shown. 4. Spacer plate to case gasket (47) and spacer plate to valve body gasket (52) onto the spacer plate (48). - Gasket (47) identified by a "C". Gasket (52) identified by a "V". - Retain with Transjel TM J 36850 or equivalent. 5. Spacer plate and gaskets onto the case. IMPORTANT - Be careful not to damage screens when installing the spacer plate and gaskets. 6. Spacer plate support (53) and bolts (77). TIGHTEN - Bolts to 11 Nm (8 lb. ft.) Control Valve Body CONTROL VALVE BODY Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4692 Case Checkballs And Filters Filter Screen - Locations Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4693 Control Valve Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4694 Control Valve Assembly - Legend Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4695 Valve Body Checkball Locations Valve Body Bolt Locations Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4696 Manual Valve Link Outside Electrical Connector CLEAN - Control valve assembly thoroughly in clean solvent. A. Move the valves with a pick or small screwdriver to dislodge any dirt or debris that may have accumulated. B. Air dry. REMOVE OR DISCONNECT IMPORTANT - Some valves are under pressure - cover the bores while removing roll pins and retainer clips. - Valves, springs and bushings must be laid out on a clean surface in the exact sequence they are removed. 1. Pressure control solenoid retainer bolt (364) retainer (378) and solenoid. 2. Bore plug retainer clip (395), bore plug (376) and valve train (374 and 375). 3. 2-3 shift solenoid retainer (379), solenoid (367) and valve train (368 and 369). 4. 1-2 shift solenoid retainer (379), solenoid (367) and valve train (365 and 366). 5. Accumulator valve train retainer pin (360), bore plug (373) and valve train (370 and 371). 6. Forward accumulator cover bolts (364) and cover (363). 7. Forward accumulator spring (356), piston (354) and pin (355). 8. Lo overrun valve spring (362) and valve (361). 9. Retainer pin (360), bore plug (359) and forward abuse valve train (357 and 358). 10. Manual valve (340). 11. 3-2 control solenoid retainer clip (379) and solenoid (394). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4697 12. Bore plug retainer (395), bore plug (381) and 3-2 control valve train (391 - 393). 13. 3-2 downshift bore plug retainer (395), bore plug (381) and valve train (389 - 390). 14. Reverse abuse bore plug retainer pin (360), bore plug (359) and valve train (387 - 388). 15. 3-4 shift valve bore plug retainer (395), bore plug (381) and valve train (385 - 386). 16. 3-4 relay bore plug retainer (395), bore plug (381) and valve train (382 - 384). 17. Torque converter clutch signal valve bore plug retainer (395), bore plug (381) and valve (380). CLEAN - All valves, springs, bushings and control valve body in clean solvent. - Dry using compressed air. INSPECT - All valves and bushings for: Porosity - Scoring - Nicks - Scratches - Springs for damaged or distorted coils. - Valve body casting for: Porosity - Cracks - Inter connected oil passages - Damaged machined surfaces ASSEMBLE - Control valve assembly (350) exactly as shown. Notice the position of the valve lands and bushing passages. - Position the pressure control solenoid so the connector tabs face outward. NOTICE: TCC PWM solenoid (396) cannot be installed until TCC solenoid has been installed and torqued to proper specifications. INSTALL OR CONNECT 1. Checkballs into the valve body assembly (350). - Retain with Transjell TM J 36850 or equivalent. 2. Valve body assembly (350). - Connect the manual valve link (89) to the inside detent lever (88). - Be careful not to damage screens when installing the valve body assembly. 3. Wiring harness (66), manual spring assembly (63), pressure switch assembly(69), dipstick, stop bracket (93) and all remaining valve body bolts. NOTICE: Torque valve body bolts in a spiral pattern starting from the center. If bolts are torqued at random, valve bores may be distorted and inhibit valve operation. 4. TCC solenoid (66) and bolts (68). TIGHTEN - Bolts to 11 Nm (8 lb. ft.). 5. TCC PWM solenoid (396), and retainer clip (379). INSTALL OR CONNECT - Wiring harness connections to electrical components. - To correctly hook up the wires, see the wiring diagrams. - The pressure control solenoid (377) has two different colored connectors. The black connector should be installed on the tab farthest from the valve body. INSTALL OR CONNECT 1. Parking bracket (86). TIGHTEN - Bolts to 31 Nm (23 lb. ft.). 2. The 1-2 accumulator piston seal (55) onto the 1-2 accumulator piston (56). 3. The 1-2 accumulator spring (54) and 1-2 accumulator inner spring (54A) onto the piston (56). 4. The 1-2 accumulator piston (56) into the 1-2 accumulator cover and pin assembly (57). - The three legs on the piston must face away from the case when installed. 5. The 1-2 accumulator cover and pin assembly (57) onto the case. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4698 TIGHTEN - Torque to 11 Nm (8 lb. ft.). Pan and Filter Assembly PAN AND FILTER ASSEMBLY Case, Pan And Filter Assembly INSTALL OR CONNECT 1. Filter seal (71) into the pump. 2. Oil filter (72). 3. Oil pan gasket (73). 4. Chip magnet (74) onto oil pan (75). 5. Oil pan (75) and bolts (76). TIGHTEN - Torque to 12 Nm (9 lb. ft.). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4699 Shift Solenoid: Service and Repair 4L80-E Automatic Transmission Pan and Filter Assembly PAN AND FILTER ASSEMBLY Pan, Filter And Seal Removal REMOVE OR DISCONNECT 1. Drain the transmission fluid Out case extension by rotating transmission to a vertical position. 2. Seventeen bolts (27), using 10 mm socket, drain transmission fluid. 3. Pan (28), seal (29) and magnet (30). IMPORTANT - Seal (29) is reusable. 4. Filter assembly (31). INSPECT - Filter neck seal (32), replace if necessary. Wire Harness Assembly WIRE HARNESS ASSEMBLY Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4700 Pan, Filter And Seal Removal REMOVE OR DISCONNECT 1. Wire harness connectors from electrical components. NOTICE: Excessive force on the case pass through connector may damage the connector. IMPORTANT - If the wire harness assembly does not need servicing, it is not necessary to remove it from the case. 2. Wire harness assembly (34) from case using a 1-5/16" 12 point socket to release the connector retaining clips. Control Valve Assembly CONTROL VALVE ASSEMBLY Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4701 REMOVE OR DISCONNECT 1. Rotate transmission bottom pan surface up and lock in place. 2. Wire harness assembly (34) connectors from components. IMPORTANT - If the wire harness assembly does not need servicing, it is not necessary to remove it from the case. - Use a cap to cover electrical pin at case connection. 3. Six bolts (76) using 8 mm socket, and transmission fluid pressure switch assembly (40). NOTICE: Be sure five O-rings are attached to transmission fluid pressure switch assembly. 4. Twenty-one bolts (35) using 10 mm socket, from valve body assembly, manual detent spring and roller assembly (41). 5. Three wiring clamps (33), fluid level indicator stop (43), one bolt (36) using 10 mm socket, lube pipe (39), lube pipe retainer (37) and clamp (38). 6. Control valve assembly (44) including the accumulator housing assembly (51), valve body gaskets (45 and 48), spacer plate (46) and accumulator gasket (47). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4702 7. Manual valve (319) from control valve assembly (44) to prevent any damage. 8. Checkballs (54) from case passages. NOTICE: Do not use a magnet. It could cause checkball(s) to be magnetized causing metal particles to stick to the ball. 9. Pulse Width Modulated (PWM) solenoid screen (75). INSPECT - Screen PWM solenoid (75), replace if necessary. DISASSEMBLE Control Valve Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4703 - Control valve assembly. A. Position as shown on a clean surface. B. Remove blind hole retainer pins with a drill bit. CAUTION: Some valves are under pressure - cover the bores while removing the retaining pins or personal injury could result. C. Remove valve trains, shift solenoids (311 and 313), PCS (320), PWM solenoid (323), PCS screen (302) and shift solenoid filter (317). D. Valves, springs, bushings and pistons must be laid out on a clean surface. CLEAN - All valves, springs, bushings, pistons, control valve body and accumulator housing in clean solvent. - Dry using compressed air. INSPECT 1. All valves, pistons and bushings for: - Porosity. - Scoring. - Nicks. - Scratches. 2. Pistons for: - Seal damage. 3. Springs for: - Damaged or distorted coils. 4. Valve body casting and accumulator housing for: - Porosity. - Cracks. - Interconnected passages. - Damaged machined surfaces. 5. Solenoid connectors and filter (317). 6. PCS (Pressure Control Solenoid) screen (302). Control Valve Assembly/Accumulator Housing CONTROL VALVE ASSEMBLY/ACCUMULATOR HOUSING Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4704 Control Valve Assembly/Accumulator Housing Accumulator Housing Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4705 Control Valve Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4706 Torque Sequence And Guide Pin Location Fig. 11 Check Ball Location. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4707 Fig. 10 Control Valve Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4708 Torque Sequence, Control Valve And Switch Assembly NOTICE: The use of a honing stone, fine sandpaper or crocus cloth is not recommended for servicing stuck valves. All valve lands have sharply machined comers that are necessary for cleaning the bore. If these corners are rounded, foreign material could wedge between the valve and the bore causing the valve to stick. If it is found necessary to clean a valve, micro fine lapping compound 900 grit (J 38459) or finer should be used. Too much lapping of the valve will cause excessive clearances and increase the chance of a valve not operating. CLEAN - Control valve assembly and accumulator housing (51) thoroughly in clean solvent. - Air dry. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4709 Accumulator Housing Assembly ACCUMULATOR HOUSING ASSEMBLY Control Valve Assembly/Accumulator Housing Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4710 Accumulator Housing Assembly DISASSEMBLE 1. Six bolts (53), using 8 mm socket. 2. Accumulator housing assembly. 3. Gasket accumulator housing (47). 4. Spacer plate (46). 5. Gasket (45) valve body spacer. 6. Snap ring (402) from outside housing, pin (408), snap ring (402), piston (407) and spring (49). 7. 3rd clutch piston (405) and spring (50). 8. Seals (404 and 406). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4711 CLEAN - All components. INSPECT - All valves, pistons, springs and seals for: - Porosity. - Scoring. - Nicks. - Scratches. Accumulator Housing Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4712 ASSEMBLE - Accumulator housing assembly components exactly as shown. Notice the positions of the pistons. Control Valve Assembly CONTROL VALVE ASSEMBLY Control Valve Assembly ASSEMBLE - Control valve assembly components exactly as shown. Notice the position of the valve lands and bushing passages. Control Valve Assembly/Accumulator Housing Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4713 CONTROL VALVE ASSEMBLY AND ACCUMULATOR HOUSING Control Valve Assembly/Accumulator Housing Torque Sequence And Guide Pin Location TOOL REQUIRED: - Guide Pin J 25025-5 ASSEMBLE 1. Guide pin J 25025-5 into valve body. Located at back bolt hole of detent spring and roller assembly bolt bole. 2. Gasket (45) valve body to spacer plate. 3. Spacer plate (46). 4. Gasket (47) accumulator housing to spacer plate. 5. Accumulator housing assembly (51) onto valve body assembly (44). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4714 6. Six bolts (53) using (8 mm) socket through accumulator housing into valve body assembly. Torque Sequence And Guide Pin Location NOTE: Start accumulator housing bolts finger tight and work towards opposite end. TIGHTEN - Bolt (53) to 11 Nm (97 lb. in.). 7. Remove guide pin J 25025-5. Fig. 11 Check Ball Location. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4715 Fig. 10 Control Valve Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4716 Torque Sequence, Control Valve And Switch Assembly INSTALL OR CONNECT 1. Install checkballs (54) in proper location into case fluid passages. Use TRANSJEL TM J 36850 or equivalent to hold in place. NOTICE: Do not use any type of grease to retain parts during assembly of this unit. Greases other than the recommended assembly lube will change transmission fluid characteristics and cause undesirable shift conditions and/or filter clogging. - # 2 checkball is used only on RCP RDP, ZJP and ZLP models. 2. PWM solenoid screen (75). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4717 3. Gasket (48) spacer plate to case. 4. Manual valve (319) into valve body. 5. Complete valve body assembly (44) onto case (7). Use 1 25025-5 guide pin set. IMPORTANT - Attach manual valve to detent lever. 6. Transmission fluid pressure switch assembly (40) onto valve body assembly (44). 7. Spring and roller assembly (41) into place. 8. Three wiring clamps (33), fluid indicator stop (43) and lube pipe clamp (38). 9. Twenty-one bolts (35). Using 10 mm socket. 10. Six bolts (76) using 8 mm socket into transmission fluid pressure switch assembly (40). 11. Lube pipe (39) long end into case, short end into valve body. 12. Lube pipe retainer (37) with short bolt (36). TIGHTEN - Bolts (35, 36 and 76) to 11 Nm (97 lb. in.). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4718 Torque Sequence, Control Valve And Switch Assembly NOTICE: Torque valve body bolts in a spiral pattern starting from the center. If bolts are torqued at random, valve bores may be distorted and inhibit valve operation. 13. Attach wiring harness (34) to 5 connectors. - Put large end into case first, pressure switch hook up, 1-2 shift solenoid (purple) and 2-3 shift solenoid (tan), PWM (Pulse Width Modulated) solenoid and PCS (Pressure Control Solenoid). Pan and Filter Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4719 PAN AND FILTER ASSEMBLY Installing Pan And Filter INSTALL OR CONNECT 1. Seal (32) inside of case (7). 2. Filter assembly (31). 3. Bottom pan seal (29). 4. Magnet (30) into bottom pan. 5. Pan (29). 6. Seventeen bolts (27) using 10 mm socket. TIGHTEN - Bolts (27) to 24 Nm (18 lb. ft.). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Torque Converter Clutch Solenoid, A/T > Component Information > Technical Service Bulletins > A/T 2-4 Band, TCC Solenoid, 3-4 Clutch Friction/Plates Torque Converter Clutch Solenoid: Technical Service Bulletins A/T - 2-4 Band, TCC Solenoid, 3-4 Clutch Friction/Plates File In Section: 7 - Transmission Bulletin No.: 47-71-41 Date: January, 1995 Subject: New 2-4 Band Assembly, 3-4 Clutch Friction and Steel Plates and Torque Clutch PWM Solenoid Models: 1995 Buick Roadmaster 1995 Cadillac Fleetwood 1995 Chevrolet Camaro, Caprice, Corvette 1995 Pontiac Firebird 1995 Chevrolet and GMC Truck C/K Models and M/L, G Vans 1994-95 Chevrolet and GMC Truck S/T Models 1994 Oldsmobile Bravada (1994 Models with RPO +CTF Package) Transmission Applications: 1995 Hydra-Matic 4L60-E (RPO M30) A new 2-4 Band Assembly was introduced at the start of production for the 1995 Model Year and 1994 Bravadas and S/T trucks. The 2-4 Band friction material has changed appearance from a brown material to a gray/black material. This change was made to enhance durability. When servicing a 1995 Hydra-Matic 4L60-E transmission, do NOT assume that the 2-4 Band is burned/damaged due to its dark color. This dark color is normal. Before replacing the 2-4 Band inspect it for scoring, chunking or heavily worn friction material. Before Replacing the Reverse Input Housing and Drum Assembly inspect for scoring or signs of excessive heat. The 2-4 Band and/or Reverse Input Housing and Drum Assembly should be replaced ONLY if the above listed damage is found. Note: The new 2-4 Band Assembly will NOT service past model Hydra-Matic 4L60-E or 4L60 transmissions. A new 3-4 clutch friction plate was introduced at the start of production for the 1995 Model Year and 1994 Bravadas and S/T Trucks. The 3-4 clutch plate friction material has changed appearance from a brown material to a green/black material. This change was made to enhance durability. When servicing a 1995 Hydra-Matic 4L60-E transmission, do NOT assume that the 3-4 clutch friction plates are burned/damaged due to their dark color. This dark color is normal. Before replacing the 3-4 clutch friction plates inspect for scoring, chunking or heavily worn friction material. Before replacing the 3-4 clutch steel plates inspect for scoring or signs of excessive heat. The 3-4 clutch friction plates and/or 3-4 clutch steel plates should be replaced ONLY if the above listed damage is found. Note: The new 3-4 friction plates will NOT service past model Hydra-Matic 4L60-E or 4L60 transmissions. A new Torque Converter Clutch PWM Solenoid was introduced at the start of production for the 1995 Model Year and 1994 Bravadas and S/T trucks. The new torque converter clutch PWM solenoid is used to control fluid acting on the converter clutch valve, which then controls TCC apply and release. The solenoid is attached to the control valve body assembly within the transmission. The TCC PWM solenoid is used to provide smooth engagement of the torque converter by operating on a negative duty cycle percent of "ON" time. It a fault is detected in the TCC PWM circuit, DTC 83 will set. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Torque Converter Clutch Solenoid, A/T > Component Information > Technical Service Bulletins > A/T 2-4 Band, TCC Solenoid, 3-4 Clutch Friction/Plates > Page 4724 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Torque Converter Clutch Solenoid, A/T > Component Information > Technical Service Bulletins > A/T 2-4 Band, TCC Solenoid, 3-4 Clutch Friction/Plates > Page 4725 Included is a Service Manual update for the 1-2 and 3-4 accumulator spring color chart. Replace these pages in your 1995 Service Manual. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Torque Converter Clutch Solenoid, A/T > Component Information > Technical Service Bulletins > Page 4726 Torque Converter Clutch Solenoid: Locations Inside automatic transmission attached to valve body. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Torque Converter Clutch Solenoid, A/T > Component Information > Technical Service Bulletins > Page 4727 C216 - TCC Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Actuators and Solenoids - A/T > Torque Converter Clutch Solenoid, A/T > Component Information > Technical Service Bulletins > Page 4728 Torque Converter Clutch Solenoid: Description and Operation Torque Converter Clutch Solenoid PURPOSE The Transmission Converter Clutch (TCC) feature eliminates the power loss of the torque converter stage when the vehicle is in a cruise mode. OPERATION The TCC system uses a solenoid operated valve in the automatic transmission to couple the engine flexplate to the output shaft of the transmission through the torque converter. This reduces the slippage losses in the converter, which increases fuel economy. For the converter clutch to apply, two hydraulic conditions must be met: Internal transmission fluid pressure must be correct. - The control module completes a ground circuit to energize the TCC solenoid in the transmission, which moves a check ball in the fluid line. Control module control is based on the input of these sensors: Vehicle Speed Sensor (VSS): Vehicle equipped with A/C will allow TCC engagement at about 35 mph when the A/C is selected "ON". Engagement will occur at a vehicle speed of about 30 mph (25 mph for 92) when A/C is selected "OFF". - Engine Coolant Temperature (ECT) Sensor: Engine at normal operating temperature (above 65°C/149°F). - Throttle Position Sensor (TPS): Output not changing, indicating a steady road speed. - Transmission Fluid (TFT) sensor. Control module is also controlled by these switches: Brake switch closed: 12 volts supplied when brake is depressed. - Transmission Range (TR) pressure switch assembly. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Accumulator, A/T > Component Information > Technical Service Bulletins > A/T - 1-2 Accumulator Piston/Outer Spring Replacement Accumulator: Technical Service Bulletins A/T - 1-2 Accumulator Piston/Outer Spring Replacement File In Section: 7 - Transmission Bulletin No.: 87-71-74 Date: November, 1998 INFORMATION Subject: 1-2 Accumulator Piston and Outer Spring Replacement Models: 1982-96 Buick Roadmaster 1982-96 Cadillac Brougham, Fleetwood, DeVille 1982-86 Chevrolet Caprice 1982-99 Chevrolet Camaro, Corvette 1982-99 Pontiac Firebird with HYDRA-MATIC 4L60, 4L60-E Transmission (RPOs MD8, M30) 1982-99 Chevrolet and GMC C/K, M/L, S/T, G Models 1991-99 Oldsmobile Bravada with HYDRA-MATIC 4L60, 4L60-E Transmission (RPOs MD8, M30) Transmissions built from 1982 through 1999 were built with one of two styles of 1-2 accumulator pistons and outer springs. Important: The 1-2 accumulator pistons and outer springs are not interchangeable. For replacement of the 1-2 accumulator piston and outer spring, remove the 1-2 accumulator assembly and inspect the interior for the presence of either an aluminum or composite (plastic) 1-2 accumulator piston. Design 1 1-2 accumulator assemblies with an aluminum piston and a round wire outer spring, use service package P/N 24204495 (1982-1993) or P/N 24204496 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Accumulator, A/T > Component Information > Technical Service Bulletins > A/T - 1-2 Accumulator Piston/Outer Spring Replacement > Page 4733 (1994-1997). Design 2 1-2 accumulator assemblies with a composite (plastic) piston and an ovate wire outer spring, started May 11, 1998 (Julian Date 131), use service package P/N 24214343 (1998-1999). Notice: Failure to follow the above instructions may result in transmission distress. Parts Information Parts are currently available from GMSPO. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Accumulator, A/T > Component Information > Technical Service Bulletins > A/T - 1-2 Accumulator Piston/Outer Spring Replacement > Page 4734 Accumulator: Technical Service Bulletins A/T - Accumulator Assembly Service Manual Update Group Ref.: Transmission Bulletin No.: 377143 Date: November, 1993 SERVICE MANUAL UPDATE SUBJECT: SECTION 7A - AUTOMATIC - TRANSMISSION UNIT REPAIR - ACCUMULATOR ASSEMBLY MODELS: 1994 BUICK ROADMASTER 1994 CADILLAC FLEETWOOD 1994 CHEVROLET CAPRICE, CAMARO, CORVETTE 1994 PONTIAC FIREBIRD 1994 CHEVROLET AND GMC C/K, S/T TRUCKS AND L/M, G VANS 1994 OLDSMOBILE BRAVADA TRANSAXLE APPLICATIONS: 1994 HYDRA-MATIC 4L60-E (RPO M30) BULLETIN COVERS: New product information for 1994 HYDRA-MATIC 4L60-E transmissions. This information has been updated since publication of the 1994 Service Manual and should be noted accordingly. Be certain to familiarize yourself with these updates to properly repair the 1994 HYDRA-MATIC 4L60-E transmission. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Accumulator, A/T > Component Information > Technical Service Bulletins > A/T - 1-2 Accumulator Piston/Outer Spring Replacement > Page 4735 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Accumulator, A/T > Component Information > Technical Service Bulletins > A/T - 1-2 Accumulator Piston/Outer Spring Replacement > Page 4736 DATE OF PRODUCTION CHANGE: (Figures 1, 2 & 3) Beginning with start of production 1994, HYDRA-MATIC 4L60-E transmissions were built with a new calibration that has two (2) springs in the 1-2 accumulator. The 3-4 accumulator has also changed. Some models do not use a 3-4 accumulator spring. SERVICE MANUAL REFERENCE: Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Accumulator, A/T > Component Information > Technical Service Bulletins > A/T - 1-2 Accumulator Piston/Outer Spring Replacement > Page 4737 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Accumulator, A/T > Component Information > Technical Service Bulletins > A/T - 1-2 Accumulator Piston/Outer Spring Replacement > Page 4738 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Accumulator, A/T > Component Information > Technical Service Bulletins > A/T - 1-2 Accumulator Piston/Outer Spring Replacement > Page 4739 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Accumulator, A/T > Component Information > Technical Service Bulletins > A/T - 1-2 Accumulator Piston/Outer Spring Replacement > Page 4740 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Accumulator, A/T > Component Information > Technical Service Bulletins > A/T - 1-2 Accumulator Piston/Outer Spring Replacement > Page 4741 Update your 1994 Service Manual with the five (5) pages. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Accumulator, A/T > Component Information > Technical Service Bulletins > Page 4742 Accumulator: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Accumulator Cover To Case ............................................................................................................... ................................................................................. 8 FWD Accumulator Cover To Valve Body ....... .............................................................................................................................................................. ...... 8 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Band, A/T > Component Information > Technical Service Bulletins > A/T - 2-4 Band, TCC Solenoid, 3-4 Clutch Friction/Plates Band: Technical Service Bulletins A/T - 2-4 Band, TCC Solenoid, 3-4 Clutch Friction/Plates File In Section: 7 - Transmission Bulletin No.: 47-71-41 Date: January, 1995 Subject: New 2-4 Band Assembly, 3-4 Clutch Friction and Steel Plates and Torque Clutch PWM Solenoid Models: 1995 Buick Roadmaster 1995 Cadillac Fleetwood 1995 Chevrolet Camaro, Caprice, Corvette 1995 Pontiac Firebird 1995 Chevrolet and GMC Truck C/K Models and M/L, G Vans 1994-95 Chevrolet and GMC Truck S/T Models 1994 Oldsmobile Bravada (1994 Models with RPO +CTF Package) Transmission Applications: 1995 Hydra-Matic 4L60-E (RPO M30) A new 2-4 Band Assembly was introduced at the start of production for the 1995 Model Year and 1994 Bravadas and S/T trucks. The 2-4 Band friction material has changed appearance from a brown material to a gray/black material. This change was made to enhance durability. When servicing a 1995 Hydra-Matic 4L60-E transmission, do NOT assume that the 2-4 Band is burned/damaged due to its dark color. This dark color is normal. Before replacing the 2-4 Band inspect it for scoring, chunking or heavily worn friction material. Before Replacing the Reverse Input Housing and Drum Assembly inspect for scoring or signs of excessive heat. The 2-4 Band and/or Reverse Input Housing and Drum Assembly should be replaced ONLY if the above listed damage is found. Note: The new 2-4 Band Assembly will NOT service past model Hydra-Matic 4L60-E or 4L60 transmissions. A new 3-4 clutch friction plate was introduced at the start of production for the 1995 Model Year and 1994 Bravadas and S/T Trucks. The 3-4 clutch plate friction material has changed appearance from a brown material to a green/black material. This change was made to enhance durability. When servicing a 1995 Hydra-Matic 4L60-E transmission, do NOT assume that the 3-4 clutch friction plates are burned/damaged due to their dark color. This dark color is normal. Before replacing the 3-4 clutch friction plates inspect for scoring, chunking or heavily worn friction material. Before replacing the 3-4 clutch steel plates inspect for scoring or signs of excessive heat. The 3-4 clutch friction plates and/or 3-4 clutch steel plates should be replaced ONLY if the above listed damage is found. Note: The new 3-4 friction plates will NOT service past model Hydra-Matic 4L60-E or 4L60 transmissions. A new Torque Converter Clutch PWM Solenoid was introduced at the start of production for the 1995 Model Year and 1994 Bravadas and S/T trucks. The new torque converter clutch PWM solenoid is used to control fluid acting on the converter clutch valve, which then controls TCC apply and release. The solenoid is attached to the control valve body assembly within the transmission. The TCC PWM solenoid is used to provide smooth engagement of the torque converter by operating on a negative duty cycle percent of "ON" time. It a fault is detected in the TCC PWM circuit, DTC 83 will set. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Band, A/T > Component Information > Technical Service Bulletins > A/T - 2-4 Band, TCC Solenoid, 3-4 Clutch Friction/Plates > Page 4747 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Band, A/T > Component Information > Technical Service Bulletins > A/T - 2-4 Band, TCC Solenoid, 3-4 Clutch Friction/Plates > Page 4748 Included is a Service Manual update for the 1-2 and 3-4 accumulator spring color chart. Replace these pages in your 1995 Service Manual. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Band Apply Servo, A/T > Component Information > Service and Repair Band Apply Servo: Service and Repair 1. Raise and support vehicle. 2. Remove two oil pan bolts from below servo cover. 3. Install servo cover compressor tool No. J-29714 or equivalent on oil pan flange and depress servo cover. 4. Remove servo cover retaining ring. 5. Remove servo cover and seal ring. 6. Remove servo piston and bore-apply pin assembly. 7. Reverse procedure to install. Whenever any servo parts are replaced, apply-pin length must be checked. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Bell Housing, A/T > Component Information > Specifications Bell Housing: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Bellhousing To Case ........................................................................................................................... ............................................................................... 55 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Brake Switch - TCC > Component Information > Locations > Stoplamp/TCC Brake Switch Stoplamp/TCC Brake Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Brake Switch - TCC > Component Information > Locations > Stoplamp/TCC Brake Switch > Page 4759 I/P Harness Wiring, LH Side Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Brake Switch - TCC > Component Information > Locations > Page 4760 C217 - Brake Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Case, A/T > Component Information > Technical Service Bulletins > A/T - Cracked Case Diagnosis Case: Technical Service Bulletins A/T - Cracked Case Diagnosis Bulletin No.: 02-07-30-024B Date: August 18, 2005 INFORMATION Subject: Diagnosis of Cracked or Broken Transmission Case Models: 2006 and Prior Cars and Light Duty Trucks 2006 and Prior HUMMER H2 2006 HUMMER H3 2005-2006 Saab 9-7X with 4L60/4L60-E/4L65-E or 4L80-E/4L85-E or Allison(R) Series 1000 Automatic Transmission Supercede: This bulletin is being revised to add models and model years. Please discard Corporate Bulletin Number 02-07-30-024A (Section 07 - Transmission/Transaxle). Diagnosing the cause of a cracked or broken transmission case requires additional diagnosis and repair or a repeat failure will occur. A cracked or broken transmission case is most often the result of abnormal external torsional forces acting on the transmission case. If none of the conditions listed below are apparent, an internal transmission component inspection may be required. Repairs of this type may be the result of external damage or abuse for which General Motors is not responsible. They are not the result of defects in materials or workmanship. If in doubt, contact your General Motors Service Representative. The following items should be considered: ^ It is important to inspect the vehicle for signs of an out of line condition, impact damage or foreign material to the following components: - The transmission - The engine mounts - The transmission rear mount and crossmember - Vehicle frame damage that alters the front to rear alignment of the driveshaft - The driveshafts (both front and rear) - The wheels (caked with mud, concrete, etc.) - The tires (roundness, lack of cupping, excessive balance weights) - The transfer case (if the vehicle is 4WD) ^ A worn or damaged driveshaft U-Joint has shown to be a frequent cause of transmission case cracking, especially on vehicles that see extended periods of highway driving. Always inspect the U-joint condition when diagnosing this condition. ^ For driveshaft damage or imbalance, Inspect the driveshafts (both front and rear) for dents, straightness/runout or signs of missing balance weights. Also, inspect for foreign material such as undercoat sprayed on the driveshaft. ^ The driveshaft working angles may be excessive or non-canceling, especially if the vehicle carrying height has been altered (lifted or lowered) or if the frame has been extended or modified. ^ Damaged or worn upper or lower rear control arms or bushings. ^ A rear axle that is not seated in the rear spring properly (leaf spring vehicles). ^ Broken rear springs and or worn leaf spring bushings. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Case, A/T > Component Information > Technical Service Bulletins > A/T - Cracked Case Diagnosis > Page 4765 In some cases, the customer may not comment about a vibration but it is important to test drive the vehicle while using the electronic vibration analysis tool in an attempt to locate the cause of the torsional vibration. Refer to the Vibration Diagnosis and Correction sub-section of the appropriate Service Manual for more details on diagnosing and correcting vibrations. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Case, A/T > Component Information > Technical Service Bulletins > A/T - Cracked Case Diagnosis > Page 4766 Case: Technical Service Bulletins A/T - New Low and Reverse Support to Case Retainer Ring GROUP REF.: Transmission BULLETIN NO.: 477104 DATE: March, 1994 SUBJECT: NEW LOW AND REVERSE SUPPORT TO CASE RETAINER RING MODELS: 1994 BUICK ROADMASTER 1994 CADILLAC FLEETWOOD 1994 CHEVROLET CAPRICE, CAMARO, CORVETTE 1994 PONTIAC FIREBIRD 1994 CHEVROLET AND GMC C/K, S/T TRUCKS AND M/L, G VANS 1994 OLDSMOBILE BRAVADA TRANSMISSION APPLICATIONS: 1994 HYDRA-MATIC 4L60-E (RPO M30) BULLETIN COVERS: (Figure 1) New product information for 1994 HYDRA-MATIC 4L60-E transmissions. An enhanced low and reverse support to case retainer ring (ill. 676) has been released. The new low and reverse support to case retainer ring has been enhanced to contact the case ring groove around the entire ring. This will ultimately improve the retention of the ring. Also, the low and reverse support to case retainer ring must be located with the opening in the five o'clock position as shown in Figure 1. NOTE: The GMC Bulletin No. 367106 Automatic Transmission Service Procedure, will remain in effect for GMC trucks only. DATE OF PRODUCTION CHANGE: On August 08, 1993 the HYDRA-MATIC 4L60-E transmissions were built with the new low and reverse support to case retainer ring. SERVICE PARTS INFORMATION: Parts are expected to be available on February 28, 1994. PART NUMBER PART NAME Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Case, A/T > Component Information > Technical Service Bulletins > A/T - Cracked Case Diagnosis > Page 4767 24200278 Low and Reverse Support to Case Retainer Ring The new low and reverse support to case retainer ring can also be used for 1982-1993 HYDRA-MATIC 4L60 and 4L60-E transmissions. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Case, A/T > Component Information > Technical Service Bulletins > Page 4768 Case: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Accumulator Cover To Case ............................................................................................................... ................................................................................. 8 Case Extension To Case ................................ .............................................................................................................................................................. ....... 26 Auxiliary Valve Body To Case ................................................................................................ ............................................................................................ 8 Bellhousing To Case ........................... .............................................................................................................................................................. ................. 55 Pump Assembly To Case ............................................................................................. ...................................................................................................... 18 Solenoid Assembly To Case ... .............................................................................................................................................................. .............................. 18 Spacer Plate Support To Case ........................................................................ ...................................................................................................................... 8 Transmission Oil Pan To Case ............................................................................................................................................... .............................................. 8 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Channel Plate, A/T > Component Information > Technical Service Bulletins > A/T Control - DTC P0756 Diagnostic Tips Channel Plate: Technical Service Bulletins A/T Control - DTC P0756 Diagnostic Tips INFORMATION Bulletin No.: 01-07-30-036H Date: January 29, 2009 Subject: Diagnostic Tips for Automatic Transmission DTC P0756, Second, Third, Fourth Gear Start Models: 2009 and Prior GM Passenger Cars and Light Duty Trucks 2009 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X with 4L60-E, 4L65-E or 4L70E Automatic Transmission (RPOs M30, M32 or M70) Supercede: This bulletin is being revised to add the 2009 model year and add details regarding spacer plates. Please discard Corporate Bulletin Number 01-07-30-036G (Section 07 - Transmission/Transaxle). Some dealership technicians may have difficulty diagnosing DTC P0756, 2-3 Shift Valve Performance on 4L60-E, 4L65-E or 4L70E automatic transmissions. As detailed in the Service Manual, when the PCM detects a 4-3-3-4 shift pattern, DTC P0756 will set. Some customers may also describe a condition of a second, third or fourth gear start that may have the same causes but has not set this DTC yet. Below are some tips when diagnosing this DTC: ^ This is a performance code. This means that a mechanical malfunction exists. ^ This code is not set by electrical issues such as a damaged wiring harness or poor electrical connections. Electrical problems would cause a DTC P0758, P0787 or P0788 to set. ^ The most likely cause is chips/debris plugging the filtered AFL oil at orifice # 29 on the top of the spacer plate (48). This is a very small hole and is easily plugged by a small amount of debris. It is important to remove the spacer plate and inspect orifice # 29 and the immediate area for the presence of chips/debris. Also, the transmission case passage directly above this orifice and the valve body passage directly below should be inspected and cleaned of any chips/debris. For 2003 and newer vehicles the spacer plate should be replaced. The service replacement spacer plate is a bonded style with gaskets and solenoid filter screens bonded to the spacer plate. These screens can help to prevent plugging of orifice # 29 caused by small debris or chips. ^ This code could be set if the 2-3 shift valve (368) were stuck or hung-up in its bore. Inspect the 2-3 shift valve (368) and the 2-3 shuttle valve (369) for free movement or damage and clean the valves, the bore and the valve body passages. ^ This code could be set by a 2-3 shift solenoid (367b) if it were cracked, broken or leaking. Refer to Shift Solenoid Leak Test in the appropriate Service Manual for the leak test procedure. Based on parts return findings, a damaged or leaking shift solenoid is the least likely cause of this condition. Simply replacing a shift solenoid will not correct this condition unless the solenoid has been found to be cracked, broken or leaking. It is important to also refer to the appropriate Service Manual or Service Information (SI) for further possible causes of this condition. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Clutch, A/T > Component Information > Technical Service Bulletins > Customer Interest: > 08-07-30-027 > Jun > 08 > A/T - No Movement in Drive or 3rd Gear Clutch: Customer Interest A/T - No Movement in Drive or 3rd Gear TECHNICAL Bulletin No.: 08-07-30-027 Date: June 04, 2008 Subject: No Movement When Transmission is Shifted to Drive or Third - Normal Operation When Shifted to Second, First or Reverse (Replace Forward Sprag Assembly) Models: 1982 - 2005 GM Passenger Cars and Light Duty Trucks 2006 - 2007 Buick Rainier 2006 Cadillac Escalade, Escalade ESV, Escalade EXT 2006 Chevrolet SSR 2006 - 2008 Chevrolet Avalanche, Colorado, Express, Silverado Classic, Silverado, Suburban, Tahoe, TrailBlazer 2006 GMC Yukon Denali, Yukon Denali XL 2006 - 2008 GMC Canyon, Envoy, Savana, Sierra Classic, Sierra, Yukon, Yukon XL 2006 Pontiac GTO 2006 - 2007 HUMMER H2 2006 - 2008 HUMMER H3 2006 - 2008 Saab 9-7X with 4L60, 4L60E, 4L65E or 4L70E Automatic Transmission (RPOs MD8, M30, M32, M33 or M70) Condition Some customers may comment that the vehicle has no movement when the transmission is shifted to DRIVE or THIRD position, but there is normal operation when it is shifted to SECOND, FIRST or REVERSE position. Cause This condition may be caused by a damaged forward sprag assembly (642). Correction When inspecting the sprag, it is important to test the sprag for proper operation by holding the outer race (644) with one hand while rotating the input sun gear (640) with the other hand. The sun gear should rotate only in the counterclockwise direction with the input sun gear facing upward. If the sprag rotates in both directions or will not rotate in either direction, the sprag elements should be inspected by removing one of the sprag assembly retaining rings (643). Refer to SI Unit Repair section for forward clutch sprag disassembly procedures. If the sprag is found to be damaged, make repairs to the transmission as necessary. A new forward roller clutch sprag assembly is now available from GMSPO. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Clutch, A/T > Component Information > Technical Service Bulletins > Customer Interest: > 08-07-30-027 > Jun > 08 > A/T - No Movement in Drive or 3rd Gear > Page 4781 If clutch debris is found, it is also very important to inspect the Pressure Control (PC) solenoid valve (377) fluid screens. Clean or replace the PC solenoid (377) as necessary. It is also important to flush and flow check the transmission oil cooler using J45096. Refer to SI Automatic Transmission Oil Cooler Flushing and Flow Test for the procedure. The notches above each sprag must point up as shown when assembled into the outer race. Bearing Assembly, Input Sun Gear Snap Ring, Overrun Clutch Hub Retaining Hub, Overrun Clutch Wear Plate, Sprag Assembly Retainer and Race Assembly, Sprag Forward Sprag Assembly Retainer Rings, Sprag Assembly Outer Race, Forward Clutch Washer, Thrust (Input Carrier to Race) The following information applies when this sprag is used in 1982-86 transmissions. The new design sprag can be used on models 1982 through 1986, by replacing the entire assembly (637 - 644). Individual components are NOT Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Clutch, A/T > Component Information > Technical Service Bulletins > Customer Interest: > 08-07-30-027 > Jun > 08 > A/T - No Movement in Drive or 3rd Gear > Page 4782 interchangeable. Important: The wear plate (640) and input thrust washer (660) are not required with the new sprag. Use of the thrust washer and wear plate with the new sprag assembly will cause a misbuild (correct end play cannot be obtained). Parts Information Warranty Information For vehicles repaired under warranty, use the table. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Clutch, A/T > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Clutch: > 08-07-30-027 > Jun > 08 > A/T - No Movement in Drive or 3rd Gear Clutch: All Technical Service Bulletins A/T - No Movement in Drive or 3rd Gear TECHNICAL Bulletin No.: 08-07-30-027 Date: June 04, 2008 Subject: No Movement When Transmission is Shifted to Drive or Third - Normal Operation When Shifted to Second, First or Reverse (Replace Forward Sprag Assembly) Models: 1982 - 2005 GM Passenger Cars and Light Duty Trucks 2006 - 2007 Buick Rainier 2006 Cadillac Escalade, Escalade ESV, Escalade EXT 2006 Chevrolet SSR 2006 - 2008 Chevrolet Avalanche, Colorado, Express, Silverado Classic, Silverado, Suburban, Tahoe, TrailBlazer 2006 GMC Yukon Denali, Yukon Denali XL 2006 - 2008 GMC Canyon, Envoy, Savana, Sierra Classic, Sierra, Yukon, Yukon XL 2006 Pontiac GTO 2006 - 2007 HUMMER H2 2006 - 2008 HUMMER H3 2006 - 2008 Saab 9-7X with 4L60, 4L60E, 4L65E or 4L70E Automatic Transmission (RPOs MD8, M30, M32, M33 or M70) Condition Some customers may comment that the vehicle has no movement when the transmission is shifted to DRIVE or THIRD position, but there is normal operation when it is shifted to SECOND, FIRST or REVERSE position. Cause This condition may be caused by a damaged forward sprag assembly (642). Correction When inspecting the sprag, it is important to test the sprag for proper operation by holding the outer race (644) with one hand while rotating the input sun gear (640) with the other hand. The sun gear should rotate only in the counterclockwise direction with the input sun gear facing upward. If the sprag rotates in both directions or will not rotate in either direction, the sprag elements should be inspected by removing one of the sprag assembly retaining rings (643). Refer to SI Unit Repair section for forward clutch sprag disassembly procedures. If the sprag is found to be damaged, make repairs to the transmission as necessary. A new forward roller clutch sprag assembly is now available from GMSPO. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Clutch, A/T > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Clutch: > 08-07-30-027 > Jun > 08 > A/T - No Movement in Drive or 3rd Gear > Page 4788 If clutch debris is found, it is also very important to inspect the Pressure Control (PC) solenoid valve (377) fluid screens. Clean or replace the PC solenoid (377) as necessary. It is also important to flush and flow check the transmission oil cooler using J45096. Refer to SI Automatic Transmission Oil Cooler Flushing and Flow Test for the procedure. The notches above each sprag must point up as shown when assembled into the outer race. Bearing Assembly, Input Sun Gear Snap Ring, Overrun Clutch Hub Retaining Hub, Overrun Clutch Wear Plate, Sprag Assembly Retainer and Race Assembly, Sprag Forward Sprag Assembly Retainer Rings, Sprag Assembly Outer Race, Forward Clutch Washer, Thrust (Input Carrier to Race) The following information applies when this sprag is used in 1982-86 transmissions. The new design sprag can be used on models 1982 through 1986, by replacing the entire assembly (637 - 644). Individual components are NOT Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Clutch, A/T > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Clutch: > 08-07-30-027 > Jun > 08 > A/T - No Movement in Drive or 3rd Gear > Page 4789 interchangeable. Important: The wear plate (640) and input thrust washer (660) are not required with the new sprag. Use of the thrust washer and wear plate with the new sprag assembly will cause a misbuild (correct end play cannot be obtained). Parts Information Warranty Information For vehicles repaired under warranty, use the table. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Clutch, A/T > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Clutch: > 577112A > Sep > 95 > A/T - Low/Reverse Clutch Spacer Plate Selection Clutch: All Technical Service Bulletins A/T - Low/Reverse Clutch Spacer Plate Selection File In Section: 7 - Transmission Bulletin No.: 57-71-12A Date: September, 1995 Subject: Section 7 - Lo and Reverse Clutch Spacer Plate Selection Models: 1993-95 Buick Roadmaster 1993-95 Cadillac Fleetwood 1993-95 Chevrolet Camaro, Caprice, Corvette 1993-95 Pontiac Firebird 1993-95 Chevrolet and GMC Truck C/K, S/T; M/L, G Models 1993-94 Oldsmobile Bravada with 4L60/4L60-E Transmission (RPOs M30, MD8) This bulletin is being revised to Include the 4L60 Transmission. Please discard Corporate Bulletin Number 57-71-12 (Section 7 - Transmission). The dimension "D" for the overall height for the lo reverse clutch plates is in error. The correct measurement should be 29.22 to 29.90 mm (1.15 to 1.18 inches). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Clutch, A/T > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Clutch: > 577112A > Sep > 95 > A/T - Low/Reverse Clutch Spacer Plate Selection > Page 4794 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Clutch, A/T > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Clutch: > 577112A > Sep > 95 > A/T - Low/Reverse Clutch Spacer Plate Selection > Page 4795 Included are the updated pages for your Service Manual. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Clutch, A/T > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Clutch: > 477141 > Jan > 95 > A/T - 2-4 Band, TCC Solenoid, 3-4 Clutch Friction/Plates Clutch: All Technical Service Bulletins A/T - 2-4 Band, TCC Solenoid, 3-4 Clutch Friction/Plates File In Section: 7 - Transmission Bulletin No.: 47-71-41 Date: January, 1995 Subject: New 2-4 Band Assembly, 3-4 Clutch Friction and Steel Plates and Torque Clutch PWM Solenoid Models: 1995 Buick Roadmaster 1995 Cadillac Fleetwood 1995 Chevrolet Camaro, Caprice, Corvette 1995 Pontiac Firebird 1995 Chevrolet and GMC Truck C/K Models and M/L, G Vans 1994-95 Chevrolet and GMC Truck S/T Models 1994 Oldsmobile Bravada (1994 Models with RPO +CTF Package) Transmission Applications: 1995 Hydra-Matic 4L60-E (RPO M30) A new 2-4 Band Assembly was introduced at the start of production for the 1995 Model Year and 1994 Bravadas and S/T trucks. The 2-4 Band friction material has changed appearance from a brown material to a gray/black material. This change was made to enhance durability. When servicing a 1995 Hydra-Matic 4L60-E transmission, do NOT assume that the 2-4 Band is burned/damaged due to its dark color. This dark color is normal. Before replacing the 2-4 Band inspect it for scoring, chunking or heavily worn friction material. Before Replacing the Reverse Input Housing and Drum Assembly inspect for scoring or signs of excessive heat. The 2-4 Band and/or Reverse Input Housing and Drum Assembly should be replaced ONLY if the above listed damage is found. Note: The new 2-4 Band Assembly will NOT service past model Hydra-Matic 4L60-E or 4L60 transmissions. A new 3-4 clutch friction plate was introduced at the start of production for the 1995 Model Year and 1994 Bravadas and S/T Trucks. The 3-4 clutch plate friction material has changed appearance from a brown material to a green/black material. This change was made to enhance durability. When servicing a 1995 Hydra-Matic 4L60-E transmission, do NOT assume that the 3-4 clutch friction plates are burned/damaged due to their dark color. This dark color is normal. Before replacing the 3-4 clutch friction plates inspect for scoring, chunking or heavily worn friction material. Before replacing the 3-4 clutch steel plates inspect for scoring or signs of excessive heat. The 3-4 clutch friction plates and/or 3-4 clutch steel plates should be replaced ONLY if the above listed damage is found. Note: The new 3-4 friction plates will NOT service past model Hydra-Matic 4L60-E or 4L60 transmissions. A new Torque Converter Clutch PWM Solenoid was introduced at the start of production for the 1995 Model Year and 1994 Bravadas and S/T trucks. The new torque converter clutch PWM solenoid is used to control fluid acting on the converter clutch valve, which then controls TCC apply and release. The solenoid is attached to the control valve body assembly within the transmission. The TCC PWM solenoid is used to provide smooth engagement of the torque converter by operating on a negative duty cycle percent of "ON" time. It a fault is detected in the TCC PWM circuit, DTC 83 will set. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Clutch, A/T > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Clutch: > 477141 > Jan > 95 > A/T - 2-4 Band, TCC Solenoid, 3-4 Clutch Friction/Plates > Page 4800 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Clutch, A/T > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Clutch: > 477141 > Jan > 95 > A/T - 2-4 Band, TCC Solenoid, 3-4 Clutch Friction/Plates > Page 4801 Included is a Service Manual update for the 1-2 and 3-4 accumulator spring color chart. Replace these pages in your 1995 Service Manual. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Clutch, A/T > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Clutch: > 477105 > Mar > 94 > A/T - New Long Lip Seal Design 3-4 and Forward Clutches Clutch: All Technical Service Bulletins A/T - New Long Lip Seal Design 3-4 and Forward Clutches GROUP REF.: Transmission BULLETIN NO.: 477105 DATE: March, 1994 SUBJECT: NEW LONG LIP SEAL DESIGN 3A AND FORWARD CLUTCHES MODELS: 1994 BUICK ROADMASTER 1994 CADILLAC FLEETWOOD 1994 CHEVROLET CAPRICE, CAMARO, CORVETTE 1994 PONTIAC FIREBIRD 1994 CHEVROLET AND GMC C/K, S/T TRUCKS AND M/L, G VANS 1994 OLDSMOBILE BRAVADA TRANSMISSION APPLICATIONS: 1994 HYDRA-MATIC 4L60-E (RPO M30) BULLETIN COVERS: (Figure 1) New product information for 1994 HYDRA-MATIC 4L60-E transmissions. New clutch piston seal design. The 3-4 clutch piston outer seal and the forward clutch piston outer seals have been redesigned to include a long lip profile for enhanced sealing. Be certain to familiarize yourself with these updates to properly repair the 1994 HYDRA-MATIC 4L60-E transmission. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Clutch, A/T > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Clutch: > 477105 > Mar > 94 > A/T - New Long Lip Seal Design 3-4 and Forward Clutches > Page 4806 DATE OF PRODUCTION CHANGE: (Figure 2) Beginning with August 09, 1993, the HYDRA-MATIC 4L60-E transmissions were built with a new 3-4 clutch outer seal (long lip). On September 20,1993 the HYDRA-MATIC 4L60-E transmissions were built with a new forward clutch outer seal (long lip). SERVICE PARTS INFORMATION: The new 3-4 clutch outer seal and forward clutch outer seal should be used when rebuilding transmissions that operate under -25°F or if the 3-4 clutch plates or forward clutch plates exhibit a burnt condition. The long lip seals are interchangeable with the current seals. The new design will replace the current seal in service packages as stock is depleted. To order the long lip seals individually use the following part numbers: PART NUMBER PART NAME 8642138 3-4 Clutch Outer Seal 8686146 Forward Clutch Outer Seal These seals can also be used for 1982-1993 HYDRA-MATIC 4L60 and 4L60-E transmissions. NOTE: The GMC Bulletin No. 367106 Automatic Transmission Service Procedure, will remain in effect for GMC trucks only. Parts are currently available from GMSPO. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Clutch, A/T > Component Information > Technical Service Bulletins > All Other Service Bulletins for Clutch: > 577112A > Sep > 95 > A/T Low/Reverse Clutch Spacer Plate Selection Clutch: All Technical Service Bulletins A/T - Low/Reverse Clutch Spacer Plate Selection File In Section: 7 - Transmission Bulletin No.: 57-71-12A Date: September, 1995 Subject: Section 7 - Lo and Reverse Clutch Spacer Plate Selection Models: 1993-95 Buick Roadmaster 1993-95 Cadillac Fleetwood 1993-95 Chevrolet Camaro, Caprice, Corvette 1993-95 Pontiac Firebird 1993-95 Chevrolet and GMC Truck C/K, S/T; M/L, G Models 1993-94 Oldsmobile Bravada with 4L60/4L60-E Transmission (RPOs M30, MD8) This bulletin is being revised to Include the 4L60 Transmission. Please discard Corporate Bulletin Number 57-71-12 (Section 7 - Transmission). The dimension "D" for the overall height for the lo reverse clutch plates is in error. The correct measurement should be 29.22 to 29.90 mm (1.15 to 1.18 inches). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Clutch, A/T > Component Information > Technical Service Bulletins > All Other Service Bulletins for Clutch: > 577112A > Sep > 95 > A/T Low/Reverse Clutch Spacer Plate Selection > Page 4812 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Clutch, A/T > Component Information > Technical Service Bulletins > All Other Service Bulletins for Clutch: > 577112A > Sep > 95 > A/T Low/Reverse Clutch Spacer Plate Selection > Page 4813 Included are the updated pages for your Service Manual. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Clutch, A/T > Component Information > Technical Service Bulletins > All Other Service Bulletins for Clutch: > 477141 > Jan > 95 > A/T 2-4 Band, TCC Solenoid, 3-4 Clutch Friction/Plates Clutch: All Technical Service Bulletins A/T - 2-4 Band, TCC Solenoid, 3-4 Clutch Friction/Plates File In Section: 7 - Transmission Bulletin No.: 47-71-41 Date: January, 1995 Subject: New 2-4 Band Assembly, 3-4 Clutch Friction and Steel Plates and Torque Clutch PWM Solenoid Models: 1995 Buick Roadmaster 1995 Cadillac Fleetwood 1995 Chevrolet Camaro, Caprice, Corvette 1995 Pontiac Firebird 1995 Chevrolet and GMC Truck C/K Models and M/L, G Vans 1994-95 Chevrolet and GMC Truck S/T Models 1994 Oldsmobile Bravada (1994 Models with RPO +CTF Package) Transmission Applications: 1995 Hydra-Matic 4L60-E (RPO M30) A new 2-4 Band Assembly was introduced at the start of production for the 1995 Model Year and 1994 Bravadas and S/T trucks. The 2-4 Band friction material has changed appearance from a brown material to a gray/black material. This change was made to enhance durability. When servicing a 1995 Hydra-Matic 4L60-E transmission, do NOT assume that the 2-4 Band is burned/damaged due to its dark color. This dark color is normal. Before replacing the 2-4 Band inspect it for scoring, chunking or heavily worn friction material. Before Replacing the Reverse Input Housing and Drum Assembly inspect for scoring or signs of excessive heat. The 2-4 Band and/or Reverse Input Housing and Drum Assembly should be replaced ONLY if the above listed damage is found. Note: The new 2-4 Band Assembly will NOT service past model Hydra-Matic 4L60-E or 4L60 transmissions. A new 3-4 clutch friction plate was introduced at the start of production for the 1995 Model Year and 1994 Bravadas and S/T Trucks. The 3-4 clutch plate friction material has changed appearance from a brown material to a green/black material. This change was made to enhance durability. When servicing a 1995 Hydra-Matic 4L60-E transmission, do NOT assume that the 3-4 clutch friction plates are burned/damaged due to their dark color. This dark color is normal. Before replacing the 3-4 clutch friction plates inspect for scoring, chunking or heavily worn friction material. Before replacing the 3-4 clutch steel plates inspect for scoring or signs of excessive heat. The 3-4 clutch friction plates and/or 3-4 clutch steel plates should be replaced ONLY if the above listed damage is found. Note: The new 3-4 friction plates will NOT service past model Hydra-Matic 4L60-E or 4L60 transmissions. A new Torque Converter Clutch PWM Solenoid was introduced at the start of production for the 1995 Model Year and 1994 Bravadas and S/T trucks. The new torque converter clutch PWM solenoid is used to control fluid acting on the converter clutch valve, which then controls TCC apply and release. The solenoid is attached to the control valve body assembly within the transmission. The TCC PWM solenoid is used to provide smooth engagement of the torque converter by operating on a negative duty cycle percent of "ON" time. It a fault is detected in the TCC PWM circuit, DTC 83 will set. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Clutch, A/T > Component Information > Technical Service Bulletins > All Other Service Bulletins for Clutch: > 477141 > Jan > 95 > A/T 2-4 Band, TCC Solenoid, 3-4 Clutch Friction/Plates > Page 4818 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Clutch, A/T > Component Information > Technical Service Bulletins > All Other Service Bulletins for Clutch: > 477141 > Jan > 95 > A/T 2-4 Band, TCC Solenoid, 3-4 Clutch Friction/Plates > Page 4819 Included is a Service Manual update for the 1-2 and 3-4 accumulator spring color chart. Replace these pages in your 1995 Service Manual. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Clutch, A/T > Component Information > Technical Service Bulletins > All Other Service Bulletins for Clutch: > 477105 > Mar > 94 > A/T New Long Lip Seal Design 3-4 and Forward Clutches Clutch: All Technical Service Bulletins A/T - New Long Lip Seal Design 3-4 and Forward Clutches GROUP REF.: Transmission BULLETIN NO.: 477105 DATE: March, 1994 SUBJECT: NEW LONG LIP SEAL DESIGN 3A AND FORWARD CLUTCHES MODELS: 1994 BUICK ROADMASTER 1994 CADILLAC FLEETWOOD 1994 CHEVROLET CAPRICE, CAMARO, CORVETTE 1994 PONTIAC FIREBIRD 1994 CHEVROLET AND GMC C/K, S/T TRUCKS AND M/L, G VANS 1994 OLDSMOBILE BRAVADA TRANSMISSION APPLICATIONS: 1994 HYDRA-MATIC 4L60-E (RPO M30) BULLETIN COVERS: (Figure 1) New product information for 1994 HYDRA-MATIC 4L60-E transmissions. New clutch piston seal design. The 3-4 clutch piston outer seal and the forward clutch piston outer seals have been redesigned to include a long lip profile for enhanced sealing. Be certain to familiarize yourself with these updates to properly repair the 1994 HYDRA-MATIC 4L60-E transmission. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Clutch, A/T > Component Information > Technical Service Bulletins > All Other Service Bulletins for Clutch: > 477105 > Mar > 94 > A/T New Long Lip Seal Design 3-4 and Forward Clutches > Page 4824 DATE OF PRODUCTION CHANGE: (Figure 2) Beginning with August 09, 1993, the HYDRA-MATIC 4L60-E transmissions were built with a new 3-4 clutch outer seal (long lip). On September 20,1993 the HYDRA-MATIC 4L60-E transmissions were built with a new forward clutch outer seal (long lip). SERVICE PARTS INFORMATION: The new 3-4 clutch outer seal and forward clutch outer seal should be used when rebuilding transmissions that operate under -25°F or if the 3-4 clutch plates or forward clutch plates exhibit a burnt condition. The long lip seals are interchangeable with the current seals. The new design will replace the current seal in service packages as stock is depleted. To order the long lip seals individually use the following part numbers: PART NUMBER PART NAME 8642138 3-4 Clutch Outer Seal 8686146 Forward Clutch Outer Seal These seals can also be used for 1982-1993 HYDRA-MATIC 4L60 and 4L60-E transmissions. NOTE: The GMC Bulletin No. 367106 Automatic Transmission Service Procedure, will remain in effect for GMC trucks only. Parts are currently available from GMSPO. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Extension Housing, A/T > Component Information > Specifications Extension Housing: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Case Extension To Case ..................................................................................................................... ................................................................................ 26 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Fluid - A/T > Component Information > Technical Service Bulletins > A/T - DEXRON(R)-VI Fluid Information Fluid - A/T: Technical Service Bulletins A/T - DEXRON(R)-VI Fluid Information INFORMATION Bulletin No.: 04-07-30-037E Date: April 07, 2011 Subject: Release of DEXRON(R)-VI Automatic Transmission Fluid (ATF) Models: 2008 and Prior GM Passenger Cars and Light Duty Trucks 2003-2008 HUMMER H2 2006-2008 HUMMER H3 2005-2007 Saturn Relay 2005 and Prior Saturn L-Series 2005-2007 Saturn ION 2005-2008 Saturn VUE with 4T45-E 2005-2008 Saab 9-7X Except 2008 and Prior Chevrolet Aveo, Equinox Except 2006 and Prior Chevrolet Epica Except 2007 and Prior Chevrolet Optra Except 2008 and Prior Pontiac Torrent, Vibe, Wave Except 2003-2005 Saturn ION with CVT or AF23 Only Except 1991-2002 Saturn S-Series Except 2008 and Prior Saturn VUE with CVT, AF33 or 5AT (MJ7/MJ8) Transmission Only Except 2008 Saturn Astra Attention: DEXRON(R)-VI Automatic Transmission Fluid (ATF) is the only approved fluid for warranty repairs for General Motors transmissions/transaxles requiring DEXRON(R)-III and/or prior DEXRON(R) transmission fluids. Supercede: This bulletin is being revised to update information. Please discard Corporate Bulletin Number 04-07-30-037D (Section 07 - Transmission/Transaxle). MANUAL TRANSMISSIONS / TRANSFER CASES and POWER STEERING The content of this bulletin does not apply to manual transmissions or transfer cases. Any vehicle that previously required DEXRON(R)-III for a manual transmission or transfer case should now use P/N 88861800. This fluid is labeled Manual Transmission and Transfer Case Fluid. Some manual transmissions and transfer cases require a different fluid. Appropriate references should be checked when servicing any of these components. Power Steering Systems should now use P/N 9985010 labeled Power Steering Fluid. Consult the Parts Catalog, Owner's Manual, or Service Information (SI) for fluid recommendations. Some of our customers and/or General Motors dealerships/Saturn Retailers may have some concerns with DEXRON(R)-VI and DEXRON(R)-III Automatic Transmission Fluid (ATF) and transmission warranty claims. DEXRON(R)-VI is the only approved fluid for warranty repairs for General Motors transmissions/transaxles requiring DEXRON(R)-III and/or prior DEXRON(R) transmission fluids (except as noted above). Please remember that the clean oil reservoirs of the J-45096 - Flushing and Flow Tester machine should be purged of DEXRON(R)-III and filled with DEXRON(R)-VI for testing, flushing or filling General Motors transmissions/transaxles (except as noted above). DEXRON(R)-VI can be used in any proportion in past model vehicles equipped with an automatic transmission/transaxle in place of DEXRON(R)-III (i.e. topping off the fluid in the event of a repair or fluid change). DEXRON(R)-VI is also compatible with any former version of DEXRON(R) for use in automatic transmissions/transaxles. DEXRON(R)-VI ATF General Motors Powertrain has upgraded to DEXRON(R)-VI ATF with the start of 2006 vehicle production. Current and prior automatic transmission models that had used DEXRON(R)-III must now only use DEXRON(R)-VI. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Fluid - A/T > Component Information > Technical Service Bulletins > A/T - DEXRON(R)-VI Fluid Information > Page 4832 All 2006 and future model transmissions that use DEXRON(R)-VI are to be serviced ONLY with DEXRON(R)-VI fluid. DEXRON(R)-VI is an improvement over DEXRON(R)-III in the following areas: * These ATF change intervals remain the same as DEXRON(R)-III for the time being. 2006-2008 Transmission Fill and Cooler Flushing Some new applications of the 6L80 six speed transmission will require the use of the J 45096 Flushing and Flow Tester to accomplish transmission fluid fill. The clean oil reservoir of the machine should be purged of DEXRON(R)-III and filled with DEXRON(R)-VI. Parts Information Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Fluid - A/T > Component Information > Technical Service Bulletins > A/T - DEXRON(R)-VI Fluid Information > Page 4833 Fluid - A/T: Technical Service Bulletins A/T - Water Or Coolant Contamination Information INFORMATION Bulletin No.: 08-07-30-035B Date: November 01, 2010 Subject: Information on Water or Ethylene Glycol in Transmission Fluid Models: 2011 and Prior GM Passenger Cars and Light Duty Trucks with Automatic Transmission Supercede: This bulletin is being revised to update model years. Please discard Corporate Bulletin Number 08-07-30-035A (Section 07 - Transmission/Transaxle). Water or ethylene glycol in automatic transmission fluid (ATF) is harmful to internal transmission components and will have a negative effect on reliability and durability of these parts. Water or ethylene glycol in ATF will also change the friction of the clutches, frequently resulting in shudder during engagement or gear changes, especially during torque converter clutch engagement. Indications of water in the ATF may include: - ATF blowing out of the transmission vent tube. - ATF may appear cloudy or, in cases of extreme contamination, have the appearance of a strawberry milkshake. - Visible water in the oil pan. - A milky white substance inside the pan area. - Spacer plate gaskets that appear to be glued to the valve body face or case. - Spacer plate gaskets that appear to be swollen or wrinkled in areas where they are not compressed. - Rust on internal transmission iron/steel components. If water in the ATF has been found and the source of the water entry has not been identified, or if a leaking in-radiator transmission oil cooler is suspected (with no evidence of cross-contamination in the coolant recovery reservoir), a simple and quick test kit is available that detects the presence of ethylene glycol in ATF. The "Gly-Tek" test kit, available from the Nelco Company, should be obtained and the ATF tested to make an accurate decision on the need for radiator replacement. This can help to prevent customer comebacks if the in-radiator transmission oil cooler is leaking and reduce repair expenses by avoiding radiator replacement if the cooler is not leaking. These test kits can be obtained from: Nelco Company Test kits can be ordered by phone or through the website listed above. Orders are shipped standard delivery time but can be shipped on a next day delivery basis for an extra charge. One test kit will complete 10 individual fluid sample tests. For vehicles repaired under warranty, the cost of the complete test kit plus shipping charges should be divided by 10 and submitted on the warranty claim as a net item. The transmission should be repaired or replaced based on the normal cost comparison procedure. Important If water or coolant is found in the transmission, the following components MUST be replaced. - Replace all of the rubber-type seals. - Replace all of the composition-faced clutch plates and/or bands. - Replace all of the nylon parts. - Replace the torque converter. - Thoroughly clean and rebuild the transmission, using new gaskets and oil filter. Important The following steps must be completed when repairing or replacing. Flush and flow check the transmission oil cooler using J 45096. Refer to Corporate Bulletin Number 02-07-30-052F- Automatic Transmission Oil Cooler Flush and Flow Test Essential Tool J 45096 TransFlow. - Thoroughly inspect the engine cooling system and hoses and clean/repair as necessary. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Fluid - A/T > Component Information > Technical Service Bulletins > A/T - DEXRON(R)-VI Fluid Information > Page 4834 Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Fluid - A/T > Component Information > Technical Service Bulletins > A/T - DEXRON(R)-VI Fluid Information > Page 4835 Fluid - A/T: Technical Service Bulletins A/T - Dexron IIE Preferred Fluid for All Hydra-matic BULLETIN No.: 9274T60-E-02 CORP. REF. NO.: 177125 DATE: October 1991 TRANSMISSION APPLICATIONS: All TRANSMISSION MODELS: All SUBJECT: Dexron(R)-IIE Automatic Transmission/Transaxle Fluid VEHICLE APPLICATIONS: All Hydra-matic Automatic Transmissions/Transaxles BULLETIN COVERS: General Motors has developed a new service fill automatic transmission/transaxle fluid which is designated DEXRON(R)-IIE. This fluid is the preferred fluid for all HYDRA-MATIC automatic transmissions/transaxles and will eventually replace DEXRON(R)-II. DEXRON(R)-IIE is acceptable for use whenever DEXRON(R)-II was previously specified. DEXRON(R)-II is acceptable for use when DEXRON(R)-IIE is not available. DEXRON(R)-II and DEXRON(R)-IIE can be used in both electronically and hydraulically controlled transmissions/ transaxles. DEXRON(R)-IIE Advantages Over DEXRON(R)-II: ^ Has better anti-foaming characteristic. ^ Improved high temperature oxidation stability and improved low temperature flow characteristics (low temperature viscosity). ^ DEXRON(R)-IIE and DEXRON(R)-II can be mixed in any ratio. No draining or flushing of system is required. ^ DEXRON(R)-IIE is back serviceable to 1949 for all General Motors automatic transmissions/transaxles. ^ No change in transmission/transaxle calibration or reduction in transmission/transaxle durability will occur as a result of using DEXRON(R)-IIE. SERVICE PART INFORMATION: PART NUMBER DESCRIPTION 12345881 1 quart container 12345882 1 gallon container 12345883 55 gallon drum Parts are currently available from GMSPO. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Fluid - A/T > Component Information > Technical Service Bulletins > A/T - DEXRON(R)-VI Fluid Information > Page 4836 Fluid - A/T: Technical Service Bulletins A/T - DEXRON III Fluid Introduction File In Section: 0 - General Information Bulletin No.: 57-02-01 Date: March, 1995 SERVICE MANUAL UPDATE Subject: Section 0 - General Information - DEXRON(R)-III Transmission Fluid Introduction Models: 1995 and Prior Passenger Cars and Trucks General Motors has phased in a new automatic transmission fluid, DEXRON(R)-III, that does not need replacing under normal service. DEXRON(R)-III is designed to help the transmission deliver the best possible performance under all conditions. Refer to Figure 1. The improvements in DEXRON(R)-III include better friction stability, more high temperature oxidation stability and better material compatibility. DEXRON(R)-III has the same low temperature fluidity as DEXRON(R)-IIE, for better transmission performance in cold weather. DEXRON(R)-IIE and DEXRON(R)-III are fully compatible. DEXRON(R)-III is fully compatible with any General Motors passenger vehicle or light truck with automatic transmission and built since 1949. Dealers should require their supplier to include the DEXRON(R)-III license number on all automatic transmission fluid invoices. Starting February 1, 1994 DEXRON(R)-III was phased into all North American assembly plants. DEXRON(R)-III fluid is available from GMSPO (see fluid numbers below): U.S. 1 Quart 12346143 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Fluid - A/T > Component Information > Technical Service Bulletins > A/T - DEXRON(R)-VI Fluid Information > Page 4837 1 Gallon 12346144 55 Gallon 12346145 In Canada 1 Liter 10952622 4 Liter 10952623 200 Liter 10952624 The 1995 Automatic Transmission/Transaxle fluid change intervals are the following: (1994 and prior should use the schedules as written in the Owner's Manual.) If the vehicle is mainly driven under one or more of these conditions: In heavy city traffic where the outside temperature regularly reaches 90°F (32°C) or higher. In hilly or mountainous terrain. When doing frequent trailer towing. Uses such as found in taxi, police car or delivery service. Change the fluid and filter every 50,000 miles (63,000 km). If the vehicle is not used mainly under any of these conditions, the fluid and filter do not require periodic changing for vehicles under 8,600 GVWR. Vehicles over 8,600 GVWR change the fluid and filter every 50,000 miles (83,000 km) regardless of driving conditions. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Fluid - A/T > Component Information > Specifications > Capacity Specifications Fluid - A/T: Capacity Specifications CAPACITIES ....................................................................................................................................... ................................................................ QUARTS Pan Capacity ....................................................................................................................................... .............................................................................. 5.0 Total (Overhaul) Capacity ............................... .............................................................................................................................................................. .. 11.2 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Fluid - A/T > Component Information > Specifications > Capacity Specifications > Page 4840 Fluid - A/T: Fluid Type Specifications Fluid Type ............................................................................................................................................ ............................................................... Dexron IIE Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Fluid - A/T > Component Information > Specifications > Page 4841 Fluid - A/T: Testing and Inspection Fluid level should be checked at every engine oil change. Frequency of change for transmission fluid is dependent on the type of driving conditions in which the vehicle is used. If the transmission is subjected to severe service such as: use in heavy city traffic when the outside temperature regularly reaches 90°F, use in very hilly or mountainous areas, commercial use such as taxi or delivery service, the fluid should be changed every 15,000 miles when using Dexron II and 50,000 miles when using Dexron III or equivalent. Otherwise, change the fluid every 100,000 miles, using Dexron II, III or equivalent automatic transmission fluid. When checking fluid, ensure vehicle is at operating temperature (190°-200°F), which can be obtained by 15 miles of highway-type driving. After transmission fluid is at operating temperature, use the following procedure to check fluid level: 1. Ensure vehicle is on a level surface, then move gear selector to the Park position. 