Chevrolet - S 10 - Workshop Manual - 1988 - 1988

Engine - Blue Smoke On Start-Up Valve: Technical Service Bulletins Engine - Blue Smoke On Start-Up Group Ref.: Engine Fuel & Emission Bulletin No.: 376514 Date: December, 1993 SUBJECT: BLUE SMOKE ON START-UP (REPLACE VALVE STEM SEALS) MODELS: 1985-93 CHEVROLET CAPRICE WITH 4.3L (LB4) ENGINE 1985-86 PONTIAC PARISIENNE, GRAND PRIX AND BONNEVILLE WITH 4.3L (LB4) ENGINE 1985-93 CHEVROLET AND GMC C/K, G, M/L, S/T, AND P TRUCKS WITH 4.3L ENGINE 1991-93 OLDSMOBILE BRAVADA WITH 4.3L ENGINE CONDITION: Some owners may comment that they observe blue smoke coming from the tailpipe of their vehicle immediately after they start their engine. The condition generally occurs after the vehicle has been parked for several hours. CAUSE: Oil leaking down the valve stem(s) into the cylinder(s) after the engine is shutdown. When the engine is restarted, the oil that has leaked into the cylinder is ignited, causing the blue smoke. CORRECTION: Replace all intake and exhaust valve stem seals. Use the V8 umbrella style exhaust valve stem seal. The umbrella style seal is recommended for service because it is easier to install than the O-ring style exhaust valve stem seal used in production. Barrel style seals continue to be used on the intake valve (same as production). Follow the procedure published in the appropriate service manual for valve stem seal replacement. WARNING: Improper seal installation may cause a condition worse than the original concern. PARTS INFORMATION: Parts are currently available from GMPSO. WARRANTY INFORMATION: For vehicles repaired under warranty, use: Labor Operation: J0547 Labor Time: Use published labor operation time. 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. Page 7519 Fuel Gauge: Testing and Inspection Gauge Stays at Empty This condition is generally caused by a short in the fuel tank wiring circuit. 1. Ensure fuel tank is full, then disconnect lead at fuel tank. 2. If gauge moves but not past full mark, replace fuel tank sending unit. 3. If gauge stays at empty, repair short in circuit between gauge and fuel tank. Drive Axle (Front) - Will Not Disengage Transfer Case Actuator: All Technical Service Bulletins Drive Axle (Front) - Will Not Disengage Number: 91-476-4C Section: 4C Date: JAN. 1992 Corporate Bulletin No.: 167402 ASE No.: A3 Subject: FRONT AXLE WILL NOT DISENGAGE Model and Year: 1983-1991 T TRUCKS Owners of some 1983-1991 T vehicles may comment about inappropriate front axle disengagement. This condition may be due to a corroded transfer case vacuum actuator switch. To correct this condition a revised switch (P/N 15664811), constructed of noncorrosive stainless steel, should be installed. SERVICE PROCEDURE: The vacuum switch is located on the left upper side of the transfer case (Figure 1). 1. Raise the vehicle and support with suitable safety stands. 2. Remove the vacuum lines from the switch. 3. Remove the corroded switch from the transfer case. 4. Install a revised switch (P/N 15664811), coat the threads with thread sealant. 5. Connect the vacuum lines. 6. Lower the vehicle. 7. Check for oil leaks at the threads and vacuum leaks around the vacuum lines. Page 7461 FIGURE 1 2. Remove the cowl vent panel fasteners (Figure No. 1). Page 6090 Blower Motor: Component Tests and General Diagnostics Test A Blower Switch Test Test B Blower Resistors Test Page 1264 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 Specifications Counter Gear: Specifications Countergear End Play Check Attach dial indicator, check end play. If end play is greater than 0.025 in. new selective thrust washers must be installed. Lighting - Headlamp Polycarbonate Lens Damage Prevention Headlamp Lens: Technical Service Bulletins Lighting - Headlamp Polycarbonate Lens Damage Prevention INFORMATION Bulletin No.: 02-08-42-001D Date: June 21, 2010 Subject: Headlamp Lens Overheating When Covered and Chemical Damage to Exterior Polycarbonate Headlamp Lenses 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 and to revise the warning statements. Please discard Corporate Bulletin Number 02-08-42-001C (Section 08 - Body and Accessories). The bulletin is being issued to make dealers and customers aware of chemical damage that may be caused to exterior polycarbonate headlamp lenses. Most late model vehicles have these types of headlamp lenses. This material is used because of its temperature and high impact resistance. A variety of chemicals can cause crazing or cracking of the headlamp lens. Headlamp lenses are very sensitive. Care should be exercised to avoid contact with all exterior headlamp lenses when treating a vehicle with any type of chemical, such as those recommended for rail dust removal. Rubbing compound, grease tar and oil removers, tire cleaners, cleaner waxes and even car wash soaps in too high a concentration may also attribute to this condition. This could result in the need to replace the entire headlamp housing. Warning Use only lukewarm or cold water, a soft cloth and a car washing soap to clean exterior lamps and lenses. Also, crazing or deformations of the lens may occur if a shop mat or fender cover is draped over the fender and covers a portion or all of the headlamp assembly while the DRL or headlamps are on. This action restricts the amount of heat dissipated by the headlamps. Warning Care should be taken to not cover headlamps with shop mats or fender covers if the vehicle is being serviced with the headlamps or DRL illuminated. Covering an illuminated lamp can cause excessive heat build up and crazing/deformation of the lens may occur. The degradation of the lens can be unnoticeable at first and eventually become hairline cracks in the lens. In extreme cases, it could cause the lens to deform. This damage can also be caused by aftermarket shields that are often tinted in color. Once a heat buildup is generated by the headlamp, a degradation of the headlamp lens begins. This degradation of the lens can be unnoticeable at first and eventually manifest as spider cracks. In more extreme cases, it will begin to melt the lens of the headlamp. Notice Headlamps damaged by chemicals, improper cleaning, or overheating due to being covered are not covered under the new vehicle warranty. Disclaimer Page 1090 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 Page 6917 Figure 4 Figure 5 Figure 6 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 7 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. Pressure Values Valve Spring: Specifications Intake Exhaust Closed 76-84 lbf at 1.70 in 76-84 lbf at 1.70 in open 194-206 lbf at 1.25 in 194-206 lbf at 1.25 in Page 3575 Page 7380 Symbol Identification Fuse Block - Deforms Hazard Warning Flasher: All Technical Service Bulletins Fuse Block - Deforms Number: 90-432-8B Section: 8B Date: SEPT. 1991 Corporate Bulletin No.: 168102 ASE No.: A6 Subject: FUSE BLOCK DEFORMS Model and Year: 1988-90 SI (LLV) POSTAL VEHICLES Some 1988 to 1990 LLV postal vehicles built prior to August 3, 1990, may exhibit a condtion where the fuse block is partially deformed due to heat generated by continuous operation of the hazard flasher. This condition may be corrected by the repositioning of the hazard flasher to a remote location. SERVICE PROCEDURE: 1. Disconnect positive battery cable. 2. Remove old flasher. 3. Back out terminals for circuit 140A (orange wire) and circuit 27 (brown wire) using a small flat screwdriver or pick. Using the same tool, raise the locking tang on the back of the terminal. 4. Cut electrical tape used to wrap main wiring harness a sufficient amount to provide 2 to 3 inches of flasher wiring for relocation. 5. Insert terminals of circuits 140A and 27 into new connector (P/N 2973385). 6. Install electronic flasher (P/N 15504673) into the new connector. 7. Using nylon ties, strap the connector and flasher assembly to the wiring harness that runs above the fuse block. Verify that the relocated flasher and all wiring is secured so it does not cause interference with the throttle linkage. 8. Reconnect battery cable. 9. Test operation of hazard flasher system. SERVICE PARTS INFORMATION PART NUMBER DESCRIPTION QTY 2973385 Connector 1 15504673 Flasher (Electronic) 1 NPN Nylon Tie Straps 2 Parts are currently available from GMSPO. Page 5123 Figure 4 Figure 5 Figure 6 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 7 Page 4344 Fig. 22 Relieving Binding Condition At Point C ASSEMBLY Ball Socket & Constant Velocity Joint During assembly, make sure that marks made during disassembly, Fig. 12, are aligned to maintain balance. 1. To install centering ball onto stud, use tool C-4365 or equivalent, and drive ball until it can be seen that ball has seated firmly against shoulder at base of stud. 2. To install cross assembly, install one bearing cup part way into one side of yoke and turn this yoke to the bottom. Insert cross into yoke so that the trunnion seats into bearing, Fig. 18. Install opposite bearing cup part way, Fig. 19. Make sure that both cross journals are started straight into both bearing cups. 3. Press bearing cups, while moving cross to ensure free movement of trunnions in bearing. If any binding is felt, stop pressing and check needle bearings to make sure that needle bearings have not been trapped under the ends of the cross journals. 4. As soon as one of the retaining ring grooves clears the inside of yoke, stop pressing and install retaining ring. 5. Continue to press until opposite retaining ring can be snapped into place. If difficulty is encountered, strike the yoke firmly in locations shown in Figs. 20, 21 and 22, to spring the yoke ears slightly. 6. Lubricate center ball and socket, and assemble other half universal joint, if disassembled. Lubrication Fig. 23 Lubrication Fitting Adapter Campaign - Paint Delamination Policy Adjustment Technical Service Bulletin # 8931810 Date: 900901 Campaign - Paint Delamination Policy Adjustment Number: 89-318-10 Section: 10 Date: September, 1990 Corp. Bulletin No.: SPECIAL Subject: SPECIAL POLICY ADJUSTMENT PAINT DELAMINATION (PEELING) Model and Year: 1988-89 CHEVROLET S/T PICKUPS AND S/T BLAZERS (SHREVEPORT ASSEMBLY PLANT ONLY - PLANT CODE "8") TO: ALL CHEVROLET DEALERS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 89-305-10, DATED APRIL 1990. ALL COPIES OF 89-305-10 SHOULD BE DISCARDED AS THIS BULLETIN CONTAINS AN EXPANDED SERVICE PROCEDURE. General Motors has determined that some 1988-89 Chevrolet S/T pickups and S/T Blazers built at the Shreveport Assembly Plant may exhibit a delamination (peeling) of the paint on exterior surfaces due to continued ultraviolet exposure. If one of these vehicles should require repairs for a paint peeling condition, all exterior surfaces painted with affected colors should be refinished even though the peeling may be evident in only a few places. VEHICLES INVOLVED Involved are certain 1988-89 Chevrolet S/T model trucks painted Galaxy Blue (paint code 28), Aspen Blue (paint code 24) or Steel Gray (paint code 90) and built at the Shreveport Assembly Plant within the following VIN breakpoints: SPECIAL POLICY ADJUSTMENT This special policy covers the condition described above on 1988 involved vehicles for 12 months from the date of this bulletin. 1989 involved vehicles will be covered for a period of 3 years from the date of original vehicle purchase regardless of ownership with no deductible. Correction, at no charge to the customer, will consist of refinishing exterior surfaces painted with affected colors on involved vehicles. Customers may also be eligible for reimbursement of previous repairs with supporting documentation. NOTICE: Only exterior surface areas painted Galaxy Blue, Aspen Blue or Steel Gray should be refinished. If peeling of colors other than those described above should occur, handle as described in the Chevrolet Claims Processing Manual, Section XIII, Warranty Management System. This "Special Policy Adjustment Bulletin" should be filed in the three ring binder previously furnished to dealers by General Motors. PARTS INFORMATION No parts are required to complete this special policy. Paint supplies should be obtained through normal supplier. Service Procedure 1. After washing vehicle, verify that condition is delamination of topcoat by applying a 2 inch width piece of masking tape firmly over suspect area, pulling upward quickly. If topcoat and/or clear coat flake or peel away from primer, leaving primer intact, the topcoat is delaminating and the following service procedure should be performed. Page 351 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 4. Make repair. Page 2274 Engine Control Module: Service and Repair Figure 1 *** THIS PROCEDURE HAS BEEN UPDATED BY TSB # 88-42, dated 9/87 Some replacement ECM's may come with a replacement PROM already installed in them. If this situation occurs, remove prom from old ECM and install in rebuilt ECM. When replacing a production ECM with a service ECM, transfer the broadcast code and production number from the production unit to the service unit. Also, during replacement, the PROM, and if equipped, the CALPAK must be removed from the ECM being replaced and transferred to the new unit. Refer to "PROM, REPLACE" and "CALPAK, REPLACE" for procedure. 1. Disconnect battery ground cable. 2. Locate ECM on passenger side under the instrument panel hush panel. (see figure 1.). 3. Remove ECM mounting hardware. 4. Remove ECM from passenger compartment. 5. Reverse procedure to install. Page 13 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) A/T - Water Or Coolant Contamination Information Fluid - A/T: All 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. Transfer Case - Increased Shift Effort From 2H to 4H Technical Service Bulletin # 914047A Date: 910801 Transfer Case - Increased Shift Effort From 2H to 4H Number: 91-404-7A Section: 7A Date: AUGUST 1991 Corporate Bulletin No.: 167401 ASE No.: A2 Subject: HIGH TRANSFER CASK SHIFT EFFORT Model and Year: 1988-91 T1 TRUCKS Some 1988-91 T-Trucks may experience high transfer case shift effort or total blockouts when "shifting on the fly" from 2H to 4H under cold weather conditions. This condition may be corrected by the installation of the synthetic 75W90 gear lube described in Dealer Service Bulletin No. 91-128-7A. This fluid maintains a more constant viscosity under cold weather conditions allowing quicker front axle synchronization and easier transfer case engagement. If the installation of the synthetic fluid does not result in a satisfactory shift effort, an "Easy Shift" package may be installed in the transfer case. This package features a roller pin (53) rather than a solid pin on the mode shift fork (54) and revised ramp angles on the sector (55) to reduce engagement forces. This package was installed in the 1991 model year and will provide reduced transfer case shift effort under cold weather conditions. Figure 1 VEHICLES INVOLVED: Group A: Some 1988-91 T-Trucks equipped with transfer cases identified by the following part numbers: 15568078 15627441 15568079 15627442 15568597 15653450 Page 3611 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: Page 6091 Test C Blower Motor Test Page 7016 PAINT air dry only Note: Only items marked with an asterisk are "add" conditions to the Major Operation being performed. Removal time for all other items listed is included in the refinish time. LIGHT DUTY TRUCKS C/K TRUCKS Grille Front bumper filler panel Antenna Tail lamps Door edge guards Metal wheel opening moldings *Roof marker lamps "Luggage rack *West coast style mirrors "Stripes Emblems/decals if necessary Swing out windows/seals Tail gate handle bezel S/T TRUCKS Windshield molding Bumper filler panels, Ft./Rr. Wiper arms Antenna Wheel opening moldings Cowl vent grille Door edge guards Side view mirrors Tail lamps *Wind deflector Rear Window (Jimmy) *Luggage rack *Stripes Emblems/decals if necessary Swing out windows/seals *Spare tire carrier and latch-external mount (Jimmy) M/L VANS Windshield molding Wheel opening moldings Headlamp bezels Antenna Tail lamps Door edge guards *Luggage rack *Stripes Emblems/decals if necessary R/V TRUCKS Wiper arms Cowl vent grille Antenna Tail lamps Hood ornaments Wheel opening moldings Side view mirrors Grille and headlamp bezels Page 5029 NOTE: There may be a locking screw installed on the adjusting knob, by the Post Office, which will need to be removed prior to adjusting.) Begin the brake adjustment with the lever in the applied position, continue to turn the knob counter-clockwise until the brake lever starts to move forward. 5. Turn parking brake knob (#7) one full turn clockwise. 6. Make certain handbrake is still in fully applied position. 7. Adjust equalizer nut (#6) using one of two methods: A. Preferred Method Using a Kent-Moore cable tension gage P/N J34651-A or a Burroughs Cable Tension Gage, P/N BT3375-W, installed on the right hand intermediate cable between its connecting links, tighten the equalizer nut (#6) to obtain 75-80 inch lbs. (Kent-Moore) or 150 lbs. (Burroughs) cable tension. B. Alternate Method Tighten the equalizer nut (#6) until a light drag is felt while rotating the rear wheels forward. Adjust knob (#7) on parking brake lever clockwise until a definite snap over center is felt when parking brake is applied. 8. Inspection of Front Cable Thread Adjustment: With the cable system fully adjusted, there should be a minimum of 12 mm (1/2 inch) of thread available between points X and Y. If less than 12 mm (1/2 inch) see Procedure B. 9. If new parking brake cables have been installed, release and fully apply the hand brake lever three times to obtain cable pre-stretch. Re-adjust equalizer nut (#6) and brake lever knob (#7) as necessary. 10. Release brake lever and rotate rear wheels forward. There should be no brake drag. 11. Remove safety stand, lower vehicle, and remove blocks from front wheels. PARTS REQUIRED No service parts are required for this adjustment procedure. Labor Time to perform this procedure is .3 hour. Use Labor Op: H2800. Service Procedure B Transfer Case - Increased Shift Effort From 2H to 4H Technical Service Bulletin # 914047A Date: 910801 Transfer Case - Increased Shift Effort From 2H to 4H Number: 91-404-7A Section: 7A Date: AUGUST 1991 Corporate Bulletin No.: 167401 ASE No.: A2 Subject: HIGH TRANSFER CASK SHIFT EFFORT Model and Year: 1988-91 T1 TRUCKS Some 1988-91 T-Trucks may experience high transfer case shift effort or total blockouts when "shifting on the fly" from 2H to 4H under cold weather conditions. This condition may be corrected by the installation of the synthetic 75W90 gear lube described in Dealer Service Bulletin No. 91-128-7A. This fluid maintains a more constant viscosity under cold weather conditions allowing quicker front axle synchronization and easier transfer case engagement. If the installation of the synthetic fluid does not result in a satisfactory shift effort, an "Easy Shift" package may be installed in the transfer case. This package features a roller pin (53) rather than a solid pin on the mode shift fork (54) and revised ramp angles on the sector (55) to reduce engagement forces. This package was installed in the 1991 model year and will provide reduced transfer case shift effort under cold weather conditions. Figure 1 VEHICLES INVOLVED: Group A: Some 1988-91 T-Trucks equipped with transfer cases identified by the following part numbers: 15568078 15627441 15568079 15627442 15568597 15653450 Page 1929 Spark Plug Wire: 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. Page 3548 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 Page 6643 Symbol Identification Page 6579 Page 6937 2. Remove the end gate inner panel reinforcement from the end gate (Figure 1, Item 1). 3. Disconnect the end gate lock rods (Figure 2, Items 1 and 2). 4. Remove the lock cylinder retainer (Figure 3, Item 2). 5. Working through the access hole, remove the lock cylinder and gasket (Figure 3, Items 4 and 3) through the outer panel. 6. Remove the spring (located on the lock assembly) and carefully bend the spring ends just far enough to eliminate any clearance between the lock pawl assembly and the lock cylinder housing (Figure 3, Items 6 and 4). Note: Page 2282 Fuel Pump Relay: Description and Operation Fuel Pump Relay 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). - 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. Engine Controls - Aftermarket Accessory Usage Engine Control Module: All 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 A/T - Proper Usage of Spacer Plate Gaskets, Overhaul Kit Valve Body: All Technical Service Bulletins A/T - Proper Usage of Spacer Plate Gaskets, Overhaul Kit Number: 89-203-7A Section: 7A Date: July 1989 Subject: PROPER USAGE OF SPACER PLATE GASKETS IN OVERHAUL KIT Model and Year: 1982-89 PASSENGER CAR AND TRUCK MODELS WITH 700R4/4L60 TRANSMISSION Figure 1 - THM 700-R4/HYDRA-MATIC 4L60 Transmission Identification Information Figure 2 - Spacer Plate Gaskets-Transmission Overhaul Kit TO: ALL CHEVROLET DEALERS This bulletin covers instructions for choosing the correct spacer plate gaskets from the transmission overhaul service package. Current information enclosed with the service package may be unclear when explaining which spacer plate gaskets are appropriate for use. SERVICE PROCEDURE: (Figure 2) Two sets of spacer plate gaskets are supplied with each transmission overhaul service kit. One set of gaskets is for use on model years 1982 through 1986, and the other set is for use on model years 1987-89. Page 334 SERVICE PARTS INFORMATION Part Number Application Description 15636850 1988-1991 Plate kit I/P (no switches). (Gray) Switch trim plate (gray) bracket, covers for switch trim plate holes (quantity 2), and 4 bolts/screws. 15636853 1986-1987 Plate kit I/P (no switches). (Black) Switch trim plate (black), bracket, covers for switch trim plate holes (quantity 2), and 4 bolts/screws. Important: Torque 11508898 bolts/screws supplied in kit to 0.4-0.7 N-m. (4-6 lbs.in.). Parts are expected to be available on January 21, 1991. Until then, normal part orders will not be accepted by GMSPO. Only verifiable emergency VIP orders will be accepted. GMSPO will make every effort to obtain parts. All parts will be placed on 400 control to waive VIP surcharges. However, the parts will be shipped premium transportation at dealer's expense. All other order types will be canceled as incorrectly ordered while 400 control is in place. WARRANTY INFORMATION For vehicle repaired under warranty use: Labor Operation: T7101 Labor Time: .3 hr. Trouble Code: 92 NOTE: Labor Operation is coded to base vehicle coverage in the warranty system. Page 4820 Brake Caliper: Service and Repair Installation For additional information see Installation Notes. See: Fundamentals and Basics Retracting Piston 1. Retract piston in caliper bore and position caliper over disc, lining up holes in caliper with holes in mounting bracket. If brake hose was not disconnected during removal, be sure not to kink it during installation. Caliper Mounting Bolts 2. Start mounting bolts through sleeves in inboard caliper ears and the mounting bracket, making sure ends of bolts pass under ears on inboard pad. NOTICE: If the caliper was removed for service, make sure it is installed on the correct knuckle. The caliper bleed screw should be positioned on top of caliper when assembled on vehicle. 3. Push mounting bolts through to engage holes in the outboard ears. Then thread mounting bolts into bracket. 4. Torque mounting bolts to 50 Nm (37 ft lb). Page 4200 Differential Axle Housing: Service and Repair Chevrolet Salisbury Semi-Floating Axle 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 stand jacks under frame side rails. 2. Remove rear wheels and drums. 3. Support rear axle assembly with a suitable jack so that tension is relieved in springs and tie rod, if equipped. 4. Disconnect tie rod at axle housing bracket, if equipped. 5. Remove trunnion bearing U-bolts from rear yoke, split universal joint, position propeller shaft to one side and tie it to frame side rail. 6. Remove axle U-bolt nuts and allow shock absorbers to hang freely so that they do not interfere with axle. On K and V Series trucks, remove spacer from axle housing. 7. Disconnect hydraulic brake hose at connector on axle housing. 8. Remove brake drum and disconnect parking brake cable at lever and at flange plate. 9. Lower axle and remove from vehicle. 10. Reverse procedure to install axle assembly. Page 3411 (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). Ignition System - Diagnosis Precautions Spark Plug Wire: All Technical Service Bulletins Ignition System - Diagnosis Precautions Number: 88-138-6D Section: 6D Date: Feb., 1988 Subject: ENGINE MISS, HESITATION, OR ROUGHNESS DUE TO PIERCED SECONDARY IGNITION COMPONENTS Model and Year: ALL MODELS WITH GASOLINE ENGINE TO: ALL CHEVROLET DEALERS During the diagnosis procedures for an engine miss, hesitation, or roughness condition, a spark plug or spark plug wire condition may be suspected. Several types of commercial or homemade diagnostic equipment require the secondary ignition boots or wire to be pierced. This is normally done to check for spark plug firing or to perform a cylinder balance test. Similarly, the use of pliers or other such tools to disengage a spark plug boot may pierce or damage the boot or wire. NOTICE: SECONDARY IGNITION COMPONENTS SHOULD NOT BE PIERCED FOR ANY REASON. Piercing a spark plug wire and/or distributor or direct fire module nipple may create a failure condition that will not be immediately apparent. Over time, the hole in the pierced boot may allow a ground path to develop, creating a plug misfire condition. Heavily moisture-laden air in the vicinity of the pierced boot may accelerate this effect. Piercing a secondary ignition wire creates a gap in the wire's conductive core. This gap is a point of high resistance. The current flow in the wire will increase to compensate for the higher wire resistance. Over time, the wire may fail, creating a plug misfire condition. The time required for the condition to appear depends upon the extent of damage to the conductive core. To help prevent future customer comments that are spark plug wire related, do not pierce or otherwise damage any secondary ignition component. Only use diagnostic equipment containing an inductive pick-up to check for spark plug firing or to perform cylinder balance tests. When disengaging a spark plug boot from the spark plug, twist the flanged boot 1/2 turn, then pull only on the boot to remove the wire. Page 5177 LIGHT BLUE LT BLU BROWN BRN GRAY GRY GREEN GRN DARK GREEN DK GRN LIGHT GREEN LT GRN ORANGE ORN PINK PNK PURPLE PPL RED RED TAN TAN WHITE WHT YELLOW YEL Page 5593 6. Tape the solder and diode. 7. Reinstall the black plastic conduit. 8. Reconnect connector to the generator. 9. Reconnect battery. This procedure will not affect the operation of the generator light during the bulb check at the beginning of the start cycle. For vehicles repaired under warranty use, Labor Operation Number: T7990 Labor Time: .4 Hr Brake Spring Removal and Installation Brake Shoe: Fundamentals and Basics Brake Spring Removal and Installation HOLD-DOWN SPRINGS Purpose Hold-down springs hold the shoes/linings against the backing-plate. The springs provide a flexible grip so that the shoes/linings will still be able to slide back and forth across the surface of the backing-plate. Tools Needed Specialized brake spring tool or - Pliers / needle nose locking pliers - Duct Tape (optional) Removal The hold-down spring must first be compressed so that the tip of the retaining pin is cleared of the spring. - The spring is then rotated so that the slot in top of the spring lines up with the tip of the retaining pin. NOTE: Be sure to hold the retaining pin from the rear of the backing-plate to prevent the pin from rotating with the spring. - The hold-down spring can then be released and the pin should slide through the slot in the top of the spring. - A specialized brake spring tool makes the job very simple. The tool firmly grips the surface of the hold-down spring while providing a clear view of the pin/slot relationship. Page 6178 1. Clutch plate and hub assembly (2). Clean ^ The inside of the compressor around the shaft (38). Prevent dust and dirt from entering the compressor. 2. Sleeve retainer (10). 3. Absorbent felt sleeve (11). Removing/Installing The Shaft Seal Retaining Ring 4. Shaft seat retaining ring (12) with J 5403. Removing/Installing The Shaft Seal Seat And Seal 5. Shaft seat (13). ^ Place J 22974-A over the end of the shaft (38) to prevent chipping the ceramic seat (13). ^ Engage J 23128 into the recessed portion of the seat by turning J 23128 to the right (clockwise). ^ Lift the seat (13) from the compressor with a rotary motion. Page 4587 - Tighten poppet screw to 31 N-m (23 lbs.ft.). - New poppet plunger P/N 15633556 (70) group A vehicles only. - New poppet spring P/N 15633557 (71) group A vehicles only. - New poppet screw P/N 15633558 (68) group A vehicles only. 23. Vacuum switch (46) and new O-ring P/N 14071849 (47) to the front case housing. - Tighten switch to 24 N-m (17 lbs.ft.). 24. Front output flange (74), rubber sealing washer (75), washer (76) and flange nut (77). - Tighten nut (26) to 149 N-m (110 lbs.ft). 25. New vent pipe P/N 15581915 in new front case half (group A vehicles only). - Lightly coat end of vent pipe with Loctite 609 (R) or equivalent. 26. Transfer case into vehicle. - Refer to section 7D of the appropriate S/T Service Manual for complete transfer case replacement procedure. Service Parts & Warranty Information SERVICE PARTS INFORMATION: The "Easy Shift" package consists of the following parts. Parts must be ordered individually. Required Parts Part Quantity Figure 1 Group A Group B Number Description Required Reference Trucks Trucks 15635347 Front case half 1 45 X 15637215 Sector W/shaft 1 55 X X 15637217 Mode shift fork 1 54 X X 15633556 Poppet plunger 1 70 X 15633557 Poppet spring 1 71 X 15633558 Plug 1 68 X 14071849 O-ring 2 69 & 47 X X 15581915 Vent Pipe 1 N/S X 14095609 Input seal 1 42 X 14037958 Retainer 1 66 X X 14095598 Range sector seal 1 67 X X 15579788 Output front seal 1 72 X 15642511 Adapter gasket 1 N/S X X 15579803 Drive Sprocket 1 20 * * 14071703 Synchronizer 1 28 * * Blocking Ring * These parts required only if damaged or in cases of customer complaint of clash when shifting from 2Hi to 4Hi. Parts are currently available from GMSPO. WARRANTY INFORMATION: For vehicles repaired under warranty use: Labor Labor Operation Truck Time Page 3518 Band Apply Servo: Technical Service Bulletins A/T - THM 700R4 New Second Servo Apply Pin Number: 87-177 Section: 7A Date: JULY, 1987 Subject: NEW SECOND SERVO APPLY PIN THM 700-R4 Model and Year: 1987 PASSENGER CARS 1987-88 LIGHT DUTY TRUCKS WITH THM 700-R4 TRANSMISSION TO: ALL CHEVROLET DEALERS FIGURE 1 - THM 700-R4 TRANSMISSION IDENTIFICATION INFORMATION THM 700-R4 transmissions assembled beginning January 5, 1987, (Julian date 005, refer to Figure 1), were built with a new design second servo apply pin. Page 5637 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: Page 1546 Valve: Specifications Stem To Guide Clearance Stem To Guide Clearance Stem To Guide Clearance Intake Standard 0.0010-0.0027 in Service Limit 0.0037 in Exhaust Standard 0.0010-0.0027 in Service Limit 0.0047 in Page 7921 Symbol Identification Wire Color Code Identification WIRE COLOR ABBREVIATION BLACK BLK BLUE BLU DARK BLUE DK BLU A/T - 4L60 Binding/Inoperative In Reverse Valve Body: Customer Interest A/T - 4L60 Binding/Inoperative In Reverse Number: 91-283-7A Section: 7A Date: APRIL 1991 Corp. Bulletin No.: 977143R Subject: BINDING OR INOPERATIVE IN REVERSE - STUCK 4-3 SEQUENCE VALVE AND/OR 2-3 SHIFT VALVE Model and Year: 1982-91 PASSENGER CARS AND TRUCKS WITH 700R4 (4L60) AUTOMATIC TRANSMISSION THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 89-271-7A, DATED OCTOBER 1989. THE 1990-91 MODEL YEARS HAVE BEEN ADDED, AS WELL AS INFORMATION CONCERNING BOLT TIGHTENING PATTERN. ALL COPIES OF 89-271-7A SHOULD BE DISCARDED. Figure 1 - Control Valve Assembly SERVICE PROCEDURE: When servicing a HYDRA-MATIC 4L60 transmission for a binding in reverse condition, remove the control valve assembly and inspect the 4-3 sequence valve and the 2-3 shift valve. Refer to Figure 1. Either valve, if stuck in the upshifted position, will result in a binding condition. To correct this condition, the valve body must be completely disassembled and reconditioned according to procedures contaihed in the HYDRA-MATIC 4L60/THM 700-R4 Unit Repair section of the appropriate Service Manual. Inspect the transmission bottom pan for clutch material or burned fluid. Evidence of this will necessitate further transmission diagnosis. Repairs may include complete transmission reconditioning, inc.luding disassembly and reconditioning of the transmission pump and possible torque converter replacement. Complete the cleaning of the hydraulic circuit by changing the transmission fluid and filter and flushing the transmission cooler and cooler pipes. Page 6732 Disclaimer Page 1255 FIGURE 3 FIGURE 1 Page 1616 Drive Belt Tensioner: Service and Repair Fig. 20 Serpentine Drive Belt Routing 1. Remove belt tensioner pulley retaining bolt. 2. Remove belt tensioner pulley. then the belt. 3. Reverse procedure to install, refer to Fig. 20 for belt routing. Rearview Mirror, Outside - Vibration Mirrors: All Technical Service Bulletins Rearview Mirror, Outside - Vibration Group Ref.: Body Bulletin No.: 461001 Date: April, 1994 SUBJECT: OUTSIDE REAR VIEW MIRROR VIBRATION (INSTALL SET SCREW FASTENER) MODELS: 1982-93 CHEVROLET AND GMC TRUCK S/T PICKUPS 1983-94 CHEVROLET AND GMC TRUCK S/T UTILITIES WITH D44 OR D45 MIRRORS CONDITION: Some owners may comment that their outside rear view mirrors vibrate. CAUSE: Force is applied against the mirror arm by a retention spring wedged between the mirror bracket and mirror arm to prevent mirror rotation. Over time, this spring force decreases allowing the mirror arm to move or vibrate. CORRECTION: This condition can be corrected by drilling and tapping a hole in the retention spring to accept a set screw fastener. The fastener can be adjusted to force the spring against the mirror arm, restoring the original pressure. SERVICE PROCEDURE: 1. From outside the vehicle, remove the screws which secure the mirror cover and the mirror assembly to the door (Figure 1). 2. Remove the mirror assembly from the door. 3. Remove the mirror head and arm from the mirror bracket. Page 973 Figure 3 INSTALL (Figures 2 & 3) Tools required: J8092 Drive handle J33790 Bearing installer and remover J33833 Bearing installer and remover 1. Front output bearing (61) to the new front case half P/N 15635347 (45) using J 8092 and J 33833. 2. New front output shaft seal P/N 15579788 (72) to the new front case half (45). 3. Front output bearing retainer ring (snap ring) (60) to the new case half. 4. New input seal P/N 14095609 (42) into retainer (44) if it was removed in step 24 above. 5. Input bearing (40) and input bearing retainer (39) to the new case half using J 36372. 6. Planetary carrier (36) and the input gear (38) to the annulus gear (62) using a soft hammer. 7. Retainer snap ring to the input gear (38). Input bearing retainer (44) and input bearing retainer bolts (43) to the front case half (45). - Clean mating surfaces and apply RTV or equivalent on bearing retainer mating surfaces. NOTE Do not block oil feed hole from case to bearing retainer. - Apply Loctite 242 (R) or equivalent on bearing retainer bolts. - Tighten bolts to 19 N-m (14 lbs.ft.). Page 5262 Disclaimer Page 4586 8. New O-ring seal P/N 14095598 (67) and new plastic washer (retainer) P/N 14037958 (66) into the front case half. 9. New sector with shaft P/N 15637215 (55) into the front case half. 10. Range shift fork (51), range shift hub (34) into the planetary carrier (36). - It is necessary to rotate the sector with shaft (55) to obtain clearance when installing the range fork (51). INSPECT: The teeth of the synchronizer stop ring (28) and drive sprocket (20) for damage. If the parts are to be replaced due to damage or in cases of customer complaint of clash when shifting from 2Hi to 4Hi, follow steps 11, 12, & 13, otherwise skip to step 14. 11. New drive sprocket P/N 15579803 (20) to the main shaft (19). 12. New synchronizer stop ring P/N 14071703 (28) to the drive sprocket (20). 13. Synchronizer assembly (81) to the main shaft. 14. Mainshaft (19)/drive sprocket (20), chain (58) and front output shaft (21) as a unit. Mode shift fork (54) and shift rail (48) will be installed with the mainshaft. 15. Fork shift spring (52). Mainshaft Extension and Oil Pump 16. Rear case (17) over mainshaft (19) and onto the front case half (45). - Clean case mating surfaces and apply RTV sealer or equivalent to the mating surfaces. - Transfer dowels from old case half to new case half if necessary. IMPORTANT: Be careful not to damage the oil pump (12) while installing the rear case half (Figure 7). 17. Case bolts (3) into case halves. - Apply Loctite 242 (R) or equivalent on pump housing bolt threads. - The two longer bolts and washers into the doweled case holes (33). - Tighten bolts to 31 N-m (23 lbs.ft.). 18. Speedometer tone wheel (11) to the main shaft (19). 19. Pump retainer housing (8) and pump housing bolts (7) to the rear case half (17). - Clean mating surfaces and apply RTV sealer or equivalent to the mating surfaces. - Apply Loctite (R) or equivalent on pump housing threads. - Pump housing bolts are shouldered (7). - Tighten bolts to 41 N-m (30 lbs.ft.). 20. Output bearing retainer (snap ring) (5), to the main shaft (19). 21. Rear extension housing (4) and extension housing bolts (3) to the pump retainer housing (8). - Clean mating surfaces and apply RTV sealer or equivalent to the mating surfaces. - Apply Loctite 242 (R) or equivalent on the extension housing bolts. - Tighten bolts to 31 N-m (23 lbs.ft.). External Components 22. Poppet plunger (70), poppet spring (71), new O-ring seal P/N 14071849 (69), and poppet screw (68) to the front case half (45). 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 Page 7359 Vacuum Vent Valve: Locations Vacuum Valve (Manual Trans.) LH Side Of Steering Column Behind Instrument Cluster Page 6295 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 Page 3712 Labor Operation No.: K6550 Valve, Pressure Regulator-R&R; or Replace Use the appropriate labor time in the labor time guide. Parts are currently available from GMSPO. Page 2337 Wiring Diagram For Chart C-1D - Manifold Absolute Pressure (MAP) Output Check CHART C-1D - MANIFOLD ABSOLUTE PRESSURE (MAP) OUTPUT CHECK Circuit Description: The Manifold Absolute Pressure (MAP) sensor measures manifold pressure (vacuum) and sends that signal to the ECM. The MAP sensor is mainly used for fuel calculation, when the ECM is running in the throttle body backup mode. The MAP sensor is also used to determine the barometric pressure and to help calculate fuel delivery. Test Description: Numbers below refer to circled numbers on the diagnostic chart. 1. Checks MAP sensor output voltage to the ECM. This voltage, without engine running, represents a barometer reading to the ECM. 2. Applying 34 kPa (10" Hg.) vacuum to the MAP sensor should cause the voltage to be 1.2 - 2.3 volts less than the voltage at Step 1. 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 no other vacuum devices are connected tot he MAP hose. Electrical Connectors - Service Procedure Multiple Junction Connector: All Technical Service Bulletins Electrical Connectors - Service Procedure Number: 91-85-8A Section: 8A Date: October 1990 Corp. Bulletin No.: 018115 Subject: PROCEDURE FOR CHECKING CONNECTOR TERMINAL CONTACT Model and Year: 1982-91 PASSENGER CARS AND TRUCKS Figure 1 TO: ALL CHEVROLET DEALERS Page 588 (Figure 1) Tie rod clamp & sleeve positioning NOTE: Tie rod adjuster parts often become rusted in service. If the torque required to remove the nut from the bolt after breakaway exceeds 9 Nm (7 ft Lbs), discard the nuts and bolts. Apply penetrating oil between the clamp and tube and rotate the clamps until they move freely and install new bolts and nuts. PROCEDURE Toe-in can be increased or decreased by changing the length of the tie rods. A threaded sleeve is provided for this purpose. When the tie rods are mounted ahead of the steering knuckle they must be: ^ Decreased in length to increase toe-in. ^ Increased in length to decrease toe-in. To adjust, loosen clamp bolts at each end of steering tie rod adjustable sleeves. With steering wheel in straight ahead position, turn tie rod adjusting sleeves to obtain proper adjustment. - After adjusting, check that number of threads showing on each end of sleeve are equal to within 3 threads and that the tie rod end housings are at the right angles to steering arm. - Position tie rod clamps and sleeves, refer to (Figure 1) and torque nuts to 15 ft. lbs. Page 2853 Catalytic Converter: Description and Operation Catalytic Converters 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. 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. Engine Controls - Aftermarket Accessory Usage Engine Control Module: All 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 Page 5065 Vacuum Brake Booster: Description and Operation Tandem Diaphragm Type Fig. 6 Exploded View Of Delco-Moraine Tandem Power Brake Unit Fig. 7 Exploded View Of Delco-Moraine Tandem Diaphragm Power Piston Assembly These units, Figs. 6 and 7, have a vacuum power chamber that consists of a front and rear shell, a housing divider, front and rear diaphragm and plate assemblies, an hydraulic pushrod and a diaphragm return spring. The unit operates in much the same manner as the Single Diaphragm unit described above. The diaphragm and plate assemblies use the pressure differential created by engine intake manifold vacuum and atmospheric pressure to assist the hydraulic pushrod. Page 34 - 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 Page 5107 Figure 4 Figure 5 Figure 6 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 7 Page 344 Symbol Identification Page 4291 Figure 13 - Proper Inboard Stroke Positioning 9. Install convolute retainer over seal capturing four convolutes (Figure 13). Important: Joint must be assembled with convolute retainer in position as shown in Figure 13. Seal damage will result if joint is not assembled to dimension shown. Figure 14 - Spider Assembly Installation 10. Install spacer ring and spider assembly (with counterbore toward end of shaft) on the shaft far enough to allow installation of the retaining ring at the end of the halfshaft (Figure 14). 11. Install the retaining ring and push the spider assembly toward the end of the shaft until retaining ring is covered by the spider assembly counterbore. Install the spacer ring and make sure it is seated in its groove. 12. Pack the seal and housing with grease supplied in the kit, (the amount of grease supplied in this kit has been premeasured for this application), place the large metal clamp on the seal, then place the housing over the spider assembly and snap the seal onto the housing. Preliminary Inspection Alignment: Service and Repair Preliminary Inspection INSPECTION Steering and vibration problems are not always the result of alignment. An additional problem to be checked is tire lead due to worn or improperly manufactured tires. "Lead" is the deviation of the vehicle from a straight path on a level road without hand pressure on the steering wheel. To insure correct alignment readings and alignment specifications, the following checks and inspections should be made: 1. Check tire for proper inflation and thread wear. 2. Check front wheel bearings for looseness (0.001 - 0.008 inch end play is correct) and adjust if necessary. 3. Check for loose ball joints and tie rod ends. If excessive looseness is noted, replace defective parts before adjusting toe. 4. Check for wheel and tire assembly runout. 5. Check trim heights. If not within specifications, correct before adjusting toe. 6. Check for loose control arms and steering gear at frame. 7. Check for loose or missing stabilizer bar components. 8. Consideration must be given to excess loads, such as tool boxes, etc. If excess load is normally carried in vehicle, it should remain during alignment checks. Page 4269 Coat components with specified lubricant during assembly. If components are reused, they should be installed in original position. 1. Press rear bearing onto pinion using suitable spacers. 2. Install front and rear bearing races in housing, using suitable drivers to ensure that races are properly seated. 3. Install straddle bearing in axle housing using straddle bearing installer tool No. J-23322 or equivalent to ensure that bearing is properly seated. 4. Insert pinion through housing, install new collapsible spacer and front bearing over pinion shaft, support pinion and press front bearing onto shaft. 5. Lubricate lips of new seal with grease and install seal using suitable driver to seat seal against shoulder of housing. 6. Install driveshaft companion flange, washer and new pinion nut. 7. Clamp housing in vise, hold flange with suitable tool and torque pinion nut just until all endplay is removed. 8. Check pinion bearing preload (rotating torque) using suitable torque wrench. 9. Continue tightening pinion nut in small increments until specified preload is obtained, checking preload after each adjustment. Exceeding specified preload will collapse spacer too far to be reused. If preload specification is exceeded, spacer must be replaced and adjustment procedure must be repeated. Do not loosen pinion nut to reduce bearing preload. Page 666 Distributor: Description and Operation Typical Distributor Components The distributor has a separate coil which connects to the rotor through a high tension wire. The distributor uses a magnetic pick-up assembly located inside the distributor consists of a permanent magnet, a pole piece with internal teeth, and a pick-up coil. When the teeth of the timer core, rotating inside the pole piece, line up with the teeth of the pole piece, an induced voltage in the pick-up coil signals the electronic module to trigger the coil primary circuit. The primary current decreases and a high voltage of 35,000 volts is induced in the ignition coil secondary winding which is directed through the rotor and secondary leads to fire the spark plugs. The capacitor in the distributor is for radio noise suppression. This distributor also features a longer spark duration, made possible by the higher amount of energy that is stored in the coil. This is desirable for firing leaner mixtures. Page 6347 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 Page 7463 FIGURE 1 7. Measure 1 1/4" down from the bottom of the windshield and make a horizontal mark on the windshield frame inboard of the cowl screen lock tab (Figure No. 1). 8. Measure 7/8" inboard from the cowl screen lock tab and make a vertical mark through the line made in the previous step. 9. Center punch the windshield frame at the point the lines intersect. Use a one inch hole saw to cut a hole in the windshield frame (cut through only the first layer of sheet metal) and remove the circular piece of metal that remains from cutting the hole. DO NOT CUT THE SECOND LAYER PANEL. Page 769 Clutch Fluid: Fluid Type Specifications Hydraulic Clutch Fluid ........................................................................................................................................................... DOT 3 or DOT 4 Brake Fluid Page 439 Oil Pressure Switch (For Fuel Pump): Testing and Inspection Refer to DIAGNOSTIC CHARTS/FUEL PUMP RELAY CIRCUIT DIAGNOSIS (CHART A-5), for fuel related oil pressure switch problems. Page 5150 Symbol Identification Engine - Improved Head Gasket Cylinder Head Gasket: All Technical Service Bulletins Engine - Improved Head Gasket Number: 89-283-6A Section: 6A Date: December 1989 Corporate Bulletin No.: 836537 Subject: REVISED CYLINDER HEAD GASKET Model and Year: 1987-89 PASSENGER CARS AND LIGHT DUTY TRUCKS TO: ALL CHEVROLET DEALERS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 89-06-6A, DATED SEPTEMBER 1988. THE 4.3L ENGINE APPLICATION AND PART NUMBER HAS BEEN ADDED. ALL COPIES OF 89-06-6A SHOULD BE DISCARDED. A cylinder head gasket with improved sealing characteristics is now available for service use on all 4.3L, 5.0L and 5.7L engine applications. The applicable part numbers are listed below: Application Cylinder Head Gasket P/N 4.3L Engines 10105110 5.0L Engines 10105115 5.7L Engines 10105117 These parts are currently available from GMSPO. When replacing head gaskets on vehicles under warranty, use: Labor Operation Numbers: J0500 - Right Bank J0501 - Left Bank J0507 - Both Banks Refer to Labor Time Guide for applicable labor times for various models. Page 2050 11. Install cowl vent grille. Refer to "Cowl Vent Grille Replacement" in Section 2B of the Service Manual. PARTS INFORMATION Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty, use: Labor Operation Description Labor Time B1717 Replace Use Published Labor Hood Hinge Operation Time Page 5786 Figure 3 - Inboard Flange Bolt Removal 5. Loosen (do not remove at this time) six bolts securing inboard C/V joint drive flange to output shaft companion flange (Figure 3). Figure 4 - Brake Line Bracket Removal 6. Remove brake line support bracket from upper control arm to allow extra travel of knuckle (Figure 4). 7. Remove cotter pin and nut from the outer tie rod. Figure 5 - Disconnecting the Tie Rod 8. Separate the outer tie rod ball stud from the steering knuckle using J24319-01 (Figure 5). Notice: Do not attempt to disengage the joint by driving a wedge-type tool between the joint and the knuckle because the seal may be damaged. 9. Push linkage to opposite side of the vehicle and secure outer tie rod up and out of the way. This will provide the needed clearance to remove the halfshaft. Page 7955 e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors Do Not require all the steps shown. Skip the steps that Do Not apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. 1. Separate connector halves (see Figures 2 through 6). Figure 2 Figure 3 Page 8066 Note: Labor Operation is coded to base vehicle coverage in the warranty system. Page 1181 Fusible Link: Locations Fuse Link B Center Of Dash Panel (engine Compartment) At Rear Of Generator Applicable to: V6-262/4.3L Engine Page 7040 ** Refer to the applicable labor time guide for paint mix time allowance and include in "Other Hours." *** Select corresponding material allowances to combine with proper "Above Belt Line" material allowance in "Net Amount" as required for appropriate vehicle type and operations performed. Reimbursement Customer claims for reimbursement on previously paid repairs to correct paint topcoat delamination (peeling) are to be submitted according to the forms and instructions included in this bulletin (additional copies to be reproduced locally). Owners must submit original documentation that reasonably confirms the amount of unreimbursed repair expenses, a description of the repair, the date of the repair, and the person or entity performing the repair. Page 5559 15. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 16. Install the electrical ground wire terminal to the rivet stud. 17. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 18. Install the M6 conductive nut to the rivet stud and: Tighten Tighten to 8 Nm (71 lb in). 19. Verify proper system operation. M6 Weld Nut Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M6 weld nut at the electrical ground location is damaged or stripped, a M7 conductive self-threading bolt may be used to secure the ground wire terminal. 2. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the weld nut and allow to dry. 3. Remove any loose metal particles from the damaged or stripped weld nut with a stiff brush. 4. Select a M7 conductive self-threading bolt. Refer to the Parts Information section of this bulletin 5. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M7 conductive self-threading bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 6. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 7. Install the electrical ground wire terminal to the M7 conductive self-threading bolt. 8. Install the M7 conductive self-threading bolt and: Tighten Tighten to 9 Nm (80 lb in). 9. Verify proper system operation. M6 Weld Nut Alternative Repair Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the electrical ground location is accessible from both sides of the panel, a M6 conductive bolt and a M6 conductive nut may be used to secure the electrical ground wire terminal. Refer to the Parts Information section of this bulletin. 2. Select a location adjacent the damaged M6 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the new electrical ground site. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the ground location and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 8.5 mm (0.33 in) diameter hole through the panel. 5. Remove paint and primer from the area surrounding the 8.5 mm (0.33 in) hole until bare metal is visible. 6. Select a M6 conductive bolt. Refer to the Parts Information section of this bulletin. 7. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 8. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 9. Install the electrical ground wire terminal and the M6 conductive bolt to the ground location. 10. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 11. Install the M6 conductive nut to the bolt and: Page 1637 For vehicles repaired under warranty, use: Specifications Reverse Gear Shaft: Specifications Reverse Idler Shaft Bolt ....................................................................................................................... ................................................................... 17 ft. lbs. How to Read A Brake Drum Micrometer Brake Drum: Fundamentals and Basics How to Read A Brake Drum Micrometer HOW TO READ On a standard micrometer each division on the scale is equal to 0.001 inches. To obtain the total drum diameter the measurement shown on the dial is added to the value for which the micrometer scale is set. NOTE: When the dial is at 0.0 the dial indicator styles is fully inserted. When the styles is fully withdrawn the dial is at its maximum value. EXAMPLES In example "A" a new 10 inch drum is being measured. The micrometer scale is set to 10 inches, the styles is fully inserted, and the dial indicates 0.0. The drum diameter is 10.000 inches. In example "B" an older worn 10 inch drum is being measured. The micrometer scale is still set to 10 inches but now the styles is only partially inserted and the dial indicates 90. The total drum diameter is equal to 10.090 inches. Page 2044 Labor Operation: J3390 Use applicable labor time guide for labor hours. 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. Page 5125 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 4. Make repair. Page 7514 When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 5mm (3/16") of insulation from wire. e. Crimp a new terminal to the wire. f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. Figure 17 To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Figure 18 Figure 19 Page 6991 Door edge guards Bumper filler panel, Frt./Rr. Front side marker lamps *Roof marker lamps *West coast style mirrors *Stripes Emblems/decals if necessary G VANS Wiper arms Cowl vent grille Grille and headlamp bezels Front bumper filler panel Antenna Side view mirrors Side marker lamps Tail lamps Door edge guards Wheel opening moldings *Roof marker lamps *West coast style mirrors *Stripes Emblems/decals if necessary Swing out windows/seals WARRANTY INFORMATION For vehicles repaired under warranty. and for customer satisfaction. use: Labor Op (Labor Operations include mix time) A6100 Refinish the entire exterior body surface ABOVE THE BODY SIDE MOLDING AND INSERT COLOR on two tone vehicles if equipped. A6101 Refinish the entire exterior body surface INSERT COLOR only. A61O2 Refinish the PICKUP BOX LOAD FLOOR AND INNER FENDERS when applicable. A61O3 On units with an insert color, included is the entire exterior body surface ABOVE THE BREAKLINE. (If the insert color and the entire body surface above the break-line requires refinishing, use A6100). Page 1961 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 Page 3823 A new pressure regulator valve (III. 218) has been made which will improve the oil pressure stability at lower RPM. SERVICE PARTS INFORMATION: Description Part Number Valve, Pressure Regulator (III. 218) 8684048 Part numbers are for Reference Only. Check with your Parts Department for latest information. Page 7232 Figure No. 6 With tailgate window closed, grab handle and attempt to move it forward and backward in a quick motion. If the window creates a glassy sounding rattle then perform the following service procedure. 1) Remove trim panel by taking out the eight fastening screws and sliding the panel rearward. 2) Locate the guide bushing shown in Figure 6. 3) Remove guide bushing and place a bead of Black RTV (P/N 1052917) around the perimeter of the guide bushing hole and reinstall the bushing. Allow RTV to cure with the window open. The RTV absorbs the vibration of the guide against the bushing and then ultimately between the bushing and the metal. If, after going through the initial checks, you have completed the above service procedures, test drive the vehicle to see if the rattle condition has been eliminated. If noise persists, continue with the following procedure. Service Procedure 5 Page 1352 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 Page 7722 Courtesy & Dome Generator Light - Flickers During Pulse Wiper Use Diode: Customer Interest Generator Light - Flickers During Pulse Wiper Use Number: 90-84-8A Section: 8A Date: November 1989 Corporate Bulletin No: 966402 Subject: GENERATOR LIGHT FLICKER DURING PULSE WIPER OPERATION Model and Year: 1988-89 S, T TRUCKS WITH 2.8L OR 4.3L (VIN CODES R, Z) ENGINES TO: ALL CHEVROLET DEALERS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 89-219-8A, DATED JULY 1989. THE 1990 MODEL S/T VEHICLES ARE INCLUDED IN THE LATEST BULLETIN ALONG WITH A CORRECTION TO THE ELECTRICAL CONNECTOR NUMBER. ALL COPIES OF 89-219-8A SHOULD BE DISCARDED. The generator light flicker condition during pulse wiper switch operation in the 1988, 1989 and 1990 S/T instrument panel, with standard cluster, can be caused by negative voltage transients from the wiper motor. There is no possibility of a system failure as a result of this condition. The effect of this condition is that the generator light will turn on for 80 milliseconds (if gages, the voltage drop on the voltmeter lasts 2.5 seconds). This causes no harm to the generator or other electrical components. Subject condition can be eliminated by installing a diode (industry part number 1N4003) or diode/connector kit (diode kit part number 12085207) in the brown wire at the generator connector (circuit 25 at connector C118). See the following pages in the 1988, 89 and 90 S/T Electrical Wiring Diagrams for circuit 25, connector C118 locations: 1988 4.3L: Section C - Page 24 1988 2.8L: Section C - Page 22 1989 4.3L: Page 40 1989 2.8L: Page 39 1990 2.8L: Page 44 1990 4.3L: Page 45 PARTS INFORMATION: Quantity Part Number Description 1 12085207 Diode ----OR---1 *1N4003 Diode * This part available locally. Parts are currently available from GMSPO. INSTALLATION PROCEDURE: 1. Disconnect the battery. 2. Remove the connector from the generator. 3. Peel back the black plastic conduit covering the wires. 4. If installing diode 1N4003: cut out a section of the brown wire that matches the length of the diode. 4A. A diode/connector kit is also available (GMSPO diode kit part number 12085207). If using the kit cut out approximately four inches of the brown wire, following crimping and soldering instructions in the kit. Spiral tape the solder joints and tuck the wire back into the conduit away from the generator. Secure the diode/connector to the outside of the conduit with electrical tape. 5. Solder in diode with the banded end toward the generator. Page 7245 Figure No. 6 WINDOW LATCH This third form of vibration can occur in the window latch region. This rattle noise is caused by the vibrations mentioned above and occurs as the window guide vibrates in the guide bushing (see Figure 6). The following four procedures can be done in any order as a single or as a multiple repair. Service Procedure 1 Page 4265 Pinion Gear: Service and Repair Timken/Rockwell - 12 Inch Ring Gear Fig. 1 Exploded View Of Timken/Rockwell Drive Axle With 12 inch Ring Gear DISASSEMBLY 1. Tap or press pinion from cage, taking care not to damage shaft threads, then remove outer pinion bearing, Fig. 1. 2. Remove spacer from pinion, then the inner bearing, using suitable separator and press or puller. 3. If straddle bearing must be replaced, remove snap ring and washer, then the bearing, using suitable puller. 4. If bearings are to be replaced, press outer races from bearing cage, taking care not to distort cage. 5. Inspect components as outlined, and replace as needed, keeping components in order for assembly. ASSEMBLY & PRELOAD 1. When installing new cups, press them firmly against pinion bearing cage shoulders. 2. Lubricate bearings and cups with suitable lubricant. 3. Press rear thrust and radial bearings firmly against pinion shoulders, using suitable sleeve that will bear only on bearing inner race. 4. Install radial bearing lock ring, then squeeze ring into pinion shaft groove. 5. Insert pinion and bearing assembly in pinion cage and position spacer or spacer combination over pinion shaft. 6. Press front bearing firmly against spacer. 7. Rotate cage several revolutions to assure normal bearing contact. 8. Press flange or yoke against forward bearing and install washer and pinion shaft nut. 9. Place pinion and cage assembly over carrier studs, hold flange with suitable tool and torque pinion shaft nut to 240 ft. lbs. 10. Check pinion bearing preload torque. If rotating torque is not within 5 to 15 pound inches, disassemble, adjust spacer, reassemble, and recheck preload torque. Use thinner spacer to increase or thicker spacer to decrease preload. Page 203 Ignition Control Module: Service and Repair Typical Distributor Components REMOVAL: 1. Remove distributor cap and rotor. 2. Remove two module attaching screws, and lift module up. 3. Disconnect leads from module. Observe color code on leads as these cannot be interchanged. 4. Remove module. INSTALLATION: NOTE: Be sure there is a sufficient amount of silicone grease on the metal face of the module and on the distributor base (where the module seats), when reinstalling the module. The purpose of the silicone grease is to cool the module. 1. Install module. 2. Connect leads to module. 3. Install module attaching screws. 4. Install pick up coil. 5. Install cap and rotor. Page 1426 sure the retainer cup is tree from dirt, grease, and gouges. Most wheel balancers now offer this type of protected retainer. DO NOT allow the retainer cup to rotate against the wheel's surface when tightening the wheel to the balancer. DO NOT OVERTIGHTEN. Most balancers use a large "wing nut" design to clamp the retainer against the wheel. Hand tight is sufficient. This procedure will allow accurate balancing using the conventional back cone method. Important: Coated balance weights must be used on aluminum wheels to prevent damage to the rim flange. Except for the N9O 4X4 wheel used on T trucks, all light truck aluminum wheels will accept either "AW" series or "MO" series clip-on coated weights on both the inside and outside rim flanges. The N9O T truck wheel will accept "AW" series weights on the inside rim flange only. The outside rim flange is not designed to accept a clip-on weight. If such a weight installation is attempted, a poor fit will result, and the weight may fall off and/or cause cosmetic damage to the rim flange. This wheel can be 1) static balanced by clipping all the weight on the inside rim flange (as is done in the assembly plant), or 2) dynamic balanced by clipping a weight on the inside flange and using an adhesive weight near the outside flange. The charts show "AW" and "MC" balance weight usage. These original equipment coated weights are available at competitive prices through the GM Dealer Equipment program. Page 3084 Wiring Diagram For Chart C-2 - Idle Air Control Check CHART C-2 - IDLE AIR CONTROL CHECK Circuit Description: The ECM sends voltage pulses to the IAC motor winding causing the motor shaft and valve to move "in" and "out" a given distance for each pulse (called counts) received. This movement controls air flow around the throttle plate, which, in turn, controls engine idle speed. Test Description: Numbers below refer to circled numbers on the diagnostic chart "Scan" tool must be in open mode during test. Keep A/C "OFF" during entire check. 1. Test with engine in drive and continue with test, even if idle is erratic. If idle is too low, "Scan" will display 80, or more, counts or steps. Engine speed may vary 200 RPM, or more, up and down. Disconnect IAC. If the condition is unchanged, the IAC is not at fault. There is a system problem. Proceed to step "3" below. 2. When the engine was stopped with ignition "OFF", the IAC valve retracted (more air) to a fixed "Park" position, for increased air now and idle speed during the next engine start. A "Scan" will display 100 or more counts. 3. Be sure to disconnect the IAC valve prior to this test. The test light will confirm the ECM signals by a steady or flashing light, on all circuits. 4. There is a remote possibility that one of the circuits is shorted to voltage, which would have been indicated by a steady light. Disconnect ECM and turn the ignition "ON" and probe terminals to check for this condition. Diagnostic Aids: An unstable idle may be a system problem that cannot be overcome by the IAC. "Scan" counts will be above 80 counts, if too low, and 0 counts, if too high. ^ If IAC valve pintle position counts are low or zero, check with vacuum leaks at vacuum fitting, tees and hoses, the throttle body and the intake manifold. A bottomed (zero count) IAC valve pintle may result in an idle speed above specification. Refer to minimum air rate check. ^ If IAC valve pintle position counts are high, look for carbon build-up in the IAC valve air inlet passage or evidence of tampering with stop screw. Also check for low engine power or excessive accessory loads. ^ System Too Lean (High Tailpipe Air/Fuel Ratio - Engine speed may vary up and down and disconnecting the LAC may not stabilize engine speed. If "Scan" and/or Voltmeter reads an oxygen sensor output less than 300 mv (.3v), check for low regulated fuel pressure or water in fuel. A code 44 (lean O2 sensor) may be set. A lean tailpipe exhaust with an oxygen sensor-output fixed above 800 mv (.8v) could be a contaminated sensor, usually Silicon. This may set a Code 45 (rich O2 sensor) even with lean tailpipe exhaust. ^ System Too Rich (Low Tailpipe Air/Fuel Ratio - System obviously rich and may exhibit black smoke exhaust. "Scan" toot and/or Voltmeter will read an oxygen sensor signal fixed above 800mv (.8v). Check for: - Injector leaking or sticking - High fuel pressure - Air leak in MAP transducer line - If O2 is normal or low, inspect for air being pumped into exhaust manifold in front of O2 sensor (or exhaust leak) ^ Throttle body - Remove IAC and inspect bore for foreign material or evidence of IAC valve dragging the bore. (Repair as required) ^ A/C Compressor or relay failure - See A/C diagnosis if circuit is shorted to ground. If the relay is faulty, idle problem may exist. ^ Refer to Rough, Unstable, Incorrect Idle or Stalling. See Diagnosis By Symptoms - No Trouble Codes. Page 7189 Figure 1 TO: ALL CHEVROLET DEALERS Some S/T vehicles with option (RPO V54 and V55) roof racks may experience a roof rack howl. This howl has been determined to be caused by the height difference between the roof rack cross rails and the rubber strip within the rail. This condition results in a howl/wind noise as air flows across the rail, much like a reed in a wind instrument. To eliminate this condition a new rubber cross rail cap (part # 15659287) should be installed. This new cap will repair the condition because it sits closer to the cross rail. See Figure 1 for the view of cross rail with installed rubber cap. Page 1396 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 Page 679 Compression Check: Testing and Inspection COMPRESSION CHECK - Disconnect the primary terminal from the ignition coil. - Remove all spark plugs. - Block the throttle plate wide open. - Make sure the battery is fully charged. Starting with the compression gauge at zero, crank the engine through four compression strokes (four "puffs"). - Make the compression check at each cylinder and record each reading. - If some cylinders have low compression, inject 15 ml (one table spoon, or 3 squirts from a pump type oil can) of engine oil into the combustion chamber through the spark plug hole. - Minimum compression recorded in any one cylinder should not be less than 70 percent of the highest cylinder, and no cylinder should read less than 690 kPa (100 psi). Normal Compression: Compression builds up quickly and evenly to specified compression on each cylinder. Piston Rings Leaking: Compression low on first stroke, tends to build up on following strokes, but does not reach normal. Improves considerably with addition of oil. Valves Leaking: Low on first stroke. Does not tend to build up on following strokes. Does not improve much with addition of oil. Head Gasket Leakage: If two adjacent cylinder have lower than normal compression, and injecting oil into cylinders does not increase the compression, the cause may be a head gasket leak between the cylinders. Audio - Poor AM or FM Radio Reception Antenna, Radio: All Technical Service Bulletins Audio - Poor AM or FM Radio Reception Number: 89-108-9A Section: 9A Date: MARCH, 1989 Subject: POOR AM OR FM RADIO RECEPTION Model and Year: 1980-89 CHEVROLET VEHICLES TO: ALL CHEVROLET DEALERS Page 6967 R3261 LH mirror R&R; 0.4 Hr. (Time is different than published time in Labor Operation Guide.) Tires - Proper Rotation and Warranty Coverage Tires: All Technical Service Bulletins Tires - Proper Rotation and Warranty Coverage GMC NUMBER: 88-T-66 GROUP: 3E - Wheels & Tires DATE: December, 1987 CORPORATE NUMBER: 893504R SUBJECT: GM DEALER'S RESPONSIBILITY CONCERNING TIRE WARRANTIES, INCLUDING IRREGULAR/PREMATURE WEAR MODELS: ALL LIGHT DUTY TRUCKS As in the past, tires continue to be warranted by the tire manufacturer against defects in material or workmanship. Details of this limited warranty may be found in each tire company warranty booklet, which is part of the glove box material. The GM Warranty and Owner Assistance Booklet also now states that the GM dealer will assist the customer in obtaining a tire adjustment if necessary. Tire conditions caused by vehicle defects are warranted by General Motors. This statement is now included in the GM Warranty and Owner Assistance Booklet. This applies during the basic coverage period, which is 12 Months/ 12,000 Miles, and should be applied to all past and current models. Examples of tire conditions that fall within GM's responsibility may include tire damage during vehicle assembly, tire damage due to tire-to-vehicle interference, and irregular/premature tire wear. Tire wear due to abusive driving is not covered by warranty. FIGURE 1 Page 4863 An acceptable finish can be obtained using the Ammco Model 8350 Safe Swirl Disc Rotor Grinder, or equivalent, using 120 grit sandpaper and sanding each rotor surface with moderate pressure for a minimum of 60 seconds with the rotor turning at 150 RPM. An alternate method is to use a sanding block with 150 grit sandpaper. With the rotor turning at approximately 150 RPM, sand each side for a minimum of 60 seconds using moderate pressure. After the rotor has been sanded, the surfaces must be cleaned with a solvent such as brake cleaning, denatured alcohol, or equivalent. THE FINISHED ROTOR SURFACE SHOULD BE AS CLOSE TO THAT OF A NEW ROTOR AS POSSIBLE. FAILURE TO OBTAIN THE BEST POSSIBLE ROTOR FINISH WILL AFFECT INITIAL BRAKING PERFORMANCE. CAUTION: ROTORS OR DRUMS SHOULD ALWAYS BE REPLACED IF TURNING WILL RESULT IN A ROTOR OR DRUM THAT DOES NOT MEET MANUFACTURER SPECIFICATIONS FOR MINIMUM ROTOR THICKNESS OR MAXIMUM DRUM DIAMETER. NOTICE: When re-installing tire and wheel assemblies, it is very important that proper procedures be followed when installing and torquing the wheel nuts: A. Finger start all wheel nuts. B. Tighten wheel nuts to specified torque (use the "star," or alternating nut pattern) using a torque wrench. DO NOT USE AN IMPACT WRENCH. UNEVEN AND/OR EXCESSIVE TORQUING OF THE WHEEL NUTS HAS BEEN FOUND TO DISTORT ROTORS, RESULTING IN PREMATURE CUSTOMER COMEBACKS FOR BRAKE PULSATION 3. After brake pads have been replaced and/or rotors have been refinished, it is recommended that the new braking surfaces be broken in, or burnished, to properly seat them. This can be accomplished by making 20 stops from 30 mph, using medium to firm pressure. Take care to avoid overheating the brakes. 4. It is strongly recommended that the correct, specified General Motors replacement part(s) be used when servicing G.M. vehicles. General Motors does not test non-G.M. parts for proper performance on G.M. vehicles. Therefore, the use of non-G.M. parts may result in unacceptable vehicle performance. It is also important that the correct G.M. part(s) be used in the correct G.M. application. For example, some "A" model disc brake pads ("A" Heavy) will fit on "C" and "H" models, but will not provide the same performance as the pads specified for use on C and H vehicles. It may seem preferable to stock fewer brake pad part numbers, but customer dissatisfaction may result if vehicle performance is affected. Page 1809 Warranty Information (excluding Saab U.S. Models) For vehicles repaired under warranty, use the appropriate labor operation for the source of the water leak Warranty Information (Saab U.S. Models) For vehicles repaired under warranty, use the table. Disclaimer Body & Frame - Misalignment of Pickup Box to Cab Truck Bed: Customer Interest Body & Frame - Misalignment of Pickup Box to Cab Number: 93-91-10 Section: 10 Date: JAN. 1993 Corporate Bulletin No.: 261514 ASE No.: B1 Subject: MISALIGNMENT OF PICKUP BOX TO CAB Model and Year: 1982-93 S/T TRUCKS Some owners of 1982-1993 S/T pickups may comment about misalignment of the pickup box to the cab. CAUSE: Misalignment may occur as a result of the frame mounting hole not allowing side to side adjustment. CORRECTION: To correct, it is necessary to enlarge the left front hole on the frame at the front of the pickup box and realign the box to the cab. SERVICE PROCEDURE: 1. Loosen all of the pickup box to frame bracket mounting bolts. Remove only the left corner bolt. 2. Raise and support the front left corner of the box approximately one inch (1"). 3. Drill, from the bottom up, the left front hole in the frame mounting bracket enlarging the hole to approximately 17 mm (11/16") ID. 4. Lower the box and loosely reinstall the left front corner mounting bolt. 5. Align the box to the cab body. Torque all the box to frame bracket mounting bolts 40-54 N-m (30-40 lbs.ft.). WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: B5300 Use applicable labor time guide for labor hours. Page 1525 Valve Cover: Service and Repair ROCKER ARM COVER REPLACEMENT REMOVAL - RIGHT SIDE Remove or Disconnect 1. Battery negative cable. 2. Air cleaner. 3. PCV valve 4. Heater pipe at the intake manifold. 5. Emissions relays with bracket. Lay aside. 6. Wiring harnesses from the clips. Move aside. 7. Spark plug wires at clips. 8. Dipstick tube bracket at the cylinder head. Move the dipstick tube aside. 9. Rocker arm cover bolts. 10. Rocker arm cover and gasket. REMOVAL - LEFT SIDE Remove or Disconnect 1. Battery negative cable. 2. Air cleaner and heat stove tube. 3. Crankcase ventilation pipe. 4. Fuel pipes at the TBI and retaining clips. Move the pipes aside. 5. Generator rear bracket. 6. Spark plug wires from clips. 7. Power brake vacuum line at the intake manifold. Move aside. 8. Rocker arm cover bolts. 9. Rocker arm cover and gasket. CLEANING AND INSPECTION Clean All traces of old gasket from the rocker arm cover and cylinder head. Inspect Rocker arm cover sealing surface for distortion and damage. Replace if necessary. Page 6254 ^ The valve cavity to remove any dust or dirt before installing a new seal. Install or Connect 1. Seal (57) to the compressor ^ Dip the seal (57) in 525 viscosity refrigerant oil. 2. Valve (56) to the compressor Tighten ^ Valve (56) to 19 N.m (14 ft. lbs.). Windshield/A Pillar - Pop Noise Diagnosis Dashboard / Instrument Panel: All Technical Service Bulletins Windshield/A Pillar - Pop Noise Diagnosis Number: 93-25-10 Section: 10 Date: OCT. 1992 Corporate Bulletin No.: 262001 ASE No.: B1 Subject: POP NOISE FROM WINDSHIELD PILLAR AREA Model and Year: 1983-93 S/T TRUCKS REFERENCE COWL "POP" TAPPING NOISE CHEVROLET DEALER SERVICE BULLETIN NUMBER 91-351-10, DATED JUNE 1991. Owners of some 1983-1993 S/T Pickups and Utilities may comment on a cowl "pop" noise transmitted through the "A" pillar. It has been determined that sections other than the windshield cowl area may produce a sound which imitates cowl "pop". PRIOR TO PERFORMING ANY CORRECTION FOR COWL "POP" TAPPING NOISES, VERIFY THE SOURCE OF THE NOISE(S) TO DETERMINE IF IT IS A VALID COWL "POP" CONDITION. Possible noise areas to check are: ^ Instrument panel "pop"/noise. ^ Loose door lock rods. ^ Loose wires/harnesses contacting the wall of the engine/passenger compartment (cowl). ^ A lack of door hinge lubrication. ^ An Electronic Control Module (ECM) bracket "pop". ^ An ash tray rattle. ^ An air vent squeak. ^ Hood hinge "flutter"/rattle. INFORMATION: 1. INSTRUMENT PANEL (I/P) "POP"/NOISE sound at the front edge of the I/P may occur if the I/P pad rubs against the cowl/dash support panel. Refer to "Instrument Panel Pad to Cowl Panel "Pop" Noise" Chevrolet Dealer Service Bulletin Number 92-286-10, dated Sept. 1992. 2. LOOSE DOOR LOCK RODS may vibrate during vehicle operation creating a rattle type noise. Refer to "Front Door Lock Rod Rattle" Chevrolet Dealer Service Bulletin No. 91-406-10, dated August 1991. 3. THE ELECTRONIC CONTROL MODULE (ECM) WIRING HARNESS CLIP may not be properly attached at the transmission bellhousing bolt allowing contact with the floor pan/front of dash area. This sound may be amplified by the HVAC ductwork. 4. LOOSE WIRES/HARNESSES maybe tapping against the engine/passenger compartment wall (cowl). 5. LACK OF DOOR HINGE LUBRICATION - Insufficient lubrication may create a binding/squeaking condition. 6. AN ECM BRACKET "POP" sound may occur if the ECM moves within its mounting bracket. 7. AN ASH TRAY BRACKET RATTLE coming from the ash tray or radio area of the instrument panel may occur if the bracket is loose and vibrating against the I/P. 8. AN AIR VENT "POP" may occur if the louvered vent and A/C duct rub together. 9. HOOD "FLUTTER"/RATTLE may occur if there is movement in the hood hinge attachment to the truck frame. Sound may accompany the hood Page 8117 Figure 2 Page 941 Fluid - Differential: Fluid Type Specifications 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. Page 1263 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. 3L30 (180C) Transmission Fluid Pressure Sensor/Switch: Specifications 3L30 (180C) Transmission Component .......................................................................................................................................... .................................................................... Ft. Lbs. Governor Pressure Switch ................................................................................................................... ................................................................................. 7 Page 1028 Specifications Fluid Pan: Specifications Oil Pan To Case 7-10 ft.lb Oil Pressure Check Plug 6 ft.lb Oil Strainer 14 ft.lb Page 7083 The AFFECTED AREAS MAY REQUIRE RECLEARCOATING/COLORCOATING OR REFINISHING. 8. In any case, once the proper repairs have been made, the final step in the repair process involves polishing the vehicle. A WORD ABOUT CLEARCOAT THICKNESS The clearcoat on the vehicle is typically 1.5 to 2.0 mils thick (one mil equals .001" or 1/1,000 of an inch). At least one mil thickness is required to provide lasting protection to the vehicle basecoat. PAINT GAGES The best way to accurately measure how much clearcoat has been removed is to use a paint gage before, during and after the sanding process. Paint gages measure the total thickness of the finish and when used, can determine how much clearcoat has been removed during the repair process. Paint gages range from magnetic pull types to sophisticated electronic types, are available from a variety of sources, and can cost from $30 to $1800. The older magnetic type gages, at best, a +/- 5% accuracy range and are not sensitive enough to detect removal of .5 mil clearcoat. The newer type magnetic gages have improved accuracy ranges. Most gages are confined to checking either a ferrous metal (steel) or non-ferrous metal (aluminum) panels. At this time, there are no viable gages for reading film thickness on non-metallic panels. A more sophisticated gage is the digital Elcometer 300 fn Paint Thickness gage (or equivalent). It has an ability to read film thickness on both ferrous and non-ferrous metal panels. This instrument has an accuracy range of +/- 1% and has thickness standards included for recalibration. Approximate cost = $1750. An alternative (for use on steel panels only) would be the digital Elcometer 246 model, or equivalent. This gage has a +/- 3% accuracy range and include thickness standards for recalibration. Approximate cost - $575. REPAIRING RAIL DUST DAMAGE Rail dust damage comes from the tiny iron particles produced from the friction between the train wheels and the track. It can also be deposited on vehicles if stored near any operation producing iron dust (steel ore yards, etc.). This dust can either lay on top of, or embed into the paint surface. It is usually diagnosed as; bumps in the paint surface OR - rust colored spots in the paint. PROCEDURE: 1. Wash the vehicle with soap and water, dry it and clean the affected area with wax and grease remover. 2. Keeping the vehicle in a cool or shaded area, rinse the surface with cold water. CAUTION: RAIL DUST REMOVER (OXALIC ACID) IS AN ACIDIC SUBSTANCE CONTAINING CHEMICALS THAT WILL BREAK DOWN THE IRON PARTICLES EMBEDDED IN THE FINISH. WHEN WORKING WITH IT, USE THE NECESSARY SAFETY EQUIPMENT, INCLUDING GLOVES AND GOGGLES. FOLLOW THE MANUFACTURER'S DIRECTIONS CLOSELY BECAUSE IT MAY REQUIRE SPECIAL HANDLING AND DISPOSAL. 3. Soak several terry cloth towels in a container of rail dust remover solution and, after the damaged areas have been rinsed with cold water, lay the wet towels on the damaged areas. 4. Allow the towels to remain in place for 20 minutes, keeping them moist by spraying with water and not allowing to dry on the surface of the vehicle. 5. After 20 minutes of applying the towels, remove them and rinse the area thoroughly with cold water. Inspect the affected area to ensure the dust has been removed. Use both touch (feeling for bumpy surface) and sight (magnifying glass for close inspection). 6. If upon inspection some particles are still present, the process of applying the towels can be repeated 3 times. 7. Select a test area and hand wet sand with American ultra fine 1,500 grit to 2,000 grit sandpaper to repair damage (surface pitting from dust). a. Use ample amounts of water. b. Go slow to prevent removing too much clearcoat. NOTICE: USE A PAINT GAGE TO DETERMINE THE AMOUNT OF CLEARCOAT REMOVED. IF TOO MUCH HAS BEEN REMOVED, ADDITIONAL CLEARCOAT WILL HAVE TO BE APPLIED. IF RAIL DUST HAS PENETRATED INTO THE BASECOAT, THE PANEL REQUIRES REFINISHING. MAKE SURE ALL RAIL DUST HAS BEEN REMOVED PRIOR TO REFINISHING OR THE RUST SPOTS WILL RETURN, CAUSING CUSTOMER COMEBACKS. 8. If the damage has been repaired, complete the repair to the entire panel. 9. Once the damage has been repaired, the final step in the repair process involves polishing the vehicle. PREVENTING INDUSTRIAL FALLOUT DAMAGE A/T - 4L60 Steel 3-4 Clutch Plate Availability Clutch: All Technical Service Bulletins A/T - 4L60 Steel 3-4 Clutch Plate Availability Number: 91-112-7A Section: 7A Date: November 1990 Corp. Bulletin No.: 077138 Subject: NEW 3-4 CLUTCH PLATES Model and Year: 1987-91 CAPRICE, CAMARO, CORVETTE WITH 4L60 AUTOMATIC TRANSMISSION 1987-91 C/K, G, M, R/V, S/T TRUCK AND 1990-91 L TRUCK WITH 4L60 AUTOMATIC TRANSMISSION TO: ALL CHEVROLET DEALERS BULLETIN COVERS: New 3-4 clutch plates (steel) are available for 1987-1990 HYDRA-MATIC 4L60 transmissions. The new clutch plates have a slightly smaller outer radius to let them move more freely in the clutch housing. DATE OF PRODUCTION CHANGE: Beginning July 27, 1990 (Julian Date 208), all HYDRA-MATIC 4L60 transmissions were built using the new 3-4 clutch plates. SERVICE INFORMATION: The new 3-4 clutch plates can be used to service any HYDRA-MATIC 4L60 transmission produced after February 9, 1987 (Julian Date 040). SERVICE PARTS INFORMATION: Description New Part # Plate - 3rd and 4th (steel - 4 or 5 needed) 8678053 Plate - 3rd and 4th (steel - 1 needed) 8678054 Parts are currently available from GMSPO. SERVICE MANUAL REFERENCE: Refer to the Automatic Transmission Unit Repair Section of the appropriate service manual for 3-4 clutch plate removal and installation information. Service and Repair Blower Motor Switch: Service and Repair S/T-10/15 1. Disconnect battery ground cable. 2. Remove instrument panel center bezel. 3. Remove control assembly attaching screws, then pull control assembly outward and remove blower switch. 4. Reverse procedure to install. Page 4322 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. Page 7382 Symbol Identification Wire Color Code Identification WIRE COLOR ABBREVIATION BLACK BLK BLUE BLU DARK BLUE DK BLU 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). Electronic Spark Control (ESC) Knock Sensor: Description and Operation Electronic Spark Control (ESC) Electronic Spark Control (ESC) is used on some models. The ESC system is used in conjunction with the EST system to provide additional spark retard during engine detonation. A knock sensor signals a separate ESC controller to retard the timing when it senses engine knock. The ESC controller signals the ECM which reduces spark advance until no more signals are received from the knock sensor. Page 4198 Differential Axle Housing: Service and Repair GMC Single Speed Axle Refer to ``Chevrolet Full Floating Axles'' for axle housing replacement procedures, since procedures are identical for both axles. Page 3238 Electronic Spark Timing: Testing and Inspection Chart C-5 - Electronic Spark Control System Check Page 4268 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. Disassembly Fig. 9 Drive Pinion Removal Fig. 10 Pinion Straddle Bearing Removal 1. Clamp pinion assembly in vise taking care not to damage housing or gear. 2. Hold driveshaft flange with suitable tool, then remove pinion nut and washer. 3. Remove driveshaft flange from pinion shaft using suitable puller. 4. Support housing in press as shown in Fig. 9, and press pinion from housing. Do not allow pinion to drop on floor. 5. Separate pinion flange, oil seal, front bearing and bearing retainer, driving seal from housing with suitable drift. 6. Remove bearing races from housing using suitable drift and place front bearing race with bearing. 7. Press rear bearing from pinion and place bearing with race. 8. Remove straddle bearing from axle housing using suitable drift, Fig. 10. 9. Inspect components keeping all components in order, and replace as needed. Assembly & Preload Engine - Performance Problems PROM - Programmable Read Only Memory: All Technical Service Bulletins Engine - Performance Problems Number: 88-193-6E Section: 6E Date: April, 1988 Subject: INCREASED PERFORMANCE Model and Year: 1988 S/T TRUCKS WITH 4.3L (VIN CODE Z) ENGINE AND CALIFORNIA EMISSIONS TO: ALL CHEVROLET DEALERS Customer comments of lack of performance, poor tip-in response, or engine flatness may be received in connection with some early built S/T trucks with a 4.3L engine and California emissions. A new prom was put into production that addresses these concerns. This new prom is now available for trucks built before the following breakpoints: 172008 The new PROM, part number for the LB4 (4.3L) engine is listed below: Page 1382 Capacity Specifications Fluid - A/T: Capacity Specifications 3L30 (180C) Transmission Fluid Capacity Pan Capacity ............................................................................................................... ........................................................................................... 1.5 Qts. Total Capacity ............................ .............................................................................................................................................................. ............. 2.3 Qts. 4L60 - 700R4 Transmission Fluid Capacity Pan Capacity ....................................................................................................................................... ......................................................................... 5.0 qts Overhaul Capacity ......................................... ............................................................................................................................................................ 11.5 qts Page 2291 Electronic Spark Timing: Testing and Inspection Chart C-5 - Electronic Spark Control System Check Page 1308 Refer to the appropriate section of SI for specifications and repair procedures that are related to the vibration concern. Disclaimer Page 6583 Radio/Stereo: Service and Repair 1. Disconnect battery ground cable. 2. Remove ashtray, then disconnect any wires necessary to provide access for radio removal. 3. Remove radio trim plate attaching screws and the trim plate. 4. Remove radio support clip retaining nuts, then the support bracket attaching screws. 5. Pull radio assembly from dash panel, then disconnect antenna lead and electrical connectors and remove radio from vehicle. 6. Reverse procedure to install. Page 4840 1. Wedge a flat chisel between the brake pad and rotor hat so that there is maximum clearance between the shoe tab and caliper casting ear (Figure 1). 2. Using a brass punch and hammer, carefully drive the upper brake pad tab down against the caliper ear. Repeat this step for the lower tab (Figure 1). 3. Push on back of pad with your thumb to insure clinch is tight. Pads should not move (Figure 2). NOTICE: Do not attempt to clinch inboard pads as they must be allowed to freely move in the brake caliper. Page 1781 Warranty Information (excluding Saab U.S. Models) For vehicles repaired under warranty, use the appropriate labor operation for the source of the water leak Warranty Information (Saab U.S. Models) For vehicles repaired under warranty, use the table. Disclaimer Page 6157 Installing The Shaft Key 1. Shaft key (2). ^ Allow the shaft key (21) to extend 4.8 mm (3/16-inch) out of the key way. ^ The shaft key (2) is curved slightly to give an interference fit in the groove. Installing The Clutch Plate & Hub Assembly 2. Clutch drive hub (3). ^ Install J 9480-B. ^ Hold the hex portion of J 9480-B with a wrench and tighten the center screw to press the hub onto the shaft until there is a 0.5-1.0 mm (0.20-.040-inch) air gap between the frictional surfaces of the clutch plate and clutch rotor. ^ Remove J 9480-B. 2. Shaft nut (1) with J 9399. ^ Use J 25030 to hold the clutch plate and hub assembly. Tighten ^ Shaft nut (1) to 17 N.m (13 ft. lbs.). Hand spin the pulley (11) to check for free rotation. V-Groove Type Remove or Disconnect Tools Required: J 6083 Snap Rings Pliers J 9398 Rotor Bearing Remover J 25031 Rotor and Bearing J 8092 Driver Handle 1. Clutch drive hub (3). Page 4537 Wiring Diagram For Chart C-1A - Park/Neutral Switch Diagnosis CHART C-1A - PARK/NEUTRAL SWITCH DIAGNOSIS Circuit Description: The Park/Neutral Switch contacts are closed to ground in park or neutral and open in drive ranges. The ECM supplies ignition voltage, through a current limiting resistor, to CKT 434 and senses a closed switch, when the voltage on CKT 434 drops to less than one volt. The ECM uses the P/N signal as one of the inputs to control: Idle Air Control VSS Diagnostics EGR Test Description: Numbers below refer to circled numbers on the diagnostic chart. 1. Checks for a closed switch to ground in park position. Different makes of "Scan" tools will read P/N differently. Refer to operators manual for type of display used for a specific tool. 2. Checks for an open switch in drive or reverse range. 3. Be sure "Scan" indicates drive, even while wiggling shifter to test for an intermittent or misadjusted switch in drive range. Diagnostic Aids: If CKT 434 indicates PIN (grounded), while in drive range, the EGR would be inoperative, resulting in possible detonation. If CKT 434 always indicates drive (open), a drop in the idle may exist when the gear selector is moved into drive range. Page 2025 Labor Operation: J3390 Use applicable labor time guide for labor hours. Electronic Spark Control (ESC) Knock Sensor: Description and Operation Electronic Spark Control (ESC) Electronic Spark Control (ESC) is used on some models. The ESC system is used in conjunction with the EST system to provide additional spark retard during engine detonation. A knock sensor signals a separate ESC controller to retard the timing when it senses engine knock. The ESC controller signals the ECM which reduces spark advance until no more signals are received from the knock sensor. Page 4337 Universal Joint: Specifications Universal joint flange locknut ............................................................................................................... ........................................................... 90-120 ft. lbs. Page 7196 Figure 1 TO: ALL CHEVROLET DEALERS Some S/T vehicles with option (RPO V54 and V55) roof racks may experience a roof rack howl. This howl has been determined to be caused by the height difference between the roof rack cross rails and the rubber strip within the rail. This condition results in a howl/wind noise as air flows across the rail, much like a reed in a wind instrument. To eliminate this condition a new rubber cross rail cap (part # 15659287) should be installed. This new cap will repair the condition because it sits closer to the cross rail. See Figure 1 for the view of cross rail with installed rubber cap. Page 5601 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 Page 3506 (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. Page 4180 Fig. 2 Exploded View Of Eaton Locking Differential 1. Remove guide clips and clutch discs from gear keeping components in order. 2. Clean and inspect components, and replace as needed. If side gear shim is defective, it must be replaced with one of equal thickness. If side gear is replaced, and/or if side gear shim thickness cannot be determined, perform SIDE GEAR SHIM SELECTION procedure. 3. Install eared and splined clutch discs on side gear, starting with eared disc as shown in Fig. 2. If components are reused, they must be installed in original position. 4. Install selected shim on side gear. Page 1595 10129561 IDLER PULLEY ASM. DRIVE BELT TENSIONER PULLEY ONLY: 1. Using procedures in 6B-Engine Cooling, remove and discard the serpentine belt. 2. On trucks with 4.3L, 5.0L, 5.7L and 7.4L engines, using metal pulley (P/N 10129561) perform the following steps: A. Remove O-ring, aluminum spacer, bolt, and metal bearing shield and discard (see illustration). B. Retain the metal pulley. 3. With tensioner on engine, remove worn tensioner pulley, bolt, and metal bearing shield. Discard pulley and retain bolt and shield for reassembly. IMPORTANT: 4.3L, 5.0L, and 5.7L bolt have left-hand threads. 7.4L bolt has right-hand threads. 4. Install new metal pulley and the original shield and bolt on the tensioner. 5. Install new serpentine belt. Labor Operation Number: T-7960. Labor Time: .3 hr. to replace idler pulley. .1 hr. to rework tensioner pulley. Page 3994 11501033 Nut 1 Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: K2283 (Manual Trans.) Labor Time: 0.4 Hrs. Labor Operation: K6723 (Automatic Trans.) Labor Time: 0.4 Hrs. Page 7957 Figure 8 Figure 9 Figure 10 Figure 11 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). Page 3641 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 Page 7134 Page 2380 Throttle Position Sensor: Service and Repair REMOVAL: 1. Disconnect electrical connectors. 2. Remove the TPS attaching screw assemblies and retainer, (if applicable). 3. Remove TPS from throttle body assembly. NOTE: The TPS is an electrical component and must not be soaked in any liquid cleaner or solvent, as damage may result. INSTALLATION: 1. Install TPS to throttle body assembly, while lining up TPS lever with TPS drive lever on throttle body. 2. Install the two attaching screw assemblies. Tighten screw assemblies to 2.0 Nm (18.0 lb-in). 3. Install electrical connector to TPS. 4. Check for TPS output as follows: a. Connect an ALDL scanner to read TPS output voltage. b. With ignition ON and engine stopped, TPS voltage should be less than 1.25 volts. If more than 1.25 volts, replace TPS. 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). Page 4257 7. Rotate cage several revolutions to assure normal bearing contact. 8. Press flange or yoke against forward bearing and install washer and pinion shaft nut. 9. Place pinion and cage assembly over carrier studs, hold flange with suitable tool, and torque pinion shaft nut to 350 ft. lbs. 10. Check pinion bearing preload torque. If rotating torque is not within 5 to 15 pound inches, disassemble, adjust spacer, reassemble, and recheck preload torque. Use thinner spacer to increase or thicker spacer to decrease preload. 11. Hold flange with suitable tool and remove pinion shaft nut and flange. 12. Lubricate pinion shaft oil seal and cover outer edge of seal body with non-hardening sealing compound, then press seal against cover shoulder with suitable tool. 13. Install new gasket and bearing cover. 14. Press flange against forward bearing and install washer and pinion shaft nut, torquing nut to 350 ft. lbs. Page 3395 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. Locations Expansion Block/Orifice Tube: Locations Fig 26. Evaporator And Blower Assembly The Expansion (Orifice) Tube is located in the evaporator inlet pipe as shown in fig. 26. Page 4552 SERVICE PARTS INFORMATION Part Number Description 15664811 Vacuum Actuator Switch Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: K4120 Use applicable labor time guide for labor hours. Page 6345 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 Page 226 Radiator Cooling Fan Temperature Sensor / Switch: Locations Coolant Temperature Switch Center Of Dash Panel (engine Compartment) Lower RH Side Of Engine Applicable to: V6-262/4.3L Engine Page 1101 Refrigerant Oil: Fluid Type Specifications REFRIGERANT OIL TYPE ^ R-12 refrigerant oil, 525 viscosity (See Note). NOTE: If vehicle has been converted to R-134a use PAG (Polyalkaline Glycol) synthetic refrigerant oil (GM Part No. 12345923) or equivalent. Wipers - Intermittent Phantom Wipe (No Driver Input) Wiper Switch: All Technical Service Bulletins Wipers - Intermittent Phantom Wipe (No Driver Input) Number: 90-266-8E Section: 8E Date: May 1990 Corp. Bulletin No.: 968302 Subject: WINDSHIELD WIPER PHANTOM WIPE Model and Year: 1985-90 S/T/M TRUCK AND 1990 L TRUCK THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 90-171-8E, DATED FEBRUARY 1990. THE LABOR TIMES HAVE BEEN UPDATED. ALL COPIES OF 90-171-8E SHOULD BE DISCARDED. Some 1985-1990 M vans, 1990 L Vans and S/T model trucks may exhibit intermittent phantom wipe - occasional wiper sweep of the windshield with no driver input. A new steering column wiper switch has been developed with an internal resistor to correct this condition. The following parts can be installed to repair intermiftent phantom wipe. They will service subject M/L vans and S/T trucks. SERVICE PARTS INFORMATION Part Number Description 26020403 Switch (Standard) 26020404 Switch (Tilt Wheel) Parts are currently available through GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Time Labor Time Labor Operation Models (standard) (tilt wheel) N2610 S/T M/L 1.2 hrs 1.0 hrs. Page 4959 Brake Caliper: Testing and Inspection Should it become necessary to remove the caliper for installation of new parts, clean all parts in denatured alcohol or brake parts cleaner, wipe dry using lint-free cloths. Using compressed air, blow out drilled passages and bores. Check dust boots for punctures or tears. If punctures or tears are evident, new boots should be installed upon reassembly. Inspect piston bores in both housings for scoring or pitting. Bores that show light scratches or corrosion can usually be cleaned with crocus cloth. However, bores that have deep scratches or scoring may be honed, provided the diameter of the bore is not increased more than 0.05 mm (0.002 inch). If the bore does not clean up within this specification, a new caliper housing should be installed (black stains on the bore walls are caused by piston seals and will do no harm). When using a hone, be sure to install the hone baffle before honing bore. The baffle is used to protect the hone stones from damage. Use extreme care in cleaning the caliper after honing. Remove all dust and grit by flushing the caliper with denatured alcohol or brake parts cleaner. Wipe dry with clean lint-free cloth and then clean a second time in the same manner. Page 5613 Measuring "D" Height PROCEDURE 1. Lift the front bumper of the vehicle up about 38 mm (1.5 inch). Let the vehicle settle. Do this three times. Measure "Z" dimension. 2. Push the front bumper down 38 mm (1.5 inch). Let the vehicle settle. Do this three times. Measure dimension. NOTE: True height is the average of the high and low measurements. 3. Lift the rear bumper of the vehicle up about 38 mm (1.5 inch). Let the vehicle settle on its own. Do this three times. Measure "D" dimension. 4. Push the rear bumper of the vehicle down about 38 mm (1.5 inch). Let the vehicle rise on its own. Do this three times. Measure the "D" dimension. Page 3005 To reduce the possibility of such an occurrence, especially if the reason for removing the air cleaner is a pinched wire, carefully remove the injector wires. Route the green and white wire under the blue and red wire and carefully twist once (Figure 2). Reconnect injector wires. One twist will reduce the slack in the injector wires so that there is less chance of them being trapped between the mating surfaces during assembly. Page 7772 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 4. Make repair. Page 4504 Labor Operation No.: K6550 Valve, Pressure Regulator-R&R; or Replace Use the appropriate labor time in the labor time guide. Parts are currently available from GMSPO. Engine - Drive Belt Misalignment Diagnostics Drive Belt: All 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. Page 419 Throttle Position Sensor: Description and Operation Typical Throttle Position Sensor (TPS) Wiring The Throttle Position Sensor (TPS), is mounted on the side of the throttle body opposite the throttle lever assembly. Its function is to sense the current throttle valve position and relay that information to the ECM. Throttle position information allows the ECM to generate the required injector control signals (base pulse). If the TPS senses a wide open throttle, a voltage signal indicating this condition is sent to the ECM. The ECM then increases the injector pulse width, permitting increased fuel flow. As the throttle valve rotates in response to movement of the accelerator pedal, the throttle shaft transfers this rotation to the TPS. A potentiometer (variable resistor) within the TPS assembly changes its resistance (and voltage drop) in proportion to throttle movement. By applying a reference voltage (5.0 volts) to the TPS input, a varying voltage (reflecting throttle position) is available at the TPS output. For example, approximately 2.5 volts results from a 50% throttle valve opening (depending on TPS calibration). The voltage output from the TPS assembly is routed to the ECM for use in determining throttle position. Page 7230 Figure No. 4 3) Remove existing weatherstrip and replace with revised weatherstrip (P/N 15659207). The revised weatherstrip will have plugs inserted inside of it. When installing the weather-strip align these plugs so that half of the plug is above the striker and half is below (see Figure 4. This is a friction fit, therefore, no adhesive is required. NOTE: If the subject vehicle was manufactured after the following break points then Service Procedure 2 will not be required as the material called out was incorporated in production. Shreveport: 1GNCS18Z2L8144761 Pontiac West: 1GNCT18Z7L0122931 Moraine: 1GNDT13Z6M2115163 Service Procedure 3 Page 5353 Tighten Tighten to 8 Nm (71 lb in). Note The repair area MUST BE properly refinished to maintain a secure, stable and corrosion-free electrical ground. 12. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 13. Verify proper system operation. M8 Weld Nut Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M8 weld nut electrical ground location is accessible from both sides of the panel, a M8 conductive bolt and a M8 conductive nut may be used to secure the electrical ground wire terminal. Refer to the Parts Information section of this bulletin. 2. Select a location adjacent the M8 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the new electrical ground site. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the ground location and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 10 mm (0.40 in) diameter hole through the panel. 5. Remove paint and primer from the area surrounding the 10 mm (0.40 in) hole until bare metal is visible. 6. Select a M8 conductive bolt. Refer to the Parts Information section of this bulletin. 7. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M8 conductive bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 8. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 9. Install the electrical ground wire terminal and the M8 conductive bolt to the ground location. 10. Select a M8 conductive nut. Refer to the Parts Information section of this bulletin. 11. Install the M8 conductive nut to the bolt and: Tighten Tighten to 22 Nm (16 lb ft). Note The repair area MUST BE properly refinished to maintain a secure, stable and corrosion-free electrical ground. 12. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 13. Verify proper system operation. M8 Weld Nut Alternative Repair Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M8 weld nut electrical ground location is not accessible from both sides of the panel, a M6 conductive rivet stud and a M6 conductive nut may be used to secure the electrical ground wire terminal. 2. Select a location adjacent the damaged M8 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the M6 conductive rivet stud flange. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the repair site and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 10 mm (0.40 in) diameter hole through the panel. Page 3851 Transmission Position Switch/Sensor: Testing and Inspection Chart C-1A - Park/Neutral Switch Diagnosis Page 2763 Manifold Pressure/Vacuum Sensor: Testing and Inspection Chart C-1D - Manifold Absolute Pressure (MAP) Output Check Diagnostic Trouble Code Descriptions Engine Control Module: Diagnostic Trouble Code Descriptions For information regarding B, C, P, U and Manufacturer Code Descriptions - Page 2759 - Diagnostic Chart Code 64. 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. Page 2491 SPARK PLUGS Page 4484 Labor operation T7990 Labor time .4 Hr Backup Lamps/Tailgate Window Release - Inoperative Shift Interlock Switch: All Technical Service Bulletins Backup Lamps/Tailgate Window Release Inoperative Number: 91-459-8A Section: 8A Date: DEC. 1991 Corporate Bulletin No.: 168104 ASE No.: A6 Subject: BACKUP LAMPS OR TAILGATE WINDOW RELEASE INOPERATIVE Model and Year: 1980-91 ALL LIGHT DUTY TRUCKS (EXCEPT GEO) Owners of some 1980-1991 C/K, 1982-1991 G, 1985-1991 M/L, 1984-1991 P2,P3, 1987-1991 R/V, 1983- 1991 ST (including LLV) with automatic transmissions may comment on a condition of inoperative back-up lamps or inoperative tailgate window release. This condition occurs when the vehicle's gear shift lever is placed in the "reverse" position, but the back-up lamps do not illuminate. In addition, on the S/T utility vehicles, the electric tailgate window release does not release when the transmission gear shift lever is placed in the "park" or "neutral" position and the endgate window release button is depressed. The park/neutral and back-up lamp switch comes out of adjustment which does not allow for the contact points to remain engaged. To correct these conditions, the contact carrier on the park/neutral and back-up lamp switch has been modified to increase switch carrier travel. SERVICE PROCEDURE: 1. Disconnect the battery ground cable from the battery. 2. Disconnect the switch assembly harness. 3. Place the gear selector in neutral. 4. Squeeze the tangs on the switch together and remove the switch assembly. 5. Install the new switch assembly (P/N 15679680) by: -aligning the actuator with the cutout in the steering column jacket. -inserting the tangs into the rectangular holes and pushing down on the switch assembly. 6. Adjust the switch by moving the gear selector to park. 7. Connect the switch assembly harness. 8. Connect the negative battery cable. 9. Check for proper switch operation. Readjust the switch as necessary. 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. 3L30 (180C) Transmission Shift Solenoid: Specifications 3L30 (180C) Transmission Component .......................................................................................................................................... .................................................................... Ft. Lbs. Solenoid ............................................................. .............................................................................................................................................................. .. 14 Page 3226 Pick-Up Coil: Testing and Inspection Tester J-24624 is required to test the module. If this tester is not available, and malfunction still exists after performing the following checks, replace module. Fig. 3 Ignition coil test connections IGNITION COIL TEST 1. Connect ohmmeter as shown in step 1, Fig. 3, and set meter on high scale. Meter should indicate very high or infinite resistance. If not, coil is defective. 2. Connect ohmmeter as shown in step 2, Fig. 3, and set meter on low scale. Meter should indicate low or no resistance. If not, coil is defective. 3. Connect ohmmeter as shown in step 3, Fig. 3, and set meter on high scale. If meter indicates infinite resistance, coil is defective. Page 8146 6. Tape the solder and diode. 7. Reinstall the black plastic conduit. 8. Reconnect connector to the generator. 9. Reconnect battery. This procedure will not affect the operation of the generator light during the bulb check at the beginning of the start cycle. For vehicles repaired under warranty use, Labor Operation Number: T7990 Labor Time: .4 Hr Page 5351 Important The M6 conductive rivet stud as shown, can accommodate a panel thickness range of 0.7-4.2 mm (0.03-0.17 in). If there are layers of sheet metal, they should be touching without any air gaps to ensure a good ground. 5. Select a M6 conductive rivet stud. Refer to the Parts Information section of this bulletin. Note Use the GE-50317 rivet stud tool kit. 6. Place the M6 conductive rivet stud (1) in the 10 mm (0.40 in) hole. Assemble the rivet stud tool (2) with the groove and flare side facing the rivet stud, then the washer and the M6 nut (3). 7. Using a wrench on the rivet stud tool, and a socket on the M6 nut, secure the M6 conductive rivet stud. 8. Ensure the rivet stud is securely fastened, WITHOUT ANY detectable movement. 9. Completely wrap the threads of the rivet stud with painters tape or equivalent. Note The rivet stud and surrounding panel area MUST BE properly refinished PRIOR to the installation of the ground wire terminal and conductive nut to maintain a secure, stable and corrosion-free electrical ground. 10. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 11. Allow the refinished repair area to cure sufficiently before removing the protective material applied to the rivet stud threads. 12. Remove the painters tape or equivalent from the rivet stud threads. 13. Using GM approved residue-free solvent or equivalent, thoroughly clean the rivet stud threads to remove any adhesive and allow to dry. 14. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive rivet stud. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. Removal Brake Rotor/Disc: Service and Repair Removal Fig. 5 Hub, knuckle & bearing components. 1. Raise and support vehicle 2. Remove brake caliper. See Brake Caliper / Service and Repair. See: Brake Caliper/Service and Repair 3. Remove cap from hub/disc assembly, Fig. 5. 4. Remove cotter pin, nut and washer. 5. Remove hub/disc from spindle. 6. Remove outer bearing, seal, inner bearing and cup. Isolation Diodes - Replacement Information Diode: All Technical Service Bulletins Isolation Diodes - Replacement Information Number: 93-163-8A Section: 8A Date: MAY 1993 Corporate Bulletin No.: 178201R ASE No.: A6 Subject: ISOLATION DIODES REPLACEMENT INFORMATION Model and Year: 1993 AND PRIOR YEAR PASSENGER CARS AND TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 92-47-8A, DATED NOV. 1991. THE 1993 MODEL YEAR HAS BEEN ADDED AS WELL AS PART NUMBERS HAVE BEEN REVISED. THIS WILL ALSO UPDATE CERTAIN SERVICE MANUALS. ALL COPIES OF 92-47-8A SHOULD BE DISCARDED. Many of the electrical systems on our vehicles use a diode to isolate certain circuits and protect them from voltage spikes. Some of the circuits which may use such a diode are listed below: A/C Compressor Clutch ABS/4WAL NOTE: The ABS diode on the Delco Moraine system is hidden inside of an electrical connector under the carpet at the right kick panel. Wiper Charging System (hidden in wire harness) Parking Brake (vehicles with ABS) Relays Solenoids Diesel Glow Plug Circuit Day Time Running Lights Obtaining replacement diodes can sometimes be a problem. A universal diode, that meets the specifications in the chart below, may be used for the applications listed above. Since certain diode applications have specific part numbers, always reference the applicable GM parts catalogue before installing one of the universal diodes listed in this bulletin. When installing the new diode, use the following procedures to obtain a lasting repair: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to current flow direction, remove inoperative 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 needed to attach the new diode. 4. Check current flow direction of the new diode, being sure to install the diode with correct bias. Reference the appropriate service manual wiring schematic to obtain the correct diode installation position. Reference Figure 1 for replacement diode symbols and current flow explanations. Page 7512 Figure 8 Figure 9 Figure 10 Figure 11 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). Page 5695 Fig. 1 Troubleshooting power steering system Excessive Wheel Kickback or Loose Steering 1. Air in power steering system. 2. Steering gear attachments loose. 3. Joints from column to steering gear loose. 4. Tie rod ends loose. 5. Wheel bearings worn. 6. Loose thrust bearing preload adjustment. 7. Low fluid level. Hard Steering or Lack of Assist 1. Brakes applied while turning steering wheel. 2. Joints from column to steering gear loose or worn. 3. Sticky steering gear valve. Diagram Information and Instructions Trailer Adapter Kit: Diagram Information and Instructions 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 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. A/C - Erratic HVAC Operation & Self Diagnostic Blinks Air Conditioning Indicator Lamp: 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). Page 28 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/. Page 4911 Backing Plate: Testing and Inspection Inspect backing plate shoe contact surface for grooves that may restrict shoe movement and cannot be removed by lightly sanding with emery cloth or other suitable abrasive. If backing plate exhibits above condition, it should be replaced. Also inspect for signs of cracks, warpage and excessive rust, indicating need for replacement. Page 3217 Center Of Dash Panel (engine Compartment) Page 6095 Figure 12 - Blower Motor Case Replacement REMOVE OR DISCONNECT (Figures 2 and 12) 1. Negative battery cable. 2. Electrical connection (91) at the blower motor (54). 3. Blower motor retaining screws (99) (figure 12). 4. Blower motor (54). INSTALL OR CONNECT 1. Blower motor (54). 2. Screws (99) (figure 12). ^ Tighten-Screws (99) to 2 Nm (18 in. lbs.). 3. Electrical connection (91) to the blower motor (54). 4. Negative battery cable. Page 4734 - 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 Glass/Body - Windshield Wiper Performance Windshield: All Technical Service Bulletins Glass/Body - Windshield Wiper Performance INFORMATION Bulletin No.: 06-08-43-003C Date: February 21, 2011 Subject: Windshield Wiper Performance, Cleaning Instructions and Maintenance Models: 2012 and Prior GM Passenger Cars and Trucks (including Saturn) 2010 and Prior HUMMER H2, H3 2010 and Prior Isuzu Medium Duty Trucks 2005-2009 Saab 9-7X Supercede: This bulletin is being revised to add the 2011 and 2012 model year. Please discard Corporate Bulletin Number 06-08-43-003B (Section 08 - Body and Accessories). Wiper Concerns Most concerns about windshield wiper performance are the result of dirty wiper blades, damaged wiper blades, or worn out blades that are continuing to be used beyond their useful life. Depending on environmental conditions, wiper blades can have dramatic differences in lifespan. Here are some tips and guidelines to maximize wiper performance to avoid damage to the blades, and to avoid unnecessary replacements. Many wiper blades are being replaced under warranty with reviews showing there is nothing wrong with the returned blades other than a build-up of dirt. Additionally, advise the customer to review the information in their Owner Manual. Inspection and Cleaning Scheduled Maintenance - Inspect your wipers rubber blades every 4-6 months or 12,000 km (7,500 mi) for wear, cracking or contamination. - Clean the windshield and the rubber wiper blades (using the procedure below) if the blades are not clearing the glass satisfactorily. If this does not correct the problem, then replace the rubber elements. Cleaning Procedure Important Avoid getting windshield washer fluid on your hands. Wear rubber gloves or avoid direct contact with washer fluid. Important Do not use gasoline, kerosene, or petroleum based products to clean wiper blades. - Clean the rubber blades using a lint free cloth or paper towel soaked with windshield washer fluid or a mild detergent. You should see significant amounts of dirt being removed on the cloth. - Be sure to wash the windshield thoroughly when you clean the blades. Bugs, road grime, sap and a buildup of car wash/wax treatments may additionally cause wiper streaking. Tip For a larger scale buildup on the windshield, use a non-abrasive cleaner such as Bon-Ami* (www.faultless.com) cleanser with a wet sponge, being sure to use plenty of water to avoid scratching the glass. Flush the surface and body panels completely. Tip For day-to-day exterior glass cleaning and to maintain a streak free appearance, suggest Vehicle Care Glass Cleaner, P/N 88862560 (in Canada, 992727). This product is an easy to use foaming cleaner that quickly removes dirt and grime from glass surfaces. Tip Interior glass should be cleaned with plain, clean water to eliminate any film or haze on the window and help prevent fogging, a major customer dissatisfier. Refer to Corporate Bulletin Number 03-00-89-006D for more information. The New Vehicle Pre-Delivery Inspection form also recommends using plain water to clean interior glass. *"We believe this material 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 or equipment from these firms or any such items which may be available from other sources. Page 6353 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 A/T Rear Case Bushing - Removal & Installation Procedure Output Shaft Bearing/Bushing: Technical Service Bulletins A/T Rear Case Bushing - Removal & Installation Procedure Number: 90-162-7A Section: 7A Date: February 1990 Corp. Bulletin No.: 077103 Subject: REMOVE REAR CASE BUSHING OR REAR EXTENSION BUSHING - NEW ON-VEHICLE SERVICE PROCEDURE Model and Year: 1976-90 B, F, G, Y CARS & 1976-90 C, G, K, L, M, R, S, T, V TRUCKS WITH THM 200-4R, THM 200-C, THM 200 & 4L60/THM 700R4 AUTOMATIC TRANSMISSION Figure 1 This bulletin covers a new rear bushing (or rear extension bushing) removal/installation procedure that can be performed while the transmission is in the vehicle. This procedure saves labor time on each of the following transmission models: THM 200-4R THM 200-C THM 200 HYDRA-MATIC 4L60/THM 700-R4 Labor savings are different on each model but can be significant. This tool is currently available from Kent-Moore: J 38119 - Rear Case Extension Bushing Remover and Installer IMPORTANT: J 38119 includes two expansion tubes - one silver and one black. Use the BLACK tube for GM transmissions. Begin each procedure by raising vehicle on a hoist. Cooling - Cold Start Fan Noise Higher Than Normal Fan Clutch: All Technical Service Bulletins Cooling - Cold Start Fan Noise Higher Than Normal Number: 92-118-6B Section: 6B Date: FEB. 1992 Corporate Bulletin No.: 166203 ASE No.: A8 Subject: COLD START FAN NOISE Model and Year: 1988-92 S/T TRUCKS WITH 4.3L ENGINES Owners of some 1988-1992 S/T vehicles equipped with a 4.3L engine (RPO LB4 or L35) and air conditioning (RPO C60) may experience higher than normal fan noise upon oold start up. This condition may be due to incorrect engagement of the fan clutch. The condition may be corrected by installing a revised fan clutch (P/N 15672779). Vehicles built after the following VIN Breakpoints have the new fan clutch installed in production: Plant VIN Moraine 1GNDT13Z3N2151684 Shreveport 1GCCS19Z3N8156864 Pontiac West 1GNCS18Z2N0125676 SERVICE PROCEDURE: Refer to section 6B1 "FAN/FAN CLUTCH REPLACEMENT" in the appropriate S/T Service Manual for removal and installation of the fan clutch. Specifications Transmission Speed Sensor: Specifications Electronic Speed Sensor Retainer Bolt ............................................................................................... ...................................................................... 7 ft. lbs. Specifications Idle/Throttle Speed Control Unit: Specifications IDLE SPEED CONTROL Measured between terminals A& B and C & D. Body - Vehicle Glass Distortion Information Front Door Window Glass: Technical Service Bulletins Body - Vehicle Glass Distortion Information INFORMATION Bulletin No.: 00-08-48-005D Date: September 10, 2010 Subject: Distortion in Outer Surface of Vehicle Glass Models: 2011 and Prior GM Passenger Cars and Trucks 2009 and Prior HUMMER H2 2010 and Prior HUMMER H3 2005-2009 Saab 9-7X 2010 and Prior Saturn Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 00-08-48-005C (Section 08 - Body and Accessories). Distortion in the outer surface of the windshield glass, door glass or backlite glass may appear after the vehicle has: - Accumulated some mileage. - Been frequently washed in automatic car washes, particularly "touchless" car washes. This distortion may look like a subtle orange peel pattern, or may look like a drip or sag etched into the surface of the glass. Some car wash solutions contain a buffered solution of hydrofluoric acid which is used to clean the glass. This should not cause a problem if used in the correct concentration. However, if not used correctly, hydrofluoric acid will attack the glass, and over time, will cause visual distortion in the outer surface of the glass which cannot be removed by scraping or polishing. If this condition is suspected, look at the area of the windshield under the wipers or below the belt seal on the side glass. The area of the glass below the wipers or belt seal will not be affected and what looks like a drip or sag may be apparent at the edge of the wiper or belt seal. You may also see a line on the glass where the wiper blade or the belt seal contacts the glass. Important The repair will require replacing the affected glass and is not a result of a defect in material or workmanship. Therefore, is not covered by New Vehicle Warranty. Disclaimer Page 7797 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 4. Make repair. Page 1955 Water Pump: Service and Repair Fig. 19 Water Pump Bolt Location 1. Drain cooling system. 2. Remove serpentine drive belt, then the upper fan shroud. 3. Remove fan, fan clutch assembly and water pump pulley, Fig. 19. 4. Remove hoses from pump. 5. Remove water pump attaching bolts, then pump. 6. Reverse procedure to install. Torque bolts to specification. Page 6225 2. Place the Temperature and Mode controls in the upper position. 3. Apply thumb pressure to each of these control knobs to hold them in the upper position while using a small screw driver to pry off the knobs (Figure 1). 4. Use the same procedure to remove the blower switch knob. 5. Disconnect the 2 light sockets from the housing by twisting the sockets counterclockwise. Page 7153 panel(s) that can be used as a starting/ stopping point when making a repair. Clearcoat: A clear topcoat required to cover a color basecoat. DELAMINATION: Loss of adhesion between one coat of paint to succeeding coats or coatings. Ultraviolet DELAMINATION is between the E coat (ELPO) and color topcoat(s). ELPO: (Electrocoating or "E" coat): The process by which electrically charged primer is plated on conductive surfaces of an opposite charge. This process provides outstanding corrosion resistance. Guidecoat: A light coat (almost overspray) of color applied over primer surfacer prior to wetsanding to highlight any low spots. Insert Color: The secondary two-tone color between the break line and body side molding. Monocoat: A color topcoat that does not require a clearcoat. Primer: The coating applied to a properly prepared substrate (bare metal) to give adhesion, corrosion and chemical resistance. Primer Sealer: An undercoat that provides maximum adhesion. color coating and corrosion protection. Primer Surfacer: An undercoat used to fill imperfections, with primer qualities, that must be sanded. Refinish: The act of replacing a painted surface, usually undercoat and topcoat. Scuff Sand: A method of sanding a painted surface using a fine grit sandpaper to promote paint adhesion. Topcoat: A finish material over an undercoat material. Ultraviolet Light: The portion of the spectrum of light which can cause fading of paint. It is located below the visible part of the spectrum. V.O.C.: "Volatile Organic Compound" or "Volatile Organic Content" relates to certain emission requirements in specific areas of the country. Technical Service Bulletin # 8931810 Date: 900901 Campaign - Paint Delamination Policy Adjustment Locations Parking Brake Warning Switch: Locations LH Side Of I/P Behind Instrument Cluster Page 5171 Starter Solenoid: Specifications Hold-In Windings And Pull-In Windings Amperes Hold-In Windings And Pull-In Windings Amperes Hold-In Windings Pull-In Windings Starter Identification Number 10455016 13-19 A 23-30 A 10455017 13-19 A 23-30 A 10455018 13-19 A 23-30 A 10455024 10-20 A 50-65 A 10455025 10-20 A 50-65 A 10455048 10-20 A 50-65 A Page 864 FIGURE 2 FIGURE 3 ^ THM 125C, 440-T4 (Refer to Figures 2 and 3): When cold, 27 Degrees C (80 Degrees F), a full transaxle will show the fluid level to be above the "Full Hot" mark. This is a result of fluid stored in the bottom pan when cold. As the transaxle warms to normal operating temperature, fluid is captured in the side pan, lowering the fluid level to within the cross-hatched area. NOTICE: The "cold" check procedure cannot take the place of a "hot check. The "cold" check will let the technician know there is enough fluid to perform a Preliminary check Procedure, an accurate road test, and allow normal operating temperature to be obtained prior to the necessary "hot" check. B. "HOT" CHECK PROCEDURE: 1. Drive vehicle in all ranges to attain a fluid temperature of 80 to 90 Degrees C (180 to 200 Degrees F). 2. Idle at normal idle speed in Park for 3 minutes. 3. With vehicle level, accessories turned off, and engine idling in Park, check fluid level. 4. Fluid level should be within the cross-hatched area. (Read front and back, use the lowest level.) Page 5047 Hydraulic Brake Booster: Testing and Inspection Slow Brake Pedal Return 1. Excessive seal friction in booster. 2. Faulty spool action. 3. Restriction in return line from booster to pump reservoir. 4. Damaged input rod end. Speed Sensor Buffer Vehicle Speed Sensor Signal Buffer: Locations Speed Sensor Buffer LH Side Of I/P Diagram Information and Instructions Tail Lamp: Diagram Information and Instructions 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 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. Page 1384 A. Obtain a straight edge approximately 8-9 inches long and, while holding it in two hands, as shown in the attached illustration, place it on the inboard mounting surface of the wheel and try to rock it up and down. B. Repeat the above procedure on three or four different positions on the wheel inboard mounting surface. C. The outer ring of the mounting surface is normally raised above everything inside it. If a wheel mounting surface has been bent on a tire changer, it will be raised above the outer ring and the straight edge will rock on this "raised" portion. D. If a bent wheel is found, it must be replaced. Page 1060 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. Description and Operation Fuel Economy Warning System: Description and Operation This system actually monitors the engine vacuum just like the vacuum gauge, but registers only low vacuum readings. The light on the instrument panel warns the vehicle operator when engine manifold vacuum drops below the economical limit. Switch operation is similar to that of the oil pressure indicating light, except that the switch opens when vacuum pressure, rather than oil pressure, is applied. Page 6041 1990-1991 "W" Car 1988-1990 "Y" Car "AW" Type Weight 1989-1991 "L" Car Used On All Other 1991 "B" Car, "U" Van Series Vehicles 2-1/4 oz. 9591382 9591366 2-1/2 oz. 9591383 9591367 3oz. 9591385 9591369 Parts are currently available from GMSPO. Dealers should make sure they have a supply of both types weights for balancing GM aluminum wheels. When installing the coated weights, care must be taken so that the coating does not crack. It is recommended that a Teflon tipped hammer be used, such as 85403 Nicholson Industrial Hammer, their part number CAS 3340551, available through the Charles Strelinger Company, Warren, Mi (313-268-4100), or equivalent. Page 7665 Backup Lamp Switch: Locations LH Side Of Manual Transmission LH Side Of Transmission Page 2515 Reference Signal: Testing and Inspection Chart C-1B - Crank Signal Diagnosis Description and Operation Diode Trio: Description and Operation Alternators are composed of the same functional parts as the conventional D.C. generator but they operate differently. The field is called a rotor and is the turning portion of the unit. The generating part, called a stator, is the stationary member, comparable to the armature in a D.C. generator. The regulator, similar to those used in a D.C. system, regulates the output of the alternator-rectifier system. The power source of the system is the alternator. Current is transmitted from the field terminal of the regulator through a slip ring to the field coil and back to ground through another slip ring. The strength of the field regulates the output of the alternating current. This alternating current is then transmitted from the alternator to the rectifier where it is converted to direct current. These alternators employ a three-phase stator winding in which the phase windings are electrically 120 degrees apart. The rotor consists of a field coil encased between interleaved sections producing. When the rotor is energized, a magnetic field with alternate north and south poles is created. By rotating the rotor inside the stator the alternating current is induced in the stator windings. This alternating current is rectified (changed to D.C.) by silicon diodes and brought out to the output terminal of the alternator. DIODE RECTIFIERS Six silicon diode rectifiers are used and act as electrical one-way valves. Three of the diodes have ground polarity and are pressed or screwed into a heat sink which is grounded. The other three diodes (ungrounded) are pressed or screwed into and insulated from the end head; these diodes are connected to the alternator output terminal. Since the diodes have a high resistance to the flow of current in one direction and a low resistance in the opposite direction, they may be connected in a manner which allows current to flow from the alternator to the battery in the low resistance direction. The high resistance in the opposite direction prevents the flow of current from the battery to the alternator. Because of this feature no circuit breaker is required between the alternator and battery. Page 1625 2. Loosen engine mount through bolts (Figure 1, "B") and transmission mount to crossmember bolts and ensure the exhaust flexible hose is free to - move. - Loosen exhaust pipe/converter pipe clamp U-bolt (Figure 3). - Move U-bolt out of position. - Heat the exhaust pipe/converter connection joint to loosen the converter. Page 3538 Case: Specifications THM180 & 180 C Automatic Trans Application ........................................................................................................................................... ................................................................... Ft. Lbs. Reinforcement Plate To Case ............................................................................................................. ........................................................................... 13-15 Page 6950 If the functional brake switch adjustment check does not repair the condition, refer to Section 5 of the appropriate Service Information Manual for aid in diagnosing other causes. For warranty purposes use: Labor Operation Number: N2440 Labor Time: .3 hour TRUCK ONLY: Service Procedure: 1. Depress the brake pedal and press the switch in until it is firmly seated in the clip. * Audible "clicks" can be heard as the threaded portion of the switch is pushed through the clip. 2. Pull the brake pedal against the pedal stop until the audible "click" can no longer be heard. For stop lamp switch adjustments on vehicles repaired under warranty use: Labor Operation Number: T7945 Labor Time: .2 Hr. 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 Page 4891 FIGURE 4 - ROTOR MOUNTING ADAPTER - J 37160 ^ Adapters, if used, must be clean and free of nicks. Adapters may be used because of a two piece composite rotor design. (Refer to Figure 4). ^ The rotor surface contacting the arbor and/or the adapter must be free of debris and coarse surface corrosion. ^ If the dealership's rotor turning equipment cannot produce a finish cut equivalent to a new rotor's surface, finish cuts may be further improved and made non-directional by dressing the rotor surface with a sanding disc power tool. Light scoring of the rotor surfaces not exceeding 0.38 mm (0.015 inch) in depth, which may result from normal use, will not affect brake operation. To become familiar with the required surface finish, drag a fingernail over the surface of a new rotor from the parts stock or one on a new vehicle. If your brake equipment cannot produce this smooth a finish when correctly used, contact the equipment manufacturer for corrective instructions. Following these refinishing specifications and recommendations will help to hold the rotor surface finish to the specified range. Controlling the braking surface finish of the rotor is necessary to provide adequate early stopping ability and to avoid pulls and erratic performance and will aid in extending lining life. Specifications TEMPERATURE SENSORS VIN W Engine Intake Manifold: Service and Repair VIN W Engine 1. Disconnect battery ground cable. 2. Drain engine coolant from radiator, then remove plastic cover. 3. Disconnect engine wiring harness from throttle position sensor, idle air control motor, MAP sensor and communicator valve. 4. Disconnect throttle and T.V. linkage from upper intake manifold. 5. Remove ignition coil, then disconnect PCV hose from rear of upper intake manifold. 6. Disconnect vacuum hoses at front and rear of upper intake manifold. 7. Remove upper intake manifold bolts and studs. Mark location of bolts and studs for assembly reference. 8. Remove upper intake manifold. 9. Remove distributor and distributor wiring. Mark relationship of distributor housing and rotor for installation reference. 10. Remove upper radiator hose from thermostat housing, then the heater hose at lower intake manifold. 11. Disconnect fuel supply and return lines at rear of lower intake manifold. 12. Remove brace from lower intake manifold to A/C Compressor brace. 13. Disconnect engine wiring harness from fuel injector, EGR valve and coolant temperature sensor. 14. Remove lower intake manifold bolts, then the manifold from the vehicle. Fig. 8 Lower Intake Manifold Tightening Sequence Fig. 9 Upper Intake Manifold Tightening Sequence 15. Reverse procedure to install, noting the following: a. Apply RTV to the front and rear sealing surfaces on the block. b. Apply a 3/16 inch bead of RTV to the front and rear of the block, extend bead 1/2 inch up each cylinder head to seal and retain gaskets. c. Apply sealer part No. 1052080 or equivalent to lower intake manifold bolts. d. Torque lower intake manifold bolts to 35 ft. lbs. using tightening sequence shown in Fig. 8. e. Torque upper intake manifold bolts to 124 inch lbs. using tightening sequence shown in Fig. 9. Adjustments Brake Switch (Cruise Control): Adjustments With brake or clutch pedal depressed, push valve or switch fully into tubular clip until seated. Pull brake or clutch pedal rearward until pedal is against stop. Valve or switch will travel in tubular clip to provide proper adjustment. Page 3522 Band Apply Servo: Specifications THM180 & 180 C Automatic Trans Application ........................................................................................................................................... ................................................................... Ft. Lbs. Servo Adjusting Bolt Locknut ............................................................................................................... ....................................................................... 12-15 Brakes - Trailers Towing Information: Technical Service Bulletins Brakes - Trailers Number: 88-36 Section: OA Date: August, 1987 SUBJECT: TRAILER BRAKES MODELS: ALL LIGHT DUTY MODELS Trailer brakes of adequate size are required on trailers over 1,000 lbs (45 Kg) loaded weight. Follow the instructions of the manufacturer for proper installation and balance. Typically, trailer brake installations require less than 0.02 cubic inches (0.3 cubic centimeters) of fluid from the master cylinder to operate. Systems requiring more than 0.02 cubic inches of fluid must not be installed because the truck brake fluid capacity will NOT be sufficient to operate the truck and trailer brakes under every condition. The brake fluid tap on light duty trucks including the 1988 C/K models equipped with rear wheel anti-lock (RWAL) brakes, must be made to the master cylinder port supplying fluid to rear brakes before the combination valve. On the 1988 C/K, this installation will allow the truck to continue operating with RWAL brakes while the trailer brakes operate independently of the RWAL brake system. 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 A/T - THM 700-R4 TCC Applies During 1 to 2 Gear Shift Valve Body: All Technical Service Bulletins A/T - THM 700-R4 TCC Applies During 1 to 2 Gear Shift Number: 88-449-7A Section: 7A Date: JULY 1991 Corporate Bulletin No.: 177112R Subject: TCC APPLIES DURING 1-2 SHIFT Model and Year: 1988 G2, R1, S1 AND T1 TRUCKS WITH 700-R4 SERVICE REPLACEMENT TRANSMISSION ASSEMBLY Figure 1 - Control Valve Body Bulletin Covers: Some 1988 Service Replacement Transmission Assemblies (SRTA) may have been built with a bore plug in the TCC valve bore. The 8MHM, 8TAM, 8TBM, and 8TNM models should have the TCC shift valve lineup in this bore instead of the bore plug. If the bore plug is present, TCC will apply during the 1-2 shift. Service Information: If the control valve assembly contains a bore plug in place of the TCC shift valve lineup, the control valve assembly must be replaced. Service Parts Information: Reference the GMSPO Service Parts Catalog for the correct control valve assembly part number. Service Manual Reference: Refer to the THM 700-R4 Automatic Transmission Unit Repair Section of the appropriate Service Manual for instructions on replacing the control valve assembly. Page 6150 Installing The Pulley Rotor Bearing 2. Pulley bearing (4) into the hub using J 29886, J 9481-A and J 21352-A. Staking The Pulley Bearing In The Rotor Bore ^ J 33019-1 in the pulley bore. ^ Seat the pulley and bearing assembly on J 21352-A to support to the hub under the staking pin location. ^ Strike the staking pin with a hammer until a metal stake, similar to the original, is formed down to, but not touching the bearing. Position the stake pin after striking. - The staked metal should not contact the outer race of the bearing to prevent the possibility of bending the outer race. Staking Locations 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 ECM - Intermittent Connection Engine Control Module: Customer Interest ECM - Intermittent Connection Number: 88-251-8A Section: 8A Date: JUNE, 1988 Subject: INTERMITTENT CONNECTION TO THE ECM Model and Year: 1988 CHEVROLET PASSENGER CARS AND LIGHT DUTY TRUCKS TO: ALL CHEVROLET DEALERS A condition may exist in which the female terminals in the connector to the ECM do not make a solid connection to the male pins in the ECM (see illustration). This can result in an intermittent condition, in any circuit operated by the ECM. The Service Manuals direct a check of connections any time an intermittent condition is found, and this may be the cause of some of these conditions. Visually inspect the terminal using a flashlight, or use a .95 mm pin gauge. The gauge should not pass freely through the female terminal. Do not probe the terminal with anything other than the pin gauge, as probing could damage the terminal. If the female terminal does not grip properly, replace the terminal with P/N 12020757. General directions on wiring repair are shown in Section 8A of the service Manual. Detonation Sensor LH Rear Of Engine, At Rear Of Cylinder Head Page 4737 Fluid Pressure Sensor/Switch: Specifications 4L60 - 700R4 Transmission Pressure Switches ............................................................................................................................... ....................................................................... 8 ft. lbs. Page 6011 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 Automatic Trans. Neutral Safety Switch: Locations Automatic Trans. LH Side Of I/P Behind Instrument Cluster Specifications EGR Valve: Specifications Valve To Manifold Torque Valve To Manifold Torque EGR Valve To Manifold 15 ft.lb Number 1 Cylinder Location Number One Cylinder: Locations Number 1 Cylinder Location NUMBER ONE CYLINDER LOCATION Description and Operation Electronic Spark Timing: Description and Operation Varying octane levels in today's gasoline can cause detonation in engines. Detonation is sometimes called spark knock. To control spark knock an Electronic Spark Control (ESC) system has been added. This system is designed to retard spark timing up to 20~ to reduce spark knock in the engine. This allows the engine to use maximum spark advance to improve driveability and fuel economy. The ESC system has three major components: ^ ESC module ^ ESC knock sensor ^ ECM The ESC knock sensor detects abnormal vibration (spark knocking) in the engine. The sensor is mounted in the engine block near the cylinders. The ESC module receives the knock sensor information and sends a signal to the ECM. The ECM then adjusts the timing to reduce spark knocking. The ESC module sends a voltage signal (8 to 10 volts) to the ECM when no spark knocking is detected by the ESC knock sensor, and the ECM provides normal spark advance. When the knock sensor detects spark knock, the module turns "OFF" the circuit to the ECM. The ECM then retards EST to reduce spark knock. Loss of the ESC knock sensor signal or loss of ground at ESC module would cause the signal to the ECM to remain high. This condition would cause the ECM to control EST as if no spark knock were happening. No retard would occur, and spark knocking could become severe under heavy engine load conditions, possibly leading to pre-ignition and severe engine damage. Loss of the ESC signal to the ECM would cause the ECM to constantly retard EST. This could result in sluggish performance and cause a Code 43 to set. Spark retard without the knock sensor connected could indicate a noise signal on the wire to the ESC module or a malfunctioning ESC module. 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. Page 5790 Figure 11 - Snap Ring and Spider Removal 5. To remove the spider assembly (also required for seal replacement), spread the spacer ring with tool J8059 or equivalent and slide the ring and spider assembly up on the shaft (Figure 11). This will provide access to the shaft retaining ring in the groove at the end of the shaft. Remove the retaining ring, spider assembly, spacer ring, and seal. Figure 12 - Small Retaining Clamp Installation 6. Clean the shaft. If rust is present in the seal mounting area (grooves), wire brush this area (Figure 12). 7. Slide the new small seal clamp and seal onto the shaft to the proper position. 8. Secure the clamp with tool J35910, breaker bar and torque wrench. Torque small clamp to 136 N-m (100 lbs.ft.). Check clamp ear gap dimension (Figure 12). Page 7856 If the functional brake switch adjustment check does not repair the condition, refer to Section 5 of the appropriate Service Information Manual for aid in diagnosing other causes. For warranty purposes use: Labor Operation Number: N2440 Labor Time: .3 hour TRUCK ONLY: Service Procedure: 1. Depress the brake pedal and press the switch in until it is firmly seated in the clip. * Audible "clicks" can be heard as the threaded portion of the switch is pushed through the clip. 2. Pull the brake pedal against the pedal stop until the audible "click" can no longer be heard. For stop lamp switch adjustments on vehicles repaired under warranty use: Labor Operation Number: T7945 Labor Time: .2 Hr. Page 6074 Blower Motor: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. Figure 21 Figure 22 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. Page 246 Cruise Control Switch: Description and Operation Fig. 1 Cruise Control Switch The mode control assembly, Fig. 1, consists of a 3 position slide-type switch and a set/coast switch button. To operate the system, the slide switch must be in on position and vehicle speed must be above 25 mph. The system is engaged at the desired speed by fully depressing, then releasing the set/coast button. Cruise speed can be increased from set position by accelerating vehicle to desired speed, then pressing and releasing button. In order to decrease speed, the set/coast button is held in the fully depressed position (disengaging system), then released when the desired speed is reached. The system can be disengaged at any time by depressing the brake or clutch pedal, or by moving the slide switch to off position. If the system is disengaged by depressing the brake or clutch pedal, the last set speed will be retained in the module memory until the slide switch or ignition switch is moved to off position. Momentarily moving the slide switch to the resume/accel position will cause the vehicle to accelerate to the last set speed and maintain that speed. If the slide switch is held in the resume/accel position, the vehicle will continue to accelerate until the switch is released. When the switch is released, the speed that the vehicle accelerated to becomes the new set speed. The slide switch also allows a tap-up function to increase cruise set speed in 1 mph increments. With the cruise control engaged and operating, tapping-up is done by pressing the slide switch to the resume position, then quickly releasing it. This procedure can be repeated 10 times before the system must be reset to a new speed in the conventional manner. Page 4286 Figure 3 - Inboard Flange Bolt Removal 5. Loosen (do not remove at this time) six bolts securing inboard C/V joint drive flange to output shaft companion flange (Figure 3). Figure 4 - Brake Line Bracket Removal 6. Remove brake line support bracket from upper control arm to allow extra travel of knuckle (Figure 4). 7. Remove cotter pin and nut from the outer tie rod. Figure 5 - Disconnecting the Tie Rod 8. Separate the outer tie rod ball stud from the steering knuckle using J24319-01 (Figure 5). Notice: Do not attempt to disengage the joint by driving a wedge-type tool between the joint and the knuckle because the seal may be damaged. 9. Push linkage to opposite side of the vehicle and secure outer tie rod up and out of the way. This will provide the needed clearance to remove the halfshaft. Page 5318 When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 5mm (3/16") of insulation from wire. e. Crimp a new terminal to the wire. f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. Figure 17 To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Figure 18 Figure 19 Speedometer Gear - Malfunctions Speedometer Gear, M/T: All Technical Service Bulletins Speedometer Gear - Malfunctions Number: 91-98-8C Section: 8C Dates: October 1990 Corporate Bulletin No.: 067104 Subject: MALFUNCTION OF THE SPEEDOMETER DRIVE GEAR, DRIVEN GEAR AND/OR SPEEDOMETER Model and Year: 1987-91 S1 (LLV POST OFFICE VEHICLES) TO: ALL CHEVROLET DEALERS Some of the above postal vehicle chassis may experience a malfunction of the speedometer drive gear, driven gear, and/or speedometer adapter. Effective January 24, 1990 with chassis' VIN 1GBCS10E2M2901183, a new driven gear was installed in production. The new driven gear can be recognized visually as the following table illustrates. GM PART # COLOR # OF TEETH NEW 3987920 BLUE 20 OLD 3860347 YELLOW 24 IMPORTANT: The new driven gear has eliminated the need for the speedometer adapter. Recommended service procedures are outlined below: Service Procedure # 1 1. Remove and discard speedometer adapter (GM Part # 368025). 2. Remove original speedometer driven gear and inspect for damaged teeth. If damaged, follow service procedure # 2. If it is not damaged, replace the (yellow) 24 tooth driven gear with the (blue) 20 tooth driven gear (GM Part # 3987920). For vehicles repaired under warranty use: Labor Operation: # T1611 Labor Time: .3 hr. FAILURE CODE: 92 NOTE: The above procedures do not apply to 1991 Postal Vehicles (LLV) with L38 engines. Effective August 13, 1990 with chassis VIN 1GBCS10A0M2912017, a new engine (L38) and rear axle ratio (GU6) were installed in production. As a result of the axle ratio change, a new driven gear is required. Use (gray) 22 tooth driven gear (GM Part Number 3987922) if vehicle is equipped with L38 and GU6. Service Procedure # 2 1. Remove and discard speedometer adapter. 2. Remove driveshaft and rear transmission extension housing. 3. Replace both speedometer drive and driven gear with: Drive Gear (blue) GM Part 96040176 Driven Gear (blue) GM Part 3987920 NOTE: The above procedures do not apply to 1991 Postal Vehicles (LLV) with L38 engines. Effective August 13, 1990 with chassis VIN 1GBCS10A0M2912017, a new engine (L38) and rear axle ratio (GU6) were installed in production. As a result of the axle ratio change, a Paint - Removal of Minor Imperfections Paint: Customer Interest Paint - Removal of Minor Imperfections Number: 88-135-10 Section: 10 Date: Jan., 1988 Subject: REMOVAL OF "CHEMICAL SPOTTING" AND OTHER MINOR PAINT IMPERFECTIONS WITHOUT REPAINTING Model and Year: ALL MODELS WITH BASECOAT/CLEARCOAT PAINT TO: ALL CHEVROLET DEALERS This bulletin cancels and supersedes Chevrolet Dealer Service Bulletin 87-166 (Section 10) dated June 1987. This bulletin provides new materials which are available for use on basecoat/clearcoat systems. Some Chevrolet models equipped with basecoat/clearcoat paint applications may experience a condition of small etched spots on horizontal surfaces of the paint finish. This condition is referred to as chemical spotting and may be caused by industrial fallout (acid rain). FIGURE 1 Chemical spotting along with other minor paint imperfections on basecoat/clearcoat finishes, such as sand scratches, dirt in paint, sags and orange peel may be repaired without paint application. Examples of these imperfections are shown in Figure 1. To repair these conditions use the following procedures: ECM - Packard 32 Way Connector Identification Engine Control Module: All Technical Service Bulletins ECM - Packard 32 Way Connector Identification Number: 90-56-8 Section: 8 Date: September 1989 Corporate Bulletin No.: 916521R Subject: PACKARD 32 WAY CONNECTOR IDENTIFICATION Model and Year: 1980-90 A, B, F, G, J, L, W, Y CARS AND ALL TRUCKS WITH GMP4 ECM APPLICATIONS TO: ALL CHEVROLET DEALERS This bulletin serves to clarify the labeling of the Packard 32 way connectors used on the GMP4 under dash ECMS. Currently a common strain relief is used in both the C-D 32 pin and the E-F 32 pin connectors. To properly identify these connectors, the strain reliefs must be removed. Use the lettering on the connector as shown on figure. The colors used at this time for the 32 pin E-F connector are yellow, mint green or orange. This updates any previous information released concerning identification that indicates any of these colors as being C & D connectors, found in the 6E and 8D Sections of the affected Service Manuals. Page 8180 Avoiding Wiper Damage The following are major contributors to wiper damage. Some of these you can control and others are environmental concerns. - Extremely dusty areas (such as driving on dirt roads) may cause the wipers rubber edge to wear quickly and unevenly. - Sand and salt used on roads for increasing winter traction and ice control will cause the wiper blades to wear quicker. Areas with significant snowfall require more frequent blade replacements. - Heat and time may cause the rubber blades to take a "permanent set" resulting in the rubber not flexing and turning over uniformly. This condition may result in streaking and/or unwiped areas. - Rubber blades are easily cut or torn when using ice scrapers. Likewise pulling blades up off a frozen windshield can tear the rubber. Exercise caution when clearing ice and snow. - Using your wipers to "wear through" frost and ice, instead of allowing the defrosters to melt the ice, can dull, nick or tear the rubber blades. - Banging wipers on the glass to remove ice and snow may cause the blade to bend, dislodging the rubber and causing potential scratching of the windshield. - Ice can form in the pin joints of the wipers, which can cause streaking and unwiped areas. To remove ice from pin joints, compress the blade and rubber edge with your hand to loosen the frozen joints. Consider using Winter Blades that have a rubber cover to avoid this condition. Note GM does not recommend the use of any spray on/wipe on windshield treatments or washer fluid additives. The variation in friction that results on the glass from the use of these products causes wipers to chatter and have premature wear. Disclaimer Page 5179 e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors Do Not require all the steps shown. Skip the steps that Do Not apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. 1. Separate connector halves (see Figures 2 through 6). Figure 2 Figure 3 Page 1728 e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors Do Not require all the steps shown. Skip the steps that Do Not apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. 1. Separate connector halves (see Figures 2 through 6). Figure 2 Figure 3 Page 585 Measuring "D" Height PROCEDURE 1. Lift the front bumper of the vehicle up about 38 mm (1.5 inch). Let the vehicle settle. Do this three times. Measure "Z" dimension. 2. Push the front bumper down 38 mm (1.5 inch). Let the vehicle settle. Do this three times. Measure dimension. NOTE: True height is the average of the high and low measurements. 3. Lift the rear bumper of the vehicle up about 38 mm (1.5 inch). Let the vehicle settle on its own. Do this three times. Measure "D" dimension. 4. Push the rear bumper of the vehicle down about 38 mm (1.5 inch). Let the vehicle rise on its own. Do this three times. Measure the "D" dimension. Page 956 8. New O-ring seal P/N 14095598 (67) and new plastic washer (retainer) P/N 14037958 (66) into the front case half. 9. New sector with shaft P/N 15637215 (55) into the front case half. 10. Range shift fork (51), range shift hub (34) into the planetary carrier (36). - It is necessary to rotate the sector with shaft (55) to obtain clearance when installing the range fork (51). INSPECT: The teeth of the synchronizer stop ring (28) and drive sprocket (20) for damage. If the parts are to be replaced due to damage or in cases of customer complaint of clash when shifting from 2Hi to 4Hi, follow steps 11, 12, & 13, otherwise skip to step 14. 11. New drive sprocket P/N 15579803 (20) to the main shaft (19). 12. New synchronizer stop ring P/N 14071703 (28) to the drive sprocket (20). 13. Synchronizer assembly (81) to the main shaft. 14. Mainshaft (19)/drive sprocket (20), chain (58) and front output shaft (21) as a unit. Mode shift fork (54) and shift rail (48) will be installed with the mainshaft. 15. Fork shift spring (52). Mainshaft Extension and Oil Pump 16. Rear case (17) over mainshaft (19) and onto the front case half (45). - Clean case mating surfaces and apply RTV sealer or equivalent to the mating surfaces. - Transfer dowels from old case half to new case half if necessary. IMPORTANT: Be careful not to damage the oil pump (12) while installing the rear case half (Figure 7). 17. Case bolts (3) into case halves. - Apply Loctite 242 (R) or equivalent on pump housing bolt threads. - The two longer bolts and washers into the doweled case holes (33). - Tighten bolts to 31 N-m (23 lbs.ft.). 18. Speedometer tone wheel (11) to the main shaft (19). 19. Pump retainer housing (8) and pump housing bolts (7) to the rear case half (17). - Clean mating surfaces and apply RTV sealer or equivalent to the mating surfaces. - Apply Loctite (R) or equivalent on pump housing threads. - Pump housing bolts are shouldered (7). - Tighten bolts to 41 N-m (30 lbs.ft.). 20. Output bearing retainer (snap ring) (5), to the main shaft (19). 21. Rear extension housing (4) and extension housing bolts (3) to the pump retainer housing (8). - Clean mating surfaces and apply RTV sealer or equivalent to the mating surfaces. - Apply Loctite 242 (R) or equivalent on the extension housing bolts. - Tighten bolts to 31 N-m (23 lbs.ft.). External Components 22. Poppet plunger (70), poppet spring (71), new O-ring seal P/N 14071849 (69), and poppet screw (68) to the front case half (45). Page 4912 Backing Plate: Service and Repair Backing Plate REMOVE 1. Raise and support vehicle. 2. Remove wheel and tire assembly. 3. Remove brake drum. See Brake Drum / Service and Repair. See: Brake Drum/Service and Repair 4. Remove brake shoes. See Brake Shoes / Service and Repair. See: Brake Shoe/Service and Repair 5. Disconnect hydraulic line at wheel cylinder. CAUTION: Do not pull metal line away from cylinder, as this may kink or bend line. Line will separate from cylinder when cylinder is moved away from brake backing plate. 6. Remove wheel cylinder-to-brake plate attaching screws, then the wheel cylinder. 7. Remove axle shaft. 8. Remove the four backing plate attaching bolts then remove the backing plate. INSTALL 1. Install backing plate and retaining bolts. 2. Install wheel cylinder. See Wheel Cylinder / Service and Repair. See: Wheel Cylinder/Service and Repair 3. Install brake shoes. See Brake Shoes / Service and Repair. See: Brake Shoe/Service and Repair 4. Install brake drum. See Brake Drum / Service and Repair. See: Brake Drum/Service and Repair 5. Install wheel and tire assembly. 6. Lower vehicle. Locations TIMING MARK 4.3L (262) Page 5103 Symbol Identification Wire Color Code Identification WIRE COLOR ABBREVIATION BLACK BLK BLUE BLU DARK BLUE DK BLU Page 4266 11. Hold flange with suitable tool and remove pinion shaft nut and flange. 12. Lubricate pinion shaft oil seal and cover outer edge of seal body with non-hardening sealing compound, then press seal against cover shoulder with suitable tool. 13. Install new gasket and bearing cover. 14. Press flange against forward bearing and install washer and pinion shaft nut, torquing nut to 240 ft. lbs. Page 2269 Engine Control Module: Description and Operation Throttle Body Fuel Injection Engine Control Module Fig. 5 ECM Unit (Showing PROM & CALPAK Locations) The Electronic Control Module (ECM), located in the passenger compartment, is the control center of the fuel injection system. The ECM continually monitors and processes the input information and generates output commands to the various systems affecting vehicle performance. A removable calibration unit (PROM) enables the ECM to recognize and adjust for vehicle variations (vehicle weight, axle ratio, etc.). There are specific ECM/PROM combinations for each specific vehicle which are not interchangeable, Fig. 4. On V6 models, a CALPAK is also installed in the ECM. The CALPAK allows fuel delivery in the case that other parts of the ECM are damaged, Fig. 5. The ECM also performs the diagnostic function of the fuel injection system. When the ECM senses an operational problem, it will illuminate the "Check Engine" or "Service Engine Soon" light and store the appropriate code(s) to identify the problem area. Suspension - Shock Absorber/Strut Replacement Guidlines Suspension Strut / Shock Absorber: All Technical Service Bulletins Suspension - Shock Absorber/Strut Replacement Guidlines File In Section: Warranty Administration Bulletin No.: 72-05-12 Date: January, 1998 WARRANTY ADMINISTRATION Subject: Replacement of Shock Absorbers and Struts Labor Operations E3800, E3801, E3807, E5800, E5801, E5807, E3850, E3851, E3857, E5750, E5751, and E5757 Models: All Past, Present, and Future Passenger Cars & Trucks The purpose of this bulletin is to provide retail and wholesale service personnel with enhanced service policies for the above listed subject labor operations. Service Management should make certain that all dealership personnel responsible for replacement of suspension components are familiar with GM Service Manual procedures. Effective with repair orders dated on or after January 15, 1998 the following must also be followed: - Shock absorber/strut assemblies are fluid filled components and will normally exhibit seepage. Seepage is defined as oil film or dust accumulation on the exterior of the shock housing. Shock absorber/strut assemblies are not to be replaced under warranty or seepage. - Defective shock absorber/strut assemblies will have a visible oil path or drip coming from the component. A visible oil path or drip coming from the shock absorber/strut assembly should be replaced as a defective component. - Only defective shock absorber/strut assemblies should be replaced. DO NOT replace pairs unless both are defective, unless otherwise instructed in the Service Manual and/or Service Bulletin. - Service Management approval is required on the repair order for replacement of struts or shocks in pairs. This approval includes noting the reason for replacement. Wheels - Finish Damage During Off Car Balancing Wheels: All Technical Service Bulletins Wheels - Finish Damage During Off Car Balancing BULLETIN NUMBER: 93-3E-67 SECTION: 3E Wheels & Tires NUMBER: 3 CORPORATE REFERENCE NUMBER: 3935O2R DATE: June 1993 SUBJECT: INFORMATION ON COSMETIC DAMAGE TO ALUMINUM WHEELS DURING BALANCING MODELS: 1985-93 MODELS WITH ALUMINUM WHEELS Some aluminum wheels on GM models may incur cosmetic damage during balancing if proper care and procedures are not used. All aluminum wheels have a clearcoat paint on them that must be cared for like any other painted surface. Some off-car vehicle balancer retaining cups used to clamp the wheel to the balancer may put a circular mark into the clearcoat on the face of the wheel. Like any other clearcoat damage, this may be difficult to remove or repair, depending on severity. ALWAYS use balancer retainer cups that are protected with rubber, plastic, or other nonmetallic materials where contact is made with the wheel. Make Page 1075 - 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. Page 5319 Multiple Junction Connector: Electrical Diagrams Ashtray, Glove Box, Engine Compartment & Lighted Rearview Mirror Diagram Information and Instructions Check Gauges Lamp: Diagram Information and Instructions 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 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. Page 2422 Disclaimer Page 4588 T7251 Group A 3.2 hr. T7261 Group B 2.8 hr. NOTE: Labor Operation is coded to base vehicle coverage in the warranty system. Page 5118 Symbol Identification Page 5155 e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors Do Not require all the steps shown. Skip the steps that Do Not apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. 1. Separate connector halves (see Figures 2 through 6). Figure 2 Figure 3 Page 2761 Manifold Pressure/Vacuum Sensor: Locations Center Of Dash Panel (engine Compartment) Center Rear Of Engine Applicable to: V6-262/4.3L Engine Restraints - Seat Belt Warning Lamp On/Buckling Issues Seat Belt Buckle: Customer Interest Restraints - Seat Belt Warning Lamp On/Buckling Issues INFORMATION Bulletin No.: 09-09-40-001A Date: February 02, 2011 Subject: Seat Belt Buckle Latching Issues and/or Seat Belt Warning Lights Illuminated Models: 2011 and Prior GM Passenger Cars and Trucks (Including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7 X Supercede: This bulletin is being revised to add the 2011 model year. Please discard Corporate Bulletin Number 09-09-40-001 (Section 09 - Restraints). This bulletin is being published to advise dealers about seat belt buckles not operating and/or seat belt warning light illumination, as well as difficulty latching and unlatching the buckle or the buckle release button sticking. Analysis of warranty data has determined that this condition may be caused by sticky beverages being spilled onto or into the seat belt buckle assembly. Foreign debris from food, candy wrappers, paper and coins can also contribute to this condition. Important If foreign material (debris) or sticky liquids are the cause of the concern, show the customer the condition of the component (buckle assembly) and explain how it is affecting the function of the restraint system. Strongly recommend that the component be replaced. Point out the fact that this is not a manufacturing defect and is not covered by the new vehicle warranty. If the customer declines to have parts replaced, the service department management must make a notation on the service record that the lack of functionality of seating position with an inoperative buckle was fully explained to the customer. The service department management must advise the customer that having a non-functioning buckle in a seating position voids ability to use that seating position (no one should ride in the seat). Also make the customer aware that it may be against the law to ride in a vehicle without wearing a restraint system. Important Never insert anything other than the seat belt latch plate into the buckle assembly. Do not attempt to dig anything out of a buckle with a tool. Never try to wash out a buckle to remove a spilled liquid as this may damage the buckle. Use the following steps to determine the cause of the concern. 1. Inspect the buckle assembly with a light shining on the latch plate insertion area. Look for any debris or foreign objects in the buckle. 2. If any debris or foreign objects are observed, try to vacuum out the item. After the foreign material is removed, latch and unlatch the seat belt. If the system functions properly, do not replace the seat belt buckle assembly. 3. If the condition has not been corrected, inspect the buckle assembly for any sticky residue. If sticky residue is found, inform the customer that a substance was spilled on the seat belt buckle assembly causing the malfunction. The buckle assembly will need to be replaced at the customer's expense. 4. Refer to SI for seat belt component replacement. Important If foreign material (debris) or sticky liquids are the cause of the concern, show the customer the condition of the component (buckle assembly) and explain how it is affecting the function of the restraint system. Strongly recommend that the component be replaced at the customer's expense. Point out the fact that this is not a manufacturing defect and is not covered by the new vehicle warranty. If the customer declines to have parts replaced, the service department management must make a notation on the service record that the lack of functionality of seating position with an inoperative buckle was fully explained to the customer. The service department management must advise customer that having a non-functioning buckle in a seating position voids ability to use that seating position (no one should ride in the seat). Also make the customer aware that it may be against the law to ride in a vehicle without wearing a restraint system. 5. If further restraint diagnosis is required, refer to Seat Belt System Operational and Functional Checks in SI. Page 2218 Electronic Spark Timing: Testing and Inspection Chart C-5 - Electronic Spark Control System Check Page 5320 Courtesy & Dome (Less Cargo Lamp) Page 4873 FIGURE 3 - LUBRICATING CALIPER CAVITY When servicing the caliper, the caliper bolts should be cleaned and the space between the caliper bolt bushings should be filled with silicone grease such as Part Number 1052863 or equivalent. This will prevent the caliper dragging or binding on the mounting bolts. Refer to Figure 3. LINING MATERIAL ABRASIVENESS: The degree of abrasiveness of the brake lining material is determined by the manufacturer. A highly abrasive material will tend to create a rotor out-of-parallel condition if system runout and caliper drag are present. The properties and characteristics of brake linings are specified by Product Engineering. Some brake lining designs may be more aggressive when stopping, i.e. higher friction coefficient, while others are less aggressive but may be very durable and long lasting. The linings for any specific vehicle are selected on the basis of friction, wear, etc., to optimize front and rear braking for that specific vehicle. The brake lining used should be whatever is recommended by the manufacturer in the parts catalog or in the latest service bulletin. Brake pedal pulsation can also occur in the rear on drum brakes if there is radial runout in the drum and/or axle flange, or bearing. Thickness Variation Check: If a brake pedal pulsation condition is felt, a thickness variation check should be performed on the rotor. Thickness variation can be checked by measuring the thickness of the rotor at four or more points around the circumference of the rotor. Use a micrometer calibrated in one tenth increments per .001 inch. All measurements must be made at the same distance in, from the edge of the rotor. A rotor that varies by more than 0.013 mm (0.0005-inch) can cause pedal pulsation and/or front end vibration during brake applications. A rotor that does not meet these specifications should be refinished or replaced as necessary. Rotor Refinish Recommendations: Rotor refinish should only be performed because of non-parallelism (thickness variation), runout, or deep scoring grooves deeper than .015 inches. When replacing a rotor with a new rotor from stock it should NOT require refinishing unless ons of the conditions mentioned above is present. Also, routine replacement of disc brake linings does NOT require rotor refinishing. When rotor refinishing is required the following recommended procedures should be used to obtain the proper micro-inch surface finish which is required for new rotors (10 to 50 micro-inches with non-directional swirl pattern). When refinishing a rotor for a pulsation condition it is recommended that at least 0.010 inch be removed from the inboard and outboard side of the rotor surface to insure removal of the high and low spots on the face of the rotor. Rough Cut Finish Cut Spindle 150 rpm 150 rpm Depth of Cut Per Side .005 inch .002 inch Tool Cross Feed Per Rev. 0.006-.010 inch .002 inch max. Vibration Dampener Yes Yes Swirl Pattern-120 GRIT No yes The following is also important: ^ The brake lathe must be in good working order and have capability to produce the intended surface finish. ^ Excessive spindle speed or too deep a cut can result in a rough finish. ^ Cutting tools must be sharp. Page 5007 Brake Master Cylinder: Service and Repair Master Cylinder Removal Master Cylinder CAUTION: Brake fluid will damage electrical connections and painted surfaces. Use shop cloths, drip pans and fender covers to prevent brake fluid from contacting these areas. 1. On vehicles with manual brakes, disconnect the master cylinder pushrod from the brake pedal. 2. On all models, disconnect all wire connectors from master cylinder components. 3. Disconnect the brake lines from master cylinder. Cover the ends of the lines to prevent dirt from entering system. 4. Remove the master cylinder mounting nuts. 5. Remove the combination valve bracket. 6. Remove the master cylinder. For additional information see Notes, Warnings, and Hints. See: Fundamentals and Basics Page 1073 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. Page 2815 Vehicle Speed Sensor: Description and Operation VSS Buffer Amplifier On vehicles with conventional instrumentation, a vehicle speed sensor (VSS) buffer amplifier is used to supply the vehicle speed signal to the cruise control module. On this type system, a speedometer frame mounted optic head is used to pick up light reflected by a speedometer cable mounted blade. The reflected light is produced by a light emitting diode (L.E.D.). As the speedometer cable mounted blade enters the L.E.D. light beam, the light is reflected into the optic head. From there, the light enters a photocell in the optic head and produces a low power signal. This signal is sent to a buffer for amplification and conditioning, then to the controller. Digital Ratio Adapter Controller On vehicles with electronic instrumentation, a digital ratio adapter controller (DRAC) is used to supply the vehicle speed signal to the cruise control module. On this type system, the DRAC receives vehicle speed signals from a transmission or transfer case mounted vehicle speed sensor. The DRAC is calibrated according to axle ratio and tire combination, and provides 40 electronic pulses per revolution of the transmission or transfer case output shaft. Page 1513 Valve Clearance: Adjustments Fig. 14 Valve Adjustment 1. Remove rocker arm covers as described under COMPONENT REPLACEMENT AND REPAIR PROCEDURES/ROCKER ARM & PUSHRODS. 2. Crank engine until mark on torsional damper is aligned with ``0'' mark on timing tab and engine is in No. one cylinder firing position. Ensure engine is in No. 1 firing position by placing fingers on rocker arms of No. 1 cylinder as timing mark approaches ``0'' mark. If rocker arms are not moving engine is at the No. 1 firing position. If rocker arms are moving, engine is in the No. 4 firing position and should be rotated one revolution to the No. 1 position. 3. Adjust the following valves with the engine in the No. 1 firing position: exhaust 1, 5 and 6; intake 1, 2 and 3. Adjust valves by backing off nut until lash is felt at the pushrod, then tightening nut until all lash is removed. This can be determined by rotating pushrod while tightening nut. Fig. 14. When all lash is removed, tighten nut one full turn to center pushrod in lifter plunger. 4. Crank engine one full revolution until mark on torsional damper and ``0'' mark on timing tab are aligned. This is the No. 4 cylinder firing position. Adjust the following valves: exhaust 2, 3 and 4; intake 4, 5 and 6. 5. Install valve covers and related components. Page 7475 Page 6309 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 Page 2292 Wiring Diagram For Chart C-5 - Electronic Spark Control System Check CIRCUIT DESCRIPTION: Electronic spark control is accomplished with a module that sends a voltage signal to the ECM. As the knock sensor detects engine knock, the voltage from the ESC module to the ECM is shut "OFF" and this signals the ECM to retard timing, if engine RPM is over about 900. TEST DESCRIPTION: Numbers below refer to circled numbers on the diagnostic chart. 1. If A Code 43 is not set, but a knock signal is indicated while running at 1500 RPM, listen for an internal engine noise. Under a no load condition there should not be any detonation, and if knock is indicated, an internal engine problem may exist. 2. Usually a knock signal can be generated by tapping on the right exhaust manifold. This test can also be performed at idle. Test number 1 was run at 1500 RPM to determine if a constant knock signal was present, which would affect engine performance. 3. This tests whether the knock signal is due to the sensor, a basic engine problem, or the ESC module. 4. If the module ground circuit is faulty, the ESC module will not function correctly. The test light should light indicating the ground circuit is OK. 5. Contacting CKT 496, with a test light to 12 volts, should generate a knock signal to determine whether the knock sensor is faulty, or the ESC module can't recognize a knock signal. DIAGNOSTIC AIDS: "Scan" tools have two positions to diagnose the ESC system. The knock signal can be monitored to see if the knock sensor is detecting a knock condition and if the ESC module is functioning, knock signal should display "yes", whenever detonation is present. The knock retard position on the "Scan" displays the amount of spark retard the ECM is commanding. The ECM can retard the timing up to 20 degrees. This check should be used after other causes of spark knock have been checked such as engine timing, EGR systems, engine temperature or excessive engine noise. Page 5893 new driven gear is required. Use (gray) 22 tooth driven gear (GM Part Number 3987922) if vehicle is equipped with L38 and GU6. Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: # T1612 Labor Time: 1.0 hr. FAILURE CODE: 92 Page 6179 Removing/Installing The Shaft Seal And Seal 6. Shaft seal (14). ^ Insert J 9392-01 over the compressor shaft (39). ^ Engage the tabs on the seal (14) by twisting the J 9392-01 downward to the right. ^ Engage the tabs and lift the seal (14) out of the shaft (39) cavity. 7. Seal (O-ring) (15) with J 9553-01. Install or Connect Tools Required: J 5403 Snap Ring Pliers J 9392-01 Shaft Seal Remover and Installer J 9393-A Seal Seat Remover and Installer J 9366 Compressor Shaft Nut Socket J 9625-A Pressure Test Set with Schrader Valves J 22974-A Shaft Seal Protector J 23128-A Ceramic Seal Remover and Installer J 24340 Retainer Ring Pliers J 33011 Seal Remover 1. Seal (O-ring) (15) with J 33011. ^ Dip the seal (15) into clean 525 viscosity refrigerant oil. ^ Insert J 33011 down into the compressor neck until the tool "bottoms." ^ Lower the movable slide of J 33011 into the lower groove. ^ Rotate J 33011 to seat the seal (15). ^ Remove J 33011. 2. Seal seat (14). ^ Coat the seal (14) with clean 525 viscosity refrigerant oil. ^ Mount the seal (14) to J 9392-01 by engaging the tabs of the seal with the tangs of J 9392-01. ^ Place J 22974 over the end of the compressor shaft (39). ^ Slide the seal (14) and J 22974 down onto the compressor shaft (38). ^ Twist J 9392-01 to the right (clockwise) while pushing the seal assembly down the shaft (38) until the seal assembly (14) engages the flats on the shaft and seat in place. ^ Disengage J 9392-01 by pressing downward and twisting to the left (counterclockwise). 3. Ceramic seat seat (13). ^ Seal (13) to J 23128. ^ Dip the seal (13) into clean 525 viscosity refrigerant oil. ^ Install J 23128 and the seal (13) over the compressor shaft (39). ^ Push the seal (13) info place with a rotary motion. Important Page 6143 ^ J 8433-1 with through bolts, washers and forcing screw over J 33024. ^ Be sure J 8433-1 and the clutch coil assembly (27) stay "in line" during installation. Staking The Clutch Coil To The Front Head ^ When the clutch coil assembly (27) is seated on the front head (33) use a 3 mm (1/8-inch) diameter drift punch to stake the head (33) at 3 places, 120 degrees apart to assure the clutch coil assembly (27) remains in position. Clutch Coil Staking Locations - Stake size should be one half the area of the punch tip and 0.28-0.35 mm (0.010-0.015-inch) deep. 2. Pulley (24). 3. Clutch plate and hub assembly (22). Locations Power Steering Pressure Switch: Locations LH Fender Apron LH Front Corner Of Engine Compartment Page 5277 Note The rivet stud and surrounding panel area MUST BE properly refinished PRIOR to the installation of the electrical ground wire terminal and conductive nut to maintain a secure, stable and corrosion-free electrical ground. 11. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 12. Allow the refinished repair area to cure sufficiently before removing the protective material applied to the rivet stud threads. 13. Remove the painters tape or equivalent from the rivet stud threads. 14. Using GM approved residue-free solvent or equivalent, thoroughly clean the rivet stud threads to remove any adhesive and allow to dry. 15. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive rivet stud. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 16. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 17. Install the electrical ground wire terminal to the M6 conductive rivet stud. 18. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 19. Install the M6 conductive nut to the rivet stud and: Tighten Tighten to 8 Nm (71 lb in) 20. Verify proper system operation. Parts Information Warranty Information (excluding Saab Models) For vehicles repaired under warranty, use: Warranty Information (Saab Models) Page 3114 Throttle Position Sensor: Description and Operation Typical Throttle Position Sensor (TPS) Wiring The Throttle Position Sensor (TPS), is mounted on the side of the throttle body opposite the throttle lever assembly. Its function is to sense the current throttle valve position and relay that information to the ECM. Throttle position information allows the ECM to generate the required injector control signals (base pulse). If the TPS senses a wide open throttle, a voltage signal indicating this condition is sent to the ECM. The ECM then increases the injector pulse width, permitting increased fuel flow. As the throttle valve rotates in response to movement of the accelerator pedal, the throttle shaft transfers this rotation to the TPS. A potentiometer (variable resistor) within the TPS assembly changes its resistance (and voltage drop) in proportion to throttle movement. By applying a reference voltage (5.0 volts) to the TPS input, a varying voltage (reflecting throttle position) is available at the TPS output. For example, approximately 2.5 volts results from a 50% throttle valve opening (depending on TPS calibration). The voltage output from the TPS assembly is routed to the ECM for use in determining throttle position. A/T - New Governor Driven Gear for No Upshift or Erratic Governor Pressure Switch: Customer Interest A/T - New Governor Driven Gear for No Upshift or Erratic Number: 88-161-7A Section: 7A Date: MARCH, 1988 Subject: ERRATIC OR NO UPSHIFT - NEW GOVERNOR DRIVEN GEAR Model and Year: 1987-88 VEHICLES WITH THM 400/475 OR THM 700-R4 TRANSMISSIONS FIGURE 2 - "APPLECORED" GOVERNOR DRIVEN GEAR TO: ALL CHEVROLET DEALERS A THM 400/475 or THM 700-R4 transmission with an erratic or no upshift condition may be created by "applecoring" of the governor driven gear. "Applecoring" is pictured in the illustration below. A new governor driven gear with a higher fiberglass content entered production on all THM 400/475 transmissions December 11, 1987 (Julian date 345). THM 700-R4 transmissions were produced with a new gear beginning July 6, 1987 (Julian date 187). "Applecoring" of the governor driven gear may be the result of nicks or burrs present on the output shaft drive gear. Inspection of the output shaft should be performed and if nicks or burrs are present the output shaft should be replaced. The new service part numbers are listed below for each model transmission. Part No. Description 8663995 THM 700-R4 - Governor Driven Gear and Pin Package 8629977 THM 400 - Governor Driven Gear and Pin Package Page 311 If the functional brake switch adjustment check does not repair the condition, refer to Section 5 of the appropriate Service Information Manual for aid in diagnosing other causes. For warranty purposes use: Labor Operation Number: N2440 Labor Time: .3 hour TRUCK ONLY: Service Procedure: 1. Depress the brake pedal and press the switch in until it is firmly seated in the clip. * Audible "clicks" can be heard as the threaded portion of the switch is pushed through the clip. 2. Pull the brake pedal against the pedal stop until the audible "click" can no longer be heard. For stop lamp switch adjustments on vehicles repaired under warranty use: Labor Operation Number: T7945 Labor Time: .2 Hr. Page 840 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. Electrical - VSS Connector Mislabeled Vehicle Speed Sensor: Technical Service Bulletins Electrical - VSS Connector Mislabeled GMC NUMBER: 88-T-145 GROUP: 6D-Engine Electrical DATE: August, 1988 CORPORATE NUMBER: 818107 SUBJECT: CONNECTOR MISLABELED MODELS: 1985-88 G, S, R, AND M VEHICLES FIGURE NO. 1VEHICLE SPEED SENSOR BUFFER CORRECT CONNECTOR LABEL Some 1985-88 vehicles may have an electrical connector at the vehicle speed sensor (VSS), which is improperly labeled. The connector will work properly but could cause confusion if electrical troubleshooting is necessary. Figure No. 1 shows a properly labeled connector. The improperly labeled connectors have the "A" and "C" reversed. All Service Manual terminal call-outs use the labeling as shown in Figure No. 1. Endgate Window - Will Not Release/Opens Without Key Trunk / Liftgate Latch: Customer Interest Endgate Window - Will Not Release/Opens Without Key Number: 91-504-10 Section: 10 Date: MAY 1992 Corporate Bulletin No.: 161506 ASE No.: B1 Subject: ENDGATE WINDOW LATCH NOT RELEASING OR ENDGATE OPENS WITHOUT KEY Model and Year: 1983-91 S/T TRUCKS Some owners of 1983-1991 S/T utility vehicles may experience difficulty releasing the rear endgate window latch and/or the endgate may be opened without a key. These conditions may be caused by an endgate window latch which has dirt contamination, a deformed spring leg, a missing or broken spring, a bent release lever, a bent frame or a latch which is misadjusted. To correct this condition, it is necessary to properly adjust the endgate window latch assembly and/or replace it. ADJUSTMENT PROCEDURE: 1. Check for proper window latch assembly adjustment by performing the following steps: NOTICE: To open the end gate, insert the key into the lock assembly and rotate the handle COUNTERCLOCKWISE. Turning the key/handle clockwise and exerting excessive force may result in a broken lock assembly. * Hold the window/glass handle and try to move the glass in and out. If the latch is misaligned to the striker, a rattle condition will exist. * Inspect the endgate glass for a snug fit against the top and sides of the body opening. Cruise Control - Works Intermittently Cruise Control Switch: All Technical Service Bulletins Cruise Control - Works Intermittently Number: 92-195-9B Section: 9B Date: MAY 1992 Corporate Bulletin No.: 268102R ASE No.: A8 Subject: CRUISE CONTROL WORKS INTERMITTENTLY Model and Year: 1985-92 M VANS 1990-92 L VANS 1986-92 S/T TRUCKS Some owners of 1985-1992 WL vehicles or 1986-1992 S/T vehicles with cruise control (RPO K34) may comment that their cruise control operates intermittently. This condition may be caused by the wires becoming pinched as they exit the multi-functional lever. These wires may ground out on the lever rod and short the cruise function. To correct this condition in production, the wiring harness that exits the lever has been rerouted and the opening in the multi-functional lever has been redesigned to allow the wires more clearance. The diagnostic procedures in the applicable Service Manual should be followed before replacing the multi-functional lever. If the multi-functional lever requires replacement, the following procedure should be performed: SERVICE PROCEDURE: 1. Disconnect the wire harness connector. 2. Remove the harness protector cover. 3. Attach a long piece of mechanic's wire to the end of the harness connector. 4. Remove the multi-functional lever from the turn signal switch. 5. Gently pull the harness up and out so the mechanic's wire can be used to install the new unit. 6. Attach the upper end of the mechanic's wire to the new harness connector. Gently pull the mechanic's wire at the lower end of the column, feeding the harness into the proper location in the column. 7. Install a redesigned multi-functional lever (P/N 25111290) into the turn signal switch. 8. Disconnect the mechanic's wire from the harness connector. 9. Install the harness protector cover. 10. Reconnect the wire harness connector. SERVICE PARTS INFORMATION Part Number Description 25111290 Multi-functional Lever Use applicable labor time guide for labor hours. Important: The new Part Number (P/N 25111290) should be used when correcting this condition in the above listed vehicles. Electrical - MIL ON/DTC's Set By Various Control Modules Wiring Harness: 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 Page 5513 RH Side Of Engine. Center Of Firewall Applicable to: V6-262/4.3L Engine Page 7145 Paint: By Symptom Technical Service Bulletin # 231054R Date: 930701 Paint - Identification/Repair of Colorcoat Delamination BULLETIN NUMBER: 92-1O-134A SECTION: 10 Body NUMBER: 4 CORPORATE REFERENCE NUMBER: 231054R DATE: July 1993 SUBJECT: SERVICE PROCEDURES FOR IDENTIFICATION AND REPAIR OF PAINT COLORCOAT DELAMINATION FROM ELPO PRIMER MODELS: 1988-92 TRUCKS THIS BULLETIN CANCELS AND REPLACES TRUCK SERVICE BULLETIN 92-10-134 (CORP # 231054R), DATED OCTOBER 1992. IT IS BEING REVISED TO REMOVE THE COVER LETTER PORTION AND SUBJECT STATEMENT NOW INCLUDES NOTE FOR TRUCKS AND REVISES THE MONOCOAT MATERIAL ALLOWANCES ON "G", "S/T" AND SOME "R/V" MODELS. THE ALLOWANCE FOR "ADD FOR TWO-TONE" ON G AND S/T TRUCKS HAS BEEN CHANGED. ALL COPIES OF 92-10-134 SHOULD BE DISCARDED. The revisions are the result of changes to the MONOCOAT (ENAMEL) material allowance charts published in June, 1993. Six (6) of the "G" model revisions use Basecoat/Clearcoat material allowance codes. THESE ARE TO BE USED AS DOLLAR REFERENCES ONLY, AND ARE MARKED WITH A # INDICATOR. Continue to repair these vehicles with monocoat materials. DO NOT repair these vehicles with Basecoat/Clearcoat products. Use the latest (June, 1993) material allowance charts when submitting claims. SUBJECT: Service procedures for the repair of paint colorcoat delamination from elpo primer (repaint entire body above the body side moldings, except trucks as noted). APPLICATION: 1988-1992 LIGHT DUTY TRUCKS (C/K, R/V, S/T, M/L AND G) This bulletin cancels and supersedes service procedures and time allowances on all previous bulletins regarding paint DELAMINATION. Due to the use of new procedures, add times for optional equipment, and designating specific hardware items for removal, the published labor times will not be the same as previously published. CONDITION This bulletin is being issued to assure that the correct procedure is followed to repair a condition known as DELAMINATION. Some of the above listed passenger cars, light duty trucks, and vans may have DELAMINATION (peeling) of the paint color-coat from the ELPO primer depending upon variable factors including prolonged exposure to sunlight and humidity. Blues, Grays, Silvers and Black Metallics are the colors that have the highest potential for this condition. On rare occasions, other colors may be involved. Important DELAMINATION is different than other paint conditions and/or damage. A proper problem identification is necessary, and the service procedure that follows is specific to the proper repair of DELAMINATION and must be followed. The information in this bulletin covers Paint DELAMINATION of the colorcoat from the ELPO primer ONLY. It does not address any other paint conditions. Procedures for the repair of other paint conditions (stone chips, scratches, environmental damage, clearcoat peeling, runs, dirt, fading, etc.) will not effectively repair DELAMINATION and customer dissatisfaction will result. CAUSE This condition may occur on vehicles produced in plants where the paint process does not call for application of a primer surfacer. Under certain conditions, ultraviolet light can penetrate the colorcoat, sometimes causing a reaction and separation of portions of the colorcoat from the ELPO Service and Repair Window Handle: Service and Repair Front Door Window Regulator Handle TOOL REQUIRED: J-9886-O1, Door Handle Remover. REMOVE OR DISCONNECT 1. Window regulator handle. ^ Insert J-9886-O1 between the handle and the bearing plate. ^ Align the tool parallel with the door handle, and push to disengage the clip. ^ Pull the handle from the door. 2. Bearing plate. INSTALL OR CONNECT 1. Bearing plate. 2. Window regulator handle. ^ Place the window in the raised position. ^ Put the clip onto the handle, ^ Insert the handle onto the door so the handle is pointing towards the front of the door. ^ Push on the handle until the clip engages the window regulator shaft. Page 5309 Symbol Identification Page 4917 (unsafe) and the new shoes/linings will be subject to overheating and brake fade. How To Measure NOTE: For additional information on how to use a drum micrometer see Fundamentals and Basics. See: Fundamentals and Basics - A drum micrometer is used to measure the drum diameter. - The micrometer scale should be initially set to the original (new) thickness of the drum. - The base of the micrometer should be placed in the deepest groove in the drum and held steady while the measuring point is swiveled to find the maximum diameter. - The base and measuring point should be kept at the same depth in the drum. Drum Micrometer - The measurement should be repeated at 3 or more places around the circumference of the drum to determine if the drum is out of round. If the measurements differ by more than 0.004 inches the drum should be resurfaced. Page 1793 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) Page 7253 Figure No. 7 1) Replace the Spare tire carrier arm with part number 15659234. This arm has a new adjustable bumper that will take up the additional play that the striker assembly could not remove (See Figure 7). 2) If the striker, shown in Figure 1, was not replaced during service procedure 1 then do so now. This is done because the adjustment outlined below will push the spare tire carrier arm away from the smaller rubber bumper on the old style striker plate. The resultant gap will continue to allow a rattle condition. 3) To adjust the rubber bumper begin by removing the spare tire, and closing the spare tire carrier. Loosen adjustable nut shown in Figure 7. Turn the bumper screw until the bumper contacts the the surface of the tailgate. Open the carrier arm and turn the bumper screw 1 and 1/2 turns to the left (counter clockwise). This will move the rubber bumper closer to the striker plate. Tighten adjustable nut and close carrier making sure that latching mechanisms are securely latched. Check to be sure that carrier arm sleeve rests against the striker plate's rubber bumper. If this is not the case then move the adjustable rubber bumper until contact results. IMPORTANT: The rubber bumper will cause the tailgate to close hard for a couple of weeks. Eventually the rubber will take a permanent set and the carrier will close with reasonable effort. NOTE: If the subject vehicle was manufactured after the following break points then Service Procedure 5 will not be required as the material called out was incorporated in production. Shreveport: 1GNCS18ZXM8104025 Page 445 Throttle Position Sensor: Adjustments The TPS is not adjustable. The ECM utilizes the IAC position reading at idle for its zero reading, therefore no adjustment is necessary. Page 2072 For vehicles repaired under warranty, use the table. Disclaimer Page 8003 PARTS INFORMATION: Pads are currently available from GMSPO. WARRANTY INFORMATION: For vehicles repaired under warranty use: Labor Op. C-0152-RH C-0153-LH Use applicable labor time guide for labor hours. Engine - Shake At Low RPM & At Idle, Engine Mount Engine Mount: Customer Interest Engine - Shake At Low RPM & At Idle, Engine Mount Group Ref.: Engine Mechanical Bulletin No.: 166102 Date: November, 1993 SUBJECT: ENGINE SHAKE AT LOW SPEEDS AND AT IDLE (MOUNT NEUTRALIZATION PROCEDURE) MODELS: 1988-92 S/T TRUCKS WITH 4.3L ENGINE (RPO LB4) This bulletin is being revised to change the service parts availability information. Previous divisional publication numbers were: Chevrolet 92-353-6 GMC Truck 92-6A-158 CONDITION Owners of some 1988-92 S/T Trucks equipped with a 4.3L engine (VIN Code Z) may comment about excessive engine shake slightly above idle (800-1800 RPM). CAUSE Due to the cylinder arrangement, design, and firing order, the 4.3L engine has inherent natural vibrations. Before attempting to repair any of these disturbances, it is necessary to compare it to another known good vehicle, same model, year, etc. Some engine shake is normal. However, if the engine shake is more than normal, it may be due to powertrain mount and/or exhaust system positioning and/or movement. The following procedure addresses the condition. CORRECTION This diagnosis is designed to identify engine mount ground out. Pay special attention to engine mounts, transmission mounts, and exhaust system hangers. The vibration or ground out location must be isolated. 1. Apply parking brake. 2. Block the front wheels. 3. Place the vehicle in DRIVE (1st gear for standard transmission). 4. Bring engine rpm up to 1500-2000, listen for ground out (knocks or booming noise) and/or increased vibrations. 5. If no ground out is found, repeat step 3 with transmission in REVERSE. CAUTION: DO NOT ACCELERATE AGAINST THE BRAKES FOR LONGER THAN 15 SECONDS. CARE SHOULD BE TAKEN NOT TO OVERHEAT THE ENGINE OR TRANSMISSION. ALSO, CARE SHOULD BE TAKEN DURING DIAGNOSIS DUE TO THE FACT THAT SOME DISTURBANCES MAY BE CREATED DURING BRAKE TORQUE THAT NORMALLY DO NOT EXIST. Note: Pay special attention to engine mounts making hard contact, check for proper clearance at tangs. If ground out or crushed mounts are confirmed, replace worn or torn components as required, refer to the neutralization procedure below. To neutralize the engine and align the exhaust system properly: 1. Allow vehicle to warm up fully. Raise vehicle and support with suitable safety stands. Page 7927 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 4. Make repair. Page 1091 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 Page 5176 Symbol Identification Wire Color Code Identification WIRE COLOR ABBREVIATION BLACK BLK BLUE BLU DARK BLUE DK BLU Speedometer Gear - Malfunctions Speedometer Gear, A/T: Customer Interest Speedometer Gear - Malfunctions Number: 91-98-8C Section: 8C Dates: October 1990 Corporate Bulletin No.: 067104 Subject: MALFUNCTION OF THE SPEEDOMETER DRIVE GEAR, DRIVEN GEAR AND/OR SPEEDOMETER Model and Year: 1987-91 S1 (LLV POST OFFICE VEHICLES) TO: ALL CHEVROLET DEALERS Some of the above postal vehicle chassis may experience a malfunction of the speedometer drive gear, driven gear, and/or speedometer adapter. Effective January 24, 1990 with chassis' VIN 1GBCS10E2M2901183, a new driven gear was installed in production. The new driven gear can be recognized visually as the following table illustrates. GM PART # COLOR # OF TEETH NEW 3987920 BLUE 20 OLD 3860347 YELLOW 24 IMPORTANT: The new driven gear has eliminated the need for the speedometer adapter. Recommended service procedures are outlined below: Service Procedure # 1 1. Remove and discard speedometer adapter (GM Part # 368025). 2. Remove original speedometer driven gear and inspect for damaged teeth. If damaged, follow service procedure # 2. If it is not damaged, replace the (yellow) 24 tooth driven gear with the (blue) 20 tooth driven gear (GM Part # 3987920). For vehicles repaired under warranty use: Labor Operation: # T1611 Labor Time: .3 hr. FAILURE CODE: 92 NOTE: The above procedures do not apply to 1991 Postal Vehicles (LLV) with L38 engines. Effective August 13, 1990 with chassis VIN 1GBCS10A0M2912017, a new engine (L38) and rear axle ratio (GU6) were installed in production. As a result of the axle ratio change, a new driven gear is required. Use (gray) 22 tooth driven gear (GM Part Number 3987922) if vehicle is equipped with L38 and GU6. Service Procedure # 2 1. Remove and discard speedometer adapter. 2. Remove driveshaft and rear transmission extension housing. 3. Replace both speedometer drive and driven gear with: Drive Gear (blue) GM Part 96040176 Driven Gear (blue) GM Part 3987920 NOTE: The above procedures do not apply to 1991 Postal Vehicles (LLV) with L38 engines. Effective August 13, 1990 with chassis VIN 1GBCS10A0M2912017, a new engine (L38) and rear axle ratio (GU6) were installed in production. As a result of the axle ratio change, a Page 1089 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: 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 Page 4287 Figure 6 - Disconnecting Lower Shock Mount 10. Remove the lower shock mounting nut and bolt (Figure 6). 11. Collapse the shock absorber. 12. Move the shock absorber up, away, and secure. 13. Depending on the type of hoist, it may be required to position floor stand between the spring seats and the lower control arm ball joint for miximum leverage. The weight of the vehicle is used to relieve the spring tension on the upper control arm. Caution: The floor jack or stand must remain under the control arm spring seat while servicing the halfshaft to maintain spring and control arm position. Failure to do so could result in personal injury. 14. Disconnect the cotter pin. 15. Remove the stud nut from the upper ball joint. Figure 7 - Ball Joint from Knuckle Separation 16. Loosen the stud using J34026 and move away from the knuckle (Figure 7). Page 395 Page 1934 Distributor: Description and Operation Typical Distributor Components The distributor has a separate coil which connects to the rotor through a high tension wire. The distributor uses a magnetic pick-up assembly located inside the distributor consists of a permanent magnet, a pole piece with internal teeth, and a pick-up coil. When the teeth of the timer core, rotating inside the pole piece, line up with the teeth of the pole piece, an induced voltage in the pick-up coil signals the electronic module to trigger the coil primary circuit. The primary current decreases and a high voltage of 35,000 volts is induced in the ignition coil secondary winding which is directed through the rotor and secondary leads to fire the spark plugs. The capacitor in the distributor is for radio noise suppression. This distributor also features a longer spark duration, made possible by the higher amount of energy that is stored in the coil. This is desirable for firing leaner mixtures. Page 245 Note the difference between the wire exit openings of the new multi-functional lever and the old lever (Figure 1). Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Op. Description E7060 Multi-functional lever, replace Use applicable labor time guide for labor hours. Page 7212 - 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 Page 4053 HYDRA-MATIC 4L60 IMPORTANT: Overtorquing or uneven torquing of the bolts during unit reassembly can cause valves to bind. This condition may become more apparent as the unit warms to operating temperature. The correct bolt torque specifications for the HYDRA-MATIC 4L60 control valve assembly are 8-14 N-m (6-10 lb.ft.). Torquing bolts to the minimum specification, 8 N-m (6 lb.ft.) is recommended. The bolts should be tightened in a spiral pattern starting at the center and working toward the outside of the control valve assembly as shown in Figure 2. Page 5104 LIGHT BLUE LT BLU BROWN BRN GRAY GRY GREEN GRN DARK GREEN DK GRN LIGHT GREEN LT GRN ORANGE ORN PINK PNK PURPLE PPL RED RED TAN TAN WHITE WHT YELLOW YEL Description and Operation Transmission Position Switch/Sensor: Description and Operation The park/neutral switch indicates to the ECM when the transmission is in park or neutral. This information is used by the ECM for ignition timing, IAC operation and transmission Torque Converter Clutch (TCC) operation. Do not drive vehicle with park/neutral switch disconnected, as idle quality may be affected. Page 4626 - Tighten poppet screw to 31 N-m (23 lbs.ft.). - New poppet plunger P/N 15633556 (70) group A vehicles only. - New poppet spring P/N 15633557 (71) group A vehicles only. - New poppet screw P/N 15633558 (68) group A vehicles only. 23. Vacuum switch (46) and new O-ring P/N 14071849 (47) to the front case housing. - Tighten switch to 24 N-m (17 lbs.ft.). 24. Front output flange (74), rubber sealing washer (75), washer (76) and flange nut (77). - Tighten nut (26) to 149 N-m (110 lbs.ft). 25. New vent pipe P/N 15581915 in new front case half (group A vehicles only). - Lightly coat end of vent pipe with Loctite 609 (R) or equivalent. 26. Transfer case into vehicle. - Refer to section 7D of the appropriate S/T Service Manual for complete transfer case replacement procedure. Service Parts & Warranty Information SERVICE PARTS INFORMATION: The "Easy Shift" package consists of the following parts. Parts must be ordered individually. Required Parts Part Quantity Figure 1 Group A Group B Number Description Required Reference Trucks Trucks 15635347 Front case half 1 45 X 15637215 Sector W/shaft 1 55 X X 15637217 Mode shift fork 1 54 X X 15633556 Poppet plunger 1 70 X 15633557 Poppet spring 1 71 X 15633558 Plug 1 68 X 14071849 O-ring 2 69 & 47 X X 15581915 Vent Pipe 1 N/S X 14095609 Input seal 1 42 X 14037958 Retainer 1 66 X X 14095598 Range sector seal 1 67 X X 15579788 Output front seal 1 72 X 15642511 Adapter gasket 1 N/S X X 15579803 Drive Sprocket 1 20 * * 14071703 Synchronizer 1 28 * * Blocking Ring * These parts required only if damaged or in cases of customer complaint of clash when shifting from 2Hi to 4Hi. Parts are currently available from GMSPO. WARRANTY INFORMATION: For vehicles repaired under warranty use: Labor Labor Operation Truck Time Page 2332 - Diagnostic Chart Code 64. Page 1018 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 Page 6981 A/T - Manual Update For ATF Level & Condition Fluid - A/T: All Technical Service Bulletins A/T - Manual Update For ATF Level & Condition GMC NUMBER: 89-7A-104 GROUP: 7A Automatic Transmission DATE: September, 1989 CORPORATE NUMBER: 977126R SUBJECT: AUTOMATIC TRANSMISSION FLUID COLOR/LEVEL CHECK INFORMATION MODELS: ALL 1987-89 S/T, C/K, R/V TRUCKS AND M, G, P VANS EQUIPPED WITH HYDRAMATIC AUTOMATIC TRANSMISSIONS BULLETIN COVERS: Service Manual update for Transmission fluid level and condition information. This information is updated for 1989 service manuals printed prior to June 1989. TRANSMISSION FLUID LEVEL INFORMATION: Checking fluid level and condition (color and odor) at regular intervals will provide early diagnosis information about the transmission. This information may then be used to correct a condition that, if not detected early, could result in major transmission repairs. When adding or changing fluid, use only DEXRON II. Refer to Maintenance and Lubrication (Service Manual Section OB) for maintenance information and servicing intervals. NOTICE: Do not overfill. Overfilling will cause foaming, loss of fluid, shift complaints and possible damage to the transmission. ^ Fluid level should only be checked when it reaches a normal operating temperature of 82-93C (180-200F). This temperature is reached after approximately 24 km (15 miles) of driving. TRANSMISSION FLUID COLOR: ^ Fluid color will be red when new. IMPORTANT: When new, automatic transmission fluid is red in color. The red dye is added so the assembly plant can identify it as transmission fluid and distinguish it from engine oil or anti-freeze. The red dye is not an indicator of fluid quality and is not permanent. As the vehicle is driven, the transmission fluid will begin to look darker in color. The color may eventually appear light brown. A dark brown color along with a burnt odor may indicate excessive fluid deterioration and signal a need for fluid change. Page 4671 SERVICE PARTS INFORMATION Part Number Description 15664811 Vacuum Actuator Switch Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: K4120 Use applicable labor time guide for labor hours. Specifications Engine Oil Pressure: Specifications Normal Oil Pressure 30-35 psi Specifications Fuel Pressure: Specifications FUEL PRESSURE: Ignition ON Engine OFF ...................................................................................................................... ................................................. 62-90 kPa (9-13 psi) Page 171 ECM Connector Terminal Identification & Voltage Specifications. Page 3277 Shift Solenoid: 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. Wheels (Steel) - Damage Due to Improper Mounting Wheels: All Technical Service Bulletins Wheels (Steel) - Damage Due to Improper Mounting Number: 92-232-3E Section: 3E Date: JUNE 1992 Corporate Bulletin No.: 233002 ASE No.: A4 Subject: AVOIDING DAMAGE TO STEEL WHEELS FROM IMPROPER WHEEL/TIRE CHANGING TECHNIQUES Model and Year: 1983-92 ALL PASSENGER CARS AND TRUCKS WITH STEEL WHEELS It is important to use proper procedures to prevent damage to either the tire mounting surface or the wheel mounting holes. Damage can result from the improper wheel attachment or tire mounting techniques on vehicles with steel wheels. 1. IMPROPER TIRE CHANGING TECHNIQUES: It takes about 70 seconds for the air to completely exhaust from a large tire. If the technician doesn't wait this amount of time after removing the valve core, the bead breaker on the tire change could put enough force on the tire to bend the wheel at the mounting surface. Such damage can result in vibration, shimmy, and under severe usage (i.e. police vehicle) lead to cracking. 2. OVER TORQUING OF THE WHEEL NUTS: The service specification for wheel nuts is listed in the Service Manuals. Some wheels have been observed with wheel nuts that were over torqued by as much as 50 percent. This may damage the wheel mounting holes and may also lead to cracks. I. PROPER TIRE CHANGING TECHNIQUES: Completely deflate the tire before attempting to break the tire bead loose. MOUNTING SURFACE CHECKING PROCEDURE Page 7197 SERVICE PROCEDURE 1. Check cross rails for proper installation. 2. Remove and install cross rail, wide side forward (if required). 3. Mark old rubber cap to distinguish from new part (the new part is the same as the old part, except for an increased width which is not detectable. 4. Remove old rubber cap. 5. Lube the cross rail cap with mild soap and water or equivalent. 6. Slide in new rubber cap, wide side forward. (Cross rail does not need to be removed as the new part can be worked into place by hand.) 7. Test vehicle for howl condition. In most cases only the front cross rail cap will be needed to eliminate the howl condition. However, if appropriate, this procedure may be applied to the rear cross rail cap as well. NOTE: Install cross rail and cross rail cap with wide side forward as shown in Fig. 1. Do not cut cross rail cap to fit, work into cross rail until all slack has been removed. SERVICE PARTS INFORMATION Part Number Description Quantity 15659287 rubber cross rail cap 1 per rail (as needed) Parts are currently available through GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: R2380 Labor Time: 0.4 hr. Page 5068 Vacuum Brake Booster: Testing and Inspection Hard Pedal 1. Internal vacuum leak. 2. Faulty control valve. 3. Broken or damaged hydraulic brake lines. 4. Collapsed or damaged vacuum hose. 5. Plugged or loose vacuum fitting. 6. Bad stud welds on front or rear housing on power head. 7. Faulty booster diaphragm. 8. Restricted air filter element. 9. Worn or distorted reaction plate or levers. 10. Cracked or broken power pistons or retainers. Page 4902 Brake Rotor/Disc: Fundamentals and Basics Tightening Notes WHEN TIGHTENING LUG NUTS, REMEMBER... Always tighten the lug nuts to the correct torque specification. Lightly lubricate the studs with an anti-seize compound to ensure proper torque and prevent damage to the threads. Tighten in an alternating pattern around the wheel until the wheel is centered on the studs. Do your final tightening with a torque wrench. When servicing disc brakes it is very important to properly torque the wheel assembly. Lug nuts which are installed with an air impact tool are often over-torqued. This may distort the rotor and result in excessive lateral runout (rotor wobble) and a pedal pulsation upon braking. Recheck the wheel bearings once the tires are installed. With the vehicle raised and properly supported, grasp the tire at the top and bottom and attempt to rock them back and forth. There should be no detectable lateral (wobble) movement. Specifications Valve Guide: Specifications Inside Diameter Inside Diameter Inside Diameter Standard 0.3437 in Page 7057 Page 409 Oxygen Sensor: Specifications Oxygen Sensor 30 ft.lb A/C - Levers Loose or Binding Control Assembly: Customer Interest A/C - Levers Loose or Binding Number: 92-277-1A Section: 1A Date: AUGUST 1992 Corporate Bulletin No.: 261106 ASE No.: A7 Subject: TEMPERATURE CONTROL OR HVAC LEVERS LOOSE OR BINDING Model and Year: 1986-92 S/T TRUCKS Engine - Generator Belt Tension Drive Belt: All Technical Service Bulletins Engine - Generator Belt Tension GMC NUMBER: 88-T-36 GROUP: 6D - Engine Electrical DATE: September, 1987 CORPORATE NUMBER: 866403 SUBJECT: GENERATOR BELT TENSIONING - CS-130 GENERATORS MODELS: 1986 - 1988 LIGHT DUTY MODELS EQUIPPED WITH CS-130 GENERATORS Some 1986-1988 Light Duty models are equipped with CS-130 Delcotron generators and without automatic belt tensioning equipment. On these applications, the generator belt tension is adjusted by forcing the generator against the belt until the belt tension specification is reached. FIGURE 1 As with several other Delcotron models, the CS-Series housing includes an adjustment lug on the drive end frame (see Figure No. 1) which should be used to push the generator against the belt while the adjustment bolt is tightened. A 3/4" wrench (or equivalent) should be used when holding the generator by this lug. If the vehicle configuration does not permit use of the adjustment lug, pressure may be applied to the side of the drive end frame to tighten the belt. If pressure cannot be applied directly to the drive end frame, a block of wood should be inserted between the prying instrument and the side of the generator to distribute the force to a wider area which includes the drive end frame. Do not pry directly against the stator or slip ring end frame. Wipers - Intermittent Phantom Wipe (No Driver Input) Wiper Switch: Customer Interest Wipers - Intermittent Phantom Wipe (No Driver Input) Number: 90-266-8E Section: 8E Date: May 1990 Corp. Bulletin No.: 968302 Subject: WINDSHIELD WIPER PHANTOM WIPE Model and Year: 1985-90 S/T/M TRUCK AND 1990 L TRUCK THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 90-171-8E, DATED FEBRUARY 1990. THE LABOR TIMES HAVE BEEN UPDATED. ALL COPIES OF 90-171-8E SHOULD BE DISCARDED. Some 1985-1990 M vans, 1990 L Vans and S/T model trucks may exhibit intermittent phantom wipe - occasional wiper sweep of the windshield with no driver input. A new steering column wiper switch has been developed with an internal resistor to correct this condition. The following parts can be installed to repair intermiftent phantom wipe. They will service subject M/L vans and S/T trucks. SERVICE PARTS INFORMATION Part Number Description 26020403 Switch (Standard) 26020404 Switch (Tilt Wheel) Parts are currently available through GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Time Labor Time Labor Operation Models (standard) (tilt wheel) N2610 S/T M/L 1.2 hrs 1.0 hrs. Page 3429 High emissions, exhaust odor, starting and driveability problems (G046). 7271 7030 AMBT 16087029 3551 16121174 Chevrolet 88-235-6E High emissions, exhaust odor, starting and driveability problems (G046). 7281 7035 AMBU 16087034 3531 16121170 Chevrolet 88-235-6E High emissions, exhaust odor, starting and driveability problems (G046). 7811 8777 AYWH 16168776 6935 16206836 7941 8235 ABUL 16068234 3651 16076251 7951 8240 ABUM 16068238 3661 16076255 8351 8364 AMDA 16088362 3541 16121198 Chevrolet 88-235-6E High emissions, exhaust odor, starting and driveability problems (G046). 8401 8402 AMJL 16088400 3561 16120722 Chevrolet 88-235-6E High emissions, exhaust odor, starting and driveability problems (G046). 8411 8408 AMJM 16088407 See Footnote 332 8545 8645 BDSP 16188644 6615 16196536 8791 8820 ACDY 16068819 4871 16083476 8801 8825 ACDZ 16068824 4901 16083489 8951 9235 AJST 16079234 8411 16088407 Chevrolet 88-235-6E High emissions, exhaust odor, starting and driveability problems (G046). 8961 9240 AJSU 16079238 Chevrolet 88-235-6E High emissions, exhaust odor, starting and driveability problems (G046). 9491 7297 AJTH 16087296 9571 16089598 9501 7288 AJTJ 16087287 5551 16124986 9531 7293 AJTM 16087292 5551 16124986 9571 9600 AMRW 16089598 Running change. 9581 9605 AMRX 16089604 5551 16124986 9851 9827 APAL 16129826 5931 16156045 9961 0045 ACSY 16070044 Page 6140 Staking Locations - Stake 3 places 120 degrees apart. 3. Pulley (26) on the front head. Installing The Pulley Bearing Assembly ^ Position J 33017 and J 33023 over the inner race of the bearing. ^ Position J 8433-1 on J 33023 and assemble the through bolts and washers through the puller bar slots and thread them into J 33026. The thread of the through bolts should engage the full thickness of the compressor holding fixture. ^ Tighten the center screw in J 8433-1 to force the pulley and bearing assembly onto the compressor front head (33). Should J 33017 become misaligned with the inner race of the bearing, back off J 8433-1 and relocate center, then continue installation. 4. Pulley bearing retainer (24) using J 6083. 5. Clutch plate and hub assembly (22). Clutch Coil Assembly Page 7903 Light Switch Details (Part 2 Of 3) Diagram Information and Instructions Fuel Gauge: Diagram Information and Instructions 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 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. Page 6156 ^ Clamp J 25008-A to the compressor. ^ Mount J 25008-A and the compressor in a vise. Removing The Shaft Nut 1. Shaft nut (1) with J 9399. ^ Hold the clutch plate and hub assembly (3) with J 25030. Clutch Plate And Hub Removal 2. Clutch drive hub (3). ^ Thread J 34019 into the clutch plate and hub assembly (2). Important ^ Do not drive or pound on the clutch hub or the shaft. This may cause internal damage. ^ Make sure the contact surfaces of the clutch plate and the pulley are clean. ^ Align the shaft key with the shaft key way and place the clutch plate and hub assembly onto the compressor shaft. ^ Hold the body of J 34019 with a wrench and turn the center screw into the remover body. 3. Shaft key (2). ^ Retain the shaft key (2) if usable. Inspect ^ All parts and replace if necessary. Install or Connect Tools Required: J 9399 Thin Wall Socket J 9408-B Clutch Plate and Hub Installer J 25030 Clutch Hub Holding Tool Brakes (ABS) - 'False' or Dropping Pedal Hydraulic Control Assembly - Antilock Brakes: All Technical Service Bulletins Brakes (ABS) 'False' or Dropping Pedal Bulletin No. 24 Date November, 1982 Vehicle Make/Model DODGE, FORD and GENERAL MOTORS TRUCKS Equipped with Rear Anti-Lock Brake Systems Ford: RABB (Rear Anti-Lock Brake System) GM & Dodge: RWAL (Rear Wheel Anti-Lock) Topic False or Dropping Pedal Some of the above mentioned vehicles may experience a "false" or dropping pedal condition that may feel very similer to a master cylinder with an excessive amount of by-pass. Upon installation of the replacement master cylinder, there is little or no improvement in pedal feel or height, This condition may be caused by the dump valve in the E-H (Electro Hydraulic) valve being held slightly open by a small particle of foreign material. This allows fluid to flow into the accumulator and create the low or dropping brake pedal. To determine if this is the cause of the dropping pedal, begin by disconnecting the steel line at the master cylinder that serves the rear brakes. Install a solid tubing plug into the outlet that serves the rear brakes. Note: When installing the plug, have an assistent depress the pedal about one inch to purge any air from the outlet. Tighter, the plug while the assistant holds the pedal in this position. After tightening the plug, continue to apply pressure to the pedal. This will prevent damage to the primary cup in the master cylinder as the cup moves across the vent port. If the pedal no longer drops as it did with the rear brakes connected, this would indicate that the problem is in the rearbrakes and not the master cylinder. The next step would be to block off the outlet port of the E-H valve and retest the brake pedal as done previously. If the dropping pedal reappears, the problem is in the E-H valve and most likely caused by fluid leaking into the accumulator of the E-H valve. If this is the case, it will be necessary to change the valve. The E-H valve, including the accumulator and valving, is not serviceable. Note that brake fluid over a period of time absorbs contaminants, therefore, annual flushing and replacement with clean, fresh brake fluid will help to prevent this condition from occurring. Page 1737 Oil Pressure Gauge: Testing and Inspection Gauge Reads ``80'' or Above 1. Disconnect lead from sensor, then ground lead. 2. Gauge should read ``0'' psi. If gauge read ``0'' replace replace sensor, and if gauge reads ``80'' psi, check for short between sensor and gauge. Page 7072 * 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. Important Additional time or payment beyond established allowances in this bulletin will not be allowed. - The use of a razor blade on large flat surfaces is not recommended because of the potential to chip. gouge or otherwise damage the primer surface. If razor blade technique is used, the application of a "guide coat" prior to wet sanding should also be used. Note: Chemical stripping is not recommended because of negative impact to moldings, non-metal components, ELPO and environmental concerns. 4. Blow off with air to remove all dirt and sanding residue from cracks and vehicle surface. 5. Clean sanded surface with an appropriate wax and grease remover. 6. Tack wipe entire area to be primed. 7. Spray entire prepared area with a coat of anti-corrosion primer to ensure maximum adhesion and corrosion resistance. Be sure to cover any bare metal surfaces exposed during the sanding operations. Follow manufacturer's instructions and recommended dry times. Typical materials for this application would be: DuPont 615S/616S, BASE DE17/PR8O/DA18, PPG DP4O/DP401, or equivalent. V.O.C. materials would be: DuPont 615S/616S, BASF DE15/PA16/PRB0, PPG DCP21/DCX211 or equivalent. 8. Apply two to three medium wet coats of primer surfacer to the primed surface of the vehicle, following the manufacturer's instructions for application and film build requirements. Important Failure to apply primer surfacer will likely result in future delamination. Typical materials for this application would be: DuPont 1120S/1130S/1125S, BASF DP20/PR80/PH36, PPG K36/DT870/K201, or equivalent. V.O.C. materials would be: DuPont 210S, BASF HP400, PPG DCP21/DCX211, or equivalent. 9. After allowing adequate drying time, wet sand with 400 grit (or finer) or dry sand with 320 grit (or finer) sandpaper. 10. Repeat steps 4 through 6. 11. Apply a medium coat of corrosion resistant primer sealer (tintable base) to the entire surface to be refinished. This will provide maximum adhesion, uniform color coating and corrosion protection to areas "sanded through" during wet sanding. Follow manufacturer's instructions and recommended dry times. Typical materials for this application would be: DuPont 2610S/2605S, BASF DP21/DH6O/PR80, PPG DP40/DP402 or equivalent. V.O.C. materials for this application would be: DuPont 21255, PPG DPW1834 or equivalent. 12. Apply two to three medium wet coats of color (or until primer color is hidden). Follow manufacturer's instructions and recommended dry times. 13. If vehicle has basecoat/clearcoat paint, apply clearcoat. Follow manufacturer's instructions and recommended dry times. 14. After sufficient air or force dry time, unmask the vehicle. 15. Finesse/polish as required. 16. Reinstall all previously removed items. 17. Wash and prepare the vehicle for delivery. HARDWARE ITEMS REMOVAL LIST Note: Some technicians may apply a small cord (wire, plastic tube, etc.) behind or underneath moldings that remain on the vehicle to improve sanding and painting. If the vehicle paint system is baked with cord in place, damage to some moldings may occur. If this technique is used, DO NOT BAKE Service and Repair Fuel Pressure Release: Service and Repair Before performing any procedure that requires disconnecting fuel lines, relieve fuel system pressure as described below. 1. Remove Fuel Pump fuse from fuse block. 2. Start engine and allow to run out of fuel, then crank engine an additional 3 seconds. 3. Service fuel system as necessary. Page 3486 Disclaimer Page 2881 Operating Modes The Thermostatic Air cleaner is designed to keep air entering the engine between 100~-120~F. Keeping intake air between this temperature reduces exhaust emissions by permitting leaner mixtures and shorter choke on periods. The TAC also improves cold engine. The thermostatic air cleaner includes a temperature sensor, vacuum motor, control damper and connecting vacuum hoses. The temperature sensor controls the vacuum motor. The vacuum motor then operates the control damper, which regulates the flow of pre-heated and unheated air. When engine compartment temperatures are below the calibration value of the sensor, the sensor closes, allowing engine vacuum to be directed to the vacuum motor. The vacuum motor then closes the control damper to outside air, allowing heated air from the exhaust manifold to flow up through the heat tube to the air cleaner. As the temperature in the air cleaner reaches the calibration value of the sensor, it begins to open bleeding off vacuum to the vacuum motor. The vacuum motor causes the control damper to partially open, allowing outside air to blend with heated air. This regulated air then enters the air cleaner assembly. During periods of wide open throttle or when ambient temperatures are very high, there is not enough vacuum available to the vacuum motor to overcome diaphragm spring tension. The diaphragm then causes the control damper to move downward, closing the hot air duct and allowing only outside air to enter the air cleaner. Page 4317 Ignition System - Diagnosis Precautions Spark Plug Wire: All Technical Service Bulletins Ignition System - Diagnosis Precautions Number: 88-138-6D Section: 6D Date: Feb., 1988 Subject: ENGINE MISS, HESITATION, OR ROUGHNESS DUE TO PIERCED SECONDARY IGNITION COMPONENTS Model and Year: ALL MODELS WITH GASOLINE ENGINE TO: ALL CHEVROLET DEALERS During the diagnosis procedures for an engine miss, hesitation, or roughness condition, a spark plug or spark plug wire condition may be suspected. Several types of commercial or homemade diagnostic equipment require the secondary ignition boots or wire to be pierced. This is normally done to check for spark plug firing or to perform a cylinder balance test. Similarly, the use of pliers or other such tools to disengage a spark plug boot may pierce or damage the boot or wire. NOTICE: SECONDARY IGNITION COMPONENTS SHOULD NOT BE PIERCED FOR ANY REASON. Piercing a spark plug wire and/or distributor or direct fire module nipple may create a failure condition that will not be immediately apparent. Over time, the hole in the pierced boot may allow a ground path to develop, creating a plug misfire condition. Heavily moisture-laden air in the vicinity of the pierced boot may accelerate this effect. Piercing a secondary ignition wire creates a gap in the wire's conductive core. This gap is a point of high resistance. The current flow in the wire will increase to compensate for the higher wire resistance. Over time, the wire may fail, creating a plug misfire condition. The time required for the condition to appear depends upon the extent of damage to the conductive core. To help prevent future customer comments that are spark plug wire related, do not pierce or otherwise damage any secondary ignition component. Only use diagnostic equipment containing an inductive pick-up to check for spark plug firing or to perform cylinder balance tests. When disengaging a spark plug boot from the spark plug, twist the flanged boot 1/2 turn, then pull only on the boot to remove the wire. Page 3139 Throttle Position Sensor: Description and Operation Typical Throttle Position Sensor (TPS) Wiring The Throttle Position Sensor (TPS), is mounted on the side of the throttle body opposite the throttle lever assembly. Its function is to sense the current throttle valve position and relay that information to the ECM. Throttle position information allows the ECM to generate the required injector control signals (base pulse). If the TPS senses a wide open throttle, a voltage signal indicating this condition is sent to the ECM. The ECM then increases the injector pulse width, permitting increased fuel flow. As the throttle valve rotates in response to movement of the accelerator pedal, the throttle shaft transfers this rotation to the TPS. A potentiometer (variable resistor) within the TPS assembly changes its resistance (and voltage drop) in proportion to throttle movement. By applying a reference voltage (5.0 volts) to the TPS input, a varying voltage (reflecting throttle position) is available at the TPS output. For example, approximately 2.5 volts results from a 50% throttle valve opening (depending on TPS calibration). The voltage output from the TPS assembly is routed to the ECM for use in determining throttle position. Torque Specifications Crankshaft: Specifications Main Bearing Cap Bolts 80 ft.lb Page 3468 SERVICE PARTS INFORMATION Part Number Description 15664811 Vacuum Actuator Switch Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: K4120 Use applicable labor time guide for labor hours. 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 ECM/PCM - Damaged and/or Misdiagnosed Engine Control Module: All Technical Service Bulletins ECM/PCM - Damaged and/or Misdiagnosed Number: 91-384-6E Section: 6E Date: AUGUST 1991 Corporate Bulletin No.: 176503 Subject: DAMAGED ECM/PCM AND/OR MIS-DIAGNOSED ECM/PCM SYMPTOMS DUE TO INCORRECT "TAP-TESTING" PROCEDURES Model and Year: 1982-91 ALL PASSENGER CARS AND TRUCKS CONDITION: Because of the intermittent nature of some Electronic Control Module (ECM) or Powertrain Control Modules (PCM) symptoms, some service technicians have been subjecting the ECM/PCM to vibration and/or shock testing. Commonly known as tap-testing, this procedure involves tapping on the ECM/PCM case, while the engine is running. It is generally accepted that if the engine or ECM/PCM falters due to the tapping, an intermittent internal ECM/PCM defect may be indicated. However, this may not always be true. If too much force is applied to the ECM/PCM during the test the following symptoms may result: ^ Immediate ECM/PCM failure. ^ ECM/PCM suffers damage which may cause a failure at a later date. ^ ECM/PCM Reset (or Glitch), creating a momentary stall, miss Service Engine Soon (SES) light and/or loss of serial data. CAUSE: The ECM/PCM should be tapped using only the fingertips of one hand. Use of the palm, fist, or any type of tool subjects the ECM/PCM to forces that can cause both the circuit board and the outer aluminum case to flex and distort beyond design limits. The Integrated Circuits (IC) used in today's ECM/PCMs are mounted to the circuit board using a mounting process referred to as "surface technology." There are no circuit board holes for IC leads to go through. The IC leads set on pads, (28 pads or 52 pads depending on the IC) and solder is flowed around the leads to make the electrical connection to the circuit board. ^ Any flexing of the circuit board, beyond design limits, places the IC solder connections at risk of damage. Such damage may be apparent immediately, or it may appear at a future date. Circuit board deflection can occur as a result of striking the ECM/PCM, using ONLY THE PALM OF THE HAND. ^ If struck on the bottom side (the side opposite the service label), the ECM/PCM's aluminum outer case may deflect inward far enough to contact the electrical leads attached to the circuit board. Once in contact with the case the ECM/PCM electrical components will be shorted directly to ground. Although such shorting certainly has the potential to damage the ECM/PCM, it may not be permanent damage, depending on which circuit is involved. However, even if permanent damage is avoided, a short on any of the circuits will cause a disruption of normal ECM/PCM operation for the instant that the short occurs. This disruption may cause the ECM/PCM to reset (see "reset" above), creating the false impression that it is vibration sensitive or faulty. Reset is the ECM/PCM's normal way of coping with large voltage spikes. An ECM/PCM reset does not indicate that the ECM/PCM is defective or faulty, only that it is being subjected to abnormal conditions. CORRECTION: 1. TAP THE ECM/PCM ONLY ON THE TOP SIDE (The top side is where the service label is located.) ^ This will minimize the chance of deflecting the ECM/PCM case into the electrical leads on the circuit board. The clearance between the case and the circuit board is closest on the bottom side of the ECM/PCM. 2. TAP THE ECM/PCM USING ONLY THE FINGERTIPS - NO TOOLS. ^ To avoid excessive case deflection, avoid tapping in the center of the case. Tapping close to the edge of the ECM/PCM, especially in the corners, is best. ^ While using greater force may seem more effective, the test itself may cause the ECM/PCM to fail. Page 807 The toll free number for Kent Moore is 1-800-345-2233. Portions of this article were reprinted with permission, from Dow Chemical Canada, Inc., P.O. Box 1012, Sarnia, Ontario N7T 7K7. Restraints - Driver/Passenger Seat Head Rest Information Head Restraint System: Technical Service Bulletins Restraints - Driver/Passenger Seat Head Rest Information INFORMATION Bulletin No.: 10-08-50-003A Date: March 24, 2011 Subject: Information on Driver or Passenger Seat Head Restraint Concerns with Comfort, Custom Upholstery or Other Comfort Enhancing Devices Models: 2012 and Prior GM Passenger Cars and Trucks Equipped with Adjustable Head Restraints Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 10-08-50-003 (Section 08 - Body and Accessories). Important ON A GM VEHICLE EQUIPPED WITH ADJUSTABLE HEAD RESTRAINTS, USE THE HEAD RESTRAINT COVERS, FOAM AND OTHER SEAT-RELATED EQUIPMENT AS RELEASED BY GM FOR THAT VEHICLE. DO NOT ALTER OR REPOSITION THE HEAD RESTRAINT SYSTEM. ANY ALTERATIONS TO HEAD RESTRAINTS DEFEATS THE INTENDED DESIGN OF THE SYSTEM. GM WILL NOT BE LIABLE FOR ANY PROBLEMS CAUSED BY USE OF SUCH IMPROPER DESIGN ALTERATIONS, INCLUDING ANY WARRANTY REPAIRS INCURRED. You may have a customer with a concern that the head restraint is uncomfortable or sits too far forward. The front driver and passenger seats are equipped with head restraints that have been designed to help minimize injuries while still providing comfort to the occupants. Each GM vehicle has its own specifically designed head restraint. The head restraints should only be used in the vehicle for which they were designed. The head restraint will not operate to its design intent if the original foam is replaced (1) by non-GM foam or head restraint, (2) by GM foam or head restraint designed for a different vehicle, (3) by GM foam or head restraint that has been altered by a trim shop or (4) if any object, such as an aftermarket comfort enhancing pad or device, is installed. Never modify the design of the head restraint or remove the head restraint from the vehicle as this may interfere with the operation of the seating and restraint systems and may prevent proper positioning of the passenger within the vehicle. Disclaimer A/T - DEXRON III Fluid Introduction Fluid - A/T: All 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 Page 2019 SERVICE PARTS INFORMATION RPO DEFINITIONS: C60 - AIR CONDITIONER, FRONT, MANUAL CONTROLS C41 - HEATER, OUTSIDE AIR W/FAN AND DEFROSTER C42 - HEATER, DELUXE GU2 - AXLE REAR 2.73 RATIO GU4 - AXLE REAR 3.08 RATIO GU5 - AXLE REAR 3.23 RATIO GU6 - AXLE REAR 3.42 RATIO GT4 - AXLE REAR 3.73 RATIO K01 - FAN CLUTCH DRIVE L84 - ENGINE, 4.3L, (4.3Z) V6 LU2 - ENGINE, 4.3B, (4.3B) V6 HI-OUTPUT TBI L35 - ENGINE, 4.3L, (4.3W) CENTRAL PORT INJECTION V6 90 DEG WARRANTY INFORMATION For vehicles repaired under warranty, use: Labor Op: J3390 Labor Time: See Applicable Labor Time Guide Engine - Miss, Hesitation, or Roughness Spark Plug Wire: All Technical Service Bulletins Engine - Miss, Hesitation, or Roughness Number: 93-35-6D Section: 6D Date: OCT. 1992 Corporate Bulletin No.: 716404R ASE No.: A1, A8 Subject: ENGINE MISS HESITATION OR ROUGHNESS DUE TO PIERCED SECONDARY IGNITION COMPONENTS Model and Year: 1980-93 ALL PASSENGER CARS AND TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 87-121, DATED MAY 1987. THE 1989-93 MODEL YEARS HAVE BEEN ADDED. ALL COPIES OF 87-121 SHOULD BE DISCARDED. During the diagnosis procedure for an engine miss, hesitation or roughness, a spark plug or spark plug wire condition may be suspected. Several types of commercial or homemade diagnostic equipment required the secondary ignition boots or wire to be pierced. This is normally done to check for spark plug firing or to perform a cylinder balance test. Similarly the use of pliers or other such tools to disengage a spark plug boot may pierce or damage the boot or wire. Secondary ignition components should not be pierced for any reason. Piercing a spark plug wire and/or distributor boot may create a condition that will not be immediately apparent. Over time, the hole in the pierced boot may allow a ground path to develop creating a plug misfire condition. Heavily moisture laden air in the vicinity of the pierced boot may accelerate this effect. Piercing a secondary ignition wire creates a gap in the wire's conductive core. This gap is a point of high resistance. The current flow in the wire will increase to compensate for the higher wire resistance. Over time, the wire may fail creating a plug misfire condition. The time required for the condition to appear depends upon the extent of damage to the conductive core. To help prevent future condition that are spark plug wire related, do not pierce or otherwise damage any secondary ignition component. Only use diagnostic equipment containing an inductive pick-up to check for spark plug firing or to perform cylinder balance tests. When disengaging a spark plug boot from the spark plug, twist the flanged boot 1/2 turn then pull on the boot only to remove the wire. Page 4461 FIGURE 1 If this condition is encountered, and cannot be corrected using normal diagnostics, a newly released rear transmission mount may be installed (see Figure 1). This rear transmission mount is currently in use on 1988-90 Cl, C2, and C3 pickups with 4.3 L engines and 3- speed automatic transmissions (M40). When installing this mount, new service washers (one washer per bolt) are required for retaining mount to transmission. Also install a new nut on the stud when attaching mount to cross member. IMPORTANT: This mount is not for use on 1991 S/T 4 door utility or any 1988-91 T model pickup or utility. PARTS INFORMATION PART NUMBER DESCRIPTION QUANTITY 15567796 Mount 1 15614758 Washer 2 Page 7506 Symbol Identification Page 3273 FIGURE 2 - THM 700-R4 WIRING DIAGRAM DATE OF PRODUCTION CHANGE: (Figure 1) On April 20, 1988 (Julian Date 111), the 1988 THM 700-R4, THM and TLM models were built with the new Type 18 Solenoid Assembly and Wiring Harness. Beginning May 9, 1988 (Julian Date 130), the remaining 1988 THM 700-R4 models listed above were built using the new Type 18 Solenoid Assembly. SERVICE NOTES: Any 1988 THM 700-R4 transmission models built with the Type 18 Solenoid Assembly, refer to models and Julian Dates listed above, must be serviced with the Type 18 Solenoid Assembly and Wiring Harness Complete listed under "Service Parts Information". Any 1988 THM 700-R4 transmission model built with a Type 15 Solenoid Assembly may be serviced with the new Type 18 assembly; however, there will be no wire connection for the 4-3 pulse switch. The 4-3 pulse switch, which can be left installed, will then function as a plug. SERVICE PARTS INFORMATION: Part No. Description 10478100 Type 18 Solenoid Assembly - Complete 8654415 Type 15 Solenoid Assembly - Complete Parts are currently available from GMSPO. SERVICE MANUAL REFERENCE: Please update the 1988 THM 700-R4 Hydraulic Diagnosis section of your service manual accordingly. Page 2771 Oxygen Sensor: Locations The oxygen sensor is located in the LH exhaust manifold just above the flange. Page 6291 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 Page 3233 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. Page 2367 Vehicle Speed Sensor: Service and Repair 1. Disconnect vehicle speed sensor electrical connector. 2. Remove sensor attaching bolt. 3. Using speed sensor remover and installer, tool No. J 38417, remove sensor, then O-ring seal. 4. Reverse procedure to install, coating the new O-ring seal with transmission fluid. Torque attaching bolt to 97 inch lbs. Page 3810 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 Page 5366 Disclaimer Page 400 Manifold Pressure/Vacuum Sensor: Locations Center Of Dash Panel (engine Compartment) Center Rear Of Engine Applicable to: V6-262/4.3L Engine Page 4007 Transmission Mount: Specifications THM180 & 180 C Automatic Trans Transmission Support to Extension ..................................................................................................... ................................................................ 29-36 ft lbs Locations Rear LH Corner Of Engine Compartment. Page 2031 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. Fuse Block - Deforms Fuse Block: Customer Interest Fuse Block - Deforms Number: 90-432-8B Section: 8B Date: SEPT. 1991 Corporate Bulletin No.: 168102 ASE No.: A6 Subject: FUSE BLOCK DEFORMS Model and Year: 1988-90 SI (LLV) POSTAL VEHICLES Some 1988 to 1990 LLV postal vehicles built prior to August 3, 1990, may exhibit a condtion where the fuse block is partially deformed due to heat generated by continuous operation of the hazard flasher. This condition may be corrected by the repositioning of the hazard flasher to a remote location. SERVICE PROCEDURE: 1. Disconnect positive battery cable. 2. Remove old flasher. 3. Back out terminals for circuit 140A (orange wire) and circuit 27 (brown wire) using a small flat screwdriver or pick. Using the same tool, raise the locking tang on the back of the terminal. 4. Cut electrical tape used to wrap main wiring harness a sufficient amount to provide 2 to 3 inches of flasher wiring for relocation. 5. Insert terminals of circuits 140A and 27 into new connector (P/N 2973385). 6. Install electronic flasher (P/N 15504673) into the new connector. 7. Using nylon ties, strap the connector and flasher assembly to the wiring harness that runs above the fuse block. Verify that the relocated flasher and all wiring is secured so it does not cause interference with the throttle linkage. 8. Reconnect battery cable. 9. Test operation of hazard flasher system. SERVICE PARTS INFORMATION PART NUMBER DESCRIPTION QTY 2973385 Connector 1 15504673 Flasher (Electronic) 1 NPN Nylon Tie Straps 2 Parts are currently available from GMSPO. Page 713 Disclaimer Page 383 Knock Sensor: Testing and Inspection Chart C-5 - Electronic Spark Control System Check Page 1029 Campaign - Paint Delamination Policy Adjustment Technical Service Bulletin # 8931810 Date: 900901 Campaign - Paint Delamination Policy Adjustment Number: 89-318-10 Section: 10 Date: September, 1990 Corp. Bulletin No.: SPECIAL Subject: SPECIAL POLICY ADJUSTMENT PAINT DELAMINATION (PEELING) Model and Year: 1988-89 CHEVROLET S/T PICKUPS AND S/T BLAZERS (SHREVEPORT ASSEMBLY PLANT ONLY - PLANT CODE "8") TO: ALL CHEVROLET DEALERS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 89-305-10, DATED APRIL 1990. ALL COPIES OF 89-305-10 SHOULD BE DISCARDED AS THIS BULLETIN CONTAINS AN EXPANDED SERVICE PROCEDURE. General Motors has determined that some 1988-89 Chevrolet S/T pickups and S/T Blazers built at the Shreveport Assembly Plant may exhibit a delamination (peeling) of the paint on exterior surfaces due to continued ultraviolet exposure. If one of these vehicles should require repairs for a paint peeling condition, all exterior surfaces painted with affected colors should be refinished even though the peeling may be evident in only a few places. VEHICLES INVOLVED Involved are certain 1988-89 Chevrolet S/T model trucks painted Galaxy Blue (paint code 28), Aspen Blue (paint code 24) or Steel Gray (paint code 90) and built at the Shreveport Assembly Plant within the following VIN breakpoints: SPECIAL POLICY ADJUSTMENT This special policy covers the condition described above on 1988 involved vehicles for 12 months from the date of this bulletin. 1989 involved vehicles will be covered for a period of 3 years from the date of original vehicle purchase regardless of ownership with no deductible. Correction, at no charge to the customer, will consist of refinishing exterior surfaces painted with affected colors on involved vehicles. Customers may also be eligible for reimbursement of previous repairs with supporting documentation. NOTICE: Only exterior surface areas painted Galaxy Blue, Aspen Blue or Steel Gray should be refinished. If peeling of colors other than those described above should occur, handle as described in the Chevrolet Claims Processing Manual, Section XIII, Warranty Management System. This "Special Policy Adjustment Bulletin" should be filed in the three ring binder previously furnished to dealers by General Motors. PARTS INFORMATION No parts are required to complete this special policy. Paint supplies should be obtained through normal supplier. Service Procedure 1. After washing vehicle, verify that condition is delamination of topcoat by applying a 2 inch width piece of masking tape firmly over suspect area, pulling upward quickly. If topcoat and/or clear coat flake or peel away from primer, leaving primer intact, the topcoat is delaminating and the following service procedure should be performed. Exhaust Manifold Heat Shield - Rattles Heat Shield: All Technical Service Bulletins Exhaust Manifold Heat Shield - Rattles Number: 91-421-6F Section: 6F Date: SEPT. 1991 Corporate Bulletin No.: 166604 ASE No.: A8 Subject: EXHAUST HEAT SHIELD RATTLE Model and Year: 1988-91 S1/T1 TRUCKS WITH 4.3L ENGINE Page 2643 Oxygen Sensor: Locations The oxygen sensor is located in the LH exhaust manifold just above the flange. A/T - Proper Fluid Level Checking Procedure Fluid - A/T: All Technical Service Bulletins A/T - Proper Fluid Level Checking Procedure Number: 88-41 Section: 7A Date: AUG., 1987 Subject: PROPER TRANSMISSION FLUID LEVEL CHECKING PROCEDURE Model and Year: 1987-88 CHEVROLET VEHICLES WITH THM 125C, 200-4R, 400, 440-T4, AND 700-R4 TRANSMISSIONS TO: ALL CHEVROLET DEALERS This bulletin outlines proper hot and cold fluid level checking procedures for the transmissions and transaxles listed above. A. "COLD" CHECK PROCEDURE: 1. Start vehicle and let idle in Park for 3 minutes. Note for THM 440-T4: Start vehicle and cycle range selector through 1, 2, D, OD, and R for approximately 3 seconds in eash range. Complete check preparation by letting vehicle idle in Park for 3 minutes. 2. With vehicle level, accessories turned off, and engine idling in Park, check fluid level as outlined below. FIGURE 1 ^ THM 200-4R, 400, 700-R4 (Refer to Figure 1): When cold, 27 Degrees C (80 Degrees F), a full transmission will show the fluid level below the "Add" mark on the indicator. As the transmission warms to normal operating temperature, the fluid expands, raising the level to within the cross-hatched area. Specifications Fluid Line/Hose: Specifications Oil Cooler Fittings to Case 15 ft.lb Oil Cooler Fittings to Radiator 20 ft.lb Page 4964 Fig. 7 Installing boot to caliper 5. Position dust boot in caliper counterbore and install, Fig. 7. Check the boot installation to be sure the retaining ring molded into the boot is not bent and that the boot is installed below the caliper face and evenly all around. If the boot is not fully installed, dirt and moisture may enter the bore and cause corrosion. 6. Install the brake hose in the caliper using a new copper gasket. 7. Install pads and caliper assembly. Page 5985 Page 5031 FIGURE 2 - PARKING BRAKE LEVER ASSEMBLY 4. Remove two bolts (A Figure 2) attaching parking brake lever to the steering column. Disconnect parking brake switch wires from lever. 5. Remove cotter key and pin (B Figure 2) attaching the cable to the parking brake lever. 6. Remove bolt/nut (C Figure 2) that attaches the cable to the parking brake lever. Electrical Connectors - Service Procedure Multiple Junction Connector: All Technical Service Bulletins Electrical Connectors - Service Procedure Number: 91-85-8A Section: 8A Date: October 1990 Corp. Bulletin No.: 018115 Subject: PROCEDURE FOR CHECKING CONNECTOR TERMINAL CONTACT Model and Year: 1982-91 PASSENGER CARS AND TRUCKS Figure 1 TO: ALL CHEVROLET DEALERS Page 7761 SERVICE PARTS INFORMATION Part Number Application Description 15636850 1988-1991 Plate kit I/P (no switches). (Gray) Switch trim plate (gray) bracket, covers for switch trim plate holes (quantity 2), and 4 bolts/screws. 15636853 1986-1987 Plate kit I/P (no switches). (Black) Switch trim plate (black), bracket, covers for switch trim plate holes (quantity 2), and 4 bolts/screws. Important: Torque 11508898 bolts/screws supplied in kit to 0.4-0.7 N-m. (4-6 lbs.in.). Parts are expected to be available on January 21, 1991. Until then, normal part orders will not be accepted by GMSPO. Only verifiable emergency VIP orders will be accepted. GMSPO will make every effort to obtain parts. All parts will be placed on 400 control to waive VIP surcharges. However, the parts will be shipped premium transportation at dealer's expense. All other order types will be canceled as incorrectly ordered while 400 control is in place. WARRANTY INFORMATION For vehicle repaired under warranty use: Labor Operation: T7101 Labor Time: .3 hr. Trouble Code: 92 NOTE: Labor Operation is coded to base vehicle coverage in the warranty system. Specifications Throttle Body: Specifications TBI Unit To Manifold Torque TBI Unit To Manifold Torque TBI Unit To Manifold 12 ft.lb A/T - Buzzing Noise at Idle Fluid Pressure Sensor/Switch: Customer Interest A/T - Buzzing Noise at Idle Number: 93-29-7A Section: 7A Date: OCT. 1992 Corporate Bulletin No.: 277142 ASE No.: A2 Subject: BUZZING NOISE AT IDLE Model and Year: 1982-93 CAPRICE, CAMARO AND CORVETTE 1982-93 C/K, R/V, S/T, M/L AND G TRUCKS WTIH 4L60 AUTOMATIC TRANSMISSION TRANSMISSION APPLICATIONS: 1982-1993 HYDRA-MATIC 4L60 (MD8) TRANSMISSION MODELS: All SUBJECT: Pressure Regulator Valve Buzz VEHICLE APPLICATIONS: B, D, F, Y - Cars C/K, R/V, S/T Trucks G, M, L - Vans CONDITION: Some 1982-1993 vehicles equipped with a HYDRA-MATIC 4L60 transmission may have a buzzing noise coming from the transmission when the vehicle is at idle. The buzzing noise may be noticed more when the vehicle is in reverse at idle. CAUSE: The buzzing noise may be a result of pressure regulator valve oscillating due to oil pressure instability at lower idle RPM. CORRECTION: Page 1462 Camshaft: Specifications Camshaft Lift Specs Camshaft lift should measure .357 inch at intake valves and .390 inch at exhaust valves. Locations Rear LH Corner Of Engine Compartment. Wipers - Intermittent Phantom Wipe (No Driver Input) Wiper Switch: All Technical Service Bulletins Wipers - Intermittent Phantom Wipe (No Driver Input) Number: 90-266-8E Section: 8E Date: May 1990 Corp. Bulletin No.: 968302 Subject: WINDSHIELD WIPER PHANTOM WIPE Model and Year: 1985-90 S/T/M TRUCK AND 1990 L TRUCK THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 90-171-8E, DATED FEBRUARY 1990. THE LABOR TIMES HAVE BEEN UPDATED. ALL COPIES OF 90-171-8E SHOULD BE DISCARDED. Some 1985-1990 M vans, 1990 L Vans and S/T model trucks may exhibit intermittent phantom wipe - occasional wiper sweep of the windshield with no driver input. A new steering column wiper switch has been developed with an internal resistor to correct this condition. The following parts can be installed to repair intermiftent phantom wipe. They will service subject M/L vans and S/T trucks. SERVICE PARTS INFORMATION Part Number Description 26020403 Switch (Standard) 26020404 Switch (Tilt Wheel) Parts are currently available through GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Time Labor Time Labor Operation Models (standard) (tilt wheel) N2610 S/T M/L 1.2 hrs 1.0 hrs. Page 2343 Oxygen Sensor: Specifications Oxygen Sensor 30 ft.lb Page 7037 Figure No. 1 NOTICE: For two tone vehicles, it is only necessary to refinish surfaces painted Galaxy Blue, Aspen Blue or Steel Gray. Other colors should not be affected by this condition. The front bumper filler panel and all surfaces painted with affected colors above the belt line (Fig. 1, page 3) must be refinished according to the procedure listed below (regardless of previous paint repairs). If surfaces below the belt line and the interior of the pickup box (on pickup models) appear to be in good condition, the dealer should scuff sand, seal and color coat those painted surfaces rather than refinish. However, if any peeling or topcoat delamination is evident, or If scuff sanding produces any topcoat delamination, it will be necessary to refinish these surfaces as well, according to the procedures. It should not be necessary to paint inside of door jambs, or underneath exterior moldings or decals (sunshine stripes), as these areas are not normally subjected to continued ultraviolet exposure. 2. Sand original finish coat of paint down to electro-coat (Elpo) primer, making sure factory pretreatment and Elpo primer are still intact for good corrosion protection. DO NOT USE CHEMICALS TO REMOVE PAINT AS THIS MAY DAMAGE THE ELPO PRIMER. NOTICE: Rough tape vehicle as necessary (window glass, etc.), and remove nameplates, weatherstrips, and reveal moldings as needed to properly refinish all surfaces as required. 3. Finish sand exposed Elpo primer with 240 grit sandpaper to assure removal of any chalky residue or degraded Elpo primer that may remain as a result of overbaking the primer. NOTICE: Avoid sanding through Elpo to bare metal when possible. 4. Use an air gun to remove all dirt from cracks and surfaces of truck. 5. Clean sanded surfaces with grease and wax remover. Page 3696 Fluid - A/T: Service and Repair Turbo Hydra-Matic 4L60 (700-R4) Checking & Adding Fluid Check fluid at regular intervals. Noticing a change in color, odor or fluid level can serve as a warning of possible transmission problems. To check fluid level, bring fluid to operating temperature of 200°F. With vehicle on a level surface, engine idling in park and parking brake applied, the level on the dipstick should be at the Full mark. To bring the fluid level from the Add mark to the Full mark requires one pint of fluid. If additional fluid is required, use only Dexron II or Dexron IIE automatic transmission fluid. When adding fluid, do not overfill, as foaming and loss of fluid through the vent may occur as the fluid heats up. Also, If fluid level is too low, complete loss of drive may occur especially when cold, Which can cause transmission failure. Every 100,000 miles, the oil should be drained, the pan removed, the screen should be cleaned or replaced if applicable, and fresh fluid added. For vehicles subjected to more severe use such as heavy city traffic especially in hot weather, prolonged periods of idling or use as a tow vehicle, this maintenance should be performed every 15,000 miles. Changing Oil 1. Raise vehicle and position drain pan under transmission pan. 2. Remove front and side attaching bolts form the oil pan. 3. Loosen rear attaching bolts approximately four turns. 4. Carefully pry transmission pan loose and allow fluid to drain. 5. Remove rear attaching bolts, pan and pan gasket. 6. Drain remaining fluid from pan, then clean pan and gasket surfaces with solvent and dry with compressed air. 7. Remove transmission screen. Remove O-ring seal from intake pipe or case bore. 8. Replace screen if applicable, or thoroughly clean screen assembly with solvent and dry with compressed air. 9. Install O-ring on intake pipe, then install screen assembly. 10. Install gasket on pan, then install pan and torque attaching bolts to 12 ft. lbs. 11. Lower vehicle and add approximately 5 qts. of Dexron II or Dexron III type transmission fluid through filler tube. 12. Start engine and let run at idle, then with brakes applied move selector lever through each gear range. 13. Place transmission in Park position and check fluid level. Page 2882 Thermostatic Air Cleaner: Testing and Inspection SYSTEM CHECK Results of Incorrect THERMAC Operation May Cause hesitation during warm up, check for: ^ Heat stove tube disconnected. ^ Vacuum diaphragm motor inoperative (open to snorkel). ^ No manifold vacuum. ^ Damper door does not move. ^ Missing air cleaner to carburetor seal. ^ Missing air cleaner cover seal or loose cover. ^ Loose air cleaner. Lack of power, sluggish, pinging or spongy, on a hot engine check for: ^ Damper door does not open to outside air. ^ Temperature sensor doesn't bleed off vacuum. THERMAC AIR CLEANER CHECK 1. Inspect system to be sure all hoses and heat stove tube are connected. Check for kinked, plugged, or deteriorated hoses. 2. Check for presence and condition of air cleaner to carburetor gasket seal. 3. With air cleaner assembly installed, damper door should be open to outside air. 4. Start engine. Watch damper door in air cleaner snorkel. When engine is first started, damper door should move and close off outside air. As air cleaner warms up, damper door should open slowly to outside air. 5. If the air cleaner fails to operate as described above, perform vacuum motor check. If it operates, the door may not be moving at the right temperature. If the driveability problem is during warm-up, make the temperature sensor check. VACUUM MOTOR CHECK 1. With engine "OFF," disconnect vacuum hose at vacuum diaphragm motor. 2. Apply at least 23 kPa (7" Hg) of vacuum to the vacuum diaphragm motor. Damper door should completely block off outside air when vacuum is applied. If not, check to see if linkage is hooked up correctly. 3. With vacuum still applied, trap vacuum in vacuum diaphragm motor by bending hose. Damper door should remain closed. If not, replace vacuum diaphragm motor assembly. (Failure of the vacuum diaphragm motor assembly is more likely to be caused from binding linkage or a corroded snorkel than from a failed diaphragm. This should be checked first, before replacing the diaphragm.) 4. If vacuum motor checks OK, check vacuum hoses and connections. If OK, replace the temperature sensor. TEMPERATURE SENSOR CHECK 1. Start test with air cleaner temperature below 30~C (86~F). If engine has been run recently, remove air cleaner cover and place thermometer as close as possible to the sensor. Let air cleaner cool until thermometer reads below 30~C (86~F) about 5 to 10 minutes. Reinstall air cleaner on engine and continue to step 2. 2. Start and idle engine. Damper door should move to close off outside air immediately if engine is cool enough. When damper door starts to open the snorkel passage, remove air cleaner cover and read thermometer. It must read about 55~C (131~F). Page 1493 Crankshaft Main Bearing: Service and Repair Main bearings are available in standard size and undersizes of .001, .002, .009, .010 and .020 inch. Connecting rod bearings are available in standard size and .001 and .002 inch undersize for use with new and used standard size crankshafts and .010 and .020 inch undersize for use with reconditioned crankshafts. Page 455 Knock Sensor: Description and Operation Knock Sensor Operation ESC Wiring Diagram The Electronic Spark Control (ESC) system is comprised of a knock sensor, the ESC module, and the ECM. As the knock sensor detects engine knock, it sends a voltage signal to the ECM. The ECM responds by retarding the ignition timing until the knocking ceases. As detonation is reduced, the ECM advances the timing again in small increments back to the pre-programmed point for that engine speed and load. Page 4975 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 Page 3040 Fuel Injector: Testing and Inspection Kent-Moore Fuel Injector Tester, tool J-39021, has the capability of performing injector balance and coil tests on all GM and many non-GM fuel injection systems. In addition to the familiar fuel pressure drop test, the injector coil test is a new test whereby the injector's resistance is measured during normal operation by feeding a fixed current through the injector and measuring the voltage drop across the injector. Injector coil failures are more accurately detected using this method than by simply measuring the injector's resistance with an ohmmeter. Refer to the instructions included with the tool. For further information, refer to TSB 93-6E-14, dated June 1993. (Corp. Ref. No.: 316501R) NOTE: Measuring injector resistance is not a fool-proof method of determining the condition of the injectors. A Fuel Injector Balance Test will more accurately determine the mechanical condition of the injector, while the injector resistance will determine the electrical condition of the injector. If available, use applicable C-Charts at Computers and Control Systems, Testing and Inspection. You should also start at Diagnostic System Check if you have not already done so. See: Computers and Control Systems/Testing and Inspection Tailgate - Latch Rattle, Revised Striker & Latch Trunk / Liftgate Latch: All Technical Service Bulletins Tailgate - Latch Rattle, Revised Striker & Latch Number: 92-153-10 Section: 10 Date: APRIL 1992 Corporate Bulletin No.: 161514 ASE No.: B1 Subject: END GATE LATCH RATTLE Model and Year: 1983-92 S/T TRUCKS Owners of some 1983-1992 S/T 2 and 4 door utility vehicles may comment that their end gate latch rattles. One possible cause of this condition is the end gate latch fork bolts contacting the striker assembly (metal-tometal) causing a rattle. To correct this condition, it is necessary to install a new striker assembly that has a urethane sleeve over the striker post. The urethane sleeve preventsmetal-to-metal contact and may eliminate the rattle. SERVICE PROCEDURE: Page 7375 - 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 Page 4764 Transmission Position Switch/Sensor: Testing and Inspection Chart C-1A - Park/Neutral Switch Diagnosis Page 3198 Spark Plug Wire: 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. Page 3331 Fluid Pressure Sensor/Switch: Specifications 4L60 - 700R4 Transmission Pressure Switches ............................................................................................................................... ....................................................................... 8 ft. lbs. Cooling System - Reconstituted Anti-Freeze Information Coolant: Technical Service Bulletins Cooling System - Reconstituted Anti-Freeze Information Number: 90-49-6B Section: 6B Date: August 1989 Corporate Bulletin No.: 930107 Subject: RECONSTITUTED ANTI-FREEZE Model and Year: ALL MODELS, ALL MODEL YEARS TO: ALL CHEVROLET DEALERS This bulletin provides information on "reconstituted anti-freeze". It has been brought to our attention that a number of manufacturers claim to have the capability of reconstituting engine coolant on site. At this time, General Motors does not endorse this practice or any equipment. Anti-freeze recycling is a very complex issue. In use as an engine coolant, ethylene glycol becomes oxidized producing a very degraded and deteriorated substance. Contamination by other automotive fluids during draining, handling and storage is also a major detriment to the reclaiming process. There is no additive we are aware of that can be merely put into used coolant that will restore it to an acceptable state. Typically, a multi-million dollar facility, utilizing sophisticated technology with distillation capabilities along with appropriate quality control would be required to adequately process used coolant to bring it to GM specifications. Disposal of all chemical products should be done in accordance with all applicable federal, state and local laws and regulations. Review engine coolant substitutes Dealer Service Bulletin No. 89-57-6B, dated January 1989. Transfer Case - Increased Shift Effort From 2H to 4H Technical Service Bulletin # 914047A Date: 910801 Transfer Case - Increased Shift Effort From 2H to 4H Number: 91-404-7A Section: 7A Date: AUGUST 1991 Corporate Bulletin No.: 167401 ASE No.: A2 Subject: HIGH TRANSFER CASK SHIFT EFFORT Model and Year: 1988-91 T1 TRUCKS Some 1988-91 T-Trucks may experience high transfer case shift effort or total blockouts when "shifting on the fly" from 2H to 4H under cold weather conditions. This condition may be corrected by the installation of the synthetic 75W90 gear lube described in Dealer Service Bulletin No. 91-128-7A. This fluid maintains a more constant viscosity under cold weather conditions allowing quicker front axle synchronization and easier transfer case engagement. If the installation of the synthetic fluid does not result in a satisfactory shift effort, an "Easy Shift" package may be installed in the transfer case. This package features a roller pin (53) rather than a solid pin on the mode shift fork (54) and revised ramp angles on the sector (55) to reduce engagement forces. This package was installed in the 1991 model year and will provide reduced transfer case shift effort under cold weather conditions. Figure 1 VEHICLES INVOLVED: Group A: Some 1988-91 T-Trucks equipped with transfer cases identified by the following part numbers: 15568078 15627441 15568079 15627442 15568597 15653450 Page 6257 High Pressure Safety Valve HVAC: Service and Repair With R-4 Compressor R-4 Compressor Component View Remove or Disconnect 1. Valve (24). 2. Seal (23). Install or Connect 1. Seal (23). ^ Dip the seal in clean 525 viscosity refrigerant oil before inserting it into the valve cavity. 2. Valve (24). Tighten ^ Valve (24) to 17 N.m (13 ft. lbs.). Windshield Washer Bottle - Cracking Windshield Washer Reservoir: All Technical Service Bulletins Windshield Washer Bottle - Cracking Number: 91-31-8E Section: 8E Date: July 1990 Corp. Bulletin No.: 061010 Subject: WASHER BOTTLES CRACKING Model and Year: 1988-91 S/T TRUCKS TO: ALL CHEVROLET DEALERS Some 1988 - 1991 S/T trucks may be experiencing a condition of windshield wiper washer bottles cracking and then leaking washer fluid. This condition can be caused by an increased amount of pressure exerted by the two fastening nuts and screws. This increase of pressure causes the screws to cut into the plastic and initiate cracks. To correct the situation new parts have been released with a wider flange, and the torque requirement has also been revised. The new torque requirement is now 5-8 N-m (3.7 - 5.9 lbs. ft.) instead of the old 8-11 N-m (5.9 - 8.1 lbs. ft.). When ordering a new washer bottle be sure and order new bolts and nuts with the revised flanges. SERVICE PARTS INFORMATION Part Number Description Usage 11509005 nut 2 per bottle 15653669 bolt 2 per vehicle 22072762 container and grommet 1 per vehicle Parts are currently available through GMSPO. WARRANTY INFORMATION For vehicle repaired under warranty use: Labor Operation: N3750 Labor Time: .2 hr. Page 7520 Fuel Gauge: Testing and Inspection Gauge Stays at Full or Beyond This condition is generally caused by a open circuit between the gauge and sending unit. 1. Disconnect sender lead at fuel tank, then ground lead. 2. If fuel gauge reads at empty position, replace tank sending unit. 3. If gauge read at full or beyond, repair open between gauge and fuel tank. Adjustments Ride Height Sensor: Adjustments When repair or adjustment procedures require that vehicle be raised on a hoist, it is important that the rear axle assembly remains in the normal trim height position at all times. When a frame contact hoist is used, two additional jack stands should be used to support the rear axle or control arms in the normal trim height position. Fig. 21 Adjusting Height Sensor The link should be properly attached to the sensor arm and track bar, when making this adjustment. 1. Loosen lock bolt that secures metal arm to height sensor plastic arm, Fig. 21. 2. To raise vehicle trim height, move plastic arm upward and tighten lock bolt. If no adjustment remains, refer to FRONT SUSPENSION/SPECIFICATIONS/VEHICLE TRIM HEIGHT. 3. To lower vehicle trim height, follow step 1 and move plastic arm down. 4. If adjustment cannot be made, check for correct sensor. Fuel System - Fuel Injector Maintenance Cleaning Fuel Injector: All 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 Page 6161 R-4 Compressor Component View Remove or Disconnect Tools Required: J 6083 Snap Ring Pliers J 8092 Driver Handle J 9398 Rotor Bearing Remover J 9481-A Pulley Bearing and Pulley Installer 1. Rotor (5) and hub (3) assembly. Removing The Rotor & Bearing Assembly Retainer Ring 2. Retaining ring (4) with J 6083. Specifications Transmission Speed Sensor: Specifications Electronic Speed Sensor Retainer Bolt ............................................................................................... ...................................................................... 7 ft. lbs. Page 6076 Figure 4 Figure 5 Figure 6 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 7 Page 6262 1. Pressure relief valve (32) with new seal. Tighten ^ Pressure relief valve (32) to 9 N.m (84 in. lbs.). Important ^ Leak test the compressor. Page 7896 Headlamp Switch: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. Figure 21 Figure 22 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. 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). Aluminum Wheels - New Coated Wheel Weights Wheels: All Technical Service Bulletins Aluminum Wheels - New Coated Wheel Weights Number: 91-35-3E Section: 3E Date: August 1990 Corporate Bulletin No.: 003502 Subject: COATED WHEEL WEIGHTS FOR ALUMINUM WHEELS Model and Year: 1985-91 MODELS WITH CAST ALUMINUM WHEELS TO: ALL CHEVROLET DEALERS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 89-65-3E, DATED JANUARY 1989. POLYESTER COATED WHEEL WEIGHTS NOW AVAILABLE FROM GMSPO. THE 1990-91 MODEL YEARS HAVE ALSO BEEN ADDED. ALL COPIES OF 89-65-3E SHOULD BE DISCARDED. Vehicles with cast aluminum wheels use a coated clip on wheel weight. The coating has recently changed from nylon to polyester, giving a more natural appearance that more closely matches the wheel. Coated balance weights are used on both the inboard and outboard rim flanges. They will not discolor, corrode or damage the appearance of the wheel as may have been the case in the past with uncoated clip on weights. These coated weights will fit most GM cast aluminum wheels. There are two types of coated wheel weights available to fit the GM vehicles (see illustration). Both types of weights are available from GMSPO in 1/4 ounce increments. See usage chart below to determine which type weight is correct for the vehicle. "MC" Type Weight Used On: 1990-1991 "W" Car 1988-1990 "Y" Car "AW" Type Weight 1989-1991 "L" Car Used On All Other 1991 "B" Car, "U" Van Series Vehicles 1/4 oz. P/N 9591670 P/N 9591669 1/2 oz. 9591584 9591582 3/4 oz. 9591585 9591583 1-1/4 oz. 9591378 9591362 1-1/2 oz. 9591379 9591363 1-3/4 oz. 9591380 9591364 2 oz. 9591381 9591365 "MC" Type Weight Used On: Transfer Case - Increased Shift Effort From 2H to 4H Technical Service Bulletin # 914047A Date: 910801 Transfer Case - Increased Shift Effort From 2H to 4H Number: 91-404-7A Section: 7A Date: AUGUST 1991 Corporate Bulletin No.: 167401 ASE No.: A2 Subject: HIGH TRANSFER CASK SHIFT EFFORT Model and Year: 1988-91 T1 TRUCKS Some 1988-91 T-Trucks may experience high transfer case shift effort or total blockouts when "shifting on the fly" from 2H to 4H under cold weather conditions. This condition may be corrected by the installation of the synthetic 75W90 gear lube described in Dealer Service Bulletin No. 91-128-7A. This fluid maintains a more constant viscosity under cold weather conditions allowing quicker front axle synchronization and easier transfer case engagement. If the installation of the synthetic fluid does not result in a satisfactory shift effort, an "Easy Shift" package may be installed in the transfer case. This package features a roller pin (53) rather than a solid pin on the mode shift fork (54) and revised ramp angles on the sector (55) to reduce engagement forces. This package was installed in the 1991 model year and will provide reduced transfer case shift effort under cold weather conditions. Figure 1 VEHICLES INVOLVED: Group A: Some 1988-91 T-Trucks equipped with transfer cases identified by the following part numbers: 15568078 15627441 15568079 15627442 15568597 15653450 Saginaw Integral Power Steering Gear Steering Gear: Service and Repair Saginaw Integral Power Steering Gear System Bleeding Four factors affect operation of the steering system: fluid level and condition, drive belt tension, pump pressure and steering gear adjustment. These should always be checked before any major service operations are performed. Conditions such as, hard or loose steering, road shock or vibrations are not always due to steering gear or pump, but are often related instead to such factors as low tire pressure and front end alignment. These factors should be checked and corrected before any adjustment of the steering gear is made. If fluid level is low, add power steering fluid to proper level on dipstick and replace filler cap. 1. Fill pump fluid reservoir to proper level and let fluid settle for at least two minutes. 2. Start and run engine for a few seconds. Do not turn steering wheel. 3. Turn engine Off. Check fluid level, add fluid if necessary. 4. Repeat above procedure until fluid level remains constant after running engine. 5. Raise front end of vehicle so wheels are off ground. 6. Start engine. Slowly turn steering wheel in both directions, lightly contacting wheel stops. 7. Add power steering fluid, if necessary. 8. Lower vehicle and turn steering wheel slowly from lock to lock. 9. Stop engine. Check fluid level and refill as required. 10. If fluid is extremely foamy, allow vehicle to stand a few minutes and repeat above procedure. Flushing Power Steering System Four factors affect operation of the steering system: fluid level and condition, drive belt tension, pump pressure and steering gear adjustment. These should always be checked before any major service operations are performed. Conditions such as, hard or loose steering, road shock or vibrations are not always due to steering gear or pump, but are often related instead to such factors as low tire pressure and front end alignment. These factors should be checked and corrected before any adjustment of the steering gear is made. If fluid level is low, add power steering fluid to proper level on dipstick and replace filler cap. 1. Raise front end of vehicle off ground until wheels are free to turn. 2. Remove fluid return hose at pump inlet connector and plug connector port on pump. Position hose in large container. 3. While an assistant is filling reservoir with new power steering fluid, run engine at idle. turn steering wheel from stop to stop. Do not contact wheel stops or hold wheel in a corner as fluid will stop and pump will be in pressure relief mode. A sudden overflow from reservoir may develop if wheel is held at a stop. 4. Install all pipes and hoses. Fill system with new power steering fluid and bleed system as outlined under SYSTEM BLEEDING. 5. Operate engine for 15 minutes. 6. Remove pump return hose at pump inlet and plug connection on pump. While refilling reservoir, check draining fluid for contamination. If foreign material is still evident, replace all hoses, disassemble and clean or replace power steering system components. Do not reuse any drained power steering fluid. Disassembly If broken components or foreign materials are found during disassembly of the gear, the hydraulic system should be inspected, cleaned and flushed before service is complete. The ball nut and control rings are not generally replaced unless cut or damaged. If replacing, inspect all mating parts for burrs, cracks, scratches or damage. Replace or repair as needed. Page 7693 If the functional brake switch adjustment check does not repair the condition, refer to Section 5 of the appropriate Service Information Manual for aid in diagnosing other causes. For warranty purposes use: Labor Operation Number: N2440 Labor Time: .3 hour TRUCK ONLY: Service Procedure: 1. Depress the brake pedal and press the switch in until it is firmly seated in the clip. * Audible "clicks" can be heard as the threaded portion of the switch is pushed through the clip. 2. Pull the brake pedal against the pedal stop until the audible "click" can no longer be heard. For stop lamp switch adjustments on vehicles repaired under warranty use: Labor Operation Number: T7945 Labor Time: .2 Hr. Locations Brake Proportioning/Combination Valve: Locations LH Side Of Engine Compartment At Master Cylinder 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. ECM - Intermittent Connection Engine Control Module: All Technical Service Bulletins ECM - Intermittent Connection Number: 88-251-8A Section: 8A Date: JUNE, 1988 Subject: INTERMITTENT CONNECTION TO THE ECM Model and Year: 1988 CHEVROLET PASSENGER CARS AND LIGHT DUTY TRUCKS TO: ALL CHEVROLET DEALERS A condition may exist in which the female terminals in the connector to the ECM do not make a solid connection to the male pins in the ECM (see illustration). This can result in an intermittent condition, in any circuit operated by the ECM. The Service Manuals direct a check of connections any time an intermittent condition is found, and this may be the cause of some of these conditions. Visually inspect the terminal using a flashlight, or use a .95 mm pin gauge. The gauge should not pass freely through the female terminal. Do not probe the terminal with anything other than the pin gauge, as probing could damage the terminal. If the female terminal does not grip properly, replace the terminal with P/N 12020757. General directions on wiring repair are shown in Section 8A of the service Manual. Backup Lamps/Tailgate Window Release - Inoperative Shift Interlock Switch: Customer Interest Backup Lamps/Tailgate Window Release - Inoperative Number: 91-459-8A Section: 8A Date: DEC. 1991 Corporate Bulletin No.: 168104 ASE No.: A6 Subject: BACKUP LAMPS OR TAILGATE WINDOW RELEASE INOPERATIVE Model and Year: 1980-91 ALL LIGHT DUTY TRUCKS (EXCEPT GEO) Owners of some 1980-1991 C/K, 1982-1991 G, 1985-1991 M/L, 1984-1991 P2,P3, 1987-1991 R/V, 1983- 1991 ST (including LLV) with automatic transmissions may comment on a condition of inoperative back-up lamps or inoperative tailgate window release. This condition occurs when the vehicle's gear shift lever is placed in the "reverse" position, but the back-up lamps do not illuminate. In addition, on the S/T utility vehicles, the electric tailgate window release does not release when the transmission gear shift lever is placed in the "park" or "neutral" position and the endgate window release button is depressed. The park/neutral and back-up lamp switch comes out of adjustment which does not allow for the contact points to remain engaged. To correct these conditions, the contact carrier on the park/neutral and back-up lamp switch has been modified to increase switch carrier travel. SERVICE PROCEDURE: 1. Disconnect the battery ground cable from the battery. 2. Disconnect the switch assembly harness. 3. Place the gear selector in neutral. 4. Squeeze the tangs on the switch together and remove the switch assembly. 5. Install the new switch assembly (P/N 15679680) by: -aligning the actuator with the cutout in the steering column jacket. -inserting the tangs into the rectangular holes and pushing down on the switch assembly. 6. Adjust the switch by moving the gear selector to park. 7. Connect the switch assembly harness. 8. Connect the negative battery cable. 9. Check for proper switch operation. Readjust the switch as necessary. Page 7777 Light Switch Details (Part 1 Of 3) Paint - Removal of Minor Imperfections Paint: All Technical Service Bulletins Paint - Removal of Minor Imperfections Number: 88-135-10 Section: 10 Date: Jan., 1988 Subject: REMOVAL OF "CHEMICAL SPOTTING" AND OTHER MINOR PAINT IMPERFECTIONS WITHOUT REPAINTING Model and Year: ALL MODELS WITH BASECOAT/CLEARCOAT PAINT TO: ALL CHEVROLET DEALERS This bulletin cancels and supersedes Chevrolet Dealer Service Bulletin 87-166 (Section 10) dated June 1987. This bulletin provides new materials which are available for use on basecoat/clearcoat systems. Some Chevrolet models equipped with basecoat/clearcoat paint applications may experience a condition of small etched spots on horizontal surfaces of the paint finish. This condition is referred to as chemical spotting and may be caused by industrial fallout (acid rain). FIGURE 1 Chemical spotting along with other minor paint imperfections on basecoat/clearcoat finishes, such as sand scratches, dirt in paint, sags and orange peel may be repaired without paint application. Examples of these imperfections are shown in Figure 1. To repair these conditions use the following procedures: Aluminum Wheels - New Coated Wheel Weights Wheels: All Technical Service Bulletins Aluminum Wheels - New Coated Wheel Weights Number: 91-35-3E Section: 3E Date: August 1990 Corporate Bulletin No.: 003502 Subject: COATED WHEEL WEIGHTS FOR ALUMINUM WHEELS Model and Year: 1985-91 MODELS WITH CAST ALUMINUM WHEELS TO: ALL CHEVROLET DEALERS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 89-65-3E, DATED JANUARY 1989. POLYESTER COATED WHEEL WEIGHTS NOW AVAILABLE FROM GMSPO. THE 1990-91 MODEL YEARS HAVE ALSO BEEN ADDED. ALL COPIES OF 89-65-3E SHOULD BE DISCARDED. Vehicles with cast aluminum wheels use a coated clip on wheel weight. The coating has recently changed from nylon to polyester, giving a more natural appearance that more closely matches the wheel. Coated balance weights are used on both the inboard and outboard rim flanges. They will not discolor, corrode or damage the appearance of the wheel as may have been the case in the past with uncoated clip on weights. These coated weights will fit most GM cast aluminum wheels. There are two types of coated wheel weights available to fit the GM vehicles (see illustration). Both types of weights are available from GMSPO in 1/4 ounce increments. See usage chart below to determine which type weight is correct for the vehicle. "MC" Type Weight Used On: 1990-1991 "W" Car 1988-1990 "Y" Car "AW" Type Weight 1989-1991 "L" Car Used On All Other 1991 "B" Car, "U" Van Series Vehicles 1/4 oz. P/N 9591670 P/N 9591669 1/2 oz. 9591584 9591582 3/4 oz. 9591585 9591583 1-1/4 oz. 9591378 9591362 1-1/2 oz. 9591379 9591363 1-3/4 oz. 9591380 9591364 2 oz. 9591381 9591365 "MC" Type Weight Used On: 3L30 (180C) Transmission Fluid Pressure Sensor/Switch: Specifications 3L30 (180C) Transmission Component .......................................................................................................................................... .................................................................... Ft. Lbs. Governor Pressure Switch ................................................................................................................... ................................................................................. 7 Page 4395 Mainshaft Bearing/Bushing: Specifications Warner T-5 (77MM) 5 Speed Front Bearing Cap Retaining Bolts ...................................................................................................... ................................................................... 15 ft. lbs. Page 4305 Figure 13 - Proper Inboard Stroke Positioning 9. Install convolute retainer over seal capturing four convolutes (Figure 13). Important: Joint must be assembled with convolute retainer in position as shown in Figure 13. Seal damage will result if joint is not assembled to dimension shown. Figure 14 - Spider Assembly Installation 10. Install spacer ring and spider assembly (with counterbore toward end of shaft) on the shaft far enough to allow installation of the retaining ring at the end of the halfshaft (Figure 14). 11. Install the retaining ring and push the spider assembly toward the end of the shaft until retaining ring is covered by the spider assembly counterbore. Install the spacer ring and make sure it is seated in its groove. 12. Pack the seal and housing with grease supplied in the kit, (the amount of grease supplied in this kit has been premeasured for this application), place the large metal clamp on the seal, then place the housing over the spider assembly and snap the seal onto the housing. Page 6866 Page 2316 Knock Sensor: Description and Operation Knock Sensor Operation ESC Wiring Diagram The Electronic Spark Control (ESC) system is comprised of a knock sensor, the ESC module, and the ECM. As the knock sensor detects engine knock, it sends a voltage signal to the ECM. The ECM responds by retarding the ignition timing until the knocking ceases. As detonation is reduced, the ECM advances the timing again in small increments back to the pre-programmed point for that engine speed and load. Page 438 Oil Pressure Switch (For Fuel Pump): Description and Operation As a back-up system to the fuel pump relay, the fuel pump can also be turned ON by the oil pressure switch. The oil pressure switch is a normally open switch which closes when oil pressure reaches about 28.0 kPa (4.0 psi). If the fuel pump relay fails, the oil pressure switch will power the fuel pump. 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 Page 4874 FIGURE 4 - ROTOR MOUNTING ADAPTER - J 37160 ^ Adapters, if used, must be clean and free of nicks. Adapters may be used because of a two piece composite rotor design. (Refer to Figure 4). ^ The rotor surface contacting the arbor and/or the adapter must be free of debris and coarse surface corrosion. ^ If the dealership's rotor turning equipment cannot produce a finish cut equivalent to a new rotor's surface, finish cuts may be further improved and made non-directional by dressing the rotor surface with a sanding disc power tool. Light scoring of the rotor surfaces not exceeding 0.38 mm (0.015 inch) in depth, which may result from normal use, will not affect brake operation. To become familiar with the required surface finish, drag a fingernail over the surface of a new rotor from the parts stock or one on a new vehicle. If your brake equipment cannot produce this smooth a finish when correctly used, contact the equipment manufacturer for corrective instructions. Following these refinishing specifications and recommendations will help to hold the rotor surface finish to the specified range. Controlling the braking surface finish of the rotor is necessary to provide adequate early stopping ability and to avoid pulls and erratic performance and will aid in extending lining life. Page 5014 Brake Master Cylinder: Fundamentals and Basics Bench Bleeding Notes BENCH BLEEDING Why A master-cylinder will develop little or no pressure if air is trapped in cylinder bore. Normal brake bleeding will not remove air trapped within the master-cylinder. How Clamp the master-cylinder securely in a vice. It is usually best to clamp the side of the vice onto the flat surface that is used to secure the master-cylinder to the brake booster. There are two basic methods for bleeding master-cylinder, one utilizes stroking the master-cylinder to expel air from the cylinder bore while the other utilizes a large syringe to backflush fluid from the outlet ports to the reservoir. Stroking Fill the master-cylinder with clean brake fluid. - The brake line fittings on the master-cylinder should be capped or plugged. NOTE: Special "bench bleeding" plastic fittings are available which allow for recirculating the brake fluid back into the reservoir. - Using a dull object, slowly stroke the master-cylinder piston, air and brake fluid will be expelled from the brake line fittings. Prior to releasing the piston plug or cap the outlet ports. - Repeat this procedure 8-10 times or until no air is emitted from the outlet ports. - When finished, cap the outlet ports and install the master-cylinder. Syringe Fill the syringe (one especially designed for brake bleeding) with clean brake fluid. - Insert the end of the syringe into one of the outlet ports on the master-cylinder. - Slowly compress the syringe and back flush the brake fluid through the master-cylinder. - A combination of air and brake fluid will be emitted from the inlet port in the fluid reservoir. - Repeat this procedure until only brake fluid is emitted into the reservoir. - Cap the outlet ports and install the master-cylinder. Page 2002 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. Page 5776 Do Not Replace coil-over shock absorbers displaying condition 1 or 2 levels of seepage. 1. Oil or fluid residue only on the bottom of the lower shock absorber tube or the coil-over shock absorber components and not originating from the shaft seal (located at the top of the coil-over shock tube). 2. Light film/residue on the shock absorber tube, but not on the spring seat and originating from the shaft seal. Replace coil-over shock absorbers displaying conditions 3 and 4 levels of leaks. 3. Oil drip or trail down the lower shock tube and originating from the shaft seal. 4. An extreme, wet film of oil covering the shock absorber tube and pooling in the spring seat and originating from the shaft seal. Struts Do Not Replace Struts displaying condition 1 or 2 levels of seepage. 1. Oil or fluid residue only on the bottom of the strut tube or on other strut components and not originating from the shaft seal. 2. Light film/residue on the strut tube, but not on the spring seat and originating from the shaft seal. Replace Struts displaying conditions 3 and 4 levels of leaks. 3. Oil drip or trail down the strut tube and originating from the shaft seal (located at the top of the strut tube). 4. Extreme wet film of oil covering the strut tube and pooling in the spring seat and originating from the shaft seal. Correction Use the information published in SI for diagnosis and repair. Use the applicable published labor operation. Disclaimer Page 1563 Disclaimer Page 5111 Neutral Safety Switch: Service and Repair 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. 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 Generator Light - Flickers During Pulse Wiper Use Diode: All Technical Service Bulletins Generator Light - Flickers During Pulse Wiper Use Number: 90-84-8A Section: 8A Date: November 1989 Corporate Bulletin No: 966402 Subject: GENERATOR LIGHT FLICKER DURING PULSE WIPER OPERATION Model and Year: 1988-89 S, T TRUCKS WITH 2.8L OR 4.3L (VIN CODES R, Z) ENGINES TO: ALL CHEVROLET DEALERS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 89-219-8A, DATED JULY 1989. THE 1990 MODEL S/T VEHICLES ARE INCLUDED IN THE LATEST BULLETIN ALONG WITH A CORRECTION TO THE ELECTRICAL CONNECTOR NUMBER. ALL COPIES OF 89-219-8A SHOULD BE DISCARDED. The generator light flicker condition during pulse wiper switch operation in the 1988, 1989 and 1990 S/T instrument panel, with standard cluster, can be caused by negative voltage transients from the wiper motor. There is no possibility of a system failure as a result of this condition. The effect of this condition is that the generator light will turn on for 80 milliseconds (if gages, the voltage drop on the voltmeter lasts 2.5 seconds). This causes no harm to the generator or other electrical components. Subject condition can be eliminated by installing a diode (industry part number 1N4003) or diode/connector kit (diode kit part number 12085207) in the brown wire at the generator connector (circuit 25 at connector C118). See the following pages in the 1988, 89 and 90 S/T Electrical Wiring Diagrams for circuit 25, connector C118 locations: 1988 4.3L: Section C - Page 24 1988 2.8L: Section C - Page 22 1989 4.3L: Page 40 1989 2.8L: Page 39 1990 2.8L: Page 44 1990 4.3L: Page 45 PARTS INFORMATION: Quantity Part Number Description 1 12085207 Diode ----OR---1 *1N4003 Diode * This part available locally. Parts are currently available from GMSPO. INSTALLATION PROCEDURE: 1. Disconnect the battery. 2. Remove the connector from the generator. 3. Peel back the black plastic conduit covering the wires. 4. If installing diode 1N4003: cut out a section of the brown wire that matches the length of the diode. 4A. A diode/connector kit is also available (GMSPO diode kit part number 12085207). If using the kit cut out approximately four inches of the brown wire, following crimping and soldering instructions in the kit. Spiral tape the solder joints and tuck the wire back into the conduit away from the generator. Secure the diode/connector to the outside of the conduit with electrical tape. 5. Solder in diode with the banded end toward the generator. Page 662 Spark Plug Wire: Locations Spark Plug Wire Routing Page 3884 Shifter A/T: Specifications THM 180 & 180 C Auto Transmission Shift Lever to Selector Lever Shaft ...................................................................................................... ................................................................ 15-25 ft lbs Selector Lever Locknut ........................................................................................................................ .................................................................. 8-11 ft lbs Page 2620 Manifold Pressure/Vacuum Sensor: Description and Operation MAP Sensor The Manifold Absolute Pressure (MAP) sensor measures changes in the intake manifold pressure resulting from engine load and speed changes and converts this to a voltage output, Fig. 7. The ECM sends a 5 volt reference signal to the MAP sensor. As pressure changes in the intake manifold occur, the electrical resistance of the MAP sensor also changes. By monitoring the sensor output voltage, the ECM can determine the MAP. The higher the MAP, the lower the engine vacuum and the higher the sensor output, which requires more fuel. The lower the MAP, the higher the engine vacuum and the lower the sensor output, which requires less fuel. Page 4536 Transmission Position Switch/Sensor: Testing and Inspection Chart C-1A - Park/Neutral Switch Diagnosis Page 6292 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 Page 6959 4. Remove the retention spring from the mirror bracket (Figure 2, Item A). 5. Drill and tap the retention spring, on the rear side wing, so that it will accept a 6.0 mm X 1.0 mm (diameter X thread pitch) set screw fastener (Figure 3, Item A) (procured locally). The approximate fastener length should be 10 mm. NOTE: The hole must be drilled perpendicular to the flat surface of the retention spring's wing. 6. Reinstall the retention spring in the mirror bracket. 7. Reinstall the mirror head and arm to the mirror bracket. 8. Reinstall the mirror assembly to the door. 9. Install the 6.0 mm X 1.0 mm headed fastener, adjusting it to obtain the original pressure against the mirror arm. DO NOT over-torque this fastener. 10. Reinstall the screws which secure the mirror cover to the door. WARRANTY INFORMATION For vehicles repaired under warranty, use: Labor Description Labor Time Operation R3260 RH mirror R&R; 0.4 Hr. Compressor Clutch Air Gap Compressor Clutch: Specifications Compressor Clutch Air Gap With A-6 Compressor Air Gap ................................................................................................................................................ ............................ 0.56-1.34 mm (0.022-0.057 inch) With DA-6 Compressor Clutch Air Gap ..................................................................................................................................... ........................... 0.38-0.64 mm (0.015-0.025 inch) With R-4 Compressor Clutch Plate to Rotor Air Gap ............................................................................................................................................. 0.5-1.0 mm (0.020-0.040 inch) With DA-V5 Compressor Clutch Air Gap ..................................................................................................................................... ........................... 0.38-0.64 mm (0.015-0.025 inch) With HR-6 Compressor Clutch Plate Air Gap ....................................................................................................................................................... 0.38-0.64 mm (0.015-0.025 inch) Page 2959 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"). Page 7678 e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors Do Not require all the steps shown. Skip the steps that Do Not apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. 1. Separate connector halves (see Figures 2 through 6). Figure 2 Figure 3 A/C - Erratic HVAC Operation & Self Diagnostic Blinks Air Conditioning Indicator Lamp: 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). Engine - Generator Belt Tension Drive Belt: All Technical Service Bulletins Engine - Generator Belt Tension GMC NUMBER: 88-T-36 GROUP: 6D - Engine Electrical DATE: September, 1987 CORPORATE NUMBER: 866403 SUBJECT: GENERATOR BELT TENSIONING - CS-130 GENERATORS MODELS: 1986 - 1988 LIGHT DUTY MODELS EQUIPPED WITH CS-130 GENERATORS Some 1986-1988 Light Duty models are equipped with CS-130 Delcotron generators and without automatic belt tensioning equipment. On these applications, the generator belt tension is adjusted by forcing the generator against the belt until the belt tension specification is reached. FIGURE 1 As with several other Delcotron models, the CS-Series housing includes an adjustment lug on the drive end frame (see Figure No. 1) which should be used to push the generator against the belt while the adjustment bolt is tightened. A 3/4" wrench (or equivalent) should be used when holding the generator by this lug. If the vehicle configuration does not permit use of the adjustment lug, pressure may be applied to the side of the drive end frame to tighten the belt. If pressure cannot be applied directly to the drive end frame, a block of wood should be inserted between the prying instrument and the side of the generator to distribute the force to a wider area which includes the drive end frame. Do not pry directly against the stator or slip ring end frame. Page 7675 Symbol Identification Wire Color Code Identification WIRE COLOR ABBREVIATION BLACK BLK BLUE BLU DARK BLUE DK BLU Page 1969 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 Description and Operation Fuel Economy Warning System: Description and Operation This system actually monitors the engine vacuum just like the vacuum gauge, but registers only low vacuum readings. The light on the instrument panel warns the vehicle operator when engine manifold vacuum drops below the economical limit. Switch operation is similar to that of the oil pressure indicating light, except that the switch opens when vacuum pressure, rather than oil pressure, is applied. Page 5355 Note The rivet stud and surrounding panel area MUST BE properly refinished PRIOR to the installation of the electrical ground wire terminal and conductive nut to maintain a secure, stable and corrosion-free electrical ground. 11. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 12. Allow the refinished repair area to cure sufficiently before removing the protective material applied to the rivet stud threads. 13. Remove the painters tape or equivalent from the rivet stud threads. 14. Using GM approved residue-free solvent or equivalent, thoroughly clean the rivet stud threads to remove any adhesive and allow to dry. 15. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive rivet stud. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 16. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 17. Install the electrical ground wire terminal to the M6 conductive rivet stud. 18. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 19. Install the M6 conductive nut to the rivet stud and: Tighten Tighten to 8 Nm (71 lb in) 20. Verify proper system operation. Parts Information Warranty Information (excluding Saab Models) For vehicles repaired under warranty, use: Warranty Information (Saab Models) Page 5741 15522278 Insulator, Front Spring Upper 2 15522279 Insulator, Front Spring Lower 2 12345097 Adhesive, Weatherstrip, 5 oz. 1 Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: E3907 Use applicable labor time guide for labor hours. Page 2780 Throttle Position Sensor: Description and Operation Typical Throttle Position Sensor (TPS) Wiring The Throttle Position Sensor (TPS), is mounted on the side of the throttle body opposite the throttle lever assembly. Its function is to sense the current throttle valve position and relay that information to the ECM. Throttle position information allows the ECM to generate the required injector control signals (base pulse). If the TPS senses a wide open throttle, a voltage signal indicating this condition is sent to the ECM. The ECM then increases the injector pulse width, permitting increased fuel flow. As the throttle valve rotates in response to movement of the accelerator pedal, the throttle shaft transfers this rotation to the TPS. A potentiometer (variable resistor) within the TPS assembly changes its resistance (and voltage drop) in proportion to throttle movement. By applying a reference voltage (5.0 volts) to the TPS input, a varying voltage (reflecting throttle position) is available at the TPS output. For example, approximately 2.5 volts results from a 50% throttle valve opening (depending on TPS calibration). The voltage output from the TPS assembly is routed to the ECM for use in determining throttle position. Page 7771 Figure 8 Figure 9 Figure 10 Figure 11 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). Page 2150 Catalytic Converter: Description and Operation Catalytic Converters 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. Page 6765 2. If the latch is misaligned and/or the endgate glass is not snug against the weatherstrip, remove the endgate inner trim panel and loosen the latch assembly by adjusting the nuts located on the side of the latch assembly (Figure 1, Item 4). Adjust the location of the latch and tighten the adjusting nuts to 8.5-11.0 N-m (6-8 lbs.ft.). 3. Check the endgate window latch for proper operation. If necessary, repeat steps 1 and 2. REPLACEMENT PROCEDURE If the latch assembly is properly adjusted and the condition still occurs, the latch assembly should be replaced by performing the following steps: Page 1444 4WD Without Aluminum Wheels, 6 lug..............................................................................................................................................88 ft/lbs 1987-88 R-, V-Suburban: 2WD...................................................................................................................................................... .............................................103 ft/lbs 4WD With Aluminum Wheels, 6 lug.................................................................................................................................................103 ft/lbs 4WD Without Aluminum Wheels, 6 lug..............................................................................................................................................88 ft/lbs 1987 R-, V-Pickup: 2WD...................................................................................................................................................... ...............................................88 ft/lbs 4WD......................................................................................... ............................................................................................................80 ft/lbs 1987 Van: G10-25.................................................................................................................................................. ...............................................88 ft/lbs G30-35, exc. 8 lug.................................................................... ..........................................................................................................103 ft/lbs G30-35, with 8 lug....... .............................................................................................................................................................. ........125 ft/lbs 1986-87 S-10,15................................................................................................................................... ....................................................................90 ft/lbs 1984-86 C-K Models (Blazer, Jimmy, Suburban): 5 lug (1/2")............................................................................................................................................ .............................................100 ft/lbs 5 lug (9/16")............................................................................. ..........................................................................................................120 ft/lbs 6 lug............................ .............................................................................................................................................................. ...........90 ft/lbs 8 lug............................................................................................................................. ......................................................................140 ft/lbs 1984-86 Van: G10-25.................................................................................................................................................. .............................................100 ft/lbs G30-35 (5 lug).......................................................................... .........................................................................................................120 ft/lbs G30-35 (Dual Rear Wheels, 8 lug)....................................................................................................................................... .............140 ft/lbs 1983-85 S-10, 15: With Standard Wheels.......................................................................................................................... ...............................................81 ft/lbs With Optional Wheels.............................................................. ..........................................................................................................100 ft/lbs 1983 C-K Models (Blazer, Jimmy, Suburban): 5 lug...................................................................................................................................................... .............................................100 ft/lbs 6 lug......................................................................................... ............................................................................................................90 ft/lbs 8 lug............................ .............................................................................................................................................................. .........120 ft/lbs 1983 Van: G10-25.................................................................................................................................................. .............................................100 ft/lbs G30-35 (Single Rear Wheel).................................................... ..........................................................................................................120 ft/lbs G30-35 (Dual Rear W heels).................................................................................................................................................... ..........140 ft/lbs Page 371 Coolant Temperature Sensor/Switch (For Computer): Service and Repair The coolant sensor must be handled carefully. If sensor is damaged, fuel injection operation will be affected. 1. Disconnect battery ground cable. 2. Drain coolant from radiator so level is below sensor. 3. Disconnect coolant sensor electrical connector. 4. Carefully back out coolant sensor and remove. 5. Reverse procedure to install. Page 5003 Pedal Reserve Checks - The pedal should be firm and not leak down. Prior to replacing a master-cylinder for poor pedal travel or feel verify the following: There were no problems with any of the related systems. - The entire brake system has been bled. - Rear brakes are properly adjusted. Page 396 - Diagnostic Chart Code 63. Drivetrain - Recommended Axle Lubricant Fluid - Differential: All 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. Fuels - Effect of Volatility on Driveability Fuel: All Technical Service Bulletins Fuels - Effect of Volatility on Driveability Number: 93-31-6C Section: 6C Date: OCT. 1992 Corporate Bulletin No.: 249128R ASE No.: A1, A8 Subject: EFFECT OF FUEL VOLATILITY ON DRIVEABILITY CONDITIONS Model and Year: ALL MODEL YEARS, ALL PASSENGER CARS AND TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 92-281-6C, DATED SEPT. 1992. THE 1993 MODEL YEAR HAS BEEN ADDED. ALL COPIES OF 92-281-6C SHOULD BE DISCARDED. Recent changes in EPA regulations have effectively lowered the maximum allowable fuel volatility. Volatility, which can be defined as a gasoline's ability to change from a liquid to a vapor, directly affects the amount of evaporative emissions produced by the fuel. Higher volatility means that more unburned hydrocarbons will be released into the atmosphere. Unfortunately, reducing fuel volatility can cause problems during cold engine operation when low temperatures impede the fuel's ability to vaporize and burn. Two terms are often used to describe volatility characteristics. These are: Distillation Curve A graph showing the relationship between temperature and the percentage of fuel evaporated. The fuel components that boil at relatively low temperatures (below about 90 degrees F) are known as the "light ends", and are essential for good cold engine performance. The "heavy ends", which begin to boil at about 300 degrees F, contain the most energy but are more difficult to burn. Laboratory analysis is usually required to determine the distillation curve of a gasoline sample. - Reid Vapor Pressure (RVP) RVP is the pressure (psi) that vaporized fuel exerts within a sealed container as it is heated to 100 degrees F. The higher the RVP the higher the fuel volatility. While RVP is readily tested in the field, fuels of the same RVP can have different distillation curves and cold driveability characteristics. Fuel volatility will vary depending on geographic location and time of year (fuel intended to be used in higher ambient conditions is formulated with less volatility). This can make cold driveability as big a problem during summer months as during the winter. There may be additional variation in the volatility characteristics of pump gasoline, caused by the differences in fuel manufacturers, blends and storage times. As EPA fuel volatility standards are lowered, variations between fuels (which may further reduce volatility) becomes a critical factor influencing cold engine performance. No matter how thoroughly the relationship between fuel quality and cold driveability is understood, eliminating fuel quality as an issue can be difficult, because: TOOLS WHICH TEST FUEL VOLATILITY MEASURE ONLY RVP, NOT THE DISTILLATION CURVE. The distillation curve has a greater effect on cold driveability than RVP. THE CUSTOMER MAY PERCEIVE RAISING THE FUEL QUALITY ISSUE AS AN ATTEMPT TO EVADE HIS PROBLEM. This may cause difficulty in getting accurate fuel usage information. WATER, AND OTHER TYPES OF FUEL CONTAMINATION, MAY CAUSE CONTINUED DRIVEABILITY COMPLAINTS. - The problem symptoms may remain even though the vehicle has been refueled several times with a quality gasoline. CUSTOMER CONCERNS CONDITION: Poor Cold Engine Operation, symptoms may include; hard start/extended crank, stalling, backfiring, hesitation and/or lack of power. POSSIBLE CAUSE: Low volatility fuel will not vaporize sufficiently to allow normal combustion. CORRECTION: Replace Fuel. DIAGNOSTIC PROCEDURE: 1. Perform basic system checks in section 6E of the service manual. 2. Check for service bulletins which relate to cold driveability issues specific to the problem vehicle. Campaign - 90-33O-3E Spare Tire Carrier Rattle Update Spare Tire Carrier: All Technical Service Bulletins Campaign - 90-33O-3E Spare Tire Carrier Rattle Update ADMINISTRATIVE MESSAGE 01-330 CREATED ON 11/16/90 TO: ALL CHEVROLET/GEO DEALERS SUBJECT: DEALER SERVICE BULLETIN 90-33O-3E - "SPARE TIRE CARRIER RATTLE" THE FOLLOWING INFORMATION SHOULD BE COMMUNICATED TO ALL TECHNICIANS INVOLVED IN REPAIRING SPARE TIRE CARRIER RATTLE ON 1986-1991 S/T BLAZERS. A COPY OF THIS MESSAGE SHOULD ALSO BE ATTACHED TO DEALER SERVICE BULLETIN 90-33O-3E. 1. THE LATCH SYSTEM USED ON THE 1986-91 S/T SPARE TIRE CARRIER CONSISTS OF A DOUBLE LATCH MECHANISM AND FUNCTIONS SIMILAR TO THE DOUBLE LATCH EMPLOYED ON HOOD ASSEMBLIES. THE INITIAL LATCH PROVIDES FOR A BACKUP, SHOULD THE MAIN LATCH BECOME DISENGAGED. HOWEVER, THE VEHICLE IS INTENDED TO BE OPERATED WITH THE SPARE TIRE CARRIER LOCKED IN PLACE BY THE MAIN LATCH. CONCERNS OF SPARE TIRE CARRIER RATTLE MAY BE CAUSED DUE TO THE CARRIER ASSEMBLY NOT BEING COMPLETELY CLOSED, BUT RATHER ENGAGED BY THE INITIAL (BACKUP) LATCH ONLY. PRIOR TO ATTEMPTING ANY REPAIRS, AND BEFORE PROCEEDING WITH BULLETIN 90-33O-3E, TECHNICIANS SHOULD OPEN AND THEN FIRMLY CLOSE THE SPARE TIRE CARRIER, VERIFYING THAT THE MAIN LATCH IS FULLY ENGAGED. IF NECESSARY, ROAD TEST THE VEHICLE TO CONFIRM THAT A RATTLE CONDITION STILL EXISTS BEFORE PROCEEDING WITH THE BULLETIN. 2. PRIOR TO ADJUSTING THE RUBBER BUMPER, ASSURE THAT THE NEW ARM IS FULLY ENGAGED IN THE MAIN LATCH MECHANISM. FAILURE TO HAVE THE CARRIER ARM LOCKED IN THE MAIN LATCH WILL RESULT IN AN IMPROPER ADJUSTMENT TO THE BUMPER. 3. THERE IS A TYPOGRAPHICAL ERROR AT THE BOTTOM OF PAGE 4 IN THE PARAGRAPH DIRECTLY FOLLOWING THE WORD IMPORTANT! THE PARAGRAPH SHOULD READ: "THE RUBBER BUMPER WILL CAUSE THE SPARE TIRE CARRIER TO CLOSE HARD FOR A COUPLE OF WEEKS. EVENTUALLY THE RUBBER WILL TAKE A PERMANENT SET AND THE CARRIER WILL CLOSE WITH REASONABLE EFFORT." Page 4176 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. Page 6079 When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 5mm (3/16") of insulation from wire. e. Crimp a new terminal to the wire. f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. Figure 17 To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Figure 18 Figure 19 Specifications Water Pump: Specifications Water Outlet Bolts 21 ft.lb Water Pump Bolts 30 ft.lb Page 7591 Oil Pressure & Temperature Gauge (Gauges Cluster) Base Heater Figure 5 - Heater Functional Test - Base Heater Page 2273 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 module's 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 flexible ducting 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. Page 4715 Labor Operation No.: K6550 Valve, Pressure Regulator-R&R; or Replace Use the appropriate labor time in the labor time guide. Parts are currently available from GMSPO. MAP - Revised Check Chart for DTC's 33, 34, 63, 64 Manifold Pressure/Vacuum Sensor: Technical Service Bulletins MAP - Revised Check Chart for DTC's 33, 34, 63, 64 Number: 90-199-6E Section: 6E Date: March 1990 Corporate Bulletin No.: 016510 Subject: REVISED CHART C-1D, CODE 33, 34, 63, 64 Model and Year: 1980-90 PASSENGER CARS AND TRUCKS TO: ALL CHEVROLET DEALERS This bulletin revises the Manifold Absolute Pressure (MAP) Output Check Chart C-1D and updates Code 33, Code 34, Code 63, and Code 64 in the Service Manual section on "Driveability And Emissions" (Section 6E1, 6E2, and 6E3). This information applies to all MAP Sensors on 1980-1990 vehicles with gasoline engines (except turbocharged) with green (standard) MAP sensor electrical connector insert or the solid black MAP sensor electrical connector insert. The revised chart information: Transfer Case - Increased Shift Effort From 2H to 4H Technical Service Bulletin # 914047A Date: 910801 Transfer Case - Increased Shift Effort From 2H to 4H Number: 91-404-7A Section: 7A Date: AUGUST 1991 Corporate Bulletin No.: 167401 ASE No.: A2 Subject: HIGH TRANSFER CASK SHIFT EFFORT Model and Year: 1988-91 T1 TRUCKS Some 1988-91 T-Trucks may experience high transfer case shift effort or total blockouts when "shifting on the fly" from 2H to 4H under cold weather conditions. This condition may be corrected by the installation of the synthetic 75W90 gear lube described in Dealer Service Bulletin No. 91-128-7A. This fluid maintains a more constant viscosity under cold weather conditions allowing quicker front axle synchronization and easier transfer case engagement. If the installation of the synthetic fluid does not result in a satisfactory shift effort, an "Easy Shift" package may be installed in the transfer case. This package features a roller pin (53) rather than a solid pin on the mode shift fork (54) and revised ramp angles on the sector (55) to reduce engagement forces. This package was installed in the 1991 model year and will provide reduced transfer case shift effort under cold weather conditions. Figure 1 VEHICLES INVOLVED: Group A: Some 1988-91 T-Trucks equipped with transfer cases identified by the following part numbers: 15568078 15627441 15568079 15627442 15568597 15653450 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 Cruise Control - Works Intermittently Cruise Control Switch: All Technical Service Bulletins Cruise Control - Works Intermittently Number: 92-195-9B Section: 9B Date: MAY 1992 Corporate Bulletin No.: 268102R ASE No.: A8 Subject: CRUISE CONTROL WORKS INTERMITTENTLY Model and Year: 1985-92 M VANS 1990-92 L VANS 1986-92 S/T TRUCKS Some owners of 1985-1992 WL vehicles or 1986-1992 S/T vehicles with cruise control (RPO K34) may comment that their cruise control operates intermittently. This condition may be caused by the wires becoming pinched as they exit the multi-functional lever. These wires may ground out on the lever rod and short the cruise function. To correct this condition in production, the wiring harness that exits the lever has been rerouted and the opening in the multi-functional lever has been redesigned to allow the wires more clearance. The diagnostic procedures in the applicable Service Manual should be followed before replacing the multi-functional lever. If the multi-functional lever requires replacement, the following procedure should be performed: SERVICE PROCEDURE: 1. Disconnect the wire harness connector. 2. Remove the harness protector cover. 3. Attach a long piece of mechanic's wire to the end of the harness connector. 4. Remove the multi-functional lever from the turn signal switch. 5. Gently pull the harness up and out so the mechanic's wire can be used to install the new unit. 6. Attach the upper end of the mechanic's wire to the new harness connector. Gently pull the mechanic's wire at the lower end of the column, feeding the harness into the proper location in the column. 7. Install a redesigned multi-functional lever (P/N 25111290) into the turn signal switch. 8. Disconnect the mechanic's wire from the harness connector. 9. Install the harness protector cover. 10. Reconnect the wire harness connector. SERVICE PARTS INFORMATION Part Number Description 25111290 Multi-functional Lever Use applicable labor time guide for labor hours. Important: The new Part Number (P/N 25111290) should be used when correcting this condition in the above listed vehicles. W/Integral Reservoir Power Steering Pump: Description and Operation W/Integral Reservoir The hydraulic pump is a submerged, vane-type design. Submerged pumps have a housing and internal parts inside the reservoir and operate submerged in fluid. There are two openings at the rear of the pump housing. The larger opening contains the cam ring, pressure plate, thrust plate, rotor and vane assembly and the end plate. The smaller opening contains the pressure line union, flow control valve, and spring. The flow control orifice is part of the pressure line union. The pressure relief valve, located inside the flow control valve, limits pump pressure. Page 6239 Expansion Block/Orifice Tube: Service and Repair Fig 1. CCOT A/C System Components Fig 5. Orifice Tube. Torque Spark Plug: Specifications Spark Plugs 22 ft.lb Page 6346 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 Electrical - Instrument Panel & General Wiring Repair Wiring Harness: All Technical Service Bulletins Electrical - Instrument Panel & General Wiring Repair Bulletin No.: 06-08-45-004 Date: May 02, 2006 INFORMATION Subject: Instrument Panel (I/P), Body and General Wiring Harness Repair Models: 2007 and Prior GM Cars and Trucks 2003-2007 HUMMER H2 2006-2007 HUMMER H3 Important: A part restriction has been implemented on all Body and I/P harnesses and is being administered by the PQC. If a body or I/P harness replacement is required, it can take 12-28 weeks for a harness to be built and delivered to a dealer. The dealer technician is expected to repair any harness damage as the first and best choice before replacing a harness. In an effort to standardize repair practices, General Motors is requiring that all wiring harnesses be repaired instead of replaced. If there is a question concerning which connector and/or terminal you are working on, refer to the information in the appropriate Connector End Views in SI. The Instruction Manual J 38125-620, which is sent with each new update of the J 38125 Terminal Repair Kit, also has terminal crimping and terminal remove information. Important: There are some parts in the J 38125 Terminal Repair Kit (i.e. SIR connector CPAs and heat shrink tube (used in high heat area pigtail replacement) and some TPAs that are not available from GMSPO. It is vitally important that each update to the J 38125 Terminal Repair Kit be done as soon as it arrives at the dealer. Utilize the Terminal Repair Kit (J 38125) to achieve an effective wiring repair. The Terminal Repair Kit has been an essential tool for all GM Dealers since 1987. Replacement terminals and tools for this kit are available through SPX/Kent Moore. Refer to Corporate Bulletin Number 06-08-45-001 for more information. The Instruction Manual J 38125-620, which is sent with each new update to the J 38125 Terminal Repair Kit, also has terminal crimping and terminal removal information. U.S. Dealers Only - Training courses (including Tech Assists, Emerging Issues, Web, IDL and Hands-on) are available through the GM Training website. Refer to Resources and then Training Materials for a complete list of available courses. Canadian Dealers Only - Refer to the Training section of GM infoNet for a complete list of available courses and a copy of the J 38125 Terminal Repair Kit Instruction Manual. Wiring repair information is also available in Service Information (SI). The Wiring Repair section contains information for the following types of wiring repairs: - Testing for intermittent conditions and poor conditions - Flat wire repairs - GMLAN wiring repairs - High temperature wiring repairs - Splicing copper wire using splice clips - Splicing copper wire using splice sleeves - Splicing twisted or shielded cable - Splicing inline harness diodes Page 2950 - 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 Page 4814 Brake Caliper: Testing and Inspection Should it become necessary to remove the caliper for installation of new parts, clean all parts in denatured alcohol or brake parts cleaner, wipe dry using lint-free cloths. Using compressed air, blow out drilled passages and bores. Check dust boots for punctures or tears. If punctures or tears are evident, new boots should be installed upon reassembly. Inspect piston bores in both housings for scoring or pitting. Bores that show light scratches or corrosion can usually be cleaned with crocus cloth. However, bores that have deep scratches or scoring may be honed, provided the diameter of the bore is not increased more than 0.05 mm (0.002 inch). If the bore does not clean up within this specification, a new caliper housing should be installed (black stains on the bore walls are caused by piston seals and will do no harm). When using a hone, be sure to install the hone baffle before honing bore. The baffle is used to protect the hone stones from damage. Use extreme care in cleaning the caliper after honing. Remove all dust and grit by flushing the caliper with denatured alcohol or brake parts cleaner. Wipe dry with clean lint-free cloth and then clean a second time in the same manner. Page 354 Light Switch Details (Part 2 Of 3) Modes of Operation Engine Control Module: Description and Operation Modes of Operation Acceleration Mode In the Acceleration Mode, the ECM senses rapid change in throttle position and manifold pressure and provides a corresponding amount of added fuel. Battery Voltage Correction Mode When battery voltage is low, the ECM compensates to maintain acceptable system performance by increasing injector pulses, idle speed and ignition dwell time. Clear Flood Mode (Port and TBI Injection) A flooded engine is cleared by fully depressing the accelerator pedal, which causes the ECM to pulse the injectors at a air/fuel ratio of 20:1. The ECM will maintain this air/fuel ratio as long as the throttle is wide open and engine RPM is less than 600. If throttle position becomes less than 80% of wide open throttle, the ECM returns to "Starting Mode". Deceleration Mode In the Deceleration Mode, the ECM senses changes in throttle position and manifold pressure and reduces fuel delivery. When decelerating very rapidly, the ECM can cut off fuel completely for short periods of time. Electronic Spark Timing (EST) The Electronic Spark Timing (EST) distributor contains no vacuum or centrifugal advance mechanisms. In addition to the connectors normally found on HEI distributors, the HEI-EST distributor also has four wires going to a four terminal connector. A reference pulse, indicating engine RPM and crankshaft position is sent to the ECM. The ECM determines the proper spark advance for the engine operating conditions and sends an "EST" pulse to the distributor. In the case of EST failure, a back-up spark advance system is incorporated in the module. Run Mode The Run Mode consists of two separate operating conditions; open loop and closed loop. The engine operates in open loop when it is first started and RPM is above 400 RPM. During open loop operation, the ECM disregards the oxygen sensor signal and determines air/fuel mixture primarily from the coolant and MAP sensors. The engine will continue to operate in open loop until the following conditions are met: 1. The Oxygen sensor has varying voltage output, indicating it is hot enough to operate properly. 2. The Coolant sensor is above a specified temperature. 3. A specific amount of time has elapsed since the engine was started. The specified values for conditions mentioned above vary from model to model, and are stored in the ECM PROM. When the above conditions are met, the engine goes into closed loop operation. When operating in closed loop, the ECM determines the air/fuel ratio (injector pulse rate) based on signals from the oxygen sensor. This allows the air/fuel mixture to remain close to the optimum 14.7:1 ratio. During idling conditions, the V6-173 and V8-454 engines automatically goes into open loop operation. Starting Mode (Port and TBI Injection) When the ignition switch is rotated to the "On" position, the ECM energizes the fuel pump for two seconds and fuel pressure is built up to the TBI unit. The ECM then checks the coolant temperature sensor, the TPS and determines the proper air/fuel mixture for starting. The ECM controls the air/fuel ratio by changing the length of time the injectors are turned on and off. This is accomplished by "Pulsing" the injectors for short periods of time. Detonation Sensor LH Rear Of Engine, At Rear Of Cylinder Head Page 2083 Coolant Level Indicator Lamp: Service and Repair This lamp will be illuminated when engine coolant level in the radiator drops below a pre-determined level. To turn lamp "OFF," check cooling system, then add coolant to bring system to proper level. Page 577 What corrected the customer concern and was the repair verified? Please Explain: ............. Disclaimer Page 7906 Light Switch Details (Part 2 Of 3) Coolant Temperature Sensor Radiator Cooling Fan Temperature Sensor / Switch: Locations Coolant Temperature Sensor Center Of Dash Panel (engine Compartment) Center Front Of Engine Applicable to: V6-262/4.3L Engine Page 1077 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 Page 3109 Oil Pressure Switch (For Fuel Pump): Testing and Inspection Refer to DIAGNOSTIC CHARTS/FUEL PUMP RELAY CIRCUIT DIAGNOSIS (CHART A-5), for fuel related oil pressure switch problems. Lighting - Exterior Lamp Condensation and Replacement Parking Lamp: Technical Service Bulletins Lighting - Exterior Lamp Condensation and Replacement INFORMATION Bulletin No.: 01-08-42-001H Date: January 05, 2011 Subject: Exterior Lamp Condensation and Replacement Guidelines Models: 2011 and Prior GM Passenger Cars and Trucks (including Saturn) Supercede: This bulletin is being revised to add the 2011 model year. Please discard Corporate Bulletin Number 01-08-42-001G (Section 08 - Body and Accessories). The following information is being provided to better define the causes of condensation in exterior lamps and includes guidelines for determining the difference between a lamp with a normal atmospheric condition (condensation) and a lamp with a water leak. Some exterior lamps, such as cornering, turn signal, backup, headlamps or tail lamps may exhibit very small droplets of water, a fine mist or white fog (condensation) on the inside of the lamp lens. This may be more noticeable on lamps with "multi-lens" designs and may be normal during certain weather conditions. Condensation occurs when the air inside the lamp assembly, through atmospheric changes, reaches the "dew point". When this takes place, the moisture in the air within the lamp assembly condenses, creating a fine mist or white fog on the inside surface of the lamp lens. Most exterior lamps on General Motors vehicles use a vented design and feature a replaceable bulb assembly. They are designed to remove any accumulated moisture vapor by expelling it through a vent system. The vent system operates at all times, however, it is most effective when the lamps are ON or when the vehicle is in motion. Depending on the size, shape and location of the lamp on the vehicle, and the atmospheric conditions occurring, the amount of time required to clear the lamp may vary from 2 to 6 hours. Completely sealed headlamp assemblies (sealed beams) are still used on a limited number of models being manufactured today. These lamps require the replacement of the complete lamp assembly if a bulb filament burns out. Condensation 2006 TrailBlazer Shown A Fine Mist or White Fog on the Inside Surface of the Lamp Lens Occurring After a Period of High Humidity - May be located primarily in the lens corners (near the vents) and SHOULD NOT cover more than half the lens surface. - The condition should clear of moisture when the vehicle is parked in a dry environment, or when the vehicle is driven with the lights ON. - A comparison of the equivalent lamp on the opposing side of the vehicle indicates a SIMILAR performance. If the above conditions are noted, the customer should be advised that replacement of a lamp assembly may not correct this condition. Water Leak New Style Pickup Shown Page 343 Symbol Identification Page 7248 Figure No. 3 Open the carrier and swing it out of the way. Lower the tailgate window and grab hold of the tailgate. If there is any movement fore or aft or play other than normal tailgate flex, then perform the following service procedure. If there is no play in the tailgate then continue on to Service Procedure 3 1) Disconnect wiper motor wire, wiper fluid hose (if so equipped), and the two tail-gate supports. See Figures 2 and 3 for disconnection areas. 2) Remove tailgate bumpers shown in figure 3. Seal the holes in the body with a clear RTV sealer (Permatex C6B or equivalent). Page 3129 Throttle Body: Service and Repair Concealment Plug Removal Concealment Plug Removal If necessary to adjust minimum idle speed, the concealment plug must first be removed. Refer to Fig. 343 when removing plug. Main Bearing Dimensions Crankshaft & Bearings SIR - Operating Vehicle with Warning Light On Malfunction Lamp / Indicator: Customer Interest SIR - Operating Vehicle with Warning Light On File In Section: 8 - Chassis/Body Electrical Bulletin No.: 83-81-34 Date: March, 1999 INFORMATION Subject: Operating Vehicle with Supplemental Inflatable Restraint (SIR) Warning Light Illuminated Models: 1999 and Prior Passenger Cars and Light Duty Trucks with SDM Controlled Air Bag System The AIR BAG warning light is the key to driver notification of Supplemental Inflatable Restraint (SIR) system malfunctions. When the warning light remains illuminated or continues to flash, one or more of the following conditions may occur if vehicle operation is continued. ^ Non-deployment of the air bags in the event of a crash. ^ Deployment of the air bags without a crash. ^ Deployment of the air bags in crashes less severe than intended. If an AIR BAG warning light is illuminated or flashing, you should advise the customer of these possibilities and that the vehicle should be serviced right away. 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. Transfer Case - High Shift Effort When Shifting Fluid - Transfer Case: Customer Interest Transfer Case - High Shift Effort When Shifting Number: 91-165-7A Section: 7A Date: January 1991 Corporate Bulletin No.: 967402R Subject: HIGH TRANSFER CASE SHIFT EFFORT Model and Year: 1983-91 T1 TRUCKS 1988-91 K TRUCKS TO: ALL CHEVROLET DEALERS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 91-128-7A, DATED NOVEMBER 1990. THE BULLETIN NUMBER HAS BEEN CORRECTED IN THE FIRST PARAGRAPH. ALL COPIES OF 91-128-7A SHOULD BE DISCARDED. Some four wheel drive K and T trucks may experience high transfer case shift effort and/ or total blockouts when "SHIFTING ON THE FLY" from 2H to 4H under cold weather conditions (usually 25 degrees or less). In order to shift to 4H the speed of the front propshaft must be increased to allow proper engagement of front axles. As the transfer case shift lever is moved into 4H the front propshaft begins rotating to synchronize the front axle assembly. In cold weather conditions regular production lube has high viscosity which may delay or prohibit the synchronizing of the front propshaft and axle resulting in high transfer case shift effort. To reduce high shift effort, regular production front axle gear lube may be replaced with a 75W-90 synthetic gear lube which maintains a lower viscosity under cold weather conditions. This synthetic gear lube is now available in one quart containers from GMSPO. Before installing, it is important to drain and flush the front axle with clean mineral based (non synthetic) axle lube. The front axle should then be refilled to the level of the filler hole with synthetic lube listed below. Front Axle Lube Capacities: K1, K2 - 1.66 liter (1.75 qts) K3 - 2.13 Liter (2.2 qts) T1 - 1.20 liter (1.3 qts) SERVICE PARTS INFORMATION P/N DESCRIPTION 12345836 SAE 75W-90 synthetic gear lube, 1 qt. bottle Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation Number: T7980 Labor Time: .4 hr Trouble Code: 92 NOTE: Labor Operation is coded to base vehicle coverage in the warranty system. Page 7157 * Select applicable additional "Labor Hours" and add to above "Labor Hours" as needed. Fuse Block - Deforms Fuse Block: All Technical Service Bulletins Fuse Block - Deforms Number: 90-432-8B Section: 8B Date: SEPT. 1991 Corporate Bulletin No.: 168102 ASE No.: A6 Subject: FUSE BLOCK DEFORMS Model and Year: 1988-90 SI (LLV) POSTAL VEHICLES Some 1988 to 1990 LLV postal vehicles built prior to August 3, 1990, may exhibit a condtion where the fuse block is partially deformed due to heat generated by continuous operation of the hazard flasher. This condition may be corrected by the repositioning of the hazard flasher to a remote location. SERVICE PROCEDURE: 1. Disconnect positive battery cable. 2. Remove old flasher. 3. Back out terminals for circuit 140A (orange wire) and circuit 27 (brown wire) using a small flat screwdriver or pick. Using the same tool, raise the locking tang on the back of the terminal. 4. Cut electrical tape used to wrap main wiring harness a sufficient amount to provide 2 to 3 inches of flasher wiring for relocation. 5. Insert terminals of circuits 140A and 27 into new connector (P/N 2973385). 6. Install electronic flasher (P/N 15504673) into the new connector. 7. Using nylon ties, strap the connector and flasher assembly to the wiring harness that runs above the fuse block. Verify that the relocated flasher and all wiring is secured so it does not cause interference with the throttle linkage. 8. Reconnect battery cable. 9. Test operation of hazard flasher system. SERVICE PARTS INFORMATION PART NUMBER DESCRIPTION QTY 2973385 Connector 1 15504673 Flasher (Electronic) 1 NPN Nylon Tie Straps 2 Parts are currently available from GMSPO. Page 7159 Page 4084 Valve Body: Specifications THM 180 & 180 C Auto Transmission Transfer Plate to Valve Body ............................................................................................................... .................................................................... 6-8 ft lbs Valve Body to Case ......................................... .................................................................................................................................................... 13-15 ft lbs Page 2492 Spark Plug: Description and Operation Resistor type, copper core, tapered seat quantum spark plugs are used on all engines. No gasket is used on these tapered seat plugs. A dot before the spark plug code or the letter C after the number in the code indicates that the plug has a copper core. For the correct gap information refer to the Vehicle Emissions Control Information label under the hood or refer to SPECIFICATIONS/ELECTRICAL AND ELECTRONIC SPECIFICATIONS. Normal or average service is assumed to be a mixture of idling, slow speed, and high speed operation with some of each making up the daily total driving. Occasional or intermittent high-speed driving is essential to good spark plug performance as it provides increased and sustained combustion heat that burns away any excess deposits or carbon or oxides that may have accumulated from frequent idling or continual stop and go or slow speed driving. Spark plugs are protected by an insulating boot made of special heat-resistant material which covers the spark plug terminal and extends over a portion of the plug insulator. These boots prevent flash-over with resultant missing of the engine, even though a film is allowed to accumulate on the exposed portion of the plug porcelains. Do not mistake corona discharge for flash-over or a shorted insulator. Corona is a steady blue light appearing around the insulator, just above the shell crimp. It is the visible evidence of a high-tension field, and has no effect on ignition performance. Usually it can be detected only in the darkness. This discharge may repel dust particles, leaving a clear ring on the insulator just above the shell. This ring is sometimes mistakenly regarded as evidence that combustion gases have blown out between the shell and the insulator. Page 1712 Intake Manifold: Specifications Intake Manifold Bolts 35 ft.lb Page 3419 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. Page 4468 6. Tape the solder and diode. 7. Reinstall the black plastic conduit. 8. Reconnect connector to the generator. 9. Reconnect battery. This procedure will not affect the operation of the generator light during the bulb check at the beginning of the start cycle. For vehicles repaired under warranty use, Labor Operation Number: T7990 Labor Time: .4 Hr Removal Brake Caliper: Service and Repair Removal For additional information see Removal Notes. See: Fundamentals and Basics 1. Siphon enough brake fluid out of the master cylinder to bring fluid level to 1/3 full to avoid fluid overflow when the caliper piston is pushed back into its bore. 2. Raise vehicle and remove front wheels. Fig. 2 Compressing piston & shoes with C-clamp 3. Using a C-clamp, push piston back into its bore. Fig. 3 Caliper & Mounting Bolts 4. Remove two mounting bolts and lift caliper away from disc. Hang caliper from coil spring with wire. CAUTION: Do not allow caliper to hang from brake hose. Page 2757 - Diagnostic Chart Code 63. Page 257 Oil Pressure Switch (For Fuel Pump): Testing and Inspection Refer to DIAGNOSTIC CHARTS/FUEL PUMP RELAY CIRCUIT DIAGNOSIS (CHART A-5), for fuel related oil pressure switch problems. 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. Diagram Information and Instructions Courtesy Lamp: Diagram Information and Instructions 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 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. Camshaft Dimesions Camshaft: Specifications Vin Z, Camshaft Dimensions Vin Z, Camshaft Dimensions Camshaft Journal Diameter 1.8682-1.8692 in Camahaft Endplay 0.004-0.012 in Camshaft Runout Maximum 0.001 in Page 8035 Front Door Window Regulator NOTE: Images shown are for manual windows, power windows are similar REMOVE OR DISCONNECT 1. Door trim panel. 2. Armrest bracket. 3. Water deflector. ^ Raise the window to the full-up position secure the glass to the door frame using cloth backed tape. 4. Bolts securing the regulator to the door inner panel. 5. Regulator lift arm roller from the window mount sash. 6. Regulator from the door. INSTALL OR CONNECT 1. Regulator to the door. 2. Regulator lift arm roller to the window mount sash. 3. Bolts securing the regulator to the door inner panel. 4. Water deflector. 5. Armrest bracket. 6. Door trim panel. Page 7717 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 4. Make repair. Page 4038 HYDRA-MATIC 4L60 IMPORTANT: Overtorquing or uneven torquing of the bolts during unit reassembly can cause valves to bind. This condition may become more apparent as the unit warms to operating temperature. The correct bolt torque specifications for the HYDRA-MATIC 4L60 control valve assembly are 8-14 N-m (6-10 lb.ft.). Torquing bolts to the minimum specification, 8 N-m (6 lb.ft.) is recommended. The bolts should be tightened in a spiral pattern starting at the center and working toward the outside of the control valve assembly as shown in Figure 2. Fuse Link A Fusible Link: Locations Fuse Link A Center Of Dash Panel (engine Compartment) At Rear Of Generator Applicable to: V6-262/4.3L Engine 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. Page 4966 Caliper Knuckle Clearances 5. Measure the clearance between the caliper and the steering knuckle. The clearance at each end of the caliper should be measured individually and added together. this total should be between 0.26-0.60 mm (0.010-0.024 inch). 6. If brake hose was removed, reconnect it and bleed the brakes. 7. Install wheels and tires, lower vehicle and add brake fluid to master cylinder to bring level to 1/4 inch from top. WARNING: Before moving vehicle, pump brake pedal several times to be sure it is firm. Do not move vehicle until a firm pedal is obtained. ECM - Packard 32 Way Connector Identification Engine Control Module: All Technical Service Bulletins ECM - Packard 32 Way Connector Identification Number: 90-56-8 Section: 8 Date: September 1989 Corporate Bulletin No.: 916521R Subject: PACKARD 32 WAY CONNECTOR IDENTIFICATION Model and Year: 1980-90 A, B, F, G, J, L, W, Y CARS AND ALL TRUCKS WITH GMP4 ECM APPLICATIONS TO: ALL CHEVROLET DEALERS This bulletin serves to clarify the labeling of the Packard 32 way connectors used on the GMP4 under dash ECMS. Currently a common strain relief is used in both the C-D 32 pin and the E-F 32 pin connectors. To properly identify these connectors, the strain reliefs must be removed. Use the lettering on the connector as shown on figure. The colors used at this time for the 32 pin E-F connector are yellow, mint green or orange. This updates any previous information released concerning identification that indicates any of these colors as being C & D connectors, found in the 6E and 8D Sections of the affected Service Manuals. 3L30 (180C) Transmission Bell Housing: Specifications 3L30 (180C) Transmission Component .......................................................................................................................................... .................................................................... Ft. Lbs. Converter Housing To Case ................................................................................................................ ............................................................................... 25 Converter Housing To Cylinder Block ............ .............................................................................................................................................................. ..... 25 Converter Housing To Oil Pump ............................................................................................... ......................................................................................... 14 Lower Cover To Converter Housing ..... .............................................................................................................................................................. ................. 7 Page 7776 Light Switch Details (Part 3 Of 3) Page 1095 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. Page 3043 Fuel Injector: Tools and Equipment Kent-Moore Fuel Injector Tester, tool J-39021, has the capability of performing injector balance and coil tests on all GM and many non-GM fuel injection systems. In addition to the familiar fuel pressure drop test, the injector coil test is a new test whereby the injector's resistance is measured during normal operation by feeding a fixed current through the injector and measuring the voltage drop across the injector. Injector coil failures are more accurately detected using this method than by simply measuring the injector's resistance with an ohmmeter. Refer to the instructions included with the tool. For further information, refer to TSB 93-6E-14, dated June 1993. (Corp. Ref. No.: 316501R) NOTE: Measuring injector resistance is not a fool-proof method of determining the condition of the injectors. A Fuel Injector Balance Test will more accurately determine the mechanical condition of the injector, while the injector resistance will determine the electrical condition of the injector. If available, use applicable C-Charts at Computers and Control Systems, Testing and Inspection. You should also start at Diagnostic System Check if you have not already done so. See: Computers and Control Systems/Testing and Inspection Page 1369 sure the retainer cup is tree from dirt, grease, and gouges. Most wheel balancers now offer this type of protected retainer. DO NOT allow the retainer cup to rotate against the wheel's surface when tightening the wheel to the balancer. DO NOT OVERTIGHTEN. Most balancers use a large "wing nut" design to clamp the retainer against the wheel. Hand tight is sufficient. This procedure will allow accurate balancing using the conventional back cone method. Important: Coated balance weights must be used on aluminum wheels to prevent damage to the rim flange. Except for the N9O 4X4 wheel used on T trucks, all light truck aluminum wheels will accept either "AW" series or "MO" series clip-on coated weights on both the inside and outside rim flanges. The N9O T truck wheel will accept "AW" series weights on the inside rim flange only. The outside rim flange is not designed to accept a clip-on weight. If such a weight installation is attempted, a poor fit will result, and the weight may fall off and/or cause cosmetic damage to the rim flange. This wheel can be 1) static balanced by clipping all the weight on the inside rim flange (as is done in the assembly plant), or 2) dynamic balanced by clipping a weight on the inside flange and using an adhesive weight near the outside flange. The charts show "AW" and "MC" balance weight usage. These original equipment coated weights are available at competitive prices through the GM Dealer Equipment program. Page 3327 A new pressure regulator valve (III. 218) has been made which will improve the oil pressure stability at lower RPM. SERVICE PARTS INFORMATION: Description Part Number Valve, Pressure Regulator (III. 218) 8684048 Part numbers are for Reference Only. Check with your Parts Department for latest information. Page 4619 This part number can be found on the identification tag (80) located on the rear case half (Figure 1). Group B: Some 1991 T-Trucks equipped with transfer cases identified by the following part numbers and built before 10/22/90: 15653414 15659232 This part number and build number can be found on the identification tag (80) located on the rear case half (Figure 1). Service Procedure: Group A: These transfer cases require the replacement of the parts indicated in the Group A column of the PARTS INFORMATION section. Group B: These transfer cases require the replacement of the parts indicated in the Group B column of the PARTS INFORMATION section. Remove Page 6348 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: Specifications TEMPERATURE SENSORS Page 970 Figure 3 REMOVE (Figures 2 & 3) Tools required: J8092 Drive handle J33790 Bearing installer and remover 1. Transfer case from vehicle. - Refer to Section 7D of the appropriate S/T Service Manual for complete transfer case removal procedure. 2. Front output flange nut (77), washer (76), rubber sealing washer (75) and front output flange (74) from the front output shaft. 3. Vacuum switch (46) and O-ring seal (47). 4. Poppet screw (68), O-ring seal (69), poppet spring (71) and poppet plunger (70). Mainshaft Extension and Oil Pump Housing 5. Rear extension housing bolts (3) and rear extension (4). 6. Bearing retainer (snap ring) (5) from the mainshaft (19). 7. Pump retainer housing bolts (7). 8. Pump retainer housing (8) from the rear case half (17). 9. Speedometer tone wheel (11) from the mainshaft (19). Page 7215 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 Page 764 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 Description and Operation Oil Pressure Warning Lamp/Indicator: Description and Operation Many trucks utilize 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. Page 5322 Courtesy & Dome Body & Frame - Misalignment of Pickup Box to Cab Truck Bed: All Technical Service Bulletins Body & Frame - Misalignment of Pickup Box to Cab Number: 93-91-10 Section: 10 Date: JAN. 1993 Corporate Bulletin No.: 261514 ASE No.: B1 Subject: MISALIGNMENT OF PICKUP BOX TO CAB Model and Year: 1982-93 S/T TRUCKS Some owners of 1982-1993 S/T pickups may comment about misalignment of the pickup box to the cab. CAUSE: Misalignment may occur as a result of the frame mounting hole not allowing side to side adjustment. CORRECTION: To correct, it is necessary to enlarge the left front hole on the frame at the front of the pickup box and realign the box to the cab. SERVICE PROCEDURE: 1. Loosen all of the pickup box to frame bracket mounting bolts. Remove only the left corner bolt. 2. Raise and support the front left corner of the box approximately one inch (1"). 3. Drill, from the bottom up, the left front hole in the frame mounting bracket enlarging the hole to approximately 17 mm (11/16") ID. 4. Lower the box and loosely reinstall the left front corner mounting bolt. 5. Align the box to the cab body. Torque all the box to frame bracket mounting bolts 40-54 N-m (30-40 lbs.ft.). WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: B5300 Use applicable labor time guide for labor hours. Page 3532 Bell Housing: Specifications THM 180 & 180 C Auto Transmission Converter Housing to Cylinder Block ................................................................................................... ............................................................... 