2. Apply parking brake and block wheels, then allow engine to run at idle speed for three minutes with accessories off. 3. Check fluid level, color and condition. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Fluid - A/T > Component Information > Service and Repair > Changing Fluid Fluid - A/T: Service and Repair Changing Fluid 1. Raise and support vehicle. 2. Loosen two bolts attaching right side of transmission support to frame rail. 3. Remove two bolts attaching left side transmission support to frame rail. 4. Using suitable transmission jack, support and slightly raise transmission. 5. Slide transmission support rearward enough to access rear oil pan attaching bolts. 6. Place drain pan under transmission oil pan, loosen pan bolts on front of pan, pry carefully with screwdriver to loosen oil pan, and allow fluid to drain. 7. Remove remaining oil pan bolts, oil pan, and gasket. 8. Drain fluid from pan, then clean pan and dry thoroughly with compressed air. 9. Remove oil filter to valve body bolt, then remove filter and gasket, replace with new filter and gasket. 10. Install new gasket on oil pan, then oil pan and attaching bolts. Tighten attaching bolts to specification. 11. Lower vehicle and add five quarts of automatic transmission fluid through filler tube. 12. With selector lever in Park and parking brake applied, start engine and let idle. Do not race engine. 13. Move selector lever through each gear range, then return lever to park. 14. Check fluid, then add additional fluid to bring level between dimples on dipstick. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Fluid - A/T > Component Information > Service and Repair > Changing Fluid > Page 4844 Fluid - A/T: Service and Repair Adding Fluid to A DRY Transmission 1. Add transmission fluid through filler tube until oil level is between the "ADD" and "HOT" marks on dipstick. 2. Place selector lever in park, depress accelerator to place carburetor on fast idle cam, and move selector lever through each range. Do not race engine. 3. With selector lever in park, engine running at idle (1-3 minutes), and vehicle on level surface, check fluid level and add additional fluid to bring level between dimples on dipstick. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Fluid Filter - A/T > Component Information > Technical Service Bulletins > A/T - Updated Design Oil Filter Assembly & Seal Fluid Filter - A/T: Technical Service Bulletins A/T - Updated Design Oil Filter Assembly & Seal Group Ref.: Transmission Bulletin No.: 377142A Date: February, 1994 INFORMATION SUBJECT: NEW TRANSMISSION OIL FILTER ASSEMBLY MODELS: 1994 BUICK ROADMASTER 1994 CADILLAC FLEETWOOD 1994 CHEVROLET CAPRICE, CAMARO, CORVETTE 1994 PONTIAC FIREBIRD 1994 CHEVROLET AND GMC C/K AND S/T TRUCKS 1994 CHEVROLET AND GMC M/L AND G VANS 1994 OLDSMOBILE BRAVADA TRANSMISSION APPLICATIONS: 1994 HYDRA-MATIC 4L60-E (M30) THIS BULLETIN IS BEING REVISED TO CLARIFY TRANSMISSION USAGE. PLEASE DISCARD BULLETIN 377142. BULLETIN COVERS: New product information for 1994 HYDRA-MATIC 4L60-E transmissions. Be certain to familiarize yourself with these updates to properly repair the 1994 HYDRA-MATIC 4L60-E transmission. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Fluid Filter - A/T > Component Information > Technical Service Bulletins > A/T - Updated Design Oil Filter Assembly & Seal > Page 4849 DATE OF PRODUCTION CHANGE: (Figure 1 and 2) On August 10, 1993 (Julian Date 222), HYDRA-MATIC 4L60-E transmissions were built with a new filter seal (ill. 71) and transmission oil filter assembly (ill. 72). The previous transmission oil filter assembly and filter seal had an assembly method of installing the seal on the filter neck and then installing the filter in the transmission. When using the new filter seal and transmission oil filter assembly, the filter seal must be installed in the transmission first and then install the transmission oil filter assembly into the transmission. NOTE: The new filter seal and transmission oil filter assembly can be used on all HYDRA-MATIC 4L60-E transmissions 1993-1994. The new filter seal and transmission oil filter assembly cannot be used on any HYDRA-MATIC 4L60 transmission. The new filter seal cannot be used with the old transmission oil filter assembly and the new transmission oil filter assembly cannot be used with the old filter seal. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Fluid Line/Hose, A/T > Component Information > Specifications Fluid Line/Hose: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Connector Cooler Pipe ........................................................................................................................ ............................................................................... 28 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Fluid Pan, A/T > Component Information > Specifications Fluid Pan: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Transmission Oil Pan To Case ............................................................................................................ ................................................................................. 8 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Fluid Pan, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission Fluid Pan: Service and Repair 4L60-E Automatic Transmission Removal PAN AND FILTER ASSEMBLY Pan, Filter And Seal Removal CLEAN - Exposed ends of bottom pan screws and spray with penetrating oil. REMOVE OR DISCONNECT 1. Screws (76), oil pan (75) and gasket (73). 2. Oil filter (72) and filter seal (71). - Filter seal may be stuck in the pump. INSPECT - Filter (72), open filter by prying the metal crimping away from the top of the filter (black) and pull apart. The filter may contain evidence for root cause diagnosis. Clutch material. - Bronze slivers indicating bushing wear. - Steel particles. Installation PAN AND FILTER ASSEMBLY Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Fluid Pan, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4858 Case, Pan And Filter Assembly INSTALL OR CONNECT 1. Filter seal (71) into the pump. 2. Oil filter (72). 3. Oil pan gasket (73). 4. Chip magnet (74) onto oil pan (75). 5. Oil pan (75) and bolts (76). TIGHTEN - Torque to 12 Nm (9 lb. ft.). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Fluid Pan, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4859 Fluid Pan: Service and Repair 4L80-E Automatic Transmission Removal PAN AND FILTER ASSEMBLY Pan, Filter And Seal Removal REMOVE OR DISCONNECT 1. Drain the transmission fluid Out case extension by rotating transmission to a vertical position. 2. Seventeen bolts (27), using 10 mm socket, drain transmission fluid. 3. Pan (28), seal (29) and magnet (30). IMPORTANT - Seal (29) is reusable. 4. Filter assembly (31). INSPECT - Filter neck seal (32), replace if necessary. Installation PAN AND FILTER ASSEMBLY Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Fluid Pan, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4860 Installing Pan And Filter INSTALL OR CONNECT 1. Seal (32) inside of case (7). 2. Filter assembly (31). 3. Bottom pan seal (29). 4. Magnet (30) into bottom pan. 5. Pan (29). 6. Seventeen bolts (27) using 10 mm socket. TIGHTEN - Bolts (27) to 24 Nm (18 lb. ft.). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Fluid Pressure Sensor/Switch, A/T > Component Information > Specifications Fluid Pressure Sensor/Switch: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Pressure Plugs (1/8 - 27) ..................................................................................................................... ................................................................................. 8 Pressure Plugs (1/4 - 18) ................................ .............................................................................................................................................................. ...... 18 Pressure Switches ................................................................................................................... .............................................................................................. 8 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Fluid Pump, A/T > Component Information > Specifications Fluid Pump: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Pump Assembly To Case .................................................................................................................... ............................................................................... 18 Pump Cover To Body ..................................... .............................................................................................................................................................. ..... 18 Solenoid Assembly To Pump ................................................................................................... ............................................................................................ 8 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Governor, A/T > Component Information > Service and Repair Governor: Service and Repair 1. Raise and support vehicle 2. Remove governor cover from case using extreme care not to damage cover. If cover is damaged, it should be replaced. 3. Remove governor. 4. Reverse procedure to install and check fluid level. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Lamps and Indicators A/T > Shift Indicator > Component Information > Locations Shift Indicator: Locations Instrument cluster. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Output Shaft, A/T > Component Information > Technical Service Bulletins > A/T - 2-3 Upshift or 3-2 Downshift Clunk Noise Output Shaft: Technical Service Bulletins A/T - 2-3 Upshift or 3-2 Downshift Clunk Noise INFORMATION Bulletin No.: 01-07-30-042F Date: February 05, 2010 Subject: Information on 2-3 Upshift or 3-2 Downshift Clunk Noise Models: 2010 and Prior GM Passenger Cars and Light Duty Trucks 2010 and Prior HUMMER H2, H3 2005-2009 Saab 9-7X with 4L60-E, 4L65-E or 4L70-E Automatic Transmission (RPOs M30, M32, M70) Supercede: This bulletin is being revised to add the 2010 model year and 4L70E transmission. Please discard Corporate Bulletin Number 01-07-30-042E (Section 07 - Transmission/Transaxle). Important For 2005 model year fullsize utilities and pickups, refer to Corporate Bulletin 05-07-30-012. Some vehicles may exhibit a clunk noise that can be heard on a 2-3 upshift or a 3-2 downshift. During a 2-3 upshift, the 2-4 band is released and the 3-4 clutch is applied. The timing of this shift can cause a momentary torque reversal of the output shaft that results in a clunk noise. This same torque reversal can also occur on a 3-2 downshift when the 3-4 clutch is released and the 2-4 band applied. This condition may be worse on a 4-wheel drive vehicle due to the additional tolerances in the transfer case. This is a normal condition. No repairs should be attempted. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Pressure Regulating Solenoid, A/T > Component Information > Description and Operation Pressure Regulating Solenoid: Description and Operation PURPOSE This electrical device, controlled by the PCM, is used to control fluid line pressure. OPERATION The solenoid controls line pressure by controlling actuator feed limit fluid flow acting on internal spool valve and spring pressure. The solenoid is a normally closed solenoid valve that controls fluid pressure when operating on a duty cycle. LOCATION The solenoid is attached to the control valve body within the transmission. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Seals and Gaskets, A/T > System Information > Technical Service Bulletins > Customer Interest: > 467108 > Dec > 94 > A/T - Extension Seal Leaks Seals and Gaskets: Customer Interest A/T - Extension Seal Leaks File In Section: 7 - Transmission Bulletin No. 46-71-08 Date: December, 1994 Subject: Transmission Extension Seal Leaks (Install Revised Seal) Models: 1988-94 Chevrolet and GMC Truck C1-2, G, S, M Models with 4L60 (MD8) or 4L60-E (M3O) and One-Piece Propeller Shaft CONDITION Some vehicles may experience a leak from the transmission extension seal. CAUSE This leak may occur if the seal lips are damaged by a corroded slip yoke barrel. As the rear suspension moves, the slip yoke slides past the seal lips. If the slip yoke barrel is corroded, seal damage can occur resulting in a leak. CORRECTION Install a revised seal P/N 24201470. The seal features a flexible boot which covers the slip yoke barrel to prevent corrosion. This seal is used in production starting with the 1995 model year. SERVICE PROCEDURE Refer to the appropriate year and model Light Truck Service Manual, Section 7A - Automatic Transmission On Vehicle Service for correct seal replacement procedure. Tailshaft Seal Important: This seal has a small vent hole in the flexible boot. This hole must be installed facing down or the boot could collect and hold water. Use sandpaper or crocus cloth to clean any rust or corrosion off the slip yoke barrel before installation. If the slip yoke barrel is not clean, the seal could be damaged. Parts Information P/N DESCRIPTION QTY 24201470 Seal, trans extension oil 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: Labor OPERATION DESCRIPTION LABOR TIME K6360 Seal, Extension Use Published Housing Rear - Labor Operation Replace Time Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Seals and Gaskets, A/T > System Information > Technical Service Bulletins > All Technical Service Bulletins for Seals and Gaskets: > 467108 > Dec > 94 > A/T - Extension Seal Leaks Seals and Gaskets: All Technical Service Bulletins A/T - Extension Seal Leaks File In Section: 7 - Transmission Bulletin No. 46-71-08 Date: December, 1994 Subject: Transmission Extension Seal Leaks (Install Revised Seal) Models: 1988-94 Chevrolet and GMC Truck C1-2, G, S, M Models with 4L60 (MD8) or 4L60-E (M3O) and One-Piece Propeller Shaft CONDITION Some vehicles may experience a leak from the transmission extension seal. CAUSE This leak may occur if the seal lips are damaged by a corroded slip yoke barrel. As the rear suspension moves, the slip yoke slides past the seal lips. If the slip yoke barrel is corroded, seal damage can occur resulting in a leak. CORRECTION Install a revised seal P/N 24201470. The seal features a flexible boot which covers the slip yoke barrel to prevent corrosion. This seal is used in production starting with the 1995 model year. SERVICE PROCEDURE Refer to the appropriate year and model Light Truck Service Manual, Section 7A - Automatic Transmission On Vehicle Service for correct seal replacement procedure. Tailshaft Seal Important: This seal has a small vent hole in the flexible boot. This hole must be installed facing down or the boot could collect and hold water. Use sandpaper or crocus cloth to clean any rust or corrosion off the slip yoke barrel before installation. If the slip yoke barrel is not clean, the seal could be damaged. Parts Information P/N DESCRIPTION QTY 24201470 Seal, trans extension oil 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: Labor OPERATION DESCRIPTION LABOR TIME K6360 Seal, Extension Use Published Housing Rear - Labor Operation Replace Time Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Seals and Gaskets, A/T > System Information > Technical Service Bulletins > All Other Service Bulletins for Seals and Gaskets: > 04-07-30-013B > Feb > 07 > Engine, A/T - Shift/Driveability Concerns/MIL ON Air Filter Element: All Technical Service Bulletins Engine, A/T - Shift/Driveability Concerns/MIL ON Bulletin No.: 04-07-30-013B Date: February 01, 2007 INFORMATION Subject: Automatic Transmission Shift, Engine Driveability Concerns or Service Engine Soon (SES) Light On as a Result of the Use of an Excessively/Over-Oiled Aftermarket, Reusable Air Filter Models: 2007 and Prior GM Cars and Light Duty Trucks 2007 and Prior Saturn Models 2003-2007 HUMMER H2 2006-2007 HUMMER H3 2005-2007 Saab 9-7X Supercede: This bulletin is being revised to add models and model years. Please discard Corporate Bulletin Number 04-07-30-013A (Section 07 - Transmission/Transaxle). The use of an excessively/over-oiled aftermarket, reusable air filter may result in: Service Engine Soon (SES) light on Transmission shift concerns, slipping and damaged clutch(es) or band(s) Engine driveability concerns, poor acceleration from a stop, limited engine RPM range The oil that is used on these air filter elements may be transferred onto the Mass Air Flow (MAF) sensor causing contamination of the sensor. As a result, the Grams per Second (GPS) signal from the MAF may be low and any or all of the concerns listed above may occur. When servicing a vehicle with any of these concerns, be sure to check for the presence of an aftermarket reusable, excessively/over-oiled air filter. The MAF, GPS reading should be compared to a like vehicle with an OEM air box and filter under the same driving conditions to verify the concern. The use of an aftermarket reusable air filter DOES NOT void the vehicle's warranty. If an aftermarket reusable air filter is used, technicians should inspect the MAF sensor element and the air induction hose for contamination of oil prior to making warranty repairs. Transmission or engine driveability concerns (related to the MAF sensor being contaminated with oil) that are the result of the use of an aftermarket reusable, excessively/over-oiled air filter are not considered to be warrantable repair items. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Seals and Gaskets, A/T > System Information > Technical Service Bulletins > All Other Service Bulletins for Seals and Gaskets: > 04-07-30-013B > Feb > 07 > Engine, A/T - Shift/Driveability Concerns/MIL ON > Page 4899 Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Seals and Gaskets, A/T > System Information > Technical Service Bulletins > All Other Service Bulletins for Seals and Gaskets: > Page 4900 Seals and Gaskets: By Symptom Technical Service Bulletin # 467108 Date: 941201 A/T - Extension Seal Leaks File In Section: 7 - Transmission Bulletin No. 46-71-08 Date: December, 1994 Subject: Transmission Extension Seal Leaks (Install Revised Seal) Models: 1988-94 Chevrolet and GMC Truck C1-2, G, S, M Models with 4L60 (MD8) or 4L60-E (M3O) and One-Piece Propeller Shaft CONDITION Some vehicles may experience a leak from the transmission extension seal. CAUSE This leak may occur if the seal lips are damaged by a corroded slip yoke barrel. As the rear suspension moves, the slip yoke slides past the seal lips. If the slip yoke barrel is corroded, seal damage can occur resulting in a leak. CORRECTION Install a revised seal P/N 24201470. The seal features a flexible boot which covers the slip yoke barrel to prevent corrosion. This seal is used in production starting with the 1995 model year. SERVICE PROCEDURE Refer to the appropriate year and model Light Truck Service Manual, Section 7A - Automatic Transmission On Vehicle Service for correct seal replacement procedure. Tailshaft Seal Important: This seal has a small vent hole in the flexible boot. This hole must be installed facing down or the boot could collect and hold water. Use sandpaper or crocus cloth to clean any rust or corrosion off the slip yoke barrel before installation. If the slip yoke barrel is not clean, the seal could be damaged. Parts Information P/N DESCRIPTION QTY 24201470 Seal, trans extension oil 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: Labor OPERATION DESCRIPTION LABOR TIME K6360 Seal, Extension Use Published Housing Rear - Labor Operation Replace Time Technical Service Bulletin # 467108 Date: 941201 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Seals and Gaskets, A/T > System Information > Technical Service Bulletins > All Other Service Bulletins for Seals and Gaskets: > Page 4901 A/T - Extension Seal Leaks File In Section: 7 - Transmission Bulletin No. 46-71-08 Date: December, 1994 Subject: Transmission Extension Seal Leaks (Install Revised Seal) Models: 1988-94 Chevrolet and GMC Truck C1-2, G, S, M Models with 4L60 (MD8) or 4L60-E (M3O) and One-Piece Propeller Shaft CONDITION Some vehicles may experience a leak from the transmission extension seal. CAUSE This leak may occur if the seal lips are damaged by a corroded slip yoke barrel. As the rear suspension moves, the slip yoke slides past the seal lips. If the slip yoke barrel is corroded, seal damage can occur resulting in a leak. CORRECTION Install a revised seal P/N 24201470. The seal features a flexible boot which covers the slip yoke barrel to prevent corrosion. This seal is used in production starting with the 1995 model year. SERVICE PROCEDURE Refer to the appropriate year and model Light Truck Service Manual, Section 7A - Automatic Transmission On Vehicle Service for correct seal replacement procedure. Tailshaft Seal Important: This seal has a small vent hole in the flexible boot. This hole must be installed facing down or the boot could collect and hold water. Use sandpaper or crocus cloth to clean any rust or corrosion off the slip yoke barrel before installation. If the slip yoke barrel is not clean, the seal could be damaged. Parts Information P/N DESCRIPTION QTY 24201470 Seal, trans extension oil 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: Labor OPERATION DESCRIPTION LABOR TIME K6360 Seal, Extension Use Published Housing Rear - Labor Operation Replace Time Technical Service Bulletin # 467108 Date: 941201 A/T - Extension Seal Leaks File In Section: 7 - Transmission Bulletin No. 46-71-08 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Seals and Gaskets, A/T > System Information > Technical Service Bulletins > All Other Service Bulletins for Seals and Gaskets: > Page 4902 Date: December, 1994 Subject: Transmission Extension Seal Leaks (Install Revised Seal) Models: 1988-94 Chevrolet and GMC Truck C1-2, G, S, M Models with 4L60 (MD8) or 4L60-E (M3O) and One-Piece Propeller Shaft CONDITION Some vehicles may experience a leak from the transmission extension seal. CAUSE This leak may occur if the seal lips are damaged by a corroded slip yoke barrel. As the rear suspension moves, the slip yoke slides past the seal lips. If the slip yoke barrel is corroded, seal damage can occur resulting in a leak. CORRECTION Install a revised seal P/N 24201470. The seal features a flexible boot which covers the slip yoke barrel to prevent corrosion. This seal is used in production starting with the 1995 model year. SERVICE PROCEDURE Refer to the appropriate year and model Light Truck Service Manual, Section 7A - Automatic Transmission On Vehicle Service for correct seal replacement procedure. Tailshaft Seal Important: This seal has a small vent hole in the flexible boot. This hole must be installed facing down or the boot could collect and hold water. Use sandpaper or crocus cloth to clean any rust or corrosion off the slip yoke barrel before installation. If the slip yoke barrel is not clean, the seal could be damaged. Parts Information P/N DESCRIPTION QTY 24201470 Seal, trans extension oil 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: Labor OPERATION DESCRIPTION LABOR TIME K6360 Seal, Extension Use Published Housing Rear - Labor Operation Replace Time Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Seals and Gaskets, A/T > System Information > Technical Service Bulletins > Page 4903 Seals and Gaskets: Service and Repair 1. Remove driveshaft, and tunnel strap, if equipped. 2. Using suitable tool, pry out lip oil seal. 3. Coat outer casting of new oil seal with suitable sealer and drive into place with seal installer tool No. J-21426 or equivalent. 4. Install tunnel strap if used, then install driveshaft. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Sensors and Switches A/T > Brake Switch - TCC > Component Information > Locations > Stoplamp/TCC Brake Switch Stoplamp/TCC Brake Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Sensors and Switches A/T > Brake Switch - TCC > Component Information > Locations > Stoplamp/TCC Brake Switch > Page 4909 I/P Harness Wiring, LH Side Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Sensors and Switches A/T > Brake Switch - TCC > Component Information > Locations > Page 4910 C217 - Brake Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Sensors and Switches A/T > Fluid Pressure Sensor/Switch, A/T > Component Information > Specifications Fluid Pressure Sensor/Switch: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Pressure Plugs (1/8 - 27) ..................................................................................................................... ................................................................................. 8 Pressure Plugs (1/4 - 18) ................................ .............................................................................................................................................................. ...... 18 Pressure Switches ................................................................................................................... .............................................................................................. 8 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Sensors and Switches A/T > Transmission Position Switch/Sensor, A/T > Component Information > Description and Operation Transmission Position Switch/Sensor: Description and Operation Automatic Transmission Electrical Components PURPOSE This device is a set of five presure switches (two normally closed and three normally open), that detect fluid pressure within the valve body passages and signals the PCM which transmission range is selected (PRNDL). OPERATION The five pressure switches are connected to three signal circuits referred to as range signals A, B, C. The combination of pressure switch states determines the voltage signal (B+ or 0) on each range signal to the PCM. LOCATION The transmission range fluid pressure switch assembly is attached to the control valve body within the transmission. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Sensors and Switches A/T > Transmission Speed Sensor, A/T > Component Information > Specifications Transmission Speed Sensor: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Vehicle Speed Sensor Retainer ........................... .............................................................................................................................................................. ... 8 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Sensors and Switches A/T > Transmission Temperature Sensor/Switch, A/T > Component Information > Description and Operation Transmission Temperature Sensor/Switch: Description and Operation Automatic Transmission Electrical Components PURPOSE The Transmission Fluid Temperature (TFT) Sensor is used by the control module to control: Torque Converter Clutch (TCC) apply and release schedule. - Hot mode determination. - Shift quality. OPERATION The TFT is a thermistor used to indicate transmission fluid temperature. The control module sends a 5.0 volt signal to the TFT through a resistor in the computer and measures the voltage. High sensor resistance produces high signal input voltage which corresponds to low fluid temperature. Low sensor resistance produces low signal input voltage which corresponds to high fluid temperature. With the TFT varying its resistance, the control module can sense transmission fluid temperature by reading the varying voltage. LOCATION The sensor is part of the transmission range fluid pressure switch assembly and is attached to the control valve body within the transmission. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Specifications > Electrical Specifications Shift Solenoid: Electrical Specifications Component Resistance Chart Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Specifications > Electrical Specifications > Page 4927 Shift Solenoid: Mechanical Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Pressure Control Solenoid To Valve Body .......................................................................................... ................................................................................ 8 Solenoid Assembly To Pump .......................... .............................................................................................................................................................. ....... 8 Solenoid Assembly To Case .................................................................................................... ........................................................................................... 18 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Locations > 4L60-E Automatic Transmission Electronic Component Location Views Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Locations > 4L60-E Automatic Transmission > Page 4930 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Description and Operation > 1 -2 Shift Solenoid Shift Solenoid: Description and Operation 1 -2 Shift Solenoid PURPOSE This electrical device, controlled by the PCM, is used to control fluid flow acting on the 1-2 and 3-4 shift valves. OPERATION The solenoid is a normally open exhaust valve that is used with the 2-3 shift solenoid to allow four different shifting combinations. LOCATION The solenoid is attached to the control valve body within the transmission. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Description and Operation > 1 -2 Shift Solenoid > Page 4933 Shift Solenoid: Description and Operation 2-3 Shift Solenoid PURPOSE This electrical device, controlled by the PCM, is used to control fluid flow acting on the 2-3 shift valves. OPERATION The solenoid is a normally open exhaust valve that is used with the 1-2 shift solenoid to allow four different shifting combinations. LOCATION The solenoid is attached to the control valve body within the transmission. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Description and Operation > 1 -2 Shift Solenoid > Page 4934 Shift Solenoid: Description and Operation 3-2 Control Solenoid PURPOSE This electrical device, controlled by the PCM, is used to control fluid flow acting on the 3-2 shift valve, which then controls the 2-4 band apply rate and 3-4 clutch release rate. The solenoid also controls the 3-2 downshift feel. OPERATION The solenoid is a pulse width modulated solenoid that operates on a negative duty cycle. LOCATION The solenoid is attached to the control valve body within the transmission. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission Shift Solenoid: Service and Repair 4L60-E Automatic Transmission Pan and Filter Assembly PAN AND FILTER ASSEMBLY Pan, Filter And Seal Removal CLEAN - Exposed ends of bottom pan screws and spray with penetrating oil. REMOVE OR DISCONNECT 1. Screws (76), oil pan (75) and gasket (73). 2. Oil filter (72) and filter seal (71). - Filter seal may be stuck in the pump. INSPECT - Filter (72), open filter by prying the metal crimping away from the top of the filter (black) and pull apart. The filter may contain evidence for root cause diagnosis. Clutch material. - Bronze slivers indicating bushing wear. - Steel particles. Valve Body and Wiring Harness VALVE BODY AND WIRING HARNESS Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4937 Valve Body Bolt Location Control Valve And Pressure Switch Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4938 Manual Valve Link Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4939 Valve Body Checkballs Case Checkballs And Filters REMOVE OR DISCONNECT 1. Electrical connections from components. 2. TCC PWM Solenoid Retainer Clip (379) and Solenoid (396). 3. TCC Solenoid bolts (68) and solenoid assembly (66) with O-ring seal (65) and wiring harness. 4. Pressure switch assembly bolts (70) and pressure switch assembly (69). 5. Accumulator cover bolts (58 and 59) and 1-2 accumulator cover and pin assembly (57). 6. 1-2 accumulator piston (56) and seal (55). 7. Spring (54). 8. Dipstick stop bracket (93). REMOVE OR DISCONNECT 1. Bolt (64) and manual detent spring assembly (63). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4940 2. Wiring harness retaining bolts. REMOVE OR DISCONNECT 1. Remaining valve body bolts (62). 2. Manual valve link (89). 3. Control valve assembly (60). 4. Bolts (58 and 59), accumulator cover (57), piston (56, spring (54) and spring (54A). 5. Bolts (77) and plate (53). 6. Spacer plate (48) and spacer plate gaskets (47 and 52). 7. Spring (46), piston (44), and pin (43). - Seven checkballs are located under the valve body and one is located in the case. The large copper flash colored ball is # 1A checkball (91). Valve Body and Associated Parts VALVE BODY AND ASSOCIATED PARTS Accumulator Assembly, Spacer Plate And Gaskets Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4941 Case Checkballs And Filters TOOL REQUIRED: - J 25025-5 Guide Pins NOTICE: The use of a honing stone, fine sandpaper or crocus cloth is not recommended for servicing stuck valves. All valve lands have sharply machined corners that are necessary for "cleaning" the bore. If these corners are rounded, foreign material could wedge between the valve and bore causing the valve to stick. If it is found necessary to clean a valve, "micro fine" lapping compound 900 grit or finer should be used. Too much "lapping" of a valve will cause excessive clearances and increase the chance of a valve not operating. INSTALL OR CONNECT 1. The wiring harness pass-thru connector into the case. 2. The 3-4 accumulator pin (43) into the case. 3. The 3-4 accumulator piston seal (45) onto the 3-4 accumulator piston. 4. The 3-4 accumulator piston (44) onto the pin. - The end with three legs must face the valve body. 5. The 3-4 accumulator piston spring (46). INSTALL OR CONNECT 1. Checkball (91) into case as shown. - Retain with Transjel TM J 36850 or equivalent. 2. J 25025-5 into the case. 3. Screens onto spacer plate as shown. 4. Spacer plate to case gasket (47) and spacer plate to valve body gasket (52) onto the spacer plate (48). - Gasket (47) identified by a "C". Gasket (52) identified by a "V". - Retain with Transjel TM J 36850 or equivalent. 5. Spacer plate and gaskets onto the case. IMPORTANT - Be careful not to damage screens when installing the spacer plate and gaskets. 6. Spacer plate support (53) and bolts (77). TIGHTEN - Bolts to 11 Nm (8 lb. ft.) Control Valve Body CONTROL VALVE BODY Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4942 Case Checkballs And Filters Filter Screen - Locations Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4943 Control Valve Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4944 Control Valve Assembly - Legend Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4945 Valve Body Checkball Locations Valve Body Bolt Locations Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4946 Manual Valve Link Outside Electrical Connector CLEAN - Control valve assembly thoroughly in clean solvent. A. Move the valves with a pick or small screwdriver to dislodge any dirt or debris that may have accumulated. B. Air dry. REMOVE OR DISCONNECT IMPORTANT - Some valves are under pressure - cover the bores while removing roll pins and retainer clips. - Valves, springs and bushings must be laid out on a clean surface in the exact sequence they are removed. 1. Pressure control solenoid retainer bolt (364) retainer (378) and solenoid. 2. Bore plug retainer clip (395), bore plug (376) and valve train (374 and 375). 3. 2-3 shift solenoid retainer (379), solenoid (367) and valve train (368 and 369). 4. 1-2 shift solenoid retainer (379), solenoid (367) and valve train (365 and 366). 5. Accumulator valve train retainer pin (360), bore plug (373) and valve train (370 and 371). 6. Forward accumulator cover bolts (364) and cover (363). 7. Forward accumulator spring (356), piston (354) and pin (355). 8. Lo overrun valve spring (362) and valve (361). 9. Retainer pin (360), bore plug (359) and forward abuse valve train (357 and 358). 10. Manual valve (340). 11. 3-2 control solenoid retainer clip (379) and solenoid (394). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4947 12. Bore plug retainer (395), bore plug (381) and 3-2 control valve train (391 - 393). 13. 3-2 downshift bore plug retainer (395), bore plug (381) and valve train (389 - 390). 14. Reverse abuse bore plug retainer pin (360), bore plug (359) and valve train (387 - 388). 15. 3-4 shift valve bore plug retainer (395), bore plug (381) and valve train (385 - 386). 16. 3-4 relay bore plug retainer (395), bore plug (381) and valve train (382 - 384). 17. Torque converter clutch signal valve bore plug retainer (395), bore plug (381) and valve (380). CLEAN - All valves, springs, bushings and control valve body in clean solvent. - Dry using compressed air. INSPECT - All valves and bushings for: Porosity - Scoring - Nicks - Scratches - Springs for damaged or distorted coils. - Valve body casting for: Porosity - Cracks - Inter connected oil passages - Damaged machined surfaces ASSEMBLE - Control valve assembly (350) exactly as shown. Notice the position of the valve lands and bushing passages. - Position the pressure control solenoid so the connector tabs face outward. NOTICE: TCC PWM solenoid (396) cannot be installed until TCC solenoid has been installed and torqued to proper specifications. INSTALL OR CONNECT 1. Checkballs into the valve body assembly (350). - Retain with Transjell TM J 36850 or equivalent. 2. Valve body assembly (350). - Connect the manual valve link (89) to the inside detent lever (88). - Be careful not to damage screens when installing the valve body assembly. 3. Wiring harness (66), manual spring assembly (63), pressure switch assembly(69), dipstick, stop bracket (93) and all remaining valve body bolts. NOTICE: Torque valve body bolts in a spiral pattern starting from the center. If bolts are torqued at random, valve bores may be distorted and inhibit valve operation. 4. TCC solenoid (66) and bolts (68). TIGHTEN - Bolts to 11 Nm (8 lb. ft.). 5. TCC PWM solenoid (396), and retainer clip (379). INSTALL OR CONNECT - Wiring harness connections to electrical components. - To correctly hook up the wires, see the wiring diagrams. - The pressure control solenoid (377) has two different colored connectors. The black connector should be installed on the tab farthest from the valve body. INSTALL OR CONNECT 1. Parking bracket (86). TIGHTEN - Bolts to 31 Nm (23 lb. ft.). 2. The 1-2 accumulator piston seal (55) onto the 1-2 accumulator piston (56). 3. The 1-2 accumulator spring (54) and 1-2 accumulator inner spring (54A) onto the piston (56). 4. The 1-2 accumulator piston (56) into the 1-2 accumulator cover and pin assembly (57). - The three legs on the piston must face away from the case when installed. 5. The 1-2 accumulator cover and pin assembly (57) onto the case. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4948 TIGHTEN - Torque to 11 Nm (8 lb. ft.). Pan and Filter Assembly PAN AND FILTER ASSEMBLY Case, Pan And Filter Assembly INSTALL OR CONNECT 1. Filter seal (71) into the pump. 2. Oil filter (72). 3. Oil pan gasket (73). 4. Chip magnet (74) onto oil pan (75). 5. Oil pan (75) and bolts (76). TIGHTEN - Torque to 12 Nm (9 lb. ft.). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4949 Shift Solenoid: Service and Repair 4L80-E Automatic Transmission Pan and Filter Assembly PAN AND FILTER ASSEMBLY Pan, Filter And Seal Removal REMOVE OR DISCONNECT 1. Drain the transmission fluid Out case extension by rotating transmission to a vertical position. 2. Seventeen bolts (27), using 10 mm socket, drain transmission fluid. 3. Pan (28), seal (29) and magnet (30). IMPORTANT - Seal (29) is reusable. 4. Filter assembly (31). INSPECT - Filter neck seal (32), replace if necessary. Wire Harness Assembly WIRE HARNESS ASSEMBLY Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4950 Pan, Filter And Seal Removal REMOVE OR DISCONNECT 1. Wire harness connectors from electrical components. NOTICE: Excessive force on the case pass through connector may damage the connector. IMPORTANT - If the wire harness assembly does not need servicing, it is not necessary to remove it from the case. 2. Wire harness assembly (34) from case using a 1-5/16" 12 point socket to release the connector retaining clips. Control Valve Assembly CONTROL VALVE ASSEMBLY Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4951 REMOVE OR DISCONNECT 1. Rotate transmission bottom pan surface up and lock in place. 2. Wire harness assembly (34) connectors from components. IMPORTANT - If the wire harness assembly does not need servicing, it is not necessary to remove it from the case. - Use a cap to cover electrical pin at case connection. 3. Six bolts (76) using 8 mm socket, and transmission fluid pressure switch assembly (40). NOTICE: Be sure five O-rings are attached to transmission fluid pressure switch assembly. 4. Twenty-one bolts (35) using 10 mm socket, from valve body assembly, manual detent spring and roller assembly (41). 5. Three wiring clamps (33), fluid level indicator stop (43), one bolt (36) using 10 mm socket, lube pipe (39), lube pipe retainer (37) and clamp (38). 6. Control valve assembly (44) including the accumulator housing assembly (51), valve body gaskets (45 and 48), spacer plate (46) and accumulator gasket (47). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4952 7. Manual valve (319) from control valve assembly (44) to prevent any damage. 8. Checkballs (54) from case passages. NOTICE: Do not use a magnet. It could cause checkball(s) to be magnetized causing metal particles to stick to the ball. 9. Pulse Width Modulated (PWM) solenoid screen (75). INSPECT - Screen PWM solenoid (75), replace if necessary. DISASSEMBLE Control Valve Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4953 - Control valve assembly. A. Position as shown on a clean surface. B. Remove blind hole retainer pins with a drill bit. CAUTION: Some valves are under pressure - cover the bores while removing the retaining pins or personal injury could result. C. Remove valve trains, shift solenoids (311 and 313), PCS (320), PWM solenoid (323), PCS screen (302) and shift solenoid filter (317). D. Valves, springs, bushings and pistons must be laid out on a clean surface. CLEAN - All valves, springs, bushings, pistons, control valve body and accumulator housing in clean solvent. - Dry using compressed air. INSPECT 1. All valves, pistons and bushings for: - Porosity. - Scoring. - Nicks. - Scratches. 2. Pistons for: - Seal damage. 3. Springs for: - Damaged or distorted coils. 4. Valve body casting and accumulator housing for: - Porosity. - Cracks. - Interconnected passages. - Damaged machined surfaces. 5. Solenoid connectors and filter (317). 6. PCS (Pressure Control Solenoid) screen (302). Control Valve Assembly/Accumulator Housing CONTROL VALVE ASSEMBLY/ACCUMULATOR HOUSING Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4954 Control Valve Assembly/Accumulator Housing Accumulator Housing Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4955 Control Valve Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4956 Torque Sequence And Guide Pin Location Fig. 11 Check Ball Location. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4957 Fig. 10 Control Valve Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4958 Torque Sequence, Control Valve And Switch Assembly NOTICE: The use of a honing stone, fine sandpaper or crocus cloth is not recommended for servicing stuck valves. All valve lands have sharply machined comers that are necessary for cleaning the bore. If these corners are rounded, foreign material could wedge between the valve and the bore causing the valve to stick. If it is found necessary to clean a valve, micro fine lapping compound 900 grit (J 38459) or finer should be used. Too much lapping of the valve will cause excessive clearances and increase the chance of a valve not operating. CLEAN - Control valve assembly and accumulator housing (51) thoroughly in clean solvent. - Air dry. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4959 Accumulator Housing Assembly ACCUMULATOR HOUSING ASSEMBLY Control Valve Assembly/Accumulator Housing Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4960 Accumulator Housing Assembly DISASSEMBLE 1. Six bolts (53), using 8 mm socket. 2. Accumulator housing assembly. 3. Gasket accumulator housing (47). 4. Spacer plate (46). 5. Gasket (45) valve body spacer. 6. Snap ring (402) from outside housing, pin (408), snap ring (402), piston (407) and spring (49). 7. 3rd clutch piston (405) and spring (50). 8. Seals (404 and 406). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4961 CLEAN - All components. INSPECT - All valves, pistons, springs and seals for: - Porosity. - Scoring. - Nicks. - Scratches. Accumulator Housing Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4962 ASSEMBLE - Accumulator housing assembly components exactly as shown. Notice the positions of the pistons. Control Valve Assembly CONTROL VALVE ASSEMBLY Control Valve Assembly ASSEMBLE - Control valve assembly components exactly as shown. Notice the position of the valve lands and bushing passages. Control Valve Assembly/Accumulator Housing Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4963 CONTROL VALVE ASSEMBLY AND ACCUMULATOR HOUSING Control Valve Assembly/Accumulator Housing Torque Sequence And Guide Pin Location TOOL REQUIRED: - Guide Pin J 25025-5 ASSEMBLE 1. Guide pin J 25025-5 into valve body. Located at back bolt hole of detent spring and roller assembly bolt bole. 2. Gasket (45) valve body to spacer plate. 3. Spacer plate (46). 4. Gasket (47) accumulator housing to spacer plate. 5. Accumulator housing assembly (51) onto valve body assembly (44). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4964 6. Six bolts (53) using (8 mm) socket through accumulator housing into valve body assembly. Torque Sequence And Guide Pin Location NOTE: Start accumulator housing bolts finger tight and work towards opposite end. TIGHTEN - Bolt (53) to 11 Nm (97 lb. in.). 7. Remove guide pin J 25025-5. Fig. 11 Check Ball Location. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4965 Fig. 10 Control Valve Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4966 Torque Sequence, Control Valve And Switch Assembly INSTALL OR CONNECT 1. Install checkballs (54) in proper location into case fluid passages. Use TRANSJEL TM J 36850 or equivalent to hold in place. NOTICE: Do not use any type of grease to retain parts during assembly of this unit. Greases other than the recommended assembly lube will change transmission fluid characteristics and cause undesirable shift conditions and/or filter clogging. - # 2 checkball is used only on RCP RDP, ZJP and ZLP models. 2. PWM solenoid screen (75). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4967 3. Gasket (48) spacer plate to case. 4. Manual valve (319) into valve body. 5. Complete valve body assembly (44) onto case (7). Use 1 25025-5 guide pin set. IMPORTANT - Attach manual valve to detent lever. 6. Transmission fluid pressure switch assembly (40) onto valve body assembly (44). 7. Spring and roller assembly (41) into place. 8. Three wiring clamps (33), fluid indicator stop (43) and lube pipe clamp (38). 9. Twenty-one bolts (35). Using 10 mm socket. 10. Six bolts (76) using 8 mm socket into transmission fluid pressure switch assembly (40). 11. Lube pipe (39) long end into case, short end into valve body. 12. Lube pipe retainer (37) with short bolt (36). TIGHTEN - Bolts (35, 36 and 76) to 11 Nm (97 lb. in.). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4968 Torque Sequence, Control Valve And Switch Assembly NOTICE: Torque valve body bolts in a spiral pattern starting from the center. If bolts are torqued at random, valve bores may be distorted and inhibit valve operation. 13. Attach wiring harness (34) to 5 connectors. - Put large end into case first, pressure switch hook up, 1-2 shift solenoid (purple) and 2-3 shift solenoid (tan), PWM (Pulse Width Modulated) solenoid and PCS (Pressure Control Solenoid). Pan and Filter Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 4969 PAN AND FILTER ASSEMBLY Installing Pan And Filter INSTALL OR CONNECT 1. Seal (32) inside of case (7). 2. Filter assembly (31). 3. Bottom pan seal (29). 4. Magnet (30) into bottom pan. 5. Pan (29). 6. Seventeen bolts (27) using 10 mm socket. TIGHTEN - Bolts (27) to 24 Nm (18 lb. ft.). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Linkage, A/T > Component Information > Technical Service Bulletins > Customer Interest for Shift Linkage: > 467102 > May > 94 > A/T No Reverse, Perceived Second Gear Lack of Power Technical Service Bulletin # 467102 Date: 940501 A/T - No Reverse, Perceived Second Gear Lack of Power Group Ref.: Transmission Bulletin No.: 467102 Date: May 1994 SUBJECT: NO REVERSE, OR PERCEIVED LACK OF POWER (TIE UP) IN 2ND GEAR (SHIFT LINKAGE ADJUSTMENT PROCEDURE) MODELS: 1994 CHEVROLET AND GMC TRUCK S/T, M/L, C/K 1, 2 MODELS 1994 OLDSMOBILE BRAVADA WITH 4L60E AUTOMATIC TRANSMISSION (RPO M30) AND ROD STYLE SHIFT LINKAGE Condition Some owners may experience a loss of reverse or a tie-up (perceived lack of power) in 2nd gear. Inspection of these transmissions often indicates heavy wear and evidence of high heat on the low-reverse clutch and 2-4 band. CAUSE: The transmission shift linkage may be improperly adjusted (the manual valve is not properly positioned in relationship to the "PRNDL" position). This may prevent the low-reverse clutch apply circuit from exhausting after a shift from park or reverse to a forward range. If the low-reverse clutch remains partially applied, a tie-up may occur when the transmission shifts from first to second gear. This could result in low-reverse clutch and 2-4 band failure. Correction The transmission shift linkage must be properly adjusted following repair or replacement of the transmission or if the "PRNDL" indicator does not match the actual transmission range. The following procedure must be followed when adjusting the rod style linkage on a 4L60E equipped vehicle: - S/T models use adjustment procedure # 1 - M/L models use adjustment procedure # 2 - C/K models use adjustment procedure # 3 Adjustment procedure # 1 applies to 1994 S/T vehicles with 4L60E transmission: (Figure 1) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Linkage, A/T > Component Information > Technical Service Bulletins > Customer Interest for Shift Linkage: > 467102 > May > 94 > A/T No Reverse, Perceived Second Gear Lack of Power > Page 4978 1. Linkage adjustment must be performed at the transmission prior to any "PRNDL" indicator adjustment at the steering column. 2. Full weight of vehicle must be on wheels (curb height). Do not use a frame hoist to raise the vehicle for this procedure. Mandatory that vehicle be raised on a twin post hoist or utilize an alignment rack. 3. Position the steering column shift lever in the neutral gate notch. (Do not use the indicator to find neutral.) 4. Loosen the bolt (2) in the swivel (4) that clamps the shift rod (1) to the transmission equalizer lever (3). Make sure that the shift rod moves freely in the swivel. 5. Set trans lever (5) in neutral detent. Obtain neutral detent by indexing trans lever all the way clockwise to "PARK", then counter-clockwise two detents to "NEUTRAL". (Alternate procedure is to rotate trans lever counter-clockwise all the way to "L1", then rotate it clockwise four detents.) 6. Make sure that trans control lever (3) is fully seated in trans lever (5). Hold the rod (1) tightly in the swivel (4). Tighten clamp screw (2) against rod (1) to 25 N-m (18 lbs.ft.). Make sure the rod does not move in the swivel while tightening the screw. 7. Verify proper adjustment: - When moving the transmission shift lever in either direction, all detent positions will be attainable without a binding condition present. - With the key on and the shift lever in "Reverse", the key will not be removable and the steering column will not be locked. - With the key in the lock position and the shift lever in the "Park" position, the key will be removable, the steering wheel will be locked, and the shift lever will not disengage from "Park". In addition, verify that the vehicle is held stationary in "Park". - The engine must start in the "Neutral" or "Park" positions only. Adjust neutral safety *switch as required. - Verify that shift indicator position matches actual transmission range. Adjust "PRNDL" switch as required. Adjustment procedure # 2 applies to 1994 M/L vehicles with 4L60E transmission: (Figure 2) 1. Linkage adjustment must be performed at the transmission prior to any "PRNDL" indicator adjustment at the steering column. 2. Full weight of vehicle must be on wheels (curb height). Do not use a frame hoist to raise the vehicle for this procedure. Mandatory that vehicle be raised on a twin post hoist or utilize an alignment rack. 3. Position the steering column shift lever in the neutral gate notch. (Do not use the indicator to find neutral). 4. Loosen the bolt (2) from the swivel (4) that clamps the shift rod (1) to the transmission equalizer lever (3), Make sure the rod slides freely in the swivel. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Linkage, A/T > Component Information > Technical Service Bulletins > Customer Interest for Shift Linkage: > 467102 > May > 94 > A/T No Reverse, Perceived Second Gear Lack of Power > Page 4979 5. Set trans lever (5) in neutral detent. Obtain neutral detent by indexing trans lever all the way clockwise to "PARK", then counter-clockwise two detents to "NEUTRAL". (Alternate procedure is to rotate trans lever counter-clockwise all the way to "L1", then rotate it clockwise four detents.) 6. Make sure that transmission equalizer lever (3) is fully seated in trans lever (5). Hold the shift rod (1) tightly in the swivel (4) and tighten the bolt (2) to 25 N-m (18 lbs.ft.). Do not allow the rod to slide in the swivel while tightening. 7. Verify proper adjustment: - When moving the transmission shift lever in either direction, all detent positions will be attainable without a binding condition present. - With the key on and the shift lever in "Reverse", the key will not be removable and the steering column will not be locked. - With the key in the lock position and the shift lever in the "Park" position, the key will be removable, the steering wheel will be locked, and the shift lever will not disengage from "Park". In addition, verify that the vehicle is held stationary in "Park". - The engine must start in the "Neutral" or "Park" positions only. Adjust neutral safety switch as required. - Verify that shift indicator position matches actual transmission range. Adjust "PRNDL" switch as required. Adjustment procedure # 3 applies to 1994 C/K vehicles with 4L60E transmission: (Figure 3) 1. Linkage adjustment must be performed at the lower end of the steering column prior to any "PRNDL" indicator adjustment. 2. Full weight of vehicle must be on wheels (curb height). Do not use a frame hoist to raise the vehicle for this procedure. Mandatory that vehicle be raised on a twin post hoist or utilize an alignment rack. 3. Position the steering column shift lever in the neutral gate notch. (Do not use the indicator to find neutral). 4. Loosen the bolt (2) from the swivel (4) that clamps the shift rod (1) to the transmission equalizer lever (3). Make sure the rod slides freely in the swivel. 5. Set trans lever (3) in neutral detent. Obtain neutral detent by indexing trans lever all the way clockwise to "PARK", then counter-clockwise two detents to "NEUTRAL". (Alternate procedure is to rotate trans lever counter-clockwise all the way to "L1", then rotate it clockwise four detents.) 6. Hold the rod (1) tightly in the swivel (4) and tighten screw (2) to 25 N-m (18 lbs.ft.). Do not allow the rod to move in the swivel while tightening. 7. Verify proper adjustment: Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Linkage, A/T > Component Information > Technical Service Bulletins > Customer Interest for Shift Linkage: > 467102 > May > 94 > A/T No Reverse, Perceived Second Gear Lack of Power > Page 4980 - When moving the transmission shift lever in either direction, all detent positions will be attainable without a binding condition present. - With the key on and the shift lever in "Reverse", the key will not be removable and the steering column will not be locked. - With the key in the lock position and the shift lever in the "Park" position, the key will be removable, the steering wheel will be locked, and the shift lever will not disengage from "Park". In addition, verify that the vehicle is held stationary in "Park". - The engine must start in the "Neutral" or "Park" positions only. Adjust neutral safety switch as required. - Verify that shift indicator position matches actual transmission range. Adjust "PRNDL" switch as required. Please note these new procedures in the appropriate Service Manual, Section 7A. WARRANTY INFORMATION: For vehicles repaired under warranty, use: Labor 0p Description Labor Time K5244 Linkage, Shift Use Published Adjust Labor Operation Time Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Linkage, A/T > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Shift Linkage: > 467102 > May > 94 > A/T - No Reverse, Perceived Second Gear Lack of Power Technical Service Bulletin # 467102 Date: 940501 A/T - No Reverse, Perceived Second Gear Lack of Power Group Ref.: Transmission Bulletin No.: 467102 Date: May 1994 SUBJECT: NO REVERSE, OR PERCEIVED LACK OF POWER (TIE UP) IN 2ND GEAR (SHIFT LINKAGE ADJUSTMENT PROCEDURE) MODELS: 1994 CHEVROLET AND GMC TRUCK S/T, M/L, C/K 1, 2 MODELS 1994 OLDSMOBILE BRAVADA WITH 4L60E AUTOMATIC TRANSMISSION (RPO M30) AND ROD STYLE SHIFT LINKAGE Condition Some owners may experience a loss of reverse or a tie-up (perceived lack of power) in 2nd gear. Inspection of these transmissions often indicates heavy wear and evidence of high heat on the low-reverse clutch and 2-4 band. CAUSE: The transmission shift linkage may be improperly adjusted (the manual valve is not properly positioned in relationship to the "PRNDL" position). This may prevent the low-reverse clutch apply circuit from exhausting after a shift from park or reverse to a forward range. If the low-reverse clutch remains partially applied, a tie-up may occur when the transmission shifts from first to second gear. This could result in low-reverse clutch and 2-4 band failure. Correction The transmission shift linkage must be properly adjusted following repair or replacement of the transmission or if the "PRNDL" indicator does not match the actual transmission range. The following procedure must be followed when adjusting the rod style linkage on a 4L60E equipped vehicle: - S/T models use adjustment procedure # 1 - M/L models use adjustment procedure # 2 - C/K models use adjustment procedure # 3 Adjustment procedure # 1 applies to 1994 S/T vehicles with 4L60E transmission: (Figure 1) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Linkage, A/T > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Shift Linkage: > 467102 > May > 94 > A/T - No Reverse, Perceived Second Gear Lack of Power > Page 4986 1. Linkage adjustment must be performed at the transmission prior to any "PRNDL" indicator adjustment at the steering column. 2. Full weight of vehicle must be on wheels (curb height). Do not use a frame hoist to raise the vehicle for this procedure. Mandatory that vehicle be raised on a twin post hoist or utilize an alignment rack. 3. Position the steering column shift lever in the neutral gate notch. (Do not use the indicator to find neutral.) 4. Loosen the bolt (2) in the swivel (4) that clamps the shift rod (1) to the transmission equalizer lever (3). Make sure that the shift rod moves freely in the swivel. 5. Set trans lever (5) in neutral detent. Obtain neutral detent by indexing trans lever all the way clockwise to "PARK", then counter-clockwise two detents to "NEUTRAL". (Alternate procedure is to rotate trans lever counter-clockwise all the way to "L1", then rotate it clockwise four detents.) 6. Make sure that trans control lever (3) is fully seated in trans lever (5). Hold the rod (1) tightly in the swivel (4). Tighten clamp screw (2) against rod (1) to 25 N-m (18 lbs.ft.). Make sure the rod does not move in the swivel while tightening the screw. 7. Verify proper adjustment: - When moving the transmission shift lever in either direction, all detent positions will be attainable without a binding condition present. - With the key on and the shift lever in "Reverse", the key will not be removable and the steering column will not be locked. - With the key in the lock position and the shift lever in the "Park" position, the key will be removable, the steering wheel will be locked, and the shift lever will not disengage from "Park". In addition, verify that the vehicle is held stationary in "Park". - The engine must start in the "Neutral" or "Park" positions only. Adjust neutral safety *switch as required. - Verify that shift indicator position matches actual transmission range. Adjust "PRNDL" switch as required. Adjustment procedure # 2 applies to 1994 M/L vehicles with 4L60E transmission: (Figure 2) 1. Linkage adjustment must be performed at the transmission prior to any "PRNDL" indicator adjustment at the steering column. 2. Full weight of vehicle must be on wheels (curb height). Do not use a frame hoist to raise the vehicle for this procedure. Mandatory that vehicle be raised on a twin post hoist or utilize an alignment rack. 3. Position the steering column shift lever in the neutral gate notch. (Do not use the indicator to find neutral). 4. Loosen the bolt (2) from the swivel (4) that clamps the shift rod (1) to the transmission equalizer lever (3), Make sure the rod slides freely in the swivel. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Linkage, A/T > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Shift Linkage: > 467102 > May > 94 > A/T - No Reverse, Perceived Second Gear Lack of Power > Page 4987 5. Set trans lever (5) in neutral detent. Obtain neutral detent by indexing trans lever all the way clockwise to "PARK", then counter-clockwise two detents to "NEUTRAL". (Alternate procedure is to rotate trans lever counter-clockwise all the way to "L1", then rotate it clockwise four detents.) 6. Make sure that transmission equalizer lever (3) is fully seated in trans lever (5). Hold the shift rod (1) tightly in the swivel (4) and tighten the bolt (2) to 25 N-m (18 lbs.ft.). Do not allow the rod to slide in the swivel while tightening. 7. Verify proper adjustment: - When moving the transmission shift lever in either direction, all detent positions will be attainable without a binding condition present. - With the key on and the shift lever in "Reverse", the key will not be removable and the steering column will not be locked. - With the key in the lock position and the shift lever in the "Park" position, the key will be removable, the steering wheel will be locked, and the shift lever will not disengage from "Park". In addition, verify that the vehicle is held stationary in "Park". - The engine must start in the "Neutral" or "Park" positions only. Adjust neutral safety switch as required. - Verify that shift indicator position matches actual transmission range. Adjust "PRNDL" switch as required. Adjustment procedure # 3 applies to 1994 C/K vehicles with 4L60E transmission: (Figure 3) 1. Linkage adjustment must be performed at the lower end of the steering column prior to any "PRNDL" indicator adjustment. 2. Full weight of vehicle must be on wheels (curb height). Do not use a frame hoist to raise the vehicle for this procedure. Mandatory that vehicle be raised on a twin post hoist or utilize an alignment rack. 3. Position the steering column shift lever in the neutral gate notch. (Do not use the indicator to find neutral). 4. Loosen the bolt (2) from the swivel (4) that clamps the shift rod (1) to the transmission equalizer lever (3). Make sure the rod slides freely in the swivel. 5. Set trans lever (3) in neutral detent. Obtain neutral detent by indexing trans lever all the way clockwise to "PARK", then counter-clockwise two detents to "NEUTRAL". (Alternate procedure is to rotate trans lever counter-clockwise all the way to "L1", then rotate it clockwise four detents.) 6. Hold the rod (1) tightly in the swivel (4) and tighten screw (2) to 25 N-m (18 lbs.ft.). Do not allow the rod to move in the swivel while tightening. 7. Verify proper adjustment: Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Linkage, A/T > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Shift Linkage: > 467102 > May > 94 > A/T - No Reverse, Perceived Second Gear Lack of Power > Page 4988 - When moving the transmission shift lever in either direction, all detent positions will be attainable without a binding condition present. - With the key on and the shift lever in "Reverse", the key will not be removable and the steering column will not be locked. - With the key in the lock position and the shift lever in the "Park" position, the key will be removable, the steering wheel will be locked, and the shift lever will not disengage from "Park". In addition, verify that the vehicle is held stationary in "Park". - The engine must start in the "Neutral" or "Park" positions only. Adjust neutral safety switch as required. - Verify that shift indicator position matches actual transmission range. Adjust "PRNDL" switch as required. Please note these new procedures in the appropriate Service Manual, Section 7A. WARRANTY INFORMATION: For vehicles repaired under warranty, use: Labor 0p Description Labor Time K5244 Linkage, Shift Use Published Adjust Labor Operation Time Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Linkage, A/T > Component Information > Specifications > Shift Rod Swivel Attaching Nuts Shift Linkage: Specifications Shift Rod Swivel Attaching Nuts Shift Rod Swivel Attaching Nut ............................................................................................................ ................................................................. 18 Ft.Lbs. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Linkage, A/T > Component Information > Specifications > Shift Rod Swivel Attaching Nuts > Page 4991 Shift Linkage: Specifications 4L60 & 4L60-E Transmission COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Manual Shaft To Inside Detent Lever .................................................................................................. .............................................................................. 23 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Shift Linkage, A/T > Component Information > Specifications > Page 4992 Shift Linkage: Adjustments Fig.8 Shift Linkage Adjustment 1. Apply parking brake, then loosen swivel nut, Fig. 8. 2. Place column selector lever in neutral. 3. Place transmission in Neutral by moving shift lever to its forward position, then back to the second detent position. 4. Holding shift rod tightly in the swivel, tighten swivel nut to specifications. 5. Place column selector lever into park position and check adjustment. The column selector lever must move through all the detents. The engine must start in the park or Neutral positions. With the selector lever in the park position, the parking pawl should freely engage within the rear (reaction) internal gear lugs or the output ring gear lugs and prevent the vehicle from rolling, which could result in personal injury. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Speedometer Gear, A/T > Component Information > Service and Repair Speedometer Gear, A/T: Service and Repair 1. Disconnect speedometer cable or P.M. generator electrical connector at transmission. 2. Remove retainer bolt, retainer, P.M. generator if equipped, speedometer driven gear and O-ring seal. 3. Reverse procedure to install, using new O-ring and adding fluid as necessary. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Sun Gear > Component Information > Technical Service Bulletins > Customer Interest for Sun Gear: > 00-07-30-022D > Jun > 08 > A/T - 4L60/65E, No Reverse/2nd or 4th Gear Sun Gear: Customer Interest A/T - 4L60/65E, No Reverse/2nd or 4th Gear TECHNICAL Bulletin No.: 00-07-30-022D Date: June 10, 2008 Subject: No Reverse, Second Gear or Fourth Gear (Replace Reaction Sun Shell with More Robust Heat Treated Parts) Models: 1993 - 2005 GM Passenger Cars and Light Duty Trucks 2003 - 2005 HUMMER H2 with 4L60/65-E Automatic Transmission (RPOs M30 or M32) Supercede: This bulletin is being revised to add 2005 model year to the parts information. Please discard Corporate Bulletin Number 00-07-30-022C (Section 07 - Transmission/Transaxle). Condition Some customers may comment on a no reverse, no second or no fourth gear condition. First and third gears will operate properly. Cause The reaction sun gear (673) may not hold inside the reaction sun shell (670). Correction Important: There are FOUR distinct groups of vehicles and repair procedures involved. Vehicles built in the 2001 model year and prior that make use of a reaction shaft to shell thrust washer: ^ The sun shell can be identified by four square holes used to retain the thrust washer. Use reaction sun shell P/N 24228345, reaction carrier to shell thrust washer (699B) P/N 8642202 and reaction sun gear shell thrust washer (674) P/N 8642331er (674) P/N 8642331along with the appropriate seals and washers listed below. ^ Vehicles built in the 2001 model year and prior that have had previous service to the reaction sun shell: It is possible that some 2001 and prior model year vehicles have had previous service to the reaction sun shell. At the time of service, these vehicles may have been updated with a Reaction Sun Shell Kit (Refer to Service Bulletin 020730003) without four square holes to retain the thrust washer. If it is found in a 2001 model year and prior vehicles that the reaction sun shell DOES NOT have four square holes to retain the thrust washer, these vehicles must be serviced with P/Ns 24229825 (674), 24217328 and 8642331 along with the appropriate seals and washers listed below. ^ Vehicles built in the 2001 model year and later that make use of a reaction shaft to shell thrust bearing: The sun shell can be identified by no holes to retain the thrust washer. Use reaction sun shell, P/N 24229825, reaction carrier shaft to shell thrust bearing (669A), P/N 24217328 and reaction sun gear shell thrust washer (674), P/N 8642331 along with the appropriate seals and washers listed below. ^ Vehicles built from November, 2001 through June, 2002: These vehicles should have the reaction carrier shaft replaced when the sun shell is replaced. Use shell kit P/N 24229853, which contains a sun shell (670), a reaction carrier shaft (666), a reaction carrier shaft to shell thrust bearing (669A) and a reaction sun gear shell thrust washer (674). The appropriate seals and washers listed below should also be used. When servicing the transmission as a result of this condition, the transmission oil cooler and lines MUST be flushed. Refer to Corporate Bulletin Number 02-07-30-052. Follow the service procedure below for diagnosis and correction of the no reverse, no second, no forth condition. Important: If metallic debris is found on the transmission magnet, the transmission must be completely disassembled and cleaned. Metallic debris is defined as broken parts and pieces of internal transmission components. This should not be confused with typical "normal" fine particles found on all transmission magnets. Failure to properly clean the transmission case and internal components may lead to additional repeat repairs. 1. Remove the transmission oil pan and inspect the magnet in the bottom of the pan for metal debris. Refer to SI Document ID # 825141. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Sun Gear > Component Information > Technical Service Bulletins > Customer Interest for Sun Gear: > 00-07-30-022D > Jun > 08 > A/T - 4L60/65E, No Reverse/2nd or 4th Gear > Page 5004 2. Remove the transmission from the vehicle. Refer to the appropriate SI document. Important: ^ Inspect all the transmission components for damage or wear. Replace all damaged or worn components. The parts shown above should be sufficient to correct this concern. ^ This condition does not normally require replacement of the transmission completely. Components such as clutches, valve body, pump and torque converters will NOT require replacement to correct this condition. Disassemble the transmission and replace the appropriate parts listed below. Refer to the Unit Repair Manual - Repair Instructions. 3. Reinstall the transmission in the vehicle. Refer to appropriate service information. When servicing the transmission as a result of this condition, the transmission oil cooler and lines MUST be flushed. Refer to Corporate Bulletin Number 02-07-30-052. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Sun Gear > Component Information > Technical Service Bulletins > Customer Interest for Sun Gear: > 00-07-30-022D > Jun > 08 > A/T - 4L60/65E, No Reverse/2nd or 4th Gear > Page 5005 Parts Information Warranty Information For vehicles repaired under warranty, use the table. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Sun Gear > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Sun Gear: > 00-07-30-022D > Jun > 08 > A/T - 4L60/65E, No Reverse/2nd or 4th Gear Sun Gear: All Technical Service Bulletins A/T - 4L60/65E, No Reverse/2nd or 4th Gear TECHNICAL Bulletin No.: 00-07-30-022D Date: June 10, 2008 Subject: No Reverse, Second Gear or Fourth Gear (Replace Reaction Sun Shell with More Robust Heat Treated Parts) Models: 1993 - 2005 GM Passenger Cars and Light Duty Trucks 2003 - 2005 HUMMER H2 with 4L60/65-E Automatic Transmission (RPOs M30 or M32) Supercede: This bulletin is being revised to add 2005 model year to the parts information. Please discard Corporate Bulletin Number 00-07-30-022C (Section 07 - Transmission/Transaxle). Condition Some customers may comment on a no reverse, no second or no fourth gear condition. First and third gears will operate properly. Cause The reaction sun gear (673) may not hold inside the reaction sun shell (670). Correction Important: There are FOUR distinct groups of vehicles and repair procedures involved. Vehicles built in the 2001 model year and prior that make use of a reaction shaft to shell thrust washer: ^ The sun shell can be identified by four square holes used to retain the thrust washer. Use reaction sun shell P/N 24228345, reaction carrier to shell thrust washer (699B) P/N 8642202 and reaction sun gear shell thrust washer (674) P/N 8642331er (674) P/N 8642331along with the appropriate seals and washers listed below. ^ Vehicles built in the 2001 model year and prior that have had previous service to the reaction sun shell: It is possible that some 2001 and prior model year vehicles have had previous service to the reaction sun shell. At the time of service, these vehicles may have been updated with a Reaction Sun Shell Kit (Refer to Service Bulletin 020730003) without four square holes to retain the thrust washer. If it is found in a 2001 model year and prior vehicles that the reaction sun shell DOES NOT have four square holes to retain the thrust washer, these vehicles must be serviced with P/Ns 24229825 (674), 24217328 and 8642331 along with the appropriate seals and washers listed below. ^ Vehicles built in the 2001 model year and later that make use of a reaction shaft to shell thrust bearing: The sun shell can be identified by no holes to retain the thrust washer. Use reaction sun shell, P/N 24229825, reaction carrier shaft to shell thrust bearing (669A), P/N 24217328 and reaction sun gear shell thrust washer (674), P/N 8642331 along with the appropriate seals and washers listed below. ^ Vehicles built from November, 2001 through June, 2002: These vehicles should have the reaction carrier shaft replaced when the sun shell is replaced. Use shell kit P/N 24229853, which contains a sun shell (670), a reaction carrier shaft (666), a reaction carrier shaft to shell thrust bearing (669A) and a reaction sun gear shell thrust washer (674). The appropriate seals and washers listed below should also be used. When servicing the transmission as a result of this condition, the transmission oil cooler and lines MUST be flushed. Refer to Corporate Bulletin Number 02-07-30-052. Follow the service procedure below for diagnosis and correction of the no reverse, no second, no forth condition. Important: If metallic debris is found on the transmission magnet, the transmission must be completely disassembled and cleaned. Metallic debris is defined as broken parts and pieces of internal transmission components. This should not be confused with typical "normal" fine particles found on all transmission magnets. Failure to properly clean the transmission case and internal components may lead to additional repeat repairs. 