20-30 ft lbs Page 3396 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. Page 6549 Some Chevrolet models may exhibit a condition of poor AM or FM radio reception. This may be caused by a poor contact on the female terminal of the antenna coaxial cable lead. The illustration contains a four-step procedure to test and repair the female terminal. The opening in the female terminal should range from .120" to .125" in diameter. If the gage passes through freely, the terminal should be repaired as illustrated. Gage sets are available from Kent Moore, tool number J26900-14. For warranty purposes use Labor Operation T6369 at .5 hour for all carlines. Automatic Trans. Neutral Safety Switch: Locations Automatic Trans. LH Side Of I/P Behind Instrument Cluster Transfer Case - 231HD Noisy in 4WD High Drive Chain: All Technical Service Bulletins Transfer Case - 231HD Noisy in 4WD High Number: 91-63-7D Section: 7D Date: August 1990 Corp. Bulletin No.: 067405 Subject: NOISY TRANSFER CASE IN 4-HIGH Model and Year: 1988-91 T TRUCKS WITH 231HD TRANSFER CASE TO: ALL CHEVROLET DEALERS Some 1988-1991 T trucks may experience a noisy transfer case when the truck is in 4-high. The noise is caused by rotation of the chain and gears and is transmitted through the transfer case shift linkage into the body interior. A quieter "T" pattern transfer case chain and softer durometer shift rod grommets have been released to decrease the noise level. The chain can be identified by two blue links while the previous design contained one blue link. The softer grommets are orange or beige while the previous design grommets were white. SERVICE MANUAL REFERENCE Refer to the Unit Repair Section of the appropriate Service Manual for the proper replacement procedures. SERVICE PARTS INFORMATION Quantity Part Number Description Required 15635937 Chain 1 15659238 Shift Rod Grommet 2 Parts are currently available through GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Labor Operation Description Time T7036 Replace Chain and 2.1 hrs. Install Grommets FAILURE CODE: 92 A/T - Buzzing Noise at Idle Fluid Pressure Sensor/Switch: All Technical Service Bulletins A/T - Buzzing Noise at Idle Number: 93-29-7A Section: 7A Date: OCT. 1992 Corporate Bulletin No.: 277142 ASE No.: A2 Subject: BUZZING NOISE AT IDLE Model and Year: 1982-93 CAPRICE, CAMARO AND CORVETTE 1982-93 C/K, R/V, S/T, M/L AND G TRUCKS WTIH 4L60 AUTOMATIC TRANSMISSION TRANSMISSION APPLICATIONS: 1982-1993 HYDRA-MATIC 4L60 (MD8) TRANSMISSION MODELS: All SUBJECT: Pressure Regulator Valve Buzz VEHICLE APPLICATIONS: B, D, F, Y - Cars C/K, R/V, S/T Trucks G, M, L - Vans CONDITION: Some 1982-1993 vehicles equipped with a HYDRA-MATIC 4L60 transmission may have a buzzing noise coming from the transmission when the vehicle is at idle. The buzzing noise may be noticed more when the vehicle is in reverse at idle. CAUSE: The buzzing noise may be a result of pressure regulator valve oscillating due to oil pressure instability at lower idle RPM. CORRECTION: Instrument Panel - Upper Surface Reflection Instrument Cluster / Carrier: Customer Interest Instrument Panel - Upper Surface Reflection File In Section: 08 - Body and Accessories Bulletin No.: 99-08-49-006 Date: April, 1999 INFORMATION Subject: Cleaning of Upper Instrument Panel Surfaces Models: 1999 and Prior Passenger Cars and Light Duty Trucks Comments on a reflection of the upper instrument panel pad into the windshield, when driving in direct sunlight, may be received. This condition, sometimes referred to as a "veiling reflection", may be aggravated by the use of wax or silicone based products when cleaning the surface. Advise customers, technicians and new car prep or make ready personnel, that products containing wax or silicone should not be used to clean the top instrument panel pad. A warm water and mild soap solution such as saddle soap, oil soap or an equivalent, should be used whenever the top instrument panel pad needs cleaning. If a customer requests that a protectant type product be applied, ONLY USE THOSE THAT LEAVE A FLAT OR SATIN FINISH. Do NOT apply products that leave a glossy finish or those that Increase the shine level above the original production level. Page 1006 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: Page 1675 Symbol Identification Tires - Slipping on Rim Wheels: All Technical Service Bulletins Tires - Slipping on Rim Number: 93-169-3E Section: 3E Date: APRIL 1993 Corporate Bulletin No.: 393501 ASE No.: A4 Subject: TIRES SLIPPING ON WHEELS (USE PROPER TIRE MOUNTING PROCEDURE) Model and Year: 1988-93 ALL PASSENGER CARS AND LIGHT DUTY TRUCKS Some incidents of tires slipping (rotating) on wheels have been reported on 1988-93 passenger cars and light duty trucks. Most incidents have occurred when driven aggressively immediately after tire mounting. Hard acceleration and/or braking is usually required. This condition will affect wheel balance, which could result in a vibration. To reduce the chance of tires rotating on their wheels, any excess lube should be wiped from the tire and rim after tire mounting, but before inflating to seat the bead. (Never exceed 40 psi to seat the bead.) Also, the vehicle should not be driven aggressively for at least four hours after tire mounting to allow the lube to dry. GM Goodwrench Rubber Lubricant, p/n 12345884, is the recommended lube for tire mounting. Testing and Inspection Ignition Control Module: Testing and Inspection If the vehicle cranks for at least 5 seconds and the Engine Control Module doesn't see a referance signal, some Models will set a code, 42 (Hard) or 12 (Soft). If your vehicle has one of these codes, begin with the Diagnostic System Check in Computers and Controls, then proceed to the Trouble Code Chart (Yes, some vehicles have a DTC Chart for Code 12). If the vehicle does not set a code, begin with the Diagnostic System Check, and it will send you to a Diagnostic Chart that checks for your particular condition. These types of tests are found under Computers and Control Systems. See: Computers and Control Systems/Testing and Inspection Generator Light - Flickers During Pulse Wiper Use Wiper Switch: All Technical Service Bulletins Generator Light - Flickers During Pulse Wiper Use Number: 90-84-8A Section: 8A Date: November 1989 Corporate Bulletin No: 966402 Subject: GENERATOR LIGHT FLICKER DURING PULSE WIPER OPERATION Model and Year: 1988-89 S, T TRUCKS WITH 2.8L OR 4.3L (VIN CODES R, Z) ENGINES TO: ALL CHEVROLET DEALERS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 89-219-8A, DATED JULY 1989. THE 1990 MODEL S/T VEHICLES ARE INCLUDED IN THE LATEST BULLETIN ALONG WITH A CORRECTION TO THE ELECTRICAL CONNECTOR NUMBER. ALL COPIES OF 89-219-8A SHOULD BE DISCARDED. The generator light flicker condition during pulse wiper switch operation in the 1988, 1989 and 1990 S/T instrument panel, with standard cluster, can be caused by negative voltage transients from the wiper motor. There is no possibility of a system failure as a result of this condition. The effect of this condition is that the generator light will turn on for 80 milliseconds (if gages, the voltage drop on the voltmeter lasts 2.5 seconds). This causes no harm to the generator or other electrical components. Subject condition can be eliminated by installing a diode (industry part number 1N4003) or diode/connector kit (diode kit part number 12085207) in the brown wire at the generator connector (circuit 25 at connector C118). See the following pages in the 1988, 89 and 90 S/T Electrical Wiring Diagrams for circuit 25, connector C118 locations: 1988 4.3L: Section C - Page 24 1988 2.8L: Section C - Page 22 1989 4.3L: Page 40 1989 2.8L: Page 39 1990 2.8L: Page 44 1990 4.3L: Page 45 PARTS INFORMATION: Quantity Part Number Description 1 12085207 Diode ----OR---1 *1N4003 Diode * This part available locally. Parts are currently available from GMSPO. INSTALLATION PROCEDURE: 1. Disconnect the battery. 2. Remove the connector from the generator. 3. Peel back the black plastic conduit covering the wires. 4. If installing diode 1N4003: cut out a section of the brown wire that matches the length of the diode. 4A. A diode/connector kit is also available (GMSPO diode kit part number 12085207). If using the kit cut out approximately four inches of the brown wire, following crimping and soldering instructions in the kit. Spiral tape the solder joints and tuck the wire back into the conduit away from the generator. Secure the diode/connector to the outside of the conduit with electrical tape. 5. Solder in diode with the banded end toward the generator. Page 4679 FIGURE 2 - THM 700-R4 WIRING DIAGRAM DATE OF PRODUCTION CHANGE: (Figure 1) On April 20, 1988 (Julian Date 111), the 1988 THM 700-R4, THM and TLM models were built with the new Type 18 Solenoid Assembly and Wiring Harness. Beginning May 9, 1988 (Julian Date 130), the remaining 1988 THM 700-R4 models listed above were built using the new Type 18 Solenoid Assembly. SERVICE NOTES: Any 1988 THM 700-R4 transmission models built with the Type 18 Solenoid Assembly, refer to models and Julian Dates listed above, must be serviced with the Type 18 Solenoid Assembly and Wiring Harness Complete listed under "Service Parts Information". Any 1988 THM 700-R4 transmission model built with a Type 15 Solenoid Assembly may be serviced with the new Type 18 assembly; however, there will be no wire connection for the 4-3 pulse switch. The 4-3 pulse switch, which can be left installed, will then function as a plug. SERVICE PARTS INFORMATION: Part No. Description 10478100 Type 18 Solenoid Assembly - Complete 8654415 Type 15 Solenoid Assembly - Complete Parts are currently available from GMSPO. SERVICE MANUAL REFERENCE: Please update the 1988 THM 700-R4 Hydraulic Diagnosis section of your service manual accordingly. Controlled Idle Speed / IAC Counts Idle Speed: Specifications Controlled Idle Speed / IAC Counts Controlled Idle Speed / IAC Counts Idle Speed IAC Counts Note: Let engine idle until proper fuel control status is Note: Add 2 counts for engines with less than 500 miles. closed loop. Add 2 count for every 1000 ft above sea level. Manual Transmission Neutral 500-550 rpm 2-12 Auto Transmission Drive 500-550 rpm 2-20 Page 4179 Differential Clutch: Service and Repair 10 1/2 Inch Ring Gear Cam Gear Clutch Fig. 6 Cam Gear Thrust Ring Removal. Eaton Locking Differential Fig. 4 Exploded View Of Cam Gear Assembly. Eaton Locking Differential 1. Measure and record overall length of cam gear assembly from front face of gear to back face of thrust ring, including shim. 2. Compress disc pack and insert jaws of bearing separator tool No. J-22912 or equivalent between thrust ring and top clutch disc with chamfer of separator facing thrust ring. 3. Support separator in press and press cam gear from thrust ring using suitable spacer, Fig. 3, keeping components in order as cam gear is removed. 4. Remove discs, spring and cam plate from gear, Fig. 4, clean and inspect components and replace any that are damaged or excessively worn. Do not replace cam gear and/or thrust ring unless necessary. If ring or gear is excessively worn or scored, inspect bore in case. If case bore is scored, differential assembly must be replaced. If cam gear or thrust ring is replaced, shim thickness must be selected to provide original assembly dimension and proper differential pinion backlash. 5. Position cam gear with hub facing up and install cam plate with cam form down to mesh with form on gear. 6. Assemble two eared discs and one disc with large splines on cam plate, starting with eared disc as shown in Fig. 4, then install wave spring. If components are reused, they must be installed in original position. 7. Assemble four eared discs and three splined discs on cam gear, starting with eared disc as shown in Fig. 4. 8. Position cam gear assembly in press and install thrust ring on hub of gear, ensuring that ring is square with hub. 9. Compress disc pack to prevent disc from being trapped, then press thrust ring onto cam gear until ring is seated against shoulder of gear. 10. Inspect assembly and ensure that components are properly installed. Side Gear (LH) Clutch Page 2074 REMOVE OR DISCONNECT 1. Coolant from the radiator. 2. Inlet and Outlet Hoses. Refer to "Heater Hose Replacement". - Plug or cap the hoses to prevent spillage. 3. Rear cover and screws. 4. Brackets. 5. Core. INSTALL OR CONNECT 1. Core. 2. Brackets. 3. Rear cover and screws. TIGHTEN - Screws to 3 Nm (27 lb in). 4. Inlet and Outlet Hoses. Refer to "Heater Hose Replacement". Page 7387 Figure 8 Figure 9 Figure 10 Figure 11 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). Page 3789 2. Place new bushing over segmented collet. 3. Slide black expansion tube into segments. 4. Turn cap to lock collet into place. 5. Install new bushing into transmission by driving J 38119 in firmly with a plastic hammer. 6. Turn cap to unlock collet. 7. Remove J 38119. 8. Remove collet. 9. Install rear case seal. 10. Connect propshaft to rear of transmission. SERVICE MANUAL REFERENCE: This procedure is not currently included in any Service Manual. Page 5012 Brake Master Cylinder: Fundamentals and Basics Master Cylinder / Brake Pedal Relationship MASTER CYLINDER / BRAKE PEDAL RELATIONSHIP WARNING: Master Cylinders can be easily misdiagnosed for problems related to excessive brake pedal travel. Excessive brake pedal travel is often associated with a defective master-cylinder, however total pedal travel is affected by a wide variety of components and issues. Issues Affecting Pedal Travel Brake Fluid Specifications Clutch Master Cylinder: Specifications Master cylinder retaining nuts .............................................................................................................. ................................................................ 10-15 ft lbs Page 1601 10129561 IDLER PULLEY ASM. DRIVE BELT TENSIONER PULLEY ONLY: 1. Using procedures in 6B-Engine Cooling, remove and discard the serpentine belt. 2. On trucks with 4.3L, 5.0L, 5.7L and 7.4L engines, using metal pulley (P/N 10129561) perform the following steps: A. Remove O-ring, aluminum spacer, bolt, and metal bearing shield and discard (see illustration). B. Retain the metal pulley. 3. With tensioner on engine, remove worn tensioner pulley, bolt, and metal bearing shield. Discard pulley and retain bolt and shield for reassembly. IMPORTANT: 4.3L, 5.0L, and 5.7L bolt have left-hand threads. 7.4L bolt has right-hand threads. 4. Install new metal pulley and the original shield and bolt on the tensioner. 5. Install new serpentine belt. Labor Operation Number: T-7960. Labor Time: .3 hr. to replace idler pulley. .1 hr. to rework tensioner pulley. Page 3813 Seals and Gaskets: Service and Repair Turbo Hydra-Matic 3L30 (180C) 1. Remove propeller shaft. 2. Remove oil seal with a screwdriver or suitable tool. 3. Lubricate new seal lip with transmission fluid and install seal into extension housing using a suitable driver. 4. Install propeller shaft. Interior - Itch Noise From Windshield Pillar Area Dashboard / Instrument Panel: Customer Interest Interior - Itch Noise From Windshield Pillar Area Number: 92-286-10 Section: 10 Date: SEPT. 1992 Corporate Bulletin No.: 261610 ASE No.: B1 Subject: ITCH NOISE FROM WINDSHIELD PILLAR AREA Model and Year: 1986-92 S/T TRUCKS Some 1986-1992 S/T utility trucks may exhibit a plastic to metal or plastic to plastic "itch" noise from the left or right windshield pillar area. This noise may be caused by the instrument panel pad rubbing against the cowl or dash support panel. An adhesive backed felt tape has been released to insulate the dash pad outer corners from the dash support panel. This tape may also be used on the non-visible surfaces of other trim panels as necessary to eliminate itch noises. The felt tape, P/N 12541499, is released in a 10 ft. x 30 mm x 1 mm roll to provide the technician sufficient material to insulate numerous trim panels. SERVICE PROCEDURE: Prior to installing the felt tape, it should be determined if the IP pad to dash support panel is the area that is generating the noise. Refer to the Squeak and Rattle Diagnosis and Correction Manual to identify other possible sources such as ECM Mounting Bracket or Air Vent. If it is determined the IP pad is the source of the noise: 1. Remove the instrument panel radio speaker(s) to obtain better access to the metal ledge on which the instrument panel pad rests. 2. Remove the 4 IP upper retaining screws located in the defroster duct openings and pull the pad back slightly. NOTICE: Do not remove the dash pad any further than necessary to perform the repair. The possibility exists that additional noises may be generated due to the wiring and HVAC ducts being mispositioned upon reinstallation. 3. Cut a strip of felt tape 6 inches long, remove the protective backing and apply the tape to the top of the metal ledges in front of the speaker openings where the instrument panel pad rests. NOTICE: Installation is easier if 2 screwdrivers are wedged between instrument panel pad and the cowl panel to raise the IP pad. 4. Push the IP pad forward and reinstall the retaining screws and speakers. Page 7161 The following information regards the use of finesse type repairs to environmental (industrial fallout) and rail dust damage of base coat/clear coat paint finishes. Since the severity of the condition varies from area to area, PROPER DIAGNOSIS of the damage extent is CRITICAL TO THE SUCCESS OF REPAIRS. Diagnosis should be performed under high intensity fluorescent lighting, on horizontal surfaces (hood, roof, decklid) after they have been properly cleaned. INDUSTRIAL FALLOUT (ACID RAIN) There are three basic types of acid rain damage: Surface level contamination, - may be repaired by simply washing the vehicle, cleaning the surface with a wax and grease remover, neutralizing acidic residue and finesse polishing. - Clearcoat etching, - slight etching still noticeable after the above washing and finesse polishing procedure. - Basecoat etching, - severe etching beyond the clearcoat into the basecoat. PROCEDURES FOR SURFACE LEVEL CONTAMINATION REPAIRS 1. Wash the vehicle with standard car detergent and water and dry thoroughly. 2. Clean the affected area with a wax and grease remover. 3. Neutralize any left over acidic residue by cleaning the damaged areas with a mixture of baking soda and water (one tablespoon per quart of water), rinse THOROUGHLY and dry the panels completely. 4. Apply a finesse type polish with a foam pad. CLEAN AND INSPECT THE SURFACE A. If the damage has been repaired, remove any swirl marks with a dual action orbital polisher and foam pad. B. If some damage remains, proceed to step 5. SLIGHT CLEARCOAT DAMAGE - WET SANDING, FINESSE POLISHING 5. Select a small test area on a damaged panel. 6. Wet sand the damaged area with an American Grade ultra fine sandpaper of 1,500 to 2,000 grit and a rubber sponge sanding block. During the wet sand process; a. Use ample amounts of water b. Go slow to prevent removing too much clearcoat. Note: Be sure to use American Sandpaper. European Sandpaper has a "P" before the grit number and European grits do not align with American grits the majority of the time. 7. Remove the excess water with a rubber squeegee and inspect the area. A. If this has repaired the damage, continue the sanding procedure on the entire panel, apply a finesse type polish with a foam pad and remove any swirl marks with a dual action orbital polisher and foam pad. B. If (during the repair) it is suspected or observed that; - etching has penetrated into the base coat OR - too much clearcoat has been removed during sanding OR - base color is transferred to pad during polishing, The AFFECTED AREAS MAY REQUIRE RECLEARCOATING/COLORCOATING OR REFINISHING. 8. In any case, once the proper repairs have been made, the final step in the repair process involves polishing the vehicle. A WORD ABOUT CLEARCOAT THICKNESS The clearcoat on the vehicle is typically 1.5 to 2.0 mils thick (one mil equals .001" or 1/1,000 of an inch). At least one mil thickness is required to provide lasting protection to the vehicle basecoat. PAINT GAGES The best way to accurately measure how much clearcoat has been removed is to use a paint gage before, during and after the sanding process. Paint gages measure the total thickness of the finish and when used, can determine how much clearcoat has been removed during the repair process. Paint gages range from magnetic pull types to sophisticated electronic types, are available from a variety of sources, and can cost from $30 to $1800. The older magnetic type gages, at best, a +/- 5% accuracy range and are not sensitive enough to detect removal of .5 mil clearcoat. The newer type magnetic gages have improved accuracy ranges. Most gages are confined to checking either a ferrous metal (steel) or non-ferrous metal (aluminum) panels. At this time, there are no viable gages for reading film thickness on non-metallic panels. Page 712 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. Electrical - Information For Electrical Ground Repair Wiring Harness: All Technical Service Bulletins Electrical - Information For Electrical Ground Repair INFORMATION Bulletin No.: 10-08-45-001B Date: October 25, 2010 Subject: Information for Electrical Ground Repair - Use New Replacement Fasteners with Conductive Finish 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 the 2011 model year and update the Warranty Information. Please discard Corporate Bulletin Number 10-08-45-001A (Section 08 - Body and Accessories). Electrical Ground Repair Overview Proper electrical system function relies on secure, stable and corrosion-free electrical ground connections. Loose, stripped, or corroded connections increase the possibility of improper system function and loss of module communication. These conditions may also lead to unnecessary repairs and component replacement. In general, electrical ground connections are accomplished using one, or a combination of the following attachment methods: - Welded M6 stud and nut - Welded M6 nut and bolt - Welded M8 nut and bolt Determine which attachment method is used and perform the appropriate or alternative repair as described in this bulletin. M6 Weld Stud Replacement Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. Select a location adjacent the damaged or missing M6 ground stud having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the M6 conductive rivet stud flange. 2. Using GM approved residue-free solvent or equivalent, remove any grease from the repair site and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 3. Drill a 10 mm (0.40 in) diameter hole through the panel. 4. Remove paint and primer from the area surrounding the 10 mm (0.40 in) hole until bare metal is visible. Page 972 Figure 2 Page 4925 If the drum was resurfaced, verify that all metal shavings have been removed. - If the wheel cylinders were replaced or overhauled, verify that the pistons are fully compressed. Newly installed or rebuilt wheel cylinders may initially stick in the extended position (prior to bleeding the system). Using brake assembly lubricant when overhauling the wheel-cylinder will help prevent this. Page 2754 Page 1346 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. Description and Operation Transmission Position Switch/Sensor: Description and Operation The park/neutral switch indicates to the ECM when the transmission is in park or neutral. This information is used by the ECM for ignition timing, IAC operation and transmission Torque Converter Clutch (TCC) operation. Do not drive vehicle with park/neutral switch disconnected, as idle quality may be affected. Page 1970 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). Page 1684 When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 5mm (3/16") of insulation from wire. e. Crimp a new terminal to the wire. f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. Figure 17 To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Figure 18 Figure 19 Page 5147 Neutral Safety Switch: Locations Manual Trans. LH Side Of I/P Behind Instrument Cluster Page 5652 SERVICE PARTS INFORMATION Page 1733 Oil Pressure & Temperature Gauge (Gauges Cluster) Page 5646 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. Page 1023 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 Page 3399 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. Page 6820 Figure 8 Figure 9 Figure 10 Figure 11 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). Aluminum Wheels - Cosmetic Damage During Balancing Wheels: All Technical Service Bulletins Aluminum Wheels - Cosmetic Damage During Balancing Number: 93-197-3E Section: 3E Date: MAY 1993 Corporate Bulletin No.: 393502 ASE No.: A4 Subject: INFORMATION ON COSMETIC DAMAGE TO ALUMINUM WHEELS DURING BALANCING Model and Year: 1988-93 C1, K1, G, E/J, L/M, P, S/T, R/V 1990-93 LUMINA APV Some aluminum wheels on GM models may incur cosmetic damage during balancing if proper care and procedures are not used. All aluminum wheels have a clearcoat paint on them that must be cared for like any other painted surface. Some off-car wheel balancer retaining cups used to clamp the wheel to the balancer may put a circular mark into the clearcoat on the face of the wheel. Like any other clearcoat damage, this may be difficult to remove or repair, depending on severity. ALWAYS use balancer retainer cups that are protected with rubber, plastic, or other nonmetallic materials where contact is made with the wheel. Make sure the retainer cup is free from dirt, grease, and gouges. Most wheel balancers now offer this type of protected retainer. DO NOT allow the retainer cup to rotate against the wheel's surface when tightening the wheel to the balancer. DO NOT OVERTIGHTEN. Most balancers use a large "wing nut" design to clamp the retainer against the wheel. Hand tight is sufficient. This procedure will allow accurate balancing using the conventional back cone method. IMPORTANT: Coated balance weights must be used on aluminum wheels to prevent damage to the rim flange. Specifications Fuel Pressure: Specifications FUEL PRESSURE: Ignition ON Engine OFF ...................................................................................................................... ................................................. 62-90 kPa (9-13 psi) Page 6338 ^ 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. Page 5304 When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit J 38125-4 instruction manual 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 or replace...". Mating terminals must be inspected to assure good terminal 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 to 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, see Figure 1, 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 38125-4 instruction manual. 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 connection 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 38125-2, 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 38125-2, 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 38125-2. Page 2668 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 Page 6130 DA-6 Component View Remove or Disconnect Tools Required: J 8433-1 Puller Bar J 08433-3 Puller Screw J 33023-A Puller Pilot J 33025 Clutch Coil Puller Legs 1. Clutch plate and hub assembly (2). 2. Pulley (5). ^ Mark or scribe the location of the clutch coil (6) to terminal on the compressor front head (11). 3. Clutch coil assembly (6). ^ Install J 33023-A on the head (11) of the compressor Page 5344 - 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 Page 7146 (electrocoat) primer. PROBLEM IDENTIFICATION: On a clean surface, at or above room temperature, firmly apply a 2" wide piece of masking tape and pull upward quickly. DO NOT USE duct tape, cloth backed tape or other aggressive tapes. If the colorcoat flakes or peels away from the ELPO (leaving the ELPO intact) the colorcoat is delaminating and the vehicle should be repaired using the "Paint Repair Procedure" contained in this bulletin. This test SHOULD ONLY BE APPLIED TO A VEHICLE SHOWING THE CONDITION, (peeling/delamination) and NOT in areas of stone chipping or other obvious damage. These "other" conditions should be repaired following standard paint repair procedures. CORRECTION Refinish the ENTIRE BODY ABOVE THE BODY SIDE MOLDINGS using the following repair procedure. It is important that ALL surfaces above the body side moldings (including recessed areas around door handles) be refinished, as these surfaces may show the same DELAMINATION (peeling) condition at a later date. Note: Many vehicles have some type of plastic exterior body panels (cowl vent grilles, fascias, front end panels, rear fenders, etc.). These panels are not subject to DELAMINATION and therefore do not require refinishing. If painting of these panels is required for color uniformity, scuff sand and colorcoat only (and clearcoat if basecoat/clearcoat system is used). Note: Two tone lines, feature lines or body side molding treatments near mid-door height are appropriate break lines. If no such convenient break lines are present, the entire panel above the next lower break line must be refinished and the portion of the panel below that break line should be COLORCOATED ONLY (and clearcoated if basecoat/clearcoat system is used) for color uniformity of the repair. Note: Pickup boxes which are covered by caps, bedliners or tonneau covers do not receive direct exposure to sunlight, and normally would not be repaired under this procedure. However, if the inside of the box has been uncovered and experienced DELAMINATION, use the appropriate Labor Operation Number. Note: Certain two tone applications on trucks using the high potential colors (Blues, Grays and Silvers) may require that only portions of the vehicle surface be refinished. Examples would be: Example 1. Blues, Grays and Silvers as "insert colors" on vertical surfaces with other, non-high potential colors above the insert (or break line). Action: Refinish the "insert color" only, between the break line and body side molding (or to the lower feature line on certain vehicles). Example 2. Blues, Grays and Silvers on surfaces above the break line with other, non-high potential colors as "insert colors". Action: Refinish the surfaces above the "insert color" or break line only. Example 3. Blues, Grays and Silvers used as both the primary and "insert colors". Action: Refinish both high potential color surfaces above the body side moldings (or to the lower feature line on certain vehicles). Vehicles should be repaired with the same type materials they were manufactured with; repair basecoat/clearcoat with basecoat/clearcoat materials and monocoat with monocoat. PAINT REPAIR PROCEDURE 1. Some vehicle components will be removed from the vehicle while others will require masking. The list located at the end of this bulletin will establish the removal items. Items not found on the list and non-repair areas are to be masked. 2. Prior to removing the paint finish, clean the area to be refinished with an appropriate wax and grease remover to remove any contaminants. 3. Remove the original finish of paint down to the ELPO primer surface using an orbital D.A. sander, leaving the ELPO surface intact. This can be done in "stages" using 80 grit (or finer) discs to remove the majority of coating, followed with 180 grit (or finer) discs to remove the remainder of material down to the ELPO surface and any chalky residue or degraded ELPO that may remain. Avoid sanding through ELPO to bare metal in order to retain maximum corrosion protection. Generator Light - Flickers During Pulse Wiper Use Wiper Switch: All Technical Service Bulletins Generator Light - Flickers During Pulse Wiper Use Number: 90-84-8A Section: 8A Date: November 1989 Corporate Bulletin No: 966402 Subject: GENERATOR LIGHT FLICKER DURING PULSE WIPER OPERATION Model and Year: 1988-89 S, T TRUCKS WITH 2.8L OR 4.3L (VIN CODES R, Z) ENGINES TO: ALL CHEVROLET DEALERS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 89-219-8A, DATED JULY 1989. THE 1990 MODEL S/T VEHICLES ARE INCLUDED IN THE LATEST BULLETIN ALONG WITH A CORRECTION TO THE ELECTRICAL CONNECTOR NUMBER. ALL COPIES OF 89-219-8A SHOULD BE DISCARDED. The generator light flicker condition during pulse wiper switch operation in the 1988, 1989 and 1990 S/T instrument panel, with standard cluster, can be caused by negative voltage transients from the wiper motor. There is no possibility of a system failure as a result of this condition. The effect of this condition is that the generator light will turn on for 80 milliseconds (if gages, the voltage drop on the voltmeter lasts 2.5 seconds). This causes no harm to the generator or other electrical components. Subject condition can be eliminated by installing a diode (industry part number 1N4003) or diode/connector kit (diode kit part number 12085207) in the brown wire at the generator connector (circuit 25 at connector C118). See the following pages in the 1988, 89 and 90 S/T Electrical Wiring Diagrams for circuit 25, connector C118 locations: 1988 4.3L: Section C - Page 24 1988 2.8L: Section C - Page 22 1989 4.3L: Page 40 1989 2.8L: Page 39 1990 2.8L: Page 44 1990 4.3L: Page 45 PARTS INFORMATION: Quantity Part Number Description 1 12085207 Diode ----OR---1 *1N4003 Diode * This part available locally. Parts are currently available from GMSPO. INSTALLATION PROCEDURE: 1. Disconnect the battery. 2. Remove the connector from the generator. 3. Peel back the black plastic conduit covering the wires. 4. If installing diode 1N4003: cut out a section of the brown wire that matches the length of the diode. 4A. A diode/connector kit is also available (GMSPO diode kit part number 12085207). If using the kit cut out approximately four inches of the brown wire, following crimping and soldering instructions in the kit. Spiral tape the solder joints and tuck the wire back into the conduit away from the generator. Secure the diode/connector to the outside of the conduit with electrical tape. 5. Solder in diode with the banded end toward the generator. Page 6071 Symbol Identification Page 2653 Electronic Spark Timing: Testing and Inspection Chart C-5 - Electronic Spark Control System Check Page 4598 This part number can be found on the identification tag (80) located on the rear case half (Figure 1). Group B: Some 1991 T-Trucks equipped with transfer cases identified by the following part numbers and built before 10/22/90: 15653414 15659232 This part number and build number can be found on the identification tag (80) located on the rear case half (Figure 1). Service Procedure: Group A: These transfer cases require the replacement of the parts indicated in the Group A column of the PARTS INFORMATION section. Group B: These transfer cases require the replacement of the parts indicated in the Group B column of the PARTS INFORMATION section. Remove Page 1716 Intake Manifold: Service and Repair VIN Z Non Turbo Engine Fig. 5 Intake Manifold Sealant Application Fig. 6 Intake Manifold Tightening Sequence. Fig. 7 Intake Manifold Tightening Sequence. Bravada 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: Page 3781 Output Shaft: Technical Service Bulletins A/T- THM 700-R4 New Output Shafts and Seal Number: 91-390-7A Section: 7A Date: AUGUST 1991 Corporate Bulletin No.: 177118 Subject: NEW OUTPUT SHAFTS AND INPUT HOUSING TO OUTPUT SHAFT SEAL Model and Year: 1982-91 CAPRICE, CAMARO AND CORVETTE, 1982-91 C1/C2, G1/G2, K1/K2, S/T; 1987-91 R/V; 1985-91 M AND 1990-91 L TRUCKS WITH 4L60/THM 700-R4 AUTOMATIC TRANSMISSION TRANSMISSION APPLICATIONS: 1982-91 HYDRA-MATIC 4L60 (MD8) THM 700-R4 SUBJECT: New Output Shafts and Input Housing to Output Shaft Seal (Product Service Information) TRANSMISSION MODELS: All VEHICLE APPLICATIONS: B, F, Y - Cars C/K, R/V, S/T - Trucks G, L, M - Vans Figure 1 Bulletin Covers: HYDRA-MATIC 4L60 output shafts and input housing to output shaft seals have been revised to provide increased lube flow. Since lube hole locations have changed, the input housing to output shaft seal has been revised to accommodate them. Date of Production Change: Beginning January 28, 1991 (Julian Date 028), all HYDRA-MATIC 4L60 transmissions were built using the new output shafts and seals. Page 2854 NOTICE: When jacking or lifting vehicle from frame side rails, be certain lift pads do not contact catalytic converter or damage to converter may result. 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. This device sometimes requires the use of heat shields, due to its high operating temperatures. The heat shields are necessary to protect chassis components, passenger compartment and other areas from heat related damage. 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. A small diameter fuel tank filler tube 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. Page 5158 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 4. Make repair. Page 2744 Knock Sensor: Testing and Inspection Chart C-5 - Electronic Spark Control System Check Page 3400 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). Page 5401 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 wire ends to protect the diode from excess heat. Follow the manufacturers instructions for the solderin equipment you are using. 5. Install terminal(s) into the connector body if previously removed in step number 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. NOTE: A universal diode with a 3 amp, 400 PIV (Peak Inverse Voltage) rating can be used in all of the previously mentioned applications. The following 1993 Service Manuals will need to be updated with the correct part numbers and rating changes. Carline Page All J, L, W, and UO 8A-5-12 Heat sink, part number 276-1567, can be obtained from Radio Shack. We believe the diodes and heat sink listed in this article as well as their manufacturer to be reliable. There may be additional manufacturers or equivalent products. General Motors does not endorse, indicate any preference for or assume any responsibility for the products from these firms or for any such items which may be available from other sources. Page 1717 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 Figs. 6 and 7. Page 2520 Assembly Line Diagnostic Link (ALDL) Connector: Description and Operation Figure 1 Terminal Arrangement In Connector This connector is used in the assembly plant to connect a computer for checking of the system to see that it is functioning properly before shipping the vehicle. To obtain trouble codes with the ignition switch on and the engine either stopped or running the "test" terminal in this connector should be grounded. The "test" terminal should be ungrounded when starting the engine or the "Check Engine" lamp will not function properly. Cruise Control - Works Intermittently Cruise Control Switch: Customer Interest Cruise Control - Works Intermittently Number: 92-195-9B Section: 9B Date: MAY 1992 Corporate Bulletin No.: 268102R ASE No.: A8 Subject: CRUISE CONTROL WORKS INTERMITTENTLY Model and Year: 1985-92 M VANS 1990-92 L VANS 1986-92 S/T TRUCKS Some owners of 1985-1992 WL vehicles or 1986-1992 S/T vehicles with cruise control (RPO K34) may comment that their cruise control operates intermittently. This condition may be caused by the wires becoming pinched as they exit the multi-functional lever. These wires may ground out on the lever rod and short the cruise function. To correct this condition in production, the wiring harness that exits the lever has been rerouted and the opening in the multi-functional lever has been redesigned to allow the wires more clearance. The diagnostic procedures in the applicable Service Manual should be followed before replacing the multi-functional lever. If the multi-functional lever requires replacement, the following procedure should be performed: SERVICE PROCEDURE: 1. Disconnect the wire harness connector. 2. Remove the harness protector cover. 3. Attach a long piece of mechanic's wire to the end of the harness connector. 4. Remove the multi-functional lever from the turn signal switch. 5. Gently pull the harness up and out so the mechanic's wire can be used to install the new unit. 6. Attach the upper end of the mechanic's wire to the new harness connector. Gently pull the mechanic's wire at the lower end of the column, feeding the harness into the proper location in the column. 7. Install a redesigned multi-functional lever (P/N 25111290) into the turn signal switch. 8. Disconnect the mechanic's wire from the harness connector. 9. Install the harness protector cover. 10. Reconnect the wire harness connector. SERVICE PARTS INFORMATION Part Number Description 25111290 Multi-functional Lever Use applicable labor time guide for labor hours. Important: The new Part Number (P/N 25111290) should be used when correcting this condition in the above listed vehicles. Page 7800 License, Stop, Tail & Turn Lamps (Part 4 Of 4) Page 5885 FIGURE 2 Irregular/premature tire wear is aggravated by excessive toe-in (or toe-out). Excessive camber can also be a contributor, as can operating conditions, such as city driving with a lot of cornering. Irregular tire wear usually occurs on non-drive axles, such as the front wheel positions of rear drive vehicles. An early indication may be an increase in tire noise. In most cases, modified "X" tire rotation, which is a scheduled maintenance at 7500 miles, will equalize tire wear (See Figure No. 1). Some amount of wear is expected and should be considered normal. To determine if questionable tires meet the replacement criteria, follow the particular service procedure outlined for that brand tire. Whenever tires are replaced due to vehicle caused premature wear, alignment should be checked and reset to specification if necessary. FIRESTONE AND GOODYEAR IF WITHIN THE NEW VEHICLE WARRANTY PERIOD (12/12): A. Outer shoulder wear has progressed to the point that the outer shoulder is smooth (no tread visible), replace both front tires. B. The outer shoulder tread is visible, use a tread depth gauge (such as provided with Truck Service Bulletin 86-B-94) to determine the extent of the wear. Measurements must be made in a full depth tread groove shown in Figure No. 2. If tread depth is 5/32" or less, tire replacement will be necessary. It should be noted that at 5/32" tread depth the tire is normally only half worn in this area. If greater than 5/32", the tires should be rotated using the modified "X" pattern (See Figure No. 1). This method will best equalize wear after a few thousand miles. Description and Operation Brake Caliper: Description and Operation Fig. 1 Exploded View The Delco-Moraine Single Piston Caliper is held in place by two mounting bolts. The caliper assembly, Fig. 1, slides on its mounting surfaces. Upon brake application, hydraulic pressure against the piston forces the inboard pad against the inboard side of the disc. This action causes the caliper assembly to slide until the outboard pad comes into contact with the disc, which in turn creates a slowing or stopping action. Page 3421 [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. Page 6177 Compressor Shaft Seal: Service and Repair With A-6 Compressor A-6 Compressor Component View Remove or Disconnect Tools Required: J 5403 Snap Ring Pliers J 9392-01 Shaft Seal Remover and Installer J 9553 Seal Remover J 22974-A Compressor Shaft Oil Seal Protector J 23128-A Compressor Shaft Seal Seat Remover and Installer A/C - R12 Loss From Loose or Missing Access Fitting Caps Service Port HVAC: All Technical Service Bulletins A/C - R12 Loss From Loose or Missing Access Fitting Caps Number: 89-127-1B Section: 1B Date: APRIL, 1989 Subject: A/C REFRIGERANT LOSS DUE TO LOOSE OR MISSING ACCESS FITTING CAPS Model and Year: 1980-89 CHEVROLET MODELS WITH A/C FIGURE 1 TO: ALL CHEVROLET DEALERS All Chevrolet air conditioning Hi side and Low side access fittings are supplied with a black plastic cap and seal assembly which provides the primary refrigerant seal for the service fittings. If the cap and seal assembly is missing or loose, a significant amount of refrigerant may leak through the valve core located in the access fitting, which could result in poor A/C performance or failure. When servicing any vehicle's A/C system, make sure all access fitting cap seals (refer to Figure 1) are in place and tight. Caps should be threaded on until contact with the O-ring seal is made and then tightened another 1/4 - 1/2 turn to ensure proper sealing. High Side Low Side Valve - Cap and Seal Valve - Cap and Seal P/N 3033974 P/N 6551640 Parts are currently available from GMSPO. Page 5073 Fig. 8 Exploded View Of Delco-Moraine Tandem Diaphragm Brake Booster Components 1. Remove boot, silencer, vacuum check valve, grommet and front housing seal Fig. 8. 2. Scribe a line across front and rear housing, then install brake booster to brake mounting fixture tool No. J 23456 or equivalent, Fig. 4. 3. Turn fixture handle to unlock housings. 4. Remove return spring, power piston assembly and power piston bearing from rear housing, Fig. 8. 5. Remove piston rod, reaction retainer and power head silencer, Fig. 8. 6. Remove power piston and pushrod assembly as follows: a. While holding the pushrod down against a hard surface, grasp outside edge of diaphragm support and diaphragm, Fig. 8. b. Use a slight force to dislodge diaphragm retainer, Fig. 8. 7. Remove primary diaphragm and primary support plate from housing divider, Fig. 8. 8. Remove primary diaphragm from primary support plate, Fig. 8. 9. Remove secondary diaphragm and secondary support plate from housing divider, Fig. 8. 10. Remove secondary piston bearing from housing divider, Fig. 8. 11. Remove secondary diaphragm from secondary support plate, Fig. 8. 12. Remove reaction body retainer, reaction body, reaction disc and reaction piston from reaction body, Fig. 8. 13. Remove air valve spring and reaction bumper from end of air valve pushrod, Fig. 8. 14. Remove retaining ring from air valve pushrod assembly. 15. Remove air valve pushrod assembly by inserting a screwdriver through the pushrod eyelet and pulling pushrod assembly straight out. 16. Remove filter, retainer and O-ring from air valve pushrod assembly. 17. Inspect all parts for corrosion, nicks, cracks, cuts, scoring, distortion or excessive wear. Replace as necessary. 18. Clean all parts in denatured alcohol and dry with clean compressed air. Do not immerse power piston and pushrod assembly in alcohol. Assembly 1. Install lubricated O-ring onto air valve pushrod assembly. 2. Install air valve pushrod into the power piston. 3. Install retainer and seat. 4. Install filter over pushrod eyelet and into power piston. 5. Install retaining ring onto air valve pushrod assembly. 6. Install reaction bumper, air valve spring, reaction piston and reaction disc onto reaction body. 7. Install reaction body, then reaction body retainer. 8. Lubricate inside diameter of secondary diaphragm lip, inside diameter of primary diaphragm lip and the secondary piston bearing with a thin layer of silicone grease. 9. Install secondary diaphragm into the secondary support plate, Fig. 8. 10. Install secondary diaphragm and secondary support plate over the power piston and pushrod assembly. 11. Install secondary piston bearing into housing divider with flat surface of bearing on the same side as the six raised lugs on the divider. Backup Lamps/Tailgate Window Release - Inoperative Backup Lamp Switch: Customer Interest Backup Lamps/Tailgate Window Release - Inoperative Number: 91-459-8A Section: 8A Date: DEC. 1991 Corporate Bulletin No.: 168104 ASE No.: A6 Subject: BACKUP LAMPS OR TAILGATE WINDOW RELEASE INOPERATIVE Model and Year: 1980-91 ALL LIGHT DUTY TRUCKS (EXCEPT GEO) Owners of some 1980-1991 C/K, 1982-1991 G, 1985-1991 M/L, 1984-1991 P2,P3, 1987-1991 R/V, 1983- 1991 ST (including LLV) with automatic transmissions may comment on a condition of inoperative back-up lamps or inoperative tailgate window release. This condition occurs when the vehicle's gear shift lever is placed in the "reverse" position, but the back-up lamps do not illuminate. In addition, on the S/T utility vehicles, the electric tailgate window release does not release when the transmission gear shift lever is placed in the "park" or "neutral" position and the endgate window release button is depressed. The park/neutral and back-up lamp switch comes out of adjustment which does not allow for the contact points to remain engaged. To correct these conditions, the contact carrier on the park/neutral and back-up lamp switch has been modified to increase switch carrier travel. SERVICE PROCEDURE: 1. Disconnect the battery ground cable from the battery. 2. Disconnect the switch assembly harness. 3. Place the gear selector in neutral. 4. Squeeze the tangs on the switch together and remove the switch assembly. 5. Install the new switch assembly (P/N 15679680) by: -aligning the actuator with the cutout in the steering column jacket. -inserting the tangs into the rectangular holes and pushing down on the switch assembly. 6. Adjust the switch by moving the gear selector to park. 7. Connect the switch assembly harness. 8. Connect the negative battery cable. 9. Check for proper switch operation. Readjust the switch as necessary. Wheels (Steel) - Damage Due to Improper Mounting Wheels: All Technical Service Bulletins Wheels (Steel) - Damage Due to Improper Mounting Number: 92-232-3E Section: 3E Date: JUNE 1992 Corporate Bulletin No.: 233002 ASE No.: A4 Subject: AVOIDING DAMAGE TO STEEL WHEELS FROM IMPROPER WHEEL/TIRE CHANGING TECHNIQUES Model and Year: 1983-92 ALL PASSENGER CARS AND TRUCKS WITH STEEL WHEELS It is important to use proper procedures to prevent damage to either the tire mounting surface or the wheel mounting holes. Damage can result from the improper wheel attachment or tire mounting techniques on vehicles with steel wheels. 1. IMPROPER TIRE CHANGING TECHNIQUES: It takes about 70 seconds for the air to completely exhaust from a large tire. If the technician doesn't wait this amount of time after removing the valve core, the bead breaker on the tire change could put enough force on the tire to bend the wheel at the mounting surface. Such damage can result in vibration, shimmy, and under severe usage (i.e. police vehicle) lead to cracking. 2. OVER TORQUING OF THE WHEEL NUTS: The service specification for wheel nuts is listed in the Service Manuals. Some wheels have been observed with wheel nuts that were over torqued by as much as 50 percent. This may damage the wheel mounting holes and may also lead to cracks. I. PROPER TIRE CHANGING TECHNIQUES: Completely deflate the tire before attempting to break the tire bead loose. MOUNTING SURFACE CHECKING PROCEDURE Brakes - Front Pad Noise, Revised Tab Clinch Procedure Brake Pad: All Technical Service Bulletins Brakes - Front Pad Noise, Revised Tab Clinch Procedure Number: 89-164-5 Section: 5 Date: May, 1989 Subject: FRONT BRAKE NOISE Model and Year: 1983-89 M, G, S/T, R/V, P TRUCKS (EXC G3 W/RPO JB8) TO ALL CHEVROLET DEALERS: Some front brake noise (clicking, popping and squealing) can be caused by insufficiently clinch outboard brake pad tabs. Loose outboard pads can move within the caliper generating noise. The outboard brake pad clinch can be checked by pushing on the back of the pad with your thumb. The pad should not move. If any movement is felt, the pad should be re-clinched. Pad tab clinching must be checked whenever pads are removed or replaced. All future light duty service manuals will be updated with the following revised brake pad clinch procedure. Figure No. 1 Figure No. 2 Revised Service Procedure Page 5527 Courtesy & Dome (Less Cargo Lamp) 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 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. Page 6816 LIGHT BLUE LT BLU BROWN BRN GRAY GRY GREEN GRN DARK GREEN DK GRN LIGHT GREEN LT GRN ORANGE ORN PINK PNK PURPLE PPL RED RED TAN TAN WHITE WHT YELLOW YEL Testing and Inspection Fig. 4 Thermostat Diagnosis Page 8040 Tool Required: J-21104 Trim Pad Remover. REMOVE OR DISCONNECT 1. Door pillar molding. 2. Window regulator handle. 3. Armrest. 4. Trim panel. Pry the fasteners from their seats using J-21104. INSTALL OR CONNECT 1. Trim panel to the door. 2. Armrest. 3. Window regulator handle 4. Door pillar molding. Window Regulator Handle Replacement Front Door Window Regulator Handle TOOL REQUIRED: J-9886-O1, Door Handle Remover. REMOVE OR DISCONNECT 1. Window regulator handle. ^ Insert J-9886-O1 between the handle and the bearing plate. ^ Align the tool parallel with the door handle, and push to disengage the clip. ^ Pull the handle from the door. 2. Bearing plate. INSTALL OR CONNECT 1. Bearing plate. 2. Window regulator handle. ^ Place the window in the raised position. ^ Put the clip onto the handle, ^ Insert the handle onto the door so the handle is pointing towards the front of the door. ^ Push on the handle until the clip engages the window regulator shaft. Window Regulator Replacement Page 3062 NOTE: If a fuel filler cap requires replacement, only a cap with the same features should be used. Failure to use the correct cap can result in a serious malfunction of the system. FUEL AND VAPOR PIPES The fuel feed and return pipes extend from the fuel pump/gauge sending unit to the engine compartment. The pipes are secured to the underbody with clip and screw assemblies. Both fuel feed pipes and return pipe must be properly routed and retained, and should be inspected occasionally for leaks, kinks, or dents. If evidence of dirt is found in the fuel injector assembly or fuel filter during disassembly, the pipes should be disconnected and blown out. Check the fuel strainer on the fuel pump/fuel gauge assembly for damage or omission. The vapor pipe extends from the fuel pump/gauge assembly to the canister. However, it does not follow the same route as the fuel feed pipe. Due to the fact that the fuel pipes/hoses are under high pressure on fuel injected systems these systems require special consideration for service. NOTE: All fuel feed and return line attachments in the system are screw type fittings. Always use a backup wrench when loosening or tightening the fittings. Screw fittings used on the two systems utilize O-rings for the fuel feed and return pipes and the two sizes of O-rings are not interchangeable. Any time that the fuel or return pipes are disconnected, inspect the O-rings for cuts or other type of damage and replace as necessary. The flare used on these fuel pipes is not compatible with the flare used on other fuel pipes. FUEL LINE O-RINGS The fuel line O-rings used are made of Viton. They are brown in color. Viton is less affected than rubber by the additives used in many fuels. Therefore, rubber should not be used. Page 508 A new pressure regulator valve (III. 218) has been made which will improve the oil pressure stability at lower RPM. SERVICE PARTS INFORMATION: Description Part Number Valve, Pressure Regulator (III. 218) 8684048 Part numbers are for Reference Only. Check with your Parts Department for latest information. Page 3320 A new pressure regulator valve (III. 218) has been made which will improve the oil pressure stability at lower RPM. SERVICE PARTS INFORMATION: Description Part Number Valve, Pressure Regulator (III. 218) 8684048 Part numbers are for Reference Only. Check with your Parts Department for latest information. Page 1079 ^ 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. Page 6289 Page 1786 Disclaimer Page 1963 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 Locations Turn Signal Flasher: Locations The fuse block is located at the far left side of the dash panel. The hazard and turn signal flashers are located under the left side of the dash panel on the convenience center. Specifications Backing Plate: Specifications Backing Plate Retaining Bolts.............................................................................................................. ........................................................ 47 Nm (35 ft lb) Page 6335 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. Service and Repair Timing Cover: Service and Repair 1. Remove torsional damper. 2. Remove water pump, then the upper radiator hose. 3. Remove oil pan as described under OIL PAN. 4. Remove A/C compressor and position aside. 5. Remove right side engine accessory bracket. 6. Remove front cover attaching bolts and reinforcements. 7. Remove front cover. 8. Reverse procedure to install, torquing cover bolts to specification. Diagnostic Trouble Code Descriptions Engine Control Module: Diagnostic Trouble Code Descriptions For information regarding B, C, P, U and Manufacturer Code Descriptions - Page 2794 Vehicle Speed Sensor: Service and Repair 1. Disconnect vehicle speed sensor electrical connector. 2. Remove sensor attaching bolt. 3. Using speed sensor remover and installer, tool No. J 38417, remove sensor, then O-ring seal. 4. Reverse procedure to install, coating the new O-ring seal with transmission fluid. Torque attaching bolt to 97 inch lbs. Page 5931 *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 Page 7481 FIGURE 2 3. Place tape on the fender edge and cowl panel edge to prevent paint damage (Figure No. 2) . 4. Disconnect the windshield washer hose from the nozzle. 5. Remove the cowl panel, being careful not to scrape the cowl on the inner hood edge or fender. 6. Pull back the hood hinge seal to expose the windshield frame and close the hood. Page 7131 * Select applicable additional "Labor Hours" and add to above "Labor Hours" as needed. Page 7929 License, Stop, Tail & Turn Lamps (Part 3 Of 4, W/Trailer Tow Package) Service and Repair Fuel Pressure Release: Service and Repair Before performing any procedure that requires disconnecting fuel lines, relieve fuel system pressure as described below. 1. Remove Fuel Pump fuse from fuse block. 2. Start engine and allow to run out of fuel, then crank engine an additional 3 seconds. 3. Service fuel system as necessary. Page 5431 1. With the end gate open, use a grease pencil to mark around the circumference of each washer (Figure 1, "7") located behind the strikers. 2. Unscrew and remove the existing striker assemblies (Figure 1, "6") from the vehicle. 3. Loosely assemble the new striker (Figure 1, "6") (P/N 15700881) and washer (Figure 1, "7") and reinstall using the pencil marks as a guide. 4. Install the striker assemblies (Figure 1, "6") using a T50 Torx(R). Torque to 63 N-m. (47 lbs.ft.). 5. Check for proper operation and end gate flushness. Adjust the striker assemblies if required. The end gate lock strikers can be adjusted up or down, fore or aft, to obtain proper closure of the end gate. The end gate should seal completely with minimum closing effort. Torque the striker bolts to 63 N-m. (47 lbs.ft.). SERVICE PARTS INFORMATION PART NUMBER DESCRIPTION QTY/VEH 15700881 Striker Asm. 2 Page 8220 Wiper Switch: Service and Repair Fig. 8 Windshield Wiper Switch Removal (Front). Except Tilt Column Fig. 9 Windshield Wiper Switch Removal (Front). Tilt Column FRONT 1. Remove turn signal switch. Refer to Vehicle Lighting/Turn Signals/Turn Signal Switch/Service and Repair procedure. 2. Refer to Figs. 8 and 9 for wiper switch replacement. Page 6443 Page 3439 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. Page 3559 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 Wheels - Sealing Leaking Cast Aluminum Wheels: All Technical Service Bulletins Wheels - Sealing Leaking Cast Aluminum Bulletin Number: 93-3-16 Reference Number: 393504 Publish Date: 7/93 Subject: LEAKING CAST ALUMINUM WHEELS (REPAIR WITH ADHESIVE SEALANT) Models Affected: 1985-1993 ALL MODELS Should a vehicle equipped with cast aluminum wheels exhibit a slow leak due to a porous condition existing in the wheel, the wheel can be repaired by using Dow Corning Silastic 732 RTV, p/n 1052366 or equivalent, as described in the following procedure: 1. Remove tire-wheel assembly from vehicle. 2. Locate leaking area by inflating tire to 40 psi and dipping tire-wheel assembly in water bath. 3. If air bubbles are observed, mark leak area and remove tire from wheel. 4. Scuff INSIDE rim surface at leak area with # 80 grit paper and clean area with general purpose cleaner, such as 3M # 08984. 5. Apply 1/8" thick layer of adhesive/sealant to leak area on INSIDE of rim and allow six hours of drying time. 6. Mount tire on wheel, pressurizing to 40 psi and check for leaks. NOTICE: Caution must be used when mounting the tire so as not to damage the sealer. 7. Adjust tire pressure to meet placard specification. 8. Balance tire-wheel assembly, using proper coated weights. 9. Water test wheel again. 10. Reinstall tire-wheel assembly on vehicle. Parts are currently available from GMSPO. WARRANTY INFORMATION: Labor Operation Number: E0420 Page 3083 Idle Speed/Throttle Actuator - Electronic: Testing and Inspection Chart C-2 - Idle Air Control (IAC) System Check Transmission Mount - Idle Shake or Vibration Transmission Mount: Customer Interest Transmission Mount - Idle Shake or Vibration Number: 91-16-7A Section: 7A Date: May 1990 Corp. Bulletin No: 066101 Subject: IDLE SHAKE OR VIBRATION Model and Year: 1988-91 S1 TRUCKS Some 1988-91 S truck (two wheel drive) and 2 door utility models equipped with 4.3L engines and either automatic or manual transmissions, may experience an idle shake or vibration. This condition is most noticeable at engine speeds below 1500 RPM. Audio - Poor AM or FM Radio Reception Radio/Stereo: All Technical Service Bulletins Audio - Poor AM or FM Radio Reception Number: 89-108-9A Section: 9A Date: MARCH, 1989 Subject: POOR AM OR FM RADIO RECEPTION Model and Year: 1980-89 CHEVROLET VEHICLES TO: ALL CHEVROLET DEALERS Page 6979 * Select applicable additional "Labor Hours" and add to above "Labor Hours" as needed. Page 6126 Removing The Pulley Rotor And Bearing Retainer Ring 2. Pulley bearing retainer (3) using J 6083. 3. Pulley (5). Installing The Puller Pilot And Pulley Rotor Slot Location ^ Install J 33023-A to the front head. Installing J-33020 In The Pulley Rotor Slots ^ Install J 33020 tangs into the inner circle of slots in the pulley (5) contact surface. Rotate J 33020 clockwise so the tangs will lock into the segments between the slots. Page 593 Fuel Pressure: Testing and Inspection NOTE: A fuel system pressure test is part of several of the Diagnostic Charts and Symptom Checks. To perform this test, follow this procedure: FUEL PRESSURE TEST 1. Turn engine OFF to relieve system pressure. 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. - The constant bleed feature relieves fuel pump system pressure when the engine is turned "OFF". 2. Uncouple fuel supply flexible hose in engine compartment. Install fuel pressure gauge between steel line and flexible hose. 3. Tighten gauge in line to insure no leaks occur during testing. 4. Connect negative battery terminal and START engine and observe fuel pressure reading. It should be 62-90 kPa (9-13 psi). If not, refer to DIAGNOSTIC CHARTS/FUEL SYSTEM PRESSURE TEST (CHART A-6). 5. Turn engine OFF to relieve system pressure. 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. - The constant bleed feature relieves fuel pump system pressure when the engine is turned "OFF". 6. Remove fuel pressure gauge. 7. Reinstall fuel line. 8. Connect negative battery terminal and START engine and check for fuel leaks. 9. Install air cleaner assembly. Page 1397 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 Page 5999 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 A/T - DEXRON III Fluid Introduction Fluid - A/T: All 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 Page 393 Page 6290 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 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). Page 955 Figure 3 INSTALL (Figures 2 & 3) Tools required: J8092 Drive handle J33790 Bearing installer and remover J33833 Bearing installer and remover 1. Front output bearing (61) to the new front case half P/N 15635347 (45) using J 8092 and J 33833. 2. New front output shaft seal P/N 15579788 (72) to the new front case half (45). 3. Front output bearing retainer ring (snap ring) (60) to the new case half. 4. New input seal P/N 14095609 (42) into retainer (44) if it was removed in step 24 above. 5. Input bearing (40) and input bearing retainer (39) to the new case half using J 36372. 6. Planetary carrier (36) and the input gear (38) to the annulus gear (62) using a soft hammer. 7. Retainer snap ring to the input gear (38). Input bearing retainer (44) and input bearing retainer bolts (43) to the front case half (45). - Clean mating surfaces and apply RTV or equivalent on bearing retainer mating surfaces. NOTE Do not block oil feed hole from case to bearing retainer. - Apply Loctite 242 (R) or equivalent on bearing retainer bolts. - Tighten bolts to 19 N-m (14 lbs.ft.). Page 7000 1. Wash the subject panel with water to remove any foreign material such as dirt, grit, etc. 2. Wet sand subject panel with 3M Micro fine 1500 grit sandpaper, P/N 2023 or equivalent. Wrap the sandpaper around a 3M rubber sponge back up pad, P/N 5530, to prevent leaving finger marks in the clearcoat. NOTE: Always sand the length of the panel and use a mild dish soap detergent in the wet sand operation for sandpaper lubricant. 3. Wheel compound sanded panel with 3M Finesse it II, P/N 5928, polishing compound and 3M Super Buff Polishing Pad, P/N 5705 or equivalent. 4. Swirl marks, left in the clearcoat, can be removed by rebuffing the affected area with a non-directional, dual action (D.A.) orbital sander. A clean terry cloth polishing bonnet and 3M Finesse II compound should be used. CAUTION: Buffing wheels are not recommended for routine new car pre-delivery preparation of basecoat/ clearcoat finishes. 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. Page 782 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 Page 675 Spark Plug: Description and Operation Resistor type, copper core, tapered seat quantum spark plugs are used on all engines. No gasket is used on these tapered seat plugs. A dot before the spark plug code or the letter C after the number in the code indicates that the plug has a copper core. For the correct gap information refer to the Vehicle Emissions Control Information label under the hood or refer to SPECIFICATIONS/ELECTRICAL AND ELECTRONIC SPECIFICATIONS. Normal or average service is assumed to be a mixture of idling, slow speed, and high speed operation with some of each making up the daily total driving. Occasional or intermittent high-speed driving is essential to good spark plug performance as it provides increased and sustained combustion heat that burns away any excess deposits or carbon or oxides that may have accumulated from frequent idling or continual stop and go or slow speed driving. Spark plugs are protected by an insulating boot made of special heat-resistant material which covers the spark plug terminal and extends over a portion of the plug insulator. These boots prevent flash-over with resultant missing of the engine, even though a film is allowed to accumulate on the exposed portion of the plug porcelains. Do not mistake corona discharge for flash-over or a shorted insulator. Corona is a steady blue light appearing around the insulator, just above the shell crimp. It is the visible evidence of a high-tension field, and has no effect on ignition performance. Usually it can be detected only in the darkness. This discharge may repel dust particles, leaving a clear ring on the insulator just above the shell. This ring is sometimes mistakenly regarded as evidence that combustion gases have blown out between the shell and the insulator. Page 7089 Cleveland, OH 44146-0478 708-671-3000 216-439-1200 Can-Am Croix Can-Am Engineered Croix Air Products Products. Inc. 520 Airport Rd./Flemingfield 30850 Industrial Rd. So. St Paul, MN 55074 Livinoia, MI 48150 612-455-1213 313-427-2020 DevilBiss Graco Inc. The Devilbiss Co. P.O. Box 1441 320 Phillips Ave. Minneapolis, MN 55440-1441 P.O. Box 913 1-800-367-4023 Toledo, OH 43962 419-470-2169 Lex-Air Turbine Spray Mattson Lex-Air South 230 West Coleman 5874 Buford Hwy. P.O. Box 132 Doraville, GA 30340 Rice Lake, WI 54868 404-454-8417 715-234-1617 Sata Sharpe Mfg. Sata Spray Equipment 1224 Wall St. P.O. Box 46 Hwy. 16&63 N. P.O. Box 15042 Spring Valley, MN 55975 Los Angeles, CA 90015-0042 507-346-7102 213-749-4368 Xcel Spray Smith Eastern Corporation 5020 Sunnyside Ave. #207 Beltsville, MD 20705 301-937-4548 We believe the sources listed in this bulletin 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 this firm or for any such item which may be available from other sources. Page 4581 Figure 2 3L30 (180C) Transmission Shifter A/T: Specifications 3L30 (180C) Transmission Component .......................................................................................................................................... .................................................................... Ft. Lbs. Selector Lever Locknut ........................................................................................................................ ................................................................................ 9 Shift Lever To Selector Lever Shaft ................. .............................................................................................................................................................. .... 20 Shifter Assembly To Console .................................................................................................... ........................................................................................... 7 Specifications TEMPERATURE SENSORS Page 4439 new driven gear is required. Use (gray) 22 tooth driven gear (GM Part Number 3987922) if vehicle is equipped with L38 and GU6. Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: # T1612 Labor Time: 1.0 hr. FAILURE CODE: 92 Backup Lamps/Tailgate Window Release - Inoperative Backup Lamp Switch: All Technical Service Bulletins Backup Lamps/Tailgate Window Release Inoperative Number: 91-459-8A Section: 8A Date: DEC. 1991 Corporate Bulletin No.: 168104 ASE No.: A6 Subject: BACKUP LAMPS OR TAILGATE WINDOW RELEASE INOPERATIVE Model and Year: 1980-91 ALL LIGHT DUTY TRUCKS (EXCEPT GEO) Owners of some 1980-1991 C/K, 1982-1991 G, 1985-1991 M/L, 1984-1991 P2,P3, 1987-1991 R/V, 1983- 1991 ST (including LLV) with automatic transmissions may comment on a condition of inoperative back-up lamps or inoperative tailgate window release. This condition occurs when the vehicle's gear shift lever is placed in the "reverse" position, but the back-up lamps do not illuminate. In addition, on the S/T utility vehicles, the electric tailgate window release does not release when the transmission gear shift lever is placed in the "park" or "neutral" position and the endgate window release button is depressed. The park/neutral and back-up lamp switch comes out of adjustment which does not allow for the contact points to remain engaged. To correct these conditions, the contact carrier on the park/neutral and back-up lamp switch has been modified to increase switch carrier travel. SERVICE PROCEDURE: 1. Disconnect the battery ground cable from the battery. 2. Disconnect the switch assembly harness. 3. Place the gear selector in neutral. 4. Squeeze the tangs on the switch together and remove the switch assembly. 5. Install the new switch assembly (P/N 15679680) by: -aligning the actuator with the cutout in the steering column jacket. -inserting the tangs into the rectangular holes and pushing down on the switch assembly. 6. Adjust the switch by moving the gear selector to park. 7. Connect the switch assembly harness. 8. Connect the negative battery cable. 9. Check for proper switch operation. Readjust the switch as necessary. Engine - Vibration On Acceleration Catalytic Converter: All Technical Service Bulletins Engine - Vibration On Acceleration Number: 88-270-6F Section: 6F Date: JULY, 1988 Subject VIBRATION ON ACCELERATION Model and Year 1988 S/T TRUCK W/4.3L (VIN CODE Z) ENGINE TO: ALL CHEVROLET DEALERS Some 1988 S/T Trucks equipped with 4.3L engines may experience a vibration that can be felt in the floor pan area near the shifter, in the right hand passenger seat foot area, or on the steering column. These conditions may be caused by the following items: 1. The shifter rod that goes from the steering column to the transmission equalizer lever (#340 and #338 in Figure 36 page 7A-45 of the 1988 S/T Manual) hitting the exhaust crossover pipe and/or the equalizer lever making firm contact at the shift lever (T-truck only). 2. The exhaust pipe to catalytic converter clamp (Figure 7, page 6F-6 of the 1988 S/T Manual) hitting the catalytic converter heat shield. 3. The exhaust pipe to converter installation allows the exhaust pipe to contact the transmission crossmember. To repair these conditions, use the following procedures: 1. A. Raise vehicle on hoist. B. Check Transmission linkage for correct adjustment. C. Check exhaust pipe for shifter rod interference (shiny spot on pipe). D. If linkage hits pipe, remove 15 mm (5/8 in) from bottom of rod. E. Put transmission into low gear and mark exhaust pipe area near linkage. F. Put transmission in park. Using a hammer, lightly dimple exhaust pipe for additional clearance. Page 6682 Loosen and Shim # 1 Body Mount: 1. Loosen the # 1 body mount to zero torque. 2. Raise the body off the mount to obtain clearance between the floor and the top of the body mount. 3. Cut a 4" x 4" square of 1/32 inch thick teflon or nylon (obtain locally) and drill a 5/8" hole through the center. Insert this between the floor pan and the body mount and lower the body. An alternative material is three washer pump shields, P/N 22063244. If three washer pump shields are used, cut three shields (sheets) to size and locate a 5/8" hole in the center of each shield. Place the three shields between the floor pan and mount, then lower the body on the mount. 4. Apply Loctite 242 thread locking compound (GM P/N 12345382), or equivalent, to the body mount, bolt and retorque to 60-80 N-m (44-59 Lbs.Ft.). NOTE: Some insulating materials may compress over time resulting in a loss of torque to the body mount bolt. For this reason, nylon or teflon 1/32" thick and the thread locking compound on the bolt are being specified. Parts are currently available from GMSPO. WARRANTY INFORMATION: For vehicles repaired under warranty use: Labor Operation: T7276 Labor Time: 0.8 hr. Trouble Code: 92 NOTE: Labor Operation is coded to base vehicle coverage in the warranty system. Glass/Body - Windshield Wiper Performance Wiper Blade: Technical Service Bulletins Glass/Body - Windshield Wiper Performance INFORMATION Bulletin No.: 06-08-43-003C Date: February 21, 2011 Subject: Windshield Wiper Performance, Cleaning Instructions and Maintenance Models: 2012 and Prior GM Passenger Cars and Trucks (including Saturn) 2010 and Prior HUMMER H2, H3 2010 and Prior Isuzu Medium Duty Trucks 2005-2009 Saab 9-7X Supercede: This bulletin is being revised to add the 2011 and 2012 model year. Please discard Corporate Bulletin Number 06-08-43-003B (Section 08 - Body and Accessories). Wiper Concerns Most concerns about windshield wiper performance are the result of dirty wiper blades, damaged wiper blades, or worn out blades that are continuing to be used beyond their useful life. Depending on environmental conditions, wiper blades can have dramatic differences in lifespan. Here are some tips and guidelines to maximize wiper performance to avoid damage to the blades, and to avoid unnecessary replacements. Many wiper blades are being replaced under warranty with reviews showing there is nothing wrong with the returned blades other than a build-up of dirt. Additionally, advise the customer to review the information in their Owner Manual. Inspection and Cleaning Scheduled Maintenance - Inspect your wipers rubber blades every 4-6 months or 12,000 km (7,500 mi) for wear, cracking or contamination. - Clean the windshield and the rubber wiper blades (using the procedure below) if the blades are not clearing the glass satisfactorily. If this does not correct the problem, then replace the rubber elements. Cleaning Procedure Important Avoid getting windshield washer fluid on your hands. Wear rubber gloves or avoid direct contact with washer fluid. Important Do not use gasoline, kerosene, or petroleum based products to clean wiper blades. - Clean the rubber blades using a lint free cloth or paper towel soaked with windshield washer fluid or a mild detergent. You should see significant amounts of dirt being removed on the cloth. - Be sure to wash the windshield thoroughly when you clean the blades. Bugs, road grime, sap and a buildup of car wash/wax treatments may additionally cause wiper streaking. Tip For a larger scale buildup on the windshield, use a non-abrasive cleaner such as Bon-Ami* (www.faultless.com) cleanser with a wet sponge, being sure to use plenty of water to avoid scratching the glass. Flush the surface and body panels completely. Tip For day-to-day exterior glass cleaning and to maintain a streak free appearance, suggest Vehicle Care Glass Cleaner, P/N 88862560 (in Canada, 992727). This product is an easy to use foaming cleaner that quickly removes dirt and grime from glass surfaces. Tip Interior glass should be cleaned with plain, clean water to eliminate any film or haze on the window and help prevent fogging, a major customer dissatisfier. Refer to Corporate Bulletin Number 03-00-89-006D for more information. The New Vehicle Pre-Delivery Inspection form also recommends using plain water to clean interior glass. *"We believe this material 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 or equipment from these firms or any such items which may be available from other sources. Page 894 6. Check fluid level, color and condition (refer to Figure 1). ^ Inaccurate fluid level readings will result if the fluid is checked immediately after the vehicle has been operated under certain conditions: - In high ambient temperature above 32C (90F). - At sustained high speeds. - In heavy city traffic during hot weather. - As a towing vehicle. Page 1334 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 Page 4603 Figure 3 INSTALL (Figures 2 & 3) Tools required: J8092 Drive handle J33790 Bearing installer and remover J33833 Bearing installer and remover 1. Front output bearing (61) to the new front case half P/N 15635347 (45) using J 8092 and J 33833. 2. New front output shaft seal P/N 15579788 (72) to the new front case half (45). 3. Front output bearing retainer ring (snap ring) (60) to the new case half. 4. New input seal P/N 14095609 (42) into retainer (44) if it was removed in step 24 above. 5. Input bearing (40) and input bearing retainer (39) to the new case half using J 36372. 6. Planetary carrier (36) and the input gear (38) to the annulus gear (62) using a soft hammer. 7. Retainer snap ring to the input gear (38). Input bearing retainer (44) and input bearing retainer bolts (43) to the front case half (45). - Clean mating surfaces and apply RTV or equivalent on bearing retainer mating surfaces. NOTE Do not block oil feed hole from case to bearing retainer. - Apply Loctite 242 (R) or equivalent on bearing retainer bolts. - Tighten bolts to 19 N-m (14 lbs.ft.). Page 7041 Page 6612 - 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 Page 2009 Radiator Cooling Fan Temperature Sensor / Switch: Locations Coolant Temperature Switch Center Of Dash Panel (engine Compartment) Lower RH Side Of Engine Applicable to: V6-262/4.3L Engine A/T - Buzzing Noise at Idle Fluid Pressure Sensor/Switch: Customer Interest A/T - Buzzing Noise at Idle Number: 93-29-7A Section: 7A Date: OCT. 1992 Corporate Bulletin No.: 277142 ASE No.: A2 Subject: BUZZING NOISE AT IDLE Model and Year: 1982-93 CAPRICE, CAMARO AND CORVETTE 1982-93 C/K, R/V, S/T, M/L AND G TRUCKS WTIH 4L60 AUTOMATIC TRANSMISSION TRANSMISSION APPLICATIONS: 1982-1993 HYDRA-MATIC 4L60 (MD8) TRANSMISSION MODELS: All SUBJECT: Pressure Regulator Valve Buzz VEHICLE APPLICATIONS: B, D, F, Y - Cars C/K, R/V, S/T Trucks G, M, L - Vans CONDITION: Some 1982-1993 vehicles equipped with a HYDRA-MATIC 4L60 transmission may have a buzzing noise coming from the transmission when the vehicle is at idle. The buzzing noise may be noticed more when the vehicle is in reverse at idle. CAUSE: The buzzing noise may be a result of pressure regulator valve oscillating due to oil pressure instability at lower idle RPM. CORRECTION: Page 6235 REMOVE OR DISCONNECT (Figures 26 and 27) 1. Refrigerant from the system. 2. Negative battery cable. 3. Resistor (145) with the wire attached. 4. Blower electrical connection. 5. Inlet line (111) to the evaporator (143). 6. Blower assembly mounting screws (139) and nuts (147). 7. Blower assembly from the vehicle. 8. Accumulator inlet line (108) from the evaporator (143). 9. Accumulator bracket (150) and screw (148). 10. Accumulator (4). 11. Screws (147). 12. Case sections (146 and 140). 13. Core (143). INSTALL OR CONNECT 1. Core (143) to case sections (146 and 140) with screws (147). 2. Accumulator bracket (150) to the accumulator (4). 3. Accumulator (4) and bracket (150) to core (143) with screw (148). NOTE: Add 60 ml (2 oz.) of clean refrigerant oil PLUS an amount equal to that drained. 4. Inlet line (108) to the accumulator (4). NOTE: Use clean 525 viscosity oil on the seals. ^ Tighten connection to 24 Nm (18 ft. lbs.). 5. Blower assembly to the vehicle with screws (139) and nuts (147). ^ Tighten screws (139) to 3 Nm (3 in. lbs.). Nuts (147) to 2 Nm (2 in. lbs.). 6. Inlet line (111) to the evaporator core (143). NOTE: Use clean 525 viscosity oil on the seals. ^ Tighten connection to 24 Nm (18 ft. lbs.). 7. Outlet line (109) to the accumulator (4). ^ Tighten connection to 24 Nm (18 ft. lbs.). 8. Blower electrical connection. 9. Resistor (145) and electrical wire to the blower assembly. 10. Negative battery cable. 11. Evacuate, charge, and leak test system. Page 3434 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. Page 7233 Figure No. 1 Page 7038 6. Spray entire prepared area with a coat of DP40/DP401 anti-corrosion primer (PPG/ Ditzler) or equivalent. Follow manufacturers instructions and recommended dry times. 7. Apply 2 to 3 medium wet coats of primer-surfacer to primed surfaces of truck, making sure to follow manufacturers instructions for application. 8. After allowing adequate drying time, wet sand with 400 grit (or finer) sandpaper or dry sand with 320 grit (or finer) sandpaper. 9. Repeat steps 4 and 5. 10. Apply 1 medium wet coat of primer sealer, following manufacturers instructions. 11. Apply 3 to 4 medium wet coats (or until primer color is well hidden) of Acrylic/Urethane Enamel Color. Follow manufacturers instructions. NOTICE: Reinstall all trim and other items removed in step 2. 12. Final wash and detail vehicle. Claim Information Submit a claim with the information indicated below: * Select times as listed below for "Labor Hours" and material allowances for "Net Amount" as required for appropriate vehicle type and operation performed. Ignition System - Spark Plug Usage Change Spark Plug: Technical Service Bulletins Ignition System - Spark Plug Usage Change GMC NUMBER: 88-T-64 GROUP: 6D - Engine Electrical DATE: December, 1987 CORPORATE NUMBER: 836402R SUBJECT: SPARK PLUG USAGE CHANGE MODELS: 1988 LIGHT DUTY TRUCKS WITH 4.3L, 5.0L AND 5.7L ENGINES (VIN CODES Z, H AND K) This bulletin is to advise dealers that there has been a spark plug usage change in production for 1988 trucks with the 4.3L, 5.0L and 5.7L engines. Engines built through August 30, 1987, have spark plugs AC CR43TS, P/N 5614029. Engines built starting August 31, 1987, have spark plugs AC R43TS, P/N 5613325. Due to design differences between the CR43TS and R43TS spark plugs, a radio popping noise may be encountered in vehicles equipped with CR43TS spark plugs. This condition can be repaired by replacing CR43TS spark plugs with R43TS spark plugs. Spark plug gap is 0.035". Page 3063 Fuel Return Line: Service and Repair NOTES: a. 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. b. 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. Page 5984 Installation Notes Brake Rotor/Disc: Fundamentals and Basics Installation Notes WHEN INSTALLING A ROTOR/DISC, REMEMBER... Thoroughly clean the rotors with brake cleaner. - Any grease or brake fluid which comes in contact with the rotor should be thoroughly cleaned prior to installing the new pads/linings. - Grease and other contaminants become lodged in the microscopic pores of the rotor's surface. This prolongs the brake-in time of the new linings and contaminates the friction material. - Commercially produced aerosol brake cleaners should be used to clean the rotor. Unlike carburetor cleaner or other petroleum based solvents, brake cleaner does not leave a residue on the rotor's surface. Recheck the wheel bearings once the tires are installed. - With the vehicle raised and properly supported, grasp the tire at the top and bottom and attempt to rock them back and forth. There should be no detectable lateral (wobble) movement. Service and Repair Fuel Pressure Release: Service and Repair Before performing any procedure that requires disconnecting fuel lines, relieve fuel system pressure as described below. 1. Remove Fuel Pump fuse from fuse block. 2. Start engine and allow to run out of fuel, then crank engine an additional 3 seconds. 3. Service fuel system as necessary. Page 565 Fig. 10 Windshield Wiper Switch Removal (Rear) REAR Refer to Fig. 10, for wiper switch replacement. 1. Disconnect battery ground cable. 2. Remove switch trim plate and screws from instrument panel. 3. Disconnect electrical connector, then remove switch. 4. Reverse procedure to install. Windshield - Wind Noise Windshield: All Technical Service Bulletins Windshield - Wind Noise Number: 91-83-10 Section: 10 Date: October 1990 Corp. Bulletin No.: 061007 Subject: WINDNOISE AT DASH Model and Year: 1982-91 S/T TRUCKS AND UTILITY VEHICLES TO: ALL CHEVROLET DEALERS Some owners of 1982 - 1991 S/T pickup and utility vehicles may experience a condition described as wind noise near the windshield. SERVICE PROCEDURE: This condition may result from a sealer gap or a light application of the sealer to the seam between the windshield and the cab frame. This light application can separate and create a gap for air to pass through. To determine if either of these conditions have occurred perform the following steps. Page 78 - An updated engine control calibration, or service procedure, may be available to make the engine less susceptible to low volatility fuels. 3. If basic checks do not reveal a vehicle fault, then advise the customer that fuel quality may be an issue. Recommend the following actions: Change brands of fuel - Use 87 octane gasoline, unless the vehicle is designed for premium gasoline. - Try to empty the fuel tank as much as practical before refilling. - Run a minimum of three tanks of new fuel before returning for service. 4. If above steps are ineffective, do not proceed with additional vehicle diagnosis and/or parts replacement until the fuel tank has been drained and refilled with a known good quality gasoline AT THE DEALERSHIP. 5. If the problem remains refer to service manual, service bulletins and/or technical assistance. Page 4090 FIGURE 3 - CHECKBALL LOCATIONS ON TRANSMISSIONS WITHOUT AUXILIARY VALVE BODIES SERVICE ACTION: When servicing any 1982 through 1987 THM 700-R4 transmission without an auxiliary valve body (Figure No. 3), the lo and reverse #5 checkball (#55B) must be located in the control valve body. FIGURE 1 - CHECKBALL LOCATIONS ON TRANSMISSIONS WITH AUXILIARY VALVE BODIES When servicing any 1987 THM 700-R4 transmission produced after October 6, 1986 (Julian Date 279) the forward clutch #12 checkball must be located in the auxiliary valve body (#55BFigure No. 1). Do not install a checkball in the control valve body. NOTICE: If the forward clutch #12 checkball is installed in either the valve body or over the orificed cup plug (359-Figure No. 1) in the auxiliary valve body, the following conditions can occur: ^ Delayed N-D, P-D or R-D Page 5156 Figure 4 Figure 5 Figure 6 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 7 Page 5669 Power Steering Pump: Service and Repair Vane Type Power Steering Pump Flushing Power Steering System 1. Raise front end of vehicle off ground until wheels are free to turn. 2. Remove fluid return hose at pump inlet connector and plug connector port on pump. Position hose in large container. 3. While an assistant is filling reservoir with new power steering fluid, run engine at idle. turn steering wheel from stop to stop. Do not contact wheel stops or hold wheel in a corner as fluid will stop and pump will be in pressure relief mode. A sudden overflow from reservoir may develop if wheel is held at a stop. 4. Install all pipes and hoses. Fill system with new power steering fluid and bleed system as outlined under SYSTEM BLEEDING. 5. Operate engine for 15 minutes. 6. Remove pump return hose at pump inlet and plug connection on pump. While refilling reservoir, check draining fluid for contamination. If foreign material is still evident, replace all hoses, disassemble and clean or replace power steering system components. Do not reuse any drained power steering fluid. System Bleeding 1. Fill pump fluid reservoir to proper level and let fluid settle for at least two minutes. 2. Start and run engine for a few seconds. Do not turn steering wheel. 3. Turn engine Off. Check fluid level, add fluid if necessary. 4. Repeat above procedure until fluid level remains constant after running engine. 5. Raise front end of vehicle so wheels are off ground. 6. Start engine. Slowly turn steering wheel in both directions, lightly contacting wheel stops. 7. Add power steering fluid, if necessary. 8. Lower vehicle and turn steering wheel slowly from lock to lock. 9. Stop engine. Check fluid level and refill as required. 10. If fluid is extremely foamy, allow vehicle to stand a few minutes and repeat above procedure. Page 3414 [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 Engine Controls - ECM May Contain Wrong PROM PROM - Programmable Read Only Memory: All Technical Service Bulletins Engine Controls - ECM May Contain Wrong PROM Number: 88-42 Section: 6E Date: Sept., 1987 Subject: SERVICE REPLACEMENT ELECTRONIC MODULES (ECM) WITH PROM INSTALLED Model and Year: 1981-88 ALL MODELS TO: ALL CHEVROLET DEALERS It has been brought to our attention that some service replacement electronic control modules (ECM's) have contained a PROM. A PROM should not have been included in a replacement ECM as it may not be the correct PROM for the vehicle. When this situation is encountered, the PROM should be removed from the replacement ECM and the PROM from the vehicle should be installed. Page 2608 Description and Operation Transmission Position Switch/Sensor: Description and Operation The park/neutral switch indicates to the ECM when the transmission is in park or neutral. This information is used by the ECM for ignition timing, IAC operation and transmission Torque Converter Clutch (TCC) operation. Do not drive vehicle with park/neutral switch disconnected, as idle quality may be affected. Page 3954 SERVICE PARTS INFORMATION Part Number Description 15664811 Vacuum Actuator Switch Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: K4120 Use applicable labor time guide for labor hours. Page 7132 ** Refer to the applicable labor time guide for paint mix time allowance and include in "Other Hours." *** Select corresponding material allowances to combine with proper "Above Belt Line" material allowance in "Net Amount" as required for appropriate vehicle type and operations performed. Reimbursement Customer claims for reimbursement on previously paid repairs to correct paint topcoat delamination (peeling) are to be submitted according to the forms and instructions included in this bulletin (additional copies to be reproduced locally). Owners must submit original documentation that reasonably confirms the amount of unreimbursed repair expenses, a description of the repair, the date of the repair, and the person or entity performing the repair. Page 3228 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. Page 5696 4. Insufficient pump pressure. 5. Excessive internal pump leakage. 6. Excessive internal steering gear leakage. Momentary Increase In Effort When Turning Wheel Fast 1. High internal leakage. 2. Low fluid level. 3. Insufficient pump pressure. Poor Return of Steering Wheel to Center 1. Front wheel alignment. 2. Wheel bearing worn. 3. Joints from column to steering gear binding or loose. 4. Tie rod end binding. 5. Ball joint binding. 6. Steering wheel rubbing against turn signal housing. 7. Tight or frozen steering shaft bearings. 8. Steering gear adjustments. 9. Sticky or plugged steering gear valve. 10. Steering column shaft seal rubbing shaft. Rattle or Chuckle Noise 1. Pressure hose grounding out. 2. Tie rod ends loose. 3. Rack bearing adjustment loose. Steering Wheel Surges/Jerks When Turning W/Engine Running 1. Insufficient pump pressure. 2. Sticky steering gear valve. Page 7619 Fuel Gauge Sender: Service and Repair Fuel Pump And Sender Assembly (Typical) REMOVAL: 1. Disconnect the negative battery cable. 2. Raise vehicle. 3. Remove fuel tank. Refer to FUEL TANK ASSEMBLY. 4. Remove pump and sending unit assembly by turning the cam lock counterclockwise using tool J-36608 or J-24187 or equivalent. ^ Pull the fuel pump up into the attaching hose while pulling outward from the bottom support. ^ Do not damage the rubber insulator or the strainer. INSPECTION: 1. Inspect the fuel pump attaching hose for signs of deterioration. 2. Inspect the rubber sound insulation at the bottom of the pump for deterioration. INSTALLATION: 1. Install pump assembly into the attaching hose. NOTE: Care should be taken not to fold over or twist the strainer, when installing the sending unit as this will restrict fuel flow. 2. Install sending unit and fuel pump assembly into the fuel tank. (Always use a new O-ring seal). 3. Install the cam lock assembly. Turn the cam lock clockwise to lock it. 4. Install fuel tank assembly. 5. Connect the negative battery cable. 6. START vehicle and check for fuel leaks. Page 7603 Oil Pressure Warning Lamp/Indicator: Testing and Inspection On some models, the oil pressure indicator light also serves as the electric choke defect indicator. If Oil or ENG. indicator light does not light, check to ensure electric choke is not disconnected at carburetor. Also check for defect in electric choke heater, blown gauge fuse or defect in lamp or wiring circuit. If indicator light stays on with engine running possible causes are: low oil pressure, switch to indicator light open circuit, disconnected oil pressure switch connector or oil pressure gauge or radio fuse has blown. 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. Page 7589 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 4. Make repair. Page 7441 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. Page 603 Man. N 500-550 2-12 CL Auto D 500-550 2-20 CL [1] Add 2 counts for engines with less than 500 miles. Add 2 counts for every 1000 ft. above sea level. [2] Let engine idle until proper fuel control status is reached (OPEN/CLOSED LOOP). MINIMUM IDLE AIR RATE Transmission Gear Engine Speed OPEN/CLOSED LOOP [1] Man. N 450 +/- 50 CL Auto. N 475 +/- 50 CL [1] Let engine idle until proper fuel control status (OPEN/CLOSED LOOP) is reached. 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 Fuse Block - Deforms Fuse Block: All Technical Service Bulletins Fuse Block - Deforms Number: 90-432-8B Section: 8B Date: SEPT. 1991 Corporate Bulletin No.: 168102 ASE No.: A6 Subject: FUSE BLOCK DEFORMS Model and Year: 1988-90 SI (LLV) POSTAL VEHICLES Some 1988 to 1990 LLV postal vehicles built prior to August 3, 1990, may exhibit a condtion where the fuse block is partially deformed due to heat generated by continuous operation of the hazard flasher. This condition may be corrected by the repositioning of the hazard flasher to a remote location. SERVICE PROCEDURE: 1. Disconnect positive battery cable. 2. Remove old flasher. 3. Back out terminals for circuit 140A (orange wire) and circuit 27 (brown wire) using a small flat screwdriver or pick. Using the same tool, raise the locking tang on the back of the terminal. 4. Cut electrical tape used to wrap main wiring harness a sufficient amount to provide 2 to 3 inches of flasher wiring for relocation. 5. Insert terminals of circuits 140A and 27 into new connector (P/N 2973385). 6. Install electronic flasher (P/N 15504673) into the new connector. 7. Using nylon ties, strap the connector and flasher assembly to the wiring harness that runs above the fuse block. Verify that the relocated flasher and all wiring is secured so it does not cause interference with the throttle linkage. 8. Reconnect battery cable. 9. Test operation of hazard flasher system. SERVICE PARTS INFORMATION PART NUMBER DESCRIPTION QTY 2973385 Connector 1 15504673 Flasher (Electronic) 1 NPN Nylon Tie Straps 2 Parts are currently available from GMSPO. Body - Vehicle Glass Distortion Information Windshield: All Technical Service Bulletins Body - Vehicle Glass Distortion Information INFORMATION Bulletin No.: 00-08-48-005D Date: September 10, 2010 Subject: Distortion in Outer Surface of Vehicle Glass Models: 2011 and Prior GM Passenger Cars and Trucks 2009 and Prior HUMMER H2 2010 and Prior HUMMER H3 2005-2009 Saab 9-7X 2010 and Prior Saturn Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 00-08-48-005C (Section 08 - Body and Accessories). Distortion in the outer surface of the windshield glass, door glass or backlite glass may appear after the vehicle has: - Accumulated some mileage. - Been frequently washed in automatic car washes, particularly "touchless" car washes. This distortion may look like a subtle orange peel pattern, or may look like a drip or sag etched into the surface of the glass. Some car wash solutions contain a buffered solution of hydrofluoric acid which is used to clean the glass. This should not cause a problem if used in the correct concentration. However, if not used correctly, hydrofluoric acid will attack the glass, and over time, will cause visual distortion in the outer surface of the glass which cannot be removed by scraping or polishing. If this condition is suspected, look at the area of the windshield under the wipers or below the belt seal on the side glass. The area of the glass below the wipers or belt seal will not be affected and what looks like a drip or sag may be apparent at the edge of the wiper or belt seal. You may also see a line on the glass where the wiper blade or the belt seal contacts the glass. Important The repair will require replacing the affected glass and is not a result of a defect in material or workmanship. Therefore, is not covered by New Vehicle Warranty. Disclaimer Testing and Inspection Ignition Control Module: Testing and Inspection If the vehicle cranks for at least 5 seconds and the Engine Control Module doesn't see a referance signal, some Models will set a code, 42 (Hard) or 12 (Soft). If your vehicle has one of these codes, begin with the Diagnostic System Check in Computers and Controls, then proceed to the Trouble Code Chart (Yes, some vehicles have a DTC Chart for Code 12). If the vehicle does not set a code, begin with the Diagnostic System Check, and it will send you to a Diagnostic Chart that checks for your particular condition. These types of tests are found under Computers and Control Systems. See: Computers and Control Systems/Testing and Inspection Page 5644 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". Engine Controls - ECM May Contain Wrong PROM Engine Control Module: All Technical Service Bulletins Engine Controls - ECM May Contain Wrong PROM Number: 88-42 Section: 6E Date: Sept., 1987 Subject: SERVICE REPLACEMENT ELECTRONIC MODULES (ECM) WITH PROM INSTALLED Model and Year: 1981-88 ALL MODELS TO: ALL CHEVROLET DEALERS It has been brought to our attention that some service replacement electronic control modules (ECM's) have contained a PROM. A PROM should not have been included in a replacement ECM as it may not be the correct PROM for the vehicle. When this situation is encountered, the PROM should be removed from the replacement ECM and the PROM from the vehicle should be installed. Page 4445 new driven gear is required. Use (gray) 22 tooth driven gear (GM Part Number 3987922) if vehicle is equipped with L38 and GU6. Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: # T1612 Labor Time: 1.0 hr. FAILURE CODE: 92 Page 2793 Vehicle Speed Sensor: Description and Operation VSS Buffer Amplifier On vehicles with conventional instrumentation, a vehicle speed sensor (VSS) buffer amplifier is used to supply the vehicle speed signal to the cruise control module. On this type system, a speedometer frame mounted optic head is used to pick up light reflected by a speedometer cable mounted blade. The reflected light is produced by a light emitting diode (L.E.D.). As the speedometer cable mounted blade enters the L.E.D. light beam, the light is reflected into the optic head. From there, the light enters a photocell in the optic head and produces a low power signal. This signal is sent to a buffer for amplification and conditioning, then to the controller. Digital Ratio Adapter Controller On vehicles with electronic instrumentation, a digital ratio adapter controller (DRAC) is used to supply the vehicle speed signal to the cruise control module. On this type system, the DRAC receives vehicle speed signals from a transmission or transfer case mounted vehicle speed sensor. The DRAC is calibrated according to axle ratio and tire combination, and provides 40 electronic pulses per revolution of the transmission or transfer case output shaft. Page 6930 2. Remove the end gate inner panel reinforcement from the end gate (Figure 1, Item 1). 3. Disconnect the end gate lock rods (Figure 2, Items 1 and 2). 4. Remove the lock cylinder retainer (Figure 3, Item 2). 5. Working through the access hole, remove the lock cylinder and gasket (Figure 3, Items 4 and 3) through the outer panel. 6. Remove the spring (located on the lock assembly) and carefully bend the spring ends just far enough to eliminate any clearance between the lock pawl assembly and the lock cylinder housing (Figure 3, Items 6 and 4). Note: Page 5263 Fuse Block: Locations LH Side Of I/P Behind Instrument Cluster Page 4239 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. 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. Page 2865 Electronic Vacuum Regulator Valve (EVRV): Locations Exhaust Gas Recirculation Solenoid Center Of Dash Panel (engine Compartment) RH Side Of Engine Applicable to: V6-262/4.3L Engine Page 1081 Engine Controls - ECM May Contain Wrong PROM Engine Control Module: All Technical Service Bulletins Engine Controls - ECM May Contain Wrong PROM Number: 88-42 Section: 6E Date: Sept., 1987 Subject: SERVICE REPLACEMENT ELECTRONIC MODULES (ECM) WITH PROM INSTALLED Model and Year: 1981-88 ALL MODELS TO: ALL CHEVROLET DEALERS It has been brought to our attention that some service replacement electronic control modules (ECM's) have contained a PROM. A PROM should not have been included in a replacement ECM as it may not be the correct PROM for the vehicle. When this situation is encountered, the PROM should be removed from the replacement ECM and the PROM from the vehicle should be installed. A/T - Manual Update For ATF Level & Condition Fluid - A/T: All Technical Service Bulletins A/T - Manual Update For ATF Level & Condition GMC NUMBER: 89-7A-104 GROUP: 7A Automatic Transmission DATE: September, 1989 CORPORATE NUMBER: 977126R SUBJECT: AUTOMATIC TRANSMISSION FLUID COLOR/LEVEL CHECK INFORMATION MODELS: ALL 1987-89 S/T, C/K, R/V TRUCKS AND M, G, P VANS EQUIPPED WITH HYDRAMATIC AUTOMATIC TRANSMISSIONS BULLETIN COVERS: Service Manual update for Transmission fluid level and condition information. This information is updated for 1989 service manuals printed prior to June 1989. TRANSMISSION FLUID LEVEL INFORMATION: Checking fluid level and condition (color and odor) at regular intervals will provide early diagnosis information about the transmission. This information may then be used to correct a condition that, if not detected early, could result in major transmission repairs. When adding or changing fluid, use only DEXRON II. Refer to Maintenance and Lubrication (Service Manual Section OB) for maintenance information and servicing intervals. NOTICE: Do not overfill. Overfilling will cause foaming, loss of fluid, shift complaints and possible damage to the transmission. ^ Fluid level should only be checked when it reaches a normal operating temperature of 82-93C (180-200F). This temperature is reached after approximately 24 km (15 miles) of driving. TRANSMISSION FLUID COLOR: ^ Fluid color will be red when new. IMPORTANT: When new, automatic transmission fluid is red in color. The red dye is added so the assembly plant can identify it as transmission fluid and distinguish it from engine oil or anti-freeze. The red dye is not an indicator of fluid quality and is not permanent. As the vehicle is driven, the transmission fluid will begin to look darker in color. The color may eventually appear light brown. A dark brown color along with a burnt odor may indicate excessive fluid deterioration and signal a need for fluid change. Diagram Information and Instructions Neutral Safety Switch: Diagram Information and Instructions 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 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. Page 1481 Connecting Rod Bearing: Specifications Bearing Undersize Availability Main bearings are available in standard size and undersizes of .001, .002, .009, .010 and .020 inch. Connecting rod bearings are available in standard size and .001 and .002 inch undersize for use with new and used standard size crankshafts and .010 and .020 inch undersize for use with reconditioned crankshafts. ECM/PCM - Damage Prevention Engine Control Module: All Technical Service Bulletins ECM/PCM - Damage Prevention Number: 91-318-6E Section: 6E Date: MAY 1991 Corp. Bulletin No.: 176502R Subject: DAMAGE TO ECM/PCM CIRCUIT BOARD WHEN INSTALLING A MEM-CAL Model and Year: 1986-91 ALL PASSENGER CARS AND TRUCKS CONDITION: When installing a service replacement ECM/PCM, the use of incorrect MEMCAL installation procedures may cause the ECM/PCM to fail before it can be installed in the vehicle. This condition may appear as if the ECM/PCM were defective when it was shipped to the dealership, when in fact it was damaged while being installed. In addition this condition may also occur when installing an "updated" service MEM-CAL into the vehicles original equipment ECM/PCM. CAUSE: Excessive vertical force may be applied to the MEM-CAL resulting in flexing of the circuit board and damage to the connections between the circuit board and attached components. Excessive verticle force may be generated in two ways. 1. Incorrect MEM-CAL installation procedure. 2. Interference between MEM-CAL and cover. CORRECTION: Use the following procedure. Service Procedure: Important: This procedure supersedes any instructions regarding MEM-CAL installation dated prior to September 1990. 1. Inspect the MEM-CAL to determine if a cork spacer is glued to the top side of the MEM-CAL assembly. If so, remove it prior to installation. 2. Align small notches with matching notches in the ECM/PCM MEM-CAL socket. 3. VERY GENTLY press down on the ends of the MEM-CAL until the locking levers are rotated toward the sides of the MEM-CAL. Notice: To avoid ECM/PCM damage, do not press on the ends of the MEM-CAL until the levers snap into place. Do not use any vertical force beyond the minimum required to engage the MEM-CAL into its socket. 4. While continuing light pressure on the ends of MEM-CAL, use your index fingers to press the locking levers inward until they are snapped into place. Listen for click. 5. Install MEM-CAL cover and install ECM/PCM in vehicle. Audio - Poor AM or FM Radio Reception Radio/Stereo: Customer Interest Audio - Poor AM or FM Radio Reception Number: 89-108-9A Section: 9A Date: MARCH, 1989 Subject: POOR AM OR FM RADIO RECEPTION Model and Year: 1980-89 CHEVROLET VEHICLES TO: ALL CHEVROLET DEALERS Page 2772 Oxygen Sensor: Description and Operation Fig. 6 Oxygen Sensor (Typical) The exhaust oxygen sensor is located in the exhaust system and monitors oxygen content in the exhaust gas stream. The oxygen content of the exhaust gas reacts with the oxygen sensor to produce a voltage output, Fig. 6. By monitoring the oxygen sensor output voltage, the ECM can determine the amount of oxygen in the exhaust gas and adjust the air/fuel mixture accordingly. Page 6651 When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 5mm (3/16") of insulation from wire. e. Crimp a new terminal to the wire. f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. Figure 17 To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Figure 18 Figure 19 Service and Repair Blower Motor Switch: Service and Repair S/T-10/15 1. Disconnect battery ground cable. 2. Remove instrument panel center bezel. 3. Remove control assembly attaching screws, then pull control assembly outward and remove blower switch. 4. Reverse procedure to install. Page 4093 FIGURE 3 - CHECKBALL LOCATIONS ON TRANSMISSIONS WITHOUT AUXILIARY VALVE BODIES SERVICE ACTION: When servicing any 1982 through 1987 THM 700-R4 transmission without an auxiliary valve body (Figure No. 3), the lo and reverse #5 checkball (#55B) must be located in the control valve body. FIGURE 1 - CHECKBALL LOCATIONS ON TRANSMISSIONS WITH AUXILIARY VALVE BODIES When servicing any 1987 THM 700-R4 transmission produced after October 6, 1986 (Julian Date 279) the forward clutch #12 checkball must be located in the auxiliary valve body (#55BFigure No. 1). Do not install a checkball in the control valve body. NOTICE: If the forward clutch #12 checkball is installed in either the valve body or over the orificed cup plug (359-Figure No. 1) in the auxiliary valve body, the following conditions can occur: ^ Delayed N-D, P-D or R-D Page 6748 11. Install cowl vent grille. Refer to "Cowl Vent Grille Replacement" in Section 2B of the Service Manual. PARTS INFORMATION Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty, use: Labor Operation Description Labor Time B1717 Replace Use Published Labor Hood Hinge Operation Time Page 1044 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. Page 5432 Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Description Labor Op. Striker and/or Support - Replace (RH) B5820 Striker and/or Support - Replace (LH) B5821 Page 4541 Transmission Speed Sensor: Service and Repair 1. Disconnect battery ground cable. 2. Raise and support vehicle, then disconnect sensor electrical connector. 3. Remove sensor retaining bolt, then the sensor. 4. Reverse procedure to install. Page 3141 Throttle Position Sensor: Service and Repair REMOVAL: 1. Disconnect electrical connectors. 2. Remove the TPS attaching screw assemblies and retainer, (if applicable). 3. Remove TPS from throttle body assembly. NOTE: The TPS is an electrical component and must not be soaked in any liquid cleaner or solvent, as damage may result. INSTALLATION: 1. Install TPS to throttle body assembly, while lining up TPS lever with TPS drive lever on throttle body. 2. Install the two attaching screw assemblies. Tighten screw assemblies to 2.0 Nm (18.0 lb-in). 3. Install electrical connector to TPS. 4. Check for TPS output as follows: a. Connect an ALDL scanner to read TPS output voltage. b. With ignition ON and engine stopped, TPS voltage should be less than 1.25 volts. If more than 1.25 volts, replace TPS. Page 6717 Parts Information Parts required to complete this special coverage are to be obtained from General Motors Service and Parts Operations (GMSPO). Customer Notification General Motors will notify customers of this special coverage on their vehicles. Service Procedure Replacement of interior door handle assembly(s) Provide the customer with one or two interior front door handle assemblies. The customer is to self-install the assemblies or pay the dealer for the installation. Application of Lithium Grease Apply lithium based lubricant to the door handle springs. The lubricant should be applied so that it works into and between the spring coils, allowing the coils to move past each other freely. Claim Information Due to the age of the vehicles involved in this program, most involved VINs will be added to GMVIS to allow submission of claims. However, there are a few VINs that were not legible and could not be loaded into GMVIS. If a customer presents a letter authorizing repairs but the VIN is not found in GMVIS, H-route the claim to your AVM for approval. Page 1578 Disclaimer Ignition System - Diagnosis Precautions Spark Plug Wire: All Technical Service Bulletins Ignition System - Diagnosis Precautions Number: 88-138-6D Section: 6D Date: Feb., 1988 Subject: ENGINE MISS, HESITATION, OR ROUGHNESS DUE TO PIERCED SECONDARY IGNITION COMPONENTS Model and Year: ALL MODELS WITH GASOLINE ENGINE TO: ALL CHEVROLET DEALERS During the diagnosis procedures for an engine miss, hesitation, or roughness condition, a spark plug or spark plug wire condition may be suspected. Several types of commercial or homemade diagnostic equipment require the secondary ignition boots or wire to be pierced. This is normally done to check for spark plug firing or to perform a cylinder balance test. Similarly, the use of pliers or other such tools to disengage a spark plug boot may pierce or damage the boot or wire. NOTICE: SECONDARY IGNITION COMPONENTS SHOULD NOT BE PIERCED FOR ANY REASON. Piercing a spark plug wire and/or distributor or direct fire module nipple may create a failure condition that will not be immediately apparent. Over time, the hole in the pierced boot may allow a ground path to develop, creating a plug misfire condition. Heavily moisture-laden air in the vicinity of the pierced boot may accelerate this effect. Piercing a secondary ignition wire creates a gap in the wire's conductive core. This gap is a point of high resistance. The current flow in the wire will increase to compensate for the higher wire resistance. Over time, the wire may fail, creating a plug misfire condition. The time required for the condition to appear depends upon the extent of damage to the conductive core. To help prevent future customer comments that are spark plug wire related, do not pierce or otherwise damage any secondary ignition component. Only use diagnostic equipment containing an inductive pick-up to check for spark plug firing or to perform cylinder balance tests. When disengaging a spark plug boot from the spark plug, twist the flanged boot 1/2 turn, then pull only on the boot to remove the wire. Fuels - Effect of Volatility on Driveability Fuel: All Technical Service Bulletins Fuels - Effect of Volatility on Driveability Number: 93-31-6C Section: 6C Date: OCT. 1992 Corporate Bulletin No.: 249128R ASE No.: A1, A8 Subject: EFFECT OF FUEL VOLATILITY ON DRIVEABILITY CONDITIONS Model and Year: ALL MODEL YEARS, ALL PASSENGER CARS AND TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 92-281-6C, DATED SEPT. 1992. THE 1993 MODEL YEAR HAS BEEN ADDED. ALL COPIES OF 92-281-6C SHOULD BE DISCARDED. Recent changes in EPA regulations have effectively lowered the maximum allowable fuel volatility. Volatility, which can be defined as a gasoline's ability to change from a liquid to a vapor, directly affects the amount of evaporative emissions produced by the fuel. Higher volatility means that more unburned hydrocarbons will be released into the atmosphere. Unfortunately, reducing fuel volatility can cause problems during cold engine operation when low temperatures impede the fuel's ability to vaporize and burn. Two terms are often used to describe volatility characteristics. These are: Distillation Curve A graph showing the relationship between temperature and the percentage of fuel evaporated. The fuel components that boil at relatively low temperatures (below about 90 degrees F) are known as the "light ends", and are essential for good cold engine performance. The "heavy ends", which begin to boil at about 300 degrees F, contain the most energy but are more difficult to burn. Laboratory analysis is usually required to determine the distillation curve of a gasoline sample. - Reid Vapor Pressure (RVP) RVP is the pressure (psi) that vaporized fuel exerts within a sealed container as it is heated to 100 degrees F. The higher the RVP the higher the fuel volatility. While RVP is readily tested in the field, fuels of the same RVP can have different distillation curves and cold driveability characteristics. Fuel volatility will vary depending on geographic location and time of year (fuel intended to be used in higher ambient conditions is formulated with less volatility). This can make cold driveability as big a problem during summer months as during the winter. There may be additional variation in the volatility characteristics of pump gasoline, caused by the differences in fuel manufacturers, blends and storage times. As EPA fuel volatility standards are lowered, variations between fuels (which may further reduce volatility) becomes a critical factor influencing cold engine performance. No matter how thoroughly the relationship between fuel quality and cold driveability is understood, eliminating fuel quality as an issue can be difficult, because: TOOLS WHICH TEST FUEL VOLATILITY MEASURE ONLY RVP, NOT THE DISTILLATION CURVE. The distillation curve has a greater effect on cold driveability than RVP. THE CUSTOMER MAY PERCEIVE RAISING THE FUEL QUALITY ISSUE AS AN ATTEMPT TO EVADE HIS PROBLEM. This may cause difficulty in getting accurate fuel usage information. WATER, AND OTHER TYPES OF FUEL CONTAMINATION, MAY CAUSE CONTINUED DRIVEABILITY COMPLAINTS. - The problem symptoms may remain even though the vehicle has been refueled several times with a quality gasoline. CUSTOMER CONCERNS CONDITION: Poor Cold Engine Operation, symptoms may include; hard start/extended crank, stalling, backfiring, hesitation and/or lack of power. POSSIBLE CAUSE: Low volatility fuel will not vaporize sufficiently to allow normal combustion. CORRECTION: Replace Fuel. DIAGNOSTIC PROCEDURE: 1. Perform basic system checks in section 6E of the service manual. 2. Check for service bulletins which relate to cold driveability issues specific to the problem vehicle. Page 1214 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 Tires (Front) - Irregular Wear Tires: All Technical Service Bulletins Tires (Front) - Irregular Wear Number: 91-26-3E Section: 3E Date: June 1990 Corp. Bulletin No: 053501 Subject: FRONT TIRE WEAR Model and Year: 1982-91 LIGHT DUTY TRUCKS (REAR WHEEL DRIVE) THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 91-12-3E. THE KILOMETERS HAVE BEEN TRANSLATED INTO MILES. ALL COPIES OF 91-12-3E SHOULD BE DISCARDED. Rear wheel drive trucks, equipped with All Season and/or On-Off road tires may exhibit irregular wear of; the front tires. Small amounts of irregular wear is considered normal and is not necessarily a result of incorrect alignment. Incorrect alignment (especially toe) may result in premature wear of the front tires, however agressive cornering may also have a similar effect. Drive axle tires are much less prone to irregular wear, therefore they should not be considered for comparison of wear to non-drive axle tires. The rate of irregular wear is also dependent upon the depth of tread. New tires are more prone to irregular wear, so it is essential that tires are rotated at the proper intervals to normalize the wear. Page 3573 Interior - Itch Noise From Windshield Pillar Area Instrument Cluster / Carrier: Customer Interest Interior - Itch Noise From Windshield Pillar Area Number: 92-286-10 Section: 10 Date: SEPT. 1992 Corporate Bulletin No.: 261610 ASE No.: B1 Subject: ITCH NOISE FROM WINDSHIELD PILLAR AREA Model and Year: 1986-92 S/T TRUCKS Some 1986-1992 S/T utility trucks may exhibit a plastic to metal or plastic to plastic "itch" noise from the left or right windshield pillar area. This noise may be caused by the instrument panel pad rubbing against the cowl or dash support panel. An adhesive backed felt tape has been released to insulate the dash pad outer corners from the dash support panel. This tape may also be used on the non-visible surfaces of other trim panels as necessary to eliminate itch noises. The felt tape, P/N 12541499, is released in a 10 ft. x 30 mm x 1 mm roll to provide the technician sufficient material to insulate numerous trim panels. SERVICE PROCEDURE: Prior to installing the felt tape, it should be determined if the IP pad to dash support panel is the area that is generating the noise. Refer to the Squeak and Rattle Diagnosis and Correction Manual to identify other possible sources such as ECM Mounting Bracket or Air Vent. If it is determined the IP pad is the source of the noise: 1. Remove the instrument panel radio speaker(s) to obtain better access to the metal ledge on which the instrument panel pad rests. 2. Remove the 4 IP upper retaining screws located in the defroster duct openings and pull the pad back slightly. NOTICE: Do not remove the dash pad any further than necessary to perform the repair. The possibility exists that additional noises may be generated due to the wiring and HVAC ducts being mispositioned upon reinstallation. 3. Cut a strip of felt tape 6 inches long, remove the protective backing and apply the tape to the top of the metal ledges in front of the speaker openings where the instrument panel pad rests. NOTICE: Installation is easier if 2 screwdrivers are wedged between instrument panel pad and the cowl panel to raise the IP pad. 4. Push the IP pad forward and reinstall the retaining screws and speakers. Page 4307 15. Insert a drift-through brake caliper to prevent drive axle from turning and torque inboard flange bolts to 80 N-m (60 lbs.ft.). 16. Torque hub nut to 220-270 N-m (162-199 lbs.ft.). 17. Attach retainer. 18. Align cotter pin hole with retainer slot by rotating retainer. Important: DO NOT back off or tighten hub nut more than specified to install cotter pin. 19. Install new cotter pin. Cotter pin must be bent so retainer is held snugly to prevent rattling. 20. Remove drift, install wheels, and lower vehicle. Service Parts Information: Part Number Description Quantity Required 26027964 Seal Kit, Tripot 1 per side Parts are expected to be available on June 17, 1991. Until then, normal part orders will not be accepted by GMSPO. Only verifiable emergency VIP orders will be accepted. GMSPO will make every effort to obtain parts. All parts will be placed on 400 control to waive VIP surcharges. However, the parts will be shipped premium transportation at dealer's expense. All other order types will be cancelled as incorrectly ordered while 400 control is in place. Warranty Information: For Vehicle repaired under warranty use: Labor Operation: T7271 Labor Time: 1.6 hrs. each side Trouble Code: 92 Page 403 Wiring Diagram For Chart C-1D - Manifold Absolute Pressure (MAP) Output Check CHART C-1D - MANIFOLD ABSOLUTE PRESSURE (MAP) OUTPUT CHECK Circuit Description: The Manifold Absolute Pressure (MAP) sensor measures manifold pressure (vacuum) and sends that signal to the ECM. The MAP sensor is mainly used for fuel calculation, when the ECM is running in the throttle body backup mode. The MAP sensor is also used to determine the barometric pressure and to help calculate fuel delivery. Test Description: Numbers below refer to circled numbers on the diagnostic chart. 1. Checks MAP sensor output voltage to the ECM. This voltage, without engine running, represents a barometer reading to the ECM. 2. Applying 34 kPa (10" Hg.) vacuum to the MAP sensor should cause the voltage to be 1.2 - 2.3 volts less than the voltage at Step 1. 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 no other vacuum devices are connected tot he MAP hose. Page 7976 Front Door Trim Panel Components NOTE: Images shown are for manual windows, power windows are similar. Page 3526 Band Apply Servo: Service and Repair Hydra-Matic 700-R4 (4L60) 1. Disconnect negative battery cable. 2. Raise and support vehicle. 3. On Corvette convertible models, remove upper and lower underbody braces. 4. On all Corvette models, disconnect exhaust system. If necessary, remove driveline support beam, then the propeller shaft. 5. On all models, remove two oil pan bolts, then install servo cover compressor tool No. J-29714 or equivalent on oil pan flange and depress servo cover. 6. Remove servo cover retaining ring. 7. Remove servo cover and seal ring. 8. Remove servo piston and bore-apply pin assembly. 9. Reverse procedure to install. Whenever any servo parts are replaced, apply-pin length must be checked. Locations Htr-A/C, Pwr Wdo Circuit Breaker Page 1021 - 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. Page 5681 Fig. 24 Exploded view of tilt steering column (floor shift) Page 1239 more apparent than the other. Both the above described conditions occur very infrequently, with ongoing enhancements underway to reduce their occurance even further. Page 6931 If the spring breaks while bending, it will be necessary to replace the lock cylinder assembly 7. Reinstall the spring in the lock assembly. Next, shake the assembly to check for looseness. If loose, replace the lock cylinder assembly. 8. Reinstall the gasket, lock cylinder and retainer (Figure 3, Items 3, 4 and 2). 9. Reconnect the end gate lock rods (Figure 2, Items 1 and 2). 10. Reinstall the end gate inner panel reinforcement to the end gate (Figure 1, Item 1). 11. Reinstall the inner trim panel. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Op: B5810 Use applicable labor time guide for labor hours. Page 6904 Each user will be required to accept the following agreement each time the KeyCode application is used. Key Code User Agreement - Key codes are proprietary information belonging to General Motors Corporation and to the vehicle owner. - Unauthorized access to, or use of, key code information is unlawful and may subject the user to criminal and civil penalties. - This information should be treated as strictly confidential and should not be disclosed to anyone unless authorized. I will ensure that the following information is obtained prior to releasing any Key Code information: 1. Government issued picture ID (Drivers License) 2. Registration or other proof of ownership. Registration should have normal markings from the Province that issued the registration and possibly the receipt for payment recorded as well. Important - GM takes this agreement seriously. Each user must be certain of vehicle ownership before giving out key codes. - When the ownership of the vehicle is in doubt, dealership personnel should not provide the information. Key code requests should never be received via a fax or the internet and key codes should never be provided to anyone in this manner. A face to face contact with the owner of the vehicle is the expected manner that dealers will use to release a key code or as otherwise stipulated in this bulletin or other materials. - Key codes should NEVER be sent via a fax or the internet. - Each Dealership should create a permanent file to document all KeyCode Look Up transactions. Requests should be filed by VIN and in each folder retain copies of the following: - Government issued picture ID (Drivers License) - Registration or other proof of ownership. - Copy of the paid customer receipt which has the name of the employee who cut and sold the key to the customer. - Do not put yourself or your Dealership in the position of needing to "explain" a KeyCode Look Up to either GM or law enforcement officials. - Dealership Management has the ability to review all KeyCode Look-Up transactions. - Dealership KeyCode documentation must be retained for two years. Frequently Asked Questions (FAQs) for GM of Canada Dealers How do I request a KeyCode for customer owned vehicle that is not registered? Scrapped, salvaged or stored vehicles that do not have a current registration should still have the ownership verified by requesting the vehicle title, current insurance policy and / or current lien holder information from the customers financing source. If you cannot determine if the customer is the owner of the vehicle, do not provide the key code information. In these cases, a short description of the vehicle (scrapped, salvaged, etc.) and the dealership location should be kept on file. Any clarifying explanation should be entered into the comments field. How do I document a KeyCode request for a vehicle that is being repossessed? The repossessor must document ownership of the vehicle by providing a court ordered repossession order and lien-holder documents prior to providing key code information. Copies of the repossessors Drivers License and a business card should be retained by the dealership for documentation. What do I do if the registration information is locked in the vehicle? Every effort should be made to obtain complete information for each request. Each Dealership will have to decide on a case by case basis if enough information is available to verify the customer's ownership of the vehicle. Other forms of documentation include vehicle title, insurance policy, and or current lien information from the customers financing source. Dealership Management must be involved in any request without complete information. If you cannot determine if the customer is the owner of the vehicle, do not provide the key code information. Can I get a print out of the information on the screen? It is important to note that the Key Code Look Up Search Results contain sensitive and/or proprietary information. For this reason GM recommends against printing it. If the Search Results must be printed, store and/or dispose of the printed copy properly to minimize the risk of improper or illegal use. Who in the dealership has access to the KeyCode application? Dealership Parts Manager (or assigned management) will determine, and control, who is authorized to access the KeyCode Look Up application. However, we anticipate that dealership parts and service management will be the primary users of the application. The KeyCode Look Up application automatically tracks each user activity session. Information tracked by the system includes: User name, User ID, all other entered data and the date/time of access. Service and Repair Fuel Pressure Release: Service and Repair Before performing any procedure that requires disconnecting fuel lines, relieve fuel system pressure as described below. 1. Remove Fuel Pump fuse from fuse block. 2. Start engine and allow to run out of fuel, then crank engine an additional 3 seconds. 3. Service fuel system as necessary. Page 7627 Page 4325 Figure 1 Controlled Idle Speed / IAC Counts Idle Speed: Specifications Controlled Idle Speed / IAC Counts Controlled Idle Speed / IAC Counts Idle Speed IAC Counts Note: Let engine idle until proper fuel control status is Note: Add 2 counts for engines with less than 500 miles. closed loop. Add 2 count for every 1000 ft above sea level. Manual Transmission Neutral 500-550 rpm 2-12 Auto Transmission Drive 500-550 rpm 2-20 C/V Boot - Contacts Front Shock Technical Service Bulletin # 913114C Date: 910501 C/V Boot - Contacts Front Shock Number: 91-311-4C Section: 4C Date: MAY 1991 Corporate Bulletin No.: 164301R Subject: FRONT AXLE INNER C/V BOOT CONTACTS FRONT SHOCK Model and Year: 1985-91 T TRUCKS Some 1985-91 T trucks may experience a condition of the front axle tripot seals (commonly referred to as the inner C/V boots) contacting the front shock absorbers. This contact usually occurs during suspension operation and may be evidenced as torn seals, premature wear on the outer edges of the seal convolutes or grooves worn into the body of the shock absorber. This condition can be relieved by correcting problems with shock absorber or axle installation and installing smaller profile tripot seals. VEHICLES INVOLVED: 1985-91 T trucks. SERVICE PROCEDURE: The following items should be checked and verified to provide the greatest amount of clearance for the tripot seals. - The shock absorbers are installed correctly with the fluid reservoir on the bottom and the shield on the top. - If aftermarket shock absorbers have been installed, their diameter must measure 50.4 mm (1.98") or less. - The output shaft retaining ring is in place. To check, pull outward on the output shaft. Outward movement should measure 5 mm (.200") or less. IMPORTANT: DO NOT cut or relocate shock absorber mounting brackets. If the contact between the tripot joint and shock absorber is occurring on the passenger side of the vehicle, the axle assembly may be shifted in the frame too far toward the passenger side. To correct this condition the procedure below should be followed: Figure 16 - Carrier Assembly Installation Page 6448 Service Port HVAC: Locations The high side service port is located in the evaporator inlet pipe (high side line) between the condenser and the evaporator. The low side service port is located on the accumulator. Page 5306 RH Side Of Engine. Center Of Firewall Applicable to: V6-262/4.3L Engine Cruise Control - Works Intermittently Cruise Control Switch: Customer Interest Cruise Control - Works Intermittently Number: 92-195-9B Section: 9B Date: MAY 1992 Corporate Bulletin No.: 268102R ASE No.: A8 Subject: CRUISE CONTROL WORKS INTERMITTENTLY Model and Year: 1985-92 M VANS 1990-92 L VANS 1986-92 S/T TRUCKS Some owners of 1985-1992 WL vehicles or 1986-1992 S/T vehicles with cruise control (RPO K34) may comment that their cruise control operates intermittently. This condition may be caused by the wires becoming pinched as they exit the multi-functional lever. These wires may ground out on the lever rod and short the cruise function. To correct this condition in production, the wiring harness that exits the lever has been rerouted and the opening in the multi-functional lever has been redesigned to allow the wires more clearance. The diagnostic procedures in the applicable Service Manual should be followed before replacing the multi-functional lever. If the multi-functional lever requires replacement, the following procedure should be performed: SERVICE PROCEDURE: 1. Disconnect the wire harness connector. 2. Remove the harness protector cover. 3. Attach a long piece of mechanic's wire to the end of the harness connector. 4. Remove the multi-functional lever from the turn signal switch. 5. Gently pull the harness up and out so the mechanic's wire can be used to install the new unit. 6. Attach the upper end of the mechanic's wire to the new harness connector. Gently pull the mechanic's wire at the lower end of the column, feeding the harness into the proper location in the column. 7. Install a redesigned multi-functional lever (P/N 25111290) into the turn signal switch. 8. Disconnect the mechanic's wire from the harness connector. 9. Install the harness protector cover. 10. Reconnect the wire harness connector. SERVICE PARTS INFORMATION Part Number Description 25111290 Multi-functional Lever Use applicable labor time guide for labor hours. Important: The new Part Number (P/N 25111290) should be used when correcting this condition in the above listed vehicles. Page 6352 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. Page 8116 Figure 1, 3 1) Remove the cowl vent grille to expose the base of the windshield and the windshield frame and plenum assembly (see Figure 1). 2) Visually look for any sealer skips at the base on the windshield. 3) If no gaps are found, then blow compressed air at the sealer and attempt to locate air movement inside of the cab. This will help locate any non-visible gaps. 4) If either of the above conditions is found then; reseal area with GMS type B silicone base sealant, part # 1052917 or equivalent. Repeat step 3 to insure all gaps have been located. Page 3413 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. Page 7160 Technical Service Bulletin # 923310 Date: 911101 Paint - Acid Rain Damage to Base Coat/Clear Coat Number: 92-33-10 Section: 10 Date: NOV. 1991 Corporate Bulletin No.: 131060 ASE No.: B2 Subject: INDUSTRIAL FALLOUT/RAIL DUST DAMAGE TO BASE COAT/CLEAR COAT Model and Year: 1983-92 ALL PASSENGER CARS AND TRUCKS Application: 1992 (and previous) models with Base Coat/Clear Coat Paint 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. 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. Page 4818 Removing Dust Boot 6. Carefully pry dust boot out of bore. 7. Using a small piece of wood or plastic, remove piston seal from bore. CAUTION: Do not use a metal tool of any kind to remove seal as it may damage bore. 8. Remove bleeder screw. ASSEMBLY NOTICE: Clean all parts in denatured alcohol or brake parts cleaner before assembly and dry the parts with dry compressed air. 1. Inspect caliper bore for scoring, nicks, corrosion or wear. Replace caliper housing if bore will not clean up with crocus cloth. 2. Lubricate caliper piston bore and new piston seal with clean brake fluid. Position seal in bore groove. Fig. 6 Installing boot to piston 3. Lubricate piston with clean brake fluid and assemble a new boot into the groove in the piston so the fold faces the open end of the piston, Fig. 6. 4. Using care not to unseat the seal, insert piston into bore and force the piston to the bottom of the bore. Page 7251 Figure No. 6 With tailgate window closed, grab handle and attempt to move it forward and backward in a quick motion. If the window creates a glassy sounding rattle then perform the following service procedure. 1) Remove trim panel by taking out the eight fastening screws and sliding the panel rearward. 2) Locate the guide bushing shown in Figure 6. 3) Remove guide bushing and place a bead of Black RTV (P/N 1052917) around the perimeter of the guide bushing hole and reinstall the bushing. Allow RTV to cure with the window open. The RTV absorbs the vibration of the guide against the bushing and then ultimately between the bushing and the metal. If, after going through the initial checks, you have completed the above service procedures, test drive the vehicle to see if the rattle condition has been eliminated. If noise persists, continue with the following procedure. Service Procedure 5 Page 6560 Page 6080 Blower Motor: Electrical Diagrams Blower Controls Wiring Diagram. Locations Oil Pressure Switch Page 4697 SERVICE PARTS INFORMATION Part Number Description 15664811 Vacuum Actuator Switch Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: K4120 Use applicable labor time guide for labor hours. Page 4665 SERVICE PARTS INFORMATION Part Number Description 15664811 Vacuum Actuator Switch Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: K4120 Use applicable labor time guide for labor hours. Page 7424 Check Gauges Lamp: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. Figure 21 Figure 22 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. 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 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 Page 1019 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. Wheels - Finish Damage During Off Car Balancing Wheels: All Technical Service Bulletins Wheels - Finish Damage During Off Car Balancing BULLETIN NUMBER: 93-3E-67 SECTION: 3E Wheels & Tires NUMBER: 3 CORPORATE REFERENCE NUMBER: 3935O2R DATE: June 1993 SUBJECT: INFORMATION ON COSMETIC DAMAGE TO ALUMINUM WHEELS DURING BALANCING MODELS: 1985-93 MODELS WITH ALUMINUM WHEELS Some aluminum wheels on GM models may incur cosmetic damage during balancing if proper care and procedures are not used. All aluminum wheels have a clearcoat paint on them that must be cared for like any other painted surface. Some off-car vehicle balancer retaining cups used to clamp the wheel to the balancer may put a circular mark into the clearcoat on the face of the wheel. Like any other clearcoat damage, this may be difficult to remove or repair, depending on severity. ALWAYS use balancer retainer cups that are protected with rubber, plastic, or other nonmetallic materials where contact is made with the wheel. Make Brakes - Pulsations and Rotor Surface Refinish Technical Service Bulletin # 883125 Date: 880801 Brakes - Pulsations and Rotor Surface Refinish Number: 88-312-5 Section: 5 Date: AUGUST, 1988 Subject BRAKE PULSATIONS AND DISC BRAKE ROTOR SURFACE REFINISH Model and Year 1982-88 CHEVROLET MODELS TO: ALL CHEVROLET DEALERS On today's vehicles the primary reason for brake pulsation is variation in the thickness of the rotor, which generally occurs after some mileage. The causes of rotor thickness variation tend to occur while the vehicle is in motion and the brake pedal is in the unapplied position. Three events must occur simultaneously: 1. The rotor/bearing system runout must be out of specification enough to produce high spots on the rotor face in relation to the caliper. 2. There must be a condition of caliper drag which causes the inboard and/or outboard shoe to rub on the rotor high spots. 3. The lining material must be sufficiently abrasive to cause wear on the high spots and therefore to develop rotor thickness variation after accumulated mileage. Following is a discussion of each of these events along with information about the conditions which can contribute to each. System Runout Information SYSTEM RUNOUT: Excessive system runout can exist as a result of the stack up of the tolerances of a rotor and a bearing which has been manufactured at one end or the other of their respective design specifications, or if either the rotor or bearing are out of specification. The manufacturing process controls which determine the amount of rotor or bearing runout are continuously being improved to reduce the amount of system and/or component runout. During manufacturing of the brake rotor, tolerances of the braking surfaces for flatness, thickness variation and lateral runout are held very close. Maintaining these close tolerances on the rotor's braking surface is necessary to prevent brake roughness. A lateral runout check of the rotor must be performed to determine the extent of runout. Lateral Runout Check: 1. Remove the wheel and tire. Invert the wheel nuts and reinstall them on the studs to the specified torque. Be sure to follow the alternating nut torquing sequence to ensure proper rotor alignment. 2. Fasten a dial indicator to the caliper so the dial indictor button contacts the rotor about 13 mm (0.500 inch) from the outer edge. 3. Zero the dial indicator. 4. Move the rotor one complete revolution and observe total indicated runout (T.I.R.). Lateral runout cannot exceed 0.08 mm (0.003-inch). ^ On front wheel drive vehicles, excessive lateral runout of the rotor can often be improved by indexing the rotor on the hub one or two bolt positions from the original position. If the lateral runout CANNOT be corrected by indexing the rotor, check the hub and bearing assembly for looseness. NOTICE: Whenever the brake rotor has been separated from the wheel bearing flange, remove any rust or foreign material from the mating surfaces of the wheel bearing flange and rotor. Failure to do this may result in excessive lateral runout of the rotor, causing brake pedal pulsation. 5. If lateral runout exceeds that specified in Step 4, refinish the rotor to specifications, reinstall rotor, and remeasure lateral runout. Wheel Bolt Torque, Caliper and Lining Material 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. Page 3480 Disclaimer Automatic Trans. Neutral Safety Switch: Locations Automatic Trans. LH Side Of I/P Behind Instrument Cluster 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". Page 4916 Brake Drum: Testing and Inspection VISUAL INSPECTION Inspect the drum for cracks. If any large, through-the-drum cracks are located the drum must be replaced. NOTE: Cracks in drums are often difficult to locate. To quickly determine if a drum is cracked lightly drop the drum (from a height of 4-5 inches) onto a flat hard surface. A cracked drum will make a dull thud sound while a good drum will make a ringing sound. Inspect for signs of overheating. An overheated drum will often be discolored (blue/gold), warped, or heat checked. Heat checks are small cracks in the drum friction surface. Heat checks can be removed by resurfacing. NOTE: The cause of the overheating should be determined prior to replacing the shoes/linings or drums. Inspect for scoring. Any grooves or scores in excess of 0.008 inches should be resurfaced. SPECIFICATIONS - See: Specifications MAXIMUM DIAMETER Purpose The thickness of the drum friction surface is directly proportional to the drums ability to absorb and release heat during braking. As the drum becomes thinner due to normal wear and resurfacing it looses its ability to absorb and release heat and is more prone to brake fade, distortion, and cracking. As the drum wears the inside diameter of the drum increases. The amount of drum thickness lost to wear is equal to 1/2 the increase in diameter. There are two specifications related to drum thickness. Discard Diameter - This is the maximum diameter at which it becomes unsafe to operate. A drum which has reached this thickness should not be machined and should be discarded. Maximum Refinish - This is the maximum diameter to which a drum may be machined or resurfaced to. This diameter is smaller (thicker) than the Discard diameter because it assumes the drum will need to have a sufficient thickness left, after machining, to allow for further wear from a new set of shoes/linings. Which One Should Be Used? If you install a new pair of shoes with the drum diameter at or less than the "Maximum Refinish" specification the drums should have a sufficient thickness to last the normal life of the new shoes/linings. The "Discard Diameter" should be used to determine if a drum needs to be replaced at the present time of inspection. If you install a new pair of shoes with the drums machined at or near "Discard Diameter", within a short time the drums will be too thin Engine - Miss, Hesitation, or Roughness Spark Plug Wire: Customer Interest Engine - Miss, Hesitation, or Roughness Number: 93-35-6D Section: 6D Date: OCT. 1992 Corporate Bulletin No.: 716404R ASE No.: A1, A8 Subject: ENGINE MISS HESITATION OR ROUGHNESS DUE TO PIERCED SECONDARY IGNITION COMPONENTS Model and Year: 1980-93 ALL PASSENGER CARS AND TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 87-121, DATED MAY 1987. THE 1989-93 MODEL YEARS HAVE BEEN ADDED. ALL COPIES OF 87-121 SHOULD BE DISCARDED. During the diagnosis procedure for an engine miss, hesitation or roughness, a spark plug or spark plug wire condition may be suspected. Several types of commercial or homemade diagnostic equipment required the secondary ignition boots or wire to be pierced. This is normally done to check for spark plug firing or to perform a cylinder balance test. Similarly the use of pliers or other such tools to disengage a spark plug boot may pierce or damage the boot or wire. Secondary ignition components should not be pierced for any reason. Piercing a spark plug wire and/or distributor boot may create a condition that will not be immediately apparent. Over time, the hole in the pierced boot may allow a ground path to develop creating a plug misfire condition. Heavily moisture laden air in the vicinity of the pierced boot may accelerate this effect. Piercing a secondary ignition wire creates a gap in the wire's conductive core. This gap is a point of high resistance. The current flow in the wire will increase to compensate for the higher wire resistance. Over time, the wire may fail creating a plug misfire condition. The time required for the condition to appear depends upon the extent of damage to the conductive core. To help prevent future condition that are spark plug wire related, do not pierce or otherwise damage any secondary ignition component. Only use diagnostic equipment containing an inductive pick-up to check for spark plug firing or to perform cylinder balance tests. When disengaging a spark plug boot from the spark plug, twist the flanged boot 1/2 turn then pull on the boot only to remove the wire. Engine - Miss, Hesitation, or Roughness Spark Plug Wire: Customer Interest Engine - Miss, Hesitation, or Roughness Number: 93-35-6D Section: 6D Date: OCT. 1992 Corporate Bulletin No.: 716404R ASE No.: A1, A8 Subject: ENGINE MISS HESITATION OR ROUGHNESS DUE TO PIERCED SECONDARY IGNITION COMPONENTS Model and Year: 1980-93 ALL PASSENGER CARS AND TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 87-121, DATED MAY 1987. THE 1989-93 MODEL YEARS HAVE BEEN ADDED. ALL COPIES OF 87-121 SHOULD BE DISCARDED. During the diagnosis procedure for an engine miss, hesitation or roughness, a spark plug or spark plug wire condition may be suspected. Several types of commercial or homemade diagnostic equipment required the secondary ignition boots or wire to be pierced. This is normally done to check for spark plug firing or to perform a cylinder balance test. Similarly the use of pliers or other such tools to disengage a spark plug boot may pierce or damage the boot or wire. Secondary ignition components should not be pierced for any reason. Piercing a spark plug wire and/or distributor boot may create a condition that will not be immediately apparent. Over time, the hole in the pierced boot may allow a ground path to develop creating a plug misfire condition. Heavily moisture laden air in the vicinity of the pierced boot may accelerate this effect. Piercing a secondary ignition wire creates a gap in the wire's conductive core. This gap is a point of high resistance. The current flow in the wire will increase to compensate for the higher wire resistance. Over time, the wire may fail creating a plug misfire condition. The time required for the condition to appear depends upon the extent of damage to the conductive core. To help prevent future condition that are spark plug wire related, do not pierce or otherwise damage any secondary ignition component. Only use diagnostic equipment containing an inductive pick-up to check for spark plug firing or to perform cylinder balance tests. When disengaging a spark plug boot from the spark plug, twist the flanged boot 1/2 turn then pull on the boot only to remove the wire. Page 6089 Heater System Symptom Table Do the test listed for your symptom in the symptom table. If your symptom does not appear in the Symptom Table do all of the diagnostic test. 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 Steering/Suspension - Wheel Alignment Specifications Alignment: 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. 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. Engine Controls - ECM May Contain Wrong PROM Engine Control Module: All Technical Service Bulletins Engine Controls - ECM May Contain Wrong PROM Number: 88-42 Section: 6E Date: Sept., 1987 Subject: SERVICE REPLACEMENT ELECTRONIC MODULES (ECM) WITH PROM INSTALLED Model and Year: 1981-88 ALL MODELS TO: ALL CHEVROLET DEALERS It has been brought to our attention that some service replacement electronic control modules (ECM's) have contained a PROM. A PROM should not have been included in a replacement ECM as it may not be the correct PROM for the vehicle. When this situation is encountered, the PROM should be removed from the replacement ECM and the PROM from the vehicle should be installed. Page 4965 Brake Caliper: Service and Repair Installation For additional information see Installation Notes. See: Fundamentals and Basics Retracting Piston 1. Retract piston in caliper bore and position caliper over disc, lining up holes in caliper with holes in mounting bracket. If brake hose was not disconnected during removal, be sure not to kink it during installation. Caliper Mounting Bolts 2. Start mounting bolts through sleeves in inboard caliper ears and the mounting bracket, making sure ends of bolts pass under ears on inboard pad. NOTICE: If the caliper was removed for service, make sure it is installed on the correct knuckle. The caliper bleed screw should be positioned on top of caliper when assembled on vehicle. 3. Push mounting bolts through to engage holes in the outboard ears. Then thread mounting bolts into bracket. 4. Torque mounting bolts to 50 Nm (37 ft lb). Page 4234 Pinion Bearing: Adjustments Dana/Spicer Fig. 5 Pinion setting chart If original ring gear and pinion assembly are to be reused, measure original shim pack and build a new shim pack to the same dimension. If baffle is in the axle assembly, it is considered part of the shim pack. Ring gears and pinions are supplied in matched sets only. If a new gear is being used, verify numbers on pinion and ring gear before proceeding with assembly. On the button end of the pinion there is a ``+'', `` - '', or ``0'' number which indicates the best running position for each particular gear set. This position is controlled by shims installed behind the inner bearing cup. If baffles or oil slingers are used, they are considered part of the adjusting shim pack. If a new gear set is being installed, note the plus or minus mark on both old and new pinions and adjust thickness of shim pack to compensate for the difference between these two numbers. Refer to chart, Fig. 5, when determining shim size. 1. Install inner shim pack and, on 9-3/4 inch ring gear axle, the oil slinger in inner or rear cup bore, then drive cup into position using suitable tool. 2. Add or remove an equal amount to the outer shim pack as was added to the inner shim pack. 3. Drive outer cup into carrier bore, then press rear pinion bearing onto pinion shaft. 4. Install drive pinion and bearing into differential carrier. 5. Install shims and outer or front pinion bearing. 6. Install companion flange, then the washer and nut on pinion shaft. Torque nut to 250 ft. lbs. with a suitable holding bar in place. 7. Remove holding bar, then measure rotating torque of pinion shaft. Rotating torque should measure 10-20 inch lbs. with original bearings installed, or 20-40 inch lbs. with new bearings installed, discounting torque required to start turning shaft. 8. If rotating torque is not within specifications, adjust shim pack as necessary. Increase outer shim pack to reduce torque, or decrease shim pack to increase torque. 9. Remove nut, washer and companion flange from pinion shaft. 10. Install oil slinger, gasket (if equipped) and oil seal onto pinion shaft. 11. Install companion flange, washer and nut and torque nut to 250 ft. lbs. Page 349 Figure 4 Figure 5 Figure 6 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 7 Page 7178 Coolant - Used Anti-Freeze Policy Coolant: Technical Service Bulletins Coolant - Used Anti-Freeze Policy Number: 91-09-0A Section: OA Date: April 1990 Corporate Bulletin No.: 976202 Subject: INFORMATION REGARDING RECONSTITUTED ANTI-FREEZE COOLANT TESTING AND THE USE OF A REFRACTOMETER Model and Year: ALL MODELS AND YEARS TO: ALL CHEVROLET DEALERS RECONSTITUTED ANTIFREEZE At present, three types of recycling systems are available: 1) chemical addition to coolant; 2) filtration and addition of supplemental additives; and 3) separation of pure glycol from used coolant and reinhibition. 1) Chemical Addition-NOT RECOMMENDED With chemical addition, chemicals are added to the used engine coolant in an attempt to "clean up" the coolant. This system is the easiest since the only work involved is the addition of chemicals to the radiator. Most of these types of recycling systems use a strong acid to change precipitated corrosion products into a more soluble form. However, in addition to dissolving the corrosion products, the strong acid also attacks and corrodes the metals of the cooling system. 2) Filtration and Addition of Supplemental Additives-NOT RECOMMENDED In this type of system, the used coolant is either taken out of the vehicle or a flush-type unit is connected to the cooling system. The current technology consists simply of filtration and reinhibition of the spent coolant. While this does remove suspended solids, filtration does nothing to remove harmful degradation and corrosion products that are soluble in glycol solution. The reinhibition step used in current recycling systems may fail to produce a coolant which adequately protects all metals including aluminum in the most critical heat transfer applications, such as occurs in the cylinder heads and blocks. 3) Separation of Pure Glycol and InhibitionThe separation of pure glycol and the addition of fresh inhibitors is the ideal method for recycling coolants. Unfortunately, this method is expensive from both a collection standpoint and the technology available to economically extract pure ethylene glycol from used coolant. At this time, General Motors does not endorse these practices or equipment. Due to a worldwide shortage of ethylene glycol in 1988, some coolant manufacturers have started to mix other types of glycol in their coolant formulations; propylene glycol is the most common new ingredient. A hydrometer will not provide a correct measurement of freeze protection when anything other than ethylene glycol and water is being tested. The degree of inaccuracy will vary depending on the proportion of other glycols present in the coolant. Hydrometers test the amount of glycol in a mixture by measuring the specific gravity of the mixture; the more ethylene glycol, the higher the float balls go, and the better the freeze protection. Because ethylene glycol and propylene glycol do not have the same specific gravities, hydrometer readings of mixtures containing propylene glycol give incorrect values. As the shortage of ethylene glycol continues and/or worsens, more and more variations in antifreeze formulas will be marketed. It is, therefore, recommended that you purchase a "refractometer" and encourage your technicians to use it. Refractometers test for the amount of glycol in a coolant mixture by measuring the speed of light as it passes through the fluid and are not affected by the specific gravity of the glycol. The freeze protection of solutions of ethylene glycol in water, solutions of propylene glycol in water, and solutions of mixtures of propylene glycol and ethylene glycol in water may all be tested with sufficient accuracy using a refractometer. The following refractometers are available from Kent Moore: J 23688 Farenheit scale, measures to -50 F J 26568 Centigrade scale, measures to -45.5 C J 38633 Farenheit scale, measures to -84 F (For extreme cold weather regions) Service and Repair Wiper Gear Box: Service and Repair 1. Disconnect battery ground cable. 2. Remove windshield wiper arms. 3. Remove cowl vent and grille. 4. Remove motor assembly to wiper linkage retaining nut. 5. Remove screws securing wiper linkage to cowl panel and lift out linkage. 6. Reverse procedure to install. Torque all attaching fasteners to 49-80 inch lbs. Page 3681 FIGURE 1(T-TRUCK ONLY) G. (T-truck only) Check equalizer lever for firm contact at the shift lever inboard side of the guide slot. (See Figure 1) H. If firm contact is evident, add an additional washer (#10 in Figure #1) P/N 14074908 to adjust equalizer lever outboard toward the center of the guide slot to eliminate contact. 2. A. Raise vehicle on hoist. B. Note location of clamp rotation on pipe. Some clamps are located with the lower lock ring (nuts) pointed towards the transmission. If the clamp is located in such a manner, loosen clamp and rotate it down so the nuts point toward the ground and retighten to 58 N-m (43 ft/lbs.) 3. A. Loosen converter clamp until it will rotate around the pipe. Using a suitable pry bar, move exhaust system rearward to obtain a minimum of 5/8 in. clearance between any point on the exhaust system and the transmission crossmember. For repairs performed under warranty, use the following labor operations and times: Labor Operation Labor Time Exhaust/muffler clamp L2020 .3 Hr Exhaust system align L2004 .3 Hr Shift Linkage (shorten) K5244 .3 Hr Page 2152 Catalytic Converter: Testing and Inspection Proper diagnosis for a restricted exhaust system is essential before any components are replaced. The following procedures may be used for diagnosis, depending upon engine or tool used: Exhaust System Check CHECK AT A.I.R. PIPE: 1. Remove the rubber hose at the exhaust manifold A.I.R. pipe check valve. Remove check valve. 2. Connect a fuel pump pressure gauge to a hose and nipple from a Propane Enrichment Device. 3. Insert the nipple into the exhaust manifold A.I.R. pipe. CHECK AT 02 SENSOR: 1. Carefully remove O2 sensor. 2. Install Exhaust Backpressure Tester in place of 02 sensor. 3. After completing test described below, be sure to coat threads of 02 sensor with antiseize compound prior to re-installation. DIAGNOSIS: 1. With the engine at normal operating temperature and running at 2500 rpm, observe the exhaust system backpressure reading on the gauge. 2. If the backpressure exceeds 1-1/4 psi (8.62 kPa), a restricted exhaust system is indicated. 3. Inspect the entire exhaust system for a collapsed pipe, heat distress, or possible internal muffler failure. 4. If there are no obvious reasons for the excessive backpressure, a restricted catalytic converter should be suspected, and replaced. Description and Operation Brake Caliper: Description and Operation Fig. 1 Exploded View The Delco-Moraine Single Piston Caliper is held in place by two mounting bolts. The caliper assembly, Fig. 1, slides on its mounting surfaces. Upon brake application, hydraulic pressure against the piston forces the inboard pad against the inboard side of the disc. This action causes the caliper assembly to slide until the outboard pad comes into contact with the disc, which in turn creates a slowing or stopping action. Page 974 8. New O-ring seal P/N 14095598 (67) and new plastic washer (retainer) P/N 14037958 (66) into the front case half. 9. New sector with shaft P/N 15637215 (55) into the front case half. 10. Range shift fork (51), range shift hub (34) into the planetary carrier (36). - It is necessary to rotate the sector with shaft (55) to obtain clearance when installing the range fork (51). INSPECT: The teeth of the synchronizer stop ring (28) and drive sprocket (20) for damage. If the parts are to be replaced due to damage or in cases of customer complaint of clash when shifting from 2Hi to 4Hi, follow steps 11, 12, & 13, otherwise skip to step 14. 11. New drive sprocket P/N 15579803 (20) to the main shaft (19). 12. New synchronizer stop ring P/N 14071703 (28) to the drive sprocket (20). 13. Synchronizer assembly (81) to the main shaft. 14. Mainshaft (19)/drive sprocket (20), chain (58) and front output shaft (21) as a unit. Mode shift fork (54) and shift rail (48) will be installed with the mainshaft. 15. Fork shift spring (52). Mainshaft Extension and Oil Pump 16. Rear case (17) over mainshaft (19) and onto the front case half (45). - Clean case mating surfaces and apply RTV sealer or equivalent to the mating surfaces. - Transfer dowels from old case half to new case half if necessary. IMPORTANT: Be careful not to damage the oil pump (12) while installing the rear case half (Figure 7). 17. Case bolts (3) into case halves. - Apply Loctite 242 (R) or equivalent on pump housing bolt threads. - The two longer bolts and washers into the doweled case holes (33). - Tighten bolts to 31 N-m (23 lbs.ft.). 18. Speedometer tone wheel (11) to the main shaft (19). 19. Pump retainer housing (8) and pump housing bolts (7) to the rear case half (17). - Clean mating surfaces and apply RTV sealer or equivalent to the mating surfaces. - Apply Loctite (R) or equivalent on pump housing threads. - Pump housing bolts are shouldered (7). - Tighten bolts to 41 N-m (30 lbs.ft.). 20. Output bearing retainer (snap ring) (5), to the main shaft (19). 21. Rear extension housing (4) and extension housing bolts (3) to the pump retainer housing (8). - Clean mating surfaces and apply RTV sealer or equivalent to the mating surfaces. - Apply Loctite 242 (R) or equivalent on the extension housing bolts. - Tighten bolts to 31 N-m (23 lbs.ft.). External Components 22. Poppet plunger (70), poppet spring (71), new O-ring seal P/N 14071849 (69), and poppet screw (68) to the front case half (45). Page 6122 Compressor Clutch: Service and Repair With DA-6 Compressor Clutch Plate and Hub Assembly DA-6 Component View Clean ^ The compressor assembly with solvent and blow dry with dry air Remove or Disconnect Tools Required: J 33026 Compressor Holding Fixture J 33027 Clutch Hub Holding Tool J 33022 6-Point 13 mm Socket J 33013 Hub and Drive Plate Remover and Installer. Page 4154 Disclaimer Page 6646 Trailer Adapter Kit: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. Figure 21 Figure 22 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. ECM/PCM - Damage Prevention Engine Control Module: All Technical Service Bulletins ECM/PCM - Damage Prevention Number: 91-318-6E Section: 6E Date: MAY 1991 Corp. Bulletin No.: 176502R Subject: DAMAGE TO ECM/PCM CIRCUIT BOARD WHEN INSTALLING A MEM-CAL Model and Year: 1986-91 ALL PASSENGER CARS AND TRUCKS CONDITION: When installing a service replacement ECM/PCM, the use of incorrect MEMCAL installation procedures may cause the ECM/PCM to fail before it can be installed in the vehicle. This condition may appear as if the ECM/PCM were defective when it was shipped to the dealership, when in fact it was damaged while being installed. In addition this condition may also occur when installing an "updated" service MEM-CAL into the vehicles original equipment ECM/PCM. CAUSE: Excessive vertical force may be applied to the MEM-CAL resulting in flexing of the circuit board and damage to the connections between the circuit board and attached components. Excessive verticle force may be generated in two ways. 1. Incorrect MEM-CAL installation procedure. 2. Interference between MEM-CAL and cover. CORRECTION: Use the following procedure. Service Procedure: Important: This procedure supersedes any instructions regarding MEM-CAL installation dated prior to September 1990. 1. Inspect the MEM-CAL to determine if a cork spacer is glued to the top side of the MEM-CAL assembly. If so, remove it prior to installation. 2. Align small notches with matching notches in the ECM/PCM MEM-CAL socket. 3. VERY GENTLY press down on the ends of the MEM-CAL until the locking levers are rotated toward the sides of the MEM-CAL. Notice: To avoid ECM/PCM damage, do not press on the ends of the MEM-CAL until the levers snap into place. Do not use any vertical force beyond the minimum required to engage the MEM-CAL into its socket. 4. While continuing light pressure on the ends of MEM-CAL, use your index fingers to press the locking levers inward until they are snapped into place. Listen for click. 5. Install MEM-CAL cover and install ECM/PCM in vehicle. A/T - Paint Flakes In Fluid Fluid - A/T: All Technical Service Bulletins A/T - Paint Flakes In Fluid Number: 88-400-7A Section: 7A Date: APRIL, 1989 Subject: EVIDENCE OF PAINT FLAKES IN TRANSMISSION FLUID Model and Year: 1988 PASSENGER CARS WITH AUTOMATIC TRANSAXLES TO: ALL CHEVROLET DEALERS Black paint flakes may be found in the transaxle fluid, bottom pan, fluid level indicator and filter assembly as the result of paint peeling from inside the transaxle fill tube. After the paint peels the unprotected areas of the fill tubes can corrode (interior and exterior), leaving corrosion on the fluid level indicator and the fill tube. The fill tube paints used on the interior and exterior of the tube may not withstand temperatures over 260 degrees Fahrenheit. Transaxle durability should not be affected in vehicles equipped with these fill tubes, but paint flakes can cause filter clogging over a period of time. DATE OF PRODUCTION CHANGE: The suspect fill tubes may be found in vehicles produced between October 17, 1987 (Julian Date 289) through June 30, 1988 (Julian Date 184). SERVICE ACTION: If vehicles are found with flaking paint fill tubes they should be changed along with Transaxle Fluid, Filter and Fluid Level Indicator. Labor Operation Number: T5181 Labor Time: .9 SERVICE MANUAL REFERENCE: Refer to the On-Car Section of your Service Manual whenever service of the Fluid Level Indicator and Fill Tube is necessary. Page 969 Figure 2 Electrical - Intermittent MIL/DTC P2138/Reduced Power Wiring Harness: All Technical Service Bulletins Electrical - Intermittent MIL/DTC P2138/Reduced Power TECHNICAL Bulletin No.: 07-06-04-019D Date: June 28, 2010 Subject: Intermittent Malfunction Indicator Lamp (MIL) Illuminated, DTC P2138 with Reduced Engine Power (Repair Instrument Panel (IP) to Body Harness Connector) Models: 2005-2011 GM Passenger Cars and Light Duty Trucks (Including Saturn) 2005-2009 HUMMER H2 2006-2010 HUMMER H3 2005-2009 Saab 9-7X Supercede: This bulletin is being revised to update the model years and warranty information. Please discard Corporate Bulletin Number 07-06-04-019C (Section 06 - Engine/Propulsion System) Condition - Some customers may comment on an intermittent malfunction indicator lamp (MIL) being Illuminated with a message or an indicator that displays Reduced Engine Power. - The technician may observe on a scan tool DTC P2138 - Accelerator Pedal Position (APP) Sensor 1-2 Correlation set as Current or in History. Cause This condition may be caused by water intrusion into the instrument panel (IP) to body harness connector, which carries the APP sensor signals to the ECM/PCM. This water intrusion results in a voltage difference between APP Sensor 1 and APP Sensor 2 that exceeds a predetermined value for more than a calibrated period of time, setting P2138. Correction Note Aftermarket equipment can generate DTC P2138 and/or other DTCs. 1. Verify that aftermarket equipment is not electrically connected to any of the APP sensor signal or low reference circuits or to any other ECM/PCM 5V reference or low reference circuits. Refer to Checking Aftermarket Accessories in SI. 2. Perform the Diagnostic System Check - Vehicle. ‹› If any 5V reference DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle. ‹› If any 5V reference DTCs are not set, proceed to Step 3. 3. Locate the IP to body harness connector, which may be located in and around the left hand kick panel area or inside the IP. Depending on the vehicle and model year, refer to Wiring Systems or Power and Signal Distribution in SI. Note Some examples of potential water leaks are: A-pillar seals, sunroof drain lines (if equipped) and windshield/cowl sealing. 4. Inspect for a water leak in the area. If necessary use a water hose to determine the source of the leak. Refer to General Information > Water Leaks in SI. ‹› If a water leak is observed, repair as necessary. Verify the effectiveness of the repair. 5. Inspect the IP to body harness connector terminals for corrosion and debris. Refer to Testing for Intermittent Conditions and Poor Connections in SI. ‹› If any corrosion and/or debris is observed, repair as necessary. 6. After completing the repair, verify the proper operation of the system. Depending on the vehicle and model year, perform the Diagnostic Repair Verification procedure or refer to Diagnostic Trouble Code (DTC) List - Vehicle in SI. A/T TCC - MIL ON/False Code 32 Set Diagnostics Torque Converter Clutch Solenoid: Technical Service Bulletins A/T TCC - MIL ON/False Code 32 Set Diagnostics Number: 91-149-6E Section: 6E Date: January 1991 Corporate Bulletin No.: 066502R Subject: "SERVICE ENGINE SOON" LIGHT POSSIBLE FALSE CODE 32 Model and Year: ALL 1987-91 TRUCKS WITH 4L60 AUTOMATIC TRANSMISSION (700-R4) TO: ALL CHEVROLET DEALERS Some 1987-91 light duty trucks equipped with 4L60 transmissions may experience a possible false Code 32 - EGR System Malfunction. The customer may not experience a change in performance or driveability with a Code 32 set. If normal EGR diagnostics do not reveal the cause for Code 32, the following steps should be taken to correct the condition: Check the TCC (Torque Converter Clutch) engagement solenoid/wiring harness for a short-circuit. 1. Disconnect the TCC harness connector from the left side of the transmission. 2. Measure resistance between TCC transmission connector terminals "A" and "D" with a Digital Volt Ohmmeter (DVOM). Solenoid resistance must measure 20 - 25 ohms at 20 degrees C (68 degrees F). Resistance will be slightly higher if the transmission is at operating temperature. If the resistance is less than 20 ohms the TCC solenoid diode or wiring is shorted and the solenoid must be replaced. 3. With key on, using a DVOM check for voltage at pin "D" of the TCC wiring harness. Voltage greater than one volt should not be found. If voltage exceeding one volt is present, circuit 422 is shorted to voltage and the short must be repaired. Refer to the appropriate service manual for circuit 422 diagnosis and repair. Test operation of the TCC through the use of a scan tool connected to the vehicle ALDL connector. The following conditions must be satisfied when testing TCC operation. ^ Clear stored trouble codes. ^ Engine at normal operating temperature (above 65 degrees C, 149 degrees F) and in closed loop. ^ Constant throttle position. TPS voltage = 1.3 V (minimum = 1.1 V, maximum = 1.5 V). ^ Vehicle speed = 45 mph (minimum = 35 mph, maximum = 55 mph). ^ Brake switch closed (brake pedal not applied). ^ 3rd or 4th gear. Confirmation The scan tool will display the ECM command for TCC engagement when the above conditions are satisfied. When the TCC engages there should be a decrease in engine speed by a minimum of 100 RPM. If TCC operation is normal, it is not necessary to replace the solenoid assembly. After verification of TCC operation, check for stored trouble codes. If TCC fails to engage consult Section 10, Transmission Controls located in Fuel and Emissions Manual and section 7A of the appropriate service manual. Page 3890 Shift Cable: Specifications THM180 & 180 C Automatic Trans Application ........................................................................................................................................... ................................................................... Ft. Lbs. Detent Cable, Retainer To Case: 180 ................................................................................................. ............................................................................................................................. 8-12 180C .............. .............................................................................................................................................................. ..................................................... 7 Page 7775 Light Switch Details (Part 2 Of 3) Page 4117 Clutch Slave Cylinder: Service and Repair Clutch Slave Cylinder Replace Fig. 2 Clutch slave cylinder REMOVE OR DISCONNECT 1. Negative battery cable. 2. Raise and support vehicle. 3. Hydraulic line from slave cylinder. 4. Slave cylinder retaining nuts and the slave cylinder. INSTALL OR CONNECT 1. Hydraulic line to slave cylinder. 2. Slave cylinder and retaining nuts, torque to 14-20 Nm (10-15 ft lbs). 3. Lower vehicle. 4. Negative battery cable. 5. Fill reservoir and bleed system. Page 4381 Extension Housing: Specifications Saginaw 3 Speed Extension housing to case bolts .......................................................................................................... ...................................................................... 45 ft.lbs. Isuzu M-150 (77.5 mm) 4-Speed Extension housing bolts ....................................................................................................................... ................................................................... 30 ft. lbs. Warner 83 mm 4 Speed Extension housing long bolts ............................................................................................................... ................................................................... 40 ft. lbs. Extension housing short bolts .......................... ........................................................................................................................................................ 25 ft. lbs. MUNCIE 5LM60 (HM-290) 4 & 5 Speed Rear Housing Bolts .............................................................................................................................. ................................................................... 17 ft. lbs. Warner T-4C 4 Speed Extension housing retaining bolts ........................................................................................................ ................................................................... 25 ft. lbs. Warner T-5 (77MM) 5 Speed Adapter Housing Bolts ......................................................................................................................... ................................................................... 25 ft. lbs. Tremec 3 Speed Extension housing attaching cap screws .............................................................................................................................................................. 42-50 ft lbs Page 3920 Throttle Valve Cable/Linkage: Description and Operation The throttle cable controls line pressures, shift points, shift feel, part throttle downshifts, and detent downshifts. The function of the cable is similar to the combined functions of a vacuum modulator and detent downshift cable. The cable operates the throttle lever and bracket assembly. Page 7922 LIGHT BLUE LT BLU BROWN BRN GRAY GRY GREEN GRN DARK GREEN DK GRN LIGHT GREEN LT GRN ORANGE ORN PINK PNK PURPLE PPL RED RED TAN TAN WHITE WHT YELLOW YEL Page 6160 Staking The Rotor Bearing ^ Using a center punch with a 45 degree angle point, stake 1.1-1.4 mm (0.045-0.055-inch) deep the bearing in three places 120 degrees apart. Installing The Rotor & Bearing Assembly - V-Groove Type 2. Rotor (6) and bearing (5) assembly to the compressor with J 8092. 3. Retainer ring (4) with J 6083. 4. Pulley rim mounting screws (10) and washers (9). ^ Apply Loctite 601 or equivalent to the threads. ^ Hand spin the pulley to check for free rotation. Tighten ^ Screws to 11 N.m (100 in. lbs.). ^ Bend the washers to lock the rim in place. 5. Rotor (5) and hub (3) assembly. Poly-Groove Type Page 4841 Brake Pad: Testing and Inspection Remove the front wheels and inspect the brake disc, caliper and linings. CAUTION: Do not get any oil or grease on the linings. All linings must be replaced in sets when worn or damaged. If the caliper is cracked or fluid leakage through the casting is evident, it must be replaced as a unit. Page 3620 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. Page 1682 Figure 8 Figure 9 Figure 10 Figure 11 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). Page 6855 10. Drive the door frame (the second layer of sheet metal) down with a punch approximately 1/4" all the way around the hole. 11. Paint the bare metal edges left from cutting the hole with a zinc rich primer. 12. Completely fill the hole with black RTV, GM P/N 1052917, or equivalent and level for good adhesion and appearance. 13. Follow Steps 6-12 on each side of the vehicle. 14. Reinstall the hood hinge seals in their original position to prevent water leakage into the cowl. If it is necessary, additional adhesive (3M weather strip adhesive P/N 08001 or equivalent) should be used to secure the hood hinge seal. 15. Reinstall the windshield washer hose, cowl vent panel, radio antenna, and windshield wipers, and remove the protective tape from the fender and cowl vent panel. Page 2598 Knock Sensor: Description and Operation Knock Sensor Operation ESC Wiring Diagram The Electronic Spark Control (ESC) system is comprised of a knock sensor, the ESC module, and the ECM. As the knock sensor detects engine knock, it sends a voltage signal to the ECM. The ECM responds by retarding the ignition timing until the knocking ceases. As detonation is reduced, the ECM advances the timing again in small increments back to the pre-programmed point for that engine speed and load. Page 3725 4. Remove the retention spring from the mirror bracket (Figure 2, Item A). 5. Drill and tap the retention spring, on the rear side wing, so that it will accept a 6.0 mm X 1.0 mm (diameter X thread pitch) set screw fastener (Figure 3, Item A) (procured locally). The approximate fastener length should be 10 mm. NOTE: The hole must be drilled perpendicular to the flat surface of the retention spring's wing. 6. Reinstall the retention spring in the mirror bracket. 7. Reinstall the mirror head and arm to the mirror bracket. 8. Reinstall the mirror assembly to the door. 9. Install the 6.0 mm X 1.0 mm headed fastener, adjusting it to obtain the original pressure against the mirror arm. DO NOT over-torque this fastener. 10. Reinstall the screws which secure the mirror cover to the door. WARRANTY INFORMATION For vehicles repaired under warranty, use: Labor Description Labor Time Operation R3260 RH mirror R&R; 0.4 Hr. Suspension - Shock Absorber/Strut Replacement Guidlines Suspension Strut / Shock Absorber: All Technical Service Bulletins Suspension - Shock Absorber/Strut Replacement Guidlines File In Section: Warranty Administration Bulletin No.: 72-05-12 Date: January, 1998 WARRANTY ADMINISTRATION Subject: Replacement of Shock Absorbers and Struts Labor Operations E3800, E3801, E3807, E5800, E5801, E5807, E3850, E3851, E3857, E5750, E5751, and E5757 Models: All Past, Present, and Future Passenger Cars & Trucks The purpose of this bulletin is to provide retail and wholesale service personnel with enhanced service policies for the above listed subject labor operations. Service Management should make certain that all dealership personnel responsible for replacement of suspension components are familiar with GM Service Manual procedures. Effective with repair orders dated on or after January 15, 1998 the following must also be followed: - Shock absorber/strut assemblies are fluid filled components and will normally exhibit seepage. Seepage is defined as oil film or dust accumulation on the exterior of the shock housing. Shock absorber/strut assemblies are not to be replaced under warranty or seepage. - Defective shock absorber/strut assemblies will have a visible oil path or drip coming from the component. A visible oil path or drip coming from the shock absorber/strut assembly should be replaced as a defective component. - Only defective shock absorber/strut assemblies should be replaced. DO NOT replace pairs unless both are defective, unless otherwise instructed in the Service Manual and/or Service Bulletin. - Service Management approval is required on the repair order for replacement of struts or shocks in pairs. This approval includes noting the reason for replacement. Page 8218 6. Tape the solder and diode. 7. Reinstall the black plastic conduit. 8. Reconnect connector to the generator. 9. Reconnect battery. This procedure will not affect the operation of the generator light during the bulb check at the beginning of the start cycle. For vehicles repaired under warranty use, Labor Operation Number: T7990 Labor Time: .4 Hr A/T - THM 700-R4 TCC Applies During 1 to 2 Gear Shift Torque Converter Clutch: All Technical Service Bulletins A/T - THM 700-R4 TCC Applies During 1 to 2 Gear Shift Number: 88-449-7A Section: 7A Date: JULY 1991 Corporate Bulletin No.: 177112R Subject: TCC APPLIES DURING 1-2 SHIFT Model and Year: 1988 G2, R1, S1 AND T1 TRUCKS WITH 700-R4 SERVICE REPLACEMENT TRANSMISSION ASSEMBLY Figure 1 - Control Valve Body Bulletin Covers: Some 1988 Service Replacement Transmission Assemblies (SRTA) may have been built with a bore plug in the TCC valve bore. The 8MHM, 8TAM, 8TBM, and 8TNM models should have the TCC shift valve lineup in this bore instead of the bore plug. If the bore plug is present, TCC will apply during the 1-2 shift. Service Information: If the control valve assembly contains a bore plug in place of the TCC shift valve lineup, the control valve assembly must be replaced. Service Parts Information: Reference the GMSPO Service Parts Catalog for the correct control valve assembly part number. Service Manual Reference: Refer to the THM 700-R4 Automatic Transmission Unit Repair Section of the appropriate Service Manual for instructions on replacing the control valve assembly. Page 2102 Coolant Temperature Sensor/Switch (For Computer): Service and Repair The coolant sensor must be handled carefully. If sensor is damaged, fuel injection operation will be affected. 1. Disconnect battery ground cable. 2. Drain coolant from radiator so level is below sensor. 3. Disconnect coolant sensor electrical connector. 4. Carefully back out coolant sensor and remove. 5. Reverse procedure to install. Page 2613 - Diagnostic Chart Code 34. Saginaw Rack & Pinion Gear Steering Gear: Description and Operation Saginaw Rack & Pinion Gear Fig. 1 Exploded view of rack & pinion gear The power rack and pinion steering system, Fig. 1, has a rotary control valve which directs hydraulic fluid coming from the pump to one or the other side of the rack piston. The piston is attached to the rack. The piston converts hydraulic pressure to a linear force which moves the rack left or right. The force is then transmitted through the inner and outer tie rods to the steering knuckles, which turn the wheels. If hydraulic assist is not available, manual control is maintained, however more steering effort is required. The movement of the steering wheel is transferred to the pinion. The movement of the pinion is transferred through the pinion teeth, which mesh with teeth on the rack, causing the rack to move. 3L30 (180C) Transmission Transmission Mount: Specifications 3L30 (180C) Transmission Component .......................................................................................................................................... .................................................................... Ft. Lbs. Transmission Support To Extension .................................................................................................... .............................................................................. 33 Page 2760 Manifold Pressure/Vacuum Sensor: Specifications MANIFOLD ABSOLUTE, VACUUM AND BAROMETRIC PRESSURE SENSORS Engines may use one, or a combination of these sensors. All sensors appear the same. Manifold Absolute Pressure sensors have a vacuum line connected between the unit and manifold vacuum. On Barometric Pressure sensors, the line is not used and the connector is either open or has a filter installed over it. Pressure sensors also have a vacuum line between the sensor and intake manifold and only appear on carburetted models. Barometric Pressure Sensors: Measure voltage with ignition on and engine off. Manifold Absolute Pressure Sensors: Measure voltage with ignition on and engine off. Start engine and apply 10 in./ 250 mm Hg to unit, voltage should be 1.2-2.3 volts less. Pressure Sensors: Measure voltage as indicated. Page 6135 Installing The Clutch Plate & Hub Assembly 2. Clutch plate and hub assembly (2). ^ Make sure the contact surfaces of the clutch plate (22) and the pulley (26) are clean. ^ Remove the forcing screw tip from J 33013-B and reverse the body direction on the center screw. ^ Install J 33013-B with bearing (B). ^ Back off J 33013-B body enough to allow the center screw to be threaded against the end of the compressor shaft (38). ^ Hold the center screw with a wrench and tighten the hex portion of J 33013-B body while pressing the hub onto the shaft (38). After tightening the body several turns, remove J 33013-B and check that the shaft key (21) is properly in place in the keyway, then install the clutch plate and hub assembly (22) to its final position. ^ Measure the air gap between contact surfaces of the clutch plate and hub assembly (22) and the pulley (26). The gap should be 0.38-0.64 mm (0.015-0.025-inch). ^ Remove J 33013-B Inspect ^ Position of the shaft (38) (even with or slightly above the clutch hub). ^ Use J 33027 to hold the clutch plate and hub assembly (22). Tighten ^ Shaft nut (21) to 17 N.m (12 ft. lbs.) with J 33022. - Hand spin the pulley (26) to check for free rotation. - Remove the compressor from J 34992. Pulley and Bearing Assembly Page 4656 Date of Production Change: Vehicles in which the new detent poppet spring and poppet screw have been incorporated can be identified in two ways. First, the new screw is designed with a shoulder on the face (See Figure 3). Second, the transfer cases with build dates after 3/16/89 will have the new spring and screw installed. The build date is located on the transfer case I.D. tag as the serial number i.e. 5-26 88-1 is May 26, 1988, 1st shift. The I.D. tag is red. Labor Operation Number: T7950 Labor Time: .9 Hr Page 2617 - Diagnostic Chart Code 64. Page 3134 Throttle Cable/Linkage: Service and Repair ACCELERATOR PEDAL: When performing service on the accelerator pedal, observe the following: Accelerator Pedal Assembly Control Cable And Linkage ^ 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 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. Page 1070 - 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. Page 1216 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 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 Page 6172 The chart shown will help to properly identify the seals. Use the chart by placing the seal over the pictured seal to identity inside and outside diameters and thickness. Because these seals are very similar in size, specifications are also listed in the chart. Important: If seals are damaged upon installation, obtain new seal kit. Seals will be available separately at a later date. Page 8033 Front Door Trim Panel Page 1776 For vehicles repaired under warranty, use the table. Disclaimer Page 5551 - 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 Page 5160 Neutral Safety Switch: Service and Repair 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. Generator Light - Flickers During Pulse Wiper Use Wiper Switch: All Technical Service Bulletins Generator Light - Flickers During Pulse Wiper Use Number: 90-84-8A Section: 8A Date: November 1989 Corporate Bulletin No: 966402 Subject: GENERATOR LIGHT FLICKER DURING PULSE WIPER OPERATION Model and Year: 1988-89 S, T TRUCKS WITH 2.8L OR 4.3L (VIN CODES R, Z) ENGINES TO: ALL CHEVROLET DEALERS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 89-219-8A, DATED JULY 1989. THE 1990 MODEL S/T VEHICLES ARE INCLUDED IN THE LATEST BULLETIN ALONG WITH A CORRECTION TO THE ELECTRICAL CONNECTOR NUMBER. ALL COPIES OF 89-219-8A SHOULD BE DISCARDED. The generator light flicker condition during pulse wiper switch operation in the 1988, 1989 and 1990 S/T instrument panel, with standard cluster, can be caused by negative voltage transients from the wiper motor. There is no possibility of a system failure as a result of this condition. The effect of this condition is that the generator light will turn on for 80 milliseconds (if gages, the voltage drop on the voltmeter lasts 2.5 seconds). This causes no harm to the generator or other electrical components. Subject condition can be eliminated by installing a diode (industry part number 1N4003) or diode/connector kit (diode kit part number 12085207) in the brown wire at the generator connector (circuit 25 at connector C118). See the following pages in the 1988, 89 and 90 S/T Electrical Wiring Diagrams for circuit 25, connector C118 locations: 1988 4.3L: Section C - Page 24 1988 2.8L: Section C - Page 22 1989 4.3L: Page 40 1989 2.8L: Page 39 1990 2.8L: Page 44 1990 4.3L: Page 45 PARTS INFORMATION: Quantity Part Number Description 1 12085207 Diode ----OR---1 *1N4003 Diode * This part available locally. Parts are currently available from GMSPO. INSTALLATION PROCEDURE: 1. Disconnect the battery. 2. Remove the connector from the generator. 3. Peel back the black plastic conduit covering the wires. 4. If installing diode 1N4003: cut out a section of the brown wire that matches the length of the diode. 4A. A diode/connector kit is also available (GMSPO diode kit part number 12085207). If using the kit cut out approximately four inches of the brown wire, following crimping and soldering instructions in the kit. Spiral tape the solder joints and tuck the wire back into the conduit away from the generator. Secure the diode/connector to the outside of the conduit with electrical tape. 5. Solder in diode with the banded end toward the generator. Specifications Input Shaft: Specifications Input Shaft Bearing Retainer Bolts (204) ............................................................................................. ..................................................................... 7 ft. lbs. Page 6249 5. Coolant to the radiator. Page 6355 Refrigerant: Specifications Refrigerant Capacity ............................................................................................................................ ......................................................... 1.1kg (37 fl oz) Drivetrain - Recommended Axle Lubricant Fluid - Differential: All 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. Page 412 Oxygen Sensor: Service and Repair 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. 1. Disconnect electrical connector from oxygen sensor. 2. Using suitable wrench, carefully remove sensor from exhaust manifold or pipe. The oxygen sensor may be difficult to remove when engine temperature is below 120°F. Use caution, since excessive force may damage threads in exhaust manifold or pipe. 3. If new sensor is being used, install sensor into manifold or pipe. 4. If old sensor is being reused, coat threads with anti-seize compound, Part No. 5613695 or equivalent, then install into manifold or pipe. 5. Torque oxygen sensor to 30 ft. lbs., then reconnect electrical connector. Roof Rack - Wind Noise Roof Rack Frame: All Technical Service Bulletins Roof Rack - Wind Noise Number: 91-70-10 Section: 10 Date: September 1990 Corp. Bulletin No.: 061003 Subject: ROOF RACK HOWL WIND NOISE Model and Year: ALL S/T UTILITY VEHICLES WITH ROOF RACK Page 1390 1990-1991 "W" Car 1988-1990 "Y" Car "AW" Type Weight 1989-1991 "L" Car Used On All Other 1991 "B" Car, "U" Van Series Vehicles 2-1/4 oz. 9591382 9591366 2-1/2 oz. 9591383 9591367 3oz. 9591385 9591369 Parts are currently available from GMSPO. Dealers should make sure they have a supply of both types weights for balancing GM aluminum wheels. When installing the coated weights, care must be taken so that the coating does not crack. It is recommended that a Teflon tipped hammer be used, such as 85403 Nicholson Industrial Hammer, their part number CAS 3340551, available through the Charles Strelinger Company, Warren, Mi (313-268-4100), or equivalent. Page 7673 Symbol Identification Wheels - Sealing Leaking Cast Aluminum Wheels: All Technical Service Bulletins Wheels - Sealing Leaking Cast Aluminum Bulletin Number: 93-3-16 Reference Number: 393504 Publish Date: 7/93 Subject: LEAKING CAST ALUMINUM WHEELS (REPAIR WITH ADHESIVE SEALANT) Models Affected: 1985-1993 ALL MODELS Should a vehicle equipped with cast aluminum wheels exhibit a slow leak due to a porous condition existing in the wheel, the wheel can be repaired by using Dow Corning Silastic 732 RTV, p/n 1052366 or equivalent, as described in the following procedure: 1. Remove tire-wheel assembly from vehicle. 2. Locate leaking area by inflating tire to 40 psi and dipping tire-wheel assembly in water bath. 3. If air bubbles are observed, mark leak area and remove tire from wheel. 4. Scuff INSIDE rim surface at leak area with # 80 grit paper and clean area with general purpose cleaner, such as 3M # 08984. 5. Apply 1/8" thick layer of adhesive/sealant to leak area on INSIDE of rim and allow six hours of drying time. 6. Mount tire on wheel, pressurizing to 40 psi and check for leaks. NOTICE: Caution must be used when mounting the tire so as not to damage the sealer. 7. Adjust tire pressure to meet placard specification. 8. Balance tire-wheel assembly, using proper coated weights. 9. Water test wheel again. 10. Reinstall tire-wheel assembly on vehicle. Parts are currently available from GMSPO. WARRANTY INFORMATION: Labor Operation Number: E0420 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. Page 5523 Figure 8 Figure 9 Figure 10 Figure 11 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). Page 1995 Coolant: Technical Service Bulletins Coolant - Specification/Usage Number: 91-62-6B Section: 6B Date: August 1990 Corp. Bulletin No.: 066202 Subject: COOLANT USAGE Model and Year: ALL 1988-91 PASSENGER CARS AND TRUCKS TO: ALL CHEVROLET DEALERS THIS INFORMATION SUPERSEDES INFORMATION PROVIDED BY GMSPO IN PARTS AND ACCESSORIES BULLETINS IB NO. 90-55 AND 90-60 AND INFORMATION PROVIDED IN VARIOUS TRUCK SERVICE AND OWNERS MANUALS AND SHOULD BE USED TO DETERMINE CORRECT COOLANT USAGE IN LIGHT AND MEDIUM DUTY TRUCK APPLICATIONS. GM coolant specification 6038-M or 1899-M (P/N 1052103) is for use in all light duty trucks with gasoline or diesel engines. This coolant features a low silicate formulation and is intended only for use in engines that have cylinder heads and cylinder blocks made of cast iron. GM coolant specification 1825-M or 6043-M (P/N 1052753) which until recently has been the recommended coolant for light duty trucks has been superseded by GM coolant 6038-M or 1899-M (P/N 1052103) in cast iron truck engines. GM coolant specification 1825-M has a higher silicate formulation which is recommended for all passenger car engines with cylinder heads or cylinder blocks made of aluminum. Page 6354 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. Page 7168 WARRANTY INFORMATION For vehicles repaired under warranty. and for customer satisfaction. use: Labor Op (Labor Operations include mix time) A6100 Refinish the entire exterior body surface ABOVE THE BODY SIDE MOLDING AND INSERT COLOR on two tone vehicles if equipped. A6101 Refinish the entire exterior body surface INSERT COLOR only. A61O2 Refinish the PICKUP BOX LOAD FLOOR AND INNER FENDERS when applicable. A61O3 On units with an insert color, included is the entire exterior body surface ABOVE THE BREAKLINE. (If the insert color and the entire body surface above the break-line requires refinishing, use A6100). Specifications Absolute Pressure Sensor: Specifications MANIFOLD ABSOLUTE, VACUUM AND BAROMETRIC PRESSURE SENSORS Engines may use one, or a combination of these sensors. All sensors appear the same. Manifold Absolute Pressure sensors have a vacuum line connected between the unit and manifold vacuum. On Barometric Pressure sensors, the line is not used and the connector is either open or has a filter installed over it. Pressure sensors also have a vacuum line between the sensor and intake manifold and only appear on carburetted models. Barometric Pressure Sensors: Measure voltage with ignition on and engine off. Manifold Absolute Pressure Sensors: Measure voltage with ignition on and engine off. Start engine and apply 10 in./ 250 mm Hg to unit, voltage should be 1.2-2.3 volts less. Pressure Sensors: Measure voltage as indicated. Page 6118 Removing The Pulley & Bearing Retainer Ring 4. Bearing (5) from the pulley (6). ^ Remove the retaining ring (3). Removing The Bearing From The Pulley ^ Pulley (6) to J 21352. ^ Drive the bearing (95) from the pulley (6) with J 9398 and J 8092. Install or Connect Tools Required: J 6435 Snap Ring Pliers J 8092 Driver Handle J 9481-A Pulley Bearing and Pulley Installer Installing The Pulley Bearing 1. Bearing (5) to the pulley (6) with J 8092 and J 9481-A. Page 3773 Governor Pressure Switch: Specifications THM 180 & 180 C Auto Transmission Governor Body to Governor Hub ......................................................................................................... ................................................................... 6-7 ft lbs Page 7582 Symbol Identification Electronic Spark Control (ESC) Knock Sensor: Description and Operation Electronic Spark Control (ESC) Electronic Spark Control (ESC) is used on some models. The ESC system is used in conjunction with the EST system to provide additional spark retard during engine detonation. A knock sensor signals a separate ESC controller to retard the timing when it senses engine knock. The ESC controller signals the ECM which reduces spark advance until no more signals are received from the knock sensor. Page 181 Engine Control Module: Service and Repair Figure 1 *** THIS PROCEDURE HAS BEEN UPDATED BY TSB # 88-42, dated 9/87 Some replacement ECM's may come with a replacement PROM already installed in them. If this situation occurs, remove prom from old ECM and install in rebuilt ECM. When replacing a production ECM with a service ECM, transfer the broadcast code and production number from the production unit to the service unit. Also, during replacement, the PROM, and if equipped, the CALPAK must be removed from the ECM being replaced and transferred to the new unit. Refer to "PROM, REPLACE" and "CALPAK, REPLACE" for procedure. 1. Disconnect battery ground cable. 2. Locate ECM on passenger side under the instrument panel hush panel. (see figure 1.). 3. Remove ECM mounting hardware. 4. Remove ECM from passenger compartment. 5. Reverse procedure to install. Page 2732 Coolant Temperature Sensor/Switch (For Computer): Service and Repair The coolant sensor must be handled carefully. If sensor is damaged, fuel injection operation will be affected. 1. Disconnect battery ground cable. 2. Drain coolant from radiator so level is below sensor. 3. Disconnect coolant sensor electrical connector. 4. Carefully back out coolant sensor and remove. 5. Reverse procedure to install. Page 29 Disclaimer Page 7430 Check Gauges Lamp: Electrical Diagrams Page 835 Disclaimer Engine Controls - ECM May Contain Wrong PROM Engine Control Module: All Technical Service Bulletins Engine Controls - ECM May Contain Wrong PROM Number: 88-42 Section: 6E Date: Sept., 1987 Subject: SERVICE REPLACEMENT ELECTRONIC MODULES (ECM) WITH PROM INSTALLED Model and Year: 1981-88 ALL MODELS TO: ALL CHEVROLET DEALERS It has been brought to our attention that some service replacement electronic control modules (ECM's) have contained a PROM. A PROM should not have been included in a replacement ECM as it may not be the correct PROM for the vehicle. When this situation is encountered, the PROM should be removed from the replacement ECM and the PROM from the vehicle should be installed. Description and Operation Vacuum Pump: Description and Operation These vehicles use either a belt driven or gear driven vacuum pump to aid the engine in maintaining a proper vacuum level for the power brake system and other vacuum powered accessories. The gear driven pump is a diaphragm pump that requires no periodic maintenance. This pump is driven by a cam inside the drive assembly on which the pump is mounted. The drive housing assembly includes a gear on the lower end that meshes with the camshaft gear in the engine. This gear causes the cam in the drive housing to turn. The gear also operates the engine oil lubricating pump. Ignition System - Diagnosis Precautions Spark Plug Wire: All Technical Service Bulletins Ignition System - Diagnosis Precautions Number: 88-138-6D Section: 6D Date: Feb., 1988 Subject: ENGINE MISS, HESITATION, OR ROUGHNESS DUE TO PIERCED SECONDARY IGNITION COMPONENTS Model and Year: ALL MODELS WITH GASOLINE ENGINE TO: ALL CHEVROLET DEALERS During the diagnosis procedures for an engine miss, hesitation, or roughness condition, a spark plug or spark plug wire condition may be suspected. Several types of commercial or homemade diagnostic equipment require the secondary ignition boots or wire to be pierced. This is normally done to check for spark plug firing or to perform a cylinder balance test. Similarly, the use of pliers or other such tools to disengage a spark plug boot may pierce or damage the boot or wire. NOTICE: SECONDARY IGNITION COMPONENTS SHOULD NOT BE PIERCED FOR ANY REASON. Piercing a spark plug wire and/or distributor or direct fire module nipple may create a failure condition that will not be immediately apparent. Over time, the hole in the pierced boot may allow a ground path to develop, creating a plug misfire condition. Heavily moisture-laden air in the vicinity of the pierced boot may accelerate this effect. Piercing a secondary ignition wire creates a gap in the wire's conductive core. This gap is a point of high resistance. The current flow in the wire will increase to compensate for the higher wire resistance. Over time, the wire may fail, creating a plug misfire condition. The time required for the condition to appear depends upon the extent of damage to the conductive core. To help prevent future customer comments that are spark plug wire related, do not pierce or otherwise damage any secondary ignition component. Only use diagnostic equipment containing an inductive pick-up to check for spark plug firing or to perform cylinder balance tests. When disengaging a spark plug boot from the spark plug, twist the flanged boot 1/2 turn, then pull only on the boot to remove the wire. Page 6778 1. With the end gate open, use a grease pencil to mark around the circumference of each washer (Figure 1, "7") located behind the strikers. 2. Unscrew and remove the existing striker assemblies (Figure 1, "6") from the vehicle. 3. Loosely assemble the new striker (Figure 1, "6") (P/N 15700881) and washer (Figure 1, "7") and reinstall using the pencil marks as a guide. 4. Install the striker assemblies (Figure 1, "6") using a T50 Torx(R). Torque to 63 N-m. (47 lbs.ft.). 5. Check for proper operation and end gate flushness. Adjust the striker assemblies if required. The end gate lock strikers can be adjusted up or down, fore or aft, to obtain proper closure of the end gate. The end gate should seal completely with minimum closing effort. Torque the striker bolts to 63 N-m. (47 lbs.ft.). SERVICE PARTS INFORMATION PART NUMBER DESCRIPTION QTY/VEH 15700881 Striker Asm. 2 Description and Operation Electronic Spark Timing: Description and Operation Varying octane levels in today's gasoline can cause detonation in engines. Detonation is sometimes called spark knock. To control spark knock an Electronic Spark Control (ESC) system has been added. This system is designed to retard spark timing up to 20~ to reduce spark knock in the engine. This allows the engine to use maximum spark advance to improve driveability and fuel economy. The ESC system has three major components: ^ ESC module ^ ESC knock sensor ^ ECM The ESC knock sensor detects abnormal vibration (spark knocking) in the engine. The sensor is mounted in the engine block near the cylinders. The ESC module receives the knock sensor information and sends a signal to the ECM. The ECM then adjusts the timing to reduce spark knocking. The ESC module sends a voltage signal (8 to 10 volts) to the ECM when no spark knocking is detected by the ESC knock sensor, and the ECM provides normal spark advance. When the knock sensor detects spark knock, the module turns "OFF" the circuit to the ECM. The ECM then retards EST to reduce spark knock. Loss of the ESC knock sensor signal or loss of ground at ESC module would cause the signal to the ECM to remain high. This condition would cause the ECM to control EST as if no spark knock were happening. No retard would occur, and spark knocking could become severe under heavy engine load conditions, possibly leading to pre-ignition and severe engine damage. Loss of the ESC signal to the ECM would cause the ECM to constantly retard EST. This could result in sluggish performance and cause a Code 43 to set. Spark retard without the knock sensor connected could indicate a noise signal on the wire to the ESC module or a malfunctioning ESC module. Page 4342 5. Disengage cross trunnions, still attached to flange yoke, from coupling yoke. Pull flange yoke and cross from centering ball on ball support tube yoke. The ball socket is part of the flange yoke. The ball on some joints is not replaceable. The joints with a replaceable ball can be recognized as shown in Fig. 15. Do not attempt to remove solid ball, as removal tool may be damaged. 6. Pry seal from ball cavity, then remove washers, spring and shoes, Fig. 16. Fig. 17 Removing Centering Ball Ball Socket 1. To remove ball, separate universal joint between coupling yoke and flange yoke by pressing out trunnion bearing in coupling yoke. Pull flange yoke and cross with ball socket from centering ball as a unit. 2. Clean and inspect ball seat insert bushing for wear. If worn, replace flange yoke and cross assembly. 3. Pry seal from ball cavity, then remove washers, spring and ball seats. 4. Clean and inspect centering ball surface, seal, ball seats, spring and washer. If parts are worn or broken, replace with a service kit. 5. Remove centering ball as shown in Fig. 17, using components of tool C-4365 or equivalent. Install components as shown, and draw ball off ball stud. Fig. 12 Alignment Punch Marks Fig. 18 Inserting Cross Into Yoke Page 4233 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. Page 7026 The AFFECTED AREAS MAY REQUIRE RECLEARCOATING/COLORCOATING OR REFINISHING. 8. In any case, once the proper repairs have been made, the final step in the repair process involves polishing the vehicle. A WORD ABOUT CLEARCOAT THICKNESS The clearcoat on the vehicle is typically 1.5 to 2.0 mils thick (one mil equals .001" or 1/1,000 of an inch). At least one mil thickness is required to provide lasting protection to the vehicle basecoat. PAINT GAGES The best way to accurately measure how much clearcoat has been removed is to use a paint gage before, during and after the sanding process. Paint gages measure the total thickness of the finish and when used, can determine how much clearcoat has been removed during the repair process. Paint gages range from magnetic pull types to sophisticated electronic types, are available from a variety of sources, and can cost from $30 to $1800. The older magnetic type gages, at best, a +/- 5% accuracy range and are not sensitive enough to detect removal of .5 mil clearcoat. The newer type magnetic gages have improved accuracy ranges. Most gages are confined to checking either a ferrous metal (steel) or non-ferrous metal (aluminum) panels. At this time, there are no viable gages for reading film thickness on non-metallic panels. A more sophisticated gage is the digital Elcometer 300 fn Paint Thickness gage (or equivalent). It has an ability to read film thickness on both ferrous and non-ferrous metal panels. This instrument has an accuracy range of +/- 1% and has thickness standards included for recalibration. Approximate cost = $1750. An alternative (for use on steel panels only) would be the digital Elcometer 246 model, or equivalent. This gage has a +/- 3% accuracy range and include thickness standards for recalibration. Approximate cost - $575. REPAIRING RAIL DUST DAMAGE Rail dust damage comes from the tiny iron particles produced from the friction between the train wheels and the track. It can also be deposited on vehicles if stored near any operation producing iron dust (steel ore yards, etc.). This dust can either lay on top of, or embed into the paint surface. It is usually diagnosed as; bumps in the paint surface OR - rust colored spots in the paint. PROCEDURE: 1. Wash the vehicle with soap and water, dry it and clean the affected area with wax and grease remover. 2. Keeping the vehicle in a cool or shaded area, rinse the surface with cold water. CAUTION: RAIL DUST REMOVER (OXALIC ACID) IS AN ACIDIC SUBSTANCE CONTAINING CHEMICALS THAT WILL BREAK DOWN THE IRON PARTICLES EMBEDDED IN THE FINISH. WHEN WORKING WITH IT, USE THE NECESSARY SAFETY EQUIPMENT, INCLUDING GLOVES AND GOGGLES. FOLLOW THE MANUFACTURER'S DIRECTIONS CLOSELY BECAUSE IT MAY REQUIRE SPECIAL HANDLING AND DISPOSAL. 3. Soak several terry cloth towels in a container of rail dust remover solution and, after the damaged areas have been rinsed with cold water, lay the wet towels on the damaged areas. 4. Allow the towels to remain in place for 20 minutes, keeping them moist by spraying with water and not allowing to dry on the surface of the vehicle. 5. After 20 minutes of applying the towels, remove them and rinse the area thoroughly with cold water. Inspect the affected area to ensure the dust has been removed. Use both touch (feeling for bumpy surface) and sight (magnifying glass for close inspection). 6. If upon inspection some particles are still present, the process of applying the towels can be repeated 3 times. 7. Select a test area and hand wet sand with American ultra fine 1,500 grit to 2,000 grit sandpaper to repair damage (surface pitting from dust). a. Use ample amounts of water. b. Go slow to prevent removing too much clearcoat. NOTICE: USE A PAINT GAGE TO DETERMINE THE AMOUNT OF CLEARCOAT REMOVED. IF TOO MUCH HAS BEEN REMOVED, ADDITIONAL CLEARCOAT WILL HAVE TO BE APPLIED. IF RAIL DUST HAS PENETRATED INTO THE BASECOAT, THE PANEL REQUIRES REFINISHING. MAKE SURE ALL RAIL DUST HAS BEEN REMOVED PRIOR TO REFINISHING OR THE RUST SPOTS WILL RETURN, CAUSING CUSTOMER COMEBACKS. 8. If the damage has been repaired, complete the repair to the entire panel. 9. Once the damage has been repaired, the final step in the repair process involves polishing the vehicle. PREVENTING INDUSTRIAL FALLOUT DAMAGE Page 5072 Fig. 5 Brake Booster Lock Tab & Staking Positions 1. Lubricate inside diameter of diaphragm lip with a thin layer of silicone grease, then install diaphragm into the diaphragm support, Fig. 3. 2. Install diaphragm and diaphragm support onto power piston and pushrod assembly. 3. Install new diaphragm retainer. Ensure retainer is fully seated. 4. Install filter, reaction retainer, piston rod and reaction body retainer. 5. Apply silicone grease to the power piston bearing and install it into the rear housing, then install return spring. 6. Mount housings to holding fixture and turn fixture handle in a clockwise direction to lock the front and rear housings. 7. Stake housing in locations shown, Fig. 5. Do not stake a tab that has been staked previously. 8. Lubricate inside and outside edges of grommet and front housing seal, then install grommet and seal. 9. Install vacuum check valve, silencer and boot. 10. Ensure piston rod depth is within specifications using gauge tool No. J-37839 or equivalent. Tandem Daphragm Type Disassembly Fig. 4 Brake Booster Holding Fixture 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 Page 1727 Oil Pressure Gauge: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. Figure 21 Figure 22 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. Page 3558 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 Page 880 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. Page 6231 Control Assembly: Service and Repair S/T-10/15 1. Disconnect battery ground cable. 2. Remove instrument panel center bezel. 3. Remove control retaining screws, then pull control assembly away from instrument panel. 4. Disconnect harness leads, cables and vacuum lines, then remove control. 5. Reverse procedure to install. Page 5665 Fig. 2 Clip and reservoir removal Fig. 3 Return tube removal Fig. 4 Control valve assembly removal Fig. 5 Driveshaft retaining ring removal Page 6911 Symbol Identification Description and Operation Reference Signal: Description and Operation This signal is used to inform the ECM that the engine is cranking. The ECM uses this information to tell when the engine is in the cranking mode. Page 2324 - Diagnostic Chart C-1D. The updated chart information: Page 3830 A new pressure regulator valve (III. 218) has been made which will improve the oil pressure stability at lower RPM. SERVICE PARTS INFORMATION: Description Part Number Valve, Pressure Regulator (III. 218) 8684048 Part numbers are for Reference Only. Check with your Parts Department for latest information. A/T - New Case Assembly, Removal of Pressure Taps Transmission Pressure Test Port: Technical Service Bulletins A/T - New Case Assembly, Removal of Pressure Taps Number: 89-116-7A Section: 7A Date: MARCH, 1989 Subject: NEW CASE ASSEMBLY - REMOVAL OF 2ND, 3RD, AND 4TH CLUTCH PRESSURE TAPS Model and Year: 1982-89 B, F, Y CARS WITH 700-R4 TRANSMISSION 1982-89 C, G, K, M, R, S, T, V TRUCKS WITH 700-R4 TRANSMISSION Figure 1 - Removal Of 2nd, 3rd And 4th Clutch Pressure Taps Figure 2 - THM 700-R4 / HYDRA-MATIC 4L60 Transmission Identification Information TO: ALL CHEVROLET DEALERS This bulletin covers service information for new THM 700-R4/HYDRA-MATIC 4L60 Case assemblies (Figure 1). Starting December 2, 1988 (Julian Date 337) (Figure 2) all THM 700-R4/HYDRA-MATIC 4L60 transmissions were built without drilling and tapping the 2nd, 3rd, or 4th clutch pressure taps. The case bosses will be removed through normal die maintenance. Mainline pressure tap remains unchanged. The clutch pressure taps require case bosses to bring the channeling to the exterior of the case and provide an area to tap and plug the pressure ports. The casting process necessary to provide the case bosses and channeling increase the chance of case porosity in those areas. By removing the clutch pressure taps, the casting can be changed to reduce incidences of case porosity and leaks. Even though individual clutch pressure readings are no longer available, use of basic diagnostic procedures, as outlined in the Service Manuals, will result in successful diagnosis of an automatic transmission concern. The first step in systematic transmission diagnosis is to obtain a complete description of the condition from the vehicle owner. Gather as much information from the owner as they can provide. As an example, under what driving Electrical - Information For Electrical Ground Repair Wiring Harness: All Technical Service Bulletins Electrical - Information For Electrical Ground Repair INFORMATION Bulletin No.: 10-08-45-001B Date: October 25, 2010 Subject: Information for Electrical Ground Repair - Use New Replacement Fasteners with Conductive Finish 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 the 2011 model year and update the Warranty Information. Please discard Corporate Bulletin Number 10-08-45-001A (Section 08 - Body and Accessories). Electrical Ground Repair Overview Proper electrical system function relies on secure, stable and corrosion-free electrical ground connections. Loose, stripped, or corroded connections increase the possibility of improper system function and loss of module communication. These conditions may also lead to unnecessary repairs and component replacement. In general, electrical ground connections are accomplished using one, or a combination of the following attachment methods: - Welded M6 stud and nut - Welded M6 nut and bolt - Welded M8 nut and bolt Determine which attachment method is used and perform the appropriate or alternative repair as described in this bulletin. M6 Weld Stud Replacement Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. Select a location adjacent the damaged or missing M6 ground stud having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the M6 conductive rivet stud flange. 2. Using GM approved residue-free solvent or equivalent, remove any grease from the repair site and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 3. Drill a 10 mm (0.40 in) diameter hole through the panel. 4. Remove paint and primer from the area surrounding the 10 mm (0.40 in) hole until bare metal is visible. Torque Spark Plug: Specifications Spark Plugs 22 ft.lb Page 975 - Tighten poppet screw to 31 N-m (23 lbs.ft.). - New poppet plunger P/N 15633556 (70) group A vehicles only. - New poppet spring P/N 15633557 (71) group A vehicles only. - New poppet screw P/N 15633558 (68) group A vehicles only. 23. Vacuum switch (46) and new O-ring P/N 14071849 (47) to the front case housing. - Tighten switch to 24 N-m (17 lbs.ft.). 24. Front output flange (74), rubber sealing washer (75), washer (76) and flange nut (77). - Tighten nut (26) to 149 N-m (110 lbs.ft). 25. New vent pipe P/N 15581915 in new front case half (group A vehicles only). - Lightly coat end of vent pipe with Loctite 609 (R) or equivalent. 26. Transfer case into vehicle. - Refer to section 7D of the appropriate S/T Service Manual for complete transfer case replacement procedure. Service Parts & Warranty Information SERVICE PARTS INFORMATION: The "Easy Shift" package consists of the following parts. Parts must be ordered individually. Required Parts Part Quantity Figure 1 Group A Group B Number Description Required Reference Trucks Trucks 15635347 Front case half 1 45 X 15637215 Sector W/shaft 1 55 X X 15637217 Mode shift fork 1 54 X X 15633556 Poppet plunger 1 70 X 15633557 Poppet spring 1 71 X 15633558 Plug 1 68 X 14071849 O-ring 2 69 & 47 X X 15581915 Vent Pipe 1 N/S X 14095609 Input seal 1 42 X 14037958 Retainer 1 66 X X 14095598 Range sector seal 1 67 X X 15579788 Output front seal 1 72 X 15642511 Adapter gasket 1 N/S X X 15579803 Drive Sprocket 1 20 * * 14071703 Synchronizer 1 28 * * Blocking Ring * These parts required only if damaged or in cases of customer complaint of clash when shifting from 2Hi to 4Hi. Parts are currently available from GMSPO. WARRANTY INFORMATION: For vehicles repaired under warranty use: Labor Labor Operation Truck Time Page 5207 6. Tape the solder and diode. 7. Reinstall the black plastic conduit. 8. Reconnect connector to the generator. 9. Reconnect battery. This procedure will not affect the operation of the generator light during the bulb check at the beginning of the start cycle. For vehicles repaired under warranty use, Labor Operation Number: T7990 Labor Time: .4 Hr Fuel - Use of Gasoline Containing 15 Percent MTBE Fuel: All Technical Service Bulletins Fuel - Use of Gasoline Containing 15 Percent MTBE Number: 89-268-08 Section: 0B Date: October 1989 Corporate Bulletin No.: 930108 Subject: USE OF GASOLINE CONTAINING 15 PERCENT MTBE Model and Year: ALL 1980-89 PASSENGER CARS AND LIGHT DUTY TRUCKS TO: ALL CHEVROLET DEALERS In August of the U.S. Environmental Protection Agency approved the use of methyltertiary-butyl ether (MTBE) in gasolines at concentrations of 15 percent or Prior to that time, the legal limit was 11 percent; Generai Motors owners manuals stated that the use of gasolines containing 11 percent or less MTBE should not adversely affect the operation of the vehicle and would be covered by the New Vehicle and Emission Control Systems Warranties. The use of 15 percent MTBE in gasoline should also not adversely affect the operation of 1989 and earlier model vehicles and therefore, will not void any warranties covering those vehicles. In the interest of contributing to cleaner air, General Motors recommends that all model year vehicles use such fuels whenever available. The 1990 and future owners manuals will reflect this position. Page 1774 5. Remove paint and primer from the area surrounding the 10 mm (0.40 in) until bare metal is visible. Important The M6 conductive rivet stud as shown, can accommodate a panel thickness range of 0.7-4.2 mm (0.03-0.17 in). If there are layers of sheet metal, they should be touching without any air gaps to ensure a good ground. 6. Select a M6 conductive rivet stud. Refer to the Parts Information section of this bulletin. Note Use the GE-50317 rivet stud tool kit. 7. Place the M6 conductive rivet stud (1) in the 10 mm (0.40 in) hole. Assemble the rivet stud tool (2) with the groove and flare side facing the rivet stud, then the washer and the M6 nut (3). 8. Using a wrench on the rivet stud tool, and a socket on the M6 nut, secure the M6 conductive rivet stud. 9. Ensure the new rivet stud is securely fastened, WITHOUT ANY detectable movement. 10. Completely wrap the threads of the rivet stud with painters tape or equivalent. Page 58 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/. Page 950 This part number can be found on the identification tag (80) located on the rear case half (Figure 1). Group B: Some 1991 T-Trucks equipped with transfer cases identified by the following part numbers and built before 10/22/90: 15653414 15659232 This part number and build number can be found on the identification tag (80) located on the rear case half (Figure 1). Service Procedure: Group A: These transfer cases require the replacement of the parts indicated in the Group A column of the PARTS INFORMATION section. Group B: These transfer cases require the replacement of the parts indicated in the Group B column of the PARTS INFORMATION section. Remove Page 7816 Parking Lamp: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. Figure 21 Figure 22 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. Page 4585 Figure 3 INSTALL (Figures 2 & 3) Tools required: J8092 Drive handle J33790 Bearing installer and remover J33833 Bearing installer and remover 1. Front output bearing (61) to the new front case half P/N 15635347 (45) using J 8092 and J 33833. 2. New front output shaft seal P/N 15579788 (72) to the new front case half (45). 3. Front output bearing retainer ring (snap ring) (60) to the new case half. 4. New input seal P/N 14095609 (42) into retainer (44) if it was removed in step 24 above. 5. Input bearing (40) and input bearing retainer (39) to the new case half using J 36372. 6. Planetary carrier (36) and the input gear (38) to the annulus gear (62) using a soft hammer. 7. Retainer snap ring to the input gear (38). Input bearing retainer (44) and input bearing retainer bolts (43) to the front case half (45). - Clean mating surfaces and apply RTV or equivalent on bearing retainer mating surfaces. NOTE Do not block oil feed hole from case to bearing retainer. - Apply Loctite 242 (R) or equivalent on bearing retainer bolts. - Tighten bolts to 19 N-m (14 lbs.ft.). 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 ECM/PCM - Damaged and/or Misdiagnosed Engine Control Module: All Technical Service Bulletins ECM/PCM - Damaged and/or Misdiagnosed Number: 91-384-6E Section: 6E Date: AUGUST 1991 Corporate Bulletin No.: 176503 Subject: DAMAGED ECM/PCM AND/OR MIS-DIAGNOSED ECM/PCM SYMPTOMS DUE TO INCORRECT "TAP-TESTING" PROCEDURES Model and Year: 1982-91 ALL PASSENGER CARS AND TRUCKS CONDITION: Because of the intermittent nature of some Electronic Control Module (ECM) or Powertrain Control Modules (PCM) symptoms, some service technicians have been subjecting the ECM/PCM to vibration and/or shock testing. Commonly known as tap-testing, this procedure involves tapping on the ECM/PCM case, while the engine is running. It is generally accepted that if the engine or ECM/PCM falters due to the tapping, an intermittent internal ECM/PCM defect may be indicated. However, this may not always be true. If too much force is applied to the ECM/PCM during the test the following symptoms may result: ^ Immediate ECM/PCM failure. ^ ECM/PCM suffers damage which may cause a failure at a later date. ^ ECM/PCM Reset (or Glitch), creating a momentary stall, miss Service Engine Soon (SES) light and/or loss of serial data. CAUSE: The ECM/PCM should be tapped using only the fingertips of one hand. Use of the palm, fist, or any type of tool subjects the ECM/PCM to forces that can cause both the circuit board and the outer aluminum case to flex and distort beyond design limits. The Integrated Circuits (IC) used in today's ECM/PCMs are mounted to the circuit board using a mounting process referred to as "surface technology." There are no circuit board holes for IC leads to go through. The IC leads set on pads, (28 pads or 52 pads depending on the IC) and solder is flowed around the leads to make the electrical connection to the circuit board. ^ Any flexing of the circuit board, beyond design limits, places the IC solder connections at risk of damage. Such damage may be apparent immediately, or it may appear at a future date. Circuit board deflection can occur as a result of striking the ECM/PCM, using ONLY THE PALM OF THE HAND. ^ If struck on the bottom side (the side opposite the service label), the ECM/PCM's aluminum outer case may deflect inward far enough to contact the electrical leads attached to the circuit board. Once in contact with the case the ECM/PCM electrical components will be shorted directly to ground. Although such shorting certainly has the potential to damage the ECM/PCM, it may not be permanent damage, depending on which circuit is involved. However, even if permanent damage is avoided, a short on any of the circuits will cause a disruption of normal ECM/PCM operation for the instant that the short occurs. This disruption may cause the ECM/PCM to reset (see "reset" above), creating the false impression that it is vibration sensitive or faulty. Reset is the ECM/PCM's normal way of coping with large voltage spikes. An ECM/PCM reset does not indicate that the ECM/PCM is defective or faulty, only that it is being subjected to abnormal conditions. CORRECTION: 1. TAP THE ECM/PCM ONLY ON THE TOP SIDE (The top side is where the service label is located.) ^ This will minimize the chance of deflecting the ECM/PCM case into the electrical leads on the circuit board. The clearance between the case and the circuit board is closest on the bottom side of the ECM/PCM. 2. TAP THE ECM/PCM USING ONLY THE FINGERTIPS - NO TOOLS. ^ To avoid excessive case deflection, avoid tapping in the center of the case. Tapping close to the edge of the ECM/PCM, especially in the corners, is best. ^ While using greater force may seem more effective, the test itself may cause the ECM/PCM to fail. Page 2484 Distributor: Service and Repair INSTALLATION: REMOVAL: 1. Disconnect the negative battery terminal. 2. Disconnect the wiring connectors at the side of the distributor cap. 3. Remove the distributor cap and move it out of the way. a. Scribe a mark on the engine in line with the rotor. b. Note the position of the distributor housing in relation to the engine. 4. Remove the distributor hold-down nut and clamp. 5. Remove the distributor. INSTALLATION: NOTE: a. To ensure correct timing of the distributor, the distributor must be installed with the rotor correctly positioned as noted. If the engine was accidentally cranked after the distributor was removed, the following procedure can be used for installing. a. Remove the number 1 spark plug. b. Place finger over the number 1 spark plug hole and crank engine slowly until compression is felt. c. Align timing mark on pulley to "0" on engine timing indicator. d. Turn rotor to point to the 1 spark plug tower on the distributor cap. b. If the distributor shaft will not drop down flush with the engine, it may be necessary to rotate the oil pump drive shaft to align it with the slot on the bottom of the distributor drive gear. Insert a screwdriver into the distributor hole in the engine and turn the oil pump drive shaft slightly to allow alignment. 1. Install the distributor. 2. Install the distributor hold-down clamp and retaining nut. 3. Install the distributor cap. 4. Connect the wiring harness connector at the side of the distributor cap. 5. Connect the negative battery cable. 6. Set ignition timing to specification. Transfer Case - High Shift Effort When Shifting Fluid - Transfer Case: All Technical Service Bulletins Transfer Case - High Shift Effort When Shifting Number: 91-165-7A Section: 7A Date: January 1991 Corporate Bulletin No.: 967402R Subject: HIGH TRANSFER CASE SHIFT EFFORT Model and Year: 1983-91 T1 TRUCKS 1988-91 K TRUCKS TO: ALL CHEVROLET DEALERS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 91-128-7A, DATED NOVEMBER 1990. THE BULLETIN NUMBER HAS BEEN CORRECTED IN THE FIRST PARAGRAPH. ALL COPIES OF 91-128-7A SHOULD BE DISCARDED. Some four wheel drive K and T trucks may experience high transfer case shift effort and/ or total blockouts when "SHIFTING ON THE FLY" from 2H to 4H under cold weather conditions (usually 25 degrees or less). In order to shift to 4H the speed of the front propshaft must be increased to allow proper engagement of front axles. As the transfer case shift lever is moved into 4H the front propshaft begins rotating to synchronize the front axle assembly. In cold weather conditions regular production lube has high viscosity which may delay or prohibit the synchronizing of the front propshaft and axle resulting in high transfer case shift effort. To reduce high shift effort, regular production front axle gear lube may be replaced with a 75W-90 synthetic gear lube which maintains a lower viscosity under cold weather conditions. This synthetic gear lube is now available in one quart containers from GMSPO. Before installing, it is important to drain and flush the front axle with clean mineral based (non synthetic) axle lube. The front axle should then be refilled to the level of the filler hole with synthetic lube listed below. Front Axle Lube Capacities: K1, K2 - 1.66 liter (1.75 qts) K3 - 2.13 Liter (2.2 qts) T1 - 1.20 liter (1.3 qts) SERVICE PARTS INFORMATION P/N DESCRIPTION 12345836 SAE 75W-90 synthetic gear lube, 1 qt. bottle Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation Number: T7980 Labor Time: .4 hr Trouble Code: 92 NOTE: Labor Operation is coded to base vehicle coverage in the warranty system. Paint - High Volume Low Pressure Paint Application Paint: All Technical Service Bulletins Paint - High Volume Low Pressure Paint Application Number: 91-334-10 Section: 10 Date: MAY 1991 Corporate Bulletin No.: 161701R Subject: HVLP-HIGH VOLUME LOW PRESSURE PAINT APPLICATION Model and Year: 1982-91 ALL PASSENGER CARS AND TRUCKS VOC stands for Volatile Organic Compounds. Most solvents used in automotive refinishing paints are considered volatile organic compounds. Volatile organic compounds react chemically with sunlight and make a variety of pollutants generally referred to as "Photochemical Smog." VOC regulations seek to reduce the amount of VOC getting into the air and thereby limit pollution. One way to reduce the amount of volatile organic compounds being emitted into the air is to increase the transfer efficiency rate of the paint material being transferred between the spray gun and the surface being painted. Different states throughout the country, such as California, New York, New Jersey, etc., are in the process of writing VOC emission regulations. As an example, the South Coast Air Quality Management District (SCAOMD) in Southern California has a Rule 1151 for automotive refinishing that stipulates that coating applications must be done with either electrostatic application, high-volume, low-pressure (HVLP) spray or "such other coating application methods that are demonstrated to the executive officer to be capable of achieving at least 65 percent transfer efficiency." HVLP spray is defined as "to spray a coating by means of a gun that operates between 0.1 and 10.0 psi air pressure." What is the difference between the high pressure conventional spray guns now in use and the HVLP spray guns being stipulated in VOC regulations? In the conventional spray gun high pressure air leaves the air cap and rapidly expands. As this air expands, the paint from the fluid tip is blasted apart, sending small paint droplets in all directions at a high velocity. This explosion of paint causes much of the paint to pass or bounce off the surface being painted. Transfer efficiency on conventional spray guns is usually between 20 percent and 50 percent efficiency. HVLP stands for (H)igh (V)olume (L)ow (P)ressure. HVLP spray guns utilize lower spray pressures upon atomization. The relatively low air pressure causes a much "softer" explosion. The resultant paint droplets are larger and slower. The large volume of air from the air caps can now better control the flight of the droplets. The paint spray tends to move in one direction. Bounce back and paint passing by the substrate are reduced, resulting in increased transfer efficiency. Transfer efficiency of HVLP guns is usually between 65 percent to 90 percent efficient. The amount of savings and transfer efficiency varies with the skill of the painter, gun adjustment, the air pressures, the size of the object being painted, and the viscosity of the paint. Basically, there are three types of HVLP spray equipment available; turbine units, air conversion units, and spray guns with the air conversion units inside the gun. The turbine unit is normally a portable or wall-mounted unit that generates a high volume of air at between 3 to 7 psi. Due to friction, the turbine generates heat. The amount of heat generated and the temperature of the air depend on the size of the turbine and length of hose. A large size diameter air hose is used between the turbine and the HVLP spray gun. Air conversion units are normally portable or wall-mounted units that use high pressure air from an air compressor and then convert it to a high volume of air at a lower pressure set on a regulator. Most air regulators on these units do not exceed 10 psi. A large size diameter air hose is used between the air conversion unit and the HVLP spray gun. These units do not generate any heat, but can be purchased with a heat source. HVLP spray guns with the air conversion units inside the gun use high pressure air from an air compressor and then convert it to a high volume of air at a preset pressure normally dependent on incoming air line pressure. The spray guns cannot exceed 10 psi no matter how high the incoming air line pressure is. There is no large diameter air hoses or heat to contend with. HVLP equipment that can maintain precise control and maintain close to 10 psi air cap pressure will provide better atomization of materials, especially low VOC paints. A GM training course on HVLP Paint Application is currently available (Course # 22001.42). Please refer to the GM monthly training schedule for more information. MANUFACTURERS of HVLP SPRAY EQUIPMENT Accuspray System Binks Bessam-Aire Binks Manufacturing Co. 26881 Cannon Road 9201 West Belmont Ave. P.O. Box 46478 Franklin Park, IL 60131 Backup Lamps/Tailgate Window Release - Inoperative Shift Interlock Switch: All Technical Service Bulletins Backup Lamps/Tailgate Window Release Inoperative Number: 91-459-8A Section: 8A Date: DEC. 1991 Corporate Bulletin No.: 168104 ASE No.: A6 Subject: BACKUP LAMPS OR TAILGATE WINDOW RELEASE INOPERATIVE Model and Year: 1980-91 ALL LIGHT DUTY TRUCKS (EXCEPT GEO) Owners of some 1980-1991 C/K, 1982-1991 G, 1985-1991 M/L, 1984-1991 P2,P3, 1987-1991 R/V, 1983- 1991 ST (including LLV) with automatic transmissions may comment on a condition of inoperative back-up lamps or inoperative tailgate window release. This condition occurs when the vehicle's gear shift lever is placed in the "reverse" position, but the back-up lamps do not illuminate. In addition, on the S/T utility vehicles, the electric tailgate window release does not release when the transmission gear shift lever is placed in the "park" or "neutral" position and the endgate window release button is depressed. The park/neutral and back-up lamp switch comes out of adjustment which does not allow for the contact points to remain engaged. To correct these conditions, the contact carrier on the park/neutral and back-up lamp switch has been modified to increase switch carrier travel. SERVICE PROCEDURE: 1. Disconnect the battery ground cable from the battery. 2. Disconnect the switch assembly harness. 3. Place the gear selector in neutral. 4. Squeeze the tangs on the switch together and remove the switch assembly. 5. Install the new switch assembly (P/N 15679680) by: -aligning the actuator with the cutout in the steering column jacket. -inserting the tangs into the rectangular holes and pushing down on the switch assembly. 6. Adjust the switch by moving the gear selector to park. 7. Connect the switch assembly harness. 8. Connect the negative battery cable. 9. Check for proper switch operation. Readjust the switch as necessary. Specifications Oil Pressure Sender: Specifications Oil Pressure Switch 10 ft.lb Page 2061 Coolant Temperature Sensor/Switch (For Computer): Service and Repair The coolant sensor must be handled carefully. If sensor is damaged, fuel injection operation will be affected. 1. Disconnect battery ground cable. 2. Drain coolant from radiator so level is below sensor. 3. Disconnect coolant sensor electrical connector. 4. Carefully back out coolant sensor and remove. 5. Reverse procedure to install. Tires - Slipping on Rim Wheels: Customer Interest Tires - Slipping on Rim Number: 93-169-3E Section: 3E Date: APRIL 1993 Corporate Bulletin No.: 393501 ASE No.: A4 Subject: TIRES SLIPPING ON WHEELS (USE PROPER TIRE MOUNTING PROCEDURE) Model and Year: 1988-93 ALL PASSENGER CARS AND LIGHT DUTY TRUCKS Some incidents of tires slipping (rotating) on wheels have been reported on 1988-93 passenger cars and light duty trucks. Most incidents have occurred when driven aggressively immediately after tire mounting. Hard acceleration and/or braking is usually required. This condition will affect wheel balance, which could result in a vibration. To reduce the chance of tires rotating on their wheels, any excess lube should be wiped from the tire and rim after tire mounting, but before inflating to seat the bead. (Never exceed 40 psi to seat the bead.) Also, the vehicle should not be driven aggressively for at least four hours after tire mounting to allow the lube to dry. GM Goodwrench Rubber Lubricant, p/n 12345884, is the recommended lube for tire mounting. Page 5268 Fusible Link: Locations Fuse Link B Center Of Dash Panel (engine Compartment) At Rear Of Generator Applicable to: V6-262/4.3L Engine Locations Vacuum Restrictor: Locations RH Side Of Cowl Center Of Firewall Page 1681 Figure 4 Figure 5 Figure 6 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 7 Page 6176 Inspect ^ Make sure the compressor neck area is clean. All parts. Replace as necessary. Install or Connect Tools Required: J 33011 O-Ring Seal Installer J 23128-A Seal Seat Remover and Installer J 34614 Shaft Seal Protector J 5403 Snap Ring Pliers ^ Dip the new O-ring seal in clean 525 viscosity refrigerant oil ^ J 34614 onto the shaft (20). Installing The Seal Seat O-Ring 1. O-ring seal using J 33011. ^ Insert J 33011 into the compressor neck until the installer "bottoms." ^ Lower the movable slide of J 33011, releasing the O-ring seal into the lower groove. ^ Rotate J 33011 to seat the O-ring seal and remove J 33011. 2. Shaft lip seal using J 23128-A. ^ Dip the shaft lip seal in clean 525 viscosity refrigerant oil and install shaft lip seal on J 23128-A. ^ Bottom the shaft lip seal into the compressor neck area using J 23128-A. ^ Release and remove J 23128-A. 3. Shaft seal retainer ring using J 5403. ^ Install flat side of shaft seal retainer ring against the lip seal. ^ Remove J 34614. Important ^ Leak test the compressor Clean ^ Shaft (20) and inside the compressor neck area. 4. Clutch plate and hub assembly (2). Page 5703 Fig. 3 Over-center preload adjustment Prior to adjusting the steering gear, all outside loads must be removed. 1. Disconnect battery ground cable, then raise and support vehicle. 2. Remove pitman arm nut, then mark relationship of pitman arm to pitman shaft to aid during reassembly. 3. Remove pitman arm using a suitable puller. 4. Loosen steering gear adjuster plug lock nut, then back off adjuster plug 1/4 turn, Fig. 2. 5. Remove horn cap or cover to gain access to the steering wheel attaching nut. 6. Turn steering wheel gently in one direction to stop, then turn back 1/2 turn to position steering gear away from ``high point'' load position. Do not turn wheel hard against steering stops with pitman arm disconnected as damage to gear ball guides can result. 7. Position suitable inch pound torque wrench on steering wheel hub nut, Fig. 3, then while rotating steering wheel with inch pound wrench through a 90 ° arc, record and measure ``bearing drag.'' Do not use an inch pound wrench of more than 50 inch pound capacity. 8. Adjust thrust bearing preload as follows: a. Torque adjuster plug, Fig. 2, until proper loading preload is 0 (6.5 inch lbs.). b. Tighten adjuster nut to specifications. c. If gear feels lumpy after adjustment, bearing damage is indicated. Gear should be disassembled and inspected as necessary. Speedometer Gear - Malfunctions Speedometer Gear, M/T: All Technical Service Bulletins Speedometer Gear - Malfunctions Number: 91-98-8C Section: 8C Dates: October 1990 Corporate Bulletin No.: 067104 Subject: MALFUNCTION OF THE SPEEDOMETER DRIVE GEAR, DRIVEN GEAR AND/OR SPEEDOMETER Model and Year: 1987-91 S1 (LLV POST OFFICE VEHICLES) TO: ALL CHEVROLET DEALERS Some of the above postal vehicle chassis may experience a malfunction of the speedometer drive gear, driven gear, and/or speedometer adapter. Effective January 24, 1990 with chassis' VIN 1GBCS10E2M2901183, a new driven gear was installed in production. The new driven gear can be recognized visually as the following table illustrates. GM PART # COLOR # OF TEETH NEW 3987920 BLUE 20 OLD 3860347 YELLOW 24 IMPORTANT: The new driven gear has eliminated the need for the speedometer adapter. Recommended service procedures are outlined below: Service Procedure # 1 1. Remove and discard speedometer adapter (GM Part # 368025). 2. Remove original speedometer driven gear and inspect for damaged teeth. If damaged, follow service procedure # 2. If it is not damaged, replace the (yellow) 24 tooth driven gear with the (blue) 20 tooth driven gear (GM Part # 3987920). For vehicles repaired under warranty use: Labor Operation: # T1611 Labor Time: .3 hr. FAILURE CODE: 92 NOTE: The above procedures do not apply to 1991 Postal Vehicles (LLV) with L38 engines. Effective August 13, 1990 with chassis VIN 1GBCS10A0M2912017, a new engine (L38) and rear axle ratio (GU6) were installed in production. As a result of the axle ratio change, a new driven gear is required. Use (gray) 22 tooth driven gear (GM Part Number 3987922) if vehicle is equipped with L38 and GU6. Service Procedure # 2 1. Remove and discard speedometer adapter. 2. Remove driveshaft and rear transmission extension housing. 3. Replace both speedometer drive and driven gear with: Drive Gear (blue) GM Part 96040176 Driven Gear (blue) GM Part 3987920 NOTE: The above procedures do not apply to 1991 Postal Vehicles (LLV) with L38 engines. Effective August 13, 1990 with chassis VIN 1GBCS10A0M2912017, a new engine (L38) and rear axle ratio (GU6) were installed in production. As a result of the axle ratio change, a Locks - Key Code Security Rules and Information Key: Technical Service Bulletins Locks - Key Code Security Rules and Information INFORMATION Bulletin No.: 10-00-89-010 Date: May 27, 2010 Subject: Key Code Security Rules and Information on GM KeyCode Look-Up Application (Canada Only) Models: 2011 and Prior GM Passenger Cars and Trucks 2010 and Prior HUMMER H2, H3 2009 and Prior Saturn and Saab 2002 and Prior Isuzu Attention: This bulletin has been created to address potential issues and questions regarding KeyCode security. This bulletin should be read by all parties involved in KeyCode activity, including dealer operator, partner security coordinator, sales, service and parts departments. A copy of this bulletin should be printed and maintained in the parts department for use as a reference. Important U.S. dealers should refer to Corporate Bulletin Number 10-00-89-009. Where Are Key Codes Located? General Motors provides access to KeyCodes through three sources when a vehicle is delivered to a dealer. Vehicle KeyCodes are located on the original vehicle invoice to the dealership. There is a small white bar coded tag sent with most new vehicles that also has the key code printed on it. Dealerships should make a practice of comparing the tag's keycode numbers to the keycode listed on the invoice. Any discrepancy should be reported immediately to the GM of Canada Key Code Inquiry Desk. Remember to remove the key tag prior to showing vehicles to potential customers. The third source for Key codes is through the GM KeyCode Look-Up feature within the OEConnection D2DLink application. KeyCode Look-Up currently goes back 17 previous model years from the current model year. When a vehicle is received by the dealership, care should be taken to safeguard the original vehicle invoice and KeyCode tag provided with the vehicle. Potential customers should not have access to the invoice or this KeyCode tag prior to the sale being completed. After a sale has been completed, the KeyCode information belongs to the customer and General Motors. Tip Only the original invoice contains key code information, a re-printed invoice does not. GM KeyCode Look-Up Application for GM of Canada Dealers All dealers should review the General Motors of Canada KeyCode Look-Up Policies and Procedures (Service Policy & Procedures Manual Section 3.1.6 "Replacement of VIN plates & keys"). Please note that the KeyCode Access site is restricted. Only authorized users should be using this application. Please see your Parts Manager for site authorized users. KeyCode Look-Up currently goes back 17 years from current model year. Important notes about security: - Users may not access the system from multiple computers simultaneously. - Users may only request one KeyCode at a time. - KeyCode information will only be available on the screen for 2 minutes. - Each user is personally responsible for maintaining and protecting their password. - Never share your password with others. - User Id's are suspended after 6 consecutive failed attempts. - User Id's are disabled if not used for 90 days. - Processes must be in place for regular dealership reviews. - The Parts Manager (or assigned management) must have processes in place for employee termination or life change events. Upon termination individuals access must be turned off immediately and access should be re-evaluated upon any position changes within the dealership. - If you think your password or ID security has been breached, contact Dealer Systems Support at 1-800-265-0573. Page 8102 movement. Refer to Dealer Service Bulletin Number 91-181-10, Dated February 1991. Page 7895 LIGHT BLUE LT BLU BROWN BRN GRAY GRY GREEN GRN DARK GREEN DK GRN LIGHT GREEN LT GRN ORANGE ORN PINK PNK PURPLE PPL RED RED TAN TAN WHITE WHT YELLOW YEL ECM - Packard 32 Way Connector Identification Engine Control Module: All Technical Service Bulletins ECM - Packard 32 Way Connector Identification Number: 90-56-8 Section: 8 Date: September 1989 Corporate Bulletin No.: 916521R Subject: PACKARD 32 WAY CONNECTOR IDENTIFICATION Model and Year: 1980-90 A, B, F, G, J, L, W, Y CARS AND ALL TRUCKS WITH GMP4 ECM APPLICATIONS TO: ALL CHEVROLET DEALERS This bulletin serves to clarify the labeling of the Packard 32 way connectors used on the GMP4 under dash ECMS. Currently a common strain relief is used in both the C-D 32 pin and the E-F 32 pin connectors. To properly identify these connectors, the strain reliefs must be removed. Use the lettering on the connector as shown on figure. The colors used at this time for the 32 pin E-F connector are yellow, mint green or orange. This updates any previous information released concerning identification that indicates any of these colors as being C & D connectors, found in the 6E and 8D Sections of the affected Service Manuals. Page 3094 Oil Pressure Switch (For Fuel Pump): Service and Repair REMOVAL: 1. Disconnect negative battery cable from battery. 2. Remove sensor or switch connectors. 3. Remove sensor or switch. INSTALLATION: 1. Install sensor or switch. 2. Connect sensor or switch. 3. Reconnect negative battery cable. Page 6938 If the spring breaks while bending, it will be necessary to replace the lock cylinder assembly 7. Reinstall the spring in the lock assembly. Next, shake the assembly to check for looseness. If loose, replace the lock cylinder assembly. 8. Reinstall the gasket, lock cylinder and retainer (Figure 3, Items 3, 4 and 2). 9. Reconnect the end gate lock rods (Figure 2, Items 1 and 2). 10. Reinstall the end gate inner panel reinforcement to the end gate (Figure 1, Item 1). 11. Reinstall the inner trim panel. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Op: B5810 Use applicable labor time guide for labor hours. Page 6872 FIGURE 2 3. Place tape on the fender edge and cowl panel edge to prevent paint damage (Figure No. 2) . 4. Disconnect the windshield washer hose from the nozzle. 5. Remove the cowl panel, being careful not to scrape the cowl on the inner hood edge or fender. 6. Pull back the hood hinge seal to expose the windshield frame and close the hood. Page 6159 ^ Place J 25031 down into the rotor until the puller legs engage the recessed edge of the rotor hub. ^ Tighten the puller screw against the puller guide and remove the clutch rotor and bearing. Important ^ If the pulley rim mounting screws (10) and washers (9) were removed, only the clutch rotor and bearing assembly will be removed for replacement. The clutch coil and housing assembly is pressed into the compressor and will not be removed unless the pulley rim mounting screws are left in place and the pulley rim pulls the coil and housing assembly off with the clutch rotor and pulley rim assembly. Removing The Clutch Rotor Bearing 4. Bearing (6) from the clutch rotor (5) with J 8092 and J 9398-A. ^ Place the clutch assembly face on wood blocks to remove the bearing. Important ^ It is not necessary to remove the staking at the rear of the rotor hub to remove the bearing. However, file away the old staked metal to provide a dearance for the new bearing. Install or Connect Tools Required: J 6083 External Snap Ring Pliers J 8092 Drive Handle J 9481-A Pulley Bearing and Pulley Installer Installing The Clutch Rotor Bearing 1. Bearing (6) to the rotor hub with J 8092 and J 9481-A. ^ Place the rotor and hub assembly face down on a clean, flat surface. ^ Align the bearing with the hub bore. ^ Drive the bearing with J 8092 and J 9481-A. Page 4954 Brake Bleeding: Service and Repair Master Cylinder Bleeding THIS PROCEDURE CAN BE PERFORMED WITH MASTER CYLINDER ON OR OFF VEHICLE. 1. Disconnect brake lines at master cylinder, if necessary. 2. Connect suitable lengths of brake lines to master cylinder and immerse other ends of lines in master cylinder reservoirs. 3. Apply master cylinder pushrod or brake pedal with full strokes until air bubbles have disappeared in reservoirs. It may require 20-30 applications to fully eliminate air bubbles. 4. Remove bleeding lines from master cylinder, then install master cylinder on vehicle, if necessary, and connect brake lines. 5. Fill the reservoir. Normal bleeding procedures should be followed after the master cylinder is installed. For additional information see Bench Bleeding Notes. See: Brake Master Cylinder/Fundamentals and Basics Engine - Vibration On Acceleration Heat Shield: Customer Interest Engine - Vibration On Acceleration Number: 88-270-6F Section: 6F Date: JULY, 1988 Subject VIBRATION ON ACCELERATION Model and Year 1988 S/T TRUCK W/4.3L (VIN CODE Z) ENGINE TO: ALL CHEVROLET DEALERS Some 1988 S/T Trucks equipped with 4.3L engines may experience a vibration that can be felt in the floor pan area near the shifter, in the right hand passenger seat foot area, or on the steering column. These conditions may be caused by the following items: 1. The shifter rod that goes from the steering column to the transmission equalizer lever (#340 and #338 in Figure 36 page 7A-45 of the 1988 S/T Manual) hitting the exhaust crossover pipe and/or the equalizer lever making firm contact at the shift lever (T-truck only). 2. The exhaust pipe to catalytic converter clamp (Figure 7, page 6F-6 of the 1988 S/T Manual) hitting the catalytic converter heat shield. 3. The exhaust pipe to converter installation allows the exhaust pipe to contact the transmission crossmember. To repair these conditions, use the following procedures: 1. A. Raise vehicle on hoist. B. Check Transmission linkage for correct adjustment. C. Check exhaust pipe for shifter rod interference (shiny spot on pipe). D. If linkage hits pipe, remove 15 mm (5/8 in) from bottom of rod. E. Put transmission into low gear and mark exhaust pipe area near linkage. F. Put transmission in park. Using a hammer, lightly dimple exhaust pipe for additional clearance. 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. Page 4963 Removing Dust Boot 6. Carefully pry dust boot out of bore. 7. Using a small piece of wood or plastic, remove piston seal from bore. CAUTION: Do not use a metal tool of any kind to remove seal as it may damage bore. 8. Remove bleeder screw. ASSEMBLY NOTICE: Clean all parts in denatured alcohol or brake parts cleaner before assembly and dry the parts with dry compressed air. 1. Inspect caliper bore for scoring, nicks, corrosion or wear. Replace caliper housing if bore will not clean up with crocus cloth. 2. Lubricate caliper piston bore and new piston seal with clean brake fluid. Position seal in bore groove. Fig. 6 Installing boot to piston 3. Lubricate piston with clean brake fluid and assemble a new boot into the groove in the piston so the fold faces the open end of the piston, Fig. 6. 4. Using care not to unseat the seal, insert piston into bore and force the piston to the bottom of the bore. Specifications Tightening Specifications Page 4378 Extension Housing: Specifications Isuzu M-150 (77.5 mm) 4-Speed Extension housing bolts ....................................................................................................................... ................................................................... 30 ft. lbs. Electrical - Instrument Panel & General Wiring Repair Wiring Harness: All Technical Service Bulletins Electrical - Instrument Panel & General Wiring Repair Bulletin No.: 06-08-45-004 Date: May 02, 2006 INFORMATION Subject: Instrument Panel (I/P), Body and General Wiring Harness Repair Models: 2007 and Prior GM Cars and Trucks 2003-2007 HUMMER H2 2006-2007 HUMMER H3 Important: A part restriction has been implemented on all Body and I/P harnesses and is being administered by the PQC. If a body or I/P harness replacement is required, it can take 12-28 weeks for a harness to be built and delivered to a dealer. The dealer technician is expected to repair any harness damage as the first and best choice before replacing a harness. In an effort to standardize repair practices, General Motors is requiring that all wiring harnesses be repaired instead of replaced. If there is a question concerning which connector and/or terminal you are working on, refer to the information in the appropriate Connector End Views in SI. The Instruction Manual J 38125-620, which is sent with each new update of the J 38125 Terminal Repair Kit, also has terminal crimping and terminal remove information. Important: There are some parts in the J 38125 Terminal Repair Kit (i.e. SIR connector CPAs and heat shrink tube (used in high heat area pigtail replacement) and some TPAs that are not available from GMSPO. It is vitally important that each update to the J 38125 Terminal Repair Kit be done as soon as it arrives at the dealer. Utilize the Terminal Repair Kit (J 38125) to achieve an effective wiring repair. The Terminal Repair Kit has been an essential tool for all GM Dealers since 1987. Replacement terminals and tools for this kit are available through SPX/Kent Moore. Refer to Corporate Bulletin Number 06-08-45-001 for more information. The Instruction Manual J 38125-620, which is sent with each new update to the J 38125 Terminal Repair Kit, also has terminal crimping and terminal removal information. U.S. Dealers Only - Training courses (including Tech Assists, Emerging Issues, Web, IDL and Hands-on) are available through the GM Training website. Refer to Resources and then Training Materials for a complete list of available courses. Canadian Dealers Only - Refer to the Training section of GM infoNet for a complete list of available courses and a copy of the J 38125 Terminal Repair Kit Instruction Manual. Wiring repair information is also available in Service Information (SI). The Wiring Repair section contains information for the following types of wiring repairs: - Testing for intermittent conditions and poor conditions - Flat wire repairs - GMLAN wiring repairs - High temperature wiring repairs - Splicing copper wire using splice clips - Splicing copper wire using splice sleeves - Splicing twisted or shielded cable - Splicing inline harness diodes Page 1635 - Adjust converter to center the mounting pins in the insulators. This equalizes the hanger load at the insulators (Figure 2). - Move U-bolt back to original position and tighten. 3. Settle the powertrain by shifting from DRIVE to REVERSE with automatic transmission or 1ST to REVERSE with manual transmission, at least three times with engine at idle. Then turn engine off. 4. Tighten all fasteners with the powertrain in a relaxed position (vehicle in neutral). Torque to specifications in Service Manual X-9129. Note: Be sure that the catalytic converter hanger and hanger pins are centered in the insulators, the pins should have 6.0-16.0 mm (1/4 in. - 5/8 in.) clearance as shown in Figure 2. Booster Assembly Vacuum Brake Booster: Service and Repair Booster Assembly Single Diaphragm Type Disassembly Fig. 3 Exploded View Of Delco-Moraine Single Diaphragm Brake Booster Components Fig. 4 Brake Booster Holding Fixture 1. Remove boot, silencer, vacuum check valve, grommet and front housing seal, Fig. 3. 2. Scribe a line across front and rear housing, then mount brake booster to brake mounting fixture tool No. J 23456 or equivalent, Fig. 4. 3. Turn fixture handle counterclockwise to unlock housings. 4. Remove return spring, power piston assembly and power piston bearing from rear housing, Fig. 3. 5. Remove reaction body retainer, piston rod, reaction retainer and filter, Fig. 3. 6. Remove power piston and pushrod assembly as follows: a. While holding the pushrod down against a hard surface, grasp outside edge of diaphragm support and diaphragm, Fig. 3. b. Use a slight force to dislodge diaphragm retainer, Fig. 3. 7. Remove diaphragm from diaphragm support, Fig. 3. 8. Inspect all parts for corrosion, nicks, cracks, cuts, scoring, distortion or excessive wear. Replace as necessary. 9. Clean all parts in denatured alcohol. Dry with clean compressed air. Do not immerse power piston and pushrod assembly in alcohol. Assembly Page 1313 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 Page 247 Cruise Control Switch: Service and Repair Fig. 40 Mode control replacement 1. Remove steering wheel, lower steering column covers and steering lock plate cover, if equipped. 2. Disconnect mode control connector from main harness connector and attach a suitable length of flexible wire to mode control harness. 3. Tape joint between wire and control harness to aid removal, then remove control assembly as shown in Fig. 40. 4. Reverse procedure to install. Page 7646 Page 6248 REMOVE OR DISCONNECT 1. Coolant from the radiator. 2. Inlet and Outlet Hoses. Refer to "Heater Hose Replacement". - Plug or cap the hoses to prevent spillage. 3. Rear cover and screws. 4. Brackets. 5. Core. INSTALL OR CONNECT 1. Core. 2. Brackets. 3. Rear cover and screws. TIGHTEN - Screws to 3 Nm (27 lb in). 4. Inlet and Outlet Hoses. Refer to "Heater Hose Replacement". Campaign - Interior Front Door Handles Technical Service Bulletin # 06027A Date: 070523 Campaign - Interior Front Door Handles Bulletin No.: 06027A Date: May 23, 2007 SPECIAL COVERAGE Subject: 06027A - SPECIAL COVERAGE ADJUSTMENT - CLASS ACTION SETTLEMENT - INTERIOR DOOR HANDLE SPRING BREAKAGE Models: 1982-1994 CHEVROLET S/T PICKUP AND UTILITY 1982-1994 GMC S/T PICKUP AND UTILITY, JIMMY 1991-1994 OLDSMOBILE BRAVADA INVOLVED IN SOUTH CAROLINA CLASS ACTION SETTLEMENT Supercede: The expiration date for this special coverage has been extended to December 31, 2007. The mailing of letters to customers was delayed. Letters will be mailed to customers on May 30, 2007. Due to the age of the vehicles involved in this program, most involved VINs will be added to GMVIS to allow submission of claims. However, there are a few VINs that were not legible and could not be loaded into GMVIS. If a customer presents a letter authorizing repairs but the VIN is not found in GMVIS, H-route the claim to your AVM for approval. Condition Some customers of 1982-1994 Chevrolet S/T pickup and utility vehicles; 1982-1994 GMC S/T pickup and utility vehicles; and 1991-1994 Oldsmobile Bravada vehicles are entitled to the benefits of a class action settlement. The benefits are listed below and customers will be provided with a letter to present to dealers that details the remedy that they chose. Special Coverage Adjustment This special coverage covers the conditions described below until December 31, 2007. Customers may have any combination of the benefits listed below. Please see the customer's letter to determine the appropriate remedy. Reimbursement - Customers who have replaced an interior front door handle assembly have already submitted a request for reimbursement. GM is handling the reimbursements. There is no action required from the dealer. Replacement of broken interior front door handle assembly(s) - Some customers have chosen to receive a replacement interior front door handle assembly(s). Dealers are to provide the customer with the assembly(s) at no charge. The customer is to self-install or pay the dealer for the installation of the assembly(s). Application of lithium grease - Customers who have the original front door handle assembly(s) in which the spring is not broken, are entitled to have the spring(s) greased. Dealers are to apply lithium grease to the unbroken spring(s) of the original front door handle assembly(s) at no charge. Vehicles Involved Customers involved will present the dealer their vehicle with a letter that authorizes the repair. If the customer requests a new interior front door handle, dealer must verify it replaces a broken interior front door handle assembly. Page 5583 6. Tape the solder and diode. 7. Reinstall the black plastic conduit. 8. Reconnect connector to the generator. 9. Reconnect battery. This procedure will not affect the operation of the generator light during the bulb check at the beginning of the start cycle. For vehicles repaired under warranty use, Labor Operation Number: T7990 Labor Time: .4 Hr Hydra-Matic 700-R4 (4L60) Seals and Gaskets: Service and Repair Hydra-Matic 700-R4 (4L60) 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. 4. Install tunnel strap if used, then install driveshaft. Page 5763 Figure 15 - Large Retaining Clamp Installation 13. Secure the large metal clamp and seal to the housing with tool J35910, breaker bar and torque wrench. Torque the large clamp to 176 N-m (130 lbs.ft.). Check clamp ear gap dimension (Figure 15). Halfshaft Installation: 1. Prior to halfshaft installation, cover shock mounting bracket, lower control arm ball stud, and all other sharp edges with shop towels so that the seal is not damaged during assembly. 2. Remove convolute retainer. 3. Insert and draw up outer C/V joint splined shank into knuckle hub; then secure inboard C/V joint flange to companion flange with bolts (do not tighten). Install hub nut washer and nut. Seat shank splines in hub. 4. Connect the upper ball joint to the steering knuckle. 5. Attach the stud nut and torque 83 N-m (61 lbs.ft.). 6. Install new cotter pin. 7. Lubricate the upper ball joint until grease appears at the seal. 8. Remove floor jack or stand from beneath lower control arm, if used. 9. Connect the shock absorber to the lower shock mounting bracket. 10. Attach the shock mounting bolt and nut. Torque the nut and bolt to 73 N-m (54 lbs.ft.). 11. Attach outer tie rod to steering knuckle. 12. Install tie rod nut and torque to 47 N-m (35 lbs.ft.). Important: Advance the nut to align the nut slot with the cotter pin hole. Never back the nut off to align the cotter pin hole. 13. Install new cotter pin and spread the ends to secure. 14. Attach the brake line support bracket to the upper control arm. Torque to 17 N-m (13 lbs.ft.). Important: Make sure that the brake hose is not twisted or kinked or damage to the hose could result. 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 Page 1445 Wheel Fastener: Specifications Wheel Fastener Tightening Sequence Lug Nut Torque Patterns IMPORTANT Check all parts, including rims, lug studs, lug nuts, and mating surfaces of hubs and tire rims for rust, damage, or dirt. Clean mating surfaces with a wire brush to remove any foreign material. Replace any damaged parts as needed. Careless installation of tire/rim assemblies in a vehicle is a major cause of tire installation problems. Proper installation, including fastener torque, is essential to economical, safe and trouble free service. Use only the proper sizes and types of fasteners for safe and proper service. Tighten the fasteners a quarter turn at a time using the tightening sequence diagram as a guide. This is very important to prevent misalignment of the wheel. Continue tightening the fasteners in sequence until the fasteners are tightened to the proper torque (See WHEEL FASTENER TORQUE). CAUTION: Improper torque or tightening sequence can cause distortion, fatigue cracks, or alignment problems. After driving the vehicle for a short distance, recheck the wheel fastener torque. Parts will usually seat naturally, reducing the torque on the fasteners. Retorque all fasteners to the proper torque. Page 2354 Throttle Position Sensor: Adjustments The TPS is not adjustable. The ECM utilizes the IAC position reading at idle for its zero reading, therefore no adjustment is necessary. Tires - Slipping on Rim Wheels: All Technical Service Bulletins Tires - Slipping on Rim Number: 93-169-3E Section: 3E Date: APRIL 1993 Corporate Bulletin No.: 393501 ASE No.: A4 Subject: TIRES SLIPPING ON WHEELS (USE PROPER TIRE MOUNTING PROCEDURE) Model and Year: 1988-93 ALL PASSENGER CARS AND LIGHT DUTY TRUCKS Some incidents of tires slipping (rotating) on wheels have been reported on 1988-93 passenger cars and light duty trucks. Most incidents have occurred when driven aggressively immediately after tire mounting. Hard acceleration and/or braking is usually required. This condition will affect wheel balance, which could result in a vibration. To reduce the chance of tires rotating on their wheels, any excess lube should be wiped from the tire and rim after tire mounting, but before inflating to seat the bead. (Never exceed 40 psi to seat the bead.) Also, the vehicle should not be driven aggressively for at least four hours after tire mounting to allow the lube to dry. GM Goodwrench Rubber Lubricant, p/n 12345884, is the recommended lube for tire mounting. Crankshft & Bearing Specs Crankshaft & Bearings Page 3422 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. Nippon Seiko Recirculating Ball Gear Steering Gear: Adjustments Nippon Seiko Recirculating Ball Gear Fig. 2 Pitman Arm Alignment Fig. 3 Adjusting Worm Shaft Starting Torque 1. Ensure worm shaft is free from thrust play. 2. Position pitman arm 11 degrees from the parallel to the worm shaft, Fig. 2. Front wheels should be in the straight ahead position. 3. Measure shaft starting torque with front wheels straight ahead, using pinion socket J-34871-A or equivalent and a torque wrench, Fig. 3. Torque should be 5-8 inch lbs., if not within range adjust as necessary. 4. Check worm shaft operating torque. Torque should be 12 inch lbs. 5. If torque is not as specified, adjust worm shaft starting torque, then recheck operating torque. 6. If specifications are not obtained after adjustment, replace gear box. Page 7951 Symbol Identification Page 4245 Pinion Bearing: Service and Repair Timken/Rockwell - 12 Inch Ring Gear Fig. 1 Exploded View Of Timken/Rockwell Drive Axle With 12 inch Ring Gear DISASSEMBLY 1. Tap or press pinion from cage, taking care not to damage shaft threads, then remove outer pinion bearing, Fig. 1. 2. Remove spacer from pinion, then the inner bearing, using suitable separator and press or puller. 3. If straddle bearing must be replaced, remove snap ring and washer, then the bearing, using suitable puller. 4. If bearings are to be replaced, press outer races from bearing cage, taking care not to distort cage. 5. Inspect components as outlined, and replace as needed, keeping components in order for assembly. ASSEMBLY & PRELOAD 1. When installing new cups, press them firmly against pinion bearing cage shoulders. 2. Lubricate bearings and cups with suitable lubricant. 3. Press rear thrust and radial bearings firmly against pinion shoulders, using suitable sleeve that will bear only on bearing inner race. 4. Install radial bearing lock ring, then squeeze ring into pinion shaft groove. 5. Insert pinion and bearing assembly in pinion cage and position spacer or spacer combination over pinion shaft. 6. Press front bearing firmly against spacer. 7. Rotate cage several revolutions to assure normal bearing contact. 8. Press flange or yoke against forward bearing and install washer and pinion shaft nut. 9. Place pinion and cage assembly over carrier studs, hold flange with suitable tool and torque pinion shaft nut to 240 ft. lbs. 10. Check pinion bearing preload torque. If rotating torque is not within 5 to 15 pound inches, disassemble, adjust spacer, reassemble, and recheck preload torque. Use thinner spacer to increase or thicker spacer to decrease preload. Page 2944 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/. Page 4583 10. Case bolts (3) from the case halves. - Note the two longer bolts (16) and washers go into doweled case holes (33). - Separate case halves, insert screwdrivers into the slot cast in the case ends and pry apart. Do not attempt to wedge the case halves apart at any point on the mating surfaces. - Be careful not to damage the oil pump (12) (located in the rear case half) while removing the rear case half (17). Internal Components 11. Fork shift spring (52). 12. Mainshaft (19)/drive sprocket 14071703 (20), chain (58) and front output shaft (21) as a unit. Mode shift fork (54) and shift rail (48) will be removed with the mainshaft. INSPECT: The teeth of the synchronizer stop ring (28) and drive sprocket (20) for damage. If they are damaged, or in cases of customer complaint of clash when shifting from 2Hi to 4Hi, follow steps 13, 14 & 15, otherwise skip to step 16. 13. Retainer (snag ring) (83) from the mainshaft (19). 14. Synchronizer assembly (81). 15. Drive sprocket (20) from the mainshaft (19). 16. Range shift fork (51), range shift hub (34) and sector with shaft (55) from the planetary carrier (36). - It is necessary to rotate the sector with shaft (55) to obtain clearance when removing the range fork (51). 17. Plastic washer (retainer) (66) and O-ring seal (67) from the front case half. IMPORTANT: Group B vehicles should complete step 17 and skip to INSTALL step 8. 18. Input bearing retainer bolts (43) and input bearing retainer (44) from the front case half (45). 19. Retainer snap ring from the input gear (38). 20. Planetary carrier (36) and the input gear (38) from the annulus gear (62) using a soft hammer. 21. Input bearing retainer (39) and input bearing (40). 22. Front output bearing retainer ring (snap ring) (60). 23. Front output bearing (61) from the front case half (45) using J33790, and J8092. 24. Seal (42) from the input bearing retainer (44) if it shows signs of damage. Install Specifications Piston Ring: Specifications End Gap Compression 0.01 in Note: Minimum Oil 0.015 in Side Clearance Compression 0.0012-0.0032 in Oil 0.002-0.007 in Page 2344 Oxygen Sensor: Locations The oxygen sensor is located in the LH exhaust manifold just above the flange. Page 3891 Shift Cable: Adjustments Fig. 4 Detent Downshift Cable Adjustment 1. Depress and hold readjust tab on cable, Fig. 4. 2. Move slider back through fitting, in direction away from throttle lever, until slider contacts fitting. 3. Release readjust tab, then move throttle to wide open position. Slider will ratchet automatically to correct position. Page 2644 Oxygen Sensor: Description and Operation Fig. 6 Oxygen Sensor (Typical) The exhaust oxygen sensor is located in the exhaust system and monitors oxygen content in the exhaust gas stream. The oxygen content of the exhaust gas reacts with the oxygen sensor to produce a voltage output, Fig. 6. By monitoring the oxygen sensor output voltage, the ECM can determine the amount of oxygen in the exhaust gas and adjust the air/fuel mixture accordingly. Page 5374 Tighten Tighten to 8 Nm (71 lb in). Note The repair area MUST BE properly refinished to maintain a secure, stable and corrosion-free electrical ground. 12. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 13. Verify proper system operation. M8 Weld Nut Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M8 weld nut electrical ground location is accessible from both sides of the panel, a M8 conductive bolt and a M8 conductive nut may be used to secure the electrical ground wire terminal. Refer to the Parts Information section of this bulletin. 2. Select a location adjacent the M8 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the new electrical ground site. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the ground location and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 10 mm (0.40 in) diameter hole through the panel. 5. Remove paint and primer from the area surrounding the 10 mm (0.40 in) hole until bare metal is visible. 6. Select a M8 conductive bolt. Refer to the Parts Information section of this bulletin. 7. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M8 conductive bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 8. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 9. Install the electrical ground wire terminal and the M8 conductive bolt to the ground location. 10. Select a M8 conductive nut. Refer to the Parts Information section of this bulletin. 11. Install the M8 conductive nut to the bolt and: Tighten Tighten to 22 Nm (16 lb ft). Note The repair area MUST BE properly refinished to maintain a secure, stable and corrosion-free electrical ground. 12. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 13. Verify proper system operation. M8 Weld Nut Alternative Repair Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M8 weld nut electrical ground location is not accessible from both sides of the panel, a M6 conductive rivet stud and a M6 conductive nut may be used to secure the electrical ground wire terminal. 2. Select a location adjacent the damaged M8 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the M6 conductive rivet stud flange. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the repair site and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 10 mm (0.40 in) diameter hole through the panel. Page 6134 Removing The Clutch Plate & Hub Assembly ^ Hold the body of J 33013-B with a wrench and tighten the center screw into the remover body. 3. Shaft key (21). ^ Retain shaft key (21) if usable. Inspect ^ All parts and replace as necessary. Install or Connect Tools Required: J 33013-B Hub and Drive Plate Remover and Installer J 33022 6-Point 13 mm Socket J 33027 Clutch Hub Holding Tool J 34992 Compressor Holding Fixture 1. Shaft key (21). Removing The Clutch Plate & Hub And Shaft Key ^ Allow the shaft key (21) to extend 3.2 mm (11a-inch) out of the bottom of the hub keyway. ^ The shaft key (21) is curved slightly to give an interference fit in the groove. Important ^ Do not drive or pound on the clutch hub or the shaft (38). Internal damage to the compressor may result. Coolant Temperature Sensor Radiator Cooling Fan Temperature Sensor / Switch: Locations Coolant Temperature Sensor Center Of Dash Panel (engine Compartment) Center Front Of Engine Applicable to: V6-262/4.3L Engine Page 6370 Refrigerant Pressure Sensor / Switch: Service and Repair High-Side-High Pressure Cut Off Switch R-4 COMPRESSOR R-4 Compressor Component View Remove or Disconnect Tools Required: J 5403 Snap Ring Pliers J 9553 O-Ring Remover 1. Protective cap (28). 2. Retainer ring (27) with J 5403. 3. Valve (26). 4. Seal (25) with J 9553-01. Clean ^ Remove any dirt from the valve cavity. Install or Connect 1. New seal (O-ring) (25) to the cavity. ^ Dip the new seal in clean 525 viscosity refrigerant oil. 2. Pressure relief valve (26). 3. Retainer ring (27) with J 5403-A. 4. Cap (28). Page 5910 Refer to the appropriate section of SI for specifications and repair procedures that are related to the vibration concern. Disclaimer Page 801 The toll free number for Kent Moore is 1-800-345-2233. Portions of this article were reprinted with permission, from Dow Chemical Canada, Inc., P.O. Box 1012, Sarnia, Ontario N7T 7K7. ECM/PCM - Damage Prevention Engine Control Module: All Technical Service Bulletins ECM/PCM - Damage Prevention Number: 91-318-6E Section: 6E Date: MAY 1991 Corp. Bulletin No.: 176502R Subject: DAMAGE TO ECM/PCM CIRCUIT BOARD WHEN INSTALLING A MEM-CAL Model and Year: 1986-91 ALL PASSENGER CARS AND TRUCKS CONDITION: When installing a service replacement ECM/PCM, the use of incorrect MEMCAL installation procedures may cause the ECM/PCM to fail before it can be installed in the vehicle. This condition may appear as if the ECM/PCM were defective when it was shipped to the dealership, when in fact it was damaged while being installed. In addition this condition may also occur when installing an "updated" service MEM-CAL into the vehicles original equipment ECM/PCM. CAUSE: Excessive vertical force may be applied to the MEM-CAL resulting in flexing of the circuit board and damage to the connections between the circuit board and attached components. Excessive verticle force may be generated in two ways. 1. Incorrect MEM-CAL installation procedure. 2. Interference between MEM-CAL and cover. CORRECTION: Use the following procedure. Service Procedure: Important: This procedure supersedes any instructions regarding MEM-CAL installation dated prior to September 1990. 1. Inspect the MEM-CAL to determine if a cork spacer is glued to the top side of the MEM-CAL assembly. If so, remove it prior to installation. 2. Align small notches with matching notches in the ECM/PCM MEM-CAL socket. 3. VERY GENTLY press down on the ends of the MEM-CAL until the locking levers are rotated toward the sides of the MEM-CAL. Notice: To avoid ECM/PCM damage, do not press on the ends of the MEM-CAL until the levers snap into place. Do not use any vertical force beyond the minimum required to engage the MEM-CAL into its socket. 4. While continuing light pressure on the ends of MEM-CAL, use your index fingers to press the locking levers inward until they are snapped into place. Listen for click. 5. Install MEM-CAL cover and install ECM/PCM in vehicle. Page 4169 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. Page 5500 Warranty Information (excluding Saab U.S. Models) For vehicles repaired under warranty, use the appropriate labor operation for the source of the water leak Warranty Information (Saab U.S. Models) For vehicles repaired under warranty, use the table. Disclaimer Page 2740 Center Of Dash Panel (engine Compartment) Page 5050 Hydraulic Brake Booster: Service and Repair Bendix Brake Boosters Hydro-Boost Assembly DISASSEMBLY Fig. 2 Removing Accumulator Fig. 3 Typical Hydro-Boost Unit Disassembled 1. Place accumulator compressor tool No. J-26889 or equivalent, around the end of accumulator, and install nut onto stud as shown in Fig. 2, then depress the accumulator with a C-clamp. 2. Remove retainer by using a suitable punch. 3. Release the C-clamp and remove accumulator compressor tool No. J-26889 or equivalent. 4. Remove accumulator, O-ring, retainer, plug and spring as shown in Fig. 3. 5. Remove retainer, output pushrod, baffle, piston return spring and retainer. 6. With a suitable saw, cut off the eyelet of the pedal rod, then remove the boot. 7. Remove nut, bracket and bolts, then separate cover from housing. 8. Remove piston assembly and seals. 9. Remove spool valve, then with a wire hook remove accumulator valve. 10. Remove return line fitting and seal. Child Restraint - Auxiliary Seat Belt Child Restraint: Technical Service Bulletins Child Restraint - Auxiliary Seat Belt File In Section: 09 - Restraints Bulletin No.: 99-09-40-008 Date: January, 2000 INFORMATION Subject: Auxiliary Seat Belt for Securing Child Restraint Models: 1996 and Prior Passenger Cars with Door Mounted Lap/Shoulder Belts Accident statistics show that children are safer if they are restrained in the rear rather than the front seat. We at General Motors, therefore, recommend that child restraints (seats) be used only in the rear seat. In addition, NEVER put a REAR-FACING child restraint in the front passenger seat if the vehicle is equipped with a passenger side air bag. In the event that it becomes necessary to use a child seat in the right front seat position, the door mounted seat and shoulder belt restraint system used in the described vehicles can be used to secure it. However, to improve stability during normal driving, GM recommends that customers use an auxiliary seat belt that is specifically designed for this purpose. The use of an auxiliary seat belt is described in detail, including several illustrations, in the vehicle Owner's Manual. For additional information, refer to the subject vehicle Owner's Manual. Parts Information To install an auxiliary seat belt, you must have the correct attaching hardware. For auxiliary seat belt and attaching hardware package part numbers and usage, see Groups 14.870, 21.041 or 21.042 of the appropriate GMSPO parts catalog. Warranty Information Auxiliary seat belts are a NO CHARGE item to all GM customers who request them for their specific vehicles. Page 4326 Figure 1 *IMPORTANT: This measurement must be taken at the tapered hole on the splined shaft after the rear propeller shaft is removed. **IMPORTANT: This measurement must be taken with the rear propeller shaft mounted on the front shaft which is within specifications. A/T - THM 700-R4 New Harness/Solenoid Assembly Shift Solenoid: Technical Service Bulletins A/T - THM 700-R4 New Harness/Solenoid Assembly Number: 88-335-7A Section: 7A Date: SEPT., 1988 Subject: SERVICE MANUAL UPDATE: NEW SOLENOID ASSEMBLY AND WIRING HARNESS Model and Year: 1988 C, K, R, V, S, T, G SERIES TRUCKS WITH THM 700-R4 TO: ALL CHEVROLET DEALERS This bulletin covers the introduction of a new Solenoid Assembly and Wiring Harness (Type 18) and new Control Valve Assembly for some 1988 THM 700-R4 models (refer to models listed below). Transmission Models: MAM, MDM, MFM, MKM, MLM, MPM, MRM MWM, MXM, MZM, THM, TJM, TKM, TLM TUM, TXM The new control valve assembly uses a plug in place of the 4-3 pulse switch. The function of the 4-3 pulse switch, to momentarily release the torque converter clutch during a 4-3 downshift, was programmed into the ECM for the 1988 model year. These models had previously used a Type 15 Solenoid Assembly. FIGURE 1 - THM 700-R4 TRANSMISSION IDENTIFICATION INFORMATION Locations Oil Pressure Switch Hydra-Matic 700-R4 (4L60) Governor Pressure Switch: Service and Repair Hydra-Matic 700-R4 (4L60) Refer to "Service Bulletins" section prior to performing the following procedure. 1. Raise and support vehicle 2. If necessary, remove exhaust system. 3. Remove governor cover from case using extreme care not to damage cover. If cover is damaged, it should be replaced. 4. Remove governor. 5. Reverse procedure to install and check fluid level. Page 397 Locations Oil Pressure Switch Page 6125 ^ Remove J 33013-B. Inspect ^ Position of the shaft (20) (even with or slightly above the clutch hub). ^ Use J 33027 to hold the clutch plate and hub assembly (2). Tighten ^ Shaft nut (1) to 16 N.m (12 ft. lbs.) with J 33022. - Hand spin the pulley (5) to check for free rotation. ^ Remove J 33026. Pulley and Bearing Assembly DA-6 Component View Remove or Disconnect Tools Required: J 6983 Snap Ring Pliers J 8092 Driver Handle J 9398-A Pulley Bearing Remover J 33020 Pulley Puller J 33023-A Puller Pilot 1. Clutch plate and hub assembly (2). Service and Repair Tie Rod: Service and Repair Fig. 4 Inner tie rod removal Removal 1. Remove outer tie rod and hex jam nut from inner tie rod. 2. Remove tie rod end clamp and boot clamp. 3. Mark location of breather tube on housing, then remove boot and breather tube. 4. Disconnect shock dampener from inner tie rod and slide back on rack. 5. Secure rack assembly and remove tie rod assembly as follows: a. Place wrench on flat of rack assembly, Fig. 4. b. Place wrench on flats of tie rod housing. c. Rotate housing counterclockwise until tie rod separates from rack. Fig. 5 Inner tie rod installation Installation 1. Install shock dampener, then inner tie rod and tighten to specifications. 2. Ensure tie rod rocks freely in housing. Stake both sides of tie rod housing to flats on rack, Fig. 5. 3. Check both stakes by inserting .010 inch feeler gage between rack and tie rod housing as shown in Fig. 5. Feeler must not pass between rack and housing stake. 4. Slide shock dampener over housing until it engages, then install pinion boot and new clamp. 5. Apply grease to tie rod and housing. Install boot onto tie rod and up to housing. 6. Align breather tube with mark made during removal. Connect elbow of boot to breather tube. 7. Crimp boot clamp onto boot and position tie rod end clamp with pliers on boot. 8. Install hex jam nut onto inner tie rod, then install outer tie rod. Page 48 - An updated engine control calibration, or service procedure, may be available to make the engine less susceptible to low volatility fuels. 3. If basic checks do not reveal a vehicle fault, then advise the customer that fuel quality may be an issue. Recommend the following actions: Change brands of fuel - Use 87 octane gasoline, unless the vehicle is designed for premium gasoline. - Try to empty the fuel tank as much as practical before refilling. - Run a minimum of three tanks of new fuel before returning for service. 4. If above steps are ineffective, do not proceed with additional vehicle diagnosis and/or parts replacement until the fuel tank has been drained and refilled with a known good quality gasoline AT THE DEALERSHIP. 5. If the problem remains refer to service manual, service bulletins and/or technical assistance. Page 5870 more apparent than the other. Both the above described conditions occur very infrequently, with ongoing enhancements underway to reduce their occurance even further. Page 5563 For vehicles repaired under warranty, use the table. Disclaimer Service and Repair Evaporative Canister Filter: Service and Repair NOTE: NOT ALL EVAPORATIVE EMISSION CONTROL CANISTERS HAVE A SERVICEABLE FILTER. At intervals recommended, usually every 24 months or 30,000 miles, the filter on an open bottom canister should be replaced, 1. Remove all hoses from the top of the canister and mark. Remove the canister. 2. Remove the filter element by squeezing it out from under the lip surface at bottom of canister and from under retainer bar, where used. 3. 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. 4. Reinstall the canister to its original position on the vehicle, following normal service procedures. 5. Reconnect the hoses to the top of the canister, according to the labeling on top of canister. Page 5793 15. Insert a drift-through brake caliper to prevent drive axle from turning and torque inboard flange bolts to 80 N-m (60 lbs.ft.). 16. Torque hub nut to 220-270 N-m (162-199 lbs.ft.). 17. Attach retainer. 18. Align cotter pin hole with retainer slot by rotating retainer. Important: DO NOT back off or tighten hub nut more than specified to install cotter pin. 19. Install new cotter pin. Cotter pin must be bent so retainer is held snugly to prevent rattling. 20. Remove drift, install wheels, and lower vehicle. Service Parts Information: Part Number Description Quantity Required 26027964 Seal Kit, Tripot 1 per side Parts are expected to be available on June 17, 1991. Until then, normal part orders will not be accepted by GMSPO. Only verifiable emergency VIP orders will be accepted. GMSPO will make every effort to obtain parts. All parts will be placed on 400 control to waive VIP surcharges. However, the parts will be shipped premium transportation at dealer's expense. All other order types will be cancelled as incorrectly ordered while 400 control is in place. Warranty Information: For Vehicle repaired under warranty use: Labor Operation: T7271 Labor Time: 1.6 hrs. each side Trouble Code: 92 Page 5760 21. Lubricate the seal lip. - If seal is cut or torn, inspect the wheel bearing for damage and replace the seal. 22. If necessary, replace the seal as follows: - Pry old seal from knuckle and discard. - Lubricate the new seal lip. - Use a flat plate to press the seal down flush with the knuckle. Tripot Housing/Tripot Seal Replacement Figure 10 - Inboard Joint Disassembly Required Tools: J8059 Snap Ring Pliers J35910 Seal Clamp Tool 1. Place halfshaft in vise (use protective covers over vise jaws). 2. Remove seal clamp protectors (Figure 10) if used, from inner C/V joint and cut clamp(s) from seal with a pair of side cutters. For swage ring removal use a hand grinder to cut through the ring (taking care not to damage the housing). 3. Remove tripot housing from halfshaft and wipe grease from tripot assembly roller bearings and housing. Thoroughly degrease the housing and allow to dry prior to assembly. Important: Handle tripot spider assembly with care. Tripot balls and needle rollers may separate from spider trunnions. 4. Slide seal up on the shaft and inspect rollers, needle bearings, and trunnions. Check housing for unusual wear, cracks, and other damage. Replace housing and/or tripot assembly as needed. Page 6195 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 wire ends to protect the diode from excess heat. Follow the manufacturers instructions for the solderin equipment you are using. 5. Install terminal(s) into the connector body if previously removed in step number 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. NOTE: A universal diode with a 3 amp, 400 PIV (Peak Inverse Voltage) rating can be used in all of the previously mentioned applications. The following 1993 Service Manuals will need to be updated with the correct part numbers and rating changes. Carline Page All J, L, W, and UO 8A-5-12 Heat sink, part number 276-1567, can be obtained from Radio Shack. We believe the diodes and heat sink listed in this article as well as their manufacturer to be reliable. There may be additional manufacturers or equivalent products. General Motors does not endorse, indicate any preference for or assume any responsibility for the products from these firms or for any such items which may be available from other sources. Page 4074 The difference between the two sets of gaskets is the addition of holes in 1987 to accomodate an auxiliary valve body. Transmissions produced Start of Production or after the 1987 model year may or may not have an auxiliary valve body, but 1987-89 model years must use gaskets with holes for an auxiliary valve body even if an auxiliary valve body is not used. If a 1987 or later transmission does not have an auxiliary valve body - the spacer plate covers up the unused holes in the spacer plate gaskets. NOTICE: If the incorrect (1982-1986) gasket set is used on a 1987-89 model year transmission, with or without an auxiliary valve body, the third clutch exhaust passage will be blocked. This may cause slipping or flaring during a 3-2 shift, a delayed 3-2 downshift, or a burned 3-4 clutch. SERVICE PARTS INFORMATION: Model Year Part # Gasket Set Only Part # Overhaul Kit 1982-1986 8642993 8649995 1987-1989 8657938 8649995 Parts are currently available from GMSPO. Lighting - Exterior Lamp Condensation and Replacement Brake Lamp: Technical Service Bulletins Lighting - Exterior Lamp Condensation and Replacement INFORMATION Bulletin No.: 01-08-42-001H Date: January 05, 2011 Subject: Exterior Lamp Condensation and Replacement Guidelines Models: 2011 and Prior GM Passenger Cars and Trucks (including Saturn) Supercede: This bulletin is being revised to add the 2011 model year. Please discard Corporate Bulletin Number 01-08-42-001G (Section 08 - Body and Accessories). The following information is being provided to better define the causes of condensation in exterior lamps and includes guidelines for determining the difference between a lamp with a normal atmospheric condition (condensation) and a lamp with a water leak. Some exterior lamps, such as cornering, turn signal, backup, headlamps or tail lamps may exhibit very small droplets of water, a fine mist or white fog (condensation) on the inside of the lamp lens. This may be more noticeable on lamps with "multi-lens" designs and may be normal during certain weather conditions. Condensation occurs when the air inside the lamp assembly, through atmospheric changes, reaches the "dew point". When this takes place, the moisture in the air within the lamp assembly condenses, creating a fine mist or white fog on the inside surface of the lamp lens. Most exterior lamps on General Motors vehicles use a vented design and feature a replaceable bulb assembly. They are designed to remove any accumulated moisture vapor by expelling it through a vent system. The vent system operates at all times, however, it is most effective when the lamps are ON or when the vehicle is in motion. Depending on the size, shape and location of the lamp on the vehicle, and the atmospheric conditions occurring, the amount of time required to clear the lamp may vary from 2 to 6 hours. Completely sealed headlamp assemblies (sealed beams) are still used on a limited number of models being manufactured today. These lamps require the replacement of the complete lamp assembly if a bulb filament burns out. Condensation 2006 TrailBlazer Shown A Fine Mist or White Fog on the Inside Surface of the Lamp Lens Occurring After a Period of High Humidity - May be located primarily in the lens corners (near the vents) and SHOULD NOT cover more than half the lens surface. - The condition should clear of moisture when the vehicle is parked in a dry environment, or when the vehicle is driven with the lights ON. - A comparison of the equivalent lamp on the opposing side of the vehicle indicates a SIMILAR performance. If the above conditions are noted, the customer should be advised that replacement of a lamp assembly may not correct this condition. Water Leak New Style Pickup Shown Engine - Miss, Hesitation, or Roughness Spark Plug Wire: Customer Interest Engine - Miss, Hesitation, or Roughness Number: 93-35-6D Section: 6D Date: OCT. 1992 Corporate Bulletin No.: 716404R ASE No.: A1, A8 Subject: ENGINE MISS HESITATION OR ROUGHNESS DUE TO PIERCED SECONDARY IGNITION COMPONENTS Model and Year: 1980-93 ALL PASSENGER CARS AND TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 87-121, DATED MAY 1987. THE 1989-93 MODEL YEARS HAVE BEEN ADDED. ALL COPIES OF 87-121 SHOULD BE DISCARDED. During the diagnosis procedure for an engine miss, hesitation or roughness, a spark plug or spark plug wire condition may be suspected. Several types of commercial or homemade diagnostic equipment required the secondary ignition boots or wire to be pierced. This is normally done to check for spark plug firing or to perform a cylinder balance test. Similarly the use of pliers or other such tools to disengage a spark plug boot may pierce or damage the boot or wire. Secondary ignition components should not be pierced for any reason. Piercing a spark plug wire and/or distributor boot may create a condition that will not be immediately apparent. Over time, the hole in the pierced boot may allow a ground path to develop creating a plug misfire condition. Heavily moisture laden air in the vicinity of the pierced boot may accelerate this effect. Piercing a secondary ignition wire creates a gap in the wire's conductive core. This gap is a point of high resistance. The current flow in the wire will increase to compensate for the higher wire resistance. Over time, the wire may fail creating a plug misfire condition. The time required for the condition to appear depends upon the extent of damage to the conductive core. To help prevent future condition that are spark plug wire related, do not pierce or otherwise damage any secondary ignition component. Only use diagnostic equipment containing an inductive pick-up to check for spark plug firing or to perform cylinder balance tests. When disengaging a spark plug boot from the spark plug, twist the flanged boot 1/2 turn then pull on the boot only to remove the wire. 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 Page 5287 Warranty Information (excluding Saab U.S. Models) For vehicles repaired under warranty, use the appropriate labor operation for the source of the water leak Warranty Information (Saab U.S. Models) For vehicles repaired under warranty, use the table. Disclaimer C/V Boot - Contacts Front Shock Technical Service Bulletin # 913114C Date: 910501 C/V Boot - Contacts Front Shock Number: 91-311-4C Section: 4C Date: MAY 1991 Corporate Bulletin No.: 164301R Subject: FRONT AXLE INNER C/V BOOT CONTACTS FRONT SHOCK Model and Year: 1985-91 T TRUCKS Some 1985-91 T trucks may experience a condition of the front axle tripot seals (commonly referred to as the inner C/V boots) contacting the front shock absorbers. This contact usually occurs during suspension operation and may be evidenced as torn seals, premature wear on the outer edges of the seal convolutes or grooves worn into the body of the shock absorber. This condition can be relieved by correcting problems with shock absorber or axle installation and installing smaller profile tripot seals. VEHICLES INVOLVED: 1985-91 T trucks. SERVICE PROCEDURE: The following items should be checked and verified to provide the greatest amount of clearance for the tripot seals. - The shock absorbers are installed correctly with the fluid reservoir on the bottom and the shield on the top. - If aftermarket shock absorbers have been installed, their diameter must measure 50.4 mm (1.98") or less. - The output shaft retaining ring is in place. To check, pull outward on the output shaft. Outward movement should measure 5 mm (.200") or less. IMPORTANT: DO NOT cut or relocate shock absorber mounting brackets. If the contact between the tripot joint and shock absorber is occurring on the passenger side of the vehicle, the axle assembly may be shifted in the frame too far toward the passenger side. To correct this condition the procedure below should be followed: Figure 16 - Carrier Assembly Installation Brakes - Change In Brake Feel After Rotor Refinishing Brake Rotor/Disc: All Technical Service Bulletins Brakes - Change In Brake Feel After Rotor Refinishing Number: 91-133-5 5 Section: 5 Date: December 1990 Corporate Bulletin No.: 075003R Subject: CHANGE IN BRAKE EFFECTIVENESS AFTER DISC BRAKE ROTOR REFINISHING/PAD REPLACEMENT Model and Year: ALL PASSENGER CARS ALL LIGHT DUTY TRUCKS TO: ALL CHEVROLET DEALERS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 90-316-5, DATED AUGUST 1990. INFORMATION HAS BEEN ADDED REGARDING HUB AND ROTOR CLEANING, PROPER TORQUING TECHNIQUE, REVISED MACHINING TABLE, CHANGE SPECIFICATION FOR MAXIMUM SCORINGING DEPTH. THE 1991 MODEL YEAR WAS ALSO ADDED. ALL COPIES OF 90-316-5 SHOULD BE DISCARDED. Some comments have been received about a change in preceived braking effectiveness which occurs after rotors have been refinished and/or disc brake pads have been replaced. New lining materials have been formulated for increased lining life and to reduce brake squeal. Also, Federal regulations currently prohibit the use of asbestos in Original Equipment Manufactured (O.E.M.) front disc brake linings, and will totally ban asbestos from all O.E.M. brake linings in the near future. Due to these changes, initial rotor surface finish is more critical than in the past, and is required for good brake performance. Following are some recommended actions/procedures to assure proper performance of the brake systems on all vehicles after rotor and/or pad service has been performed: 1 . When performing routine brake maintenance such as replacing worn disc brake pads or shoes, DO NOT refinish disc brake rotors or drums unless: A. There is a brake pulsation condition present, and this pulsation is found to be caused by the brake rotors or drums, or B. The rotors and/or drums are excessively scored. Surface scoring that does not exceed 1.2 MM (0.050 in.) on rotors or drums should not affect brake operation. Before removing rotors from the hub assembly, mark the rotor and on wheel stud so that the rotor may be re-installed in the same position. If rotors are removed, it is very important that rust and scale be removed from the rotor and hub mating surfaces. Failure to do so may introduce excessive lateral runout when the rotor is mounted on the brake lathe, or when the rotor is re-installed to the hub. 2. When refinishing disc brake rotors, it is important that the brake lathe be in good operating condition and that all tools or bits are sharp. Recommended vibration dampeners and/or adaptors should be used and should be clean and free of nicks (remember, 1988-91 W models require the use of an adaptor, J37160, because of the two-piece design). The following table shows the recommended procedure for rotor machining: ROUGH CUT FINISH CUT Spindle Speed 150 RPM 150 RPM Depth of Cut (per side) 0.127 mm (0.005") 0.051 mm (0.002") Tool Cross Feed per Rev 0.152 mm - 0.254 mm 0.051 mm (0.002")Max (0.006" - 0.010") Vibration Damper Yes Yes Sand Rotors-Final Finish No Yes It is important that a rough and a finish cut be made. All brake lathes use a single-point cutting tool which is not capable of giving the necessary surface finish. A SECONDARY FINISHING OPERATION MUST BE PERFORMED TO OBTAIN THE NECESSARY SURFACE FINISH. Page 4496 A new pressure regulator valve (III. 218) has been made which will improve the oil pressure stability at lower RPM. SERVICE PARTS INFORMATION: Description Part Number Valve, Pressure Regulator (III. 218) 8684048 Part numbers are for Reference Only. Check with your Parts Department for latest information. Page 3572 Page 2786 Transmission Position Switch/Sensor: Testing and Inspection Chart C-1A - Park/Neutral Switch Diagnosis Page 6795 2. Remove the end gate inner panel reinforcement from the end gate (Figure 1, Item 1). 3. Disconnect the end gate lock rods (Figure 2, Items 1 and 2). 4. Remove the lock cylinder retainer (Figure 3, Item 2). 5. Working through the access hole, remove the lock cylinder and gasket (Figure 3, Items 4 and 3) through the outer panel. 6. Remove the spring (located on the lock assembly) and carefully bend the spring ends just far enough to eliminate any clearance between the lock pawl assembly and the lock cylinder housing (Figure 3, Items 6 and 4). Note: Locations Blower Motor Relay: Locations Fig 26. Evaporator And Blower Assembly The Blower Motor Relay (152) is located on the front of the Evaporator and Blower Assembly. Page 1285 more apparent than the other. Both the above described conditions occur very infrequently, with ongoing enhancements underway to reduce their occurance even further. Page 3896 Transmission Vacuum Regulator Valve: Specifications THM 180 & 180 C Auto Transmission Modulator Assembly THM 180 .............................................................................................................................................. ..................................................................... 38 ft lbs THM 180C ........................................................................................................................................... ..................................................................... 33 ft lbs Page 1698 Oil Pressure Switch (For Fuel Pump): Testing and Inspection Refer to DIAGNOSTIC CHARTS/FUEL PUMP RELAY CIRCUIT DIAGNOSIS (CHART A-5), for fuel related oil pressure switch problems. Page 7246 Figure No. 1 Before beginning this procedure, make sure that the spare tire carrier striker latch is double latched in order to assure that the following check is accurate. Grasp the carrier arm where the release handle is located and move the arm in a forward and backward direction relative to the vehicle. If a metallic sound is heard or if the arm moves easily then replace the striker plate with a new revised striker plate (P/N 15659235). This new striker plate has a thickened rubber bumper to reduce the movement of the carrier arm as well as an additional reinforcement bracket to absorb the additional force on the striker as a result of the thickened bumper. Old and new bumper sizes as well as the reinforcement bracket are shown in Figure 1. Note: If the subject vehicle was manufactured after the following breakpoints then Service Procedure 1 will not be required as the latest design striker was used in production. Shreveport: 1GNCT18Z9M8104384 Pontiac West: 1GNCT18Z4MO103321 Moraine: 1GNDT13Z6M2115163 Service Procedure 2 Specifications Transmission Speed Sensor: Specifications Electronic Speed Sensor Retainer Bolt ............................................................................................... ...................................................................... 7 ft. lbs. Page 4969 Brake Caliper: Fundamentals and Basics Installation Notes WHEN INSTALLING CALIPERS AND PADS, REMEMBER... - Clean and lubricate caliper slide joint/pins with high temperature silicone grease: Unlike drum brakes, disc brakes do not utilize a spring to withdraw the pads/linings when the brake pedal is released. Disc brakes rely on the elasticity of the piston seals, and the unrestricted movement of the caliper slide assemblies to release the brakes. If the slide joints/pins are not cleaned and lubricated properly the disc brake linings will drag upon the release of the brake pedal. This will result in overheated brakes and premature brake wear. Disc Brake Mechanical Force Diagram NOTE: Floating calipers require free and unrestricted movement on the caliper mounting. Floating or sliding calipers have pistons only on one side of the rotor. The first part of the piston's travel forces the inner pad against the rotor, then further travel forces the movable part of the caliper to pull the outer pad against the rotor. High temperature silicone lubricant must be used. Low temperature grease can melt and contaminate the pads and rotors, or can bake into a very hard substance which binds the slides. Petroleum based grease can cause the slide boots to soften and swell. Work on one side at a time. If you forget how to reassemble the parts you can always use the other side as a model. Anti-squeal Coating - Apply an anti-squeal coating to the back side of the pads/linings. This coatings acts as an insulator to dampen high frequency vibrations that are generated during normal braking. These compounds are highly effective in preventing brake squeal. - Many professional repair shops recommend always rebuilding or replacing the calipers when replacing the brake linings, because: When the pistons are forced back into the calipers, the piston seals are dragged across any corrosion or abrasives that may be deposited on the inside of the caliper. Damage to the seals may not be initially evident. As the new brake linings begin to wear, the piston is gradually withdrawn from the caliper. Electrical - Information For Electrical Ground Repair Grounding Point: Technical Service Bulletins Electrical - Information For Electrical Ground Repair INFORMATION Bulletin No.: 10-08-45-001B Date: October 25, 2010 Subject: Information for Electrical Ground Repair - Use New Replacement Fasteners with Conductive Finish 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 the 2011 model year and update the Warranty Information. Please discard Corporate Bulletin Number 10-08-45-001A (Section 08 - Body and Accessories). Electrical Ground Repair Overview Proper electrical system function relies on secure, stable and corrosion-free electrical ground connections. Loose, stripped, or corroded connections increase the possibility of improper system function and loss of module communication. These conditions may also lead to unnecessary repairs and component replacement. In general, electrical ground connections are accomplished using one, or a combination of the following attachment methods: - Welded M6 stud and nut - Welded M6 nut and bolt - Welded M8 nut and bolt Determine which attachment method is used and perform the appropriate or alternative repair as described in this bulletin. M6 Weld Stud Replacement Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. Select a location adjacent the damaged or missing M6 ground stud having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the M6 conductive rivet stud flange. 2. Using GM approved residue-free solvent or equivalent, remove any grease from the repair site and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 3. Drill a 10 mm (0.40 in) diameter hole through the panel. 4. Remove paint and primer from the area surrounding the 10 mm (0.40 in) hole until bare metal is visible. Page 806 Coolant: Technical Service Bulletins Coolant - Used Anti-Freeze Policy Number: 91-09-0A Section: OA Date: April 1990 Corporate Bulletin No.: 976202 Subject: INFORMATION REGARDING RECONSTITUTED ANTI-FREEZE COOLANT TESTING AND THE USE OF A REFRACTOMETER Model and Year: ALL MODELS AND YEARS TO: ALL CHEVROLET DEALERS RECONSTITUTED ANTIFREEZE At present, three types of recycling systems are available: 1) chemical addition to coolant; 2) filtration and addition of supplemental additives; and 3) separation of pure glycol from used coolant and reinhibition. 1) Chemical Addition-NOT RECOMMENDED With chemical addition, chemicals are added to the used engine coolant in an attempt to "clean up" the coolant. This system is the easiest since the only work involved is the addition of chemicals to the radiator. Most of these types of recycling systems use a strong acid to change precipitated corrosion products into a more soluble form. However, in addition to dissolving the corrosion products, the strong acid also attacks and corrodes the metals of the cooling system. 2) Filtration and Addition of Supplemental Additives-NOT RECOMMENDED In this type of system, the used coolant is either taken out of the vehicle or a flush-type unit is connected to the cooling system. The current technology consists simply of filtration and reinhibition of the spent coolant. While this does remove suspended solids, filtration does nothing to remove harmful degradation and corrosion products that are soluble in glycol solution. The reinhibition step used in current recycling systems may fail to produce a coolant which adequately protects all metals including aluminum in the most critical heat transfer applications, such as occurs in the cylinder heads and blocks. 3) Separation of Pure Glycol and InhibitionThe separation of pure glycol and the addition of fresh inhibitors is the ideal method for recycling coolants. Unfortunately, this method is expensive from both a collection standpoint and the technology available to economically extract pure ethylene glycol from used coolant. At this time, General Motors does not endorse these practices or equipment. Due to a worldwide shortage of ethylene glycol in 1988, some coolant manufacturers have started to mix other types of glycol in their coolant formulations; propylene glycol is the most common new ingredient. A hydrometer will not provide a correct measurement of freeze protection when anything other than ethylene glycol and water is being tested. The degree of inaccuracy will vary depending on the proportion of other glycols present in the coolant. Hydrometers test the amount of glycol in a mixture by measuring the specific gravity of the mixture; the more ethylene glycol, the higher the float balls go, and the better the freeze protection. Because ethylene glycol and propylene glycol do not have the same specific gravities, hydrometer readings of mixtures containing propylene glycol give incorrect values. As the shortage of ethylene glycol continues and/or worsens, more and more variations in antifreeze formulas will be marketed. It is, therefore, recommended that you purchase a "refractometer" and encourage your technicians to use it. Refractometers test for the amount of glycol in a coolant mixture by measuring the speed of light as it passes through the fluid and are not affected by the specific gravity of the glycol. The freeze protection of solutions of ethylene glycol in water, solutions of propylene glycol in water, and solutions of mixtures of propylene glycol and ethylene glycol in water may all be tested with sufficient accuracy using a refractometer. The following refractometers are available from Kent Moore: J 23688 Farenheit scale, measures to -50 F J 26568 Centigrade scale, measures to -45.5 C J 38633 Farenheit scale, measures to -84 F (For extreme cold weather regions) Page 8043 Front Door Window Regulator REMOVE OR DISCONNECT 1. Door trim panel. 2. Armrest bracket. 3. Water deflector. ^ Raise the window to the full-up position secure the glass to the door frame using cloth backed tape. 4. Bolts securing the regulator to the door inner panel. 5. Regulator lift arm roller from the window mount sash. 6. Regulator from the door. INSTALL OR CONNECT 1. Regulator to the door. 2. Regulator lift arm roller to the window mount sash. 3. Bolts securing the regulator to the door inner panel. 4. Water deflector. 5. Armrest bracket. 6. Door trim panel. Page 7954 Heated Glass Element: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. Figure 21 Figure 22 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. Page 2989 Fuel: Specifications ALCOHOL FUEL TYPES Methyl Tertiary-Butyl Ether (MTBE) Fuel containing Methyl Tertiary-butyl Ether (MTBE) may be used, providing there is no more than 15% alcohol by volume. Ethanol Fuel containing ethanol (ethyl) or grain alcohol may be used, providing there is no more than 10% ethanol alcohol by volume. Methanol Fuel containing methanol (methyl) or wood alcohol may be used, providing there is no more than 5% methanol by volume. Use of fuel (gasohol) that contains more than 5% methanol can corrode metal fuel system components and damage plastic and rubber parts. GASOLINE Unleaded gasoline must be used with a minimum octane rating of 87. A/T - DEXRON(R)-VI Fluid Information Fluid - A/T: All 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. ECM - Packard 32 Way Connector Identification Engine Control Module: All Technical Service Bulletins ECM - Packard 32 Way Connector Identification Number: 90-56-8 Section: 8 Date: September 1989 Corporate Bulletin No.: 916521R Subject: PACKARD 32 WAY CONNECTOR IDENTIFICATION Model and Year: 1980-90 A, B, F, G, J, L, W, Y CARS AND ALL TRUCKS WITH GMP4 ECM APPLICATIONS TO: ALL CHEVROLET DEALERS This bulletin serves to clarify the labeling of the Packard 32 way connectors used on the GMP4 under dash ECMS. Currently a common strain relief is used in both the C-D 32 pin and the E-F 32 pin connectors. To properly identify these connectors, the strain reliefs must be removed. Use the lettering on the connector as shown on figure. The colors used at this time for the 32 pin E-F connector are yellow, mint green or orange. This updates any previous information released concerning identification that indicates any of these colors as being C & D connectors, found in the 6E and 8D Sections of the affected Service Manuals. Page 8018 Disclaimer Page 575 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. Locations TIMING MARK 4.3L (262) Page 401 Manifold Pressure/Vacuum Sensor: Description and Operation MAP Sensor The Manifold Absolute Pressure (MAP) sensor measures changes in the intake manifold pressure resulting from engine load and speed changes and converts this to a voltage output, Fig. 7. The ECM sends a 5 volt reference signal to the MAP sensor. As pressure changes in the intake manifold occur, the electrical resistance of the MAP sensor also changes. By monitoring the sensor output voltage, the ECM can determine the MAP. The higher the MAP, the lower the engine vacuum and the higher the sensor output, which requires more fuel. The lower the MAP, the higher the engine vacuum and the lower the sensor output, which requires less fuel. Page 5992 1990-1991 "W" Car 1988-1990 "Y" Car "AW" Type Weight 1989-1991 "L" Car Used On All Other 1991 "B" Car, "U" Van Series Vehicles 2-1/4 oz. 9591382 9591366 2-1/2 oz. 9591383 9591367 3oz. 9591385 9591369 Parts are currently available from GMSPO. Dealers should make sure they have a supply of both types weights for balancing GM aluminum wheels. When installing the coated weights, care must be taken so that the coating does not crack. It is recommended that a Teflon tipped hammer be used, such as 85403 Nicholson Industrial Hammer, their part number CAS 3340551, available through the Charles Strelinger Company, Warren, Mi (313-268-4100), or equivalent. Page 6914 LIGHT BLUE LT BLU BROWN BRN GRAY GRY GREEN GRN DARK GREEN DK GRN LIGHT GREEN LT GRN ORANGE ORN PINK PNK PURPLE PPL RED RED TAN TAN WHITE WHT YELLOW YEL Page 1306 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 Page 5043 Hydraulic Brake Booster: Description and Operation Hydro-Boost II Hydro-Boost II is an hydraulically operated power brake booster. The hydraulic brake booster consists of an open center spool valve and an hydraulic cylinder combined into a single housing. The power steering pump provides the hydraulic fluid pressure to operate both the power brake booster and the power steering gear. A dual master cylinder is bolted to the brake booster and is operated by a pushrod projecting from the booster cylinder bore. The Hydro-Boost II also has an accumulator system which stores sufficient fluid under pressure to provide one power assisted brake application when steering pump failure occurs. Suspension - Knocking/Rattling Noise Torsion Bar: All Technical Service Bulletins Suspension - Knocking/Rattling Noise Number: 91-362-3C Section: 3C Date: JULY 1991 Corporate Bulletin No.: 163302 Subject: KNOCKING NOISE-TORSION BAR SUPPORT INSULATOR DAMAGED/BROKEN Model and Year: 1988-91 T TRUCKS Some owners of 1988-1991 T trucks may comment about a knocking or rattling sound coming from the underside of their vehicle. This sound can occur if the torsion bar support insulator is damaged or breaks. To correct this condition, a new more durable torsion bar insulator has been released. The new insulator is visually identical to the previous insulator and the installation procedure has not changed (reference S-10 Service Manual, Section 3C). VEHICLES INVOLVED: The new torsion bar support insulators have been installed on vehicles after the following VIN breakpoints. Shreveport 1GDCT14Z9M8801063 Pontiac West 1GCCS14A7M0190577 Moraine 1GCCS19R1M2273070 SERVICE PARTS INFORMATION: Part Number Description 15677665 Insulator, Torsion Bar Support Parts are currently available from GMSPO. WARRANTY INFORMATION: Labor Operation: E3340 Use applicable labor time guide for labor hours. 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 Page 3782 Service Information: The NEW SEAL can only be used on the NEW OUTPUT SHAFTS. If the new seal is used on a previous model output shaft, the seal will block one of the lube passages. The previous seal can be used on both the new and previous output shafts. The new output shafts and seal will service any HYDRA-MATIC 4L60/THM 700-R4 transmission ever built. The new output shafts can be identified by lube hole location. They have a lube hole on the chamfer at the front of the output shaft. The lube hole was previously located on the shank of the output shaft. Service Parts Information: The new output shafts and seals will become available for service as current stock is depleted at GMSPO. Reference the GMSPO parts catalog for the correct output shaft to order for your specific transmission application. Service Manual Reference: Refer to the Automatic Transmission Unit Repair Section of the appropriate service manual for output shaft and seal removal and installation information. Page 1647 Engine Mount: Service and Repair Fig. 1 Front Engine Mount Installation FRONT ENGINE MOUNTING REPLACEMENT Remove or Disconnect -Raise the vehicle. Support with suitable safety stands. 1. Cab or body mounting bolts. Raise the body and block in position. 2. Engine mounting through-bolts on both sides. NOTICE: When raising or supporting the engine for any reason, do not use a jack under the oil pan, any sheet metal, or the crankshaft pulley. Due to the small clearance between the oil pan and the oil pump screen, jacking against the oil pan may cause it to be bent against the pump screen, resulting in a damaged oil pickup unit. -Raise the engine and block in position. 3. Engine mounting to frame bolts. 4. Engine mounting. Install or Connect NOTICE: When fasteners are removed, always reinstall them at the same location from which they were removed. If a fastener needs to be replaced, use the correct part number fastener for that application. If the correct part number fastener is not available, a fastener of equal size and strength (or stronger) may be used. Fasteners that are not reused and those requiring thread locking compound will be called out. The correct torque value must be used when installing fasteners that require it. If the above condition are not followed, parts or system damage could result. 1. Engine mounting to the frame. 2. Engine mounting to frame bolts and nuts. -Tighten bolts to 57 Nm (42 ft.lbs) or nuts to 47Nm (35 ft.lbs) -Lower the engine. Page 1799 Important The M6 conductive rivet stud as shown, can accommodate a panel thickness range of 0.7-4.2 mm (0.03-0.17 in). If there are layers of sheet metal, they should be touching without any air gaps to ensure a good ground. 5. Select a M6 conductive rivet stud. Refer to the Parts Information section of this bulletin. Note Use the GE-50317 rivet stud tool kit. 6. Place the M6 conductive rivet stud (1) in the 10 mm (0.40 in) hole. Assemble the rivet stud tool (2) with the groove and flare side facing the rivet stud, then the washer and the M6 nut (3). 7. Using a wrench on the rivet stud tool, and a socket on the M6 nut, secure the M6 conductive rivet stud. 8. Ensure the rivet stud is securely fastened, WITHOUT ANY detectable movement. 9. Completely wrap the threads of the rivet stud with painters tape or equivalent. Note The rivet stud and surrounding panel area MUST BE properly refinished PRIOR to the installation of the ground wire terminal and conductive nut to maintain a secure, stable and corrosion-free electrical ground. 10. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 11. Allow the refinished repair area to cure sufficiently before removing the protective material applied to the rivet stud threads. 12. Remove the painters tape or equivalent from the rivet stud threads. 13. Using GM approved residue-free solvent or equivalent, thoroughly clean the rivet stud threads to remove any adhesive and allow to dry. 14. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive rivet stud. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. Diagnostic Trouble Code Descriptions Engine Control Module: Diagnostic Trouble Code Descriptions For information regarding B, C, P, U and Manufacturer Code Descriptions - A/C Compressor Seal Washer - Reference Chart Compressor Shaft Seal: Technical Service Bulletins A/C Compressor Seal Washer - Reference Chart File In Section: 1 - HVAC Bulletin No.: 63-12-15 Date: November, 1996 INFORMATION Subject: Reference Chart for A/C Compressor Seal Washers Models: 1997 and Prior Passenger Cars (Except Corvette and GEO) 1997 and Prior Light Duty Trucks (Except Tracker) GMSPO A/C compressors include a seal washer kit. These kits contain various color edge painted washer seals and inserts in which only two (2) washers and possibly one (1) insert are used. It has come to our attention that some packaging discrepancies were found and some of the seals cannot be properly identified for installation. These seals are very close in size and some of the seals were inadvertently edge painted the wrong color or not painted. Page 4894 2. Attach a dial indicator to a solid non-rotating portion of the hub assembly or suspension. - The point of the styles must contact the rotor face about 25 mm (1-inch) from the rotor edge. 3. Move the rotor one complete rotation and observe the dial indicator. 4. Rotate the bezel on the dial indicator such that "0" is at the low deflection point. 5. Again rotate the rotor at least one complete turn and observe the needle deflection. Total needle deflection will equal lateral runout. - The lateral runout should not exceed 0.08 mm (0.003-inch). 6. Readjust the wheel bearings. MINIMUM THICKNESS The thickness of a rotor is important for two reasons: 1. Rotors which are too thin are not able to properly absorb and release heat during heavy braking. This results in reduced braking capacity and brake fade. 2. Rotors worn below minimum thickness in combination with worn pads/linings can result in the caliper piston extending too far becoming cocked or jammed. Rotor thickness should be measured at the thinnest point on the rotor. Any rotor which is worn below its minimum thickness should be replaced. For accurate measurements, it is best to remove the caliper to allow for complete access to the inboard side of the rotor. Page 6123 Removing The Shaft Nut ^ Clamp J 33026 in a vise and attach the compressor to the holding fixture with thumb screws. 1. Shaft nut (1) using J 33022. ^ Hold the clutch plate and hub assembly (2) steady using J 33027. 2. Clutch plate and hub assembly (2). ^ Thread J 33013-A into the clutch plate and hub assembly (2). Removing The Clutch Plate & Hub Assembly ^ Hold the body of J 33013-A with a wrench and tighten the center screw into the remover body. 3. Shaft key (21). ^ Retain shaft key (21) if usable. Inspect ^ All pants and replace as necessary. Install or Connect Tools Required: J 33026 Compressor Holding Fixture J 33027 Clutch Hub Holding Tool J 33022 6-Point 13 mm Socket J 33013-B Hub and Drive Plate Remover and Installer Isolation Diodes - Replacement Information Compressor Clutch Diode HVAC: Technical Service Bulletins Isolation Diodes - Replacement Information Number: 93-163-8A Section: 8A Date: MAY 1993 Corporate Bulletin No.: 178201R ASE No.: A6 Subject: ISOLATION DIODES REPLACEMENT INFORMATION Model and Year: 1993 AND PRIOR YEAR PASSENGER CARS AND TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 92-47-8A, DATED NOV. 1991. THE 1993 MODEL YEAR HAS BEEN ADDED AS WELL AS PART NUMBERS HAVE BEEN REVISED. THIS WILL ALSO UPDATE CERTAIN SERVICE MANUALS. ALL COPIES OF 92-47-8A SHOULD BE DISCARDED. Many of the electrical systems on our vehicles use a diode to isolate certain circuits and protect them from voltage spikes. Some of the circuits which may use such a diode are listed below: A/C Compressor Clutch ABS/4WAL NOTE: The ABS diode on the Delco Moraine system is hidden inside of an electrical connector under the carpet at the right kick panel. Wiper Charging System (hidden in wire harness) Parking Brake (vehicles with ABS) Relays Solenoids Diesel Glow Plug Circuit Day Time Running Lights Obtaining replacement diodes can sometimes be a problem. A universal diode, that meets the specifications in the chart below, may be used for the applications listed above. Since certain diode applications have specific part numbers, always reference the applicable GM parts catalogue before installing one of the universal diodes listed in this bulletin. When installing the new diode, use the following procedures to obtain a lasting repair: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to current flow direction, remove inoperative 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 needed to attach the new diode. 4. Check current flow direction of the new diode, being sure to install the diode with correct bias. Reference the appropriate service manual wiring schematic to obtain the correct diode installation position. Reference Figure 1 for replacement diode symbols and current flow explanations. ECM - Intermittent Connection Engine Control Module: All Technical Service Bulletins ECM - Intermittent Connection Number: 88-251-8A Section: 8A Date: JUNE, 1988 Subject: INTERMITTENT CONNECTION TO THE ECM Model and Year: 1988 CHEVROLET PASSENGER CARS AND LIGHT DUTY TRUCKS TO: ALL CHEVROLET DEALERS A condition may exist in which the female terminals in the connector to the ECM do not make a solid connection to the male pins in the ECM (see illustration). This can result in an intermittent condition, in any circuit operated by the ECM. The Service Manuals direct a check of connections any time an intermittent condition is found, and this may be the cause of some of these conditions. Visually inspect the terminal using a flashlight, or use a .95 mm pin gauge. The gauge should not pass freely through the female terminal. Do not probe the terminal with anything other than the pin gauge, as probing could damage the terminal. If the female terminal does not grip properly, replace the terminal with P/N 12020757. General directions on wiring repair are shown in Section 8A of the service Manual. 3L30 (180C) Transmission Shift Solenoid: Specifications 3L30 (180C) Transmission Component .......................................................................................................................................... .................................................................... Ft. Lbs. Solenoid ............................................................. .............................................................................................................................................................. .. 14 Electrical - Intermittent MIL/DTC P2138/Reduced Power Wiring Harness: All Technical Service Bulletins Electrical - Intermittent MIL/DTC P2138/Reduced Power TECHNICAL Bulletin No.: 07-06-04-019D Date: June 28, 2010 Subject: Intermittent Malfunction Indicator Lamp (MIL) Illuminated, DTC P2138 with Reduced Engine Power (Repair Instrument Panel (IP) to Body Harness Connector) Models: 2005-2011 GM Passenger Cars and Light Duty Trucks (Including Saturn) 2005-2009 HUMMER H2 2006-2010 HUMMER H3 2005-2009 Saab 9-7X Supercede: This bulletin is being revised to update the model years and warranty information. Please discard Corporate Bulletin Number 07-06-04-019C (Section 06 - Engine/Propulsion System) Condition - Some customers may comment on an intermittent malfunction indicator lamp (MIL) being Illuminated with a message or an indicator that displays Reduced Engine Power. - The technician may observe on a scan tool DTC P2138 - Accelerator Pedal Position (APP) Sensor 1-2 Correlation set as Current or in History. Cause This condition may be caused by water intrusion into the instrument panel (IP) to body harness connector, which carries the APP sensor signals to the ECM/PCM. This water intrusion results in a voltage difference between APP Sensor 1 and APP Sensor 2 that exceeds a predetermined value for more than a calibrated period of time, setting P2138. Correction Note Aftermarket equipment can generate DTC P2138 and/or other DTCs. 1. Verify that aftermarket equipment is not electrically connected to any of the APP sensor signal or low reference circuits or to any other ECM/PCM 5V reference or low reference circuits. Refer to Checking Aftermarket Accessories in SI. 2. Perform the Diagnostic System Check - Vehicle. ‹› If any 5V reference DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle. ‹› If any 5V reference DTCs are not set, proceed to Step 3. 3. Locate the IP to body harness connector, which may be located in and around the left hand kick panel area or inside the IP. Depending on the vehicle and model year, refer to Wiring Systems or Power and Signal Distribution in SI. Note Some examples of potential water leaks are: A-pillar seals, sunroof drain lines (if equipped) and windshield/cowl sealing. 4. Inspect for a water leak in the area. If necessary use a water hose to determine the source of the leak. Refer to General Information > Water Leaks in SI. ‹› If a water leak is observed, repair as necessary. Verify the effectiveness of the repair. 5. Inspect the IP to body harness connector terminals for corrosion and debris. Refer to Testing for Intermittent Conditions and Poor Connections in SI. ‹› If any corrosion and/or debris is observed, repair as necessary. 6. After completing the repair, verify the proper operation of the system. Depending on the vehicle and model year, perform the Diagnostic Repair Verification procedure or refer to Diagnostic Trouble Code (DTC) List - Vehicle in SI. Page 321 Brake Light Switch: Locations Stop Light Switch LH Side Of I/P Behind Instrument Cluster Page 5791 Figure 13 - Proper Inboard Stroke Positioning 9. Install convolute retainer over seal capturing four convolutes (Figure 13). Important: Joint must be assembled with convolute retainer in position as shown in Figure 13. Seal damage will result if joint is not assembled to dimension shown. Figure 14 - Spider Assembly Installation 10. Install spacer ring and spider assembly (with counterbore toward end of shaft) on the shaft far enough to allow installation of the retaining ring at the end of the halfshaft (Figure 14). 11. Install the retaining ring and push the spider assembly toward the end of the shaft until retaining ring is covered by the spider assembly counterbore. Install the spacer ring and make sure it is seated in its groove. 12. Pack the seal and housing with grease supplied in the kit, (the amount of grease supplied in this kit has been premeasured for this application), place the large metal clamp on the seal, then place the housing over the spider assembly and snap the seal onto the housing. Page 1431 Page 4366 Case: Specifications Warner T-5 (77MM) 5 Speed Shift Cover Retaining Bolts .................................................................................................................. .................................................................... 9 ft. lbs. Adapter Housing Bolts ...................................... ...................................................................................................................................................... 25 ft. lbs. ECM/PCM - Damage Prevention PROM - Programmable Read Only Memory: All Technical Service Bulletins ECM/PCM - Damage Prevention Number: 91-318-6E Section: 6E Date: MAY 1991 Corp. Bulletin No.: 176502R Subject: DAMAGE TO ECM/PCM CIRCUIT BOARD WHEN INSTALLING A MEM-CAL Model and Year: 1986-91 ALL PASSENGER CARS AND TRUCKS CONDITION: When installing a service replacement ECM/PCM, the use of incorrect MEMCAL installation procedures may cause the ECM/PCM to fail before it can be installed in the vehicle. This condition may appear as if the ECM/PCM were defective when it was shipped to the dealership, when in fact it was damaged while being installed. In addition this condition may also occur when installing an "updated" service MEM-CAL into the vehicles original equipment ECM/PCM. CAUSE: Excessive vertical force may be applied to the MEM-CAL resulting in flexing of the circuit board and damage to the connections between the circuit board and attached components. Excessive verticle force may be generated in two ways. 1. Incorrect MEM-CAL installation procedure. 2. Interference between MEM-CAL and cover. CORRECTION: Use the following procedure. Service Procedure: Important: This procedure supersedes any instructions regarding MEM-CAL installation dated prior to September 1990. 1. Inspect the MEM-CAL to determine if a cork spacer is glued to the top side of the MEM-CAL assembly. If so, remove it prior to installation. 2. Align small notches with matching notches in the ECM/PCM MEM-CAL socket. 3. VERY GENTLY press down on the ends of the MEM-CAL until the locking levers are rotated toward the sides of the MEM-CAL. Notice: To avoid ECM/PCM damage, do not press on the ends of the MEM-CAL until the levers snap into place. Do not use any vertical force beyond the minimum required to engage the MEM-CAL into its socket. 4. While continuing light pressure on the ends of MEM-CAL, use your index fingers to press the locking levers inward until they are snapped into place. Listen for click. 5. Install MEM-CAL cover and install ECM/PCM in vehicle. Wipers - Intermittent Phantom Wipe (No Driver Input) Wiper Switch: Customer Interest Wipers - Intermittent Phantom Wipe (No Driver Input) Number: 90-266-8E Section: 8E Date: May 1990 Corp. Bulletin No.: 968302 Subject: WINDSHIELD WIPER PHANTOM WIPE Model and Year: 1985-90 S/T/M TRUCK AND 1990 L TRUCK THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 90-171-8E, DATED FEBRUARY 1990. THE LABOR TIMES HAVE BEEN UPDATED. ALL COPIES OF 90-171-8E SHOULD BE DISCARDED. Some 1985-1990 M vans, 1990 L Vans and S/T model trucks may exhibit intermittent phantom wipe - occasional wiper sweep of the windshield with no driver input. A new steering column wiper switch has been developed with an internal resistor to correct this condition. The following parts can be installed to repair intermiftent phantom wipe. They will service subject M/L vans and S/T trucks. SERVICE PARTS INFORMATION Part Number Description 26020403 Switch (Standard) 26020404 Switch (Tilt Wheel) Parts are currently available through GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Time Labor Time Labor Operation Models (standard) (tilt wheel) N2610 S/T M/L 1.2 hrs 1.0 hrs. Page 3209 Ignition Control Module: Service and Repair Typical Distributor Components REMOVAL: 1. Remove distributor cap and rotor. 2. Remove two module attaching screws, and lift module up. 3. Disconnect leads from module. Observe color code on leads as these cannot be interchanged. 4. Remove module. INSTALLATION: NOTE: Be sure there is a sufficient amount of silicone grease on the metal face of the module and on the distributor base (where the module seats), when reinstalling the module. The purpose of the silicone grease is to cool the module. 1. Install module. 2. Connect leads to module. 3. Install module attaching screws. 4. Install pick up coil. 5. Install cap and rotor. Page 6155 Compressor Clutch: Service and Repair With R-4 Compressor Clutch Drive Hub R-4 Compressor Component View Clean ^ The compressor with solvent and blow dry with air Remove or Disconnect Tools Required: J 9399 Thin Wall Socket J 25008-A Holding Fixture J 25030 Clutch Hub Holding Tool J 34019 Clutch Plate and Hub Assembly Remover Compressor In J 25008-A Holding Fixture A/C - Use of R-22 Refrigerant Not Recommended Refrigerant: Technical Service Bulletins A/C - Use of R-22 Refrigerant Not Recommended GMC NUMBER: 88-T-65 GROUP: 1B - Air Conditioning DATE: December, 1987 CORPORATE NUMBER: 861201 SUBJECT: R-22 REFRIGERANT MODELS: ALL TRUCK MODELS Use of R-22 refrigerant in any GMC truck A/C system is not recommended. R-22 refrigerant will not mix with the compressor lubricant currently used. Any mixture of R-12 and R-22 may cause the following to occur: ^ A/C compressor relief valve to blow at idle due to the build up of head pressures. ^ Loss of A/C system charge due to R-22 seeping through A/C hoses. ^ Compressor failure due to insufficient lubrication. R-12 is the only refrigerant that should be used in GMC truck A/C systems. Differential - Growl Noise Differential Axle Housing: Customer Interest Differential - Growl Noise Number: 8-416-4C Section: 4C Date: May, 1989 Subject: FRONT AXLE GROWL NOISE Model and Year: 1983-88 T1 TRUCKS Figure 1 TO ALL CHEVROLET DEALERS: Beginning with start of production 1989, the material in the thrust washers in the front axle tube of T Model Trucks was changed to reduce thrust washer wear. The washers involved are # 7, # 20 and # 24 as shown in Figure # 1. When worn, the metal in the washer will be smeared from slipping. Number 24 may also be dished. Page 7456 Brake Light Switch Brake Light Switch: Locations Brake Light Switch LH Side Of I/P Behind Instrument Cluster Page 6823 Trailer Adapter Kit: Electrical Diagrams Trailer Adapter Wiring Circuit (W/Heavy Duty Suspension) Page 3055 Fuel Pump Relay: Description and Operation Fuel Pump Relay 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). - 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. Compact Disc Players - CD Changer Loading Procedures Compact Disc Player (CD): All Technical Service Bulletins Compact Disc Players - CD Changer Loading Procedures File In Section: 9 - Accessories Bulletin No.: 64-96-01 Date: January, 1997 INFORMATION Subject: Compact Disc Players - Procedures for Correct Use and Maintenance Models: 1997 and Prior Passenger Cars and Trucks CD Changer Loading Procedures Because of differences in CD changer loading procedures, some confusion exists regarding this issue. Although correct loading procedures are included with each changer's Owner's Manual, often this information is not available to the dealer service personnel. Verify proper loading when evaluating customer concerns of "CD inoperative". Delco Electronics Product Type Loading Procedure Radio w/intergral CD label side up 6 disc changer (LLAI) label side up 10 disc changer (FMI) label side up 12 disc changer (LLAI) label side down Important: Failure to load magazine/player correctly will disable the operation. Important: Only the 12 disc changer is to be loaded with the label side down. CD Cleaners Avoid use of commercially available CD cleaners. The use of CD cleaners is not recommended and can damage the player's CD mechanism. Description and Operation Transmission Position Switch/Sensor: Description and Operation The park/neutral switch indicates to the ECM when the transmission is in park or neutral. This information is used by the ECM for ignition timing, IAC operation and transmission Torque Converter Clutch (TCC) operation. Do not drive vehicle with park/neutral switch disconnected, as idle quality may be affected. Speedometer Gear - Malfunctions Speedometer Gear, M/T: Customer Interest Speedometer Gear - Malfunctions Number: 91-98-8C Section: 8C Dates: October 1990 Corporate Bulletin No.: 067104 Subject: MALFUNCTION OF THE SPEEDOMETER DRIVE GEAR, DRIVEN GEAR AND/OR SPEEDOMETER Model and Year: 1987-91 S1 (LLV POST OFFICE VEHICLES) TO: ALL CHEVROLET DEALERS Some of the above postal vehicle chassis may experience a malfunction of the speedometer drive gear, driven gear, and/or speedometer adapter. Effective January 24, 1990 with chassis' VIN 1GBCS10E2M2901183, a new driven gear was installed in production. The new driven gear can be recognized visually as the following table illustrates. GM PART # COLOR # OF TEETH NEW 3987920 BLUE 20 OLD 3860347 YELLOW 24 IMPORTANT: The new driven gear has eliminated the need for the speedometer adapter. Recommended service procedures are outlined below: Service Procedure # 1 1. Remove and discard speedometer adapter (GM Part # 368025). 2. Remove original speedometer driven gear and inspect for damaged teeth. If damaged, follow service procedure # 2. If it is not damaged, replace the (yellow) 24 tooth driven gear with the (blue) 20 tooth driven gear (GM Part # 3987920). For vehicles repaired under warranty use: Labor Operation: # T1611 Labor Time: .3 hr. FAILURE CODE: 92 NOTE: The above procedures do not apply to 1991 Postal Vehicles (LLV) with L38 engines. Effective August 13, 1990 with chassis VIN 1GBCS10A0M2912017, a new engine (L38) and rear axle ratio (GU6) were installed in production. As a result of the axle ratio change, a new driven gear is required. Use (gray) 22 tooth driven gear (GM Part Number 3987922) if vehicle is equipped with L38 and GU6. Service Procedure # 2 1. Remove and discard speedometer adapter. 2. Remove driveshaft and rear transmission extension housing. 3. Replace both speedometer drive and driven gear with: Drive Gear (blue) GM Part 96040176 Driven Gear (blue) GM Part 3987920 NOTE: The above procedures do not apply to 1991 Postal Vehicles (LLV) with L38 engines. Effective August 13, 1990 with chassis VIN 1GBCS10A0M2912017, a new engine (L38) and rear axle ratio (GU6) were installed in production. As a result of the axle ratio change, a Page 5121 Battery Cable: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. Figure 21 Figure 22 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. Page 7630 Speedometer Head: Testing and Inspection The following material covers only that service on speedometers which is feasible to perform. Repairs on the units themselves are not included as they require special tools and extreme care when making repairs and adjustments that only an experienced speedometer technician should attempt. The speedometer has two main parts-the speedometer head and the speedometer drive cable. When the speedometer fails to indicate speed or mileage, check the cable or cable housing for cracks or breaks. SPEEDOMETER CABLE Most cables are broken due to lack of lubrication, or a sharp bend or kink in the housing. A cable might break because of the speedometer head mechanism binds. In such cases, the speedometer head should be repaired or replaced before a new cable or housing is installed. A ``jumpy'' pointer condition, together with a scraping noise, is due, in most instances, to a dry or kinked speedometer cable. The kinked cable rubs on the housing and winds up, slowing down the pointer. The cable then unwinds and the pointer ``jumps.'' To check for kinks, remove the cable, lay it on a flat surface and twist one end with the fingers. If it turns over smoothly the cable is not kinked. But if part of the cable flops over as it is twisted, the cable is kinked and should be replaced. LUBRICATION The speedometer cable should be lubricated with special cable lubricant. Fill the ferrule on the upper end of the housing with the cable lubricant. Insert the cable in the housing, starting at the upper end. Turn the cable around carefully while feeding it into the housing. Repeat filling the ferrule except for the last six inches of cable. Too much lubricant at this point may cause the lubricant to work into the speedometer head. INSTALLING CABLE During installation, if the cable sticks when inserted in the housing and will not go through, the housing is damaged inside or kinked. Be sure to check the housing from end to end. Straighten any sharp bends by relocating clamps or elbows. Replace housing if badly kinked or broken. Position the cable and housing so that they lead into the head as straight as possible. Check the new cable for kinks before installing it. Use wide, sweeping, gradual curves where the cable comes out of the transmission and connects to the head so the cable will not be damaged during installation. Arrange the housing so it does not lean against the engine because heat from the engine may dry out the lubricant. If inspection indicates that the cable and housing are in good condition, yet pointer action is erratic, check the speedometer head for possible binding. The speedometer drive pinion should also be checked. If the pinion is dry or its teeth are stripped, the speedometer may not register properly. Page 7148 Note: Some technicians may apply a small cord (wire, plastic tube, etc.) behind or underneath moldings that remain on the vehicle to improve sanding and painting. If the vehicle paint system is baked with cord in place, damage to some moldings may occur. If this technique is used, DO NOT BAKE PAINT air dry only Note: Only items marked with an asterisk are "add" conditions to the Major Operation being performed. Removal time for all other items listed is included in the refinish time. LIGHT DUTY TRUCKS C/K TRUCKS Grille Front bumper filler panel Antenna Tail lamps Door edge guards Metal wheel opening moldings *Roof marker lamps "Luggage rack *West coast style mirrors "Stripes Emblems/decals if necessary Swing out windows/seals Tail gate handle bezel S/T TRUCKS Windshield molding Bumper filler panels, Ft./Rr. Wiper arms Antenna Wheel opening moldings Cowl vent grille Door edge guards Side view mirrors Tail lamps *Wind deflector Rear Window (Jimmy) *Luggage rack *Stripes Emblems/decals if necessary Swing out windows/seals *Spare tire carrier and latch-external mount (Jimmy) M/L VANS Windshield molding Wheel opening moldings Headlamp bezels Antenna Tail lamps Door edge guards *Luggage rack *Stripes Emblems/decals if necessary R/V TRUCKS Wiper arms Cowl vent grille Antenna Tail lamps Removal Brake Pad: Service and Repair Removal Caliper Assembly 1. Remove caliper assembly. See Brake Caliper / Service and Repair. See: Brake Caliper/Service and Repair 2. Remove inboard pad. Dislodge outboard pad and position caliper on the front suspension so the brake hose will not support the weight of the caliper. CAUTION: Do not allow caliper to hang from brake hose. 3. Remove pad support spring from piston. 4. Remove two sleeves from inboard ears of the caliper. 5. Remove four rubber bushings from the grooves in each of the caliper ears. Wheels - Finish Damage During Off Car Balancing Wheels: All Technical Service Bulletins Wheels - Finish Damage During Off Car Balancing BULLETIN NUMBER: 93-3E-67 SECTION: 3E Wheels & Tires NUMBER: 3 CORPORATE REFERENCE NUMBER: 3935O2R DATE: June 1993 SUBJECT: INFORMATION ON COSMETIC DAMAGE TO ALUMINUM WHEELS DURING BALANCING MODELS: 1985-93 MODELS WITH ALUMINUM WHEELS Some aluminum wheels on GM models may incur cosmetic damage during balancing if proper care and procedures are not used. All aluminum wheels have a clearcoat paint on them that must be cared for like any other painted surface. Some off-car vehicle balancer retaining cups used to clamp the wheel to the balancer may put a circular mark into the clearcoat on the face of the wheel. Like any other clearcoat damage, this may be difficult to remove or repair, depending on severity. ALWAYS use balancer retainer cups that are protected with rubber, plastic, or other nonmetallic materials where contact is made with the wheel. Make Page 7850 If the functional brake switch adjustment check does not repair the condition, refer to Section 5 of the appropriate Service Information Manual for aid in diagnosing other causes. For warranty purposes use: Labor Operation Number: N2440 Labor Time: .3 hour TRUCK ONLY: Service Procedure: 1. Depress the brake pedal and press the switch in until it is firmly seated in the clip. * Audible "clicks" can be heard as the threaded portion of the switch is pushed through the clip. 2. Pull the brake pedal against the pedal stop until the audible "click" can no longer be heard. For stop lamp switch adjustments on vehicles repaired under warranty use: Labor Operation Number: T7945 Labor Time: .2 Hr. Page 6283 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) Page 5006 Brake Master Cylinder: Service and Repair Master Cylinder Rebuild Fig. 2 Exploded View Of Master Cylinder DISASSEMBLY 1. Remove master cylinder from vehicle. 2. Remove reservoir cover and diaphragm. Discard old brake fluid in reservoir. 3. Inspect cover and diaphragm. Replace if cut, cracked or deformed. 4. Remove fluid level switch and proportioner valve assembly, if equipped. 5. Depress primary piston and remove lock ring. 6. Plug primary fluid outlet (outlet nearest to cowl when master cylinder is installed), then apply compressed air into secondary fluid outlet to remove primary and secondary pistons. 7. Remove spring retainer and seals from secondary piston. Do not attempt to remove quick take up valve, valve is not serviced separately. 8. Clamp master cylinder in a vise, then remove reservoir using a pry bar. Remove reservoir grommets. 9. Inspect master cylinder bore for corrosion. CAUTION: Do not use abrasive material on master cylinder bore. Replace if bore is corroded. ASSEMBLY Clean all parts not included in repair kit with brake fluid. CAUTION: Do not dry with compressed air. Lubricate all rubber parts with clean brake fluid prior to installation. 1. Lubricate new reservoir grommets with silicone brake lube, then press grommets into master cylinder body. Ensure grommets are properly seated. 2. Lay reservoir upside down on flat, hard surface. Press master cylinder body onto reservoir using rocking motion. 3. Install new seals on secondary piston, then the spring retainer. 4. Install spring and secondary piston assembly into cylinder. 5. Install primary piston. Depress primary piston into cylinder, then install lock ring. 6. Install fluid level switch and proportioner valve assembly, if equipped. 7. Fit diaphragm into reservoir cover, then install cover onto reservoir. 8. Install master cylinder in vehicle. Page 6036 II. OVER TORQUING OF WHEEL NUTS: 1. A TORQUE WRENCH MUST BE USED to insure that the wheel nuts are tightened to specification. This should be done in two steps using the star pattern. First, snug the nuts down by hand. Then, using the star pattern and a torque wrench, tighten the wheel nuts to about half the final torque. Finally, tighten the wheel nuts to specification using the star pattern and a torque wrench. 2. NEVER use lubricants or penetrating fluids on wheel studs, nuts, or mounting surfaces, as this can raise the actual torque on the nut without a corresponding torque reading on the wrench. Wheel nuts, studs, and mounting surfaces must be clean and dry. Page 3973 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 Page 6337 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) Page 602 Idle Speed: Adjustments *** UPDATED BY TSB # 88T556E DATED NOV. 1987 CONTROLLED IDLE SPEED CHECK 1. Set parking brake and block drive wheels. 2. Connect a SCAN tool to the assembly line data link (ALDL) connect with tool in Open Mode. 3. START engine and bring it to normal operating temperature. 4. Check for correct state of PARK/NEUTRAL switch on SCAN tool. 5. Check specifications chart for controlled idle speed and IAC valve pintle position (counts). 6. If within specifications, the idle speed is being correctly controlled by the ECM. 7. If not within specifications, perform MINIMUM IDLE AIR RATE CHECK. If still not within specifications, Refer to Diagnosis By Symptom / No Trouble Codes Stored. MINIMUM IDLE AIR RATE CHECK 1. Check controlled idle speed and perform idle air control check first. 2. Set parking brake and block drive wheels. 3. START engine and bring it to normal operating temperatures 185-212 degrees Fahrenheit (85-100 degrees Celsius). Turn engine OFF. 4. Remove air cleaner, adapter and gaskets. Check that the throttle lever is not being bound by the throttle, throttle valve or cruise control cables. 5. With IAC valve connected, ground the diagnostic terminal (ALDL). 6. Turn ON ignition, DO NOT START engine. Wait at least 10 seconds (this will allow the IAC pintle to extend and seat in the throttle body.). 