1. Remove the transmission oil pan and inspect the magnet in the bottom of the pan for metal debris. Refer to SI Document ID # 825141. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Sun Gear > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Sun Gear: > 00-07-30-022D > Jun > 08 > A/T - 4L60/65E, No Reverse/2nd or 4th Gear > Page 5011 2. Remove the transmission from the vehicle. Refer to the appropriate SI document. Important: ^ Inspect all the transmission components for damage or wear. Replace all damaged or worn components. The parts shown above should be sufficient to correct this concern. ^ This condition does not normally require replacement of the transmission completely. Components such as clutches, valve body, pump and torque converters will NOT require replacement to correct this condition. Disassemble the transmission and replace the appropriate parts listed below. Refer to the Unit Repair Manual - Repair Instructions. 3. Reinstall the transmission in the vehicle. Refer to appropriate service information. When servicing the transmission as a result of this condition, the transmission oil cooler and lines MUST be flushed. Refer to Corporate Bulletin Number 02-07-30-052. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Sun Gear > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Sun Gear: > 00-07-30-022D > Jun > 08 > A/T - 4L60/65E, No Reverse/2nd or 4th Gear > Page 5012 Parts Information Warranty Information For vehicles repaired under warranty, use the table. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Torque Converter > Component Information > Technical Service Bulletins > A/T - Torque Converter Replacement Information Torque Converter: Technical Service Bulletins A/T - Torque Converter Replacement Information INFORMATION Bulletin No.: 01-07-30-010C Date: May 12, 2008 Subject: Automatic Transmission/Transaxle Torque Converter Replacement Models: 2009 and Prior GM Passenger Cars and Trucks 2009 and Prior HUMMER H2, H3 2009 and Prior Saturn Cars and Light Duty Trucks (Except VTi Equipped Vehicles (RPO M16 and M75) 2009 and Prior Saab 9-7X with ALL Automatic Transmissions and Transaxles Supercede: This bulletin is being revised to add the 2007-2009 model years. Please discard Corporate Bulletin Number 01-07-30-010B (Section 07 - Transmission/Transaxle). The purpose of this bulletin is to help technicians determine when a torque converter should be replaced. Below is a list of general guidelines to follow. The converter should NOT be replaced if the following apply: ^ DTC P0742 - TCC stuck on is set. This code is almost always the result of a controls condition (i.e. stuck TCC solenoid/valve). Experience has shown that this code rarely indicates a mechanical concern within the torque converter. ^ The fluid has an odor or is discolored but no evidence of metal contamination. ^ Fine metal particles (traces of metal flakes/gray color to fluid ) are found in the converter. This is not harmful to the torque converter. ^ The vehicle has been exposed to high mileage. ^ A small amount of wear appears on the hub where the oil pump drive gear mates to the converter (RWD only). A certain amount of such wear is normal for both the hub and oil pump gear. Neither the converter nor the front pump assembly should be replaced. The torque converter should be replaced under any of the following conditions: ^ The vehicle has TCC shudder and/or no TCC apply. First complete all electrical and hydraulic diagnosis and check for proper engine operation. The converter clutch may be damaged. Also the converter bushing and/or internal 0-ring may be damaged. ^ Evidence of damage to the oil pump assembly pump shaft turbine shaft drive sprocket support and bearing or metal chips/debris in the converter. ^ Metal chips/debris are found in the converter or when flushing the cooler and the cooler lines. ^ External leaks in the hub weld area lug weld or closure weld. ^ Converter pilot is broken damaged or fits poorly into the crankshaft. ^ The converter hub is scored or damaged. ^ The transmission oil is contaminated with engine coolant engine oil or water. ^ If excessive end play is found after measuring the converter for proper end play (refer to Service Manual). ^ If metal chips/debris are found in the fluid filter or on the magnet and no internal parts in the unit are worn or damaged. This indicates that the material came from the converter. ^ The converter has an unbalanced condition that results in a vibration that cannot be corrected by following Converter Vibration Procedures. ^ Blue converter or dark circular ring between lugs. This condition will also require a complete cleaning of the cooler and a check for adequate flow Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Torque Converter > Component Information > Technical Service Bulletins > A/T - Torque Converter Replacement Information > Page 5017 through the cooler. ^ Converter bearing noise determined by noise from the bell housing area in Drive or Reverse at idle. The noise is gone in Neutral and Park. ^ If silicon from the viscous clutch is found in the lower pan (4T80-E ONLY). Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Torque Converter Clutch Solenoid, A/T > Component Information > Technical Service Bulletins > A/T - 2-4 Band, TCC Solenoid, 3-4 Clutch Friction/Plates Torque Converter Clutch Solenoid: Technical Service Bulletins A/T - 2-4 Band, TCC Solenoid, 3-4 Clutch Friction/Plates File In Section: 7 - Transmission Bulletin No.: 47-71-41 Date: January, 1995 Subject: New 2-4 Band Assembly, 3-4 Clutch Friction and Steel Plates and Torque Clutch PWM Solenoid Models: 1995 Buick Roadmaster 1995 Cadillac Fleetwood 1995 Chevrolet Camaro, Caprice, Corvette 1995 Pontiac Firebird 1995 Chevrolet and GMC Truck C/K Models and M/L, G Vans 1994-95 Chevrolet and GMC Truck S/T Models 1994 Oldsmobile Bravada (1994 Models with RPO +CTF Package) Transmission Applications: 1995 Hydra-Matic 4L60-E (RPO M30) A new 2-4 Band Assembly was introduced at the start of production for the 1995 Model Year and 1994 Bravadas and S/T trucks. The 2-4 Band friction material has changed appearance from a brown material to a gray/black material. This change was made to enhance durability. When servicing a 1995 Hydra-Matic 4L60-E transmission, do NOT assume that the 2-4 Band is burned/damaged due to its dark color. This dark color is normal. Before replacing the 2-4 Band inspect it for scoring, chunking or heavily worn friction material. Before Replacing the Reverse Input Housing and Drum Assembly inspect for scoring or signs of excessive heat. The 2-4 Band and/or Reverse Input Housing and Drum Assembly should be replaced ONLY if the above listed damage is found. Note: The new 2-4 Band Assembly will NOT service past model Hydra-Matic 4L60-E or 4L60 transmissions. A new 3-4 clutch friction plate was introduced at the start of production for the 1995 Model Year and 1994 Bravadas and S/T Trucks. The 3-4 clutch plate friction material has changed appearance from a brown material to a green/black material. This change was made to enhance durability. When servicing a 1995 Hydra-Matic 4L60-E transmission, do NOT assume that the 3-4 clutch friction plates are burned/damaged due to their dark color. This dark color is normal. Before replacing the 3-4 clutch friction plates inspect for scoring, chunking or heavily worn friction material. Before replacing the 3-4 clutch steel plates inspect for scoring or signs of excessive heat. The 3-4 clutch friction plates and/or 3-4 clutch steel plates should be replaced ONLY if the above listed damage is found. Note: The new 3-4 friction plates will NOT service past model Hydra-Matic 4L60-E or 4L60 transmissions. A new Torque Converter Clutch PWM Solenoid was introduced at the start of production for the 1995 Model Year and 1994 Bravadas and S/T trucks. The new torque converter clutch PWM solenoid is used to control fluid acting on the converter clutch valve, which then controls TCC apply and release. The solenoid is attached to the control valve body assembly within the transmission. The TCC PWM solenoid is used to provide smooth engagement of the torque converter by operating on a negative duty cycle percent of "ON" time. It a fault is detected in the TCC PWM circuit, DTC 83 will set. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Torque Converter Clutch Solenoid, A/T > Component Information > Technical Service Bulletins > A/T - 2-4 Band, TCC Solenoid, 3-4 Clutch Friction/Plates > Page 5022 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Torque Converter Clutch Solenoid, A/T > Component Information > Technical Service Bulletins > A/T - 2-4 Band, TCC Solenoid, 3-4 Clutch Friction/Plates > Page 5023 Included is a Service Manual update for the 1-2 and 3-4 accumulator spring color chart. Replace these pages in your 1995 Service Manual. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Torque Converter Clutch Solenoid, A/T > Component Information > Technical Service Bulletins > Page 5024 Torque Converter Clutch Solenoid: Locations Inside automatic transmission attached to valve body. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Torque Converter Clutch Solenoid, A/T > Component Information > Technical Service Bulletins > Page 5025 C216 - TCC Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Torque Converter Clutch Solenoid, A/T > Component Information > Technical Service Bulletins > Page 5026 Torque Converter Clutch Solenoid: Description and Operation Torque Converter Clutch Solenoid PURPOSE The Transmission Converter Clutch (TCC) feature eliminates the power loss of the torque converter stage when the vehicle is in a cruise mode. OPERATION The TCC system uses a solenoid operated valve in the automatic transmission to couple the engine flexplate to the output shaft of the transmission through the torque converter. This reduces the slippage losses in the converter, which increases fuel economy. For the converter clutch to apply, two hydraulic conditions must be met: Internal transmission fluid pressure must be correct. - The control module completes a ground circuit to energize the TCC solenoid in the transmission, which moves a check ball in the fluid line. Control module control is based on the input of these sensors: Vehicle Speed Sensor (VSS): Vehicle equipped with A/C will allow TCC engagement at about 35 mph when the A/C is selected "ON". Engagement will occur at a vehicle speed of about 30 mph (25 mph for 92) when A/C is selected "OFF". - Engine Coolant Temperature (ECT) Sensor: Engine at normal operating temperature (above 65°C/149°F). - Throttle Position Sensor (TPS): Output not changing, indicating a steady road speed. - Transmission Fluid (TFT) sensor. Control module is also controlled by these switches: Brake switch closed: 12 volts supplied when brake is depressed. - Transmission Range (TR) pressure switch assembly. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Transmission Cooler, A/T > Component Information > Technical Service Bulletins > A/T - Fluid Oil Cooler Flush Transmission Cooler: Technical Service Bulletins A/T - Fluid Oil Cooler Flush INFORMATION Bulletin No.: 02-07-30-052G Date: March 02, 2011 Subject: Automatic Transmission Oil Cooler Flush and Flow Test Essential Tool J 45096 TransFlow(R) Models: 2011 and Prior Passenger Cars and Light Duty Trucks 2003-2010 HUMMER H2 2006-2010 HUMMER H3 with Automatic Transmission/Transaxle including Allison(R) Transmissions Supercede: This bulletin is being revised to update the model years. Please discard Corporate Bulletin Number 02-07-30-052F (Section 07 - Transmission/Transaxle). Important All labor operations that include removal of the transmission from the vehicle include labor time to flush the transmission oil cooler system. The J 45096 transmission oil cooling system flush and flow test tool replaces current tool J 35944-A. J 45096 is a self-contained unit utilizing a 12-volt flow meter, shop air supply and DEXRON(R) VI automatic transmission fluid (ATF). In the flush mode, transmission fluid is cycled through the transmission oil cooling system. High-pressure air is automatically injected into the fluid stream adding agitation to the ATF oil to enhance the removal of contaminated ATF oil and debris. In the flow mode, an electronic flow meter is used to measure the flow capability of the ATF oil cooling system. A digital display indicates the ATF oil flow rate in gallons per minute (GPM) along with the amount of ATF oil in the supply vessel, supply vessel ATF oil temperature, machine cycles and the operating mode. The supply oil vessel has 30 L (32 qt) capacity and the waste oil vessel has 32 L (34 qt) capacity. The waste oil vessel is constructed of a translucent composite material that allows the user to easily identify the oil level. The waste oil vessel can accommodate vacuum evacuation and gravity draining. In the code mode, a random, encrypted code is generated that can be used for verification of flow test results. Current essential cooler line adapters are used to connect the J 45096 to the automatic transmission oil cooler lines that allows J 45096 to adapt to General Motors passenger cars and light duty trucks, current and past models (except the Pontiac Vibe, Wave and Chevrolet Aveo). The tool may be adapted for use on the Pontiac Vibe, Wave and Chevrolet Aveo by dealership personnel with a barbed hose connector and rubber hose obtained locally. The Vibe's/Wave's/Aveo's transmission has a transmission oil requirement which is slightly different than DEXRON(R) VI ATF. However, flushing the cooler with DEXRON(R) VI automatic transmission fluid is an acceptable service procedure. Very little fluid remains in the cooler after the flush procedure and the residual DEXRON(R) VI ATF in the cooler is compatible with the Vibe's/Wave's/Aveo's transmission fluid. Notice Insufficient oil flow through the ATF oil cooling system will cause premature transmission failure. The required minimum ATF oil flow rate reading is directly related to the supply oil temperature. Refer to the flow rate reference chart for the oil flow rate specification based on the temperature of the ATF in the supply vessel. Helpful Hints for Maintaining the Temperature at or above 18°C (65°F) Important - The temperature of the supply vessel oil must be 18°C (65°F) or greater for J 45096 to operate. It is recommended to store the J 45096 in an area of the dealership where the room temperature remains at or above 18°C (65°F) when not in use. - Do not attempt to increase the fluid temperature in the Transflow(R) machine with an engine oil dipstick, or any other immersion type heater. The Transflow(R) machine has a check valve in the supply reservoir. Inserting a heater will damage the check valve and the subsequent repair expense would be the dealer's responsibility. - A heater blanket, P/N J-45096-10, is available for the Transflow(R) transmission cooling system flushing tool. This heater fastens around the Transflow(R) internal supply vessel and runs on 110 volts AC. The heater will warm the ATF in the supply vessel to at least 18°C (65° F) and has a thermostat to hold a constant temperature. Store the Transmission Cooling System Service Tool, J 45096, Transflow(R) machine in a room where the temperature is maintained at or above 18°C (65°F). Keep the ATF level in the reservoir low when the Transmission Cooling System Service Tool, J 45096, Transflow(R), is not in use. Store several gallons of oil in an area where the temperature is maintained at or above 18°C (65°F). Fill the reservoir of the J 45096 as needed before using the machine on Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Transmission Cooler, A/T > Component Information > Technical Service Bulletins > A/T - Fluid Oil Cooler Flush > Page 5031 each repair. With the ATF in a tightly sealed container, place the container in a tub of hot water for a period of time. Then pour the ATF into the reservoir. This method works best with a low fluid level in the reservoir. Place the Transflow(R) machine in the direct sunlight with the cabinet door open to expose the reservoir to the rays of the warm sun. Flush / Flow Test Procedure Important All labor operations that include removal of the transmission from the vehicle and require the transmission oil pan or transmission side cover to be removed include labor time to flush the transmission oil cooler system. Refer to SI for Automatic Transmission Oil Cooler Flushing and Flow Test J 45096 for the appropriate procedure. Important The J 45096 can be used to flush the transmission oil cooler system on an Allison equipped vehicle, but the flow meter should not be utilized. Refer to SI for Automatic Transmission Oil Cooler Flushing and Flow Test J 45096 for the appropriate flow check procedure. Machine Displays After completion of the flush and flow test, the following information is to be recorded on the repair order. This information is displayed on the Transmission Cooling System Service Tool, J 45096, Transflow(R) machine when the dial is in the code position. - Tested flow rate (displayed in Gallons Per Minute (GPM) - Temperature (displayed is degrees Fahrenheit) - Cycle number (a number) - Seven digit Alpha/Numeric flow code (i.e. A10DFB2) Warranty Information Important All labor operations that include removal of the transmission from the vehicle include labor time to flush the transmission oil cooler system. Performing a transmission oil cooling system flush and flow test will use between 4.7-7.5 L (5-8 qts) of DEXRON(R)VI transmission fluid. The amount Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Transmission Cooler, A/T > Component Information > Technical Service Bulletins > A/T - Fluid Oil Cooler Flush > Page 5032 of transmission fluid (ATF), (DEXRON(R)VI) (fluid) that is to be charged for the flush portion of the repair should not exceed the allowable charge for 7.5 L (2 gal) of fluid. This expense should be shown in the Parts Section of the warranty claim document. The Seven digit Alpha/Numeric flow code, i.e. A10DFB2, "MUST" be written on the job card and placed in the comments section of the warranty claim. Any repair that requires the technician to contact the Product Quality Center (PQC) must also include the seven digit flow code. The agent will request the seven digit flow code and add the information to the PQC case prior to providing authorization for the warranty claim. The Seven digit Alpha/Numeric flow code, i.e. A10DFB2, "MUST" be written on the job card, entered in the warranty claim labor operation Flush Code additional field (when available) and placed in the comments section of the warranty claim. Any repair that requires the technician to contact the Product Quality Center (PQC) must also include the seven digit flow code. The agent will request the seven digit flow code and add the information to the PQC case prior to providing authorization for the warranty claim. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Transmission Cooler, A/T > Component Information > Technical Service Bulletins > A/T - Fluid Oil Cooler Flush > Page 5033 Transmission Cooler: Technical Service Bulletins A/T - Water Or Coolant Contamination Information INFORMATION Bulletin No.: 08-07-30-035B Date: November 01, 2010 Subject: Information on Water or Ethylene Glycol in Transmission Fluid Models: 2011 and Prior GM Passenger Cars and Light Duty Trucks with Automatic Transmission Supercede: This bulletin is being revised to update model years. Please discard Corporate Bulletin Number 08-07-30-035A (Section 07 - Transmission/Transaxle). Water or ethylene glycol in automatic transmission fluid (ATF) is harmful to internal transmission components and will have a negative effect on reliability and durability of these parts. Water or ethylene glycol in ATF will also change the friction of the clutches, frequently resulting in shudder during engagement or gear changes, especially during torque converter clutch engagement. Indications of water in the ATF may include: - ATF blowing out of the transmission vent tube. - ATF may appear cloudy or, in cases of extreme contamination, have the appearance of a strawberry milkshake. - Visible water in the oil pan. - A milky white substance inside the pan area. - Spacer plate gaskets that appear to be glued to the valve body face or case. - Spacer plate gaskets that appear to be swollen or wrinkled in areas where they are not compressed. - Rust on internal transmission iron/steel components. If water in the ATF has been found and the source of the water entry has not been identified, or if a leaking in-radiator transmission oil cooler is suspected (with no evidence of cross-contamination in the coolant recovery reservoir), a simple and quick test kit is available that detects the presence of ethylene glycol in ATF. The "Gly-Tek" test kit, available from the Nelco Company, should be obtained and the ATF tested to make an accurate decision on the need for radiator replacement. This can help to prevent customer comebacks if the in-radiator transmission oil cooler is leaking and reduce repair expenses by avoiding radiator replacement if the cooler is not leaking. These test kits can be obtained from: Nelco Company Test kits can be ordered by phone or through the website listed above. Orders are shipped standard delivery time but can be shipped on a next day delivery basis for an extra charge. One test kit will complete 10 individual fluid sample tests. For vehicles repaired under warranty, the cost of the complete test kit plus shipping charges should be divided by 10 and submitted on the warranty claim as a net item. The transmission should be repaired or replaced based on the normal cost comparison procedure. Important If water or coolant is found in the transmission, the following components MUST be replaced. - Replace all of the rubber-type seals. - Replace all of the composition-faced clutch plates and/or bands. - Replace all of the nylon parts. - Replace the torque converter. - Thoroughly clean and rebuild the transmission, using new gaskets and oil filter. Important The following steps must be completed when repairing or replacing. Flush and flow check the transmission oil cooler using J 45096. Refer to Corporate Bulletin Number 02-07-30-052F- Automatic Transmission Oil Cooler Flush and Flow Test Essential Tool J 45096 TransFlow. - Thoroughly inspect the engine cooling system and hoses and clean/repair as necessary. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Transmission Cooler, A/T > Component Information > Technical Service Bulletins > A/T - Fluid Oil Cooler Flush > Page 5034 Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Transmission Cooler, A/T > Component Information > Technical Service Bulletins > A/T - Fluid Oil Cooler Flush > Page 5035 Transmission Cooler: Technical Service Bulletins A/T - Oil Cooler Flushing Frequently Asked Questions File In Section: 07 - Transmission/Transaxle Bulletin No.: 03-07-30-027 Date: June, 2003 INFORMATION Subject: Most Frequently Asked Questions and Answers for J 45096 TransFlow Transmission Oil Cooling System Flushing Machine Models: 2004 and Prior Passenger Cars and Light Duty Trucks with Automatic Transmission/Transaxle 2004 and Prior HUMMER H2 This bulletin is issued to help answer the most frequently asked questions and concerns about essential tool J 45096. Q: Why doesn't the machine work below 18°C (65°F)? A: The flow characteristics of ATF at temperatures below 18°C (65°F) does not provide accurate flow test results with the electronics used in the J 45096. Q: Why didn't the unit come with a tank heater? A: The vast majority of dealerships do not require a heater to keep the ATF above 18°C (65°F). As a result, the heater was deleted as a cost-savings measure. A tank heater, J 45096-10, is currently available from Kent-Moore if your dealership requires it. Refer to Corporate Bulletin Number 03-07-30-002A for suggestions on warming the ATF without using a heater blanket. Q: Why does the machine fail new oil coolers? A: Several reasons have been found. The most likely reason is the air pressure at the air hose connected to the J 45096 is less than 586 kPa (85 psi). Other reasons include a twisted hose inside the J 45096 at the bulkhead as a result of the nut turning when the waste or supply hose was installed, the internal pressure regulator was improperly set at the factory or a problem with the cooler lines on the vehicle. Perform the J 45096 self-test as described on pages 9 and 10 of the Operation Manual. If a problem is still detected, refer to Troubleshooting on page 19 of the Operation Manual. If a problem still persists, contact Kent-Moore Customer Service at 1-800-345-2233. Q: What is the difference between steel and aluminum oil coolers? A: The aluminum oil cooler tube is slightly thinner in construction than the steel oil cooler tube, which affects the oil flow rate. The fitting that is protruding out of the radiator tank easily identifies the aluminum oil cooler. Refer to the Quick Reference card provided with the J 45096 in order to identify the proper flow rate for the aluminum oil cooler. Q: Why can't I use TransFlow for Allison transmission cooling Systems? A: Validation of TransFlow is currently under development for light duty trucks equipped with the Allison automatic transmission. TransFlow is based on the existing MINIMUM flow rate specification through the transmission oil cooling system. The Allison transmission oil cooling system only has MAXIMUM oil flow rates specified and J 45096 does not have the capability to test the transmission oil cooling system at the maximum oil flow rate specification. Q: Why doesn't GM publish a specification for auxiliary transmission oil coolers? A: The auxiliary oil cooler used with GM vehicles does not contain an internal turbulator plate like the radiator tank oil cooler does. Therefore, there is no internal restriction that would affect the flow rate through the oil cooling system so a specification for auxiliary oil cooler is not required. Keep in mind, kinks and damage to the auxiliary cooler and lines can affect the flow rate through the system. Q: Why did GM drop the labor time for transmission repairs? A: The labor for flushing and flow testing the transmission oil cooling system is included with the R&R; labor of the "K" labor operations that require transmission removal. The time required to use the J 45096 to perform the flush and flow test is much less than that of the J 35944-A. The warranty labor savings allowed GM to provide the J 45096 at no cost to dealerships. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Transmission Cooler, A/T > Component Information > Technical Service Bulletins > A/T - Fluid Oil Cooler Flush > Page 5036 Q: Why didn't the machine come with the adapters to hook up to the car? A: The J 45096 was designed to use the previously released essential cooler line adapters for the J 35944-A. All adapters are listed on page 17 of the Operation Manual and can be ordered from Kent-Moore at 1-800-345-2233. Q: How do I connect the J 45096 to a Catera, Prizm or a Vibe? A: These vehicles, along with many other models, only require barbed fittings to connect to the rubber cooler hose. These fittings are commercially available and already found in many shops. Q: Why didn't I receive an Operation Manual with the machine? A: The Operation Manual was packaged in the upper portion of the shipping carton. If the shipping carton was lifted off the base without opening the top of the carton, the Operation Manual could have been discarded with the carton. Replacement Operation Manual packages can be obtained from Kent-Moore Customer Service at 1-800-345-2233. Q: Why can't I re-use the transmission fluid I use for flushing? A: The very fine metal and clutch material debris from the transmission failure in the ATF causes failures with the hall effect speed sensors that are used to measure the flow rate. To avoid costly repairs, expensive filters, regular maintenance and problems caused by a partially restricted filter, the filter was not included. Q: What do I do if I need service on my machine? A: Call Kent-Moore Customer Service at 1-800-345-2233. The J 45096 has a one-year warranty. Q: Can I flush and flow engine oil coolers? A: The engine oil cooler flow rates, the appropriate adapters and an acceptable procedure are currently under development. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Transmission Position Switch/Sensor, A/T > Component Information > Description and Operation Transmission Position Switch/Sensor: Description and Operation Automatic Transmission Electrical Components PURPOSE This device is a set of five presure switches (two normally closed and three normally open), that detect fluid pressure within the valve body passages and signals the PCM which transmission range is selected (PRNDL). OPERATION The five pressure switches are connected to three signal circuits referred to as range signals A, B, C. The combination of pressure switch states determines the voltage signal (B+ or 0) on each range signal to the PCM. LOCATION The transmission range fluid pressure switch assembly is attached to the control valve body within the transmission. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Transmission Pressure Test Port, A/T > Component Information > Locations Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Transmission Speed Sensor, A/T > Component Information > Specifications Transmission Speed Sensor: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Vehicle Speed Sensor Retainer ........................... .............................................................................................................................................................. ... 8 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Transmission Temperature Sensor/Switch, A/T > Component Information > Description and Operation Transmission Temperature Sensor/Switch: Description and Operation Automatic Transmission Electrical Components PURPOSE The Transmission Fluid Temperature (TFT) Sensor is used by the control module to control: Torque Converter Clutch (TCC) apply and release schedule. - Hot mode determination. - Shift quality. OPERATION The TFT is a thermistor used to indicate transmission fluid temperature. The control module sends a 5.0 volt signal to the TFT through a resistor in the computer and measures the voltage. High sensor resistance produces high signal input voltage which corresponds to low fluid temperature. Low sensor resistance produces low signal input voltage which corresponds to high fluid temperature. With the TFT varying its resistance, the control module can sense transmission fluid temperature by reading the varying voltage. LOCATION The sensor is part of the transmission range fluid pressure switch assembly and is attached to the control valve body within the transmission. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Technical Service Bulletins > A/T Control - DTC P0756 Diagnostic Tips Valve Body: Technical Service Bulletins A/T Control - DTC P0756 Diagnostic Tips INFORMATION Bulletin No.: 01-07-30-036H Date: January 29, 2009 Subject: Diagnostic Tips for Automatic Transmission DTC P0756, Second, Third, Fourth Gear Start Models: 2009 and Prior GM Passenger Cars and Light Duty Trucks 2009 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7X with 4L60-E, 4L65-E or 4L70E Automatic Transmission (RPOs M30, M32 or M70) Supercede: This bulletin is being revised to add the 2009 model year and add details regarding spacer plates. Please discard Corporate Bulletin Number 01-07-30-036G (Section 07 - Transmission/Transaxle). Some dealership technicians may have difficulty diagnosing DTC P0756, 2-3 Shift Valve Performance on 4L60-E, 4L65-E or 4L70E automatic transmissions. As detailed in the Service Manual, when the PCM detects a 4-3-3-4 shift pattern, DTC P0756 will set. Some customers may also describe a condition of a second, third or fourth gear start that may have the same causes but has not set this DTC yet. Below are some tips when diagnosing this DTC: ^ This is a performance code. This means that a mechanical malfunction exists. ^ This code is not set by electrical issues such as a damaged wiring harness or poor electrical connections. Electrical problems would cause a DTC P0758, P0787 or P0788 to set. ^ The most likely cause is chips/debris plugging the filtered AFL oil at orifice # 29 on the top of the spacer plate (48). This is a very small hole and is easily plugged by a small amount of debris. It is important to remove the spacer plate and inspect orifice # 29 and the immediate area for the presence of chips/debris. Also, the transmission case passage directly above this orifice and the valve body passage directly below should be inspected and cleaned of any chips/debris. For 2003 and newer vehicles the spacer plate should be replaced. The service replacement spacer plate is a bonded style with gaskets and solenoid filter screens bonded to the spacer plate. These screens can help to prevent plugging of orifice # 29 caused by small debris or chips. ^ This code could be set if the 2-3 shift valve (368) were stuck or hung-up in its bore. Inspect the 2-3 shift valve (368) and the 2-3 shuttle valve (369) for free movement or damage and clean the valves, the bore and the valve body passages. ^ This code could be set by a 2-3 shift solenoid (367b) if it were cracked, broken or leaking. Refer to Shift Solenoid Leak Test in the appropriate Service Manual for the leak test procedure. Based on parts return findings, a damaged or leaking shift solenoid is the least likely cause of this condition. Simply replacing a shift solenoid will not correct this condition unless the solenoid has been found to be cracked, broken or leaking. It is important to also refer to the appropriate Service Manual or Service Information (SI) for further possible causes of this condition. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Specifications > Electrical Specifications Valve Body: Electrical Specifications Component Resistance Chart Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Specifications > Electrical Specifications > Page 5055 Valve Body: Mechanical Specifications 4L60 Automatic Transmission COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. FWD Accumulator Cover To Valve Body ............................................................................................ ............................................................................... 8 Valve Body To Case ......................................... .............................................................................................................................................................. ..... 8 Pressure Control Solenoid To Valve Body ................................................................................. ......................................................................................... 8 Detent Spring To Valve Body ................. .............................................................................................................................................................. ............. 18 Auxiliary Valve Body To Case .......................................................................................... .................................................................................................. 8 4L60-E Automatic Transmission COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. FWD Accumulator Cover To Valve Body ............................................................................................ ............................................................................... 8 Valve Body To Case ......................................... .............................................................................................................................................................. ..... 8 Pressure Control Solenoid To Valve Body ................................................................................. ......................................................................................... 8 Detent Spring To Valve Body ................. .............................................................................................................................................................. ............. 18 Auxiliary Valve Body To Case .......................................................................................... .................................................................................................. 8 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Locations > Checkball Locations Valve Body: Locations Checkball Locations Case Checkballs and Filters Locations Control Valve Body Checkball Locations Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Locations > Checkball Locations > Page 5058 Fig. 11 Check Ball Location. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Locations > Checkball Locations > Page 5059 Valve Body: Locations Shift Solenoids Electronic Component Location Views Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Locations > Checkball Locations > Page 5060 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service Valve Body: Service and Repair In-Vehicle Service Control Valve Assembly 1. Disconnect battery ground cable. 2. Disconnect TV cable at throttle lever, then raise and support vehicle. 3. Drain transmission fluid, then remove transmission oil pan, filter and gasket. Fig.12 Auxiliary Valve Body Replacement 4. Remove two bolts that attach auxiliary accumulator valve tube to control valve assembly and accumulator valve body assembly, Fig. 12. 5. Remove two tube clamps, gently pry tube loose from oil pump assembly, then the auxiliary accumulator valve body assembly. 6. Disconnect electrical connectors at valve body. 7. Remove detent spring and roller assembly from valve body and remove valve body to case bolts. 8. Remove valve body assembly while disconnecting manual control valve link from range selector inner lever and removing throttle lever bracket from TV link. 9. Reverse procedure to install. Auxiliary Valve Body 1. Raise and support vehicle, then drain transmission fluid. 2. Remove transmission oil pan and filter. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 5063 Fig.12 Auxiliary Valve Body Replacement 3. Remove two bolts that attach auxiliary accumulator valve tube to control valve assembly and accumulator valve body assembly, Fig. 12. 4. Remove two tube clamps, gently pry tube loose from oil pump assembly and auxiliary accumulator valve body assembly. 5. Remove three auxiliary accumulator valve body to transmission case attaching bolts. 6. Remove auxiliary valve body and check ball. 7. Reverse procedure to install. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 5064 Valve Body: Service and Repair Unit Repair Pan and Filter Assembly PAN AND FILTER ASSEMBLY Pan, Filter And Seal Removal CLEAN - Exposed ends of bottom pan screws and spray with penetrating oil. REMOVE OR DISCONNECT 1. Screws (76), oil pan (75) and gasket (73). 2. Oil filter (72) and filter seal (71). - Filter seal may be stuck in the pump. INSPECT - Filter (72), open filter by prying the metal crimping away from the top of the filter (black) and pull apart. The filter may contain evidence for root cause diagnosis. Clutch material. - Bronze slivers indicating bushing wear. - Steel particles. Valve Body and Wiring Harness VALVE BODY AND WIRING HARNESS Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 5065 Valve Body Bolt Location Control Valve And Pressure Switch Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 5066 Manual Valve Link Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 5067 Valve Body Checkballs Case Checkballs And Filters REMOVE OR DISCONNECT 1. Electrical connections from components. 2. TCC PWM Solenoid Retainer Clip (379) and Solenoid (396). 3. TCC Solenoid bolts (68) and solenoid assembly (66) with O-ring seal (65) and wiring harness. 4. Pressure switch assembly bolts (70) and pressure switch assembly (69). 5. Accumulator cover bolts (58 and 59) and 1-2 accumulator cover and pin assembly (57). 6. 1-2 accumulator piston (56) and seal (55). 7. Spring (54). 8. Dipstick stop bracket (93). REMOVE OR DISCONNECT 1. Bolt (64) and manual detent spring assembly (63). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 5068 2. Wiring harness retaining bolts. REMOVE OR DISCONNECT 1. Remaining valve body bolts (62). 2. Manual valve link (89). 3. Control valve assembly (60). 4. Bolts (58 and 59), accumulator cover (57), piston (56, spring (54) and spring (54A). 5. Bolts (77) and plate (53). 6. Spacer plate (48) and spacer plate gaskets (47 and 52). 7. Spring (46), piston (44), and pin (43). - Seven checkballs are located under the valve body and one is located in the case. The large copper flash colored ball is # 1A checkball (91). Valve Body and Associated Parts VALVE BODY AND ASSOCIATED PARTS Accumulator Assembly, Spacer Plate And Gaskets Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 5069 Case Checkballs And Filters TOOL REQUIRED: - J 25025-5 Guide Pins NOTICE: The use of a honing stone, fine sandpaper or crocus cloth is not recommended for servicing stuck valves. All valve lands have sharply machined corners that are necessary for "cleaning" the bore. If these corners are rounded, foreign material could wedge between the valve and bore causing the valve to stick. If it is found necessary to clean a valve, "micro fine" lapping compound 900 grit or finer should be used. Too much "lapping" of a valve will cause excessive clearances and increase the chance of a valve not operating. INSTALL OR CONNECT 1. The wiring harness pass-thru connector into the case. 2. The 3-4 accumulator pin (43) into the case. 3. The 3-4 accumulator piston seal (45) onto the 3-4 accumulator piston. 4. The 3-4 accumulator piston (44) onto the pin. - The end with three legs must face the valve body. 5. The 3-4 accumulator piston spring (46). INSTALL OR CONNECT 1. Checkball (91) into case as shown. - Retain with Transjel TM J 36850 or equivalent. 2. J 25025-5 into the case. 3. Screens onto spacer plate as shown. 4. Spacer plate to case gasket (47) and spacer plate to valve body gasket (52) onto the spacer plate (48). - Gasket (47) identified by a "C". Gasket (52) identified by a "V". - Retain with Transjel TM J 36850 or equivalent. 5. Spacer plate and gaskets onto the case. IMPORTANT - Be careful not to damage screens when installing the spacer plate and gaskets. 6. Spacer plate support (53) and bolts (77). TIGHTEN - Bolts to 11 Nm (8 lb. ft.) Control Valve Body CONTROL VALVE BODY Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 5070 Case Checkballs And Filters Filter Screen - Locations Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 5071 Control Valve Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 5072 Control Valve Assembly - Legend Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 5073 Valve Body Checkball Locations Valve Body Bolt Locations Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 5074 Manual Valve Link Outside Electrical Connector CLEAN - Control valve assembly thoroughly in clean solvent. A. Move the valves with a pick or small screwdriver to dislodge any dirt or debris that may have accumulated. B. Air dry. REMOVE OR DISCONNECT IMPORTANT - Some valves are under pressure - cover the bores while removing roll pins and retainer clips. - Valves, springs and bushings must be laid out on a clean surface in the exact sequence they are removed. 1. Pressure control solenoid retainer bolt (364) retainer (378) and solenoid. 2. Bore plug retainer clip (395), bore plug (376) and valve train (374 and 375). 3. 2-3 shift solenoid retainer (379), solenoid (367) and valve train (368 and 369). 4. 1-2 shift solenoid retainer (379), solenoid (367) and valve train (365 and 366). 5. Accumulator valve train retainer pin (360), bore plug (373) and valve train (370 and 371). 6. Forward accumulator cover bolts (364) and cover (363). 7. Forward accumulator spring (356), piston (354) and pin (355). 8. Lo overrun valve spring (362) and valve (361). 9. Retainer pin (360), bore plug (359) and forward abuse valve train (357 and 358). 10. Manual valve (340). 11. 3-2 control solenoid retainer clip (379) and solenoid (394). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 5075 12. Bore plug retainer (395), bore plug (381) and 3-2 control valve train (391 - 393). 13. 3-2 downshift bore plug retainer (395), bore plug (381) and valve train (389 - 390). 14. Reverse abuse bore plug retainer pin (360), bore plug (359) and valve train (387 - 388). 15. 3-4 shift valve bore plug retainer (395), bore plug (381) and valve train (385 - 386). 16. 3-4 relay bore plug retainer (395), bore plug (381) and valve train (382 - 384). 17. Torque converter clutch signal valve bore plug retainer (395), bore plug (381) and valve (380). CLEAN - All valves, springs, bushings and control valve body in clean solvent. - Dry using compressed air. INSPECT - All valves and bushings for: Porosity - Scoring - Nicks - Scratches - Springs for damaged or distorted coils. - Valve body casting for: Porosity - Cracks - Inter connected oil passages - Damaged machined surfaces ASSEMBLE - Control valve assembly (350) exactly as shown. Notice the position of the valve lands and bushing passages. - Position the pressure control solenoid so the connector tabs face outward. NOTICE: TCC PWM solenoid (396) cannot be installed until TCC solenoid has been installed and torqued to proper specifications. INSTALL OR CONNECT 1. Checkballs into the valve body assembly (350). - Retain with Transjell TM J 36850 or equivalent. 2. Valve body assembly (350). - Connect the manual valve link (89) to the inside detent lever (88). - Be careful not to damage screens when installing the valve body assembly. 3. Wiring harness (66), manual spring assembly (63), pressure switch assembly(69), dipstick, stop bracket (93) and all remaining valve body bolts. NOTICE: Torque valve body bolts in a spiral pattern starting from the center. If bolts are torqued at random, valve bores may be distorted and inhibit valve operation. 4. TCC solenoid (66) and bolts (68). TIGHTEN - Bolts to 11 Nm (8 lb. ft.). 5. TCC PWM solenoid (396), and retainer clip (379). INSTALL OR CONNECT - Wiring harness connections to electrical components. - To correctly hook up the wires, see the wiring diagrams. - The pressure control solenoid (377) has two different colored connectors. The black connector should be installed on the tab farthest from the valve body. INSTALL OR CONNECT 1. Parking bracket (86). TIGHTEN - Bolts to 31 Nm (23 lb. ft.). 2. The 1-2 accumulator piston seal (55) onto the 1-2 accumulator piston (56). 3. The 1-2 accumulator spring (54) and 1-2 accumulator inner spring (54A) onto the piston (56). 4. The 1-2 accumulator piston (56) into the 1-2 accumulator cover and pin assembly (57). - The three legs on the piston must face away from the case when installed. 5. The 1-2 accumulator cover and pin assembly (57) onto the case. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 5076 TIGHTEN - Torque to 11 Nm (8 lb. ft.). Pan and Filter Assembly PAN AND FILTER ASSEMBLY Case, Pan And Filter Assembly INSTALL OR CONNECT 1. Filter seal (71) into the pump. 2. Oil filter (72). 3. Oil pan gasket (73). 4. Chip magnet (74) onto oil pan (75). 5. Oil pan (75) and bolts (76). TIGHTEN - Torque to 12 Nm (9 lb. ft.). Pan and Filter Assembly PAN AND FILTER ASSEMBLY Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 5077 Pan, Filter And Seal Removal REMOVE OR DISCONNECT 1. Drain the transmission fluid Out case extension by rotating transmission to a vertical position. 2. Seventeen bolts (27), using 10 mm socket, drain transmission fluid. 3. Pan (28), seal (29) and magnet (30). IMPORTANT - Seal (29) is reusable. 4. Filter assembly (31). INSPECT - Filter neck seal (32), replace if necessary. Wire Harness Assembly WIRE HARNESS ASSEMBLY Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 5078 Pan, Filter And Seal Removal REMOVE OR DISCONNECT 1. Wire harness connectors from electrical components. NOTICE: Excessive force on the case pass through connector may damage the connector. IMPORTANT - If the wire harness assembly does not need servicing, it is not necessary to remove it from the case. 2. Wire harness assembly (34) from case using a 1-5/16" 12 point socket to release the connector retaining clips. Control Valve Assembly CONTROL VALVE ASSEMBLY Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 5079 REMOVE OR DISCONNECT 1. Rotate transmission bottom pan surface up and lock in place. 2. Wire harness assembly (34) connectors from components. IMPORTANT - If the wire harness assembly does not need servicing, it is not necessary to remove it from the case. - Use a cap to cover electrical pin at case connection. 3. Six bolts (76) using 8 mm socket, and transmission fluid pressure switch assembly (40). NOTICE: Be sure five O-rings are attached to transmission fluid pressure switch assembly. 4. Twenty-one bolts (35) using 10 mm socket, from valve body assembly, manual detent spring and roller assembly (41). 5. Three wiring clamps (33), fluid level indicator stop (43), one bolt (36) using 10 mm socket, lube pipe (39), lube pipe retainer (37) and clamp (38). 6. Control valve assembly (44) including the accumulator housing assembly (51), valve body gaskets (45 and 48), spacer plate (46) and accumulator gasket (47). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 5080 7. Manual valve (319) from control valve assembly (44) to prevent any damage. 8. Checkballs (54) from case passages. NOTICE: Do not use a magnet. It could cause checkball(s) to be magnetized causing metal particles to stick to the ball. 9. Pulse Width Modulated (PWM) solenoid screen (75). INSPECT - Screen PWM solenoid (75), replace if necessary. DISASSEMBLE Control Valve Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 5081 - Control valve assembly. A. Position as shown on a clean surface. B. Remove blind hole retainer pins with a drill bit. CAUTION: Some valves are under pressure - cover the bores while removing the retaining pins or personal injury could result. C. Remove valve trains, shift solenoids (311 and 313), PCS (320), PWM solenoid (323), PCS screen (302) and shift solenoid filter (317). D. Valves, springs, bushings and pistons must be laid out on a clean surface. CLEAN - All valves, springs, bushings, pistons, control valve body and accumulator housing in clean solvent. - Dry using compressed air. INSPECT 1. All valves, pistons and bushings for: - Porosity. - Scoring. - Nicks. - Scratches. 2. Pistons for: - Seal damage. 3. Springs for: - Damaged or distorted coils. 4. Valve body casting and accumulator housing for: - Porosity. - Cracks. - Interconnected passages. - Damaged machined surfaces. 5. Solenoid connectors and filter (317). 6. PCS (Pressure Control Solenoid) screen (302). Control Valve Assembly/Accumulator Housing CONTROL VALVE ASSEMBLY/ACCUMULATOR HOUSING Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 5082 Control Valve Assembly/Accumulator Housing Accumulator Housing Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 5083 Control Valve Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 5084 Torque Sequence And Guide Pin Location Fig. 11 Check Ball Location. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 5085 Fig. 10 Control Valve Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 5086 Torque Sequence, Control Valve And Switch Assembly NOTICE: The use of a honing stone, fine sandpaper or crocus cloth is not recommended for servicing stuck valves. All valve lands have sharply machined comers that are necessary for cleaning the bore. If these corners are rounded, foreign material could wedge between the valve and the bore causing the valve to stick. If it is found necessary to clean a valve, micro fine lapping compound 900 grit (J 38459) or finer should be used. Too much lapping of the valve will cause excessive clearances and increase the chance of a valve not operating. CLEAN - Control valve assembly and accumulator housing (51) thoroughly in clean solvent. - Air dry. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 5087 Accumulator Housing Assembly ACCUMULATOR HOUSING ASSEMBLY Control Valve Assembly/Accumulator Housing Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 5088 Accumulator Housing Assembly DISASSEMBLE 1. Six bolts (53), using 8 mm socket. 2. Accumulator housing assembly. 3. Gasket accumulator housing (47). 4. Spacer plate (46). 5. Gasket (45) valve body spacer. 6. Snap ring (402) from outside housing, pin (408), snap ring (402), piston (407) and spring (49). 7. 3rd clutch piston (405) and spring (50). 8. Seals (404 and 406). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 5089 CLEAN - All components. INSPECT - All valves, pistons, springs and seals for: - Porosity. - Scoring. - Nicks. - Scratches. Accumulator Housing Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 5090 ASSEMBLE - Accumulator housing assembly components exactly as shown. Notice the positions of the pistons. Control Valve Assembly CONTROL VALVE ASSEMBLY Control Valve Assembly ASSEMBLE - Control valve assembly components exactly as shown. Notice the position of the valve lands and bushing passages. Control Valve Assembly/Accumulator Housing Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 5091 CONTROL VALVE ASSEMBLY AND ACCUMULATOR HOUSING Control Valve Assembly/Accumulator Housing Torque Sequence And Guide Pin Location TOOL REQUIRED: - Guide Pin J 25025-5 ASSEMBLE 1. Guide pin J 25025-5 into valve body. Located at back bolt hole of detent spring and roller assembly bolt bole. 2. Gasket (45) valve body to spacer plate. 3. Spacer plate (46). 4. Gasket (47) accumulator housing to spacer plate. 5. Accumulator housing assembly (51) onto valve body assembly (44). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 5092 6. Six bolts (53) using (8 mm) socket through accumulator housing into valve body assembly. Torque Sequence And Guide Pin Location NOTE: Start accumulator housing bolts finger tight and work towards opposite end. TIGHTEN - Bolt (53) to 11 Nm (97 lb. in.). 7. Remove guide pin J 25025-5. Fig. 11 Check Ball Location. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 5093 Fig. 10 Control Valve Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 5094 Torque Sequence, Control Valve And Switch Assembly INSTALL OR CONNECT 1. Install checkballs (54) in proper location into case fluid passages. Use TRANSJEL TM J 36850 or equivalent to hold in place. NOTICE: Do not use any type of grease to retain parts during assembly of this unit. Greases other than the recommended assembly lube will change transmission fluid characteristics and cause undesirable shift conditions and/or filter clogging. - # 2 checkball is used only on RCP RDP, ZJP and ZLP models. 2. PWM solenoid screen (75). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 5095 3. Gasket (48) spacer plate to case. 4. Manual valve (319) into valve body. 5. Complete valve body assembly (44) onto case (7). Use 1 25025-5 guide pin set. IMPORTANT - Attach manual valve to detent lever. 6. Transmission fluid pressure switch assembly (40) onto valve body assembly (44). 7. Spring and roller assembly (41) into place. 8. Three wiring clamps (33), fluid indicator stop (43) and lube pipe clamp (38). 9. Twenty-one bolts (35). Using 10 mm socket. 10. Six bolts (76) using 8 mm socket into transmission fluid pressure switch assembly (40). 11. Lube pipe (39) long end into case, short end into valve body. 12. Lube pipe retainer (37) with short bolt (36). TIGHTEN - Bolts (35, 36 and 76) to 11 Nm (97 lb. in.). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 5096 Torque Sequence, Control Valve And Switch Assembly NOTICE: Torque valve body bolts in a spiral pattern starting from the center. If bolts are torqued at random, valve bores may be distorted and inhibit valve operation. 13. Attach wiring harness (34) to 5 connectors. - Put large end into case first, pressure switch hook up, 1-2 shift solenoid (purple) and 2-3 shift solenoid (tan), PWM (Pulse Width Modulated) solenoid and PCS (Pressure Control Solenoid). Pan and Filter Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Automatic Transmission/Transaxle > Valve Body, A/T > Component Information > Service and Repair > In-Vehicle Service > Page 5097 PAN AND FILTER ASSEMBLY Installing Pan And Filter INSTALL OR CONNECT 1. Seal (32) inside of case (7). 2. Filter assembly (31). 3. Bottom pan seal (29). 4. Magnet (30) into bottom pan. 5. Pan (29). 6. Seventeen bolts (27) using 10 mm socket. TIGHTEN - Bolts (27) to 24 Nm (18 lb. ft.). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Clutch, M/T > Clutch Hydraulic System > Clutch Fluid > Component Information > Specifications > Capacity Specifications Clutch Fluid: Capacity Specifications Fill the clutch master cylinder to the "Full" or "MAX" mark on the reservoir. Do not overfill. Caution: Should accidental spillage occur, rinse the area thoroughly with water. Pay special attention to any electrical wires, parts, harnesses, rubber or painted surfaces. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Clutch, M/T > Clutch Hydraulic System > Clutch Fluid > Component Information > Specifications > Capacity Specifications > Page 5104 Clutch Fluid: Fluid Type Specifications Hydraulic Clutch Fluid ........................................................................................................................................................... DOT 3 or DOT 4 Brake Fluid Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Clutch, M/T > Clutch Hydraulic System > Clutch Master Cylinder > Component Information > Specifications Clutch Master Cylinder: Specifications Master Cylinder Retaining Nuts ........................................................................................................... ............................................................... 10-15ft. lbs. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Clutch, M/T > Clutch Hydraulic System > Clutch Master Cylinder > Component Information > Service and Repair > Removal and Installation Clutch Master Cylinder: Service and Repair Removal and Installation Fig. 1 Clutch Master Cylinder. REMOVAL 1. Remove sound absorbing panel from upper left side foot well. Remove lower air conditioning duct, if necessary. 2. Disconnect master cylinder push rod from clutch pedal. 3. Remove master cylinder retaining nuts. 4. Disconnect reservoir hose and slave cylinder hydraulic line from master cylinder. 5. Remove clutch master cylinder. INSTALLATION 1. Position master cylinder at front of dash, then install retaining nuts and torque to 10-15ft. lbs. 2. Connect master cylinder push rod to clutch pedal and install retaining clip. 3. Install sound absorbing panel. 4. Install lower air conditioning duct, if removed. 5. Connect reservoir hose and slave cylinder hydraulic line to master cylinder. 6. Bleed system as described under "Hydraulic Clutch System Bleed." Refer to Hydraulic Clutch System Bleed. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Clutch, M/T > Clutch Hydraulic System > Clutch Master Cylinder > Component Information > Service and Repair > Removal and Installation > Page 5110 Clutch Master Cylinder: Service and Repair Clutch Master Cylinder Replace Fig. 1 Clutch Master Cylinder. REMOVAL 1. Disconnect battery ground cable. 2. Remove sound absorbing panel from upper left side foot well. 3. Remove lower left side air conditioning duct if needed. 4. Disconnect master cylinder pushrod from clutch pedal. 5. Remove master cylinder retaining nuts, Fig. 1. 6. Disconnect reservoir hose and slave cylinder hydraulic line from master cylinder. 7. Remove clutch master cylinder. INSTALLATION 1. Position master cylinder at front of dash, then install retaining nuts and torque to 10-15 ft. lbs., Fig. 1. 2. Connect master cylinder pushrod to clutch pedal and install retaining clip. 3. Install sound absorbing panel. 4. Install lower left air conditioning duct if removed. 5. Connect reservoir hose and slave cylinder hydraulic line to master cylinder. 6. Connect battery ground cable. 7. Bleed system. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Clutch, M/T > Clutch Hydraulic System > Clutch Slave Cylinder > Component Information > Specifications Clutch Slave Cylinder: Specifications Clutch Actuator Cylinder Nuts ............................................................................................................. ................................................................... 18 ft. lbs. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Clutch, M/T > Clutch Hydraulic System > Clutch Slave Cylinder > Component Information > Service and Repair > Removal and Installation Clutch Slave Cylinder: Service and Repair Removal and Installation When servicing the clutch actuator with hydraulic line intact, disconnect the clutch master cylinder pushrod from the clutch pedal in order to prevent damage to the actuator should the pedal be depressed. 1. Raise and support vehicle, then remove actuator cylinder to clutch housing nuts and actuator assembly. 2. Drive out hydraulic line to actuator retaining pin using a 7/64 inch punch. 3. Use hydraulic clutch line separator tool No. J-36221 or equivalent to disconnect actuator cylinder hydraulic line coupling, then remove line from clips if necessary. 4. Reverse procedure to install, noting the following: a. Torque actuator cylinder nuts to 18 ft. lbs. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Clutch, M/T > Clutch Hydraulic System > Clutch Slave Cylinder > Component Information > Service and Repair > Removal and Installation > Page 5116 Clutch Slave Cylinder: Service and Repair Secondary (Slave) Cylinder Fig. 3 Clutch Slave Cylinder. REMOVAL 1. Raise and support vehicle. 2. Disconnect hydraulic line from slave cylinder, Fig. 3. 3. Remove slave cylinder retaining nuts, then the slave cylinder. INSTALLATION 1. Connect hydraulic line to slave cylinder, Fig. 3. 2. Bleed system. 3. Position slave cylinder on bellhousing, then install retaining nuts and tighten to specifications. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Clutch, M/T > Clutch Linkage > Component Information > Service and Repair Clutch Linkage: Service and Repair Never use fluid which has been bled from a system to fill the reservoir. It may be aerated, have too high of a moisture content and possibly be contaminated. 1. Fill reservoir with new DOT 3 brake fluid, then press and hold down clutch pedal. 2. Open bleed screw on actuator cylinder to expel air, then close bleed screw and release clutch pedal. 3. Repeat procedure until all air is out of system, noting the following: a. Check and refill reservoir as needed during bleeding so air is not drawn into system. b. After bleeding, pump clutch pedal several times. If clutch engagement is not satisfactory, repeat bleeding procedure. 4. If this procedure is unsuccessful, perform the following: a. Remove reservoir cap, then pump pedal very fast for 30.0 seconds. b. Stop to let air escape. c. Repeat as necessary. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Clutch, M/T > Clutch Pedal Assembly > Component Information > Technical Service Bulletins > Customer Interest: > 467303 > Oct > 94 > Clutch Pedal - Pop or Scrape Noise When Depressed Clutch Pedal Assembly: Customer Interest Clutch Pedal - Pop or Scrape Noise When Depressed File In Section: 7 - Transmission Bulletin No.: 46-73-03 Date: October, 1994 Subject: Clutch Pedal Return Spring Fractured (Remove Spring) Models: 1988-94 Chevrolet and GMC Truck C/K, S/T Models with Manual Transmission Condition Some owners may comment that they hear a pop or scrape noise, or feel a catch as they depress the clutch pedal. They may also comment that the clutch pedal return spring is fractured. This spring is located at the clutch pedal pivot. Cause Spring fatigue resulting in short service life. Correction Remove the clutch pedal return spring and DO NOT replace it. Refer to the appropriate Service Manual Section 7C - Clutch, Clutch Pedal Replacement for the correct procedure. Testing has shown that this spring is not needed for proper clutch pedal return or clutch pedal feel. This spring was eliminated in production as follows: ^ C/K all models, mid-1994 model year ^ S/T pickups, mid-1994 model year ^ S/T utilities, start of production 1995 model year Warranty Information For vehicles repaired under warranty, use: Labor Operation Description Labor Time K0100 Spring, Clutch Use Published Labor Pedal Return Operation Time Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Clutch, M/T > Clutch Pedal Assembly > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 467303 > Oct > 94 > Clutch Pedal - Pop or Scrape Noise When Depressed Clutch Pedal Assembly: All Technical Service Bulletins Clutch Pedal - Pop or Scrape Noise When Depressed File In Section: 7 - Transmission Bulletin No.: 46-73-03 Date: October, 1994 Subject: Clutch Pedal Return Spring Fractured (Remove Spring) Models: 1988-94 Chevrolet and GMC Truck C/K, S/T Models with Manual Transmission Condition Some owners may comment that they hear a pop or scrape noise, or feel a catch as they depress the clutch pedal. They may also comment that the clutch pedal return spring is fractured. This spring is located at the clutch pedal pivot. Cause Spring fatigue resulting in short service life. Correction Remove the clutch pedal return spring and DO NOT replace it. Refer to the appropriate Service Manual Section 7C - Clutch, Clutch Pedal Replacement for the correct procedure. Testing has shown that this spring is not needed for proper clutch pedal return or clutch pedal feel. This spring was eliminated in production as follows: ^ C/K all models, mid-1994 model year ^ S/T pickups, mid-1994 model year ^ S/T utilities, start of production 1995 model year Warranty Information For vehicles repaired under warranty, use: Labor Operation Description Labor Time K0100 Spring, Clutch Use Published Labor Pedal Return Operation Time Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Clutch, M/T > Clutch Pedal Assembly > Component Information > Technical Service Bulletins > All Other Service Bulletins for Clutch Pedal Assembly: > 04-08-50-006D > Sep > 10 > Interior - Seat Cover Wrinkle/Crease/Burn Info Seat Cover: All Technical Service Bulletins Interior - Seat Cover Wrinkle/Crease/Burn Info INFORMATION Bulletin No.: 04-08-50-006D Date: September 09, 2010 Subject: Minor Wrinkles/Creases, Discoloration, Cigarette Burns and Customer Induced Cuts and Stains on Front and Rear Driver and Passenger Seats with Leather, Vinyl or Cloth Seat Covers Models: 2011 and Prior GM Passenger Cars and Light Duty Trucks 2009 and Prior HUMMER H2 2010 and Prior HUMMER H3 2009 and Prior Saab 9-7X 2010 and Prior Saturn Supercede: This bulletin is being revised to add a model year. Please discard Corporate Bulletin Number 04-08-50-006C (Section 08 - Body and Accessories). If a customer comes in to your dealership due to certain conditions of the seat covers (splits, wrinkles, loose stitching, etc.), you must examine the seat cover in order to determine the validity of the customer claim. Some components from the above listed vehicles have been returned to the Warranty Parts Center (WPC) and analysis of these parts showed "customer induced damage" or No Trouble Found (NTF). The dealer should pay particular attention to the following conditions: - Cigarette burns Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Clutch, M/T > Clutch Pedal Assembly > Component Information > Technical Service Bulletins > All Other Service Bulletins for Clutch Pedal Assembly: > 04-08-50-006D > Sep > 10 > Interior - Seat Cover Wrinkle/Crease/Burn Info > Page 5138 - Customer induced cuts (knife cuts, cut by customer tools, etc.) - Paint stains (customer should have cleaned paint stains while paint was still wet) - Coffee stains and other removable dirt These should be cleaned as described in the Owner's Manual under Appearance Care. Also, refer to Corporate Bulletin Number 06-00-89-029A or later. - Evidence of chemicals used for cleaning, other than those specified in the Owner's Manual - Other chemical spills - Minor and normal leather wrinkles as a result of use - Other defects to the seat cover not detected during the pre-delivery inspection (PDI). Inform the customer that the above issues were not present when the vehicle was purchased and cannot be replaced under warranty. The covers, however, may be repaired or replaced at the customer's expense. The following conditions are not caused by the customer and should be covered by warranty: - Split seams Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Clutch, M/T > Clutch Pedal Assembly > Component Information > Technical Service Bulletins > All Other Service Bulletins for Clutch Pedal Assembly: > 04-08-50-006D > Sep > 10 > Interior - Seat Cover Wrinkle/Crease/Burn Info > Page 5139 - Wear/cracking/peeling - Discoloration/dye transfer from customer clothing (if discoloration/dye transfer is not removed after using GM Leather and Vinyl Plastic Cleaner, P/N 88861401 (in Canada, P/N 88861409), replace the covers.) Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Clutch, M/T > Clutch Pedal Assembly > Component Information > Technical Service Bulletins > All Other Service Bulletins for Clutch Pedal Assembly: > 00-00-89-027E > Sep > 08 > Interior - Elimination Of Unwanted Odors Seat Cover: All Technical Service Bulletins Interior - Elimination Of Unwanted Odors INFORMATION Bulletin No.: 00-00-89-027E Date: September 29, 2008 Subject: Eliminating Unwanted Odors in Vehicles Models: 2009 and Prior GM Passenger Cars and Trucks (including Saturn) 2009 and Prior HUMMER H2, H3 Vehicles 2009 and Prior Saab 9-7X Supercede: This bulletin is being revised to add model years and refine the instructions. Please discard Corporate Bulletin Number 00-00-89-027D (Section 00 - General Information). Vehicle Odor Elimination General Motors offers a product that may control or eliminate odors in the interior and luggage compartment areas of GM vehicles. GM Vehicle Care Odor Eliminator is a non-toxic, biodegradable odor remover. This odorless product has been shown to greatly reduce or remove objectionable smells of mold and mildew resulting from vehicle water leaks (as well as customer created odors, i.e. smoke). You may use GM Vehicle Care Odor Eliminator on fabrics, vinyl, leather, carpet and sound deadening materials. It may also be induced into HVAC modules and instrument panel ducts (for the control of non-bacterial related odors). Important: This product leaves no residual scent and should not be sold as or considered an air freshener. Product action may result in the permanent elimination of an odor and may be preferable to customers with allergies who are sensitive to perfumes. How to Use This Product GM Vehicle Care Odor Eliminator may be sprayed on in a ready-to-use formula or used in steam cleaners as an additive with carpet shampoo. This water-based, odorless product is safe for all vehicle interiors. Do not wet or soak any interior surface that plain water would cause to deteriorate, as this product will have the same effect. Also avoid letting this product come into contact with vinegar or any acidic substance. Acid-based products will hamper the effectiveness of, or render GM Vehicle Care Odor Eliminator inert. Note: Complete eight page treatment sheets are enclosed within each case of GM Vehicle Care Odor Eliminator. These treatment instructions range from simple vehicle odor elimination to full step by step procedures for odor removal from water leaks. If lost, contact 800-977-4145 to get a replacement set faxed or e-mailed to your dealership. Instructions and cautions are printed on the bottle, but additional help is available. If you encounter a difficult to eliminate or reoccurring odor, you may call 1-800-955-8591 (in Canada, 1-800-977-4145) to obtain additional information and usage suggestions. Important: This product may effectively remove odors when directly contacting the odor source. It should be used in conjunction with diagnostic procedures (in cases such as a water leak) to first eliminate the root cause of the odor, and then the residual odor to permanently correct the vehicle condition. Vehicle Waterleak Odor Elimination STEP ONE: Confirm that all water leaks have been repaired. Determine what areas of the vehicle were water soaked or wet. Components with visible mold/mildew staining should be replaced. Isolate the odor source inside the vehicle. Often an odor can be isolated to an area or component of the vehicle interior by careful evaluation. Odor evaluation may need to be performed by multiple persons. Another method of isolating an odor source is to remove and segregate interior trim and components. Plastic sheeting or drop cloths can be used to confine seats, headliners, etc. to assist in evaluation and diagnoses. If appropriate the vehicle and interior trim should be evaluated separately to determine if the odor stays with the vehicle or the interior components. Odors that stay with the vehicle may be isolated to insulating and sound deadening materials (i.e. water leak at the windshield or standing water in the front foot well area caused mold/mildew to form on the bulkhead or kick panel sound deadening pads. If the interior is removed the floor pan and primed/painted surfaces should be treated with bleach/soap solution, rinsed with clean water and dried. Interior surfaces should then be treated with GM Vehicle Care Odor Eliminator product before reinstalling carpet or reassembling. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Clutch, M/T > Clutch Pedal Assembly > Component Information > Technical Service Bulletins > All Other Service Bulletins for Clutch Pedal Assembly: > 00-00-89-027E > Sep > 08 > Interior - Elimination Of Unwanted Odors > Page 5144 The GM Vehicle Care Odor Eliminator product is an effective odor elimination product when used properly. It must come into direct contact with the odor source. It should be used in conjunction with diagnostic procedures to first eliminate the root cause of the odor. Some procedures for use after odor root cause correction are: STEP TWO: ^ Use the trigger spray head. ^ Put a drop of dish soap the size of a quarter in the bottom of a bottle. ^ Add 8 oz. of GM Vehicle Care Odor Eliminator (1 cup) to the dish soap and top off the bottle with tap water. ^ This formula should be used on hard surfaces (dash, interior plastic molding, and floor pan) STEP THREE: The third step to neutralizing the vehicle is a light to medium treatment of all carpeting and upholstered seats with the GM Vehicle Care Odor Eliminator formula and a wide fan spray setting (at full strength) (i.e.: carpeting on the driver's side requires 4-5 triggers pulls for coverage). The headliner and trunk should be sprayed next. Lightly brushing the formula into the carpeting and upholstery is a recommended step for deep odor problems. The dash and all hard surfaces should be sprayed with dish soap/water mixture. Let stand for 1-2 minutes then wipe off the surface. STEP FOUR: (vehicle ventilation system treatment) The ventilation system is generally the last step in the treatment of the vehicle. a. Spray the GM Vehicle Care Odor Eliminator formula into all dash vents. (1-2 trigger pulls per vent). b. Start the vehicle and turn the vehicle fan on high cool (not A/C setting). c. Spray the formula (10 trigger pulls) into the outside fresh air intake vent (cowl at base of windshield) d. Enter the vehicle after 1 minute and wipe off the excess formula spurting out of the dash vents. e. Smell the air coming from the dash vents. If odors are still present, spray another 5 triggers into the cowl, wait another minute and smell the results. Once you have obtained a fresh, clean smell coming from the vents, turn the system to the A/C re-circulation setting. Roll up the windows, spray 3-5 pumps into the right lower IP area and let the vehicle run with the fan set on high for 5-7 minutes. Please follow this diagnosis process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed. If these steps do not resolve the condition, please contact GM TAC for further diagnostic assistance. Additional Suggestions to Increase Customer Satisfaction Here are some additional ideas to benefit your dealership and to generate greater customer enthusiasm for this product. ^ Keep this product on-hand for both the Service Department and the Used Car lot. Add value to your used car trades; treat loaner and demo cars during service and at final sale to eliminate smoke, pet, and other common odors offensive to customers. Make deodorizing a vehicle part of your normal vehicle detailing service. ^ Consider including GM Vehicle Care Odor Eliminator as a give-away item with new vehicle purchases. Many dealers give away as "gifts" various cleaning supplies at time of delivery. GM Odor Eliminator is one of a few products GM offers that has as many uses in the home as in the vehicle. Customers may find this product can be used for a host of recreational activities associated with their new vehicle, such as deodorizing a boat they tow, or a camper. ^ GM Odor Eliminator and many of the GM Vehicle Care products offer you the chance to increase dealership traffic as these superior quality products cannot be purchased in stores. Many Dealerships have product displays at the parts counter. Consider additional displays in the Customer Service Lounge, the Showroom and at the Service Desk or Cashier Window. Many customers who purchase vehicles and receive regular maintenance at your dealership may never visit the parts counter, and subsequently are not exposed to the variety and value that these products offer. Parts Information Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Clutch, M/T > Clutch Pedal Assembly > Component Information > Technical Service Bulletins > All Other Service Bulletins for Clutch Pedal Assembly: > 00-00-89-027E > Sep > 08 > Interior - Elimination Of Unwanted Odors > Page 5145 Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Clutch, M/T > Clutch Pedal Assembly > Component Information > Technical Service Bulletins > All Other Service Bulletins for Clutch Pedal Assembly: > 00-08-50-002 > Apr > 00 > Driver/Passenger Seat - Wear on Outboard Recliner Hinge Seat Cover: All Technical Service Bulletins Driver/Passenger Seat - Wear on Outboard Recliner Hinge File In Section: 08 - Body and Accessories Bulletin No.: 00-08-50-002 Date: April, 2000 TECHNICAL Subject: Driver/Passenger Seat Wear at Outboard Recliner Hinge Area (Add Protector Cover/Replace Seat Cushion Trim Cover) Models: 1994-97 Chevrolet and GMC S/T Pickups and 2 Door Utility Models With Front Reclining Bucket Seats or 60/40 Bench Seats (RPOs AV5 or AM6) Condition: Some customers may comment that there appears to be premature wear of the cover material on the driver's or passenger seat cushion in the outboard recliner hinge area. Correction: Add a protector cover to the outboard recliner hinge and replace the seat cushion trim cover with a new cover. The new cover has an added plastic patch sewn in to improve durability. Please be advised that all seat cushion trim covers currently at GMSPO have this change. Refer to group number 16.717 of the parts catalog for part description and usage. Determine if a protector cover has already been installed per Campaign Bulletin 97033(A)-Seat Belt Separation. Look for a campaign label under the hood. 1. If a cover has already been installed, replace the worn seat cushion trim cover. Refer to the Seats subsection of the appropriate Service Manual for information on replacing the seat cushion trim cover material. 