7. With ignition ON, engine stopped, test terminal still grounded, disconnect IAC valve electrical connector. (This disables the IAC valve in the seated position). Remove the ground from the diagnostic terminal. 8. Connect a SCAN tool to the ALDL connector and place in open mode. If a tool is not available connect a tachometer to the engine. 9. START engine. With transmission in NEUTRAL, allow engine rpm to stabilize. 10. Check rpm against specifications. Disregard IAC counts on SCAN tool with the IAC disconnected. If the engine has less than 500 miles or is checked at altitudes above 1500 feet, the idle rpm with a seated IAC valve should be lower than values in chart. 11. If the minimum idle air rate is within specifications, no further check is required. 12. If the minimum idle air rate is not within specifications, perform the following procedures: 13. If present, remove the stop screw plug by piercing it with an awl, then applying leverage. The screw is covered to discourage unauthorized adjustments. 14. With the engine at normal operating temperature 185-212 degrees Fahrenheit (85-100 degrees Celsius), adjust stop screw to obtain nominal rpm per specifications with seated IAC valve. 15. Turn ignition OFF and reconnect IAC valve electrical connector. 16. Disconnect the SCAN tool or tachometer. 17. Use silicon sealant or equivalent to cover stop screw hole. 18. Install air cleaner, adapter and gasket. CONTROLLED IDLE SPEED Transmission Gear Idle Speed IAC Counts [1] OPEN/CLOSED LOOP [2] Page 2024 IMPORTANT: To maintain a balanced fan assembly, align the yellow paint mark on the fan clutch with the yellow paint mark on the water pump hub. SERVICE PARTS INFORMATION Part Number Description 15672779 Fan Clutch Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Page 14 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 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 Page 5761 Figure 11 - Snap Ring and Spider Removal 5. To remove the spider assembly (also required for seal replacement), spread the spacer ring with tool J8059 or equivalent and slide the ring and spider assembly up on the shaft (Figure 11). This will provide access to the shaft retaining ring in the groove at the end of the shaft. Remove the retaining ring, spider assembly, spacer ring, and seal. Figure 12 - Small Retaining Clamp Installation 6. Clean the shaft. If rust is present in the seal mounting area (grooves), wire brush this area (Figure 12). 7. Slide the new small seal clamp and seal onto the shaft to the proper position. 8. Secure the clamp with tool J35910, breaker bar and torque wrench. Torque small clamp to 136 N-m (100 lbs.ft.). Check clamp ear gap dimension (Figure 12). Page 2618 Manifold Pressure/Vacuum Sensor: Specifications MANIFOLD ABSOLUTE, VACUUM AND BAROMETRIC PRESSURE SENSORS Engines may use one, or a combination of these sensors. All sensors appear the same. Manifold Absolute Pressure sensors have a vacuum line connected between the unit and manifold vacuum. On Barometric Pressure sensors, the line is not used and the connector is either open or has a filter installed over it. Pressure sensors also have a vacuum line between the sensor and intake manifold and only appear on carburetted models. Barometric Pressure Sensors: Measure voltage with ignition on and engine off. Manifold Absolute Pressure Sensors: Measure voltage with ignition on and engine off. Start engine and apply 10 in./ 250 mm Hg to unit, voltage should be 1.2-2.3 volts less. Pressure Sensors: Measure voltage as indicated. Page 7551 A/T - Intermittent Downshift/Slip/Cycling Diagnosis Fan Clutch: All 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. Specifications Absolute Pressure Sensor: Specifications MANIFOLD ABSOLUTE, VACUUM AND BAROMETRIC PRESSURE SENSORS Engines may use one, or a combination of these sensors. All sensors appear the same. Manifold Absolute Pressure sensors have a vacuum line connected between the unit and manifold vacuum. On Barometric Pressure sensors, the line is not used and the connector is either open or has a filter installed over it. Pressure sensors also have a vacuum line between the sensor and intake manifold and only appear on carburetted models. Barometric Pressure Sensors: Measure voltage with ignition on and engine off. Manifold Absolute Pressure Sensors: Measure voltage with ignition on and engine off. Start engine and apply 10 in./ 250 mm Hg to unit, voltage should be 1.2-2.3 volts less. Pressure Sensors: Measure voltage as indicated. Aluminum Wheels - Cosmetic Damage During Balancing Wheels: All Technical Service Bulletins Aluminum Wheels - Cosmetic Damage During Balancing Number: 93-197-3E Section: 3E Date: MAY 1993 Corporate Bulletin No.: 393502 ASE No.: A4 Subject: INFORMATION ON COSMETIC DAMAGE TO ALUMINUM WHEELS DURING BALANCING Model and Year: 1988-93 C1, K1, G, E/J, L/M, P, S/T, R/V 1990-93 LUMINA APV Some aluminum wheels on GM models may incur cosmetic damage during balancing if proper care and procedures are not used. All aluminum wheels have a clearcoat paint on them that must be cared for like any other painted surface. Some off-car wheel balancer retaining cups used to clamp the wheel to the balancer may put a circular mark into the clearcoat on the face of the wheel. Like any other clearcoat damage, this may be difficult to remove or repair, depending on severity. ALWAYS use balancer retainer cups that are protected with rubber, plastic, or other nonmetallic materials where contact is made with the wheel. Make sure the retainer cup is free from dirt, grease, and gouges. Most wheel balancers now offer this type of protected retainer. DO NOT allow the retainer cup to rotate against the wheel's surface when tightening the wheel to the balancer. DO NOT OVERTIGHTEN. Most balancers use a large "wing nut" design to clamp the retainer against the wheel. Hand tight is sufficient. This procedure will allow accurate balancing using the conventional back cone method. IMPORTANT: Coated balance weights must be used on aluminum wheels to prevent damage to the rim flange. Page 6287 Specifications Valve Clearance: Specifications All ......................................................................................................................................................... ................................................................ E-I-E-I-I-E Page 2233 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 Page 1403 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 Page 5140 Each user will be required to accept the following agreement each time the KeyCode application is used. Key Code User Agreement - Key codes are proprietary information belonging to General Motors Corporation and to the vehicle owner. - Unauthorized access to, or use of, key code information is unlawful and may subject the user to criminal and civil penalties. - This information should be treated as strictly confidential and should not be disclosed to anyone unless authorized. I will ensure that the following information is obtained prior to releasing any Key Code information: 1. Government issued picture ID (Drivers License) 2. Registration or other proof of ownership. Registration should have normal markings from the Province that issued the registration and possibly the receipt for payment recorded as well. Important - GM takes this agreement seriously. Each user must be certain of vehicle ownership before giving out key codes. - When the ownership of the vehicle is in doubt, dealership personnel should not provide the information. Key code requests should never be received via a fax or the internet and key codes should never be provided to anyone in this manner. A face to face contact with the owner of the vehicle is the expected manner that dealers will use to release a key code or as otherwise stipulated in this bulletin or other materials. - Key codes should NEVER be sent via a fax or the internet. - Each Dealership should create a permanent file to document all KeyCode Look Up transactions. Requests should be filed by VIN and in each folder retain copies of the following: - Government issued picture ID (Drivers License) - Registration or other proof of ownership. - Copy of the paid customer receipt which has the name of the employee who cut and sold the key to the customer. - Do not put yourself or your Dealership in the position of needing to "explain" a KeyCode Look Up to either GM or law enforcement officials. - Dealership Management has the ability to review all KeyCode Look-Up transactions. - Dealership KeyCode documentation must be retained for two years. Frequently Asked Questions (FAQs) for GM of Canada Dealers How do I request a KeyCode for customer owned vehicle that is not registered? Scrapped, salvaged or stored vehicles that do not have a current registration should still have the ownership verified by requesting the vehicle title, current insurance policy and / or current lien holder information from the customers financing source. If you cannot determine if the customer is the owner of the vehicle, do not provide the key code information. In these cases, a short description of the vehicle (scrapped, salvaged, etc.) and the dealership location should be kept on file. Any clarifying explanation should be entered into the comments field. How do I document a KeyCode request for a vehicle that is being repossessed? The repossessor must document ownership of the vehicle by providing a court ordered repossession order and lien-holder documents prior to providing key code information. Copies of the repossessors Drivers License and a business card should be retained by the dealership for documentation. What do I do if the registration information is locked in the vehicle? Every effort should be made to obtain complete information for each request. Each Dealership will have to decide on a case by case basis if enough information is available to verify the customer's ownership of the vehicle. Other forms of documentation include vehicle title, insurance policy, and or current lien information from the customers financing source. Dealership Management must be involved in any request without complete information. If you cannot determine if the customer is the owner of the vehicle, do not provide the key code information. Can I get a print out of the information on the screen? It is important to note that the Key Code Look Up Search Results contain sensitive and/or proprietary information. For this reason GM recommends against printing it. If the Search Results must be printed, store and/or dispose of the printed copy properly to minimize the risk of improper or illegal use. Who in the dealership has access to the KeyCode application? Dealership Parts Manager (or assigned management) will determine, and control, who is authorized to access the KeyCode Look Up application. However, we anticipate that dealership parts and service management will be the primary users of the application. The KeyCode Look Up application automatically tracks each user activity session. Information tracked by the system includes: User name, User ID, all other entered data and the date/time of access. Brakes - Light Brake Drag While Driving Brake Light Switch: All Technical Service Bulletins Brakes - Light Brake Drag While Driving Number: 89-262-5 Section: 5 Date: September 1989 Corporate Bulletin No.: 915002 Subject: LIGHT BRAKE DRAG - BRAKE SWITCH ADJUSTMENT Model and Year: 1980-89 A, B, F, G, J, L, X, Y 1980-89 ALL TRUCKS Figure 1 TO: ALL CHEVROLET DEALERS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 89-178-5, DATED JUNE 1989, IN ORDER THAT WE MAY CORRECTLY IDENTIFY THE SWITCH REQUIRING ADJUSTMENT. ALL COPIES OF 89-178-5 SHOULD BE DISCARDED. Some vehicles may experience a condition of light brake drag while driving. These conditions have been found to be more noticeable on vehicles which have an anti-lock brake system. This may be caused by improper brake switch adjustment. If the brake switch is not adjusted properly, the switch may push on the brake pedal and cause the brake to remain partially applied. If a vehicle exhibits any of the above conditions, perform the following functional brake switch adjustment check: Passenger Cars Only: The following steps should be used to check brake switch adjustment: 1. Remove the driver-side hush panel (refer to Figure 1). 2. Gently pull back on the brake pedal until no audible clicks are heard. The switch will be moved in the tubular retainer providing adjustment. 3. Replace the hush panel. 4. Verify that the brake drag condition is no longer present and that the cruise control and brake lights function properly. Page 5354 5. Remove paint and primer from the area surrounding the 10 mm (0.40 in) until bare metal is visible. Important The M6 conductive rivet stud as shown, can accommodate a panel thickness range of 0.7-4.2 mm (0.03-0.17 in). If there are layers of sheet metal, they should be touching without any air gaps to ensure a good ground. 6. Select a M6 conductive rivet stud. Refer to the Parts Information section of this bulletin. Note Use the GE-50317 rivet stud tool kit. 7. Place the M6 conductive rivet stud (1) in the 10 mm (0.40 in) hole. Assemble the rivet stud tool (2) with the groove and flare side facing the rivet stud, then the washer and the M6 nut (3). 8. Using a wrench on the rivet stud tool, and a socket on the M6 nut, secure the M6 conductive rivet stud. 9. Ensure the new rivet stud is securely fastened, WITHOUT ANY detectable movement. 10. Completely wrap the threads of the rivet stud with painters tape or equivalent. Page 5929 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 Brakes - Pulsations and Rotor Surface Refinish Technical Service Bulletin # 883125 Date: 880801 Brakes - Pulsations and Rotor Surface Refinish Number: 88-312-5 Section: 5 Date: AUGUST, 1988 Subject BRAKE PULSATIONS AND DISC BRAKE ROTOR SURFACE REFINISH Model and Year 1982-88 CHEVROLET MODELS TO: ALL CHEVROLET DEALERS On today's vehicles the primary reason for brake pulsation is variation in the thickness of the rotor, which generally occurs after some mileage. The causes of rotor thickness variation tend to occur while the vehicle is in motion and the brake pedal is in the unapplied position. Three events must occur simultaneously: 1. The rotor/bearing system runout must be out of specification enough to produce high spots on the rotor face in relation to the caliper. 2. There must be a condition of caliper drag which causes the inboard and/or outboard shoe to rub on the rotor high spots. 3. The lining material must be sufficiently abrasive to cause wear on the high spots and therefore to develop rotor thickness variation after accumulated mileage. Following is a discussion of each of these events along with information about the conditions which can contribute to each. System Runout Information SYSTEM RUNOUT: Excessive system runout can exist as a result of the stack up of the tolerances of a rotor and a bearing which has been manufactured at one end or the other of their respective design specifications, or if either the rotor or bearing are out of specification. The manufacturing process controls which determine the amount of rotor or bearing runout are continuously being improved to reduce the amount of system and/or component runout. During manufacturing of the brake rotor, tolerances of the braking surfaces for flatness, thickness variation and lateral runout are held very close. Maintaining these close tolerances on the rotor's braking surface is necessary to prevent brake roughness. A lateral runout check of the rotor must be performed to determine the extent of runout. Lateral Runout Check: 1. Remove the wheel and tire. Invert the wheel nuts and reinstall them on the studs to the specified torque. Be sure to follow the alternating nut torquing sequence to ensure proper rotor alignment. 2. Fasten a dial indicator to the caliper so the dial indictor button contacts the rotor about 13 mm (0.500 inch) from the outer edge. 3. Zero the dial indicator. 4. Move the rotor one complete revolution and observe total indicated runout (T.I.R.). Lateral runout cannot exceed 0.08 mm (0.003-inch). ^ On front wheel drive vehicles, excessive lateral runout of the rotor can often be improved by indexing the rotor on the hub one or two bolt positions from the original position. If the lateral runout CANNOT be corrected by indexing the rotor, check the hub and bearing assembly for looseness. NOTICE: Whenever the brake rotor has been separated from the wheel bearing flange, remove any rust or foreign material from the mating surfaces of the wheel bearing flange and rotor. Failure to do this may result in excessive lateral runout of the rotor, causing brake pedal pulsation. 5. If lateral runout exceeds that specified in Step 4, refinish the rotor to specifications, reinstall rotor, and remeasure lateral runout. Wheel Bolt Torque, Caliper and Lining Material Page 6710 For vehicles repaired under the terms of this special coverage, submit a claim with the information shown. Customer Reimbursement All customer requests for reimbursement for previous repairs for the special coverage condition will be handled by the Customer Assistance Center, not by dealers. Disclaimer Page 1539 Valve Spring: Specifications Free Length Outer Spring 2.03 in Damper Spring 1.86 in Out Of Square Limit 0.062 in Installed Height 1.687-1.750 in Page 3576 Page 3220 Knock Sensor: Description and Operation Knock Sensor Operation ESC Wiring Diagram The Electronic Spark Control (ESC) system is comprised of a knock sensor, the ESC module, and the ECM. As the knock sensor detects engine knock, it sends a voltage signal to the ECM. The ECM responds by retarding the ignition timing until the knocking ceases. As detonation is reduced, the ECM advances the timing again in small increments back to the pre-programmed point for that engine speed and load. Page 3039 Fuel Injector: Description and Operation Throttle Body Injection Unit Fuel Injector Parts The fuel injectors are solenoid activated, controlled by the ECM. The ECM turns on the solenoids, which lifts a normally closed ball off a seat. Fuel, under pressure, is injected in a conical spray pattern at the walls of the throttle body bore above the throttle valve. The fuel that is not used by the injectors passes through the pressure regulator before being returned to the fuel tank. Page 1666 Oil Filter: 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. Page 1295 FIGURE 2 Irregular/premature tire wear is aggravated by excessive toe-in (or toe-out). Excessive camber can also be a contributor, as can operating conditions, such as city driving with a lot of cornering. Irregular tire wear usually occurs on non-drive axles, such as the front wheel positions of rear drive vehicles. An early indication may be an increase in tire noise. In most cases, modified "X" tire rotation, which is a scheduled maintenance at 7500 miles, will equalize tire wear (See Figure No. 1). Some amount of wear is expected and should be considered normal. To determine if questionable tires meet the replacement criteria, follow the particular service procedure outlined for that brand tire. Whenever tires are replaced due to vehicle caused premature wear, alignment should be checked and reset to specification if necessary. FIRESTONE AND GOODYEAR IF WITHIN THE NEW VEHICLE WARRANTY PERIOD (12/12): A. Outer shoulder wear has progressed to the point that the outer shoulder is smooth (no tread visible), replace both front tires. B. The outer shoulder tread is visible, use a tread depth gauge (such as provided with Truck Service Bulletin 86-B-94) to determine the extent of the wear. Measurements must be made in a full depth tread groove shown in Figure No. 2. If tread depth is 5/32" or less, tire replacement will be necessary. It should be noted that at 5/32" tread depth the tire is normally only half worn in this area. If greater than 5/32", the tires should be rotated using the modified "X" pattern (See Figure No. 1). This method will best equalize wear after a few thousand miles. Page 444 Throttle Position Sensor: Description and Operation Typical Throttle Position Sensor (TPS) Wiring The Throttle Position Sensor (TPS), is mounted on the side of the throttle body opposite the throttle lever assembly. Its function is to sense the current throttle valve position and relay that information to the ECM. Throttle position information allows the ECM to generate the required injector control signals (base pulse). If the TPS senses a wide open throttle, a voltage signal indicating this condition is sent to the ECM. The ECM then increases the injector pulse width, permitting increased fuel flow. As the throttle valve rotates in response to movement of the accelerator pedal, the throttle shaft transfers this rotation to the TPS. A potentiometer (variable resistor) within the TPS assembly changes its resistance (and voltage drop) in proportion to throttle movement. By applying a reference voltage (5.0 volts) to the TPS input, a varying voltage (reflecting throttle position) is available at the TPS output. For example, approximately 2.5 volts results from a 50% throttle valve opening (depending on TPS calibration). The voltage output from the TPS assembly is routed to the ECM for use in determining throttle position. Locations Throttle Position Sensor: Locations Center Of Dash Panel (engine Compartment) Center Rear Of Engine Applicable to: V6-262/4.3L Engine Page 6131 Removing The Clutch Coil Assembly ^ Install J 8433-1 with J 33025. ^ Tighten J 8433-1 forcing screw against J 33025-A. Inspect ^ Clutch coil assembly (6). Replace as necessary. Install or Connect Tools Required: J 8433-1 Puller Bar J 33024 Clutch Coil Installer Adapter. J 33026 Compressor Holding Fixture 1. Compressor assembly on J 33026. 2. Clutch coil assembly (6) onto the front head (11) with the terminals positioned at the "marked" location. ^ J 33024 over the internal opening of the clutch coil assembly (6). ^ J 8433-1 with through oils, washers and forcing screw over J 33024. Page 7389 When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 5mm (3/16") of insulation from wire. e. Crimp a new terminal to the wire. f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. Figure 17 To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Figure 18 Figure 19 Page 5180 Figure 4 Figure 5 Figure 6 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 7 Page 3140 Throttle Position Sensor: Adjustments The TPS is not adjustable. The ECM utilizes the IAC position reading at idle for its zero reading, therefore no adjustment is necessary. Page 2787 Wiring Diagram For Chart C-1A - Park/Neutral Switch Diagnosis CHART C-1A - PARK/NEUTRAL SWITCH DIAGNOSIS Circuit Description: The Park/Neutral Switch contacts are closed to ground in park or neutral and open in drive ranges. The ECM supplies ignition voltage, through a current limiting resistor, to CKT 434 and senses a closed switch, when the voltage on CKT 434 drops to less than one volt. The ECM uses the P/N signal as one of the inputs to control: Idle Air Control VSS Diagnostics EGR Test Description: Numbers below refer to circled numbers on the diagnostic chart. 1. Checks for a closed switch to ground in park position. Different makes of "Scan" tools will read P/N differently. Refer to operators manual for type of display used for a specific tool. 2. Checks for an open switch in drive or reverse range. 3. Be sure "Scan" indicates drive, even while wiggling shifter to test for an intermittent or misadjusted switch in drive range. Diagnostic Aids: If CKT 434 indicates PIN (grounded), while in drive range, the EGR would be inoperative, resulting in possible detonation. If CKT 434 always indicates drive (open), a drop in the idle may exist when the gear selector is moved into drive range. Page 154 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 Locations Combination Switch: Locations LH Side Of Steering Column Behind Instrument Cluster Page 1764 - 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 Page 8181 Wiper Blade: Technical Service Bulletins Wiper Blades - Chattering on Windshield Number: 91-126-8E Section: 8E Date: November 1990 Corporate Bulletin No.: 031066 Subject: CHATTERING WIPER BLADES OR BLADE WIPEABILITY Model and Year: ALL PASSENGER CARS AND TRUCKS TO: ALL CHEVROLET DEALERS Condition: Chattering and poor wipeability comments may be due to the windshield glass and/or wiper blades becoming contaminated by insect residue, dirt, road grime, carwax etc. Correction: 1. Clean the windshield glass with GM # 1050011 (Bon Ami) glass cleaner or equivalent. Important: The glass is clean when rinse water does not "bead-up," but "sheets" across the entire glass surface. Multiple cleanings may be required to remove all contaminants. 2. Clean the wiper blades by using a cloth that has been saturated with full strength washer solution and wipe vigorously. Rinse the blades with water after cleaning. Page 6028 sure the retainer cup is tree from dirt, grease, and gouges. Most wheel balancers now offer this type of protected retainer. DO NOT allow the retainer cup to rotate against the wheel's surface when tightening the wheel to the balancer. DO NOT OVERTIGHTEN. Most balancers use a large "wing nut" design to clamp the retainer against the wheel. Hand tight is sufficient. This procedure will allow accurate balancing using the conventional back cone method. Important: Coated balance weights must be used on aluminum wheels to prevent damage to the rim flange. Except for the N9O 4X4 wheel used on T trucks, all light truck aluminum wheels will accept either "AW" series or "MO" series clip-on coated weights on both the inside and outside rim flanges. The N9O T truck wheel will accept "AW" series weights on the inside rim flange only. The outside rim flange is not designed to accept a clip-on weight. If such a weight installation is attempted, a poor fit will result, and the weight may fall off and/or cause cosmetic damage to the rim flange. This wheel can be 1) static balanced by clipping all the weight on the inside rim flange (as is done in the assembly plant), or 2) dynamic balanced by clipping a weight on the inside flange and using an adhesive weight near the outside flange. The charts show "AW" and "MC" balance weight usage. These original equipment coated weights are available at competitive prices through the GM Dealer Equipment program. Page 7513 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 4. Make repair. Page 3612 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. Page 2378 Throttle Position Sensor: Description and Operation Typical Throttle Position Sensor (TPS) Wiring The Throttle Position Sensor (TPS), is mounted on the side of the throttle body opposite the throttle lever assembly. Its function is to sense the current throttle valve position and relay that information to the ECM. Throttle position information allows the ECM to generate the required injector control signals (base pulse). If the TPS senses a wide open throttle, a voltage signal indicating this condition is sent to the ECM. The ECM then increases the injector pulse width, permitting increased fuel flow. As the throttle valve rotates in response to movement of the accelerator pedal, the throttle shaft transfers this rotation to the TPS. A potentiometer (variable resistor) within the TPS assembly changes its resistance (and voltage drop) in proportion to throttle movement. By applying a reference voltage (5.0 volts) to the TPS input, a varying voltage (reflecting throttle position) is available at the TPS output. For example, approximately 2.5 volts results from a 50% throttle valve opening (depending on TPS calibration). The voltage output from the TPS assembly is routed to the ECM for use in determining throttle position. Fuel - Injector Wires Trapped Under Air Cleaner Fuel Injector: All Technical Service Bulletins Fuel - Injector Wires Trapped Under Air Cleaner Number: 93-86A-6C Section: 6C Date: MAY 1993 Corporate Bulletin No.: 266402R ASE No.: A1, A8 Subject: FUEL INJECTOR WIRES MAY BECOME TRAPPED WHEN REINSTALLING THE AIR CLEANER (TWIST WIRES ONCE) Model and Year: 1988-93 LIGHT DUTY TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 93-8-6C, DATED JAN. 1993. CALL LIGHT DUTY TRUCKS HAVE BEEN ADDED AS WELL AS THE REFERENCED ARTWORK REVISED. CONDITION: When an air cleaner is removed on 1988-93 Light duty trucks, the potential for trapping the injector wires between the air cleaner and the throttle body or between the extension ring and throttle body is present during reinstallation (Figure 1). CORRECTION: Page 7897 e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors Do Not require all the steps shown. Skip the steps that Do Not apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. 1. Separate connector halves (see Figures 2 through 6). Figure 2 Figure 3 Page 5713 Steering Gear: Service and Repair Nippon Seiko Recirculating Ball Gear Fig. 4 Checking Steering Gear Oil Level Ensure that oil level is up to level A, Fig. 4. If level is low, add GM Manual Steering Gear Lube 1052182 or equivalent. Ignition System - Diagnosis Precautions Spark Plug Wire: All Technical Service Bulletins Ignition System - Diagnosis Precautions Number: 88-138-6D Section: 6D Date: Feb., 1988 Subject: ENGINE MISS, HESITATION, OR ROUGHNESS DUE TO PIERCED SECONDARY IGNITION COMPONENTS Model and Year: ALL MODELS WITH GASOLINE ENGINE TO: ALL CHEVROLET DEALERS During the diagnosis procedures for an engine miss, hesitation, or roughness condition, a spark plug or spark plug wire condition may be suspected. Several types of commercial or homemade diagnostic equipment require the secondary ignition boots or wire to be pierced. This is normally done to check for spark plug firing or to perform a cylinder balance test. Similarly, the use of pliers or other such tools to disengage a spark plug boot may pierce or damage the boot or wire. NOTICE: SECONDARY IGNITION COMPONENTS SHOULD NOT BE PIERCED FOR ANY REASON. Piercing a spark plug wire and/or distributor or direct fire module nipple may create a failure condition that will not be immediately apparent. Over time, the hole in the pierced boot may allow a ground path to develop, creating a plug misfire condition. Heavily moisture-laden air in the vicinity of the pierced boot may accelerate this effect. Piercing a secondary ignition wire creates a gap in the wire's conductive core. This gap is a point of high resistance. The current flow in the wire will increase to compensate for the higher wire resistance. Over time, the wire may fail, creating a plug misfire condition. The time required for the condition to appear depends upon the extent of damage to the conductive core. To help prevent future customer comments that are spark plug wire related, do not pierce or otherwise damage any secondary ignition component. Only use diagnostic equipment containing an inductive pick-up to check for spark plug firing or to perform cylinder balance tests. When disengaging a spark plug boot from the spark plug, twist the flanged boot 1/2 turn, then pull only on the boot to remove the wire. Page 3442 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. Page 4301 Figure 6 - Disconnecting Lower Shock Mount 10. Remove the lower shock mounting nut and bolt (Figure 6). 11. Collapse the shock absorber. 12. Move the shock absorber up, away, and secure. 13. Depending on the type of hoist, it may be required to position floor stand between the spring seats and the lower control arm ball joint for miximum leverage. The weight of the vehicle is used to relieve the spring tension on the upper control arm. Caution: The floor jack or stand must remain under the control arm spring seat while servicing the halfshaft to maintain spring and control arm position. Failure to do so could result in personal injury. 14. Disconnect the cotter pin. 15. Remove the stud nut from the upper ball joint. Figure 7 - Ball Joint from Knuckle Separation 16. Loosen the stud using J34026 and move away from the knuckle (Figure 7). A/T - Paint Flakes In Fluid Fluid - A/T: Customer Interest A/T - Paint Flakes In Fluid Number: 88-400-7A Section: 7A Date: APRIL, 1989 Subject: EVIDENCE OF PAINT FLAKES IN TRANSMISSION FLUID Model and Year: 1988 PASSENGER CARS WITH AUTOMATIC TRANSAXLES TO: ALL CHEVROLET DEALERS Black paint flakes may be found in the transaxle fluid, bottom pan, fluid level indicator and filter assembly as the result of paint peeling from inside the transaxle fill tube. After the paint peels the unprotected areas of the fill tubes can corrode (interior and exterior), leaving corrosion on the fluid level indicator and the fill tube. The fill tube paints used on the interior and exterior of the tube may not withstand temperatures over 260 degrees Fahrenheit. Transaxle durability should not be affected in vehicles equipped with these fill tubes, but paint flakes can cause filter clogging over a period of time. DATE OF PRODUCTION CHANGE: The suspect fill tubes may be found in vehicles produced between October 17, 1987 (Julian Date 289) through June 30, 1988 (Julian Date 184). SERVICE ACTION: If vehicles are found with flaking paint fill tubes they should be changed along with Transaxle Fluid, Filter and Fluid Level Indicator. Labor Operation Number: T5181 Labor Time: .9 SERVICE MANUAL REFERENCE: Refer to the On-Car Section of your Service Manual whenever service of the Fluid Level Indicator and Fill Tube is necessary. Page 7905 Light Switch Details (Part 1 Of 3) Fuels - Effect of Volatility on Driveability Fuel: Customer Interest Fuels - Effect of Volatility on Driveability Number: 93-31-6C Section: 6C Date: OCT. 1992 Corporate Bulletin No.: 249128R ASE No.: A1, A8 Subject: EFFECT OF FUEL VOLATILITY ON DRIVEABILITY CONDITIONS Model and Year: ALL MODEL YEARS, ALL PASSENGER CARS AND TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 92-281-6C, DATED SEPT. 1992. THE 1993 MODEL YEAR HAS BEEN ADDED. ALL COPIES OF 92-281-6C SHOULD BE DISCARDED. Recent changes in EPA regulations have effectively lowered the maximum allowable fuel volatility. Volatility, which can be defined as a gasoline's ability to change from a liquid to a vapor, directly affects the amount of evaporative emissions produced by the fuel. Higher volatility means that more unburned hydrocarbons will be released into the atmosphere. Unfortunately, reducing fuel volatility can cause problems during cold engine operation when low temperatures impede the fuel's ability to vaporize and burn. Two terms are often used to describe volatility characteristics. These are: Distillation Curve A graph showing the relationship between temperature and the percentage of fuel evaporated. The fuel components that boil at relatively low temperatures (below about 90 degrees F) are known as the "light ends", and are essential for good cold engine performance. The "heavy ends", which begin to boil at about 300 degrees F, contain the most energy but are more difficult to burn. Laboratory analysis is usually required to determine the distillation curve of a gasoline sample. - Reid Vapor Pressure (RVP) RVP is the pressure (psi) that vaporized fuel exerts within a sealed container as it is heated to 100 degrees F. The higher the RVP the higher the fuel volatility. While RVP is readily tested in the field, fuels of the same RVP can have different distillation curves and cold driveability characteristics. Fuel volatility will vary depending on geographic location and time of year (fuel intended to be used in higher ambient conditions is formulated with less volatility). This can make cold driveability as big a problem during summer months as during the winter. There may be additional variation in the volatility characteristics of pump gasoline, caused by the differences in fuel manufacturers, blends and storage times. As EPA fuel volatility standards are lowered, variations between fuels (which may further reduce volatility) becomes a critical factor influencing cold engine performance. No matter how thoroughly the relationship between fuel quality and cold driveability is understood, eliminating fuel quality as an issue can be difficult, because: TOOLS WHICH TEST FUEL VOLATILITY MEASURE ONLY RVP, NOT THE DISTILLATION CURVE. The distillation curve has a greater effect on cold driveability than RVP. THE CUSTOMER MAY PERCEIVE RAISING THE FUEL QUALITY ISSUE AS AN ATTEMPT TO EVADE HIS PROBLEM. This may cause difficulty in getting accurate fuel usage information. WATER, AND OTHER TYPES OF FUEL CONTAMINATION, MAY CAUSE CONTINUED DRIVEABILITY COMPLAINTS. - The problem symptoms may remain even though the vehicle has been refueled several times with a quality gasoline. CUSTOMER CONCERNS CONDITION: Poor Cold Engine Operation, symptoms may include; hard start/extended crank, stalling, backfiring, hesitation and/or lack of power. POSSIBLE CAUSE: Low volatility fuel will not vaporize sufficiently to allow normal combustion. CORRECTION: Replace Fuel. DIAGNOSTIC PROCEDURE: 1. Perform basic system checks in section 6E of the service manual. 2. Check for service bulletins which relate to cold driveability issues specific to the problem vehicle. Page 5395 6. Tape the solder and diode. 7. Reinstall the black plastic conduit. 8. Reconnect connector to the generator. 9. Reconnect battery. This procedure will not affect the operation of the generator light during the bulb check at the beginning of the start cycle. For vehicles repaired under warranty use, Labor Operation Number: T7990 Labor Time: .4 Hr Locations Side Marker Lamp: Locations LH Side Of Engine Compartment LH Front Corner Of Engine Compartment 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. Tires - Rotation and Warranty Coverage Tires: All Technical Service Bulletins Tires - Rotation and Warranty Coverage Number: 88-116-3E Section: 3E Date: Jan., 1988 Subject: CHEVROLET'S RESPONSIBILITIES CONCERNING TIRE WARRANTIES, INCLUDING IRREGULAR/ PREMATURE WEAR Model and Year: ALL MODELS TO: ALL CHEVROLET DEALERS As in the past, tires continue to be warranted by the tire manufacturer against defects in material or workmanship. Details of this limited warranty may be found in each tire company warranty booklet, which is part of the glove box material. The GM warranty and owner assistance booklet also now states that the GM dealer will assist the customer in obtaining a tire adjustment, if necessary. Tire conditions caused by vehicle defects are warranted by General Motors. This statement is now included in the GM warranty and owner assistance booklet. This applies during the basic warranty coverage period, which is 12 months/12,000 miles, and should be applied to all past and current models. Examples of tire conditions that fall within GM's responsibility may include tire damage during vehicle assembly, tire damage due to tire-to-vehicle interference, and irregular/premature tire wear. Tire wear due to abusive driving is not covered by warranty. FIGURE 1 Page 7813 Symbol Identification 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). Page 1699 Oil Pressure Switch (For Fuel Pump): Service and Repair REMOVAL: 1. Disconnect negative battery cable from battery. 2. Remove sensor or switch connectors. 3. Remove sensor or switch. INSTALLATION: 1. Install sensor or switch. 2. Connect sensor or switch. 3. Reconnect negative battery cable. Page 6718 For vehicles repaired under the terms of this special coverage, submit a claim with the information shown. Customer Reimbursement All customer requests for reimbursement for previous repairs for the special coverage condition will be handled by the Customer Assistance Center, not by dealers. Disclaimer Windshield/A Pillar - Pop Noise Diagnosis Dashboard / Instrument Panel: All Technical Service Bulletins Windshield/A Pillar - Pop Noise Diagnosis Number: 93-25-10 Section: 10 Date: OCT. 1992 Corporate Bulletin No.: 262001 ASE No.: B1 Subject: POP NOISE FROM WINDSHIELD PILLAR AREA Model and Year: 1983-93 S/T TRUCKS REFERENCE COWL "POP" TAPPING NOISE CHEVROLET DEALER SERVICE BULLETIN NUMBER 91-351-10, DATED JUNE 1991. Owners of some 1983-1993 S/T Pickups and Utilities may comment on a cowl "pop" noise transmitted through the "A" pillar. It has been determined that sections other than the windshield cowl area may produce a sound which imitates cowl "pop". PRIOR TO PERFORMING ANY CORRECTION FOR COWL "POP" TAPPING NOISES, VERIFY THE SOURCE OF THE NOISE(S) TO DETERMINE IF IT IS A VALID COWL "POP" CONDITION. Possible noise areas to check are: ^ Instrument panel "pop"/noise. ^ Loose door lock rods. ^ Loose wires/harnesses contacting the wall of the engine/passenger compartment (cowl). ^ A lack of door hinge lubrication. ^ An Electronic Control Module (ECM) bracket "pop". ^ An ash tray rattle. ^ An air vent squeak. ^ Hood hinge "flutter"/rattle. INFORMATION: 1. INSTRUMENT PANEL (I/P) "POP"/NOISE sound at the front edge of the I/P may occur if the I/P pad rubs against the cowl/dash support panel. Refer to "Instrument Panel Pad to Cowl Panel "Pop" Noise" Chevrolet Dealer Service Bulletin Number 92-286-10, dated Sept. 1992. 2. LOOSE DOOR LOCK RODS may vibrate during vehicle operation creating a rattle type noise. Refer to "Front Door Lock Rod Rattle" Chevrolet Dealer Service Bulletin No. 91-406-10, dated August 1991. 3. THE ELECTRONIC CONTROL MODULE (ECM) WIRING HARNESS CLIP may not be properly attached at the transmission bellhousing bolt allowing contact with the floor pan/front of dash area. This sound may be amplified by the HVAC ductwork. 4. LOOSE WIRES/HARNESSES maybe tapping against the engine/passenger compartment wall (cowl). 5. LACK OF DOOR HINGE LUBRICATION - Insufficient lubrication may create a binding/squeaking condition. 6. AN ECM BRACKET "POP" sound may occur if the ECM moves within its mounting bracket. 7. AN ASH TRAY BRACKET RATTLE coming from the ash tray or radio area of the instrument panel may occur if the bracket is loose and vibrating against the I/P. 8. AN AIR VENT "POP" may occur if the louvered vent and A/C duct rub together. 9. HOOD "FLUTTER"/RATTLE may occur if there is movement in the hood hinge attachment to the truck frame. Sound may accompany the hood Hydro-Boost Hydraulic Brake Booster: Description and Operation Hydro-Boost Fig. 1 Cross-sectional View Of Bendix Hydro-Boost Unit The Hydro-Boost system, Fig. 1, provides an additional cylinder in the brake system. This cylinder contains no brake fluid. The Hydro-Boost cylinder is hydraulically operated, by pressurized fluid from the power steering pump, providing power assist to operate a dual master cylinder brake system. The booster is composed of two sections; the linkage section and the power section. The booster is designed so that if a total absence of power assist occurs, the brakes can be applied manually, but somewhat greater pressure on the brake pedal is required. ECM - Intermittent Connection Engine Control Module: Customer Interest ECM - Intermittent Connection Number: 88-251-8A Section: 8A Date: JUNE, 1988 Subject: INTERMITTENT CONNECTION TO THE ECM Model and Year: 1988 CHEVROLET PASSENGER CARS AND LIGHT DUTY TRUCKS TO: ALL CHEVROLET DEALERS A condition may exist in which the female terminals in the connector to the ECM do not make a solid connection to the male pins in the ECM (see illustration). This can result in an intermittent condition, in any circuit operated by the ECM. The Service Manuals direct a check of connections any time an intermittent condition is found, and this may be the cause of some of these conditions. Visually inspect the terminal using a flashlight, or use a .95 mm pin gauge. The gauge should not pass freely through the female terminal. Do not probe the terminal with anything other than the pin gauge, as probing could damage the terminal. If the female terminal does not grip properly, replace the terminal with P/N 12020757. General directions on wiring repair are shown in Section 8A of the service Manual. Interior - Noise From Windshield Pillar Area Windshield: All Technical Service Bulletins Interior - Noise From Windshield Pillar Area BULLETIN NUMBER: 92-10-130 SECTION: 10 NUMBER: 1 CORPORATE REFERENCE NUMBER: 261610 DATE: September 1992 SUBJECT: NOISE FROM WINDSHIELD PILLAR AREA (DIAGNOSE/INSTALL FELT TAPE) MODELS: 1986-92 S1/T1 UTILITY TRUCKS Some 1986-92 S/T utility trucks may exhibit a plastic to metal or plastic to plastic "itch" noise from the left or right windshield pillar area. This noise may be caused by the instrument panel pad rubbing against the cowl or dash support panel. An adhesive backed felt tape has been released to insulate the dash pad outer corners from the dash support panel. This tape may also be used on the non-visible surfaces of other trim panels as necessary to eliminate itch noises. The felt tape, P/N 12541499, is released in a 10 ft. x 30 mm x 1 mm mil to provide the technician sufficient material to insulate numerous trim panels. SERVICE PROCEDURE Prior to installing the felt tape, it should be determined IP pad to dash support panel is the area that is generating the noise. Refer to the Squeak and Rattle Diagnosis and Correction Manual to identify other possible sources such as ECM Mounting Bracket or Air Vent. If it is determined the IP pad is the source of the noise: 1. Remove the instrument panel radio speaker(s) to obtain better access to the metal ledge on which the instrument panel pad rests. 2. Remove the 4 IP upper retaining screws located in the defroster duct openings and pull the pad back slightly. NOTICE: Do not remove the dash pad any further than necessary to perform the repair. The possibility exists that additional noises may be generated due to the wiring and HVAC ducts being mispositioned upon reinstallation. 3. Cut a strip of felt tape 6 inches long, remove the protective backing and apply the tape to the top of the metal ledges in fmnt of the speaker openings where the instrument panel pad rests. NOTICE: Installation is easier if 2 screw drivers are wedged between instrument panel pad and the cowl panel to raise the IP pad. 4. Push the IP pad forward and reinstall the retaining screws and speakers. SERVICE PARTS INFORMATION Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty, see chart. Page 2571 Engine Control Module: Locations Figure 1 Located under the passenger side hush panel, under the dash. Page 7928 When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 5mm (3/16") of insulation from wire. e. Crimp a new terminal to the wire. f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. Figure 17 To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Figure 18 Figure 19 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. Page 4946 Wheel Cylinder: Service and Repair Installation For additional information see Notes, Warnings, and Hints. See: Fundamentals and Basics 1. Wipe end of hydraulic line to remove any foreign matter, then place wheel cylinder in position. Enter tubing into cylinder and start threads on fitting. 2. Install wheel cylinder bolts and tighten to backing plate. 3. Tighten brake line. 4. Install brake shoes. 5. Install brake drum. 6. Install wheel and tire assembly. 7. Bleed the brake system. 8. Adjust parking brake. Page 7924 e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors Do Not require all the steps shown. Skip the steps that Do Not apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. 1. Separate connector halves (see Figures 2 through 6). Figure 2 Figure 3 Page 4246 11. Hold flange with suitable tool and remove pinion shaft nut and flange. 12. Lubricate pinion shaft oil seal and cover outer edge of seal body with non-hardening sealing compound, then press seal against cover shoulder with suitable tool. 13. Install new gasket and bearing cover. 14. Press flange against forward bearing and install washer and pinion shaft nut, torquing nut to 240 ft. lbs. Capacity Specifications Refrigerant Oil: Capacity Specifications With A-6 Compressor Compressor Oil .................................................................................................................................... ..................................................... 0.284 Kg (10 oz.) With DA-6 Compressor Compressor Oil .................................................................................................................................... ....................................................... 0.227 Kg (8 oz.) With R-4 Compressor Compressor Oil .................................................................................................................................... ...................................................... 0.312 kg (11 oz.) With DA-V5 Compressor Oil Capacity ......................................................................................................................................... ............................................................. 0.226 (8 oz.) With HR-6 Compressor Oil Capacity ......................................................................................................................................... ............................................................. 0.226 (8 oz.) Refrigerant Oil Capacity With DA-6 Compressor ........................................................................................................................ ........................................................................... 8 oz With R-4 Compressor .......................................................................................................................... ............................................................................ 6 oz 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 Page 6642 Symbol Identification Interior - Itch Noise From Windshield Pillar Area Dashboard / Instrument Panel: All Technical Service Bulletins Interior - Itch Noise From Windshield Pillar Area Number: 92-286-10 Section: 10 Date: SEPT. 1992 Corporate Bulletin No.: 261610 ASE No.: B1 Subject: ITCH NOISE FROM WINDSHIELD PILLAR AREA Model and Year: 1986-92 S/T TRUCKS Some 1986-1992 S/T utility trucks may exhibit a plastic to metal or plastic to plastic "itch" noise from the left or right windshield pillar area. This noise may be caused by the instrument panel pad rubbing against the cowl or dash support panel. An adhesive backed felt tape has been released to insulate the dash pad outer corners from the dash support panel. This tape may also be used on the non-visible surfaces of other trim panels as necessary to eliminate itch noises. The felt tape, P/N 12541499, is released in a 10 ft. x 30 mm x 1 mm roll to provide the technician sufficient material to insulate numerous trim panels. SERVICE PROCEDURE: Prior to installing the felt tape, it should be determined if the IP pad to dash support panel is the area that is generating the noise. Refer to the Squeak and Rattle Diagnosis and Correction Manual to identify other possible sources such as ECM Mounting Bracket or Air Vent. If it is determined the IP pad is the source of the noise: 1. Remove the instrument panel radio speaker(s) to obtain better access to the metal ledge on which the instrument panel pad rests. 2. Remove the 4 IP upper retaining screws located in the defroster duct openings and pull the pad back slightly. NOTICE: Do not remove the dash pad any further than necessary to perform the repair. The possibility exists that additional noises may be generated due to the wiring and HVAC ducts being mispositioned upon reinstallation. 3. Cut a strip of felt tape 6 inches long, remove the protective backing and apply the tape to the top of the metal ledges in front of the speaker openings where the instrument panel pad rests. NOTICE: Installation is easier if 2 screwdrivers are wedged between instrument panel pad and the cowl panel to raise the IP pad. 4. Push the IP pad forward and reinstall the retaining screws and speakers. 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. Page 4098 Valve Body 4. Remove two bolts that attach auxiliary accumulator valve tube to control valve assembly and accumulator valve body assembly. 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. Page 7226 Figure No. 6 WINDOW LATCH This third form of vibration can occur in the window latch region. This rattle noise is caused by the vibrations mentioned above and occurs as the window guide vibrates in the guide bushing (see Figure 6). The following four procedures can be done in any order as a single or as a multiple repair. Service Procedure 1 Page 5511 When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit J 38125-4 instruction manual 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 or replace...". Mating terminals must be inspected to assure good terminal 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 to 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, see Figure 1, 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 38125-4 instruction manual. 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 connection 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 38125-2, 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 38125-2, 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 38125-2. Page 7152 Time Allowance: See Chants NOTE: The time allowances provided on the chart include the hardware removal and installation (as indicated by the list guidelines), the masking and unmasking of the vehicle, stripping of the surface (as indicated by the guidelines), the refinish (and colorcoat when required), mix time for primer/ paint (and clearcoat when required), finesse/polish where required, washing and preparing the vehicle for delivery. OPERATION DESCRIPTION: PAINT COLORCOAT DELAMINATION FROM ELPO PRIMER, REFINISH ENTIRE BODY ABOVE BODY SIDE MOLDINGS. PAINT TERM DEFINITIONS Following are definitions of paint repair terms used in this bulletin: Basecoat: A color topcoat that requires a clear topcoat over it. Break line: A natural dividing line on Page 7483 10. Drive the door frame (the second layer of sheet metal) down with a punch approximately 1/4" all the way around the hole. 11. Paint the bare metal edges left from cutting the hole with a zinc rich primer. 12. Completely fill the hole with black RTV, GM P/N 1052917, or equivalent and level for good adhesion and appearance. 13. Follow Steps 6-12 on each side of the vehicle. 14. Reinstall the hood hinge seals in their original position to prevent water leakage into the cowl. If it is necessary, additional adhesive (3M weather strip adhesive P/N 08001 or equivalent) should be used to secure the hood hinge seal. 15. Reinstall the windshield washer hose, cowl vent panel, radio antenna, and windshield wipers, and remove the protective tape from the fender and cowl vent panel. Testing and Inspection Brake Hose/Line: Testing and Inspection Remove one of the front wheels and inspect the brake disc, caliper and linings. Do not get any oil or grease on the linings. It is recommended that all linings be replaced in sets when worn or damaged. If the caliper is cracked or fluid leakage through the casting is evident, it must be replaced as a unit. 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. Page 3619 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: M/T - Shift Lever Vibration/Rattle In Third Gear Shifter M/T: All Technical Service Bulletins M/T - Shift Lever Vibration/Rattle In Third Gear Number: 89-169-7B Section: 7B Date: May, 1989 Subject: THIRD GEAR SHIFT LEVER VIBRATION/RATTLE Model and Year: 1986-89 S/T TRUCKS W/BORG WARNER FIVE SPEED MAN TRANSMISSION Figure 1 - Identification Tag Explanation Chart TO: ALL CHEVROLET DEALERS Some 1986-89 S/T Trucks may experience a shift lever vibration while the vehicle is in third gear. This condition may also be described as a rattle. The vibration may be most prominent on a coast down (deceleration) while in third gear. Production Change A new design shift lever was put Into production during the 1989 model year. Vehicles which have the new design lever can be identified by the serial number on the transmission identification tag. An example of the tag and its location on the transmission is shown in Figure 1. Vehicles with transmission serial numbers equal to or higher than those given below have the new design lever. Vehicle Serial Number Breakpoint T Series 21564 Locations Power Window Relay: Locations Behind Instrument Cluster Page 6801 1. With the end gate open, use a grease pencil to mark around the circumference of each washer (Figure 1, "7") located behind the strikers. 2. Unscrew and remove the existing striker assemblies (Figure 1, "6") from the vehicle. 3. Loosely assemble the new striker (Figure 1, "6") (P/N 15700881) and washer (Figure 1, "7") and reinstall using the pencil marks as a guide. 4. Install the striker assemblies (Figure 1, "6") using a T50 Torx(R). Torque to 63 N-m. (47 lbs.ft.). 5. Check for proper operation and end gate flushness. Adjust the striker assemblies if required. The end gate lock strikers can be adjusted up or down, fore or aft, to obtain proper closure of the end gate. The end gate should seal completely with minimum closing effort. Torque the striker bolts to 63 N-m. (47 lbs.ft.). SERVICE PARTS INFORMATION PART NUMBER DESCRIPTION QTY/VEH 15700881 Striker Asm. 2 Page 7755 SERVICE PARTS INFORMATION Part Number Application Description 15636850 1988-1991 Plate kit I/P (no switches). (Gray) Switch trim plate (gray) bracket, covers for switch trim plate holes (quantity 2), and 4 bolts/screws. 15636853 1986-1987 Plate kit I/P (no switches). (Black) Switch trim plate (black), bracket, covers for switch trim plate holes (quantity 2), and 4 bolts/screws. Important: Torque 11508898 bolts/screws supplied in kit to 0.4-0.7 N-m. (4-6 lbs.in.). Parts are expected to be available on January 21, 1991. Until then, normal part orders will not be accepted by GMSPO. Only verifiable emergency VIP orders will be accepted. GMSPO will make every effort to obtain parts. All parts will be placed on 400 control to waive VIP surcharges. However, the parts will be shipped premium transportation at dealer's expense. All other order types will be canceled as incorrectly ordered while 400 control is in place. WARRANTY INFORMATION For vehicle repaired under warranty use: Labor Operation: T7101 Labor Time: .3 hr. Trouble Code: 92 NOTE: Labor Operation is coded to base vehicle coverage in the warranty system. Page 6822 When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 5mm (3/16") of insulation from wire. e. Crimp a new terminal to the wire. f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. Figure 17 To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Figure 18 Figure 19 Page 7953 LIGHT BLUE LT BLU BROWN BRN GRAY GRY GREEN GRN DARK GREEN DK GRN LIGHT GREEN LT GRN ORANGE ORN PINK PNK PURPLE PPL RED RED TAN TAN WHITE WHT YELLOW YEL 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. Page 816 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. Troubleshooting Power Steering Pump: Testing and Inspection Troubleshooting Fig. 1 Troubleshooting power steering system 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. Page 4258 Pinion Gear: Adjustments Corporate and Eaton 7 1/2 - 8 7/8 Inch Ring Gear Fig. 16 Pinion depth gauge tool installation. Models w/7-1/2 inch ring gear Fig. 17 Pinion depth gauge tool installation. Models w/8-1/2 & 8-7/8 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. Use gauge assembly J-23597-01 for models with 7-1/2 inch ring gear, J-21777-01 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. Page 302 Backup Lamp Switch: Locations LH Side Of Manual Transmission LH Side Of Transmission Page 900 FIGURE 2 FIGURE 3 ^ THM 125C, 440-T4 (Refer to Figures 2 and 3): When cold, 27 Degrees C (80 Degrees F), a full transaxle will show the fluid level to be above the "Full Hot" mark. This is a result of fluid stored in the bottom pan when cold. As the transaxle warms to normal operating temperature, fluid is captured in the side pan, lowering the fluid level to within the cross-hatched area. NOTICE: The "cold" check procedure cannot take the place of a "hot check. The "cold" check will let the technician know there is enough fluid to perform a Preliminary check Procedure, an accurate road test, and allow normal operating temperature to be obtained prior to the necessary "hot" check. B. "HOT" CHECK PROCEDURE: 1. Drive vehicle in all ranges to attain a fluid temperature of 80 to 90 Degrees C (180 to 200 Degrees F). 2. Idle at normal idle speed in Park for 3 minutes. 3. With vehicle level, accessories turned off, and engine idling in Park, check fluid level. 4. Fluid level should be within the cross-hatched area. (Read front and back, use the lowest level.) Campaign - Interior Front Door Handles Technical Service Bulletin # 06027A Date: 070523 Campaign - Interior Front Door Handles Bulletin No.: 06027A Date: May 23, 2007 SPECIAL COVERAGE Subject: 06027A - SPECIAL COVERAGE ADJUSTMENT - CLASS ACTION SETTLEMENT - INTERIOR DOOR HANDLE SPRING BREAKAGE Models: 1982-1994 CHEVROLET S/T PICKUP AND UTILITY 1982-1994 GMC S/T PICKUP AND UTILITY, JIMMY 1991-1994 OLDSMOBILE BRAVADA INVOLVED IN SOUTH CAROLINA CLASS ACTION SETTLEMENT Supercede: The expiration date for this special coverage has been extended to December 31, 2007. The mailing of letters to customers was delayed. Letters will be mailed to customers on May 30, 2007. Due to the age of the vehicles involved in this program, most involved VINs will be added to GMVIS to allow submission of claims. However, there are a few VINs that were not legible and could not be loaded into GMVIS. If a customer presents a letter authorizing repairs but the VIN is not found in GMVIS, H-route the claim to your AVM for approval. Condition Some customers of 1982-1994 Chevrolet S/T pickup and utility vehicles; 1982-1994 GMC S/T pickup and utility vehicles; and 1991-1994 Oldsmobile Bravada vehicles are entitled to the benefits of a class action settlement. The benefits are listed below and customers will be provided with a letter to present to dealers that details the remedy that they chose. Special Coverage Adjustment This special coverage covers the conditions described below until December 31, 2007. Customers may have any combination of the benefits listed below. Please see the customer's letter to determine the appropriate remedy. Reimbursement - Customers who have replaced an interior front door handle assembly have already submitted a request for reimbursement. GM is handling the reimbursements. There is no action required from the dealer. Replacement of broken interior front door handle assembly(s) - Some customers have chosen to receive a replacement interior front door handle assembly(s). Dealers are to provide the customer with the assembly(s) at no charge. The customer is to self-install or pay the dealer for the installation of the assembly(s). Application of lithium grease - Customers who have the original front door handle assembly(s) in which the spring is not broken, are entitled to have the spring(s) greased. Dealers are to apply lithium grease to the unbroken spring(s) of the original front door handle assembly(s) at no charge. Vehicles Involved Customers involved will present the dealer their vehicle with a letter that authorizes the repair. If the customer requests a new interior front door handle, dealer must verify it replaces a broken interior front door handle assembly. Page 390 - Diagnostic Chart C-1D. The updated chart information: Tires - Slipping on Rim Tires: All Technical Service Bulletins Tires - Slipping on Rim Number: 93-169-3E Section: 3E Date: APRIL 1993 Corporate Bulletin No.: 393501 ASE No.: A4 Subject: TIRES SLIPPING ON WHEELS (USE PROPER TIRE MOUNTING PROCEDURE) Model and Year: 1988-93 ALL PASSENGER CARS AND LIGHT DUTY TRUCKS Some incidents of tires slipping (rotating) on wheels have been reported on 1988-93 passenger cars and light duty trucks. Most incidents have occurred when driven aggressively immediately after tire mounting. Hard acceleration and/or braking is usually required. This condition will affect wheel balance, which could result in a vibration. To reduce the chance of tires rotating on their wheels, any excess lube should be wiped from the tire and rim after tire mounting, but before inflating to seat the bead. (Never exceed 40 psi to seat the bead.) Also, the vehicle should not be driven aggressively for at least four hours after tire mounting to allow the lube to dry. GM Goodwrench Rubber Lubricant, p/n 12345884, is the recommended lube for tire mounting. Page 2272 Engine Control Module: Component Tests and General Diagnostics Chart C-9A - ECM QDR Check Procedure Checking Control Module For Bad Solder Joints Some control module's 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 A/T - Buzzing Noise at Idle Fluid Pressure Sensor/Switch: All Technical Service Bulletins A/T - Buzzing Noise at Idle Number: 93-29-7A Section: 7A Date: OCT. 1992 Corporate Bulletin No.: 277142 ASE No.: A2 Subject: BUZZING NOISE AT IDLE Model and Year: 1982-93 CAPRICE, CAMARO AND CORVETTE 1982-93 C/K, R/V, S/T, M/L AND G TRUCKS WTIH 4L60 AUTOMATIC TRANSMISSION TRANSMISSION APPLICATIONS: 1982-1993 HYDRA-MATIC 4L60 (MD8) TRANSMISSION MODELS: All SUBJECT: Pressure Regulator Valve Buzz VEHICLE APPLICATIONS: B, D, F, Y - Cars C/K, R/V, S/T Trucks G, M, L - Vans CONDITION: Some 1982-1993 vehicles equipped with a HYDRA-MATIC 4L60 transmission may have a buzzing noise coming from the transmission when the vehicle is at idle. The buzzing noise may be noticed more when the vehicle is in reverse at idle. CAUSE: The buzzing noise may be a result of pressure regulator valve oscillating due to oil pressure instability at lower idle RPM. CORRECTION: Page 2765 Manifold Pressure/Vacuum Sensor: Service and Repair Fig. 337 MAP Sensor Removal (V6 Models Similar) The MAP sensor unit is not serviceable and must be replaced as a unit. 1. Disconnect vacuum hose from MAP sensor, then remove top of air cleaner assembly. 2. Remove MAP sensor unit retaining clip, then the sensor, Fig. 337. 3. Reverse procedure to install. Page 4929 Brake Shoe: Adjustments These brakes have self adjusting shoe mechanisms that ensure correct lining-to-drum clearances at all times. The automatic adjusters operate only when brakes are applied as vehicle is moving rearward. Although the brakes are self-adjusting, an initial adjustment is necessary after brake shoes have been relined or replaced, or when length of star wheel adjuster has been changed during some other service operation. Frequent usage of an automatic transmission forward range to halt reverse vehicle motion may prevent automatic adjusters from functioning, thereby inducing low pedal heights. Should low pedal heights be encountered, it is recommended that numerous forward and reverse stops be made until satisfactory pedal height is obtained. If a low pedal height condition cannot be corrected by making numerous reverse stops (provided hydraulic system is free of air), the self-adjusting mechanism is not functioning. Therefore it will be necessary to remove brake drum, clean, free up and lubricate adjusting mechanism. Then adjust brakes as follows, being sure parking brake is fully released. Upon initial adjustment, a lanced area in the brake backing plate must be removed prior to adjusting brakes. To remove lanced area, knock out with a suitable hammer and punch, then remove brake drum to clear any metal particles caught inside the brake compartment. Install brake drum and proceed with adjustment. After adjustment is complete, install brake adjustment hole cover to prevent entry of water and dirt. 1. Turn brake adjusting screw to expand shoes until wheel can just be turned by hand. 2. Using a suitable tool to hold actuator lever off adjuster, back adjuster off 24 notches. If shoes still drag, back off one or two additional notches. NOTICE: Brakes should be free of drag when adjuster has been backed off approximately 12 notches. Heavy drag at this point indicates tight parking brake cables. 3. Install adjusting hole cover on brake drum or backing plate. 4. Check parking brake adjustment. Page 4604 8. New O-ring seal P/N 14095598 (67) and new plastic washer (retainer) P/N 14037958 (66) into the front case half. 9. New sector with shaft P/N 15637215 (55) into the front case half. 10. Range shift fork (51), range shift hub (34) into the planetary carrier (36). - It is necessary to rotate the sector with shaft (55) to obtain clearance when installing the range fork (51). INSPECT: The teeth of the synchronizer stop ring (28) and drive sprocket (20) for damage. If the parts are to be replaced due to damage or in cases of customer complaint of clash when shifting from 2Hi to 4Hi, follow steps 11, 12, & 13, otherwise skip to step 14. 11. New drive sprocket P/N 15579803 (20) to the main shaft (19). 12. New synchronizer stop ring P/N 14071703 (28) to the drive sprocket (20). 13. Synchronizer assembly (81) to the main shaft. 14. Mainshaft (19)/drive sprocket (20), chain (58) and front output shaft (21) as a unit. Mode shift fork (54) and shift rail (48) will be installed with the mainshaft. 15. Fork shift spring (52). Mainshaft Extension and Oil Pump 16. Rear case (17) over mainshaft (19) and onto the front case half (45). - Clean case mating surfaces and apply RTV sealer or equivalent to the mating surfaces. - Transfer dowels from old case half to new case half if necessary. IMPORTANT: Be careful not to damage the oil pump (12) while installing the rear case half (Figure 7). 17. Case bolts (3) into case halves. - Apply Loctite 242 (R) or equivalent on pump housing bolt threads. - The two longer bolts and washers into the doweled case holes (33). - Tighten bolts to 31 N-m (23 lbs.ft.). 18. Speedometer tone wheel (11) to the main shaft (19). 19. Pump retainer housing (8) and pump housing bolts (7) to the rear case half (17). - Clean mating surfaces and apply RTV sealer or equivalent to the mating surfaces. - Apply Loctite (R) or equivalent on pump housing threads. - Pump housing bolts are shouldered (7). - Tighten bolts to 41 N-m (30 lbs.ft.). 20. Output bearing retainer (snap ring) (5), to the main shaft (19). 21. Rear extension housing (4) and extension housing bolts (3) to the pump retainer housing (8). - Clean mating surfaces and apply RTV sealer or equivalent to the mating surfaces. - Apply Loctite 242 (R) or equivalent on the extension housing bolts. - Tighten bolts to 31 N-m (23 lbs.ft.). External Components 22. Poppet plunger (70), poppet spring (71), new O-ring seal P/N 14071849 (69), and poppet screw (68) to the front case half (45). Page 8107 Note: Labor Operation is coded to base vehicle coverage in the warranty system. A/T - Buzzing Noise at Idle Fluid Pressure Sensor/Switch: Customer Interest A/T - Buzzing Noise at Idle Number: 93-29-7A Section: 7A Date: OCT. 1992 Corporate Bulletin No.: 277142 ASE No.: A2 Subject: BUZZING NOISE AT IDLE Model and Year: 1982-93 CAPRICE, CAMARO AND CORVETTE 1982-93 C/K, R/V, S/T, M/L AND G TRUCKS WTIH 4L60 AUTOMATIC TRANSMISSION TRANSMISSION APPLICATIONS: 1982-1993 HYDRA-MATIC 4L60 (MD8) TRANSMISSION MODELS: All SUBJECT: Pressure Regulator Valve Buzz VEHICLE APPLICATIONS: B, D, F, Y - Cars C/K, R/V, S/T Trucks G, M, L - Vans CONDITION: Some 1982-1993 vehicles equipped with a HYDRA-MATIC 4L60 transmission may have a buzzing noise coming from the transmission when the vehicle is at idle. The buzzing noise may be noticed more when the vehicle is in reverse at idle. CAUSE: The buzzing noise may be a result of pressure regulator valve oscillating due to oil pressure instability at lower idle RPM. CORRECTION: Page 903 Fluid - A/T: Fluid Type Specifications 3L30 (180C) Transmission Lubricant Types ................................................................................................................................... ................................................................... Dexron II 4L60 - 700R4 Transmission Lubricant Type ..................................................................................................................................... ......................................................... Dextron II ATF Page 5528 Courtesy & Dome (W/Cargo Lamp) Page 6796 If the spring breaks while bending, it will be necessary to replace the lock cylinder assembly 7. Reinstall the spring in the lock assembly. Next, shake the assembly to check for looseness. If loose, replace the lock cylinder assembly. 8. Reinstall the gasket, lock cylinder and retainer (Figure 3, Items 3, 4 and 2). 9. Reconnect the end gate lock rods (Figure 2, Items 1 and 2). 10. Reinstall the end gate inner panel reinforcement to the end gate (Figure 1, Item 1). 11. Reinstall the inner trim panel. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Op: B5810 Use applicable labor time guide for labor hours. Page 2219 Wiring Diagram For Chart C-5 - Electronic Spark Control System Check CIRCUIT DESCRIPTION: Electronic spark control is accomplished with a module that sends a voltage signal to the ECM. As the knock sensor detects engine knock, the voltage from the ESC module to the ECM is shut "OFF" and this signals the ECM to retard timing, if engine RPM is over about 900. TEST DESCRIPTION: Numbers below refer to circled numbers on the diagnostic chart. 1. If A Code 43 is not set, but a knock signal is indicated while running at 1500 RPM, listen for an internal engine noise. Under a no load condition there should not be any detonation, and if knock is indicated, an internal engine problem may exist. 2. Usually a knock signal can be generated by tapping on the right exhaust manifold. This test can also be performed at idle. Test number 1 was run at 1500 RPM to determine if a constant knock signal was present, which would affect engine performance. 3. This tests whether the knock signal is due to the sensor, a basic engine problem, or the ESC module. 4. If the module ground circuit is faulty, the ESC module will not function correctly. The test light should light indicating the ground circuit is OK. 5. Contacting CKT 496, with a test light to 12 volts, should generate a knock signal to determine whether the knock sensor is faulty, or the ESC module can't recognize a knock signal. DIAGNOSTIC AIDS: "Scan" tools have two positions to diagnose the ESC system. The knock signal can be monitored to see if the knock sensor is detecting a knock condition and if the ESC module is functioning, knock signal should display "yes", whenever detonation is present. The knock retard position on the "Scan" displays the amount of spark retard the ECM is commanding. The ECM can retard the timing up to 20 degrees. This check should be used after other causes of spark knock have been checked such as engine timing, EGR systems, engine temperature or excessive engine noise. Page 7369 - 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 Page 7154 Number: 89-318-10 Section: 10 Date: September, 1990 Corp. Bulletin No.: SPECIAL Subject: SPECIAL POLICY ADJUSTMENT PAINT DELAMINATION (PEELING) Model and Year: 1988-89 CHEVROLET S/T PICKUPS AND S/T BLAZERS (SHREVEPORT ASSEMBLY PLANT ONLY - PLANT CODE "8") TO: ALL CHEVROLET DEALERS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 89-305-10, DATED APRIL 1990. ALL COPIES OF 89-305-10 SHOULD BE DISCARDED AS THIS BULLETIN CONTAINS AN EXPANDED SERVICE PROCEDURE. General Motors has determined that some 1988-89 Chevrolet S/T pickups and S/T Blazers built at the Shreveport Assembly Plant may exhibit a delamination (peeling) of the paint on exterior surfaces due to continued ultraviolet exposure. If one of these vehicles should require repairs for a paint peeling condition, all exterior surfaces painted with affected colors should be refinished even though the peeling may be evident in only a few places. VEHICLES INVOLVED Involved are certain 1988-89 Chevrolet S/T model trucks painted Galaxy Blue (paint code 28), Aspen Blue (paint code 24) or Steel Gray (paint code 90) and built at the Shreveport Assembly Plant within the following VIN breakpoints: SPECIAL POLICY ADJUSTMENT This special policy covers the condition described above on 1988 involved vehicles for 12 months from the date of this bulletin. 1989 involved vehicles will be covered for a period of 3 years from the date of original vehicle purchase regardless of ownership with no deductible. Correction, at no charge to the customer, will consist of refinishing exterior surfaces painted with affected colors on involved vehicles. Customers may also be eligible for reimbursement of previous repairs with supporting documentation. NOTICE: Only exterior surface areas painted Galaxy Blue, Aspen Blue or Steel Gray should be refinished. If peeling of colors other than those described above should occur, handle as described in the Chevrolet Claims Processing Manual, Section XIII, Warranty Management System. This "Special Policy Adjustment Bulletin" should be filed in the three ring binder previously furnished to dealers by General Motors. PARTS INFORMATION No parts are required to complete this special policy. Paint supplies should be obtained through normal supplier. Service Procedure 1. After washing vehicle, verify that condition is delamination of topcoat by applying a 2 inch width piece of masking tape firmly over suspect area, pulling upward quickly. If topcoat and/or clear coat flake or peel away from primer, leaving primer intact, the topcoat is delaminating and the following service procedure should be performed. Page 4253 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. Page 3221 Knock Sensor: Testing and Inspection Chart C-5 - Electronic Spark Control System Check Locations TIMING MARK 4.3L (262) Page 4682 Shift Solenoid: Specifications 4L60 - 700R4 Transmission Pressure Control Solenoid To Valve Body .............................................................................................................................................................. 8 ft. lbs. Solenoid Assembly To Case .................................................................................................. .................................................................................. 18 ft. lbs. Solenoid Assembly To Pump ............ .............................................................................................................................................................. .......... 8 ft. lbs. With DA-6 Compressor Compressor Shaft Seal: Service and Repair With DA-6 Compressor DA-6 Component View Remove or Disconnect Tools Required: J 5403 Snap Ring Pliers J 34614 Shaft Seal Protector J 23128-A Seal Remover and Installer J 9553-01 O-Ring Seal Remover 1. Clutch plate and hub assembly (2). ^ Install J 34614 over the threaded end of the shaft (20). Page 7893 Symbol Identification Campaign - Interior Front Door Handles Technical Service Bulletin # 06027A Date: 070523 Campaign - Interior Front Door Handles Bulletin No.: 06027A Date: May 23, 2007 SPECIAL COVERAGE Subject: 06027A - SPECIAL COVERAGE ADJUSTMENT - CLASS ACTION SETTLEMENT - INTERIOR DOOR HANDLE SPRING BREAKAGE Models: 1982-1994 CHEVROLET S/T PICKUP AND UTILITY 1982-1994 GMC S/T PICKUP AND UTILITY, JIMMY 1991-1994 OLDSMOBILE BRAVADA INVOLVED IN SOUTH CAROLINA CLASS ACTION SETTLEMENT Supercede: The expiration date for this special coverage has been extended to December 31, 2007. The mailing of letters to customers was delayed. Letters will be mailed to customers on May 30, 2007. Due to the age of the vehicles involved in this program, most involved VINs will be added to GMVIS to allow submission of claims. However, there are a few VINs that were not legible and could not be loaded into GMVIS. If a customer presents a letter authorizing repairs but the VIN is not found in GMVIS, H-route the claim to your AVM for approval. Condition Some customers of 1982-1994 Chevrolet S/T pickup and utility vehicles; 1982-1994 GMC S/T pickup and utility vehicles; and 1991-1994 Oldsmobile Bravada vehicles are entitled to the benefits of a class action settlement. The benefits are listed below and customers will be provided with a letter to present to dealers that details the remedy that they chose. Special Coverage Adjustment This special coverage covers the conditions described below until December 31, 2007. Customers may have any combination of the benefits listed below. Please see the customer's letter to determine the appropriate remedy. Reimbursement - Customers who have replaced an interior front door handle assembly have already submitted a request for reimbursement. GM is handling the reimbursements. There is no action required from the dealer. Replacement of broken interior front door handle assembly(s) - Some customers have chosen to receive a replacement interior front door handle assembly(s). Dealers are to provide the customer with the assembly(s) at no charge. The customer is to self-install or pay the dealer for the installation of the assembly(s). Application of lithium grease - Customers who have the original front door handle assembly(s) in which the spring is not broken, are entitled to have the spring(s) greased. Dealers are to apply lithium grease to the unbroken spring(s) of the original front door handle assembly(s) at no charge. Vehicles Involved Customers involved will present the dealer their vehicle with a letter that authorizes the repair. If the customer requests a new interior front door handle, dealer must verify it replaces a broken interior front door handle assembly. 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. Removal Brake Shoe: Service and Repair Removal For additional information see Notes, Warnings, and Hints. See: Fundamentals and Basics Exploded View 1. Raise and support vehicle, then remove tire and wheel assembly. 2. Remove brake drum. If brake lining is dragging on brake drum, back off brake adjustment by rotating adjustment screw. If brake drum is rusted or corroded to axle flange and cannot be removed, lightly tap axle flange to drum mounting surface with a suitable hammer. 3. Using brake spring pliers or equivalent, unhook primary and secondary return springs. Observe location of brake parts being removed to aid during installation. NOTE: For additional information see Brake Spring Removal and Installation Notes. See: Fundamentals and Basics 4. Remove brake hold-down springs with suitable tool. 5. Lift actuating lever, then unhook actuator link from anchor pin and remove. 6. Remove actuating lever and return spring. 7. Spread shoes apart and remove parking brake strut and spring. 8. Disconnect parking brake cable from lever, then remove brake shoes from backing plate. 9. Separate brake shoes by removing adjusting screw and spring, then unhook parking brake lever from shoe assembly. 10. Clean dirt from brake drum, backing plate and all other components. WARNING: Do not use compressed air or dry brush to clean brake parts. Many brake parts contain asbestos fibers which, if inhaled, can cause serious injury. Clean brake parts with a water soaked rag or a suitable vacuum cleaner to minimize airborne dust. Page 2096 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. Page 2500 Valve Clearance: Adjustments Fig. 14 Valve Adjustment 1. Remove rocker arm covers as described under COMPONENT REPLACEMENT AND REPAIR PROCEDURES/ROCKER ARM & PUSHRODS. 2. Crank engine until mark on torsional damper is aligned with ``0'' mark on timing tab and engine is in No. one cylinder firing position. Ensure engine is in No. 1 firing position by placing fingers on rocker arms of No. 1 cylinder as timing mark approaches ``0'' mark. If rocker arms are not moving engine is at the No. 1 firing position. If rocker arms are moving, engine is in the No. 4 firing position and should be rotated one revolution to the No. 1 position. 3. Adjust the following valves with the engine in the No. 1 firing position: exhaust 1, 5 and 6; intake 1, 2 and 3. Adjust valves by backing off nut until lash is felt at the pushrod, then tightening nut until all lash is removed. This can be determined by rotating pushrod while tightening nut. Fig. 14. When all lash is removed, tighten nut one full turn to center pushrod in lifter plunger. 4. Crank engine one full revolution until mark on torsional damper and ``0'' mark on timing tab are aligned. This is the No. 4 cylinder firing position. Adjust the following valves: exhaust 2, 3 and 4; intake 4, 5 and 6. 5. Install valve covers and related components. Coolant - Information on Propylene Glycol Usage 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. Drive Axle (Front) - Will Not Disengage Transfer Case Actuator: All Technical Service Bulletins Drive Axle (Front) - Will Not Disengage Number: 91-476-4C Section: 4C Date: JAN. 1992 Corporate Bulletin No.: 167402 ASE No.: A3 Subject: FRONT AXLE WILL NOT DISENGAGE Model and Year: 1983-1991 T TRUCKS Owners of some 1983-1991 T vehicles may comment about inappropriate front axle disengagement. This condition may be due to a corroded transfer case vacuum actuator switch. To correct this condition a revised switch (P/N 15664811), constructed of noncorrosive stainless steel, should be installed. SERVICE PROCEDURE: The vacuum switch is located on the left upper side of the transfer case (Figure 1). 1. Raise the vehicle and support with suitable safety stands. 2. Remove the vacuum lines from the switch. 3. Remove the corroded switch from the transfer case. 4. Install a revised switch (P/N 15664811), coat the threads with thread sealant. 5. Connect the vacuum lines. 6. Lower the vehicle. 7. Check for oil leaks at the threads and vacuum leaks around the vacuum lines. Page 6568 Some Chevrolet models may exhibit a condition of poor AM or FM radio reception. This may be caused by a poor contact on the female terminal of the antenna coaxial cable lead. The illustration contains a four-step procedure to test and repair the female terminal. The opening in the female terminal should range from .120" to .125" in diameter. If the gage passes through freely, the terminal should be repaired as illustrated. Gage sets are available from Kent Moore, tool number J26900-14. For warranty purposes use Labor Operation T6369 at .5 hour for all carlines. Body - Polypropylene Energy Absorber Replacement Front Bumper Reinforcement: Technical Service Bulletins Body - Polypropylene Energy Absorber Replacement Bulletin No.: 07-08-63-001 Date: April 17, 2007 INFORMATION Subject: Information on Repair of Polypropylene Energy Absorbers Models: 2007 and Prior GM Passenger Cars and Trucks (including Saturn) 2007 and Prior HUMMER H2, H3 2005-2007 Saab 9-7X Supercede: This bulletin is being revised to change the repair information. Please discard Corporate Bulletin Number 63-20-02 (Section 8 - Body and Accessories). Because the energy absorbers are relatively low in cost to replace, it is now more cost efficient to replace the energy absorbers whenever they are damaged. Disclaimer Specifications Brake Drum: Specifications Original Drum Size 9.50 in Maximum Refinish 9.560 in Discard 9.590 in Page 5505 When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit J 38125-4 instruction manual 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 or replace...". Mating terminals must be inspected to assure good terminal 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 to 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, see Figure 1, 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 38125-4 instruction manual. 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 connection 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 38125-2, 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 38125-2, 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 38125-2. Page 1461 Camshaft: Specifications Camshaft Sprocket Bolts 21 ft.lb Camshaft Thrust Plate Screws 8.75 ft.lb Page 2390 Knock Sensor: Testing and Inspection Chart C-5 - Electronic Spark Control System Check 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. 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 A/T - Updated ATF Fluid Color/Level Check Information Fluid - A/T: All Technical Service Bulletins A/T - Updated ATF Fluid Color/Level Check Information Number: 89-234-7A Section: 7A Date: August 1989 Corporate Bulletin No.: 977126 Subject: AUTOMATIC TRANSMISSION/TRANSAXLE FLUID COLOR/LEVEL CHECK INFORMATION Model and Year: 1987-89 PASSENGER CARS AND TRUCKS WITH AUTOMATIC TRANSMISSIONS TO: ALL CHEVROLET DEALERS THE INFORMATION PROVIDED IN THIS BULLETIN SUPERSEDES THE PUBLISHED INFORMATION PERTAINING TO AUTOMATIC TRANSMISSIONS COVERED ON PAGES 3 AND 4 OF DEALER SERVICE BULLETIN 89-145-08 DATED MAY 1989. PLEASE MARK YOUR COPIES OF 89-145-08 TO INDICATE THE INFORMATION CONTAINED IN THIS BULLETIN. This bulletin provides Service Manual updates for Transmission/Transaxle fluid level and condition information. This information is updated for 1989 service manuals printed prior to June 1989. TRANSMISSION/TRANSAXLE FLUID LEVEL INFORMATION: Checking fluid level and condition (color and odor) at regular intervals will provide early diagnosis information about the transmission. This information may then be used to correct a condition that, if not detected early, could result in major transmission repairs. When adding or changing fluid, use only DEXRONR II. Refer to Maintenance and Lubricaton (Service Manual Section OB) for maintenance information and servicing intervals. NOTICE: Do not overfill. Overfilling will cause foaming, loss of fluid, shift complaints and possible damage to to transmission. ^ Fluid level should only be checked when it reaches a normal operating temperature of 82-93C (180-200F). This temperature is reached after approximately 24 km (15 miles) of driving. ^ Fluid color will be red when new. IMPORTANT: When new, automatic transmission fluid is red in color. The red dye is added so the assembly plant can identify as transmission fluid and distinguish it from engine oil or anti-freeze. The red dye is not an indicator of fluid quality and is not permanent. As the vehicle is driven, the transmission fluid will begin to look darker in color. The color may eventually appear light brown. A dark brown color along with a burnt odor may indicate excessive fluid deterioration and signal a need for fluid change. TRANSMISSION/TRANSAXLE FLUID CHECKING PROCEDURE: 1. Start engine and drive vehicle for a minimum of 24 km (15 miles), or until normal operating temperature is reached. NOTICE: The automatic transmission fluid level must be checked with the vehicle at normal operating temperature, 82-93C (180-200F). Temperature will greatly affect transmission fluid level. If the vehicle is not at normal operating temperature and the proper checking procedures are not followed, the result could be a false reading of the fluid level indicator and an incorrect adjustment of the fluid level. 2. Park vehicle on level ground. 3. Move gear selector to "PARK". 4. Apply parking brake and block wheels. 5. Let vehicle idle for 3 minutes with accessories off. Engine - Vibration On Acceleration Exhaust Pipe/Muffler Hanger: All Technical Service Bulletins Engine - Vibration On Acceleration Number: 88-270-6F Section: 6F Date: JULY, 1988 Subject VIBRATION ON ACCELERATION Model and Year 1988 S/T TRUCK W/4.3L (VIN CODE Z) ENGINE TO: ALL CHEVROLET DEALERS Some 1988 S/T Trucks equipped with 4.3L engines may experience a vibration that can be felt in the floor pan area near the shifter, in the right hand passenger seat foot area, or on the steering column. These conditions may be caused by the following items: 1. The shifter rod that goes from the steering column to the transmission equalizer lever (#340 and #338 in Figure 36 page 7A-45 of the 1988 S/T Manual) hitting the exhaust crossover pipe and/or the equalizer lever making firm contact at the shift lever (T-truck only). 2. The exhaust pipe to catalytic converter clamp (Figure 7, page 6F-6 of the 1988 S/T Manual) hitting the catalytic converter heat shield. 3. The exhaust pipe to converter installation allows the exhaust pipe to contact the transmission crossmember. To repair these conditions, use the following procedures: 1. A. Raise vehicle on hoist. B. Check Transmission linkage for correct adjustment. C. Check exhaust pipe for shifter rod interference (shiny spot on pipe). D. If linkage hits pipe, remove 15 mm (5/8 in) from bottom of rod. E. Put transmission into low gear and mark exhaust pipe area near linkage. F. Put transmission in park. Using a hammer, lightly dimple exhaust pipe for additional clearance. Page 7773 When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 5mm (3/16") of insulation from wire. e. Crimp a new terminal to the wire. f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. Figure 17 To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Figure 18 Figure 19 Rocker Arm Studs Replace Rocker Arm Assembly: Service and Repair Rocker Arm Studs Replace Fig. 10 Rocker Arm Stud Removal Fig. 11 Reaming Of Rocker Arm Stud Bore Fig. 12 Installing Rocker Arm Stud Rocker arm studs that have damaged threads or are loose should be replaced with oversize studs. Oversize studs are available in .003 and .013 inch and can be installed after properly reaming the holes as follows: 1. Remove stud using stud reamer tool No. J-5802-01, Fig. 10 or equivalent with a nut and flat washer placed over the tool. 2. Ream hole to proper size using reamer tool No. J-5715, Fig. 11 for .003 inch oversize or reamer tool No. J-6036 for .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. 12. Ignition Firing Order Firing Order: Specifications Ignition Firing Order Firing Order ......................................................................................................................................... ............................................................... 1-6-5-4-3-2 Page 5313 Multiple Junction Connector: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. Figure 21 Figure 22 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. Page 3583 Speedometer Gear - Malfunctions Speedometer Gear, A/T: All Technical Service Bulletins Speedometer Gear - Malfunctions Number: 91-98-8C Section: 8C Dates: October 1990 Corporate Bulletin No.: 067104 Subject: MALFUNCTION OF THE SPEEDOMETER DRIVE GEAR, DRIVEN GEAR AND/OR SPEEDOMETER Model and Year: 1987-91 S1 (LLV POST OFFICE VEHICLES) TO: ALL CHEVROLET DEALERS Some of the above postal vehicle chassis may experience a malfunction of the speedometer drive gear, driven gear, and/or speedometer adapter. Effective January 24, 1990 with chassis' VIN 1GBCS10E2M2901183, a new driven gear was installed in production. The new driven gear can be recognized visually as the following table illustrates. GM PART # COLOR # OF TEETH NEW 3987920 BLUE 20 OLD 3860347 YELLOW 24 IMPORTANT: The new driven gear has eliminated the need for the speedometer adapter. Recommended service procedures are outlined below: Service Procedure # 1 1. Remove and discard speedometer adapter (GM Part # 368025). 2. Remove original speedometer driven gear and inspect for damaged teeth. If damaged, follow service procedure # 2. If it is not damaged, replace the (yellow) 24 tooth driven gear with the (blue) 20 tooth driven gear (GM Part # 3987920). For vehicles repaired under warranty use: Labor Operation: # T1611 Labor Time: .3 hr. FAILURE CODE: 92 NOTE: The above procedures do not apply to 1991 Postal Vehicles (LLV) with L38 engines. Effective August 13, 1990 with chassis VIN 1GBCS10A0M2912017, a new engine (L38) and rear axle ratio (GU6) were installed in production. As a result of the axle ratio change, a new driven gear is required. Use (gray) 22 tooth driven gear (GM Part Number 3987922) if vehicle is equipped with L38 and GU6. Service Procedure # 2 1. Remove and discard speedometer adapter. 2. Remove driveshaft and rear transmission extension housing. 3. Replace both speedometer drive and driven gear with: Drive Gear (blue) GM Part 96040176 Driven Gear (blue) GM Part 3987920 NOTE: The above procedures do not apply to 1991 Postal Vehicles (LLV) with L38 engines. Effective August 13, 1990 with chassis VIN 1GBCS10A0M2912017, a new engine (L38) and rear axle ratio (GU6) were installed in production. As a result of the axle ratio change, a Specifications TEMPERATURE SENSORS Page 1080 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 Page 3426 Prom Information Scan Prom Prom Prom Superseding ID Code Bcc Part # ID Part # TSB Reference # 0281 5354 FWL 16065353 0291 5358 FWM 16065357 0561 7084 FXW 16067083 4881 16083480 0611 7137 FYB 16067136 4891 16083485 2251 2084 AKDW 16082083 3441 16121150 Chevrolet 88-235-6E High emissions, exhaust odor, starting and driveability problems (G046). 2261 2088 AKDX 16082087 3051 16121142 Chevrolet 88-235-6E High emissions, exhaust odor, starting and driveability problems (G046). 2271 2094 AKDY 16082093 3491 16121158 Chevrolet 88-235-6E High emissions, exhaust odor, starting and driveability problems (G046). 2291 2104 AKFA 16082103 3561 16120722 Chevrolet 88-235-6E High emissions, exhaust odor, starting and driveability problems (G046). 3051 1143 AKMH 16121142 3461 16121154 Chevrolet 88-255-6E Exhaust odor (G046). Needs Y-pipe P/N 15598249, Plug P/N Chevrolet 88-306-6E 10017198. GMC Truck 88-T-126 GMC Truck 88-T-153 3061 1147 AKMJ 16121146 Chevrolet 88-255-6E Exhaust odor, requires Y-pipe and plug (G046). Chevrolet 88-306-6E GMC Truck 88-T-126 GMC Truck 88-T-153 3151 7594 ATBA 16147593 Chevrolet 91-44-6E Rough idle/stall after cold start. GMC Truck 91-6E-17 3441 1151 AKRZ 16121150 Chevrolet 88-424-6E Rough idle. GMC Truck 88-T-213 3451 6234 ADUD 16076233 2271 16082093 3461 1155 AKSB 16121154 Chevrolet 88-424-6E Rough idle. GMC Truck 88-T-213 3461 6238 ADUF 16076237 3471 0713 AKSC 16120712 3051 16121142 3471 6292 ADUH 16076291 3521 16121166 Chevrolet 88-235-6E High emissions, exhaust odor, starting and driveability problems (G046). 3481 0718 AKSD 16120717 3061 16121146 3481 6318 ADUJ 16076317 2261 16082087 3491 1159 AKSF 16121158 4731 16154687 Chevrolet 88-424-6E Rough idle. GMC Truck 88-T-213 Locations Oil Pressure Switch Page 6918 Figure 8 Figure 9 Figure 10 Figure 11 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). Page 6141 DA-V5 Compressor Component View Remove or Disconnect Tools Required: J 8433-1 Puller Bar J 8433-3 Puller Screw J 33023-A Puller Pilot J 33025 Clutch Coil Puller Legs 1. Clutch plate and hub assembly (22). 2. Pulley (26). ^ Mark or scribe the location of the clutch coil (27) to terminal on the compressor front head (33). 3. Clutch coil assembly (27). ^ Install J 33023-A on the head (33) of the compressor. Specifications Clutch Slave Cylinder: Specifications Slave cylinder retaining nuts ................................................................................................................ ................................................................ 10-15 ft lbs Page 5315 Figure 4 Figure 5 Figure 6 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 7 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. Warranty - Rail Dust Removal & Chemical Spotting Labor Paint: All Technical Service Bulletins Warranty - Rail Dust Removal & Chemical Spotting Labor File In Section: Warranty Administration Bulletin No.: 72-05-11 Date: December, 1997 WARRANTY ADMINISTRATION Subject: Clarification of Rail Dust Removal (A5575-A5580) and Chemical Spotting (A5541-A5544) Labor Operations Models: All Past and Future Passenger Cars and Light Duty Trucks The purpose of this Warranty Administration Bulletin is to clarify the usage, limits and guidelines for the proper use of the above subject labor operations. The above subject labor operations were introduced to correct paint imperfections caused by fallout that occurred either during shipment to the dealer or within the first 12 months or 12,000 miles (20,000 kms) of vehicle ownership. GM vehicle owners are informed that although no defect in the factory applied paint causes this, GM will repair, at no charge to the owner, the surfaces of new vehicles damaged by fallout condition within 12 months or 12,000 miles (20,000 kms) whichever occurs first. Effective with repair orders dated on or after December 1, 1997, labor operations A5575-A5580 Rail Dust Removal and A5541 through A5544 Chemical Spotting will be limited to within the first 12 months or 12,000 miles of the Base Vehicle Warranty (20,000 kms) whichever occurs first. Service and Repair 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 go 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 Electronic Control Module (ECM). After diagnosis and repair, the ECM memory can be cleared of codes by removing the ECM fuse or disconnecting the battery ground cable for approximately 30 seconds, with ignition switch in the Off position. It should be noted, that if battery ground cable is disconnected to clear codes, components such as clocks, electronically tuned radios etc., will have to be reset. Page 8037 Front Inner Panel Water Deflector NOTE: Waterproof deflectors are used to seal the door inner panel, and to prevent water from entering into the body. The deflector is secured by a strip of adhesive between the deflector and the door, as well as waterproof sealing tape. REMOVE OR DISCONNECT 1. Door trim panel. 2. Plastic fasteners (when used). 3. Armrest bracket. 4. Water deflector. ^ Pull the waterproof sealing tape from the deflector. ^ Break the bond between the sealer and the door with a flat-bladed tool. INSTALL OR CONNECT 1. Water deflector strip caulking as a sealant between the deflector and the door, If needed. 2. Plastic fasteners (when used). 3. Waterproof tape. 4. Armrest bracket. 5. Door trim panel. Door Trim Panel Replacement Page 3203 Ignition Coil: Locations Center Of Dash Panel (engine Compartment) Center Rear Of Engine Applicable to: V6-262/4.3L Engine Page 2890 Fuel Pressure: Testing and Inspection NOTE: A fuel system pressure test is part of several of the Diagnostic Charts and Symptom Checks. To perform this test, follow this procedure: FUEL PRESSURE TEST 1. Turn engine OFF to relieve system pressure. 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. - The constant bleed feature relieves fuel pump system pressure when the engine is turned "OFF". 2. Uncouple fuel supply flexible hose in engine compartment. Install fuel pressure gauge between steel line and flexible hose. 3. Tighten gauge in line to insure no leaks occur during testing. 4. Connect negative battery terminal and START engine and observe fuel pressure reading. It should be 62-90 kPa (9-13 psi). If not, refer to DIAGNOSTIC CHARTS/FUEL SYSTEM PRESSURE TEST (CHART A-6). 5. Turn engine OFF to relieve system pressure. 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. - The constant bleed feature relieves fuel pump system pressure when the engine is turned "OFF". 6. Remove fuel pressure gauge. 7. Reinstall fuel line. 8. Connect negative battery terminal and START engine and check for fuel leaks. 9. Install air cleaner assembly. Page 3092 Oil Pressure Switch (For Fuel Pump): Description and Operation As a back-up system to the fuel pump relay, the fuel pump can also be turned ON by the oil pressure switch. The oil pressure switch is a normally open switch which closes when oil pressure reaches about 28.0 kPa (4.0 psi). If the fuel pump relay fails, the oil pressure switch will power the fuel pump. Page 2964 - An updated engine control calibration, or service procedure, may be available to make the engine less susceptible to low volatility fuels. 3. If basic checks do not reveal a vehicle fault, then advise the customer that fuel quality may be an issue. Recommend the following actions: Change brands of fuel - Use 87 octane gasoline, unless the vehicle is designed for premium gasoline. - Try to empty the fuel tank as much as practical before refilling. - Run a minimum of three tanks of new fuel before returning for service. 4. If above steps are ineffective, do not proceed with additional vehicle diagnosis and/or parts replacement until the fuel tank has been drained and refilled with a known good quality gasoline AT THE DEALERSHIP. 5. If the problem remains refer to service manual, service bulletins and/or technical assistance. Description and Operation Electric Air Control Valve: Description and Operation The ECM energizes an AIR CONTROL solenoid. This allows air to flow to an AIR SWITCHING valve. When the engine is cold, the air switching valve is energized to direct air to the exhaust ports. On a warm engine when in closed loop, the ECM deenergizes the air switching valve, directing air to the dual-bed converter. On some engines during deceleration, the air is diverted to the air cleaner or the converter depending on the application. Others do not divert during deceleration. Also, under an enrichment condition or when the ECM has recognized a failure in the system and set a code, the ECM will cause the air to be diverted to the air cleaner or atmosphere depending on the application. If the system senses a lean condition for too long, air will be diverted to the air cleaner. When coolant temperature is below a specified value, air will divert to the air cleaner. Brakes - Light Brake Drag While Driving Brake Light Switch: Customer Interest Brakes - Light Brake Drag While Driving Number: 89-262-5 Section: 5 Date: September 1989 Corporate Bulletin No.: 915002 Subject: LIGHT BRAKE DRAG - BRAKE SWITCH ADJUSTMENT Model and Year: 1980-89 A, B, F, G, J, L, X, Y 1980-89 ALL TRUCKS Figure 1 TO: ALL CHEVROLET DEALERS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 89-178-5, DATED JUNE 1989, IN ORDER THAT WE MAY CORRECTLY IDENTIFY THE SWITCH REQUIRING ADJUSTMENT. ALL COPIES OF 89-178-5 SHOULD BE DISCARDED. Some vehicles may experience a condition of light brake drag while driving. These conditions have been found to be more noticeable on vehicles which have an anti-lock brake system. This may be caused by improper brake switch adjustment. If the brake switch is not adjusted properly, the switch may push on the brake pedal and cause the brake to remain partially applied. If a vehicle exhibits any of the above conditions, perform the following functional brake switch adjustment check: Passenger Cars Only: The following steps should be used to check brake switch adjustment: 1. Remove the driver-side hush panel (refer to Figure 1). 2. Gently pull back on the brake pedal until no audible clicks are heard. The switch will be moved in the tubular retainer providing adjustment. 3. Replace the hush panel. 4. Verify that the brake drag condition is no longer present and that the cruise control and brake lights function properly. 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 Page 3719 Labor Operation No.: K6550 Valve, Pressure Regulator-R&R; or Replace Use the appropriate labor time in the labor time guide. Parts are currently available from GMSPO. Page 1276 ^ 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 Page 5987 II. OVER TORQUING OF WHEEL NUTS: 1. A TORQUE WRENCH MUST BE USED to insure that the wheel nuts are tightened to specification. This should be done in two steps using the star pattern. First, snug the nuts down by hand. Then, using the star pattern and a torque wrench, tighten the wheel nuts to about half the final torque. Finally, tighten the wheel nuts to specification using the star pattern and a torque wrench. 2. NEVER use lubricants or penetrating fluids on wheel studs, nuts, or mounting surfaces, as this can raise the actual torque on the nut without a corresponding torque reading on the wrench. Wheel nuts, studs, and mounting surfaces must be clean and dry. Page 3239 Wiring Diagram For Chart C-5 - Electronic Spark Control System Check CIRCUIT DESCRIPTION: Electronic spark control is accomplished with a module that sends a voltage signal to the ECM. As the knock sensor detects engine knock, the voltage from the ESC module to the ECM is shut "OFF" and this signals the ECM to retard timing, if engine RPM is over about 900. TEST DESCRIPTION: Numbers below refer to circled numbers on the diagnostic chart. 1. If A Code 43 is not set, but a knock signal is indicated while running at 1500 RPM, listen for an internal engine noise. Under a no load condition there should not be any detonation, and if knock is indicated, an internal engine problem may exist. 2. Usually a knock signal can be generated by tapping on the right exhaust manifold. This test can also be performed at idle. Test number 1 was run at 1500 RPM to determine if a constant knock signal was present, which would affect engine performance. 3. This tests whether the knock signal is due to the sensor, a basic engine problem, or the ESC module. 4. If the module ground circuit is faulty, the ESC module will not function correctly. The test light should light indicating the ground circuit is OK. 5. Contacting CKT 496, with a test light to 12 volts, should generate a knock signal to determine whether the knock sensor is faulty, or the ESC module can't recognize a knock signal. DIAGNOSTIC AIDS: "Scan" tools have two positions to diagnose the ESC system. The knock signal can be monitored to see if the knock sensor is detecting a knock condition and if the ESC module is functioning, knock signal should display "yes", whenever detonation is present. The knock retard position on the "Scan" displays the amount of spark retard the ECM is commanding. The ECM can retard the timing up to 20 degrees. This check should be used after other causes of spark knock have been checked such as engine timing, EGR systems, engine temperature or excessive engine noise. 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 Page 7163 Zep Corporation Atlanta, GA. Telephone # 404-352-1680 Stain Away # HBY 0160 Hornby Chemical Milwaukee, WI. Telephone # 414-462-2833 If the rail dust remover is not available in your area, call one of the numbers listed above for a distributor near your location. PAINT GAGES - USE BELOW OR EQUIVALENT Elcometer Inc. 1893 Rochester Ind. Drive Rochester Hills, MI. 48309 (800) 521-0635 or (313) 650-0500 Zelcro, Ltd./Zormco 8520 Garfield Rd. Cleveland, OH 44125 (216) 441-6102 Delfesko Corp. 410 Cedar St. Ogdensburg, NY 13669 (800) 267-0607 or (613) 925-5987 Pro Motorcar Products Inc. 22025 US-19 North Clearwater, FL 34625 (800) 323-1090 (813) 726-9225 "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." Technical Service Bulletin # 231054R Date: 930701 Paint - Identification/Repair of Colorcoat Delamination BULLETIN NUMBER: 92-1O-134A SECTION: 10 Body NUMBER: 4 CORPORATE REFERENCE NUMBER: 231054R DATE: July 1993 SUBJECT: SERVICE PROCEDURES FOR IDENTIFICATION AND REPAIR OF PAINT COLORCOAT DELAMINATION FROM ELPO PRIMER MODELS: 1988-92 TRUCKS THIS BULLETIN CANCELS AND REPLACES TRUCK SERVICE BULLETIN 92-10-134 (CORP # 231054R), DATED OCTOBER 1992. IT IS BEING REVISED TO REMOVE THE COVER LETTER PORTION AND SUBJECT STATEMENT NOW INCLUDES NOTE FOR TRUCKS AND REVISES THE MONOCOAT MATERIAL ALLOWANCES ON "G", "S/T" AND SOME "R/V" MODELS. THE ALLOWANCE FOR "ADD FOR TWO-TONE" ON G AND S/T TRUCKS HAS BEEN CHANGED. ALL COPIES OF 92-10-134 SHOULD BE DISCARDED. The revisions are the result of changes to the MONOCOAT (ENAMEL) material allowance charts published in June, 1993. Six (6) of the "G" model revisions use Basecoat/Clearcoat material allowance codes. THESE ARE TO BE USED AS DOLLAR REFERENCES ONLY, Page 3915 Speedometer Gear, A/T: Service and Repair Turbo Hydra-Matic 3L30 (180C) 1. Remove bolt securing driven gear housing retainer, then the retainer. 2. Pull speedometer driven gear from housing. 3. Install speedometer driven gear into housing, then the retainer into slot of driven gear housing. 4. Install retainer attaching bolt. Engine - Vibration On Acceleration Heat Shield: All Technical Service Bulletins Engine - Vibration On Acceleration Number: 88-270-6F Section: 6F Date: JULY, 1988 Subject VIBRATION ON ACCELERATION Model and Year 1988 S/T TRUCK W/4.3L (VIN CODE Z) ENGINE TO: ALL CHEVROLET DEALERS Some 1988 S/T Trucks equipped with 4.3L engines may experience a vibration that can be felt in the floor pan area near the shifter, in the right hand passenger seat foot area, or on the steering column. These conditions may be caused by the following items: 1. The shifter rod that goes from the steering column to the transmission equalizer lever (#340 and #338 in Figure 36 page 7A-45 of the 1988 S/T Manual) hitting the exhaust crossover pipe and/or the equalizer lever making firm contact at the shift lever (T-truck only). 2. The exhaust pipe to catalytic converter clamp (Figure 7, page 6F-6 of the 1988 S/T Manual) hitting the catalytic converter heat shield. 3. The exhaust pipe to converter installation allows the exhaust pipe to contact the transmission crossmember. To repair these conditions, use the following procedures: 1. A. Raise vehicle on hoist. B. Check Transmission linkage for correct adjustment. C. Check exhaust pipe for shifter rod interference (shiny spot on pipe). D. If linkage hits pipe, remove 15 mm (5/8 in) from bottom of rod. E. Put transmission into low gear and mark exhaust pipe area near linkage. F. Put transmission in park. Using a hammer, lightly dimple exhaust pipe for additional clearance. Page 5708 Fig. 7 Stub shaft pin disengage 8. Remove adjuster nut, then remove adjuster plug using spanner wrench tool J-7624 or equivalent, Fig. 4. 9. Disassemble adjuster plug as follows: a. Remove retaining ring, washer, seal and bearing. b. Remove bearing retainer by prying at raised area, then remove seal and needle bearing with adjuster plug bearing installer tool J-8524-2 and driver tool J-7079-2 or equivalents, Fig. 5. 10. Remove valve and worm shaft as an assembly with both races and bearing. Separate as follows: a. Remove worm shaft from valve body, Fig. 6. b. Remove races and bearing from worm shaft, them remove seal. 11. Remove stub shaft from valve body as follows: a. Hold assembly and lightly tap stub shaft against a bench until shaft cap is free from valve body, Fig. 7. b. Pull shaft assembly until shaft cap clears valve body by approximately 1/4 inch. c. Remove valve spool and seals. 12. Remove screws, clamp and ball guide from rack piston, then remove balls. 13. Remove connectors from housing. Assembly Fig. 8 Connector installation Wheels (Steel) - Damage Due to Improper Mounting Wheels: All Technical Service Bulletins Wheels (Steel) - Damage Due to Improper Mounting Number: 92-232-3E Section: 3E Date: JUNE 1992 Corporate Bulletin No.: 233002 ASE No.: A4 Subject: AVOIDING DAMAGE TO STEEL WHEELS FROM IMPROPER WHEEL/TIRE CHANGING TECHNIQUES Model and Year: 1983-92 ALL PASSENGER CARS AND TRUCKS WITH STEEL WHEELS It is important to use proper procedures to prevent damage to either the tire mounting surface or the wheel mounting holes. Damage can result from the improper wheel attachment or tire mounting techniques on vehicles with steel wheels. 1. IMPROPER TIRE CHANGING TECHNIQUES: It takes about 70 seconds for the air to completely exhaust from a large tire. If the technician doesn't wait this amount of time after removing the valve core, the bead breaker on the tire change could put enough force on the tire to bend the wheel at the mounting surface. Such damage can result in vibration, shimmy, and under severe usage (i.e. police vehicle) lead to cracking. 2. OVER TORQUING OF THE WHEEL NUTS: The service specification for wheel nuts is listed in the Service Manuals. Some wheels have been observed with wheel nuts that were over torqued by as much as 50 percent. This may damage the wheel mounting holes and may also lead to cracks. I. PROPER TIRE CHANGING TECHNIQUES: Completely deflate the tire before attempting to break the tire bead loose. MOUNTING SURFACE CHECKING PROCEDURE ECM/PCM - Damaged and/or Misdiagnosed Engine Control Module: All Technical Service Bulletins ECM/PCM - Damaged and/or Misdiagnosed Number: 91-384-6E Section: 6E Date: AUGUST 1991 Corporate Bulletin No.: 176503 Subject: DAMAGED ECM/PCM AND/OR MIS-DIAGNOSED ECM/PCM SYMPTOMS DUE TO INCORRECT "TAP-TESTING" PROCEDURES Model and Year: 1982-91 ALL PASSENGER CARS AND TRUCKS CONDITION: Because of the intermittent nature of some Electronic Control Module (ECM) or Powertrain Control Modules (PCM) symptoms, some service technicians have been subjecting the ECM/PCM to vibration and/or shock testing. Commonly known as tap-testing, this procedure involves tapping on the ECM/PCM case, while the engine is running. It is generally accepted that if the engine or ECM/PCM falters due to the tapping, an intermittent internal ECM/PCM defect may be indicated. However, this may not always be true. If too much force is applied to the ECM/PCM during the test the following symptoms may result: ^ Immediate ECM/PCM failure. ^ ECM/PCM suffers damage which may cause a failure at a later date. ^ ECM/PCM Reset (or Glitch), creating a momentary stall, miss Service Engine Soon (SES) light and/or loss of serial data. CAUSE: The ECM/PCM should be tapped using only the fingertips of one hand. Use of the palm, fist, or any type of tool subjects the ECM/PCM to forces that can cause both the circuit board and the outer aluminum case to flex and distort beyond design limits. The Integrated Circuits (IC) used in today's ECM/PCMs are mounted to the circuit board using a mounting process referred to as "surface technology." There are no circuit board holes for IC leads to go through. The IC leads set on pads, (28 pads or 52 pads depending on the IC) and solder is flowed around the leads to make the electrical connection to the circuit board. ^ Any flexing of the circuit board, beyond design limits, places the IC solder connections at risk of damage. Such damage may be apparent immediately, or it may appear at a future date. Circuit board deflection can occur as a result of striking the ECM/PCM, using ONLY THE PALM OF THE HAND. ^ If struck on the bottom side (the side opposite the service label), the ECM/PCM's aluminum outer case may deflect inward far enough to contact the electrical leads attached to the circuit board. Once in contact with the case the ECM/PCM electrical components will be shorted directly to ground. Although such shorting certainly has the potential to damage the ECM/PCM, it may not be permanent damage, depending on which circuit is involved. However, even if permanent damage is avoided, a short on any of the circuits will cause a disruption of normal ECM/PCM operation for the instant that the short occurs. This disruption may cause the ECM/PCM to reset (see "reset" above), creating the false impression that it is vibration sensitive or faulty. Reset is the ECM/PCM's normal way of coping with large voltage spikes. An ECM/PCM reset does not indicate that the ECM/PCM is defective or faulty, only that it is being subjected to abnormal conditions. CORRECTION: 1. TAP THE ECM/PCM ONLY ON THE TOP SIDE (The top side is where the service label is located.) ^ This will minimize the chance of deflecting the ECM/PCM case into the electrical leads on the circuit board. The clearance between the case and the circuit board is closest on the bottom side of the ECM/PCM. 2. TAP THE ECM/PCM USING ONLY THE FINGERTIPS - NO TOOLS. ^ To avoid excessive case deflection, avoid tapping in the center of the case. Tapping close to the edge of the ECM/PCM, especially in the corners, is best. ^ While using greater force may seem more effective, the test itself may cause the ECM/PCM to fail. Page 4292 Figure 15 - Large Retaining Clamp Installation 13. Secure the large metal clamp and seal to the housing with tool J35910, breaker bar and torque wrench. Torque the large clamp to 176 N-m (130 lbs.ft.). Check clamp ear gap dimension (Figure 15). Halfshaft Installation: 1. Prior to halfshaft installation, cover shock mounting bracket, lower control arm ball stud, and all other sharp edges with shop towels so that the seal is not damaged during assembly. 2. Remove convolute retainer. 3. Insert and draw up outer C/V joint splined shank into knuckle hub; then secure inboard C/V joint flange to companion flange with bolts (do not tighten). Install hub nut washer and nut. Seat shank splines in hub. 4. Connect the upper ball joint to the steering knuckle. 5. Attach the stud nut and torque 83 N-m (61 lbs.ft.). 6. Install new cotter pin. 7. Lubricate the upper ball joint until grease appears at the seal. 8. Remove floor jack or stand from beneath lower control arm, if used. 9. Connect the shock absorber to the lower shock mounting bracket. 10. Attach the shock mounting bolt and nut. Torque the nut and bolt to 73 N-m (54 lbs.ft.). 11. Attach outer tie rod to steering knuckle. 12. Install tie rod nut and torque to 47 N-m (35 lbs.ft.). Important: Advance the nut to align the nut slot with the cotter pin hole. Never back the nut off to align the cotter pin hole. 13. Install new cotter pin and spread the ends to secure. 14. Attach the brake line support bracket to the upper control arm. Torque to 17 N-m (13 lbs.ft.). Important: Make sure that the brake hose is not twisted or kinked or damage to the hose could result. Page 1771 Important The M6 conductive rivet stud as shown, can accommodate a panel thickness range of 0.7-4.2 mm (0.03-0.17 in). If there are layers of sheet metal, they should be touching without any air gaps to ensure a good ground. 5. Select a M6 conductive rivet stud. Refer to the Parts Information section of this bulletin. Note Use the GE-50317 rivet stud tool kit. 6. Place the M6 conductive rivet stud (1) in the 10 mm (0.40 in) hole. Assemble the rivet stud tool (2) with the groove and flare side facing the rivet stud, then the washer and the M6 nut (3). 7. Using a wrench on the rivet stud tool, and a socket on the M6 nut, secure the M6 conductive rivet stud. 8. Ensure the rivet stud is securely fastened, WITHOUT ANY detectable movement. 9. Completely wrap the threads of the rivet stud with painters tape or equivalent. Note The rivet stud and surrounding panel area MUST BE properly refinished PRIOR to the installation of the ground wire terminal and conductive nut to maintain a secure, stable and corrosion-free electrical ground. 10. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 11. Allow the refinished repair area to cure sufficiently before removing the protective material applied to the rivet stud threads. 12. Remove the painters tape or equivalent from the rivet stud threads. 13. Using GM approved residue-free solvent or equivalent, thoroughly clean the rivet stud threads to remove any adhesive and allow to dry. 14. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive rivet stud. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 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. A/T - Water Or Coolant Contamination Information Fluid - A/T: All 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. Page 4803 Brake Warning Indicator: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. Figure 21 Figure 22 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. Specifications TEMPERATURE SENSORS Page 5373 15. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 16. Install the electrical ground wire terminal to the rivet stud. 17. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 18. Install the M6 conductive nut to the rivet stud and: Tighten Tighten to 8 Nm (71 lb in). 19. Verify proper system operation. M6 Weld Nut Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M6 weld nut at the electrical ground location is damaged or stripped, a M7 conductive self-threading bolt may be used to secure the ground wire terminal. 2. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the weld nut and allow to dry. 3. Remove any loose metal particles from the damaged or stripped weld nut with a stiff brush. 4. Select a M7 conductive self-threading bolt. Refer to the Parts Information section of this bulletin 5. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M7 conductive self-threading bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 6. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 7. Install the electrical ground wire terminal to the M7 conductive self-threading bolt. 8. Install the M7 conductive self-threading bolt and: Tighten Tighten to 9 Nm (80 lb in). 9. Verify proper system operation. M6 Weld Nut Alternative Repair Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the electrical ground location is accessible from both sides of the panel, a M6 conductive bolt and a M6 conductive nut may be used to secure the electrical ground wire terminal. Refer to the Parts Information section of this bulletin. 2. Select a location adjacent the damaged M6 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the new electrical ground site. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the ground location and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 8.5 mm (0.33 in) diameter hole through the panel. 5. Remove paint and primer from the area surrounding the 8.5 mm (0.33 in) hole until bare metal is visible. 6. Select a M6 conductive bolt. Refer to the Parts Information section of this bulletin. 7. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 8. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 9. Install the electrical ground wire terminal and the M6 conductive bolt to the ground location. 10. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 11. Install the M6 conductive nut to the bolt and: Page 3960 SERVICE PARTS INFORMATION Part Number Description 15664811 Vacuum Actuator Switch Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: K4120 Use applicable labor time guide for labor hours. Rearview Mirror, Outside - Vibration Mirrors: Customer Interest Rearview Mirror, Outside - Vibration Group Ref.: Body Bulletin No.: 461001 Date: April, 1994 SUBJECT: OUTSIDE REAR VIEW MIRROR VIBRATION (INSTALL SET SCREW FASTENER) MODELS: 1982-93 CHEVROLET AND GMC TRUCK S/T PICKUPS 1983-94 CHEVROLET AND GMC TRUCK S/T UTILITIES WITH D44 OR D45 MIRRORS CONDITION: Some owners may comment that their outside rear view mirrors vibrate. CAUSE: Force is applied against the mirror arm by a retention spring wedged between the mirror bracket and mirror arm to prevent mirror rotation. Over time, this spring force decreases allowing the mirror arm to move or vibrate. CORRECTION: This condition can be corrected by drilling and tapping a hole in the retention spring to accept a set screw fastener. The fastener can be adjusted to force the spring against the mirror arm, restoring the original pressure. SERVICE PROCEDURE: 1. From outside the vehicle, remove the screws which secure the mirror cover and the mirror assembly to the door (Figure 1). 2. Remove the mirror assembly from the door. 3. Remove the mirror head and arm from the mirror bracket. Page 6982 Page 4806 Figure 8 Figure 9 Figure 10 Figure 11 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). Page 5419 Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Description Labor Op. Striker and/or Support - Replace (RH) B5820 Striker and/or Support - Replace (LH) B5821 Page 6181 ^ To check the position of the axial plate on the shaft. remove the clutch driven plate and measure the distance between the front head extension and the flat shoulder on the shaft with a wire gage. The clearance should be 0.66-1.9 mm (0.026-0.075-inch). ^ If the shaft has been pushed back in the axial plate (measurement greater than 1.9 mm (0.075-inch), disassemble the compressor and replace the shaft and axial plate assembly. thrust races and thrust bearings. ^ If there is too much or not enough air gap between the drive and driven plates. check for shaft dislocation. It will not be possible to service the compressor if the carbon seat is not seating against the seal seat. 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 Page 5475 Fusible Link: Locations Fuse Link B Center Of Dash Panel (engine Compartment) At Rear Of Generator Applicable to: V6-262/4.3L Engine Page 2171 FIGURE 1(T-TRUCK ONLY) G. (T-truck only) Check equalizer lever for firm contact at the shift lever inboard side of the guide slot. (See Figure 1) H. If firm contact is evident, add an additional washer (#10 in Figure #1) P/N 14074908 to adjust equalizer lever outboard toward the center of the guide slot to eliminate contact. 2. A. Raise vehicle on hoist. B. Note location of clamp rotation on pipe. Some clamps are located with the lower lock ring (nuts) pointed towards the transmission. If the clamp is located in such a manner, loosen clamp and rotate it down so the nuts point toward the ground and retighten to 58 N-m (43 ft/lbs.) 3. A. Loosen converter clamp until it will rotate around the pipe. Using a suitable pry bar, move exhaust system rearward to obtain a minimum of 5/8 in. clearance between any point on the exhaust system and the transmission crossmember. For repairs performed under warranty, use the following labor operations and times: Labor Operation Labor Time Exhaust/muffler clamp L2020 .3 Hr Exhaust system align L2004 .3 Hr Shift Linkage (shorten) K5244 .3 Hr Page 2924 Disclaimer Steering - System Bleed Procedures Power Steering Pump: Technical Service Bulletins Steering - System Bleed Procedures Group Ref.: Steering/Suspension Bulletin No.: 383001 Date: December, 1993 INFORMATION SUBJECT: ILLUSTRATED STEERING SYSTEM BLEED PROCEDURE MODELS: 1994 AND PRIOR PASSENGER CARS AND LIGHT DUTY TRUCKS THIS BULLETIN IS BEING REVISED TO ADD THE 1994 MODEL YEAR AND CHANGE THE ARTWORK. PREVIOUS DIVISIONAL PUBLICATION NUMBERS WERE: BUICK 93-3-5 3/02/93 CADILLAC T-93-76 5/12/93 CHEVROLET 93-146-3B 3/29/93 GM OF CANADA 93-3-102 5/05/93 OLDSMOBILE 2-93-59 (S.G.) 5/14/93 The steering system in 1994 and prior model year cars and light duty trucks should be bled after any of the following: - A power steering component is replaced. - A fluid line is disconnected. - A customer comments on steering system noise. Bleeding air from the steering system should be done in order to prevent pump damage, ensure proper operation, and to eliminate steering system noise. Cowl - Popping/Tapping Noise Cowl: Customer Interest Cowl - Popping/Tapping Noise Number: 91-351-10 Section: 10 Date: JUNE 1991 Corporate Bulletin No.: 162001R Subject: COWL "POP"/TAPPING NOISE Model and Year: 1983-91 S/T TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 86-58, DATED APRIL 1986. THE SERVICE PROCEDURE HAS BEEN UPDATED AND THE 1987-91 MODEL YEARS ADDED. ALL COPIES OF 86-58 SHOULD BE DISCARDED. Some 1983-1991 S/T pickup and utility vehicles may experience a "popping" noise from the cowl area (at the base of the "A" pillar in front of the speaker grills). The sound may emanate from either side of the vehicle. The exact cause of this condition is currently unknown. Cowl "pop" is defined as a tapping noise at the lower corner of the windshield or base of the "A" pillar that usually, but not always, occurs when the vehicle is cold (below 45 degrees F). The sound is simiiar to the noise made when tapping a pencil point on the windshield. Some success has been achieved in correcting this condition by trimming areas of hood flange that may contact the cowl vent panel, by relieving any stress that may be created by the front fender mounting sequence, and by loosening the # 1 body mount and/or shimming one or both front body mounts. SERVICE PROCEDURE: NOTE: Typically this condition occurs only when the vehicle sheet metal is at a temperature below 45 degrees F. The condition may temporarily disappear if vehicle evaluation is performed after a vehicle has been in a warm environment. REMOVAL OF HOOD FLANGE MATERIAL: Some ST vehicles experiencing a cowl "pop" tapping noise may be corrected by trimming the back edge of the hood flange. On a small number of vehicles, excess material on the rear edge of the hood flange contacts the front of the cowl vent panel causing a tapping noise when the vehicle goes over a bump. 1. Visually inspect for witness marks in the painted area of the cowl vent panel to determine if the hood flange contacts any cowl panel surfaces. 2. If witness marks are not present, it is not necessary to perform Steps 3 and 4. Continue to "Relieving Fender Mounting Stress" Section. If witness marks are present, trim off approximately 1/8" of the hood flange only in the areas contacting the cowl vent panel using Jilson Tool 1451 SS or equivalent. 3. Refinish the bare metal on the trimmed areas and on matching cowl vent panel areas to prevent corrosion. RELIEVING FENDER MOUNTING STRESS: Some success has been achieved in correcting the cowl "pop" tapping condition by relieving the stress caused by the front fender mounting sequence. 1. Remove windshield wiper arms using Kent-Moore Tool J-8966 Remover and Installer, or equivalent. 2. Remove cowl vent panel assembly. 3. Loosen the four rear fender mounting bolts to zero torque. (One of the upper fender mounting bolts is located underneath the hood hinge seal.) 4. Retorque the two lower fender bolts to 20-34 N-m (15-25 Lbs.Ft.). 5. The upper hinge mounting bolt should be left at zero torque. Apply Loctite 242 thread locking compound (GM P/N 12345382), or equivalent, to hold in place. Retorque the remaining upper fender bolt to 20-34 N-m (15-25 Lbs.Ft.). 6. Reinstall cowl vent panel assembly and windshield wiper arms. Fastener Tightening Specifications Wheel Fastener: Specifications Fastener Tightening Specifications 1992 S Series Pickups......................................................................................................................... ................................................................95 ft/lbs 1992 Safari........................................................................................................................................... .............................................................100 ft/lbs 1992 M Van.......................................................................................................................................... ............................................................100 ft/lbs 1992 S Series Jimmy............................................................................................................................ ...............................................................95 ft/lbs 1992 S Series Sonoma......................................................................................................................... ................................................................95 ft/lbs 1991-92 C-, K10-20.............................................................................................................................. .................................................................120 ft/lbs 1991-92 C-, K30: Single Rear Wheel................................................................................................................................ .............................................120 ft/lbs Dual Rear Wheels (8 lug)......................................................... ..........................................................................................................140 ft/lbs Dual Rear Wheels (10 lug)........................................................................................................................................................ .........175 ft/lbs 1991-92 R-, V30: Single Rear Wheel................................................................................................................................ .............................................120 ft/lbs Dual Rear Wheels (8 lug)......................................................... ..........................................................................................................140 ft/lbs Dual Rear Wheels (10 lug)........................................................................................................................................................ .........175 ft/lbs 1990-92 Lumina APV........................................................................................................................... .................................................................100 ft/lbs 1989-92 Van: G10-25.................................................................................................................................................. .............................................100 ft/lbs G30-35 Single Rear Wheel...................................................... ..........................................................................................................120 ft/lbs G30-35 Dual Rear Wh eels....................................................................................................................................................... ..........140 ft/lbs 1991 R-, V10........................................................................................................................................ .............................................................100 ft/lbs 1991 R-, V20........................................................................................................................................ .............................................................120 ft/lbs 1990-91 S Series: 2WD...................................................................................................................................................... ...............................................80 ft/lbs 4WD......................................................................................... ..........................................................................................................100 ft/lbs 1990 C-, K-, Pickup.............................................................................................................................. ............................................................105 ft/lbs 1990 C-, K-, Sierra................................................................................................................................ ............................................................105 ft/lbs 1990 C-, K-35 W/Dual Rear Wheels..................................................................................................... ...........................................................125 ft/lbs 1990 R-, V-Pickup: Single Rear Wheel................................................................................................................................ .............................................120 ft/lbs Dual Rear Wheels.................................................................... ..........................................................................................................140 ft/lbs 1989 Pickups: Single Rear Wheel................................................................................................................................ .............................................120 ft/lbs Dual Rear Wheels.................................................................... ..........................................................................................................140 ft/lbs 1989 Sierra: Single Rear Wheel................................................................................................................................ .............................................120 ft/lbs Dual Rear Wheels.................................................................... ..........................................................................................................140 ft/lbs 1989 Safari........................................................................................................................................... .............................................................102 ft/lbs 1988-89 S Series: With Aluminum Wheels........................................................................................................................ ...............................................90 ft/lbs Without Aluminum Wheels....................................................... ...........................................................................................................73 ft/lbs 1988 R-, V-Pickup: Single Rear Wheels.............................................................................................................................. ..............................................103 ft/lbs Dual Rear Wheels................................................................... ...........................................................................................................140 ft/lbs 1988 C-, K10-15: Single Rear Wheel................................................................................................................................ ...............................................90 ft/lbs Dual Rear Wheels.................................................................... ..........................................................................................................125 ft/lbs 1988 Sierra: Single Rear Wheel................................................................................................................................ ...............................................90 ft/lbs Dual Rear Wheels.................................................................... ..........................................................................................................125 ft/lbs 1988 Astro............................................................................................................................................ .............................................................102 ft/lbs 1988 Safari........................................................................................................................................... .............................................................102 ft/lbs 1988 Van G10-25................................................................................................................................. .............................................................102 ft/lbs 1988 Van G30-35: 5 bolts................................................................................................................................................... ..............................................117 ft/lbs 8 bolts..................................................................................... ............................................................................................................139 ft/lbs 1987-88 R-, V-Blazer: 2WD...................................................................................................................................................... .............................................103 ft/lbs 4WD With Aluminum Wheels, 6 lug.................................................................................................................................................103 ft/lbs 4WD Without Aluminum Wheels, 6 lug..............................................................................................................................................88 ft/lbs 1987-88 R-, V-Jimmy: 2WD...................................................................................................................................................... .............................................103 ft/lbs 4WD With Aluminum Wheels, 6 lug.................................................................................................................................................103 ft/lbs Page 5607 Alignment: Specifications (Figure 1) Front End Alignment Specifications NOTE: Vehicle must be jounced three times before checking alignment to eliminate false geometry readings. (A) Front suspension "Z" dimension and rear suspension "D" dimension are held as indicated in Adjustments / Curb Trim Heights. See: Service and Repair/Ride/Trim Height Measurement and Adjustment Front end alignment specifications are indicated in (Figure 1). (B) Left and right side to be equal within 0.50 degree. (C) Left and right side to be equal within 1.0 degree. (D) Toe-in-left and right side to be set separately per wheel and steering wheel must be held in straight ahead position within ± 5.0 degree. Page 1636 5. Replace the previous transmission mount with the revised mount (P/N 22145724 - for two wheel drive only) as shown in Figure 4. Some residual vibrations may be normal. Compare with a vehicle of same model, year, engine/transmission combination, etc. to get a feel for what is normal. SERVICE PARTS INFORMATION Parts are expected to be available from GMSPO on 8/2/93. WARRANTY INFORMATION Page 7388 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 4. Make repair. Page 4454 FIGURE 1 If this condition is encountered, and cannot be corrected using normal diagnostics, a newly released rear transmission mount may be installed (see Figure 1). This rear transmission mount is currently in use on 1988-90 Cl, C2, and C3 pickups with 4.3 L engines and 3- speed automatic transmissions (M40). When installing this mount, new service washers (one washer per bolt) are required for retaining mount to transmission. Also install a new nut on the stud when attaching mount to cross member. IMPORTANT: This mount is not for use on 1991 S/T 4 door utility or any 1988-91 T model pickup or utility. PARTS INFORMATION PART NUMBER DESCRIPTION QUANTITY 15567796 Mount 1 15614758 Washer 2 Page 6649 Figure 8 Figure 9 Figure 10 Figure 11 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). Page 1951 Valve Clearance: Adjustments Fig. 14 Valve Adjustment 1. Remove rocker arm covers as described under COMPONENT REPLACEMENT AND REPAIR PROCEDURES/ROCKER ARM & PUSHRODS. 2. Crank engine until mark on torsional damper is aligned with ``0'' mark on timing tab and engine is in No. one cylinder firing position. Ensure engine is in No. 1 firing position by placing fingers on rocker arms of No. 1 cylinder as timing mark approaches ``0'' mark. If rocker arms are not moving engine is at the No. 1 firing position. If rocker arms are moving, engine is in the No. 4 firing position and should be rotated one revolution to the No. 1 position. 3. Adjust the following valves with the engine in the No. 1 firing position: exhaust 1, 5 and 6; intake 1, 2 and 3. Adjust valves by backing off nut until lash is felt at the pushrod, then tightening nut until all lash is removed. This can be determined by rotating pushrod while tightening nut. Fig. 14. When all lash is removed, tighten nut one full turn to center pushrod in lifter plunger. 4. Crank engine one full revolution until mark on torsional damper and ``0'' mark on timing tab are aligned. This is the No. 4 cylinder firing position. Adjust the following valves: exhaust 2, 3 and 4; intake 4, 5 and 6. 5. Install valve covers and related components. Page 273 DA-V5 Compressor Component View Remove or Disconnect Tool Required: J 9553-01 O-ring Remover 1. Retainers (44) from switches (3) and (4). 2. Switches (3) and (4). 3. O-ring seals (44) from the switch cavities with J 9553-01. Clean ^ Switch cavity and O-ring seal groove. Install or Connect Tools Required: Page 2855 Catalytic Converter: Testing and Inspection Proper diagnosis for a restricted exhaust system is essential before any components are replaced. The following procedures may be used for diagnosis, depending upon engine or tool used: Exhaust System Check CHECK AT A.I.R. PIPE: 1. Remove the rubber hose at the exhaust manifold A.I.R. pipe check valve. Remove check valve. 2. Connect a fuel pump pressure gauge to a hose and nipple from a Propane Enrichment Device. 3. Insert the nipple into the exhaust manifold A.I.R. pipe. CHECK AT 02 SENSOR: 1. Carefully remove O2 sensor. 2. Install Exhaust Backpressure Tester in place of 02 sensor. 3. After completing test described below, be sure to coat threads of 02 sensor with antiseize compound prior to re-installation. DIAGNOSIS: 1. With the engine at normal operating temperature and running at 2500 rpm, observe the exhaust system backpressure reading on the gauge. 2. If the backpressure exceeds 1-1/4 psi (8.62 kPa), a restricted exhaust system is indicated. 3. Inspect the entire exhaust system for a collapsed pipe, heat distress, or possible internal muffler failure. 4. If there are no obvious reasons for the excessive backpressure, a restricted catalytic converter should be suspected, and replaced. 3L30 (180C) Transmission Valve Body: Specifications 3L30 (180C) Transmission Component .......................................................................................................................................... .................................................................... Ft. Lbs. Transfer Plate To Valve Body .............................................................................................................. ................................................................................ 7 Valve Body To Case ........................................ .............................................................................................................................................................. .... 14 Locking Differential - Chattering on Turns Fluid - Differential: All Technical Service Bulletins Locking Differential - Chattering on Turns Number: 91-370-0B Section: 0B Date: JULY 1991 Corporate Bulletin No.: 964201R Subject: LOCKING DIFFERENTIAL LUBRICANT Model and Year: 1982-91 ALL TRUCKS WITH G80 REAR AXLE THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 90-139-4A, DATED JANUARY 1990. CONDITION DESCRIPTION AND CORRECTION HAVE BEEN ADDED AS WELL AS THE 1991 MODEL YEAR. ALL COPIES OF 90-139-4A SHOULD BE DISCARDED. Some light duty trucks equipped with locking rear axles (G80) may exhibit rear axle chatter, especially when turning a corner from a stop. This condition of alternate engagement and disengagement of the clutches in the differential assembly is usually caused by contaminated axle lubricant. To correct this condition, drain and refill the rear axle with SAE 80W-90 GL5 (P/N 1052271). The use of any additive in locking rear axles (G80) is not recommended. Rear axle additives are designed for use in limited slip differentials which are normally installed in cars. All light duty trucks equipped with RPO G80 make use of a locking differential and the use of additives will delay the engagement of the locking mechanism and may decrease axle life. VEHICLES/COMPONENTS INVOLVED: Some light duty trucks equipped with locking rear axles, RPO G80. SERVICE PARTS INFORMATION: Part Number Description 1052271 Lubricant, Rear Axle (24 oz.) See Appropriate Parts Manual Gasket, Rear Axle Housing Cover Parts are currently available through GMSPO. WARRANTY INFORMATION: As specified in Light Duty Truck Maintenance Schedules, locking rear axle fluid drain and refill is required owner maintenance at the first engine oil change. Failure to drain and refill the rear axle as specified may contribute to a later axle chatter condition. Refer to the appropriate Light Duty Truck Maintenance Schedule or service manual, section 0B, for further details on change intervals. For those vehicles repaired under warranty, which have had the axle fluid changed at the first oil change and have experienced rear axle chatter use: Labor Operation: F2010 Use applicable labor time guide for labor hours. Page 4722 Labor Operation No.: K6550 Valve, Pressure Regulator-R&R; or Replace Use the appropriate labor time in the labor time guide. Parts are currently available from GMSPO. Page 889 Figure 1 TRANSMISSION FLUID CHECKING PROCEDURE: 1. Start engine and drive vehicle for a minimum of 24 km (15 miles), or until normal operating temperature is reached. NOTICE: The automatic transmission fluid level must be checked with the vehicle at normal operating temperature, 82-93C (180- 200F). Temperature will greatly affect transmission fluid level. If the vehicle is not at normal operating temperature and the proper checking procedures are not followed, the result could be a false reading of the fluid level indicator and an incorrect adjustment of the fluid level. 2. Park vehicle on level ground. 3. Move gear selector to "PARK". 4. Apply parking brake and block wheels. 5. Let vehicle idle for 3 minutes with accessories off. 6. Check fluid level, color and condition (refer to Figure 1). * Inaccurate fluid level readings win result if the fluid is checked immediately after the vehicle has been operated under certain conditions: - In high ambient temperature above 32C (90F). - At sustained high speeds. - In heavy city traffic during hot weather - As a towing vehicle. - In commercial service (taxi or police use). * If the vehicle has been operated under these conditions, shut the engine off and allow the vehicle to "cool" for thirty (30) minutes. After the cooldown period, restart the vehicle and continue from step "2" above. Engine - Drive Belt Misalignment Diagnostics Drive Belt: All 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. Page 4647 - Tighten poppet screw to 31 N-m (23 lbs.ft.). - New poppet plunger P/N 15633556 (70) group A vehicles only. - New poppet spring P/N 15633557 (71) group A vehicles only. - New poppet screw P/N 15633558 (68) group A vehicles only. 23. Vacuum switch (46) and new O-ring P/N 14071849 (47) to the front case housing. - Tighten switch to 24 N-m (17 lbs.ft.). 24. Front output flange (74), rubber sealing washer (75), washer (76) and flange nut (77). - Tighten nut (26) to 149 N-m (110 lbs.ft). 25. New vent pipe P/N 15581915 in new front case half (group A vehicles only). - Lightly coat end of vent pipe with Loctite 609 (R) or equivalent. 26. Transfer case into vehicle. - Refer to section 7D of the appropriate S/T Service Manual for complete transfer case replacement procedure. Service Parts & Warranty Information SERVICE PARTS INFORMATION: The "Easy Shift" package consists of the following parts. Parts must be ordered individually. Required Parts Part Quantity Figure 1 Group A Group B Number Description Required Reference Trucks Trucks 15635347 Front case half 1 45 X 15637215 Sector W/shaft 1 55 X X 15637217 Mode shift fork 1 54 X X 15633556 Poppet plunger 1 70 X 15633557 Poppet spring 1 71 X 15633558 Plug 1 68 X 14071849 O-ring 2 69 & 47 X X 15581915 Vent Pipe 1 N/S X 14095609 Input seal 1 42 X 14037958 Retainer 1 66 X X 14095598 Range sector seal 1 67 X X 15579788 Output front seal 1 72 X 15642511 Adapter gasket 1 N/S X X 15579803 Drive Sprocket 1 20 * * 14071703 Synchronizer 1 28 * * Blocking Ring * These parts required only if damaged or in cases of customer complaint of clash when shifting from 2Hi to 4Hi. Parts are currently available from GMSPO. WARRANTY INFORMATION: For vehicles repaired under warranty use: Labor Labor Operation Truck Time Detonation Sensor LH Rear Of Engine, At Rear Of Cylinder Head Page 1800 15. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 16. Install the electrical ground wire terminal to the rivet stud. 17. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 18. Install the M6 conductive nut to the rivet stud and: Tighten Tighten to 8 Nm (71 lb in). 19. Verify proper system operation. M6 Weld Nut Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M6 weld nut at the electrical ground location is damaged or stripped, a M7 conductive self-threading bolt may be used to secure the ground wire terminal. 2. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the weld nut and allow to dry. 3. Remove any loose metal particles from the damaged or stripped weld nut with a stiff brush. 4. Select a M7 conductive self-threading bolt. Refer to the Parts Information section of this bulletin 5. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M7 conductive self-threading bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 6. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 7. Install the electrical ground wire terminal to the M7 conductive self-threading bolt. 8. Install the M7 conductive self-threading bolt and: Tighten Tighten to 9 Nm (80 lb in). 9. Verify proper system operation. M6 Weld Nut Alternative Repair Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the electrical ground location is accessible from both sides of the panel, a M6 conductive bolt and a M6 conductive nut may be used to secure the electrical ground wire terminal. Refer to the Parts Information section of this bulletin. 2. Select a location adjacent the damaged M6 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the new electrical ground site. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the ground location and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 8.5 mm (0.33 in) diameter hole through the panel. 5. Remove paint and primer from the area surrounding the 8.5 mm (0.33 in) hole until bare metal is visible. 6. Select a M6 conductive bolt. Refer to the Parts Information section of this bulletin. 7. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 8. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 9. Install the electrical ground wire terminal and the M6 conductive bolt to the ground location. 10. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 11. Install the M6 conductive nut to the bolt and: Specifications Distributor: Specifications Distributor Hold-down Clamp Bolt ............................................................................................................................................................. 27 Nm (20 lb-ft) Page 7352 Note the difference between the wire exit openings of the new multi-functional lever and the old lever (Figure 1). Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Op. Description E7060 Multi-functional lever, replace Use applicable labor time guide for labor hours. Page 6203 1. Valve (5). 2. O-ring seal (44) with J 33011. ^ Dip the seals into new clean 525 refrigerant oil. 3. Retainer (45) with J 5403. Page 6977 Figure No. 1 NOTICE: For two tone vehicles, it is only necessary to refinish surfaces painted Galaxy Blue, Aspen Blue or Steel Gray. Other colors should not be affected by this condition. The front bumper filler panel and all surfaces painted with affected colors above the belt line (Fig. 1, page 3) must be refinished according to the procedure listed below (regardless of previous paint repairs). If surfaces below the belt line and the interior of the pickup box (on pickup models) appear to be in good condition, the dealer should scuff sand, seal and color coat those painted surfaces rather than refinish. However, if any peeling or topcoat delamination is evident, or If scuff sanding produces any topcoat delamination, it will be necessary to refinish these surfaces as well, according to the procedures. It should not be necessary to paint inside of door jambs, or underneath exterior moldings or decals (sunshine stripes), as these areas are not normally subjected to continued ultraviolet exposure. 2. Sand original finish coat of paint down to electro-coat (Elpo) primer, making sure factory pretreatment and Elpo primer are still intact for good corrosion protection. DO NOT USE CHEMICALS TO REMOVE PAINT AS THIS MAY DAMAGE THE ELPO PRIMER. NOTICE: Rough tape vehicle as necessary (window glass, etc.), and remove nameplates, weatherstrips, and reveal moldings as needed to properly refinish all surfaces as required. 3. Finish sand exposed Elpo primer with 240 grit sandpaper to assure removal of any chalky residue or degraded Elpo primer that may remain as a result of overbaking the primer. NOTICE: Avoid sanding through Elpo to bare metal when possible. 4. Use an air gun to remove all dirt from cracks and surfaces of truck. 5. Clean sanded surfaces with grease and wax remover. Page 199 Wiring Diagram For Chart C-5 - Electronic Spark Control System Check CIRCUIT DESCRIPTION: Electronic spark control is accomplished with a module that sends a voltage signal to the ECM. As the knock sensor detects engine knock, the voltage from the ESC module to the ECM is shut "OFF" and this signals the ECM to retard timing, if engine RPM is over about 900. TEST DESCRIPTION: Numbers below refer to circled numbers on the diagnostic chart. 1. If A Code 43 is not set, but a knock signal is indicated while running at 1500 RPM, listen for an internal engine noise. Under a no load condition there should not be any detonation, and if knock is indicated, an internal engine problem may exist. 2. Usually a knock signal can be generated by tapping on the right exhaust manifold. This test can also be performed at idle. Test number 1 was run at 1500 RPM to determine if a constant knock signal was present, which would affect engine performance. 3. This tests whether the knock signal is due to the sensor, a basic engine problem, or the ESC module. 4. If the module ground circuit is faulty, the ESC module will not function correctly. The test light should light indicating the ground circuit is OK. 5. Contacting CKT 496, with a test light to 12 volts, should generate a knock signal to determine whether the knock sensor is faulty, or the ESC module can't recognize a knock signal. DIAGNOSTIC AIDS: "Scan" tools have two positions to diagnose the ESC system. The knock signal can be monitored to see if the knock sensor is detecting a knock condition and if the ESC module is functioning, knock signal should display "yes", whenever detonation is present. The knock retard position on the "Scan" displays the amount of spark retard the ECM is commanding. The ECM can retard the timing up to 20 degrees. This check should be used after other causes of spark knock have been checked such as engine timing, EGR systems, engine temperature or excessive engine noise. Adjustments Ride Height Sensor: Adjustments When repair or adjustment procedures require that vehicle be raised on a hoist, it is important that the rear axle assembly remains in the normal trim height position at all times. When a frame contact hoist is used, two additional jack stands should be used to support the rear axle or control arms in the normal trim height position. Fig. 21 Adjusting Height Sensor The link should be properly attached to the sensor arm and track bar, when making this adjustment. 1. Loosen lock bolt that secures metal arm to height sensor plastic arm, Fig. 21. 2. To raise vehicle trim height, move plastic arm upward and tighten lock bolt. If no adjustment remains, refer to FRONT SUSPENSION/SPECIFICATIONS/VEHICLE TRIM HEIGHT. 3. To lower vehicle trim height, follow step 1 and move plastic arm down. 4. If adjustment cannot be made, check for correct sensor. Page 5689 Steering Gear: Description and Operation Nippon Seiko Recirculating Ball Gear Manual Steering Fig. 1 Cross Sectional View Of Nippon Seiko Steering Gear The pitman arm is rigidly connected to the outer end of the sector gear shaft. Between the ball nut and the worm, Fig. 1, is a row of steel balls, which serves two purposes: to provide rolling contact between the ball nut and worm shaft and to keep the ball nut engaged with the worm as if the two were threaded together. With the nut prevented from turning, the rotation of the worm causes the nut to move up or down the shaft. The worm shaft is an extension of the steering shaft. As the steering wheel is turned, the steel balls roll along in the groove and the nut moves up or down. The steel ball that has reached the end of the groove in the nut enters the return guide. The guide sends the ball back to the other end of the same groove and the row of balls recirculates. The nut then turns the sector gear which turns the pitman arm. This steering gear is a precision machined unit, calling for special tools for internal repair. The unit should be replaced instead of being repaired. Description and Operation Cruise Control Vacuum Vent Solenoid: Description and Operation These devices are used to disengage the cruise control system when the brake and/or clutch pedal is depressed. The electrical release interrupts the electrical signal to the controller to disengage the system. The vacuum release vents trapped vacuum in the servo into the atmosphere, allowing the servo to return to throttle idle position. These release mechanisms can also be found combined with TCC and/or stop lamp switches. Page 7978 Power Window Motor: Service and Repair Power Window Motor Replacement Tools Front Door Components NOTE: Images shown are for manual windows, power windows are similar. REMOVE OR DISCONNECT Page 2743 Knock Sensor: Description and Operation Knock Sensor Operation ESC Wiring Diagram The Electronic Spark Control (ESC) system is comprised of a knock sensor, the ESC module, and the ECM. As the knock sensor detects engine knock, it sends a voltage signal to the ECM. The ECM responds by retarding the ignition timing until the knocking ceases. As detonation is reduced, the ECM advances the timing again in small increments back to the pre-programmed point for that engine speed and load. Page 1547 Valve: Specifications Valve Arrangement All ......................................................................................................................................................... ................................................................ E-I-E-I-I-E Constant Velocity Type Universal Joint: Service and Repair Constant Velocity Type Disassembly and Assembly Fig. 10 Constant Velocity (CV) Universal Joint This type of universal joint, Fig. 10, consists of two conventional cross and roller joints connected with a special link yoke. Because the two joint angles are the same, even though the usual universal joint fluctuation is present within the unit, the acceleration of the front joint (within the yoke) is always neutralized by the deceleration of the rear joint (within the yoke) and vice versa. The end result is the front and rear propeller shafts always turn at a constant velocity. 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) 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 with relation to the propeller shaft so they may be reassembled in the same relative position. Failure to observe these precautions may produce rough vehicle operation which results in rapid wear and failure of parts, and place 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. Some driveshafts use an injected nylon retainer to hold the bearing cups. When service is necessary, pressing the cups out will sheer the nylon retainer, Page 4303 21. Lubricate the seal lip. - If seal is cut or torn, inspect the wheel bearing for damage and replace the seal. 22. If necessary, replace the seal as follows: - Pry old seal from knuckle and discard. - Lubricate the new seal lip. - Use a flat plate to press the seal down flush with the knuckle. Tripot Housing/Tripot Seal Replacement Figure 10 - Inboard Joint Disassembly Required Tools: J8059 Snap Ring Pliers J35910 Seal Clamp Tool 1. Place halfshaft in vise (use protective covers over vise jaws). 2. Remove seal clamp protectors (Figure 10) if used, from inner C/V joint and cut clamp(s) from seal with a pair of side cutters. For swage ring removal use a hand grinder to cut through the ring (taking care not to damage the housing). 3. Remove tripot housing from halfshaft and wipe grease from tripot assembly roller bearings and housing. Thoroughly degrease the housing and allow to dry prior to assembly. Important: Handle tripot spider assembly with care. Tripot balls and needle rollers may separate from spider trunnions. 4. Slide seal up on the shaft and inspect rollers, needle bearings, and trunnions. Check housing for unusual wear, cracks, and other damage. Replace housing and/or tripot assembly as needed. Page 6081 Heater Wiring Diagram. Brake Light Switch Brake Light Switch: Locations Brake Light Switch LH Side Of I/P Behind Instrument Cluster Page 7130 6. Spray entire prepared area with a coat of DP40/DP401 anti-corrosion primer (PPG/ Ditzler) or equivalent. Follow manufacturers instructions and recommended dry times. 7. Apply 2 to 3 medium wet coats of primer-surfacer to primed surfaces of truck, making sure to follow manufacturers instructions for application. 8. After allowing adequate drying time, wet sand with 400 grit (or finer) sandpaper or dry sand with 320 grit (or finer) sandpaper. 9. Repeat steps 4 and 5. 10. Apply 1 medium wet coat of primer sealer, following manufacturers instructions. 11. Apply 3 to 4 medium wet coats (or until primer color is well hidden) of Acrylic/Urethane Enamel Color. Follow manufacturers instructions. NOTICE: Reinstall all trim and other items removed in step 2. 12. Final wash and detail vehicle. Claim Information Submit a claim with the information indicated below: * Select times as listed below for "Labor Hours" and material allowances for "Net Amount" as required for appropriate vehicle type and operation performed. Campaign - 90-33O-3E Spare Tire Carrier Rattle Update Spare Tire Carrier: All Technical Service Bulletins Campaign - 90-33O-3E Spare Tire Carrier Rattle Update ADMINISTRATIVE MESSAGE 01-330 CREATED ON 11/16/90 TO: ALL CHEVROLET/GEO DEALERS SUBJECT: DEALER SERVICE BULLETIN 90-33O-3E - "SPARE TIRE CARRIER RATTLE" THE FOLLOWING INFORMATION SHOULD BE COMMUNICATED TO ALL TECHNICIANS INVOLVED IN REPAIRING SPARE TIRE CARRIER RATTLE ON 1986-1991 S/T BLAZERS. A COPY OF THIS MESSAGE SHOULD ALSO BE ATTACHED TO DEALER SERVICE BULLETIN 90-33O-3E. 1. THE LATCH SYSTEM USED ON THE 1986-91 S/T SPARE TIRE CARRIER CONSISTS OF A DOUBLE LATCH MECHANISM AND FUNCTIONS SIMILAR TO THE DOUBLE LATCH EMPLOYED ON HOOD ASSEMBLIES. THE INITIAL LATCH PROVIDES FOR A BACKUP, SHOULD THE MAIN LATCH BECOME DISENGAGED. HOWEVER, THE VEHICLE IS INTENDED TO BE OPERATED WITH THE SPARE TIRE CARRIER LOCKED IN PLACE BY THE MAIN LATCH. CONCERNS OF SPARE TIRE CARRIER RATTLE MAY BE CAUSED DUE TO THE CARRIER ASSEMBLY NOT BEING COMPLETELY CLOSED, BUT RATHER ENGAGED BY THE INITIAL (BACKUP) LATCH ONLY. PRIOR TO ATTEMPTING ANY REPAIRS, AND BEFORE PROCEEDING WITH BULLETIN 90-33O-3E, TECHNICIANS SHOULD OPEN AND THEN FIRMLY CLOSE THE SPARE TIRE CARRIER, VERIFYING THAT THE MAIN LATCH IS FULLY ENGAGED. IF NECESSARY, ROAD TEST THE VEHICLE TO CONFIRM THAT A RATTLE CONDITION STILL EXISTS BEFORE PROCEEDING WITH THE BULLETIN. 2. PRIOR TO ADJUSTING THE RUBBER BUMPER, ASSURE THAT THE NEW ARM IS FULLY ENGAGED IN THE MAIN LATCH MECHANISM. FAILURE TO HAVE THE CARRIER ARM LOCKED IN THE MAIN LATCH WILL RESULT IN AN IMPROPER ADJUSTMENT TO THE BUMPER. 3. THERE IS A TYPOGRAPHICAL ERROR AT THE BOTTOM OF PAGE 4 IN THE PARAGRAPH DIRECTLY FOLLOWING THE WORD IMPORTANT! THE PARAGRAPH SHOULD READ: "THE RUBBER BUMPER WILL CAUSE THE SPARE TIRE CARRIER TO CLOSE HARD FOR A COUPLE OF WEEKS. EVENTUALLY THE RUBBER WILL TAKE A PERMANENT SET AND THE CARRIER WILL CLOSE WITH REASONABLE EFFORT." Page 1093 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. Page 2191 Figure 1 Some 1988-1991 S/T vehicles with a 4.3L engine may experience exhaust manifold heat shield rattle. This condition can occur if the heat shield is improperly installed. To correct this condition, it is necessary to reposition the heat shield and bend its rear tab for proper fit throughout the mounting bracket. It may also be necessary to bend the mounting bracket slightly. SERVICE PROCEDURE: 1. Raise the vehicle on a hoist following proper lift procedures. 2. Allow the exhaust manifold and catalytic converter to cool. CAUTION: Exhaust manifold and/or catalytic converter may be extremely hot. Allow them to cool to avoid personal injury. 3. Reposition the exhaust manifold heat shield rearward insuring the full length of the rear tab is completely through the mounting bracket slot (Figure 1). The rear tab is "folded". This "fold" should extend approximately 1/2 in. (12.7 mm) beyond mounting bracket slot. 4. Slide the heat shield inboard as far as possible within the mounting bracket slot. 5. Bend the accessible portion of the rear tab down to limit up and down movement of the shield. 6. Check heat shield for possible side movement and/or rattle. 7. If the heat shield can be moved and/or rattles, bend the mounting bracket toward the front of the vehicle and slightly upward snugging the mounting bracket against the heat shield. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: L2280 Use applicable labor time guide for labor hours. Aluminum Wheels - Cosmetic Damage During Balancing Wheels: Customer Interest Aluminum Wheels - Cosmetic Damage During Balancing Number: 93-197-3E Section: 3E Date: MAY 1993 Corporate Bulletin No.: 393502 ASE No.: A4 Subject: INFORMATION ON COSMETIC DAMAGE TO ALUMINUM WHEELS DURING BALANCING Model and Year: 1988-93 C1, K1, G, E/J, L/M, P, S/T, R/V 1990-93 LUMINA APV Some aluminum wheels on GM models may incur cosmetic damage during balancing if proper care and procedures are not used. All aluminum wheels have a clearcoat paint on them that must be cared for like any other painted surface. Some off-car wheel balancer retaining cups used to clamp the wheel to the balancer may put a circular mark into the clearcoat on the face of the wheel. Like any other clearcoat damage, this may be difficult to remove or repair, depending on severity. ALWAYS use balancer retainer cups that are protected with rubber, plastic, or other nonmetallic materials where contact is made with the wheel. Make sure the retainer cup is free from dirt, grease, and gouges. Most wheel balancers now offer this type of protected retainer. DO NOT allow the retainer cup to rotate against the wheel's surface when tightening the wheel to the balancer. DO NOT OVERTIGHTEN. Most balancers use a large "wing nut" design to clamp the retainer against the wheel. Hand tight is sufficient. This procedure will allow accurate balancing using the conventional back cone method. IMPORTANT: Coated balance weights must be used on aluminum wheels to prevent damage to the rim flange. Transfer Case - Hopout From 4-High to 2-High Shift Linkage: Technical Service Bulletins Transfer Case - Hopout From 4-High to 2-High Number: 89-202-7D Section: 7D Date: July 1989 Subject: TRANSFER CASE HOPOUT FROM 4-HIGH TO 2-HIGH Model and Year: 1988-89 T TRUCKS WITH 231 TRANSFER CASE TO: ALL CHEVROLET DEALERS Some 1988-89 T trucks may experience transfer case "hopout" from four-wheel drive high range to two-wheel drive mode. This condition is most prevalent under extreme cold weather conditions (below 0 degrees F). Some probable causes are listed below: 1. Transfer case not fully engaged into 4-High position. 2. Transfer case boot convolute trapped beneath the floor console. 3. Transfer case shift linkage (detent bracket) improperly adjusted. 4. Inadequate transfer case detent spring load. Page 6119 2. Retainer ring (4) to the pulley (6). 3. Pulley (6) and bearing (5) to shaft (38) with J 8092 and J 9481-A. 4. Retainer ring (4) to pulley (6) and bearing (5). 5. Pulley retainer ring (3) with J 0435. 6. Clutch plate and hub assembly(2). Clutch Coil and Housing Assembly A-6 Compressor Component View Remove or Disconnect Tool Required: Page 6147 body several turns, remove J 33013-B and check that the shaft key (21) is properly in place in the keyway, then install the clutch plate and hub assembly (2) to its final position. ^ Measure the air gap between contact surfaces of the clutch plate and hub assembly (2) and the pulley (5). The gap should be 0.38-0.64 mm (0.015-0.025-inch). ^ Remove J 33013-B. Inspect ^ Position of the shaft (20) (even with or slightly above the clutch hub). ^ Use J 33027 to hold the clutch plate and hub assembly (2). Tighten ^ Shaft nut (1) to 16 N.m (12 ft. lbs.) with J 33022. - Hand spin the pulley (5) to check for free rotation. ^ Remove J 33026. Pulley and Bearing Assembly HR-6 Component View Remove or Disconnect Tools Required: J 6983 Snap Ring Pliers J 8092 Driver Handle J 9398-A Pulley Bearing Remover J 33020 Pulley Puller J 33023-A Puller Pilot 1. Clutch plate and hub assembly (2). A/T TCC - MIL ON/False Code 32 Set Diagnostics Torque Converter Clutch Solenoid: Technical Service Bulletins A/T TCC - MIL ON/False Code 32 Set Diagnostics Number: 91-149-6E Section: 6E Date: January 1991 Corporate Bulletin No.: 066502R Subject: "SERVICE ENGINE SOON" LIGHT POSSIBLE FALSE CODE 32 Model and Year: ALL 1987-91 TRUCKS WITH 4L60 AUTOMATIC TRANSMISSION (700-R4) TO: ALL CHEVROLET DEALERS Some 1987-91 light duty trucks equipped with 4L60 transmissions may experience a possible false Code 32 - EGR System Malfunction. The customer may not experience a change in performance or driveability with a Code 32 set. If normal EGR diagnostics do not reveal the cause for Code 32, the following steps should be taken to correct the condition: Check the TCC (Torque Converter Clutch) engagement solenoid/wiring harness for a short-circuit. 1. Disconnect the TCC harness connector from the left side of the transmission. 2. Measure resistance between TCC transmission connector terminals "A" and "D" with a Digital Volt Ohmmeter (DVOM). Solenoid resistance must measure 20 - 25 ohms at 20 degrees C (68 degrees F). Resistance will be slightly higher if the transmission is at operating temperature. If the resistance is less than 20 ohms the TCC solenoid diode or wiring is shorted and the solenoid must be replaced. 3. With key on, using a DVOM check for voltage at pin "D" of the TCC wiring harness. Voltage greater than one volt should not be found. If voltage exceeding one volt is present, circuit 422 is shorted to voltage and the short must be repaired. Refer to the appropriate service manual for circuit 422 diagnosis and repair. Test operation of the TCC through the use of a scan tool connected to the vehicle ALDL connector. The following conditions must be satisfied when testing TCC operation. ^ Clear stored trouble codes. ^ Engine at normal operating temperature (above 65 degrees C, 149 degrees F) and in closed loop. ^ Constant throttle position. TPS voltage = 1.3 V (minimum = 1.1 V, maximum = 1.5 V). ^ Vehicle speed = 45 mph (minimum = 35 mph, maximum = 55 mph). ^ Brake switch closed (brake pedal not applied). ^ 3rd or 4th gear. Confirmation The scan tool will display the ECM command for TCC engagement when the above conditions are satisfied. When the TCC engages there should be a decrease in engine speed by a minimum of 100 RPM. If TCC operation is normal, it is not necessary to replace the solenoid assembly. After verification of TCC operation, check for stored trouble codes. If TCC fails to engage consult Section 10, Transmission Controls located in Fuel and Emissions Manual and section 7A of the appropriate service manual. 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 Page 3665 6. Check fluid level, color and condition (refer to Figure 1). ^ Inaccurate fluid level readings will result if the fluid is checked immediately after the vehicle has been operated under certain conditions: - In high ambient temperature above 32C (90F). - At sustained high speeds. - In heavy city traffic during hot weather. - As a towing vehicle. Page 1562 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. Page 6190 ^ All parts. Replace as necessary. Install or Connect Tools Required: J 33011 O-Ring Seal Installer J 23128-A Seal Seat Remover and Installer J 34614 Shaft Seal Protector J 5403 Snap Ring Pliers ^ Dip the new O-ring seal in clean 525 viscosity refrigerant oil. ^ J 34614 onto the shaft (20). Installing The Seal Seat O-Ring 1. O-ring seal using J 33011. ^ Insert J 33011 into the compressor neck until the installer "bottoms." ^ Lower the movable slide of J 33011, releasing the O-ring seal into the lower groove. ^ Rotate J 33011 to seat the O-ring seal and remove J 33011. 2. Shaft lip seal using J 23128-A. ^ Dip the shaft lip seal in clean 525 viscosity refrigerant oil and install shaft lip seal on J 23128-A. ^ Bottom the shaft lip seal into the compressor neck area using J 23128-A. ^ Release and remove J 23128-A. 3. Shaft seal retainer ring using J 5403. ^ Install flat side of shaft seal retainer ring against the lip seal. ^ Remove J 34614. Important ^ Leak test the compressor. Clean ^ Shaft (20) and inside the compressor neck area. 4. Clutch plate and hub assembly (2). Page 2636 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. Page 571 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. Backup Lamps/Tailgate Window Release - Inoperative Shift Interlock Switch: All Technical Service Bulletins Backup Lamps/Tailgate Window Release Inoperative Number: 91-459-8A Section: 8A Date: DEC. 1991 Corporate Bulletin No.: 168104 ASE No.: A6 Subject: BACKUP LAMPS OR TAILGATE WINDOW RELEASE INOPERATIVE Model and Year: 1980-91 ALL LIGHT DUTY TRUCKS (EXCEPT GEO) Owners of some 1980-1991 C/K, 1982-1991 G, 1985-1991 M/L, 1984-1991 P2,P3, 1987-1991 R/V, 1983- 1991 ST (including LLV) with automatic transmissions may comment on a condition of inoperative back-up lamps or inoperative tailgate window release. This condition occurs when the vehicle's gear shift lever is placed in the "reverse" position, but the back-up lamps do not illuminate. In addition, on the S/T utility vehicles, the electric tailgate window release does not release when the transmission gear shift lever is placed in the "park" or "neutral" position and the endgate window release button is depressed. The park/neutral and back-up lamp switch comes out of adjustment which does not allow for the contact points to remain engaged. To correct these conditions, the contact carrier on the park/neutral and back-up lamp switch has been modified to increase switch carrier travel. SERVICE PROCEDURE: 1. Disconnect the battery ground cable from the battery. 2. Disconnect the switch assembly harness. 3. Place the gear selector in neutral. 4. Squeeze the tangs on the switch together and remove the switch assembly. 5. Install the new switch assembly (P/N 15679680) by: -aligning the actuator with the cutout in the steering column jacket. -inserting the tangs into the rectangular holes and pushing down on the switch assembly. 6. Adjust the switch by moving the gear selector to park. 7. Connect the switch assembly harness. 8. Connect the negative battery cable. 9. Check for proper switch operation. Readjust the switch as necessary. Page 4532 S Series with 2.5L Engine 72267 S Series with 2.8L Engine 23911 Service Action For vehicles exhibiting third gear vibration that were built prior to the production incorporation of the new lever, the shift lever should be replaced with the new design lever. Reference Section 7B-3 of the Service Manual for replacement procedure. The new design shift lever P/N is 15618925. IMPORTANT: After shift lever replacement, assure that the boot assembly is positioned to ride as high as possible on the shift lever to reduce transmission noise into the cab. For vehicles repaired under warranty, use the following Labor Operations and Times: Labor Operation: K1060 Labor Time: .3 Hr Page 6817 Trailer Adapter Kit: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. Figure 21 Figure 22 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. Page 5545 Warranty Information (excluding Saab U.S. Models) For vehicles repaired under warranty, use the appropriate labor operation for the source of the water leak Warranty Information (Saab U.S. Models) For vehicles repaired under warranty, use the table. Disclaimer Warranty - Rail Dust Removal & Chemical Spotting Labor Paint: All Technical Service Bulletins Warranty - Rail Dust Removal & Chemical Spotting Labor File In Section: Warranty Administration Bulletin No.: 72-05-11 Date: December, 1997 WARRANTY ADMINISTRATION Subject: Clarification of Rail Dust Removal (A5575-A5580) and Chemical Spotting (A5541-A5544) Labor Operations Models: All Past and Future Passenger Cars and Light Duty Trucks The purpose of this Warranty Administration Bulletin is to clarify the usage, limits and guidelines for the proper use of the above subject labor operations. The above subject labor operations were introduced to correct paint imperfections caused by fallout that occurred either during shipment to the dealer or within the first 12 months or 12,000 miles (20,000 kms) of vehicle ownership. GM vehicle owners are informed that although no defect in the factory applied paint causes this, GM will repair, at no charge to the owner, the surfaces of new vehicles damaged by fallout condition within 12 months or 12,000 miles (20,000 kms) whichever occurs first. Effective with repair orders dated on or after December 1, 1997, labor operations A5575-A5580 Rail Dust Removal and A5541 through A5544 Chemical Spotting will be limited to within the first 12 months or 12,000 miles of the Base Vehicle Warranty (20,000 kms) whichever occurs first. Page 6653 Trailer Adapter Wiring Circuit (W/Light Duty Suspension) Page 5706 Fig. 1 Exploded view of power steering gear Fig. 2 Rack piston plug removal Fig. 3 Bearing removal Refer to Fig. 1, when performing the following procedures. 1. Pry retaining ring out of housing groove with a screwdriver. 2. Turn stub shaft to the left until plug on opposite end is forced out of cylinder, then remove seal. 3. Remove plug from rack piston, Fig. 2. Electronic Spark Control (ESC) Knock Sensor: Description and Operation Electronic Spark Control (ESC) Electronic Spark Control (ESC) is used on some models. The ESC system is used in conjunction with the EST system to provide additional spark retard during engine detonation. A knock sensor signals a separate ESC controller to retard the timing when it senses engine knock. The ESC controller signals the ECM which reduces spark advance until no more signals are received from the knock sensor. Interior - Itch Noise From Windshield Pillar Area Dashboard / Instrument Panel: Customer Interest Interior - Itch Noise From Windshield Pillar Area Number: 92-286-10 Section: 10 Date: SEPT. 1992 Corporate Bulletin No.: 261610 ASE No.: B1 Subject: ITCH NOISE FROM WINDSHIELD PILLAR AREA Model and Year: 1986-92 S/T TRUCKS Some 1986-1992 S/T utility trucks may exhibit a plastic to metal or plastic to plastic "itch" noise from the left or right windshield pillar area. This noise may be caused by the instrument panel pad rubbing against the cowl or dash support panel. An adhesive backed felt tape has been released to insulate the dash pad outer corners from the dash support panel. This tape may also be used on the non-visible surfaces of other trim panels as necessary to eliminate itch noises. The felt tape, P/N 12541499, is released in a 10 ft. x 30 mm x 1 mm roll to provide the technician sufficient material to insulate numerous trim panels. SERVICE PROCEDURE: Prior to installing the felt tape, it should be determined if the IP pad to dash support panel is the area that is generating the noise. Refer to the Squeak and Rattle Diagnosis and Correction Manual to identify other possible sources such as ECM Mounting Bracket or Air Vent. If it is determined the IP pad is the source of the noise: 1. Remove the instrument panel radio speaker(s) to obtain better access to the metal ledge on which the instrument panel pad rests. 2. Remove the 4 IP upper retaining screws located in the defroster duct openings and pull the pad back slightly. NOTICE: Do not remove the dash pad any further than necessary to perform the repair. The possibility exists that additional noises may be generated due to the wiring and HVAC ducts being mispositioned upon reinstallation. 3. Cut a strip of felt tape 6 inches long, remove the protective backing and apply the tape to the top of the metal ledges in front of the speaker openings where the instrument panel pad rests. NOTICE: Installation is easier if 2 screwdrivers are wedged between instrument panel pad and the cowl panel to raise the IP pad. 4. Push the IP pad forward and reinstall the retaining screws and speakers. Page 198 Electronic Spark Timing: Testing and Inspection Chart C-5 - Electronic Spark Control System Check Page 7144 Page 1971 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 Page 3440 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 Transfer Case - High Shift Effort When Shifting Fluid - Transfer Case: All Technical Service Bulletins Transfer Case - High Shift Effort When Shifting Number: 91-165-7A Section: 7A Date: January 1991 Corporate Bulletin No.: 967402R Subject: HIGH TRANSFER CASE SHIFT EFFORT Model and Year: 1983-91 T1 TRUCKS 1988-91 K TRUCKS TO: ALL CHEVROLET DEALERS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 91-128-7A, DATED NOVEMBER 1990. THE BULLETIN NUMBER HAS BEEN CORRECTED IN THE FIRST PARAGRAPH. ALL COPIES OF 91-128-7A SHOULD BE DISCARDED. Some four wheel drive K and T trucks may experience high transfer case shift effort and/ or total blockouts when "SHIFTING ON THE FLY" from 2H to 4H under cold weather conditions (usually 25 degrees or less). In order to shift to 4H the speed of the front propshaft must be increased to allow proper engagement of front axles. As the transfer case shift lever is moved into 4H the front propshaft begins rotating to synchronize the front axle assembly. In cold weather conditions regular production lube has high viscosity which may delay or prohibit the synchronizing of the front propshaft and axle resulting in high transfer case shift effort. To reduce high shift effort, regular production front axle gear lube may be replaced with a 75W-90 synthetic gear lube which maintains a lower viscosity under cold weather conditions. This synthetic gear lube is now available in one quart containers from GMSPO. Before installing, it is important to drain and flush the front axle with clean mineral based (non synthetic) axle lube. The front axle should then be refilled to the level of the filler hole with synthetic lube listed below. Front Axle Lube Capacities: K1, K2 - 1.66 liter (1.75 qts) K3 - 2.13 Liter (2.2 qts) T1 - 1.20 liter (1.3 qts) SERVICE PARTS INFORMATION P/N DESCRIPTION 12345836 SAE 75W-90 synthetic gear lube, 1 qt. bottle Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation Number: T7980 Labor Time: .4 hr Trouble Code: 92 NOTE: Labor Operation is coded to base vehicle coverage in the warranty system. Page 870 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 Page 7179 Backup Lamps/Tailgate Window Release - Inoperative Backup Lamp Switch: Customer Interest Backup Lamps/Tailgate Window Release - Inoperative Number: 91-459-8A Section: 8A Date: DEC. 1991 Corporate Bulletin No.: 168104 ASE No.: A6 Subject: BACKUP LAMPS OR TAILGATE WINDOW RELEASE INOPERATIVE Model and Year: 1980-91 ALL LIGHT DUTY TRUCKS (EXCEPT GEO) Owners of some 1980-1991 C/K, 1982-1991 G, 1985-1991 M/L, 1984-1991 P2,P3, 1987-1991 R/V, 1983- 1991 ST (including LLV) with automatic transmissions may comment on a condition of inoperative back-up lamps or inoperative tailgate window release. This condition occurs when the vehicle's gear shift lever is placed in the "reverse" position, but the back-up lamps do not illuminate. In addition, on the S/T utility vehicles, the electric tailgate window release does not release when the transmission gear shift lever is placed in the "park" or "neutral" position and the endgate window release button is depressed. The park/neutral and back-up lamp switch comes out of adjustment which does not allow for the contact points to remain engaged. To correct these conditions, the contact carrier on the park/neutral and back-up lamp switch has been modified to increase switch carrier travel. SERVICE PROCEDURE: 1. Disconnect the battery ground cable from the battery. 2. Disconnect the switch assembly harness. 3. Place the gear selector in neutral. 4. Squeeze the tangs on the switch together and remove the switch assembly. 5. Install the new switch assembly (P/N 15679680) by: -aligning the actuator with the cutout in the steering column jacket. -inserting the tangs into the rectangular holes and pushing down on the switch assembly. 6. Adjust the switch by moving the gear selector to park. 7. Connect the switch assembly harness. 8. Connect the negative battery cable. 9. Check for proper switch operation. Readjust the switch as necessary. Page 7588 Figure 8 Figure 9 Figure 10 Figure 11 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). Page 5936 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 Page 5658 Fig. 1 Troubleshooting power steering system Page 5276 5. Remove paint and primer from the area surrounding the 10 mm (0.40 in) until bare metal is visible. Important The M6 conductive rivet stud as shown, can accommodate a panel thickness range of 0.7-4.2 mm (0.03-0.17 in). If there are layers of sheet metal, they should be touching without any air gaps to ensure a good ground. 6. Select a M6 conductive rivet stud. Refer to the Parts Information section of this bulletin. Note Use the GE-50317 rivet stud tool kit. 7. Place the M6 conductive rivet stud (1) in the 10 mm (0.40 in) hole. Assemble the rivet stud tool (2) with the groove and flare side facing the rivet stud, then the washer and the M6 nut (3). 8. Using a wrench on the rivet stud tool, and a socket on the M6 nut, secure the M6 conductive rivet stud. 9. Ensure the new rivet stud is securely fastened, WITHOUT ANY detectable movement. 10. Completely wrap the threads of the rivet stud with painters tape or equivalent. Page 7415 Labor operation T7990 Labor time .4 Hr Page 6336 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 Locations Convenience Center A/T - New 2-4 Band Apply, Anchor Brackets, Lube Window Band: Technical Service Bulletins A/T - New 2-4 Band Apply, Anchor Brackets, Lube Window Number: 90-121-7A Section: 7A Date: December 1989 Corporate Bulletin No.: 977161 Subject: 2-4 BAND CHANGES-APPLY/ANCHOR BRACKETS AND NEW LUBE WINDOW Model and Year: 1982-90 LIGHT DUTY TRUCKS WITH 4L60 (700-R4) AUTOMATIC TRANSMISSION Figure 1 - 2-4 Band Assembly Figure 2 - THM 700-R4/HYDRA-MATIC 4L60 Transmission Identification Information TO: ALL CHEVROLET DEALERS This bulletin covers a new HYDRA-MATIC 4L60 transmission 2-4 band with changes to the apply and anchor brackets, locating tabs, and the addition of a "lube window." The lube window was added to direct lubricating transmission fluid to the band friction material while the band is not applied. Structural changes to the apply and anchor brackets increase their durability and the locating tabs were added to aid in assembly. (See Figure 1.) Starting September 8, 1989 (Julian Date 251), all HYDRA-MATIC 4L60 transmissions were built using the new 2-4 band assembly. (See Figure 2.) Tires (Front) - Irregular Wear Tires: All Technical Service Bulletins Tires (Front) - Irregular Wear Number: 91-26-3E Section: 3E Date: June 1990 Corp. Bulletin No: 053501 Subject: FRONT TIRE WEAR Model and Year: 1982-91 LIGHT DUTY TRUCKS (REAR WHEEL DRIVE) THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 91-12-3E. THE KILOMETERS HAVE BEEN TRANSLATED INTO MILES. ALL COPIES OF 91-12-3E SHOULD BE DISCARDED. Rear wheel drive trucks, equipped with All Season and/or On-Off road tires may exhibit irregular wear of; the front tires. Small amounts of irregular wear is considered normal and is not necessarily a result of incorrect alignment. Incorrect alignment (especially toe) may result in premature wear of the front tires, however agressive cornering may also have a similar effect. Drive axle tires are much less prone to irregular wear, therefore they should not be considered for comparison of wear to non-drive axle tires. The rate of irregular wear is also dependent upon the depth of tread. New tires are more prone to irregular wear, so it is essential that tires are rotated at the proper intervals to normalize the wear. Page 5110 When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 5mm (3/16") of insulation from wire. e. Crimp a new terminal to the wire. f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. Figure 17 To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Figure 18 Figure 19 Description and Operation Transmission Position Switch/Sensor: Description and Operation The park/neutral switch indicates to the ECM when the transmission is in park or neutral. This information is used by the ECM for ignition timing, IAC operation and transmission Torque Converter Clutch (TCC) operation. Do not drive vehicle with park/neutral switch disconnected, as idle quality may be affected. Specifications Output Shaft: Specifications Output Shaft Thrust Ring ..................................................................................................................... ................................................................... 12 ft. lbs. Description and Operation Fuel Pressure Regulator: Description and Operation IAC Valve Operation And Fuel Pressure Regulation The pressure regulator is a diaphragm-operated relief valve with system operating pressure on one side and and atmospheric pressure on the other side. The function of the regulator is to maintain a constant pressure to the injectors at all times, by controlling the flow in the return line by means of a calibrated bypass. NOTE: The pressure regulator on this unit is serviced as part of the fuel meter cover and should not be disassembled. Page 7505 Symbol Identification 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 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. Page 6282 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 Page 7979 ^ Raise the window to the full up position secure the glass to the door frame using cloth backed tape. 1. Door trim panel. 2. Armrest bracket. 3. Water deflector. 4. Battery ground cable. 5. Wire harness from motor. 6. Regulator lift arm roller from the window mount sash. CAUTION: Sector gear must be locked into position. Regulator lift arm is under tension from the counterbalance spring and could cause personal injury if the sector gear is not locked in position. Drilling Hole In Window Regulator. (97 Shown, This Model Similar) Using A Bolt And Nut To Lock Window Regulator. (97 Shown, This Model Similar NOTE: The Manufacturer did not provide a specific image for this year. The two images above are from a 1997 model but are typical. 7. Motor from window regulator. ^ Drill hole through the regulator sector gear and backplate install bolt and nut to lock sector gear in position. ^ Drill Out the motor mounting rivets. INSTALL OR CONNECT TOOL REQUIRED: ^ J-9022-A, Rivet Installer 1. Motor to the regulator. 2. Rivets to the motor and regulator. ^ Use tool J-9022-A. ^ Install 4.8 mm (3/16-inch) rivets. ^ Remove nut and bolt used to lock the sector gear in position. Page 2635 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. Locations Throttle Cable/Linkage: Locations Accelerator Pedal Assembly Control Cable And Linkage Service and Repair 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 go 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 Electronic Control Module (ECM). After diagnosis and repair, the ECM memory can be cleared of codes by removing the ECM fuse or disconnecting the battery ground cable for approximately 30 seconds, with ignition switch in the Off position. It should be noted, that if battery ground cable is disconnected to clear codes, components such as clocks, electronically tuned radios etc., will have to be reset. Suspension - Shock Absorber/Strut Leakage Information Suspension Strut / Shock Absorber: All Technical Service Bulletins Suspension - Shock Absorber/Strut Leakage Information INFORMATION Bulletin No.: 05-03-08-002C Date: October 16, 2009 Subject: Information on Replacement of Shock Absorbers and Struts Due to Fluid Leaks Models: 2010 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 the 2010 model year and Inspection Procedures. Please discard Corporate Bulletin Number 05-03-08-002B (Section 03 - Suspension). This bulletin is intended to help identify the severity of shock absorber and strut fluid seepage. Improper diagnosis may lead to components being replaced that are within the manufacturer's specification. Shock absorbers and strut assemblies are fluid-filled components and will normally exhibit some seepage. Seepage is defined as oil film or dust accumulation on the exterior of the shock housing. Shock absorbers and struts are not to be replaced under warranty for seepage. Use the following information to determine if the condition is normal acceptable seepage or a defective component. Important Electronically controlled shock absorbers (MR) may have a tendency to attract dust to this oil film. Often this film and dust can be wiped off and will not return until similar mileage is accumulated again. Inspection Procedure Note The shock absorber or strut assembly DOES NOT have to be removed from the vehicle to perform the following inspection procedure. Use the following descriptions and graphics to determine the serviceability of the component. Shock Absorbers Do Not Replace shock absorbers displaying condition 1 or 2 levels of seepage. 1. Oil or fluid residue only on the bottom or top of the shock absorber and not originating from the shaft seal (the upper part of the lower shock tube). 2. Light film/residue on approximately 1/3 (a) or less of the lower shock tube (A) and originating from the shaft seal. Replace shock absorbers displaying conditions 3 and 4 levels of leaks. 3. Oil drip or trail down the lower shock tube and originating from the shaft seal. 4. An extreme wet film of oil covering more than 1/3 (b) of the lower shock tube and originating from the shaft seal. Coil-over Shock Absorber C/V Boot - Contacts Front Shock Technical Service Bulletin # 913114C Date: 910501 C/V Boot - Contacts Front Shock Number: 91-311-4C Section: 4C Date: MAY 1991 Corporate Bulletin No.: 164301R Subject: FRONT AXLE INNER C/V BOOT CONTACTS FRONT SHOCK Model and Year: 1985-91 T TRUCKS Some 1985-91 T trucks may experience a condition of the front axle tripot seals (commonly referred to as the inner C/V boots) contacting the front shock absorbers. This contact usually occurs during suspension operation and may be evidenced as torn seals, premature wear on the outer edges of the seal convolutes or grooves worn into the body of the shock absorber. This condition can be relieved by correcting problems with shock absorber or axle installation and installing smaller profile tripot seals. VEHICLES INVOLVED: 1985-91 T trucks. SERVICE PROCEDURE: The following items should be checked and verified to provide the greatest amount of clearance for the tripot seals. - The shock absorbers are installed correctly with the fluid reservoir on the bottom and the shield on the top. - If aftermarket shock absorbers have been installed, their diameter must measure 50.4 mm (1.98") or less. - The output shaft retaining ring is in place. To check, pull outward on the output shaft. Outward movement should measure 5 mm (.200") or less. IMPORTANT: DO NOT cut or relocate shock absorber mounting brackets. If the contact between the tripot joint and shock absorber is occurring on the passenger side of the vehicle, the axle assembly may be shifted in the frame too far toward the passenger side. To correct this condition the procedure below should be followed: Figure 16 - Carrier Assembly Installation Page 6993 Brakes - Light Brake Drag While Driving Brake Light Switch: Customer Interest Brakes - Light Brake Drag While Driving Number: 89-262-5 Section: 5 Date: September 1989 Corporate Bulletin No.: 915002 Subject: LIGHT BRAKE DRAG - BRAKE SWITCH ADJUSTMENT Model and Year: 1980-89 A, B, F, G, J, L, X, Y 1980-89 ALL TRUCKS Figure 1 TO: ALL CHEVROLET DEALERS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 89-178-5, DATED JUNE 1989, IN ORDER THAT WE MAY CORRECTLY IDENTIFY THE SWITCH REQUIRING ADJUSTMENT. ALL COPIES OF 89-178-5 SHOULD BE DISCARDED. Some vehicles may experience a condition of light brake drag while driving. These conditions have been found to be more noticeable on vehicles which have an anti-lock brake system. This may be caused by improper brake switch adjustment. If the brake switch is not adjusted properly, the switch may push on the brake pedal and cause the brake to remain partially applied. If a vehicle exhibits any of the above conditions, perform the following functional brake switch adjustment check: Passenger Cars Only: The following steps should be used to check brake switch adjustment: 1. Remove the driver-side hush panel (refer to Figure 1). 2. Gently pull back on the brake pedal until no audible clicks are heard. The switch will be moved in the tubular retainer providing adjustment. 3. Replace the hush panel. 4. Verify that the brake drag condition is no longer present and that the cruise control and brake lights function properly. Page 7428 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 4. Make repair. Page 7229 Figure No. 3 Open the carrier and swing it out of the way. Lower the tailgate window and grab hold of the tailgate. If there is any movement fore or aft or play other than normal tailgate flex, then perform the following service procedure. If there is no play in the tailgate then continue on to Service Procedure 3 1) Disconnect wiper motor wire, wiper fluid hose (if so equipped), and the two tail-gate supports. See Figures 2 and 3 for disconnection areas. 2) Remove tailgate bumpers shown in figure 3. Seal the holes in the body with a clear RTV sealer (Permatex C6B or equivalent). 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. Page 1463 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 as described under ROCKER ARM & PUSHRODS. 4. Remove distributor. 5. Remove intake manifold as described under INTAKE MANIFOLD. 6. Remove valve lifters as described under 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. Page 7019 Page 7162 A more sophisticated gage is the digital Elcometer 300 fn Paint Thickness gage (or equivalent). It has an ability to read film thickness on both ferrous and non-ferrous metal panels. This instrument has an accuracy range of +/- 1% and has thickness standards included for recalibration. Approximate cost = $1750. An alternative (for use on steel panels only) would be the digital Elcometer 246 model, or equivalent. This gage has a +/- 3% accuracy range and include thickness standards for recalibration. Approximate cost - $575. REPAIRING RAIL DUST DAMAGE Rail dust damage comes from the tiny iron particles produced from the friction between the train wheels and the track. It can also be deposited on vehicles if stored near any operation producing iron dust (steel ore yards, etc.). This dust can either lay on top of, or embed into the paint surface. It is usually diagnosed as; bumps in the paint surface OR - rust colored spots in the paint. PROCEDURE: 1. Wash the vehicle with soap and water, dry it and clean the affected area with wax and grease remover. 2. Keeping the vehicle in a cool or shaded area, rinse the surface with cold water. CAUTION: RAIL DUST REMOVER (OXALIC ACID) IS AN ACIDIC SUBSTANCE CONTAINING CHEMICALS THAT WILL BREAK DOWN THE IRON PARTICLES EMBEDDED IN THE FINISH. WHEN WORKING WITH IT, USE THE NECESSARY SAFETY EQUIPMENT, INCLUDING GLOVES AND GOGGLES. FOLLOW THE MANUFACTURER'S DIRECTIONS CLOSELY BECAUSE IT MAY REQUIRE SPECIAL HANDLING AND DISPOSAL. 3. Soak several terry cloth towels in a container of rail dust remover solution and, after the damaged areas have been rinsed with cold water, lay the wet towels on the damaged areas. 4. Allow the towels to remain in place for 20 minutes, keeping them moist by spraying with water and not allowing to dry on the surface of the vehicle. 5. After 20 minutes of applying the towels, remove them and rinse the area thoroughly with cold water. Inspect the affected area to ensure the dust has been removed. Use both touch (feeling for bumpy surface) and sight (magnifying glass for close inspection). 6. If upon inspection some particles are still present, the process of applying the towels can be repeated 3 times. 7. Select a test area and hand wet sand with American ultra fine 1,500 grit to 2,000 grit sandpaper to repair damage (surface pitting from dust). a. Use ample amounts of water. b. Go slow to prevent removing too much clearcoat. NOTICE: USE A PAINT GAGE TO DETERMINE THE AMOUNT OF CLEARCOAT REMOVED. IF TOO MUCH HAS BEEN REMOVED, ADDITIONAL CLEARCOAT WILL HAVE TO BE APPLIED. IF RAIL DUST HAS PENETRATED INTO THE BASECOAT, THE PANEL REQUIRES REFINISHING. MAKE SURE ALL RAIL DUST HAS BEEN REMOVED PRIOR TO REFINISHING OR THE RUST SPOTS WILL RETURN, CAUSING CUSTOMER COMEBACKS. 8. If the damage has been repaired, complete the repair to the entire panel. 9. Once the damage has been repaired, the final step in the repair process involves polishing the vehicle. PREVENTING INDUSTRIAL FALLOUT DAMAGE Customers should be urged to wash and dry their vehicles frequently and garage them, or at least cover them with a quality car cover when not in use. Vehicles in dealer inventories should be kept clean and dry. A vehicle that sits unattended, especially after the sun has dried any water on the body surface, is a target for acid rain damage. MATERIALS DESCRIBED IN THIS BULLETIN* WAX AND GREASE REMOVER - USE BELOW OR EQUIVALENT Dupont # 3919S, PPG # DX440, BASF # 900, SIKKENS # 6041 FINESSE POLISHES - USE BELOW OR EQUIVALENT Dupont # 1500S, 3000S; BASF # 563-808, 560-1502; PPG # DRX10; 3M PERFECT-IT * USE V.O.C. EQUIVALENTS IN STATES WITH V.O.C. RESTRICTIONS RAIL DUST REMOVER - USE BELOW OR EQUIVALENT Industrial Fallout Remover # 5029 Page 4939 - Place the pointed tip of the pliers onto the brake shoe lining surface directly across from the spring (if the shoes are to be reused, place the tip into a rivet hole or place a thin sheet of wood between the linings and pointed tip). - Squeeze the pliers and lift the return spring from the hole. - Release the pliers slowly and remove the other end of the spring. Installation Use the same technique for installing the spring as was used for removing it. - If a rivet hole is not available, place a thin sheet of wood between the lining and pointed end of the tool. - A pair of needle nosed pliers may be helpful for guiding the end of the return spring into the hole. WARNING: Do not attempt to help the spring into the hole with your fingers. Should the return spring slip off the tool it could seriously lacerate your hand. Page 8208 6. Tape the solder and diode. 7. Reinstall the black plastic conduit. 8. Reconnect connector to the generator. 9. Reconnect battery. This procedure will not affect the operation of the generator light during the bulb check at the beginning of the start cycle. For vehicles repaired under warranty use, Labor Operation Number: T7990 Labor Time: .4 Hr Page 2516 Wiring Diagram For Chart C-1B - Crank Signal Diagnosis CHART C-1B - CRANK SIGNAL DIAGNOSIS CCircuit Description: Crank signal is a 12 volts signal to the ECM during cranking to allow enrichment and cancel diagnostics until engine is running or 12 volts is no longer on circuit. Test Description: Numbers below refer to circled numbers on the diagnostic chart. 1. Checks for normal (cranking) voltage to terminal "C9" of ECM. Test light should be "ON" during cranking and then go "OFF" when engine is running. 2. Checks to determine if source of or fuse link was a faulty ECM. Service and Repair Fuel Pressure Release: Service and Repair Before performing any procedure that requires disconnecting fuel lines, relieve fuel system pressure as described below. 1. Remove Fuel Pump fuse from fuse block. 2. Start engine and allow to run out of fuel, then crank engine an additional 3 seconds. 3. Service fuel system as necessary. Page 2037 Figure 1 - Typical Fan Assembly Important To maintain a balanced fan assembly, align the yellow paint mark on the fan clutch with the yellow paint mark on the water pump hub (Figure 1.) Page 854 6. Check fluid level, color and condition (refer to Figure 1). ^ Inaccurate fluid level readings will result if the fluid is checked immediately after the vehicle has been operated under certain conditions: - In high ambient temperature above 32C (90F). - At sustained high speeds. - In heavy city traffic during hot weather. - As a towing vehicle. Generator Light - Flickers During Pulse Wiper Use Diode: All Technical Service Bulletins Generator Light - Flickers During Pulse Wiper Use Number: 90-84-8A Section: 8A Date: November 1989 Corporate Bulletin No: 966402 Subject: GENERATOR LIGHT FLICKER DURING PULSE WIPER OPERATION Model and Year: 1988-89 S, T TRUCKS WITH 2.8L OR 4.3L (VIN CODES R, Z) ENGINES TO: ALL CHEVROLET DEALERS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 89-219-8A, DATED JULY 1989. THE 1990 MODEL S/T VEHICLES ARE INCLUDED IN THE LATEST BULLETIN ALONG WITH A CORRECTION TO THE ELECTRICAL CONNECTOR NUMBER. ALL COPIES OF 89-219-8A SHOULD BE DISCARDED. The generator light flicker condition during pulse wiper switch operation in the 1988, 1989 and 1990 S/T instrument panel, with standard cluster, can be caused by negative voltage transients from the wiper motor. There is no possibility of a system failure as a result of this condition. The effect of this condition is that the generator light will turn on for 80 milliseconds (if gages, the voltage drop on the voltmeter lasts 2.5 seconds). This causes no harm to the generator or other electrical components. Subject condition can be eliminated by installing a diode (industry part number 1N4003) or diode/connector kit (diode kit part number 12085207) in the brown wire at the generator connector (circuit 25 at connector C118). See the following pages in the 1988, 89 and 90 S/T Electrical Wiring Diagrams for circuit 25, connector C118 locations: 1988 4.3L: Section C - Page 24 1988 2.8L: Section C - Page 22 1989 4.3L: Page 40 1989 2.8L: Page 39 1990 2.8L: Page 44 1990 4.3L: Page 45 PARTS INFORMATION: Quantity Part Number Description 1 12085207 Diode ----OR---1 *1N4003 Diode * This part available locally. Parts are currently available from GMSPO. INSTALLATION PROCEDURE: 1. Disconnect the battery. 2. Remove the connector from the generator. 3. Peel back the black plastic conduit covering the wires. 4. If installing diode 1N4003: cut out a section of the brown wire that matches the length of the diode. 4A. A diode/connector kit is also available (GMSPO diode kit part number 12085207). If using the kit cut out approximately four inches of the brown wire, following crimping and soldering instructions in the kit. Spiral tape the solder joints and tuck the wire back into the conduit away from the generator. Secure the diode/connector to the outside of the conduit with electrical tape. 5. Solder in diode with the banded end toward the generator. Page 2317 Knock Sensor: Testing and Inspection Chart C-5 - Electronic Spark Control System Check Removal/Installation Power Steering Pump: Service and Repair Removal/Installation Fig. 22 Power Steering Pump Replacement. Except Turbo EXCEPT TURBO 1. Disconnect pressure and return hoses from power steering pump or steering gear housing, then secure ends in raised position to prevent oil drainage. Cap all open lines and fittings. 2. Remove power steering pump belt, then power steering pump attaching bolts. 3. Remove power steering pump assembly, Fig. 22. Fig. 23 Power Steering Pump Replacement. Turbo TURBO 1. Remove air cleaner duct, upper fan shroud, serpentine belt, fan and pulley. 2. Using power steering pump pulley remover tool No. J 25034-B, remove pulley. 3. Ensure pilot bolt bottoms in pump shaft by turning nut to top of pilot bolt. Hold pilot bolt and turn nut counterclockwise. 4. Raise and support vehicle. 5. Remove left wheel assembly and wheelhouse panel. 6. Remove attaching bolt from hose bracket. Allow fluid to drain into a suitable container, Fig. 23. 7. Disconnect return and pressure hoses from power steering pump, then cap hoses. 8. Remove attaching bolts from rear bracket at alternator. 9. Lower vehicle. 10. Remove pump and attaching nuts from rear bracket. 11. Reverse procedure to install. Page 1049 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 Page 5666 Fig. 6 Driveshaft & bearing removal Fig. 7 Thrust plate retaining ring removal Fig. 8 Thrust plate removal Prior to disassembly of the pump, remove filler cap and drain fluid. If broken components or foreign materials are found during disassembly, the hydraulic system should be disassembled, inspected, cleaned and flushed before service is complete. Refer to Fig. 1, for pump disassembly. 1. Clean exterior of pump with solvent, then clamp front hub of pump into a soft jaw vise. 2. Pry tab and slide retaining clip off of pump, Fig. 2. 3. Remove reservoir, then return tube as follows: a. Assemble five 5/8 inch washers and a 9/16 inch-12 nut outside of tube, Fig. 3. b. Plug tube to prevent chips from entering, then insert a 9/16 X 12 tap into return tube and turn until tube is pulled out of housing, Fig. 3. 4. Remove O-ring, fitting, O-ring seal, flow control valve and spring. Fig. 4. 5. Using snap ring pliers, remove retaining ring. Note position of large lug in housing before removal. Fig. 5. 6. Remove driveshaft and bearing, Fig. 6. Note and measure any clearance between collar and shaft. Press bearing from shaft using a support ring under bearing. 7. Remove driveshaft seal by prying seal loose with a screwdriver. 8. Insert a punch into access hole, then pry retaining ring loose with a screwdriver, Fig. 7. 9. Using a 5/16 inch piece of bar stock or a suitable brass drift, remove thrust plate, Fig. 8. 10. Remove pump ring, rotor, vanes and dowel pins. 11. Remove pressure plate and O-ring, then the spring, seal and remaining dowel pin. 12. Using a suitable punch, remove sleeve assembly. Inspection Locations Fig. 42 Typical ALCL Connector Location Brakes (ABS) - 'False' or Dropping Pedal Hydraulic Control Assembly - Antilock Brakes: Customer Interest Brakes (ABS) - 'False' or Dropping Pedal Bulletin No. 24 Date November, 1982 Vehicle Make/Model DODGE, FORD and GENERAL MOTORS TRUCKS Equipped with Rear Anti-Lock Brake Systems Ford: RABB (Rear Anti-Lock Brake System) GM & Dodge: RWAL (Rear Wheel Anti-Lock) Topic False or Dropping Pedal Some of the above mentioned vehicles may experience a "false" or dropping pedal condition that may feel very similer to a master cylinder with an excessive amount of by-pass. Upon installation of the replacement master cylinder, there is little or no improvement in pedal feel or height, This condition may be caused by the dump valve in the E-H (Electro Hydraulic) valve being held slightly open by a small particle of foreign material. This allows fluid to flow into the accumulator and create the low or dropping brake pedal. To determine if this is the cause of the dropping pedal, begin by disconnecting the steel line at the master cylinder that serves the rear brakes. Install a solid tubing plug into the outlet that serves the rear brakes. Note: When installing the plug, have an assistent depress the pedal about one inch to purge any air from the outlet. Tighter, the plug while the assistant holds the pedal in this position. After tightening the plug, continue to apply pressure to the pedal. This will prevent damage to the primary cup in the master cylinder as the cup moves across the vent port. If the pedal no longer drops as it did with the rear brakes connected, this would indicate that the problem is in the rearbrakes and not the master cylinder. The next step would be to block off the outlet port of the E-H valve and retest the brake pedal as done previously. If the dropping pedal reappears, the problem is in the E-H valve and most likely caused by fluid leaking into the accumulator of the E-H valve. If this is the case, it will be necessary to change the valve. The E-H valve, including the accumulator and valving, is not serviceable. Note that brake fluid over a period of time absorbs contaminants, therefore, annual flushing and replacement with clean, fresh brake fluid will help to prevent this condition from occurring. Suspension - Shock Absorber/Strut Leakage Information Suspension Strut / Shock Absorber: All Technical Service Bulletins Suspension - Shock Absorber/Strut Leakage Information INFORMATION Bulletin No.: 05-03-08-002C Date: October 16, 2009 Subject: Information on Replacement of Shock Absorbers and Struts Due to Fluid Leaks Models: 2010 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 the 2010 model year and Inspection Procedures. Please discard Corporate Bulletin Number 05-03-08-002B (Section 03 - Suspension). This bulletin is intended to help identify the severity of shock absorber and strut fluid seepage. Improper diagnosis may lead to components being replaced that are within the manufacturer's specification. Shock absorbers and strut assemblies are fluid-filled components and will normally exhibit some seepage. Seepage is defined as oil film or dust accumulation on the exterior of the shock housing. Shock absorbers and struts are not to be replaced under warranty for seepage. Use the following information to determine if the condition is normal acceptable seepage or a defective component. Important Electronically controlled shock absorbers (MR) may have a tendency to attract dust to this oil film. Often this film and dust can be wiped off and will not return until similar mileage is accumulated again. Inspection Procedure Note The shock absorber or strut assembly DOES NOT have to be removed from the vehicle to perform the following inspection procedure. Use the following descriptions and graphics to determine the serviceability of the component. Shock Absorbers Do Not Replace shock absorbers displaying condition 1 or 2 levels of seepage. 1. Oil or fluid residue only on the bottom or top of the shock absorber and not originating from the shaft seal (the upper part of the lower shock tube). 2. Light film/residue on approximately 1/3 (a) or less of the lower shock tube (A) and originating from the shaft seal. Replace shock absorbers displaying conditions 3 and 4 levels of leaks. 3. Oil drip or trail down the lower shock tube and originating from the shaft seal. 4. An extreme wet film of oil covering more than 1/3 (b) of the lower shock tube and originating from the shaft seal. Coil-over Shock Absorber Page 5789 21. Lubricate the seal lip. - If seal is cut or torn, inspect the wheel bearing for damage and replace the seal. 22. If necessary, replace the seal as follows: - Pry old seal from knuckle and discard. - Lubricate the new seal lip. - Use a flat plate to press the seal down flush with the knuckle. Tripot Housing/Tripot Seal Replacement Figure 10 - Inboard Joint Disassembly Required Tools: J8059 Snap Ring Pliers J35910 Seal Clamp Tool 1. Place halfshaft in vise (use protective covers over vise jaws). 2. Remove seal clamp protectors (Figure 10) if used, from inner C/V joint and cut clamp(s) from seal with a pair of side cutters. For swage ring removal use a hand grinder to cut through the ring (taking care not to damage the housing). 3. Remove tripot housing from halfshaft and wipe grease from tripot assembly roller bearings and housing. Thoroughly degrease the housing and allow to dry prior to assembly. Important: Handle tripot spider assembly with care. Tripot balls and needle rollers may separate from spider trunnions. 4. Slide seal up on the shaft and inspect rollers, needle bearings, and trunnions. Check housing for unusual wear, cracks, and other damage. Replace housing and/or tripot assembly as needed. 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 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 Accumulator Leak-Down, System Does Not Hold Charge Hydraulic Brake Booster: Testing and Inspection Accumulator Leak-Down, System Does Not Hold Charge 1. Contamination in steering hydro-boost system. 2. Internal leakage in accumulator system. Backup Lamps/Tailgate Window Release - Inoperative Shift Interlock Switch: Customer Interest Backup Lamps/Tailgate Window Release - Inoperative Number: 91-459-8A Section: 8A Date: DEC. 1991 Corporate Bulletin No.: 168104 ASE No.: A6 Subject: BACKUP LAMPS OR TAILGATE WINDOW RELEASE INOPERATIVE Model and Year: 1980-91 ALL LIGHT DUTY TRUCKS (EXCEPT GEO) Owners of some 1980-1991 C/K, 1982-1991 G, 1985-1991 M/L, 1984-1991 P2,P3, 1987-1991 R/V, 1983- 1991 ST (including LLV) with automatic transmissions may comment on a condition of inoperative back-up lamps or inoperative tailgate window release. This condition occurs when the vehicle's gear shift lever is placed in the "reverse" position, but the back-up lamps do not illuminate. In addition, on the S/T utility vehicles, the electric tailgate window release does not release when the transmission gear shift lever is placed in the "park" or "neutral" position and the endgate window release button is depressed. The park/neutral and back-up lamp switch comes out of adjustment which does not allow for the contact points to remain engaged. To correct these conditions, the contact carrier on the park/neutral and back-up lamp switch has been modified to increase switch carrier travel. SERVICE PROCEDURE: 1. Disconnect the battery ground cable from the battery. 2. Disconnect the switch assembly harness. 3. Place the gear selector in neutral. 4. Squeeze the tangs on the switch together and remove the switch assembly. 5. Install the new switch assembly (P/N 15679680) by: -aligning the actuator with the cutout in the steering column jacket. -inserting the tangs into the rectangular holes and pushing down on the switch assembly. 6. Adjust the switch by moving the gear selector to park. 7. Connect the switch assembly harness. 8. Connect the negative battery cable. 9. Check for proper switch operation. Readjust the switch as necessary. Page 5141 What if I input the VIN incorrectly? If an incorrect VIN is entered into the system (meaning that the system does not recognize the VIN or that the VIN has been entered incorrectly) the system will return an error message. If I am an authorized user for the KeyCode application, can I access the application from home? Yes. What if I suspect key code misuse? Your dealership should communicate the proper procedures for requesting key codes. Any suspicious activity either within the dealership or externally should be reported to Dealer Systems Support at 1-800-265-0573 or GM of Canada Key Code Inquiry Desk at 1-905-644-4892. Whose key codes can I access through the system? At this time the following Canadian vehicle codes are available through the system: Chevrolet, Cadillac, Buick, Pontiac, GMC, HUMMER (H2 and H3 only), Oldsmobile, Saturn, Saab and Isuzu (up to 2002 model year) for a maximum of 17 model years. What should I do if I enter a valid VIN and the system does not produce any key code information? Occasionally, the KeyCode Look Up application may not produce a key code for a valid VIN. This may be the result of new vehicle information not yet available. In addition, older vehicle information may have been sent to an archive status. If you do not receive a key code returned for valid VIN, you should contact GM of Canada Key Code Inquiry Desk at 1-905-644-4892. How do I access KeyCodes if the KeyCode Look-up system is down? If the KeyCode Look-up system is temporarily unavailable, you can contact the original selling dealer who may have it on file or contact GM of Canada Key Code Inquiry Desk at 1-905-644-4892. If the customer is dealing with an emergency lock-out situation, you need to have the customer contact Roadside assistance, OnStar if subscribed, or 911. What should I do if the KeyCode from the look-up system does not work on the vehicle? On occasion a dealer may encounter a KeyCode that will not work on the vehicle in question. In cases where the KeyCode won't work you will need to verify with the manufacturer of the cutting equipment that the key has been cut correctly. If the key has been cut correctly you may be able to verify the proper KeyCode was given through the original selling dealer. When unable to verify the KeyCode through the original selling dealer contact GM of Canada Key Code Inquiry Desk at 1-905-644-4892. If the key has been cut correctly and the code given does not work, the lock cylinder may have been changed. In these situations following the proper SI document for recoding a key or replacing the lock cylinder may be necessary. How long do I have to keep KeyCode Records? Dealership KeyCode documentation must be retained for two years. Can I get a KeyCode changed in the Look-Up system? Yes, KeyCodes can be changed in the Look-Up system if a lock cylinder has been changed. Contact GM of Canada Key Code Inquiry Desk at 1-905-644-4892. What information do I need before I can provide a driver of a company fleet vehicle Keys or KeyCode information? The dealership should have a copy of the individual's driver's license, proof of employment and registration. If there is any question as to the customer's employment by the fleet company, the dealer should attempt to contact the fleet company for verification. If there is not enough information to determine ownership and employment, this information should not be provided. How do I document a request from an Independent Repair facility for a KeyCode or Key? The independent must provide a copy of their driver's license, proof of employment and signed copy of the repair order for that repair facility. The repair order must include customer's name, address, VIN, city, province and license plate number. Copies of this information must be included in your dealer KeyCode file. 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). Page 6084 Heater System Check Table Page 476 e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors Do Not require all the steps shown. Skip the steps that Do Not apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. 1. Separate connector halves (see Figures 2 through 6). Figure 2 Figure 3 Page 480 When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 5mm (3/16") of insulation from wire. e. Crimp a new terminal to the wire. f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. Figure 17 To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Figure 18 Figure 19 Page 784 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 A/T - Proper Fluid Level Checking Procedure Fluid - A/T: All Technical Service Bulletins A/T - Proper Fluid Level Checking Procedure Number: 88-41 Section: 7A Date: AUG., 1987 Subject: PROPER TRANSMISSION FLUID LEVEL CHECKING PROCEDURE Model and Year: 1987-88 CHEVROLET VEHICLES WITH THM 125C, 200-4R, 400, 440-T4, AND 700-R4 TRANSMISSIONS TO: ALL CHEVROLET DEALERS This bulletin outlines proper hot and cold fluid level checking procedures for the transmissions and transaxles listed above. A. "COLD" CHECK PROCEDURE: 1. Start vehicle and let idle in Park for 3 minutes. Note for THM 440-T4: Start vehicle and cycle range selector through 1, 2, D, OD, and R for approximately 3 seconds in eash range. Complete check preparation by letting vehicle idle in Park for 3 minutes. 2. With vehicle level, accessories turned off, and engine idling in Park, check fluid level as outlined below. FIGURE 1 ^ THM 200-4R, 400, 700-R4 (Refer to Figure 1): When cold, 27 Degrees C (80 Degrees F), a full transmission will show the fluid level below the "Add" mark on the indicator. As the transmission warms to normal operating temperature, the fluid expands, raising the level to within the cross-hatched area. Page 2121 Water Pump: Service and Repair Fig. 19 Water Pump Bolt Location 1. Drain cooling system. 2. Remove serpentine drive belt, then the upper fan shroud. 3. Remove fan, fan clutch assembly and water pump pulley, Fig. 19. 4. Remove hoses from pump. 5. Remove water pump attaching bolts, then pump. 6. Reverse procedure to install. Torque bolts to specification. Radio - Popping Noise Due to Spark Plugs Radio/Stereo: Customer Interest Radio - Popping Noise Due to Spark Plugs Number: 88-107-6E Section: 6E Date: JAN., 1988 Subject: RADIO POPPING NOISE DUE TO SPARK PLUGS Model and Year: 1988 LIGHT DUTY TRUCKS WITH 4.3L, 5.0L AND 5.7L ENGINES (VIN CODES Z, H AND K) TO: ALL CHEVROLET DEALERS Some 1988 trucks with 4.3L, 5.0L and 5.7L engines may experience a popping noise in the radio due to the use of AC CR43TS spark plugs. This condition can be repaired by replacing the CR43TS plugs with R43TS plugs (P/N 5613325). R43TS plugs entered production with engines produced since August 30, 1987. Spark plug gap specification is 0.035". Locations Parking Brake Warning Switch: Locations LH Side Of I/P Behind Instrument Cluster Service and Repair 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 go 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 Electronic Control Module (ECM). After diagnosis and repair, the ECM memory can be cleared of codes by removing the ECM fuse or disconnecting the battery ground cable for approximately 30 seconds, with ignition switch in the Off position. It should be noted, that if battery ground cable is disconnected to clear codes, components such as clocks, electronically tuned radios etc., will have to be reset. Page 4558 SERVICE PARTS INFORMATION Part Number Description 15664811 Vacuum Actuator Switch Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: K4120 Use applicable labor time guide for labor hours. Page 4580 This part number can be found on the identification tag (80) located on the rear case half (Figure 1). Group B: Some 1991 T-Trucks equipped with transfer cases identified by the following part numbers and built before 10/22/90: 15653414 15659232 This part number and build number can be found on the identification tag (80) located on the rear case half (Figure 1). Service Procedure: Group A: These transfer cases require the replacement of the parts indicated in the Group A column of the PARTS INFORMATION section. Group B: These transfer cases require the replacement of the parts indicated in the Group B column of the PARTS INFORMATION section. Remove Page 6582 Page 985 - 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 Page 6128 Installing The Puller Rotor Bearing 2. Pulley bearing (4) into the hub using J 8092, J 9481-A and J 21352-A. Staking The Pulley Bearing In The Rotor Bore ^ J 33019 in the pulley bore. ^ Seat the pulley and bearing assembly on J 21352-A to support to the hub under the staking pin location. ^ Strike the staking pin with a hammer until a metal stake, similar to the original, is formed down to, but not touching the bearing. Position the stake pin after striking. - The staked metal should not contact the outer race of the bearing to prevent the po5sibility of bending the outer race. Staking Locations Page 1859 Idle Speed: Specifications Minimum Idle Air Rate Minimum Idle Air Rate Engine Speed Note: Let engine idle until proper fuel control status is closed loop. Manual Transmission Neutral 450 +/- 50 rpm Auto Transmission Drive 400 +/- 50 rpm Neutral 475 +/- 50 rpm Testing and Inspection Shift Light: Testing and Inspection Chart C-8B - Manual Transmission Shift Light Check (Below 8500 GVW) Page 5316 Figure 8 Figure 9 Figure 10 Figure 11 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). Controlled Idle Speed / IAC Counts Idle Speed: Specifications Controlled Idle Speed / IAC Counts Controlled Idle Speed / IAC Counts Idle Speed IAC Counts Note: Let engine idle until proper fuel control status is Note: Add 2 counts for engines with less than 500 miles. closed loop. Add 2 count for every 1000 ft above sea level. Manual Transmission Neutral 500-550 rpm 2-12 Auto Transmission Drive 500-550 rpm 2-20 3L30 (180C) Transmission Transmission Vacuum Regulator Valve: Specifications 3L30 (180C) Transmission Component .......................................................................................................................................... .................................................................... Ft. Lbs. Modulator Assembly ............................................................................................................................ .............................................................................. 33 Turbo Hydra-Matic 3L30 (180C) Band Apply Servo: Service and Repair Turbo Hydra-Matic 3L30 (180C) 1. Remove valve body from transmission as outlined previously. 2. Compress servo piston with tool No. J-23075. 3. With suitable pliers, remove servo piston snap ring and slowly loosen the tool. Remove tool, servo piston return spring and apply rod from transmission. 4. Install apply rod, return spring and piston into case. 5. Use tool No. J-23075 to compress spring and install ring. Remove tool. 6. With a 3/16 inch wrench on servo adjusting bolt, adjust apply rod by torquing bolt to 40 inch lbs. then back off bolt exactly 5 turns. tighten locknut, while holding apply rod in position. 7. Install valve body. Page 6163 Installing The Clutch Rotor Bearing 1. Bearing to the rotor and hub assembly with J 8029 and J 9481-A. ^ Place the pulley rotor and hub assembly face down on a flat surface. ^ Align the bearing to the pulley rotor and hub bore. ^ Using a center punch with a 45 degree angle point, stake 1.1-1.4 mm (0.45-0.55 inch) deep in the places 120 degrees apart. Installing The Rotor & Bearing Assembly - Poly-Groove Type 2. Rotor (5) and bearing (6) assembly to the compressor with J 26271-A and J 8092. ^ Position the pulley rotor and bearing assembly to the compressor ^ Drive with J 26271-A and J 8092. 3. Retainer ring (4) with J 6083. 4. Clutch drive hub (3). V-Groove Drive Page 7014 On a clean surface, at or above room temperature, firmly apply a 2" wide piece of masking tape and pull upward quickly. DO NOT USE duct tape, cloth backed tape or other aggressive tapes. If the colorcoat flakes or peels away from the ELPO (leaving the ELPO intact) the colorcoat is delaminating and the vehicle should be repaired using the "Paint Repair Procedure" contained in this bulletin. This test SHOULD ONLY BE APPLIED TO A VEHICLE SHOWING THE CONDITION, (peeling/delamination) and NOT in areas of stone chipping or other obvious damage. These "other" conditions should be repaired following standard paint repair procedures. CORRECTION Refinish the ENTIRE BODY ABOVE THE BODY SIDE MOLDINGS using the following repair procedure. It is important that ALL surfaces above the body side moldings (including recessed areas around door handles) be refinished, as these surfaces may show the same DELAMINATION (peeling) condition at a later date. Note: Many vehicles have some type of plastic exterior body panels (cowl vent grilles, fascias, front end panels, rear fenders, etc.). These panels are not subject to DELAMINATION and therefore do not require refinishing. If painting of these panels is required for color uniformity, scuff sand and colorcoat only (and clearcoat if basecoat/clearcoat system is used). Note: Two tone lines, feature lines or body side molding treatments near mid-door height are appropriate break lines. If no such convenient break lines are present, the entire panel above the next lower break line must be refinished and the portion of the panel below that break line should be COLORCOATED ONLY (and clearcoated if basecoat/clearcoat system is used) for color uniformity of the repair. Note: Pickup boxes which are covered by caps, bedliners or tonneau covers do not receive direct exposure to sunlight, and normally would not be repaired under this procedure. However, if the inside of the box has been uncovered and experienced DELAMINATION, use the appropriate Labor Operation Number. Note: Certain two tone applications on trucks using the high potential colors (Blues, Grays and Silvers) may require that only portions of the vehicle surface be refinished. Examples would be: Example 1. Blues, Grays and Silvers as "insert colors" on vertical surfaces with other, non-high potential colors above the insert (or break line). Action: Refinish the "insert color" only, between the break line and body side molding (or to the lower feature line on certain vehicles). Example 2. Blues, Grays and Silvers on surfaces above the break line with other, non-high potential colors as "insert colors". Action: Refinish the surfaces above the "insert color" or break line only. Example 3. Blues, Grays and Silvers used as both the primary and "insert colors". Action: Refinish both high potential color surfaces above the body side moldings (or to the lower feature line on certain vehicles). Vehicles should be repaired with the same type materials they were manufactured with; repair basecoat/clearcoat with basecoat/clearcoat materials and monocoat with monocoat. PAINT REPAIR PROCEDURE 1. Some vehicle components will be removed from the vehicle while others will require masking. The list located at the end of this bulletin will establish the removal items. Items not found on the list and non-repair areas are to be masked. 2. Prior to removing the paint finish, clean the area to be refinished with an appropriate wax and grease remover to remove any contaminants. 3. Remove the original finish of paint down to the ELPO primer surface using an orbital D.A. sander, leaving the ELPO surface intact. This can be done in "stages" using 80 grit (or finer) discs to remove the majority of coating, followed with 180 grit (or finer) discs to remove the remainder of material down to the ELPO surface and any chalky residue or degraded ELPO that may remain. Avoid sanding through ELPO to bare metal in order to retain maximum corrosion protection. - An alternative in some geographic areas may be plastic media blasting such as may be provided by members of: - Dry Stripping Facilities Network 1-800-634-9185 * Brakes - ECU Software Improvement Electronic Brake Control Module: Technical Service Bulletins Brakes - ECU Software Improvement Number: 91-101-5 Section: 5 Date: November 1990 Corp. Bulletin No.: 065021 Subject: INTRODUCTION OF CODES 6, 9 AND 10 AS SOFT CODES Model and Year: 1988-91 C/K, S/T, R/V, G AND M TRUCKS WITH RWAL TO: ALL CHEVROLET DEALERS Beginning in August 1990, a software change was made to the Electronic Control Units on all RWAL equipped vehicles. This software improvement will change codes 6, 9, and 10 to "Soft Codes." The conditions which set these codes remain the same, as well as the diagnostics technicians should follow to determine the root cause. Codes 6 and 9 will light the brake light when a fault is detected and the applicable code will be stored in memory. The brake light will remain on until the next ignition cycle at which time if the fault is not present, the brake light will remain off. The code, will still remain in memory as a "Soft Code." If the code should reoccur, the brake light will again be illuminated for the duration of that ignition cycle. A code 10 will set if the brake pedal is depressed or the brake switch circuit is opened and remains open until vehicle speed passes approximately 38 MPH. This soft code differs from codes 6 and 9 in that the red brake light will be illuminated only while the fault is detected. Code 10 will remain stored in the ECU memory after the light has been turned off. IMPORTANT: Technicians MUST use a Tech One scan tool to read codes. This is because soft codes will be erased by grounding terminals A to H and a false code 9 could be set if this is attempted. The new ECUs can be identified by the code printed on the bottom of the longer of two bar code labels on the module. Older ECUs will have a fifteen digit alphanumeric code beginning with 912349K. New ECUs with the soft code software will have a code that begins with 919220K. Page 4602 Figure 2 Page 5539 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) Page 661 Spark Plug Wire: 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. Page 6854 FIGURE 1 7. Measure 1 1/4" down from the bottom of the windshield and make a horizontal mark on the windshield frame inboard of the cowl screen lock tab (Figure No. 1). 8. Measure 7/8" inboard from the cowl screen lock tab and make a vertical mark through the line made in the previous step. 9. Center punch the windshield frame at the point the lines intersect. Use a one inch hole saw to cut a hole in the windshield frame (cut through only the first layer of sheet metal) and remove the circular piece of metal that remains from cutting the hole. DO NOT CUT THE SECOND LAYER PANEL. Page 5346 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 Capacity Specifications Refrigerant Oil: Capacity Specifications With A-6 Compressor Compressor Oil .................................................................................................................................... ..................................................... 0.284 Kg (10 oz.) With DA-6 Compressor Compressor Oil .................................................................................................................................... ....................................................... 0.227 Kg (8 oz.) With R-4 Compressor Compressor Oil .................................................................................................................................... ...................................................... 0.312 kg (11 oz.) With DA-V5 Compressor Oil Capacity ......................................................................................................................................... ............................................................. 0.226 (8 oz.) With HR-6 Compressor Oil Capacity ......................................................................................................................................... ............................................................. 0.226 (8 oz.) Refrigerant Oil Capacity With DA-6 Compressor ........................................................................................................................ ........................................................................... 8 oz With R-4 Compressor .......................................................................................................................... ............................................................................ 6 oz Brakes - Rotor & Hub Flange Cleaning Tool Revision Brake Rotor/Disc: All Technical Service Bulletins Brakes - Rotor & Hub Flange Cleaning Tool Revision File In Section: 5 - Brakes Bulletin No.: 73-50-37 Date: January, 1998 INFORMATION Subject: Revision to J 42450 Tool; Proper Brake Rotor and Hub Flange Surface Cleaning Models: 1998 and Prior Passenger Cars and Light Duty Trucks - with Disc Brakes (Rotor and Hub Separate) This bulletin is being revised to update the following text. This bulletin is being issued to inform the dealer about a revision to tool J 42450 and reinforce the need for proper hub flange and brake rotor mating surface cleaning during service. Tool J 42450 is a cleaning pad arbor and pad system that fits over the wheel stud and cleans the portion of the hub surface that is very difficult to reach with normal rotary cleaning pads. Tool J 42450 is being revised to J 42450-A to improve the hook and loop material retention. Any dealer experiencing problems with tool J 42450 should contact Kent-Moore at 1-800-345-2233 for a revised arbor at no charge. Anytime the brake rotor has been separated from the hub bearing flange or if rotor machining is necessary, the rotor and hub should be marked to maintain the original position. Clean the hub flange of all dirt and foreign material using special tool J 42450 or J 42450-A. Clean both sides of the brake rotor hub using an aggressive (80 grit) abrasive sanding pad on a rotary disc. Properly cleaning the rotor surfaces before rotor machining or reassembly ensures that dirt and corrosion will not add lateral runout to the rotor. Proper cleaning of the hub flange will also minimize the stack-up of lateral runout. On reassembly, the rotor should be reinstalled aligning the marks made on disassembly. Always use a torque wrench or the appropriate Torque Socket found in J 39544-KIT on an impact wrench when installing the wheel and tire assembly. Torque all wheel nuts using the correct sequence and torque. Refer to the Tire and Wheel Sub-Section in the applicable Service Manual. Excessive torque or torque variation between wheel nuts may cause distortion of the hub and rotor mating surface. This distortion may cause lateral runout and lead to brake pulsation. Page 270 Refrigerant Pressure Sensor / Switch: Locations Pressure Cycling Switch Pressure Cycling Switch Location The Pressure Cycling Switch is located on the Accumulator. Page 6224 Owners of some 1986-92 S/T Trucks equipped with air conditioning may comment on loose or binding temperature control or HVAC mode selection levers. These conditions may be caused by broken housing bosses at the plate mounting screws on the A/C control (Figure 3). The result may be inability to actuate certain HVAC modes or obtain maximum heating or cooling. Previously it was necessary to replace the complete A/C control assembly to correct this condition. The control assembly included the valves, switches, bezel and lighting. The housing, P/N 16074394, is now available allowing this condition to be corrected when other parts of the control are operating properly. Partial disassembly of the A/C control is required. SERVICE PROCEDURE: 1. Remove the A/C control assembly from the instrument panel. Page 909 Fluid - A/T: Service and Repair Turbo Hydra-Matic 4L60 (700-R4) Checking & Adding Fluid Check fluid at regular intervals. Noticing a change in color, odor or fluid level can serve as a warning of possible transmission problems. To check fluid level, bring fluid to operating temperature of 200°F. With vehicle on a level surface, engine idling in park and parking brake applied, the level on the dipstick should be at the Full mark. To bring the fluid level from the Add mark to the Full mark requires one pint of fluid. If additional fluid is required, use only Dexron II or Dexron IIE automatic transmission fluid. When adding fluid, do not overfill, as foaming and loss of fluid through the vent may occur as the fluid heats up. Also, If fluid level is too low, complete loss of drive may occur especially when cold, Which can cause transmission failure. Every 100,000 miles, the oil should be drained, the pan removed, the screen should be cleaned or replaced if applicable, and fresh fluid added. For vehicles subjected to more severe use such as heavy city traffic especially in hot weather, prolonged periods of idling or use as a tow vehicle, this maintenance should be performed every 15,000 miles. Changing Oil 1. Raise vehicle and position drain pan under transmission pan. 2. Remove front and side attaching bolts form the oil pan. 3. Loosen rear attaching bolts approximately four turns. 4. Carefully pry transmission pan loose and allow fluid to drain. 5. Remove rear attaching bolts, pan and pan gasket. 6. Drain remaining fluid from pan, then clean pan and gasket surfaces with solvent and dry with compressed air. 7. Remove transmission screen. Remove O-ring seal from intake pipe or case bore. 8. Replace screen if applicable, or thoroughly clean screen assembly with solvent and dry with compressed air. 9. Install O-ring on intake pipe, then install screen assembly. 10. Install gasket on pan, then install pan and torque attaching bolts to 12 ft. lbs. 11. Lower vehicle and add approximately 5 qts. of Dexron II or Dexron III type transmission fluid through filler tube. 12. Start engine and let run at idle, then with brakes applied move selector lever through each gear range. 13. Place transmission in Park position and check fluid level. Specifications Flywheel: Specifications Flywheel Bolts 75 ft.lb Flywheel Housing Bolts 32 ft.lb A/T - Manual Update For ATF Level & Condition Fluid - A/T: All Technical Service Bulletins A/T - Manual Update For ATF Level & Condition GMC NUMBER: 89-7A-104 GROUP: 7A Automatic Transmission DATE: September, 1989 CORPORATE NUMBER: 977126R SUBJECT: AUTOMATIC TRANSMISSION FLUID COLOR/LEVEL CHECK INFORMATION MODELS: ALL 1987-89 S/T, C/K, R/V TRUCKS AND M, G, P VANS EQUIPPED WITH HYDRAMATIC AUTOMATIC TRANSMISSIONS BULLETIN COVERS: Service Manual update for Transmission fluid level and condition information. This information is updated for 1989 service manuals printed prior to June 1989. TRANSMISSION FLUID LEVEL INFORMATION: Checking fluid level and condition (color and odor) at regular intervals will provide early diagnosis information about the transmission. This information may then be used to correct a condition that, if not detected early, could result in major transmission repairs. When adding or changing fluid, use only DEXRON II. Refer to Maintenance and Lubrication (Service Manual Section OB) for maintenance information and servicing intervals. NOTICE: Do not overfill. Overfilling will cause foaming, loss of fluid, shift complaints and possible damage to the transmission. ^ Fluid level should only be checked when it reaches a normal operating temperature of 82-93C (180-200F). This temperature is reached after approximately 24 km (15 miles) of driving. TRANSMISSION FLUID COLOR: ^ Fluid color will be red when new. IMPORTANT: When new, automatic transmission fluid is red in color. The red dye is added so the assembly plant can identify it as transmission fluid and distinguish it from engine oil or anti-freeze. The red dye is not an indicator of fluid quality and is not permanent. As the vehicle is driven, the transmission fluid will begin to look darker in color. The color may eventually appear light brown. A dark brown color along with a burnt odor may indicate excessive fluid deterioration and signal a need for fluid change. Page 2345 Oxygen Sensor: Description and Operation Fig. 6 Oxygen Sensor (Typical) The exhaust oxygen sensor is located in the exhaust system and monitors oxygen content in the exhaust gas stream. The oxygen content of the exhaust gas reacts with the oxygen sensor to produce a voltage output, Fig. 6. By monitoring the oxygen sensor output voltage, the ECM can determine the amount of oxygen in the exhaust gas and adjust the air/fuel mixture accordingly. Isuzu M-150 (77.5 mm) 4-Speed Reverse Idler Gear: Specifications Isuzu M-150 (77.5 mm) 4-Speed Reverse gear to mainshaft nut ............................................................................................................ ..................................................................... 95 ft. lbs. Electrical - Instrument Panel & General Wiring Repair Wiring Harness: All Technical Service Bulletins Electrical - Instrument Panel & General Wiring Repair Bulletin No.: 06-08-45-004 Date: May 02, 2006 INFORMATION Subject: Instrument Panel (I/P), Body and General Wiring Harness Repair Models: 2007 and Prior GM Cars and Trucks 2003-2007 HUMMER H2 2006-2007 HUMMER H3 Important: A part restriction has been implemented on all Body and I/P harnesses and is being administered by the PQC. If a body or I/P harness replacement is required, it can take 12-28 weeks for a harness to be built and delivered to a dealer. The dealer technician is expected to repair any harness damage as the first and best choice before replacing a harness. In an effort to standardize repair practices, General Motors is requiring that all wiring harnesses be repaired instead of replaced. If there is a question concerning which connector and/or terminal you are working on, refer to the information in the appropriate Connector End Views in SI. The Instruction Manual J 38125-620, which is sent with each new update of the J 38125 Terminal Repair Kit, also has terminal crimping and terminal remove information. Important: There are some parts in the J 38125 Terminal Repair Kit (i.e. SIR connector CPAs and heat shrink tube (used in high heat area pigtail replacement) and some TPAs that are not available from GMSPO. It is vitally important that each update to the J 38125 Terminal Repair Kit be done as soon as it arrives at the dealer. Utilize the Terminal Repair Kit (J 38125) to achieve an effective wiring repair. The Terminal Repair Kit has been an essential tool for all GM Dealers since 1987. Replacement terminals and tools for this kit are available through SPX/Kent Moore. Refer to Corporate Bulletin Number 06-08-45-001 for more information. The Instruction Manual J 38125-620, which is sent with each new update to the J 38125 Terminal Repair Kit, also has terminal crimping and terminal removal information. U.S. Dealers Only - Training courses (including Tech Assists, Emerging Issues, Web, IDL and Hands-on) are available through the GM Training website. Refer to Resources and then Training Materials for a complete list of available courses. Canadian Dealers Only - Refer to the Training section of GM infoNet for a complete list of available courses and a copy of the J 38125 Terminal Repair Kit Instruction Manual. Wiring repair information is also available in Service Information (SI). The Wiring Repair section contains information for the following types of wiring repairs: - Testing for intermittent conditions and poor conditions - Flat wire repairs - GMLAN wiring repairs - High temperature wiring repairs - Splicing copper wire using splice clips - Splicing copper wire using splice sleeves - Splicing twisted or shielded cable - Splicing inline harness diodes Page 5875 Light Duty truck tire rotation recommendations are pictured on the following page. Rotation Guidelines for Tires used on Light Duty Trucks: Tires used on Pickups, Vans and Utility vehicles should be rotated at the first 6,000 miles for Schedule 1 or 7,500 miles for Schedule 2 and then every 15,000 miles thereafter. NOTE: Earlier rotation may be required should irregular wear pafterns develop due to harsh service use - the following rotation patterns are recommended for the various vehicle types and tire combinations. Page 1627 5. Replace the previous transmission mount with the revised mount (P/N 22145724 - for two wheel drive only) as shown in Figure 4. Some residual vibrations may be normal. Compare with a vehicle of same model, year, engine/transmission combination, etc. to get a feel for what is normal. SERVICE PARTS INFORMATION Parts are expected to be available from GMSPO on 8/2/93. WARRANTY INFORMATION Page 322 Brake Light Switch: Service and Repair Fig. 2 Stop Light Switch Installation 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. 2. 5. Pull brake pedal rearward against pedal stop to adjust switch. Switch is properly adjusted when brake lights operate when brake pedal is depressed .53 inch from normal position. If further adjustment of switch is necessary, switch can be rotated or pulled in clip. Electrical - Information For Electrical Ground Repair Grounding Point: Technical Service Bulletins Electrical - Information For Electrical Ground Repair INFORMATION Bulletin No.: 10-08-45-001B Date: October 25, 2010 Subject: Information for Electrical Ground Repair - Use New Replacement Fasteners with Conductive Finish 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 the 2011 model year and update the Warranty Information. Please discard Corporate Bulletin Number 10-08-45-001A (Section 08 - Body and Accessories). Electrical Ground Repair Overview Proper electrical system function relies on secure, stable and corrosion-free electrical ground connections. Loose, stripped, or corroded connections increase the possibility of improper system function and loss of module communication. These conditions may also lead to unnecessary repairs and component replacement. In general, electrical ground connections are accomplished using one, or a combination of the following attachment methods: - Welded M6 stud and nut - Welded M6 nut and bolt - Welded M8 nut and bolt Determine which attachment method is used and perform the appropriate or alternative repair as described in this bulletin. M6 Weld Stud Replacement Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. Select a location adjacent the damaged or missing M6 ground stud having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the M6 conductive rivet stud flange. 2. Using GM approved residue-free solvent or equivalent, remove any grease from the repair site and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 3. Drill a 10 mm (0.40 in) diameter hole through the panel. 4. Remove paint and primer from the area surrounding the 10 mm (0.40 in) hole until bare metal is visible. Locking Differential - Chattering on Turns Fluid - Differential: Customer Interest Locking Differential - Chattering on Turns Number: 91-370-0B Section: 0B Date: JULY 1991 Corporate Bulletin No.: 964201R Subject: LOCKING DIFFERENTIAL LUBRICANT Model and Year: 1982-91 ALL TRUCKS WITH G80 REAR AXLE THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 90-139-4A, DATED JANUARY 1990. CONDITION DESCRIPTION AND CORRECTION HAVE BEEN ADDED AS WELL AS THE 1991 MODEL YEAR. ALL COPIES OF 90-139-4A SHOULD BE DISCARDED. Some light duty trucks equipped with locking rear axles (G80) may exhibit rear axle chatter, especially when turning a corner from a stop. This condition of alternate engagement and disengagement of the clutches in the differential assembly is usually caused by contaminated axle lubricant. To correct this condition, drain and refill the rear axle with SAE 80W-90 GL5 (P/N 1052271). The use of any additive in locking rear axles (G80) is not recommended. Rear axle additives are designed for use in limited slip differentials which are normally installed in cars. All light duty trucks equipped with RPO G80 make use of a locking differential and the use of additives will delay the engagement of the locking mechanism and may decrease axle life. VEHICLES/COMPONENTS INVOLVED: Some light duty trucks equipped with locking rear axles, RPO G80. SERVICE PARTS INFORMATION: Part Number Description 1052271 Lubricant, Rear Axle (24 oz.) See Appropriate Parts Manual Gasket, Rear Axle Housing Cover Parts are currently available through GMSPO. WARRANTY INFORMATION: As specified in Light Duty Truck Maintenance Schedules, locking rear axle fluid drain and refill is required owner maintenance at the first engine oil change. Failure to drain and refill the rear axle as specified may contribute to a later axle chatter condition. Refer to the appropriate Light Duty Truck Maintenance Schedule or service manual, section 0B, for further details on change intervals. For those vehicles repaired under warranty, which have had the axle fluid changed at the first oil change and have experienced rear axle chatter use: Labor Operation: F2010 Use applicable labor time guide for labor hours. Page 7470 movement. Refer to Dealer Service Bulletin Number 91-181-10, Dated February 1991. Suspension (Front) - Squeaking Noise Coil Spring Insulator: All Technical Service Bulletins Suspension (Front) - Squeaking Noise Number: 91-330-3C Section: 3C Date: MAY 1991 Corp. Bulletin No.: 063306R Subject: FRONT SUSPENSION SQUEAK Model and Year: 1982-91 S1 TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 91-168-3C, DATED JANUARY 1991. THE LABOR OPERATION HAS BEEN CHANGED. ALL COPIES OF 91-168-3C SHOULD BE DISCARDED. Some S1 trucks may experience a squeaking noise from the front suspension. Spraying of lubricant in the spring pocket areas may help for a short time but the squeak usually returns. The usual cause of this squeak is contact between the spring and the frame pocket or control arm. An insulator is installed in production between the spring and upper frame pocket, but this insulator will occasionally be pushed aside allowing metal to metal contact. An insulator was not installed in production between the control arm and the spring. To fix the squeak, the existing upper insulator should be removed and M-Van insulators installed at both ends of the spring; that is, between the spring and the upper frame pocket and between the spring and the lower control arm. VEHICLES INVOLVED 1982 - 1991 S trucks. SERVICE PROCEDURE: REMOVE 1. Lower control arm and spring. 2. Insulator from top end of spring. - Clean excess paint and adhesive from both ends of spring. INSTALL 1. New insulators to spring ends. - Apply a full bead of weatherstrip adhesive to the diameter of the spring insulator contact area. - Be sure upper and lower insulators are installed to respective ends of the spring. - Allow weatherstrip adhesive to cure enough to hold the insulators in place before reinstalling springs. 2. Spring. Tape should be on lower end and gripper notch on top. - Position end of lower spring coil to cover one lower control arm inspection drain hole and expose the other 3. Lower control arm. Refer to S/T Service Manual, Section 3C - Front Suspension for complete coil spring replacement procedure. SERVICE PARTS INFORMATION Quantity Part Number Description Required Page 5321 Courtesy & Dome (W/Cargo Lamp) Page 2330 - Diagnostic Chart Code 63. Page 3963 Torque Converter Clutch: Component Tests and General Diagnostics Chart C-8 - Transmission Converter Clutch (TCC) (Under 8500 GVW) Page 1877 Disclaimer MAP - Revised Check Chart for DTC's 33, 34, 63, 64 Manifold Pressure/Vacuum Sensor: Technical Service Bulletins MAP - Revised Check Chart for DTC's 33, 34, 63, 64 Number: 90-199-6E Section: 6E Date: March 1990 Corporate Bulletin No.: 016510 Subject: REVISED CHART C-1D, CODE 33, 34, 63, 64 Model and Year: 1980-90 PASSENGER CARS AND TRUCKS TO: ALL CHEVROLET DEALERS This bulletin revises the Manifold Absolute Pressure (MAP) Output Check Chart C-1D and updates Code 33, Code 34, Code 63, and Code 64 in the Service Manual section on "Driveability And Emissions" (Section 6E1, 6E2, and 6E3). This information applies to all MAP Sensors on 1980-1990 vehicles with gasoline engines (except turbocharged) with green (standard) MAP sensor electrical connector insert or the solid black MAP sensor electrical connector insert. The revised chart information: Alternator Indicator Lamp Volt Meter Gauge: Testing and Inspection Alternator Indicator Lamp DELCOTRON CHARGING SYSTEM Fig. 1 Charge Indicator Lamp Wiring System. Delcotron Charging System Before performing diagnostic procedures, ensure system wiring is good, alternator belt is tight, and battery is fully charged. 1. Check drive belt for wear and proper adjustment. 2. With ignition switch On and engine Off, charging indicator lamp should be On. 3. If indicator lamp is not On, disconnect wiring harness at alternator. Ground ``L'' terminal using a fused five amp jumper wire. Refer to Fig. 1 for wiring schematic of alternator. 4. If lamp lights, replace alternator. If lamp does not light, check for a open between the grounding lead and the ignition switch. Reconnect wiring. 5. With switch On and engine running at a moderate RPM, lamp should be Off. If not stop engine, turn switch On, then disconnect wiring harness at alternator. 6. If lamp goes out, replace alternator. 7. If lamp stays On, check for a grounded ``L'' terminal wire in harness. Page 6350 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 Description and Operation Air Conditioning Switch: Description and Operation The air conditioning "On" signal informs the ECM the A/C selector switch is turned on, and the A/C pressure cycling switch is closed. Using this information, the ECM adjusts the engine idle speed as necessary to ensure a smooth idle. Specifications Fuel Pressure: Specifications FUEL PRESSURE: Ignition ON Engine OFF ...................................................................................................................... ................................................. 62-90 kPa (9-13 psi) Page 4824 Brake Caliper: Fundamentals and Basics Installation Notes WHEN INSTALLING CALIPERS AND PADS, REMEMBER... - Clean and lubricate caliper slide joint/pins with high temperature silicone grease: Unlike drum brakes, disc brakes do not utilize a spring to withdraw the pads/linings when the brake pedal is released. Disc brakes rely on the elasticity of the piston seals, and the unrestricted movement of the caliper slide assemblies to release the brakes. If the slide joints/pins are not cleaned and lubricated properly the disc brake linings will drag upon the release of the brake pedal. This will result in overheated brakes and premature brake wear. Disc Brake Mechanical Force Diagram NOTE: Floating calipers require free and unrestricted movement on the caliper mounting. Floating or sliding calipers have pistons only on one side of the rotor. The first part of the piston's travel forces the inner pad against the rotor, then further travel forces the movable part of the caliper to pull the outer pad against the rotor. High temperature silicone lubricant must be used. Low temperature grease can melt and contaminate the pads and rotors, or can bake into a very hard substance which binds the slides. Petroleum based grease can cause the slide boots to soften and swell. Work on one side at a time. If you forget how to reassemble the parts you can always use the other side as a model. Anti-squeal Coating - Apply an anti-squeal coating to the back side of the pads/linings. This coatings acts as an insulator to dampen high frequency vibrations that are generated during normal braking. These compounds are highly effective in preventing brake squeal. - Many professional repair shops recommend always rebuilding or replacing the calipers when replacing the brake linings, because: When the pistons are forced back into the calipers, the piston seals are dragged across any corrosion or abrasives that may be deposited on the inside of the caliper. Damage to the seals may not be initially evident. As the new brake linings begin to wear, the piston is gradually withdrawn from the caliper. Locations TIMING MARK 4.3L (262) High-Side Pressure & High-Side Low Pressure Cutoff Switches Refrigerant Pressure Sensor / Switch: Service and Repair High-Side Pressure & High-Side Low Pressure Cutoff Switches DA-V5 COMPRESSOR Rear Head Details Page 5338 Warranty Information (excluding Saab U.S. Models) For vehicles repaired under warranty, use the appropriate labor operation for the source of the water leak Warranty Information (Saab U.S. Models) For vehicles repaired under warranty, use the table. Disclaimer Page 256 Oil Pressure Switch (For Fuel Pump): Description and Operation As a back-up system to the fuel pump relay, the fuel pump can also be turned ON by the oil pressure switch. The oil pressure switch is a normally open switch which closes when oil pressure reaches about 28.0 kPa (4.0 psi). If the fuel pump relay fails, the oil pressure switch will power the fuel pump. Page 6152 HR-6 Component View Remove or Disconnect Tools Required: J 8433-1 Puller Bar J 08433-3 Puller Screw J 33023-A Puller Pilot J 33025 Clutch Coil Puller Legs 1. Clutch plate and hub assembly (2). 2. Pulley (5). ^ Mark or scribe the location of the clutch coil (6) to terminal on the compressor front head (11). 3. Clutch coil assembly (6). ^ Install J 33023-A on the head (11) of the compressor A/T - Buzzing Noise at Idle Fluid Pressure Sensor/Switch: Customer Interest A/T - Buzzing Noise at Idle Number: 93-29-7A Section: 7A Date: OCT. 1992 Corporate Bulletin No.: 277142 ASE No.: A2 Subject: BUZZING NOISE AT IDLE Model and Year: 1982-93 CAPRICE, CAMARO AND CORVETTE 1982-93 C/K, R/V, S/T, M/L AND G TRUCKS WTIH 4L60 AUTOMATIC TRANSMISSION TRANSMISSION APPLICATIONS: 1982-1993 HYDRA-MATIC 4L60 (MD8) TRANSMISSION MODELS: All SUBJECT: Pressure Regulator Valve Buzz VEHICLE APPLICATIONS: B, D, F, Y - Cars C/K, R/V, S/T Trucks G, M, L - Vans CONDITION: Some 1982-1993 vehicles equipped with a HYDRA-MATIC 4L60 transmission may have a buzzing noise coming from the transmission when the vehicle is at idle. The buzzing noise may be noticed more when the vehicle is in reverse at idle. CAUSE: The buzzing noise may be a result of pressure regulator valve oscillating due to oil pressure instability at lower idle RPM. CORRECTION: Page 4642 Figure 3 REMOVE (Figures 2 & 3) Tools required: J8092 Drive handle J33790 Bearing installer and remover 1. Transfer case from vehicle. - Refer to Section 7D of the appropriate S/T Service Manual for complete transfer case removal procedure. 2. Front output flange nut (77), washer (76), rubber sealing washer (75) and front output flange (74) from the front output shaft. 3. Vacuum switch (46) and O-ring seal (47). 4. Poppet screw (68), O-ring seal (69), poppet spring (71) and poppet plunger (70). Mainshaft Extension and Oil Pump Housing 5. Rear extension housing bolts (3) and rear extension (4). 6. Bearing retainer (snap ring) (5) from the mainshaft (19). 7. Pump retainer housing bolts (7). 8. Pump retainer housing (8) from the rear case half (17). 9. Speedometer tone wheel (11) from the mainshaft (19). Locations Throttle Position Sensor: Locations Center Of Dash Panel (engine Compartment) Center Rear Of Engine Applicable to: V6-262/4.3L Engine Page 1943 Spark Plug: Description and Operation Resistor type, copper core, tapered seat quantum spark plugs are used on all engines. No gasket is used on these tapered seat plugs. A dot before the spark plug code or the letter C after the number in the code indicates that the plug has a copper core. For the correct gap information refer to the Vehicle Emissions Control Information label under the hood or refer to SPECIFICATIONS/ELECTRICAL AND ELECTRONIC SPECIFICATIONS. Normal or average service is assumed to be a mixture of idling, slow speed, and high speed operation with some of each making up the daily total driving. Occasional or intermittent high-speed driving is essential to good spark plug performance as it provides increased and sustained combustion heat that burns away any excess deposits or carbon or oxides that may have accumulated from frequent idling or continual stop and go or slow speed driving. Spark plugs are protected by an insulating boot made of special heat-resistant material which covers the spark plug terminal and extends over a portion of the plug insulator. These boots prevent flash-over with resultant missing of the engine, even though a film is allowed to accumulate on the exposed portion of the plug porcelains. Do not mistake corona discharge for flash-over or a shorted insulator. Corona is a steady blue light appearing around the insulator, just above the shell crimp. It is the visible evidence of a high-tension field, and has no effect on ignition performance. Usually it can be detected only in the darkness. This discharge may repel dust particles, leaving a clear ring on the insulator just above the shell. This ring is sometimes mistakenly regarded as evidence that combustion gases have blown out between the shell and the insulator. Page 6094 Blower Motor: Service and Repair Without Air Conditioning Figure 2 - Air Distribution System Component View Page 5122 e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors Do Not require all the steps shown. Skip the steps that Do Not apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. 1. Separate connector halves (see Figures 2 through 6). Figure 2 Figure 3 Page 475 Neutral Safety Switch: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. Figure 21 Figure 22 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. Page 1434 II. OVER TORQUING OF WHEEL NUTS: 1. A TORQUE WRENCH MUST BE USED to insure that the wheel nuts are tightened to specification. This should be done in two steps using the star pattern. First, snug the nuts down by hand. Then, using the star pattern and a torque wrench, tighten the wheel nuts to about half the final torque. Finally, tighten the wheel nuts to specification using the star pattern and a torque wrench. 2. NEVER use lubricants or penetrating fluids on wheel studs, nuts, or mounting surfaces, as this can raise the actual torque on the nut without a corresponding torque reading on the wrench. Wheel nuts, studs, and mounting surfaces must be clean and dry. Page 6484 Seat Belt: Technical Service Bulletins Seat Belt - Operations/Features and Location FILE IN SECTION: 10 - Body BULLETIN NO.: 56-16-01 DATE: April, 1995 SUBJECT:Seat Belt Operation, Features and Location MODELS: 1988-95 Chevrolet and GMC Truck C/K Pickups 1983-95 Chevrolet and GMC Truck S/T Models The following passenger seat belts operate differently from the comparable driver's seat belt. 1. Right front passenger seat belts (Figure 1, Position 1) on: 1988-95 C/K Pickups 1992-95 C/K Crew Cabs 1983-95 S/T Pickups and Utilities 2. Left and right rear second seat outboard belts (Figure 1, Position 2) on: 1992-95 C/K Crew Cabs 1995 S/T Utilities The reason for the difference is to allow a child restraint (child seat) to be used in these passenger positions. Child restraints require the lap portion of the seat belt to firmly tighten around the restraint. To accommodate this requirement, belts in the aforementioned positions are equipped with a ratcheting feature activated by pulling the lap belt all the way out. Once the belt has been pulled all the way out, it becomes a one way mechanism that will retract until it contacts a solid object like a child restraint or person, but will not extend again until it has been fully retracted all the way back to the stop button attached to the belt. This feature is often referred to as a child hold out mechanism. If a passenger finds that the belt becomes tight and uncomfortable while riding, it may indicate that the belt was pulled all the way out during the buckling process, thus activating the racheting feature. This condition can be avoided by taking care not to pull the belt to its very end when buckling up. Page 4890 FIGURE 3 - LUBRICATING CALIPER CAVITY When servicing the caliper, the caliper bolts should be cleaned and the space between the caliper bolt bushings should be filled with silicone grease such as Part Number 1052863 or equivalent. This will prevent the caliper dragging or binding on the mounting bolts. Refer to Figure 3. LINING MATERIAL ABRASIVENESS: The degree of abrasiveness of the brake lining material is determined by the manufacturer. A highly abrasive material will tend to create a rotor out-of-parallel condition if system runout and caliper drag are present. The properties and characteristics of brake linings are specified by Product Engineering. Some brake lining designs may be more aggressive when stopping, i.e. higher friction coefficient, while others are less aggressive but may be very durable and long lasting. The linings for any specific vehicle are selected on the basis of friction, wear, etc., to optimize front and rear braking for that specific vehicle. The brake lining used should be whatever is recommended by the manufacturer in the parts catalog or in the latest service bulletin. Brake pedal pulsation can also occur in the rear on drum brakes if there is radial runout in the drum and/or axle flange, or bearing. Thickness Variation Check: If a brake pedal pulsation condition is felt, a thickness variation check should be performed on the rotor. Thickness variation can be checked by measuring the thickness of the rotor at four or more points around the circumference of the rotor. Use a micrometer calibrated in one tenth increments per .001 inch. All measurements must be made at the same distance in, from the edge of the rotor. A rotor that varies by more than 0.013 mm (0.0005-inch) can cause pedal pulsation and/or front end vibration during brake applications. A rotor that does not meet these specifications should be refinished or replaced as necessary. Rotor Refinish Recommendations: Rotor refinish should only be performed because of non-parallelism (thickness variation), runout, or deep scoring grooves deeper than .015 inches. When replacing a rotor with a new rotor from stock it should NOT require refinishing unless ons of the conditions mentioned above is present. Also, routine replacement of disc brake linings does NOT require rotor refinishing. When rotor refinishing is required the following recommended procedures should be used to obtain the proper micro-inch surface finish which is required for new rotors (10 to 50 micro-inches with non-directional swirl pattern). When refinishing a rotor for a pulsation condition it is recommended that at least 0.010 inch be removed from the inboard and outboard side of the rotor surface to insure removal of the high and low spots on the face of the rotor. Rough Cut Finish Cut Spindle 150 rpm 150 rpm Depth of Cut Per Side .005 inch .002 inch Tool Cross Feed Per Rev. 0.006-.010 inch .002 inch max. Vibration Dampener Yes Yes Swirl Pattern-120 GRIT No yes The following is also important: ^ The brake lathe must be in good working order and have capability to produce the intended surface finish. ^ Excessive spindle speed or too deep a cut can result in a rough finish. ^ Cutting tools must be sharp. Page 1833 Oil Pressure Sender: Locations Engine Harness Top rear of engine Page 5046 Hydraulic Brake Booster: Testing and Inspection Grabby Brakes or Booster Chatters/Pedal Vibrates 1. Faulty spool action caused by contamination in system. 2. Power steering pump belts slip. 3. Low fluid level in power steering pump. 4. Faulty spool operation caused by contamination in system. Page 3879 Shift Solenoid: 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. Head Lamp Switch Trim Plate - Cracked Headlamp Switch: Customer Interest Head Lamp Switch Trim Plate - Cracked Number: 91-109-10 Section: 10 Date: January 1991 Corporate Bulletin No.: 061605 Subject: CRACKED PLASTIC HEAD LAMP SWITCH TRIM PLATE Model and Year: 1986-91 S/T TRUCKS TO: ALL CHEVROLET DEALERS Figure 1-Plate Assembly-Instrument Panel Switch Trim Some 1986-1991 S/T trucks may experience a cracked plastic head lamp switch trim plate. This may result in the inaccessibility of the rheostat assembly (dimmer switch) and/or the switch assembly (head lamp/park lamp switch) (Figure 1). Previously, it was necessary to replace the complete head lamp switch trim plate assembly. The complete assembly includes the rheostat assembly part number 01995293 (instrument panel dimmer switch), switch assembly part number 01995313 (head lamp/ parking lamp switch) and the switch trim plate (Figure 1), and the switch trim plate hole covers. A new trim plate kit is now available which does not contain the rheostat assembly or the head lamp switch. This kit replaces the complete head lamp switch trim plate assembly when the switch trim plate is cracked and the rheostat assembly or the head lamp switches do not need replacing. This new kit includes; a switch trim plate, bracket for switch mounting, covers for the switch trim plate holes and four bolts/screws. Engine - Noise/Damage Oil Filter Application Importance Oil Filter: 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 Page 5887 FIGURE 4 GENERAL AND UNIROYAL IF WITHIN THE NEW VEHICLE WARRANTY PERIOD (12/12): A. If only slight cupping is noticed, and the cross grooves in the tire's outside shoulder are still visible (See Figure No. 3), the tires should be rotated. The modified "X" pattern should be used (See Figure No. 1). This method will best equalize wear after a few thousand miles. B. The cupping or wear is severe, and the cross grooves in the outside shoulder are not visible, tire replacement will be necessary (See Figure No. 4). It should be noted, however, that even when these grooves disappear, the tire is normally only half worn in this area. If tires are needed for any of the previous conditions, they should be purchased from your local tire outlet. If tires are not readily available, contact the manufacturers toll-free assistance number provided below. Firestone - 1-800-638-4730 General - 1-800-Tire-FIX - 1-800-426-4889 (Ohio) Goodyear - 1-800-321-2136 Uniroyal - 1-800-231-5893 (Except Texas) - 1-800-833-5906 (Texas) The tire invoice amount should be entered as a net item on the warranty claim using the E0420 labor operation code for wheel and/or tire replacement. Labor Op E0420 - Wheel and/or Tire-Replace Replace One - .6 hr. Each Additional Tire - .4 hr. Engine - Vibration On Acceleration Exhaust Pipe/Muffler Hanger: All Technical Service Bulletins Engine - Vibration On Acceleration Number: 88-270-6F Section: 6F Date: JULY, 1988 Subject VIBRATION ON ACCELERATION Model and Year 1988 S/T TRUCK W/4.3L (VIN CODE Z) ENGINE TO: ALL CHEVROLET DEALERS Some 1988 S/T Trucks equipped with 4.3L engines may experience a vibration that can be felt in the floor pan area near the shifter, in the right hand passenger seat foot area, or on the steering column. These conditions may be caused by the following items: 1. The shifter rod that goes from the steering column to the transmission equalizer lever (#340 and #338 in Figure 36 page 7A-45 of the 1988 S/T Manual) hitting the exhaust crossover pipe and/or the equalizer lever making firm contact at the shift lever (T-truck only). 2. The exhaust pipe to catalytic converter clamp (Figure 7, page 6F-6 of the 1988 S/T Manual) hitting the catalytic converter heat shield. 3. The exhaust pipe to converter installation allows the exhaust pipe to contact the transmission crossmember. To repair these conditions, use the following procedures: 1. A. Raise vehicle on hoist. B. Check Transmission linkage for correct adjustment. C. Check exhaust pipe for shifter rod interference (shiny spot on pipe). D. If linkage hits pipe, remove 15 mm (5/8 in) from bottom of rod. E. Put transmission into low gear and mark exhaust pipe area near linkage. F. Put transmission in park. Using a hammer, lightly dimple exhaust pipe for additional clearance. Transfer Case - 231HD Noisy in 4WD High Drive Chain: Customer Interest Transfer Case - 231HD Noisy in 4WD High Number: 91-63-7D Section: 7D Date: August 1990 Corp. Bulletin No.: 067405 Subject: NOISY TRANSFER CASE IN 4-HIGH Model and Year: 1988-91 T TRUCKS WITH 231HD TRANSFER CASE TO: ALL CHEVROLET DEALERS Some 1988-1991 T trucks may experience a noisy transfer case when the truck is in 4-high. The noise is caused by rotation of the chain and gears and is transmitted through the transfer case shift linkage into the body interior. A quieter "T" pattern transfer case chain and softer durometer shift rod grommets have been released to decrease the noise level. The chain can be identified by two blue links while the previous design contained one blue link. The softer grommets are orange or beige while the previous design grommets were white. SERVICE MANUAL REFERENCE Refer to the Unit Repair Section of the appropriate Service Manual for the proper replacement procedures. SERVICE PARTS INFORMATION Quantity Part Number Description Required 15635937 Chain 1 15659238 Shift Rod Grommet 2 Parts are currently available through GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Labor Operation Description Time T7036 Replace Chain and 2.1 hrs. Install Grommets FAILURE CODE: 92 Page 5182 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 4. Make repair. Instrument Panel - Upper Surface Cleaning Instrument Cluster / Carrier: All Technical Service Bulletins Instrument Panel - Upper Surface Cleaning Number: 91-285-0A Section: 0A Date: APRIL 1991 Corporate Bulletin No.: 101003 Subject: CLEANING OF UPPER INSTRUMENT PANEL SURFACES Model and Year: ALL PASSENGER CARS AND TRUCKS ALL YEARS Comments on reflection into the windshield of the upper instrument panel may be received. The condition of instrument panel reflection into the windshield in direct sunlight may be aggravated by dealers and owners applying a wax or silicone base material to the pad surface. The higher gloss of such application results in a "veiling reflection" in the windshield. Advise customers and new car make ready area that materials containing wax or silicone should not be used to clean the instrument panel pad. A warm water and mild soap solution such as saddle soap, oil soap, or an equivalent should be used whenever the instrument panel pad needs cleaning. 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. Service and Repair Crankcase Filter: Service and Repair The PCV system should be checked every 15,000 miles and also during regular engine tune-ups. If the PCV system includes a breather filter, located in the air cleaner housing, this filter should be replaced whenever the PCV valve or air cleaner is replaced. When a periodic inspection indicates the PCV is not functioning properly, it should be serviced by replacement only. Service and Repair Push Rod: Service and Repair 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 as described under ADJUSTMENT PROCEDURES/VALVES. Page 6919 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 4. Make repair. Service and Repair Evaporator Core: Service and Repair Fig 26. Evaporator And Blower Assembly Fig 27. Evaporator And Blower Assembly Page 5612 Alignment: Service and Repair Ride/Trim Height Measurement and Adjustment Measuring "Z" Height - 2WD Models Measuring "Z" Height - 4WD Models "Z" Height Adjustment - 4WD Models Page 4293 15. Insert a drift-through brake caliper to prevent drive axle from turning and torque inboard flange bolts to 80 N-m (60 lbs.ft.). 16. Torque hub nut to 220-270 N-m (162-199 lbs.ft.). 17. Attach retainer. 18. Align cotter pin hole with retainer slot by rotating retainer. Important: DO NOT back off or tighten hub nut more than specified to install cotter pin. 19. Install new cotter pin. Cotter pin must be bent so retainer is held snugly to prevent rattling. 20. Remove drift, install wheels, and lower vehicle. Service Parts Information: Part Number Description Quantity Required 26027964 Seal Kit, Tripot 1 per side Parts are expected to be available on June 17, 1991. Until then, normal part orders will not be accepted by GMSPO. Only verifiable emergency VIP orders will be accepted. GMSPO will make every effort to obtain parts. All parts will be placed on 400 control to waive VIP surcharges. However, the parts will be shipped premium transportation at dealer's expense. All other order types will be cancelled as incorrectly ordered while 400 control is in place. Warranty Information: For Vehicle repaired under warranty use: Labor Operation: T7271 Labor Time: 1.6 hrs. each side Trouble Code: 92 Page 6833 Disclaimer Page 5032 FIGURE 1 - PARKING BRAKE ADJUSTMENT 7. Remove tie strap (#8 Figure 1). 8. Remove six screws and dash panel cover. 9. Remove hood latch cable as follows for access to brake cable: A. Remove hood cable mounting nut and hood knob locking nut at dash. B. Remove hood knob. c. Pull hood cable from engine compartment and move brake cable free from under hood latch cable. Brakes - Light Brake Drag While Driving Brake Light Switch: All Technical Service Bulletins Brakes - Light Brake Drag While Driving Number: 89-262-5 Section: 5 Date: September 1989 Corporate Bulletin No.: 915002 Subject: LIGHT BRAKE DRAG - BRAKE SWITCH ADJUSTMENT Model and Year: 1980-89 A, B, F, G, J, L, X, Y 1980-89 ALL TRUCKS Figure 1 TO: ALL CHEVROLET DEALERS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 89-178-5, DATED JUNE 1989, IN ORDER THAT WE MAY CORRECTLY IDENTIFY THE SWITCH REQUIRING ADJUSTMENT. ALL COPIES OF 89-178-5 SHOULD BE DISCARDED. Some vehicles may experience a condition of light brake drag while driving. These conditions have been found to be more noticeable on vehicles which have an anti-lock brake system. This may be caused by improper brake switch adjustment. If the brake switch is not adjusted properly, the switch may push on the brake pedal and cause the brake to remain partially applied. If a vehicle exhibits any of the above conditions, perform the following functional brake switch adjustment check: Passenger Cars Only: The following steps should be used to check brake switch adjustment: 1. Remove the driver-side hush panel (refer to Figure 1). 2. Gently pull back on the brake pedal until no audible clicks are heard. The switch will be moved in the tubular retainer providing adjustment. 3. Replace the hush panel. 4. Verify that the brake drag condition is no longer present and that the cruise control and brake lights function properly. High-Side Pressure & High-Side Low Pressure Cutoff Switches Refrigerant Pressure Sensor / Switch: Service and Repair High-Side Pressure & High-Side Low Pressure Cutoff Switches DA-V5 COMPRESSOR Rear Head Details Coolant Temperature Sensor Radiator Cooling Fan Temperature Sensor / Switch: Locations Coolant Temperature Sensor Center Of Dash Panel (engine Compartment) Center Front Of Engine Applicable to: V6-262/4.3L Engine Page 3126 10. Reconnect electrical connectors to fuel injectors. 11. With engine OFF, and ignition ON, check for leaks around fuel meter body, gasket and around fuel line nuts. Page 6580 Page 3497 Shift Solenoid: 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. Page 7317 Note the difference between the wire exit openings of the new multi-functional lever and the old lever (Figure 1). Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Op. Description E7060 Multi-functional lever, replace Use applicable labor time guide for labor hours. Page 2751 - Diagnostic Chart C-1D. The updated chart information: Page 7190 SERVICE PROCEDURE 1. Check cross rails for proper installation. 2. Remove and install cross rail, wide side forward (if required). 3. Mark old rubber cap to distinguish from new part (the new part is the same as the old part, except for an increased width which is not detectable. 4. Remove old rubber cap. 5. Lube the cross rail cap with mild soap and water or equivalent. 6. Slide in new rubber cap, wide side forward. (Cross rail does not need to be removed as the new part can be worked into place by hand.) 7. Test vehicle for howl condition. In most cases only the front cross rail cap will be needed to eliminate the howl condition. However, if appropriate, this procedure may be applied to the rear cross rail cap as well. NOTE: Install cross rail and cross rail cap with wide side forward as shown in Fig. 1. Do not cut cross rail cap to fit, work into cross rail until all slack has been removed. SERVICE PARTS INFORMATION Part Number Description Quantity 15659287 rubber cross rail cap 1 per rail (as needed) Parts are currently available through GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: R2380 Labor Time: 0.4 hr. Page 1683 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 4. Make repair. Page 7923 Tail Lamp: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. Figure 21 Figure 22 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. Page 7699 If the functional brake switch adjustment check does not repair the condition, refer to Section 5 of the appropriate Service Information Manual for aid in diagnosing other causes. For warranty purposes use: Labor Operation Number: N2440 Labor Time: .3 hour TRUCK ONLY: Service Procedure: 1. Depress the brake pedal and press the switch in until it is firmly seated in the clip. * Audible "clicks" can be heard as the threaded portion of the switch is pushed through the clip. 2. Pull the brake pedal against the pedal stop until the audible "click" can no longer be heard. For stop lamp switch adjustments on vehicles repaired under warranty use: Labor Operation Number: T7945 Labor Time: .2 Hr. Page 1069 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 Page 6132 Installing The Clutch Coil Assembly ^ Thread through bolts into J 33026 to full fixture thickness. ^ Be sure J 8433-1 and the clutch coil assembly (6) stay "in line" during installation. Staking The Clutch Coil Assembly To The Coil Head ^ When the clutch coil assembly (6) is seated on the front head (11), use a 3 mm (1/e-inch) diameter drift punch to stake the head (11) at 3 places, 120 degrees apart to assure the clutch coil assembly (6) remains in position. Staking Locations On The Front Head - Stake size should be one half the area of the punch tip and 0.28-0.35 mm (0.010-0.015-inch) deep. 3. Pulley (5). 4. Clutch plate and hub assembly (2). Page 6136 DA-V5 Compressor Component View Remove or Disconnect Tools Required: J 6083 Snap Ring Pliers J 8092 Driver Handle J 9398-A Pulley Bearing Remover J 33020 Pulley Puller J 33023-A Puller Pilot 1. Clutch plate and hub assembly (22). Page 7575 Page 2131 FIGURE 1(T-TRUCK ONLY) G. (T-truck only) Check equalizer lever for firm contact at the shift lever inboard side of the guide slot. (See Figure 1) H. If firm contact is evident, add an additional washer (#10 in Figure #1) P/N 14074908 to adjust equalizer lever outboard toward the center of the guide slot to eliminate contact. 2. A. Raise vehicle on hoist. B. Note location of clamp rotation on pipe. Some clamps are located with the lower lock ring (nuts) pointed towards the transmission. If the clamp is located in such a manner, loosen clamp and rotate it down so the nuts point toward the ground and retighten to 58 N-m (43 ft/lbs.) 3. A. Loosen converter clamp until it will rotate around the pipe. Using a suitable pry bar, move exhaust system rearward to obtain a minimum of 5/8 in. clearance between any point on the exhaust system and the transmission crossmember. For repairs performed under warranty, use the following labor operations and times: Labor Operation Labor Time Exhaust/muffler clamp L2020 .3 Hr Exhaust system align L2004 .3 Hr Shift Linkage (shorten) K5244 .3 Hr Lighting - Exterior Lamp Condensation and Replacement Turn Signal Lamp: Technical Service Bulletins Lighting - Exterior Lamp Condensation and Replacement INFORMATION Bulletin No.: 01-08-42-001H Date: January 05, 2011 Subject: Exterior Lamp Condensation and Replacement Guidelines Models: 2011 and Prior GM Passenger Cars and Trucks (including Saturn) Supercede: This bulletin is being revised to add the 2011 model year. Please discard Corporate Bulletin Number 01-08-42-001G (Section 08 - Body and Accessories). The following information is being provided to better define the causes of condensation in exterior lamps and includes guidelines for determining the difference between a lamp with a normal atmospheric condition (condensation) and a lamp with a water leak. Some exterior lamps, such as cornering, turn signal, backup, headlamps or tail lamps may exhibit very small droplets of water, a fine mist or white fog (condensation) on the inside of the lamp lens. This may be more noticeable on lamps with "multi-lens" designs and may be normal during certain weather conditions. Condensation occurs when the air inside the lamp assembly, through atmospheric changes, reaches the "dew point". When this takes place, the moisture in the air within the lamp assembly condenses, creating a fine mist or white fog on the inside surface of the lamp lens. Most exterior lamps on General Motors vehicles use a vented design and feature a replaceable bulb assembly. They are designed to remove any accumulated moisture vapor by expelling it through a vent system. The vent system operates at all times, however, it is most effective when the lamps are ON or when the vehicle is in motion. Depending on the size, shape and location of the lamp on the vehicle, and the atmospheric conditions occurring, the amount of time required to clear the lamp may vary from 2 to 6 hours. Completely sealed headlamp assemblies (sealed beams) are still used on a limited number of models being manufactured today. These lamps require the replacement of the complete lamp assembly if a bulb filament burns out. Condensation 2006 TrailBlazer Shown A Fine Mist or White Fog on the Inside Surface of the Lamp Lens Occurring After a Period of High Humidity - May be located primarily in the lens corners (near the vents) and SHOULD NOT cover more than half the lens surface. - The condition should clear of moisture when the vehicle is parked in a dry environment, or when the vehicle is driven with the lights ON. - A comparison of the equivalent lamp on the opposing side of the vehicle indicates a SIMILAR performance. If the above conditions are noted, the customer should be advised that replacement of a lamp assembly may not correct this condition. Water Leak New Style Pickup Shown Description and Operation Thermostatic Air Cleaner: Description and Operation Thermostatic Air Cleaner Exploded View Thermostatic Air Cleaner Operation Page 2429 R3261 LH mirror R&R; 0.4 Hr. (Time is different than published time in Labor Operation Guide.) Page 2719 Engine Control Module: Component Tests and General Diagnostics Chart C-9A - ECM QDR Check Procedure Checking Control Module For Bad Solder Joints Some control module's 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 Page 5682 Steering Column: Service and Repair Ignition Lock Cylinder Fig. 1 Ignition Lock Replacement 1. Disconnect battery ground cable. 2. Remove steering wheel. Refer to STEERING WHEEL & HORN SOUNDER. 3. Remove turn signal switch. Refer to BODY ELECTRICAL SAFETY AND ENTERTAINMENT/INSTRUMENT PANELS AND CLUSTERS/COMPONENT REPLACEMENT AND REPAIR PROCEDURES/TURN SIGNAL SWITCH. 4. Place ignition switch in ``Run'' position, then remove lock cylinder retaining screw and lock cylinder. 5. To install, rotate lock cylinder to stop while holding housing, Fig. 1. Align cylinder key with keyway in housing, then push lock cylinder assembly into housing until fully seated. 6. Install lock cylinder retaining screw, turn signal switch and steering wheel. Compressor Low Side Cut-Off Switch Refrigerant Pressure Sensor / Switch: Locations Compressor Low Side Cut-Off Switch A/C Low Charge Pressure Switch The A/C Low Charge Protection Switch is located at the rear of the compressor. Page 2809 Wiring Diagram For Chart C-1A - Park/Neutral Switch Diagnosis CHART C-1A - PARK/NEUTRAL SWITCH DIAGNOSIS Circuit Description: The Park/Neutral Switch contacts are closed to ground in park or neutral and open in drive ranges. The ECM supplies ignition voltage, through a current limiting resistor, to CKT 434 and senses a closed switch, when the voltage on CKT 434 drops to less than one volt. The ECM uses the P/N signal as one of the inputs to control: Idle Air Control VSS Diagnostics EGR Test Description: Numbers below refer to circled numbers on the diagnostic chart. 1. Checks for a closed switch to ground in park position. Different makes of "Scan" tools will read P/N differently. Refer to operators manual for type of display used for a specific tool. 2. Checks for an open switch in drive or reverse range. 3. Be sure "Scan" indicates drive, even while wiggling shifter to test for an intermittent or misadjusted switch in drive range. Diagnostic Aids: If CKT 434 indicates PIN (grounded), while in drive range, the EGR would be inoperative, resulting in possible detonation. If CKT 434 always indicates drive (open), a drop in the idle may exist when the gear selector is moved into drive range. Specifications Mixture Control Solenoid: Specifications IDLE CONTROL SOLENOID - CARBURETTED ENGINES On some engines, the ECM will will be damaged if the resistance of the mixture control solenoid is less than specified. Page 7482 FIGURE 1 7. Measure 1 1/4" down from the bottom of the windshield and make a horizontal mark on the windshield frame inboard of the cowl screen lock tab (Figure No. 1). 8. Measure 7/8" inboard from the cowl screen lock tab and make a vertical mark through the line made in the previous step. 9. Center punch the windshield frame at the point the lines intersect. Use a one inch hole saw to cut a hole in the windshield frame (cut through only the first layer of sheet metal) and remove the circular piece of metal that remains from cutting the hole. DO NOT CUT THE SECOND LAYER PANEL. 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 Page 7018 Page 7679 Figure 4 Figure 5 Figure 6 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 7 Page 1025 ^ 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. Page 6261 High Pressure Safety Valve HVAC: Service and Repair With HR-6 Compressor HR-6 Component View DA-6 Compressor Rear Head Details Remove or Disconnect ^ Be sure the compressor has no charge. 1. Pressure relief valve (32). 2. O-ring seal (33). Install or Connect ^ Lubricate the threads of the pressure relief valve (32) and new seal with 525 viscosity refrigerant oil. Page 7916 Numerous & Various Size Drops of Water Collecting on the Inside Surface of the Lamp Lens After the Vehicle Has Been Exposed to Rain or a Car Washing Environment - A condition that covers more than half the surface of the lamp lens. - An accumulation of water in the bottom of the lamp assembly. - A condition that WON'T clear when the vehicle is parked in a dry environment, or when the vehicle is driven with the lights ON. - A comparison of the equivalent lamp on the opposing side of the vehicle indicates a different performance. Any of the above conditions would indicate the need to service the lens or lamp assembly. Disclaimer Page 6137 Removing The Pulley Rotor & Bearing Assembly Retaining Ring 2. Pulley bearing retainer (24) using J 6083. 3. Pulley (26). Installing The Pulley Rotor And Bearing Puller Guide ^ Install J 33023-A to the front head. Removing The Pulley Rotor & Bearing Assembly ^ Install J 33020 tangs into the inner circle of slots in the pulley (26) contact surface. Rotate J 33020 clockwise so the fangs will lock into the segments between the slots. ^ Hold J 33020 in place and tighten the puller screw against J 33023-A puller pilot to remove the pulley (26). Testing and Inspection Temperature Warning Lamp/Indicator: Testing and Inspection 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. 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. Page 5484 Note The rivet stud and surrounding panel area MUST BE properly refinished PRIOR to the installation of the electrical ground wire terminal and conductive nut to maintain a secure, stable and corrosion-free electrical ground. 11. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 12. Allow the refinished repair area to cure sufficiently before removing the protective material applied to the rivet stud threads. 13. Remove the painters tape or equivalent from the rivet stud threads. 14. Using GM approved residue-free solvent or equivalent, thoroughly clean the rivet stud threads to remove any adhesive and allow to dry. 15. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive rivet stud. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 16. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 17. Install the electrical ground wire terminal to the M6 conductive rivet stud. 18. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 19. Install the M6 conductive nut to the rivet stud and: Tighten Tighten to 8 Nm (71 lb in) 20. Verify proper system operation. Parts Information Warranty Information (excluding Saab Models) For vehicles repaired under warranty, use: Warranty Information (Saab Models) Page 3571 Fuel - Feed/Return Pipe Repair Fuel Return Line: Technical Service Bulletins Fuel - Feed/Return Pipe Repair Number: 89-31-6C Section: 6C Date: NOV., 1988 Subject: FUEL FEED AND/OR RETURN PIPE REPAIR Model and Year: 1984-89 CHEVROLET PASSENGER AND LIGHT DUTY TRUCK VEHICLES TO: ALL CHEVROLET DEALERS When making any repairs to the fuel system, it is IMPORTANT that the following procedures be adhered to: A minimum of 13.0 mm (1/2") clearance must be maintained around sharp edges such as flanges, pinch weld, etc., to prevent contact and chaffing. A minimum of 19 mm (3/4") clearance must be maintained around any moving parts. ^ When rubber hose is used to replace pipe, use only reinforced fuel-resistant hose which is identified with the word "Fluorelastomer" or "GM6163-M" on the hose. Hose inside diameter must match pipe outside diameter. ^ Do not use rubber hose within 100 mm (4") of any part of the exhaust system or within 254 mm (10") of the catalytic converter. ^ In the repairable areas, cut a piece of fuel hose 100 mm (4") longer than portion of the line removed. If more than a 6 inch length of pipe is removed, use a combination of steel pipe and hose so that the total hose lengths, including the 100 mm (4") additional length will not be more than 254 mm (10") long. Follow the same routing as the original pipe. ^ Cut ends of pipe remaining on car square with a tube cutter. Using the first step of a double flaring tool, form a bead on the end of both pipe sections. If 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 screw-type hose clamp No. 2494772 or equivalent. Slide clamps onto pipe and push hose 51 mm (2") onto each portion of fuel pipe. Tighten clamps on each side of repair. Page 2816 Vehicle Speed Sensor: Service and Repair 1. Disconnect vehicle speed sensor electrical connector. 2. Remove sensor attaching bolt. 3. Using speed sensor remover and installer, tool No. J 38417, remove sensor, then O-ring seal. 4. Reverse procedure to install, coating the new O-ring seal with transmission fluid. Torque attaching bolt to 97 inch lbs. Odometer/Speedometer - ACDelco Service Center Locations Odometer: 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) Page 5792 Figure 15 - Large Retaining Clamp Installation 13. Secure the large metal clamp and seal to the housing with tool J35910, breaker bar and torque wrench. Torque the large clamp to 176 N-m (130 lbs.ft.). Check clamp ear gap dimension (Figure 15). Halfshaft Installation: 1. Prior to halfshaft installation, cover shock mounting bracket, lower control arm ball stud, and all other sharp edges with shop towels so that the seal is not damaged during assembly. 2. Remove convolute retainer. 3. Insert and draw up outer C/V joint splined shank into knuckle hub; then secure inboard C/V joint flange to companion flange with bolts (do not tighten). Install hub nut washer and nut. Seat shank splines in hub. 4. Connect the upper ball joint to the steering knuckle. 5. Attach the stud nut and torque 83 N-m (61 lbs.ft.). 6. Install new cotter pin. 7. Lubricate the upper ball joint until grease appears at the seal. 8. Remove floor jack or stand from beneath lower control arm, if used. 9. Connect the shock absorber to the lower shock mounting bracket. 10. Attach the shock mounting bolt and nut. Torque the nut and bolt to 73 N-m (54 lbs.ft.). 11. Attach outer tie rod to steering knuckle. 12. Install tie rod nut and torque to 47 N-m (35 lbs.ft.). Important: Advance the nut to align the nut slot with the cotter pin hole. Never back the nut off to align the cotter pin hole. 13. Install new cotter pin and spread the ends to secure. 14. Attach the brake line support bracket to the upper control arm. Torque to 17 N-m (13 lbs.ft.). Important: Make sure that the brake hose is not twisted or kinked or damage to the hose could result. Page 3435 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. Locations Compressor Clutch Relay: Locations A/C Cutout Relay The A/C Cutout Relay is located at the LH front of the dash on the relay bracket. Page 4420 S Series with 2.5L Engine 72267 S Series with 2.8L Engine 23911 Service Action For vehicles exhibiting third gear vibration that were built prior to the production incorporation of the new lever, the shift lever should be replaced with the new design lever. Reference Section 7B-3 of the Service Manual for replacement procedure. The new design shift lever P/N is 15618925. IMPORTANT: After shift lever replacement, assure that the boot assembly is positioned to ride as high as possible on the shift lever to reduce transmission noise into the cab. For vehicles repaired under warranty, use the following Labor Operations and Times: Labor Operation: K1060 Labor Time: .3 Hr Page 7383 LIGHT BLUE LT BLU BROWN BRN GRAY GRY GREEN GRN DARK GREEN DK GRN LIGHT GREEN LT GRN ORANGE ORN PINK PNK PURPLE PPL RED RED TAN TAN WHITE WHT YELLOW YEL Page 5213 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 wire ends to protect the diode from excess heat. Follow the manufacturers instructions for the solderin equipment you are using. 5. Install terminal(s) into the connector body if previously removed in step number 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. NOTE: A universal diode with a 3 amp, 400 PIV (Peak Inverse Voltage) rating can be used in all of the previously mentioned applications. The following 1993 Service Manuals will need to be updated with the correct part numbers and rating changes. Carline Page All J, L, W, and UO 8A-5-12 Heat sink, part number 276-1567, can be obtained from Radio Shack. We believe the diodes and heat sink listed in this article as well as their manufacturer to be reliable. There may be additional manufacturers or equivalent products. General Motors does not endorse, indicate any preference for or assume any responsibility for the products from these firms or for any such items which may be available from other sources. Page 5333 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 Drive Axle (Front) - Will Not Disengage Transfer Case Actuator: Customer Interest Drive Axle (Front) - Will Not Disengage Number: 91-476-4C Section: 4C Date: JAN. 1992 Corporate Bulletin No.: 167402 ASE No.: A3 Subject: FRONT AXLE WILL NOT DISENGAGE Model and Year: 1983-1991 T TRUCKS Owners of some 1983-1991 T vehicles may comment about inappropriate front axle disengagement. This condition may be due to a corroded transfer case vacuum actuator switch. To correct this condition a revised switch (P/N 15664811), constructed of noncorrosive stainless steel, should be installed. SERVICE PROCEDURE: The vacuum switch is located on the left upper side of the transfer case (Figure 1). 1. Raise the vehicle and support with suitable safety stands. 2. Remove the vacuum lines from the switch. 3. Remove the corroded switch from the transfer case. 4. Install a revised switch (P/N 15664811), coat the threads with thread sealant. 5. Connect the vacuum lines. 6. Lower the vehicle. 7. Check for oil leaks at the threads and vacuum leaks around the vacuum lines. Page 5101 Symbol Identification Page 1005 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". Description and Operation Fuel Economy Warning System: Description and Operation This system actually monitors the engine vacuum just like the vacuum gauge, but registers only low vacuum readings. The light on the instrument panel warns the vehicle operator when engine manifold vacuum drops below the economical limit. Switch operation is similar to that of the oil pressure indicating light, except that the switch opens when vacuum pressure, rather than oil pressure, is applied. Page 7435 Page 2575 Engine Control Module: Description and Operation Throttle Body Fuel Injection Engine Control Module Fig. 5 ECM Unit (Showing PROM & CALPAK Locations) The Electronic Control Module (ECM), located in the passenger compartment, is the control center of the fuel injection system. The ECM continually monitors and processes the input information and generates output commands to the various systems affecting vehicle performance. A removable calibration unit (PROM) enables the ECM to recognize and adjust for vehicle variations (vehicle weight, axle ratio, etc.). There are specific ECM/PROM combinations for each specific vehicle which are not interchangeable, Fig. 4. On V6 models, a CALPAK is also installed in the ECM. The CALPAK allows fuel delivery in the case that other parts of the ECM are damaged, Fig. 5. The ECM also performs the diagnostic function of the fuel injection system. When the ECM senses an operational problem, it will illuminate the "Check Engine" or "Service Engine Soon" light and store the appropriate code(s) to identify the problem area. Page 4714 A new pressure regulator valve (III. 218) has been made which will improve the oil pressure stability at lower RPM. SERVICE PARTS INFORMATION: Description Part Number Valve, Pressure Regulator (III. 218) 8684048 Part numbers are for Reference Only. Check with your Parts Department for latest information. Windshield Washer Bottle - Cracking Windshield Washer Reservoir: All Technical Service Bulletins Windshield Washer Bottle - Cracking Number: 91-31-8E Section: 8E Date: July 1990 Corp. Bulletin No.: 061010 Subject: WASHER BOTTLES CRACKING Model and Year: 1988-91 S/T TRUCKS TO: ALL CHEVROLET DEALERS Some 1988 - 1991 S/T trucks may be experiencing a condition of windshield wiper washer bottles cracking and then leaking washer fluid. This condition can be caused by an increased amount of pressure exerted by the two fastening nuts and screws. This increase of pressure causes the screws to cut into the plastic and initiate cracks. To correct the situation new parts have been released with a wider flange, and the torque requirement has also been revised. The new torque requirement is now 5-8 N-m (3.7 - 5.9 lbs. ft.) instead of the old 8-11 N-m (5.9 - 8.1 lbs. ft.). When ordering a new washer bottle be sure and order new bolts and nuts with the revised flanges. SERVICE PARTS INFORMATION Part Number Description Usage 11509005 nut 2 per bottle 15653669 bolt 2 per vehicle 22072762 container and grommet 1 per vehicle Parts are currently available through GMSPO. WARRANTY INFORMATION For vehicle repaired under warranty use: Labor Operation: N3750 Labor Time: .2 hr. Page 5418 1. With the end gate open, use a grease pencil to mark around the circumference of each washer (Figure 1, "7") located behind the strikers. 2. Unscrew and remove the existing striker assemblies (Figure 1, "6") from the vehicle. 3. Loosely assemble the new striker (Figure 1, "6") (P/N 15700881) and washer (Figure 1, "7") and reinstall using the pencil marks as a guide. 4. Install the striker assemblies (Figure 1, "6") using a T50 Torx(R). Torque to 63 N-m. (47 lbs.ft.). 5. Check for proper operation and end gate flushness. Adjust the striker assemblies if required. The end gate lock strikers can be adjusted up or down, fore or aft, to obtain proper closure of the end gate. The end gate should seal completely with minimum closing effort. Torque the striker bolts to 63 N-m. (47 lbs.ft.). SERVICE PARTS INFORMATION PART NUMBER DESCRIPTION QTY/VEH 15700881 Striker Asm. 2 Page 529 Transmission Position Switch/Sensor: Testing and Inspection Chart C-1A - Park/Neutral Switch Diagnosis Page 1039 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. Specifications Absolute Pressure Sensor: Specifications MANIFOLD ABSOLUTE, VACUUM AND BAROMETRIC PRESSURE SENSORS Engines may use one, or a combination of these sensors. All sensors appear the same. Manifold Absolute Pressure sensors have a vacuum line connected between the unit and manifold vacuum. On Barometric Pressure sensors, the line is not used and the connector is either open or has a filter installed over it. Pressure sensors also have a vacuum line between the sensor and intake manifold and only appear on carburetted models. Barometric Pressure Sensors: Measure voltage with ignition on and engine off. Manifold Absolute Pressure Sensors: Measure voltage with ignition on and engine off. Start engine and apply 10 in./ 250 mm Hg to unit, voltage should be 1.2-2.3 volts less. Pressure Sensors: Measure voltage as indicated. Electrical Connectors - Service Procedure Multiple Junction Connector: All Technical Service Bulletins Electrical Connectors - Service Procedure Number: 91-85-8A Section: 8A Date: October 1990 Corp. Bulletin No.: 018115 Subject: PROCEDURE FOR CHECKING CONNECTOR TERMINAL CONTACT Model and Year: 1982-91 PASSENGER CARS AND TRUCKS Figure 1 TO: ALL CHEVROLET DEALERS Page 7680 Figure 8 Figure 9 Figure 10 Figure 11 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). Intake Manifold Gasket - Installation Intake Manifold Gasket: Technical Service Bulletins Intake Manifold Gasket - Installation Number: 90-12-6A Section: 6A Date: JUNE 1989 Subject: INTAKE MANIFOLD GASKET INSTALLATION Model and Year: 1987-90 LIGHT DUTY TRUCK WITH 4.3L, 5.0L, 5.7L TBI ENGINES Figure 1 TO: ALL CHEVROLET DEALERS Page 2066 Radiator Cooling Fan Temperature Sensor / Switch: Locations Coolant Temperature Switch Center Of Dash Panel (engine Compartment) Lower RH Side Of Engine Applicable to: V6-262/4.3L Engine Page 1492 Crankshaft Main Bearing: Specifications Bearing Undersize Availability Main bearings are available in standard size and undersizes of .001, .002, .009, .010 and .020 inch. Connecting rod bearings are available in standard size and .001 and .002 inch undersize for use with new and used standard size crankshafts and .010 and .020 inch undersize for use with reconditioned crankshafts. Page 4455 11501033 Nut 1 Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: K2283 (Manual Trans.) Labor Time: 0.4 Hrs. Labor Operation: K6723 (Automatic Trans.) Labor Time: 0.4 Hrs. 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. ECM - Packard 32 Way Connector Identification Engine Control Module: All Technical Service Bulletins ECM - Packard 32 Way Connector Identification Number: 90-56-8 Section: 8 Date: September 1989 Corporate Bulletin No.: 916521R Subject: PACKARD 32 WAY CONNECTOR IDENTIFICATION Model and Year: 1980-90 A, B, F, G, J, L, W, Y CARS AND ALL TRUCKS WITH GMP4 ECM APPLICATIONS TO: ALL CHEVROLET DEALERS This bulletin serves to clarify the labeling of the Packard 32 way connectors used on the GMP4 under dash ECMS. Currently a common strain relief is used in both the C-D 32 pin and the E-F 32 pin connectors. To properly identify these connectors, the strain reliefs must be removed. Use the lettering on the connector as shown on figure. The colors used at this time for the 32 pin E-F connector are yellow, mint green or orange. This updates any previous information released concerning identification that indicates any of these colors as being C & D connectors, found in the 6E and 8D Sections of the affected Service Manuals. Page 4799 Symbol Identification Page 6085 Blower Motor: Symptom Related Diagnostic Procedures Test A Blower Motor Does Not Operate Test B Blower Motor Operates Only In High Locations Timing Connector-In Pass Comp Behind Carpet, Below Heater Page 4728 - 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 Page 7925 Figure 4 Figure 5 Figure 6 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 7 Page 8038 Front Door Trim Panel Preliminary Inspection Alignment: Service and Repair Preliminary Inspection INSPECTION Steering and vibration problems are not always the result of alignment. An additional problem to be checked is tire lead due to worn or improperly manufactured tires. "Lead" is the deviation of the vehicle from a straight path on a level road without hand pressure on the steering wheel. To insure correct alignment readings and alignment specifications, the following checks and inspections should be made: 1. Check tire for proper inflation and thread wear. 2. Check front wheel bearings for looseness (0.001 - 0.008 inch end play is correct) and adjust if necessary. 3. Check for loose ball joints and tie rod ends. If excessive looseness is noted, replace defective parts before adjusting toe. 4. Check for wheel and tire assembly runout. 5. Check trim heights. If not within specifications, correct before adjusting toe. 6. Check for loose control arms and steering gear at frame. 7. Check for loose or missing stabilizer bar components. 8. Consideration must be given to excess loads, such as tool boxes, etc. If excess load is normally carried in vehicle, it should remain during alignment checks. Page 6334 - 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. Page 4299 Figure 16 1. Loosen bolts (90) attaching the axle tube bracket (5) to the frame bracket (6). 2. Tighten nuts (94) to 75 N-m (55 lbs.ft.). This should cause the axle assembly to move toward the driver's side approximately 1/8" to 1/4". If the axle does not move it may be pried toward the driver's side with a bar. Position bar against the frame and the end of the shaft (1). 3. Tighten bolts (90) to 75 N-m (55 lbs.ft.). Seal Replacement: After checking the shock absorber installation and front axle location, smaller profile tripot seals may be installed. These smaller seals can be identified by their visibly smaller profile and by the number 26027961 which is molded onto the seal. Required Tools: J 28733 Axle Remover J 24319-01 Tie Rod Puller J 8059 Snap Ring Pliers J 35910 Seal Clamp Tool J 34026 Ball Joint Separator Drive Axle Removal: Figure 1 - Prevent Shaft From Turning 1. Raise vehicle and support it with suitable safety stands. 2. Remove the wheel and tire assembly. 3. Insert a drift or large screwdriver through brake caliper into one of the brake rotor vanes to prevent halfshaft from turning (Figure 1). Figure 2 - Hub Nut and Washer Removal 4. Remove halfshaft cotter pin, retainer, nut, and washer (Figure 2). Page 1475 Rocker Arm Assembly: Service and Repair Rocker Arms & Pushrods 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 as described under ADJUSTMENT PROCEDURES/VALVES. 3L30 (180C) Transmission Fluid Pressure Sensor/Switch: Specifications 3L30 (180C) Transmission Component .......................................................................................................................................... .................................................................... Ft. Lbs. Governor Pressure Switch ................................................................................................................... ................................................................................. 7 Wheels - Finish Damage During Off Car Balancing Wheels: All Technical Service Bulletins Wheels - Finish Damage During Off Car Balancing BULLETIN NUMBER: 93-3E-67 SECTION: 3E Wheels & Tires NUMBER: 3 CORPORATE REFERENCE NUMBER: 3935O2R DATE: June 1993 SUBJECT: INFORMATION ON COSMETIC DAMAGE TO ALUMINUM WHEELS DURING BALANCING MODELS: 1985-93 MODELS WITH ALUMINUM WHEELS Some aluminum wheels on GM models may incur cosmetic damage during balancing if proper care and procedures are not used. All aluminum wheels have a clearcoat paint on them that must be cared for like any other painted surface. Some off-car vehicle balancer retaining cups used to clamp the wheel to the balancer may put a circular mark into the clearcoat on the face of the wheel. Like any other clearcoat damage, this may be difficult to remove or repair, depending on severity. ALWAYS use balancer retainer cups that are protected with rubber, plastic, or other nonmetallic materials where contact is made with the wheel. Make Page 8042 Front Door Trim Panel Components Front Inner Panel Water Deflector Page 7741 Hazard Warning Flasher: Locations The fuse block is located at the far left side of the dash panel. The hazard and turn signal flashers are located under the left side of the dash panel on the convenience center. Page 3432 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. Page 3417 [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. Page 6393 J 5403 Snap Ring Pliers J 33011 O-ring Seal Installer 1. O-ring seals (44) to the switch cavity with J 33011. ^ Dip the O-ring seals into clean 525 refrigerant oil. 2. Switches (3) and (4). 3. Retainers (45). Page 1586 Drive Belt: Service and Repair Fig. 20 Serpentine Drive Belt Routing 1. Remove belt tensioner pulley retaining bolt. 2. Remove belt tensioner pulley. then the belt. 3. Reverse procedure to install, refer to Fig. 20 for belt routing. Page 3124 Install the TPS onto replacement throttle body assembly, according to previous instructions. INSTALLATION: 1. Install the new throttle body to fuel meter body gasket. 2. Install the fuel meter body assembly on throttle body assembly. 3. Install the 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). 4. Install TBI unit onto intake manifold. Tighten the mounting bolts to 16.0 Nm (12.0 lb-ft). Page 4316 Page 4087 Check Ball Location Locations Throttle Position Sensor: Locations Center Of Dash Panel (engine Compartment) Center Rear Of Engine Applicable to: V6-262/4.3L Engine Page 411 Oxygen Sensor: Description and Operation Fig. 6 Oxygen Sensor (Typical) The exhaust oxygen sensor is located in the exhaust system and monitors oxygen content in the exhaust gas stream. The oxygen content of the exhaust gas reacts with the oxygen sensor to produce a voltage output, Fig. 6. By monitoring the oxygen sensor output voltage, the ECM can determine the amount of oxygen in the exhaust gas and adjust the air/fuel mixture accordingly. Page 7812 Symbol Identification Locations Blower Motor Relay: Locations Fig 26. Evaporator And Blower Assembly The Blower Motor Relay (152) is located on the front of the Evaporator and Blower Assembly. Tailgate - Latch Rattle, Revised Striker & Latch Trunk / Liftgate Striker: Technical Service Bulletins Tailgate - Latch Rattle, Revised Striker & Latch Number: 92-153-10 Section: 10 Date: APRIL 1992 Corporate Bulletin No.: 161514 ASE No.: B1 Subject: END GATE LATCH RATTLE Model and Year: 1983-92 S/T TRUCKS Owners of some 1983-1992 S/T 2 and 4 door utility vehicles may comment that their end gate latch rattles. One possible cause of this condition is the end gate latch fork bolts contacting the striker assembly (metal-tometal) causing a rattle. To correct this condition, it is necessary to install a new striker assembly that has a urethane sleeve over the striker post. The urethane sleeve preventsmetal-to-metal contact and may eliminate the rattle. SERVICE PROCEDURE: Page 6789 If the spring breaks while bending, it will be necessary to replace the lock cylinder assembly 7. Reinstall the spring in the lock assembly. Next, shake the assembly to check for looseness. If loose, replace the lock cylinder assembly. 8. Reinstall the gasket, lock cylinder and retainer (Figure 3, Items 3, 4 and 2). 9. Reconnect the end gate lock rods (Figure 2, Items 1 and 2). 10. Reinstall the end gate inner panel reinforcement to the end gate (Figure 1, Item 1). 11. Reinstall the inner trim panel. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Op: B5810 Use applicable labor time guide for labor hours. Page 1498 Crankshaft: Specifications Crankshaft Journals Crankshaft Journals Main Bearing Journal Diameter Front 2.4484-2.4493 in Intermediate 2.4481-2.4490 in Rear 2.4479-2.4488 in Connecting Rod Journal Diameter 2.2487-2.2497 in Maximum Out Of Round All 0.001 in Maximum Taper All 0.001 in Runout Service Limit Note: If main journals are misaligned, crankshaft is bent & should be replaced. Page 4905 Brake Rotor/Disc: Fundamentals and Basics How to Use A Micrometer CONSTRUCTION The spindle on a micrometer is moved in or out by rotating the thimble or ratchet. The thread pitch on the spindle is 40 threads per inch. A single full rotation of the thimble extends or retracts the spindle one thread or 1/40 of an inch (0.025, 25 thousands). The thimble is divided into 25 equal divisions. Rotating the thimble one division will extend or retract the spindle 1/25 of a thread. (1/25) x (1/40)inch = 1/1000 inch (0.001), one division on the thimble is equal to 0.001 inches. HOW TO READ As the thimble is rotated out it uncovers a scale on the sleeve. Each major division on the scale is 1/10 of an inch (0.100) Each major division is separated into 4 minor divisions, each equal to 25/1000 of an inch (0.025). Page 7017 Door edge guards Bumper filler panel, Frt./Rr. Front side marker lamps *Roof marker lamps *West coast style mirrors *Stripes Emblems/decals if necessary G VANS Wiper arms Cowl vent grille Grille and headlamp bezels Front bumper filler panel Antenna Side view mirrors Side marker lamps Tail lamps Door edge guards Wheel opening moldings *Roof marker lamps *West coast style mirrors *Stripes Emblems/decals if necessary Swing out windows/seals WARRANTY INFORMATION For vehicles repaired under warranty. and for customer satisfaction. use: Labor Op (Labor Operations include mix time) A6100 Refinish the entire exterior body surface ABOVE THE BODY SIDE MOLDING AND INSERT COLOR on two tone vehicles if equipped. A6101 Refinish the entire exterior body surface INSERT COLOR only. A61O2 Refinish the PICKUP BOX LOAD FLOOR AND INNER FENDERS when applicable. A61O3 On units with an insert color, included is the entire exterior body surface ABOVE THE BREAKLINE. (If the insert color and the entire body surface above the break-line requires refinishing, use A6100). Page 7164 AND ARE MARKED WITH A # INDICATOR. Continue to repair these vehicles with monocoat materials. DO NOT repair these vehicles with Basecoat/Clearcoat products. Use the latest (June, 1993) material allowance charts when submitting claims. SUBJECT: Service procedures for the repair of paint colorcoat delamination from elpo primer (repaint entire body above the body side moldings, except trucks as noted). APPLICATION: 1988-1992 LIGHT DUTY TRUCKS (C/K, R/V, S/T, M/L AND G) This bulletin cancels and supersedes service procedures and time allowances on all previous bulletins regarding paint DELAMINATION. Due to the use of new procedures, add times for optional equipment, and designating specific hardware items for removal, the published labor times will not be the same as previously published. CONDITION This bulletin is being issued to assure that the correct procedure is followed to repair a condition known as DELAMINATION. Some of the above listed passenger cars, light duty trucks, and vans may have DELAMINATION (peeling) of the paint color-coat from the ELPO primer depending upon variable factors including prolonged exposure to sunlight and humidity. Blues, Grays, Silvers and Black Metallics are the colors that have the highest potential for this condition. On rare occasions, other colors may be involved. Important DELAMINATION is different than other paint conditions and/or damage. A proper problem identification is necessary, and the service procedure that follows is specific to the proper repair of DELAMINATION and must be followed. The information in this bulletin covers Paint DELAMINATION of the colorcoat from the ELPO primer ONLY. It does not address any other paint conditions. Procedures for the repair of other paint conditions (stone chips, scratches, environmental damage, clearcoat peeling, runs, dirt, fading, etc.) will not effectively repair DELAMINATION and customer dissatisfaction will result. CAUSE This condition may occur on vehicles produced in plants where the paint process does not call for application of a primer surfacer. Under certain conditions, ultraviolet light can penetrate the colorcoat, sometimes causing a reaction and separation of portions of the colorcoat from the ELPO (electrocoat) primer. PROBLEM IDENTIFICATION: On a clean surface, at or above room temperature, firmly apply a 2" wide piece of masking tape and pull upward quickly. DO NOT USE duct tape, cloth backed tape or other aggressive tapes. If the colorcoat flakes or peels away from the ELPO (leaving the ELPO intact) the colorcoat is delaminating and the vehicle should be repaired using the "Paint Repair Procedure" contained in this bulletin. This test SHOULD ONLY BE APPLIED TO A VEHICLE SHOWING THE CONDITION, (peeling/delamination) and NOT in areas of stone chipping or other obvious damage. These "other" conditions should be repaired following standard paint repair procedures. CORRECTION Refinish the ENTIRE BODY ABOVE THE BODY SIDE MOLDINGS using the following repair procedure. It is important that ALL surfaces above the body side moldings (including recessed areas around door handles) be refinished, as these surfaces may show the same DELAMINATION (peeling) condition at a later date. Note: Many vehicles have some type of plastic exterior body panels (cowl vent grilles, fascias, front end panels, rear fenders, etc.). These panels are not subject to DELAMINATION and therefore do not require refinishing. If painting of these panels is required for color uniformity, scuff sand and colorcoat only (and clearcoat if basecoat/clearcoat system is used). Note: Two tone lines, feature lines or body side molding treatments near mid-door height are appropriate break lines. If no such convenient break lines are present, the entire panel above the next lower break line must be refinished and the portion of the panel below that break line should be COLORCOATED ONLY (and clearcoated if basecoat/clearcoat system is used) for color uniformity of the repair. Note: Pickup boxes which are covered by caps, bedliners or tonneau covers do not receive direct exposure to sunlight, and normally would not be repaired under this procedure. However, if the inside of the box has been uncovered and experienced DELAMINATION, use the appropriate Labor Operation Number. Page 2619 Manifold Pressure/Vacuum Sensor: Locations Center Of Dash Panel (engine Compartment) Center Rear Of Engine Applicable to: V6-262/4.3L Engine Page 3416 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. Page 392 - Diagnostic Chart Code 33. ECM - Intermittent Connection Engine Control Module: All Technical Service Bulletins ECM - Intermittent Connection Number: 88-251-8A Section: 8A Date: JUNE, 1988 Subject: INTERMITTENT CONNECTION TO THE ECM Model and Year: 1988 CHEVROLET PASSENGER CARS AND LIGHT DUTY TRUCKS TO: ALL CHEVROLET DEALERS A condition may exist in which the female terminals in the connector to the ECM do not make a solid connection to the male pins in the ECM (see illustration). This can result in an intermittent condition, in any circuit operated by the ECM. The Service Manuals direct a check of connections any time an intermittent condition is found, and this may be the cause of some of these conditions. Visually inspect the terminal using a flashlight, or use a .95 mm pin gauge. The gauge should not pass freely through the female terminal. Do not probe the terminal with anything other than the pin gauge, as probing could damage the terminal. If the female terminal does not grip properly, replace the terminal with P/N 12020757. General directions on wiring repair are shown in Section 8A of the service Manual. Locations Htr-A/C, Pwr Wdo Circuit Breaker Locations Timing Connector-In Pass Comp Behind Carpet, Below Heater Page 1822 This bulletin is for informational purposes only, and should be used as a guideline if it becomes necessary to replace the intake manifold gaskets on 4.3L, 5.0L and 5.7L TBI engines. With the introduction of TBI engines, a change was made to the intake manifold gasket by adding a restrictor plate to the rear coolant passage of the gasket in order to direct coolant to flow from the front of the intake manifold, under the TBI section of the manifold (heats TBI to prevent throttle plate icing) and exit out of the heater hose pipe at the rear of the manifold (See Figure 1). Anytime it becomes necessary to replace the intake manifold gasket, it is essential that the gaskets be properly installed. If the gasket is installed backwards i.e., with the restrictor plate at the front of the engine, the engine will overheat. When diagnosing overheat conditions, the proper installation of the gasket can be checked without removing the manifold. Both the 4.3L, 5.0L and 5.7L gaskets have metal locator tabs that can be seen sticking out from between the manifold and the cylinder head. When installed correctly, the tab on the 4.3L will be to the rear of the engine and the tab for the 5.0L and 5.7L engine will be to the front of the engine (See Figure 1). Page 5655 Power Steering Pump: Description and Operation Less Integral Reservoir The hydraulic pump is a non-submerged vane-type design. The housing and internal parts are separate from the reservoir and are not submerged in fluid. There are two bore openings at the rear of the pump housing. The larger opening contains the cam ring, pressure plate, thrust plate, rotor and vane assembly, and end plate. The smaller opening contains the pressure line union, flow control valve and spring. the pressure relief valve inside the flow control valve limits pump pressure. Page 1085 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 Page 2075 5. Coolant to the radiator. Page 8118 Figure 1, 3 Note: If performing the above procedure does not appear to correct the condition, a gap at the back of the dash, where the dash and cowl assembly come together with the windshield frame and plenum assembly, may be the cause (see Figure 2). When these two pieces are welded together in production a gap may be created on the vehicle. After the welding process this gap, as well as the rest of the joint, is sealed. If this gap is not sealed properly a howl condition can occur. To eliminate this condition the entire joint will have to be resealed. This can be done at the same time as procedure 1 (see Figure 3). 1) Using Bowman Distribution black caulking part number 19023 or equivalent it is possible to seal the area where the dash meets the plenum assembly through the exposed cowl vent windows located on the plenum assembly. 2) Remove caulking from package and apply through the exposed cowl vent grille. Firmly push the caulking into the area where the dash and cowl assembly meet the plenum assembly. To insure proper seal it is necessary to install the caulking the full length of the windshield (3.5 Page 7894 Symbol Identification Wire Color Code Identification WIRE COLOR ABBREVIATION BLACK BLK BLUE BLU DARK BLUE DK BLU Diagram Information and Instructions Battery Cable: Diagram Information and Instructions 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 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. Tires - Slipping on Rim Tires: Customer Interest Tires - Slipping on Rim Number: 93-169-3E Section: 3E Date: APRIL 1993 Corporate Bulletin No.: 393501 ASE No.: A4 Subject: TIRES SLIPPING ON WHEELS (USE PROPER TIRE MOUNTING PROCEDURE) Model and Year: 1988-93 ALL PASSENGER CARS AND LIGHT DUTY TRUCKS Some incidents of tires slipping (rotating) on wheels have been reported on 1988-93 passenger cars and light duty trucks. Most incidents have occurred when driven aggressively immediately after tire mounting. Hard acceleration and/or braking is usually required. This condition will affect wheel balance, which could result in a vibration. To reduce the chance of tires rotating on their wheels, any excess lube should be wiped from the tire and rim after tire mounting, but before inflating to seat the bead. (Never exceed 40 psi to seat the bead.) Also, the vehicle should not be driven aggressively for at least four hours after tire mounting to allow the lube to dry. GM Goodwrench Rubber Lubricant, p/n 12345884, is the recommended lube for tire mounting. Backup Lamps/Tailgate Window Release - Inoperative Shift Interlock Switch: All Technical Service Bulletins Backup Lamps/Tailgate Window Release Inoperative Number: 91-459-8A Section: 8A Date: DEC. 1991 Corporate Bulletin No.: 168104 ASE No.: A6 Subject: BACKUP LAMPS OR TAILGATE WINDOW RELEASE INOPERATIVE Model and Year: 1980-91 ALL LIGHT DUTY TRUCKS (EXCEPT GEO) Owners of some 1980-1991 C/K, 1982-1991 G, 1985-1991 M/L, 1984-1991 P2,P3, 1987-1991 R/V, 1983- 1991 ST (including LLV) with automatic transmissions may comment on a condition of inoperative back-up lamps or inoperative tailgate window release. This condition occurs when the vehicle's gear shift lever is placed in the "reverse" position, but the back-up lamps do not illuminate. In addition, on the S/T utility vehicles, the electric tailgate window release does not release when the transmission gear shift lever is placed in the "park" or "neutral" position and the endgate window release button is depressed. The park/neutral and back-up lamp switch comes out of adjustment which does not allow for the contact points to remain engaged. To correct these conditions, the contact carrier on the park/neutral and back-up lamp switch has been modified to increase switch carrier travel. SERVICE PROCEDURE: 1. Disconnect the battery ground cable from the battery. 2. Disconnect the switch assembly harness. 3. Place the gear selector in neutral. 4. Squeeze the tangs on the switch together and remove the switch assembly. 5. Install the new switch assembly (P/N 15679680) by: -aligning the actuator with the cutout in the steering column jacket. -inserting the tangs into the rectangular holes and pushing down on the switch assembly. 6. Adjust the switch by moving the gear selector to park. 7. Connect the switch assembly harness. 8. Connect the negative battery cable. 9. Check for proper switch operation. Readjust the switch as necessary. Page 2266 ECM Connector Terminal Identification & Voltage Specifications. 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. 3L30 (180C) Transmission Shift Cable: Specifications 3L30 (180C) Transmission Component .......................................................................................................................................... .................................................................... Ft. Lbs. Detent Cable Retainer To Case .......................................................................................................... .................................................................................. 6 Page 4323 Page 2808 Transmission Position Switch/Sensor: Testing and Inspection Chart C-1A - Park/Neutral Switch Diagnosis Specifications Idle/Throttle Speed Control Unit: Specifications IDLE SPEED CONTROL Measured between terminals A& B and C & D. Page 6758 2. If the latch is misaligned and/or the endgate glass is not snug against the weatherstrip, remove the endgate inner trim panel and loosen the latch assembly by adjusting the nuts located on the side of the latch assembly (Figure 1, Item 4). Adjust the location of the latch and tighten the adjusting nuts to 8.5-11.0 N-m (6-8 lbs.ft.). 3. Check the endgate window latch for proper operation. If necessary, repeat steps 1 and 2. REPLACEMENT PROCEDURE If the latch assembly is properly adjusted and the condition still occurs, the latch assembly should be replaced by performing the following steps: Hydra-Matic 700-R4 (4L60) Speedometer Gear, A/T: Service and Repair Hydra-Matic 700-R4 (4L60) 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 adjusting fluid level. Page 1996 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. Tires - Rotation and Warranty Coverage Tires: All Technical Service Bulletins Tires - Rotation and Warranty Coverage Number: 88-116-3E Section: 3E Date: Jan., 1988 Subject: CHEVROLET'S RESPONSIBILITIES CONCERNING TIRE WARRANTIES, INCLUDING IRREGULAR/ PREMATURE WEAR Model and Year: ALL MODELS TO: ALL CHEVROLET DEALERS As in the past, tires continue to be warranted by the tire manufacturer against defects in material or workmanship. Details of this limited warranty may be found in each tire company warranty booklet, which is part of the glove box material. The GM warranty and owner assistance booklet also now states that the GM dealer will assist the customer in obtaining a tire adjustment, if necessary. Tire conditions caused by vehicle defects are warranted by General Motors. This statement is now included in the GM warranty and owner assistance booklet. This applies during the basic warranty coverage period, which is 12 months/12,000 miles, and should be applied to all past and current models. Examples of tire conditions that fall within GM's responsibility may include tire damage during vehicle assembly, tire damage due to tire-to-vehicle interference, and irregular/premature tire wear. Tire wear due to abusive driving is not covered by warranty. FIGURE 1 Page 7904 Light Switch Details (Part 3 Of 3) Page 4289 21. Lubricate the seal lip. - If seal is cut or torn, inspect the wheel bearing for damage and replace the seal. 22. If necessary, replace the seal as follows: - Pry old seal from knuckle and discard. - Lubricate the new seal lip. - Use a flat plate to press the seal down flush with the knuckle. Tripot Housing/Tripot Seal Replacement Figure 10 - Inboard Joint Disassembly Required Tools: J8059 Snap Ring Pliers J35910 Seal Clamp Tool 1. Place halfshaft in vise (use protective covers over vise jaws). 2. Remove seal clamp protectors (Figure 10) if used, from inner C/V joint and cut clamp(s) from seal with a pair of side cutters. For swage ring removal use a hand grinder to cut through the ring (taking care not to damage the housing). 3. Remove tripot housing from halfshaft and wipe grease from tripot assembly roller bearings and housing. Thoroughly degrease the housing and allow to dry prior to assembly. Important: Handle tripot spider assembly with care. Tripot balls and needle rollers may separate from spider trunnions. 4. Slide seal up on the shaft and inspect rollers, needle bearings, and trunnions. Check housing for unusual wear, cracks, and other damage. Replace housing and/or tripot assembly as needed. Paint - Manufacturer Codes Paint: All Technical Service Bulletins Paint - Manufacturer Codes Number: 88-67-10 Section: 10 Date: October, 1987 SUBJECT: 1988 PAINT CODES MODELS: ALL 1988 TRUCK MODELS The following is a list of paint code numbers from various suppliers for the 1988 model year. These colors can be obtained locally. DuPont refinish paints are available in: ^ L - Lucite - Acrylic Lacquer ^ A - Centari - Acrylic Enamel ^ D - Dulux -Enamel ^ 355S - Flexible Additive ^ 1234 Vinyl Lacquer - Chip resistant NOTE: Vinyl Resin must be added to the base color when painting interior components. DuPont Vinyl Resin #304 -Instrument Panel DuPont Vinyl Resin #305 - All Remaining Interior Parts Except Seats DuPont Vinyl Resin #306 - Seats and Vinyl Roofs When ordering DuPont paint, use "L", "A", "D", 355S or 1234 with the appropriate DuPont code. Ditzler refinish paints are available in: ^ DDL - Duracryl - Acrylic Lacquer ^ DBU - Deltron - Acrylic B/C ^ DAR -Delstar -Acrylic Enamel ^ DAU - Deltron - Acrylic Urethane ^ DIA - Interior Lacquer ^ UCV -Vinyl Colors ^ DX-369 - Flexative - Flexible Finishes ^ DX-54 Roadguard - Road Abrasion Protection When ordering PPG paint use "DDL", "DBU", "DAR", "DAU", "UCV", "DX-369", or "DX-54" with appropriate Ditzler code. Sherwin-Williams, Acme/Rogers, and MartinSenour are available in acrylic lacquer or acrylic enamel. S-W use: prefix 34, J4, or L10 for acrylic lacquer prefix 35, J5, or F10 for acrylic enamel Acme use: prefix 84 for acrylic lacquer prefix 85 for acrylic enamel Rogers use: prefix 94 for acrylic lacquer prefix 95 for acrylic enamel Martin-Senour: jobber will interchange number shown when acrylic lacquer is needed Suspension (Front) - Squeaking Noise Coil Spring Insulator: Customer Interest Suspension (Front) - Squeaking Noise Number: 91-330-3C Section: 3C Date: MAY 1991 Corp. Bulletin No.: 063306R Subject: FRONT SUSPENSION SQUEAK Model and Year: 1982-91 S1 TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 91-168-3C, DATED JANUARY 1991. THE LABOR OPERATION HAS BEEN CHANGED. ALL COPIES OF 91-168-3C SHOULD BE DISCARDED. Some S1 trucks may experience a squeaking noise from the front suspension. Spraying of lubricant in the spring pocket areas may help for a short time but the squeak usually returns. The usual cause of this squeak is contact between the spring and the frame pocket or control arm. An insulator is installed in production between the spring and upper frame pocket, but this insulator will occasionally be pushed aside allowing metal to metal contact. An insulator was not installed in production between the control arm and the spring. To fix the squeak, the existing upper insulator should be removed and M-Van insulators installed at both ends of the spring; that is, between the spring and the upper frame pocket and between the spring and the lower control arm. VEHICLES INVOLVED 1982 - 1991 S trucks. SERVICE PROCEDURE: REMOVE 1. Lower control arm and spring. 2. Insulator from top end of spring. - Clean excess paint and adhesive from both ends of spring. INSTALL 1. New insulators to spring ends. - Apply a full bead of weatherstrip adhesive to the diameter of the spring insulator contact area. - Be sure upper and lower insulators are installed to respective ends of the spring. - Allow weatherstrip adhesive to cure enough to hold the insulators in place before reinstalling springs. 2. Spring. Tape should be on lower end and gripper notch on top. - Position end of lower spring coil to cover one lower control arm inspection drain hole and expose the other 3. Lower control arm. Refer to S/T Service Manual, Section 3C - Front Suspension for complete coil spring replacement procedure. SERVICE PARTS INFORMATION Quantity Part Number Description Required Engine - Drive Belt Misalignment Diagnostics Drive Belt: All 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. Page 5857 ^ 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 Page 2196 FIGURE 1(T-TRUCK ONLY) G. (T-truck only) Check equalizer lever for firm contact at the shift lever inboard side of the guide slot. (See Figure 1) H. If firm contact is evident, add an additional washer (#10 in Figure #1) P/N 14074908 to adjust equalizer lever outboard toward the center of the guide slot to eliminate contact. 2. A. Raise vehicle on hoist. B. Note location of clamp rotation on pipe. Some clamps are located with the lower lock ring (nuts) pointed towards the transmission. If the clamp is located in such a manner, loosen clamp and rotate it down so the nuts point toward the ground and retighten to 58 N-m (43 ft/lbs.) 3. A. Loosen converter clamp until it will rotate around the pipe. Using a suitable pry bar, move exhaust system rearward to obtain a minimum of 5/8 in. clearance between any point on the exhaust system and the transmission crossmember. For repairs performed under warranty, use the following labor operations and times: Labor Operation Labor Time Exhaust/muffler clamp L2020 .3 Hr Exhaust system align L2004 .3 Hr Shift Linkage (shorten) K5244 .3 Hr Interior - Noise From Windshield Pillar Area Windshield: Customer Interest Interior - Noise From Windshield Pillar Area BULLETIN NUMBER: 92-10-130 SECTION: 10 NUMBER: 1 CORPORATE REFERENCE NUMBER: 261610 DATE: September 1992 SUBJECT: NOISE FROM WINDSHIELD PILLAR AREA (DIAGNOSE/INSTALL FELT TAPE) MODELS: 1986-92 S1/T1 UTILITY TRUCKS Some 1986-92 S/T utility trucks may exhibit a plastic to metal or plastic to plastic "itch" noise from the left or right windshield pillar area. This noise may be caused by the instrument panel pad rubbing against the cowl or dash support panel. An adhesive backed felt tape has been released to insulate the dash pad outer corners from the dash support panel. This tape may also be used on the non-visible surfaces of other trim panels as necessary to eliminate itch noises. The felt tape, P/N 12541499, is released in a 10 ft. x 30 mm x 1 mm mil to provide the technician sufficient material to insulate numerous trim panels. SERVICE PROCEDURE Prior to installing the felt tape, it should be determined IP pad to dash support panel is the area that is generating the noise. Refer to the Squeak and Rattle Diagnosis and Correction Manual to identify other possible sources such as ECM Mounting Bracket or Air Vent. If it is determined the IP pad is the source of the noise: 1. Remove the instrument panel radio speaker(s) to obtain better access to the metal ledge on which the instrument panel pad rests. 2. Remove the 4 IP upper retaining screws located in the defroster duct openings and pull the pad back slightly. NOTICE: Do not remove the dash pad any further than necessary to perform the repair. The possibility exists that additional noises may be generated due to the wiring and HVAC ducts being mispositioned upon reinstallation. 3. Cut a strip of felt tape 6 inches long, remove the protective backing and apply the tape to the top of the metal ledges in fmnt of the speaker openings where the instrument panel pad rests. NOTICE: Installation is easier if 2 screw drivers are wedged between instrument panel pad and the cowl panel to raise the IP pad. 4. Push the IP pad forward and reinstall the retaining screws and speakers. SERVICE PARTS INFORMATION Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty, see chart. Page 6303 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. Backup Lamps/Tailgate Window Release - Inoperative Backup Lamp Switch: All Technical Service Bulletins Backup Lamps/Tailgate Window Release Inoperative Number: 91-459-8A Section: 8A Date: DEC. 1991 Corporate Bulletin No.: 168104 ASE No.: A6 Subject: BACKUP LAMPS OR TAILGATE WINDOW RELEASE INOPERATIVE Model and Year: 1980-91 ALL LIGHT DUTY TRUCKS (EXCEPT GEO) Owners of some 1980-1991 C/K, 1982-1991 G, 1985-1991 M/L, 1984-1991 P2,P3, 1987-1991 R/V, 1983- 1991 ST (including LLV) with automatic transmissions may comment on a condition of inoperative back-up lamps or inoperative tailgate window release. This condition occurs when the vehicle's gear shift lever is placed in the "reverse" position, but the back-up lamps do not illuminate. In addition, on the S/T utility vehicles, the electric tailgate window release does not release when the transmission gear shift lever is placed in the "park" or "neutral" position and the endgate window release button is depressed. The park/neutral and back-up lamp switch comes out of adjustment which does not allow for the contact points to remain engaged. To correct these conditions, the contact carrier on the park/neutral and back-up lamp switch has been modified to increase switch carrier travel. SERVICE PROCEDURE: 1. Disconnect the battery ground cable from the battery. 2. Disconnect the switch assembly harness. 3. Place the gear selector in neutral. 4. Squeeze the tangs on the switch together and remove the switch assembly. 5. Install the new switch assembly (P/N 15679680) by: -aligning the actuator with the cutout in the steering column jacket. -inserting the tangs into the rectangular holes and pushing down on the switch assembly. 6. Adjust the switch by moving the gear selector to park. 7. Connect the switch assembly harness. 8. Connect the negative battery cable. 9. Check for proper switch operation. Readjust the switch as necessary. Page 6114 Aligning The Drive Plate Key ^ Allow the shaft key (36) to extend 4.5 mm (3/16-inch) out of the bottom of the hub keyway. ^ The shaft key (36) is curved to give an interference fit in the groove. Important ^ Do not drive or pound on the clutch hub or the shaft (39). Internal damage to the compressor may result. 