2. If a cover has not been installed, perform Campaign Bulletin 97033(A)-Seat Belt Separation and replace the worn seat cushion trim cover. Refer to the Seats subsection of the appropriate Service Manual for information on replacing the seat cushion trim cover material. Parts Information Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use the table. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Clutch, M/T > Clutch Pedal Assembly > Component Information > Technical Service Bulletins > All Other Service Bulletins for Clutch Pedal Assembly: > 431606 > Oct > 94 > Leather Seat Covers - Cleaning Procedure Seat Cover: All Technical Service Bulletins Leather Seat Covers - Cleaning Procedure File In Section: 10 - Body Bulletin No.: 43-16-06 Date: October, 1994 Subject: Cleaning Procedure for Leather Seat Covers Models: 1995 and Prior Passenger Cars and "C/K" and "S/T" Trucks If leather seat covers are being returned only because they are dirty, a more aggressive cleaning procedure is recommended by General Motors prior to replacing covers. Procedure Dirty or soiled leather seat covers should be cleaned with a mild soap and water solution, using clean soft cloths. When this procedure proves inadequate, a commercially available leather cleaner, "Tanner's Preserve Leather Cleaner"* should be used with a 3M "Type T"* scrubbing pad. Important: The type of scrubbing pad is very critical because the common 3M Scotch-Brite green pad is too aggressive and will damage the leather finish. The cleaner is available from "First Brands" by calling 1-800-726-1001, identifying yourself as a GM dealership, requesting "Tanner's Preserve Leather Cleaner" product, number AS-330, quantity and shipping address. This product is also available at stores. The 3M "Type T" scrubbing pad is available from a 3M distributor. Call 1-800-742-9546 for the nearest distributor and then request the Scotch-Brite Clean and Finish Sheet, "Type T", in 6 x 9 inch sheets, UPC code number 048011-01276. * We believe these sources and their equipment to be reliable. There may be additional manufacturers of such equipment. General Motors does not endorse, indicate any preference for or assume any responsibility for the products or equipment from these firms or for any such items which may be available from other sources. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Clutch, M/T > Clutch Pedal Assembly > Component Information > Technical Service Bulletins > All Other Service Bulletins for Clutch Pedal Assembly: > 04-08-50-006D > Sep > 10 > Interior - Seat Cover Wrinkle/Crease/Burn Info > Page 5159 - Customer induced cuts (knife cuts, cut by customer tools, etc.) - Paint stains (customer should have cleaned paint stains while paint was still wet) - Coffee stains and other removable dirt These should be cleaned as described in the Owner's Manual under Appearance Care. Also, refer to Corporate Bulletin Number 06-00-89-029A or later. - Evidence of chemicals used for cleaning, other than those specified in the Owner's Manual - Other chemical spills - Minor and normal leather wrinkles as a result of use - Other defects to the seat cover not detected during the pre-delivery inspection (PDI). Inform the customer that the above issues were not present when the vehicle was purchased and cannot be replaced under warranty. The covers, however, may be repaired or replaced at the customer's expense. The following conditions are not caused by the customer and should be covered by warranty: - Split seams Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Clutch, M/T > Clutch Pedal Assembly > Component Information > Technical Service Bulletins > All Other Service Bulletins for Clutch Pedal Assembly: > 04-08-50-006D > Sep > 10 > Interior - Seat Cover Wrinkle/Crease/Burn Info > Page 5160 - Wear/cracking/peeling - Discoloration/dye transfer from customer clothing (if discoloration/dye transfer is not removed after using GM Leather and Vinyl Plastic Cleaner, P/N 88861401 (in Canada, P/N 88861409), replace the covers.) Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Clutch, M/T > Clutch Pedal Assembly > Component Information > Technical Service Bulletins > All Other Service Bulletins for Clutch Pedal Assembly: > 00-00-89-027E > Sep > 08 > Interior - Elimination Of Unwanted Odors > Page 5165 The GM Vehicle Care Odor Eliminator product is an effective odor elimination product when used properly. It must come into direct contact with the odor source. It should be used in conjunction with diagnostic procedures to first eliminate the root cause of the odor. Some procedures for use after odor root cause correction are: STEP TWO: ^ Use the trigger spray head. ^ Put a drop of dish soap the size of a quarter in the bottom of a bottle. ^ Add 8 oz. of GM Vehicle Care Odor Eliminator (1 cup) to the dish soap and top off the bottle with tap water. ^ This formula should be used on hard surfaces (dash, interior plastic molding, and floor pan) STEP THREE: The third step to neutralizing the vehicle is a light to medium treatment of all carpeting and upholstered seats with the GM Vehicle Care Odor Eliminator formula and a wide fan spray setting (at full strength) (i.e.: carpeting on the driver's side requires 4-5 triggers pulls for coverage). The headliner and trunk should be sprayed next. Lightly brushing the formula into the carpeting and upholstery is a recommended step for deep odor problems. The dash and all hard surfaces should be sprayed with dish soap/water mixture. Let stand for 1-2 minutes then wipe off the surface. STEP FOUR: (vehicle ventilation system treatment) The ventilation system is generally the last step in the treatment of the vehicle. a. Spray the GM Vehicle Care Odor Eliminator formula into all dash vents. (1-2 trigger pulls per vent). b. Start the vehicle and turn the vehicle fan on high cool (not A/C setting). c. Spray the formula (10 trigger pulls) into the outside fresh air intake vent (cowl at base of windshield) d. Enter the vehicle after 1 minute and wipe off the excess formula spurting out of the dash vents. e. Smell the air coming from the dash vents. If odors are still present, spray another 5 triggers into the cowl, wait another minute and smell the results. Once you have obtained a fresh, clean smell coming from the vents, turn the system to the A/C re-circulation setting. Roll up the windows, spray 3-5 pumps into the right lower IP area and let the vehicle run with the fan set on high for 5-7 minutes. Please follow this diagnosis process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed. If these steps do not resolve the condition, please contact GM TAC for further diagnostic assistance. Additional Suggestions to Increase Customer Satisfaction Here are some additional ideas to benefit your dealership and to generate greater customer enthusiasm for this product. ^ Keep this product on-hand for both the Service Department and the Used Car lot. Add value to your used car trades; treat loaner and demo cars during service and at final sale to eliminate smoke, pet, and other common odors offensive to customers. Make deodorizing a vehicle part of your normal vehicle detailing service. ^ Consider including GM Vehicle Care Odor Eliminator as a give-away item with new vehicle purchases. Many dealers give away as "gifts" various cleaning supplies at time of delivery. GM Odor Eliminator is one of a few products GM offers that has as many uses in the home as in the vehicle. Customers may find this product can be used for a host of recreational activities associated with their new vehicle, such as deodorizing a boat they tow, or a camper. ^ GM Odor Eliminator and many of the GM Vehicle Care products offer you the chance to increase dealership traffic as these superior quality products cannot be purchased in stores. Many Dealerships have product displays at the parts counter. Consider additional displays in the Customer Service Lounge, the Showroom and at the Service Desk or Cashier Window. Many customers who purchase vehicles and receive regular maintenance at your dealership may never visit the parts counter, and subsequently are not exposed to the variety and value that these products offer. Parts Information Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Clutch, M/T > Clutch Pedal Assembly > Component Information > Technical Service Bulletins > All Other Service Bulletins for Clutch Pedal Assembly: > 00-00-89-027E > Sep > 08 > Interior - Elimination Of Unwanted Odors > Page 5166 Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Clutch, M/T > Clutch Pedal Assembly > Component Information > Service and Repair > Hydraulic Clutch System Clutch Pedal Assembly: Service and Repair Hydraulic Clutch System 1. Disconnect battery ground cable, then remove lower filler panel(s) or steering column covers. Remove lower left side of air conditioning duct if necessary to gain clearance. 2. Remove clutch start switch, noting position for installation reference, then remove clutch master cylinder push rod from pedal. 3. Remove clutch pedal nut, bolt and braces, noting positions for installation reference, then the pedal and spring. When removing bolt, slide a similar long rod or screw into bracket to keep parts together and in order. 4. Reverse procedure to install. Torque clutch pedal nut to 26 ft. lbs. 5. Remove bushings and spacer, then the bumper, if worn or damaged. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Clutch, M/T > Clutch Pedal Assembly > Component Information > Service and Repair > Hydraulic Clutch System > Page 5177 Clutch Pedal Assembly: Service and Repair Less Hydraulic Clutch System 1. Disconnect battery ground cable, then remove coffer pin and washers from clutch pedal rod. 2. Remove clutch start switch, noting position for installation reference, then the nut, bolt and washers from clutch pivot arm. 3. Remove clutch pivot arm, pedal rod and bushing. Release retracting spring by depressing pedal, moving pedal laterally and releasing. 4. Remove pedal and bushings, then the bumper, if worn or damaged. 5. Reverse procedure to install. Adjust clutch linkage as described under "Clutch, Adjust." Refer to Clutch/Adjust Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Clutch, M/T > Clutch Switch > Component Information > Locations I/P Wiring, Steering Column Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Clutch, M/T > Clutch Switch > Component Information > Locations > Page 5181 C253 - Clutch Release Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Clutch, M/T > Clutch Switch > Component Information > Locations > Page 5182 Clutch Switch: Service and Repair 1. Remove lower instrument panel trim. 2. Remove clutch start switch electrical connector, Fig. 3. 3. Remove clutch start switch from clutch pedal. 4. Reverse procedure to install. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Clutch, M/T > Clutch Release Fork, M/T > Component Information > Technical Service Bulletins > Customer Interest: > 567301 > Feb > 95 > Clutch Pedal - Squeak Noise Clutch Release Fork: Customer Interest Clutch Pedal - Squeak Noise File in Section: 7 - Transmission Bulletin No.: 56-73-01 Date: February, 1995 SUBJECT: Clutch Pedal Squeak Noise (Install Greaseable Ball Stud) MODELS: 1994-95 Chevrolet and GMC Truck C/K 1, 2 and S/T Models with NV3500 5-Speed Manual Transmission (RPOs MG5, MY2, M50) CONDITION A squeak noise may come from the clutch area when the clutch pedal is fully released (foot off the clutch pedal) and the engine is running. This squeak will stop when slight pressure is placed on the clutch pedal. This noise may be confused with a squeaking or noisy clutch release bearing. CAUSE This noise is usually caused by a dry clutch fork ball stud which causes metal to metal contact with the clutch fork. The grease fitting was removed in production for the 1994 and 1995 model years so the joint is no longer greaseable. CORRECTION Install a greaseable ball stud. Service Procedure 1. Remove the transmission following directions in the appropriate Service Manual, Section 7B, Manual Transmission. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Clutch, M/T > Clutch Release Fork, M/T > Component Information > Technical Service Bulletins > Customer Interest: > 567301 > Feb > 95 > Clutch Pedal - Squeak Noise > Page 5191 2. Remove the clutch fork and ball stud from the front transmission housing using J 36510, clutch fork pivot remover/installer (Figure 1). 3. Inspect the front transmission housing to locate the raised boss where the grease zerk is to be installed (Figure 2). ^ The boss is on the right side of the transmission between the fill plug and the clutch fork pocket. 4. Drill a hole of required size (determined by diameter/thread pitch of zerk used) in the center of the raised boss located in step 3. ^ The grease zerk used should have no more than 1/4" of threaded length to avoid entering the ball stud cavity. Important: Wall thickness in this area is approximately 1/4". Use caution to prevent passing through the ball stud cavity and drilling through the inner wall of the housing. 5. Tap the hole as required and install the grease zerk. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Clutch, M/T > Clutch Release Fork, M/T > Component Information > Technical Service Bulletins > Customer Interest: > 567301 > Feb > 95 > Clutch Pedal - Squeak Noise > Page 5192 Important: Thoroughly clean out all metal chips before installing the zerk and ball stud to prevent plugging the greaseable ball stud. 6. Install greaseable ball stud P/N 23049797 using J 36510, clutch fork pivot remover/installer. 7. Grease the fitting until a small amount of grease flows from the end of the ball stud. 8. Install new clutch fork P/N 15588262. Place grease in the clutch fork pocket that contacts the clutch fork push rod. 9. Reinstall the transmission following directions in the appropriate Service Manual, Section 7B, Manual Transmission. 10. Grease the assembled ball stud lightly through the fining. Grease every 30,000 miles thereafter. Important: Grease should be added "sparingly" to the fitting. Excessive grease can contaminate the clutch disc friction surfaces resulting in slip or chatter and the need to replace the disc. PARTS INFORMATION Parts are currently available from GMPSO. WARRANTY INFORMATION For vehicles repaired under warranty, use: Labor Operation Description Labor Time K0720 Fork and/or Ball Use published labor Stud, Clutch operation time Release - Replace The document shown should be reproduced locally and provided to the owners of the vehicles modified by this procedure. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Clutch, M/T > Clutch Release Fork, M/T > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 567301 > Feb > 95 > Clutch Pedal - Squeak Noise Clutch Release Fork: All Technical Service Bulletins Clutch Pedal - Squeak Noise File in Section: 7 - Transmission Bulletin No.: 56-73-01 Date: February, 1995 SUBJECT: Clutch Pedal Squeak Noise (Install Greaseable Ball Stud) MODELS: 1994-95 Chevrolet and GMC Truck C/K 1, 2 and S/T Models with NV3500 5-Speed Manual Transmission (RPOs MG5, MY2, M50) CONDITION A squeak noise may come from the clutch area when the clutch pedal is fully released (foot off the clutch pedal) and the engine is running. This squeak will stop when slight pressure is placed on the clutch pedal. This noise may be confused with a squeaking or noisy clutch release bearing. CAUSE This noise is usually caused by a dry clutch fork ball stud which causes metal to metal contact with the clutch fork. The grease fitting was removed in production for the 1994 and 1995 model years so the joint is no longer greaseable. CORRECTION Install a greaseable ball stud. Service Procedure 1. Remove the transmission following directions in the appropriate Service Manual, Section 7B, Manual Transmission. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Clutch, M/T > Clutch Release Fork, M/T > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 567301 > Feb > 95 > Clutch Pedal - Squeak Noise > Page 5198 2. Remove the clutch fork and ball stud from the front transmission housing using J 36510, clutch fork pivot remover/installer (Figure 1). 3. Inspect the front transmission housing to locate the raised boss where the grease zerk is to be installed (Figure 2). ^ The boss is on the right side of the transmission between the fill plug and the clutch fork pocket. 4. Drill a hole of required size (determined by diameter/thread pitch of zerk used) in the center of the raised boss located in step 3. ^ The grease zerk used should have no more than 1/4" of threaded length to avoid entering the ball stud cavity. Important: Wall thickness in this area is approximately 1/4". Use caution to prevent passing through the ball stud cavity and drilling through the inner wall of the housing. 5. Tap the hole as required and install the grease zerk. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Clutch, M/T > Clutch Release Fork, M/T > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 567301 > Feb > 95 > Clutch Pedal - Squeak Noise > Page 5199 Important: Thoroughly clean out all metal chips before installing the zerk and ball stud to prevent plugging the greaseable ball stud. 6. Install greaseable ball stud P/N 23049797 using J 36510, clutch fork pivot remover/installer. 7. Grease the fitting until a small amount of grease flows from the end of the ball stud. 8. Install new clutch fork P/N 15588262. Place grease in the clutch fork pocket that contacts the clutch fork push rod. 9. Reinstall the transmission following directions in the appropriate Service Manual, Section 7B, Manual Transmission. 10. Grease the assembled ball stud lightly through the fining. Grease every 30,000 miles thereafter. Important: Grease should be added "sparingly" to the fitting. Excessive grease can contaminate the clutch disc friction surfaces resulting in slip or chatter and the need to replace the disc. PARTS INFORMATION Parts are currently available from GMPSO. WARRANTY INFORMATION For vehicles repaired under warranty, use: Labor Operation Description Labor Time K0720 Fork and/or Ball Use published labor Stud, Clutch operation time Release - Replace The document shown should be reproduced locally and provided to the owners of the vehicles modified by this procedure. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Clutch, M/T > Clutch Release Fork, M/T > Component Information > Technical Service Bulletins > All Other Service Bulletins for Clutch Release Fork: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking Fuel Pump Relay: All Technical Service Bulletins Engine - Will Not Start Readily Upon Cranking File In Section: 6E - Engine Fuel & Emission Bulletin No.: 56-63-05A Date: January, 1996 Subject: Vehicle Does Not Start Readily Upon Cranking (Replace Fuel Pump Relay) Models: 1993-94 Chevrolet and GMC Truck M/L Vans 1994 Chevrolet and GMC Truck S/T Utility 1994 Oldsmobile Bravada with 4.3L Engine (VIN W, Z - RPOs L35, LB4) This bulletin is being revised to change the correction procedure and parts information and to add the L Van and artwork. Please discard Corporate Bulletin Number 56-63-05 (Section 6E - Engine Fuel & Emission). Condition Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Clutch, M/T > Clutch Release Fork, M/T > Component Information > Technical Service Bulletins > All Other Service Bulletins for Clutch Release Fork: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking > Page 5205 Some owners may experience extended engine crank times on cold start and may set diagnostic trouble code 54 and activate the M/L (Check Engine light). Cause This condition may be due to failure of the fuel pump relay. Correction Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Clutch, M/T > Clutch Release Fork, M/T > Component Information > Technical Service Bulletins > All Other Service Bulletins for Clutch Release Fork: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking > Page 5206 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Clutch, M/T > Clutch Release Fork, M/T > Component Information > Technical Service Bulletins > All Other Service Bulletins for Clutch Release Fork: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking > Page 5207 Verify condition using the normal diagnostic procedure in the service manual. Replace the Fuel Pump Relay (P/N 12077867) following the service manual procedure. Replace the connector (Kit P/N 12166225) following the instructions in Figures 3 and 4. Note that each of the four cavities of the old connector are lettered. The new connector is numbered and it should be wired according to Figure 3 and not the instructions contained within the connector kit. Parts Information P/N Description Qty 12077867 Fuel Pump Relay 1 12166225 Connector 1 12129073 Bracket (S/T Only) 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: Labor Operation Description Labor Time J5460 Relay, Fuel Pump- Use Published Replace Labor Operation Time Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Clutch, M/T > Clutch Release Fork, M/T > Component Information > Technical Service Bulletins > All Other Service Bulletins for Clutch Release Fork: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking > Page 5213 Some owners may experience extended engine crank times on cold start and may set diagnostic trouble code 54 and activate the M/L (Check Engine light). Cause This condition may be due to failure of the fuel pump relay. Correction Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Clutch, M/T > Clutch Release Fork, M/T > Component Information > Technical Service Bulletins > All Other Service Bulletins for Clutch Release Fork: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking > Page 5214 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Clutch, M/T > Clutch Release Fork, M/T > Component Information > Technical Service Bulletins > All Other Service Bulletins for Clutch Release Fork: > 566305A > Jan > 96 > Engine - Will Not Start Readily Upon Cranking > Page 5215 Verify condition using the normal diagnostic procedure in the service manual. Replace the Fuel Pump Relay (P/N 12077867) following the service manual procedure. Replace the connector (Kit P/N 12166225) following the instructions in Figures 3 and 4. Note that each of the four cavities of the old connector are lettered. The new connector is numbered and it should be wired according to Figure 3 and not the instructions contained within the connector kit. Parts Information P/N Description Qty 12077867 Fuel Pump Relay 1 12166225 Connector 1 12129073 Bracket (S/T Only) 1 Parts are currently available from GMSPO. Warranty Information For vehicles repaired under warranty, use: Labor Operation Description Labor Time J5460 Relay, Fuel Pump- Use Published Replace Labor Operation Time Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Clutch, M/T > Pilot Bearing > Component Information > Technical Service Bulletins > M/T - Clutch Pilot Bushing and Bearings Pilot Bearing: Technical Service Bulletins M/T - Clutch Pilot Bushing and Bearings File In Section: 7 - Transmission Bulletin No.: 46-73-02 Date: October, 1994 INFORMATION Subject: Clutch Pilot Bushings and Bearings Models: 1988-95 Chevrolet and GMC Truck Light Duty Trucks with 4.3L, 5.0L, 5.7L, 6.2L, 6.5L, 7.4L Engines and Manual Transmission A worn or damaged clutch pilot bushing or bearing, located in the end of the crankshaft, can be the cause of various clutch and transmission concerns including: ^ Noise when the clutch pedal is depressed ^ Transmission noise ^ Clutch shudder on launch ^ Difficult shifting or excessive clash into reverse A worn clutch pilot bushing will not properly support the transmission input shaft. Without sufficient support, the front of the input shaft can move out of location resulting in transmission noise or clutch shudder on engagement. A damaged clutch pilot bushing or bearing may continue to turn the transmission input shaft when the clutch is released. This rotation can then cause difficult shifting or gear clash. Anytime a transmission or clutch is removed for repair, a new clutch pilot roller bearing should be installed. The end of the transmission input shaft that contacts the pilot roller bearing should also be inspected for damage. When installing the pilot roller bearing, the chamfer or lead-in to the I.D. should be installed facing the rear of the vehicle. This chamfer will help guide the input shaft into the roller bearing. This bearing is pre-lubed with a high temperature grease and does not require additional lubrication. The bearing listed below will fit all 1988-95 4.3L, 5.OL, 5.7L, 6.2L, 6.5L, and 7.4L light duty engines. Do not use a bronze clutch pilot bushing. Parts Information P/N Description Qty 14061685 Bearing, clutch Pilot 1 Parts are currently available from GMSPO. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Clutch, M/T > Pressure Plate > Component Information > Specifications Pressure Plate: Specifications Clutch Cover to Flywheel Bolts ............................................................................................................ .................................................................. 30 ft. lbs. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Continuously Variable Transmission/Transaxle, CVT > Component Information > Technical Service Bulletins > Customer Interest: > 04-07-30-013B > Feb > 07 > Engine, A/T Shift/Driveability Concerns/MIL ON Continuously Variable Transmission/Transaxle: Customer Interest Engine, A/T - Shift/Driveability Concerns/MIL ON Bulletin No.: 04-07-30-013B Date: February 01, 2007 INFORMATION Subject: Automatic Transmission Shift, Engine Driveability Concerns or Service Engine Soon (SES) Light On as a Result of the Use of an Excessively/Over-Oiled Aftermarket, Reusable Air Filter Models: 2007 and Prior GM Cars and Light Duty Trucks 2007 and Prior Saturn Models 2003-2007 HUMMER H2 2006-2007 HUMMER H3 2005-2007 Saab 9-7X Supercede: This bulletin is being revised to add models and model years. Please discard Corporate Bulletin Number 04-07-30-013A (Section 07 - Transmission/Transaxle). The use of an excessively/over-oiled aftermarket, reusable air filter may result in: Service Engine Soon (SES) light on Transmission shift concerns, slipping and damaged clutch(es) or band(s) Engine driveability concerns, poor acceleration from a stop, limited engine RPM range The oil that is used on these air filter elements may be transferred onto the Mass Air Flow (MAF) sensor causing contamination of the sensor. As a result, the Grams per Second (GPS) signal from the MAF may be low and any or all of the concerns listed above may occur. When servicing a vehicle with any of these concerns, be sure to check for the presence of an aftermarket reusable, excessively/over-oiled air filter. The MAF, GPS reading should be compared to a like vehicle with an OEM air box and filter under the same driving conditions to verify the concern. The use of an aftermarket reusable air filter DOES NOT void the vehicle's warranty. If an aftermarket reusable air filter is used, technicians should inspect the MAF sensor element and the air induction hose for contamination of oil prior to making warranty repairs. Transmission or engine driveability concerns (related to the MAF sensor being contaminated with oil) that are the result of the use of an aftermarket reusable, excessively/over-oiled air filter are not considered to be warrantable repair items. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Continuously Variable Transmission/Transaxle, CVT > Component Information > Technical Service Bulletins > Customer Interest: > 04-07-30-013B > Feb > 07 > Engine, A/T Shift/Driveability Concerns/MIL ON > Page 5231 Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Continuously Variable Transmission/Transaxle, CVT > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Continuously Variable Transmission/Transaxle: > 04-06-01-029E > Apr > 10 > Vehicle - Engine Crankcase and Subsystems Flushing Info. Continuously Variable Transmission/Transaxle: All Technical Service Bulletins Vehicle - Engine Crankcase and Subsystems Flushing Info. INFORMATION Bulletin No.: 04-06-01-029E Date: April 29, 2010 Subject: Unnecessary Flushing Services, Additive Recommendations and Proper Utilization of GM Simplified Maintenance Schedule to Enhance Customer Service Experience Models: 2011 and Prior GM Passenger Cars and Trucks (including Saturn) 2010 and Prior HUMMER H2, H3 2005-2009 Saab 9-7X Supercede: This bulletin is being revised to update the model years and add information about the proper transmission flush procedure. Please discard Corporate Bulletin Number 04-06-01-029D (Section 06 - Engine/Propulsion System). An Overview of Proper Vehicle Service General Motors is aware that some companies are marketing tools and equipment to support a subsystem flushing procedures. These dedicated machines are in addition to many engine oil, cooling system, fuel system, A/C, transmission flush and steering system additives available to the consumer. GM Vehicles under normal usage do not require any additional procedures or additives beyond what is advised under the former Vehicle Maintenance Schedules or the current Simplified Maintenance Schedules. Do not confuse machines available from Kent-Moore/SPX that are designed to aid and accelerate the process of fluid changing with these flushing machines. Engine Crankcase Flushing General Motors Corporation does not endorse or recommend engine crankcase flushing for any of its gasoline engines. Analysis of some of the aftermarket materials used for crankcase flushing indicate incompatibility with GM engine components and the potential for damage to some engine seals and bearings. Damage to engine components resulting from crankcase flushing IS NOT COVERED under the terms of the New Vehicle Warranty. GM Authorized Service Information: Detailed, Descriptive, and Complete If a specific model vehicle or powertrain need is identified, GM will issue an Authorized Service Document containing a procedure and, if required, provide, make available, or require the specific use of a machine, tool or chemical to accomplish proper vehicle servicing. An example of this is fuel injector cleaning. Due to variation in fuel quality in different areas of the country, GM has recognized the need for fuel injector cleaning methods on some engines, though under normal circumstances, this service is not part of the maintenance requirements. GM has published several gasoline fuel injector cleaning bulletins that fully outline the methods to be used in conjunction with GM Part Numbered solutions to accomplish proper and safe cleaning of the fuel injectors with preventative maintenance suggestions to maintain optimum performance. You may refer to Corporate Bulletin Numbers 03-06-04-030 and 04-06-04-051 for additional information on this subject. Subsystem Flushing Flushing of A/C lines, radiators, transmission coolers, and power steering systems are recognized practices to be performed after catastrophic failures or extreme corrosion when encountered in radiators. For acceptable A/C flushing concerns, refer to Corporate Bulletin Number 01-01-38-006. This practice is NOT required or recommended for normal service operations. The use of external transmission fluid exchange or flush machines is NOT recommended for the automatic or manual transmission. Use of external machines to replace the fluid may affect the operation or durability of the transmission. Transmission fluid should only be replaced by draining and refilling following directions in SI. Refer to Automatic/Manual Transmission Fluid and Filter Replacement. Approved Transmission Flushing Tool (Transmission Cooler Only) The Automatic Transmission Oil Cooler Flush and Flow Test Tool is recommended for GM vehicles. Refer to Transmission Fluid Cooler Flushing and Flow Test in SI using the J 45096. Service Is Important to You and Your Customer General Motors takes great pride in offering our dealerships and customers high quality vehicles that require extremely low maintenance over the life of the vehicle. This low cost of ownership builds repeat sales and offers our customers measurable economy of operation against competing vehicles. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Continuously Variable Transmission/Transaxle, CVT > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Continuously Variable Transmission/Transaxle: > 04-06-01-029E > Apr > 10 > Vehicle - Engine Crankcase and Subsystems Flushing Info. > Page 5237 Providing responsible services at the proper intervals will greatly aid your dealership with repeat business, and additional services when required. Most customers appreciate and gain trust in the dealership that informs and offers them just what they need for continued trouble-free operation. Examine your service department's practices and verify that all Service Consultants and Technicians focus on customer satisfaction, vehicle inspections, and other products at time of service. Use this opportunity to upgrade the services you provide to your customers. Here are a few suggestions: - Take the time required to align your dealership service practices with the new GM Simplified Maintenance Schedule. Use the new vehicle Owner's Manual Maintenance I and II schedules to create a "mirror image" in your advertising and dealer service pricing that is easily understandable to your customer. Taking advantage of this new service strategy may greatly increase your dealership service sales and customer retention while decreasing the frequency of visits and inconvenience to your customer. - Review your program to ensure that all vehicles coming in are evaluated for safety and wear items. Examine all vehicles for tire condition, signs of misalignment, brake wear, exterior lamp functionality, exhaust condition, A/C cooling performance, SRS or Air Bag MIL, along with Service Engine Soon or Check Engine indicators. If the Service Engine Soon or Check Engine MIL is illuminated, it is vital that you inform the customer of the concerns with ignoring the indicator and what the required repair would cost. In addition to the possibility of increased emissions and driveability concerns, many customers are unaware that lower gas mileage may also result, with additional cost to the customer. - Be complete in your service recommendations. Some sales opportunities are not being fully pursued nationally. Focus on overlooked but required maintenance that has real benefits to the customer. Many vehicles are equipped with cabin air filters. If these filters are used beyond replacement time, they may impede airflow decreasing A/C and heating performance. Make sure these filters are part of your recommended service. Note that some of our vehicles may not have been factory equipped but will accept the filters as an accessory. - Express the value in maintaining the finish quality of the customer's vehicle at the Maintenance I and II visits. More fully utilize the vehicle prep personnel you already have in place. In today's world, many people simply ignore the finish of their vehicle, at best infrequently using an automatic car wash for exterior cleaning. Offer vehicle detailing services in stages from just a wash and wax to a complete interior cleaning. When paired with the Simplified Maintenance visit, this will increase customer satisfaction. On return, the customer gets a visibly improved vehicle that will be a source of pride of ownership along with a vehicle that is now fully maintained. Also, reinforce the improved resale value of a completely maintained vehicle. - For customers who clean and maintain the appearance of their vehicles themselves encourage the use of GM Vehicle Care products. Many customers may have never used GM Car Wash/Wax Concentrate, GM Cleaner Wax or a longtime product, GM Glass Cleaner, which is a favorite of many customers who try it just once. If your dealership give samples of these products with new car purchases, customers may already be sold on the product but not willing to make a special trip to the dealership. Capitalize on sales at this time. Stock shelves right at the Service counter with these products and consider instituting compensation programs for Service Consultants who suggest these products. Many consumers faced with an intimidating wall full of car care products sold at local auto parts stores may find it comforting to purchase a fully tested product sold by GM that they know will not harm the finish of their vehicle. We suggest these competitively priced basic vehicle care products to emphasize: In USA: - #12378401 GM Vehicle Care Wash/Wax Concentrate 16 fl. oz. (0.473L) - #89021822 GM Vehicle Care Glass Cleaner Aerosol 18 oz. (510 g) - #12377966 GM Vehicle Care Cleaner Wax 16 fl. oz. (0.473L) - #1052929 GM Vehicle Care Chrome and Wire Wheel Cleaner 16 fl. oz. (0.473L) - #88861431 GM Vehicle Care Odor Eliminator 24 fl. oz. (0.710L) In Canada: - #10953203 GM Vehicle Care Wash & Wax Concentrate 473 mL - #992727 GM Glass Cleaner Aerosol 500 g - #10952905 GM Vehicle Care Liquid Cleaner/Wax 473 mL - #10953013 GM Vehicle Care Chrome Cleaner and Polish 454 mL - #10953202 GM Vehicle Care Wheel Brite 473 mL - #88901678 GM Vehicle Care Odor Eliminator 473 mL - Display signboards with the installed price for popular GM Accessories such as running boards and Tonneau Covers. Customers may not think to ask about these desirable items at the time of a service visit. - Finally, take advantage of the GM Goodwrench initiatives (Tire Program, Goodwrench Credit Card, etc. / Dealer Marketing Association (DMA) Promotions in Canada) to provide the customer with more reasons to identify your dealership as the best place to go for parts and service. Remember to utilize ALL of the service aspects you possess in your dealership to satisfy and provide value to your customer. Many businesses exist profitably as an oil change location, a vehicle repair facility, or a detailing shop alone. You already have the capabilities of all three and provide these services with the inherent trust of your customer, under the GM Mark of Excellence. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Continuously Variable Transmission/Transaxle, CVT > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Continuously Variable Transmission/Transaxle: > 04-07-30-013B > Feb > 07 > Engine, A/T - Shift/Driveability Concerns/MIL ON Continuously Variable Transmission/Transaxle: All Technical Service Bulletins Engine, A/T Shift/Driveability Concerns/MIL ON Bulletin No.: 04-07-30-013B Date: February 01, 2007 INFORMATION Subject: Automatic Transmission Shift, Engine Driveability Concerns or Service Engine Soon (SES) Light On as a Result of the Use of an Excessively/Over-Oiled Aftermarket, Reusable Air Filter Models: 2007 and Prior GM Cars and Light Duty Trucks 2007 and Prior Saturn Models 2003-2007 HUMMER H2 2006-2007 HUMMER H3 2005-2007 Saab 9-7X Supercede: This bulletin is being revised to add models and model years. Please discard Corporate Bulletin Number 04-07-30-013A (Section 07 - Transmission/Transaxle). The use of an excessively/over-oiled aftermarket, reusable air filter may result in: Service Engine Soon (SES) light on Transmission shift concerns, slipping and damaged clutch(es) or band(s) Engine driveability concerns, poor acceleration from a stop, limited engine RPM range The oil that is used on these air filter elements may be transferred onto the Mass Air Flow (MAF) sensor causing contamination of the sensor. As a result, the Grams per Second (GPS) signal from the MAF may be low and any or all of the concerns listed above may occur. When servicing a vehicle with any of these concerns, be sure to check for the presence of an aftermarket reusable, excessively/over-oiled air filter. The MAF, GPS reading should be compared to a like vehicle with an OEM air box and filter under the same driving conditions to verify the concern. The use of an aftermarket reusable air filter DOES NOT void the vehicle's warranty. If an aftermarket reusable air filter is used, technicians should inspect the MAF sensor element and the air induction hose for contamination of oil prior to making warranty repairs. Transmission or engine driveability concerns (related to the MAF sensor being contaminated with oil) that are the result of the use of an aftermarket reusable, excessively/over-oiled air filter are not considered to be warrantable repair items. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Continuously Variable Transmission/Transaxle, CVT > Component Information > Technical Service Bulletins > All Technical Service Bulletins for Continuously Variable Transmission/Transaxle: > 04-07-30-013B > Feb > 07 > Engine, A/T - Shift/Driveability Concerns/MIL ON > Page 5242 Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Continuously Variable Transmission/Transaxle, CVT > Component Information > Technical Service Bulletins > All Other Service Bulletins for Continuously Variable Transmission/Transaxle: > 04-06-01-029E > Apr > 10 > Vehicle - Engine Crankcase and Subsystems Flushing Info. Continuously Variable Transmission/Transaxle: All Technical Service Bulletins Vehicle - Engine Crankcase and Subsystems Flushing Info. INFORMATION Bulletin No.: 04-06-01-029E Date: April 29, 2010 Subject: Unnecessary Flushing Services, Additive Recommendations and Proper Utilization of GM Simplified Maintenance Schedule to Enhance Customer Service Experience Models: 2011 and Prior GM Passenger Cars and Trucks (including Saturn) 2010 and Prior HUMMER H2, H3 2005-2009 Saab 9-7X Supercede: This bulletin is being revised to update the model years and add information about the proper transmission flush procedure. Please discard Corporate Bulletin Number 04-06-01-029D (Section 06 - Engine/Propulsion System). An Overview of Proper Vehicle Service General Motors is aware that some companies are marketing tools and equipment to support a subsystem flushing procedures. These dedicated machines are in addition to many engine oil, cooling system, fuel system, A/C, transmission flush and steering system additives available to the consumer. GM Vehicles under normal usage do not require any additional procedures or additives beyond what is advised under the former Vehicle Maintenance Schedules or the current Simplified Maintenance Schedules. Do not confuse machines available from Kent-Moore/SPX that are designed to aid and accelerate the process of fluid changing with these flushing machines. Engine Crankcase Flushing General Motors Corporation does not endorse or recommend engine crankcase flushing for any of its gasoline engines. Analysis of some of the aftermarket materials used for crankcase flushing indicate incompatibility with GM engine components and the potential for damage to some engine seals and bearings. Damage to engine components resulting from crankcase flushing IS NOT COVERED under the terms of the New Vehicle Warranty. GM Authorized Service Information: Detailed, Descriptive, and Complete If a specific model vehicle or powertrain need is identified, GM will issue an Authorized Service Document containing a procedure and, if required, provide, make available, or require the specific use of a machine, tool or chemical to accomplish proper vehicle servicing. An example of this is fuel injector cleaning. Due to variation in fuel quality in different areas of the country, GM has recognized the need for fuel injector cleaning methods on some engines, though under normal circumstances, this service is not part of the maintenance requirements. GM has published several gasoline fuel injector cleaning bulletins that fully outline the methods to be used in conjunction with GM Part Numbered solutions to accomplish proper and safe cleaning of the fuel injectors with preventative maintenance suggestions to maintain optimum performance. You may refer to Corporate Bulletin Numbers 03-06-04-030 and 04-06-04-051 for additional information on this subject. Subsystem Flushing Flushing of A/C lines, radiators, transmission coolers, and power steering systems are recognized practices to be performed after catastrophic failures or extreme corrosion when encountered in radiators. For acceptable A/C flushing concerns, refer to Corporate Bulletin Number 01-01-38-006. This practice is NOT required or recommended for normal service operations. The use of external transmission fluid exchange or flush machines is NOT recommended for the automatic or manual transmission. Use of external machines to replace the fluid may affect the operation or durability of the transmission. Transmission fluid should only be replaced by draining and refilling following directions in SI. Refer to Automatic/Manual Transmission Fluid and Filter Replacement. Approved Transmission Flushing Tool (Transmission Cooler Only) The Automatic Transmission Oil Cooler Flush and Flow Test Tool is recommended for GM vehicles. Refer to Transmission Fluid Cooler Flushing and Flow Test in SI using the J 45096. Service Is Important to You and Your Customer General Motors takes great pride in offering our dealerships and customers high quality vehicles that require extremely low maintenance over the life of the vehicle. This low cost of ownership builds repeat sales and offers our customers measurable economy of operation against competing vehicles. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Continuously Variable Transmission/Transaxle, CVT > Component Information > Technical Service Bulletins > All Other Service Bulletins for Continuously Variable Transmission/Transaxle: > 04-06-01-029E > Apr > 10 > Vehicle - Engine Crankcase and Subsystems Flushing Info. > Page 5248 Providing responsible services at the proper intervals will greatly aid your dealership with repeat business, and additional services when required. Most customers appreciate and gain trust in the dealership that informs and offers them just what they need for continued trouble-free operation. Examine your service department's practices and verify that all Service Consultants and Technicians focus on customer satisfaction, vehicle inspections, and other products at time of service. Use this opportunity to upgrade the services you provide to your customers. Here are a few suggestions: - Take the time required to align your dealership service practices with the new GM Simplified Maintenance Schedule. Use the new vehicle Owner's Manual Maintenance I and II schedules to create a "mirror image" in your advertising and dealer service pricing that is easily understandable to your customer. Taking advantage of this new service strategy may greatly increase your dealership service sales and customer retention while decreasing the frequency of visits and inconvenience to your customer. - Review your program to ensure that all vehicles coming in are evaluated for safety and wear items. Examine all vehicles for tire condition, signs of misalignment, brake wear, exterior lamp functionality, exhaust condition, A/C cooling performance, SRS or Air Bag MIL, along with Service Engine Soon or Check Engine indicators. If the Service Engine Soon or Check Engine MIL is illuminated, it is vital that you inform the customer of the concerns with ignoring the indicator and what the required repair would cost. In addition to the possibility of increased emissions and driveability concerns, many customers are unaware that lower gas mileage may also result, with additional cost to the customer. - Be complete in your service recommendations. Some sales opportunities are not being fully pursued nationally. Focus on overlooked but required maintenance that has real benefits to the customer. Many vehicles are equipped with cabin air filters. If these filters are used beyond replacement time, they may impede airflow decreasing A/C and heating performance. Make sure these filters are part of your recommended service. Note that some of our vehicles may not have been factory equipped but will accept the filters as an accessory. - Express the value in maintaining the finish quality of the customer's vehicle at the Maintenance I and II visits. More fully utilize the vehicle prep personnel you already have in place. In today's world, many people simply ignore the finish of their vehicle, at best infrequently using an automatic car wash for exterior cleaning. Offer vehicle detailing services in stages from just a wash and wax to a complete interior cleaning. When paired with the Simplified Maintenance visit, this will increase customer satisfaction. On return, the customer gets a visibly improved vehicle that will be a source of pride of ownership along with a vehicle that is now fully maintained. Also, reinforce the improved resale value of a completely maintained vehicle. - For customers who clean and maintain the appearance of their vehicles themselves encourage the use of GM Vehicle Care products. Many customers may have never used GM Car Wash/Wax Concentrate, GM Cleaner Wax or a longtime product, GM Glass Cleaner, which is a favorite of many customers who try it just once. If your dealership give samples of these products with new car purchases, customers may already be sold on the product but not willing to make a special trip to the dealership. Capitalize on sales at this time. Stock shelves right at the Service counter with these products and consider instituting compensation programs for Service Consultants who suggest these products. Many consumers faced with an intimidating wall full of car care products sold at local auto parts stores may find it comforting to purchase a fully tested product sold by GM that they know will not harm the finish of their vehicle. We suggest these competitively priced basic vehicle care products to emphasize: In USA: - #12378401 GM Vehicle Care Wash/Wax Concentrate 16 fl. oz. (0.473L) - #89021822 GM Vehicle Care Glass Cleaner Aerosol 18 oz. (510 g) - #12377966 GM Vehicle Care Cleaner Wax 16 fl. oz. (0.473L) - #1052929 GM Vehicle Care Chrome and Wire Wheel Cleaner 16 fl. oz. (0.473L) - #88861431 GM Vehicle Care Odor Eliminator 24 fl. oz. (0.710L) In Canada: - #10953203 GM Vehicle Care Wash & Wax Concentrate 473 mL - #992727 GM Glass Cleaner Aerosol 500 g - #10952905 GM Vehicle Care Liquid Cleaner/Wax 473 mL - #10953013 GM Vehicle Care Chrome Cleaner and Polish 454 mL - #10953202 GM Vehicle Care Wheel Brite 473 mL - #88901678 GM Vehicle Care Odor Eliminator 473 mL - Display signboards with the installed price for popular GM Accessories such as running boards and Tonneau Covers. Customers may not think to ask about these desirable items at the time of a service visit. - Finally, take advantage of the GM Goodwrench initiatives (Tire Program, Goodwrench Credit Card, etc. / Dealer Marketing Association (DMA) Promotions in Canada) to provide the customer with more reasons to identify your dealership as the best place to go for parts and service. Remember to utilize ALL of the service aspects you possess in your dealership to satisfy and provide value to your customer. Many businesses exist profitably as an oil change location, a vehicle repair facility, or a detailing shop alone. You already have the capabilities of all three and provide these services with the inherent trust of your customer, under the GM Mark of Excellence. Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Differential Carrier > Carrier Bearings > Component Information > Adjustments > 2 - Pinion Carrier Bearings: Adjustments 2 - Pinion Fig. 3 Installing shims To adjust differential side bearing preload, change thickness of right and left shims equally so original backlash is not disturbed. 1. Ensure side bearing surfaces are clean and free of burrs. 2. Apply suitable lubricant to side bearings. If original bearings are to be reused, original outer races should also be used. 3. Install differential case in carrier, with bearing outer races in position. 4. Install left bearing cap and cap attaching bolts loosely so case may be moved during adjustment. 5. Measure original spacers and subtract .004 inch from each reading. Use caution not to interchange right and left spacers. 6. Select a service spacer for each side equal to thickness of original shim minus .004 inch, then install shim as shown in Fig. 3. Ensure flat edge of spacer faces against housing. 7. At this point, bearings should have no play and no drag (zero preload). If zero preload is not present, shims should be added or removed equally from both sides as necessary. 8. Check case for zero endplay using a suitable dial indicator. If shim installation causes excessive pinion to ring gear clearance, select thinner left shim and add difference to right side. Keep total shim thickness at a value equal to that obtained in step 6. 9. Install both bearing caps and cap attaching bolts. Torque bolts 40 ft. lbs. Fig. 4 Gear tooth contact pattern check 10. If pinion was not removed, check backlash and tooth pattern as follows: a. Apply suitable marking compound on ring gear teeth. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Differential Carrier > Carrier Bearings > Component Information > Adjustments > 2 - Pinion > Page 5255 b. Rotate drive pinion one revolution and check gear tooth contact pattern as shown on Fig. 4. Add or remove shims as required. c. After backlash and tooth pattern operation has been completed, remove shim packs using caution not to mix them. d. Select new shims for each side .004 inch thicker than those removed, then install each shim on its proper side. This additional thickness will ensure proper bearing preload. e. Check total rotational torque. Total torque with differential case preloaded and pinion installed should be 16---29 inch lbs. if new bearings are installed or 10---16 inch lbs. if original bearings are installed. f. If total rotational torque is not as specified, repeat steps 4 through 10. 11. If drive pinion was removed, remove differential case and shims, then proceed to ``Drive Pinion & Bearing Shim Adjustment'' procedure. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Differential Carrier > Carrier Bearings > Component Information > Adjustments > 2 - Pinion > Page 5256 Carrier Bearings: Adjustments 4 - Pinion Fig. 3 Installing shims To adjust differential side bearing preload, change thickness of right and left shims equally so original backlash is not disturbed. 1. Ensure side bearing surfaces are clean and free of burrs. 2. Apply suitable lubricant to side bearings. If original bearings are to be reused, original outer races should also be used. 3. Install differential case in carrier, with bearing outer races in position. 4. Install left bearing cap and cap attaching bolts loosely so case may be moved during adjustment. 5. Measure original spacers and subtract .004 inch from each reading. Use caution not to interchange right and left spacers. 6. Select a service spacer for each side equal to thickness of original shim minus .004 inch, then install shim as shown in Fig. 3. Ensure flat edge of spacer faces against housing. 7. At this point, bearings should have no play and no drag (zero preload). If zero preload is not present, shims should be added or removed equally from both sides as necessary. 8. Check case for zero endplay using a dial indicator. If shim installation causes excessive pinion to ring gear clearance, select thinner left shim and add difference to right side. Keep total shim thickness at a value equal to that obtained in step 6. 9. Install both bearing caps and cap attaching bolts. Torque bolts 40 ft. lbs. Fig. 4 Gear tooth contact pattern check 10. If pinion was not removed, check backlash and tooth pattern as follows: Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Differential Carrier > Carrier Bearings > Component Information > Adjustments > 2 - Pinion > Page 5257 a. Apply marking compound on ring gear teeth. b. Rotate drive pinion one revolution and check gear tooth contact pattern as shown on Fig. 4. Add or remove shims as required. c. After backlash and tooth pattern operation has been completed, remove shim packs using caution not to mix them. d. Select new shims for each side .004 inch thicker than those removed, then install each shim on its proper side. This additional thickness will ensure proper bearing preload. e. Check total rotational torque. Total torque with differential case preloaded and pinion installed should be 16-29 inch lbs. if new bearings are installed or 10-16 inch lbs. if original bearings are installed. f. If total rotational torque is not as specified, repeat steps 4 through 10. 11. If drive pinion was removed, remove differential case and shims, then proceed to DRIVE PINION & BEARING SHIM ADJUSTMENT procedure. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Differential Clutch > Component Information > Service and Repair > 7 1/2 - 8 1/2 Inch Ring Gear Differential Clutch: Service and Repair 7 1/2 - 8 1/2 Inch Ring Gear Cam Gear Clutch Fig. 8 Exploded View Of Eaton Locking Differential. Models With 8 1/2 Inch Ring Gear 1. Remove retaining ring from end of cam gear, Fig. 8. 2. Remove discs and cam plate from gear, keeping all components in order. 3. Clean and inspect components, and replace any that are damaged, distorted or excessively worn. If cam gear must be replaced, refer to CAM GEAR SHIM SELECTION for shim selection procedures prior to case reassembly. 4. Position gear on flat surface with hub end up, and assemble cam plate onto gear with cam form down to mate with cam form on gear. 5. Assemble two eared discs, one splined disc and one wave washer on cam gear, starting with eared disc as shown in Fig. 8. 6. Alternately assemble three eared discs and two splined discs on cam gear hub, starting with eared discs. 7. Install retaining ring, ensuring that retainer is fully seated. Side Gear (RH) Clutch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Differential Clutch > Component Information > Service and Repair > 7 1/2 - 8 1/2 Inch Ring Gear > Page 5262 Fig. 8 Exploded View Of Eaton Locking Differential. Models With 8 1/2 Inch Ring Gear 1. Remove disc pack and shim from side gear, keeping components in order. 2. Clean and inspect components, and replace any that are damaged, deformed or excessively worn. If side gear must be replaced, refer to SIDE GEAR SHIM SELECTION for shim selection prior to case assembly. If side gear hub is scored or worn, inspect bore in case and replace assembly if bore is damaged or worn. 3. Alternately assemble eared discs and splined discs on side gear hub, starting with eared disc as shown in Fig. 8. 4. Install original shim or replacement shim of same thickness if original side gear is being used. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Differential Clutch > Component Information > Service and Repair > 7 1/2 - 8 1/2 Inch Ring Gear > Page 5263 Differential Clutch: Service and Repair 8 7/8 Inch Ring Gear Cam Gear Clutch If cam plate or clutch discs must be replaced, the cam gear subassembly must be serviced as follows: 1. Measure and record overall length of gear assembly (front face of gear to back side of thrust ring, including shim). This dimension will be needed to reassemble unit if thrust ring is replaced. Do not replace thrust ring unless necessary. If ring is excessively worn or scored, check bore in case for scoring. If bore is scored, replace entire differential. 2. With gear hub end up, compress disc pack and install jaws of split ring bearing remover between the thrust ring and the top eared disc. Bevel side of bearing remover should face up toward thrust ring. 3. Place cam gear assembly with bearing remover attached in an arbor press supporting the bearing remover on both sides. 4. Install a 1-1/2 inch to 1-3/4 inch diameter plug on gear hub. Press against plug with ram of press to remove thrust ring. Keep components in proper order. 5. Place gear on bench with hub end up. 6. Assemble cam plate with cam form down to mate with cam form on gear. Fig. 8 Exploded View Of Eaton Locking Differential. Models With 8 1/2 Inch Ring Gear 7. Assemble onto cam plate: 2 eared discs, 1 splined disc, and 1 wave spring alternately, Fig. 8. 8. Assemble onto gear hub: 2 splined discs and 3 eared discs alternately, Fig. 8. 9. Locate cam gear assembly in arbor press with hub end up. Place thrust ring on gear hub and press to shoulder making sure that ring is square with hub. Compress disc pack by pushing down on the discs to keep the splined discs from becoming wedged between the thrust ring and gear shoulder while pressing the subassembly together. Side Gear (RH) Clutch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Differential Clutch > Component Information > Service and Repair > 7 1/2 - 8 1/2 Inch Ring Gear > Page 5264 Fig. 8 Exploded View Of Eaton Locking Differential. Models With 8 1/2 Inch Ring Gear 1. Remove shim and disc pack from side gear, keeping components in order. 2. Inspect discs and guide clips and replace as needed. 3. Inspect side gear and shim. If either component is damaged or excessively worn, differential assembly must be replaced. If gear hub is scored or abnormally worn, inspect corresponding bore in case. If case bore is damaged or oversize, differential assembly must be replaced. 4. Assemble eared and splined discs onto side gear hub, starting with eared disc as shown in Fig. 8. If original disc pack is used, ensure that discs are installed in original position. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Differential Clutch > Component Information > Service and Repair > 7 1/2 - 8 1/2 Inch Ring Gear > Page 5265 Differential Clutch: Service and Repair 9 1/2 Inch Ring Gear Cam Gear Clutch Fig. 6 Cam Gear Thrust Ring Removal. Eaton Locking Differential 1. Measure and record overall length of cam gear assembly from front face of gear to back side of thrust ring, including shim. 2. With gear hub facing up, compress disc pack and insert jaws of suitable split ring bearing puller between thrust ring and top eared disc with bevel side of puller facing thrust ring, Fig. 6. 3. Support bearing remover in press and press cam gear from thrust ring using 1-3/4 inch diameter spacer. Keep all component in order as cam gear is removed. 4. Remove disc pack and cam plate from gear, clean and inspect components, and replace any that are damaged or excessively worn. Do not replace thrust ring and/or cam gear unless necessary. If ring or gear is excessively worn or scored, inspect bore in case. If case bore is scored, entire assembly must be replaced. If cam gear or thrust ring are replaced, shim thickness must be selected to provide original assembly dimension and proper differential pinion backlash. 5. Position cam gear on flat surface with hub end up and install cam plate with cam form down to mate with form on gear. Fig. 5 Exploded View Of Eaton Locking Differential 6. Assemble two eared discs, one splined disc and wave spring onto cam plate as shown in Fig. 5. If components are reused, they must be installed in original position. 7. Alternately assemble three splined and four eared discs on cam gear hub, as shown in Fig. 5. 8. Mount cam gear assembly in press and position thrust ring over gear hub. 9. Compress disc pack to prevent splined disc from being trapped, then press thrust ring onto gear until seated against shoulder of gear. 10. Inspect assembly to ensure that discs are properly assembled and that first splined disc (large spline) is properly located on cam plate. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Differential Clutch > Component Information > Service and Repair > 7 1/2 - 8 1/2 Inch Ring Gear > Page 5266 Side Gear (RH) Clutch Fig. 5 Exploded View Of Eaton Locking Differential 1. Remove shim and disc pack from gear keeping components in order. 2. Inspect discs and guide clips and replace as needed. 3. Inspect side gear and shim. If either component is scored or excessively worn, inspect case and replace entire assembly if case is defective. If either side gear or shim must be replaced, shim thickness must be determined. Refer to Shim Selection. See: Differential Carrier/Service and Repair 4. Alternately assemble splined and eared discs on side gear hub as shown in Fig. 5. If components are reused, they must be installed in original position. 5. Install original shim or new shim of equal thickness. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Differential Lock > Component Information > Locations > Front Axle Vacuum Actuator Differential Lock: Locations Front Axle Vacuum Actuator Shift Cable REMOVE OR DISCONNECT 1. Vacuum hose from the vacuum actuator (130). 2. Shift cable (10) from the vacuum actuator (130). 3. Bolts (131). 4. Vacuum actuator (130). INSTALL OR CONNECT 1. Vacuum actuator (130). 2. Bolts (131). Tighten to 1.4 Nm (13 lbs. in.). 3. Shift cable (10). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Differential Lock > Component Information > Locations > Front Axle Vacuum Actuator > Page 5271 4. Vacuum hose. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Differential Lock > Component Information > Locations > Front Axle Vacuum Actuator > Page 5272 Differential Lock: Locations Shift Cable Shift Cable Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Differential Lock > Component Information > Locations > Front Axle Vacuum Actuator > Page 5273 Disconnecting The Shift Cable From The Vacuum Actuator Shift Cable And Housing Disconnecting The Shift Cable From The Carrier REMOVE OR DISCONNECT 1. Shift cable (10) from the vacuum actuator (130). A. Bend the tang on the lock spring (133). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Differential Lock > Component Information > Locations > Front Axle Vacuum Actuator > Page 5274 B. Push the diaphragm in to release the cable end. C. Squeeze the two locking fingers of the cable ferrule with pliers. Then pull the cable from the bracket. 2. Raise the vehicle and support with safety stands. 3. Bolts (6). - DO NOT unscrew the coupling nut (132) at this time. 4. Shift cable housing (11) from the carrier assembly. Pull out about 20 mm (3/4 inch). 5. Cable end from the shift fork shaft (17). Bend the tang of the locking spring (137), then pull the cable end from the shift fork shaft. 6. Shift cable (10) from the shift cable housing (11) by unscrewing the coupling nut (132). 7. Shift cable from the vehicle. Shift Cable Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Differential Lock > Component Information > Locations > Front Axle Vacuum Actuator > Page 5275 Connecting The Shift Cable To The Carrier Connecting The Shift Cable To The Vacuum Actuator INSTALL OR CONNECT 1. Shift cable housing (11) to the carrier assembly. 2. Bolts (6). Tighten bolts (6) to 48 Nm (36 lbs. ft.). 3. Shift cable (10) to the shift cable housing. A. The shift cable must be attached to the housing before it is routed. B. Guide the cable end (136) through the hole in the shift cable housing. C. Push the cable end into the shift fork shaft (17). It should snap into place. D. Thread the coupling nut (132) into the housing by hand to avoid cross threading. Tighten coupling nut to 10.0 Nm (90 lbs. in.). 4. Lower the vehicle. 5. Shift cable to the vehicle. A. Route as shown. 6. Shift cable to the vacuum actuator (130). A. Push the cable into the hole in the bracket. The cable end and ferrule should snap together. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Differential Axle Housing > Component Information > Service and Repair > Aluminum Case Front Drive Axle Differential Axle Housing: Service and Repair Aluminum Case Front Drive Axle Removal and Installation 1. Unlock steering column so linkage is free to move, then disconnect shift cable from vacuum actuator. 2. Raise and support vehicle, then remove battery and battery tray. 3. Remove front wheels, then the front axle skid plate. 4. Remove drain plug and flat washer, then drain lubricant from carrier. 5. Remove righthand side lower shock bolt. 6. Disconnect wire from indicator switch. 7. Remove shift cable housing and shift cable from carrier housing. 8. Disconnect vent hose. 9. Disconnect steering relay rod from idler arm and pitman arm. 10. Hold left drive axle by inserting drift in top of brake caliper and into vanes in brake rotor, noting the following: a. It is essential positions of all driveline components relative to propeller shaft and axles be observed and accurately reference marked before disassembling. Relative components include propeller shafts, drive axles, pinion flanges, output shafts, etc. b. All components must be assembled in exact relationship to each other as they were before removal. c. Published specifications as well as any measurements made prior to disassembly must be followed. 11. Remove bolts, then the drift from brake rotor. 12. Remove bolts and nuts, then the front prop shaft, as follows: a. Support both lower control arms with suitable stands at edge of stabilizer shaft. b. Lower vehicle until front end weight is resting on stands. 13. Hold carrier upper nut with 18mm wrench inserted through frame, then remove carrier bolts and nuts. 14. Remove carrier assembly by rolling carrier counterclockwise while lifting up to gain clearance from mounting ears. 15. Remove tube bolts from carrier. 16. Reverse procedure to install. Tube & Shaft Assembly Fig. 3 Vacuum Actuator Fig. 4 Drive Axle & Tube Assembly REMOVAL 1. Disconnect battery ground cable. 2. Disconnect shift cable from vacuum actuator. Disengage locking spring, then push actuator diaphragm into release cable, Fig. 3. 3. Unlock steering wheel so linkage is free to move. 4. Raise vehicle and place jack stands under frame side rails. 5. Remove front wheels, drive belt shield and the axle skid plate as equipped. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Differential Axle Housing > Component Information > Service and Repair > Aluminum Case Front Drive Axle > Page 5280 6. Support righthand lower control arm with a jack, then disconnect right upper ball joint and remove support so that control arm hangs free. 7. Disconnect righthand drive axle shaft from tube assembly, Fig. 4. Insert a drift through opening in top of brake caliper and into corresponding vane of brake rotor to prevent axle from turning. 8. Disconnect four-wheel drive indicator light electrical connector from switch. 9. Remove three shift cable and switch housing to carrier bolts and pull housing out to gain access to cable locking spring. Do not remove cable coupling nut unless cable is being replaced. 10. Disconnect shift cable from fork shaft by lifting spring over slot in shift fork. 11. Remove tube bracket bolts from frame and tube assembly bolts from carrier. 12. Remove tube assembly from axle. Use care not to allow sleeve, thrust washers, connector and output shaft to fall from carrier or be damaged when removing tube. Fig. 5 Thrust Washer Installation Fig. 6 Checking Operation Of Four Wheel Drive Mechanism INSTALLATION 1. Install sleeve, thrust washers, connector and output shaft in carrier. The thrust washer notch must align with tab on washer, Fig. 5. 2. Coat tube to carrier mating surface with Loctite 514 sealant or equivalent. 3. Install tube and shaft assembly to carrier using only one bolt installed finger tight at one o'clock position. 4. Pull assembly down, then install cable and switch housing and four remaining bolts. Tighten bolts to specifications. 5. Install two tube to frame bolts. Tighten to specifications. 6. Check four wheel drive mechanism for proper operation by inserting shift cable housing installation tool No. J-33799, or equivalent, into shift fork and checking for rotation of axle shaft, Fig. 6. 7. Remove tool and install shift cable switch housing, then guide cable through housing into fork shaft hole and push cable in by sliding cable through into fork shaft hole. 8. Connect four wheel drive indicator light electrical connector to switch. 9. Support and raise righthand lower control arm using a jack and connect upper ball joint. 10. Install righthand drive axle to axle tube. Install one bolt first, then rotate axle to install five remaining bolts. Tighten bolts to specifications. 11. Install front axle skid plate, if equipped, drive belt shield and front wheels. Tighten skid plate bolts to specifications. 12. Connect shift cable to vacuum actuator by pushing cable end into actuator shaft hole. Output Shaft Pilot Bearing Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Differential Axle Housing > Component Information > Service and Repair > Aluminum Case Front Drive Axle > Page 5281 Exploded View Of Front Drive Axle. 1. Remove tube and shaft assembly. Refer to TUBE & SHAFT ASSEMBLY. See: Tube & Shaft Assembly 2. Remove bearing using pilot bearing remover tool No. J-34011, or equivalent, Fig. 1. 3. Lubricate new bearing with suitable axle lubricant, then install bearing using pilot bearing installer tool No. J-33482, or equivalent. 4. Reverse procedure to complete installation. Righthand Output Shaft & Tube Disassembly 1. Remove output shaft from tube by tapping inside of flange with a rubber mallet. 2. Pry tube seal from tube, then remove bearing from tube. 3. Drive differential shift cable housing seal out of tube using a punch. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Differential Axle Housing > Component Information > Service and Repair > Aluminum Case Front Drive Axle > Page 5282 Assembly 1. Install output shaft tube bearing. 2. Install tube seal. Flange of seal must be flush with tube outer surface. 3. Install output shaft into tube by tapping flange with a rubber mallet. 4. Install differential shift cable housing seal. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Differential Axle Housing > Component Information > Service and Repair > Aluminum Case Front Drive Axle > Page 5283 Differential Axle Housing: Service and Repair Semi-Floating Rear Axle Fig. 1 Rear Suspension. L H Side Down, R H Side Similar Construction of the axle assembly is such that service operations may be performed with the housing installed in the vehicle or with the housing removed and installed in a holding fixture. The following procedure is necessary only when the housing requires replacement. 1. Raise vehicle and place jack stands under frame side rails. Position a jack under the rear axle housing and raise slightly to support axle assembly. 2. Remove rear wheels. 3. Disconnect shock absorbers from anchor plates. 4. Scribe reference marks between driveshaft and pinion flange for use during reassembly, then disconnect driveshaft and position aside. 5. Disconnect brake lines from junction block and backing plates, then remove junction block attaching bolt and position aside. 6. Remove backing plates. 7. Remove U-bolts and anchor plates, Fig. 1. 8. Disconnect vent hose from axle housing. 9. Lower rear axle assembly, then remove lower spring shackle bolts. 10. Remove rear axle assembly. 11. Reverse procedure to install. Tighten shock absorber nut, U-bolt nuts and lower spring shackle bolts to specification. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Drain Plug, Differential > Component Information > Locations Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Fluid - Differential > Component Information > Technical Service Bulletins > Drivetrain - Recommended Axle Lubricant Fluid - Differential: Technical Service Bulletins Drivetrain - Recommended Axle Lubricant File In Section: 0 - General Information Bulletin No.: 76-02-02A Date: October, 1998 INFORMATION Subject: Recommended Axle Lubricant Models: 1999 and Prior Rear Wheel Drive Passenger Cars, Light and Medium Duty Trucks, and Four Wheel Drive Vehicles This bulletin is being revised to add the 1998 and 1999 Model Years and add Vehicle Line and Recommended Axle Lubricant Information. Please discard Corporate Bulletin Number 76-02-02 (Section 0 - General Information). The following tables provide the latest information on recommended axle lubricant. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Fluid - Differential > Component Information > Technical Service Bulletins > Drivetrain - Recommended Axle Lubricant > Page 5291 Parts Information Parts are currently available from GMSPO. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Fluid - Differential > Component Information > Specifications > Capacity Specifications Fluid - Differential: Capacity Specifications Rear Axle Oil, Pints [05] ...................................................................................................................... ............................................................................. 3.9 [05] Front drive axle, 2.6 pts. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Fluid - Differential > Component Information > Specifications > Capacity Specifications > Page 5294 Fluid - Differential: Fluid Type Specifications Front Axle SAE 80W-90 GL5 Gear Lubricant. GM P/N 1052271 Locking Differential (G80) This Article has been updated by TSB # 76-02-02A. SAE 80W-90 GL5 Gear Lubricant, GM P/N 1052271. Do not use limited slip additive. Non-Locking Differential Rear Axle with Non Limited Slip or Non Locking Differentials HD-3500 Trucks (Dana 11.0 axles) Recommended Lubricant - GM P/N 12346140, SAE 75W-140 Synthetic Gear Lubricant. 1999 GMT 800 Trucks Recommended Lubricant - GM P/N 12378261, SAE 75W-90 Synthetic Axle Lubricant. All other non limited-slip or non locking differentials including B and D cars, S/T, M/L, G, P, and C/K trucks except GMT 800 trucks, and as noted above. Recommended Lubricant - GM P/N 1052271 or an SAE 80W90 GL-5 Gear Lubricant. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Pinion Bearing, Differential > Component Information > Adjustments > Aluminum Case Front Drive Axle Pinion Bearing: Adjustments Aluminum Case Front Drive Axle Fig. 22 Setting Pinion Depth The drive pinions used are ``nominal'' or ``zero'' pinions and are not marked. The thickness of the shim used will be equal to the dial indicator gauge reading. 1. Lubricate inner and outer pinion bearings with axle lubricant, then install pinion shim setting gauge tool No. J-33838 or equivalent while holding bearings in place, Fig. 22. 2. Set preload of pinion bearings to 15-25 inch lbs. by tightening mounting bolt on tool while holding end of tool shaft with a wrench. 3. Zero the dial indicator, then install it on pinion shim setting gauge tool No. J-33838 or equivalent. Push dial indicator down until needle rotates approximately three turns clockwise and tighten the dial indicator in this position. 4. Position button of pinion shim setting gauge tool No. J-33838 or equivalent in differential bearing bore, then rotate tool back and forth until lowest point of bore is indicated on dial indicator. 5. Zero the dial indicator, then repeat rocking action of tool to verify zero setting. 6. When zero setting has been obtained and verified, move tool button out of bearing bore and record the dial indicator reading. Select shim equal to this reading. 7. Install shim on drive pinion, then install pinion in carrier. Refer to Differential Carrier / Service and Repair. See: Differential Carrier/Service and Repair Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Pinion Bearing, Differential > Component Information > Adjustments > Aluminum Case Front Drive Axle > Page 5299 Pinion Bearing: Adjustments Borg Warner 2 - Pinion Fig. 8 Pinion gauge plate installation Fig. 9 Checking pinion depth Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Pinion Bearing, Differential > Component Information > Adjustments > Aluminum Case Front Drive Axle > Page 5300 Fig. 10 Pinion depth gauge tool installation. Corvette Adjustment 1. Install pinion bearing races in housing using a suitable driver. 2. Lubricate pinion bearings and install bearings in races. 3. Mount depth gauging jig in housing, Fig. 8, noting the following: a. Assemble gauge plate onto preload stud. b. Hold pinion bearings in position, insert stud through rear bearing and pilot and front bearing and pilot, then install retaining nut and tighten nut until snug. c. Rotate tool to ensure bearings are properly seated. d. Hold preload stud and tighten nut until 20 inch lbs. of torque, which is required to rotate stud. To prevent damage to bearing, tighten nut in small increments, checking rotating torque after each adjustment. e. Mount side bearing discs on arbor, using step for disc that corresponds to base of housing. f. Mount arbor and plunger assembly in housing, ensuring side bearing discs are properly seated, install bearing caps and tighten cap bolts to prevent bearing discs from moving, Fig. 9. 4. Mount dial indicator on arbor stud with indicator contact button bearing against top of arbor plunger. 5. Preload indicator 3/4 revolution and secure to arbor mounting stud in this position. 6. Place arbor plunger on gauge plate, rotating plate as needed so that plunger rests directly on button corresponding to ring gear size. 7. Slowly rock plunger rod back and forth across button while observing dial indicator. 8. At point on button where indicator registers greatest deflection, zero dial indicator. Perform steps 7 and 8 several times to ensure correct setting. 9. Once verified zero reading is obtained, swing plunger aside until it is clear of gauge plate button and record dial indicator reading. Indicator will now read required pinion depth shim thickness for a ``nominal'' pinion. 10. Inspect rear face of drive pinion to be installed for a pinion code number. This number indicates in thousandths of an inch necessary modification of pinion shim thickness obtained in step 9. 11. Select pinion depth adjusting shim as follows: a. If pinion is stamped with a plus (+) number, add that number of thousandths to dimension obtained in step 9. b. If pinion is stamped with a minus ( - ) number, subtract that many thousandths from dimension obtained in step 9. c. If pinion is not stamped with plus or minus number, dimension obtained in step 9 is correct shim thickness. 12. Remove gauging tools and pinion bearings from housing, noting installation position of bearings. Installation 1. Install selected shim onto pinion shaft, lubricate rear pinion bearing with specified axle lubricant, then press rear bearing onto pinion using suitable spacers. 2. Install new collapsible spacer onto pinion shaft, then insert pinion assembly into housing. 3. Lubricate front pinion bearing, install bearing into housing and tap bearing over pinion shaft with a drift while assistant holds pinion in place. Old pinion nut and a large washer can be used to seat front bearing on pinion, but care must be taken not to collapse spacer if this method is used. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Pinion Bearing, Differential > Component Information > Adjustments > Aluminum Case Front Drive Axle > Page 5301 4. Install new pinion seal in housing, coat seal lips with grease, then mount driveshaft yoke on pinion shaft, lightly tapping yoke until several pinion shaft threads protrude from yoke. 5. Coat rear of pinion washer with suitable sealer, then install washer and new pinion nut. 6. Hold driveshaft yoke with suitable tool, then alternately tighten pinion nut and rotate pinion until endplay is reduced to zero. 7. When endplay is reduced to zero, check pinion bearing preload using a torque wrench. 8. Continue tightening pinion nut in small increments until 35-40 inch lbs. of bearing preload is obtained with new bearings or 20-25 inch lbs. of bearing preload is obtained with used bearings, rotating pinion and checking preload after each adjustment. Exceeding preload specification will compress collapsible spacer too far, requiring replacement of spacer. If preload specification is exceeded, spacer must be replaced and adjustment procedure must be repeated. Do not loosen pinion nut to reduce preload. 4 - Pinion Fig. 5 Drive pinion & bearing shim adjustment 1. Install front pinion bearing cup in carrier using tool J-7817 or equivalent. 2. Install spacer (E) into carrier bore, Fig. 5. 3. Slide rear pinion bearing and cap (F) onto thru bolt (D) and rear bearing into axle housing. 4. Install thru bolt (D), rear bearing and cap (F) into axle housing. 5. Assemble front bearing cone (A) and spacer (B) onto thru bolt. 6. Rotate nut and shaft while increasing torque on nut until a rotational torque of 15-22 inch lbs. is obtained. Rotate thru bolt back and forth when tightening nut to properly seat bearing. 7. Install discs on thru bolt assembly as shown in Fig. 5. Position carrier so dial indicator contact rod is directly over gauging area of gauge plate J-35118-2. Discs must be fully seated in side bearing bores. 8. Install bearing caps over gauge shaft discs, then the cap attaching bolts. torque attaching bolts to 40 ft. lbs. 9. With dial indicator rod contacting gauging area of J-35118-2, rock gauge shaft back and forth until dial indicator measures the greatest deflection, then zero dial indicator. 10. Rotate gauge shaft until shaft does not contact gauge plate, then note measurement. 11. Select correct pinion shim as follows: a. If reusing production pinion, and pinion is marked with a ``+,'' correct shim will have a thickness equal to gauge reading minus amount specified on pinion. b. If reusing production pinion, and pinion is marked with a `` - ,'' correct shim will have a thickness equal to gauge reading plus amount specified on pinion. c. If using a production or service pinion which has no marking, correct shim will have a thickness equal to gauge reading. 12. Install selected pinion shim into carrier, then press rear pinion bearing cup into carrier using tool J-5590 or equivalent. 13. Press rear pinion bearing onto pinion using a bearing installation tool, then install pinion in carrier. 14. Install collapsible spacer and front bearing onto pinion while supporting pinion under head. 15. Install oil seal, companion flange and new nut on pinion, then tighten pinion nut until a rotating torque of 10-25 inch lbs. with new bearings or 5-12 inch lbs. with original bearings is obtained while rotating pinion forwards to seat bearings. 16. If preload is excessive after tightening pinion nut, replace collapsible spacer and repeat steps 14 and 15. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Pinion Bearing, Differential > Component Information > Adjustments > Aluminum Case Front Drive Axle > Page 5302 Pinion Bearing: Adjustments Corporate and Eaton 7 1/2 - 8 5/8 Inch Ring Gear PINION DEPTH ADJUSTMENT If original ring gear and pinion assembly and rear pinion bearing are to be reused, original depth adjusting shim can be used. However, if ring gear and pinion or rear pinion bearing are replaced, pinion depth must be adjusted using following procedures. 1. Install pinion bearing races to be used in housing using suitable driver. 2. Lubricate pinion bearings and install bearings in races. 3. Mount depth gauging jig in housing, noting the following: Fig. 16 Pinion depth gauge tool installation. Models w/7-1/2 inch ring gear a. On models with 7 1/2 & 7 5/8 inch ring gear, use gauge assembly tool No. J-23597-01 or equivalent, Fig. 16. Follow all tool manufacturer's recommendations when installing gauge assembly. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Pinion Bearing, Differential > Component Information > Adjustments > Aluminum Case Front Drive Axle > Page 5303 Fig. 17 Pinion depth gauge tool installation. Models w/8-1/2 & 8-7/8 inch ring gear b. On models with 8 1/2 and 8 5/8 inch ring gear, use gauge assembly tool No. J-21777-01 or equivalent, Fig. 17. Follow all tool manufacturer's recommendations when installing gauge assembly. c. Assemble gauge plate onto preload stud. d. Hold pinion bearings in position, insert stud through rear bearing and pilot and front bearing and pilot, then install retaining nut and tighten nut until snug. e. Rotate tool to ensure bearings are properly seated. f. Hold preload stud and torque nut until 20 inch lbs. is required to rotate stud. Tighten nut in small increments, checking rotating torque after each adjustment, to prevent damaging bearings. g. Mount side bearing discs on arbor, using step for disc that corresponds to base of housing. h. Mount arbor and plunger assembly in housing, ensuring that side bearing discs are properly seated, install bearing caps and tighten cap bolts to prevent bearing discs from moving. 4. Mount suitable dial indicator on arbor stud with indicator contact button bearing against top of arbor plunger. 5. Preload indicator 1/2 revolution and secure to arbor mounting stud in this position. 6. Place arbor plunger on gauge plate, rotating plate as needed so that plunger rests directly on button corresponding to ring gear size. 7. Slowly rock plunger rod back and forth across button while observing dial indicator. 8. At point on button where indicator registers greatest deflection, zero dial indicator. Perform steps 7 and 8 several times to ensure correct setting. 9. Once verified zero reading is obtained, swing plunger aside until it is clear of gauge plate button and record dial indicator reading. Indicator will now read required pinion depth shim thickness for a "nominal" pinion. 10. Inspect rear face of drive pinion to be installed for a pinion code number. This number indicates in thousandths of an inch necessary modification of pinion shim thickness obtained in step 9. 11. Select pinion depth adjusting shim as follows: a. If pinion is stamped with a plus (+) number, add that number of thousandths to dimension obtained in step 9. b. If pinion is stamped with a minus (-) number, subtract that many thousandths from dimension obtained in step 9. c. If pinion is not stamped with plus or minus number, dimension obtained in step 9 is correct shim thickness. 12. Remove gauging tools and pinion bearings from housing, noting installation position of bearings. PINION INSTALLATION 1. Install selected shim onto pinion shaft, lubricate rear pinion bearing with specified axle lubricant, then press rear bearing onto pinion using suitable spacers. 2. Install new collapsible spacer onto pinion shaft, then insert pinion assembly into housing. 3. Lubricate front pinion bearing, install bearing into housing and tap bearing over pinion shaft with suitable drift while assistant holds pinion in place. Old pinion nut and suitable large washer can be used to seat front bearing on pinion, but care must be taken not to collapse spacer if this method is used. 4. Install new pinion seal in housing, coat seal lips with grease, then mount driveshaft yoke on pinion shaft, lightly tapping yoke until several pinion shaft threads protrude from yoke. 5. Coat rear of pinion washer with suitable sealer, then install washer and new pinion nut. 6. Hold driveshaft yoke with suitable tool, then alternately tighten pinion nut and rotate pinion until endplay is reduced to zero. 7. When endplay is reduced to zero, check pinion bearing preload using suitable torque wrench. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Pinion Bearing, Differential > Component Information > Adjustments > Aluminum Case Front Drive Axle > Page 5304 8. Continue tightening pinion nut in small increments until specified pinion bearing preload is obtained, rotating pinion and checking preload after each adjustment. Exceeding preload specification will compress collapsible spacer too far, requiring replacement of spacer. If preload specification is exceeded, spacer must be replaced and adjustment procedure must be repeated. Do not loosen pinion nut to reduce preload. 9 1/2 Inch Ring Gear Fig. 9 Pinion depth gauge installation PINION DEPTH, ADJUST If original ring gear and pinion assembly and rear pinion bearing are to be reused, original depth adjusting shim can be used. However, if ring gear and pinion or rear pinion bearing requires replacement, pinion depth must be adjusted using following procedures. 1. Install pinion bearing races to be used in housing using suitable driver. 2. Lubricate pinion bearings and install bearings in races. 3. Mount depth gauging jig in housing noting the following. Use gauge assembly J-21777-01, Fig. 9, or suitable equivalent. Follow all tool manufacturer's recommendations when installing gauge assembly. a. Assemble gauge plate on preload stud. b. Hold pinion bearings in position, insert stud through rear bearing and pilot, then front bearing and pilot, install retaining nut and tighten nut hand tight. c. Rotate tool to ensure that bearings are properly seated. d. Hold preload stud and tighten nut until 20 inch lbs. torque is required to rotate stud. Tighten nut in small increments, checking rotating torque after each adjustment using suitable torque wrench. e. Mount side bearing discs on arbor, using step that corresponds to base of housing. f. Mount arbor and plunger assembly in housing ensuring that side bearing discs are properly seated, install bearing caps and tighten cap bolts to prevent bearing discs from moving. 4. Mount suitable dial indicator on arbor stud with indicator contact button bearing against top of arbor plunger. 5. Preload indicator 1/2 revolution, then secure to arbor stud in this position. 6. Place arbor plunger on gauge plate, rotate plate as needed so that plunger rests directly on button corresponding to ring gear size. 7. Slowly rock plunger rod back and forth across button while observing dial indicator. 8. At point on button where indicator registers greatest deflection, zero dial indicator. Perform steps 7 and 8 several times to ensure correct setting. 9. Once verified zero setting is obtained, swing plunger aside until it is clear of gauge plate button and record dial indicator reading. Indicator will now read required pinion depth shim thickness for ``nominal'' pinion. 10. Inspect rear face of drive pinion to be installed for a pinion code number. This number indicates in thousandths of an inch necessary modification of pinion shim thickness obtained in step 9. 11. Select pinion depth adjusting shim as follows: a. If pinion is stamped with a plus (+) number, add that number of thousandths to dimension obtained in step 9. b. If pinion is stamped with a minus ( - ) number, subtract that many thousandths from dimension obtained in step 9. c. If pinion is not stamped with plus or minus number, dimension obtained in step 9 is correct shim thickness. 12. Remove gauging tool and pinion bearings from housing. DRIVE PINION, INSTALL 1. Install pinion bearing races in housing, if not previously installed, using suitable drivers to ensure that races are squarely seated. 2. Install selected shim on pinion shaft, lubricate rear pinion bearing with specified axle lubricant, then press rear bearing onto pinion using suitable spacers. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Pinion Bearing, Differential > Component Information > Adjustments > Aluminum Case Front Drive Axle > Page 5305 3. Install new collapsible spacer on pinion and insert pinion assembly into housing. 4. Lubricate front pinion bearing, install bearing in housing and tap bearing onto pinion shaft while assistant holds pinion in place. Old pinion nut and large washer can be used to draw front bearing onto pinion, but care must be taken not to collapse spacer if this method is used. 5. Install new pinion seal in housing, coat seal lips with grease, then mount driveshaft flange on pinion shaft, lightly tapping flange until several pinion shaft threads protrude. 6. Coat rear of pinion washer with suitable sealer, then install washer and new pinion nut and adjust preload to specifications. PINION BEARING PRELOAD ADJUSTMENT 1. Ensure pinion and bearings are properly installed, as outlined. 2. Hold driveshaft companion flange with suitable tool, then alternately tighten pinion nut and rotate pinion until endplay is reduced to zero. 3. Using and inch lb. torque wrench, check pinion preload by rotating pinion with wrench. Preload should be at 20-25 inch lbs. or less on new bearings or 10-15 inch lbs. on used bearings. 4. Continue tightening pinion nut in small increments until specified bearing preload is obtained, rotating pinion and checking preload after each adjustment. Exceeding preload specification will compress collapsible spacer too far, requiring replacement of spacer. If preload specification is exceeded, spacer must be replaced and adjustment procedure must be repeated. Do not loosen pinion nut to reduce preload. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Pinion Bearing, Differential > Component Information > Service and Repair > Borg Warner - 2 Pinion Pinion Bearing: Service and Repair Borg Warner - 2 Pinion 1. Scribe reference mark between drive pinion and driveshaft yoke, then hold yoke with suitable tool and remove pinion nut and yoke. If yoke shows wear in the seal-to-flange contacting surface, the yoke should be replaced. 2. Install original pinion nut a few turns on pinion shaft, then using hammer and drift, tap pinion shaft out of pinion housing. Hold gear end of pinion shaft when removing to prevent it from falling from axle housing. On Corvette models, the pinion preload shims may stick to the pinion housing or the rear bearing during removal. These shims must be collected and kept together for use during reassembly. 3. Remove and discard pinion nut and collapsible spacer. 4. If being replaced, remove front and rear bearing races from pinion housing using drift positioned in race slots and hammer. 5. If rear pinion bearing is being replaced, remove using arbor press and adapters. Measure and record thickness of shim which is found under rear bearing. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Pinion Bearing, Differential > Component Information > Service and Repair > Borg Warner - 2 Pinion > Page 5308 Pinion Bearing: Service and Repair Corporate and Eaton 7 1/2 - 8 5/8 Inch Ring Gear PINION DEPTH ADJUSTMENT If original ring gear and pinion assembly and rear pinion bearing are to be reused, original depth adjusting shim can be used. However, if ring gear and pinion or rear pinion bearing are replaced, pinion depth must be adjusted using following procedures. 1. Install pinion bearing races to be used in housing using suitable driver. 2. Lubricate pinion bearings and install bearings in races. 3. Mount depth gauging jig in housing, noting the following: Fig. 16 Pinion depth gauge tool installation. Models w/7-1/2 inch ring gear a. On models with 7 1/2 & 7 5/8 inch ring gear, use gauge assembly tool No. J-23597-01 or equivalent, Fig. 16. Follow all tool manufacturer's recommendations when installing gauge assembly. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Pinion Bearing, Differential > Component Information > Service and Repair > Borg Warner - 2 Pinion > Page 5309 Fig. 17 Pinion depth gauge tool installation. Models w/8-1/2 & 8-7/8 inch ring gear b. On models with 8 1/2 and 8 5/8 inch ring gear, use gauge assembly tool No. J-21777-01 or equivalent, Fig. 17. Follow all tool manufacturer's recommendations when installing gauge assembly. c. Assemble gauge plate onto preload stud. d. Hold pinion bearings in position, insert stud through rear bearing and pilot and front bearing and pilot, then install retaining nut and tighten nut until snug. e. Rotate tool to ensure bearings are properly seated. f. Hold preload stud and torque nut until 20 inch lbs. is required to rotate stud. Tighten nut in small increments, checking rotating torque after each adjustment, to prevent damaging bearings. g. Mount side bearing discs on arbor, using step for disc that corresponds to base of housing. h. Mount arbor and plunger assembly in housing, ensuring that side bearing discs are properly seated, install bearing caps and tighten cap bolts to prevent bearing discs from moving. 4. Mount suitable dial indicator on arbor stud with indicator contact button bearing against top of arbor plunger. 5. Preload indicator 1/2 revolution and secure to arbor mounting stud in this position. 6. Place arbor plunger on gauge plate, rotating plate as needed so that plunger rests directly on button corresponding to ring gear size. 7. Slowly rock plunger rod back and forth across button while observing dial indicator. 8. At point on button where indicator registers greatest deflection, zero dial indicator. Perform steps 7 and 8 several times to ensure correct setting. 9. Once verified zero reading is obtained, swing plunger aside until it is clear of gauge plate button and record dial indicator reading. Indicator will now read required pinion depth shim thickness for a "nominal" pinion. 10. Inspect rear face of drive pinion to be installed for a pinion code number. This number indicates in thousandths of an inch necessary modification of pinion shim thickness obtained in step 9. 11. Select pinion depth adjusting shim as follows: a. If pinion is stamped with a plus (+) number, add that number of thousandths to dimension obtained in step 9. b. If pinion is stamped with a minus (-) number, subtract that many thousandths from dimension obtained in step 9. c. If pinion is not stamped with plus or minus number, dimension obtained in step 9 is correct shim thickness. 12. Remove gauging tools and pinion bearings from housing, noting installation position of bearings. PINION INSTALLATION 1. Install selected shim onto pinion shaft, lubricate rear pinion bearing with specified axle lubricant, then press rear bearing onto pinion using suitable spacers. 2. Install new collapsible spacer onto pinion shaft, then insert pinion assembly into housing. 3. Lubricate front pinion bearing, install bearing into housing and tap bearing over pinion shaft with suitable drift while assistant holds pinion in place. Old pinion nut and suitable large washer can be used to seat front bearing on pinion, but care must be taken not to collapse spacer if this method is used. 4. Install new pinion seal in housing, coat seal lips with grease, then mount driveshaft yoke on pinion shaft, lightly tapping yoke until several pinion shaft threads protrude from yoke. 5. Coat rear of pinion washer with suitable sealer, then install washer and new pinion nut. 6. Hold driveshaft yoke with suitable tool, then alternately tighten pinion nut and rotate pinion until endplay is reduced to zero. 7. When endplay is reduced to zero, check pinion bearing preload using suitable torque wrench. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Pinion Bearing, Differential > Component Information > Service and Repair > Borg Warner - 2 Pinion > Page 5310 8. Continue tightening pinion nut in small increments until specified pinion bearing preload is obtained, rotating pinion and checking preload after each adjustment. Exceeding preload specification will compress collapsible spacer too far, requiring replacement of spacer. If preload specification is exceeded, spacer must be replaced and adjustment procedure must be repeated. Do not loosen pinion nut to reduce preload. 9 1/2 Inch Ring Gear PINION DEPTH ADJUSTMENT Fig. 9 Pinion Depth Gauge Installation If original ring gear and pinion assembly and rear pinion bearing are to be reused, original depth adjusting shim can be used. However, if ring gear and pinion or rear pinion bearing requires replacement, pinion depth must be adjusted using following procedures. 1. Install pinion bearing races to be used in housing using suitable driver. 2. Lubricate pinion bearings and install bearings in races. 3. Mount depth gauging jig in housing noting the following. Use gauge assembly tool No. J-21777-01, Fig. 9, or suitable equivalent. Follow all tool manufacturer's recommendations when installing gauge assembly. a. Assemble gauge plate on preload stud. b. Hold pinion bearings in position, insert stud through rear bearing and pilot, then front bearing and pilot, install retaining nut and tighten nut hand tight. c. Rotate tool to ensure that bearings are properly seated. d. Hold preload stud and tighten nut until 20 inch lbs. torque is required to rotate stud. Tighten nut in small increments, checking rotating torque after each adjustment using suitable torque wrench. e. Mount side bearing discs on arbor, using step that corresponds to base of housing. f. Mount arbor and plunger assembly in housing ensuring that side bearing discs are properly seated, install bearing caps and tighten cap bolts to prevent bearing discs from moving. 4. Mount suitable dial indicator on arbor stud with indicator contact button bearing against top of arbor plunger. 5. Preload indicator 1/2 revolution, then secure to arbor stud in this position. 6. Place arbor plunger on gauge plate, rotate plate as needed so that plunger rests directly on button corresponding to ring gear size. 7. Slowly rock plunger rod back and forth across button while observing dial indicator. 8. At point on button where indicator registers greatest deflection, zero dial indicator. Perform steps 7 and 8 several times to ensure correct setting. 9. Once verified zero setting is obtained, swing plunger aside until it is clear of gauge plate button and record dial indicator reading. Indicator will now read required pinion depth shim thickness for ``nominal'' pinion. 10. Inspect rear face of drive pinion to be installed for a pinion code number. This number indicates in thousandths of an inch necessary modification of pinion shim thickness obtained in step 9. 11. Select pinion depth adjusting shim as follows: a. If pinion is stamped with a plus (+) number, add that number of thousandths to dimension obtained in step 9. b. If pinion is stamped with a minus (-) number, subtract that many thousandths from dimension obtained in step 9. c. If pinion is not stamped with plus or minus number, dimension obtained in step 9 is correct shim thickness. 12. Remove gauging tool and pinion bearings from housing. DRIVE PINION INSTALLATION 1. Install pinion bearing races in housing, if not previously installed, using suitable drivers to ensure that races are squarely seated. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Pinion Bearing, Differential > Component Information > Service and Repair > Borg Warner - 2 Pinion > Page 5311 2. Install selected shim on pinion shaft, lubricate rear pinion bearing with specified axle lubricant, then press rear bearing onto pinion using suitable spacers. 3. Install new collapsible spacer on pinion and insert pinion assembly into housing. 4. Lubricate front pinion bearing, install bearing in housing and tap bearing onto pinion shaft while assistant holds pinion in place. Old pinion nut and large washer can be used to draw front bearing onto pinion, but care must be taken not to collapse spacer if this method is used. 5. Install new pinion seal in housing, coat seal lips with grease, then mount driveshaft flange on pinion shaft, lightly tapping flange until several pinion shaft threads protrude. 6. Coat rear of pinion washer with suitable sealer, then install washer and new pinion nut and adjust preload to specifications. PINION BEARING PRELOAD ADJUSTMENT 1. Ensure that pinion and bearings are properly installed, as outlined. 2. Hold driveshaft companion flange with suitable tool, then alternately tighten pinion nut and rotate pinion until endplay is reduced to zero. 3. When endplay is reduced to zero, check pinion bearing preload by rotating pinion with suitable torque wrench. 4. Continue tightening pinion nut in small increments until specified bearing preload is obtained, rotating pinion and checking preload after each adjustment. Exceeding preload specification will compress collapsible spacer too far, requiring replacement of spacer. If preload specification is exceeded, spacer must be replaced and adjustment procedure must be repeated. Do not loosen pinion nut to reduce preload. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Pinion Gear, Differential > Component Information > Adjustments > Aluminum Case Front Drive Axle Pinion Gear: Adjustments Aluminum Case Front Drive Axle Fig. 22 Setting Pinion Depth The drive pinions used are ``nominal'' or ``zero'' pinions and are not marked. The thickness of the shim used will be equal to the dial indicator gauge reading. 1. Lubricate inner and outer pinion bearings with axle lubricant, then install pinion shim setting gauge tool No. J-33838 or equivalent while holding bearings in place, Fig. 22. 2. Set preload of pinion bearings to 15-25 inch lbs. by tightening mounting bolt on tool while holding end of tool shaft with a wrench. 3. Zero the dial indicator, then install it on pinion shim setting gauge tool No. J-33838 or equivalent. Push dial indicator down until needle rotates approximately three turns clockwise and tighten the dial indicator in this position. 4. Position button of pinion shim setting gauge tool No. J-33838 or equivalent in differential bearing bore, then rotate tool back and forth until lowest point of bore is indicated on dial indicator. 5. Zero the dial indicator, then repeat rocking action of tool to verify zero setting. 6. When zero setting has been obtained and verified, move tool button out of bearing bore and record the dial indicator reading. Select shim equal to this reading. 7. Install shim on drive pinion, then install pinion in carrier. Refer to Differential Carrier / Service and Repair. See: Differential Carrier/Service and Repair Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Pinion Gear, Differential > Component Information > Adjustments > Aluminum Case Front Drive Axle > Page 5316 Pinion Gear: Adjustments Borg Warner 2 - Pinion Fig. 8 Pinion gauge plate installation Fig. 9 Checking pinion depth Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Pinion Gear, Differential > Component Information > Adjustments > Aluminum Case Front Drive Axle > Page 5317 Fig. 10 Pinion depth gauge tool installation. Corvette Adjustment 1. Install pinion bearing races in housing using a suitable driver. 2. Lubricate pinion bearings and install bearings in races. 3. Mount depth gauging jig in housing, Fig. 8, noting the following: a. Assemble gauge plate onto preload stud. b. Hold pinion bearings in position, insert stud through rear bearing and pilot and front bearing and pilot, then install retaining nut and tighten nut until snug. c. Rotate tool to ensure bearings are properly seated. d. Hold preload stud and tighten nut until 20 inch lbs. of torque, which is required to rotate stud. To prevent damage to bearing, tighten nut in small increments, checking rotating torque after each adjustment. e. Mount side bearing discs on arbor, using step for disc that corresponds to base of housing. f. Mount arbor and plunger assembly in housing, ensuring side bearing discs are properly seated, install bearing caps and tighten cap bolts to prevent bearing discs from moving, Fig. 9. 4. Mount dial indicator on arbor stud with indicator contact button bearing against top of arbor plunger. 5. Preload indicator 3/4 revolution and secure to arbor mounting stud in this position. 6. Place arbor plunger on gauge plate, rotating plate as needed so that plunger rests directly on button corresponding to ring gear size. 7. Slowly rock plunger rod back and forth across button while observing dial indicator. 8. At point on button where indicator registers greatest deflection, zero dial indicator. Perform steps 7 and 8 several times to ensure correct setting. 9. Once verified zero reading is obtained, swing plunger aside until it is clear of gauge plate button and record dial indicator reading. Indicator will now read required pinion depth shim thickness for a ``nominal'' pinion. 10. Inspect rear face of drive pinion to be installed for a pinion code number. This number indicates in thousandths of an inch necessary modification of pinion shim thickness obtained in step 9. 11. Select pinion depth adjusting shim as follows: a. If pinion is stamped with a plus (+) number, add that number of thousandths to dimension obtained in step 9. b. If pinion is stamped with a minus ( - ) number, subtract that many thousandths from dimension obtained in step 9. c. If pinion is not stamped with plus or minus number, dimension obtained in step 9 is correct shim thickness. 12. Remove gauging tools and pinion bearings from housing, noting installation position of bearings. Installation 1. Install selected shim onto pinion shaft, lubricate rear pinion bearing with specified axle lubricant, then press rear bearing onto pinion using suitable spacers. 2. Install new collapsible spacer onto pinion shaft, then insert pinion assembly into housing. 3. Lubricate front pinion bearing, install bearing into housing and tap bearing over pinion shaft with a drift while assistant holds pinion in place. Old pinion nut and a large washer can be used to seat front bearing on pinion, but care must be taken not to collapse spacer if this method is used. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Pinion Gear, Differential > Component Information > Adjustments > Aluminum Case Front Drive Axle > Page 5318 4. Install new pinion seal in housing, coat seal lips with grease, then mount driveshaft yoke on pinion shaft, lightly tapping yoke until several pinion shaft threads protrude from yoke. 5. Coat rear of pinion washer with suitable sealer, then install washer and new pinion nut. 6. Hold driveshaft yoke with suitable tool, then alternately tighten pinion nut and rotate pinion until endplay is reduced to zero. 7. When endplay is reduced to zero, check pinion bearing preload using a torque wrench. 8. Continue tightening pinion nut in small increments until 35-40 inch lbs. of bearing preload is obtained with new bearings or 20-25 inch lbs. of bearing preload is obtained with used bearings, rotating pinion and checking preload after each adjustment. Exceeding preload specification will compress collapsible spacer too far, requiring replacement of spacer. If preload specification is exceeded, spacer must be replaced and adjustment procedure must be repeated. Do not loosen pinion nut to reduce preload. 4 - Pinion Fig. 5 Drive pinion & bearing shim adjustment 1. Install front pinion bearing cup in carrier using tool J-7817 or equivalent. 2. Install spacer (E) into carrier bore, Fig. 5. 3. Slide rear pinion bearing and cap (F) onto thru bolt (D) and rear bearing into axle housing. 4. Install thru bolt (D), rear bearing and cap (F) into axle housing. 5. Assemble front bearing cone (A) and spacer (B) onto thru bolt. 6. Rotate nut and shaft while increasing torque on nut until a rotational torque of 15-22 inch lbs. is obtained. Rotate thru bolt back and forth when tightening nut to properly seat bearing. 7. Install discs on thru bolt assembly as shown in Fig. 5. Position carrier so dial indicator contact rod is directly over gauging area of gauge plate J-35118-2. Discs must be fully seated in side bearing bores. 8. Install bearing caps over gauge shaft discs, then the cap attaching bolts. torque attaching bolts to 40 ft. lbs. 9. With dial indicator rod contacting gauging area of J-35118-2, rock gauge shaft back and forth until dial indicator measures the greatest deflection, then zero dial indicator. 10. Rotate gauge shaft until shaft does not contact gauge plate, then note measurement. 11. Select correct pinion shim as follows: a. If reusing production pinion, and pinion is marked with a ``+,'' correct shim will have a thickness equal to gauge reading minus amount specified on pinion. b. If reusing production pinion, and pinion is marked with a `` - ,'' correct shim will have a thickness equal to gauge reading plus amount specified on pinion. c. If using a production or service pinion which has no marking, correct shim will have a thickness equal to gauge reading. 12. Install selected pinion shim into carrier, then press rear pinion bearing cup into carrier using tool J-5590 or equivalent. 13. Press rear pinion bearing onto pinion using a bearing installation tool, then install pinion in carrier. 14. Install collapsible spacer and front bearing onto pinion while supporting pinion under head. 15. Install oil seal, companion flange and new nut on pinion, then tighten pinion nut until a rotating torque of 10-25 inch lbs. with new bearings or 5-12 inch lbs. with original bearings is obtained while rotating pinion forwards to seat bearings. 16. If preload is excessive after tightening pinion nut, replace collapsible spacer and repeat steps 14 and 15. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Pinion Gear, Differential > Component Information > Adjustments > Aluminum Case Front Drive Axle > Page 5319 Pinion Gear: Adjustments Corporate and Eaton 7 1/2 - 8 5/8 Inch Ring Gear PINION DEPTH ADJUSTMENT If original ring gear and pinion assembly and rear pinion bearing are to be reused, original depth adjusting shim can be used. However, if ring gear and pinion or rear pinion bearing are replaced, pinion depth must be adjusted using following procedures. 1. Install pinion bearing races to be used in housing using suitable driver. 2. Lubricate pinion bearings and install bearings in races. 3. Mount depth gauging jig in housing, noting the following: Fig. 16 Pinion depth gauge tool installation. Models w/7-1/2 inch ring gear a. On models with 7 1/2 & 7 5/8 inch ring gear, use gauge assembly tool No. J-23597-01 or equivalent, Fig. 16. Follow all tool manufacturer's recommendations when installing gauge assembly. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Pinion Gear, Differential > Component Information > Adjustments > Aluminum Case Front Drive Axle > Page 5320 Fig. 17 Pinion depth gauge tool installation. Models w/8-1/2 & 8-7/8 inch ring gear b. On models with 8 1/2 and 8 5/8 inch ring gear, use gauge assembly tool No. J-21777-01 or equivalent, Fig. 17. Follow all tool manufacturer's recommendations when installing gauge assembly. c. Assemble gauge plate onto preload stud. d. Hold pinion bearings in position, insert stud through rear bearing and pilot and front bearing and pilot, then install retaining nut and tighten nut until snug. e. Rotate tool to ensure bearings are properly seated. f. Hold preload stud and torque nut until 20 inch lbs. is required to rotate stud. Tighten nut in small increments, checking rotating torque after each adjustment, to prevent damaging bearings. g. Mount side bearing discs on arbor, using step for disc that corresponds to base of housing. h. Mount arbor and plunger assembly in housing, ensuring that side bearing discs are properly seated, install bearing caps and tighten cap bolts to prevent bearing discs from moving. 4. Mount suitable dial indicator on arbor stud with indicator contact button bearing against top of arbor plunger. 5. Preload indicator 1/2 revolution and secure to arbor mounting stud in this position. 6. Place arbor plunger on gauge plate, rotating plate as needed so that plunger rests directly on button corresponding to ring gear size. 7. Slowly rock plunger rod back and forth across button while observing dial indicator. 8. At point on button where indicator registers greatest deflection, zero dial indicator. Perform steps 7 and 8 several times to ensure correct setting. 9. Once verified zero reading is obtained, swing plunger aside until it is clear of gauge plate button and record dial indicator reading. Indicator will now read required pinion depth shim thickness for a "nominal" pinion. 10. Inspect rear face of drive pinion to be installed for a pinion code number. This number indicates in thousandths of an inch necessary modification of pinion shim thickness obtained in step 9. 11. Select pinion depth adjusting shim as follows: a. If pinion is stamped with a plus (+) number, add that number of thousandths to dimension obtained in step 9. b. If pinion is stamped with a minus (-) number, subtract that many thousandths from dimension obtained in step 9. c. If pinion is not stamped with plus or minus number, dimension obtained in step 9 is correct shim thickness. 12. Remove gauging tools and pinion bearings from housing, noting installation position of bearings. PINION INSTALLATION 1. Install selected shim onto pinion shaft, lubricate rear pinion bearing with specified axle lubricant, then press rear bearing onto pinion using suitable spacers. 2. Install new collapsible spacer onto pinion shaft, then insert pinion assembly into housing. 3. Lubricate front pinion bearing, install bearing into housing and tap bearing over pinion shaft with suitable drift while assistant holds pinion in place. Old pinion nut and suitable large washer can be used to seat front bearing on pinion, but care must be taken not to collapse spacer if this method is used. 4. Install new pinion seal in housing, coat seal lips with grease, then mount driveshaft yoke on pinion shaft, lightly tapping yoke until several pinion shaft threads protrude from yoke. 5. Coat rear of pinion washer with suitable sealer, then install washer and new pinion nut. 6. Hold driveshaft yoke with suitable tool, then alternately tighten pinion nut and rotate pinion until endplay is reduced to zero. 7. When endplay is reduced to zero, check pinion bearing preload using suitable torque wrench. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Pinion Gear, Differential > Component Information > Adjustments > Aluminum Case Front Drive Axle > Page 5321 8. Continue tightening pinion nut in small increments until specified pinion bearing preload is obtained, rotating pinion and checking preload after each adjustment. Exceeding preload specification will compress collapsible spacer too far, requiring replacement of spacer. If preload specification is exceeded, spacer must be replaced and adjustment procedure must be repeated. Do not loosen pinion nut to reduce preload. 9 1/2 Inch Ring Gear Fig. 9 Pinion depth gauge installation PINION DEPTH, ADJUST If original ring gear and pinion assembly and rear pinion bearing are to be reused, original depth adjusting shim can be used. However, if ring gear and pinion or rear pinion bearing requires replacement, pinion depth must be adjusted using following procedures. 1. Install pinion bearing races to be used in housing using suitable driver. 2. Lubricate pinion bearings and install bearings in races. 3. Mount depth gauging jig in housing noting the following. Use gauge assembly J-21777-01, Fig. 9, or suitable equivalent. Follow all tool manufacturer's recommendations when installing gauge assembly. a. Assemble gauge plate on preload stud. b. Hold pinion bearings in position, insert stud through rear bearing and pilot, then front bearing and pilot, install retaining nut and tighten nut hand tight. c. Rotate tool to ensure that bearings are properly seated. d. Hold preload stud and tighten nut until 20 inch lbs. torque is required to rotate stud. Tighten nut in small increments, checking rotating torque after each adjustment using suitable torque wrench. e. Mount side bearing discs on arbor, using step that corresponds to base of housing. f. Mount arbor and plunger assembly in housing ensuring that side bearing discs are properly seated, install bearing caps and tighten cap bolts to prevent bearing discs from moving. 4. Mount suitable dial indicator on arbor stud with indicator contact button bearing against top of arbor plunger. 5. Preload indicator 1/2 revolution, then secure to arbor stud in this position. 6. Place arbor plunger on gauge plate, rotate plate as needed so that plunger rests directly on button corresponding to ring gear size. 7. Slowly rock plunger rod back and forth across button while observing dial indicator. 8. At point on button where indicator registers greatest deflection, zero dial indicator. Perform steps 7 and 8 several times to ensure correct setting. 9. Once verified zero setting is obtained, swing plunger aside until it is clear of gauge plate button and record dial indicator reading. Indicator will now read required pinion depth shim thickness for ``nominal'' pinion. 10. Inspect rear face of drive pinion to be installed for a pinion code number. This number indicates in thousandths of an inch necessary modification of pinion shim thickness obtained in step 9. 11. Select pinion depth adjusting shim as follows: a. If pinion is stamped with a plus (+) number, add that number of thousandths to dimension obtained in step 9. b. If pinion is stamped with a minus ( - ) number, subtract that many thousandths from dimension obtained in step 9. c. If pinion is not stamped with plus or minus number, dimension obtained in step 9 is correct shim thickness. 12. Remove gauging tool and pinion bearings from housing. DRIVE PINION, INSTALL 1. Install pinion bearing races in housing, if not previously installed, using suitable drivers to ensure that races are squarely seated. 2. Install selected shim on pinion shaft, lubricate rear pinion bearing with specified axle lubricant, then press rear bearing onto pinion using suitable spacers. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Pinion Gear, Differential > Component Information > Adjustments > Aluminum Case Front Drive Axle > Page 5322 3. Install new collapsible spacer on pinion and insert pinion assembly into housing. 4. Lubricate front pinion bearing, install bearing in housing and tap bearing onto pinion shaft while assistant holds pinion in place. Old pinion nut and large washer can be used to draw front bearing onto pinion, but care must be taken not to collapse spacer if this method is used. 5. Install new pinion seal in housing, coat seal lips with grease, then mount driveshaft flange on pinion shaft, lightly tapping flange until several pinion shaft threads protrude. 6. Coat rear of pinion washer with suitable sealer, then install washer and new pinion nut and adjust preload to specifications. PINION BEARING PRELOAD ADJUSTMENT 1. Ensure pinion and bearings are properly installed, as outlined. 2. Hold driveshaft companion flange with suitable tool, then alternately tighten pinion nut and rotate pinion until endplay is reduced to zero. 3. Using and inch lb. torque wrench, check pinion preload by rotating pinion with wrench. Preload should be at 20-25 inch lbs. or less on new bearings or 10-15 inch lbs. on used bearings. 4. Continue tightening pinion nut in small increments until specified bearing preload is obtained, rotating pinion and checking preload after each adjustment. Exceeding preload specification will compress collapsible spacer too far, requiring replacement of spacer. If preload specification is exceeded, spacer must be replaced and adjustment procedure must be repeated. Do not loosen pinion nut to reduce preload. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Pinion Gear, Differential > Component Information > Service and Repair > Borg Warner - 2 Pinion Pinion Gear: Service and Repair Borg Warner - 2 Pinion 1. Scribe reference mark between drive pinion and driveshaft yoke, then hold yoke with suitable tool and remove pinion nut and yoke. If yoke shows wear in the seal-to-flange contacting surface, the yoke should be replaced. 2. Install original pinion nut a few turns on pinion shaft, then using hammer and drift, tap pinion shaft out of pinion housing. Hold gear end of pinion shaft when removing to prevent it from falling from axle housing. On Corvette models, the pinion preload shims may stick to the pinion housing or the rear bearing during removal. These shims must be collected and kept together for use during reassembly. 3. Remove and discard pinion nut and collapsible spacer. 4. If being replaced, remove front and rear bearing races from pinion housing using drift positioned in race slots and hammer. 5. If rear pinion bearing is being replaced, remove using arbor press and adapters. Measure and record thickness of shim which is found under rear bearing. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Pinion Gear, Differential > Component Information > Service and Repair > Borg Warner - 2 Pinion > Page 5325 Pinion Gear: Service and Repair Corporate and Eaton 7 1/2 - 8 5/8 Inch Ring Gear PINION DEPTH ADJUSTMENT If original ring gear and pinion assembly and rear pinion bearing are to be reused, original depth adjusting shim can be used. However, if ring gear and pinion or rear pinion bearing are replaced, pinion depth must be adjusted using following procedures. 1. Install pinion bearing races to be used in housing using suitable driver. 2. Lubricate pinion bearings and install bearings in races. 3. Mount depth gauging jig in housing, noting the following: Fig. 16 Pinion depth gauge tool installation. Models w/7-1/2 inch ring gear a. On models with 7 1/2 & 7 5/8 inch ring gear, use gauge assembly tool No. J-23597-01 or equivalent, Fig. 16. Follow all tool manufacturer's recommendations when installing gauge assembly. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Pinion Gear, Differential > Component Information > Service and Repair > Borg Warner - 2 Pinion > Page 5326 Fig. 17 Pinion depth gauge tool installation. Models w/8-1/2 & 8-7/8 inch ring gear b. On models with 8 1/2 and 8 5/8 inch ring gear, use gauge assembly tool No. J-21777-01 or equivalent, Fig. 17. Follow all tool manufacturer's recommendations when installing gauge assembly. c. Assemble gauge plate onto preload stud. d. Hold pinion bearings in position, insert stud through rear bearing and pilot and front bearing and pilot, then install retaining nut and tighten nut until snug. e. Rotate tool to ensure bearings are properly seated. f. Hold preload stud and torque nut until 20 inch lbs. is required to rotate stud. Tighten nut in small increments, checking rotating torque after each adjustment, to prevent damaging bearings. g. Mount side bearing discs on arbor, using step for disc that corresponds to base of housing. h. Mount arbor and plunger assembly in housing, ensuring that side bearing discs are properly seated, install bearing caps and tighten cap bolts to prevent bearing discs from moving. 4. Mount suitable dial indicator on arbor stud with indicator contact button bearing against top of arbor plunger. 5. Preload indicator 1/2 revolution and secure to arbor mounting stud in this position. 6. Place arbor plunger on gauge plate, rotating plate as needed so that plunger rests directly on button corresponding to ring gear size. 7. Slowly rock plunger rod back and forth across button while observing dial indicator. 8. At point on button where indicator registers greatest deflection, zero dial indicator. Perform steps 7 and 8 several times to ensure correct setting. 9. Once verified zero reading is obtained, swing plunger aside until it is clear of gauge plate button and record dial indicator reading. Indicator will now read required pinion depth shim thickness for a "nominal" pinion. 10. Inspect rear face of drive pinion to be installed for a pinion code number. This number indicates in thousandths of an inch necessary modification of pinion shim thickness obtained in step 9. 11. Select pinion depth adjusting shim as follows: a. If pinion is stamped with a plus (+) number, add that number of thousandths to dimension obtained in step 9. b. If pinion is stamped with a minus (-) number, subtract that many thousandths from dimension obtained in step 9. c. If pinion is not stamped with plus or minus number, dimension obtained in step 9 is correct shim thickness. 12. Remove gauging tools and pinion bearings from housing, noting installation position of bearings. PINION INSTALLATION 1. Install selected shim onto pinion shaft, lubricate rear pinion bearing with specified axle lubricant, then press rear bearing onto pinion using suitable spacers. 2. Install new collapsible spacer onto pinion shaft, then insert pinion assembly into housing. 3. Lubricate front pinion bearing, install bearing into housing and tap bearing over pinion shaft with suitable drift while assistant holds pinion in place. Old pinion nut and suitable large washer can be used to seat front bearing on pinion, but care must be taken not to collapse spacer if this method is used. 4. Install new pinion seal in housing, coat seal lips with grease, then mount driveshaft yoke on pinion shaft, lightly tapping yoke until several pinion shaft threads protrude from yoke. 5. Coat rear of pinion washer with suitable sealer, then install washer and new pinion nut. 6. Hold driveshaft yoke with suitable tool, then alternately tighten pinion nut and rotate pinion until endplay is reduced to zero. 7. When endplay is reduced to zero, check pinion bearing preload using suitable torque wrench. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Pinion Gear, Differential > Component Information > Service and Repair > Borg Warner - 2 Pinion > Page 5327 8. Continue tightening pinion nut in small increments until specified pinion bearing preload is obtained, rotating pinion and checking preload after each adjustment. Exceeding preload specification will compress collapsible spacer too far, requiring replacement of spacer. If preload specification is exceeded, spacer must be replaced and adjustment procedure must be repeated. Do not loosen pinion nut to reduce preload. 9 1/2 Inch Ring Gear PINION DEPTH ADJUSTMENT Fig. 9 Pinion Depth Gauge Installation If original ring gear and pinion assembly and rear pinion bearing are to be reused, original depth adjusting shim can be used. However, if ring gear and pinion or rear pinion bearing requires replacement, pinion depth must be adjusted using following procedures. 1. Install pinion bearing races to be used in housing using suitable driver. 2. Lubricate pinion bearings and install bearings in races. 3. Mount depth gauging jig in housing noting the following. Use gauge assembly tool No. J-21777-01, Fig. 9, or suitable equivalent. Follow all tool manufacturer's recommendations when installing gauge assembly. a. Assemble gauge plate on preload stud. b. Hold pinion bearings in position, insert stud through rear bearing and pilot, then front bearing and pilot, install retaining nut and tighten nut hand tight. c. Rotate tool to ensure that bearings are properly seated. d. Hold preload stud and tighten nut until 20 inch lbs. torque is required to rotate stud. Tighten nut in small increments, checking rotating torque after each adjustment using suitable torque wrench. e. Mount side bearing discs on arbor, using step that corresponds to base of housing. f. Mount arbor and plunger assembly in housing ensuring that side bearing discs are properly seated, install bearing caps and tighten cap bolts to prevent bearing discs from moving. 4. Mount suitable dial indicator on arbor stud with indicator contact button bearing against top of arbor plunger. 5. Preload indicator 1/2 revolution, then secure to arbor stud in this position. 6. Place arbor plunger on gauge plate, rotate plate as needed so that plunger rests directly on button corresponding to ring gear size. 7. Slowly rock plunger rod back and forth across button while observing dial indicator. 8. At point on button where indicator registers greatest deflection, zero dial indicator. Perform steps 7 and 8 several times to ensure correct setting. 9. Once verified zero setting is obtained, swing plunger aside until it is clear of gauge plate button and record dial indicator reading. Indicator will now read required pinion depth shim thickness for ``nominal'' pinion. 10. Inspect rear face of drive pinion to be installed for a pinion code number. This number indicates in thousandths of an inch necessary modification of pinion shim thickness obtained in step 9. 11. Select pinion depth adjusting shim as follows: a. If pinion is stamped with a plus (+) number, add that number of thousandths to dimension obtained in step 9. b. If pinion is stamped with a minus (-) number, subtract that many thousandths from dimension obtained in step 9. c. If pinion is not stamped with plus or minus number, dimension obtained in step 9 is correct shim thickness. 12. Remove gauging tool and pinion bearings from housing. DRIVE PINION INSTALLATION 1. Install pinion bearing races in housing, if not previously installed, using suitable drivers to ensure that races are squarely seated. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Pinion Gear, Differential > Component Information > Service and Repair > Borg Warner - 2 Pinion > Page 5328 2. Install selected shim on pinion shaft, lubricate rear pinion bearing with specified axle lubricant, then press rear bearing onto pinion using suitable spacers. 3. Install new collapsible spacer on pinion and insert pinion assembly into housing. 4. Lubricate front pinion bearing, install bearing in housing and tap bearing onto pinion shaft while assistant holds pinion in place. Old pinion nut and large washer can be used to draw front bearing onto pinion, but care must be taken not to collapse spacer if this method is used. 5. Install new pinion seal in housing, coat seal lips with grease, then mount driveshaft flange on pinion shaft, lightly tapping flange until several pinion shaft threads protrude. 6. Coat rear of pinion washer with suitable sealer, then install washer and new pinion nut and adjust preload to specifications. PINION BEARING PRELOAD ADJUSTMENT 1. Ensure that pinion and bearings are properly installed, as outlined. 2. Hold driveshaft companion flange with suitable tool, then alternately tighten pinion nut and rotate pinion until endplay is reduced to zero. 3. When endplay is reduced to zero, check pinion bearing preload by rotating pinion with suitable torque wrench. 4. Continue tightening pinion nut in small increments until specified bearing preload is obtained, rotating pinion and checking preload after each adjustment. Exceeding preload specification will compress collapsible spacer too far, requiring replacement of spacer. If preload specification is exceeded, spacer must be replaced and adjustment procedure must be repeated. Do not loosen pinion nut to reduce preload. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Seals and Gaskets, Differential > System Information > Service and Repair > Front Axle Seals and Gaskets: Service and Repair Front Axle Fig. 15 Pinion Flange Retaining Bolts Fig. 16 Pinion Flange Removal Fig. 17 Pinion Seal Installation 1. Remove crossmember if necessary. 2. Remove pinion flange bolts and retainers, Fig. 15. 3. Remove propeller shaft from pinion shaft and tape bearing caps to hold in place. 4. Remove pinion shaft retaining nut and washer. Mark pinion flange, pinion shaft, and pinion retaining nut to ensure proper bearing preload. 5. Using companion flange holding tool No. J-8614-01, remove pinion flange, Fig. 16. 6. Remove pinion seal using a seal puller. 7. Reverse procedure to install, using seal installer tool No. J-33782 to install pinion oil seal, Fig. 17. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Seals and Gaskets, Differential > System Information > Service and Repair > Front Axle > Page 5333 Seals and Gaskets: Service and Repair Rear Axle REMOVE OR DISCONNECT - Tools Required: - J 8614-01 Companion Flange Holder 1. Bolts and retainers. Important: It is essential that the positions of all driveling components relative to the propeller shaft and axles be observed and accurately reference marked prior to disassembly. These components include the propeller shafts, drive axles, pinion flanges, output shafts, etc. All components must be reassembled in the exact relationship to each other as they were when removed. Specifications and torque values, as well as any measurements made prior to disassembly, must be followed. - Accurately mark the installed position of the propeller shaft and pinion flange so they can be reassembled in the same position. 2. Propeller shaft from the pinion flange. A. Use a piece of tape to hold the bearing caps. B. Secure the propeller shaft up and out of the way so as not to put unnecessary stress on the universal joints. C. Make an accurate alignment mark on the pinion stem, pinion flange, and pinion flange nut. Also record the number of exposed threads on the pinion stem for reference. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Seals and Gaskets, Differential > System Information > Service and Repair > Front Axle > Page 5334 D. Measure, using an inch-pound torque wrench, the amount of torque required to turn the pinion. Record this measurement for reassemble. This will give combined pinion bearing, seal, carrier bearing, axle bearing, and seal preload. 3. Pinion flange nut and washer. - Use J 8614-01 to hold the pinion flange. 4. Pinion flange. - Have a suitable container in place to catch lubricant. 5. Oil seal using a seal removal tool. - Do not damage the carrier. Inspect 1. Seal surface of the pinion flange for tool marks, nicks, or damage such as a groove worn by the seal. Replace the flange if necessary. 2. Carrier bore for burrs that might cause leaks around the outside of the seal. INSTALL OR CONNECT - Tools Required: J 8614-01 Companion Flange Holder - J 23911 Pinion Oil Seal Installer 1. New seal using J 23911. 2. Seal lubricant to the outside of the pinion flange and the sealing lip of the new seal. 3. Pinion flange. Important: Do not attempt to hammer the pinion flange onto the pinion stem. 4. Washer and nut. - Tighten: A. The nut on the pinion stem as close to the original marks as possible without going past the mark. Use the reference mark and the thread count as reference. B. The nut a little at a time and turn the pinion flange several times after each tightening to set the rollers. Measure - Using an inch-pound torque wrench, the torque required to rotate the pinion. Compare this with the required rotating torque recorded earlier. Continue tightening and measuring a little at a time until the same preload is achieved. Important: If the original preload torque value was less than 3 inch lbs. then reset the torque specification to 3-5 inch lbs. - Align the propeller shaft with the alignment marks made previously. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Differential Assembly > Seals and Gaskets, Differential > System Information > Service and Repair > Front Axle > Page 5335 - Use J 8614-01 to hold the pinion flange. 5. Propeller shaft to the pinion flange. 6. Bolts and retainers. - Tighten bolts to 45 Nm (33 ft. lbs.). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive Axles, Bearings and Joints > Axle Bearing > Component Information > Service and Repair > Aluminum Case Front Drive Axle Axle Bearing: Service and Repair Aluminum Case Front Drive Axle Differential Pilot Bearing Fig. 1 Exploded View Of Front Axle Refer to Fig. 1, when performing this procedure. 1. Remove shaft and tube assembly as outlined under TUBE & SHAFT ASSEMBLY. 2. Remove shim (20). 3. Using pilot bearing remover No. J34011 or equivalent, remove pilot bearing. 4. Reverse procedure to install, using bearing install No. J33842 or equivalent to install pilot bearing. Differential Output Shaft Pilot Bearing Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive Axles, Bearings and Joints > Axle Bearing > Component Information > Service and Repair > Aluminum Case Front Drive Axle > Page 5341 Fig. 1 Exploded View Of Front Drive Axle. Except Bravada, Sonoma GT, Syclone & Typhoon 1. Remove tube and shaft assembly. Refer to Tube & Shaft Assembly. See: Differential Assembly/Differential Axle Housing/Service and Repair 2. Remove bearing. Refer to Fig. 1 for bearing location. 3. Install new bearing. 4. Reverse procedure to complete installation. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive Axles, Bearings and Joints > Axle Bearing > Component Information > Service and Repair > Aluminum Case Front Drive Axle > Page 5342 Axle Bearing: Service and Repair Dana/Spicer Full Floating Axle 1. Raise and support vehicle. 2. Remove axle shaft. 3. Remove hub and drum. 4. Remove oil seal, inner bearing and retaining ring. 5. Remove outer bearing. 6. Reverse procedure to install. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive Axles, Bearings and Joints > Axle Bearing > Component Information > Service and Repair > Aluminum Case Front Drive Axle > Page 5343 Axle Bearing: Service and Repair Saginaw Full Floating Axle Bearing & Cup Fig. 7 Removing Outer Bearing & Cup 1. Using a hammer and suitable drift, drive inner bearing, cup and seal from hub assembly. 2. Remove outer bearing snap ring using suitable pliers. 3. Using tools J-24426 and J-8092, Fig. 7, drive outer bearing and cup from hub assembly. 4. Install new outer bearing into hub assembly. 5. Install outer bearing cup using tools mentioned in Step 3. Drive cup beyond snap ring groove. Install outer bearing cup with tool J-8092 positioned upside down to prevent chamfer on tool from damaging cup. 6. Install snap ring into groove using suitable pliers. 7. Using tool J-24426, drive cup against snap ring. 8. Install inner bearing cup using tools J-24427 and J-8092. Drive cup into position until it seats against shoulder of hub bore. 9. Install new oil seal. Hub & Drum Fig. 6 Removing Or Installing Wheel Bearing Adjusting Nut 1. Remove wheel and axle shaft. 2. Disengage tang of locknut from slot or flat of locknut, then remove locknut from housing tube, using appropriate tool, Fig. 6. 3. Disengage tang of locknut from slot or flat of adjusting nut and remove locknut from housing tube. 4. Use appropriate tool, Fig. 6, to remove adjusting nut from housing tube. Remove thrust washer from housing tube. 5. Pull hub and drum straight off axle housing. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive Axles, Bearings and Joints > Axle Bearing > Component Information > Service and Repair > Aluminum Case Front Drive Axle > Page 5344 Axle Bearing: Service and Repair Rear Axle Fig. 3 Axle Shaft Bearing Removal Fig. 4 Axle Shaft Bearing Installation Fig. 5 Axle Shaft Seal Installation 1. Remove axle shaft as described under "Rear Axle Shaft, Replace." 2. Remove axle seal by prying behind seal steel case with a pry bar. Use caution to avoid damaging axle housing. 3. Using a puller and slide hammer, remove axle bearing, Fig. 3. 4. Lubricate new bearing with gear lubricant, then install bearing in axle housing with axle shaft bearing installer tool No. J-23765, or equivalent, until bearing is seated in housing, Fig. 4. 5. Lubricate seal lips with gear lubricant, then position seal on axle shaft seal installer tool No. J-23771, or equivalent, and install in axle housing, tapping into place until seal is flush with axle housing, Fig. 5. 6. Install axle shaft. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive Axles, Bearings and Joints > Axle Shaft Assembly > Constant Velocity Joint > Component Information > Testing and Inspection Constant Velocity Joint: Testing and Inspection CLICKING NOISE IN TURNS 1. Worn or damaged outboard joints. 2. Cut or damaged seals. NOISE DURING ACCELERATION FROM COAST TO DRIVE 1. Worn or damaged joint. SHUDDER OR VIBRATION DURING ACCELERATION 1. Excessive joint angle. 2. Excessive toe. 3. Incorrect trim height. 4. Worn or damaged joints. 5. Sticking spider assembly. VIBRATION AT HIGHWAY SPEEDS 1. Out of balance tires or wheels. 2. Out of round front tires. 3. Worn joint. 4. Binding or tight joint. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive Axles, Bearings and Joints > Axle Shaft Assembly > Constant Velocity Joint > Component Information > Testing and Inspection > Page 5349 Constant Velocity Joint: Service and Repair Exploded View Of Front Axle. Outer Constant Velocity Joint Seal Removal & Installation Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive Axles, Bearings and Joints > Axle Shaft Assembly > Constant Velocity Joint > Component Information > Testing and Inspection > Page 5350 Outer Constant Velocity Joint Disassembly & Assembly Refer to Figs. 13, 15, 16 for CV joint replacement. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive Axles, Bearings and Joints > Axle Shaft Assembly > Constant Velocity Joint Boot > Component Information > Technical Service Bulletins > Front Wheel Driveshaft Boot Damage Prevention Constant Velocity Joint Boot: Technical Service Bulletins Front Wheel Driveshaft Boot - Damage Prevention File In Section: 4 - Drive Axle Bulletin No. 56-43-01 Date: March, 1995 Subject: Preventing Front Wheel Driveshaft Boot Damage Models: 1995 and Prior Light Duty Trucks with Four Wheel Drive (4WD) or All Wheel Drive (AWD) When diagnosing a vehicle for customer concerns such as noise and/or vibrations, it is often necessary to run the vehicle while it is supported in the air by hoists or jack stands. On light duty truck models with four wheel drive (4WD) or All Wheel Drive (AWD) the front suspension should not be allowed to hang free while performing on-hoist testing. It the front suspension is allowed to hang free, the CV joint will be at a very high angle. This will likely result in damage to the front wheel driveshaft boots. In addition, extra vibrations may occur and may damage the front wheel driveshaft joints. When on-hoist testing an AWD or 4WD light duty truck, support the outer end of the lower control arm using jack stands. This will reduce the CV joint angle and prevent damage to the front wheel driveshaft assembly. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive Axles, Bearings and Joints > Axle Shaft Assembly > Constant Velocity Joint Boot > Component Information > Technical Service Bulletins > Page 5355 Constant Velocity Joint Boot: Service and Repair Fig. 13 Inner Tri-pot Seal Removal & Installation Fig. 14 Righthand Output Shaft & Tube For removal and installation procedures, refer to Figs. 13 and 14. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive Axles, Bearings and Joints > Seals and Gaskets, Drive Axles > System Information > Service and Repair Seals and Gaskets: Service and Repair Fig. 3 Axle Shaft Bearing Removal Fig. 4 Axle Shaft Bearing Installation Fig. 5 Axle Shaft Seal Installation 1. Remove axle shaft as described under AXLE SHAFT. 2. Remove axle seal by prying behind seal steel case with a suitable pry bar. Use care to avoid damaging axle housing. 3. Remove axle bearing using slide hammer J-2619, adapter J-2619-4, or axle bearing puller J-22813-01. The tangs of the axle bearing puller should engage the bearing outer race, Fig. 3. 4. Lubricate new bearing with gear lubricant, then install bearing in axle housing with axle shaft bearing installer J-23765 or equivalent until bearing is seated in housing, Fig. 4. 5. Apply suitable gear lubricant to seal lips, then position seal on axle shaft seal installer J-23771 or equivalent. Install in axle housing, tapping into place until seal is flush with housing, Fig. 5. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive Axles, Bearings and Joints > Wheel Bearing > Component Information > Adjustments Wheel Bearing: Adjustments These vehicles use sealed front wheel bearings which require no lubrication or adjustment. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive Axles, Bearings and Joints > Wheel Bearing > Component Information > Service and Repair > Front Wheel Bearing: Service and Repair Front FRONT WHEEL BEARINGS AND/OR HUB Remove or Disconnect Tools Required: J 28733-A Front Hub Spindle Remover J 24319-01 Universal Steering Linkage Puller J 28712 Axle Shaft Boot Seal Protector J 36607 Ball Joint Separator Raise the vehicle and support with safety stands. Unload the torsion bar. 1. Tire and wheel. Note: Install J 28712 to the tripot axle joint (fig. 44). 2. Cotter pin (122). 3. Retainer (121). 4. Nut (120). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive Axles, Bearings and Joints > Wheel Bearing > Component Information > Service and Repair > Front > Page 5364 Note: Insert a drift or large screwdriver through brake caliper into rotor vanes to prevent from turning (fig. 45). 5. Washer (119). 6. Brake Caliper. Note: Support the caliper with a piece of wire to prevent damage to the brake hose. 7. Rotor. 8. Bolts (116). 9. Hub and bearing assembly (114) from axle joint splined shaft using J 28733-A (fig. 46). Note: Lay the hub and bearing assembly on the hub bolt (outboard) side. This will prevent damage or contamination of the bearing seal (fig. 47). 10. Splash shield (118). 11. Cotter pin (123). 12. Nut (124). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive Axles, Bearings and Joints > Wheel Bearing > Component Information > Service and Repair > Front > Page 5365 13. Tie rod end (125) from the knuckle (117) using J 24319-01 (fig. 48). 14. Cotter pins (130). 15. Ball joints (115 and 127) from the knuckle (117) using J 36607 (fig 49). Note: Locate J 36607 on the ball joint and back off the nut (129, 131) until the ball stud is forced out of the knuckle. 16. Nuts (129 and 131). 17. Knuckle (117) from the ball joints. 18. Spacer (128) from the knuckle (117). 19. Seal (126) from the knuckle (117). Install or Connect 1. New seal (126) to the knuckle (117) using J 28574 (fig. 50). 2. Spacer (128) to the knuckle (117). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive Axles, Bearings and Joints > Wheel Bearing > Component Information > Service and Repair > Front > Page 5366 3. Knuckle (117) to the upper and lower ball joints (115 and 127). 4. Nuts (129 and 131). Tighten Nuts (129) to 83 N.m (61 lbs. ft.). Tighten Nut (131) to 113 N.m (83 lbs. ft.). Important: Tighten the nuts to align the cotter pin. Do not tighten more than 1/6 turn. 5. New cotter pins (130). Bend the pin ends against the nut flats. 6. Splash shield(118) aligned to the knuckle (117). 7. Hub and bearing assembly (114) (fig. 43). Align the threaded holes. 8. Bolts (116). Tighten Bolts (116) to 105 N.m (77 lbs. ft.). 9. Tie rod end (125) to the knuckle (117). 10. Nut (124). Tighten to 48 N.m (35 lbs. ft.). 11. New cotter pin. Bend the pin ends against the nut flats. 12. Rotor (113). 13. Brake caliper. 14. Washer (119). 15. Nut (120). Tighten to 245 N.m (181 lbs. ft.). Note: Insert a drift or large screwdriver through brake caliper into rotor vanes to prevent from turning (fig. 45). 16. Retainer (121). 17. New cotter pin (122). Note: Remove J 28712. 18. Tire and wheel. A. Lower the vehicle. B. Apply the brake pedal. C. Check vehicle trim height and align the front end. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive Axles, Bearings and Joints > Wheel Bearing > Component Information > Service and Repair > Front > Page 5367 Wheel Bearing: Service and Repair Rear REAR WHEEL BEARINGS AND/OR HUB Fig. 3 Axle Shaft Bearing Removal Fig. 4 Axle Shaft Bearing Installation Fig. 5 Axle Shaft Seal Installation 1. Remove axle shaft as described under "Rear Axle Shaft, Replace." 2. Remove axle seal by prying behind seal steel case with a pry bar. Use caution to avoid damaging axle housing. 3. Using a puller and slide hammer, remove axle bearing, Fig. 3. 4. Lubricate new bearing with gear lubricant, then install bearing in axle housing with axle shaft bearing installer tool No. J-23765, or equivalent, until bearing is seated in housing, Fig. 4. 5. Lubricate seal lips with gear lubricant, then position seal on axle shaft seal installer tool No. J-23771, or equivalent, and install in axle housing, tapping into place until seal is flush with axle housing, Fig. 5. 6. Install axle shaft. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive Axles, Bearings and Joints > Wheel Hub > Axle Nut > Component Information > Specifications Axle Nut: Specifications Component .......................................................................................................................................... ....................................................... Torque/Ft. Lbs. Axle Nut ............................................................................................................................................... ............................................................................ 180 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive/Propeller Shafts, Bearings and Joints > Slip Yoke > Component Information > Technical Service Bulletins > Slip Yoke/U-Joint - Replacement and Servicing Slip Yoke: Technical Service Bulletins Slip Yoke/U-Joint - Replacement and Servicing File In Section: 4 - Drive Axle Bulletin No.: 46-41-01 Date: September, 1994 INFORMATION Subject: Slip Yoke Replacement and U-Joint Servicing Models: 1995 and Prior Light Duty Trucks U-joints that are pressed out of the propeller shaft or slip yoke must not be re-used. When it is necessary to press out the u-joint to replace a slip yoke, a new u-joint must be installed. A new u-joint is necessary as the bearing cup seals and slingers are easily damaged. If these components are damaged, dirt and water can contaminate the bearing causing early bearing wear-out. Replacement of the rear u-joint is not required if the retaining straps holding the u-joint to the rear axle pinion flange are removed. Light duty trucks make use of three types of yokes: 1. Vented slip yoke. This yoke can be identified by a small hole in the center of the slip yoke welch plug. This yoke uses grease for internal lubrication. The internal splines of the yoke should be coated with a light covering of grease before installation to the output shaft. A small amount of grease may be forced from the vent hole during operation. No attempts should be made to plug the vent hole. 2. Non-vented slip yoke. This yoke has no vent hole and relies on transmission or transfer case fluid for internal lubrication. Grease should not be used on the yoke internal splines as it may contaminate the transmission or transfer case fluid. 3. Bolted or fixed yoke. This yoke does not slide so it needs no internal lubrication. The transmission/transfer case output shaft seal should be inspected for damage before installing the yoke. The seal lips should also be greased before yoke installation for longer seal life and better performance. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive/Propeller Shafts, Bearings and Joints > Universal Joint, Drive/Propeller Shaft > Component Information > Technical Service Bulletins > Slip Yoke/U-Joint - Replacement and Servicing Universal Joint: Technical Service Bulletins Slip Yoke/U-Joint - Replacement and Servicing File In Section: 4 - Drive Axle Bulletin No.: 46-41-01 Date: September, 1994 INFORMATION Subject: Slip Yoke Replacement and U-Joint Servicing Models: 1995 and Prior Light Duty Trucks U-joints that are pressed out of the propeller shaft or slip yoke must not be re-used. When it is necessary to press out the u-joint to replace a slip yoke, a new u-joint must be installed. A new u-joint is necessary as the bearing cup seals and slingers are easily damaged. If these components are damaged, dirt and water can contaminate the bearing causing early bearing wear-out. Replacement of the rear u-joint is not required if the retaining straps holding the u-joint to the rear axle pinion flange are removed. Light duty trucks make use of three types of yokes: 1. Vented slip yoke. This yoke can be identified by a small hole in the center of the slip yoke welch plug. This yoke uses grease for internal lubrication. The internal splines of the yoke should be coated with a light covering of grease before installation to the output shaft. A small amount of grease may be forced from the vent hole during operation. No attempts should be made to plug the vent hole. 2. Non-vented slip yoke. This yoke has no vent hole and relies on transmission or transfer case fluid for internal lubrication. Grease should not be used on the yoke internal splines as it may contaminate the transmission or transfer case fluid. 3. Bolted or fixed yoke. This yoke does not slide so it needs no internal lubrication. The transmission/transfer case output shaft seal should be inspected for damage before installing the yoke. The seal lips should also be greased before yoke installation for longer seal life and better performance. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive/Propeller Shafts, Bearings and Joints > Universal Joint, Drive/Propeller Shaft > Component Information > Technical Service Bulletins > Page 5381 Universal Joint: Description and Operation The cross and roller type universal joint is a cross-shaped spider joint connecting two Y-shaped yokes. When design angles of more than 3-4° are exceeded, joints wear faster than normal. Original equipment joints are lubricated for life and cannot be lubricated on the vehicle. Never clamp propeller shaft tubing in a vice. Always clamp one of the yokes and support shaft horizontally. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive/Propeller Shafts, Bearings and Joints > Universal Joint, Drive/Propeller Shaft > Component Information > Service and Repair > Service Notes Universal Joint: Service and Repair Service Notes Before disassembling any universal joint, examine the assembly carefully and note the position of the grease fitting (if used). Also, be sure to mark the yokes in relation to the propeller shaft for assembly reference. Failure to observe these precautions may produce rough vehicle operation resulting in rapid wear and parts failure, as well as placing an unbalanced load on transmission, engine and rear axle. When universal joints are disassembled for lubrication or inspection, and the old parts are to be reinstalled, special care must be exercised to avoid damage to universal joint spider or cross and bearing cups. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive/Propeller Shafts, Bearings and Joints > Universal Joint, Drive/Propeller Shaft > Component Information > Service and Repair > Service Notes > Page 5384 Universal Joint: Service and Repair Cross & Roller Type Fig. 1 Production Type Universal Joints Which Use Nylon Injection Rings In Place Of Snap Rings Fig. 2 Service Type Universal Joints (Internal Snap Ring Type) Production universal joints cannot be reassembled because there are no bearing retainer grooves in the production bearing caps, Figs. 2 and 3. DISASSEMBLY 1. Mark shaft for assembly reference. 2. Support shaft in a horizontal line with universal joint bearing separator tool No. J 9522-3, equivalent or suitable vice. Fig. 4 External Snap Ring Universal Joint. 3. On models with external snap rings, remove snap rings, Fig. 4. If ring does not snap out of groove, relieve pressure on ring by tapping lightly on bearing cap. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive/Propeller Shafts, Bearings and Joints > Universal Joint, Drive/Propeller Shaft > Component Information > Service and Repair > Service Notes > Page 5385 4. On all models, place joint in tool No. J 9522-3 or equivalent with lower yoke ear supported by 1 1/8 inch socket, Fig. 5, then press out cap. If cap is not completely removed, insert spacer tool No. J 9522-5 or equivalent and continue to press, Fig. 6. If using a vice in place of special tool, use 1 1/8 inch socket to receive one cap and 5/8 inch socket to push opposite cap. 5. Rotate joint in tool or vice and press opposite cap out, then remove cross from yoke. 6. Inspect and clean retaining ring grooves. 7. Check cap bores for burrs and imperfections. ASSEMBLY 1. Use finger to coat needle bearings with thin layer of grease. Do not fill cups completely or use excessive amounts. Over lubrication may damage seals. 2. Put one bearing cap part way into one side of yoke, then insert cross into cap, Fig. 7. 3. Press cross and cap into yoke until cap is flush with yoke ear. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Drive/Propeller Shafts, Bearings and Joints > Universal Joint, Drive/Propeller Shaft > Component Information > Service and Repair > Service Notes > Page 5386 4. Press opposite cap into yoke, ensuring trunnion alignment, Fig. 8. 5. Continue to press cap into yoke ear while working cross to ensure free, unbinding movement until retainer groove clears inside of yoke. If binding occurs, stop pressing and check for misaligned bearings. 6. Snap retainers into place, Fig. 9. Yoke can be sprung slightly with firm hammer blow if retainer is difficult to seat, Fig. 10. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Lamps and Indicators - Transmission and Drivetrain > Lamps and Indicators - A/T > Shift Indicator > Component Information > Locations Shift Indicator: Locations Instrument cluster. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Lamps and Indicators - Transmission and Drivetrain > Lamps and Indicators - Transfer Case > Four Wheel Drive Indicator Lamp > Component Information > Locations Four-Wheel Drive Indicator Lamp Wiring I/P Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Lamps and Indicators - Transmission and Drivetrain > Lamps and Indicators - Transfer Case > Four Wheel Drive Indicator Lamp > Component Information > Locations > Page 5396 C274 - 4WD Indicator Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Lamps and Indicators - Transmission and Drivetrain > Lamps and Indicators - Transfer Case > Four Wheel Drive Indicator Lamp > Component Information > Locations > Page 5397 Four Wheel Drive Indicator Lamp: Description and Operation The Four-Wheel Drive (4WD) Indicator Assembly provides visual information about the operating mode and gear range of the driveline. Voltage is supplied to the IGN/GAU Fuse and Indicator Assembly with the Ignition Switch in START or RUN. The circuit is completed through the Selector Quadrant Switch, which provides a ground path to light various Indicator Assembly Lamps. With the Selector Quadrant Switch in detent position 1, the "2WHL" Indicator Assembly Lamp is lit. With the Selector Quadrant Switch in detent position 2, the "4 HIGH" Indicator Assembly Lamp is lit. At this time, the Front Axle Switch is closed and the Indicator Assembly Front and Rear Axle Display is lit. With the Selector Quadrant Switch in detent position 4, the "4 LOW" Indicator Lamp is lit. At this time, the Front Axle Switch is closed, and the Indicator Assembly Front and Rear Axle Display is lit. A signal is sent to the Four-Wheel Antilock Brake Module (4WAL) whenever the 4WD is engaged. This signal turns off the 4WAL systems to prevent operation during 4WD operation. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Lamps and Indicators - Transmission and Drivetrain > Lamps and Indicators - Transfer Case > Four Wheel Drive Indicator Lamp > Component Information > Testing and Inspection > Initial Inspection and Diagnostic Overview Four Wheel Drive Indicator Lamp: Initial Inspection and Diagnostic Overview Circuit Operation - Four-Wheel Drive Indicator The Four-Wheel Drive (4WD) Indicator Assembly provides visual information about the operating mode and gear range of the driveline. Voltage is supplied to the IGN/GAU Fuse and Indicator Assembly with the Ignition Switch in START or RUN. The circuit is completed through the Selector Quadrant Switch, which provides a ground path to light various Indicator Assembly Lamps. With the Selector Quadrant Switch in detent position 1, the "2WHL" Indicator Assembly Lamp is lit. With the Selector Quadrant Switch in detent position 2, the "4 HIGH" Indicator Assembly Lamp is lit. At this time, the Front Axle Switch is closed and the Indicator Assembly Front and Rear Axle Display is lit. With the Selector Quadrant Switch in detent position 4, the "4 LOW" Indicator Lamp is lit. At this time, the Front Axle Switch is closed, and the Indicator Assembly Front and Rear Axle Display is lit. A signal is sent to the Four-Wheel Antilock Brake Module (4WAL) whenever the 4WD is engaged. This signal turns off the 4WAL systems to prevent operation during 4WD operation. Preliminary Checks - Four-Wheel Drive Indicator 1. Check condition of IGN/GAU Fuse. If fuse is Blown, locate and repair overload. Replace fuse. 2. If fuse is not blown, proceed with the Diagnostics. See: Symptom Related Diagnostic Procedures Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Lamps and Indicators - Transmission and Drivetrain > Lamps and Indicators - Transfer Case > Four Wheel Drive Indicator Lamp > Component Information > Testing and Inspection > Initial Inspection and Diagnostic Overview > Page 5400 Four Wheel Drive Indicator Lamp: Symptom Related Diagnostic Procedures Indicator Assembly Illumination Lamp Does Not Light One Or More Indicator Assembly Lamps Do Not Light Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Manual Transmission/Transaxle > Bell Housing, M/T > Component Information > Specifications Bell Housing: Specifications Clutch Housing to Engine Bolts ........................................................................................................... ................................................................... 66 ft. lbs. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Manual Transmission/Transaxle > Case, M/T > Component Information > Specifications Case: Specifications Transmission to Engine Bolts .............................................................................................................. .................................................................... 35 ft. lbs. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Manual Transmission/Transaxle > Fluid - M/T > Component Information > Specifications > Capacity Specifications Fluid - M/T: Capacity Specifications Fluid Capacity ...................................................................................................................................... ...................................................................... 6.0 Pts. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Manual Transmission/Transaxle > Fluid - M/T > Component Information > Specifications > Capacity Specifications > Page 5412 Fluid - M/T: Fluid Type Specifications Transmission Manual ................................................................................................................................................. ........................................................................ [01] [01] New Venture Gear 3500; synchromesh transmission fluid, G.M. P/N 12345349 or equivalent. Borg Warner T5; DEXRON IIE automatic transmission fluid, G.M. P/N 12345881 or equivalent. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Manual Transmission/Transaxle > Shift Linkage, M/T > Component Information > Adjustments > 4-Speed Transmissions Shift Linkage: Adjustments 4-Speed Transmissions The shift mechanism does not require adjustment and may be serviced independently of the transmission. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Manual Transmission/Transaxle > Shift Linkage, M/T > Component Information > Adjustments > 4-Speed Transmissions > Page 5417 Shift Linkage: Adjustments 5-Speed Transmissions The shift mechanism does not require adjustment and may be serviced independently of the transmission. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Relays and Modules - Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Locations Control Module: Locations Mounted on the back of the Electronic Control Module (ECM)/Powertrain Control Module (PCM) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Relays and Modules - Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Locations > Page 5423 C202A - Transfer Case Control Module Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Relays and Modules - Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting Control Module: Description and Operation Electric 4WD Shifting Transfer Case 4WD Selector Switch 4WD Selector Switch Wiring Schematic OPERATION On vehicles equipped with the Model 233 transfer case, there is no transfer case selector lever in the cab. The operator selects 4HI or 4LO by pushing a three-position (4HI, 4LO, 2HI) rocker-type selector switch mounted on the instrument panel. During normal driving the transfer case is in the 2HI mode. The switch is spring-loaded to the center position. When the transfer case is in 2HI both the 4HI and 4L0 switch circuits are open, and both lights are off. When shifting to 4HI or 4LO the rocker switch will still return to the center position and the 4HI or 4LO light will be on. The above image shows the wiring schematic of the transfer case selector switch. Mode Shifts Mode shifts are shifts from: - 2HI to 4HI - 4HI to 2HI A mode shift can be accomplished in any gear position and at any vehicle speed. If the system is in 2HI, the operator can shift into 4HI merely by pressing and releasing the 4HI area of the selector rocker switch. The green 4HI status lamp flashes whenever a 2HI or 4HI shift is initiated and continues to flash until the TCCM completes the shift (or until 30 seconds elapses). After the shift into 4HI is accomplished, the 4HI status lamp remains lit to indicate that the system is in 4HI. The operator can shift from 4HI back to 2HI by again pressing 4HI on the selector switch. Again, the green 4HI status lamp flashes until the shift to 2HI is complete, and then extinguishes once the shift is complete. Both the 4HI and 4LO lamps remain oft when the vehicle is in 2HI. Range Shifts Range shifts are shifts between the HI and LO ranges, from: Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Relays and Modules - Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 5426 - 2HI to 4LO - 4HI to 4LO - 4LO to 4HI A range shift from 4L0 directly to 2HI cannot be made. The operator must first make range shift from 4LO to 4HI, then a mode shift from 4HI to 2HI. A range shift can only be made with the automatic transmission in neutral or with the manual transmission clutch fully depressed. The vehicle speed must also be below three miles per hour before the shift can occur. Whenever a shift into 4LO is initiated, the amber 4LO status lamp flashes and continues to flash until the TCCM completes the shift (or until 30 seconds elapses). The 4LO status lamp must glow steadily before the vehicle transmission is shifted into gear or before the clutch pedal is released. If a range shift is initiated when the transmission is engaged or when the vehicle speed is above 3 mph, the 4LO status lamp flashes for 30 seconds and no range shift actually occurs; the system returns to the position before the shift was initiated. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Relays and Modules - Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 5427 Control Module: Description and Operation TCCM Power and Ground Fig. 1, Memory Power, System Power, And Ground Circuit Fig. 2, Fuse Block And Cavity Location Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Relays and Modules - Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 5428 POWER, CIRCUIT PROTECTION, AND GROUND The Transfer Case Control Module (TCCM) memory power, system power, and the ground circuit are shown in Figure 1. The vehicle fuse block and cavity location for memory power, system power, and motor power are shown in Figure 2. Memory Power Trouble code memory power is protected by a 5-amp TCCM fuse. Memory power is supplied to TCCM connector pin C6 through circuit 140. System Power Operating power is controlled by the ignition switch and is protected by a 15-amp radio fuse. System power is supplied to TCCM connector pin C8 through circuit 141. This fuse also supplies, voltage to pin B of the transfer case switch. The system power will shut down if either the 5-amp TCCM fuse or the 15-amp radio fuse are removed or blown. System Ground System ground is supplied to TCCM connector pin C10 through circuit 150. Circuit 150 is connected to the bus bar ground located on the left side of the steering column support. Refer to Figure 1. Turn/BU Fuse A 15-amp TURN/BU fuse supplies ignition voltage to the park/neutral position switch. This voltage enables the park switch to send a park signal to TCCM connector pin D2. Power Accessory Circuit Breaker The 30-amp power accessory circuit breaker supplies ignition voltage to TCCM connector pins D14 and D15. This voltage is used to control the electric-shift motor circuit. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Relays and Modules - Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 5429 Control Module: Description and Operation TCCM Inputs and Outputs General Description INPUTS The Transfer Case Control Module (TCCM) receives input signals from the following sources: - Transfer case selector switch on the instrument panel. - Park/neutral position switch on vehicles with automatic transmissions. - Clutch safety switch on vehicles with manual transmissions. - Vehicle speed sensor buffer which supplies vehicle speed signals. - Encoder switch within the electric-shift motor which provides actual mode and range information signals. - Data link connector (DLC) pin J which provides diagnostic enable. OUTPUTS After processing the input information, the Transfer Case Control Module (TCCM) outputs signals to the following: - Electric shift motor to effect mode and range shifts. - Selector switch status lamps to provide transfer case status information. - Diagnostic trouble codes (DTC) which are output via the selector switch status lamps. 2HI to 4HI Selector Switch Input 4WD Selector Switch Wiring Schematic OPERATION When the transfer case is in 2HI and the operator presses the 4HI area of the rocker switch, the 4HI contacts of the selector switch close, connecting circuits 141 and 1564, and furnishing 12-volts to pin C5 of the TCCM connector. The 12-volt signal at pin C5 commands the Transfer Case Control Module (TCCM) to signal the electric-shift motor to shift into 4HI. The contacts return to the open position as soon as the switch is released. 4HI to 2HI Selector Switch Input Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Relays and Modules - Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 5430 4WD Selector Switch Wiring Schematic OPERATION If the transfer case is in 4HI and the operator presses the 4HI area of the rocker switch, the 4HI contacts of the selector switch close, connecting circuits 141 and 1564 and furnishing 12-volts to pin C5 of the Transfer Case Control Module (TCCM) connector. The 12-volt signal at pin C5 commands the TCCM to signal the electric-shift motor to shift into 4HI. Again, the contacts return to the open position as soon as the switch is released. 2HI to 4HI to 4LO Selector Switch Input 4WD Selector Switch Wiring Schematic OPERATION When the operator presses the 4LO area of the rocker switch while the transfer case is in either 2HI or 4HI, the 4LO contacts of the selector switch close, connecting circuits 141 and 1559, and furnishing 12-volts to pin C3 of the Transfer Case Control Module (TCCM) connector. The 12-volt signal at pin C3 commands the TCCM to signal the electric-shift motor to shift the transfer case into 4LO. Once more, the contacts return to the open position as soon as the switch is released. Park/Neutral Position Switch Inputs Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Relays and Modules - Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 5431 Automatic Transmission Neutral Start Switch Neutral Start Switch Voltages OPERATION Because range shift should only be made with the automatic transmission in neutral, the park/neutral position switch informs the Transfer Case Control Module (TCCM) that the vehicle automatic transmission is in either: - Park - Neutral - One of the drive positions The park/neutral position switch consists of three switches together in one unit, and it provides three signals: - Park - When the automatic transmission is in park, the contacts of both the park switch and the park neutral switch are closed. When these contacts are closed, a battery voltage signal is sent to TCCM connector pin D2, while connector pin D16 is pulled to ground (0 voltage). The TCCM interprets this signal to mean the automatic transmission is in park. - Neutral - When the automatic transmission is in neutral, the contacts of the park switch are open and the contacts of the park neutral position switch are closed. In this condition, a 0-voltage signal is sent to TCCM connector pin D2, while connector pin D16 is pulled to ground (0 volts). The TCCM interprets this signal to mean the automatic transmission is in neutral. - In gear - When the automatic transmission is in any other gear position, the contacts of both the park switch and park neutral switch are open. In this condition, a 0-voltage signal is sent to TCCM connector pin D16. The TCCM interprets this signal to mean the automatic transmission is neither park or neutral. Important - If the backup switch connector were to be plugged in upside down, the park switch would receive no power. Such a condition would cause a 0-voltage signal at both pin D2 and pin D16 in neutral and in park. The transfer case, accordingly, would perform a range shift in park as well as in neutral. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Relays and Modules - Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 5432 - An open in circuit 75, or an open in the Turn/BU fuse would also cause this condition. - Additionally, a park/neutral position switch that is out of adjustment may prevent a range shift in park. Clutch Safety Switch Inputs Clutch Safety Switch Schematic Clutch Safety Switch Voltage Signals OPERATION Because range shifts should only be made with the manual transmission clutch fully depressed, the clutch safety switch informs the Transfer Case Control Module (TCCM) that the vehicle clutch pedal is fully depressed or released. The clutch safety switch is connected to TCCM connector pin D16. When the clutch pedal is released, the contacts of the clutch safety switch are open. When these contacts are open, a battery voltage signal is seen at TCCM connector pin D16. The TCCM interprets this signal to mean the clutch is released. When the clutch is fully depressed, the contacts of the clutch safety switch are closed. When the contacts are closed, voltage is pulled low to 0 at TCCM connector pin D16. The TCCM interprets this signal to mean the clutch pedal is fully depressed. Because TCCM connector pin D2 is not connected when the vehicle is equipped with a manual transmission, the TCCM reads a 0-volt signal at pin D2 at all times. All readings are taken while back-probing the TCCM pins with the ignition in the "Run" position. A reading of less than 0.5 volt is considered to be zero. Vehicle Speed Input Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Relays and Modules - Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 5433 Vehicle Sensor Buffer And TCCM Schematic OPERATION The vehicle speed sensor buffer informs the Transfer Case Control Module (TCCM) about the speed of the vehicle in miles per hour. Such information is essential to inform the TCCM to prohibit range shifts at speeds above 3 mph. The vehicle speed sensor (VSS) is a variable-reluctance magnetic sensing device that converts tone wheel rotation into a frequency and voltage output proportional to the vehicle speed. The frequency and voltage signal is sent to the vehicle speed sensor buffer which converts the speed sensor output into a useful pulse signal. The vehicle speed sensor buffer then, pulses circuit 1567 to ground at a rate of 4000 pulses per mile. Whenever the vehicle speed sensor buffer grounds circuit 1567, the voltage at TCCM connector pin D8 returns to 5 volts. The TCCM reads the 4000 pulses-per-mile (1.11 Hz per mph) signal to determine vehicle speed. Encoder Switch Inputs Fig 1, Electric Shift Encoder Switch Layout Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Relays and Modules - Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 5434 Fig 2, Electric Shift Encoder Switch Schematic Fig 3, Encoder Switch Channel Signals And Positions OPERATION The four-channel encoder switch indicates the current transfer case mode and range to the Transfer Case Control Module (TCCM). The encoder switch is located inside the encoder itself and is not serviceable. The TCCM reads the status of the four channels to determine the range and mode in which the transfer case is operating or whether the transfer case is shifting between modes and/or ranges. The encoder assembly is composed of an inner ground ring in contact with a three-leg wiper arm. The three legs of the wiper, spaced 120 degrees apart, make contact with the conductive areas of the four channels. When any leg of the wiper arm is in contact with the conductive area of any channel, a path to ground is provided to the inner ground ring. A schematic of the encoder switch is shown in Figure 2. The channel signals in various transfer case operating modes and ranges are shown in Figure 3. Any combination of signals not listed in Figure 3 are considered invalid by the TCCM. Encoder Switch Channel Positions These voltage readings can be obtained by back-probing either the TCCM connector pins or the transfer case connector pins. For TCCM pin numbers and encoder channels, refer to Figure 2. Diagnostic Enable Input Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Relays and Modules - Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 5435 Wiring Schematic For Enabling The Status Lamps OPERATION When pin J of the Data Link Connector (DLC) is connected either to pin A of the DLC or to a good ground while the ignition is on, the diagnostics routine of the Transfer Case Control Module (TCCM) is activated. When the diagnostics routine is activated, the transfer case selector switch 4HI and 4LO status lamps flash the diagnostic codes. Electric Shift Motor Outputs Electric Shift Motor Schematic OPERATION The Transfer Case Control Module (TCCM) provides the output for the electric shift motor as the schematic shows. - Motor control is achieved by energizing one of the two motor control relays located in the TCCM, by way of the transfer case selector switch. The TCCM operates the motor in one direction by energizing one relay while the second relay is de-energized. The TCCM operates the motor in the reverse direction by energizing the second relay while the first relay is de-energized. - Motor power to actuate the motor drive relays is input at TCCM connector pins D14 and D15. This power is supplied by the ignition through the 30-amp power circuit breaker. - Motor ground is input at TCCM connector pins D12 and D13 to provide the return line for the motor drive relays. 4HI and 4LO Status Lamps Outputs Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Relays and Modules - Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 5436 Selector Switch Status Lamp Schematic OPERATION The Transfer Case Control Module (TCCM) controls the operation of the 4HI and 4LO status lamps in the transfer case selector switch. The status lamps also show the transfer case mode and range of operation. The status lamps also provide a self-test when the ignition is first turned on. Additionally, the status lamps are used to alert the driver that there is a problem somewhere in the four-wheel drive system, and also to flash diagnostic trouble codes (DTC's). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Relays and Modules - Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Page 5437 Control Module: Service and Repair TRANSFER CASE MODULE REPLACEMENT REMOVE OR DISCONNECT 1. Negative battery cable. 2. ECM (utility only). 3. Cowl side panel (pickup only). 4. Electrical connection. 5. Module to cowl panel screws (pickup only). 6. Module. INSTALL OR CONNECT 1. Module. 2. Module to cowl panel screws (pickup only). 3. Electrical connection. 4. ECM (utility only). 5. Negative battery cable. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Sensors and Switches - Transmission and Drivetrain > Sensors and Switches - A/T > Brake Switch - TCC > Component Information > Locations > Stoplamp/TCC Brake Switch Stoplamp/TCC Brake Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Sensors and Switches - Transmission and Drivetrain > Sensors and Switches - A/T > Brake Switch - TCC > Component Information > Locations > Stoplamp/TCC Brake Switch > Page 5444 I/P Harness Wiring, LH Side Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Sensors and Switches - Transmission and Drivetrain > Sensors and Switches - A/T > Brake Switch - TCC > Component Information > Locations > Page 5445 C217 - Brake Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Sensors and Switches - Transmission and Drivetrain > Sensors and Switches - A/T > Fluid Pressure Sensor/Switch, A/T > Component Information > Specifications Fluid Pressure Sensor/Switch: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Pressure Plugs (1/8 - 27) ..................................................................................................................... ................................................................................. 8 Pressure Plugs (1/4 - 18) ................................ .............................................................................................................................................................. ...... 18 Pressure Switches ................................................................................................................... .............................................................................................. 8 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Sensors and Switches - Transmission and Drivetrain > Sensors and Switches - A/T > Transmission Position Switch/Sensor, A/T > Component Information > Description and Operation Transmission Position Switch/Sensor: Description and Operation Automatic Transmission Electrical Components PURPOSE This device is a set of five presure switches (two normally closed and three normally open), that detect fluid pressure within the valve body passages and signals the PCM which transmission range is selected (PRNDL). OPERATION The five pressure switches are connected to three signal circuits referred to as range signals A, B, C. The combination of pressure switch states determines the voltage signal (B+ or 0) on each range signal to the PCM. LOCATION The transmission range fluid pressure switch assembly is attached to the control valve body within the transmission. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Sensors and Switches - Transmission and Drivetrain > Sensors and Switches - A/T > Transmission Speed Sensor, A/T > Component Information > Specifications Transmission Speed Sensor: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Vehicle Speed Sensor Retainer ........................... .............................................................................................................................................................. ... 8 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Sensors and Switches - Transmission and Drivetrain > Sensors and Switches - A/T > Transmission Temperature Sensor/Switch, A/T > Component Information > Description and Operation Transmission Temperature Sensor/Switch: Description and Operation Automatic Transmission Electrical Components PURPOSE The Transmission Fluid Temperature (TFT) Sensor is used by the control module to control: Torque Converter Clutch (TCC) apply and release schedule. - Hot mode determination. - Shift quality. OPERATION The TFT is a thermistor used to indicate transmission fluid temperature. The control module sends a 5.0 volt signal to the TFT through a resistor in the computer and measures the voltage. High sensor resistance produces high signal input voltage which corresponds to low fluid temperature. Low sensor resistance produces low signal input voltage which corresponds to high fluid temperature. With the TFT varying its resistance, the control module can sense transmission fluid temperature by reading the varying voltage. LOCATION The sensor is part of the transmission range fluid pressure switch assembly and is attached to the control valve body within the transmission. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Sensors and Switches - Transmission and Drivetrain > Sensors and Switches - Transfer Case > Four Wheel Drive Selector Switch > Component Information > Locations > Pickup Transfer Case Select Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Sensors and Switches - Transmission and Drivetrain > Sensors and Switches - Transfer Case > Four Wheel Drive Selector Switch > Component Information > Locations > Pickup > Page 5463 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Sensors and Switches - Transmission and Drivetrain > Sensors and Switches - Transfer Case > Four Wheel Drive Selector Switch > Component Information > Locations > Page 5464 Four Wheel Drive Selector Switch: Service and Repair Fig. 2 Transfer Case Shift Linkage. Except Bravada, Sonoma GT, Syclone & Typhoon Fig. 4 Selector Switch Installation. Except Bravada, Sonoma GT, Syclone & Typhoon 1. Disconnect battery ground cable. 2. Remove console, then disconnect console wiring harness. 3. Remove shifter boot retaining screws and slide boot up shift lever. 4. Remove switch attaching screw, then the switch and harness, Fig. 2. 5. Position new switch on mounting bracket and install attaching screw.Ensure shift lever assembly pawl is on the switch contact carrier. 6. Route wiring as shown in Fig. 4. 7. Place shifter boot in proper position, then install retaining screws. 8. Connect console wiring harness, then install console. 9. Connect battery ground cable. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Sensors and Switches - Transmission and Drivetrain > Sensors and Switches - Transfer Case > Gear Sensor/Switch, Transfer Case > Component Information > Locations > Electric Shift Transfer Case Switch Gear Sensor/Switch: Locations Electric Shift Transfer Case Switch Transfer Case Electric Shift Motor Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Sensors and Switches - Transmission and Drivetrain > Sensors and Switches - Transfer Case > Gear Sensor/Switch, Transfer Case > Component Information > Locations > Electric Shift Transfer Case Switch > Page 5469 Electric Shift Transfer Case Wiring Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Sensors and Switches - Transmission and Drivetrain > Sensors and Switches - Transfer Case > Gear Sensor/Switch, Transfer Case > Component Information > Locations > Electric Shift Transfer Case Switch > Page 5470 4WD Components Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Sensors and Switches - Transmission and Drivetrain > Sensors and Switches - Transfer Case > Speed Sensor, Transfer Case > Component Information > Technical Service Bulletins > Drivetrain - Updated Transfer Case Speed Sensor Conn. Speed Sensor: Technical Service Bulletins Drivetrain - Updated Transfer Case Speed Sensor Conn. Bulletin No.: 06-04-21-001 Date: May 17, 2006 INFORMATION Subject: Updated Transfer Case Connector Service Kit Now Available For Transfer Case Speed Sensor Wire Harness Connector that Comes Loose Or Connector Retainer Clip Breaks Models: 2007 and Prior GM Light Duty Trucks 2007 and Prior HUMMER H2, H3 2005-2007 Saab 9-7X with Four-Wheel Drive or All-Wheel Drive Technicians may find that when the transfer case speed sensor wire harness connector is removed, the connector lock flexes/bends and does not return to the original position. The transfer case speed sensor wire harness connector then has no locking device. On older vehicles, the plastic connector retainer becomes brittle and the clip may break as soon as it is flexed. In the past, the only service fix was to install a wire harness connector service pack, P/N 88987183. This repair procedure involved splicing a new service connector with an integral connector lock. This connector service kit is of the same design and was still prone to failure over time. A new connector service repair kit is now available, P/N 15306187, that is an updated design. This new kit should be used whenever the speed sensor wire harness connector requires replacement. Parts Information Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Actuators and Solenoids - Transfer Case > Transfer Case Actuator > Component Information > Locations > Electronic Shift Transfer Case Position Switch Transfer Case Actuator: Locations Electronic Shift Transfer Case Position Switch Transfer Case Electric Shift Motor The Electronic Shift Transfer Case Position Switch (Encoder Switch) is located in the in the shift motor on the transfer case. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Actuators and Solenoids - Transfer Case > Transfer Case Actuator > Component Information > Locations > Electronic Shift Transfer Case Position Switch > Page 5481 Four-Wheel Drive Indicator Wiring Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Actuators and Solenoids - Transfer Case > Transfer Case Actuator > Component Information > Locations > Page 5482 Transfer Case Actuator: Diagrams C154 - Front Axle Switch C155 - Front Axle Switch In-Line C154 - Front Axle Switch C155 - Front Axle Switch In-Line Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Actuators and Solenoids - Transfer Case > Transfer Case Actuator > Component Information > Locations > Page 5483 Transfer Case Actuator: Service and Repair ELECTRIC SHIFT MOTOR REPLACEMENT Transfer Case Electric Shift Motor REMOVE OR DISCONNECT 1. Negative battery cable. - Raise vehicle and support with safety stands. 2. Transfer case shield. 3. Motor electrical connection. 4. Front propeller shaft. 5. Front output shaft yoke. 6. Motor to transfer case bolts. 7. Motor from the transfer case. INSTALL OR CONNECT 1. Motor to the transfer case. 2. Bolts. TIGHTEN - Bolts to 18 Nm (13 lbs. ft.). 3. Front output shaft yoke. 4. Front propeller shaft. 5. Motor electrical connection. 6. Transfer case shield. 7. Negative battery cable. - Lower Vehicle Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Control Module, Transfer Case > Component Information > Locations Control Module: Locations Mounted on the back of the Electronic Control Module (ECM)/Powertrain Control Module (PCM) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Control Module, Transfer Case > Component Information > Locations > Page 5487 C202A - Transfer Case Control Module Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting Control Module: Description and Operation Electric 4WD Shifting Transfer Case 4WD Selector Switch 4WD Selector Switch Wiring Schematic OPERATION On vehicles equipped with the Model 233 transfer case, there is no transfer case selector lever in the cab. The operator selects 4HI or 4LO by pushing a three-position (4HI, 4LO, 2HI) rocker-type selector switch mounted on the instrument panel. During normal driving the transfer case is in the 2HI mode. The switch is spring-loaded to the center position. When the transfer case is in 2HI both the 4HI and 4L0 switch circuits are open, and both lights are off. When shifting to 4HI or 4LO the rocker switch will still return to the center position and the 4HI or 4LO light will be on. The above image shows the wiring schematic of the transfer case selector switch. Mode Shifts Mode shifts are shifts from: - 2HI to 4HI - 4HI to 2HI A mode shift can be accomplished in any gear position and at any vehicle speed. If the system is in 2HI, the operator can shift into 4HI merely by pressing and releasing the 4HI area of the selector rocker switch. The green 4HI status lamp flashes whenever a 2HI or 4HI shift is initiated and continues to flash until the TCCM completes the shift (or until 30 seconds elapses). After the shift into 4HI is accomplished, the 4HI status lamp remains lit to indicate that the system is in 4HI. The operator can shift from 4HI back to 2HI by again pressing 4HI on the selector switch. Again, the green 4HI status lamp flashes until the shift to 2HI is complete, and then extinguishes once the shift is complete. Both the 4HI and 4LO lamps remain oft when the vehicle is in 2HI. Range Shifts Range shifts are shifts between the HI and LO ranges, from: Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 5490 - 2HI to 4LO - 4HI to 4LO - 4LO to 4HI A range shift from 4L0 directly to 2HI cannot be made. The operator must first make range shift from 4LO to 4HI, then a mode shift from 4HI to 2HI. A range shift can only be made with the automatic transmission in neutral or with the manual transmission clutch fully depressed. The vehicle speed must also be below three miles per hour before the shift can occur. Whenever a shift into 4LO is initiated, the amber 4LO status lamp flashes and continues to flash until the TCCM completes the shift (or until 30 seconds elapses). The 4LO status lamp must glow steadily before the vehicle transmission is shifted into gear or before the clutch pedal is released. If a range shift is initiated when the transmission is engaged or when the vehicle speed is above 3 mph, the 4LO status lamp flashes for 30 seconds and no range shift actually occurs; the system returns to the position before the shift was initiated. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 5491 Control Module: Description and Operation TCCM Power and Ground Fig. 1, Memory Power, System Power, And Ground Circuit Fig. 2, Fuse Block And Cavity Location Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 5492 POWER, CIRCUIT PROTECTION, AND GROUND The Transfer Case Control Module (TCCM) memory power, system power, and the ground circuit are shown in Figure 1. The vehicle fuse block and cavity location for memory power, system power, and motor power are shown in Figure 2. Memory Power Trouble code memory power is protected by a 5-amp TCCM fuse. Memory power is supplied to TCCM connector pin C6 through circuit 140. System Power Operating power is controlled by the ignition switch and is protected by a 15-amp radio fuse. System power is supplied to TCCM connector pin C8 through circuit 141. This fuse also supplies, voltage to pin B of the transfer case switch. The system power will shut down if either the 5-amp TCCM fuse or the 15-amp radio fuse are removed or blown. System Ground System ground is supplied to TCCM connector pin C10 through circuit 150. Circuit 150 is connected to the bus bar ground located on the left side of the steering column support. Refer to Figure 1. Turn/BU Fuse A 15-amp TURN/BU fuse supplies ignition voltage to the park/neutral position switch. This voltage enables the park switch to send a park signal to TCCM connector pin D2. Power Accessory Circuit Breaker The 30-amp power accessory circuit breaker supplies ignition voltage to TCCM connector pins D14 and D15. This voltage is used to control the electric-shift motor circuit. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 5493 Control Module: Description and Operation TCCM Inputs and Outputs General Description INPUTS The Transfer Case Control Module (TCCM) receives input signals from the following sources: - Transfer case selector switch on the instrument panel. - Park/neutral position switch on vehicles with automatic transmissions. - Clutch safety switch on vehicles with manual transmissions. - Vehicle speed sensor buffer which supplies vehicle speed signals. - Encoder switch within the electric-shift motor which provides actual mode and range information signals. - Data link connector (DLC) pin J which provides diagnostic enable. OUTPUTS After processing the input information, the Transfer Case Control Module (TCCM) outputs signals to the following: - Electric shift motor to effect mode and range shifts. - Selector switch status lamps to provide transfer case status information. - Diagnostic trouble codes (DTC) which are output via the selector switch status lamps. 2HI to 4HI Selector Switch Input 4WD Selector Switch Wiring Schematic OPERATION When the transfer case is in 2HI and the operator presses the 4HI area of the rocker switch, the 4HI contacts of the selector switch close, connecting circuits 141 and 1564, and furnishing 12-volts to pin C5 of the TCCM connector. The 12-volt signal at pin C5 commands the Transfer Case Control Module (TCCM) to signal the electric-shift motor to shift into 4HI. The contacts return to the open position as soon as the switch is released. 4HI to 2HI Selector Switch Input Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 5494 4WD Selector Switch Wiring Schematic OPERATION If the transfer case is in 4HI and the operator presses the 4HI area of the rocker switch, the 4HI contacts of the selector switch close, connecting circuits 141 and 1564 and furnishing 12-volts to pin C5 of the Transfer Case Control Module (TCCM) connector. The 12-volt signal at pin C5 commands the TCCM to signal the electric-shift motor to shift into 4HI. Again, the contacts return to the open position as soon as the switch is released. 2HI to 4HI to 4LO Selector Switch Input 4WD Selector Switch Wiring Schematic OPERATION When the operator presses the 4LO area of the rocker switch while the transfer case is in either 2HI or 4HI, the 4LO contacts of the selector switch close, connecting circuits 141 and 1559, and furnishing 12-volts to pin C3 of the Transfer Case Control Module (TCCM) connector. The 12-volt signal at pin C3 commands the TCCM to signal the electric-shift motor to shift the transfer case into 4LO. Once more, the contacts return to the open position as soon as the switch is released. Park/Neutral Position Switch Inputs Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 5495 Automatic Transmission Neutral Start Switch Neutral Start Switch Voltages OPERATION Because range shift should only be made with the automatic transmission in neutral, the park/neutral position switch informs the Transfer Case Control Module (TCCM) that the vehicle automatic transmission is in either: - Park - Neutral - One of the drive positions The park/neutral position switch consists of three switches together in one unit, and it provides three signals: - Park - When the automatic transmission is in park, the contacts of both the park switch and the park neutral switch are closed. When these contacts are closed, a battery voltage signal is sent to TCCM connector pin D2, while connector pin D16 is pulled to ground (0 voltage). The TCCM interprets this signal to mean the automatic transmission is in park. - Neutral - When the automatic transmission is in neutral, the contacts of the park switch are open and the contacts of the park neutral position switch are closed. In this condition, a 0-voltage signal is sent to TCCM connector pin D2, while connector pin D16 is pulled to ground (0 volts). The TCCM interprets this signal to mean the automatic transmission is in neutral. - In gear - When the automatic transmission is in any other gear position, the contacts of both the park switch and park neutral switch are open. In this condition, a 0-voltage signal is sent to TCCM connector pin D16. The TCCM interprets this signal to mean the automatic transmission is neither park or neutral. Important - If the backup switch connector were to be plugged in upside down, the park switch would receive no power. Such a condition would cause a 0-voltage signal at both pin D2 and pin D16 in neutral and in park. The transfer case, accordingly, would perform a range shift in park as well as in neutral. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 5496 - An open in circuit 75, or an open in the Turn/BU fuse would also cause this condition. - Additionally, a park/neutral position switch that is out of adjustment may prevent a range shift in park. Clutch Safety Switch Inputs Clutch Safety Switch Schematic Clutch Safety Switch Voltage Signals OPERATION Because range shifts should only be made with the manual transmission clutch fully depressed, the clutch safety switch informs the Transfer Case Control Module (TCCM) that the vehicle clutch pedal is fully depressed or released. The clutch safety switch is connected to TCCM connector pin D16. When the clutch pedal is released, the contacts of the clutch safety switch are open. When these contacts are open, a battery voltage signal is seen at TCCM connector pin D16. The TCCM interprets this signal to mean the clutch is released. When the clutch is fully depressed, the contacts of the clutch safety switch are closed. When the contacts are closed, voltage is pulled low to 0 at TCCM connector pin D16. The TCCM interprets this signal to mean the clutch pedal is fully depressed. Because TCCM connector pin D2 is not connected when the vehicle is equipped with a manual transmission, the TCCM reads a 0-volt signal at pin D2 at all times. All readings are taken while back-probing the TCCM pins with the ignition in the "Run" position. A reading of less than 0.5 volt is considered to be zero. Vehicle Speed Input Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 5497 Vehicle Sensor Buffer And TCCM Schematic OPERATION The vehicle speed sensor buffer informs the Transfer Case Control Module (TCCM) about the speed of the vehicle in miles per hour. Such information is essential to inform the TCCM to prohibit range shifts at speeds above 3 mph. The vehicle speed sensor (VSS) is a variable-reluctance magnetic sensing device that converts tone wheel rotation into a frequency and voltage output proportional to the vehicle speed. The frequency and voltage signal is sent to the vehicle speed sensor buffer which converts the speed sensor output into a useful pulse signal. The vehicle speed sensor buffer then, pulses circuit 1567 to ground at a rate of 4000 pulses per mile. Whenever the vehicle speed sensor buffer grounds circuit 1567, the voltage at TCCM connector pin D8 returns to 5 volts. The TCCM reads the 4000 pulses-per-mile (1.11 Hz per mph) signal to determine vehicle speed. Encoder Switch Inputs Fig 1, Electric Shift Encoder Switch Layout Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 5498 Fig 2, Electric Shift Encoder Switch Schematic Fig 3, Encoder Switch Channel Signals And Positions OPERATION The four-channel encoder switch indicates the current transfer case mode and range to the Transfer Case Control Module (TCCM). The encoder switch is located inside the encoder itself and is not serviceable. The TCCM reads the status of the four channels to determine the range and mode in which the transfer case is operating or whether the transfer case is shifting between modes and/or ranges. The encoder assembly is composed of an inner ground ring in contact with a three-leg wiper arm. The three legs of the wiper, spaced 120 degrees apart, make contact with the conductive areas of the four channels. When any leg of the wiper arm is in contact with the conductive area of any channel, a path to ground is provided to the inner ground ring. A schematic of the encoder switch is shown in Figure 2. The channel signals in various transfer case operating modes and ranges are shown in Figure 3. Any combination of signals not listed in Figure 3 are considered invalid by the TCCM. Encoder Switch Channel Positions These voltage readings can be obtained by back-probing either the TCCM connector pins or the transfer case connector pins. For TCCM pin numbers and encoder channels, refer to Figure 2. Diagnostic Enable Input Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 5499 Wiring Schematic For Enabling The Status Lamps OPERATION When pin J of the Data Link Connector (DLC) is connected either to pin A of the DLC or to a good ground while the ignition is on, the diagnostics routine of the Transfer Case Control Module (TCCM) is activated. When the diagnostics routine is activated, the transfer case selector switch 4HI and 4LO status lamps flash the diagnostic codes. Electric Shift Motor Outputs Electric Shift Motor Schematic OPERATION The Transfer Case Control Module (TCCM) provides the output for the electric shift motor as the schematic shows. - Motor control is achieved by energizing one of the two motor control relays located in the TCCM, by way of the transfer case selector switch. The TCCM operates the motor in one direction by energizing one relay while the second relay is de-energized. The TCCM operates the motor in the reverse direction by energizing the second relay while the first relay is de-energized. - Motor power to actuate the motor drive relays is input at TCCM connector pins D14 and D15. This power is supplied by the ignition through the 30-amp power circuit breaker. - Motor ground is input at TCCM connector pins D12 and D13 to provide the return line for the motor drive relays. 4HI and 4LO Status Lamps Outputs Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 5500 Selector Switch Status Lamp Schematic OPERATION The Transfer Case Control Module (TCCM) controls the operation of the 4HI and 4LO status lamps in the transfer case selector switch. The status lamps also show the transfer case mode and range of operation. The status lamps also provide a self-test when the ignition is first turned on. Additionally, the status lamps are used to alert the driver that there is a problem somewhere in the four-wheel drive system, and also to flash diagnostic trouble codes (DTC's). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Page 5501 Control Module: Service and Repair TRANSFER CASE MODULE REPLACEMENT REMOVE OR DISCONNECT 1. Negative battery cable. 2. ECM (utility only). 3. Cowl side panel (pickup only). 4. Electrical connection. 5. Module to cowl panel screws (pickup only). 6. Module. INSTALL OR CONNECT 1. Module. 2. Module to cowl panel screws (pickup only). 3. Electrical connection. 4. ECM (utility only). 5. Negative battery cable. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Fluid - Transfer Case > Component Information > Specifications > Capacity Specifications Fluid - Transfer Case: Capacity Specifications Fluid Capacity ...................................................................................................................................... ...................................................................... 2.5 Pts. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Fluid - Transfer Case > Component Information > Specifications > Capacity Specifications > Page 5506 Fluid - Transfer Case: Fluid Type Specifications Lubricant Type ..................................................................................................................................... .................................................... Dexron II E ATF * * 1996 Models, Dexron III ATF Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Four Wheel Drive Indicator Lamp > Component Information > Locations Four-Wheel Drive Indicator Lamp Wiring I/P Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Four Wheel Drive Indicator Lamp > Component Information > Locations > Page 5510 C274 - 4WD Indicator Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Four Wheel Drive Indicator Lamp > Component Information > Locations > Page 5511 Four Wheel Drive Indicator Lamp: Description and Operation The Four-Wheel Drive (4WD) Indicator Assembly provides visual information about the operating mode and gear range of the driveline. Voltage is supplied to the IGN/GAU Fuse and Indicator Assembly with the Ignition Switch in START or RUN. The circuit is completed through the Selector Quadrant Switch, which provides a ground path to light various Indicator Assembly Lamps. With the Selector Quadrant Switch in detent position 1, the "2WHL" Indicator Assembly Lamp is lit. With the Selector Quadrant Switch in detent position 2, the "4 HIGH" Indicator Assembly Lamp is lit. At this time, the Front Axle Switch is closed and the Indicator Assembly Front and Rear Axle Display is lit. With the Selector Quadrant Switch in detent position 4, the "4 LOW" Indicator Lamp is lit. At this time, the Front Axle Switch is closed, and the Indicator Assembly Front and Rear Axle Display is lit. A signal is sent to the Four-Wheel Antilock Brake Module (4WAL) whenever the 4WD is engaged. This signal turns off the 4WAL systems to prevent operation during 4WD operation. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Four Wheel Drive Indicator Lamp > Component Information > Testing and Inspection > Initial Inspection and Diagnostic Overview Four Wheel Drive Indicator Lamp: Initial Inspection and Diagnostic Overview Circuit Operation - Four-Wheel Drive Indicator The Four-Wheel Drive (4WD) Indicator Assembly provides visual information about the operating mode and gear range of the driveline. Voltage is supplied to the IGN/GAU Fuse and Indicator Assembly with the Ignition Switch in START or RUN. The circuit is completed through the Selector Quadrant Switch, which provides a ground path to light various Indicator Assembly Lamps. With the Selector Quadrant Switch in detent position 1, the "2WHL" Indicator Assembly Lamp is lit. With the Selector Quadrant Switch in detent position 2, the "4 HIGH" Indicator Assembly Lamp is lit. At this time, the Front Axle Switch is closed and the Indicator Assembly Front and Rear Axle Display is lit. With the Selector Quadrant Switch in detent position 4, the "4 LOW" Indicator Lamp is lit. At this time, the Front Axle Switch is closed, and the Indicator Assembly Front and Rear Axle Display is lit. A signal is sent to the Four-Wheel Antilock Brake Module (4WAL) whenever the 4WD is engaged. This signal turns off the 4WAL systems to prevent operation during 4WD operation. Preliminary Checks - Four-Wheel Drive Indicator 1. Check condition of IGN/GAU Fuse. If fuse is Blown, locate and repair overload. Replace fuse. 2. If fuse is not blown, proceed with the Diagnostics. See: Symptom Related Diagnostic Procedures Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Four Wheel Drive Indicator Lamp > Component Information > Testing and Inspection > Initial Inspection and Diagnostic Overview > Page 5514 Four Wheel Drive Indicator Lamp: Symptom Related Diagnostic Procedures Indicator Assembly Illumination Lamp Does Not Light One Or More Indicator Assembly Lamps Do Not Light Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Four Wheel Drive Selector Switch > Component Information > Locations > Pickup Transfer Case Select Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Four Wheel Drive Selector Switch > Component Information > Locations > Pickup > Page 5519 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Four Wheel Drive Selector Switch > Component Information > Locations > Page 5520 Four Wheel Drive Selector Switch: Service and Repair Fig. 2 Transfer Case Shift Linkage. Except Bravada, Sonoma GT, Syclone & Typhoon Fig. 4 Selector Switch Installation. Except Bravada, Sonoma GT, Syclone & Typhoon 1. Disconnect battery ground cable. 2. Remove console, then disconnect console wiring harness. 3. Remove shifter boot retaining screws and slide boot up shift lever. 4. Remove switch attaching screw, then the switch and harness, Fig. 2. 5. Position new switch on mounting bracket and install attaching screw.Ensure shift lever assembly pawl is on the switch contact carrier. 6. Route wiring as shown in Fig. 4. 7. Place shifter boot in proper position, then install retaining screws. 8. Connect console wiring harness, then install console. 9. Connect battery ground cable. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Gear Sensor/Switch, Transfer Case > Component Information > Locations > Electric Shift Transfer Case Switch Gear Sensor/Switch: Locations Electric Shift Transfer Case Switch Transfer Case Electric Shift Motor Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Gear Sensor/Switch, Transfer Case > Component Information > Locations > Electric Shift Transfer Case Switch > Page 5525 Electric Shift Transfer Case Wiring Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Gear Sensor/Switch, Transfer Case > Component Information > Locations > Electric Shift Transfer Case Switch > Page 5526 4WD Components Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Lamps and Indicators - Transfer Case > Four Wheel Drive Indicator Lamp > Component Information > Locations Four-Wheel Drive Indicator Lamp Wiring I/P Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Lamps and Indicators - Transfer Case > Four Wheel Drive Indicator Lamp > Component Information > Locations > Page 5531 C274 - 4WD Indicator Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Lamps and Indicators - Transfer Case > Four Wheel Drive Indicator Lamp > Component Information > Locations > Page 5532 Four Wheel Drive Indicator Lamp: Description and Operation The Four-Wheel Drive (4WD) Indicator Assembly provides visual information about the operating mode and gear range of the driveline. Voltage is supplied to the IGN/GAU Fuse and Indicator Assembly with the Ignition Switch in START or RUN. The circuit is completed through the Selector Quadrant Switch, which provides a ground path to light various Indicator Assembly Lamps. With the Selector Quadrant Switch in detent position 1, the "2WHL" Indicator Assembly Lamp is lit. With the Selector Quadrant Switch in detent position 2, the "4 HIGH" Indicator Assembly Lamp is lit. At this time, the Front Axle Switch is closed and the Indicator Assembly Front and Rear Axle Display is lit. With the Selector Quadrant Switch in detent position 4, the "4 LOW" Indicator Lamp is lit. At this time, the Front Axle Switch is closed, and the Indicator Assembly Front and Rear Axle Display is lit. A signal is sent to the Four-Wheel Antilock Brake Module (4WAL) whenever the 4WD is engaged. This signal turns off the 4WAL systems to prevent operation during 4WD operation. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Lamps and Indicators - Transfer Case > Four Wheel Drive Indicator Lamp > Component Information > Testing and Inspection > Initial Inspection and Diagnostic Overview Four Wheel Drive Indicator Lamp: Initial Inspection and Diagnostic Overview Circuit Operation - Four-Wheel Drive Indicator The Four-Wheel Drive (4WD) Indicator Assembly provides visual information about the operating mode and gear range of the driveline. Voltage is supplied to the IGN/GAU Fuse and Indicator Assembly with the Ignition Switch in START or RUN. The circuit is completed through the Selector Quadrant Switch, which provides a ground path to light various Indicator Assembly Lamps. With the Selector Quadrant Switch in detent position 1, the "2WHL" Indicator Assembly Lamp is lit. With the Selector Quadrant Switch in detent position 2, the "4 HIGH" Indicator Assembly Lamp is lit. At this time, the Front Axle Switch is closed and the Indicator Assembly Front and Rear Axle Display is lit. With the Selector Quadrant Switch in detent position 4, the "4 LOW" Indicator Lamp is lit. At this time, the Front Axle Switch is closed, and the Indicator Assembly Front and Rear Axle Display is lit. A signal is sent to the Four-Wheel Antilock Brake Module (4WAL) whenever the 4WD is engaged. This signal turns off the 4WAL systems to prevent operation during 4WD operation. Preliminary Checks - Four-Wheel Drive Indicator 1. Check condition of IGN/GAU Fuse. If fuse is Blown, locate and repair overload. Replace fuse. 2. If fuse is not blown, proceed with the Diagnostics. See: Symptom Related Diagnostic Procedures Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Lamps and Indicators - Transfer Case > Four Wheel Drive Indicator Lamp > Component Information > Testing and Inspection > Initial Inspection and Diagnostic Overview > Page 5535 Four Wheel Drive Indicator Lamp: Symptom Related Diagnostic Procedures Indicator Assembly Illumination Lamp Does Not Light One Or More Indicator Assembly Lamps Do Not Light Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Locations Control Module: Locations Mounted on the back of the Electronic Control Module (ECM)/Powertrain Control Module (PCM) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Locations > Page 5540 C202A - Transfer Case Control Module Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting Control Module: Description and Operation Electric 4WD Shifting Transfer Case 4WD Selector Switch 4WD Selector Switch Wiring Schematic OPERATION On vehicles equipped with the Model 233 transfer case, there is no transfer case selector lever in the cab. The operator selects 4HI or 4LO by pushing a three-position (4HI, 4LO, 2HI) rocker-type selector switch mounted on the instrument panel. During normal driving the transfer case is in the 2HI mode. The switch is spring-loaded to the center position. When the transfer case is in 2HI both the 4HI and 4L0 switch circuits are open, and both lights are off. When shifting to 4HI or 4LO the rocker switch will still return to the center position and the 4HI or 4LO light will be on. The above image shows the wiring schematic of the transfer case selector switch. Mode Shifts Mode shifts are shifts from: - 2HI to 4HI - 4HI to 2HI A mode shift can be accomplished in any gear position and at any vehicle speed. If the system is in 2HI, the operator can shift into 4HI merely by pressing and releasing the 4HI area of the selector rocker switch. The green 4HI status lamp flashes whenever a 2HI or 4HI shift is initiated and continues to flash until the TCCM completes the shift (or until 30 seconds elapses). After the shift into 4HI is accomplished, the 4HI status lamp remains lit to indicate that the system is in 4HI. The operator can shift from 4HI back to 2HI by again pressing 4HI on the selector switch. Again, the green 4HI status lamp flashes until the shift to 2HI is complete, and then extinguishes once the shift is complete. Both the 4HI and 4LO lamps remain oft when the vehicle is in 2HI. Range Shifts Range shifts are shifts between the HI and LO ranges, from: Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 5543 - 2HI to 4LO - 4HI to 4LO - 4LO to 4HI A range shift from 4L0 directly to 2HI cannot be made. The operator must first make range shift from 4LO to 4HI, then a mode shift from 4HI to 2HI. A range shift can only be made with the automatic transmission in neutral or with the manual transmission clutch fully depressed. The vehicle speed must also be below three miles per hour before the shift can occur. Whenever a shift into 4LO is initiated, the amber 4LO status lamp flashes and continues to flash until the TCCM completes the shift (or until 30 seconds elapses). The 4LO status lamp must glow steadily before the vehicle transmission is shifted into gear or before the clutch pedal is released. If a range shift is initiated when the transmission is engaged or when the vehicle speed is above 3 mph, the 4LO status lamp flashes for 30 seconds and no range shift actually occurs; the system returns to the position before the shift was initiated. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 5544 Control Module: Description and Operation TCCM Power and Ground Fig. 1, Memory Power, System Power, And Ground Circuit Fig. 2, Fuse Block And Cavity Location Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 5545 POWER, CIRCUIT PROTECTION, AND GROUND The Transfer Case Control Module (TCCM) memory power, system power, and the ground circuit are shown in Figure 1. The vehicle fuse block and cavity location for memory power, system power, and motor power are shown in Figure 2. Memory Power Trouble code memory power is protected by a 5-amp TCCM fuse. Memory power is supplied to TCCM connector pin C6 through circuit 140. System Power Operating power is controlled by the ignition switch and is protected by a 15-amp radio fuse. System power is supplied to TCCM connector pin C8 through circuit 141. This fuse also supplies, voltage to pin B of the transfer case switch. The system power will shut down if either the 5-amp TCCM fuse or the 15-amp radio fuse are removed or blown. System Ground System ground is supplied to TCCM connector pin C10 through circuit 150. Circuit 150 is connected to the bus bar ground located on the left side of the steering column support. Refer to Figure 1. Turn/BU Fuse A 15-amp TURN/BU fuse supplies ignition voltage to the park/neutral position switch. This voltage enables the park switch to send a park signal to TCCM connector pin D2. Power Accessory Circuit Breaker The 30-amp power accessory circuit breaker supplies ignition voltage to TCCM connector pins D14 and D15. This voltage is used to control the electric-shift motor circuit. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 5546 Control Module: Description and Operation TCCM Inputs and Outputs General Description INPUTS The Transfer Case Control Module (TCCM) receives input signals from the following sources: - Transfer case selector switch on the instrument panel. - Park/neutral position switch on vehicles with automatic transmissions. - Clutch safety switch on vehicles with manual transmissions. - Vehicle speed sensor buffer which supplies vehicle speed signals. - Encoder switch within the electric-shift motor which provides actual mode and range information signals. - Data link connector (DLC) pin J which provides diagnostic enable. OUTPUTS After processing the input information, the Transfer Case Control Module (TCCM) outputs signals to the following: - Electric shift motor to effect mode and range shifts. - Selector switch status lamps to provide transfer case status information. - Diagnostic trouble codes (DTC) which are output via the selector switch status lamps. 2HI to 4HI Selector Switch Input 4WD Selector Switch Wiring Schematic OPERATION When the transfer case is in 2HI and the operator presses the 4HI area of the rocker switch, the 4HI contacts of the selector switch close, connecting circuits 141 and 1564, and furnishing 12-volts to pin C5 of the TCCM connector. The 12-volt signal at pin C5 commands the Transfer Case Control Module (TCCM) to signal the electric-shift motor to shift into 4HI. The contacts return to the open position as soon as the switch is released. 4HI to 2HI Selector Switch Input Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 5547 4WD Selector Switch Wiring Schematic OPERATION If the transfer case is in 4HI and the operator presses the 4HI area of the rocker switch, the 4HI contacts of the selector switch close, connecting circuits 141 and 1564 and furnishing 12-volts to pin C5 of the Transfer Case Control Module (TCCM) connector. The 12-volt signal at pin C5 commands the TCCM to signal the electric-shift motor to shift into 4HI. Again, the contacts return to the open position as soon as the switch is released. 