2. Clutch plate and hub assembly (2). ^ Install the clutch plate and hub assembly (2) over the compressor shaft lining up the key slot on the hub with the keyway slot in the shaft. Installing The Drive Plate ^ Install J 9480-B on the threaded end of the shaft. ^ Back off J 9480-B body to allow the center screw to be threaded against the end of the compressor shaft (39). ^ Hold the center screw with a wrench and lighten the hex portion of J 9480-B body while pressing the hub onto the shaft (39). After tightening Electrical - Intermittent MIL/DTC P2138/Reduced Power Wiring Harness: Customer Interest Electrical - Intermittent MIL/DTC P2138/Reduced Power TECHNICAL Bulletin No.: 07-06-04-019D Date: June 28, 2010 Subject: Intermittent Malfunction Indicator Lamp (MIL) Illuminated, DTC P2138 with Reduced Engine Power (Repair Instrument Panel (IP) to Body Harness Connector) Models: 2005-2011 GM Passenger Cars and Light Duty Trucks (Including Saturn) 2005-2009 HUMMER H2 2006-2010 HUMMER H3 2005-2009 Saab 9-7X Supercede: This bulletin is being revised to update the model years and warranty information. Please discard Corporate Bulletin Number 07-06-04-019C (Section 06 - Engine/Propulsion System) Condition - Some customers may comment on an intermittent malfunction indicator lamp (MIL) being Illuminated with a message or an indicator that displays Reduced Engine Power. - The technician may observe on a scan tool DTC P2138 - Accelerator Pedal Position (APP) Sensor 1-2 Correlation set as Current or in History. Cause This condition may be caused by water intrusion into the instrument panel (IP) to body harness connector, which carries the APP sensor signals to the ECM/PCM. This water intrusion results in a voltage difference between APP Sensor 1 and APP Sensor 2 that exceeds a predetermined value for more than a calibrated period of time, setting P2138. Correction Note Aftermarket equipment can generate DTC P2138 and/or other DTCs. 1. Verify that aftermarket equipment is not electrically connected to any of the APP sensor signal or low reference circuits or to any other ECM/PCM 5V reference or low reference circuits. Refer to Checking Aftermarket Accessories in SI. 2. Perform the Diagnostic System Check - Vehicle. ‹› If any 5V reference DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle. ‹› If any 5V reference DTCs are not set, proceed to Step 3. 3. Locate the IP to body harness connector, which may be located in and around the left hand kick panel area or inside the IP. Depending on the vehicle and model year, refer to Wiring Systems or Power and Signal Distribution in SI. Note Some examples of potential water leaks are: A-pillar seals, sunroof drain lines (if equipped) and windshield/cowl sealing. 4. Inspect for a water leak in the area. If necessary use a water hose to determine the source of the leak. Refer to General Information > Water Leaks in SI. ‹› If a water leak is observed, repair as necessary. Verify the effectiveness of the repair. 5. Inspect the IP to body harness connector terminals for corrosion and debris. Refer to Testing for Intermittent Conditions and Poor Connections in SI. ‹› If any corrosion and/or debris is observed, repair as necessary. 6. After completing the repair, verify the proper operation of the system. Depending on the vehicle and model year, perform the Diagnostic Repair Verification procedure or refer to Diagnostic Trouble Code (DTC) List - Vehicle in SI. Page 5075 Vacuum Brake Booster: Service and Repair Power Brake Unit 1. Disconnect master cylinder assembly and vacuum hose from power brake unit. 2. Disconnect power brake unit pushrod from brake pedal. 3. Remove power brake unit attaching nuts from inside of vehicle. 4. Remove power brake unit. 5. Reverse procedure to install. Torque power brake unit and master cylinder mounting nuts to specification. Brakes - Updated Parking Brake Adjustment Technical Service Bulletin # 89375 Date: 881102 Brakes - Updated Parking Brake Adjustment Number: 89-37-5 Section: 5 Date: NOV., 1988 Subject: PARKING BRAKE ADJUSTMENT Model and Year: 1987-89 LLV POST OFFICE VEHICLES S/T CHASSIS TO: ALL CHEVROLET DEALERS Present service manuals do not contain a procedure for the adjustment of the hand lever parking brake as used on the Post Office vehicle. The following service procedure was developed to fill this need. REQUIREMENT FOR ADJUSTMENT The parking brake must be adjusted whenever the parking brake cables have been replaced or disconnected, or when their holding ability is not adequate. The parking brake must also be adjusted whenever the rear brakes are manually adjusted or shoes replaced. Before adjusting the parking brakes, check the condition of the rear brakes. The rear brakes must be properly adjusted (see Section 5A2-10 in Service Manual) before proceeding with the adjustment of the parking brake. 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 Adjustments Ride Height Sensor: Adjustments When repair or adjustment procedures require that vehicle be raised on a hoist, it is important that the rear axle assembly remains in the normal trim height position at all times. When a frame contact hoist is used, two additional jack stands should be used to support the rear axle or control arms in the normal trim height position. Fig. 21 Adjusting Height Sensor The link should be properly attached to the sensor arm and track bar, when making this adjustment. 1. Loosen lock bolt that secures metal arm to height sensor plastic arm, Fig. 21. 2. To raise vehicle trim height, move plastic arm upward and tighten lock bolt. If no adjustment remains, refer to FRONT SUSPENSION/SPECIFICATIONS/VEHICLE TRIM HEIGHT. 3. To lower vehicle trim height, follow step 1 and move plastic arm down. 4. If adjustment cannot be made, check for correct sensor. Tires - Rotation and Warranty Coverage Tires: All Technical Service Bulletins Tires - Rotation and Warranty Coverage Number: 88-116-3E Section: 3E Date: Jan., 1988 Subject: CHEVROLET'S RESPONSIBILITIES CONCERNING TIRE WARRANTIES, INCLUDING IRREGULAR/ PREMATURE WEAR Model and Year: ALL MODELS TO: ALL CHEVROLET DEALERS As in the past, tires continue to be warranted by the tire manufacturer against defects in material or workmanship. Details of this limited warranty may be found in each tire company warranty booklet, which is part of the glove box material. The GM warranty and owner assistance booklet also now states that the GM dealer will assist the customer in obtaining a tire adjustment, if necessary. Tire conditions caused by vehicle defects are warranted by General Motors. This statement is now included in the GM warranty and owner assistance booklet. This applies during the basic warranty coverage period, which is 12 months/12,000 miles, and should be applied to all past and current models. Examples of tire conditions that fall within GM's responsibility may include tire damage during vehicle assembly, tire damage due to tire-to-vehicle interference, and irregular/premature tire wear. Tire wear due to abusive driving is not covered by warranty. FIGURE 1 Page 6731 Front Door Window Glass: Technical Service Bulletins Body - Side Window Chipping Information INFORMATION Bulletin No.: 06-08-64-001B Date: October 20, 2009 Subject: Information on Side Door Window Glass Chipping Caused by Hanging Vehicle Key Lock Box 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 add vehicles and model years and to include all types of door window glass. Please discard Corporate Bulletin Number 06-08-64-001A (Section 08 - Body & Accessories). - In several warranty parts review cases, side door window glass was observed with a chip or chips on the top side of the window glass. Dealer contacts confirmed that they use a vehicle key lock box on the front side door window glass. - A random selection of side door glass returns will be conducted to confirm adherence. If a side door glass is discovered with a chip or chips in the location previously described, the side door glass will be returned to the dealership for debit. Example of Side Door Glass - DO NOT place a vehicle key lock box on a side door window glass. Page 5314 e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors Do Not require all the steps shown. Skip the steps that Do Not apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. 1. Separate connector halves (see Figures 2 through 6). Figure 2 Figure 3 Page 5345 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) Brakes - Light Brake Drag While Driving Brake Light Switch: All Technical Service Bulletins Brakes - Light Brake Drag While Driving Number: 89-262-5 Section: 5 Date: September 1989 Corporate Bulletin No.: 915002 Subject: LIGHT BRAKE DRAG - BRAKE SWITCH ADJUSTMENT Model and Year: 1980-89 A, B, F, G, J, L, X, Y 1980-89 ALL TRUCKS Figure 1 TO: ALL CHEVROLET DEALERS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 89-178-5, DATED JUNE 1989, IN ORDER THAT WE MAY CORRECTLY IDENTIFY THE SWITCH REQUIRING ADJUSTMENT. ALL COPIES OF 89-178-5 SHOULD BE DISCARDED. Some vehicles may experience a condition of light brake drag while driving. These conditions have been found to be more noticeable on vehicles which have an anti-lock brake system. This may be caused by improper brake switch adjustment. If the brake switch is not adjusted properly, the switch may push on the brake pedal and cause the brake to remain partially applied. If a vehicle exhibits any of the above conditions, perform the following functional brake switch adjustment check: Passenger Cars Only: The following steps should be used to check brake switch adjustment: 1. Remove the driver-side hush panel (refer to Figure 1). 2. Gently pull back on the brake pedal until no audible clicks are heard. The switch will be moved in the tubular retainer providing adjustment. 3. Replace the hush panel. 4. Verify that the brake drag condition is no longer present and that the cruise control and brake lights function properly. Page 8089 Disclaimer Page 2264 ECM Connector Terminal Identification & Voltage Specifications. Page 1741 Oil Pressure Warning Lamp/Indicator: Testing and Inspection On some models, the oil pressure indicator light also serves as the electric choke defect indicator. If Oil or ENG. indicator light does not light, check to ensure electric choke is not disconnected at carburetor. Also check for defect in electric choke heater, blown gauge fuse or defect in lamp or wiring circuit. If indicator light stays on with engine running possible causes are: low oil pressure, switch to indicator light open circuit, disconnected oil pressure switch connector or oil pressure gauge or radio fuse has blown. 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. Page 7149 Hood ornaments Wheel opening moldings Side view mirrors Grille and headlamp bezels Door edge guards Bumper filler panel, Frt./Rr. Front side marker lamps *Roof marker lamps *West coast style mirrors *Stripes Emblems/decals if necessary G VANS Wiper arms Cowl vent grille Grille and headlamp bezels Front bumper filler panel Antenna Side view mirrors Side marker lamps Tail lamps Door edge guards Wheel opening moldings *Roof marker lamps *West coast style mirrors *Stripes Emblems/decals if necessary Swing out windows/seals WARRANTY INFORMATION For vehicles repaired under warranty. and for customer satisfaction. use: Labor Op (Labor Operations include mix time) A6100 Refinish the entire exterior body surface ABOVE THE BODY SIDE MOLDING AND INSERT COLOR on two tone vehicles if equipped. A6101 Refinish the entire exterior body surface INSERT COLOR only. A61O2 Refinish the PICKUP BOX LOAD FLOOR AND INNER FENDERS when applicable. A61O3 On units with an insert color, included is the entire exterior body surface ABOVE THE BREAKLINE. (If the insert color and the entire body surface above the break-line requires refinishing, use A6100). Page 6328 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 Page 619 Disclaimer Page 8036 Window Regulator: Service and Repair Without Power Windows Door Armrest Replacement Front Door Trim Panel REMOVE OR DISCONNECT 1. Screws securing the armrest to the door trim. 2. Armrest from the door trim. ^ Slide the armrest towards the rear of the door, and then, lift the armrest from the door. INSTALL OR CONNECT 1. Armrest to the door trim. ^ Place the armrest retaining clips in the slots on the door panel. ^ Slide the armrest toward the front of the door unit the holes in the armrest align with the holes in the door trim. 2. Screws securing the armrest to the door trim. Door Inner Panel Water Deflector Replacement Page 5074 12. Install secondary piston bearing and housing divider over power piston assembly and pushrod. 13. Install primary diaphragm into the primary support plate, Fig. 8. 14. Fold primary diaphragm up away from the primary support plate, then install primary diaphragm and support plate over power piston and pushrod assembly. 15. Fold primary diaphragm back into position and pull the outside edge of diaphragm over formed flange of housing divider. 16. Install new diaphragm retainer. Ensure retainer is fully seated. 17. Install silencer, reaction retainer and piston rod. 18. Lubricate inside and outside diameters of primary piston bearings with silicone grease. 19. Install primary piston bearing into rear housing. 20. Install power piston assembly into rear housing, then the return spring. 21. Mount housing to holding fixture and turn fixture handle to lock the front and rear housings, Fig. 4. Fig. 5 Brake Booster Lock Tab & Staking Positions 22. Stake housing in locations shown, Fig. 5. Do not stake a tab that has been staked previously. 23. Lubricate inside and outside edges of grommet and front housing seal, then install grommet and seal. 24. Install vacuum check valve, silencer and boot. 25. Ensure piston rod depth is within specifications using gauge tool No. J-37839 or equivalent. Page 5787 Figure 6 - Disconnecting Lower Shock Mount 10. Remove the lower shock mounting nut and bolt (Figure 6). 11. Collapse the shock absorber. 12. Move the shock absorber up, away, and secure. 13. Depending on the type of hoist, it may be required to position floor stand between the spring seats and the lower control arm ball joint for miximum leverage. The weight of the vehicle is used to relieve the spring tension on the upper control arm. Caution: The floor jack or stand must remain under the control arm spring seat while servicing the halfshaft to maintain spring and control arm position. Failure to do so could result in personal injury. 14. Disconnect the cotter pin. 15. Remove the stud nut from the upper ball joint. Figure 7 - Ball Joint from Knuckle Separation 16. Loosen the stud using J34026 and move away from the knuckle (Figure 7). Page 12 - 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 Page 4584 Figure 2 Page 6995 panel(s) that can be used as a starting/ stopping point when making a repair. Clearcoat: A clear topcoat required to cover a color basecoat. DELAMINATION: Loss of adhesion between one coat of paint to succeeding coats or coatings. Ultraviolet DELAMINATION is between the E coat (ELPO) and color topcoat(s). ELPO: (Electrocoating or "E" coat): The process by which electrically charged primer is plated on conductive surfaces of an opposite charge. This process provides outstanding corrosion resistance. Guidecoat: A light coat (almost overspray) of color applied over primer surfacer prior to wetsanding to highlight any low spots. Insert Color: The secondary two-tone color between the break line and body side molding. Monocoat: A color topcoat that does not require a clearcoat. Primer: The coating applied to a properly prepared substrate (bare metal) to give adhesion, corrosion and chemical resistance. Primer Sealer: An undercoat that provides maximum adhesion. color coating and corrosion protection. Primer Surfacer: An undercoat used to fill imperfections, with primer qualities, that must be sanded. Refinish: The act of replacing a painted surface, usually undercoat and topcoat. Scuff Sand: A method of sanding a painted surface using a fine grit sandpaper to promote paint adhesion. Topcoat: A finish material over an undercoat material. Ultraviolet Light: The portion of the spectrum of light which can cause fading of paint. It is located below the visible part of the spectrum. V.O.C.: "Volatile Organic Compound" or "Volatile Organic Content" relates to certain emission requirements in specific areas of the country. Page 6788 2. Remove the end gate inner panel reinforcement from the end gate (Figure 1, Item 1). 3. Disconnect the end gate lock rods (Figure 2, Items 1 and 2). 4. Remove the lock cylinder retainer (Figure 3, Item 2). 5. Working through the access hole, remove the lock cylinder and gasket (Figure 3, Items 4 and 3) through the outer panel. 6. Remove the spring (located on the lock assembly) and carefully bend the spring ends just far enough to eliminate any clearance between the lock pawl assembly and the lock cylinder housing (Figure 3, Items 6 and 4). Note: Locations Blower Motor Relay: Locations Fig 26. Evaporator And Blower Assembly The Blower Motor Relay (152) is located on the front of the Evaporator and Blower Assembly. Locations Power Steering Pressure Switch: Locations LH Fender Apron LH Front Corner Of Engine Compartment 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 Description and Operation Transmission Position Switch/Sensor: Description and Operation The park/neutral switch indicates to the ECM when the transmission is in park or neutral. This information is used by the ECM for ignition timing, IAC operation and transmission Torque Converter Clutch (TCC) operation. Do not drive vehicle with park/neutral switch disconnected, as idle quality may be affected. A/C Recirculation Door - Water Leak Hood Hinge: Customer Interest A/C Recirculation Door - Water Leak File In Section: 1 - HVAC Bulletin No.: 56-12-04 Date: April, 1995 Subject: Water Leak at the A/C Recirculation Door (Install New Hood Hinge Seal) Models: 1983-93 Chevrolet and GMC Truck S/T Pickups 1983-94 Chevrolet and GMC Truck S/T Utilities 1991-94 Oldsmobile Bravada Built Prior to the Following VIN Breakpoints: Assembly Plant Division (Plant Code) VIN Breakpoint GMC Truck Pontiac West (0) R0525661 Chevrolet Pontiac West (0) R0168567 Oldsmobile Pontiac West (0) R0704953 GMC Truck Moraine (2) All Chevrolet Moraine (2) All Oldsmobile Moraine (2) All CONDITION Some owners may comment that they have a water leak at the kick panel vent when their A/C controls are in the MAX position and it is raining. CAUSE Water is entering the plenum and cowl area by way of the hood hinge. CORRECTION To correct this condition, remove the current hood hinge seal and replace with a redesigned hood hinge seal. The redesigned seal has foam flaps which restrict water entry. Service Procedure 1. Raise and support the hood. 2. Remove the cowl vent grille. Refer to "Cowl Vent Grille Replacement" in Section 2B of the Service Manual. 3. Remove hood hinge bolts from hood (both sides). 4. Remove hood from vehicle. 5. Remove fender nut and bolt from hinge (both sides). 6. Remove hood hinge from vehicle (both sides). 7. Remove hood hinge seals and replace with redesigned hood hinge seals P/N's 15995797 (LH) and 15995798 (RH). Important: Be sure that hood hinge seals are properly seated and sealed or water leakage could recur. 8. Install hood hinges to vehicle. Important: Apply lubricant to the hood hinges around the hinge to fender bolts. 9. Install fender nuts and bolts to hood hinges. 10. Install hood hinges to hood bolts. Tighten the hinge to hood bolts to 25 Nm (18 lb.ft.). Page 4641 Figure 2 Page 7587 Figure 4 Figure 5 Figure 6 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 7 Page 7703 Brake Light Switch: Locations Stop Light Switch LH Side Of I/P Behind Instrument Cluster Page 7431 Page 2525 Wiring Diagram For Chart C-5 - Electronic Spark Control System Check CIRCUIT DESCRIPTION: Electronic spark control is accomplished with a module that sends a voltage signal to the ECM. As the knock sensor detects engine knock, the voltage from the ESC module to the ECM is shut "OFF" and this signals the ECM to retard timing, if engine RPM is over about 900. TEST DESCRIPTION: Numbers below refer to circled numbers on the diagnostic chart. 1. If A Code 43 is not set, but a knock signal is indicated while running at 1500 RPM, listen for an internal engine noise. Under a no load condition there should not be any detonation, and if knock is indicated, an internal engine problem may exist. 2. Usually a knock signal can be generated by tapping on the right exhaust manifold. This test can also be performed at idle. Test number 1 was run at 1500 RPM to determine if a constant knock signal was present, which would affect engine performance. 3. This tests whether the knock signal is due to the sensor, a basic engine problem, or the ESC module. 4. If the module ground circuit is faulty, the ESC module will not function correctly. The test light should light indicating the ground circuit is OK. 5. Contacting CKT 496, with a test light to 12 volts, should generate a knock signal to determine whether the knock sensor is faulty, or the ESC module can't recognize a knock signal. DIAGNOSTIC AIDS: "Scan" tools have two positions to diagnose the ESC system. The knock signal can be monitored to see if the knock sensor is detecting a knock condition and if the ESC module is functioning, knock signal should display "yes", whenever detonation is present. The knock retard position on the "Scan" displays the amount of spark retard the ECM is commanding. The ECM can retard the timing up to 20 degrees. This check should be used after other causes of spark knock have been checked such as engine timing, EGR systems, engine temperature or excessive engine noise. Page 5027 FIGURE 1 - PARKING BRAKE ADJUSTMENT INSPECTION OF THE PARKING BRAKE Check the parking brake system for free operation. The brake lever must return to the released position without sticking or binding. If a sticking or binding condition is present, check the cable, and cable routing for kinks or binding. Clean and lubricate the parking brake assembly and cable as necessary. (see Figure No. 1) Service Procedure A Page 7174 leaving primer intact, the topcoat is delaminating and the following service procedure should be performed. Figure No. 1 NOTICE: For two tone vehicles, it is only necessary to refinish surfaces painted Galaxy Blue, Aspen Blue or Steel Gray. Other colors should not be affected by this condition. The front bumper filler panel and all surfaces painted with affected colors above the belt line (Fig. 1, page 3) must be refinished according to the procedure listed below (regardless of previous paint repairs). If surfaces below the belt line and the interior of the pickup box (on pickup models) appear to be in good condition, the dealer should scuff sand, seal and color coat those painted surfaces rather than refinish. However, if any peeling or topcoat delamination is evident, or If scuff sanding produces any topcoat delamination, it will be necessary to refinish these surfaces as well, according to the procedures. It should not be necessary to paint inside of door jambs, or underneath exterior moldings or decals (sunshine stripes), as these areas are not normally subjected to continued ultraviolet exposure. 2. Sand original finish coat of paint down to electro-coat (Elpo) primer, making sure factory pretreatment and Elpo primer are still intact for good corrosion protection. DO NOT USE CHEMICALS TO REMOVE PAINT AS THIS MAY DAMAGE THE ELPO PRIMER. NOTICE: Rough tape vehicle as necessary (window glass, etc.), and remove nameplates, weatherstrips, and reveal moldings as needed to properly refinish all surfaces as required. 3. Finish sand exposed Elpo primer with 240 grit sandpaper to assure removal of any chalky residue or degraded Elpo primer that may remain as a result of overbaking the primer. NOTICE: Avoid sanding through Elpo to bare metal when possible. 4. Use an air gun to remove all dirt from cracks and surfaces of truck. Page 6853 FIGURE 2 3. Place tape on the fender edge and cowl panel edge to prevent paint damage (Figure No. 2) . 4. Disconnect the windshield washer hose from the nozzle. 5. Remove the cowl panel, being careful not to scrape the cowl on the inner hood edge or fender. 6. Pull back the hood hinge seal to expose the windshield frame and close the hood. 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 Locations Convenience Center Page 7103 Service and Repair Hydraulic Fluid Accumulator: Service and Repair Fig. 2 Removing Accumulator Do not attempt to repair or apply heat to the accumulator. Before discarding an inoperative accumulator, drill a 1/16 inch diameter hole through the end of the accumulator pan. Do not drill through the piston end. Always wear safety glasses when performing service on the accumulator. 1. Push pedal rod several times to ensure accumulator is depleted. 2. Secure brake booster mounting bracket in a vise with pedal rod facing downward. 3. Place accumulator compressor tool No. J-26889 or equivalent, over master cylinder stud and install retaining nut. 4. Using a C-clamp, depress accumulator can, then insert a punch into hole in housing to unseat retaining ring, Fig. 2. Remove ring from housing using a small screwdriver. If accumulator cannot easily be depressed approximately .10 inch, the accumulator is still charged. This indicates an internal problem with the accumulator valves and the brake booster must be disassembled. 5. Slowly back off C-clamp until tension is relieved, then remove C-clamp, retaining cap and accumulator. 6. Reverse procedure to assemble. Lubricate accumulator can seal with power steering fluid. Ensure accumulator can retaining ring is completely seated in housing groove. Page 2901 Idle Speed: Specifications Minimum Idle Air Rate Minimum Idle Air Rate Engine Speed Note: Let engine idle until proper fuel control status is closed loop. Manual Transmission Neutral 450 +/- 50 rpm Auto Transmission Drive 400 +/- 50 rpm Neutral 475 +/- 50 rpm Page 7509 Fuel Gauge: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. Figure 21 Figure 22 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. Page 3291 SERVICE PARTS INFORMATION Part Number Description 15664811 Vacuum Actuator Switch Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: K4120 Use applicable labor time guide for labor hours. Page 457 Wiring Diagram For Chart C-5 - Electronic Spark Control System Check CHART C-5 - ELECTRONIC SPARK CONTROL SYSTEM CHECK Circuit Description: Electronic spark control is accomplished with a module that sends a voltage signal to the ECM. As the knock sensor detects engine knock, the voltage from the ESC module to the ECM is shut "OFF" and this signals the ECM to retard timing, if engine RPM is over about 900. Test Description: Numbers below refer to circled numbers on the diagnostic chart. 1. If A Code 43 is not set, but a knock signal is indicated while running at 1500 RPM, listen for an internal engine noise. Under a no load condition there should not be any detonation, and if knock is indicated, an internal engine problem may exist. 2. Usually a knock signal can be generated by tapping on the right exhaust manifold. This test can also be performed at idle. Test number 1 was run at 1500 RPM to determine if a constant knock signal was present, which would affect engine performance. 3. This tests whether the knock signal is due to the sensor, a basic engine problem, or the ESC module. 4. If the module ground circuit is faulty, the ESC module will not function correctly. The test light should light indicating the ground circuit is OK. 5. Contacting CKT 496, with a test light to 12 volts, should generate a knock signal to determine whether the knock sensor is faulty, or the ESC module can't recognize a knock signal. Diagnostic Aids: "Scan" tools have two positions to diagnose the ESC system. The knock signal can be monitored to see if the knock sensor is detecting a knock condition and if the ESC module is functioning, knock signal should display "yes", whenever detonation is present. The knock retard position on the "Scan" displays the amount of spark retard the ECM is commanding. The ECM can retard the timing up to 20 degrees. This check should be used after other causes of spark knock have been checked such as engine timing, EGR systems, engine temperature or excessive engine noise. Page 7423 LIGHT BLUE LT BLU BROWN BRN GRAY GRY GREEN GRN DARK GREEN DK GRN LIGHT GREEN LT GRN ORANGE ORN PINK PNK PURPLE PPL RED RED TAN TAN WHITE WHT YELLOW YEL Drive Belt - Making Chirp Noise Drive Belt: All Technical Service Bulletins Drive Belt - Making Chirp Noise Number: 88-291-7A Section: 7A Date: JULY, 1988 Subject: SERPENTINE BELT CHIRP Model and Year: 1988 S/T TRUCKS W/4.3L (VIN CODE Z) ENGINE TO: ALL CHEVROLET DEALERS Some owners of 1988 4.3L S/T trucks may experience a chirping noise from the accessory drive belt. "Belt Chirp" is a short duration, intermittent, high pitched sound and should not be confused with belt "squeal", which is continuous in nature. This condition can be addressed by aligning the power steering pump pulley 3/4 mm plus or minus 1/4 mm (.030" plus or minus .010") forward of flush with the power steering pump shaft (See Illustration). A wheel puller should be used to perform this realignment. Labor Operation Number: T7460 Labor Time : .3 Hours Specifications Throttle Valve Cable/Linkage: Specifications Detent Cable, Retainer to Case ........................................................................................................... ..................................................................... 5-7 ft lbs Page 7254 Pontiac West: 1GNCT18ZOM0101419 Moraine: 1GNDT13Z6M2115163 Warranty Information For vehicles repaired under warranty use: Labor Operation: T7026 Labor Time: .4 hr. FAILURE CODE: 92 Add: .1 hr. to replace tire carrier striker Add .4 hr. to replace tire carrier arm NOTE: Labor Operation is coded to base vehicle coverage in the warranty system. A/T - 4L60/700-R4 Transmissions Stuck In First Governor Pressure Switch: All Technical Service Bulletins A/T - 4L60/700-R4 Transmissions Stuck In First Number: 91-371-7A Section: 7A Date: JULY 1991 Corporate Bulletin No.: 177113R Subject: TRANSMISSION STUCK IN FIRST GEAR Model and Year: 1982-91 CAPRICE, CAMARO AND CORVETTE 1982-91 C/K, G, S/T, 1985-91 M VAN 1987-91 R/V AND 1990-91 L VAN WITH 4L60 AUTOMATIC TRANSMISSION Figure 1 Bulletin Covers: Some HYDRA-MATIC 4L60/700-R4 transmissions may experience a "no upshift" or "stuck in first gear" condition. This may be caused by the input carrier to output shaft retaining ring coming unseated, or retaining ring omitted during assembly. This can allow the output shaft to move slightly, and cause wear on the governor gear (the governor gear ON THE GOVERNOR, not the governor drive gear on the output shaft). The governor gear wear may be described as an "apple cored" condition. If the governor gear is worn, the transmission cannot upshift out of first gear. Service Information: Remove the governor and inspect the governor gear. If it is "apple cored", disassemble the transmission and look for the presence of the input carrier to output shaft retaining ring. ^ If the retaining ring is missing, replace it, but make sure the original retaining ring is not broken and stuck inside the transmission. ^ If the retaining ring has become unseated, replace the retaining ring with a new one since the original has probably been over-expanded. When installing a new retaining ring, be careful not to over-expand the retaining ring. Service Parts Information: The input carrier to output shaft retaining ring is available in several packages through GMSPO. It is included in the snap ring package, overhaul repair components package, and overhaul seals and gasket package. Page 4235 Pinion Bearing: Adjustments Timken/Rockwell - 12 Inch Ring Gear Fig. 1 Timken/Rockwell drive axle w/12 inch ring gear exploded view DISASSEMBLY 1. Tap or press pinion from cage, taking care not to damage shaft threads, then remove outer pinion bearing, Fig. 1. 2. Remove spacer from pinion, then the inner bearing, using suitable separator and press or puller. 3. If straddle bearing must be replaced, remove snap ring and washer, then the bearing, using suitable puller. 4. If bearings are to be replaced, press outer races from bearing cage, taking care not to distort cage. 5. Inspect components as outlined, and replace as needed, keeping components in order for assembly. ASSEMBLY & PRELOAD ADJUSTMENT 1. When installing new cups, press them firmly against pinion bearing cage shoulders. 2. Lubricate bearings and cups with suitable lubricant. 3. Press rear thrust and radial bearings firmly against pinion shoulders, using suitable sleeve that will bear only on bearing inner race. 4. Install radial bearing lock ring, then squeeze ring into pinion shaft groove. 5. Insert pinion and bearing assembly in pinion cage and position spacer or spacer combination over pinion shaft. 6. Press front bearing firmly against spacer. Page 2621 Manifold Pressure/Vacuum Sensor: Testing and Inspection Chart C-1D - Manifold Absolute Pressure (MAP) Output Check Number 1 Cylinder Location Number One Cylinder: Locations Number 1 Cylinder Location NUMBER ONE CYLINDER LOCATION Locations Combination Switch: Locations LH Side Of Steering Column Behind Instrument Cluster Page 4601 10. Case bolts (3) from the case halves. - Note the two longer bolts (16) and washers go into doweled case holes (33). - Separate case halves, insert screwdrivers into the slot cast in the case ends and pry apart. Do not attempt to wedge the case halves apart at any point on the mating surfaces. - Be careful not to damage the oil pump (12) (located in the rear case half) while removing the rear case half (17). Internal Components 11. Fork shift spring (52). 12. Mainshaft (19)/drive sprocket 14071703 (20), chain (58) and front output shaft (21) as a unit. Mode shift fork (54) and shift rail (48) will be removed with the mainshaft. INSPECT: The teeth of the synchronizer stop ring (28) and drive sprocket (20) for damage. If they are damaged, or in cases of customer complaint of clash when shifting from 2Hi to 4Hi, follow steps 13, 14 & 15, otherwise skip to step 16. 13. Retainer (snag ring) (83) from the mainshaft (19). 14. Synchronizer assembly (81). 15. Drive sprocket (20) from the mainshaft (19). 16. Range shift fork (51), range shift hub (34) and sector with shaft (55) from the planetary carrier (36). - It is necessary to rotate the sector with shaft (55) to obtain clearance when removing the range fork (51). 17. Plastic washer (retainer) (66) and O-ring seal (67) from the front case half. IMPORTANT: Group B vehicles should complete step 17 and skip to INSTALL step 8. 18. Input bearing retainer bolts (43) and input bearing retainer (44) from the front case half (45). 19. Retainer snap ring from the input gear (38). 20. Planetary carrier (36) and the input gear (38) from the annulus gear (62) using a soft hammer. 21. Input bearing retainer (39) and input bearing (40). 22. Front output bearing retainer ring (snap ring) (60). 23. Front output bearing (61) from the front case half (45) using J33790, and J8092. 24. Seal (42) from the input bearing retainer (44) if it shows signs of damage. Install Page 6500 Disclaimer Page 8191 Wiper Motor: Description and Operation Rectangular Motor Fig. 1 Rectangular windshield wiper motor. Shown w/washer pump installed Fig. 2 Rectangular windshield wiper motor electrical connections The rectangular motor, Fig. 1, consists of an armature, brush plate assembly, field coils and a housing which is attached to a gear housing. The motor electrical connections, park switch, and on some models a washer pump are also mounted on the gearbox. A gear on the commutator end of the armature drives an intermediate gear and pinion assembly, which in turn drives the output shaft. A crank arm on the output shaft operates wipers through a pivot link (transmission) assembly. When ignition is on, battery voltage is supplied to motor terminal 2, Fig. 2. Current flows through the series field to a splice where it is divided, and part passes through the armature and part through the shunt field. The armature and shunt field circuits are completed to ground through the wiper switch , with motor speeds determined by resistance in the shunt field ground path. Placing wiper switch in low position, grounds motor terminals 1 and 3, Fig. 2, at the wiper switch. Shunt field current flows directly to ground through terminal 3, armature current flows to ground through terminal 1 and the motor runs at low speed. Placing wiper switch in high position grounds terminal 1, but terminal 3 remains open. Armature current flows directly to ground through terminal 1, shunt field current flows to ground through a resistor connected between terminals 1 and 3, and the motor runs at high speed due to the weakened shunt field. When wiper switch is turned off, and wipers are not in park position, terminal 1 is grounded through the closed motor park switch contacts. Terminals 1 and 3 are connected through the wiper switch, and the motor runs at low speed. When wipers reach their lowest point of travel, a cam on the motor output shaft opens the park switch, and the motor stops. On models with pulse wipers, a pulse control module provides a delay wipe mode through the low speed circuit. When wiper control is in delay position, battery voltage is supplied to a capacitor in the module through a variable resistor. When the capacitor is fully charged, it activates a switching circuit which provides a ground to begin wiper operation. As the motor operates, park switch contacts close, the capacitor discharges, and the motor ground is maintained through the park switch. When wipers complete their cycle, the park switch opens and the capacitor begins to recharge. Delay between wipe cycles is determined by a variable resistor, which controls charging current to the capacitor. Higher resistance produces a longer delay. M/T - Shift Lever Vibration/Rattle In Third Gear Shifter M/T: Customer Interest M/T - Shift Lever Vibration/Rattle In Third Gear Number: 89-169-7B Section: 7B Date: May, 1989 Subject: THIRD GEAR SHIFT LEVER VIBRATION/RATTLE Model and Year: 1986-89 S/T TRUCKS W/BORG WARNER FIVE SPEED MAN TRANSMISSION Figure 1 - Identification Tag Explanation Chart TO: ALL CHEVROLET DEALERS Some 1986-89 S/T Trucks may experience a shift lever vibration while the vehicle is in third gear. This condition may also be described as a rattle. The vibration may be most prominent on a coast down (deceleration) while in third gear. Production Change A new design shift lever was put Into production during the 1989 model year. Vehicles which have the new design lever can be identified by the serial number on the transmission identification tag. An example of the tag and its location on the transmission is shown in Figure 1. Vehicles with transmission serial numbers equal to or higher than those given below have the new design lever. Vehicle Serial Number Breakpoint T Series 21564 Page 3121 Throttle Body: Description and Operation IAC Valve Operation And Fuel Pressure Regulation The Throttle Body Injector (TBI) unit is made up of two major castings: a throttle body and a fuel body. The throttle body contains an Idle Air Control (IAC) valve to control idle air flow and a throttle position sensor mounted on the throttle valve shaft. The fuel body contains a fuel meter cover with an integral fuel pressure regulator to maintain constant fuel pressure and an injector on 4 cylinder models or injectors on V6 and V8 models. The throttle body portion of the TBI may also contain several ports located above or below the throttle valve(s) to provide vacuum signals to various vacuum operated equipment. Each fuel injector is a solenoid operated device controlled by the ECM. Incoming fuel is directed towards the lower end of the injector assembly, Fig. 2. When the ECM actuates the injector solenoid, the normally closed ball valve is lifted off its seat and pressurized fuel is injected in a conical spray pattern at the TBI bore wall(s) above the throttle valve(s). Excess fuel is routed through the pressure regulator before being returned to the fuel tank. The fuel pressure regulator is integral with the TBI fuel meter cover and is serviced as an assembly with the meter cover only. Page 6561 Body - Marks/Stains on Windshield When Wet Windshield: All Technical Service Bulletins Body - Marks/Stains on Windshield When Wet TECHNICAL Bulletin No.: 09-08-48-002A Date: March 19, 2009 Subject: Marks/Stains on Windshield When Wet (Clean Windshield) Models: 2010 and Prior Passenger Cars and Trucks (Including Saturn and Saab) 2010 and Prior HUMMER H2, H3 Supercede: This bulletin is being revised to update the models and model years. Please discard Corporate Bulletin Number 09-08-48-002 (Section 08 - Body and Accessories). Condition Some owners may comment that marks/stains appear on the windshield when the windshield is wet. Cause This condition may be caused by contact between the windshield and the vacuum hoses or other tools used in the assembly process. This contact may leave a residue that creates a water repellent surface on the glass which, in wet conditions, appear as marks/stains on the surface. Correction Important DO NOT REPLACE THE WINDSHIELD FOR THIS CONDITION. To clean the windshield, use Eastwood Glass Polishing Compound*. Follow the manufacturer's directions for product use. Use only hand tools. DO NOT USE POWER TOOLS. Parts Information Eastwood Glass Polishing Compound 1-800-343-9353 (for overseas inquiries: +1-610-705-2200) http://www.eastwoodco.com/ *We believe this source 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 from this firm or for any such items which may be available from other sources. Warranty Information For vehicles repaired under warranty, use the table above. Disclaimer ECM/PCM - Damaged and/or Misdiagnosed Engine Control Module: All Technical Service Bulletins ECM/PCM - Damaged and/or Misdiagnosed Number: 91-384-6E Section: 6E Date: AUGUST 1991 Corporate Bulletin No.: 176503 Subject: DAMAGED ECM/PCM AND/OR MIS-DIAGNOSED ECM/PCM SYMPTOMS DUE TO INCORRECT "TAP-TESTING" PROCEDURES Model and Year: 1982-91 ALL PASSENGER CARS AND TRUCKS CONDITION: Because of the intermittent nature of some Electronic Control Module (ECM) or Powertrain Control Modules (PCM) symptoms, some service technicians have been subjecting the ECM/PCM to vibration and/or shock testing. Commonly known as tap-testing, this procedure involves tapping on the ECM/PCM case, while the engine is running. It is generally accepted that if the engine or ECM/PCM falters due to the tapping, an intermittent internal ECM/PCM defect may be indicated. However, this may not always be true. If too much force is applied to the ECM/PCM during the test the following symptoms may result: ^ Immediate ECM/PCM failure. ^ ECM/PCM suffers damage which may cause a failure at a later date. ^ ECM/PCM Reset (or Glitch), creating a momentary stall, miss Service Engine Soon (SES) light and/or loss of serial data. CAUSE: The ECM/PCM should be tapped using only the fingertips of one hand. Use of the palm, fist, or any type of tool subjects the ECM/PCM to forces that can cause both the circuit board and the outer aluminum case to flex and distort beyond design limits. The Integrated Circuits (IC) used in today's ECM/PCMs are mounted to the circuit board using a mounting process referred to as "surface technology." There are no circuit board holes for IC leads to go through. The IC leads set on pads, (28 pads or 52 pads depending on the IC) and solder is flowed around the leads to make the electrical connection to the circuit board. ^ Any flexing of the circuit board, beyond design limits, places the IC solder connections at risk of damage. Such damage may be apparent immediately, or it may appear at a future date. Circuit board deflection can occur as a result of striking the ECM/PCM, using ONLY THE PALM OF THE HAND. ^ If struck on the bottom side (the side opposite the service label), the ECM/PCM's aluminum outer case may deflect inward far enough to contact the electrical leads attached to the circuit board. Once in contact with the case the ECM/PCM electrical components will be shorted directly to ground. Although such shorting certainly has the potential to damage the ECM/PCM, it may not be permanent damage, depending on which circuit is involved. However, even if permanent damage is avoided, a short on any of the circuits will cause a disruption of normal ECM/PCM operation for the instant that the short occurs. This disruption may cause the ECM/PCM to reset (see "reset" above), creating the false impression that it is vibration sensitive or faulty. Reset is the ECM/PCM's normal way of coping with large voltage spikes. An ECM/PCM reset does not indicate that the ECM/PCM is defective or faulty, only that it is being subjected to abnormal conditions. CORRECTION: 1. TAP THE ECM/PCM ONLY ON THE TOP SIDE (The top side is where the service label is located.) ^ This will minimize the chance of deflecting the ECM/PCM case into the electrical leads on the circuit board. The clearance between the case and the circuit board is closest on the bottom side of the ECM/PCM. 2. TAP THE ECM/PCM USING ONLY THE FINGERTIPS - NO TOOLS. ^ To avoid excessive case deflection, avoid tapping in the center of the case. Tapping close to the edge of the ECM/PCM, especially in the corners, is best. ^ While using greater force may seem more effective, the test itself may cause the ECM/PCM to fail. Page 173 ECM Connector Terminal Identification & Voltage Specifications. Torque Spark Plug: Specifications Spark Plugs 22 ft.lb Instrument Panel - Upper Surface Cleaning Instrument Cluster / Carrier: All Technical Service Bulletins Instrument Panel - Upper Surface Cleaning Number: 91-285-0A Section: 0A Date: APRIL 1991 Corporate Bulletin No.: 101003 Subject: CLEANING OF UPPER INSTRUMENT PANEL SURFACES Model and Year: ALL PASSENGER CARS AND TRUCKS ALL YEARS Comments on reflection into the windshield of the upper instrument panel may be received. The condition of instrument panel reflection into the windshield in direct sunlight may be aggravated by dealers and owners applying a wax or silicone base material to the pad surface. The higher gloss of such application results in a "veiling reflection" in the windshield. Advise customers and new car make ready area that materials containing wax or silicone should not be used to clean the instrument panel pad. A warm water and mild soap solution such as saddle soap, oil soap, or an equivalent should be used whenever the instrument panel pad needs cleaning. A/T - 2004R/700R4 Oil Pump & Slide Service Fluid Pump: Technical Service Bulletins A/T - 2004R/700R4 Oil Pump & Slide Service SIL 86-27 (Nov) SUBJECT: 200 R4/700 4R SERVICE PROCEDURES FOR THE OIL PUMP ROTOR & SLIDE Beginning mid November, 1983, service parts became available to service the oil pump rotor and slide of the pump body assembly, on all THM 200-4R and 700-R4 transmissions. This service procedure on all THM 200-4R and 700-R4 transmissions must be followed to assure proper end clearance on the oil pump rotor and slide. SERVICE PROCEDURE: Note DO NOT attempt to service the oil pump rotor if either the pump body pocket or pump body cover surfaces are scored. Servicing of the oil pump rotor and slide should be performed ONLY if the selective pump rotor, or the slide show wear. 1. Disassembly of the oil pump: A. Disassemble the oil pump body assembly following procedures outlined in the service manual. Refer to Figure 1 for the THM 200-4R and Figure 2 for the THM 700-R4 transmission oil pump body assembly. 2. Selecting the pump rotor and slide: Page 6188 Compressor Shaft Seal: Service and Repair With HR-6 Compressor HR-6 Component View Remove or Disconnect Tools Required: J 5403 Snap Ring Pliers J 34614 Shaft Seal Protector J 23128-A Seal Remover and Installer J 9553-01 O-Ring Seal Remover. 1. Clutch plate and hub assembly (2). ^ Install J 34614 over the threaded end of the shaft (20). Locations Oil Pressure Switch Page 6559 Box 1 Verify that the condition is present, then disconnect any non-factory add-on electronics, (not including the radio) Box 2 If the condition goes away when a particular device is disconnected, reconnect the device to verify it as the source of the interference. If the condition is related to non-factory add-on electronics, consult the GM installation guidelines (See Box 6) as an example of how to add an electronic component to the vehicle's electrical system. Box 3 If the condition is ONLY present with the engine running, disconnect electrical components that are active only with the engine running. The charging system, various solenoids, and relays may be intermittently disconnected while observing the condition. In some cases a component cannot be disconnected while the engine is running. In these cases, the component can be tested independent of the vehicle (i.e. fuel injectors). For further tips on engine noise diagnostics refer to the Delco Sound Service Guide, Engine Noise Chart. Box 4 If the condition can be eliminated and the interference isolated to a component, determine if a bulletin has been published concerning this particular condition. Contact your Technical Assistance Group for additional information if no bulletins are found. Box 5 If the concern cannot be eliminated by testing in any key position and by disconnecting fuses and components, the condition most likely is not RFI. Refer to the Delco Sound Service Guide or the vehicle service manual for further diagnostic tips and check for any published bulletins. If the concern cannot be identified or eliminated, contact your Technical Assistance Group for further assistance. Box 6 The "Installation Guidelines for Aftermarket Accessories" for all model years and all trucks and carlines are located in the following Service Bulletin 91-8-2. Also, there may be separate installation guidelines for cellular phones. A search for service bulletins may be necessary to find these. Page 5275 Tighten Tighten to 8 Nm (71 lb in). Note The repair area MUST BE properly refinished to maintain a secure, stable and corrosion-free electrical ground. 12. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 13. Verify proper system operation. M8 Weld Nut Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M8 weld nut electrical ground location is accessible from both sides of the panel, a M8 conductive bolt and a M8 conductive nut may be used to secure the electrical ground wire terminal. Refer to the Parts Information section of this bulletin. 2. Select a location adjacent the M8 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the new electrical ground site. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the ground location and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 10 mm (0.40 in) diameter hole through the panel. 5. Remove paint and primer from the area surrounding the 10 mm (0.40 in) hole until bare metal is visible. 6. Select a M8 conductive bolt. Refer to the Parts Information section of this bulletin. 7. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M8 conductive bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 8. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 9. Install the electrical ground wire terminal and the M8 conductive bolt to the ground location. 10. Select a M8 conductive nut. Refer to the Parts Information section of this bulletin. 11. Install the M8 conductive nut to the bolt and: Tighten Tighten to 22 Nm (16 lb ft). Note The repair area MUST BE properly refinished to maintain a secure, stable and corrosion-free electrical ground. 12. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 13. Verify proper system operation. M8 Weld Nut Alternative Repair Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M8 weld nut electrical ground location is not accessible from both sides of the panel, a M6 conductive rivet stud and a M6 conductive nut may be used to secure the electrical ground wire terminal. 2. Select a location adjacent the damaged M8 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the M6 conductive rivet stud flange. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the repair site and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 10 mm (0.40 in) diameter hole through the panel. Page 5051 CLEANING/INSPECTION Fig. 4 Spool valve inspection 1. Clean all parts in a suitable solvent being careful to avoid losing small parts. 2. Inspect valve spool and valve spool bore in booster housing for corrosion, nicks, scoring or other damage. Discoloration of the spool or bore, particularly in the grooves, is not harmful. 3. If the valve spool or the spool bore has nicks or scoring that can be felt with a fingernail, particularly on the hands, the spool and housing should be replaced as an assembly, Fig. 4. The clearance between the valve spool and the spool bore of the housing is important. Because of this, the spool and housing make are made as a selective assembly and therefore can only be replaced as an assembly. 4. Inspect the input rod and piston assembly for corrosion, nicks, scoring or excessive wear. If the piston is damaged, the input rod and piston assembly should be replaced. 5. Inspect piston bore in booster housing for corrosion, nicks, scoring or other damage. If the bore is damaged, the valve spool and housing should be replaced as an assembly. ASSEMBLY Lubricate all the seals and metal friction points with power steering fluid. 1. Install return line seal, then the fitting Fig. 3. 2. Install accumulator valve and spool valve into housing. 3. Install seal on piston assembly using seal protector tool No. J-25083 or equivalent. 4. Install seal onto the housing, then install cover and bolts. Torque housing bolts to 22 ft. lbs. 5. Install bracket and nut, then torque to 110 ft. lbs. 6. Install boot, output pushrod, baffle, piston return spring, and retainer using seal protector tool No. 2455l or equivalent. 7. Install retainer, spring, O-ring, and plug, using accumulator compressor tool No. J-26889 or equivalent, and C-clamp. 8. Depress the accumulator, then install the retainer and remove C-clamp. 9. Jam nut from the repair kit onto pedal rod, and install eyelet onto pedal rod. 10. Adjust eyelet to required length. Hydro-Boost II Assembly DISASSEMBLY/ASSEMBLY Locations Throttle Position Sensor: Locations Center Of Dash Panel (engine Compartment) Center Rear Of Engine Applicable to: V6-262/4.3L Engine Page 4236 7. Rotate cage several revolutions to assure normal bearing contact. 8. Press flange or yoke against forward bearing and install washer and pinion shaft nut. 9. Place pinion and cage assembly over carrier studs, hold flange with suitable tool, and torque pinion shaft nut to 350 ft. lbs. 10. Check pinion bearing preload torque. If rotating torque is not within 5 to 15 pound inches, disassemble, adjust spacer, reassemble, and recheck preload torque. Use thinner spacer to increase or thicker spacer to decrease preload. 11. Hold flange with suitable tool and remove pinion shaft nut and flange. 12. Lubricate pinion shaft oil seal and cover outer edge of seal body with non-hardening sealing compound, then press seal against cover shoulder with suitable tool. 13. Install new gasket and bearing cover. 14. Press flange against forward bearing and install washer and pinion shaft nut, torquing nut to 350 ft. lbs. Page 1521 Rocker Arm Assembly: Service and Repair Rocker Arms & Pushrods 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 as described under ADJUSTMENT PROCEDURES/VALVES. Page 5108 Figure 8 Figure 9 Figure 10 Figure 11 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). Page 3051 Fuel Pressure: Testing and Inspection NOTE: A fuel system pressure test is part of several of the Diagnostic Charts and Symptom Checks. To perform this test, follow this procedure: FUEL PRESSURE TEST 1. Turn engine OFF to relieve system pressure. 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. - The constant bleed feature relieves fuel pump system pressure when the engine is turned "OFF". 2. Uncouple fuel supply flexible hose in engine compartment. Install fuel pressure gauge between steel line and flexible hose. 3. Tighten gauge in line to insure no leaks occur during testing. 4. Connect negative battery terminal and START engine and observe fuel pressure reading. It should be 62-90 kPa (9-13 psi). If not, refer to DIAGNOSTIC CHARTS/FUEL SYSTEM PRESSURE TEST (CHART A-6). 5. Turn engine OFF to relieve system pressure. 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. - The constant bleed feature relieves fuel pump system pressure when the engine is turned "OFF". 6. Remove fuel pressure gauge. 7. Reinstall fuel line. 8. Connect negative battery terminal and START engine and check for fuel leaks. 9. Install air cleaner assembly. Transmission Mount - Idle Shake or Vibration Transmission Mount: All Technical Service Bulletins Transmission Mount - Idle Shake or Vibration Number: 91-16-7A Section: 7A Date: May 1990 Corp. Bulletin No: 066101 Subject: IDLE SHAKE OR VIBRATION Model and Year: 1988-91 S1 TRUCKS Some 1988-91 S truck (two wheel drive) and 2 door utility models equipped with 4.3L engines and either automatic or manual transmissions, may experience an idle shake or vibration. This condition is most noticeable at engine speeds below 1500 RPM. Page 2296 Ignition Control Module: Service and Repair Typical Distributor Components REMOVAL: 1. Remove distributor cap and rotor. 2. Remove two module attaching screws, and lift module up. 3. Disconnect leads from module. Observe color code on leads as these cannot be interchanged. 4. Remove module. INSTALLATION: NOTE: Be sure there is a sufficient amount of silicone grease on the metal face of the module and on the distributor base (where the module seats), when reinstalling the module. The purpose of the silicone grease is to cool the module. 1. Install module. 2. Connect leads to module. 3. Install module attaching screws. 4. Install pick up coil. 5. Install cap and rotor. Engine - Miss, Hesitation, or Roughness Spark Plug Wire: All Technical Service Bulletins Engine - Miss, Hesitation, or Roughness Number: 93-35-6D Section: 6D Date: OCT. 1992 Corporate Bulletin No.: 716404R ASE No.: A1, A8 Subject: ENGINE MISS HESITATION OR ROUGHNESS DUE TO PIERCED SECONDARY IGNITION COMPONENTS Model and Year: 1980-93 ALL PASSENGER CARS AND TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 87-121, DATED MAY 1987. THE 1989-93 MODEL YEARS HAVE BEEN ADDED. ALL COPIES OF 87-121 SHOULD BE DISCARDED. During the diagnosis procedure for an engine miss, hesitation or roughness, a spark plug or spark plug wire condition may be suspected. Several types of commercial or homemade diagnostic equipment required the secondary ignition boots or wire to be pierced. This is normally done to check for spark plug firing or to perform a cylinder balance test. Similarly the use of pliers or other such tools to disengage a spark plug boot may pierce or damage the boot or wire. Secondary ignition components should not be pierced for any reason. Piercing a spark plug wire and/or distributor boot may create a condition that will not be immediately apparent. Over time, the hole in the pierced boot may allow a ground path to develop creating a plug misfire condition. Heavily moisture laden air in the vicinity of the pierced boot may accelerate this effect. Piercing a secondary ignition wire creates a gap in the wire's conductive core. This gap is a point of high resistance. The current flow in the wire will increase to compensate for the higher wire resistance. Over time, the wire may fail creating a plug misfire condition. The time required for the condition to appear depends upon the extent of damage to the conductive core. To help prevent future condition that are spark plug wire related, do not pierce or otherwise damage any secondary ignition component. Only use diagnostic equipment containing an inductive pick-up to check for spark plug firing or to perform cylinder balance tests. When disengaging a spark plug boot from the spark plug, twist the flanged boot 1/2 turn then pull on the boot only to remove the wire. Page 8061 movement. Refer to Dealer Service Bulletin Number 91-181-10, Dated February 1991. Engine - Miss, Hesitation, or Roughness Spark Plug Wire: All Technical Service Bulletins Engine - Miss, Hesitation, or Roughness Number: 93-35-6D Section: 6D Date: OCT. 1992 Corporate Bulletin No.: 716404R ASE No.: A1, A8 Subject: ENGINE MISS HESITATION OR ROUGHNESS DUE TO PIERCED SECONDARY IGNITION COMPONENTS Model and Year: 1980-93 ALL PASSENGER CARS AND TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 87-121, DATED MAY 1987. THE 1989-93 MODEL YEARS HAVE BEEN ADDED. ALL COPIES OF 87-121 SHOULD BE DISCARDED. During the diagnosis procedure for an engine miss, hesitation or roughness, a spark plug or spark plug wire condition may be suspected. Several types of commercial or homemade diagnostic equipment required the secondary ignition boots or wire to be pierced. This is normally done to check for spark plug firing or to perform a cylinder balance test. Similarly the use of pliers or other such tools to disengage a spark plug boot may pierce or damage the boot or wire. Secondary ignition components should not be pierced for any reason. Piercing a spark plug wire and/or distributor boot may create a condition that will not be immediately apparent. Over time, the hole in the pierced boot may allow a ground path to develop creating a plug misfire condition. Heavily moisture laden air in the vicinity of the pierced boot may accelerate this effect. Piercing a secondary ignition wire creates a gap in the wire's conductive core. This gap is a point of high resistance. The current flow in the wire will increase to compensate for the higher wire resistance. Over time, the wire may fail creating a plug misfire condition. The time required for the condition to appear depends upon the extent of damage to the conductive core. To help prevent future condition that are spark plug wire related, do not pierce or otherwise damage any secondary ignition component. Only use diagnostic equipment containing an inductive pick-up to check for spark plug firing or to perform cylinder balance tests. When disengaging a spark plug boot from the spark plug, twist the flanged boot 1/2 turn then pull on the boot only to remove the wire. Page 1385 II. OVER TORQUING OF WHEEL NUTS: 1. A TORQUE WRENCH MUST BE USED to insure that the wheel nuts are tightened to specification. This should be done in two steps using the star pattern. First, snug the nuts down by hand. Then, using the star pattern and a torque wrench, tighten the wheel nuts to about half the final torque. Finally, tighten the wheel nuts to specification using the star pattern and a torque wrench. 2. NEVER use lubricants or penetrating fluids on wheel studs, nuts, or mounting surfaces, as this can raise the actual torque on the nut without a corresponding torque reading on the wrench. Wheel nuts, studs, and mounting surfaces must be clean and dry. Page 4189 Whenever it is determined that one washer is worn, all three thrust washers should be replaced with kit P/N 26018721, that contains all three thrust washers. Parts are currently available from GMSPO. The kit should be used to resolve T Model front axle growl noise conditions. For vehicles under warranty, use: Labor Operations: F2115 Labor Time: 1.4 Hrs (plus applicable "adds") Page 1078 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) A/T - New Trans Fluid, Dexron IIE Fluid - A/T: All Technical Service Bulletins A/T - New Trans Fluid, Dexron IIE Number: 92-26-7A Section: 7A Date: OCT. 1991 Corporate Bulletin No.: 177125 ASE No.: A2 Subject: DEXRON-IIE AUTOMATIC TRANSMISSION/TRANSAXLE FLUID Model and Year: 1976-92 ALL TRUCKS WITH AUTOMATIC TRANSMISSION TRANSMISSION APPLICATIONS: SUBJECT: All Automatic Transmissions DEXRON-IIE Automatic Transmission/Transaxle Fluid TRANSMISSION MODELS: VEHICLE APPLICATIONS: All All HYDRA-MATIC Automatic Transmissions/Transaxles Bulletin Covers: General Motors Corporation has developed a new service fill automatic transmission/transaxle fluid which is designated DEXRON-IIE. This fluid is the preferred fluid for all HYDRA-MATIC automatic transmission/transaxles and will eventually replace DEXRON II. DEXRON-IIE is acceptable for use wherever DEXRON II was previously specified. DEXRON II is acceptable for use when DEXRON-IIE is not available. DEXRON-IIE can be used in both electronically and hydraulically controlled transmissions/transaxles. DEXRON-IIE Advantages: ^ Has better anti-foaming characteristics. ^ Improved low temperature flow characteristics (low temperature viscosity) and improved high temperature oxidation stability. ^ DEXRON-IIE and DEXRON II can be mixed in any ratio. No draining or flushing of system is required. ^ DEXRON-IIE is back serviceable to 1949 for all General Motors automatic transmission/transaxles. ^ No change in transmission/transaxle calibration or reduction in transmission/transaxle durability will occur as a result of using DEXRON-IIE. Service Parts Information: PART NUMBER DESCRIPTION 12345881 1 quart container 12345882 1 gallon container 12345883 55 gallon drum Parts are currently available from GMSPO. Page 3986 FIGURE 1 If this condition is encountered, and cannot be corrected using normal diagnostics, a newly released rear transmission mount may be installed (see Figure 1). This rear transmission mount is currently in use on 1988-90 Cl, C2, and C3 pickups with 4.3 L engines and 3- speed automatic transmissions (M40). When installing this mount, new service washers (one washer per bolt) are required for retaining mount to transmission. Also install a new nut on the stud when attaching mount to cross member. IMPORTANT: This mount is not for use on 1991 S/T 4 door utility or any 1988-91 T model pickup or utility. PARTS INFORMATION PART NUMBER DESCRIPTION QUANTITY 15567796 Mount 1 15614758 Washer 2 Page 5425 2. If the latch is misaligned and/or the endgate glass is not snug against the weatherstrip, remove the endgate inner trim panel and loosen the latch assembly by adjusting the nuts located on the side of the latch assembly (Figure 1, Item 4). Adjust the location of the latch and tighten the adjusting nuts to 8.5-11.0 N-m (6-8 lbs.ft.). 3. Check the endgate window latch for proper operation. If necessary, repeat steps 1 and 2. REPLACEMENT PROCEDURE If the latch assembly is properly adjusted and the condition still occurs, the latch assembly should be replaced by performing the following steps: Page 1088 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 Electrical - Instrument Panel & General Wiring Repair Wiring Harness: All Technical Service Bulletins Electrical - Instrument Panel & General Wiring Repair Bulletin No.: 06-08-45-004 Date: May 02, 2006 INFORMATION Subject: Instrument Panel (I/P), Body and General Wiring Harness Repair Models: 2007 and Prior GM Cars and Trucks 2003-2007 HUMMER H2 2006-2007 HUMMER H3 Important: A part restriction has been implemented on all Body and I/P harnesses and is being administered by the PQC. If a body or I/P harness replacement is required, it can take 12-28 weeks for a harness to be built and delivered to a dealer. The dealer technician is expected to repair any harness damage as the first and best choice before replacing a harness. In an effort to standardize repair practices, General Motors is requiring that all wiring harnesses be repaired instead of replaced. If there is a question concerning which connector and/or terminal you are working on, refer to the information in the appropriate Connector End Views in SI. The Instruction Manual J 38125-620, which is sent with each new update of the J 38125 Terminal Repair Kit, also has terminal crimping and terminal remove information. Important: There are some parts in the J 38125 Terminal Repair Kit (i.e. SIR connector CPAs and heat shrink tube (used in high heat area pigtail replacement) and some TPAs that are not available from GMSPO. It is vitally important that each update to the J 38125 Terminal Repair Kit be done as soon as it arrives at the dealer. Utilize the Terminal Repair Kit (J 38125) to achieve an effective wiring repair. The Terminal Repair Kit has been an essential tool for all GM Dealers since 1987. Replacement terminals and tools for this kit are available through SPX/Kent Moore. Refer to Corporate Bulletin Number 06-08-45-001 for more information. The Instruction Manual J 38125-620, which is sent with each new update to the J 38125 Terminal Repair Kit, also has terminal crimping and terminal removal information. U.S. Dealers Only - Training courses (including Tech Assists, Emerging Issues, Web, IDL and Hands-on) are available through the GM Training website. Refer to Resources and then Training Materials for a complete list of available courses. Canadian Dealers Only - Refer to the Training section of GM infoNet for a complete list of available courses and a copy of the J 38125 Terminal Repair Kit Instruction Manual. Wiring repair information is also available in Service Information (SI). The Wiring Repair section contains information for the following types of wiring repairs: - Testing for intermittent conditions and poor conditions - Flat wire repairs - GMLAN wiring repairs - High temperature wiring repairs - Splicing copper wire using splice clips - Splicing copper wire using splice sleeves - Splicing twisted or shielded cable - Splicing inline harness diodes Page 7576 AC Delco Service Centers Page 5998 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 Page 284 Fuel Gauge Sender: Service and Repair Fuel Pump And Sender Assembly (Typical) REMOVAL: 1. Disconnect the negative battery cable. 2. Raise vehicle. 3. Remove fuel tank. Refer to FUEL TANK ASSEMBLY. 4. Remove pump and sending unit assembly by turning the cam lock counterclockwise using tool J-36608 or J-24187 or equivalent. ^ Pull the fuel pump up into the attaching hose while pulling outward from the bottom support. ^ Do not damage the rubber insulator or the strainer. INSPECTION: 1. Inspect the fuel pump attaching hose for signs of deterioration. 2. Inspect the rubber sound insulation at the bottom of the pump for deterioration. INSTALLATION: 1. Install pump assembly into the attaching hose. NOTE: Care should be taken not to fold over or twist the strainer, when installing the sending unit as this will restrict fuel flow. 2. Install sending unit and fuel pump assembly into the fuel tank. (Always use a new O-ring seal). 3. Install the cam lock assembly. Turn the cam lock clockwise to lock it. 4. Install fuel tank assembly. 5. Connect the negative battery cable. 6. START vehicle and check for fuel leaks. Diagnostic Trouble Code Descriptions Instrument Cluster / Carrier: Diagnostic Trouble Code Descriptions For information regarding B, C, P, U and Manufacturer Code Descriptions - Generator Light - Flickers During Pulse Wiper Use Charge Lamp/Indicator: All Technical Service Bulletins Generator Light - Flickers During Pulse Wiper Use Number: 90-84-8A Section: 8A Date: November 1989 Corporate Bulletin No: 966402 Subject: GENERATOR LIGHT FLICKER DURING PULSE WIPER OPERATION Model and Year: 1988-89 S, T TRUCKS WITH 2.8L OR 4.3L (VIN CODES R, Z) ENGINES TO: ALL CHEVROLET DEALERS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 89-219-8A, DATED JULY 1989. THE 1990 MODEL S/T VEHICLES ARE INCLUDED IN THE LATEST BULLETIN ALONG WITH A CORRECTION TO THE ELECTRICAL CONNECTOR NUMBER. ALL COPIES OF 89-219-8A SHOULD BE DISCARDED. The generator light flicker condition during pulse wiper switch operation in the 1988, 1989 and 1990 S/T instrument panel, with standard cluster, can be caused by negative voltage transients from the wiper motor. There is no possibility of a system failure as a result of this condition. The effect of this condition is that the generator light will turn on for 80 milliseconds (if gages, the voltage drop on the voltmeter lasts 2.5 seconds). This causes no harm to the generator or other electrical components. Subject condition can be eliminated by installing a diode (industry part number 1N4003) or diode/connector kit (diode kit part number 12085207) in the brown wire at the generator connector (circuit 25 at connector C118). See the following pages in the 1988, 89 and 90 S/T Electrical Wiring Diagrams for circuit 25, connector C118 locations: 1988 4.3L: Section C - Page 24 1988 2.8L: Section C - Page 22 1989 4.3L: Page 40 1989 2.8L: Page 39 1990 2.8L: Page 44 1990 4.3L: Page 45 PARTS INFORMATION: Quantity Part Number Description 1 12085207 Diode ----OR---1 *1N4003 Diode * This part available locally. Parts are currently available from GMSPO. INSTALLATION PROCEDURE: 1. Disconnect the battery. 2. Remove the connector from the generator. 3. Peel back the black plastic conduit covering the wires. 4. If installing diode 1N4003: cut out a section of the brown wire that matches the length of the diode. 4A. A diode/connector kit is also available (GMSPO diode kit part number 12085207). If using the kit cut out approximately four inches of the brown wire, following crimping and soldering instructions in the kit. Spiral tape the solder joints and tuck the wire back into the conduit away from the generator. Secure the diode/connector to the outside of the conduit with electrical tape. 5. Solder in diode with the banded end toward the generator. Page 6288 Page 6906 Disclaimer Tire - Tread Chunking/Torn bead Tires: All Technical Service Bulletins Tire - Tread Chunking/Torn bead Number: 91-171-3E Section: 3E Date: January 1991 Corp. Bulletin No.: 993501R Subject: TIRE DAMAGE CAUSED IN GM ASSEMBLY PLANTS - TREAD CHUNKING TORN BEAD Model and Year: 1988-91 PASSENGER CARS AND TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 90-52-3E, DATED OCTOBER 1989. THE 1991 MODEL YEAR HAS BEEN ADDED. ALL COPIES OF 90-52-3E SHOULD BE DISCARDED. Isolated incidents of the following types of tire damage have recently been reported from the field. Any such damage would be present at time of delivery to the dealer. The probable cause of some of this damage has been traced to the assembly plant. Since such tire conditions are usually not the fault of the tire manufacturer, any tires requiring replacement for these reasons should be considered GM's responsibility. Assembly plant damage should not be confused with transportation damage, which continues to be the responsibility of the transportation company. The purpose of this bulletin is to help identify assembly plant tire damage. Tread Chunking This condition is identified by small pieces of tread rubber torn or "chunked" out of the tire. This usually occurs in one area of the tread, although more than one area is possible. The missing tread rubber should be apparent upon visual inspection. It can also usually be detected as a once-per-rev tire noise upon road testing. This condition can happen in the assembly plant during the end of line line roll test. Hard braking such that the tire locks up on the roll could be the cause, although other variables during the roll test can also be factors. Other types of tire tread damage noted at delivery should be considered transportation damage. Torn Bead Rubber This condition is usually not visible unless the tire is dismounted from the wheel and, therefore, may not be detected during new vehicle inspection. Depending on the extent of the tear, the condition may later be detected as a slow air loss, or a slight sidewall bulge. If the tire is dismounted from the wheel and bead rubber is torn, it is possible that this damage occurred in the assembly plant during tire mounting. If it happened in the plant, the tear will usually be on the inboard (blackwall) side of the tire. There should also be evidence of two tears, about 90 degrees apart, although one is usually much Page 3261 SPARK PLUGS Page 5522 Figure 4 Figure 5 Figure 6 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 7 Paint - Identification/Repair of Colorcoat Delamination Paint: All Technical Service Bulletins Paint - Identification/Repair of Colorcoat Delamination BULLETIN NUMBER: 92-1O-134A SECTION: 10 Body NUMBER: 4 CORPORATE REFERENCE NUMBER: 231054R DATE: July 1993 SUBJECT: SERVICE PROCEDURES FOR IDENTIFICATION AND REPAIR OF PAINT COLORCOAT DELAMINATION FROM ELPO PRIMER MODELS: 1988-92 TRUCKS THIS BULLETIN CANCELS AND REPLACES TRUCK SERVICE BULLETIN 92-10-134 (CORP # 231054R), DATED OCTOBER 1992. IT IS BEING REVISED TO REMOVE THE COVER LETTER PORTION AND SUBJECT STATEMENT NOW INCLUDES NOTE FOR TRUCKS AND REVISES THE MONOCOAT MATERIAL ALLOWANCES ON "G", "S/T" AND SOME "R/V" MODELS. THE ALLOWANCE FOR "ADD FOR TWO-TONE" ON G AND S/T TRUCKS HAS BEEN CHANGED. ALL COPIES OF 92-10-134 SHOULD BE DISCARDED. The revisions are the result of changes to the MONOCOAT (ENAMEL) material allowance charts published in June, 1993. Six (6) of the "G" model revisions use Basecoat/Clearcoat material allowance codes. THESE ARE TO BE USED AS DOLLAR REFERENCES ONLY, AND ARE MARKED WITH A # INDICATOR. Continue to repair these vehicles with monocoat materials. DO NOT repair these vehicles with Basecoat/Clearcoat products. Use the latest (June, 1993) material allowance charts when submitting claims. SUBJECT: Service procedures for the repair of paint colorcoat delamination from elpo primer (repaint entire body above the body side moldings, except trucks as noted). APPLICATION: 1988-1992 LIGHT DUTY TRUCKS (C/K, R/V, S/T, M/L AND G) This bulletin cancels and supersedes service procedures and time allowances on all previous bulletins regarding paint DELAMINATION. Due to the use of new procedures, add times for optional equipment, and designating specific hardware items for removal, the published labor times will not be the same as previously published. CONDITION This bulletin is being issued to assure that the correct procedure is followed to repair a condition known as DELAMINATION. Some of the above listed passenger cars, light duty trucks, and vans may have DELAMINATION (peeling) of the paint color-coat from the ELPO primer depending upon variable factors including prolonged exposure to sunlight and humidity. Blues, Grays, Silvers and Black Metallics are the colors that have the highest potential for this condition. On rare occasions, other colors may be involved. Important DELAMINATION is different than other paint conditions and/or damage. A proper problem identification is necessary, and the service procedure that follows is specific to the proper repair of DELAMINATION and must be followed. The information in this bulletin covers Paint DELAMINATION of the colorcoat from the ELPO primer ONLY. It does not address any other paint conditions. Procedures for the repair of other paint conditions (stone chips, scratches, environmental damage, clearcoat peeling, runs, dirt, fading, etc.) will not effectively repair DELAMINATION and customer dissatisfaction will result. CAUSE This condition may occur on vehicles produced in plants where the paint process does not call for application of a primer surfacer. Under certain conditions, ultraviolet light can penetrate the colorcoat, sometimes causing a reaction and separation of portions of the colorcoat from the ELPO (electrocoat) primer. PROBLEM IDENTIFICATION: Page 5716 14. Install lash adjuster locknut loosely. 15. To protect pitman shaft seal from damage, cover shaft splines with masking tape. Slide new seal into place and seat it against shoulder in housing. 16. Install new worm shaft seal flush with surface of housing. 17. Fill gear housing with multi-purpose lubricant and adjust gear assembly as outlined previously. Page 5899 new driven gear is required. Use (gray) 22 tooth driven gear (GM Part Number 3987922) if vehicle is equipped with L38 and GU6. Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: # T1612 Labor Time: 1.0 hr. FAILURE CODE: 92 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 Page 6581 Specifications Valve Clearance: Specifications All ......................................................................................................................................................... ................................................................ E-I-E-I-I-E Diagram Information and Instructions Blower Motor: Diagram Information and Instructions 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 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. Description and Operation Electronic Spark Timing: Description and Operation Varying octane levels in today's gasoline can cause detonation in engines. Detonation is sometimes called spark knock. To control spark knock an Electronic Spark Control (ESC) system has been added. This system is designed to retard spark timing up to 20~ to reduce spark knock in the engine. This allows the engine to use maximum spark advance to improve driveability and fuel economy. The ESC system has three major components: ^ ESC module ^ ESC knock sensor ^ ECM The ESC knock sensor detects abnormal vibration (spark knocking) in the engine. The sensor is mounted in the engine block near the cylinders. The ESC module receives the knock sensor information and sends a signal to the ECM. The ECM then adjusts the timing to reduce spark knocking. The ESC module sends a voltage signal (8 to 10 volts) to the ECM when no spark knocking is detected by the ESC knock sensor, and the ECM provides normal spark advance. When the knock sensor detects spark knock, the module turns "OFF" the circuit to the ECM. The ECM then retards EST to reduce spark knock. Loss of the ESC knock sensor signal or loss of ground at ESC module would cause the signal to the ECM to remain high. This condition would cause the ECM to control EST as if no spark knock were happening. No retard would occur, and spark knocking could become severe under heavy engine load conditions, possibly leading to pre-ignition and severe engine damage. Loss of the ESC signal to the ECM would cause the ECM to constantly retard EST. This could result in sluggish performance and cause a Code 43 to set. Spark retard without the knock sensor connected could indicate a noise signal on the wire to the ESC module or a malfunctioning ESC module. Page 5602 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 Page 6124 1. Shaft key (1). Positioning The Shaft Key, Clutch Plate, & Hub Assembly ^ Allow the shaft key (21) to extend 3.2 mm (1/8-inch) out of the bottom of the hub keyway. ^ The shaft key is curved slightly to give an interference fit in the groove. Important ^ Do not drive or pound on the clutch hub or the shaft (20). Internal damage to the compressor may result. 2. Clutch plate and hub assembly (2). ^ Make sure the contact surfaces of the clutch plate (2) and the pulley (5) are clean. ^ Remove the forcing screw tip from J 33013-B and reverse the body direction on the center screw. Installing The Clutch Plate & Hub Assembly ^ Install J 33013-B with bearing. ^ Back off J 33013-B body enough to allow the center screw to be threaded against the end of the compressor shaft. ^ Hold the center screw with a wrench and tighten the hex portion of J 33013-B body while pressing the hub onto the shaft. After tightening the body several turns, remove J 33013-B and check that the shaft key (21) is properly in place in the keyway, then install the clutch plate and hub assembly (2) to its final position. ^ Measure the air gap between contact surfaces of the clutch plate and hub assembly (2) and the pulley (5). The gap should be 0.38-0.64 mm (0.015-0.025-inch). 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 Diagram Information and Instructions Neutral Safety Switch: Diagram Information and Instructions 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 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. Page 1398 *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 Drive Axle (Front) - Will Not Disengage Transfer Case Actuator: All Technical Service Bulletins Drive Axle (Front) - Will Not Disengage Number: 91-476-4C Section: 4C Date: JAN. 1992 Corporate Bulletin No.: 167402 ASE No.: A3 Subject: FRONT AXLE WILL NOT DISENGAGE Model and Year: 1983-1991 T TRUCKS Owners of some 1983-1991 T vehicles may comment about inappropriate front axle disengagement. This condition may be due to a corroded transfer case vacuum actuator switch. To correct this condition a revised switch (P/N 15664811), constructed of noncorrosive stainless steel, should be installed. SERVICE PROCEDURE: The vacuum switch is located on the left upper side of the transfer case (Figure 1). 1. Raise the vehicle and support with suitable safety stands. 2. Remove the vacuum lines from the switch. 3. Remove the corroded switch from the transfer case. 4. Install a revised switch (P/N 15664811), coat the threads with thread sealant. 5. Connect the vacuum lines. 6. Lower the vehicle. 7. Check for oil leaks at the threads and vacuum leaks around the vacuum lines. Page 92 Fig. 3 Module Test (Part 3 of 4) Body - TPO Fascia Cleaning Prior to Painting Rear Bumper Cover / Fascia: Technical Service Bulletins Body - TPO Fascia Cleaning Prior to Painting INFORMATION Bulletin No.: 08-08-51-002 Date: March 12, 2008 Subject: New Primer For TPO Fascias and Affected Cleaning Process of Painting Operation Models: 2009 and Prior Passenger Cars and Trucks 2009 and Prior HUMMER H2, H3 The purpose of this bulletin is to inform the technician that General Motors has made a change in the primer it uses for TPO plastic for service parts. This new primer comes in several different colors from five different suppliers. This change affects the cleaning process of the painting operation. The new process is as follows. 1. Wash with soap and water. 2. Clean with a 50% mix of isopropyl alcohol and water (or a waterborne cleaner). Check with your paint supplier for product recommendations. 3. Scuff sand per your paint suppliers recommendations. Note: The use of a solvent-type cleaner will soften, or begin to dissolve the primer. Base coats do not have any affect on this primer. 4. Reclean with a 50% mix of isopropyl alcohol and water (or a waterborne cleaner). All fascias, with the exception of the Corvette, Camaro, and Cadillac XLR, are made of TPO. You may find other TPO parts with this primer. If the technician has a question as to the type of plastic they are painting, inspect the back of the part for the plastic symbol (TPO). Disclaimer 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 Service and Repair Fuel Pressure Release: Service and Repair Before performing any procedure that requires disconnecting fuel lines, relieve fuel system pressure as described below. 1. Remove Fuel Pump fuse from fuse block. 2. Start engine and allow to run out of fuel, then crank engine an additional 3 seconds. 3. Service fuel system as necessary. Page 4199 Differential Axle Housing: Service and Repair Chevrolet Full Floating Axle 1.. Raise and support vehicle, then remove rear wheels. 2. Remove the two trunnion bearing U-bolts, then split universal joint and position propeller shaft aside. 3. Remove hub and drum assembly, then disconnect parking brake cable at lever and flange plate. 4. Disconnect brake hose at axle connector, then the shock absorbers at axle brackets. 5. Support axle housing with a suitable jack, remove spring plate U-bolts and remove axle housing from vehicle. 6. Reverse procedure to install. Page 1176 Fuse Block: Locations LH Side Of I/P Behind Instrument Cluster Page 5707 4. Remove nut, bolt, side cover and gasket, then turn adjuster screw right until side cover separates from pitman shaft. 5. Remove piston shaft, then turn stub shaft left until pitman shaft teeth and rack piston disengage. 6. Remove retaining ring, washers and seals, then remove bearing with bearing removal tool No. J-6278 or equivalent if necessary. Fig. 3. 7. Remove rack piston and balls as follows: a. Insert ball retainer tool J-21552 or equivalent into rack piston bore with pilot seated into end of worm, refer to Fig. 2. b. Hold tool against worm and turn stub shaft to left. Rack piston will be forced onto the tool. c. Hold tool and pull rack piston toward handle until it is against flange. This will prevent end circuit balls from falling out. Fig. 4 Adjuster plug removal Fig. 5 Needle bearing removal Fig. 6 Worm shaft & valve body removal Page 7353 Cruise Control Switch: Description and Operation Fig. 1 Cruise Control Switch The mode control assembly, Fig. 1, consists of a 3 position slide-type switch and a set/coast switch button. To operate the system, the slide switch must be in on position and vehicle speed must be above 25 mph. The system is engaged at the desired speed by fully depressing, then releasing the set/coast button. Cruise speed can be increased from set position by accelerating vehicle to desired speed, then pressing and releasing button. In order to decrease speed, the set/coast button is held in the fully depressed position (disengaging system), then released when the desired speed is reached. The system can be disengaged at any time by depressing the brake or clutch pedal, or by moving the slide switch to off position. If the system is disengaged by depressing the brake or clutch pedal, the last set speed will be retained in the module memory until the slide switch or ignition switch is moved to off position. Momentarily moving the slide switch to the resume/accel position will cause the vehicle to accelerate to the last set speed and maintain that speed. If the slide switch is held in the resume/accel position, the vehicle will continue to accelerate until the switch is released. When the switch is released, the speed that the vehicle accelerated to becomes the new set speed. The slide switch also allows a tap-up function to increase cruise set speed in 1 mph increments. With the cruise control engaged and operating, tapping-up is done by pressing the slide switch to the resume position, then quickly releasing it. This procedure can be repeated 10 times before the system must be reset to a new speed in the conventional manner. Paint - Identification/Repair of Colorcoat Delamination Paint: Customer Interest Paint - Identification/Repair of Colorcoat Delamination BULLETIN NUMBER: 92-1O-134A SECTION: 10 Body NUMBER: 4 CORPORATE REFERENCE NUMBER: 231054R DATE: July 1993 SUBJECT: SERVICE PROCEDURES FOR IDENTIFICATION AND REPAIR OF PAINT COLORCOAT DELAMINATION FROM ELPO PRIMER MODELS: 1988-92 TRUCKS THIS BULLETIN CANCELS AND REPLACES TRUCK SERVICE BULLETIN 92-10-134 (CORP # 231054R), DATED OCTOBER 1992. IT IS BEING REVISED TO REMOVE THE COVER LETTER PORTION AND SUBJECT STATEMENT NOW INCLUDES NOTE FOR TRUCKS AND REVISES THE MONOCOAT MATERIAL ALLOWANCES ON "G", "S/T" AND SOME "R/V" MODELS. THE ALLOWANCE FOR "ADD FOR TWO-TONE" ON G AND S/T TRUCKS HAS BEEN CHANGED. ALL COPIES OF 92-10-134 SHOULD BE DISCARDED. The revisions are the result of changes to the MONOCOAT (ENAMEL) material allowance charts published in June, 1993. Six (6) of the "G" model revisions use Basecoat/Clearcoat material allowance codes. THESE ARE TO BE USED AS DOLLAR REFERENCES ONLY, AND ARE MARKED WITH A # INDICATOR. Continue to repair these vehicles with monocoat materials. DO NOT repair these vehicles with Basecoat/Clearcoat products. Use the latest (June, 1993) material allowance charts when submitting claims. SUBJECT: Service procedures for the repair of paint colorcoat delamination from elpo primer (repaint entire body above the body side moldings, except trucks as noted). APPLICATION: 1988-1992 LIGHT DUTY TRUCKS (C/K, R/V, S/T, M/L AND G) This bulletin cancels and supersedes service procedures and time allowances on all previous bulletins regarding paint DELAMINATION. Due to the use of new procedures, add times for optional equipment, and designating specific hardware items for removal, the published labor times will not be the same as previously published. CONDITION This bulletin is being issued to assure that the correct procedure is followed to repair a condition known as DELAMINATION. Some of the above listed passenger cars, light duty trucks, and vans may have DELAMINATION (peeling) of the paint color-coat from the ELPO primer depending upon variable factors including prolonged exposure to sunlight and humidity. Blues, Grays, Silvers and Black Metallics are the colors that have the highest potential for this condition. On rare occasions, other colors may be involved. Important DELAMINATION is different than other paint conditions and/or damage. A proper problem identification is necessary, and the service procedure that follows is specific to the proper repair of DELAMINATION and must be followed. The information in this bulletin covers Paint DELAMINATION of the colorcoat from the ELPO primer ONLY. It does not address any other paint conditions. Procedures for the repair of other paint conditions (stone chips, scratches, environmental damage, clearcoat peeling, runs, dirt, fading, etc.) will not effectively repair DELAMINATION and customer dissatisfaction will result. CAUSE This condition may occur on vehicles produced in plants where the paint process does not call for application of a primer surfacer. Under certain conditions, ultraviolet light can penetrate the colorcoat, sometimes causing a reaction and separation of portions of the colorcoat from the ELPO (electrocoat) primer. PROBLEM IDENTIFICATION: Page 6034 Page 1626 - Adjust converter to center the mounting pins in the insulators. This equalizes the hanger load at the insulators (Figure 2). - Move U-bolt back to original position and tighten. 3. Settle the powertrain by shifting from DRIVE to REVERSE with automatic transmission or 1ST to REVERSE with manual transmission, at least three times with engine at idle. Then turn engine off. 4. Tighten all fasteners with the powertrain in a relaxed position (vehicle in neutral). Torque to specifications in Service Manual X-9129. Note: Be sure that the catalytic converter hanger and hanger pins are centered in the insulators, the pins should have 6.0-16.0 mm (1/4 in. - 5/8 in.) clearance as shown in Figure 2. Page 5949 Refer to the appropriate section of SI for specifications and repair procedures that are related to the vibration concern. Disclaimer 3L30 (180C) Transmission Fluid Pressure Sensor/Switch: Specifications 3L30 (180C) Transmission Component .......................................................................................................................................... .................................................................... Ft. Lbs. Governor Pressure Switch ................................................................................................................... ................................................................................. 7 Body - TPO Fascia Cleaning Prior to Painting Front Bumper Cover / Fascia: Technical Service Bulletins Body - TPO Fascia Cleaning Prior to Painting INFORMATION Bulletin No.: 08-08-51-002 Date: March 12, 2008 Subject: New Primer For TPO Fascias and Affected Cleaning Process of Painting Operation Models: 2009 and Prior Passenger Cars and Trucks 2009 and Prior HUMMER H2, H3 The purpose of this bulletin is to inform the technician that General Motors has made a change in the primer it uses for TPO plastic for service parts. This new primer comes in several different colors from five different suppliers. This change affects the cleaning process of the painting operation. The new process is as follows. 1. Wash with soap and water. 2. Clean with a 50% mix of isopropyl alcohol and water (or a waterborne cleaner). Check with your paint supplier for product recommendations. 3. Scuff sand per your paint suppliers recommendations. Note: The use of a solvent-type cleaner will soften, or begin to dissolve the primer. Base coats do not have any affect on this primer. 4. Reclean with a 50% mix of isopropyl alcohol and water (or a waterborne cleaner). All fascias, with the exception of the Corvette, Camaro, and Cadillac XLR, are made of TPO. You may find other TPO parts with this primer. If the technician has a question as to the type of plastic they are painting, inspect the back of the part for the plastic symbol (TPO). Disclaimer Page 7173 pad, P/N 5530, to prevent leaving finger marks in the clearcoat. NOTE: Always sand the length of the panel and use a mild dish soap detergent in the wet sand operation for sandpaper lubricant. 3. Wheel compound sanded panel with 3M Finesse it II, P/N 5928, polishing compound and 3M Super Buff Polishing Pad, P/N 5705 or equivalent. 4. Swirl marks, left in the clearcoat, can be removed by rebuffing the affected area with a non-directional, dual action (D.A.) orbital sander. A clean terry cloth polishing bonnet and 3M Finesse II compound should be used. CAUTION: Buffing wheels are not recommended for routine new car pre-delivery preparation of basecoat/ clearcoat finishes. 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. Technical Service Bulletin # 8931810 Date: 900901 Campaign - Paint Delamination Policy Adjustment Number: 89-318-10 Section: 10 Date: September, 1990 Corp. Bulletin No.: SPECIAL Subject: SPECIAL POLICY ADJUSTMENT PAINT DELAMINATION (PEELING) Model and Year: 1988-89 CHEVROLET S/T PICKUPS AND S/T BLAZERS (SHREVEPORT ASSEMBLY PLANT ONLY - PLANT CODE "8") TO: ALL CHEVROLET DEALERS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 89-305-10, DATED APRIL 1990. ALL COPIES OF 89-305-10 SHOULD BE DISCARDED AS THIS BULLETIN CONTAINS AN EXPANDED SERVICE PROCEDURE. General Motors has determined that some 1988-89 Chevrolet S/T pickups and S/T Blazers built at the Shreveport Assembly Plant may exhibit a delamination (peeling) of the paint on exterior surfaces due to continued ultraviolet exposure. If one of these vehicles should require repairs for a paint peeling condition, all exterior surfaces painted with affected colors should be refinished even though the peeling may be evident in only a few places. VEHICLES INVOLVED Involved are certain 1988-89 Chevrolet S/T model trucks painted Galaxy Blue (paint code 28), Aspen Blue (paint code 24) or Steel Gray (paint code 90) and built at the Shreveport Assembly Plant within the following VIN breakpoints: SPECIAL POLICY ADJUSTMENT This special policy covers the condition described above on 1988 involved vehicles for 12 months from the date of this bulletin. 1989 involved vehicles will be covered for a period of 3 years from the date of original vehicle purchase regardless of ownership with no deductible. Correction, at no charge to the customer, will consist of refinishing exterior surfaces painted with affected colors on involved vehicles. Customers may also be eligible for reimbursement of previous repairs with supporting documentation. NOTICE: Only exterior surface areas painted Galaxy Blue, Aspen Blue or Steel Gray should be refinished. If peeling of colors other than those described above should occur, handle as described in the Chevrolet Claims Processing Manual, Section XIII, Warranty Management System. This "Special Policy Adjustment Bulletin" should be filed in the three ring binder previously furnished to dealers by General Motors. PARTS INFORMATION No parts are required to complete this special policy. Paint supplies should be obtained through normal supplier. Service Procedure 1. After washing vehicle, verify that condition is delamination of topcoat by applying a 2 inch width piece of masking tape firmly over suspect area, pulling upward quickly. If topcoat and/or clear coat flake or peel away from primer, Page 3834 Fluid Pressure Sensor/Switch: Specifications 4L60 - 700R4 Transmission Pressure Switches ............................................................................................................................... ....................................................................... 8 ft. lbs. Page 1433 A. Obtain a straight edge approximately 8-9 inches long and, while holding it in two hands, as shown in the attached illustration, place it on the inboard mounting surface of the wheel and try to rock it up and down. B. Repeat the above procedure on three or four different positions on the wheel inboard mounting surface. C. The outer ring of the mounting surface is normally raised above everything inside it. If a wheel mounting surface has been bent on a tire changer, it will be raised above the outer ring and the straight edge will rock on this "raised" portion. D. If a bent wheel is found, it must be replaced. Page 6180 ^ Do not dislodge the seal (O-ring) (15). 4. Seal shaft retainer ring (12) with J 5403. ^ Place the flat side against the seal seat. ^ Use the sleeve of J 9393-B to press the ring into its groove. 5. J 9625 to the rear head of the compressor: ^ Gage charging lines or pressurize the suction side (low pressure side) of the compressor with refrigerant to equalize the pressure to the drum pressure. 6. Shaft nut (1) with J 9399. ^ Place the compressor in a horizontal position with the oil sump down. ^ Rotate the compressor shaft by hand. ^ Leak test with J 23400. ^ Replace shaft nut (1) with a new one. 7. New absorbent sleeve (11). ^ Roll the material into a cylinder, overlapping the ends. ^ Slip the sleeve into the compressor neck with the overlap toward the top of the compressor ^ With a screwdriver spread the sleeve ends of the sleeve butt at the top vertical centerline. Shaft And Seal Position And Correct Position Gaging Guide 8. Sleeve retainer (10) with J 9393. ^ Place the flange face against the front end of the sleeve. ^ Press and tap with a mallet to set the retainer and sleeve into place. Place the retainer 0.7937 mm (0.03125-inch) from the face of the compressor neck. 9. Clutch plate and hub assembly (2). Important ^ Using improper procedures. pounding or collisions can damage the shaft seal and the axial plate. If the axial plate is out of position. the carbon face of the shaft seal may not contact the seal seat. Page 3788 6. Turn cap to lock collet into position. 7. Use a 15/16" end wrench and turn bolt clockwise to remove bushing. 8. Remove J 38119 with collet attached. Figure 3 Bushing Installation Procedure: (Figure 3) 1. Remove long bolt from cap of J 38119. Page 1765 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) Description and Operation Cruise Controller: Description and Operation The module monitors mode control switch position, signals from the speed sensor, servo position and release switch operation, then operates vacuum valves within the servo unit to control servo operation and vehicle speed. The module also contains a speed limiting function which prevents system operation at speeds below approximately 25 mph. Hydraulic System Bleeding Brake Bleeding: Service and Repair Hydraulic System Bleeding Manual Bleeding 1. If vehicle is equipped with power brakes, remove vacuum reserve by applying brakes several times with engine off. 2. Fill master cylinder reservoirs with suitable brake fluid. Be sure to always keep master cylinder reservoirs at least half full during entire bleeding procedure. 3. If master cylinder is suspected to have air in the bore, it must be bled first, as follows: a. Disconnect forward brake pipe connection at master cylinder. b. Allow brake fluid to fill master cylinder bore until it begins to flow from forward pipe connector port. c. Connect and tighten forward brake pipe at master cylinder. d. Depress brake pedal slowly one time and hold, then loosen forward brake pipe connection at master cylinder to purge air from bore. Tighten connection, then release brake pedal slowly. Wait 15 seconds, then repeat sequence, including 15 second wait, until all air is purged from bore. e. Bleed rear bore of master cylinder as front bore was bled. 4. Bleed right rear brake as follows: a. Depress brake pedal slowly one time and hold. b. Loosen bleeder valve to purge air from brake, then tighten bleeder valve and slowly release pedal. c. Wait 15 seconds, then repeat sequence, including 15 second wait, until all air is purged. 5. Bleed left rear, right front, and left front brakes, in that order, using same method as for right rear brake. 6. Check brake operation and ensure pedal is firm. Also check master cylinder fluid level and add fluid as necessary. 7. Turn off brake warning light by applying moderate pressure to brake pedal several times. 8. Road test vehicle. Fig. 1 Installing Pressure Bleeder Adapter Pressure Bleeding 1. Loosen, then slightly retighten bleeder valves at all four wheels. Repair any broken, stripped or frozen valves at this time. 2. Using a diaphragm type pressure bleeder, install suitable bleeder adapter to master cylinder, Fig. 1. 3. Charge bleeder ball to 20-25 psi, then depress and hold valve stem on combination valve. 4. Connect pressure bleeder line to adapter. 5. Open line valve on pressure bleeder, then depress bleed-off valve on adapter until a small amount of brake fluid is released. 6. Raise and support vehicle. 7. Bleed right rear, left rear, right front and left front brakes, in that order. 8. Place transparent tube over bleeder valve, then allow tube to hang down into transparent container. Ensure end of tube is submerged in clean brake fluid. 9. Open bleeder valve 1/2 to 3/4 turn and allow fluid to flow into container until all air is purged from line. Flushing Hydraulic System If brake fluid is old, rusty or contaminated, or whenever new parts are installed in the hydraulic system, the system must be flushed. Bleed brakes, allowing at least one quart of clean brake fluid to pass through system. Any rubber parts in hydraulic system which were exposed to contaminated fluid must be replaced. Page 7300 Fig. 3 Module Test (Part 3 of 4) Page 4497 Labor Operation No.: K6550 Valve, Pressure Regulator-R&R; or Replace Use the appropriate labor time in the labor time guide. Parts are currently available from GMSPO. Cruise Control - Works Intermittently Cruise Control Switch: All Technical Service Bulletins Cruise Control - Works Intermittently Number: 92-195-9B Section: 9B Date: MAY 1992 Corporate Bulletin No.: 268102R ASE No.: A8 Subject: CRUISE CONTROL WORKS INTERMITTENTLY Model and Year: 1985-92 M VANS 1990-92 L VANS 1986-92 S/T TRUCKS Some owners of 1985-1992 WL vehicles or 1986-1992 S/T vehicles with cruise control (RPO K34) may comment that their cruise control operates intermittently. This condition may be caused by the wires becoming pinched as they exit the multi-functional lever. These wires may ground out on the lever rod and short the cruise function. To correct this condition in production, the wiring harness that exits the lever has been rerouted and the opening in the multi-functional lever has been redesigned to allow the wires more clearance. The diagnostic procedures in the applicable Service Manual should be followed before replacing the multi-functional lever. If the multi-functional lever requires replacement, the following procedure should be performed: SERVICE PROCEDURE: 1. Disconnect the wire harness connector. 2. Remove the harness protector cover. 3. Attach a long piece of mechanic's wire to the end of the harness connector. 4. Remove the multi-functional lever from the turn signal switch. 5. Gently pull the harness up and out so the mechanic's wire can be used to install the new unit. 6. Attach the upper end of the mechanic's wire to the new harness connector. Gently pull the mechanic's wire at the lower end of the column, feeding the harness into the proper location in the column. 7. Install a redesigned multi-functional lever (P/N 25111290) into the turn signal switch. 8. Disconnect the mechanic's wire from the harness connector. 9. Install the harness protector cover. 10. Reconnect the wire harness connector. SERVICE PARTS INFORMATION Part Number Description 25111290 Multi-functional Lever Use applicable labor time guide for labor hours. Important: The new Part Number (P/N 25111290) should be used when correcting this condition in the above listed vehicles. Specifications Idle/Throttle Speed Control Unit: Specifications IDLE SPEED CONTROL Measured between terminals A& B and C & D. Page 3407 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). Body - TPO Fascia Cleaning Prior to Painting Paint: All Technical Service Bulletins Body - TPO Fascia Cleaning Prior to Painting INFORMATION Bulletin No.: 08-08-51-002 Date: March 12, 2008 Subject: New Primer For TPO Fascias and Affected Cleaning Process of Painting Operation Models: 2009 and Prior Passenger Cars and Trucks 2009 and Prior HUMMER H2, H3 The purpose of this bulletin is to inform the technician that General Motors has made a change in the primer it uses for TPO plastic for service parts. This new primer comes in several different colors from five different suppliers. This change affects the cleaning process of the painting operation. The new process is as follows. 1. Wash with soap and water. 2. Clean with a 50% mix of isopropyl alcohol and water (or a waterborne cleaner). Check with your paint supplier for product recommendations. 3. Scuff sand per your paint suppliers recommendations. Note: The use of a solvent-type cleaner will soften, or begin to dissolve the primer. Base coats do not have any affect on this primer. 4. Reclean with a 50% mix of isopropyl alcohol and water (or a waterborne cleaner). All fascias, with the exception of the Corvette, Camaro, and Cadillac XLR, are made of TPO. You may find other TPO parts with this primer. If the technician has a question as to the type of plastic they are painting, inspect the back of the part for the plastic symbol (TPO). Disclaimer Interior - Tapping Noise In Corner of Dash Dashboard / Instrument Panel: All Technical Service Bulletins Interior - Tapping Noise In Corner of Dash Number: 89-101-10 Section: 10 Date: MARCH, 1989 Subject: TAPPING NOISE IN CORNER OF DASH Model and Year: 1987-89 S/T TRUCKS TO: ALL CHEVROLET DEALERS Some 1987-89 S/T Trucks may experience a noise from the cowl area located around either of the front dash speakers. The noise has been described as a tapping or creaking noise similar to tapping a pencil lead on the windshield. This condition occurs primarily at ambient temperatures below 45 degrees Fahrenheit. Therefore, vehicles which sit inside a heated facility during repair should be "cold soaked" prior to verifying the repair. Repair Procedure Apply repair procedure exactly as described in Chevrolet Bulletin 86-58 (Section 10) dated April, 1986, which has been reproduced in this bulletin for your convenience. IMPORTANT: Windshield replacement will not resolve the situation. For repairs to vehicles under warranty, use: Labor Op: T7230 1983-86 Models - Labor Time: .6 Hr per side 1987-89 Models - Labor Time: .8 Hr. per side NOTE: On 87-89 vehicles, the location of the one inch hole will encompass a small weld. Additional time has been added to the labor operation to take this into account. Be sure to cut through only the first layer of sheet metal as specified in Step 9 on the bulletin. IMPORTANT: Dealers who have vehicles that are not repaired by this procedure should contact Technical Assistance for further assistance. Subject: COWL POPPING NOISE Model and Year: 1983-86 S/T TRUCKS Number: 86-58 Section: 10 Date: APR., 1986 TO: ALL CHEVROLET DEALERS On some S/T Trucks operating in low ambient temperatures, a condition may exist where a snapping or "popping" noise is heard coming from the cowl. This noise is caused by an "oil can" effect between the windshield frame and the door frame. The service procedure for eliminating the noise is as follows: 1. Remove the windshield wipers and radio antenna. Page 5680 Steering Column: Service and Repair - With Tilt Column Fig. 23 Exploded view of tilt steering column (column shift). Page 7883 SERVICE PARTS INFORMATION Part Number Application Description 15636850 1988-1991 Plate kit I/P (no switches). (Gray) Switch trim plate (gray) bracket, covers for switch trim plate holes (quantity 2), and 4 bolts/screws. 15636853 1986-1987 Plate kit I/P (no switches). (Black) Switch trim plate (black), bracket, covers for switch trim plate holes (quantity 2), and 4 bolts/screws. Important: Torque 11508898 bolts/screws supplied in kit to 0.4-0.7 N-m. (4-6 lbs.in.). Parts are expected to be available on January 21, 1991. Until then, normal part orders will not be accepted by GMSPO. Only verifiable emergency VIP orders will be accepted. GMSPO will make every effort to obtain parts. All parts will be placed on 400 control to waive VIP surcharges. However, the parts will be shipped premium transportation at dealer's expense. All other order types will be canceled as incorrectly ordered while 400 control is in place. WARRANTY INFORMATION For vehicle repaired under warranty use: Labor Operation: T7101 Labor Time: .3 hr. Trouble Code: 92 NOTE: Labor Operation is coded to base vehicle coverage in the warranty system. Page 4174 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. Page 426 Wiring Diagram For Chart C-1A - Park/Neutral Switch Diagnosis CHART C-1A - PARK/NEUTRAL SWITCH DIAGNOSIS Circuit Description: The Park/Neutral Switch contacts are closed to ground in park or neutral and open in drive ranges. The ECM supplies ignition voltage, through a current limiting resistor, to CKT 434 and senses a closed switch, when the voltage on CKT 434 drops to less than one volt. The ECM uses the P/N signal as one of the inputs to control: Idle Air Control VSS Diagnostics EGR Test Description: Numbers below refer to circled numbers on the diagnostic chart. 1. Checks for a closed switch to ground in park position. Different makes of "Scan" tools will read P/N differently. Refer to operators manual for type of display used for a specific tool. 2. Checks for an open switch in drive or reverse range. 3. Be sure "Scan" indicates drive, even while wiggling shifter to test for an intermittent or misadjusted switch in drive range. Diagnostic Aids: If CKT 434 indicates PIN (grounded), while in drive range, the EGR would be inoperative, resulting in possible detonation. If CKT 434 always indicates drive (open), a drop in the idle may exist when the gear selector is moved into drive range. Page 1226 ^ 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 Page 7595 Oil Pressure Gauge: Testing and Inspection Gauge Reads ``80'' or Above 1. Disconnect lead from sensor, then ground lead. 2. Gauge should read ``0'' psi. If gauge read ``0'' replace replace sensor, and if gauge reads ``80'' psi, check for short between sensor and gauge. Locations Fuel Pump And Sender Assembly (Typical) Drive Axle (Front) - Will Not Disengage Transfer Case Actuator: Customer Interest Drive Axle (Front) - Will Not Disengage Number: 91-476-4C Section: 4C Date: JAN. 1992 Corporate Bulletin No.: 167402 ASE No.: A3 Subject: FRONT AXLE WILL NOT DISENGAGE Model and Year: 1983-1991 T TRUCKS Owners of some 1983-1991 T vehicles may comment about inappropriate front axle disengagement. This condition may be due to a corroded transfer case vacuum actuator switch. To correct this condition a revised switch (P/N 15664811), constructed of noncorrosive stainless steel, should be installed. SERVICE PROCEDURE: The vacuum switch is located on the left upper side of the transfer case (Figure 1). 1. Raise the vehicle and support with suitable safety stands. 2. Remove the vacuum lines from the switch. 3. Remove the corroded switch from the transfer case. 4. Install a revised switch (P/N 15664811), coat the threads with thread sealant. 5. Connect the vacuum lines. 6. Lower the vehicle. 7. Check for oil leaks at the threads and vacuum leaks around the vacuum lines. Page 3787 Figure 2 Bushing Removal Procedure: (Figure 2) 1. Disconnect propshaft from rear of transmission. 2. Remove rear case seal. 3. Assemble tool as shown in Figure 2. 4. Insert collet into rear opening of transmission case. 5. Slide expansion tube into segmented collet. Page 6771 1. With the end gate open, use a grease pencil to mark around the circumference of each washer (Figure 1, "7") located behind the strikers. 2. Unscrew and remove the existing striker assemblies (Figure 1, "6") from the vehicle. 3. Loosely assemble the new striker (Figure 1, "6") (P/N 15700881) and washer (Figure 1, "7") and reinstall using the pencil marks as a guide. 4. Install the striker assemblies (Figure 1, "6") using a T50 Torx(R). Torque to 63 N-m. (47 lbs.ft.). 5. Check for proper operation and end gate flushness. Adjust the striker assemblies if required. The end gate lock strikers can be adjusted up or down, fore or aft, to obtain proper closure of the end gate. The end gate should seal completely with minimum closing effort. Torque the striker bolts to 63 N-m. (47 lbs.ft.). SERVICE PARTS INFORMATION PART NUMBER DESCRIPTION QTY/VEH 15700881 Striker Asm. 2 Page 2720 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 module's 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 flexible ducting 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. Paint - High Volume Low Pressure Paint Application Paint: All Technical Service Bulletins Paint - High Volume Low Pressure Paint Application Number: 91-334-10 Section: 10 Date: MAY 1991 Corporate Bulletin No.: 161701R Subject: HVLP-HIGH VOLUME LOW PRESSURE PAINT APPLICATION Model and Year: 1982-91 ALL PASSENGER CARS AND TRUCKS VOC stands for Volatile Organic Compounds. Most solvents used in automotive refinishing paints are considered volatile organic compounds. Volatile organic compounds react chemically with sunlight and make a variety of pollutants generally referred to as "Photochemical Smog." VOC regulations seek to reduce the amount of VOC getting into the air and thereby limit pollution. One way to reduce the amount of volatile organic compounds being emitted into the air is to increase the transfer efficiency rate of the paint material being transferred between the spray gun and the surface being painted. Different states throughout the country, such as California, New York, New Jersey, etc., are in the process of writing VOC emission regulations. As an example, the South Coast Air Quality Management District (SCAOMD) in Southern California has a Rule 1151 for automotive refinishing that stipulates that coating applications must be done with either electrostatic application, high-volume, low-pressure (HVLP) spray or "such other coating application methods that are demonstrated to the executive officer to be capable of achieving at least 65 percent transfer efficiency." HVLP spray is defined as "to spray a coating by means of a gun that operates between 0.1 and 10.0 psi air pressure." What is the difference between the high pressure conventional spray guns now in use and the HVLP spray guns being stipulated in VOC regulations? In the conventional spray gun high pressure air leaves the air cap and rapidly expands. As this air expands, the paint from the fluid tip is blasted apart, sending small paint droplets in all directions at a high velocity. This explosion of paint causes much of the paint to pass or bounce off the surface being painted. Transfer efficiency on conventional spray guns is usually between 20 percent and 50 percent efficiency. HVLP stands for (H)igh (V)olume (L)ow (P)ressure. HVLP spray guns utilize lower spray pressures upon atomization. The relatively low air pressure causes a much "softer" explosion. The resultant paint droplets are larger and slower. The large volume of air from the air caps can now better control the flight of the droplets. The paint spray tends to move in one direction. Bounce back and paint passing by the substrate are reduced, resulting in increased transfer efficiency. Transfer efficiency of HVLP guns is usually between 65 percent to 90 percent efficient. The amount of savings and transfer efficiency varies with the skill of the painter, gun adjustment, the air pressures, the size of the object being painted, and the viscosity of the paint. Basically, there are three types of HVLP spray equipment available; turbine units, air conversion units, and spray guns with the air conversion units inside the gun. The turbine unit is normally a portable or wall-mounted unit that generates a high volume of air at between 3 to 7 psi. Due to friction, the turbine generates heat. The amount of heat generated and the temperature of the air depend on the size of the turbine and length of hose. A large size diameter air hose is used between the turbine and the HVLP spray gun. Air conversion units are normally portable or wall-mounted units that use high pressure air from an air compressor and then convert it to a high volume of air at a lower pressure set on a regulator. Most air regulators on these units do not exceed 10 psi. A large size diameter air hose is used between the air conversion unit and the HVLP spray gun. These units do not generate any heat, but can be purchased with a heat source. HVLP spray guns with the air conversion units inside the gun use high pressure air from an air compressor and then convert it to a high volume of air at a preset pressure normally dependent on incoming air line pressure. The spray guns cannot exceed 10 psi no matter how high the incoming air line pressure is. There is no large diameter air hoses or heat to contend with. HVLP equipment that can maintain precise control and maintain close to 10 psi air cap pressure will provide better atomization of materials, especially low VOC paints. A GM training course on HVLP Paint Application is currently available (Course # 22001.42). Please refer to the GM monthly training schedule for more information. MANUFACTURERS of HVLP SPRAY EQUIPMENT Accuspray System Binks Bessam-Aire Binks Manufacturing Co. 26881 Cannon Road 9201 West Belmont Ave. P.O. Box 46478 Franklin Park, IL 60131 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. Page 6331 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 06-08-111-004B - BULLETIN CANCELLATION NOTIFICATION Body Emblem: Technical Service Bulletins 06-08-111-004B - BULLETIN CANCELLATION NOTIFICATION TECHNICAL Bulletin No.: 06-08-111-004B Date: September 25, 2009 Subject: Information on Discoloration, Blistering, Peeling or Erosion of Various Exterior Emblems Including Chevy Bowtie (Bulletin Cancelled) Models: 2009 and Prior GM Passenger Cars and Trucks (including Saturn) 2003-2009 HUMMER H2 2006-2009 HUMMER H3 2005-2009 Saab 9-7X Supercede: This bulletin is being cancelled. Please discard Corporate Bulletin Number 06-08-111-004A (Section 08 - Body & Accessories). This bulletin is being cancelled. The information is no longer applicable. Disclaimer A/T TCC - MIL ON/False Code 32 Set Diagnostics Torque Converter Clutch Solenoid: Technical Service Bulletins A/T TCC - MIL ON/False Code 32 Set Diagnostics Number: 91-149-6E Section: 6E Date: January 1991 Corporate Bulletin No.: 066502R Subject: "SERVICE ENGINE SOON" LIGHT POSSIBLE FALSE CODE 32 Model and Year: ALL 1987-91 TRUCKS WITH 4L60 AUTOMATIC TRANSMISSION (700-R4) TO: ALL CHEVROLET DEALERS Some 1987-91 light duty trucks equipped with 4L60 transmissions may experience a possible false Code 32 - EGR System Malfunction. The customer may not experience a change in performance or driveability with a Code 32 set. If normal EGR diagnostics do not reveal the cause for Code 32, the following steps should be taken to correct the condition: Check the TCC (Torque Converter Clutch) engagement solenoid/wiring harness for a short-circuit. 1. Disconnect the TCC harness connector from the left side of the transmission. 2. Measure resistance between TCC transmission connector terminals "A" and "D" with a Digital Volt Ohmmeter (DVOM). Solenoid resistance must measure 20 - 25 ohms at 20 degrees C (68 degrees F). Resistance will be slightly higher if the transmission is at operating temperature. If the resistance is less than 20 ohms the TCC solenoid diode or wiring is shorted and the solenoid must be replaced. 3. With key on, using a DVOM check for voltage at pin "D" of the TCC wiring harness. Voltage greater than one volt should not be found. If voltage exceeding one volt is present, circuit 422 is shorted to voltage and the short must be repaired. Refer to the appropriate service manual for circuit 422 diagnosis and repair. Test operation of the TCC through the use of a scan tool connected to the vehicle ALDL connector. The following conditions must be satisfied when testing TCC operation. ^ Clear stored trouble codes. ^ Engine at normal operating temperature (above 65 degrees C, 149 degrees F) and in closed loop. ^ Constant throttle position. TPS voltage = 1.3 V (minimum = 1.1 V, maximum = 1.5 V). ^ Vehicle speed = 45 mph (minimum = 35 mph, maximum = 55 mph). ^ Brake switch closed (brake pedal not applied). ^ 3rd or 4th gear. Confirmation The scan tool will display the ECM command for TCC engagement when the above conditions are satisfied. When the TCC engages there should be a decrease in engine speed by a minimum of 100 RPM. If TCC operation is normal, it is not necessary to replace the solenoid assembly. After verification of TCC operation, check for stored trouble codes. If TCC fails to engage consult Section 10, Transmission Controls located in Fuel and Emissions Manual and section 7A of the appropriate service manual. Page 6005 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 Specifications TEMPERATURE SENSORS Page 6645 LIGHT BLUE LT BLU BROWN BRN GRAY GRY GREEN GRN DARK GREEN DK GRN LIGHT GREEN LT GRN ORANGE ORN PINK PNK PURPLE PPL RED RED TAN TAN WHITE WHT YELLOW YEL Page 5317 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 4. Make repair. Page 1935 Distributor: Service and Repair INSTALLATION: REMOVAL: 1. Disconnect the negative battery terminal. 2. Disconnect the wiring connectors at the side of the distributor cap. 3. Remove the distributor cap and move it out of the way. a. Scribe a mark on the engine in line with the rotor. b. Note the position of the distributor housing in relation to the engine. 4. Remove the distributor hold-down nut and clamp. 5. Remove the distributor. INSTALLATION: NOTE: a. To ensure correct timing of the distributor, the distributor must be installed with the rotor correctly positioned as noted. If the engine was accidentally cranked after the distributor was removed, the following procedure can be used for installing. a. Remove the number 1 spark plug. b. Place finger over the number 1 spark plug hole and crank engine slowly until compression is felt. c. Align timing mark on pulley to "0" on engine timing indicator. d. Turn rotor to point to the 1 spark plug tower on the distributor cap. b. If the distributor shaft will not drop down flush with the engine, it may be necessary to rotate the oil pump drive shaft to align it with the slot on the bottom of the distributor drive gear. Insert a screwdriver into the distributor hole in the engine and turn the oil pump drive shaft slightly to allow alignment. 1. Install the distributor. 2. Install the distributor hold-down clamp and retaining nut. 3. Install the distributor cap. 4. Connect the wiring harness connector at the side of the distributor cap. 5. Connect the negative battery cable. 6. Set ignition timing to specification. Page 5412 2. If the latch is misaligned and/or the endgate glass is not snug against the weatherstrip, remove the endgate inner trim panel and loosen the latch assembly by adjusting the nuts located on the side of the latch assembly (Figure 1, Item 4). Adjust the location of the latch and tighten the adjusting nuts to 8.5-11.0 N-m (6-8 lbs.ft.). 3. Check the endgate window latch for proper operation. If necessary, repeat steps 1 and 2. REPLACEMENT PROCEDURE If the latch assembly is properly adjusted and the condition still occurs, the latch assembly should be replaced by performing the following steps: Description and Operation Air Conditioning Switch: Description and Operation The air conditioning "On" signal informs the ECM the A/C selector switch is turned on, and the A/C pressure cycling switch is closed. Using this information, the ECM adjusts the engine idle speed as necessary to ensure a smooth idle. Page 6279 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 Page 2117 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. 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 Page 3519 FIGURE 2 Changes to the second servo apply pin eliminates the potential for seal damage during assembly. The changes were the elimination of the two-ring seals as shown in Figure 2. Testing has verified that any potential leakage in this area will not affect transmission performance. The new design second servo apply pin can be used on all 1982-88 THM 700-R4 transmissions. NOTICE: If a past design second servo apply pin is used on a THM 700-R4 transmission, seal rings must be installed. SERVICE PARTS INFORMATION: SECOND SERVO APPLY PIN PART NO. DESCRIPTION PIN LENGTH 8667571 IDENTIFICATION 2-RINGS 66.37 - 66.67 mm (2.61" - 2.62") 8667572 IDENTIFICATION 3-RINGS 66.74 - 68.04 mm (2.67" - 2.68") 8667573 IDENTIFICATION WIDE BAND 69.11 - 69.41 mm (2.72" -2.73") 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. Page 7288 Loosen and Shim # 1 Body Mount: 1. Loosen the # 1 body mount to zero torque. 2. Raise the body off the mount to obtain clearance between the floor and the top of the body mount. 3. Cut a 4" x 4" square of 1/32 inch thick teflon or nylon (obtain locally) and drill a 5/8" hole through the center. Insert this between the floor pan and the body mount and lower the body. An alternative material is three washer pump shields, P/N 22063244. If three washer pump shields are used, cut three shields (sheets) to size and locate a 5/8" hole in the center of each shield. Place the three shields between the floor pan and mount, then lower the body on the mount. 4. Apply Loctite 242 thread locking compound (GM P/N 12345382), or equivalent, to the body mount, bolt and retorque to 60-80 N-m (44-59 Lbs.Ft.). NOTE: Some insulating materials may compress over time resulting in a loss of torque to the body mount bolt. For this reason, nylon or teflon 1/32" thick and the thread locking compound on the bolt are being specified. Parts are currently available from GMSPO. WARRANTY INFORMATION: For vehicles repaired under warranty use: Labor Operation: T7276 Labor Time: 0.8 hr. Trouble Code: 92 NOTE: Labor Operation is coded to base vehicle coverage in the warranty system. Page 355 Light Switch Details (Part 3 Of 3) Page 2756 Page 7778 Light Switch Details (Part 2 Of 3) Page 221 Coolant Temperature Sensor/Switch (For Computer): Service and Repair The coolant sensor must be handled carefully. If sensor is damaged, fuel injection operation will be affected. 1. Disconnect battery ground cable. 2. Drain coolant from radiator so level is below sensor. 3. Disconnect coolant sensor electrical connector. 4. Carefully back out coolant sensor and remove. 5. Reverse procedure to install. Page 4426 S Series with 2.5L Engine 72267 S Series with 2.8L Engine 23911 Service Action For vehicles exhibiting third gear vibration that were built prior to the production incorporation of the new lever, the shift lever should be replaced with the new design lever. Reference Section 7B-3 of the Service Manual for replacement procedure. The new design shift lever P/N is 15618925. IMPORTANT: After shift lever replacement, assure that the boot assembly is positioned to ride as high as possible on the shift lever to reduce transmission noise into the cab. For vehicles repaired under warranty, use the following Labor Operations and Times: Labor Operation: K1060 Labor Time: .3 Hr Locations Fuel Pump And Sender Assembly (Typical) Page 1037 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 Lighting - Exterior Lamp Condensation and Replacement Tail Lamp: Technical Service Bulletins Lighting - Exterior Lamp Condensation and Replacement INFORMATION Bulletin No.: 01-08-42-001H Date: January 05, 2011 Subject: Exterior Lamp Condensation and Replacement Guidelines Models: 2011 and Prior GM Passenger Cars and Trucks (including Saturn) Supercede: This bulletin is being revised to add the 2011 model year. Please discard Corporate Bulletin Number 01-08-42-001G (Section 08 - Body and Accessories). The following information is being provided to better define the causes of condensation in exterior lamps and includes guidelines for determining the difference between a lamp with a normal atmospheric condition (condensation) and a lamp with a water leak. Some exterior lamps, such as cornering, turn signal, backup, headlamps or tail lamps may exhibit very small droplets of water, a fine mist or white fog (condensation) on the inside of the lamp lens. This may be more noticeable on lamps with "multi-lens" designs and may be normal during certain weather conditions. Condensation occurs when the air inside the lamp assembly, through atmospheric changes, reaches the "dew point". When this takes place, the moisture in the air within the lamp assembly condenses, creating a fine mist or white fog on the inside surface of the lamp lens. Most exterior lamps on General Motors vehicles use a vented design and feature a replaceable bulb assembly. They are designed to remove any accumulated moisture vapor by expelling it through a vent system. The vent system operates at all times, however, it is most effective when the lamps are ON or when the vehicle is in motion. Depending on the size, shape and location of the lamp on the vehicle, and the atmospheric conditions occurring, the amount of time required to clear the lamp may vary from 2 to 6 hours. Completely sealed headlamp assemblies (sealed beams) are still used on a limited number of models being manufactured today. These lamps require the replacement of the complete lamp assembly if a bulb filament burns out. Condensation 2006 TrailBlazer Shown A Fine Mist or White Fog on the Inside Surface of the Lamp Lens Occurring After a Period of High Humidity - May be located primarily in the lens corners (near the vents) and SHOULD NOT cover more than half the lens surface. - The condition should clear of moisture when the vehicle is parked in a dry environment, or when the vehicle is driven with the lights ON. - A comparison of the equivalent lamp on the opposing side of the vehicle indicates a SIMILAR performance. If the above conditions are noted, the customer should be advised that replacement of a lamp assembly may not correct this condition. Water Leak New Style Pickup Shown Page 6165 Important ^ Use new screws (10) and washers (9). Apply Loctite 601 or equivalent to the screw threads, but do not tighten. ^ Before seating the assembly, place the clutch coil terminals in relation to the compressor. Align the three protrusions on the rear of the clutch coil with the locator holes in the front head. 1. Clutch coil pulley rim (8) and the clutch rotor (5) and bearing (6) to the compressor with J 26271-A and J 8092. 2. Retainer ring (4). 3. Clutch drive hub (3). Measure ^ Clutch plate to clutch rotor gap is 0.5 to 1.0 mm (0.020 to 0.040-inches). Important ^ Hand spin the pulley to check for tree rotation. Tighten ^ Pulley rim mounting screws (10) to 11 N.m (100 in. lbs.). ^ Bend the washers (9) to secure the screws (10). Poly-Groove Drive R-4 Compressor Component View Remove or Disconnect Tools Required: J 8433 Heavy Duty Pulley Puller J 24092 Clutch Coil Puller Legs J 25031 Rotor and Bearing Assembly Remover 1. Clutch drive hub (3). Page 2902 Idle Speed: Adjustments *** UPDATED BY TSB # 88T556E DATED NOV. 1987 CONTROLLED IDLE SPEED CHECK 1. Set parking brake and block drive wheels. 2. Connect a SCAN tool to the assembly line data link (ALDL) connect with tool in Open Mode. 3. START engine and bring it to normal operating temperature. 4. Check for correct state of PARK/NEUTRAL switch on SCAN tool. 5. Check specifications chart for controlled idle speed and IAC valve pintle position (counts). 6. If within specifications, the idle speed is being correctly controlled by the ECM. 7. If not within specifications, perform MINIMUM IDLE AIR RATE CHECK. If still not within specifications, Refer to Diagnosis By Symptom / No Trouble Codes Stored. MINIMUM IDLE AIR RATE CHECK 1. Check controlled idle speed and perform idle air control check first. 2. Set parking brake and block drive wheels. 3. START engine and bring it to normal operating temperatures 185-212 degrees Fahrenheit (85-100 degrees Celsius). Turn engine OFF. 4. Remove air cleaner, adapter and gaskets. Check that the throttle lever is not being bound by the throttle, throttle valve or cruise control cables. 5. With IAC valve connected, ground the diagnostic terminal (ALDL). 6. Turn ON ignition, DO NOT START engine. Wait at least 10 seconds (this will allow the IAC pintle to extend and seat in the throttle body.). 7. With ignition ON, engine stopped, test terminal still grounded, disconnect IAC valve electrical connector. (This disables the IAC valve in the seated position). Remove the ground from the diagnostic terminal. 8. Connect a SCAN tool to the ALDL connector and place in open mode. If a tool is not available connect a tachometer to the engine. 9. START engine. With transmission in NEUTRAL, allow engine rpm to stabilize. 10. Check rpm against specifications. Disregard IAC counts on SCAN tool with the IAC disconnected. If the engine has less than 500 miles or is checked at altitudes above 1500 feet, the idle rpm with a seated IAC valve should be lower than values in chart. 11. If the minimum idle air rate is within specifications, no further check is required. 12. If the minimum idle air rate is not within specifications, perform the following procedures: 13. If present, remove the stop screw plug by piercing it with an awl, then applying leverage. The screw is covered to discourage unauthorized adjustments. 14. With the engine at normal operating temperature 185-212 degrees Fahrenheit (85-100 degrees Celsius), adjust stop screw to obtain nominal rpm per specifications with seated IAC valve. 15. Turn ignition OFF and reconnect IAC valve electrical connector. 16. Disconnect the SCAN tool or tachometer. 17. Use silicon sealant or equivalent to cover stop screw hole. 18. Install air cleaner, adapter and gasket. CONTROLLED IDLE SPEED Transmission Gear Idle Speed IAC Counts [1] OPEN/CLOSED LOOP [2] Page 3441 PROM - Programmable Read Only Memory: Service and Repair MEMCAL *** UPDATED BY TSB #91-318-6E DATED MAY 1991 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. Page 5154 Neutral Safety Switch: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. Figure 21 Figure 22 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. Page 4058 The difference between the two sets of gaskets is the addition of holes in 1987 to accomodate an auxiliary valve body. Transmissions produced Start of Production or after the 1987 model year may or may not have an auxiliary valve body, but 1987-89 model years must use gaskets with holes for an auxiliary valve body even if an auxiliary valve body is not used. If a 1987 or later transmission does not have an auxiliary valve body - the spacer plate covers up the unused holes in the spacer plate gaskets. NOTICE: If the incorrect (1982-1986) gasket set is used on a 1987-89 model year transmission, with or without an auxiliary valve body, the third clutch exhaust passage will be blocked. This may cause slipping or flaring during a 3-2 shift, a delayed 3-2 downshift, or a burned 3-4 clutch. SERVICE PARTS INFORMATION: Model Year Part # Gasket Set Only Part # Overhaul Kit 1982-1986 8642993 8649995 1987-1989 8657938 8649995 Parts are currently available from GMSPO. Page 7711 Symbol Identification Wire Color Code Identification WIRE COLOR ABBREVIATION BLACK BLK BLUE BLU DARK BLUE DK BLU Page 6813 Symbol Identification Page 1096 Refrigerant: Specifications Refrigerant Capacity ............................................................................................................................ ......................................................... 1.1kg (37 fl oz) 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 Page 7213 - 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 Page 1731 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 4. Make repair. Capacity Specifications Fluid - M/T: Capacity Specifications Tremec 3 Speed Fluid capacities .................................................................................................................................... ........................................................................ 3.5 Pts Saginaw 3 Speed Fluid Capacities ................................................................................................................................... ........................................................................ 3.0 Pts Saginaw (76 mm) 4 Speed Fluid Capacities ................................................................................................................................... ........................................................................ 3.2 Pts Warner 83 mm 4 Speed Fluid Capacities ................................................................................................................................... .............................................................................. 3.0 Warner T-4C 4 Speed Fluid Capacities ................................................................................................................................... ........................................................................ 4.0 Pts Warner T-5 (77MM) 5 Speed Fluid Capacity ...................................................................................................................................... ...................................................................... 4.2 Pts. Muncie CH & SM-465 4 Speed Fluid Capacities ................................................................................................................................... ........................................................................ 8.2 Pts 4 Speed Fluid Capacity ...................................................................................................................................... ...................................................................... 4.2 Pts. 5 Speed Fluid Capacity ...................................................................................................................................... ...................................................................... 3.0 Pts. A/T - Intermittent Slip, Downshift, or Busy Cycling TCC Torque Converter Clutch: Customer Interest A/T - Intermittent Slip, Downshift, or Busy Cycling TCC Number: 92-42-7A Section: 7A Date: NOV. 1991 Corporate Bulletin No.: 167105 ASE No.: A2 Subject: INTERMITTENT TRANSMISSION DOWNSHIFT, SLIP OR BUSY/CYCLING TCC Model and Year: 1983-92 ALL PASSENGER CARS AND TRUCKS WITH AUTOMATIC TRANSMISSION Some owners may comment that their vehicle is experiencing one or more of the following transmission conditions: - Intermittent slipping. - Intermittent downshift followed by an upshift, both with no apparent reason. - Busyness or cycling of the TCC at steady throttle conditions and level roadway. The cooling fan operates when the thermostat on the fan clutch reaches a preset temperature. When this temperature is reached, the fan engages to draw additional air through the radiator and lower the engine temperature. When the cooling fan engages, noise increases and may sound very similar to an increase in engine RPM due to transmission downshift, slipping or TCC cycling. When engine temperature lowers to a preset point the fan clutch will disengage. When the cooling fan disengages, noise levels will decrease and may sound very similar to a decrease in engine RPM. The type of concern described above requires further definition and the customer should be asked several questions: - Is the situation more pronounced at higher vehicle loads or pulling a trailer? - Do warmer ambient temperatures make the situation more pronounced as well? If the customer's responses indicate that both of these conditions apply, and your observation of the vehicle confirms a properly operating vehicle, provide the customer the vehicle operating description included in this bulletin. Further action may not be necessary. A service procedure follows if further definition is required. SERVICE PROCEDURE: When attempting to diagnose an intermittent transmission downshift, slip or busy/cycling TCC: 1. Check fluid level and condition as outlined in section 7A 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 to raise engine coolant temperature to match customer conditions. 3. Monitor engine RPM and engine coolant temperature using a scan tool. 4. Listen for an apparent increase in engine RPM. If engine RPM sounds like it increases, check the scan tool RPM and coolant temperature readings. If the noise increase is due to engagement of the fan the engine RPM will not increase and 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, engine RPM will not decrease. This cycle will repeat as engine coolant temperature again rises. 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 section 7A of the appropriate service manual for transmission diagnosis information. 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 Page 4247 Pinion Bearing: Service and Repair Corporate and Eaton 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. 2. Install selected shim on pinion shaft, lubricate rear pinion bearing with specified axle lubricant, then press rear bearing onto pinion using suitable spacers. Locations Parking Brake Warning Switch: Locations LH Side Of I/P Behind Instrument Cluster Page 1725 Symbol Identification Wire Color Code Identification WIRE COLOR ABBREVIATION BLACK BLK BLUE BLU DARK BLUE DK BLU Specifications TEMPERATURE SENSORS Page 7354 Cruise Control Switch: Service and Repair Fig. 40 Mode control replacement 1. Remove steering wheel, lower steering column covers and steering lock plate cover, if equipped. 2. Disconnect mode control connector from main harness connector and attach a suitable length of flexible wire to mode control harness. 3. Tape joint between wire and control harness to aid removal, then remove control assembly as shown in Fig. 40. 4. Reverse procedure to install. 3L30 (180C) Transmission Case: Specifications 3L30 (180C) Transmission Component .......................................................................................................................................... .................................................................... Ft. Lbs. Reinforcement Plate To Case ............................................................................................................. ................................................................................ 14 Page 5159 When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 5mm (3/16") of insulation from wire. e. Crimp a new terminal to the wire. f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. Figure 17 To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Figure 18 Figure 19 Page 7156 6. Spray entire prepared area with a coat of DP40/DP401 anti-corrosion primer (PPG/ Ditzler) or equivalent. Follow manufacturers instructions and recommended dry times. 7. Apply 2 to 3 medium wet coats of primer-surfacer to primed surfaces of truck, making sure to follow manufacturers instructions for application. 8. After allowing adequate drying time, wet sand with 400 grit (or finer) sandpaper or dry sand with 320 grit (or finer) sandpaper. 9. Repeat steps 4 and 5. 10. Apply 1 medium wet coat of primer sealer, following manufacturers instructions. 11. Apply 3 to 4 medium wet coats (or until primer color is well hidden) of Acrylic/Urethane Enamel Color. Follow manufacturers instructions. NOTICE: Reinstall all trim and other items removed in step 2. 12. Final wash and detail vehicle. Claim Information Submit a claim with the information indicated below: * Select times as listed below for "Labor Hours" and material allowances for "Net Amount" as required for appropriate vehicle type and operation performed. Locations Rear LH Corner Of Engine Compartment. Page 8052 Disclaimer Page 4808 When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 5mm (3/16") of insulation from wire. e. Crimp a new terminal to the wire. f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. Figure 17 To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Figure 18 Figure 19 Page 7682 When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 5mm (3/16") of insulation from wire. e. Crimp a new terminal to the wire. f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. Figure 17 To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Figure 18 Figure 19 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 Page 7247 Figure No. 2 Testing and Inspection Ignition Control Module: Testing and Inspection If the vehicle cranks for at least 5 seconds and the Engine Control Module doesn't see a referance signal, some Models will set a code, 42 (Hard) or 12 (Soft). If your vehicle has one of these codes, begin with the Diagnostic System Check in Computers and Controls, then proceed to the Trouble Code Chart (Yes, some vehicles have a DTC Chart for Code 12). If the vehicle does not set a code, begin with the Diagnostic System Check, and it will send you to a Diagnostic Chart that checks for your particular condition. These types of tests are found under Computers and Control Systems. See: Powertrain Management/Computers and Control Systems/Testing and Inspection Page 468 Neutral Safety Switch: Locations Manual Trans. LH Side Of I/P Behind Instrument Cluster Page 2018 Figure 1 - Typical Fan Assembly Important To maintain a balanced fan assembly, align the yellow paint mark on the fan clutch with the yellow paint mark on the water pump hub (Figure 1.) Page 345 Symbol Identification Wire Color Code Identification WIRE COLOR ABBREVIATION BLACK BLK BLUE BLU DARK BLUE DK BLU ECM/PCM - Damage Prevention Engine Control Module: All Technical Service Bulletins ECM/PCM - Damage Prevention Number: 91-318-6E Section: 6E Date: MAY 1991 Corp. Bulletin No.: 176502R Subject: DAMAGE TO ECM/PCM CIRCUIT BOARD WHEN INSTALLING A MEM-CAL Model and Year: 1986-91 ALL PASSENGER CARS AND TRUCKS CONDITION: When installing a service replacement ECM/PCM, the use of incorrect MEMCAL installation procedures may cause the ECM/PCM to fail before it can be installed in the vehicle. This condition may appear as if the ECM/PCM were defective when it was shipped to the dealership, when in fact it was damaged while being installed. In addition this condition may also occur when installing an "updated" service MEM-CAL into the vehicles original equipment ECM/PCM. CAUSE: Excessive vertical force may be applied to the MEM-CAL resulting in flexing of the circuit board and damage to the connections between the circuit board and attached components. Excessive verticle force may be generated in two ways. 1. Incorrect MEM-CAL installation procedure. 2. Interference between MEM-CAL and cover. CORRECTION: Use the following procedure. Service Procedure: Important: This procedure supersedes any instructions regarding MEM-CAL installation dated prior to September 1990. 1. Inspect the MEM-CAL to determine if a cork spacer is glued to the top side of the MEM-CAL assembly. If so, remove it prior to installation. 2. Align small notches with matching notches in the ECM/PCM MEM-CAL socket. 3. VERY GENTLY press down on the ends of the MEM-CAL until the locking levers are rotated toward the sides of the MEM-CAL. Notice: To avoid ECM/PCM damage, do not press on the ends of the MEM-CAL until the levers snap into place. Do not use any vertical force beyond the minimum required to engage the MEM-CAL into its socket. 4. While continuing light pressure on the ends of MEM-CAL, use your index fingers to press the locking levers inward until they are snapped into place. Listen for click. 5. Install MEM-CAL cover and install ECM/PCM in vehicle. Page 3625 Extension Housing: Specifications THM180 & 180 C Automatic Trans Application ........................................................................................................................................... ................................................................... Ft. Lbs. Extension Housing To Case ................................................................................................................ .......................................................................... 20-25 Transmission Support To Extension .............. .............................................................................................................................................................. . 29-36 Page 3878 Shift Solenoid: Specifications 4L60 - 700R4 Transmission Pressure Control Solenoid To Valve Body .............................................................................................................................................................. 8 ft. lbs. Solenoid Assembly To Case .................................................................................................. .................................................................................. 18 ft. lbs. Solenoid Assembly To Pump ............ .............................................................................................................................................................. .......... 8 ft. lbs. Brakes - ECU Software Improvement Electronic Brake Control Module: Technical Service Bulletins Brakes - ECU Software Improvement Number: 91-101-5 Section: 5 Date: November 1990 Corp. Bulletin No.: 065021 Subject: INTRODUCTION OF CODES 6, 9 AND 10 AS SOFT CODES Model and Year: 1988-91 C/K, S/T, R/V, G AND M TRUCKS WITH RWAL TO: ALL CHEVROLET DEALERS Beginning in August 1990, a software change was made to the Electronic Control Units on all RWAL equipped vehicles. This software improvement will change codes 6, 9, and 10 to "Soft Codes." The conditions which set these codes remain the same, as well as the diagnostics technicians should follow to determine the root cause. Codes 6 and 9 will light the brake light when a fault is detected and the applicable code will be stored in memory. The brake light will remain on until the next ignition cycle at which time if the fault is not present, the brake light will remain off. The code, will still remain in memory as a "Soft Code." If the code should reoccur, the brake light will again be illuminated for the duration of that ignition cycle. A code 10 will set if the brake pedal is depressed or the brake switch circuit is opened and remains open until vehicle speed passes approximately 38 MPH. This soft code differs from codes 6 and 9 in that the red brake light will be illuminated only while the fault is detected. Code 10 will remain stored in the ECU memory after the light has been turned off. IMPORTANT: Technicians MUST use a Tech One scan tool to read codes. This is because soft codes will be erased by grounding terminals A to H and a false code 9 could be set if this is attempted. The new ECUs can be identified by the code printed on the bottom of the longer of two bar code labels on the module. Older ECUs will have a fifteen digit alphanumeric code beginning with 912349K. New ECUs with the soft code software will have a code that begins with 919220K. Page 1327 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 Page 1026 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 Page 420 Throttle Position Sensor: Adjustments The TPS is not adjustable. The ECM utilizes the IAC position reading at idle for its zero reading, therefore no adjustment is necessary. Page 3169 Electronic Spark Timing: Testing and Inspection Chart C-5 - Electronic Spark Control System Check Page 4485 Transmission Mount: Specifications Center support screws ......................................................................................................................... .................................................................... 15 ft. lbs. Page 601 Idle Speed: Specifications Minimum Idle Air Rate Minimum Idle Air Rate Engine Speed Note: Let engine idle until proper fuel control status is closed loop. Manual Transmission Neutral 450 +/- 50 rpm Auto Transmission Drive 400 +/- 50 rpm Neutral 475 +/- 50 rpm Page 578 Alignment: Technical Service Bulletins Alignment - The Importance of Four Wheel Alignment Number: 89-01-3A Section: 3A Date: SEPT., 1988 Subject: THE IMPORTANCE OF FOUR WHEEL ALIGNMENT Model and Year: 1979-89 ALL CHEVROLET MODELS TO: ALL CHEVROLET DEALERS In which direction will the vehicle pictured below travel if the steering wheel is straight ahead? The vehicle will track to the left because of the directional forces created by the rear wheels and tires. This directional force is called the "thrust angle". The front wheels aim or steer the vehicle but the rear wheels control tracking and assist in directing the car. What might the driver comment about? In the illustration, the driver may comment about the steering wheel being off center when going straight down the road. This would be true because of the added input required at the steering wheel to offset the thrust angle force caused by the rear wheels not tracking the front wheels to the geometric center line of the vehicle. The driver may also comment about unusual tire wear, not precise handling characteristics and even decreased fuel economy. A four wheel alignment allows the technician to measure the toe of each rear wheel to determine if the rear wheels are tracking the geometric center line of the car. Ideally the geometric center line will be the same as the thrust line. In the example in Figure 1, the thrust line has shifted to the right because the rear wheel toe is not tracking the front wheels. This can occur on both or on one rear wheel. On some vehicles the rear toe is adjustable; other models may require component straightening or replacement or shims. Once the rear toe is properly adjusted or set, the front wheel toe can be set so all four wheels are tracking the geometric center line of the vehicle. This will provide optimum tire wear, handling and fuel economy characteristics for the vehicle. Page 7628 Page 2428 4. Remove the retention spring from the mirror bracket (Figure 2, Item A). 5. Drill and tap the retention spring, on the rear side wing, so that it will accept a 6.0 mm X 1.0 mm (diameter X thread pitch) set screw fastener (Figure 3, Item A) (procured locally). The approximate fastener length should be 10 mm. NOTE: The hole must be drilled perpendicular to the flat surface of the retention spring's wing. 6. Reinstall the retention spring in the mirror bracket. 7. Reinstall the mirror head and arm to the mirror bracket. 8. Reinstall the mirror assembly to the door. 9. Install the 6.0 mm X 1.0 mm headed fastener, adjusting it to obtain the original pressure against the mirror arm. DO NOT over-torque this fastener. 10. Reinstall the screws which secure the mirror cover to the door. WARRANTY INFORMATION For vehicles repaired under warranty, use: Labor Description Labor Time Operation R3260 RH mirror R&R; 0.4 Hr. Locations Power Window Relay: Locations Behind Instrument Cluster Page 7020 Time Allowance: See Chants NOTE: The time allowances provided on the chart include the hardware removal and installation (as indicated by the list guidelines), the masking and unmasking of the vehicle, stripping of the surface (as indicated by the guidelines), the refinish (and colorcoat when required), mix time for primer/ paint (and clearcoat when required), finesse/polish where required, washing and preparing the vehicle for delivery. OPERATION DESCRIPTION: PAINT COLORCOAT DELAMINATION FROM ELPO PRIMER, REFINISH ENTIRE BODY ABOVE BODY SIDE MOLDINGS. PAINT TERM DEFINITIONS Following are definitions of paint repair terms used in this bulletin: Basecoat: A color topcoat that requires a clear topcoat over it. Break line: A natural dividing line on Page 2165 FIGURE 1(T-TRUCK ONLY) G. (T-truck only) Check equalizer lever for firm contact at the shift lever inboard side of the guide slot. (See Figure 1) H. If firm contact is evident, add an additional washer (#10 in Figure #1) P/N 14074908 to adjust equalizer lever outboard toward the center of the guide slot to eliminate contact. 2. A. Raise vehicle on hoist. B. Note location of clamp rotation on pipe. Some clamps are located with the lower lock ring (nuts) pointed towards the transmission. If the clamp is located in such a manner, loosen clamp and rotate it down so the nuts point toward the ground and retighten to 58 N-m (43 ft/lbs.) 3. A. Loosen converter clamp until it will rotate around the pipe. Using a suitable pry bar, move exhaust system rearward to obtain a minimum of 5/8 in. clearance between any point on the exhaust system and the transmission crossmember. For repairs performed under warranty, use the following labor operations and times: Labor Operation Labor Time Exhaust/muffler clamp L2020 .3 Hr Exhaust system align L2004 .3 Hr Shift Linkage (shorten) K5244 .3 Hr Testing and Inspection Ignition Control Module: Testing and Inspection If the vehicle cranks for at least 5 seconds and the Engine Control Module doesn't see a referance signal, some Models will set a code, 42 (Hard) or 12 (Soft). If your vehicle has one of these codes, begin with the Diagnostic System Check in Computers and Controls, then proceed to the Trouble Code Chart (Yes, some vehicles have a DTC Chart for Code 12). If the vehicle does not set a code, begin with the Diagnostic System Check, and it will send you to a Diagnostic Chart that checks for your particular condition. These types of tests are found under Computers and Control Systems. See: Computers and Control Systems/Testing and Inspection Page 6308 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 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. Page 6343 Ignition Firing Order Firing Order: Specifications Ignition Firing Order Firing Order ......................................................................................................................................... ............................................................... 1-6-5-4-3-2 Page 8074 inches from the inside of the hood opening)(see Figure 3). 3) Test with compressed air to insure all leaks have been eliminated. Once repairs have been made install cowl vent screen, grille and cowl vent screws. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: T7071 Labor Time: .6 hrs FAILURE CODE: 92 NOTE: Labor Operation is coded to base vehicle coverage in the warranty system. Page 6726 Tool Required: J-21104 Trim Pad Remover. REMOVE OR DISCONNECT 1. Door pillar molding. 2. Window regulator handle. 3. Armrest. 4. Power window switch, if used. 5. Trim panel. Pry the fasteners from their seats using J-21104. INSTALL OR CONNECT 1. Trim panel to the door. 2. Armrest. 3. Window regulator handle. 4. Power window switch, if used. 5. Door pillar molding. Page 4175 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 Page 3115 Throttle Position Sensor: Adjustments The TPS is not adjustable. The ECM utilizes the IAC position reading at idle for its zero reading, therefore no adjustment is necessary. Page 1860 Idle Speed: Adjustments *** UPDATED BY TSB # 88T556E DATED NOV. 1987 CONTROLLED IDLE SPEED CHECK 1. Set parking brake and block drive wheels. 2. Connect a SCAN tool to the assembly line data link (ALDL) connect with tool in Open Mode. 3. START engine and bring it to normal operating temperature. 4. Check for correct state of PARK/NEUTRAL switch on SCAN tool. 5. Check specifications chart for controlled idle speed and IAC valve pintle position (counts). 6. If within specifications, the idle speed is being correctly controlled by the ECM. 7. If not within specifications, perform MINIMUM IDLE AIR RATE CHECK. If still not within specifications, Refer to Diagnosis By Symptom / No Trouble Codes Stored. MINIMUM IDLE AIR RATE CHECK 1. Check controlled idle speed and perform idle air control check first. 2. Set parking brake and block drive wheels. 3. START engine and bring it to normal operating temperatures 185-212 degrees Fahrenheit (85-100 degrees Celsius). Turn engine OFF. 4. Remove air cleaner, adapter and gaskets. Check that the throttle lever is not being bound by the throttle, throttle valve or cruise control cables. 5. With IAC valve connected, ground the diagnostic terminal (ALDL). 6. Turn ON ignition, DO NOT START engine. Wait at least 10 seconds (this will allow the IAC pintle to extend and seat in the throttle body.). 7. With ignition ON, engine stopped, test terminal still grounded, disconnect IAC valve electrical connector. (This disables the IAC valve in the seated position). Remove the ground from the diagnostic terminal. 8. Connect a SCAN tool to the ALDL connector and place in open mode. If a tool is not available connect a tachometer to the engine. 9. START engine. With transmission in NEUTRAL, allow engine rpm to stabilize. 10. Check rpm against specifications. Disregard IAC counts on SCAN tool with the IAC disconnected. If the engine has less than 500 miles or is checked at altitudes above 1500 feet, the idle rpm with a seated IAC valve should be lower than values in chart. 11. If the minimum idle air rate is within specifications, no further check is required. 12. If the minimum idle air rate is not within specifications, perform the following procedures: 13. If present, remove the stop screw plug by piercing it with an awl, then applying leverage. The screw is covered to discourage unauthorized adjustments. 14. With the engine at normal operating temperature 185-212 degrees Fahrenheit (85-100 degrees Celsius), adjust stop screw to obtain nominal rpm per specifications with seated IAC valve. 15. Turn ignition OFF and reconnect IAC valve electrical connector. 16. Disconnect the SCAN tool or tachometer. 17. Use silicon sealant or equivalent to cover stop screw hole. 18. Install air cleaner, adapter and gasket. CONTROLLED IDLE SPEED Transmission Gear Idle Speed IAC Counts [1] OPEN/CLOSED LOOP [2] Page 2396 Fuel Pressure: Testing and Inspection NOTE: A fuel system pressure test is part of several of the Diagnostic Charts and Symptom Checks. To perform this test, follow this procedure: FUEL PRESSURE TEST 1. Turn engine OFF to relieve system pressure. 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. - The constant bleed feature relieves fuel pump system pressure when the engine is turned "OFF". 2. Uncouple fuel supply flexible hose in engine compartment. Install fuel pressure gauge between steel line and flexible hose. 3. Tighten gauge in line to insure no leaks occur during testing. 4. Connect negative battery terminal and START engine and observe fuel pressure reading. It should be 62-90 kPa (9-13 psi). If not, refer to DIAGNOSTIC CHARTS/FUEL SYSTEM PRESSURE TEST (CHART A-6). 5. Turn engine OFF to relieve system pressure. 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. - The constant bleed feature relieves fuel pump system pressure when the engine is turned "OFF". 6. Remove fuel pressure gauge. 7. Reinstall fuel line. 8. Connect negative battery terminal and START engine and check for fuel leaks. 9. Install air cleaner assembly. Oxygen Sensors - Silica Contamination Oxygen Sensor: 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. Page 6647 e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors Do Not require all the steps shown. Skip the steps that Do Not apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. 1. Separate connector halves (see Figures 2 through 6). Figure 2 Figure 3 Page 1615 Labor Operation No.: K6550 Valve, Pressure Regulator-R&R; or Replace Use the appropriate labor time in the labor time guide. Parts are currently available from GMSPO. Page 2323 Page 2355 Throttle Position Sensor: Service and Repair REMOVAL: 1. Disconnect electrical connectors. 2. Remove the TPS attaching screw assemblies and retainer, (if applicable). 3. Remove TPS from throttle body assembly. NOTE: The TPS is an electrical component and must not be soaked in any liquid cleaner or solvent, as damage may result. INSTALLATION: 1. Install TPS to throttle body assembly, while lining up TPS lever with TPS drive lever on throttle body. 2. Install the two attaching screw assemblies. Tighten screw assemblies to 2.0 Nm (18.0 lb-in). 3. Install electrical connector to TPS. 4. Check for TPS output as follows: a. Connect an ALDL scanner to read TPS output voltage. b. With ignition ON and engine stopped, TPS voltage should be less than 1.25 volts. If more than 1.25 volts, replace TPS. Page 1824 Figure 1 This bulletin is for informational purposes only, and should be used as a guideline if it becomes necessary to replace the intake manifold gaskets on 4.3L, 5.0L and 5.7L TBI engines. With the introduction of TBI engines, a change was made to the intake manifold gasket by adding a restrictor plate to the rear coolant passage of the gasket in order to direct coolant to flow from the front of the intake manifold, under the TBI section of the manifold (heats TBI to prevent throttle plate icing) and exit out of the heater hose pipe at the rear of the manifold (See Figure 1). Anytime it becomes necessary to replace the intake manifold gasket, it is essential that the gaskets be properly installed. If the gasket is installed backwards i.e., with the restrictor plate at the front of the engine, the engine will overheat. When diagnosing overheat conditions, the proper installation of the gasket can be checked without removing the manifold. Both the 4.3L, 5.0L, and 5.7L gaskets have metal locator tabs that can be seen sticking out from between the manifold and the cylinder head. When installed correctly, the tab on the 4.3L will be to the rear of the engine and the tab for the 5.0L and 5.7L engine will be to the front of the engine (See Figure 1). Page 7764 Symbol Identification Cooling - Cold Start Fan Noise Higher Than Normal Fan Clutch: Customer Interest Cooling - Cold Start Fan Noise Higher Than Normal Number: 92-118-6B Section: 6B Date: FEB. 1992 Corporate Bulletin No.: 166203 ASE No.: A8 Subject: COLD START FAN NOISE Model and Year: 1988-92 S/T TRUCKS WITH 4.3L ENGINES Owners of some 1988-1992 S/T vehicles equipped with a 4.3L engine (RPO LB4 or L35) and air conditioning (RPO C60) may experience higher than normal fan noise upon oold start up. This condition may be due to incorrect engagement of the fan clutch. The condition may be corrected by installing a revised fan clutch (P/N 15672779). Vehicles built after the following VIN Breakpoints have the new fan clutch installed in production: Plant VIN Moraine 1GNDT13Z3N2151684 Shreveport 1GCCS19Z3N8156864 Pontiac West 1GNCS18Z2N0125676 SERVICE PROCEDURE: Refer to section 6B1 "FAN/FAN CLUTCH REPLACEMENT" in the appropriate S/T Service Manual for removal and installation of the fan clutch. Page 275 Refrigerant Pressure Sensor / Switch: Service and Repair High-Side-High Pressure Cut Off Switch R-4 COMPRESSOR R-4 Compressor Component View Remove or Disconnect Tools Required: J 5403 Snap Ring Pliers J 9553 O-Ring Remover 1. Protective cap (28). 2. Retainer ring (27) with J 5403. 3. Valve (26). 4. Seal (25) with J 9553-01. Clean ^ Remove any dirt from the valve cavity. Install or Connect 1. New seal (O-ring) (25) to the cavity. ^ Dip the new seal in clean 525 viscosity refrigerant oil. 2. Pressure relief valve (26). 3. Retainer ring (27) with J 5403-A. 4. Cap (28). Lap/Shoulder Belts - Dealer Installed Rear Kits Seat Belt: Technical Service Bulletins Lap/Shoulder Belts - Dealer Installed Rear Kits File In Section: 09 - Restraints Bulletin No.: 99-09-40-006 Date: January, 2000 INFORMATION Subject: Dealer Installed Rear Seat Lap/Shoulder Belt Kits Models: 1988 and Prior Passenger Cars and Light Duty Trucks In 1986, General Motors made a commitment to become the first American manufacturer to provide rear seat lap/shoulder belts as standard equipment in new domestic light vehicles. In addition, GM released dealer-installed Rear Seat Lap/Shoulder Belt kits for most current and past model vehicles. At this time, certain belt kits are still available from GMSPO. Some passenger cars can still be retrofitted with belt kits in the correct matching color, while other cars can only be retrofitted with black belt kits. Light Duty Trucks only have retrofit belt kits available in black. With seat belt use required now in most states, public acceptance of all kinds of occupant restraints is increasing. As a result, you may see an increase in requests from vehicle owners. Parts Information For part number, usage, and availability of Rear Seat Lap/Shoulder Belt kits, see Group 21.040 (Accessories) of the appropriate GMSPO Parts Catalog. Warranty Information The cost associated (parts & labor) with installing these Rear Seat Lap/Shoulder Belt kits is the responsibility of the customer. Locations Convenience Center Page 2637 Quad Driver: Service and Repair Quad/Output drivers are hard wired onto the ECM/PCM/VCM, and can't be serviced separately. Page 683 Valve Clearance: Adjustments Fig. 14 Valve Adjustment 1. Remove rocker arm covers as described under COMPONENT REPLACEMENT AND REPAIR PROCEDURES/ROCKER ARM & PUSHRODS. 2. Crank engine until mark on torsional damper is aligned with ``0'' mark on timing tab and engine is in No. one cylinder firing position. Ensure engine is in No. 1 firing position by placing fingers on rocker arms of No. 1 cylinder as timing mark approaches ``0'' mark. If rocker arms are not moving engine is at the No. 1 firing position. If rocker arms are moving, engine is in the No. 4 firing position and should be rotated one revolution to the No. 1 position. 3. Adjust the following valves with the engine in the No. 1 firing position: exhaust 1, 5 and 6; intake 1, 2 and 3. Adjust valves by backing off nut until lash is felt at the pushrod, then tightening nut until all lash is removed. This can be determined by rotating pushrod while tightening nut. Fig. 14. When all lash is removed, tighten nut one full turn to center pushrod in lifter plunger. 4. Crank engine one full revolution until mark on torsional damper and ``0'' mark on timing tab are aligned. This is the No. 4 cylinder firing position. Adjust the following valves: exhaust 2, 3 and 4; intake 4, 5 and 6. 5. Install valve covers and related components. Locations Parking Brake Warning Switch: Locations LH Side Of I/P Behind Instrument Cluster Page 7871 Brake Light Switch: Service and Repair Fig. 2 Stop Light Switch Installation 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. 2. 5. Pull brake pedal rearward against pedal stop to adjust switch. Switch is properly adjusted when brake lights operate when brake pedal is depressed .53 inch from normal position. If further adjustment of switch is necessary, switch can be rotated or pulled in clip. Page 4178 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 as outlined in SIDE GEAR SHIM SELECTION. 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. 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 Page 4321 B. Disturbance may peak within this speed range. C. Visually check components for damage, looseness, missing balance weights, etc. D. This may compensate for companion flange runout E. Excessive companion flange runout may occur as high prop runout. Replace companion flange as required, see Figure 2. F. IMPORTANT: If runout is reduced to below 0.005-inch and the flange possesses a compensation weight, this part is out of spec. See Figure 2. G. Ensure the companion flange runout is still well within specifications. H. If this point has been crossed several times, it is recommended that the Technical Assistance Center be contacted. 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. Locations Power Window Relay: Locations Behind Instrument Cluster Page 2586 Wiring Diagram For Chart C-2 - Idle Air Control Check CHART C-2 - IDLE AIR CONTROL CHECK Circuit Description: The ECM sends voltage pulses to the IAC motor winding causing the motor shaft and valve to move "in" and "out" a given distance for each pulse (called counts) received. This movement controls air flow around the throttle plate, which, in turn, controls engine idle speed. Test Description: Numbers below refer to circled numbers on the diagnostic chart "Scan" tool must be in open mode during test. Keep A/C "OFF" during entire check. 1. Test with engine in drive and continue with test, even if idle is erratic. If idle is too low, "Scan" will display 80, or more, counts or steps. Engine speed may vary 200 RPM, or more, up and down. Disconnect IAC. If the condition is unchanged, the IAC is not at fault. There is a system problem. Proceed to step "3" below. 2. When the engine was stopped with ignition "OFF", the IAC valve retracted (more air) to a fixed "Park" position, for increased air now and idle speed during the next engine start. A "Scan" will display 100 or more counts. 3. Be sure to disconnect the IAC valve prior to this test. The test light will confirm the ECM signals by a steady or flashing light, on all circuits. 4. There is a remote possibility that one of the circuits is shorted to voltage, which would have been indicated by a steady light. Disconnect ECM and turn the ignition "ON" and probe terminals to check for this condition. Diagnostic Aids: An unstable idle may be a system problem that cannot be overcome by the IAC. "Scan" counts will be above 80 counts, if too low, and 0 counts, if too high. ^ If IAC valve pintle position counts are low or zero, check with vacuum leaks at vacuum fitting, tees and hoses, the throttle body and the intake manifold. A bottomed (zero count) IAC valve pintle may result in an idle speed above specification. Refer to minimum air rate check. ^ If IAC valve pintle position counts are high, look for carbon build-up in the IAC valve air inlet passage or evidence of tampering with stop screw. Also check for low engine power or excessive accessory loads. ^ System Too Lean (High Tailpipe Air/Fuel Ratio - Engine speed may vary up and down and disconnecting the LAC may not stabilize engine speed. If "Scan" and/or Voltmeter reads an oxygen sensor output less than 300 mv (.3v), check for low regulated fuel pressure or water in fuel. A code 44 (lean O2 sensor) may be set. A lean tailpipe exhaust with an oxygen sensor-output fixed above 800 mv (.8v) could be a contaminated sensor, usually Silicon. This may set a Code 45 (rich O2 sensor) even with lean tailpipe exhaust. ^ System Too Rich (Low Tailpipe Air/Fuel Ratio - System obviously rich and may exhibit black smoke exhaust. "Scan" toot and/or Voltmeter will read an oxygen sensor signal fixed above 800mv (.8v). Check for: - Injector leaking or sticking - High fuel pressure - Air leak in MAP transducer line - If O2 is normal or low, inspect for air being pumped into exhaust manifold in front of O2 sensor (or exhaust leak) ^ Throttle body - Remove IAC and inspect bore for foreign material or evidence of IAC valve dragging the bore. (Repair as required) ^ A/C Compressor or relay failure - See A/C diagnosis if circuit is shorted to ground. If the relay is faulty, idle problem may exist. ^ Refer to Rough, Unstable, Incorrect Idle or Stalling. See Diagnosis By Symptoms - No Trouble Codes. Page 382 Knock Sensor: Description and Operation Knock Sensor Operation ESC Wiring Diagram The Electronic Spark Control (ESC) system is comprised of a knock sensor, the ESC module, and the ECM. As the knock sensor detects engine knock, it sends a voltage signal to the ECM. The ECM responds by retarding the ignition timing until the knocking ceases. As detonation is reduced, the ECM advances the timing again in small increments back to the pre-programmed point for that engine speed and load. Page 7581 Symbol Identification Page 4256 Pinion Gear: Adjustments Timken/Rockwell - 12 Inch Ring Gear Fig. 1 Timken/Rockwell drive axle w/12 inch ring gear exploded view DISASSEMBLY 1. Tap or press pinion from cage, taking care not to damage shaft threads, then remove outer pinion bearing, Fig. 1. 