2HI to 4HI to 4LO Selector Switch Input 4WD Selector Switch Wiring Schematic OPERATION When the operator presses the 4LO area of the rocker switch while the transfer case is in either 2HI or 4HI, the 4LO contacts of the selector switch close, connecting circuits 141 and 1559, and furnishing 12-volts to pin C3 of the Transfer Case Control Module (TCCM) connector. The 12-volt signal at pin C3 commands the TCCM to signal the electric-shift motor to shift the transfer case into 4LO. Once more, the contacts return to the open position as soon as the switch is released. Park/Neutral Position Switch Inputs Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 5548 Automatic Transmission Neutral Start Switch Neutral Start Switch Voltages OPERATION Because range shift should only be made with the automatic transmission in neutral, the park/neutral position switch informs the Transfer Case Control Module (TCCM) that the vehicle automatic transmission is in either: - Park - Neutral - One of the drive positions The park/neutral position switch consists of three switches together in one unit, and it provides three signals: - Park - When the automatic transmission is in park, the contacts of both the park switch and the park neutral switch are closed. When these contacts are closed, a battery voltage signal is sent to TCCM connector pin D2, while connector pin D16 is pulled to ground (0 voltage). The TCCM interprets this signal to mean the automatic transmission is in park. - Neutral - When the automatic transmission is in neutral, the contacts of the park switch are open and the contacts of the park neutral position switch are closed. In this condition, a 0-voltage signal is sent to TCCM connector pin D2, while connector pin D16 is pulled to ground (0 volts). The TCCM interprets this signal to mean the automatic transmission is in neutral. - In gear - When the automatic transmission is in any other gear position, the contacts of both the park switch and park neutral switch are open. In this condition, a 0-voltage signal is sent to TCCM connector pin D16. The TCCM interprets this signal to mean the automatic transmission is neither park or neutral. Important - If the backup switch connector were to be plugged in upside down, the park switch would receive no power. Such a condition would cause a 0-voltage signal at both pin D2 and pin D16 in neutral and in park. The transfer case, accordingly, would perform a range shift in park as well as in neutral. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 5549 - An open in circuit 75, or an open in the Turn/BU fuse would also cause this condition. - Additionally, a park/neutral position switch that is out of adjustment may prevent a range shift in park. Clutch Safety Switch Inputs Clutch Safety Switch Schematic Clutch Safety Switch Voltage Signals OPERATION Because range shifts should only be made with the manual transmission clutch fully depressed, the clutch safety switch informs the Transfer Case Control Module (TCCM) that the vehicle clutch pedal is fully depressed or released. The clutch safety switch is connected to TCCM connector pin D16. When the clutch pedal is released, the contacts of the clutch safety switch are open. When these contacts are open, a battery voltage signal is seen at TCCM connector pin D16. The TCCM interprets this signal to mean the clutch is released. When the clutch is fully depressed, the contacts of the clutch safety switch are closed. When the contacts are closed, voltage is pulled low to 0 at TCCM connector pin D16. The TCCM interprets this signal to mean the clutch pedal is fully depressed. Because TCCM connector pin D2 is not connected when the vehicle is equipped with a manual transmission, the TCCM reads a 0-volt signal at pin D2 at all times. All readings are taken while back-probing the TCCM pins with the ignition in the "Run" position. A reading of less than 0.5 volt is considered to be zero. Vehicle Speed Input Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 5550 Vehicle Sensor Buffer And TCCM Schematic OPERATION The vehicle speed sensor buffer informs the Transfer Case Control Module (TCCM) about the speed of the vehicle in miles per hour. Such information is essential to inform the TCCM to prohibit range shifts at speeds above 3 mph. The vehicle speed sensor (VSS) is a variable-reluctance magnetic sensing device that converts tone wheel rotation into a frequency and voltage output proportional to the vehicle speed. The frequency and voltage signal is sent to the vehicle speed sensor buffer which converts the speed sensor output into a useful pulse signal. The vehicle speed sensor buffer then, pulses circuit 1567 to ground at a rate of 4000 pulses per mile. Whenever the vehicle speed sensor buffer grounds circuit 1567, the voltage at TCCM connector pin D8 returns to 5 volts. The TCCM reads the 4000 pulses-per-mile (1.11 Hz per mph) signal to determine vehicle speed. Encoder Switch Inputs Fig 1, Electric Shift Encoder Switch Layout Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 5551 Fig 2, Electric Shift Encoder Switch Schematic Fig 3, Encoder Switch Channel Signals And Positions OPERATION The four-channel encoder switch indicates the current transfer case mode and range to the Transfer Case Control Module (TCCM). The encoder switch is located inside the encoder itself and is not serviceable. The TCCM reads the status of the four channels to determine the range and mode in which the transfer case is operating or whether the transfer case is shifting between modes and/or ranges. The encoder assembly is composed of an inner ground ring in contact with a three-leg wiper arm. The three legs of the wiper, spaced 120 degrees apart, make contact with the conductive areas of the four channels. When any leg of the wiper arm is in contact with the conductive area of any channel, a path to ground is provided to the inner ground ring. A schematic of the encoder switch is shown in Figure 2. The channel signals in various transfer case operating modes and ranges are shown in Figure 3. Any combination of signals not listed in Figure 3 are considered invalid by the TCCM. Encoder Switch Channel Positions These voltage readings can be obtained by back-probing either the TCCM connector pins or the transfer case connector pins. For TCCM pin numbers and encoder channels, refer to Figure 2. Diagnostic Enable Input Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 5552 Wiring Schematic For Enabling The Status Lamps OPERATION When pin J of the Data Link Connector (DLC) is connected either to pin A of the DLC or to a good ground while the ignition is on, the diagnostics routine of the Transfer Case Control Module (TCCM) is activated. When the diagnostics routine is activated, the transfer case selector switch 4HI and 4LO status lamps flash the diagnostic codes. Electric Shift Motor Outputs Electric Shift Motor Schematic OPERATION The Transfer Case Control Module (TCCM) provides the output for the electric shift motor as the schematic shows. - Motor control is achieved by energizing one of the two motor control relays located in the TCCM, by way of the transfer case selector switch. The TCCM operates the motor in one direction by energizing one relay while the second relay is de-energized. The TCCM operates the motor in the reverse direction by energizing the second relay while the first relay is de-energized. - Motor power to actuate the motor drive relays is input at TCCM connector pins D14 and D15. This power is supplied by the ignition through the 30-amp power circuit breaker. - Motor ground is input at TCCM connector pins D12 and D13 to provide the return line for the motor drive relays. 4HI and 4LO Status Lamps Outputs Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 5553 Selector Switch Status Lamp Schematic OPERATION The Transfer Case Control Module (TCCM) controls the operation of the 4HI and 4LO status lamps in the transfer case selector switch. The status lamps also show the transfer case mode and range of operation. The status lamps also provide a self-test when the ignition is first turned on. Additionally, the status lamps are used to alert the driver that there is a problem somewhere in the four-wheel drive system, and also to flash diagnostic trouble codes (DTC's). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Page 5554 Control Module: Service and Repair TRANSFER CASE MODULE REPLACEMENT REMOVE OR DISCONNECT 1. Negative battery cable. 2. ECM (utility only). 3. Cowl side panel (pickup only). 4. Electrical connection. 5. Module to cowl panel screws (pickup only). 6. Module. INSTALL OR CONNECT 1. Module. 2. Module to cowl panel screws (pickup only). 3. Electrical connection. 4. ECM (utility only). 5. Negative battery cable. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Sensors and Switches - Transfer Case > Four Wheel Drive Selector Switch > Component Information > Locations > Pickup Transfer Case Select Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Sensors and Switches - Transfer Case > Four Wheel Drive Selector Switch > Component Information > Locations > Pickup > Page 5560 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Sensors and Switches - Transfer Case > Four Wheel Drive Selector Switch > Component Information > Locations > Page 5561 Four Wheel Drive Selector Switch: Service and Repair Fig. 2 Transfer Case Shift Linkage. Except Bravada, Sonoma GT, Syclone & Typhoon Fig. 4 Selector Switch Installation. Except Bravada, Sonoma GT, Syclone & Typhoon 1. Disconnect battery ground cable. 2. Remove console, then disconnect console wiring harness. 3. Remove shifter boot retaining screws and slide boot up shift lever. 4. Remove switch attaching screw, then the switch and harness, Fig. 2. 5. Position new switch on mounting bracket and install attaching screw.Ensure shift lever assembly pawl is on the switch contact carrier. 6. Route wiring as shown in Fig. 4. 7. Place shifter boot in proper position, then install retaining screws. 8. Connect console wiring harness, then install console. 9. Connect battery ground cable. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Sensors and Switches - Transfer Case > Gear Sensor/Switch, Transfer Case > Component Information > Locations > Electric Shift Transfer Case Switch Gear Sensor/Switch: Locations Electric Shift Transfer Case Switch Transfer Case Electric Shift Motor Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Sensors and Switches - Transfer Case > Gear Sensor/Switch, Transfer Case > Component Information > Locations > Electric Shift Transfer Case Switch > Page 5566 Electric Shift Transfer Case Wiring Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Sensors and Switches - Transfer Case > Gear Sensor/Switch, Transfer Case > Component Information > Locations > Electric Shift Transfer Case Switch > Page 5567 4WD Components Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Sensors and Switches - Transfer Case > Speed Sensor, Transfer Case > Component Information > Technical Service Bulletins > Drivetrain - Updated Transfer Case Speed Sensor Conn. Speed Sensor: Technical Service Bulletins Drivetrain - Updated Transfer Case Speed Sensor Conn. Bulletin No.: 06-04-21-001 Date: May 17, 2006 INFORMATION Subject: Updated Transfer Case Connector Service Kit Now Available For Transfer Case Speed Sensor Wire Harness Connector that Comes Loose Or Connector Retainer Clip Breaks Models: 2007 and Prior GM Light Duty Trucks 2007 and Prior HUMMER H2, H3 2005-2007 Saab 9-7X with Four-Wheel Drive or All-Wheel Drive Technicians may find that when the transfer case speed sensor wire harness connector is removed, the connector lock flexes/bends and does not return to the original position. The transfer case speed sensor wire harness connector then has no locking device. On older vehicles, the plastic connector retainer becomes brittle and the clip may break as soon as it is flexed. In the past, the only service fix was to install a wire harness connector service pack, P/N 88987183. This repair procedure involved splicing a new service connector with an integral connector lock. This connector service kit is of the same design and was still prone to failure over time. A new connector service repair kit is now available, P/N 15306187, that is an updated design. This new kit should be used whenever the speed sensor wire harness connector requires replacement. Parts Information Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Shifter Transfer Case > Component Information > Service and Repair Shifter Transfer Case: Service and Repair Fig. 1 Shifter & Shift Lever Mounting. REMOVAL 1. Disconnect battery ground cable. 2. Remove console, then the shift boot. 3. Loosen shift lever jam nut, then unscrew shift lever. 4. Remove transfer case selector switch. 5. Raise and support vehicle. 6. Disconnect shift rod at shifter assembly, then remove pivot and adjusting bolt, Fig. 1. 7. Remove shifter. INSTALLATION 1. Position shifter at bracket, then install pivot and adjusting bolt, Fig. 1. 2. Connect shift rod, then adjust shift linkage. 3. Lower vehicle. 4. Install shift lever on shifter, then screw lever down until pawl just clears bracket, then tighten shift lever an additional 1&1/2 turns and tighten jam nut. 5. Install selector switch, shift boot and console. 6. Install battery ground cable. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Shift Linkage, Transfer Case > Shift Cable, Transfer Case > Component Information > Adjustments Shift Cable: Adjustments Fig. 2 Transfer Case Shift Linkage. Except Bravada, Sonoma GT, Syclone & Typhoon Fig. 3 Transfer Case Shift Lever Positioning. Except Bravada, Sonoma GT, Syclone & Typhoon 1. Remove console, then pull shift boot up shift lever. 2. Loosen small bolt and washer (A) and pivot bolt (B), Fig. 2. 3. Position transfer case shift lever at 4 Hi position. 4. Install a 8 mm gage pin or 5/16 inch drill bit through shifter into bracket (C), Fig. 2. 5. Install a bolt at the transfer case lever to lock transfer case in 4 Hi, Fig. 3. 6. Torque small bolt and washer (A) to 25-35 ft. lbs., then pivot bolt (B) to 88-103 ft. lbs., Fig. 2. 7. Remove bolt installed at transfer case lever, then gage pin or drill bit from shifter and bracket. 8. Place shift boot in proper position, then install console. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Speed Sensor, Transfer Case > Component Information > Technical Service Bulletins > Drivetrain - Updated Transfer Case Speed Sensor Conn. Speed Sensor: Technical Service Bulletins Drivetrain - Updated Transfer Case Speed Sensor Conn. Bulletin No.: 06-04-21-001 Date: May 17, 2006 INFORMATION Subject: Updated Transfer Case Connector Service Kit Now Available For Transfer Case Speed Sensor Wire Harness Connector that Comes Loose Or Connector Retainer Clip Breaks Models: 2007 and Prior GM Light Duty Trucks 2007 and Prior HUMMER H2, H3 2005-2007 Saab 9-7X with Four-Wheel Drive or All-Wheel Drive Technicians may find that when the transfer case speed sensor wire harness connector is removed, the connector lock flexes/bends and does not return to the original position. The transfer case speed sensor wire harness connector then has no locking device. On older vehicles, the plastic connector retainer becomes brittle and the clip may break as soon as it is flexed. In the past, the only service fix was to install a wire harness connector service pack, P/N 88987183. This repair procedure involved splicing a new service connector with an integral connector lock. This connector service kit is of the same design and was still prone to failure over time. A new connector service repair kit is now available, P/N 15306187, that is an updated design. This new kit should be used whenever the speed sensor wire harness connector requires replacement. Parts Information Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Transfer Case Actuator > Component Information > Locations > Electronic Shift Transfer Case Position Switch Transfer Case Actuator: Locations Electronic Shift Transfer Case Position Switch Transfer Case Electric Shift Motor The Electronic Shift Transfer Case Position Switch (Encoder Switch) is located in the in the shift motor on the transfer case. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Transfer Case Actuator > Component Information > Locations > Electronic Shift Transfer Case Position Switch > Page 5587 Four-Wheel Drive Indicator Wiring Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Transfer Case Actuator > Component Information > Locations > Page 5588 Transfer Case Actuator: Diagrams C154 - Front Axle Switch C155 - Front Axle Switch In-Line C154 - Front Axle Switch C155 - Front Axle Switch In-Line Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transfer Case > Transfer Case Actuator > Component Information > Locations > Page 5589 Transfer Case Actuator: Service and Repair ELECTRIC SHIFT MOTOR REPLACEMENT Transfer Case Electric Shift Motor REMOVE OR DISCONNECT 1. Negative battery cable. - Raise vehicle and support with safety stands. 2. Transfer case shield. 3. Motor electrical connection. 4. Front propeller shaft. 5. Front output shaft yoke. 6. Motor to transfer case bolts. 7. Motor from the transfer case. INSTALL OR CONNECT 1. Motor to the transfer case. 2. Bolts. TIGHTEN - Bolts to 18 Nm (13 lbs. ft.). 3. Front output shaft yoke. 4. Front propeller shaft. 5. Motor electrical connection. 6. Transfer case shield. 7. Negative battery cable. - Lower Vehicle Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Pressure Regulating Solenoid, A/T > Component Information > Description and Operation Pressure Regulating Solenoid: Description and Operation PURPOSE This electrical device, controlled by the PCM, is used to control fluid line pressure. OPERATION The solenoid controls line pressure by controlling actuator feed limit fluid flow acting on internal spool valve and spring pressure. The solenoid is a normally closed solenoid valve that controls fluid pressure when operating on a duty cycle. LOCATION The solenoid is attached to the control valve body within the transmission. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Specifications > Electrical Specifications Shift Solenoid: Electrical Specifications Component Resistance Chart Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Specifications > Electrical Specifications > Page 5600 Shift Solenoid: Mechanical Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Pressure Control Solenoid To Valve Body .......................................................................................... ................................................................................ 8 Solenoid Assembly To Pump .......................... .............................................................................................................................................................. ....... 8 Solenoid Assembly To Case .................................................................................................... ........................................................................................... 18 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Locations > 4L60-E Automatic Transmission Electronic Component Location Views Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Locations > 4L60-E Automatic Transmission > Page 5603 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Description and Operation > 1 -2 Shift Solenoid Shift Solenoid: Description and Operation 1 -2 Shift Solenoid PURPOSE This electrical device, controlled by the PCM, is used to control fluid flow acting on the 1-2 and 3-4 shift valves. OPERATION The solenoid is a normally open exhaust valve that is used with the 2-3 shift solenoid to allow four different shifting combinations. LOCATION The solenoid is attached to the control valve body within the transmission. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Description and Operation > 1 -2 Shift Solenoid > Page 5606 Shift Solenoid: Description and Operation 2-3 Shift Solenoid PURPOSE This electrical device, controlled by the PCM, is used to control fluid flow acting on the 2-3 shift valves. OPERATION The solenoid is a normally open exhaust valve that is used with the 1-2 shift solenoid to allow four different shifting combinations. LOCATION The solenoid is attached to the control valve body within the transmission. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Description and Operation > 1 -2 Shift Solenoid > Page 5607 Shift Solenoid: Description and Operation 3-2 Control Solenoid PURPOSE This electrical device, controlled by the PCM, is used to control fluid flow acting on the 3-2 shift valve, which then controls the 2-4 band apply rate and 3-4 clutch release rate. The solenoid also controls the 3-2 downshift feel. OPERATION The solenoid is a pulse width modulated solenoid that operates on a negative duty cycle. LOCATION The solenoid is attached to the control valve body within the transmission. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission Shift Solenoid: Service and Repair 4L60-E Automatic Transmission Pan and Filter Assembly PAN AND FILTER ASSEMBLY Pan, Filter And Seal Removal CLEAN - Exposed ends of bottom pan screws and spray with penetrating oil. REMOVE OR DISCONNECT 1. Screws (76), oil pan (75) and gasket (73). 2. Oil filter (72) and filter seal (71). - Filter seal may be stuck in the pump. INSPECT - Filter (72), open filter by prying the metal crimping away from the top of the filter (black) and pull apart. The filter may contain evidence for root cause diagnosis. Clutch material. - Bronze slivers indicating bushing wear. - Steel particles. Valve Body and Wiring Harness VALVE BODY AND WIRING HARNESS Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 5610 Valve Body Bolt Location Control Valve And Pressure Switch Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 5611 Manual Valve Link Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 5612 Valve Body Checkballs Case Checkballs And Filters REMOVE OR DISCONNECT 1. Electrical connections from components. 2. TCC PWM Solenoid Retainer Clip (379) and Solenoid (396). 3. TCC Solenoid bolts (68) and solenoid assembly (66) with O-ring seal (65) and wiring harness. 4. Pressure switch assembly bolts (70) and pressure switch assembly (69). 5. Accumulator cover bolts (58 and 59) and 1-2 accumulator cover and pin assembly (57). 6. 1-2 accumulator piston (56) and seal (55). 7. Spring (54). 8. Dipstick stop bracket (93). REMOVE OR DISCONNECT 1. Bolt (64) and manual detent spring assembly (63). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 5613 2. Wiring harness retaining bolts. REMOVE OR DISCONNECT 1. Remaining valve body bolts (62). 2. Manual valve link (89). 3. Control valve assembly (60). 4. Bolts (58 and 59), accumulator cover (57), piston (56, spring (54) and spring (54A). 5. Bolts (77) and plate (53). 6. Spacer plate (48) and spacer plate gaskets (47 and 52). 7. Spring (46), piston (44), and pin (43). - Seven checkballs are located under the valve body and one is located in the case. The large copper flash colored ball is # 1A checkball (91). Valve Body and Associated Parts VALVE BODY AND ASSOCIATED PARTS Accumulator Assembly, Spacer Plate And Gaskets Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 5614 Case Checkballs And Filters TOOL REQUIRED: - J 25025-5 Guide Pins NOTICE: The use of a honing stone, fine sandpaper or crocus cloth is not recommended for servicing stuck valves. All valve lands have sharply machined corners that are necessary for "cleaning" the bore. If these corners are rounded, foreign material could wedge between the valve and bore causing the valve to stick. If it is found necessary to clean a valve, "micro fine" lapping compound 900 grit or finer should be used. Too much "lapping" of a valve will cause excessive clearances and increase the chance of a valve not operating. INSTALL OR CONNECT 1. The wiring harness pass-thru connector into the case. 2. The 3-4 accumulator pin (43) into the case. 3. The 3-4 accumulator piston seal (45) onto the 3-4 accumulator piston. 4. The 3-4 accumulator piston (44) onto the pin. - The end with three legs must face the valve body. 5. The 3-4 accumulator piston spring (46). INSTALL OR CONNECT 1. Checkball (91) into case as shown. - Retain with Transjel TM J 36850 or equivalent. 2. J 25025-5 into the case. 3. Screens onto spacer plate as shown. 4. Spacer plate to case gasket (47) and spacer plate to valve body gasket (52) onto the spacer plate (48). - Gasket (47) identified by a "C". Gasket (52) identified by a "V". - Retain with Transjel TM J 36850 or equivalent. 5. Spacer plate and gaskets onto the case. IMPORTANT - Be careful not to damage screens when installing the spacer plate and gaskets. 6. Spacer plate support (53) and bolts (77). TIGHTEN - Bolts to 11 Nm (8 lb. ft.) Control Valve Body CONTROL VALVE BODY Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 5615 Case Checkballs And Filters Filter Screen - Locations Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 5616 Control Valve Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 5617 Control Valve Assembly - Legend Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 5618 Valve Body Checkball Locations Valve Body Bolt Locations Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 5619 Manual Valve Link Outside Electrical Connector CLEAN - Control valve assembly thoroughly in clean solvent. A. Move the valves with a pick or small screwdriver to dislodge any dirt or debris that may have accumulated. B. Air dry. REMOVE OR DISCONNECT IMPORTANT - Some valves are under pressure - cover the bores while removing roll pins and retainer clips. - Valves, springs and bushings must be laid out on a clean surface in the exact sequence they are removed. 1. Pressure control solenoid retainer bolt (364) retainer (378) and solenoid. 2. Bore plug retainer clip (395), bore plug (376) and valve train (374 and 375). 3. 2-3 shift solenoid retainer (379), solenoid (367) and valve train (368 and 369). 4. 1-2 shift solenoid retainer (379), solenoid (367) and valve train (365 and 366). 5. Accumulator valve train retainer pin (360), bore plug (373) and valve train (370 and 371). 6. Forward accumulator cover bolts (364) and cover (363). 7. Forward accumulator spring (356), piston (354) and pin (355). 8. Lo overrun valve spring (362) and valve (361). 9. Retainer pin (360), bore plug (359) and forward abuse valve train (357 and 358). 10. Manual valve (340). 11. 3-2 control solenoid retainer clip (379) and solenoid (394). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 5620 12. Bore plug retainer (395), bore plug (381) and 3-2 control valve train (391 - 393). 13. 3-2 downshift bore plug retainer (395), bore plug (381) and valve train (389 - 390). 14. Reverse abuse bore plug retainer pin (360), bore plug (359) and valve train (387 - 388). 15. 3-4 shift valve bore plug retainer (395), bore plug (381) and valve train (385 - 386). 16. 3-4 relay bore plug retainer (395), bore plug (381) and valve train (382 - 384). 17. Torque converter clutch signal valve bore plug retainer (395), bore plug (381) and valve (380). CLEAN - All valves, springs, bushings and control valve body in clean solvent. - Dry using compressed air. INSPECT - All valves and bushings for: Porosity - Scoring - Nicks - Scratches - Springs for damaged or distorted coils. - Valve body casting for: Porosity - Cracks - Inter connected oil passages - Damaged machined surfaces ASSEMBLE - Control valve assembly (350) exactly as shown. Notice the position of the valve lands and bushing passages. - Position the pressure control solenoid so the connector tabs face outward. NOTICE: TCC PWM solenoid (396) cannot be installed until TCC solenoid has been installed and torqued to proper specifications. INSTALL OR CONNECT 1. Checkballs into the valve body assembly (350). - Retain with Transjell TM J 36850 or equivalent. 2. Valve body assembly (350). - Connect the manual valve link (89) to the inside detent lever (88). - Be careful not to damage screens when installing the valve body assembly. 3. Wiring harness (66), manual spring assembly (63), pressure switch assembly(69), dipstick, stop bracket (93) and all remaining valve body bolts. NOTICE: Torque valve body bolts in a spiral pattern starting from the center. If bolts are torqued at random, valve bores may be distorted and inhibit valve operation. 4. TCC solenoid (66) and bolts (68). TIGHTEN - Bolts to 11 Nm (8 lb. ft.). 5. TCC PWM solenoid (396), and retainer clip (379). INSTALL OR CONNECT - Wiring harness connections to electrical components. - To correctly hook up the wires, see the wiring diagrams. - The pressure control solenoid (377) has two different colored connectors. The black connector should be installed on the tab farthest from the valve body. INSTALL OR CONNECT 1. Parking bracket (86). TIGHTEN - Bolts to 31 Nm (23 lb. ft.). 2. The 1-2 accumulator piston seal (55) onto the 1-2 accumulator piston (56). 3. The 1-2 accumulator spring (54) and 1-2 accumulator inner spring (54A) onto the piston (56). 4. The 1-2 accumulator piston (56) into the 1-2 accumulator cover and pin assembly (57). - The three legs on the piston must face away from the case when installed. 5. The 1-2 accumulator cover and pin assembly (57) onto the case. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 5621 TIGHTEN - Torque to 11 Nm (8 lb. ft.). Pan and Filter Assembly PAN AND FILTER ASSEMBLY Case, Pan And Filter Assembly INSTALL OR CONNECT 1. Filter seal (71) into the pump. 2. Oil filter (72). 3. Oil pan gasket (73). 4. Chip magnet (74) onto oil pan (75). 5. Oil pan (75) and bolts (76). TIGHTEN - Torque to 12 Nm (9 lb. ft.). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 5622 Shift Solenoid: Service and Repair 4L80-E Automatic Transmission Pan and Filter Assembly PAN AND FILTER ASSEMBLY Pan, Filter And Seal Removal REMOVE OR DISCONNECT 1. Drain the transmission fluid Out case extension by rotating transmission to a vertical position. 2. Seventeen bolts (27), using 10 mm socket, drain transmission fluid. 3. Pan (28), seal (29) and magnet (30). IMPORTANT - Seal (29) is reusable. 4. Filter assembly (31). INSPECT - Filter neck seal (32), replace if necessary. Wire Harness Assembly WIRE HARNESS ASSEMBLY Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 5623 Pan, Filter And Seal Removal REMOVE OR DISCONNECT 1. Wire harness connectors from electrical components. NOTICE: Excessive force on the case pass through connector may damage the connector. IMPORTANT - If the wire harness assembly does not need servicing, it is not necessary to remove it from the case. 2. Wire harness assembly (34) from case using a 1-5/16" 12 point socket to release the connector retaining clips. Control Valve Assembly CONTROL VALVE ASSEMBLY Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 5624 REMOVE OR DISCONNECT 1. Rotate transmission bottom pan surface up and lock in place. 2. Wire harness assembly (34) connectors from components. IMPORTANT - If the wire harness assembly does not need servicing, it is not necessary to remove it from the case. - Use a cap to cover electrical pin at case connection. 3. Six bolts (76) using 8 mm socket, and transmission fluid pressure switch assembly (40). NOTICE: Be sure five O-rings are attached to transmission fluid pressure switch assembly. 4. Twenty-one bolts (35) using 10 mm socket, from valve body assembly, manual detent spring and roller assembly (41). 5. Three wiring clamps (33), fluid level indicator stop (43), one bolt (36) using 10 mm socket, lube pipe (39), lube pipe retainer (37) and clamp (38). 6. Control valve assembly (44) including the accumulator housing assembly (51), valve body gaskets (45 and 48), spacer plate (46) and accumulator gasket (47). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 5625 7. Manual valve (319) from control valve assembly (44) to prevent any damage. 8. Checkballs (54) from case passages. NOTICE: Do not use a magnet. It could cause checkball(s) to be magnetized causing metal particles to stick to the ball. 9. Pulse Width Modulated (PWM) solenoid screen (75). INSPECT - Screen PWM solenoid (75), replace if necessary. DISASSEMBLE Control Valve Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 5626 - Control valve assembly. A. Position as shown on a clean surface. B. Remove blind hole retainer pins with a drill bit. CAUTION: Some valves are under pressure - cover the bores while removing the retaining pins or personal injury could result. C. Remove valve trains, shift solenoids (311 and 313), PCS (320), PWM solenoid (323), PCS screen (302) and shift solenoid filter (317). D. Valves, springs, bushings and pistons must be laid out on a clean surface. CLEAN - All valves, springs, bushings, pistons, control valve body and accumulator housing in clean solvent. - Dry using compressed air. INSPECT 1. All valves, pistons and bushings for: - Porosity. - Scoring. - Nicks. - Scratches. 2. Pistons for: - Seal damage. 3. Springs for: - Damaged or distorted coils. 4. Valve body casting and accumulator housing for: - Porosity. - Cracks. - Interconnected passages. - Damaged machined surfaces. 5. Solenoid connectors and filter (317). 6. PCS (Pressure Control Solenoid) screen (302). Control Valve Assembly/Accumulator Housing CONTROL VALVE ASSEMBLY/ACCUMULATOR HOUSING Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 5627 Control Valve Assembly/Accumulator Housing Accumulator Housing Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 5628 Control Valve Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 5629 Torque Sequence And Guide Pin Location Fig. 11 Check Ball Location. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 5630 Fig. 10 Control Valve Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 5631 Torque Sequence, Control Valve And Switch Assembly NOTICE: The use of a honing stone, fine sandpaper or crocus cloth is not recommended for servicing stuck valves. All valve lands have sharply machined comers that are necessary for cleaning the bore. If these corners are rounded, foreign material could wedge between the valve and the bore causing the valve to stick. If it is found necessary to clean a valve, micro fine lapping compound 900 grit (J 38459) or finer should be used. Too much lapping of the valve will cause excessive clearances and increase the chance of a valve not operating. CLEAN - Control valve assembly and accumulator housing (51) thoroughly in clean solvent. - Air dry. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 5632 Accumulator Housing Assembly ACCUMULATOR HOUSING ASSEMBLY Control Valve Assembly/Accumulator Housing Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 5633 Accumulator Housing Assembly DISASSEMBLE 1. Six bolts (53), using 8 mm socket. 2. Accumulator housing assembly. 3. Gasket accumulator housing (47). 4. Spacer plate (46). 5. Gasket (45) valve body spacer. 6. Snap ring (402) from outside housing, pin (408), snap ring (402), piston (407) and spring (49). 7. 3rd clutch piston (405) and spring (50). 8. Seals (404 and 406). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 5634 CLEAN - All components. INSPECT - All valves, pistons, springs and seals for: - Porosity. - Scoring. - Nicks. - Scratches. Accumulator Housing Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 5635 ASSEMBLE - Accumulator housing assembly components exactly as shown. Notice the positions of the pistons. Control Valve Assembly CONTROL VALVE ASSEMBLY Control Valve Assembly ASSEMBLE - Control valve assembly components exactly as shown. Notice the position of the valve lands and bushing passages. Control Valve Assembly/Accumulator Housing Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 5636 CONTROL VALVE ASSEMBLY AND ACCUMULATOR HOUSING Control Valve Assembly/Accumulator Housing Torque Sequence And Guide Pin Location TOOL REQUIRED: - Guide Pin J 25025-5 ASSEMBLE 1. Guide pin J 25025-5 into valve body. Located at back bolt hole of detent spring and roller assembly bolt bole. 2. Gasket (45) valve body to spacer plate. 3. Spacer plate (46). 4. Gasket (47) accumulator housing to spacer plate. 5. Accumulator housing assembly (51) onto valve body assembly (44). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 5637 6. Six bolts (53) using (8 mm) socket through accumulator housing into valve body assembly. Torque Sequence And Guide Pin Location NOTE: Start accumulator housing bolts finger tight and work towards opposite end. TIGHTEN - Bolt (53) to 11 Nm (97 lb. in.). 7. Remove guide pin J 25025-5. Fig. 11 Check Ball Location. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 5638 Fig. 10 Control Valve Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 5639 Torque Sequence, Control Valve And Switch Assembly INSTALL OR CONNECT 1. Install checkballs (54) in proper location into case fluid passages. Use TRANSJEL TM J 36850 or equivalent to hold in place. NOTICE: Do not use any type of grease to retain parts during assembly of this unit. Greases other than the recommended assembly lube will change transmission fluid characteristics and cause undesirable shift conditions and/or filter clogging. - # 2 checkball is used only on RCP RDP, ZJP and ZLP models. 2. PWM solenoid screen (75). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 5640 3. Gasket (48) spacer plate to case. 4. Manual valve (319) into valve body. 5. Complete valve body assembly (44) onto case (7). Use 1 25025-5 guide pin set. IMPORTANT - Attach manual valve to detent lever. 6. Transmission fluid pressure switch assembly (40) onto valve body assembly (44). 7. Spring and roller assembly (41) into place. 8. Three wiring clamps (33), fluid indicator stop (43) and lube pipe clamp (38). 9. Twenty-one bolts (35). Using 10 mm socket. 10. Six bolts (76) using 8 mm socket into transmission fluid pressure switch assembly (40). 11. Lube pipe (39) long end into case, short end into valve body. 12. Lube pipe retainer (37) with short bolt (36). TIGHTEN - Bolts (35, 36 and 76) to 11 Nm (97 lb. in.). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 5641 Torque Sequence, Control Valve And Switch Assembly NOTICE: Torque valve body bolts in a spiral pattern starting from the center. If bolts are torqued at random, valve bores may be distorted and inhibit valve operation. 13. Attach wiring harness (34) to 5 connectors. - Put large end into case first, pressure switch hook up, 1-2 shift solenoid (purple) and 2-3 shift solenoid (tan), PWM (Pulse Width Modulated) solenoid and PCS (Pressure Control Solenoid). Pan and Filter Assembly Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Shift Solenoid, A/T > Component Information > Service and Repair > 4L60-E Automatic Transmission > Page 5642 PAN AND FILTER ASSEMBLY Installing Pan And Filter INSTALL OR CONNECT 1. Seal (32) inside of case (7). 2. Filter assembly (31). 3. Bottom pan seal (29). 4. Magnet (30) into bottom pan. 5. Pan (29). 6. Seventeen bolts (27) using 10 mm socket. TIGHTEN - Bolts (27) to 24 Nm (18 lb. ft.). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Torque Converter Clutch Solenoid, A/T > Component Information > Technical Service Bulletins > A/T - 2-4 Band, TCC Solenoid, 3-4 Clutch Friction/Plates Torque Converter Clutch Solenoid: Technical Service Bulletins A/T - 2-4 Band, TCC Solenoid, 3-4 Clutch Friction/Plates File In Section: 7 - Transmission Bulletin No.: 47-71-41 Date: January, 1995 Subject: New 2-4 Band Assembly, 3-4 Clutch Friction and Steel Plates and Torque Clutch PWM Solenoid Models: 1995 Buick Roadmaster 1995 Cadillac Fleetwood 1995 Chevrolet Camaro, Caprice, Corvette 1995 Pontiac Firebird 1995 Chevrolet and GMC Truck C/K Models and M/L, G Vans 1994-95 Chevrolet and GMC Truck S/T Models 1994 Oldsmobile Bravada (1994 Models with RPO +CTF Package) Transmission Applications: 1995 Hydra-Matic 4L60-E (RPO M30) A new 2-4 Band Assembly was introduced at the start of production for the 1995 Model Year and 1994 Bravadas and S/T trucks. The 2-4 Band friction material has changed appearance from a brown material to a gray/black material. This change was made to enhance durability. When servicing a 1995 Hydra-Matic 4L60-E transmission, do NOT assume that the 2-4 Band is burned/damaged due to its dark color. This dark color is normal. Before replacing the 2-4 Band inspect it for scoring, chunking or heavily worn friction material. Before Replacing the Reverse Input Housing and Drum Assembly inspect for scoring or signs of excessive heat. The 2-4 Band and/or Reverse Input Housing and Drum Assembly should be replaced ONLY if the above listed damage is found. Note: The new 2-4 Band Assembly will NOT service past model Hydra-Matic 4L60-E or 4L60 transmissions. A new 3-4 clutch friction plate was introduced at the start of production for the 1995 Model Year and 1994 Bravadas and S/T Trucks. The 3-4 clutch plate friction material has changed appearance from a brown material to a green/black material. This change was made to enhance durability. When servicing a 1995 Hydra-Matic 4L60-E transmission, do NOT assume that the 3-4 clutch friction plates are burned/damaged due to their dark color. This dark color is normal. Before replacing the 3-4 clutch friction plates inspect for scoring, chunking or heavily worn friction material. Before replacing the 3-4 clutch steel plates inspect for scoring or signs of excessive heat. The 3-4 clutch friction plates and/or 3-4 clutch steel plates should be replaced ONLY if the above listed damage is found. Note: The new 3-4 friction plates will NOT service past model Hydra-Matic 4L60-E or 4L60 transmissions. A new Torque Converter Clutch PWM Solenoid was introduced at the start of production for the 1995 Model Year and 1994 Bravadas and S/T trucks. The new torque converter clutch PWM solenoid is used to control fluid acting on the converter clutch valve, which then controls TCC apply and release. The solenoid is attached to the control valve body assembly within the transmission. The TCC PWM solenoid is used to provide smooth engagement of the torque converter by operating on a negative duty cycle percent of "ON" time. It a fault is detected in the TCC PWM circuit, DTC 83 will set. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Torque Converter Clutch Solenoid, A/T > Component Information > Technical Service Bulletins > A/T - 2-4 Band, TCC Solenoid, 3-4 Clutch Friction/Plates > Page 5647 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Torque Converter Clutch Solenoid, A/T > Component Information > Technical Service Bulletins > A/T - 2-4 Band, TCC Solenoid, 3-4 Clutch Friction/Plates > Page 5648 Included is a Service Manual update for the 1-2 and 3-4 accumulator spring color chart. Replace these pages in your 1995 Service Manual. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Torque Converter Clutch Solenoid, A/T > Component Information > Technical Service Bulletins > Page 5649 Torque Converter Clutch Solenoid: Locations Inside automatic transmission attached to valve body. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Torque Converter Clutch Solenoid, A/T > Component Information > Technical Service Bulletins > Page 5650 C216 - TCC Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - A/T > Torque Converter Clutch Solenoid, A/T > Component Information > Technical Service Bulletins > Page 5651 Torque Converter Clutch Solenoid: Description and Operation Torque Converter Clutch Solenoid PURPOSE The Transmission Converter Clutch (TCC) feature eliminates the power loss of the torque converter stage when the vehicle is in a cruise mode. OPERATION The TCC system uses a solenoid operated valve in the automatic transmission to couple the engine flexplate to the output shaft of the transmission through the torque converter. This reduces the slippage losses in the converter, which increases fuel economy. For the converter clutch to apply, two hydraulic conditions must be met: Internal transmission fluid pressure must be correct. - The control module completes a ground circuit to energize the TCC solenoid in the transmission, which moves a check ball in the fluid line. Control module control is based on the input of these sensors: Vehicle Speed Sensor (VSS): Vehicle equipped with A/C will allow TCC engagement at about 35 mph when the A/C is selected "ON". Engagement will occur at a vehicle speed of about 30 mph (25 mph for 92) when A/C is selected "OFF". - Engine Coolant Temperature (ECT) Sensor: Engine at normal operating temperature (above 65°C/149°F). - Throttle Position Sensor (TPS): Output not changing, indicating a steady road speed. - Transmission Fluid (TFT) sensor. Control module is also controlled by these switches: Brake switch closed: 12 volts supplied when brake is depressed. - Transmission Range (TR) pressure switch assembly. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - Transfer Case > Transfer Case Actuator > Component Information > Locations > Electronic Shift Transfer Case Position Switch Transfer Case Actuator: Locations Electronic Shift Transfer Case Position Switch Transfer Case Electric Shift Motor The Electronic Shift Transfer Case Position Switch (Encoder Switch) is located in the in the shift motor on the transfer case. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - Transfer Case > Transfer Case Actuator > Component Information > Locations > Electronic Shift Transfer Case Position Switch > Page 5657 Four-Wheel Drive Indicator Wiring Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - Transfer Case > Transfer Case Actuator > Component Information > Locations > Page 5658 Transfer Case Actuator: Diagrams C154 - Front Axle Switch C155 - Front Axle Switch In-Line C154 - Front Axle Switch C155 - Front Axle Switch In-Line Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Actuators and Solenoids Transmission and Drivetrain > Actuators and Solenoids - Transfer Case > Transfer Case Actuator > Component Information > Locations > Page 5659 Transfer Case Actuator: Service and Repair ELECTRIC SHIFT MOTOR REPLACEMENT Transfer Case Electric Shift Motor REMOVE OR DISCONNECT 1. Negative battery cable. - Raise vehicle and support with safety stands. 2. Transfer case shield. 3. Motor electrical connection. 4. Front propeller shaft. 5. Front output shaft yoke. 6. Motor to transfer case bolts. 7. Motor from the transfer case. INSTALL OR CONNECT 1. Motor to the transfer case. 2. Bolts. TIGHTEN - Bolts to 18 Nm (13 lbs. ft.). 3. Front output shaft yoke. 4. Front propeller shaft. 5. Motor electrical connection. 6. Transfer case shield. 7. Negative battery cable. - Lower Vehicle Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Lamps and Indicators Transmission and Drivetrain > Lamps and Indicators - A/T > Shift Indicator > Component Information > Locations Shift Indicator: Locations Instrument cluster. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Lamps and Indicators Transmission and Drivetrain > Lamps and Indicators - Transfer Case > Four Wheel Drive Indicator Lamp > Component Information > Locations Four-Wheel Drive Indicator Lamp Wiring I/P Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Lamps and Indicators Transmission and Drivetrain > Lamps and Indicators - Transfer Case > Four Wheel Drive Indicator Lamp > Component Information > Locations > Page 5669 C274 - 4WD Indicator Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Lamps and Indicators Transmission and Drivetrain > Lamps and Indicators - Transfer Case > Four Wheel Drive Indicator Lamp > Component Information > Locations > Page 5670 Four Wheel Drive Indicator Lamp: Description and Operation The Four-Wheel Drive (4WD) Indicator Assembly provides visual information about the operating mode and gear range of the driveline. Voltage is supplied to the IGN/GAU Fuse and Indicator Assembly with the Ignition Switch in START or RUN. The circuit is completed through the Selector Quadrant Switch, which provides a ground path to light various Indicator Assembly Lamps. With the Selector Quadrant Switch in detent position 1, the "2WHL" Indicator Assembly Lamp is lit. With the Selector Quadrant Switch in detent position 2, the "4 HIGH" Indicator Assembly Lamp is lit. At this time, the Front Axle Switch is closed and the Indicator Assembly Front and Rear Axle Display is lit. With the Selector Quadrant Switch in detent position 4, the "4 LOW" Indicator Lamp is lit. At this time, the Front Axle Switch is closed, and the Indicator Assembly Front and Rear Axle Display is lit. A signal is sent to the Four-Wheel Antilock Brake Module (4WAL) whenever the 4WD is engaged. This signal turns off the 4WAL systems to prevent operation during 4WD operation. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Lamps and Indicators Transmission and Drivetrain > Lamps and Indicators - Transfer Case > Four Wheel Drive Indicator Lamp > Component Information > Testing and Inspection > Initial Inspection and Diagnostic Overview Four Wheel Drive Indicator Lamp: Initial Inspection and Diagnostic Overview Circuit Operation - Four-Wheel Drive Indicator The Four-Wheel Drive (4WD) Indicator Assembly provides visual information about the operating mode and gear range of the driveline. Voltage is supplied to the IGN/GAU Fuse and Indicator Assembly with the Ignition Switch in START or RUN. The circuit is completed through the Selector Quadrant Switch, which provides a ground path to light various Indicator Assembly Lamps. With the Selector Quadrant Switch in detent position 1, the "2WHL" Indicator Assembly Lamp is lit. With the Selector Quadrant Switch in detent position 2, the "4 HIGH" Indicator Assembly Lamp is lit. At this time, the Front Axle Switch is closed and the Indicator Assembly Front and Rear Axle Display is lit. With the Selector Quadrant Switch in detent position 4, the "4 LOW" Indicator Lamp is lit. At this time, the Front Axle Switch is closed, and the Indicator Assembly Front and Rear Axle Display is lit. A signal is sent to the Four-Wheel Antilock Brake Module (4WAL) whenever the 4WD is engaged. This signal turns off the 4WAL systems to prevent operation during 4WD operation. Preliminary Checks - Four-Wheel Drive Indicator 1. Check condition of IGN/GAU Fuse. If fuse is Blown, locate and repair overload. Replace fuse. 2. If fuse is not blown, proceed with the Diagnostics. See: Symptom Related Diagnostic Procedures Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Lamps and Indicators Transmission and Drivetrain > Lamps and Indicators - Transfer Case > Four Wheel Drive Indicator Lamp > Component Information > Testing and Inspection > Initial Inspection and Diagnostic Overview > Page 5673 Four Wheel Drive Indicator Lamp: Symptom Related Diagnostic Procedures Indicator Assembly Illumination Lamp Does Not Light One Or More Indicator Assembly Lamps Do Not Light Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Relays and Modules Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Locations Control Module: Locations Mounted on the back of the Electronic Control Module (ECM)/Powertrain Control Module (PCM) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Relays and Modules Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Locations > Page 5679 C202A - Transfer Case Control Module Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Relays and Modules Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting Control Module: Description and Operation Electric 4WD Shifting Transfer Case 4WD Selector Switch 4WD Selector Switch Wiring Schematic OPERATION On vehicles equipped with the Model 233 transfer case, there is no transfer case selector lever in the cab. The operator selects 4HI or 4LO by pushing a three-position (4HI, 4LO, 2HI) rocker-type selector switch mounted on the instrument panel. During normal driving the transfer case is in the 2HI mode. The switch is spring-loaded to the center position. When the transfer case is in 2HI both the 4HI and 4L0 switch circuits are open, and both lights are off. When shifting to 4HI or 4LO the rocker switch will still return to the center position and the 4HI or 4LO light will be on. The above image shows the wiring schematic of the transfer case selector switch. Mode Shifts Mode shifts are shifts from: - 2HI to 4HI - 4HI to 2HI A mode shift can be accomplished in any gear position and at any vehicle speed. If the system is in 2HI, the operator can shift into 4HI merely by pressing and releasing the 4HI area of the selector rocker switch. The green 4HI status lamp flashes whenever a 2HI or 4HI shift is initiated and continues to flash until the TCCM completes the shift (or until 30 seconds elapses). After the shift into 4HI is accomplished, the 4HI status lamp remains lit to indicate that the system is in 4HI. The operator can shift from 4HI back to 2HI by again pressing 4HI on the selector switch. Again, the green 4HI status lamp flashes until the shift to 2HI is complete, and then extinguishes once the shift is complete. Both the 4HI and 4LO lamps remain oft when the vehicle is in 2HI. Range Shifts Range shifts are shifts between the HI and LO ranges, from: Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Relays and Modules Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 5682 - 2HI to 4LO - 4HI to 4LO - 4LO to 4HI A range shift from 4L0 directly to 2HI cannot be made. The operator must first make range shift from 4LO to 4HI, then a mode shift from 4HI to 2HI. A range shift can only be made with the automatic transmission in neutral or with the manual transmission clutch fully depressed. The vehicle speed must also be below three miles per hour before the shift can occur. Whenever a shift into 4LO is initiated, the amber 4LO status lamp flashes and continues to flash until the TCCM completes the shift (or until 30 seconds elapses). The 4LO status lamp must glow steadily before the vehicle transmission is shifted into gear or before the clutch pedal is released. If a range shift is initiated when the transmission is engaged or when the vehicle speed is above 3 mph, the 4LO status lamp flashes for 30 seconds and no range shift actually occurs; the system returns to the position before the shift was initiated. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Relays and Modules Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 5683 Control Module: Description and Operation TCCM Power and Ground Fig. 1, Memory Power, System Power, And Ground Circuit Fig. 2, Fuse Block And Cavity Location Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Relays and Modules Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 5684 POWER, CIRCUIT PROTECTION, AND GROUND The Transfer Case Control Module (TCCM) memory power, system power, and the ground circuit are shown in Figure 1. The vehicle fuse block and cavity location for memory power, system power, and motor power are shown in Figure 2. Memory Power Trouble code memory power is protected by a 5-amp TCCM fuse. Memory power is supplied to TCCM connector pin C6 through circuit 140. System Power Operating power is controlled by the ignition switch and is protected by a 15-amp radio fuse. System power is supplied to TCCM connector pin C8 through circuit 141. This fuse also supplies, voltage to pin B of the transfer case switch. The system power will shut down if either the 5-amp TCCM fuse or the 15-amp radio fuse are removed or blown. System Ground System ground is supplied to TCCM connector pin C10 through circuit 150. Circuit 150 is connected to the bus bar ground located on the left side of the steering column support. Refer to Figure 1. Turn/BU Fuse A 15-amp TURN/BU fuse supplies ignition voltage to the park/neutral position switch. This voltage enables the park switch to send a park signal to TCCM connector pin D2. Power Accessory Circuit Breaker The 30-amp power accessory circuit breaker supplies ignition voltage to TCCM connector pins D14 and D15. This voltage is used to control the electric-shift motor circuit. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Relays and Modules Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 5685 Control Module: Description and Operation TCCM Inputs and Outputs General Description INPUTS The Transfer Case Control Module (TCCM) receives input signals from the following sources: - Transfer case selector switch on the instrument panel. - Park/neutral position switch on vehicles with automatic transmissions. - Clutch safety switch on vehicles with manual transmissions. - Vehicle speed sensor buffer which supplies vehicle speed signals. - Encoder switch within the electric-shift motor which provides actual mode and range information signals. - Data link connector (DLC) pin J which provides diagnostic enable. OUTPUTS After processing the input information, the Transfer Case Control Module (TCCM) outputs signals to the following: - Electric shift motor to effect mode and range shifts. - Selector switch status lamps to provide transfer case status information. - Diagnostic trouble codes (DTC) which are output via the selector switch status lamps. 2HI to 4HI Selector Switch Input 4WD Selector Switch Wiring Schematic OPERATION When the transfer case is in 2HI and the operator presses the 4HI area of the rocker switch, the 4HI contacts of the selector switch close, connecting circuits 141 and 1564, and furnishing 12-volts to pin C5 of the TCCM connector. The 12-volt signal at pin C5 commands the Transfer Case Control Module (TCCM) to signal the electric-shift motor to shift into 4HI. The contacts return to the open position as soon as the switch is released. 4HI to 2HI Selector Switch Input Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Relays and Modules Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 5686 4WD Selector Switch Wiring Schematic OPERATION If the transfer case is in 4HI and the operator presses the 4HI area of the rocker switch, the 4HI contacts of the selector switch close, connecting circuits 141 and 1564 and furnishing 12-volts to pin C5 of the Transfer Case Control Module (TCCM) connector. The 12-volt signal at pin C5 commands the TCCM to signal the electric-shift motor to shift into 4HI. Again, the contacts return to the open position as soon as the switch is released. 2HI to 4HI to 4LO Selector Switch Input 4WD Selector Switch Wiring Schematic OPERATION When the operator presses the 4LO area of the rocker switch while the transfer case is in either 2HI or 4HI, the 4LO contacts of the selector switch close, connecting circuits 141 and 1559, and furnishing 12-volts to pin C3 of the Transfer Case Control Module (TCCM) connector. The 12-volt signal at pin C3 commands the TCCM to signal the electric-shift motor to shift the transfer case into 4LO. Once more, the contacts return to the open position as soon as the switch is released. Park/Neutral Position Switch Inputs Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Relays and Modules Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 5687 Automatic Transmission Neutral Start Switch Neutral Start Switch Voltages OPERATION Because range shift should only be made with the automatic transmission in neutral, the park/neutral position switch informs the Transfer Case Control Module (TCCM) that the vehicle automatic transmission is in either: - Park - Neutral - One of the drive positions The park/neutral position switch consists of three switches together in one unit, and it provides three signals: - Park - When the automatic transmission is in park, the contacts of both the park switch and the park neutral switch are closed. When these contacts are closed, a battery voltage signal is sent to TCCM connector pin D2, while connector pin D16 is pulled to ground (0 voltage). The TCCM interprets this signal to mean the automatic transmission is in park. - Neutral - When the automatic transmission is in neutral, the contacts of the park switch are open and the contacts of the park neutral position switch are closed. In this condition, a 0-voltage signal is sent to TCCM connector pin D2, while connector pin D16 is pulled to ground (0 volts). The TCCM interprets this signal to mean the automatic transmission is in neutral. - In gear - When the automatic transmission is in any other gear position, the contacts of both the park switch and park neutral switch are open. In this condition, a 0-voltage signal is sent to TCCM connector pin D16. The TCCM interprets this signal to mean the automatic transmission is neither park or neutral. Important - If the backup switch connector were to be plugged in upside down, the park switch would receive no power. Such a condition would cause a 0-voltage signal at both pin D2 and pin D16 in neutral and in park. The transfer case, accordingly, would perform a range shift in park as well as in neutral. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Relays and Modules Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 5688 - An open in circuit 75, or an open in the Turn/BU fuse would also cause this condition. - Additionally, a park/neutral position switch that is out of adjustment may prevent a range shift in park. Clutch Safety Switch Inputs Clutch Safety Switch Schematic Clutch Safety Switch Voltage Signals OPERATION Because range shifts should only be made with the manual transmission clutch fully depressed, the clutch safety switch informs the Transfer Case Control Module (TCCM) that the vehicle clutch pedal is fully depressed or released. The clutch safety switch is connected to TCCM connector pin D16. When the clutch pedal is released, the contacts of the clutch safety switch are open. When these contacts are open, a battery voltage signal is seen at TCCM connector pin D16. The TCCM interprets this signal to mean the clutch is released. When the clutch is fully depressed, the contacts of the clutch safety switch are closed. When the contacts are closed, voltage is pulled low to 0 at TCCM connector pin D16. The TCCM interprets this signal to mean the clutch pedal is fully depressed. Because TCCM connector pin D2 is not connected when the vehicle is equipped with a manual transmission, the TCCM reads a 0-volt signal at pin D2 at all times. All readings are taken while back-probing the TCCM pins with the ignition in the "Run" position. A reading of less than 0.5 volt is considered to be zero. Vehicle Speed Input Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Relays and Modules Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 5689 Vehicle Sensor Buffer And TCCM Schematic OPERATION The vehicle speed sensor buffer informs the Transfer Case Control Module (TCCM) about the speed of the vehicle in miles per hour. Such information is essential to inform the TCCM to prohibit range shifts at speeds above 3 mph. The vehicle speed sensor (VSS) is a variable-reluctance magnetic sensing device that converts tone wheel rotation into a frequency and voltage output proportional to the vehicle speed. The frequency and voltage signal is sent to the vehicle speed sensor buffer which converts the speed sensor output into a useful pulse signal. The vehicle speed sensor buffer then, pulses circuit 1567 to ground at a rate of 4000 pulses per mile. Whenever the vehicle speed sensor buffer grounds circuit 1567, the voltage at TCCM connector pin D8 returns to 5 volts. The TCCM reads the 4000 pulses-per-mile (1.11 Hz per mph) signal to determine vehicle speed. Encoder Switch Inputs Fig 1, Electric Shift Encoder Switch Layout Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Relays and Modules Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 5690 Fig 2, Electric Shift Encoder Switch Schematic Fig 3, Encoder Switch Channel Signals And Positions OPERATION The four-channel encoder switch indicates the current transfer case mode and range to the Transfer Case Control Module (TCCM). The encoder switch is located inside the encoder itself and is not serviceable. The TCCM reads the status of the four channels to determine the range and mode in which the transfer case is operating or whether the transfer case is shifting between modes and/or ranges. The encoder assembly is composed of an inner ground ring in contact with a three-leg wiper arm. The three legs of the wiper, spaced 120 degrees apart, make contact with the conductive areas of the four channels. When any leg of the wiper arm is in contact with the conductive area of any channel, a path to ground is provided to the inner ground ring. A schematic of the encoder switch is shown in Figure 2. The channel signals in various transfer case operating modes and ranges are shown in Figure 3. Any combination of signals not listed in Figure 3 are considered invalid by the TCCM. Encoder Switch Channel Positions These voltage readings can be obtained by back-probing either the TCCM connector pins or the transfer case connector pins. For TCCM pin numbers and encoder channels, refer to Figure 2. Diagnostic Enable Input Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Relays and Modules Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 5691 Wiring Schematic For Enabling The Status Lamps OPERATION When pin J of the Data Link Connector (DLC) is connected either to pin A of the DLC or to a good ground while the ignition is on, the diagnostics routine of the Transfer Case Control Module (TCCM) is activated. When the diagnostics routine is activated, the transfer case selector switch 4HI and 4LO status lamps flash the diagnostic codes. Electric Shift Motor Outputs Electric Shift Motor Schematic OPERATION The Transfer Case Control Module (TCCM) provides the output for the electric shift motor as the schematic shows. - Motor control is achieved by energizing one of the two motor control relays located in the TCCM, by way of the transfer case selector switch. The TCCM operates the motor in one direction by energizing one relay while the second relay is de-energized. The TCCM operates the motor in the reverse direction by energizing the second relay while the first relay is de-energized. - Motor power to actuate the motor drive relays is input at TCCM connector pins D14 and D15. This power is supplied by the ignition through the 30-amp power circuit breaker. - Motor ground is input at TCCM connector pins D12 and D13 to provide the return line for the motor drive relays. 4HI and 4LO Status Lamps Outputs Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Relays and Modules Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Electric 4WD Shifting > Page 5692 Selector Switch Status Lamp Schematic OPERATION The Transfer Case Control Module (TCCM) controls the operation of the 4HI and 4LO status lamps in the transfer case selector switch. The status lamps also show the transfer case mode and range of operation. The status lamps also provide a self-test when the ignition is first turned on. Additionally, the status lamps are used to alert the driver that there is a problem somewhere in the four-wheel drive system, and also to flash diagnostic trouble codes (DTC's). Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Relays and Modules Transmission and Drivetrain > Relays and Modules - Transfer Case > Control Module, Transfer Case > Component Information > Description and Operation > Page 5693 Control Module: Service and Repair TRANSFER CASE MODULE REPLACEMENT REMOVE OR DISCONNECT 1. Negative battery cable. 2. ECM (utility only). 3. Cowl side panel (pickup only). 4. Electrical connection. 5. Module to cowl panel screws (pickup only). 6. Module. INSTALL OR CONNECT 1. Module. 2. Module to cowl panel screws (pickup only). 3. Electrical connection. 4. ECM (utility only). 5. Negative battery cable. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Sensors and Switches Transmission and Drivetrain > Sensors and Switches - A/T > Brake Switch - TCC > Component Information > Locations > Stoplamp/TCC Brake Switch Stoplamp/TCC Brake Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Sensors and Switches Transmission and Drivetrain > Sensors and Switches - A/T > Brake Switch - TCC > Component Information > Locations > Stoplamp/TCC Brake Switch > Page 5700 I/P Harness Wiring, LH Side Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Sensors and Switches Transmission and Drivetrain > Sensors and Switches - A/T > Brake Switch - TCC > Component Information > Locations > Page 5701 C217 - Brake Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Sensors and Switches Transmission and Drivetrain > Sensors and Switches - A/T > Fluid Pressure Sensor/Switch, A/T > Component Information > Specifications Fluid Pressure Sensor/Switch: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Pressure Plugs (1/8 - 27) ..................................................................................................................... ................................................................................. 8 Pressure Plugs (1/4 - 18) ................................ .............................................................................................................................................................. ...... 18 Pressure Switches ................................................................................................................... .............................................................................................. 8 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Sensors and Switches Transmission and Drivetrain > Sensors and Switches - A/T > Transmission Position Switch/Sensor, A/T > Component Information > Description and Operation Transmission Position Switch/Sensor: Description and Operation Automatic Transmission Electrical Components PURPOSE This device is a set of five presure switches (two normally closed and three normally open), that detect fluid pressure within the valve body passages and signals the PCM which transmission range is selected (PRNDL). OPERATION The five pressure switches are connected to three signal circuits referred to as range signals A, B, C. The combination of pressure switch states determines the voltage signal (B+ or 0) on each range signal to the PCM. LOCATION The transmission range fluid pressure switch assembly is attached to the control valve body within the transmission. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Sensors and Switches Transmission and Drivetrain > Sensors and Switches - A/T > Transmission Speed Sensor, A/T > Component Information > Specifications Transmission Speed Sensor: Specifications COMPONENT ..................................................................................................................................... ...................................................... Torque/Ft.Lbs. Vehicle Speed Sensor Retainer ........................... .............................................................................................................................................................. ... 8 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Sensors and Switches Transmission and Drivetrain > Sensors and Switches - A/T > Transmission Temperature Sensor/Switch, A/T > Component Information > Description and Operation Transmission Temperature Sensor/Switch: Description and Operation Automatic Transmission Electrical Components PURPOSE The Transmission Fluid Temperature (TFT) Sensor is used by the control module to control: Torque Converter Clutch (TCC) apply and release schedule. - Hot mode determination. - Shift quality. OPERATION The TFT is a thermistor used to indicate transmission fluid temperature. The control module sends a 5.0 volt signal to the TFT through a resistor in the computer and measures the voltage. High sensor resistance produces high signal input voltage which corresponds to low fluid temperature. Low sensor resistance produces low signal input voltage which corresponds to high fluid temperature. With the TFT varying its resistance, the control module can sense transmission fluid temperature by reading the varying voltage. LOCATION The sensor is part of the transmission range fluid pressure switch assembly and is attached to the control valve body within the transmission. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Sensors and Switches Transmission and Drivetrain > Sensors and Switches - Transfer Case > Four Wheel Drive Selector Switch > Component Information > Locations > Pickup Transfer Case Select Switch Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Sensors and Switches Transmission and Drivetrain > Sensors and Switches - Transfer Case > Four Wheel Drive Selector Switch > Component Information > Locations > Pickup > Page 5719 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Sensors and Switches Transmission and Drivetrain > Sensors and Switches - Transfer Case > Four Wheel Drive Selector Switch > Component Information > Locations > Page 5720 Four Wheel Drive Selector Switch: Service and Repair Fig. 2 Transfer Case Shift Linkage. Except Bravada, Sonoma GT, Syclone & Typhoon Fig. 4 Selector Switch Installation. Except Bravada, Sonoma GT, Syclone & Typhoon 1. Disconnect battery ground cable. 2. Remove console, then disconnect console wiring harness. 3. Remove shifter boot retaining screws and slide boot up shift lever. 4. Remove switch attaching screw, then the switch and harness, Fig. 2. 5. Position new switch on mounting bracket and install attaching screw.Ensure shift lever assembly pawl is on the switch contact carrier. 6. Route wiring as shown in Fig. 4. 7. Place shifter boot in proper position, then install retaining screws. 8. Connect console wiring harness, then install console. 9. Connect battery ground cable. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Sensors and Switches Transmission and Drivetrain > Sensors and Switches - Transfer Case > Gear Sensor/Switch, Transfer Case > Component Information > Locations > Electric Shift Transfer Case Switch Gear Sensor/Switch: Locations Electric Shift Transfer Case Switch Transfer Case Electric Shift Motor Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Sensors and Switches Transmission and Drivetrain > Sensors and Switches - Transfer Case > Gear Sensor/Switch, Transfer Case > Component Information > Locations > Electric Shift Transfer Case Switch > Page 5725 Electric Shift Transfer Case Wiring Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Sensors and Switches Transmission and Drivetrain > Sensors and Switches - Transfer Case > Gear Sensor/Switch, Transfer Case > Component Information > Locations > Electric Shift Transfer Case Switch > Page 5726 4WD Components Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Transmission and Drivetrain > Transmission Control Systems > Sensors and Switches Transmission and Drivetrain > Sensors and Switches - Transfer Case > Speed Sensor, Transfer Case > Component Information > Technical Service Bulletins > Drivetrain - Updated Transfer Case Speed Sensor Conn. Speed Sensor: Technical Service Bulletins Drivetrain - Updated Transfer Case Speed Sensor Conn. Bulletin No.: 06-04-21-001 Date: May 17, 2006 INFORMATION Subject: Updated Transfer Case Connector Service Kit Now Available For Transfer Case Speed Sensor Wire Harness Connector that Comes Loose Or Connector Retainer Clip Breaks Models: 2007 and Prior GM Light Duty Trucks 2007 and Prior HUMMER H2, H3 2005-2007 Saab 9-7X with Four-Wheel Drive or All-Wheel Drive Technicians may find that when the transfer case speed sensor wire harness connector is removed, the connector lock flexes/bends and does not return to the original position. The transfer case speed sensor wire harness connector then has no locking device. On older vehicles, the plastic connector retainer becomes brittle and the clip may break as soon as it is flexed. In the past, the only service fix was to install a wire harness connector service pack, P/N 88987183. This repair procedure involved splicing a new service connector with an integral connector lock. This connector service kit is of the same design and was still prone to failure over time. A new connector service repair kit is now available, P/N 15306187, that is an updated design. This new kit should be used whenever the speed sensor wire harness connector requires replacement. Parts Information Disclaimer Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Antilock Brakes / Traction Control Systems > 4WD Switch > Component Information > Technical Service Bulletins > Recalls for 4WD Switch: > 99-041 > May > 00 > Recall - ABS Front Axle Signal Malfunction Technical Service Bulletin # 99-041 Date: 000501 Recall - ABS Front Axle Signal Malfunction File in: Product Section: Campaigns Bulletin No: 99041 Dates: May, 2000 SUBJECT: 99041 - INCORRECT FRONT AXLE STATUS SIGNAL TO EBC4 ABS MODELS: 1991-1996 CHEVROLET AND GMC 4WD T UTILITIES 1994-1996 CHEVROLET AND GMC 4WD T PICKUP TRUCKS DUE TO THE AVAILABILITY OF PARTS, THIS CAMPAIGN WILL BE ADMINISTERED IN PHASES. YOU WILL RECEIVE A DEALER LISTING AS PHASES ARE RELEASED. CONDITION General Motors has decided that a defect which relates to motor vehicle safety exists in certain 1991-1996 Chevrolet and GMC 4WD T utilities and 1994-1996 Chevrolet and GMC 4WD T pickup trucks. Some of these vehicles exhibit a condition in which a switch that signals the antilock brake system (ABS) module when the vehicle is in four-wheel drive (4WD) may malfunction. The ABS module is designed with two different operating algorithms; one for two-wheel drive (2WD) operation and another for 4WD drive operation. This allows the ABS system to compensate for the braking torque applied tot he rear wheels through the drivetrain when the vehicle is in 4WD drive. When the vehicle is in 2WD, a malfunctioning switch may send an incorrect signal tot he ABS module. If this occurs during an ABS stop, a somewhat longer stopping distance could result. If this occurred when minimum stopping distance was required, it could result a vehicle crash. CORRECTION Dealers are to install a new transfer case selector switch, wiring harness, and an additional switch to ensure that the ABS receives the 4WD signal only when the drivetrain is in 4WD. VEHICLES INVOLVED Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Antilock Brakes / Traction Control Systems > 4WD Switch > Component Information > Technical Service Bulletins > Recalls for 4WD Switch: > 99-041 > May > 00 > Recall - ABS Front Axle Signal Malfunction > Page 5741 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Antilock Brakes / Traction Control Systems > 4WD Switch > Component Information > Technical Service Bulletins > Recalls for 4WD Switch: > 99-041 > May > 00 > Recall - ABS Front Axle Signal Malfunction > Page 5742 Involved are certain 1991-1996 Chevrolet and GMC 4WD T utilities and 1994-1996 Chevrolet and GMC 4WD T pickup truck built within these VIN breakpoints as shown. IMPORTANT Dealers should confirm vehicle eligibility through GMVIS (GM Vehicle Inquiry System) or GM Access Screen (Canada only) or DCS Screen 445 (IPC only) before beginning campaign repairs. [Not all vehicles within the above breakpoints may be involved.] Involved vehicles have been identified by Vehicle Identification Number. Computer listing containing the complete Vehicle Identification, customer name address data have been prepared, and are being furnished to involved dealers with the campaign bulletin. The customer name address data furnished will enable dealers to follow up with the campaign bulletin has no involved vehicles currently assigned. These dealer listings may contain customer names and addresses obtained from Motor Vehicle Registration Records. The use of such motor vehicle registration data for any other purpose is a violation of law in several states/provinces/countries. Accordingly, you are urged to limit the use of this listing to the follow-up necessary to complete this campaign. PARTS INFORMATION Parts required to complete this campaign are to be obtained from General Motors Service Parts Operations (GMSPO). Please refer to your "involved vehicles listing" before ordering parts. Normal orders should be placed on a DRO = Daily Replenishment Order, in an emergency situation, parts should be ordered on a CSO = Customer Special Order. Part Number Description Quantity/Vehicle 88880028 Switch Kit, Elek Brk Cont Frt 1 Drv Axle Vac (1991-94 Utility) 88880029 Switch Kit, Elek Brk Cont Frt 1 Drv Axle Vac (1995-96 Utility, 1994-96 Pickup) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Antilock Brakes / Traction Control Systems > 4WD Switch > Component Information > Technical Service Bulletins > Recalls for 4WD Switch: > 99-041 > May > 00 > Recall - ABS Front Axle Signal Malfunction > Page 5743 CAMPAIGN IDENTIFICATION LABEL - For US IPC Place a Campaign Identification Label on each vehicle corrected in accordance with the instructions outlined in this Product Campaign Bulletin. Each label provides a space to include the campaign number and the five (5) digit dealer code of the dealer performing the campaign service. This Information may be inserted with a typewriter a ball point pen. CAMPAIGN IDENTIFICATION LABEL - For CANADA Place a Campaign Identification Label on each vehicle corrected in accordance with the instruction outlined in this Product Campaign Bulletin. Each label provides a space to include the campaign number and the five (5) digit dealer code of the dealer performing the campaign service. This information may be inserted with a typewriter or a ball point pen. CLAIM INFORMATION Submit a Product Campaign Claim with the information indicated. Refer to the General Motors WINS claims processing Manual for details on Product Campaign Claim Submission. CUSTOMER NOTIFICATION - For US and CANADA Customers will be notified of this campaign on their vehicles by General Motors (see copy of customer letter included with this bulletin. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Antilock Brakes / Traction Control Systems > 4WD Switch > Component Information > Technical Service Bulletins > Recalls for 4WD Switch: > 99-041 > May > 00 > Recall - ABS Front Axle Signal Malfunction > Page 5744 CUSTOMER NOTIFICATION - For IPC Letters will be sent to known owners of record located within areas covered by the US National Traffic and Motor Vehicle Safety Act. For owners outside these areas, dealers should notify customers using the attached suggested dealer letter. DEALER CAMPAIGN RESPONSIBILITY - For US and IPC (US States, Territories, and Possessions) The US National Traffic end Motor Vehicle safety Act provides that each vehicle that is subject to recall campaign of this type must be adequately repaired within a reasonable time after the customer has tendered it for repair. A failure to repair within sixty days after tender of vehicle is prima facie evidence of failure to repair within a reasonable time. If the condition is not adequately repaired within a reasonable time the customer may be entitled to an identical or reasonably equivalent vehicle at no charge or to a refund of the purchase price less a reasonable allowance for depreciation. To avoid having to provide these burdensome remedies, every effort must be made to promptly schedule an appointment with each customer and to repair their vehicle as soon as possible. In the recall campaign notification letters, customers are told how to contact the US National Highway Traffic Safety Administration if the campaign is not completed within a reasonable time. DEALER CAMPAIGN RESPONSIBILITY - ALL All unsold new vehicle in dealers' possession and subject to this campaign must be held an inspected/repaired per the service procedure of this campaign bulletin before customers take possession of these vehicles. Dealers are to service all vehicles subject to this campaign at no charge to customers, regardless of mileage, age of vehicle, or ownership, from this time forward. Customers who have recently purchased vehicles sold from your vehicle inventory, and for which there is no customer information indicated on the dealer listing, are to be contacted by the dealer. Arrangements are to be made to make the required correction according to the instructions contained in this bulletin. This could be done by mailing to such customers, a copy of the customer letter accompanying this bulletin. Campaign follow-up cards should not be used for this purpose, since the customer may not as yet have received the notification letter. In summary, whenever a vehicle subject to this campaign enters your vehicle inventory, or is in your dealership for service in the future, you must take the steps necessary to be sure the campaign correction has been made before selling or releasing the vehicle. Disclaimer 1991-94 T-Utility 1. Disconnect the negative battery cable. 2. Remove the front lower coolant reservoir attaching bolt. 3. Install the new vacuum switch, bracket, and hose assembly at the front lower coolant reservoir attaching location using the bolt removed in the previous step. Important The bracket must be rotated/positioned and held as close to the coolant reservoir as possible during the tightening of the bolt or nut to maintain maximum clearance between the battery and the vacuum switch. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Antilock Brakes / Traction Control Systems > 4WD Switch > Component Information > Technical Service Bulletins > Recalls for 4WD Switch: > 99-041 > May > 00 > Recall - ABS Front Axle Signal Malfunction > Page 5745 4. Position the vacuum switch, bracket, and hose assembly as shown in Figure 1 and tighten the bolt to 8 Nm (71 lb in). 5. Locate the vacuum hose leading from the front axle vacuum actuator, located under the battery tray, to the vacuum switch mounted bon the transfer case. This vacuum hose typically is routed along the right front frame rail rearward up along the wheel well towards the cowl area of the engine compartment. On some vehicle this hose may be covered with a black convoluted protective sleeve. 6. Select a point on the vacuum hose, which was located in the previous step, that will be lower in the vehicle than the new vacuum switch and will not result in the loading or stretching of either the existing or new hoses when they are connected together. Important The location where the vacuum line is tapped into must be lower than the vacuum switch to ensure condensation cannot accumulate in the switch, possibly resulting in a switch malfunction. 7. Cut the existing vacuum hose at me point located in the previous step, and connect the ends of the cut vacuum hose to the tee fitting that is part of the new vacuum switch and hose assembly. 8. Connect the new wiring harness to the vacuum switch and ensure the locking feature of the connector is engaged. Important Ensure that the new harness is routed and secured in such a manner that it will not come in contact with any moving parts or be exposed to any other conitions that may result in damage to the harness. 9. Route the new harness is shown in Figure 1 and secure it to the existing Underhood components at the locations indicated (1) using the tie straps provided in the kit. 10. Locate and disconnect the existing underhood front exle switch wiring harness connector, located in the area above the brake booster assembly, and jumper in the new wiring harness. 11. Raise the vehicle and suitably support. 12. Loate the transfer case selector switch positioned on top of the transfer case. 13. Remove any foreign material from around the transfer case selector switch or vacuum connector. Important Ensure that the O-ring is removed and discarded. 14. Disconnect the vacuum connector, remove and discard the transfer case selector switch and the O-ring. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Antilock Brakes / Traction Control Systems > 4WD Switch > Component Information > Technical Service Bulletins > Recalls for 4WD Switch: > 99-041 > May > 00 > Recall - ABS Front Axle Signal Malfunction > Page 5746 15. Hand start the new transfer case selector switch and tighten to 24 Nm (18 lb ft). 16. Ensure that the alignment feature of the vacuum harness connector is oriented correctly to engage the alignment post/pin of the transfer case selector switch and connect the harness to the switch. 17. Lower the vehicle and connect the negative battery cable. 18. Install the GM Campaign Identification Label. 1994 T-Pickup 1. Disconnect the negative battery cable. 2. Locate the new vacuum switch, bracket, and hose assembly so that the hole in the bracket align with the front inboard nut that is molded into the top of the coolant reservoir as shown in Figure 2. 3. Using the bolt provided in the kit, switch the vacuum switch, bracket, and hose assembly to the coolant reservoir by hand at starting the bolt. 4. With the vacuum switch, bracket and hose assembly positioned as shown in Figure 2, tighten the bolt to 10 Nm (88 lb in). 5. Locate the vacuum hose leading from the front axle vacuum actuator, located under the battery tray, to the vacuum switch mounted on the transfer case. This hose is routed up from the axle vacuum actuator and then rearward towards the cowl area inside the right fender as shown in Figure 2. 6. Select a point on the vacuum hose, which was located in the previous step, that will be lower in the vehicle than the new vacuum switch and will not result in the loading or stretching of either the existing or new hoses when they are connected together. Important The location where the vacuum line is tapped into must be lower than the vacuum switch to ensure condensation cannot accumulate in the switch, possibly resulting in a switch malfunction. 7. Cut the existing vacuum hose at the point located in the previous step, and connect the ends of the cut vacuum hose to the tee fitting that is a part of the new vacuum switch and hose assembly. 8. Connect the new wiring harness to the vacuum switch and ensure the locking feature of the connector is engaged. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Antilock Brakes / Traction Control Systems > 4WD Switch > Component Information > Technical Service Bulletins > Recalls for 4WD Switch: > 99-041 > May > 00 > Recall - ABS Front Axle Signal Malfunction > Page 5747 Important: Ensure that the new harness is routed and secured in such a manner that it will not come in contact with any moving parts or be exposed to any other conditions that may result in damage to the harness. 9. Route the harness as shown in Figure 2 and secure the new harness to the existing underhood components at the locations indicated (1) using the tie straps provided in the kits. 10. Disconnect the existing underhood front axle switch wiring harness connector, located in the area of the left front inner wheel well skirt under the brake master cylinder, and jumper in the new wiring harness. 11. Raise the vehicle and suitably support. 12. Locate the transfer case selector switch positioned on top of the transfer case. 13. Remove any foreign material from around the transfer case selector switch or vacuum connector. Important: Ensure that the O-ring is removed and discarded. 14. Disconnect the vacuum connector, remove and discard the transfer case selector switch and the O-ring. 15. Hand start the new transfer case selector switch and tighten to 24 Nm (18 lb ft). 16. Ensure the alignment feature of the vacuum harness connector is oriented correctly to engage the alignment post/pin of the transfer case selector switch and connect the harness to the switch. 17. Lower the vehicle and connect the negative battery cable. 18. Install the GM Campaign Identification Label. 1995-96 T-Pickup and 1995-96 T-Utility 1. Disconnect the negative battery cable. 2. Remove the front lower coolant reservoir attaching nut and discard. 3. Install the new vacuum switch, bracket, and hose assembly at the front lower coolant reservoir attaching location using the new nut contained in the kit. Important: The bracket must be rotated/positioned and held as close to the coalant reservoir as possible during the tightening of the nut to maintain maximum clearance between the battery and the vacuum switch. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Antilock Brakes / Traction Control Systems > 4WD Switch > Component Information > Technical Service Bulletins > Recalls for 4WD Switch: > 99-041 > May > 00 > Recall - ABS Front Axle Signal Malfunction > Page 5748 4. Position the vacuum switch, bracket, and hose assembly as shown in Figure 3 and tighten the nut to 8 Nm (71 lb in). 5. Locate the vacuum hose leading from the front axle vacuum actuator, located under the battery tray, to the vacuum switch mounted on the transfer case. This vacuum hose typically is route along the right front frame rail rearward up along the wheel welt towards the cowl area of the engine compartment. On come vehicle this hose may be covered with black convoluted protective sleeve. 6. Select a point on the vacuum hose, which was located in the previous step, that Will be lower in the vehicle than the new vacuum switch and will not result in the loading or stretching of either the existing or new hoses when they are connected together. Important The location where the vacuum line le tapped into must be lower than the vacuum switch to ensure condensation cannot accumulate in the switch, possibly resulting in a switch malfunction. 7. Cut the existing vacuum hose at the point located in the previous step, and connect the ends of the cut vacuum hose to the tee fitting that is part of the new vacuum switch and hose assembly. 8. Connect the new wiring harness to the vacuum switch and ensure the looking feature of the connector is engaged. Important: Ensure that the new harness is routed and secured in such a manner that it will not come in contact with any moving parts or be exposed to any other conditions that may result in damage to the harness. 9. Route the new harness as shown in Figure 3 and secure it to the existing underhood components at the locations indicated (1) using the tie straps provided in the kit. 10. Locate and disconnect the existing underhood front axle switch wiring harness connector, located in the area of the left front inner wheel well skirt under the brake master cylinder, and jumper in the new wiring harness. 11. Raise the vehicle and suitably support. 12. Locate the transfer case selector switch positioned on top of the transfer case. 13. Remove any foreign material from around the transfer case selector switch or vacuum connector. Important: Ensure that the O-ring is removed and discarded. 14. Disconnect the vacuum connector, remove and discard the transfer case selector switch and the O-ring. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Antilock Brakes / Traction Control Systems > 4WD Switch > Component Information > Technical Service Bulletins > Recalls for 4WD Switch: > 99-041 > May > 00 > Recall - ABS Front Axle Signal Malfunction > Page 5749 15. Hand start the new transfer case selector switch and tighten to 24 Nm (18 lb ft) 16. Ensure that the alignment feature of the vacuum harness connector is oriented correctly to engage the alignment post/pin of the transfer case selector switch and connect the harness to the switch. 17. Lower the vehicle and connect the negative battery cable. 18. Install the GM Campaign Identification Label. Owner Letter 99041 (Sample Of Notification Used) May, 2000 Dear General Motors Customer: This notice is sent to you in accordance with the requirements of the National Traffic and Motor Vehicle Safety Act. Reason For This Recall: General Motors has decided that a defect which relates to motor vehicle safety exists in certain 1991-1996 4WD wheel drive (4WD) Blazers and Jimmys, and 1994-1996 4WD S-10 and Sonoma pickup trucks. Some of these Vehicles exhibit a condition in which a switch that signals the antilook brake system (ADS) module when the vehicle is in 4WD may malfunction. The ABS module is designed with two different operating algorithms: one for 2-wheel drive (2WD) operation and another for 4WD drive operation. This allows the ABS system to compensate for the braking torque applied to the rear wheels through the drivetrain when the vehicle is in 4WD drive. When the vehicle is in 2WD, a malfunction switch may send an incorrect signal to the ABS module. If this occurs during an ABS stop, a somewhat longer stopping distance could result. If this occurred when minimum stopping distance was required, it could result in a vehicle crash. What Will Be Done: Your dealer will install a new transfer case selector switch, wiring harness, and an additional switch to ensure that the ABS receives the 4WD signal only when the drivetrain is in 4WD. This service will be performed for you at no charge. How Long Will The Repair Take? The length of time required to perform this service correction is approximately 30 minutes. Additional time may be required to schedule and process your vehicle. If your dealer has a large number of vehicles awaiting service, this additional time may be significant. Please ask your dealer if you wish to know how much additional time will be needed to schedule process and repair your vehicle. Contacting Your Dealer: Please contact your Chevrolet/GMC dealer as soon as possible to arrange a service date. Parts are available and instructions for making this correction have been sent to your dealer. Your Chevrolet/GMC dealer is best equipped to obtain parts and provide services to correct you vehicle as promptly as possible. Should your dealer be unable to schedule a service date within a reasonable time, you should contact the appropriate Customer Assistance Center at the listed number below: Division Number Deaf, Hearing Impaired or Speech Chevrolet 1-800-222-1020 1-800-833-2438 GMC 1-800-462-8782 1-800-462-8583 Utilize Telecommunication Devices If, after contacting the appropriate Customer Assistance Center, you are still not satisfied that we have done our best to remedy this condition without charge and within a reasonable time, you may wish to write the Administrator, National Highway Traffic Safety Administration, 400 Seventh Street, SW, Washington, DC 20590 or call 1-800-424-9393 (Washington, DC residents use (202-366-0123). Customer Reply Card: The customer reply card identifies your vehicle. Presentation of this card to your dealer will assist in making necessary correction in the shortest possible time. If you no longer own this vehicle, please let us know by completing the attached and mailing it in the postage paid envelope. We are sorry to cause you this inconvenience; however, we have taken this action in the interest of your safety and continued satisfaction with our products. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Antilock Brakes / Traction Control Systems > 4WD Switch > Component Information > Technical Service Bulletins > All Technical Service Bulletins for 4WD Switch: > 99-041 > May > 00 > Recall - ABS Front Axle Signal Malfunction Technical Service Bulletin # 99-041 Date: 000501 Recall - ABS Front Axle Signal Malfunction File in: Product Section: Campaigns Bulletin No: 99041 Dates: May, 2000 SUBJECT: 99041 - INCORRECT FRONT AXLE STATUS SIGNAL TO EBC4 ABS MODELS: 1991-1996 CHEVROLET AND GMC 4WD T UTILITIES 1994-1996 CHEVROLET AND GMC 4WD T PICKUP TRUCKS DUE TO THE AVAILABILITY OF PARTS, THIS CAMPAIGN WILL BE ADMINISTERED IN PHASES. YOU WILL RECEIVE A DEALER LISTING AS PHASES ARE RELEASED. CONDITION General Motors has decided that a defect which relates to motor vehicle safety exists in certain 1991-1996 Chevrolet and GMC 4WD T utilities and 1994-1996 Chevrolet and GMC 4WD T pickup trucks. Some of these vehicles exhibit a condition in which a switch that signals the antilock brake system (ABS) module when the vehicle is in four-wheel drive (4WD) may malfunction. The ABS module is designed with two different operating algorithms; one for two-wheel drive (2WD) operation and another for 4WD drive operation. This allows the ABS system to compensate for the braking torque applied tot he rear wheels through the drivetrain when the vehicle is in 4WD drive. When the vehicle is in 2WD, a malfunctioning switch may send an incorrect signal tot he ABS module. If this occurs during an ABS stop, a somewhat longer stopping distance could result. If this occurred when minimum stopping distance was required, it could result a vehicle crash. CORRECTION Dealers are to install a new transfer case selector switch, wiring harness, and an additional switch to ensure that the ABS receives the 4WD signal only when the drivetrain is in 4WD. VEHICLES INVOLVED Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Antilock Brakes / Traction Control Systems > 4WD Switch > Component Information > Technical Service Bulletins > All Technical Service Bulletins for 4WD Switch: > 99-041 > May > 00 > Recall - ABS Front Axle Signal Malfunction > Page 5755 Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Antilock Brakes / Traction Control Systems > 4WD Switch > Component Information > Technical Service Bulletins > All Technical Service Bulletins for 4WD Switch: > 99-041 > May > 00 > Recall - ABS Front Axle Signal Malfunction > Page 5756 Involved are certain 1991-1996 Chevrolet and GMC 4WD T utilities and 1994-1996 Chevrolet and GMC 4WD T pickup truck built within these VIN breakpoints as shown. IMPORTANT Dealers should confirm vehicle eligibility through GMVIS (GM Vehicle Inquiry System) or GM Access Screen (Canada only) or DCS Screen 445 (IPC only) before beginning campaign repairs. [Not all vehicles within the above breakpoints may be involved.] Involved vehicles have been identified by Vehicle Identification Number. Computer listing containing the complete Vehicle Identification, customer name address data have been prepared, and are being furnished to involved dealers with the campaign bulletin. The customer name address data furnished will enable dealers to follow up with the campaign bulletin has no involved vehicles currently assigned. These dealer listings may contain customer names and addresses obtained from Motor Vehicle Registration Records. The use of such motor vehicle registration data for any other purpose is a violation of law in several states/provinces/countries. Accordingly, you are urged to limit the use of this listing to the follow-up necessary to complete this campaign. PARTS INFORMATION Parts required to complete this campaign are to be obtained from General Motors Service Parts Operations (GMSPO). Please refer to your "involved vehicles listing" before ordering parts. Normal orders should be placed on a DRO = Daily Replenishment Order, in an emergency situation, parts should be ordered on a CSO = Customer Special Order. Part Number Description Quantity/Vehicle 88880028 Switch Kit, Elek Brk Cont Frt 1 Drv Axle Vac (1991-94 Utility) 88880029 Switch Kit, Elek Brk Cont Frt 1 Drv Axle Vac (1995-96 Utility, 1994-96 Pickup) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Antilock Brakes / Traction Control Systems > 4WD Switch > Component Information > Technical Service Bulletins > All Technical Service Bulletins for 4WD Switch: > 99-041 > May > 00 > Recall - ABS Front Axle Signal Malfunction > Page 5757 CAMPAIGN IDENTIFICATION LABEL - For US IPC Place a Campaign Identification Label on each vehicle corrected in accordance with the instructions outlined in this Product Campaign Bulletin. Each label provides a space to include the campaign number and the five (5) digit dealer code of the dealer performing the campaign service. This Information may be inserted with a typewriter a ball point pen. CAMPAIGN IDENTIFICATION LABEL - For CANADA Place a Campaign Identification Label on each vehicle corrected in accordance with the instruction outlined in this Product Campaign Bulletin. Each label provides a space to include the campaign number and the five (5) digit dealer code of the dealer performing the campaign service. This information may be inserted with a typewriter or a ball point pen. CLAIM INFORMATION Submit a Product Campaign Claim with the information indicated. Refer to the General Motors WINS claims processing Manual for details on Product Campaign Claim Submission. CUSTOMER NOTIFICATION - For US and CANADA Customers will be notified of this campaign on their vehicles by General Motors (see copy of customer letter included with this bulletin. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Antilock Brakes / Traction Control Systems > 4WD Switch > Component Information > Technical Service Bulletins > All Technical Service Bulletins for 4WD Switch: > 99-041 > May > 00 > Recall - ABS Front Axle Signal Malfunction > Page 5758 CUSTOMER NOTIFICATION - For IPC Letters will be sent to known owners of record located within areas covered by the US National Traffic and Motor Vehicle Safety Act. For owners outside these areas, dealers should notify customers using the attached suggested dealer letter. DEALER CAMPAIGN RESPONSIBILITY - For US and IPC (US States, Territories, and Possessions) The US National Traffic end Motor Vehicle safety Act provides that each vehicle that is subject to recall campaign of this type must be adequately repaired within a reasonable time after the customer has tendered it for repair. A failure to repair within sixty days after tender of vehicle is prima facie evidence of failure to repair within a reasonable time. If the condition is not adequately repaired within a reasonable time the customer may be entitled to an identical or reasonably equivalent vehicle at no charge or to a refund of the purchase price less a reasonable allowance for depreciation. To avoid having to provide these burdensome remedies, every effort must be made to promptly schedule an appointment with each customer and to repair their vehicle as soon as possible. In the recall campaign notification letters, customers are told how to contact the US National Highway Traffic Safety Administration if the campaign is not completed within a reasonable time. DEALER CAMPAIGN RESPONSIBILITY - ALL All unsold new vehicle in dealers' possession and subject to this campaign must be held an inspected/repaired per the service procedure of this campaign bulletin before customers take possession of these vehicles. Dealers are to service all vehicles subject to this campaign at no charge to customers, regardless of mileage, age of vehicle, or ownership, from this time forward. Customers who have recently purchased vehicles sold from your vehicle inventory, and for which there is no customer information indicated on the dealer listing, are to be contacted by the dealer. Arrangements are to be made to make the required correction according to the instructions contained in this bulletin. This could be done by mailing to such customers, a copy of the customer letter accompanying this bulletin. Campaign follow-up cards should not be used for this purpose, since the customer may not as yet have received the notification letter. In summary, whenever a vehicle subject to this campaign enters your vehicle inventory, or is in your dealership for service in the future, you must take the steps necessary to be sure the campaign correction has been made before selling or releasing the vehicle. Disclaimer 1991-94 T-Utility 1. Disconnect the negative battery cable. 2. Remove the front lower coolant reservoir attaching bolt. 3. Install the new vacuum switch, bracket, and hose assembly at the front lower coolant reservoir attaching location using the bolt removed in the previous step. Important The bracket must be rotated/positioned and held as close to the coolant reservoir as possible during the tightening of the bolt or nut to maintain maximum clearance between the battery and the vacuum switch. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Antilock Brakes / Traction Control Systems > 4WD Switch > Component Information > Technical Service Bulletins > All Technical Service Bulletins for 4WD Switch: > 99-041 > May > 00 > Recall - ABS Front Axle Signal Malfunction > Page 5759 4. Position the vacuum switch, bracket, and hose assembly as shown in Figure 1 and tighten the bolt to 8 Nm (71 lb in). 5. Locate the vacuum hose leading from the front axle vacuum actuator, located under the battery tray, to the vacuum switch mounted bon the transfer case. This vacuum hose typically is routed along the right front frame rail rearward up along the wheel well towards the cowl area of the engine compartment. On some vehicle this hose may be covered with a black convoluted protective sleeve. 6. Select a point on the vacuum hose, which was located in the previous step, that will be lower in the vehicle than the new vacuum switch and will not result in the loading or stretching of either the existing or new hoses when they are connected together. Important The location where the vacuum line is tapped into must be lower than the vacuum switch to ensure condensation cannot accumulate in the switch, possibly resulting in a switch malfunction. 7. Cut the existing vacuum hose at me point located in the previous step, and connect the ends of the cut vacuum hose to the tee fitting that is part of the new vacuum switch and hose assembly. 8. Connect the new wiring harness to the vacuum switch and ensure the locking feature of the connector is engaged. Important Ensure that the new harness is routed and secured in such a manner that it will not come in contact with any moving parts or be exposed to any other conitions that may result in damage to the harness. 9. Route the new harness is shown in Figure 1 and secure it to the existing Underhood components at the locations indicated (1) using the tie straps provided in the kit. 10. Locate and disconnect the existing underhood front exle switch wiring harness connector, located in the area above the brake booster assembly, and jumper in the new wiring harness. 11. Raise the vehicle and suitably support. 12. Loate the transfer case selector switch positioned on top of the transfer case. 13. Remove any foreign material from around the transfer case selector switch or vacuum connector. Important Ensure that the O-ring is removed and discarded. 14. Disconnect the vacuum connector, remove and discard the transfer case selector switch and the O-ring. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Antilock Brakes / Traction Control Systems > 4WD Switch > Component Information > Technical Service Bulletins > All Technical Service Bulletins for 4WD Switch: > 99-041 > May > 00 > Recall - ABS Front Axle Signal Malfunction > Page 5760 15. Hand start the new transfer case selector switch and tighten to 24 Nm (18 lb ft). 16. Ensure that the alignment feature of the vacuum harness connector is oriented correctly to engage the alignment post/pin of the transfer case selector switch and connect the harness to the switch. 17. Lower the vehicle and connect the negative battery cable. 18. Install the GM Campaign Identification Label. 1994 T-Pickup 1. Disconnect the negative battery cable. 2. Locate the new vacuum switch, bracket, and hose assembly so that the hole in the bracket align with the front inboard nut that is molded into the top of the coolant reservoir as shown in Figure 2. 3. Using the bolt provided in the kit, switch the vacuum switch, bracket, and hose assembly to the coolant reservoir by hand at starting the bolt. 4. With the vacuum switch, bracket and hose assembly positioned as shown in Figure 2, tighten the bolt to 10 Nm (88 lb in). 5. Locate the vacuum hose leading from the front axle vacuum actuator, located under the battery tray, to the vacuum switch mounted on the transfer case. This hose is routed up from the axle vacuum actuator and then rearward towards the cowl area inside the right fender as shown in Figure 2. 6. Select a point on the vacuum hose, which was located in the previous step, that will be lower in the vehicle than the new vacuum switch and will not result in the loading or stretching of either the existing or new hoses when they are connected together. Important The location where the vacuum line is tapped into must be lower than the vacuum switch to ensure condensation cannot accumulate in the switch, possibly resulting in a switch malfunction. 7. Cut the existing vacuum hose at the point located in the previous step, and connect the ends of the cut vacuum hose to the tee fitting that is a part of the new vacuum switch and hose assembly. 8. Connect the new wiring harness to the vacuum switch and ensure the locking feature of the connector is engaged. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Antilock Brakes / Traction Control Systems > 4WD Switch > Component Information > Technical Service Bulletins > All Technical Service Bulletins for 4WD Switch: > 99-041 > May > 00 > Recall - ABS Front Axle Signal Malfunction > Page 5761 Important: Ensure that the new harness is routed and secured in such a manner that it will not come in contact with any moving parts or be exposed to any other conditions that may result in damage to the harness. 9. Route the harness as shown in Figure 2 and secure the new harness to the existing underhood components at the locations indicated (1) using the tie straps provided in the kits. 10. Disconnect the existing underhood front axle switch wiring harness connector, located in the area of the left front inner wheel well skirt under the brake master cylinder, and jumper in the new wiring harness. 11. Raise the vehicle and suitably support. 12. Locate the transfer case selector switch positioned on top of the transfer case. 13. Remove any foreign material from around the transfer case selector switch or vacuum connector. Important: Ensure that the O-ring is removed and discarded. 14. Disconnect the vacuum connector, remove and discard the transfer case selector switch and the O-ring. 15. Hand start the new transfer case selector switch and tighten to 24 Nm (18 lb ft). 16. Ensure the alignment feature of the vacuum harness connector is oriented correctly to engage the alignment post/pin of the transfer case selector switch and connect the harness to the switch. 17. Lower the vehicle and connect the negative battery cable. 18. Install the GM Campaign Identification Label. 1995-96 T-Pickup and 1995-96 T-Utility 1. Disconnect the negative battery cable. 2. Remove the front lower coolant reservoir attaching nut and discard. 3. Install the new vacuum switch, bracket, and hose assembly at the front lower coolant reservoir attaching location using the new nut contained in the kit. Important: The bracket must be rotated/positioned and held as close to the coalant reservoir as possible during the tightening of the nut to maintain maximum clearance between the battery and the vacuum switch. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Antilock Brakes / Traction Control Systems > 4WD Switch > Component Information > Technical Service Bulletins > All Technical Service Bulletins for 4WD Switch: > 99-041 > May > 00 > Recall - ABS Front Axle Signal Malfunction > Page 5762 4. Position the vacuum switch, bracket, and hose assembly as shown in Figure 3 and tighten the nut to 8 Nm (71 lb in). 5. Locate the vacuum hose leading from the front axle vacuum actuator, located under the battery tray, to the vacuum switch mounted on the transfer case. This vacuum hose typically is route along the right front frame rail rearward up along the wheel welt towards the cowl area of the engine compartment. On come vehicle this hose may be covered with black convoluted protective sleeve. 6. Select a point on the vacuum hose, which was located in the previous step, that Will be lower in the vehicle than the new vacuum switch and will not result in the loading or stretching of either the existing or new hoses when they are connected together. Important The location where the vacuum line le tapped into must be lower than the vacuum switch to ensure condensation cannot accumulate in the switch, possibly resulting in a switch malfunction. 7. Cut the existing vacuum hose at the point located in the previous step, and connect the ends of the cut vacuum hose to the tee fitting that is part of the new vacuum switch and hose assembly. 8. Connect the new wiring harness to the vacuum switch and ensure the looking feature of the connector is engaged. Important: Ensure that the new harness is routed and secured in such a manner that it will not come in contact with any moving parts or be exposed to any other conditions that may result in damage to the harness. 9. Route the new harness as shown in Figure 3 and secure it to the existing underhood components at the locations indicated (1) using the tie straps provided in the kit. 10. Locate and disconnect the existing underhood front axle switch wiring harness connector, located in the area of the left front inner wheel well skirt under the brake master cylinder, and jumper in the new wiring harness. 11. Raise the vehicle and suitably support. 12. Locate the transfer case selector switch positioned on top of the transfer case. 13. Remove any foreign material from around the transfer case selector switch or vacuum connector. Important: Ensure that the O-ring is removed and discarded. 14. Disconnect the vacuum connector, remove and discard the transfer case selector switch and the O-ring. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Antilock Brakes / Traction Control Systems > 4WD Switch > Component Information > Technical Service Bulletins > All Technical Service Bulletins for 4WD Switch: > 99-041 > May > 00 > Recall - ABS Front Axle Signal Malfunction > Page 5763 15. Hand start the new transfer case selector switch and tighten to 24 Nm (18 lb ft) 16. Ensure that the alignment feature of the vacuum harness connector is oriented correctly to engage the alignment post/pin of the transfer case selector switch and connect the harness to the switch. 17. Lower the vehicle and connect the negative battery cable. 18. Install the GM Campaign Identification Label. Owner Letter 99041 (Sample Of Notification Used) May, 2000 Dear General Motors Customer: This notice is sent to you in accordance with the requirements of the National Traffic and Motor Vehicle Safety Act. Reason For This Recall: General Motors has decided that a defect which relates to motor vehicle safety exists in certain 1991-1996 4WD wheel drive (4WD) Blazers and Jimmys, and 1994-1996 4WD S-10 and Sonoma pickup trucks. Some of these Vehicles exhibit a condition in which a switch that signals the antilook brake system (ADS) module when the vehicle is in 4WD may malfunction. The ABS module is designed with two different operating algorithms: one for 2-wheel drive (2WD) operation and another for 4WD drive operation. This allows the ABS system to compensate for the braking torque applied to the rear wheels through the drivetrain when the vehicle is in 4WD drive. When the vehicle is in 2WD, a malfunction switch may send an incorrect signal to the ABS module. If this occurs during an ABS stop, a somewhat longer stopping distance could result. If this occurred when minimum stopping distance was required, it could result in a vehicle crash. What Will Be Done: Your dealer will install a new transfer case selector switch, wiring harness, and an additional switch to ensure that the ABS receives the 4WD signal only when the drivetrain is in 4WD. This service will be performed for you at no charge. How Long Will The Repair Take? The length of time required to perform this service correction is approximately 30 minutes. Additional time may be required to schedule and process your vehicle. If your dealer has a large number of vehicles awaiting service, this additional time may be significant. Please ask your dealer if you wish to know how much additional time will be needed to schedule process and repair your vehicle. Contacting Your Dealer: Please contact your Chevrolet/GMC dealer as soon as possible to arrange a service date. Parts are available and instructions for making this correction have been sent to your dealer. Your Chevrolet/GMC dealer is best equipped to obtain parts and provide services to correct you vehicle as promptly as possible. Should your dealer be unable to schedule a service date within a reasonable time, you should contact the appropriate Customer Assistance Center at the listed number below: Division Number Deaf, Hearing Impaired or Speech Chevrolet 1-800-222-1020 1-800-833-2438 GMC 1-800-462-8782 1-800-462-8583 Utilize Telecommunication Devices If, after contacting the appropriate Customer Assistance Center, you are still not satisfied that we have done our best to remedy this condition without charge and within a reasonable time, you may wish to write the Administrator, National Highway Traffic Safety Administration, 400 Seventh Street, SW, Washington, DC 20590 or call 1-800-424-9393 (Washington, DC residents use (202-366-0123). Customer Reply Card: The customer reply card identifies your vehicle. Presentation of this card to your dealer will assist in making necessary correction in the shortest possible time. If you no longer own this vehicle, please let us know by completing the attached and mailing it in the postage paid envelope. We are sorry to cause you this inconvenience; however, we have taken this action in the interest of your safety and continued satisfaction with our products. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Antilock Brakes / Traction Control Systems > ABS Main Relay > Component Information > Locations ABS Main Relay: Locations FOUR WHEEL ANTILOCK BRAKE SYSTEM (4WAL) Brake Pressure Modulator Valve The relay is located inside the Brake Pressure Modulator Valve (BPMV) and is not serviced seperately. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Antilock Brakes / Traction Control Systems > Diagnostic Connector - ABS > Component Information > Locations Steering Column Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Antilock Brakes / Traction Control Systems > Diagnostic Connector - ABS > Component Information > Locations > Page 5770 C221 - Data Link Connector Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Antilock Brakes / Traction Control Systems > Electronic Brake Control Module > Component Information > Locations Forward Lamps Harness, LH Side Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Antilock Brakes / Traction Control Systems > Electronic Brake Control Module > Component Information > Diagrams > Four-Wheel Antilock Brake Module (EHCU) Electronic Brake Control Module: Diagrams Four-Wheel Antilock Brake Module (EHCU) Fig. 34 ABS Connector Terminal Identification. Fig. 32 ALDL Connector Terminal Identification. ABS Connector Terminals. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Antilock Brakes / Traction Control Systems > Electronic Brake Control Module > Component Information > Diagrams > Four-Wheel Antilock Brake Module (EHCU) > Page 5776 Electronic Brake Control Module: Diagrams Rear Wheel Antilock Brake Module (RWAL EHCU) Fig. 13 RWAL System Electrical Connectors. RWAL system electrical connectors. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Antilock Brakes / Traction Control Systems > Electronic Brake Control Module > Component Information > Diagrams > Page 5777 Electronic Brake Control Module: Service and Repair Fig. 225 EHCU/BPMV Mounting. (EHCU) Electro-Hydraulic Control Unit / (BPMV) Brake Pressure Modulator Valve Module is not serviceable and must be replaced as a unit. 1. Remove washer tank attaching bolts, then position aside. 2. Remove EHCU/BPMV electrical connectors. 3. Disconnect module brake lines. Use caution not to get brake fluid on paint or electrical connections. 4. Remove upper to lower bracket assembly attaching bolts. 5. Remove EHCU/BPMV module and upper bracket assembly from vehicle. 6. Remove upper mounting bracket to EHCU/BPMV module attaching bolts, Fig. 225. 7. Reverse procedure to install, noting the following: a. Torque EHCU/BPMV module to bracket attaching bolts to 5 ft. lbs. b. Torque EHCU/BPMV bracket assembly attaching bolts to 20 ft. lbs. c. Torque brake line fittings to 16 ft. lbs. d. Bleed EHCU/BPMV module. See: Brake Bleeding Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Antilock Brakes / Traction Control Systems > Hydraulic Assembly, Traction Control > Component Information > Locations Forward Lamps Harness, LH Side (W/Four-Wheel Antilock Brakes) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Antilock Brakes / Traction Control Systems > Hydraulic Assembly, Traction Control > Component Information > Service and Repair > Anti-Lock Pressure Valve Hydraulic Assembly: Service and Repair Anti-Lock Pressure Valve Fig. 86 APV Valve Assembly Replacement The APV valve is not serviceable. It should be replaced when the DTC code charts show that it's the cause of a malfunction. 1. Disconnect battery ground cable. 2. Disconnect brake pipe fittings from APV. 3. Disconnect 4-way electrical connector from APV, Fig. 86. 4. Remove APV to bracket attaching bolts. 5. Remove APV valve from vehicle. 6. Reverse procedure to install, torque APV to bracket attaching bolts to 21 ft. lbs. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Antilock Brakes / Traction Control Systems > Hydraulic Assembly, Traction Control > Component Information > Service and Repair > Anti-Lock Pressure Valve > Page 5783 Hydraulic Assembly: Service and Repair Isolation/Dump Valve Assembly Fig. 46 ECU & Control Valve Assembly Installation 1. Disconnect brake lines from control valve, the plug lines and open fittings. 2. Remove bolts (25) securing control valve, Fig. 46, and support valve assembly. Do not allow valve assembly to hang from wiring. 3. Disconnect electrical connectors and remove control valve assembly. 4. Reverse procedure to install, then bleed brakes as needed. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Antilock Brakes / Traction Control Systems > Hydraulic Control Assembly - Antilock Brakes > Component Information > Service and Repair Hydraulic Control Assembly - Antilock Brakes: Service and Repair Fig. 225 EHCU/BPMV Mounting. (EHCU) Electro-Hydraulic Control Unit / (BPMV) Brake Pressure Modulator Valve Module is not serviceable and must be replaced as a unit. 1. Remove washer tank attaching bolts, then position aside. 2. Remove EHCU/BPMV electrical connectors. 3. Disconnect module brake lines. Use caution not to get brake fluid on paint or electrical connections. 4. Remove upper to lower bracket assembly attaching bolts. 5. Remove EHCU/BPMV module and upper bracket assembly from vehicle. 6. Remove upper mounting bracket to EHCU/BPMV module attaching bolts, Fig. 225. 7. Reverse procedure to install, noting the following: a. Torque EHCU/BPMV module to bracket attaching bolts to 5 ft. lbs. b. Torque EHCU/BPMV bracket assembly attaching bolts to 20 ft. lbs. c. Torque brake line fittings to 16 ft. lbs. d. Bleed EHCU/BPMV module. See: Brake Bleeding Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Antilock Brakes / Traction Control Systems > Wheel Speed Sensor > Component Information > Specifications Wheel Speed Sensor: Specifications Wheel Speed Sensor ........................................................................................................................... .......................................................... 900-2000 ohms Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Antilock Brakes / Traction Control Systems > Wheel Speed Sensor > Component Information > Specifications > Page 5790 Wheel Speed Sensor: Service and Repair 1. Raise and support vehicle, then remove wheel and tire assembly. 2. Disconnect brake caliper assembly and position aside. 3. Remove rotor, then hub and bearing assembly. 4. Disconnect wheel sensor electrical connector 5. Remove sensor wire form upper control arm clip. 6. Remove sensor and splash shield assembly attaching bolts, then remove sensor. 7. Reverse procedure to install. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Bleeding > System Information > Service and Repair > General Information Brake Bleeding: Service and Repair General Information BLEEDING BRAKE HYDRAULIC SYSTEM Bleeding is necessary if air has entered the hydraulic brake system. It may be necessary to bleed the system at all four wheels if a low fluid level allowed air to enter the system, or the brake pipes have been disconnected at the master cylinder or combination valve. If a pipe is disconnected at one wheel, then only bleed that wheel. The time required to bleed the hydraulic system when the master cylinder is removed can be reduced by bleeding the master cylinder before installing it on the vehicle. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Bleeding > System Information > Service and Repair > General Information > Page 5795 Brake Bleeding: Service and Repair With Four Wheel Antilock Brake System FOUR WHEEL ANTILOCK BRAKE BLEEDING The 4WAL brake pressure modulator valve (BPMV) should be bled after replacement or if air is trapped in it. Bleeding should not be necessary if the fluid is not contaminated or no air is in the BPMV. There are internal bleed valves on each side of the BPMV that open internal channels. Open the internal bleed valves 1/4 to 1/2 turn before bleeding. Should the module need bleeding, it must be bled after the master cylinder and before the wheel cylinders and calipers. NOTICE: The ignition switch must be in the "OFF" position or false trouble codes could be set to memory. Tools Required: - J 39177 Combination Valve Pressure Bleeding Tool - TK 00000 Tech-1 Scan Tool - TK 02650 RWAL/4WAL Cartridge Kit or 3000003 Mass Storage Cartridge - A modified J 35856 Combination Valve Pressure Bleeding Tool can be used in place of J 39177 provided that the dimple is removed from it first. Important: Expect to use two quarts of brake fluid to thoroughly bleed the system. Fig. 59 EHCU/BPMV Module Bleeding 1. Open the internal bleed valves on the sides of the BPMV 1/4 to 1/2 turn each (A). 2. Install J 39177 on the left high pressure accumulator bleed stem (C) of the BPMV. 3. Install J 39177 on the right high pressure accumulator bleed stem (C) of the BPMV. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Bleeding > System Information > Service and Repair > General Information > Page 5796 Combination Valve Pressure Bleeding Tool 4. Install J 39177 on the combination valve. 5. Check the master cylinder reservoir fluid level and fill if needed. 6. Bleed the brakes as described under Pressure Bleeding. NOTICE: Always use the correct fastener in the proper location. When you replace a fastener, use ONLY the exact part number for that application. General Motors will call out those fasteners that require a replacement after removal. General Motors will also call out the fasteners that require thread lockers or thread sealant. UNLESS OTHERWISE SPECIFIED, do not use supplemental coatings (paints, greases, or other corrosion inhibitors) on threaded fasteners or fastener joint interfaces. Generally, such coatings adversely affect the fastener torque and the joint clamping force, and may damage the fastener. When you install fasteners, use the correct tightening sequence and specifications. Following these instructions can help you avoid damage to parts and systems. 7. Close the internal bleed valves. Tighten Internal bleed valves (A) to 7 Nm (60 lbs. in.). 8. Remove the three J 39177 tools. 9. Check the master cylinder reservoir fluid level and fill if needed. 10. With the ignition switch "ON" and the engine off, do six function tests with the Tech-1 scan tool. 11. Repeat the wheel cylinder and caliper bleed procedure to remove the air that purged from the BPMV during the function tests. 12. Apply firm pressure to the brake pedal and evaluate brake pedal feel. 13. Repeat the bleed procedure if needed. - Make sure you have a good, hard brake pedal before starting the engine and moving the vehicle. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Bleeding > System Information > Service and Repair > General Information > Page 5797 Brake Bleeding: Service and Repair With VCM/Four Wheel Antilock Brake System VCM/FOUR WHEEL ANTILOCK BRAKE SYSTEM BLEEDING The brake pressure modulator valve (BPMV) should be bled after replacement or if air is trapped in it. Bleeding should not be necessary if the fluid is not contaminated or no air is in the BPMV. There are internal bleed valves on each side of the BPMV that open internal channels. Open the internal bleed valves 1/4 to 1/2 turn before bleeding. Should the module need bleeding, it must be bled after the master cylinder and before the wheel cylinders and calipers. NOTICE: The ignition switch must be in the "OFF" position or false trouble codes could be set to memory. Tools Required: - J 39177 Combination Valve Pressure Bleeding Tool (Three required) - TK 00000 Tech-1 Scan Tool - TK 02650 RWAL/4WAL Cartridge Kit or 3000003 Mass Storage Cartridge - A modified J 35856 Combination Valve Pressure Bleeding Tool can be used in place of J 39177 providing you remove the dimple from it first. Important: Expect to use two quarts of brake fluid to thoroughly bleed the system. Fig. 59 EHCU/BPMV Module Bleeding 1. Open the internal bleed valves on the sides of the BPMV 1/4 to 1/2 turn each (A). 2. Install J 39177 on the left high pressure accumulator bleed stem (C) of the BPMV. 3. Install J 39177 on the right high pressure accumulator bleed stem (C) of the BPMV. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Bleeding > System Information > Service and Repair > General Information > Page 5798 Combination Valve Pressure Bleeding Tool 4. Install J 39177 on the combination valve. 5. Check the master cylinder reservoir fluid level and fill if needed. 6. Bleed the brakes as described under Pressure Bleeding. NOTICE: Always use the correct fastener in the proper location. When you replace a fastener, use ONLY the exact part number for that application. General Motors will call out those fasteners that require a replacement after removal. General Motors will also call out the fasteners that require thread lockers or thread sealant. UNLESS OTHERWISE SPECIFIED, do not use supplemental coatings (paints, greases, or other corrosion inhibitors) on threaded fasteners or fastener joint interfaces. Generally, such coatings adversely affect the fastener torque and the joint clamping force, and may damage the fastener. When you install fasteners, use the correct tightening sequence and specifications. Following these instructions can help you avoid damage to parts and systems. 7. Close the internal bleed valves. Tighten Internal bleed valves (A) to 7 Nm (60 lbs. in.). 8. Remove the three J 39177 tools. 9. Check the master cylinder reservoir fluid level and fill if needed. 10. With the ignition switch "ON" and the engine off, do six function tests with the Tech-1 scan tool. 11. Repeat the wheel cylinder and caliper bleed procedure to remove the air that purged from the BPMV during the tunction tests. 12. Apply firm pressure to the brake pedal and evaluate brake pedal feel. 13. Repeat the bleed procedure if needed. - Make sure you have a good, hard brake pedal before starting the engine and moving the vehicle. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Bleeding > System Information > Service and Repair > General Information > Page 5799 Brake Bleeding: Service and Repair With Rear Wheel Antilock Brake System REAR WHEEL ANTILOCK BRAKE SYSTEM BLEEDING NOTICE: The ignition switch must be in the "OFF" position or false DTCs could be set to memory. Tools Required: - J 39177 Combination Valve Pressure Bleeding Tool - TK 00000 Tech-1 Scan Tool - TK 02650 RWALI4WAL Cartridge Kit or 7000001 Mass Storage Cartridge 1. Install J 39177 on the combination valve. 2. Check the master cylinder reservoir fluid level and fill it needed. 3. Bleed wheel cylinders and calipers. 4. Turn ignition switch "ON" and do three function tests with the Tech-1 scan tool. 5. Re-bleed the rear brakes as described under Pressure Bleeding. 6. Evaluate brake pedal feel. 7. Repeat the bleed procedure if needed. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Bleeding > System Information > Service and Repair > General Information > Page 5800 Brake Bleeding: Service and Repair General Information BLEEDING BRAKE HYDRAULIC SYSTEM Bleeding is necessary if air has entered the hydraulic brake system. It may be necessary to bleed the system at all four wheels if a low fluid level allowed air to enter the system, or the brake pipes have been disconnected at the master cylinder or combination valve. If a pipe is disconnected at one wheel, then only bleed that wheel. The time required to bleed the hydraulic system when the master cylinder is removed can be reduced by bleeding the master cylinder before installing it on the vehicle. With Four Wheel Antilock Brake System FOUR WHEEL ANTILOCK BRAKE BLEEDING The 4WAL brake pressure modulator valve (BPMV) should be bled after replacement or if air is trapped in it. Bleeding should not be necessary if the fluid is not contaminated or no air is in the BPMV. There are internal bleed valves on each side of the BPMV that open internal channels. Open the internal bleed valves 1/4 to 1/2 turn before bleeding. Should the module need bleeding, it must be bled after the master cylinder and before the wheel cylinders and calipers. NOTICE: The ignition switch must be in the "OFF" position or false trouble codes could be set to memory. Tools Required: - J 39177 Combination Valve Pressure Bleeding Tool - TK 00000 Tech-1 Scan Tool - TK 02650 RWAL/4WAL Cartridge Kit or 3000003 Mass Storage Cartridge - A modified J 35856 Combination Valve Pressure Bleeding Tool can be used in place of J 39177 provided that the dimple is removed from it first. Important: Expect to use two quarts of brake fluid to thoroughly bleed the system. Fig. 59 EHCU/BPMV Module Bleeding 1. Open the internal bleed valves on the sides of the BPMV 1/4 to 1/2 turn each (A). 2. Install J 39177 on the left high pressure accumulator bleed stem (C) of the BPMV. 3. Install J 39177 on the right high pressure accumulator bleed stem (C) of the BPMV. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Bleeding > System Information > Service and Repair > General Information > Page 5801 Combination Valve Pressure Bleeding Tool 4. Install J 39177 on the combination valve. 5. Check the master cylinder reservoir fluid level and fill if needed. 6. Bleed the brakes as described under Pressure Bleeding. NOTICE: Always use the correct fastener in the proper location. When you replace a fastener, use ONLY the exact part number for that application. General Motors will call out those fasteners that require a replacement after removal. General Motors will also call out the fasteners that require thread lockers or thread sealant. UNLESS OTHERWISE SPECIFIED, do not use supplemental coatings (paints, greases, or other corrosion inhibitors) on threaded fasteners or fastener joint interfaces. Generally, such coatings adversely affect the fastener torque and the joint clamping force, and may damage the fastener. When you install fasteners, use the correct tightening sequence and specifications. Following these instructions can help you avoid damage to parts and systems. 7. Close the internal bleed valves. Tighten Internal bleed valves (A) to 7 Nm (60 lbs. in.). 8. Remove the three J 39177 tools. 9. Check the master cylinder reservoir fluid level and fill if needed. 10. With the ignition switch "ON" and the engine off, do six function tests with the Tech-1 scan tool. 11. Repeat the wheel cylinder and caliper bleed procedure to remove the air that purged from the BPMV during the function tests. 12. Apply firm pressure to the brake pedal and evaluate brake pedal feel. 13. Repeat the bleed procedure if needed. - Make sure you have a good, hard brake pedal before starting the engine and moving the vehicle. With VCM/Four Wheel Antilock Brake System VCM/FOUR WHEEL ANTILOCK BRAKE SYSTEM BLEEDING The brake pressure modulator valve (BPMV) should be bled after replacement or if air is trapped in it. Bleeding should not be necessary if the fluid is not contaminated or no air is in the BPMV. There are internal bleed valves on each side of the BPMV that open internal channels. Open the internal bleed valves 1/4 to 1/2 turn before bleeding. Should the module need bleeding, it must be bled after the master cylinder and before the wheel cylinders and calipers. NOTICE: The ignition switch must be in the "OFF" position or false trouble codes could be set to memory. Tools Required: - J 39177 Combination Valve Pressure Bleeding Tool (Three required) - TK 00000 Tech-1 Scan Tool - TK 02650 RWAL/4WAL Cartridge Kit or 3000003 Mass Storage Cartridge - A modified J 35856 Combination Valve Pressure Bleeding Tool can be used in place of J 39177 providing you remove the dimple from it first. Important: Expect to use two quarts of brake fluid to thoroughly bleed the system. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Bleeding > System Information > Service and Repair > General Information > Page 5802 Fig. 59 EHCU/BPMV Module Bleeding 1. Open the internal bleed valves on the sides of the BPMV 1/4 to 1/2 turn each (A). 2. Install J 39177 on the left high pressure accumulator bleed stem (C) of the BPMV. 3. Install J 39177 on the right high pressure accumulator bleed stem (C) of the BPMV. Combination Valve Pressure Bleeding Tool 4. Install J 39177 on the combination valve. 5. Check the master cylinder reservoir fluid level and fill if needed. 6. Bleed the brakes as described under Pressure Bleeding. NOTICE: Always use the correct fastener in the proper location. When you replace a fastener, use ONLY the exact part number for that application. General Motors will call out those fasteners that require a replacement after removal. General Motors will also call out the fasteners that require thread lockers or thread sealant. UNLESS OTHERWISE SPECIFIED, do not use supplemental coatings (paints, greases, or other corrosion inhibitors) on threaded fasteners or fastener joint interfaces. Generally, such coatings adversely affect the fastener torque and the joint clamping force, and may damage the fastener. When you install fasteners, use the correct tightening sequence and specifications. Following these instructions can help you avoid damage to parts and systems. 7. Close the internal bleed valves. Tighten Internal bleed valves (A) to 7 Nm (60 lbs. in.). 8. Remove the three J 39177 tools. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Bleeding > System Information > Service and Repair > General Information > Page 5803 9. Check the master cylinder reservoir fluid level and fill if needed. 10. With the ignition switch "ON" and the engine off, do six function tests with the Tech-1 scan tool. 11. Repeat the wheel cylinder and caliper bleed procedure to remove the air that purged from the BPMV during the tunction tests. 12. Apply firm pressure to the brake pedal and evaluate brake pedal feel. 13. Repeat the bleed procedure if needed. - Make sure you have a good, hard brake pedal before starting the engine and moving the vehicle. With Rear Wheel Antilock Brake System REAR WHEEL ANTILOCK BRAKE SYSTEM BLEEDING NOTICE: The ignition switch must be in the "OFF" position or false DTCs could be set to memory. Tools Required: - J 39177 Combination Valve Pressure Bleeding Tool - TK 00000 Tech-1 Scan Tool - TK 02650 RWALI4WAL Cartridge Kit or 7000001 Mass Storage Cartridge 1. Install J 39177 on the combination valve. 2. Check the master cylinder reservoir fluid level and fill it needed. 3. Bleed wheel cylinders and calipers. 4. Turn ignition switch "ON" and do three function tests with the Tech-1 scan tool. 5. Re-bleed the rear brakes as described under Pressure Bleeding. 6. Evaluate brake pedal feel. 7. Repeat the bleed procedure if needed. Hydraulic System Flushing HYDRAULIC SYSTEM FLUSHING Flushing is done at each bleeder valve similar to the bleeding procedure. The difference-is that the bleeder valve is opened 1 1/2 turns and fluid is forced through the pipes, hoses, and bleeder valves until it comes out clear in color. Refer to Hydraulic System, Service and Repair. Check the master cylinder fluid level after flushing at each bleeder valve and refill as required. After flushing, make sure the master cylinder reservoir is filled to the correct level. Manual Bleeding MANUAL BLEEDING NOTICE: Brake fluid will damage electrical connections and painted surfaces. Use shop cloths, suitable containers, and tender covers to prevent brake fluid from contacting these areas. Always re-seal and wipe off brake fluid containers to prevent spills. Tool Required: J 28434 Wheel Cylinder Bleeder Wrench - Relieve the vacuum reserve by applying the brakes several times with the ignition "OFF" 1. Fill the master cylinder reservoirs with Delco Supreme No. 11 Hydraulic Brake Fluid (GM P/N 1052535) or an equivalent DOT 3 motor vehicle brake fluid. - Maintain the fluid level during bleeding. 2. If the master cylinder is suspected to have air in the bore, bleed it before any wheel cylinder or caliper. A. Disconnect the forward brake pipe connection at the master cylinder. B. Allow the brake fluid to flow from the connector port. C. Connect the brake pipe but do not tighten. D. Slowly apply the brake pedal and allow the air to bleed from the loose fitting. E. Tighten the fitting before releasing the pedal. F. Wait 15 seconds. G. Repeat this sequence, including the 15-second wait, until all air is purged from the bore. H. After all air has been removed from the forward connection, repeat this procedure for the rear pipe. 3. If the BPMV of the 4WAL system is replaced or suspected to have air trapped inside, it must be bled next. Refer to With ABS. 4. Bleed each wheel in the following sequence: Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Bleeding > System Information > Service and Repair > General Information > Page 5804 A. Right rear B. Left rear C. Right front D. Left front 5. Attach J 28434 to the wheel cylinder/caliper bleeder valve. - Immerse the opposite end of the hose into a container partially filled with clean brake fluid. 6. Slowly apply the brake pedal one time and hold. 7. Loosen the bleeder valve to purge the air from the wheel cylinder/caliper. 8. Tighten the bleeder valve and slowly release the pedal. 9. Wait 15 seconds. 10. Repeat this sequence, including the 15-second wait, until all air is purged from the wheel cylinder/caliper. 11. Tighten the bleeder valve to 7 N.m (62 lbs. in.). 12. Continue steps 5 through 11 at each wheel until the system is bled. 13. Check the brake pedal for "sponginess" and the brake warning lamp for an indication of unbalanced pressure. Repeat the bleeding procedure to correct either of these conditions. Pressure Bleeding PRESSURE BLEEDING A diaphragm-type pressure bleeder must be used. It must have a rubber diaphragm between the air supply and brake fluid to prevent air, moisture, oil, and other contaminants from entering the hydraulic system. NOTICE: Brake fluid will damage electrical connections and painted surfaces. Use shop cloths, suitable containers, and fender covers to prevent brake fluid from contacting these areas. Always reseal and wipe off brake fluid containers to prevent spills. Tools Required: - J 29567 Brake Bleeder Adapter - J 39177 Combination Valve Pressure Bleeding Tool - J 28434 Wheel Cylinder Bleeder Wrench 1. Fill the pressure tank at least 2/3 full of brake fluid. The bleeder must be bled each time fluid is added. 2. Charge the bleeder to 140-170 kPa (20-25 psi). Combination Valve Pressure Bleeding Tool 3. Use J 39177 to depress and hold the valve stem on the combination valve. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Bleeding > System Information > Service and Repair > General Information > Page 5805 4. Install the bleeder adapter. 5. If the BPMV of the 4WAL system is replaced or suspected to air trapped inside, it must be bled next. 6. Bleed each wheel in the following sequence: A. Right rear B. Left rear C. Right front D. Left front 7. Connect the hose from the bleeder to the adapter at the master cylinder. 8. Open the tank valve. 9. Attach J 28434 to a bleeder valve. 10. Immerse the opposite end of the hose into a contamer partially filled with clean brake fluid. 11. Open the bleeder valve at least 3/4 of a turn and allow the fluid to flow until no air is seen in the fluid. 12. Tighten the bleeder valve to 7 Nm (62 lbs. in.). 13. Repeat steps 9 through 12 at all the wheels. 14. Check the brake pedal for "sponginess". - Repeat the bleeding procedure if this condition is found. 15. Remove J 39177. 16. Disconnect the hose from the bleeder adapter. 17. Remove the bleeder adapter. 18. Fill the master cylinder to the proper level. Master Cylinder Bench Bleeding MASTER CYLINDER BENCH BLEEDING Bench bleed the master cylinder to remove the air from it prior to installation. This reduces the amount of bleeding needed after it is installed on the vehicle. 1. Plug the outlet ports and mount the master cylinder in a vise with the front end tilted slightly down. 2. Fill the reservoir with clean brake fluid. 3. Using a tool with a smooth rounded end, stroke the primary piston about 25 mm (1 inch) several times. - As air is bled from the master cylinder, the primary piston will not travel the full 25-mm (1-inch) stroke. 4. Reposition the master cylinder in the vise with the front end tilted slightly up. 5. Again stroke the primary piston about 25 mm (1 inch) several times. 6. Reposition the master cylinder in the vise to the level position. 7. Loosen the plugs one at a time and push the piston into the bore to force the air from the cylinder. - To prevent air from being sucked back into the cylinder, tighten the plug(s) before allowing the piston to return to its original position. 8. Fill the reservoir. - Normal bleeding procedures should be followed after the master cylinder is installed. Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions Brake Warning Indicator: Diagram Information and Instructions Abbreviation Following is a list of abbreviations used in the wiring diagrams. The abbreviations have been developed in such a way that their meaning should be clear. Use this page as a reference to determine the meaning of an abbreviation if necessary. A Ampere A/C Air Conditioner AC Alternating Current ACC Accessory AIR Air Injection Reaction AIR/COND Air Conditioner AMP Ampere ANT Anticipate ASM Assembly ASSY Assembly AUD Audio AUTO Automatic AUX Auxiliary BAT Battery BATT Battery Bi-LEV Bi-Level BLK Black BLT Belt BLU Blue BOT Bottom BRK Brake BRN Brown BTSI Brake/Trans Shift Interlock BU Backup BUZZ Buzzer CD Compact Disc CHMSL Center High Mount Stoplamp CID Cubic Inch Displacement CIR/BRK Circuit Breaker CIRO Circuit CLSTR Cluster CNTRL Control COMP Compartment COMP Compressor CONN Connector CONV Convenience CRNK Crank CTSY Courtesy CYL Cylinder DC Direct Current DEF Defrost DK Dark DIAG Diagnostic DIM Dimmer DIR Directional DISC Discrete DIV Diverter DLC Data Link Connector DM Dome DR Door DRL Daytime Running Lamps (Canadian Only) ECM Engine Control Module EGR Exhaust Gas Recirculation ELEC Electric ENG Engine EPR Exhaust Pressure Regulator ETR Electronically Tuned Radio EXC Except Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 5810 F-PUMP Fuel Pump FLASH Flasher FRT Front 4WD Four-Wheel Drive GAU Gauges GEN Generator GRA Gray GRD Ground GRN Green HAND Handling HAZ Hazard HD Heavy Duty HDLP Headlamp HI High HTR Heater IAC Idle Air Control IGN Ignition ILLUM Illumination I/P Instrument Panel INC Increased IND Indicator INJ Injector INST Instrument INSTR Instrument INTER Interior LD Light Duty LH Left Hand LO Low LP Lamp LPS Lamps LT Light LTR Lighter M Motor MAN Manual MAP Manifold Absolute Pressure MAX Maximum MED Medium MRKR Marker MTR Manually Tuned Radio MULT Multiple NAT Natural NEU Neutral NO Normally Open NC Normally Closed ORN Orange PCM Powertrain Control Module PK Park PLR Puller PNK Pink PNL Panel PPL Purple PRESS Pressure PVAC Partial Vacuum PWR Power RCVR Receiver REF Reference RESIST Resistance RH Right Hand RKE Remote Keyless Entry RPO Regular Production Option RST Rust RWAL Rear Wheel Antilock SEN Sensor SEND Sender SIG Signal SIL Silver Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 5811 SIR Supplemental Inflatable Restraint SKT Socket SOL Solenoid SPEEDO Speedometer STR Stripe STRG Steering SW Switch TACH Tachometer TBI Throttle Body Fuel Injection TCC Torque Converter Clutch TCM Transmission Control Module TEMP Temperature TIL Taillamp TP Throttle Position TRANS Transmission TYP Typical V Volt VAC Vacuum VCM Vehicle Control Module VEN Vent VLV Valve VSS Vehicle Speed Sensor W/ With W/O Without W/S Windshield W/WASHER Window Washer WDO Window WHT White WGR Wiring YEL Yellow Cell References CELL REFERENCES General Motors vehicles often use "CELL" references in their electrical wiring diagrams. These references are used in the Original Equipment Manual to refer to a section in the manual and not a specific diagram(s). GM Sample Diagram W/ Cell Reference For instance, in the diagram illustrated "Cell 20" is not a reference to another diagram but a reference to "Section 20" in the OE manual. In the Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 5812 example, "Section 20" is the engine control section of the manual. To navigate through these "Cell" references start at the vehicle level and go to: Diagrams / Electrical Diagrams - for a complete list of the diagrams available for the vehicle. Choose the system you are working on and view those diagrams. Note: If unsure of the system - try utilizing the search feature. Type a component in the search feature that belongs to the system and when the results are displayed note the path displayed. This will show the system the component belongs in. Electrostatic Discharge (ESD Sensitive Devices) Electrostatic Discharge (ESD) Symbol HANDLING ELECTROSTATIC DISCHARGE (ESD) SENSITIVE PARTS Many solid-state electrical components can be damaged by electrostatic discharge(ESD). Some will display a label, but many will not. NOTE: In order to avoid possibly damaging any components, observe the following: 1. Body movement produces an electrostatic charge. To discharge personal static electricity, touch a ground point (metal) on the vehicle. This should be done anytime you: ^ Slide across the vehicle seat. ^ Sit down or stand up. ^ Do any walking. 2. Do not touch exposed electric terminals or components with your fingers or tools. Remember, the connector you are checking might be tied into a circuit that could be damaged by electrostatic discharge. 3. When using a screwdriver or similar tool to disconnect a connector, never let the tool come into contact with or come between exposed terminals. 4. Never jumper, ground, or use test equipment probes on any components or connectors unless specified in diagnosis. When using test equipment, always connect the ground lead first. 5. Do not remove the solid-state component from its protective packaging until you are ready to install the part. 6. Always touch the solid-state component's package to ground before opening. Solid-state components can also be damaged if: ^ They are bumped or dropped. ^ They are laid on any metal benches or components that operate electrically such as a TV radio, or oscilloscope. Schematic Symbols Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 5813 Symbols (Part 1 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 5814 Symbols (Part 2 Of 3) Chevrolet S10 Workshop Manual (S10-T10 Blazer 4WD V6-262 4.3L VIN Z (1994)) Chevrolet Workshop Manuals > Brakes and Traction Control > Brake Warning Indicator > Component Information > Diagrams > Diagram Information and Instructions > Page 5815 Symbols (Part 3 Of 3) SOLID-STATE SYMBOLS A group of special symbols is used to represent electronic circuits used in the Solid-State modules. These symbols are greatly simplified versions of the actual circuits. They can be very useful for troubleshooting purposes if properly used. It is important to remember that these symbols apply only to modules with all connectors in place and supply voltages on.