2. Remove spacer from pinion, then the inner bearing, using suitable separator and press or puller. 3. If straddle bearing must be replaced, remove snap ring and washer, then the bearing, using suitable puller. 4. If bearings are to be replaced, press outer races from bearing cage, taking care not to distort cage. 5. Inspect components as outlined, and replace as needed, keeping components in order for assembly. ASSEMBLY & PRELOAD ADJUSTMENT 1. When installing new cups, press them firmly against pinion bearing cage shoulders. 2. Lubricate bearings and cups with suitable lubricant. 3. Press rear thrust and radial bearings firmly against pinion shoulders, using suitable sleeve that will bear only on bearing inner race. 4. Install radial bearing lock ring, then squeeze ring into pinion shaft groove. 5. Insert pinion and bearing assembly in pinion cage and position spacer or spacer combination over pinion shaft. 6. Press front bearing firmly against spacer. Page 7420 Symbol Identification Page 3041 Fuel Injector: Service and Repair Fuel Injector Removal NOTES: a. Each fuel injector is serviced as a complete assembly only. b. 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. REMOVAL: 1. Disconnect electrical connectors to fuel injectors. (Squeeze plastic tabs and pull straight up.) 2. Remove fuel meter cover assembly, refer to FUEL METER COVER ASSEMBLY. 3. With fuel meter cover gasket in place to prevent damage to casting, use a screwdriver and fulcrum to carefully lift out each injector. 4. Remove lower (small) O-rings from nozzle of injectors and discard. 5. Remove fuel meter cover gasket and discard. 6. Remove upper (large) O-rings and steel backup washers from top of fuel injector cavity and discard. INSPECTION: Inspect the 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 MAINTENANCE PROCEDURES/FUEL SYSTEM CLEANING. Fuel Injector Color Code Locations Service and Repair Evaporator Core: Service and Repair Fig 26. Evaporator And Blower Assembly Fig 27. Evaporator And Blower Assembly Page 3133 Throttle Cable/Linkage: Adjustments There are no linkage adjustments. Check cable routing to insure free operation of the throttle cable. If replacement is necessary, the throttle cable must be replaced with an identical replacement part. For replacement procedure, refer to COMPONENT REPLACEMENT AND REPAIR PROCEDURES. Page 6912 Symbol Identification Page 8080 Avoiding Wiper Damage The following are major contributors to wiper damage. Some of these you can control and others are environmental concerns. - Extremely dusty areas (such as driving on dirt roads) may cause the wipers rubber edge to wear quickly and unevenly. - Sand and salt used on roads for increasing winter traction and ice control will cause the wiper blades to wear quicker. Areas with significant snowfall require more frequent blade replacements. - Heat and time may cause the rubber blades to take a "permanent set" resulting in the rubber not flexing and turning over uniformly. This condition may result in streaking and/or unwiped areas. - Rubber blades are easily cut or torn when using ice scrapers. Likewise pulling blades up off a frozen windshield can tear the rubber. Exercise caution when clearing ice and snow. - Using your wipers to "wear through" frost and ice, instead of allowing the defrosters to melt the ice, can dull, nick or tear the rubber blades. - Banging wipers on the glass to remove ice and snow may cause the blade to bend, dislodging the rubber and causing potential scratching of the windshield. - Ice can form in the pin joints of the wipers, which can cause streaking and unwiped areas. To remove ice from pin joints, compress the blade and rubber edge with your hand to loosen the frozen joints. Consider using Winter Blades that have a rubber cover to avoid this condition. Note GM does not recommend the use of any spray on/wipe on windshield treatments or washer fluid additives. The variation in friction that results on the glass from the use of these products causes wipers to chatter and have premature wear. Disclaimer Page 6298 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. Page 2365 Vehicle Speed Sensor: Locations LH Side Of I/P Behind Instrument Cluster Page 4319 To Use Diagnosis Tree: Locate symptom on the diagnosis tree which best describes the disturbance. Follow arrows and perform the required check or service action. Never bypass or skip an inspection or assume that a component is OK. All steps must be performed as called out. Definition of Terms: "Boom" - Continuous bass drum roll sound caused by body cavity resonance excited by drivetrain. Sometimes felt as pressure in ears. "Buffeting" - High pressure pulsation. "Droning" - A low heavy reverberating often muffled sound. Sounds like a bowling ball rolling down alley. "Drumming" - A drum roll similar to "Boom." "Howling" - A mid-range continuous sound usually associated with driveline gear noise. Body - Maintaining Exterior Weatherstrip Appearance Weatherstrip: Technical Service Bulletins Body - Maintaining Exterior Weatherstrip Appearance INFORMATION Bulletin No.: 99-08-64-016C Date: July 29, 2009 Subject: Information on Maintaining Exterior Weatherstrip Appearance 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 add model years and update the parts and procedure information. Please discard Corporate Bulletin Number 99-08-64-016B (Section 08 - Body and Accessories). Exterior weatherstrips are exposed to a variety of environmental elements, including UV rays, acid rain, insect and bird residue and atmospheric fallout. All of these may effect the appearance of the weatherstrips; however, they do not effect the functionality of the weatherstrip. Weatherstrips that are discolored should not be replaced under the normal GM New Vehicle Warranty. Weatherstrip Maintenance Instructions Silicone grease on weatherstrips will make them last longer, seal better, and not stick or squeak. Clean the weatherstrips with a mild soap and water solution. Apply silicone grease with a clean cloth. During very cold, damp weather, frequent application may be required. Refer to the information below for the recommended maintenance products. Weatherstrips that are not maintained may crack and weather due to environmental elements. Parts Information Weatherstrip Conditioning Weatherstrip Lubricant (GM P/N 3634770 [in Canada, P/N 10953518]) or Dielectric Silicone Grease (GM P/N 12345579 [in Canada, P/N 992887]). Disclaimer Diagram Information and Instructions Multiple Junction Connector: Diagram Information and Instructions 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 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. Drivetrain - Recommended Axle Lubricant Fluid - Differential: All 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. Page 4411 Reverse Idler Gear: Specifications Warner T-4C 4 Speed Reverse idler gear and reverse lever on pivot bolt .................................................................................................................................................. 20 ft. lbs. Page 1087 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 Page 2331 Page 572 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 Service and Repair Seals and Gaskets: Service and Repair 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. Page 7404 Labor operation T7990 Labor time .4 Hr Page 1861 Man. N 500-550 2-12 CL Auto D 500-550 2-20 CL [1] Add 2 counts for engines with less than 500 miles. Add 2 counts for every 1000 ft. above sea level. [2] Let engine idle until proper fuel control status is reached (OPEN/CLOSED LOOP). MINIMUM IDLE AIR RATE Transmission Gear Engine Speed OPEN/CLOSED LOOP [1] Man. N 450 +/- 50 CL Auto. N 475 +/- 50 CL [1] Let engine idle until proper fuel control status (OPEN/CLOSED LOOP) is reached. Page 3675 FIGURE 2 FIGURE 3 ^ THM 125C, 440-T4 (Refer to Figures 2 and 3): When cold, 27 Degrees C (80 Degrees F), a full transaxle will show the fluid level to be above the "Full Hot" mark. This is a result of fluid stored in the bottom pan when cold. As the transaxle warms to normal operating temperature, fluid is captured in the side pan, lowering the fluid level to within the cross-hatched area. NOTICE: The "cold" check procedure cannot take the place of a "hot check. The "cold" check will let the technician know there is enough fluid to perform a Preliminary check Procedure, an accurate road test, and allow normal operating temperature to be obtained prior to the necessary "hot" check. B. "HOT" CHECK PROCEDURE: 1. Drive vehicle in all ranges to attain a fluid temperature of 80 to 90 Degrees C (180 to 200 Degrees F). 2. Idle at normal idle speed in Park for 3 minutes. 3. With vehicle level, accessories turned off, and engine idling in Park, check fluid level. 4. Fluid level should be within the cross-hatched area. (Read front and back, use the lowest level.) Page 5518 Symbol Identification Wire Color Code Identification WIRE COLOR ABBREVIATION BLACK BLK BLUE BLU DARK BLUE DK BLU Page 3974 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 Page 6061 Air Door Actuator / Motor: Service and Repair Defroster Vacuum Diaphragm Replace S/T-10/15 1. Disconnect battery ground cable. 2. Disconnect vacuum line and actuator linkage. 3. Remove actuator retaining nut and actuator. 4. Reverse procedure to install. Page 6648 Figure 4 Figure 5 Figure 6 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 7 Specifications Countershaft: Specifications Countershaft nut .................................................................................................................................. .................................................................... 80 ft. lbs. Page 1249 FIGURE 2 Irregular/premature tire wear is aggravated by excessive toe-in (or toe-out). Excessive camber can also be a contributor, as can operating conditions, such as city driving with alot of cornering. Irregular tire wear usually occurs on non-drive axles, such as the front wheel positions of rear drive vehicles. An early indication may be an increase in tire noise. In most cases, modified "X" tire rotation, which is a scheduled maintenance at 7500 miles, will equalize tire wear (see Figure 1). Some amount of wear is expected and should be considered normal. Only when the cross grooves in the tread disappear within 12,000 miles should the tires be replaced under warranty (see Figure 2). Even when these grooves disappear, however, the tire is normally only half worn in this area. Whenever tires are replaced for this reason, alignment should be checked and reset to specification, if necessary. If tires are needed for any of the above conditions, they should be purchased from your local tire outlet. If tires are not readily available, each tire manufacturer has a toll-free assistance line for car and truck dealers. These numbers have been previously provided. The tire invoice amount should be entered as a net item on the warranty claim. Labor code E0420, replace wheel and/or tire, should be used. Figure 1 modified "X" tire rotation, front wheel drive, rear wheel drive. This rotation pattern eventually gets each tire on all four positions. It gets those tires on the non-drive axle, which are most prone to irregular wear, to turn in the opposite direction. This will equalize wear quickest, and tire noise related to tread wear will actually become quieter after a few thousand miles. Figure 2 evaluating tire wear. Typical all-season tire. Tire should be replaced only if these grooves are no longer visible within first 12,000 miles. Locations Timing Connector-In Pass Comp Behind Carpet, Below Heater Page 7820 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 4. Make repair. Page 4063 When the converter clutch valve train has been eliminated, there will be a sleeve and plug installed as illustrated. Specifications Valve Clearance: Specifications All ......................................................................................................................................................... ................................................................ E-I-E-I-I-E Locations Throttle Position Sensor: Locations Center Of Dash Panel (engine Compartment) Center Rear Of Engine Applicable to: V6-262/4.3L Engine Symptom Related Diagnostic Procedures Torque Converter Clutch: Symptom Related Diagnostic Procedures No Torque Converter Clutch Apply 1. 12 volts not being supplied to the transmission. 2. Defective transmission outside electrical connector. 3. Defective inside electrical connectors, wiring harness, solenoid. 4. Defective electrical ground inside transmission. 5. Defective pressure switch or improper connection. 6. Solenoid not grounded. 7. Valve body converter clutch shift or throttle valve sticking. 8. Valve body casting or spacer plate in converter clutch valve area are improperly positioned or damaged. 9. Converter clutch apply valve, stuck or installed backwards. 10. Pump assembly signal oil orifice, restricted or missing. 11. Pump assembly O-ring on solenoid damaged or missing. 12. Pump to case gasket, damaged or improperly positioned. 13. Pump assembly cup plug missing from apply passage. 14. Pump assembly orifice plug missing from the cooler input passage. 15. High or uneven bolt torque on cover to body. 16. Converter clutch stop valve or retainer ring not installed properly. No Torque Converter Clutch Release 1. Converter clutch apply valve stuck in the open position. 2. O-ring or check ball in the end of the turbine shaft damaged. 3. Internal converter damage. Page 1086 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 Page 5298 When diagnosing an electrical system that utilizes Metri-Pack 150/280/480/630 series terminals (refer to Terminal Repair Kit J 38125-4 instruction manual 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 or replace...". Mating terminals must be inspected to assure good terminal 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 to 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, see Figure 1, 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 38125-4 instruction manual. 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 connection 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 38125-2, 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 38125-2, 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 38125-2. Page 2585 Idle Speed/Throttle Actuator - Electronic: Testing and Inspection Chart C-2 - Idle Air Control (IAC) System Check End Gate Lock Cylinder - Rattles Trunk / Liftgate Lock Cylinder: All Technical Service Bulletins End Gate Lock Cylinder - Rattles Number: 91-507-10 Section: 10 Date: AUGUST 1992 Corporate Bulletin No.: 261003 ASE No.: B1 Subject: END GATE LOCK CYLINDER ASSEMBLY RATTLE Model and Year: 1982-91 S/T TRUCKS Some owners of 1982-1991 S/T utility vehicles may experience a rattling sound emanating from the rear of the truck. This condition may occur if the end gate lock cylinder assembly is loose. To correct this condition, it is necessary to bend the ends of the spring within the lock cylinder assembly eliminating any clearance between the pawl assembly and cylinder housing. SERVICE PROCEDURE: 1. Open the end gate to the horizontal position and remove the inner trim panel. Page 7511 Figure 4 Figure 5 Figure 6 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 7 Page 1724 Symbol Identification Page 5605 What corrected the customer concern and was the repair verified? Please Explain: ............. Disclaimer Page 7015 * 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. Important Additional time or payment beyond established allowances in this bulletin will not be allowed. - The use of a razor blade on large flat surfaces is not recommended because of the potential to chip. gouge or otherwise damage the primer surface. If razor blade technique is used, the application of a "guide coat" prior to wet sanding should also be used. Note: Chemical stripping is not recommended because of negative impact to moldings, non-metal components, ELPO and environmental concerns. 4. Blow off with air to remove all dirt and sanding residue from cracks and vehicle surface. 5. Clean sanded surface with an appropriate wax and grease remover. 6. Tack wipe entire area to be primed. 7. Spray entire prepared area with a coat of anti-corrosion primer to ensure maximum adhesion and corrosion resistance. Be sure to cover any bare metal surfaces exposed during the sanding operations. Follow manufacturer's instructions and recommended dry times. Typical materials for this application would be: DuPont 615S/616S, BASE DE17/PR8O/DA18, PPG DP4O/DP401, or equivalent. V.O.C. materials would be: DuPont 615S/616S, BASF DE15/PA16/PRB0, PPG DCP21/DCX211 or equivalent. 8. Apply two to three medium wet coats of primer surfacer to the primed surface of the vehicle, following the manufacturer's instructions for application and film build requirements. Important Failure to apply primer surfacer will likely result in future delamination. Typical materials for this application would be: DuPont 1120S/1130S/1125S, BASF DP20/PR80/PH36, PPG K36/DT870/K201, or equivalent. V.O.C. materials would be: DuPont 210S, BASF HP400, PPG DCP21/DCX211, or equivalent. 9. After allowing adequate drying time, wet sand with 400 grit (or finer) or dry sand with 320 grit (or finer) sandpaper. 10. Repeat steps 4 through 6. 11. Apply a medium coat of corrosion resistant primer sealer (tintable base) to the entire surface to be refinished. This will provide maximum adhesion, uniform color coating and corrosion protection to areas "sanded through" during wet sanding. Follow manufacturer's instructions and recommended dry times. Typical materials for this application would be: DuPont 2610S/2605S, BASF DP21/DH6O/PR80, PPG DP40/DP402 or equivalent. V.O.C. materials for this application would be: DuPont 21255, PPG DPW1834 or equivalent. 12. Apply two to three medium wet coats of color (or until primer color is hidden). Follow manufacturer's instructions and recommended dry times. 13. If vehicle has basecoat/clearcoat paint, apply clearcoat. Follow manufacturer's instructions and recommended dry times. 14. After sufficient air or force dry time, unmask the vehicle. 15. Finesse/polish as required. 16. Reinstall all previously removed items. 17. Wash and prepare the vehicle for delivery. HARDWARE ITEMS REMOVAL LIST Note: Some technicians may apply a small cord (wire, plastic tube, etc.) behind or underneath moldings that remain on the vehicle to improve sanding and painting. If the vehicle paint system is baked with cord in place, damage to some moldings may occur. If this technique is used, DO NOT BAKE Page 4244 Fig. 10 Pinion Straddle Bearing Removal 1. Clamp pinion assembly in vise taking care not to damage housing or gear. 2. Hold driveshaft flange with suitable tool, then remove pinion nut and washer. 3. Remove driveshaft flange from pinion shaft using suitable puller. 4. Support housing in press as shown in Fig. 9, and press pinion from housing. Do not allow pinion to drop on floor. 5. Separate pinion flange, oil seal, front bearing and bearing retainer, driving seal from housing with suitable drift. 6. Remove bearing races from housing using suitable drift and place front bearing race with bearing. 7. Press rear bearing from pinion and place bearing with race. 8. Remove straddle bearing from axle housing using suitable drift, Fig. 10. 9. Inspect components keeping all components in order, and replace as needed. Assembly & Preload Coat components with specified lubricant during assembly. If components are reused, they should be installed in original position. 1. Press rear bearing onto pinion using suitable spacers. 2. Install front and rear bearing races in housing, using suitable drivers to ensure that races are properly seated. 3. Install straddle bearing in axle housing using straddle bearing installer tool No. J-23322 or equivalent to ensure that bearing is properly seated. 4. Insert pinion through housing, install new collapsible spacer and front bearing over pinion shaft, support pinion and press front bearing onto shaft. 5. Lubricate lips of new seal with grease and install seal using suitable driver to seat seal against shoulder of housing. 6. Install driveshaft companion flange, washer and new pinion nut. 7. Clamp housing in vise, hold flange with suitable tool and torque pinion nut just until all endplay is removed. 8. Check pinion bearing preload (rotating torque) using suitable torque wrench. 9. Continue tightening pinion nut in small increments until specified preload is obtained, checking preload after each adjustment. Exceeding specified preload will collapse spacer too far to be reused. If preload specification is exceeded, spacer must be replaced and adjustment procedure must be repeated. Do not loosen pinion nut to reduce bearing preload. Page 3776 Governor Pressure Switch: Service and Repair Turbo Hydra-Matic 4L60 (700-R4) 1. Raise and support vehicle. 2. Remove governor cover from case using extreme care not to damage cover. If cover is damaged, it must be replaced. 3. Remove governor. 4. Reverse procedure to install and check fluid level. Page 6162 Installing The Rotor And Bearing Guide 3. Rotor (5) and bearing (6) assembly with J 25031. ^ Install the J 25031 guide over the shaft (39) end. ^ Install the J 25031 puller over the guide. ^ Engage the arms of J 25031 down into the recessed edge of the rotor hub (5). ^ Hold the arms of J 25031 and tighten the screw against the guide. Removing The Clutch Rotor Bearing 4. Bearing (6) from the rotor hub (5) with J 9398 and J 8092. ^ Place the rotor hub clutch face up on wooden blocks on a flat surface. ^ Drive the bearing out with J 9398 and J 8092. Install or Connect Tools Required: J 6083 Snap Ring Pliers J 8092 Universal Handle J 9481-A Pulley and Bearing Installer Page 4889 FIGURE 1 - WHEEL NUT TIGHTENING WHEEL BOLT TORQUE: Overtorqued wheel nuts or torquing wheel nuts without alternating the tightening sequence, especially on aluminum wheels, can also create a rotor runout condition. Refer to Figure 1. The use of a torque wrench when tightening wheel nuts is necessary to prevent distortion of the rotor, hub or wheel. The wheel nuts should be tightened in two steps to assure an even clamp load. FIGURE 2 - CALL TO BRACKET CLEARANCE CALIPER DRAG: Caliper drag is usually caused by interference between the caliper to knuckle interface or a caliper bolt binding on the caliper bolt bushing. Caliper to knuckle clearance is important. Clearance should be checked with the caliper in position and the caliper mounting bolts properly torqued. If excessive clearance exists, a clunking noise may occur on each brake apply. Too little clearance can cause caliper drag. The desired clearance is .005 - .012 in. at each caliper to knuckle bracket interface, or a total of .010 - .024 in. The caliper bracket stops can be filed -to obtain proper clearance. Refer to Figure 2. Page 534 Transmission Speed Sensor: Service and Repair 1. Disconnect battery ground cable. 2. Raise and support vehicle, then disconnect sensor electrical connector. 3. Remove sensor retaining bolt, then the sensor. 4. Reverse procedure to install. Page 5109 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 4. Make repair. Page 5845 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 Modes of Operation Engine Control Module: Description and Operation Modes of Operation Acceleration Mode In the Acceleration Mode, the ECM senses rapid change in throttle position and manifold pressure and provides a corresponding amount of added fuel. Battery Voltage Correction Mode When battery voltage is low, the ECM compensates to maintain acceptable system performance by increasing injector pulses, idle speed and ignition dwell time. Clear Flood Mode (Port and TBI Injection) A flooded engine is cleared by fully depressing the accelerator pedal, which causes the ECM to pulse the injectors at a air/fuel ratio of 20:1. The ECM will maintain this air/fuel ratio as long as the throttle is wide open and engine RPM is less than 600. If throttle position becomes less than 80% of wide open throttle, the ECM returns to "Starting Mode". Deceleration Mode In the Deceleration Mode, the ECM senses changes in throttle position and manifold pressure and reduces fuel delivery. When decelerating very rapidly, the ECM can cut off fuel completely for short periods of time. Electronic Spark Timing (EST) The Electronic Spark Timing (EST) distributor contains no vacuum or centrifugal advance mechanisms. In addition to the connectors normally found on HEI distributors, the HEI-EST distributor also has four wires going to a four terminal connector. A reference pulse, indicating engine RPM and crankshaft position is sent to the ECM. The ECM determines the proper spark advance for the engine operating conditions and sends an "EST" pulse to the distributor. In the case of EST failure, a back-up spark advance system is incorporated in the module. Run Mode The Run Mode consists of two separate operating conditions; open loop and closed loop. The engine operates in open loop when it is first started and RPM is above 400 RPM. During open loop operation, the ECM disregards the oxygen sensor signal and determines air/fuel mixture primarily from the coolant and MAP sensors. The engine will continue to operate in open loop until the following conditions are met: 1. The Oxygen sensor has varying voltage output, indicating it is hot enough to operate properly. 2. The Coolant sensor is above a specified temperature. 3. A specific amount of time has elapsed since the engine was started. The specified values for conditions mentioned above vary from model to model, and are stored in the ECM PROM. When the above conditions are met, the engine goes into closed loop operation. When operating in closed loop, the ECM determines the air/fuel ratio (injector pulse rate) based on signals from the oxygen sensor. This allows the air/fuel mixture to remain close to the optimum 14.7:1 ratio. During idling conditions, the V6-173 and V8-454 engines automatically goes into open loop operation. Starting Mode (Port and TBI Injection) When the ignition switch is rotated to the "On" position, the ECM energizes the fuel pump for two seconds and fuel pressure is built up to the TBI unit. The ECM then checks the coolant temperature sensor, the TPS and determines the proper air/fuel mixture for starting. The ECM controls the air/fuel ratio by changing the length of time the injectors are turned on and off. This is accomplished by "Pulsing" the injectors for short periods of time. Windshield/A Pillar - Pop Noise Diagnosis Dashboard / Instrument Panel: Customer Interest Windshield/A Pillar - Pop Noise Diagnosis Number: 93-25-10 Section: 10 Date: OCT. 1992 Corporate Bulletin No.: 262001 ASE No.: B1 Subject: POP NOISE FROM WINDSHIELD PILLAR AREA Model and Year: 1983-93 S/T TRUCKS REFERENCE COWL "POP" TAPPING NOISE CHEVROLET DEALER SERVICE BULLETIN NUMBER 91-351-10, DATED JUNE 1991. Owners of some 1983-1993 S/T Pickups and Utilities may comment on a cowl "pop" noise transmitted through the "A" pillar. It has been determined that sections other than the windshield cowl area may produce a sound which imitates cowl "pop". PRIOR TO PERFORMING ANY CORRECTION FOR COWL "POP" TAPPING NOISES, VERIFY THE SOURCE OF THE NOISE(S) TO DETERMINE IF IT IS A VALID COWL "POP" CONDITION. Possible noise areas to check are: ^ Instrument panel "pop"/noise. ^ Loose door lock rods. ^ Loose wires/harnesses contacting the wall of the engine/passenger compartment (cowl). ^ A lack of door hinge lubrication. ^ An Electronic Control Module (ECM) bracket "pop". ^ An ash tray rattle. ^ An air vent squeak. ^ Hood hinge "flutter"/rattle. INFORMATION: 1. INSTRUMENT PANEL (I/P) "POP"/NOISE sound at the front edge of the I/P may occur if the I/P pad rubs against the cowl/dash support panel. Refer to "Instrument Panel Pad to Cowl Panel "Pop" Noise" Chevrolet Dealer Service Bulletin Number 92-286-10, dated Sept. 1992. 2. LOOSE DOOR LOCK RODS may vibrate during vehicle operation creating a rattle type noise. Refer to "Front Door Lock Rod Rattle" Chevrolet Dealer Service Bulletin No. 91-406-10, dated August 1991. 3. THE ELECTRONIC CONTROL MODULE (ECM) WIRING HARNESS CLIP may not be properly attached at the transmission bellhousing bolt allowing contact with the floor pan/front of dash area. This sound may be amplified by the HVAC ductwork. 4. LOOSE WIRES/HARNESSES maybe tapping against the engine/passenger compartment wall (cowl). 5. LACK OF DOOR HINGE LUBRICATION - Insufficient lubrication may create a binding/squeaking condition. 6. AN ECM BRACKET "POP" sound may occur if the ECM moves within its mounting bracket. 7. AN ASH TRAY BRACKET RATTLE coming from the ash tray or radio area of the instrument panel may occur if the bracket is loose and vibrating against the I/P. 8. AN AIR VENT "POP" may occur if the louvered vent and A/C duct rub together. 9. HOOD "FLUTTER"/RATTLE may occur if there is movement in the hood hinge attachment to the truck frame. Sound may accompany the hood Page 357 Light Switch Details (Part 2 Of 3) Page 1144 If the spring breaks while bending, it will be necessary to replace the lock cylinder assembly 7. Reinstall the spring in the lock assembly. Next, shake the assembly to check for looseness. If loose, replace the lock cylinder assembly. 8. Reinstall the gasket, lock cylinder and retainer (Figure 3, Items 3, 4 and 2). 9. Reconnect the end gate lock rods (Figure 2, Items 1 and 2). 10. Reinstall the end gate inner panel reinforcement to the end gate (Figure 1, Item 1). 11. Reinstall the inner trim panel. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Op: B5810 Use applicable labor time guide for labor hours. Page 8002 - The split post guide clips with new solid post guide clips (Figure 2, Views A and B). The material in the new clip has been changed and the post redesigned. The material change is not evident, but provides additional strength in the clip hinge area. The new post is solid instead of split providing better fastening characteristics (Figure 2, View A). The purpose of the guide clips is to keep the glass parallel to the door frame when the glass is cycled. SERVICE PROCEDURE: 1. Remove the window glass. Follow the "Front Door Window Replacement" instructions in "Section 10A1-Door" of the applicable Service Manual. 2. Install new redesigned guide clips on the new glass. Glass P/N's 15960877-LH and 15960878-RH for non-export vehicles or P/N's 15962245-LH and 15962246-RH for export vehicles (RPO A26). - Align the clips with the holes in the glass and carefully snap together securely at each fastener location. The clips attach to the rear upper edge and front lower edge of the front door glass through holes in the glass (Figure 2, View B). 3. Remove three screws from the weatherstrip in the run assembly and remove the weatherstrip (Figure 1). 4. Install a new low friction run assembly weatherstrip, P/N 15960867-LH or 15960868-RH (Figure 1, Section A-A). Torque the fastening screws to 1.6 - 2.2 N-m (13 - 18 lbs.in.). Ensure the weatherstrip is properly seated in the door run channels. (Special care should be taken to ensure the weatherstrip below the door daylight opening is also properly seated). Apply silicone spray lubricant to the lower portion of the run assembly as indicated in illustration. 5. Install the new glass assembly (with new guide clips). Follow "Front Door Window Replacement" instructions in "Section 10A1-Doors" in the applicable Service Manual. 6. Check for proper window operation. Torque Spark Plug: Specifications Spark Plugs 22 ft.lb 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. Page 6920 When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 5mm (3/16") of insulation from wire. e. Crimp a new terminal to the wire. f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. Figure 17 To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Figure 18 Figure 19 Generator Light - Flickers During Pulse Wiper Use Wiper Switch: All Technical Service Bulletins Generator Light - Flickers During Pulse Wiper Use Number: 90-84-8A Section: 8A Date: November 1989 Corporate Bulletin No: 966402 Subject: GENERATOR LIGHT FLICKER DURING PULSE WIPER OPERATION Model and Year: 1988-89 S, T TRUCKS WITH 2.8L OR 4.3L (VIN CODES R, Z) ENGINES TO: ALL CHEVROLET DEALERS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 89-219-8A, DATED JULY 1989. THE 1990 MODEL S/T VEHICLES ARE INCLUDED IN THE LATEST BULLETIN ALONG WITH A CORRECTION TO THE ELECTRICAL CONNECTOR NUMBER. ALL COPIES OF 89-219-8A SHOULD BE DISCARDED. The generator light flicker condition during pulse wiper switch operation in the 1988, 1989 and 1990 S/T instrument panel, with standard cluster, can be caused by negative voltage transients from the wiper motor. There is no possibility of a system failure as a result of this condition. The effect of this condition is that the generator light will turn on for 80 milliseconds (if gages, the voltage drop on the voltmeter lasts 2.5 seconds). This causes no harm to the generator or other electrical components. Subject condition can be eliminated by installing a diode (industry part number 1N4003) or diode/connector kit (diode kit part number 12085207) in the brown wire at the generator connector (circuit 25 at connector C118). See the following pages in the 1988, 89 and 90 S/T Electrical Wiring Diagrams for circuit 25, connector C118 locations: 1988 4.3L: Section C - Page 24 1988 2.8L: Section C - Page 22 1989 4.3L: Page 40 1989 2.8L: Page 39 1990 2.8L: Page 44 1990 4.3L: Page 45 PARTS INFORMATION: Quantity Part Number Description 1 12085207 Diode ----OR---1 *1N4003 Diode * This part available locally. Parts are currently available from GMSPO. INSTALLATION PROCEDURE: 1. Disconnect the battery. 2. Remove the connector from the generator. 3. Peel back the black plastic conduit covering the wires. 4. If installing diode 1N4003: cut out a section of the brown wire that matches the length of the diode. 4A. A diode/connector kit is also available (GMSPO diode kit part number 12085207). If using the kit cut out approximately four inches of the brown wire, following crimping and soldering instructions in the kit. Spiral tape the solder joints and tuck the wire back into the conduit away from the generator. Secure the diode/connector to the outside of the conduit with electrical tape. 5. Solder in diode with the banded end toward the generator. Page 6725 Front Door Trim Panel Components Tools Electronic Spark Control (ESC) Knock Sensor: Description and Operation Electronic Spark Control (ESC) Electronic Spark Control (ESC) is used on some models. The ESC system is used in conjunction with the EST system to provide additional spark retard during engine detonation. A knock sensor signals a separate ESC controller to retard the timing when it senses engine knock. The ESC controller signals the ECM which reduces spark advance until no more signals are received from the knock sensor. Page 2326 - Diagnostic Chart Code 33. Page 1766 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 Specifications Transmission Speed Sensor: Specifications Electronic Speed Sensor Retainer Bolt ............................................................................................... ...................................................................... 7 ft. lbs. Ignition Firing Order Firing Order: Specifications Ignition Firing Order Firing Order ......................................................................................................................................... ............................................................... 1-6-5-4-3-2 Page 3412 [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). Page 1962 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). Page 7779 Light Switch Details (Part 3 Of 3) Brakes Grab Vacuum Brake Booster: Testing and Inspection Brakes Grab 1. Faulty control valve. 2. Broken or damaged hydraulic brake lines. 3. Faulty master cylinder seals. 4. Cracked master cylinder casting. 5. Air in hydraulic system. Page 5153 LIGHT BLUE LT BLU BROWN BRN GRAY GRY GREEN GRN DARK GREEN DK GRN LIGHT GREEN LT GRN ORANGE ORN PINK PNK PURPLE PPL RED RED TAN TAN WHITE WHT YELLOW YEL Locking Differential - Chattering on Turns Fluid - Differential: Customer Interest Locking Differential - Chattering on Turns Number: 91-370-0B Section: 0B Date: JULY 1991 Corporate Bulletin No.: 964201R Subject: LOCKING DIFFERENTIAL LUBRICANT Model and Year: 1982-91 ALL TRUCKS WITH G80 REAR AXLE THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 90-139-4A, DATED JANUARY 1990. CONDITION DESCRIPTION AND CORRECTION HAVE BEEN ADDED AS WELL AS THE 1991 MODEL YEAR. ALL COPIES OF 90-139-4A SHOULD BE DISCARDED. Some light duty trucks equipped with locking rear axles (G80) may exhibit rear axle chatter, especially when turning a corner from a stop. This condition of alternate engagement and disengagement of the clutches in the differential assembly is usually caused by contaminated axle lubricant. To correct this condition, drain and refill the rear axle with SAE 80W-90 GL5 (P/N 1052271). The use of any additive in locking rear axles (G80) is not recommended. Rear axle additives are designed for use in limited slip differentials which are normally installed in cars. All light duty trucks equipped with RPO G80 make use of a locking differential and the use of additives will delay the engagement of the locking mechanism and may decrease axle life. VEHICLES/COMPONENTS INVOLVED: Some light duty trucks equipped with locking rear axles, RPO G80. SERVICE PARTS INFORMATION: Part Number Description 1052271 Lubricant, Rear Axle (24 oz.) See Appropriate Parts Manual Gasket, Rear Axle Housing Cover Parts are currently available through GMSPO. WARRANTY INFORMATION: As specified in Light Duty Truck Maintenance Schedules, locking rear axle fluid drain and refill is required owner maintenance at the first engine oil change. Failure to drain and refill the rear axle as specified may contribute to a later axle chatter condition. Refer to the appropriate Light Duty Truck Maintenance Schedule or service manual, section 0B, for further details on change intervals. For those vehicles repaired under warranty, which have had the axle fluid changed at the first oil change and have experienced rear axle chatter use: Labor Operation: F2010 Use applicable labor time guide for labor hours. Page 4237 Pinion Bearing: Adjustments Corporate and Eaton 7 1/2 - 8 7/8 Inch Ring Gear Fig. 16 Pinion depth gauge tool installation. Models w/7-1/2 inch ring gear Fig. 17 Pinion depth gauge tool installation. Models w/8-1/2 & 8-7/8 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. Use gauge assembly J-23597-01 for models with 7-1/2 inch ring gear, J-21777-01 Backup Lamps/Tailgate Window Release - Inoperative Shift Interlock Switch: Customer Interest Backup Lamps/Tailgate Window Release - Inoperative Number: 91-459-8A Section: 8A Date: DEC. 1991 Corporate Bulletin No.: 168104 ASE No.: A6 Subject: BACKUP LAMPS OR TAILGATE WINDOW RELEASE INOPERATIVE Model and Year: 1980-91 ALL LIGHT DUTY TRUCKS (EXCEPT GEO) Owners of some 1980-1991 C/K, 1982-1991 G, 1985-1991 M/L, 1984-1991 P2,P3, 1987-1991 R/V, 1983- 1991 ST (including LLV) with automatic transmissions may comment on a condition of inoperative back-up lamps or inoperative tailgate window release. This condition occurs when the vehicle's gear shift lever is placed in the "reverse" position, but the back-up lamps do not illuminate. In addition, on the S/T utility vehicles, the electric tailgate window release does not release when the transmission gear shift lever is placed in the "park" or "neutral" position and the endgate window release button is depressed. The park/neutral and back-up lamp switch comes out of adjustment which does not allow for the contact points to remain engaged. To correct these conditions, the contact carrier on the park/neutral and back-up lamp switch has been modified to increase switch carrier travel. SERVICE PROCEDURE: 1. Disconnect the battery ground cable from the battery. 2. Disconnect the switch assembly harness. 3. Place the gear selector in neutral. 4. Squeeze the tangs on the switch together and remove the switch assembly. 5. Install the new switch assembly (P/N 15679680) by: -aligning the actuator with the cutout in the steering column jacket. -inserting the tangs into the rectangular holes and pushing down on the switch assembly. 6. Adjust the switch by moving the gear selector to park. 7. Connect the switch assembly harness. 8. Connect the negative battery cable. 9. Check for proper switch operation. Readjust the switch as necessary. Page 7386 Figure 4 Figure 5 Figure 6 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 7 Backup Lamps/Tailgate Window Release - Inoperative Backup Lamp Switch: All Technical Service Bulletins Backup Lamps/Tailgate Window Release Inoperative Number: 91-459-8A Section: 8A Date: DEC. 1991 Corporate Bulletin No.: 168104 ASE No.: A6 Subject: BACKUP LAMPS OR TAILGATE WINDOW RELEASE INOPERATIVE Model and Year: 1980-91 ALL LIGHT DUTY TRUCKS (EXCEPT GEO) Owners of some 1980-1991 C/K, 1982-1991 G, 1985-1991 M/L, 1984-1991 P2,P3, 1987-1991 R/V, 1983- 1991 ST (including LLV) with automatic transmissions may comment on a condition of inoperative back-up lamps or inoperative tailgate window release. This condition occurs when the vehicle's gear shift lever is placed in the "reverse" position, but the back-up lamps do not illuminate. In addition, on the S/T utility vehicles, the electric tailgate window release does not release when the transmission gear shift lever is placed in the "park" or "neutral" position and the endgate window release button is depressed. The park/neutral and back-up lamp switch comes out of adjustment which does not allow for the contact points to remain engaged. To correct these conditions, the contact carrier on the park/neutral and back-up lamp switch has been modified to increase switch carrier travel. SERVICE PROCEDURE: 1. Disconnect the battery ground cable from the battery. 2. Disconnect the switch assembly harness. 3. Place the gear selector in neutral. 4. Squeeze the tangs on the switch together and remove the switch assembly. 5. Install the new switch assembly (P/N 15679680) by: -aligning the actuator with the cutout in the steering column jacket. -inserting the tangs into the rectangular holes and pushing down on the switch assembly. 6. Adjust the switch by moving the gear selector to park. 7. Connect the switch assembly harness. 8. Connect the negative battery cable. 9. Check for proper switch operation. Readjust the switch as necessary. Page 968 This part number can be found on the identification tag (80) located on the rear case half (Figure 1). Group B: Some 1991 T-Trucks equipped with transfer cases identified by the following part numbers and built before 10/22/90: 15653414 15659232 This part number and build number can be found on the identification tag (80) located on the rear case half (Figure 1). Service Procedure: Group A: These transfer cases require the replacement of the parts indicated in the Group A column of the PARTS INFORMATION section. Group B: These transfer cases require the replacement of the parts indicated in the Group B column of the PARTS INFORMATION section. Remove Page 1297 FIGURE 4 GENERAL AND UNIROYAL IF WITHIN THE NEW VEHICLE WARRANTY PERIOD (12/12): A. If only slight cupping is noticed, and the cross grooves in the tire's outside shoulder are still visible (See Figure No. 3), the tires should be rotated. The modified "X" pattern should be used (See Figure No. 1). This method will best equalize wear after a few thousand miles. B. The cupping or wear is severe, and the cross grooves in the outside shoulder are not visible, tire replacement will be necessary (See Figure No. 4). It should be noted, however, that even when these grooves disappear, the tire is normally only half worn in this area. If tires are needed for any of the previous conditions, they should be purchased from your local tire outlet. If tires are not readily available, contact the manufacturers toll-free assistance number provided below. Firestone - 1-800-638-4730 General - 1-800-Tire-FIX - 1-800-426-4889 (Ohio) Goodyear - 1-800-321-2136 Uniroyal - 1-800-231-5893 (Except Texas) - 1-800-833-5906 (Texas) The tire invoice amount should be entered as a net item on the warranty claim using the E0420 labor operation code for wheel and/or tire replacement. Labor Op E0420 - Wheel and/or Tire-Replace Replace One - .6 hr. Each Additional Tire - .4 hr. Page 2945 Disclaimer Page 7796 Figure 8 Figure 9 Figure 10 Figure 11 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). Page 5033 10. Remove parking brake cable grommet (# 9 Figure 1). 11. Remove bolt & clamp (# 10 Figure 1) in engine compartment. 12. Raise vehicle. 13. Pinch parking brake cable retainer ears (# 11 Figure 1) inward. 14. Pull cable out of frame. 15. Lower vehicle and remove parking brake cable. Installation 1. Route new parking brake cable behind dash and feed cable through grommet opening in body (#9 Figure 1). 2. Attach cable to parking brake lever. 3. Attach parking brake lever to steering column and place in the full apply position. 4. Attach hood cable handle to dash panel. 5. Install parking brake cable grommet into body opening. 6. Attach front panel. 7. Raise vehicle. 8. Insert cable through frame. 9. Attach parking brake cable to equalizer. 10. Install equalizer nut. 11. Adjust parking brake cable per Procedure A. 12. Lower vehicle. 13. Install and tighten set screw when adjustment is complete. Parts Information: Parts are expected to be available on December 5, 1988. Until then, normal part orders will not be accepted by GMSPO. Only verifiable emergency VIP orders will be accepted. SPO will make every effort to obtain parts. All parts will be placed on 400 control to waive VIP surcharges. However, the part will be shipped premium transportation at dealer's expense. All other order types will be canceled as incorrectly ordered while the 400 control is in place. Parts Required: Part Number Description Quantity 15602898 Front 1 Labor time to perform this procedure is .8 hours. Use Labor Op: T1406 Page 5758 Figure 6 - Disconnecting Lower Shock Mount 10. Remove the lower shock mounting nut and bolt (Figure 6). 11. Collapse the shock absorber. 12. Move the shock absorber up, away, and secure. 13. Depending on the type of hoist, it may be required to position floor stand between the spring seats and the lower control arm ball joint for miximum leverage. The weight of the vehicle is used to relieve the spring tension on the upper control arm. Caution: The floor jack or stand must remain under the control arm spring seat while servicing the halfshaft to maintain spring and control arm position. Failure to do so could result in personal injury. 14. Disconnect the cotter pin. 15. Remove the stud nut from the upper ball joint. Figure 7 - Ball Joint from Knuckle Separation 16. Loosen the stud using J34026 and move away from the knuckle (Figure 7). Belt Tension - Used BELT TENSION Page 7305 Fig. 3 Servo Test (Part 4 of 4) Page 7870 Brake Light Switch: Locations Stop Light Switch LH Side Of I/P Behind Instrument Cluster 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. Page 4599 Figure 2 Page 1703 Oil Pressure Warning Lamp/Indicator: Testing and Inspection On some models, the oil pressure indicator light also serves as the electric choke defect indicator. If Oil or ENG. indicator light does not light, check to ensure electric choke is not disconnected at carburetor. Also check for defect in electric choke heater, blown gauge fuse or defect in lamp or wiring circuit. If indicator light stays on with engine running possible causes are: low oil pressure, switch to indicator light open circuit, disconnected oil pressure switch connector or oil pressure gauge or radio fuse has blown. 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. Page 4805 Figure 4 Figure 5 Figure 6 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 7 Electrical - VSS Connector Mislabeled Vehicle Speed Sensor: Technical Service Bulletins Electrical - VSS Connector Mislabeled GMC NUMBER: 88-T-145 GROUP: 6D-Engine Electrical DATE: August, 1988 CORPORATE NUMBER: 818107 SUBJECT: CONNECTOR MISLABELED MODELS: 1985-88 G, S, R, AND M VEHICLES FIGURE NO. 1VEHICLE SPEED SENSOR BUFFER CORRECT CONNECTOR LABEL Some 1985-88 vehicles may have an electrical connector at the vehicle speed sensor (VSS), which is improperly labeled. The connector will work properly but could cause confusion if electrical troubleshooting is necessary. Figure No. 1 shows a properly labeled connector. The improperly labeled connectors have the "A" and "C" reversed. All Service Manual terminal call-outs use the labeling as shown in Figure No. 1. Page 4906 A full rotation will move the thimble exactly one minor division on the sleeve. To read the micrometer you must add the measurement which is visible on the sleeve to the measurement which is showing on the thimble In the example the sleeve measurement is 0.250 inches and the thimble measurement is 0.017 inches. The total measurement is then equal to the two measurements combined, 0.267 inches. NOTES The accuracy and calibration of a micrometer can be altered easily by applying too much pressure to the spindle. Use the thimble to quickly rotate the spindle in until it is near the rotor. - Use the ratchet to rotate the spindle into contact with the rotor. - The ratchet has a built in slip which prevents excessive stress or pressure from developing. Calibrate the micrometer regularly. Most micrometers come with a precision dowel which allows for easy and accurate adjustments. Page 4341 Fig. 14 Using Spacer To Completely Drive Out Bearing Cup Fig. 15 Solid Ball & Replaceable Balls. Notch Identifies Driveshaft With Replaceable Ball Fig. 16 Exploded View Of Ball & Seat DISASSEMBLY Constant Velocity Joint To disassemble the constant velocity joint, the bearing cups should be removed in sequence shown in Fig. 11. This method requires the least amount of work. 1. Mark all yokes before disassembly as shown in Fig. 12, so that they can be reassembled in their original relationship to maintain driveshaft balance. The following procedure can be performed in a vise. A cross press tool, Fig. 13, can be used in place of the socket used to drive the bearing cups. 2. Support the driveshaft horizontally in line with the base plate of a press. Place rear end of coupling yoke over a 1-1/8 inch socket to accept the bearing cup. Place a socket slightly smaller than the bearing cup, on the opposite side of the spider. 3. Press bearing cup out of coupling yoke ear. If bearing cup is not completely removed, insert spacer C-4365-4 or equivalent, Fig. 14, and complete removal of bearing cup. 4. Rotate driveshaft 180° and shear the opposite retaining ring, and press the bearing cup out of the coupling yoke as described previously, using spacer C-4365-4 or equivalent. Page 59 Disclaimer A/T - Intermittent Slip, Downshift, or Busy Cycling TCC Torque Converter Clutch: All Technical Service Bulletins A/T - Intermittent Slip, Downshift, or Busy Cycling TCC Number: 92-42-7A Section: 7A Date: NOV. 1991 Corporate Bulletin No.: 167105 ASE No.: A2 Subject: INTERMITTENT TRANSMISSION DOWNSHIFT, SLIP OR BUSY/CYCLING TCC Model and Year: 1983-92 ALL PASSENGER CARS AND TRUCKS WITH AUTOMATIC TRANSMISSION Some owners may comment that their vehicle is experiencing one or more of the following transmission conditions: - Intermittent slipping. - Intermittent downshift followed by an upshift, both with no apparent reason. - Busyness or cycling of the TCC at steady throttle conditions and level roadway. The cooling fan operates when the thermostat on the fan clutch reaches a preset temperature. When this temperature is reached, the fan engages to draw additional air through the radiator and lower the engine temperature. When the cooling fan engages, noise increases and may sound very similar to an increase in engine RPM due to transmission downshift, slipping or TCC cycling. When engine temperature lowers to a preset point the fan clutch will disengage. When the cooling fan disengages, noise levels will decrease and may sound very similar to a decrease in engine RPM. The type of concern described above requires further definition and the customer should be asked several questions: - Is the situation more pronounced at higher vehicle loads or pulling a trailer? - Do warmer ambient temperatures make the situation more pronounced as well? If the customer's responses indicate that both of these conditions apply, and your observation of the vehicle confirms a properly operating vehicle, provide the customer the vehicle operating description included in this bulletin. Further action may not be necessary. A service procedure follows if further definition is required. SERVICE PROCEDURE: When attempting to diagnose an intermittent transmission downshift, slip or busy/cycling TCC: 1. Check fluid level and condition as outlined in section 7A 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 to raise engine coolant temperature to match customer conditions. 3. Monitor engine RPM and engine coolant temperature using a scan tool. 4. Listen for an apparent increase in engine RPM. If engine RPM sounds like it increases, check the scan tool RPM and coolant temperature readings. If the noise increase is due to engagement of the fan the engine RPM will not increase and 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, engine RPM will not decrease. This cycle will repeat as engine coolant temperature again rises. 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 section 7A of the appropriate service manual for transmission diagnosis information. 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 Page 2612 Page 4904 Do not re-install the spindle nut and attempt to slide-hammer the grease seal from the hub. WHEEL BEARING REPACKING - The hub and spindle should be thoroughly cleaned of all old grease. - The bearings should be cleaned in solvent and allowed to dry completely. WARNING: Do not spin dry the bearings with compressed air, this practice can rapidly damage bearings. - If possible use a commercial wheel bearing packer, otherwise repack the bearings by hand. Hand Repacking Place a quantity of high-temperature, multi purpose wheel bearing grease in the palm of your hand. - Cup the bottom of the bearing cage (the wider end) into the palm of your hand forcing grease up through the cage. Repeat the procedure until the new grease is pushed out of the top of the cage. - Repeat this around the entire circumference of the bearing. - Apply a coating of new wheel bearing grease to the spindle and the inside of the hub. NOTE: The hub should not be completely packed with new grease. As the brakes are applied the hub will heat up and the grease will expand. If an excessive amount of grease is prepacked into the hub, upon heating it will force its way past the grease seals and contaminate the brake system. - Also apply a thin coating of grease to the inside lip of the new grease seals. NOTE: The side of the grease seal from which the spring is visible should point towards the bearing. Page 7165 Note: Certain two tone applications on trucks using the high potential colors (Blues, Grays and Silvers) may require that only portions of the vehicle surface be refinished. Examples would be: Example 1. Blues, Grays and Silvers as "insert colors" on vertical surfaces with other, non-high potential colors above the insert (or break line). Action: Refinish the "insert color" only, between the break line and body side molding (or to the lower feature line on certain vehicles). Example 2. Blues, Grays and Silvers on surfaces above the break line with other, non-high potential colors as "insert colors". Action: Refinish the surfaces above the "insert color" or break line only. Example 3. Blues, Grays and Silvers used as both the primary and "insert colors". Action: Refinish both high potential color surfaces above the body side moldings (or to the lower feature line on certain vehicles). Vehicles should be repaired with the same type materials they were manufactured with; repair basecoat/clearcoat with basecoat/clearcoat materials and monocoat with monocoat. PAINT REPAIR PROCEDURE 1. Some vehicle components will be removed from the vehicle while others will require masking. The list located at the end of this bulletin will establish the removal items. Items not found on the list and non-repair areas are to be masked. 2. Prior to removing the paint finish, clean the area to be refinished with an appropriate wax and grease remover to remove any contaminants. 3. Remove the original finish of paint down to the ELPO primer surface using an orbital D.A. sander, leaving the ELPO surface intact. This can be done in "stages" using 80 grit (or finer) discs to remove the majority of coating, followed with 180 grit (or finer) discs to remove the remainder of material down to the ELPO surface and any chalky residue or degraded ELPO that may remain. Avoid sanding through ELPO to bare metal in order to retain maximum corrosion protection. - An alternative in some geographic areas may be plastic media blasting such as may be provided by members of: - Dry Stripping Facilities Network 1-800-634-9185 * * 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. Important Additional time or payment beyond established allowances in this bulletin will not be allowed. - The use of a razor blade on large flat surfaces is not recommended because of the potential to chip. gouge or otherwise damage the primer surface. If razor blade technique is used, the application of a "guide coat" prior to wet sanding should also be used. Note: Chemical stripping is not recommended because of negative impact to moldings, non-metal components, ELPO and environmental concerns. 4. Blow off with air to remove all dirt and sanding residue from cracks and vehicle surface. 5. Clean sanded surface with an appropriate wax and grease remover. 6. Tack wipe entire area to be primed. 7. Spray entire prepared area with a coat of anti-corrosion primer to ensure maximum adhesion and corrosion resistance. Be sure to cover any bare metal surfaces exposed during the sanding operations. Follow manufacturer's instructions and recommended dry times. Typical materials for this application would be: DuPont 615S/616S, BASE DE17/PR8O/DA18, PPG DP4O/DP401, or equivalent. V.O.C. materials would be: DuPont 615S/616S, BASF DE15/PA16/PRB0, PPG DCP21/DCX211 or equivalent. Tires - Slipping on Rim Tires: All Technical Service Bulletins Tires - Slipping on Rim Number: 93-169-3E Section: 3E Date: APRIL 1993 Corporate Bulletin No.: 393501 ASE No.: A4 Subject: TIRES SLIPPING ON WHEELS (USE PROPER TIRE MOUNTING PROCEDURE) Model and Year: 1988-93 ALL PASSENGER CARS AND LIGHT DUTY TRUCKS Some incidents of tires slipping (rotating) on wheels have been reported on 1988-93 passenger cars and light duty trucks. Most incidents have occurred when driven aggressively immediately after tire mounting. Hard acceleration and/or braking is usually required. This condition will affect wheel balance, which could result in a vibration. To reduce the chance of tires rotating on their wheels, any excess lube should be wiped from the tire and rim after tire mounting, but before inflating to seat the bead. (Never exceed 40 psi to seat the bead.) Also, the vehicle should not be driven aggressively for at least four hours after tire mounting to allow the lube to dry. GM Goodwrench Rubber Lubricant, p/n 12345884, is the recommended lube for tire mounting. Locations Oil Pressure Switch Page 5971 sure the retainer cup is tree from dirt, grease, and gouges. Most wheel balancers now offer this type of protected retainer. DO NOT allow the retainer cup to rotate against the wheel's surface when tightening the wheel to the balancer. DO NOT OVERTIGHTEN. Most balancers use a large "wing nut" design to clamp the retainer against the wheel. Hand tight is sufficient. This procedure will allow accurate balancing using the conventional back cone method. Important: Coated balance weights must be used on aluminum wheels to prevent damage to the rim flange. Except for the N9O 4X4 wheel used on T trucks, all light truck aluminum wheels will accept either "AW" series or "MO" series clip-on coated weights on both the inside and outside rim flanges. The N9O T truck wheel will accept "AW" series weights on the inside rim flange only. The outside rim flange is not designed to accept a clip-on weight. If such a weight installation is attempted, a poor fit will result, and the weight may fall off and/or cause cosmetic damage to the rim flange. This wheel can be 1) static balanced by clipping all the weight on the inside rim flange (as is done in the assembly plant), or 2) dynamic balanced by clipping a weight on the inside flange and using an adhesive weight near the outside flange. The charts show "AW" and "MC" balance weight usage. These original equipment coated weights are available at competitive prices through the GM Dealer Equipment program. Page 4300 Figure 3 - Inboard Flange Bolt Removal 5. Loosen (do not remove at this time) six bolts securing inboard C/V joint drive flange to output shaft companion flange (Figure 3). Figure 4 - Brake Line Bracket Removal 6. Remove brake line support bracket from upper control arm to allow extra travel of knuckle (Figure 4). 7. Remove cotter pin and nut from the outer tie rod. Figure 5 - Disconnecting the Tie Rod 8. Separate the outer tie rod ball stud from the steering knuckle using J24319-01 (Figure 5). Notice: Do not attempt to disengage the joint by driving a wedge-type tool between the joint and the knuckle because the seal may be damaged. 9. Push linkage to opposite side of the vehicle and secure outer tie rod up and out of the way. This will provide the needed clearance to remove the halfshaft. Page 7385 e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors Do Not require all the steps shown. Skip the steps that Do Not apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. 1. Separate connector halves (see Figures 2 through 6). Figure 2 Figure 3 Page 4248 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. Page 7390 Brake Warning System Wiring Circuit Page 8190 Fig. 3 Permanent Magnet Type Windshield Wiper Motor W/Pulse Wipers Front The front wiper system consists of a permanent magnet positive park pulse wiper, a washer pump mounted under the washer bottle and a turn signal type wiper/washer switch. The die cast aluminum housing of the wiper provides superior cooling of internal parts, Fig. 3. An electronic circuit board controls all the timing and washer commands. When the washer button is pushed for more than .3 seconds, a demand wash is performed in 1.5 second intervals for as long as the button is held followed by approximately 6 seconds of dry wipes and a shutoff. Turning switch to either the Lo or Hi speed position completes the circuit and runs at that speed. The pulse and demand wash functions are controlled by a plug-in printed circuit board enclosed in the wiper housing cover. Turning switch to the Pulse position operates the motor intermittently and the delay can be varied by rotating the switch. An instantaneous wipe can be obtained by rotating the switch to the Mist position and a continuous wipe will be performed if the button is held. Rear The rear wiper system consists of a permanent magnet positive park single speed wiper mounted to the rear glass. A wiper arm is mounted directly onto the wiper motor and operation is controlled by a two position dash mounted switch. The wiper/washer switch has a momentary wash and wipe position and must be turned off manually. The wiper motor is serviced as an assembly. Audio - Radio Frequency Interference (RFI) Diagnosis/ID Technical Service Bulletin # 349212R Date: 930701 General Information Bulletin Number: 93-9-10 Reference Number: 349212R Publish Date: 7/93 Subject: RADIO FREQUENCY INTERFERENCE IDENTIFICATION AND DIAGNOSIS Models Affected: 1993 AND PRIOR ALL MODELS The purpose of this information is to help in the identification and diagnosis of Radio Frequency Interference (RFI). RFI symptoms may include noises, interference, static, whines, pops. and poor reception of stations normally receivable by the radio system. These symptoms may also apply to any two-way communications radio installed in the vehicle including HAM, police, fire, business band and cellular phones. Radio Frequency Interference is the undesirable disturbance of an electrical system or device with another electrical system or device. The following charts will help identify: 1. If the symptoms are related to RFI, and 2. The source of the interference. It may be helpful to obtain a copy of the Delco Electronics Audio Systems Diagnostics Guide 1992 edition. This is a manual aimed at identifying, diagnosing, and repairing the radio system. This manual is available from STG; item # 19007.03-1. You may also want to consult your division's service bulletin concerning Radio Telephone Installation Guidelines. This information will identify the proper methods and routing for all installations of two-way communications devices. Questionnaire To begin diagnosing RFI, it is important to understand the nature of the condition and the elements that may be involved. The following questionnaire will help determine vital pieces of information for the diagnostic process. 1. Is the vehicle equipped with any non-factory installed electronics? (This includes: radar detectors, scanners, and hand held communications devices.) 2. If the condition occurs with a non-factory installed radio or telephone, have the Radio Installation Guidelines been followed? 3. Identify the frequencies affected. 4. If the concern is with the entertainment radio, is the tape or CD affected. 5. Identify when the condition occurs: Key off, Key in accessory, Key on engine not running, Engine running, Other - describe. 6. Is the condition intermittent or related to the operation of another electrical device in the vehicle? 7. If the condition is related to a fleet vehicle answer the following: a. Who installed the radio(s)? b. Were the GM installation guidelines followed? c. Is this the only vehicle that demonstrates this condition? d. Do similar vehicles have different antennas? e. Are the antennas mounted in the same location? See RFI Diagnostic Charts that follow. RFI Determination and Identifying Chart This chart is to be used along with the diagnostic charts to help determine if the condition is RFI related, and to help identify what electronic device in the vehicle is interfering with the radio. Make sure the information in the questionnaire is as accurate as possible. You MUST be able to duplicate the customer's condition to diagnose RFI concerns. The process of identifying RFI and the source of an interference is simply the process of elimination. When the source of the interference is disconnected from power, the radio will work properly. Page 1697 Oil Pressure Switch (For Fuel Pump): Description and Operation As a back-up system to the fuel pump relay, the fuel pump can also be turned ON by the oil pressure switch. The oil pressure switch is a normally open switch which closes when oil pressure reaches about 28.0 kPa (4.0 psi). If the fuel pump relay fails, the oil pressure switch will power the fuel pump. Spare Tire Carrier - Rattle Technical Service Bulletin # 903303E Date: 900801 Spare Tire Carrier - Rattle Number: 90-330-3E Section: 3E Date: August 1990 Corp. Bulletin No.: 061005 Subject: SPARE TIRE CARRIER RATTLE Model and Year: 1986-90 S/T BLAZER TRUCK WITH SPARE TIRE CARRIER (RPO P16) TO: ALL CHEVROLET DEALERS Owners of some 1986 through 1990 S/T Blazers equipped with factory installed spare tire carriers (RPO P16) may comment on a rattle condition coming from the spare tire carrier area. This rattle condition may result from vehicle and road vibrations which are transmitted through the vehicle to the spare tire carrier region. This vibration changes to a rattle in any of the following three locations. TAILGATE Mode of vibration is a side to side motion of the tailgate and is caused by the tailgate not being properly aligned into the opening when closed. SPARE TIRE CARRIER This second form of vibration occurs in a forward and backward motion relative to the vehicle. Again, this is due to the tire carrier not being tightly held in place. This motion creates a rattle between the striker assembly and the carrier latch, and/or the carrier arm and the striker plate. Page 6280 - 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. Page 6342 Page 3061 Fuel Return Line: Description and Operation Fuel Tank Assembly FUEL TANK The fuel tank is located under the left rear of the vehicle and is the fuel reservoir. The tank has a vertical baffle installed to prevent fuel slosh. The fuel pump and fuel level sending unit assembly are mounted in the fuel tank as one assembly. The fuel tank assembly also consists of the fuel filler neck and filler cap. Fuel Filler Neck FUEL FILLER NECK To help prevent refueling with leaded fuel, the fuel filler neck has a built-in restrictor and deflector. The opening of the restrictor will accept only the smaller unleaded gasoline nozzle which must be fully inserted to bypass the deflector. Attempted refueling with a leaded fuel nozzle will result in fuel splashing back out of the filler neck. FUEL TANK FILLER CAP The fuel tank filler neck is equipped with a screw type cap. The threaded part of the cap requires several turns counterclockwise to remove. The long threaded area was designed to allow any remaining fuel tank pressure to escape during the cap removal operation. A ratchet type torque limiting device prevents over-tightening. To install, turn the cap clockwise until a clicking noise is heard. This signals that the correct torque has been reached and the cap is fully seated. Page 3423 [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. Page 4232 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. Locations Timing Connector-In Pass Comp Behind Carpet, Below Heater Page 7150 Page 6166 2. Rotor (5) and bearing (6) assembly. ^ Mark the location of the clutch coil terminals on the compressor. 3. Clutch coil (7) from the front head (15). ^ Install J 25031 guide to the shaft (34). ^ Install J 24092 with J 8433. ^ Turn the screw in J 8433 to remove the clutch coil. Install or Connect 1. Clutch coil (7) to the front head (15). ^ Position the coil terminals as marked during removed. 2. Rotor (5) and bearing (6) to the compressor with J 26271. Important ^ Before seating the assembly, position the clutch coil terminals in the proper location to the compressor. ^ Align the three protrusions on the rear of the clutch coil housing with the locator holes in the front head. 3. Retainer ring (4). Measure ^ Clutch plate to clutch rotor air gap is 0.5-1.0 mm (0.020-0.040-inch). Page 3093 Oil Pressure Switch (For Fuel Pump): Testing and Inspection Refer to DIAGNOSTIC CHARTS/FUEL PUMP RELAY CIRCUIT DIAGNOSIS (CHART A-5), for fuel related oil pressure switch problems. Tools - Duel Fuel Injector Tester Fuel Injector: All Technical Service Bulletins Tools - Duel Fuel Injector Tester Number: 93-127-6E Section: 6E Date: MARCH 1993 Corporate Bulletin No.: 316501R ASE No.: A1, A8 Subject: INTRODUCTION OF J 39021 FUEL INJECTOR TESTER DRIVEABILITY AND EMISSIONS Model and Year: 1982-93 S-TRUCK, 1985-93 M-VAN, 1983-93 T-TRUCK, 1990-93 L-VAN AND LUMINA APV SERVICE UPDATE This bulletin is being revised to add service manual update reference, to change the model years and vehicles involved. In January 1993, Kent-Moore shipped to dealers a new Fuel Injector Tester (J 39021). This tool is being shipped as part of the Essential Tool Program. The Tester will detect intermittent coil failures that may be missed using an ohmmeter alone since the ohmmeter does not load the injector coil with enough current to detect intermittent coil failures. The Fuel Injector Tester (J 39021) is capable of testing all major brands of fuel injectors; however, to use this tool with non-GM injectors you will need the appropriate injector connector adapter and the injector's resistance specifications. Refer to instructions included with tester for additional information on non-GM applications. BACKGROUND: The use of injector cleaners and gasoline blends containing high levels of alcohol may cause fuel injectors to become faulty. Alcohol may attack the injector's solenoid coil wire and insulation resulting in a shorted or open solenoid coil. Damaged coils will result in driveability problems due to improper fuel delivery. COIL TEST DESCRIPTION: The test procedure also requires the use of the J39200 Digital Volt Meter (DVM). The J39021 Fuel Injector Tester supplies one of three fixed current values throughout the duration of the test. Selection of a supply current value (0.5, 2.5, or 4.0 amp) is based on the injector's specified resistance. When the push-to-start-test button is depressed, the tool energizes the injector solenoid coil for five (5) seconds. The condition of the injector solenoid coil (Pass/Fail) is determined by the voltage reading displayed on the DVM while the injector is energized. Instructions and specifications are included with the tool. Page 394 - Diagnostic Chart Code 34. Page 5747 15522278 Insulator, Front Spring Upper 2 15522279 Insulator, Front Spring Lower 2 12345097 Adhesive, Weatherstrip, 5 oz. 1 Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: E3907 Use applicable labor time guide for labor hours. Drive Axle (Front) - Will Not Disengage Transfer Case Actuator: All Technical Service Bulletins Drive Axle (Front) - Will Not Disengage Number: 91-476-4C Section: 4C Date: JAN. 1992 Corporate Bulletin No.: 167402 ASE No.: A3 Subject: FRONT AXLE WILL NOT DISENGAGE Model and Year: 1983-1991 T TRUCKS Owners of some 1983-1991 T vehicles may comment about inappropriate front axle disengagement. This condition may be due to a corroded transfer case vacuum actuator switch. To correct this condition a revised switch (P/N 15664811), constructed of noncorrosive stainless steel, should be installed. SERVICE PROCEDURE: The vacuum switch is located on the left upper side of the transfer case (Figure 1). 1. Raise the vehicle and support with suitable safety stands. 2. Remove the vacuum lines from the switch. 3. Remove the corroded switch from the transfer case. 4. Install a revised switch (P/N 15664811), coat the threads with thread sealant. 5. Connect the vacuum lines. 6. Lower the vehicle. 7. Check for oil leaks at the threads and vacuum leaks around the vacuum lines. Page 4367 Case: Specifications MUNCIE 5LM60 (HM-290) 4 & 5 Speed Transmission Case Bolts ..................................................................................................................... .................................................................... 27 ft. lbs. Page 7421 Symbol Identification Testing and Inspection Brake Shoe: Testing and Inspection Inspect brake linings for excessive wear, damage, oil, grease or brake fluid contamination. If any of the above conditions exists, brake linings must be replaced. Brake shoes must always be replaced as an axle set to maintain equal braking forces. Examine brake shoe webbing, hold-down and return springs for signs of overheating indicated by a slight blue color. If any component exhibits signs of overheating, replace hold-down and return springs with new ones. Overheated springs lose their pull and could cause brake linings to wear out prematurely. Inspect all springs for sags, bends and external damage, and replace as necessary. Inspect hold-down retainers and pins for bends, rust and corrosion. If any of the above conditions exist, replace retainers and pins. 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 Windshield/A Pillar - Pop Noise Diagnosis Windshield: Customer Interest Windshield/A Pillar - Pop Noise Diagnosis Number: 93-25-10 Section: 10 Date: OCT. 1992 Corporate Bulletin No.: 262001 ASE No.: B1 Subject: POP NOISE FROM WINDSHIELD PILLAR AREA Model and Year: 1983-93 S/T TRUCKS REFERENCE COWL "POP" TAPPING NOISE CHEVROLET DEALER SERVICE BULLETIN NUMBER 91-351-10, DATED JUNE 1991. Owners of some 1983-1993 S/T Pickups and Utilities may comment on a cowl "pop" noise transmitted through the "A" pillar. It has been determined that sections other than the windshield cowl area may produce a sound which imitates cowl "pop". PRIOR TO PERFORMING ANY CORRECTION FOR COWL "POP" TAPPING NOISES, VERIFY THE SOURCE OF THE NOISE(S) TO DETERMINE IF IT IS A VALID COWL "POP" CONDITION. Possible noise areas to check are: ^ Instrument panel "pop"/noise. ^ Loose door lock rods. ^ Loose wires/harnesses contacting the wall of the engine/passenger compartment (cowl). ^ A lack of door hinge lubrication. ^ An Electronic Control Module (ECM) bracket "pop". ^ An ash tray rattle. ^ An air vent squeak. ^ Hood hinge "flutter"/rattle. INFORMATION: 1. INSTRUMENT PANEL (I/P) "POP"/NOISE sound at the front edge of the I/P may occur if the I/P pad rubs against the cowl/dash support panel. Refer to "Instrument Panel Pad to Cowl Panel "Pop" Noise" Chevrolet Dealer Service Bulletin Number 92-286-10, dated Sept. 1992. 2. LOOSE DOOR LOCK RODS may vibrate during vehicle operation creating a rattle type noise. Refer to "Front Door Lock Rod Rattle" Chevrolet Dealer Service Bulletin No. 91-406-10, dated August 1991. 3. THE ELECTRONIC CONTROL MODULE (ECM) WIRING HARNESS CLIP may not be properly attached at the transmission bellhousing bolt allowing contact with the floor pan/front of dash area. This sound may be amplified by the HVAC ductwork. 4. LOOSE WIRES/HARNESSES maybe tapping against the engine/passenger compartment wall (cowl). 5. LACK OF DOOR HINGE LUBRICATION - Insufficient lubrication may create a binding/squeaking condition. 6. AN ECM BRACKET "POP" sound may occur if the ECM moves within its mounting bracket. 7. AN ASH TRAY BRACKET RATTLE coming from the ash tray or radio area of the instrument panel may occur if the bracket is loose and vibrating against the I/P. 8. AN AIR VENT "POP" may occur if the louvered vent and A/C duct rub together. 9. HOOD "FLUTTER"/RATTLE may occur if there is movement in the hood hinge attachment to the truck frame. Sound may accompany the hood Cooling - Cold Start Fan Noise Fan Clutch: Customer Interest Cooling - Cold Start Fan Noise BULLETIN NUMBER: 92-66-56A SECTION: 6B Engine Cooling NUMBER: 2 CORPORATE REFERENCE NUMBER: 1662O3R DATE: May 1993 SUBJECT: COLD START FAN NOISE (INSTALL REVISED "QUICK DUMP" FAN CLUTCH) MODELS: 1987-92 M-VANS WITH 4.3L ENGINE 1990-92 L-VANS WITH 4.3L ENGINE 1988-92 S/T TRUCKS WITH 4.3L ENGINE THIS BULLETIN CANCELS AND REPLACES GMC TRUCK BULLETIN 92-6B-56. IT IS BEING REVISED TO INCLUDE M/L VANS, AND TO SERVICE PARTS INFORMATION AND RPO DEFINITIONS. ALL COPIES OF 92-6B-56 SHOULD BE DISCARDED. CONDITION Some owners of 1987-92 M-vans, 1990-92 L-vans, and 1988-92 S/T vehicles with a 4.3L engine (RPO LB4, LU2, or L35) and air conditioning (RPO C60) may experience higher than normal fan noise upon cold start up (usually fan noise extended beyond 90 seconds after start up). CAUSE This condition may be due to an extended engagement of the fan clutch. CORRECTION The condition may be corrected by installing a revised fan clutch which reduces the fan clutch engagement cycle. Vehicles built after the following VIN breakpoints have the new fan clutch installed in production: Plant VIN Moraine N2514836 Shreveport N8512403 Pontiac West N0508347 Baltimore NB534465 SERVICE PROCEDURE Refer to section 6B1 "FAN CLUTCH REPLACEMENT" in the appropriate Service Manual for removal and installation of the fan clutch. A/T - 4L60/700-R4 Transmissions Stuck In First Governor Pressure Switch: Customer Interest A/T - 4L60/700-R4 Transmissions Stuck In First Number: 91-371-7A Section: 7A Date: JULY 1991 Corporate Bulletin No.: 177113R Subject: TRANSMISSION STUCK IN FIRST GEAR Model and Year: 1982-91 CAPRICE, CAMARO AND CORVETTE 1982-91 C/K, G, S/T, 1985-91 M VAN 1987-91 R/V AND 1990-91 L VAN WITH 4L60 AUTOMATIC TRANSMISSION Figure 1 Bulletin Covers: Some HYDRA-MATIC 4L60/700-R4 transmissions may experience a "no upshift" or "stuck in first gear" condition. This may be caused by the input carrier to output shaft retaining ring coming unseated, or retaining ring omitted during assembly. This can allow the output shaft to move slightly, and cause wear on the governor gear (the governor gear ON THE GOVERNOR, not the governor drive gear on the output shaft). The governor gear wear may be described as an "apple cored" condition. If the governor gear is worn, the transmission cannot upshift out of first gear. Service Information: Remove the governor and inspect the governor gear. If it is "apple cored", disassemble the transmission and look for the presence of the input carrier to output shaft retaining ring. ^ If the retaining ring is missing, replace it, but make sure the original retaining ring is not broken and stuck inside the transmission. ^ If the retaining ring has become unseated, replace the retaining ring with a new one since the original has probably been over-expanded. When installing a new retaining ring, be careful not to over-expand the retaining ring. Service Parts Information: The input carrier to output shaft retaining ring is available in several packages through GMSPO. It is included in the snap ring package, overhaul repair components package, and overhaul seals and gasket package. Windshield - Two-Part Urethane Adhesive For Installation Windshield: All Technical Service Bulletins Windshield - Two-Part Urethane Adhesive For Installation File In Section: 10 - Body Bulletin No.: 73-10-54 Date: May, 1997 INFORMATION Subject: Two-Part Urethane Adhesive For Windshield Installations Models: 1997 And Prior Passenger Cars and Trucks (Using Urethane Adhesive To Retain Windshields) General Motors passenger cars and trucks use urethane adhesive as a means to retain the windshield in the body opening. The urethane adhesive is used to bond the windshield in the opening, increasing vehicle structure. The current recommended urethane adhesive, GM P/N 12346284, is a one-part moisture cure product that requires a minimum curing period of 6 hours at room temperature before returning the vehicle to the customer. Increasing customer demands for faster service in recent years have resulted in quicker cure two-part urethane adhesives. Essex Beta Seal U216* (two-part urethane adhesive) meets the General Motors 3651M Specification (Performance Requirements for Stationary Glass Bonding Adhesive System Service) and can be used when the customer demands quicker repair of the vehicle than the current one-part materials can provide. Either of these products can be used when glass replacement is performed. The differences between these products are as follows: The CURRENT URETHANE ADHESIVE KIT, GM P/N 12346284, IS A ONE-PART ADHESIVE. It includes the necessary glass and pinchweld primers and is specified in Service Manuals for General Motors' vehicles. Since this is a "moisture cure" product, the curing time for this one-part material will vary with changes to either temperature or humidity. The REQUIRED TIME FOR THIS ONE-PART MATERIAL to ensure a safe installation of stationary glass before returning the vehicle to the customer IS A MINIMUM OF SIX (6) HOURS AT 70°F (21°C) AND 30% RELATIVE HUMIDITY. ESSEX BETA SEAL U216 IS A TWO-PART ADHESIVE MATERIAL THAT PROVIDES FOR A ONE (1) TO ONE AND ONE HALF (11/2) HOUR CURE BEFORE RETURNING THE VEHICLE TO THE CUSTOMER. This product also requires primers on the glass and pinchweld surfaces. This product requires a special applicator for the mixing and dispensing of the adhesive. When using this (or any) product, make sure to follow the manufacturer's directions for application and drying times. Parts Information Parts are currently available from GMSPO. * We believe this source and their product 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 from this firm or for any such products which may be available from other sources. Page 4955 Brake Bleeding: Fundamentals and Basics BENCH BLEEDING Why A master-cylinder will develop little or no pressure if air is trapped in cylinder bore. Normal brake bleeding will not remove air trapped within the master-cylinder. How Clamp the master-cylinder securely in a vice. It is usually best to clamp the side of the vice onto the flat surface that is used to secure the master-cylinder to the brake booster. There are two basic methods for bleeding master-cylinder, one utilizes stroking the master-cylinder to expel air from the cylinder bore while the other utilizes a large syringe to backflush fluid from the outlet ports to the reservoir. Stroking Fill the master-cylinder with clean brake fluid. - The brake line fittings on the master-cylinder should be capped or plugged. NOTE: Special "bench bleeding" plastic fittings are available which allow for recirculating the brake fluid back into the reservoir. - Using a dull object, slowly stroke the master-cylinder piston, air and brake fluid will be expelled from the brake line fittings. Prior to releasing the piston plug or cap the outlet ports. - Repeat this procedure 8-10 times or until no air is emitted from the outlet ports. - When finished, cap the outlet ports and install the master-cylinder. Syringe Fill the syringe (one especially designed for brake bleeding) with clean brake fluid. - Insert the end of the syringe into one of the outlet ports on the master-cylinder. - Slowly compress the syringe and back flush the brake fluid through the master-cylinder. - A combination of air and brake fluid will be emitted from the inlet port in the fluid reservoir. - Repeat this procedure until only brake fluid is emitted into the reservoir. Cap the outlet ports and install the master-cylinder. Page 2570 ECM Connector Terminal Identification & Voltage Specifications. Locations Brake Fluid Pressure Sensor/Switch: Locations LH Side Of Engine Compartment At Master Cylinder Backup Lamps/Tailgate Window Release - Inoperative Backup Lamp Switch: All Technical Service Bulletins Backup Lamps/Tailgate Window Release Inoperative Number: 91-459-8A Section: 8A Date: DEC. 1991 Corporate Bulletin No.: 168104 ASE No.: A6 Subject: BACKUP LAMPS OR TAILGATE WINDOW RELEASE INOPERATIVE Model and Year: 1980-91 ALL LIGHT DUTY TRUCKS (EXCEPT GEO) Owners of some 1980-1991 C/K, 1982-1991 G, 1985-1991 M/L, 1984-1991 P2,P3, 1987-1991 R/V, 1983- 1991 ST (including LLV) with automatic transmissions may comment on a condition of inoperative back-up lamps or inoperative tailgate window release. This condition occurs when the vehicle's gear shift lever is placed in the "reverse" position, but the back-up lamps do not illuminate. In addition, on the S/T utility vehicles, the electric tailgate window release does not release when the transmission gear shift lever is placed in the "park" or "neutral" position and the endgate window release button is depressed. The park/neutral and back-up lamp switch comes out of adjustment which does not allow for the contact points to remain engaged. To correct these conditions, the contact carrier on the park/neutral and back-up lamp switch has been modified to increase switch carrier travel. SERVICE PROCEDURE: 1. Disconnect the battery ground cable from the battery. 2. Disconnect the switch assembly harness. 3. Place the gear selector in neutral. 4. Squeeze the tangs on the switch together and remove the switch assembly. 5. Install the new switch assembly (P/N 15679680) by: -aligning the actuator with the cutout in the steering column jacket. -inserting the tangs into the rectangular holes and pushing down on the switch assembly. 6. Adjust the switch by moving the gear selector to park. 7. Connect the switch assembly harness. 8. Connect the negative battery cable. 9. Check for proper switch operation. Readjust the switch as necessary. Page 7817 e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors Do Not require all the steps shown. Skip the steps that Do Not apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. 1. Separate connector halves (see Figures 2 through 6). Figure 2 Figure 3 Page 2903 Man. N 500-550 2-12 CL Auto D 500-550 2-20 CL [1] Add 2 counts for engines with less than 500 miles. Add 2 counts for every 1000 ft. above sea level. [2] Let engine idle until proper fuel control status is reached (OPEN/CLOSED LOOP). MINIMUM IDLE AIR RATE Transmission Gear Engine Speed OPEN/CLOSED LOOP [1] Man. N 450 +/- 50 CL Auto. N 475 +/- 50 CL [1] Let engine idle until proper fuel control status (OPEN/CLOSED LOOP) is reached. Page 5756 Figure 16 1. Loosen bolts (90) attaching the axle tube bracket (5) to the frame bracket (6). 2. Tighten nuts (94) to 75 N-m (55 lbs.ft.). This should cause the axle assembly to move toward the driver's side approximately 1/8" to 1/4". If the axle does not move it may be pried toward the driver's side with a bar. Position bar against the frame and the end of the shaft (1). 3. Tighten bolts (90) to 75 N-m (55 lbs.ft.). Seal Replacement: After checking the shock absorber installation and front axle location, smaller profile tripot seals may be installed. These smaller seals can be identified by their visibly smaller profile and by the number 26027961 which is molded onto the seal. Required Tools: J 28733 Axle Remover J 24319-01 Tie Rod Puller J 8059 Snap Ring Pliers J 35910 Seal Clamp Tool J 34026 Ball Joint Separator Drive Axle Removal: Figure 1 - Prevent Shaft From Turning 1. Raise vehicle and support it with suitable safety stands. 2. Remove the wheel and tire assembly. 3. Insert a drift or large screwdriver through brake caliper into one of the brake rotor vanes to prevent halfshaft from turning (Figure 1). Figure 2 - Hub Nut and Washer Removal 4. Remove halfshaft cotter pin, retainer, nut, and washer (Figure 2). Page 7815 LIGHT BLUE LT BLU BROWN BRN GRAY GRY GREEN GRN DARK GREEN DK GRN LIGHT GREEN LT GRN ORANGE ORN PINK PNK PURPLE PPL RED RED TAN TAN WHITE WHT YELLOW YEL Page 3410 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 Page 4020 Transmission Pressure Test Port: Specifications THM180 & 180 C Automatic Trans Application ........................................................................................................................................... ................................................................... Ft. Lbs. Oil Pressure Check Plug ..................................................................................................................... .............................................................................. 5-7 ECM/PCM - Damage Prevention PROM - Programmable Read Only Memory: All Technical Service Bulletins ECM/PCM - Damage Prevention Number: 91-318-6E Section: 6E Date: MAY 1991 Corp. Bulletin No.: 176502R Subject: DAMAGE TO ECM/PCM CIRCUIT BOARD WHEN INSTALLING A MEM-CAL Model and Year: 1986-91 ALL PASSENGER CARS AND TRUCKS CONDITION: When installing a service replacement ECM/PCM, the use of incorrect MEMCAL installation procedures may cause the ECM/PCM to fail before it can be installed in the vehicle. This condition may appear as if the ECM/PCM were defective when it was shipped to the dealership, when in fact it was damaged while being installed. In addition this condition may also occur when installing an "updated" service MEM-CAL into the vehicles original equipment ECM/PCM. CAUSE: Excessive vertical force may be applied to the MEM-CAL resulting in flexing of the circuit board and damage to the connections between the circuit board and attached components. Excessive verticle force may be generated in two ways. 1. Incorrect MEM-CAL installation procedure. 2. Interference between MEM-CAL and cover. CORRECTION: Use the following procedure. Service Procedure: Important: This procedure supersedes any instructions regarding MEM-CAL installation dated prior to September 1990. 1. Inspect the MEM-CAL to determine if a cork spacer is glued to the top side of the MEM-CAL assembly. If so, remove it prior to installation. 2. Align small notches with matching notches in the ECM/PCM MEM-CAL socket. 3. VERY GENTLY press down on the ends of the MEM-CAL until the locking levers are rotated toward the sides of the MEM-CAL. Notice: To avoid ECM/PCM damage, do not press on the ends of the MEM-CAL until the levers snap into place. Do not use any vertical force beyond the minimum required to engage the MEM-CAL into its socket. 4. While continuing light pressure on the ends of MEM-CAL, use your index fingers to press the locking levers inward until they are snapped into place. Listen for click. 5. Install MEM-CAL cover and install ECM/PCM in vehicle. Armrest Front Door Panel: Service and Repair Armrest Front Door Trim Panel REMOVE OR DISCONNECT 1. Screws securing the armrest to the door trim. 2. Armrest from the door trim. ^ Slide the armrest towards the rear of the door, and then, lift the armrest from the door. INSTALL OR CONNECT 1. Armrest to the door trim. ^ Place the armrest retaining clips in the slots on the door panel. ^ Slide the armrest toward the front of the door unit the holes in the armrest align with the holes in the door trim. 2. Screws securing the armrest to the door trim. 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. Page 5636 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". Page 1221 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 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 Page 4044 Figure 2 2. To verify that the spacer plate is peening evenly and the ball is sealing correctly, seat the check-ball on the spacer plate. Shine a beam of light on the opposite side and inspect for light between the spacer plate and check-ball (see Figure 2). No trace of light should be present. If light can be seen, a proper seal does not exist, and the spacer plate must be replaced. Service Manual Reference: Refer to the HYDRA-MATIC Automatic Transaxle/Transmission Diagnosis or Unit Repair section of your service manual for proper check-ball locations and functions. Page 574 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 3L30 (180C) Transmission Fluid Pressure Sensor/Switch: Specifications 3L30 (180C) Transmission Component .......................................................................................................................................... .................................................................... Ft. Lbs. Governor Pressure Switch ................................................................................................................... ................................................................................. 7 Electrical - Intermittent MIL/DTC P2138/Reduced Power Multiple Junction Connector: Customer Interest Electrical - Intermittent MIL/DTC P2138/Reduced Power TECHNICAL Bulletin No.: 07-06-04-019D Date: June 28, 2010 Subject: Intermittent Malfunction Indicator Lamp (MIL) Illuminated, DTC P2138 with Reduced Engine Power (Repair Instrument Panel (IP) to Body Harness Connector) Models: 2005-2011 GM Passenger Cars and Light Duty Trucks (Including Saturn) 2005-2009 HUMMER H2 2006-2010 HUMMER H3 2005-2009 Saab 9-7X Supercede: This bulletin is being revised to update the model years and warranty information. Please discard Corporate Bulletin Number 07-06-04-019C (Section 06 - Engine/Propulsion System) Condition - Some customers may comment on an intermittent malfunction indicator lamp (MIL) being Illuminated with a message or an indicator that displays Reduced Engine Power. - The technician may observe on a scan tool DTC P2138 - Accelerator Pedal Position (APP) Sensor 1-2 Correlation set as Current or in History. Cause This condition may be caused by water intrusion into the instrument panel (IP) to body harness connector, which carries the APP sensor signals to the ECM/PCM. This water intrusion results in a voltage difference between APP Sensor 1 and APP Sensor 2 that exceeds a predetermined value for more than a calibrated period of time, setting P2138. Correction Note Aftermarket equipment can generate DTC P2138 and/or other DTCs. 1. Verify that aftermarket equipment is not electrically connected to any of the APP sensor signal or low reference circuits or to any other ECM/PCM 5V reference or low reference circuits. Refer to Checking Aftermarket Accessories in SI. 2. Perform the Diagnostic System Check - Vehicle. ‹› If any 5V reference DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle. ‹› If any 5V reference DTCs are not set, proceed to Step 3. 3. Locate the IP to body harness connector, which may be located in and around the left hand kick panel area or inside the IP. Depending on the vehicle and model year, refer to Wiring Systems or Power and Signal Distribution in SI. Note Some examples of potential water leaks are: A-pillar seals, sunroof drain lines (if equipped) and windshield/cowl sealing. 4. Inspect for a water leak in the area. If necessary use a water hose to determine the source of the leak. Refer to General Information > Water Leaks in SI. ‹› If a water leak is observed, repair as necessary. Verify the effectiveness of the repair. 5. Inspect the IP to body harness connector terminals for corrosion and debris. Refer to Testing for Intermittent Conditions and Poor Connections in SI. ‹› If any corrosion and/or debris is observed, repair as necessary. 6. After completing the repair, verify the proper operation of the system. Depending on the vehicle and model year, perform the Diagnostic Repair Verification procedure or refer to Diagnostic Trouble Code (DTC) List - Vehicle in SI. Page 4721 A new pressure regulator valve (III. 218) has been made which will improve the oil pressure stability at lower RPM. SERVICE PARTS INFORMATION: Description Part Number Valve, Pressure Regulator (III. 218) 8684048 Part numbers are for Reference Only. Check with your Parts Department for latest information. Page 7508 LIGHT BLUE LT BLU BROWN BRN GRAY GRY GREEN GRN DARK GREEN DK GRN LIGHT GREEN LT GRN ORANGE ORN PINK PNK PURPLE PPL RED RED TAN TAN WHITE WHT YELLOW YEL Page 6073 LIGHT BLUE LT BLU BROWN BRN GRAY GRY GREEN GRN DARK GREEN DK GRN LIGHT GREEN LT GRN ORANGE ORN PINK PNK PURPLE PPL RED RED TAN TAN WHITE WHT YELLOW YEL Page 5519 LIGHT BLUE LT BLU BROWN BRN GRAY GRY GREEN GRN DARK GREEN DK GRN LIGHT GREEN LT GRN ORANGE ORN PINK PNK PURPLE PPL RED RED TAN TAN WHITE WHT YELLOW YEL Page 875 Disclaimer Page 5540 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 Sunshade - Replacement Availability Sun Shade: Technical Service Bulletins Sunshade - Replacement Availability File In Section: 08 - Body and Accessories Bulletin No.: 99-08-110-005 Date: June, 1999 INFORMATION Subject: Sunshade Replacement Models: 1999 and Prior Chevrolet and GMC Light Duty Trucks This bulletin is to inform dealers that new replacement sunshades are being introduced for service on approximately July 19, 1999. These new replacement sunshades will no longer have the map strap feature. The part numbers for these replacement sunshades will remain the same as the previous parts. Once these new sunshades become available, current replacement sunshades on hand may be used at the customer's/dealer's discretion. Page 5553 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 Coolant - Specification/Usage Coolant: Technical Service Bulletins Coolant - Specification/Usage Number: 91-62-6B Section: 6B Date: August 1990 Corp. Bulletin No.: 066202 Subject: COOLANT USAGE Model and Year: ALL 1988-91 PASSENGER CARS AND TRUCKS TO: ALL CHEVROLET DEALERS THIS INFORMATION SUPERSEDES INFORMATION PROVIDED BY GMSPO IN PARTS AND ACCESSORIES BULLETINS IB NO. 90-55 AND 90-60 AND INFORMATION PROVIDED IN VARIOUS TRUCK SERVICE AND OWNERS MANUALS AND SHOULD BE USED TO DETERMINE CORRECT COOLANT USAGE IN LIGHT AND MEDIUM DUTY TRUCK APPLICATIONS. GM coolant specification 6038-M or 1899-M (P/N 1052103) is for use in all light duty trucks with gasoline or diesel engines. This coolant features a low silicate formulation and is intended only for use in engines that have cylinder heads and cylinder blocks made of cast iron. GM coolant specification 1825-M or 6043-M (P/N 1052753) which until recently has been the recommended coolant for light duty trucks has been superseded by GM coolant 6038-M or 1899-M (P/N 1052103) in cast iron truck engines. GM coolant specification 1825-M has a higher silicate formulation which is recommended for all passenger car engines with cylinder heads or cylinder blocks made of aluminum. Page 4105 Clutch Fluid: Fluid Type Specifications Hydraulic Clutch Fluid ........................................................................................................................................................... DOT 3 or DOT 4 Brake Fluid Page 2752 Page 1947 Compression Check: Testing and Inspection COMPRESSION CHECK - Disconnect the primary terminal from the ignition coil. - Remove all spark plugs. - Block the throttle plate wide open. - Make sure the battery is fully charged. Starting with the compression gauge at zero, crank the engine through four compression strokes (four "puffs"). - Make the compression check at each cylinder and record each reading. - If some cylinders have low compression, inject 15 ml (one table spoon, or 3 squirts from a pump type oil can) of engine oil into the combustion chamber through the spark plug hole. - Minimum compression recorded in any one cylinder should not be less than 70 percent of the highest cylinder, and no cylinder should read less than 690 kPa (100 psi). Normal Compression: Compression builds up quickly and evenly to specified compression on each cylinder. Piston Rings Leaking: Compression low on first stroke, tends to build up on following strokes, but does not reach normal. Improves considerably with addition of oil. Valves Leaking: Low on first stroke. Does not tend to build up on following strokes. Does not improve much with addition of oil. Head Gasket Leakage: If two adjacent cylinder have lower than normal compression, and injecting oil into cylinders does not increase the compression, the cause may be a head gasket leak between the cylinders. Page 1676 Symbol Identification Page 6216 2. Place the Temperature and Mode controls in the upper position. 3. Apply thumb pressure to each of these control knobs to hold them in the upper position while using a small screw driver to pry off the knobs (Figure 1). 4. Use the same procedure to remove the blower switch knob. 5. Disconnect the 2 light sockets from the housing by twisting the sockets counterclockwise. Engine - Generator Belt Tension Drive Belt: All Technical Service Bulletins Engine - Generator Belt Tension GMC NUMBER: 88-T-36 GROUP: 6D - Engine Electrical DATE: September, 1987 CORPORATE NUMBER: 866403 SUBJECT: GENERATOR BELT TENSIONING - CS-130 GENERATORS MODELS: 1986 - 1988 LIGHT DUTY MODELS EQUIPPED WITH CS-130 GENERATORS Some 1986-1988 Light Duty models are equipped with CS-130 Delcotron generators and without automatic belt tensioning equipment. On these applications, the generator belt tension is adjusted by forcing the generator against the belt until the belt tension specification is reached. FIGURE 1 As with several other Delcotron models, the CS-Series housing includes an adjustment lug on the drive end frame (see Figure No. 1) which should be used to push the generator against the belt while the adjustment bolt is tightened. A 3/4" wrench (or equivalent) should be used when holding the generator by this lug. If the vehicle configuration does not permit use of the adjustment lug, pressure may be applied to the side of the drive end frame to tighten the belt. If pressure cannot be applied directly to the drive end frame, a block of wood should be inserted between the prying instrument and the side of the generator to distribute the force to a wider area which includes the drive end frame. Do not pry directly against the stator or slip ring end frame. Page 8071 Figure 1, 3 1) Remove the cowl vent grille to expose the base of the windshield and the windshield frame and plenum assembly (see Figure 1). 2) Visually look for any sealer skips at the base on the windshield. 3) If no gaps are found, then blow compressed air at the sealer and attempt to locate air movement inside of the cab. This will help locate any non-visible gaps. 4) If either of the above conditions is found then; reseal area with GMS type B silicone base sealant, part # 1052917 or equivalent. Repeat step 3 to insure all gaps have been located. Page 2265 Engine Control Module: Locations Figure 1 Located under the passenger side hush panel, under the dash. Page 348 e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors Do Not require all the steps shown. Skip the steps that Do Not apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. 1. Separate connector halves (see Figures 2 through 6). Figure 2 Figure 3 Description and Operation Oil Pressure Warning Lamp/Indicator: Description and Operation Many trucks utilize 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. Page 4259 for models with 8-1/2 or 8-7/8 inch ring gear, Figs. 16 and 17, or suitable equivalents. On models with 8-7/8 inch ring gear, substitute cloverleaf gauge plate J-21777-36 for plate J-21777-29. Follow all tool manufacturer's recommendations when installing gauge assembly. 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 that bearings are properly seated. d. Hold preload stud and tighten nut until 20 inch lbs. torque are required to rotate stud. Tighten nut in small increments, checking rotating torque after each adjustment, to prevent damaging bearings. 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 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 drive shaft 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. 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 With Air Conditioning Blower Motor: Service and Repair With Air Conditioning Fig 26. Evaporator And Blower Assembly REMOVE OR DISCONNECT (Figure 26) 1. Negative battery cable. 2. Electrical connection (135). 3. Screws (136). 4. Blower motor (155). INSTALL OR CONNECT 1. Blower motor (155). 2. Electrical connection (135). 3. Negative battery cable. Page 4918 NOTE: A drum which is out of round will cause a pedal pulsation to be felt upon braking. - The measurement should also be repeated at various depths of the drum to check for a bellmouth condition. If the measurements differ by more than .010 inches the drum should be resurfaced. NOTE: 1 inch = 25.4mm, so if your micrometer measures in inches and the specified thickness on the disc is in millimeters, convert millimeters to inches by dividing the specified number of millimeters by 25.4. Example: Specification on disc is 17.8 mm. Dividing 17.8mm by 25.4mm/in = 17.8/25.4 = 0.70 inches. Diagnosis By Symptom Wiper Motor: Testing and Inspection Diagnosis By Symptom Fig. 3 Connections to operate rectangular wiper motor independent of vehicle wiring On models with pulse wipers, check system operation with pulse control module removed. If problem is eliminated, pulse control is defective. Refer to Fig. 3, to check wiper motor independent of vehicle wiring. BLADES NO NOT RETURN TO FULL PARK POSITION 1. Loose wiper ground strap connection. 2. Defective wiper motor. HIGH SPEED TOO FAST 1. Defective wiper motor. MOTOR OPERATES AT LOW SPEED ONLY 1. Defective wiper switch. 2. Grounded wire between motor terminal 3 and wiper switch. 3. Defective wiper motor. MOTOR RUNS AT HIGH SPEED ONLY 1. Defective wiper switch. 2. Open circuit between motor terminal 3 and wiper switch. 3. Defective wiper motor. MOTOR WILL NOT SHUTOFF 1. Grounded wire between motor terminal 1 and wiper switch. 2. Defective motor park switch. 3. Defective wiper motor. WIPER INOPERATIVE OR INTERMITTENT 1. Blown fuse. 2. Open circuit in feed wire (No. 2 terminal on wiper motor). 3. Loose mounting of wiper switch. 4. Open circuit in wire to wiper switch (No. 1 terminal on wiper motor). 5. Defective wiper switch. 6. Poor solder connections at terminal board. 7. Defective wiper motor. Head Lamp Switch Trim Plate - Cracked Headlamp Switch: All Technical Service Bulletins Head Lamp Switch Trim Plate - Cracked Number: 91-109-10 Section: 10 Date: January 1991 Corporate Bulletin No.: 061605 Subject: CRACKED PLASTIC HEAD LAMP SWITCH TRIM PLATE Model and Year: 1986-91 S/T TRUCKS TO: ALL CHEVROLET DEALERS Figure 1-Plate Assembly-Instrument Panel Switch Trim Some 1986-1991 S/T trucks may experience a cracked plastic head lamp switch trim plate. This may result in the inaccessibility of the rheostat assembly (dimmer switch) and/or the switch assembly (head lamp/park lamp switch) (Figure 1). Previously, it was necessary to replace the complete head lamp switch trim plate assembly. The complete assembly includes the rheostat assembly part number 01995293 (instrument panel dimmer switch), switch assembly part number 01995313 (head lamp/ parking lamp switch) and the switch trim plate (Figure 1), and the switch trim plate hole covers. A new trim plate kit is now available which does not contain the rheostat assembly or the head lamp switch. This kit replaces the complete head lamp switch trim plate assembly when the switch trim plate is cracked and the rheostat assembly or the head lamp switches do not need replacing. This new kit includes; a switch trim plate, bracket for switch mounting, covers for the switch trim plate holes and four bolts/screws. Page 5702 Steering Gear: Adjustments Saginaw Recirculating Ball Gear Over-Center Preload Fig. 2 Steering gear adjustments Prior to adjusting the steering gear, all outside loads must be removed. 1. Turn steering wheel gently from one stop over to other. Turn wheel back exactly half-way to center position. 2. Turn over center adjuster screw, Fig. 2, clockwise to take out all lash between ball nut and pitman shaft sector teeth. 3. Tighten jam nut to specifications. 4. Check torque at steering wheel, taking highest reading as wheel is turned through center position. 5. If necessary, loosen jam nut and adjust the over-center adjuster screw to obtain proper torque of 16 inch lbs. Tighten jam nut and recheck reading through center of travel. 6. If maximum torque is exceeded, turn the over-center adjuster screw counterclockwise, then come up on adjustment by turning jam nut clockwise. 7. Install pitman arm onto shaft, lining up marks made during removal. Worm Bearing Preload Fig. 2 Steering gear adjustments Page 4630 REMOVE OR DISCONNECT (Figures 26 and 27) 1. Refrigerant from the system. 2. Negative battery cable. 3. Resistor (145) with the wire attached. 4. Blower electrical connection. 5. Inlet line (111) to the evaporator (143). 6. Blower assembly mounting screws (139) and nuts (147). 7. Blower assembly from the vehicle. 8. Accumulator inlet line (108) from the evaporator (143). 9. Accumulator bracket (150) and screw (148). 10. Accumulator (4). 11. Screws (147). 12. Case sections (146 and 140). 13. Core (143). INSTALL OR CONNECT 1. Core (143) to case sections (146 and 140) with screws (147). 2. Accumulator bracket (150) to the accumulator (4). 3. Accumulator (4) and bracket (150) to core (143) with screw (148). NOTE: Add 60 ml (2 oz.) of clean refrigerant oil PLUS an amount equal to that drained. 4. Inlet line (108) to the accumulator (4). NOTE: Use clean 525 viscosity oil on the seals. ^ Tighten connection to 24 Nm (18 ft. lbs.). 5. Blower assembly to the vehicle with screws (139) and nuts (147). ^ Tighten screws (139) to 3 Nm (3 in. lbs.). Nuts (147) to 2 Nm (2 in. lbs.). 6. Inlet line (111) to the evaporator core (143). NOTE: Use clean 525 viscosity oil on the seals. ^ Tighten connection to 24 Nm (18 ft. lbs.). 7. Outlet line (109) to the accumulator (4). ^ Tighten connection to 24 Nm (18 ft. lbs.). 8. Blower electrical connection. 9. Resistor (145) and electrical wire to the blower assembly. 10. Negative battery cable. 11. Evacuate, charge, and leak test system. Page 5614 Alignment: Service and Repair Front Wheel Alignment Front Caster and Camber Adjustment NOTE: Before checking or adjusting caster and camber angles, jounce vehicle at least 3 times to prevent false geometric readings. 4 X 2 MODELS (Figure 1) Caster & camber adjustment. 4 x 2 models Caster and camber adjustments are made by shims inserted between upper control arm shaft and frame bracket, refer to (Figure 1). Add, subtract, or transfer shims to change readings as noted below: To adjust caster and/or camber, loosen upper control arm shaft to frame nuts, then add or subtract shims as necessary and torque upper control arm shaft to frame nuts to 88 Nm (65 ft lbs). After adjustment, the shim pack should have at least two threads of bolt exposed beyond the nut. The difference between front and rear shim packs must not exceed 10 mm (0.40 inch). Caster Transfer shims from front to rear, or rear to front. The transfer of shims from rear to front bolt will decrease positive caster. Camber Change shims at both front and rear of shaft. Adding an equal amount of shims at both front and rear locations will decrease positive camber. 4 X 4 MODELS Page 5691 Steering Gear: Description and Operation Saginaw Recirculating Ball Gear Fig. 1 Cross-Sectional View Of Steering Gear The Saginaw steering gear, Fig. 1, is a recirculating ball nut and worm type. The ball nut is mounted on the worm, located on the lower end of the steering shaft. The steel balls act as a rolling thread between the worm and nut to provide low friction drive between them. Teeth on the ball nut engage teeth on the pitman shaft sector. The teeth on the ball nut are made so that a tighter fit exists between the ball nut and pitman shaft sector teeth when the front wheels are in the straight ahead position. The pitman shaft sector teeth are slightly tapered so that a proper preload may be obtained by moving the pitman shaft endways by means of a preload adjuster screw which extends through the gear housing side cover. The head of the preload adjuster and a selectively fitted shim fit snugly into a T-slot in the end of the pitman shaft, so that the screw also controls the end play of the shaft. When the wheel and steering shaft turn to the left, the ball nut is moved downward by the balls which roll between the worm and nut. As the balls reach the outer surface of the nut, they enter the return guides which direct them across and down into the ball nut where they enter the circuit again.When a right turn is made, the ball nut moves upward and the balls circulate in the reverse direction. A/C Recirculation Door - Water Leak Hood Hinge: All Technical Service Bulletins A/C Recirculation Door - Water Leak File In Section: 1 - HVAC Bulletin No.: 56-12-04 Date: April, 1995 Subject: Water Leak at the A/C Recirculation Door (Install New Hood Hinge Seal) Models: 1983-93 Chevrolet and GMC Truck S/T Pickups 1983-94 Chevrolet and GMC Truck S/T Utilities 1991-94 Oldsmobile Bravada Built Prior to the Following VIN Breakpoints: Assembly Plant Division (Plant Code) VIN Breakpoint GMC Truck Pontiac West (0) R0525661 Chevrolet Pontiac West (0) R0168567 Oldsmobile Pontiac West (0) R0704953 GMC Truck Moraine (2) All Chevrolet Moraine (2) All Oldsmobile Moraine (2) All CONDITION Some owners may comment that they have a water leak at the kick panel vent when their A/C controls are in the MAX position and it is raining. CAUSE Water is entering the plenum and cowl area by way of the hood hinge. CORRECTION To correct this condition, remove the current hood hinge seal and replace with a redesigned hood hinge seal. The redesigned seal has foam flaps which restrict water entry. Service Procedure 1. Raise and support the hood. 2. Remove the cowl vent grille. Refer to "Cowl Vent Grille Replacement" in Section 2B of the Service Manual. 3. Remove hood hinge bolts from hood (both sides). 4. Remove hood from vehicle. 5. Remove fender nut and bolt from hinge (both sides). 6. Remove hood hinge from vehicle (both sides). 7. Remove hood hinge seals and replace with redesigned hood hinge seals P/N's 15995797 (LH) and 15995798 (RH). Important: Be sure that hood hinge seals are properly seated and sealed or water leakage could recur. 8. Install hood hinges to vehicle. Important: Apply lubricant to the hood hinges around the hinge to fender bolts. 9. Install fender nuts and bolts to hood hinges. 10. Install hood hinges to hood bolts. Tighten the hinge to hood bolts to 25 Nm (18 lb.ft.). Page 3408 [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. Body - Vehicle Glass Distortion Information Back Window Glass: Technical Service Bulletins Body - Vehicle Glass Distortion Information INFORMATION Bulletin No.: 00-08-48-005D Date: September 10, 2010 Subject: Distortion in Outer Surface of Vehicle Glass Models: 2011 and Prior GM Passenger Cars and Trucks 2009 and Prior HUMMER H2 2010 and Prior HUMMER H3 2005-2009 Saab 9-7X 2010 and Prior Saturn Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 00-08-48-005C (Section 08 - Body and Accessories). Distortion in the outer surface of the windshield glass, door glass or backlite glass may appear after the vehicle has: - Accumulated some mileage. - Been frequently washed in automatic car washes, particularly "touchless" car washes. This distortion may look like a subtle orange peel pattern, or may look like a drip or sag etched into the surface of the glass. Some car wash solutions contain a buffered solution of hydrofluoric acid which is used to clean the glass. This should not cause a problem if used in the correct concentration. However, if not used correctly, hydrofluoric acid will attack the glass, and over time, will cause visual distortion in the outer surface of the glass which cannot be removed by scraping or polishing. If this condition is suspected, look at the area of the windshield under the wipers or below the belt seal on the side glass. The area of the glass below the wipers or belt seal will not be affected and what looks like a drip or sag may be apparent at the edge of the wiper or belt seal. You may also see a line on the glass where the wiper blade or the belt seal contacts the glass. Important The repair will require replacing the affected glass and is not a result of a defect in material or workmanship. Therefore, is not covered by New Vehicle Warranty. Disclaimer Page 814 Labor Operation No.: K6550 Valve, Pressure Regulator-R&R; or Replace Use the appropriate labor time in the labor time guide. Parts are currently available from GMSPO. Page 481 Neutral Safety Switch: Service and Repair 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. Page 4962 Brake Caliper: Service and Repair Rebuild Caliper Assembly DISASSEMBLY 1. Remove caliper. 2. Disconnect hose from steel line, remove U-shaped retainer and withdraw hose from frame support bracket. 3. After cleaning outside of caliper, remove brake hose and discard copper gasket. 4. Drain brake fluid from caliper. Removing Piston 5. Pad caliper interior with clean shop towels and use compressed air to remove piston. Use just enough air pressure to ease piston out of bore. Do not blow piston out of bore. WARNING: Do not place fingers in front of piston in an attempt to catch or protect it when applying compressed air. This could result in serious injury. Brakes - Poor Rotor Finish/Hard Pedal Feel Brake Rotor/Disc: Customer Interest Brakes - Poor Rotor Finish/Hard Pedal Feel Number: 90-293-5 Section: 5 Date: July 1990 Corp. Bulletin No.: 005003 Subject: BRAKE ROTOR REFINISH Model and Year: 1981-90 ALL PASSENGER CARS AND TRUCKS TO: ALL CHEVROLET DEALERS Comments have been received of poor brake rotor finish and/or hard brake pedal feel after refinishing brake rotors using the On-Vehicle Brake Lathe (VGB 320/366, Kent-Moore 38- 070400) sold through GM Dealer Equipment program. CAUSE: This condition results from using non-original cutting tips. Only original equipment replacement tips should be used. CORRECTION: When replacing the original cutting tips for an On-Vehicle Brake Lathe, use only replacement tips ordered from Kent-Moore Tool and Equipment Division. The replacement cutting tips can be ordered from Kent-Moore (1-800-GM-TOOLS) as follows: Part Number: J-37704-13 Cufting Tips (Box of Ten) 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 this firm or for any such items which may be available from other sources. Interior - Seat Cover Wrinkle/Crease/Burn Info Seat Cover: 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 Page 2609 - Diagnostic Chart C-1D. The updated chart information: Brake Light Switch Brake Light Switch: Locations Brake Light Switch LH Side Of I/P Behind Instrument Cluster Page 6905 What if I input the VIN incorrectly? If an incorrect VIN is entered into the system (meaning that the system does not recognize the VIN or that the VIN has been entered incorrectly) the system will return an error message. If I am an authorized user for the KeyCode application, can I access the application from home? Yes. What if I suspect key code misuse? Your dealership should communicate the proper procedures for requesting key codes. Any suspicious activity either within the dealership or externally should be reported to Dealer Systems Support at 1-800-265-0573 or GM of Canada Key Code Inquiry Desk at 1-905-644-4892. Whose key codes can I access through the system? At this time the following Canadian vehicle codes are available through the system: Chevrolet, Cadillac, Buick, Pontiac, GMC, HUMMER (H2 and H3 only), Oldsmobile, Saturn, Saab and Isuzu (up to 2002 model year) for a maximum of 17 model years. What should I do if I enter a valid VIN and the system does not produce any key code information? Occasionally, the KeyCode Look Up application may not produce a key code for a valid VIN. This may be the result of new vehicle information not yet available. In addition, older vehicle information may have been sent to an archive status. If you do not receive a key code returned for valid VIN, you should contact GM of Canada Key Code Inquiry Desk at 1-905-644-4892. How do I access KeyCodes if the KeyCode Look-up system is down? If the KeyCode Look-up system is temporarily unavailable, you can contact the original selling dealer who may have it on file or contact GM of Canada Key Code Inquiry Desk at 1-905-644-4892. If the customer is dealing with an emergency lock-out situation, you need to have the customer contact Roadside assistance, OnStar if subscribed, or 911. What should I do if the KeyCode from the look-up system does not work on the vehicle? On occasion a dealer may encounter a KeyCode that will not work on the vehicle in question. In cases where the KeyCode won't work you will need to verify with the manufacturer of the cutting equipment that the key has been cut correctly. If the key has been cut correctly you may be able to verify the proper KeyCode was given through the original selling dealer. When unable to verify the KeyCode through the original selling dealer contact GM of Canada Key Code Inquiry Desk at 1-905-644-4892. If the key has been cut correctly and the code given does not work, the lock cylinder may have been changed. In these situations following the proper SI document for recoding a key or replacing the lock cylinder may be necessary. How long do I have to keep KeyCode Records? Dealership KeyCode documentation must be retained for two years. Can I get a KeyCode changed in the Look-Up system? Yes, KeyCodes can be changed in the Look-Up system if a lock cylinder has been changed. Contact GM of Canada Key Code Inquiry Desk at 1-905-644-4892. What information do I need before I can provide a driver of a company fleet vehicle Keys or KeyCode information? The dealership should have a copy of the individual's driver's license, proof of employment and registration. If there is any question as to the customer's employment by the fleet company, the dealer should attempt to contact the fleet company for verification. If there is not enough information to determine ownership and employment, this information should not be provided. How do I document a request from an Independent Repair facility for a KeyCode or Key? The independent must provide a copy of their driver's license, proof of employment and signed copy of the repair order for that repair facility. The repair order must include customer's name, address, VIN, city, province and license plate number. Copies of this information must be included in your dealer KeyCode file. A/T - Click or Whine in Third or Fourth Gear Clutch: Customer Interest A/T - Click or Whine in Third or Fourth Gear Number: 93-228-7A Section: 7A Date: JUNE 1993 Corporate Bulletin No.: 277121R ASE No.: A2 Subject: CLICK/WHINE IN THIRD/FOURTH GEAR Model and Year: 1988-93 CAPRICE, CAMARO AND CORVETTE 1988-93 C/K, RN, S/T, M AND G TRUCKS 1990-93 L VAN THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 92-157-7A, DATED APRIL 1992. THE 1993 MODEL YEAR HAS BEEN ADDED, AS WELL AS A NOTE IN THE CORRECTION SECTION. ALSO THE SERVICE PARTS INFORMATION HAS BEEN CHANGED. ALL COPIES OF 92-157-7A SHOULD BE DISCARDED. CONDITION: Some 1988-93 vehicles with HYDRA-MATIC 4L60 or 4L60-E transmissions built before November 19, 1992 (Julian Date 324) may exhibit a clicking or whining noise in third and fourth gear. A customer may also describe it as a ticking or rattle noise. CAUSE: The clicking noise is caused by transmission fluid passing over the friction plates of the low and reverse clutch. The fluid causes them to vibrate when the low and reverse clutch is not applied (third and fourth gear). CORRECTION: Install five new fiber plates in the low and reverse clutch. The new plates have a non-groove configuration. NOTE: All HYDRA-MATIC 4L60 and 4L60-E transmissions built on or after November 19,1992 (Julian Date 324) have been assembled with the new low and reverse clutch fiber plates. SERVICE PARTS INFORMATION: Parts are expected to be available on 6/07/93. Tailgate - Latch Rattle, Revised Striker & Latch Trunk / Liftgate Latch: All Technical Service Bulletins Tailgate - Latch Rattle, Revised Striker & Latch Number: 92-153-10 Section: 10 Date: APRIL 1992 Corporate Bulletin No.: 161514 ASE No.: B1 Subject: END GATE LATCH RATTLE Model and Year: 1983-92 S/T TRUCKS Owners of some 1983-1992 S/T 2 and 4 door utility vehicles may comment that their end gate latch rattles. One possible cause of this condition is the end gate latch fork bolts contacting the striker assembly (metal-tometal) causing a rattle. To correct this condition, it is necessary to install a new striker assembly that has a urethane sleeve over the striker post. The urethane sleeve preventsmetal-to-metal contact and may eliminate the rattle. SERVICE PROCEDURE: A/T - New Trans Fluid, Dexron IIE Fluid - A/T: All Technical Service Bulletins A/T - New Trans Fluid, Dexron IIE Number: 92-26-7A Section: 7A Date: OCT. 1991 Corporate Bulletin No.: 177125 ASE No.: A2 Subject: DEXRON-IIE AUTOMATIC TRANSMISSION/TRANSAXLE FLUID Model and Year: 1976-92 ALL TRUCKS WITH AUTOMATIC TRANSMISSION TRANSMISSION APPLICATIONS: SUBJECT: All Automatic Transmissions DEXRON-IIE Automatic Transmission/Transaxle Fluid TRANSMISSION MODELS: VEHICLE APPLICATIONS: All All HYDRA-MATIC Automatic Transmissions/Transaxles Bulletin Covers: General Motors Corporation has developed a new service fill automatic transmission/transaxle fluid which is designated DEXRON-IIE. This fluid is the preferred fluid for all HYDRA-MATIC automatic transmission/transaxles and will eventually replace DEXRON II. DEXRON-IIE is acceptable for use wherever DEXRON II was previously specified. DEXRON II is acceptable for use when DEXRON-IIE is not available. DEXRON-IIE can be used in both electronically and hydraulically controlled transmissions/transaxles. DEXRON-IIE Advantages: ^ Has better anti-foaming characteristics. ^ Improved low temperature flow characteristics (low temperature viscosity) and improved high temperature oxidation stability. ^ DEXRON-IIE and DEXRON II can be mixed in any ratio. No draining or flushing of system is required. ^ DEXRON-IIE is back serviceable to 1949 for all General Motors automatic transmission/transaxles. ^ No change in transmission/transaxle calibration or reduction in transmission/transaxle durability will occur as a result of using DEXRON-IIE. Service Parts Information: PART NUMBER DESCRIPTION 12345881 1 quart container 12345882 1 gallon container 12345883 55 gallon drum Parts are currently available from GMSPO. Page 7789 Symbol Identification Page 7798 When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 5mm (3/16") of insulation from wire. e. Crimp a new terminal to the wire. f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. Figure 17 To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Figure 18 Figure 19 Page 8194 Wiper Motor: Testing and Inspection Test Steps Fig. 2 Rectangular windshield wiper motor electrical connections Fig. 3 Connections to operate rectangular wiper motor independent of vehicle wiring On models with pulse wipers, disconnect electrical connectors to pulse control module and connect switch and motor harnesses together. If problem is corrected, pulse control is defective. 1. Inspect wiring harness for breaks, loose or improper connections, and repair as needed. 2. Ensure motor and switch are securely mounted, and properly grounded, and repair as needed. 3. Turn ignition on and operate wipers in all switch positions, then place wiper switch in off position with wipers at top of their travel. 4. If motor fails to operate, disconnect electrical connector to motor and check for battery voltage at terminal 2 in connector, Fig. 2, using a test lamp. 5. If lamp fails to light, check and repair feed circuit. 6. If lamp lights, operate motor independent of vehicle wiring as shown in Fig. 3. If motor fails to operate, repeat test with linkage disconnected. 7. If motor still fails to operate, motor is defective. If motor operates, repair linkage. 8. If motor operates properly in step 6, check continuity of wiring between motor and switch. If wiring if satisfactory, replace switch. 9. If motor will not shutoff, or if blades do not park when switch is placed in off position, check for defective park switch or open motor ground and repair as needed. 10. If motor operates properly in all other positions, but will not operate in delay mode, proceed as follows: a. Check feed circuit to pulse control and repair as needed. b. Check continuity of red and black wires between pulse control and wiper switch, and repair as needed. c. If feed circuit and wiring are satisfactory, replace pulse control. Page 4324 Propshaft Runout Specifications 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. Description and Operation Water In Fuel Indicator: Description and Operation The Water In Fuel warning system employs a fuel detector integral with the fuel filter and fuel heater and mounted on the engine. When 2.2 ounces of water more has collected in the filter, the Water In Fuel lamp on the instrument panel will light. After the light comes on, the filter should be drained as soon as possible and must be drained within 2 hours of operation. Page 5762 Figure 13 - Proper Inboard Stroke Positioning 9. Install convolute retainer over seal capturing four convolutes (Figure 13). Important: Joint must be assembled with convolute retainer in position as shown in Figure 13. Seal damage will result if joint is not assembled to dimension shown. Figure 14 - Spider Assembly Installation 10. Install spacer ring and spider assembly (with counterbore toward end of shaft) on the shaft far enough to allow installation of the retaining ring at the end of the halfshaft (Figure 14). 11. Install the retaining ring and push the spider assembly toward the end of the shaft until retaining ring is covered by the spider assembly counterbore. Install the spacer ring and make sure it is seated in its groove. 12. Pack the seal and housing with grease supplied in the kit, (the amount of grease supplied in this kit has been premeasured for this application), place the large metal clamp on the seal, then place the housing over the spider assembly and snap the seal onto the housing. Page 7774 Headlamp Switch: Electrical Diagrams Light Switch Details (Part 1 Of 3) Page 4017 situations does the condition occur, whether the condition is more noticeable when the vehicle is hot or cold, or in what gear range does the condition become evident. Figure 3 - Range Reference Chart Before driving the vehicle, check that proper fluid level and correct T.V. cable setting have been maintained. Check minimum and maximum mainline pressures against the transmission pressure charts updated and printed each year in the appropriate Service Manuals. Also, one of the preliminary checks should include making certain that the engine is in proper tune and not contributing to or mistaken for a transmission condition. With all preliminary information collected, the vehicle should then be road tested. During the road test, note when and in what range the condition occurs. By comparing this information with the range reference chart (refer to Figure 3) you can begin to eliminate known good circuits and/or clutches. Through this process of elimination, it is possible to pinpoint the circuit and/or clutch that is causing the condition. Detonation Sensor LH Rear Of Engine, At Rear Of Cylinder Head Page 425 Transmission Position Switch/Sensor: Testing and Inspection Chart C-1A - Park/Neutral Switch Diagnosis Backup Lamps/Tailgate Window Release - Inoperative Shift Interlock Switch: Customer Interest Backup Lamps/Tailgate Window Release - Inoperative Number: 91-459-8A Section: 8A Date: DEC. 1991 Corporate Bulletin No.: 168104 ASE No.: A6 Subject: BACKUP LAMPS OR TAILGATE WINDOW RELEASE INOPERATIVE Model and Year: 1980-91 ALL LIGHT DUTY TRUCKS (EXCEPT GEO) Owners of some 1980-1991 C/K, 1982-1991 G, 1985-1991 M/L, 1984-1991 P2,P3, 1987-1991 R/V, 1983- 1991 ST (including LLV) with automatic transmissions may comment on a condition of inoperative back-up lamps or inoperative tailgate window release. This condition occurs when the vehicle's gear shift lever is placed in the "reverse" position, but the back-up lamps do not illuminate. In addition, on the S/T utility vehicles, the electric tailgate window release does not release when the transmission gear shift lever is placed in the "park" or "neutral" position and the endgate window release button is depressed. The park/neutral and back-up lamp switch comes out of adjustment which does not allow for the contact points to remain engaged. To correct these conditions, the contact carrier on the park/neutral and back-up lamp switch has been modified to increase switch carrier travel. SERVICE PROCEDURE: 1. Disconnect the battery ground cable from the battery. 2. Disconnect the switch assembly harness. 3. Place the gear selector in neutral. 4. Squeeze the tangs on the switch together and remove the switch assembly. 5. Install the new switch assembly (P/N 15679680) by: -aligning the actuator with the cutout in the steering column jacket. -inserting the tangs into the rectangular holes and pushing down on the switch assembly. 6. Adjust the switch by moving the gear selector to park. 7. Connect the switch assembly harness. 8. Connect the negative battery cable. 9. Check for proper switch operation. Readjust the switch as necessary. 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 Page 7974 Power Window Motor: Service and Repair Door Inner Panel Water Deflector Replacement Front Inner Panel Water Deflector NOTE: Waterproof deflectors are used to seal the door inner panel, and to prevent water from entering into the body. The deflector is secured by a strip of adhesive between the deflector and the door, as well as waterproof sealing tape. REMOVE OR DISCONNECT 1. Door trim panel. 2. Plastic fasteners (when used). 3. Armrest bracket. 4. Water deflector. ^ Pull the waterproof sealing tape from the deflector. ^ Break the bond between the sealer and the door with a flat-bladed tool. INSTALL OR CONNECT 1. Water deflector strip caulking as a sealant between the deflector and the door, If needed. 2. Plastic fasteners (when used). 3. Waterproof tape. 4. Armrest bracket. 5. Door trim panel. Page 7996 PARTS INFORMATION: Pads are currently available from GMSPO. WARRANTY INFORMATION: For vehicles repaired under warranty use: Labor Op. C-0152-RH C-0153-LH Use applicable labor time guide for labor hours. Page 5069 Vacuum Brake Booster: Testing and Inspection Slow or No Release 1. Faulty pushrod adjustment. 2. Binding linkage. 3. Blocked passage in power piston. 4. Air valve sticking shut. 5. Broken piston return spring or air valve spring. 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 Page 6389 Refrigerant Pressure Sensor / Switch: Locations Pressure Cycling Switch Pressure Cycling Switch Location The Pressure Cycling Switch is located on the Accumulator. Page 3474 SERVICE PARTS INFORMATION Part Number Description 15664811 Vacuum Actuator Switch Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: K4120 Use applicable labor time guide for labor hours. Page 6182 Compressor Shaft Seal: Service and Repair With R-4 Compressor R-4 Compressor Component View The shaft seal is designed to seep oil for lubrication. Replace the seal if a large leak is detected. Use J 29547 to determine refrigerant oil leakage. If the seal needs replacing, remove the accumulator. Drain, measure and replace the refrigerant oil with new 525 viscosity refrigerant oil. Remove or Disconnect Tools Required: J 5403-A Internal Snap Ring Pliers J 22974-A Compressor Shaft Oil Seal Protector J 23128-A Ceramic Seal Remover and Installer J 34614 Shaft Seal Protector 1. Clutch drive hub (3). 2. Retainer ring (11). Clean ^ The inside of the compressor neck area. 3. Shaft seal (12). Page 3610 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". Page 2379 Throttle Position Sensor: Adjustments The TPS is not adjustable. The ECM utilizes the IAC position reading at idle for its zero reading, therefore no adjustment is necessary. Page 3243 Ignition Control Module: Service and Repair Typical Distributor Components REMOVAL: 1. Remove distributor cap and rotor. 2. Remove two module attaching screws, and lift module up. 3. Disconnect leads from module. Observe color code on leads as these cannot be interchanged. 4. Remove module. INSTALLATION: NOTE: Be sure there is a sufficient amount of silicone grease on the metal face of the module and on the distributor base (where the module seats), when reinstalling the module. The purpose of the silicone grease is to cool the module. 1. Install module. 2. Connect leads to module. 3. Install module attaching screws. 4. Install pick up coil. 5. Install cap and rotor. Page 7704 Brake Light Switch: Service and Repair Fig. 2 Stop Light Switch Installation 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. 2. 5. Pull brake pedal rearward against pedal stop to adjust switch. Switch is properly adjusted when brake lights operate when brake pedal is depressed .53 inch from normal position. If further adjustment of switch is necessary, switch can be rotated or pulled in clip. Door Armrest Replacement Power Window Motor: Service and Repair Door Armrest Replacement Front Door Trim Panel REMOVE OR DISCONNECT 1. Screws securing the armrest to the door trim. 2. Armrest from the door trim. ^ Slide the armrest towards the rear of the door, and then, lift the armrest from the door. INSTALL OR CONNECT 1. Armrest to the door trim. ^ Place the armrest retaining clips in the slots on the door panel. ^ Slide the armrest toward the front of the door unit the holes in the armrest align with the holes in the door trim. 2. Screws securing the armrest to the door trim. Page 190 Fuel Pump Relay: Service and Repair Fuel Pump Relay REMOVAL 1. Verify that ignition switch is in the OFF position. 2. Disconnect the wiring harness plug. 3. Remove the fuel pump relay. INSTALLATION 1. Install the new fuel pump relay. 2. Reconnect the wiring harness plug to relay. 3. Verify correct operation to confirm repair. Page 7039 * Select applicable additional "Labor Hours" and add to above "Labor Hours" as needed. Page 4011 Transmission Position Switch/Sensor: Testing and Inspection Chart C-1A - Park/Neutral Switch Diagnosis End Gate Lock Cylinder - Rattles Trunk / Liftgate Lock Cylinder: All Technical Service Bulletins End Gate Lock Cylinder - Rattles Number: 91-507-10 Section: 10 Date: AUGUST 1992 Corporate Bulletin No.: 261003 ASE No.: B1 Subject: END GATE LOCK CYLINDER ASSEMBLY RATTLE Model and Year: 1982-91 S/T TRUCKS Some owners of 1982-1991 S/T utility vehicles may experience a rattling sound emanating from the rear of the truck. This condition may occur if the end gate lock cylinder assembly is loose. To correct this condition, it is necessary to bend the ends of the spring within the lock cylinder assembly eliminating any clearance between the pawl assembly and cylinder housing. SERVICE PROCEDURE: 1. Open the end gate to the horizontal position and remove the inner trim panel. Adjustments Cruise Control Servo Cable: Adjustments 1. Ensure throttle is completely closed and ignition is off. 2. On Astro, Safari, S-10 and S-15 models, adjust servo cable/linkage to 0.15-0.39 inch clearance at throttle stud. 3. On R/V & G models with gasoline engine, adjust servo linkage to 0.0197-0.0394 inch clearance at throttle stud. 4. On R/V models with diesel engine, adjust servo linkage to .0393 inch clearance at center of linkage. 5. On G models with diesel engines, use third ball on servo chain. Adjust cable jam nuts until cable sleeve at throttle lever is tight, without holding throttle open. 6. On Lumina APV, Silhouette and Trans Sport, pull servo end of cable assembly towards servo as far as possible without moving throttle, then connect cable to closest hole in servo without moving throttle. Page 4941 - Verify the Leading and Trailing shoes are installed in the correct relationship. - Any contamination should be removed from the new shoes immediately. If very light hand sanding will not remove the contamination the shoes should be discared. - When replacing shoes/linings or drums always replace both sides per axle. If only one side is replaced a steering pull may develop during braking. - If brake hardware is being replaced, verify that both the color and shape of the new springs match the old springs. - Prior to reinstalling the drum, the automatic adjuster will need to be backed off to accommodate for the increased thickness of the new shoes/linings. Brake Cruise Vacuum Release Valve Vacuum Vent Valve: Locations Brake Cruise Vacuum Release Valve LH Side Of Steering Column Behind Instrument Cluster Permanent Magnet Motor Wiper Motor: Description and Operation Permanent Magnet Motor Except Models W/Pulse Wipers Fig. 2 Permanent magnet type windshield wiper motor. S/T series except models w/pulse wipers Wiper motor internal components, including permanent magnet fields, armature, brush holder and gear train, are enclosed in a die cast aluminum housing with a plastic cover, Fig. 2. The brush holder contains a circuit breaker and park switch as well as common, low and high speed brushes, and it is located at the gearbox end of the motor. The common brush is connected to ground through the wiper motor ground strap. Battery voltage is supplied to the wiper switch and motor park switch fixed contacts through a fuse in the fuse block. Motor speeds are determined by supplying voltage through the wiper switch to the low or high speed motor brush, and when wiper switch is in off position, voltage supplied to the motor park switch allows wipers to park at the bottom of their travel. Pulse wiper operation, if equipped, is controlled by a variable resistor in the wiper switch and by a pulse module connected between the wiper motor and switch. Standard (Non-Pulse) Wiper Operation When ignition is on, battery voltage is supplied to low and high speed contacts in the wiper switch and to motor terminal 4, Fig. 2. Placing wiper switch in low or high position completes the feed circuit to motor terminal 2 (low speed brush) or terminal 1 (high speed brush), Fig. 2. Current flows through the armature to ground through the common brush, and the motor runs at the selected speed. Placing wiper switch in off position connects the motor low speed brush to park switch terminal 3, Fig. 2. Current flows through the closed park switch contacts, allowing the motor to run at low speed. When wipers reach their lowest point of travel, a cam on the motor output shaft opens the park switch through an actuating lever, and the motor stops. Pulse Wiper Operation In addition to standard wiper system components, models with pulse wipers use a pulse control module and a wiper switch with a variable resistor and additional contacts to control pulse module operation. Current flow between the wiper motor and switch, and battery voltage to the switch pass through the pulse control module. However, when the wiper switch is in off, low or high position, the module does not affect system operation. When the wiper switch is in delay position, voltage is supplied to the pulse module timer through the variable resistor. When the timer circuit becomes fully charged, the timer switch closes, and voltage is supplied to the motor through a second delay terminal in the wiper switch. As the motor begins to operate, the park switch closes, the timer switch opens, and voltage is supplied to the motor through a third delay contact which is linked to the park switch in the wiper switch. When wipers complete their cycle, the park switch opens, the motor stops, and the timer begins to recharge. This cycle repeats as long as wiper switch is in delay position. Delay period is controlled by varying resistance in the pulse module timer feed circuit. Models W/Pulse Wipers Page 7410 6. Tape the solder and diode. 7. Reinstall the black plastic conduit. 8. Reconnect connector to the generator. 9. Reconnect battery. This procedure will not affect the operation of the generator light during the bulb check at the beginning of the start cycle. For vehicles repaired under warranty use, Labor Operation Number: T7990 Labor Time: .4 Hr Page 7118 The AFFECTED AREAS MAY REQUIRE RECLEARCOATING/COLORCOATING OR REFINISHING. 8. In any case, once the proper repairs have been made, the final step in the repair process involves polishing the vehicle. A WORD ABOUT CLEARCOAT THICKNESS The clearcoat on the vehicle is typically 1.5 to 2.0 mils thick (one mil equals .001" or 1/1,000 of an inch). At least one mil thickness is required to provide lasting protection to the vehicle basecoat. PAINT GAGES The best way to accurately measure how much clearcoat has been removed is to use a paint gage before, during and after the sanding process. Paint gages measure the total thickness of the finish and when used, can determine how much clearcoat has been removed during the repair process. Paint gages range from magnetic pull types to sophisticated electronic types, are available from a variety of sources, and can cost from $30 to $1800. The older magnetic type gages, at best, a +/- 5% accuracy range and are not sensitive enough to detect removal of .5 mil clearcoat. The newer type magnetic gages have improved accuracy ranges. Most gages are confined to checking either a ferrous metal (steel) or non-ferrous metal (aluminum) panels. At this time, there are no viable gages for reading film thickness on non-metallic panels. A more sophisticated gage is the digital Elcometer 300 fn Paint Thickness gage (or equivalent). It has an ability to read film thickness on both ferrous and non-ferrous metal panels. This instrument has an accuracy range of +/- 1% and has thickness standards included for recalibration. Approximate cost = $1750. An alternative (for use on steel panels only) would be the digital Elcometer 246 model, or equivalent. This gage has a +/- 3% accuracy range and include thickness standards for recalibration. Approximate cost - $575. REPAIRING RAIL DUST DAMAGE Rail dust damage comes from the tiny iron particles produced from the friction between the train wheels and the track. It can also be deposited on vehicles if stored near any operation producing iron dust (steel ore yards, etc.). This dust can either lay on top of, or embed into the paint surface. It is usually diagnosed as; bumps in the paint surface OR - rust colored spots in the paint. PROCEDURE: 1. Wash the vehicle with soap and water, dry it and clean the affected area with wax and grease remover. 2. Keeping the vehicle in a cool or shaded area, rinse the surface with cold water. CAUTION: RAIL DUST REMOVER (OXALIC ACID) IS AN ACIDIC SUBSTANCE CONTAINING CHEMICALS THAT WILL BREAK DOWN THE IRON PARTICLES EMBEDDED IN THE FINISH. WHEN WORKING WITH IT, USE THE NECESSARY SAFETY EQUIPMENT, INCLUDING GLOVES AND GOGGLES. FOLLOW THE MANUFACTURER'S DIRECTIONS CLOSELY BECAUSE IT MAY REQUIRE SPECIAL HANDLING AND DISPOSAL. 3. Soak several terry cloth towels in a container of rail dust remover solution and, after the damaged areas have been rinsed with cold water, lay the wet towels on the damaged areas. 4. Allow the towels to remain in place for 20 minutes, keeping them moist by spraying with water and not allowing to dry on the surface of the vehicle. 5. After 20 minutes of applying the towels, remove them and rinse the area thoroughly with cold water. Inspect the affected area to ensure the dust has been removed. Use both touch (feeling for bumpy surface) and sight (magnifying glass for close inspection). 6. If upon inspection some particles are still present, the process of applying the towels can be repeated 3 times. 7. Select a test area and hand wet sand with American ultra fine 1,500 grit to 2,000 grit sandpaper to repair damage (surface pitting from dust). a. Use ample amounts of water. b. Go slow to prevent removing too much clearcoat. NOTICE: USE A PAINT GAGE TO DETERMINE THE AMOUNT OF CLEARCOAT REMOVED. IF TOO MUCH HAS BEEN REMOVED, ADDITIONAL CLEARCOAT WILL HAVE TO BE APPLIED. IF RAIL DUST HAS PENETRATED INTO THE BASECOAT, THE PANEL REQUIRES REFINISHING. MAKE SURE ALL RAIL DUST HAS BEEN REMOVED PRIOR TO REFINISHING OR THE RUST SPOTS WILL RETURN, CAUSING CUSTOMER COMEBACKS. 8. If the damage has been repaired, complete the repair to the entire panel. 9. Once the damage has been repaired, the final step in the repair process involves polishing the vehicle. PREVENTING INDUSTRIAL FALLOUT DAMAGE Description and Operation Air Conditioning Switch: Description and Operation The air conditioning "On" signal informs the ECM the A/C selector switch is turned on, and the A/C pressure cycling switch is closed. Using this information, the ECM adjusts the engine idle speed as necessary to ensure a smooth idle. Page 4350 Fig. 8 Removing Bearing Cup By Holding Cup In Vise & Striking Center Yoke With Hammer Disassembly 1. Place driveshaft in a vise using care to avoid damaging it. 2. Remove bearing cup retaining snap rings. Some universal joints use injected nylon retainers in place of snap rings. During servicing, the snap rings supplied with the replacement universal joint assembly must be used. 3. Mark relationship between yoke and shaft for assembly reference. 4. Position tool on shaft and press bearing cup out of yoke, Fig. 7. If the cup cannot be pressed all the way out, remove it using vise grips or channel lock pliers or position driveshaft as shown and strike center yoke with hammer, Fig. 8. 5. Reposition tool so that it presses on the spider in order to press other bearing cup from opposite side of flange. 6. Remove tool, then the flange from spider. Assembly 1. Start new bearing cup into yoke, then position spider into yoke and press cup until it is 1/4 inch below surface. 2. Remove tool and install a new snap ring. 3. Start new bearing cup in opposite side of yoke, then install tool and press until cup is fully seated. 4. Remove tool and install remaining snap ring. Page 6425 Page 3403 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. Page 7899 Figure 8 Figure 9 Figure 10 Figure 11 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). Page 5701 Fig. 14 Stub shaft torque reading 1. Loosen and remove adjuster plug nut, Fig. 12. 2. Turn adjuster plug clockwise using spanner wrench tool J-7624 or equivalent, Fig. 4, until plug and thrust bearing are firmly bottomed in housing. 3. Scribe an index mark on the housing even with a hole on adjuster plug. 4. Measure back 3/16 - 1/4 inch from first index mark and scribe a second index mark. Fig. 13. 5. Rotate adjuster plug counterclockwise until hole is aligned with second index mark. 6. Install adjuster plug nut, tighten to specifications. 7. Using an inch-pound torque wrench and a 12-point deep socket, measure torque required to turn stub shaft. Take reading with handle of torque wrench near vertical position, Fig. 14. Turn stub shaft to right stop, then back 1/4 turn at an even rate. Record torque reading. 8. Torque reading should be 4-10 inch lbs. If not, adjuster plug may not be tightened properly or may have turned during adjuster plug nut installation. Thrust bearings and races may also be damaged. Over Center Preload Fig. 15 Stub shaft alignment 1. Turn pitman shaft adjuster screw counterclockwise until fully extended, then reverse 1/2 turn clockwise. 2. Rotate stub shaft from stop to stop and count number of turns. 3. Starting at either stop, turn stub shaft halfway back. When gear is centered, flat on stub shaft will face upward and be parallel with side cover, Fig. 15. 4. Place torque wrench on stub shaft and rotate 45° each side of center. Record highest drag torque measured on or near center. 5. Adjust over-center drag torque by loosening adjuster screw jam nut and turning pitman shaft adjuster screw clockwise until correct drag torque is obtained. 6. On new steering gears, add 6-10 inch lbs. torque to previously measured worm bearing preload torque. Do not exceed a total steering gear preload of 18 inch lbs. 7. On used steering gears, add 4-5 inch lbs. torque to previously measured worm bearing preload torque. Do not exceed a total steering gear preload of 14 inch lbs. 8. Install and tighten adjuster screw jam nut to specifications. Electrical - VSS Connector Mislabeled Vehicle Speed Sensor: Technical Service Bulletins Electrical - VSS Connector Mislabeled GMC NUMBER: 88-T-145 GROUP: 6D-Engine Electrical DATE: August, 1988 CORPORATE NUMBER: 818107 SUBJECT: CONNECTOR MISLABELED MODELS: 1985-88 G, S, R, AND M VEHICLES FIGURE NO. 1VEHICLE SPEED SENSOR BUFFER CORRECT CONNECTOR LABEL Some 1985-88 vehicles may have an electrical connector at the vehicle speed sensor (VSS), which is improperly labeled. The connector will work properly but could cause confusion if electrical troubleshooting is necessary. Figure No. 1 shows a properly labeled connector. The improperly labeled connectors have the "A" and "C" reversed. All Service Manual terminal call-outs use the labeling as shown in Figure No. 1. Page 4937 RETURN SPRINGS Purpose Drum brake systems maintain a constant residual pressure on the wheel cylinders. Return springs overcome this residual pressure and keep the shoes/linings from contacting the drum when not in use. Return springs also overcome the resistance encountered by the shoes/linings as they are retracted across the contact pads on the backing-plate. Return springs can be separated into two categories, shoe-to-shoe and shoe-to-anchor pin. Tools Needed To remove and install return springs, three separate tool are useful. These three tools are often combined into a single pair of "brake pliers". Return Spring Tool Shoe-to-Anchor Pin These springs are attached at the brake shoe webbing (two 90 degree bends in the shank of the spring slide through and under webbing) and hook around the anchor pin. Removal A brake spring tool is inserted over the top of the anchor pin and rotated - As you rotate the tool a notch on the bottom side of tool slides under the spring and lifts it up and over the anchor pin. - The other end of the spring should now just pull up and out of the hole in the brake shoe webbing. Specifications Idle/Throttle Speed Control Unit: Specifications IDLE SPEED CONTROL Measured between terminals A& B and C & D. Fuse Link A Fusible Link: Locations Fuse Link A Center Of Dash Panel (engine Compartment) At Rear Of Generator Applicable to: V6-262/4.3L Engine Page 5664 1. Lubricate O-rings, pump ring, rotor and vanes with power steering fluid. 2. Install O-rings and dowel pins on pump housing. 3. Using a seal installation tool, insert seal into front of housing. 4. Install driveshaft and thrust plate. Ensure counterbore faces driveshaft end of housing and install rotor. 5. Insert vanes into rotor, ensuring rounded edge faces away from rotor. 6. Install shaft retaining ring, pump ring and pressure plate. 7. Insert control valve spring, then install control valve and O-ring. 8. Install pressure plate spring and end plate, then secure with end plate retaining ring. 9. Connect seal and reservoir, then install bolt and fitting. System Bleeding 1. Fill pump fluid reservoir to proper level and let fluid settle for at least two minutes. 2. Start and run engine for a few seconds. Do not turn steering wheel. 3. Turn engine Off. Check fluid level, add fluid if necessary. 4. Repeat above procedure until fluid level remains constant after running engine. 5. Raise front end of vehicle so wheels are off ground. 6. Start engine. Slowly turn steering wheel in both directions, lightly contacting wheel stops. 7. Add power steering fluid, if necessary. 8. Lower vehicle and turn steering wheel slowly from lock to lock. 9. Stop engine. Check fluid level and refill as required. 10. If fluid is extremely foamy, allow vehicle to stand a few minutes and repeat above procedure. Flushing Power Steering System 1. Raise front end of vehicle off ground until wheels are free to turn. 2. Remove fluid return hose at pump inlet connector and plug connector port on pump. Position hose in large container. 3. While an assistant is filling reservoir with new power steering fluid, run engine at idle. turn steering wheel from stop to stop. Do not contact wheel stops or hold wheel in a corner as fluid will stop and pump will be in pressure relief mode. A sudden overflow from reservoir may develop if wheel is held at a stop. 4. Install all pipes and hoses. Fill system with new power steering fluid and bleed system as outlined under SYSTEM BLEEDING. 5. Operate engine for 15 minutes. 6. Remove pump return hose at pump inlet and plug connection on pump. While refilling reservoir, check draining fluid for contamination. If foreign material is still evident, replace all hoses, disassemble and clean or replace power steering system components. Do not reuse any drained power steering fluid. Disassembly Fig. 1 Exploded View Of TC Series Power Steering Pump Page 2616 Testing and Inspection Temperature Warning Lamp/Indicator: Testing and Inspection 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. 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. Page 4819 Fig. 7 Installing boot to caliper 5. Position dust boot in caliper counterbore and install, Fig. 7. Check the boot installation to be sure the retaining ring molded into the boot is not bent and that the boot is installed below the caliper face and evenly all around. If the boot is not fully installed, dirt and moisture may enter the bore and cause corrosion. 6. Install the brake hose in the caliper using a new copper gasket. 7. Install pads and caliper assembly. Page 6113 Removing The Clutch Plate & Hub Assembly 2. Clutch plate and hub assembly (2). ^ Thread J 9401-A into the clutch plate and hub (2). ^ Hold the body of J 9401 with a winch and tighten the center screw into the remover body. 3. Shaft key (36). ^ Retain the shaft key (36) if usable. Inspect ^ All parts and replace as necessary. Install or Connect Tools Required: J 9399 Compressor Shaft Nut Socket J 9480-B Hub and Drive Plate Assembly Installer J 25030 Clutch Hub Holding Tool 1. Shaft key (36). Service and Repair Evaporative Canister Filter: Service and Repair NOTE: NOT ALL EVAPORATIVE EMISSION CONTROL CANISTERS HAVE A SERVICEABLE FILTER. At intervals recommended, usually every 24 months or 30,000 miles, the filter on an open bottom canister should be replaced, 1. Remove all hoses from the top of the canister and mark. Remove the canister. 2. Remove the filter element by squeezing it out from under the lip surface at bottom of canister and from under retainer bar, where used. 3. 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. 4. Reinstall the canister to its original position on the vehicle, following normal service procedures. 5. Reconnect the hoses to the top of the canister, according to the labeling on top of canister. Head Lamp Switch Trim Plate - Cracked Headlamp Switch: All Technical Service Bulletins Head Lamp Switch Trim Plate - Cracked Number: 91-109-10 Section: 10 Date: January 1991 Corporate Bulletin No.: 061605 Subject: CRACKED PLASTIC HEAD LAMP SWITCH TRIM PLATE Model and Year: 1986-91 S/T TRUCKS TO: ALL CHEVROLET DEALERS Figure 1-Plate Assembly-Instrument Panel Switch Trim Some 1986-1991 S/T trucks may experience a cracked plastic head lamp switch trim plate. This may result in the inaccessibility of the rheostat assembly (dimmer switch) and/or the switch assembly (head lamp/park lamp switch) (Figure 1). Previously, it was necessary to replace the complete head lamp switch trim plate assembly. The complete assembly includes the rheostat assembly part number 01995293 (instrument panel dimmer switch), switch assembly part number 01995313 (head lamp/ parking lamp switch) and the switch trim plate (Figure 1), and the switch trim plate hole covers. A new trim plate kit is now available which does not contain the rheostat assembly or the head lamp switch. This kit replaces the complete head lamp switch trim plate assembly when the switch trim plate is cracked and the rheostat assembly or the head lamp switches do not need replacing. This new kit includes; a switch trim plate, bracket for switch mounting, covers for the switch trim plate holes and four bolts/screws. Engine - Vibration On Acceleration Catalytic Converter: All Technical Service Bulletins Engine - Vibration On Acceleration Number: 88-270-6F Section: 6F Date: JULY, 1988 Subject VIBRATION ON ACCELERATION Model and Year 1988 S/T TRUCK W/4.3L (VIN CODE Z) ENGINE TO: ALL CHEVROLET DEALERS Some 1988 S/T Trucks equipped with 4.3L engines may experience a vibration that can be felt in the floor pan area near the shifter, in the right hand passenger seat foot area, or on the steering column. These conditions may be caused by the following items: 1. The shifter rod that goes from the steering column to the transmission equalizer lever (#340 and #338 in Figure 36 page 7A-45 of the 1988 S/T Manual) hitting the exhaust crossover pipe and/or the equalizer lever making firm contact at the shift lever (T-truck only). 2. The exhaust pipe to catalytic converter clamp (Figure 7, page 6F-6 of the 1988 S/T Manual) hitting the catalytic converter heat shield. 3. The exhaust pipe to converter installation allows the exhaust pipe to contact the transmission crossmember. To repair these conditions, use the following procedures: 1. A. Raise vehicle on hoist. B. Check Transmission linkage for correct adjustment. C. Check exhaust pipe for shifter rod interference (shiny spot on pipe). D. If linkage hits pipe, remove 15 mm (5/8 in) from bottom of rod. E. Put transmission into low gear and mark exhaust pipe area near linkage. F. Put transmission in park. Using a hammer, lightly dimple exhaust pipe for additional clearance. Specifications Idle/Throttle Speed Control Unit: Specifications IDLE SPEED CONTROL Measured between terminals A& B and C & D. Page 7177 ** Refer to the applicable labor time guide for paint mix time allowance and include in "Other Hours." *** Select corresponding material allowances to combine with proper "Above Belt Line" material allowance in "Net Amount" as required for appropriate vehicle type and operations performed. Reimbursement Customer claims for reimbursement on previously paid repairs to correct paint topcoat delamination (peeling) are to be submitted according to the forms and instructions included in this bulletin (additional copies to be reproduced locally). Owners must submit original documentation that reasonably confirms the amount of unreimbursed repair expenses, a description of the repair, the date of the repair, and the person or entity performing the repair. Page 4143 Disclaimer Page 5011 Brake Master Cylinder: Fundamentals and Basics Parts Reminder List RECOMMENDED PARTS Basic Service, Replacement New or rebuilt master-cylinder - Fresh/New brake fluid If Overhaul is Required Master cylinder overhaul kit - Brake assembly lubricant Optional Aerosol brake cleaner. New or Rebuilt Master Cylinder Always closely compare the new master-cylinder with the old master-cylinder. Minor variations in the size and depth of the primary piston can result in significant reductions in braking performance. Examine the end of the master-cylinder where the pushrod contacts the piston. The depth and diameters of the pistons should match. Brake Fluid Proper bench bleeding the master-cylinder and flushing the brake system will require a minimum of 16 oz of brake fluid. - Never Mix DOT 3 (light amber in color) with DOT 5 (purple in color). There have been reports of damage to brake system seals when DOT 3 and DOT 5 fluids are mixed - Always store brake fluid in a sealed container. When left open brake fluid will absorb moisture from the air. This reduces the boiling point of the brake fluid and could lead to a soft pedal or brake system failure during prolonged or emergency braking. - Never add automatic transmission fluid, engine oil, or power steering fluid to the master-cylinder. Petroleum based fluids will cause the rubber seals and gaskets in the brake system to swell and leak. Master Cylinder Overhaul Kit Overhaul kits will often come with a variety cup and seal sizes. Closely match the old cups and seals with the new ones. Brake Assembly Lubricant Assembly lubricant can greatly simply the master-cylinder overhaul process and prolong the life of the new seals. - Clean brake fluid can be used to lubricate the master-cylinder bore during assembly but assembly lube is much slicker and prevents any sticking or binding and possible damage to the new cups and seals. Aerosol Brake Cleaner - Commercially produced aerosol brake cleaners are designed to effectively clean brake systems while not leaving an oily residue. - Do not use carburetor cleaner or solvent based products to clean brake system components. These products will leave a residue which could contaminate the brake fluid or cause a reduction in braking performance. Page 6255 High Pressure Safety Valve HVAC: Service and Repair With DA-6 Compressor DA-6 Component View Remove or Disconnect ^ Be sure the compressor has no charge. DA-6 Compressor Rear Head Details Page 954 Figure 2 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 Fastener Tightening Specifications Wheel Fastener: Specifications Fastener Tightening Specifications 1992 S Series Pickups......................................................................................................................... ................................................................95 ft/lbs 1992 Safari........................................................................................................................................... .............................................................100 ft/lbs 1992 M Van.......................................................................................................................................... ............................................................100 ft/lbs 1992 S Series Jimmy............................................................................................................................ ...............................................................95 ft/lbs 1992 S Series Sonoma......................................................................................................................... ................................................................95 ft/lbs 1991-92 C-, K10-20.............................................................................................................................. .................................................................120 ft/lbs 1991-92 C-, K30: Single Rear Wheel................................................................................................................................ .............................................120 ft/lbs Dual Rear Wheels (8 lug)......................................................... ..........................................................................................................140 ft/lbs Dual Rear Wheels (10 lug)........................................................................................................................................................ .........175 ft/lbs 1991-92 R-, V30: Single Rear Wheel................................................................................................................................ .............................................120 ft/lbs Dual Rear Wheels (8 lug)......................................................... ..........................................................................................................140 ft/lbs Dual Rear Wheels (10 lug)........................................................................................................................................................ .........175 ft/lbs 1990-92 Lumina APV........................................................................................................................... .................................................................100 ft/lbs 1989-92 Van: G10-25.................................................................................................................................................. .............................................100 ft/lbs G30-35 Single Rear Wheel...................................................... ..........................................................................................................120 ft/lbs G30-35 Dual Rear Wh eels....................................................................................................................................................... ..........140 ft/lbs 1991 R-, V10........................................................................................................................................ .............................................................100 ft/lbs 1991 R-, V20........................................................................................................................................ .............................................................120 ft/lbs 1990-91 S Series: 2WD...................................................................................................................................................... ...............................................80 ft/lbs 4WD......................................................................................... ..........................................................................................................100 ft/lbs 1990 C-, K-, Pickup.............................................................................................................................. ............................................................105 ft/lbs 1990 C-, K-, Sierra................................................................................................................................ ............................................................105 ft/lbs 1990 C-, K-35 W/Dual Rear Wheels..................................................................................................... ...........................................................125 ft/lbs 1990 R-, V-Pickup: Single Rear Wheel................................................................................................................................ .............................................120 ft/lbs Dual Rear Wheels.................................................................... ..........................................................................................................140 ft/lbs 1989 Pickups: Single Rear Wheel................................................................................................................................ .............................................120 ft/lbs Dual Rear Wheels.................................................................... ..........................................................................................................140 ft/lbs 1989 Sierra: Single Rear Wheel................................................................................................................................ .............................................120 ft/lbs Dual Rear Wheels.................................................................... ..........................................................................................................140 ft/lbs 1989 Safari........................................................................................................................................... .............................................................102 ft/lbs 1988-89 S Series: With Aluminum Wheels........................................................................................................................ ...............................................90 ft/lbs Without Aluminum Wheels....................................................... ...........................................................................................................73 ft/lbs 1988 R-, V-Pickup: Single Rear Wheels.............................................................................................................................. ..............................................103 ft/lbs Dual Rear Wheels................................................................... ...........................................................................................................140 ft/lbs 1988 C-, K10-15: Single Rear Wheel................................................................................................................................ ...............................................90 ft/lbs Dual Rear Wheels.................................................................... ..........................................................................................................125 ft/lbs 1988 Sierra: Single Rear Wheel................................................................................................................................ ...............................................90 ft/lbs Dual Rear Wheels.................................................................... ..........................................................................................................125 ft/lbs 1988 Astro............................................................................................................................................ .............................................................102 ft/lbs 1988 Safari........................................................................................................................................... .............................................................102 ft/lbs 1988 Van G10-25................................................................................................................................. .............................................................102 ft/lbs 1988 Van G30-35: 5 bolts................................................................................................................................................... ..............................................117 ft/lbs 8 bolts..................................................................................... ............................................................................................................139 ft/lbs 1987-88 R-, V-Blazer: 2WD...................................................................................................................................................... .............................................103 ft/lbs 4WD With Aluminum Wheels, 6 lug.................................................................................................................................................103 ft/lbs 4WD Without Aluminum Wheels, 6 lug..............................................................................................................................................88 ft/lbs 1987-88 R-, V-Jimmy: 2WD...................................................................................................................................................... .............................................103 ft/lbs 4WD With Aluminum Wheels, 6 lug.................................................................................................................................................103 ft/lbs 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 Transmission Mount - Idle Shake or Vibration Transmission Mount: All Technical Service Bulletins Transmission Mount - Idle Shake or Vibration Number: 91-16-7A Section: 7A Date: May 1990 Corp. Bulletin No: 066101 Subject: IDLE SHAKE OR VIBRATION Model and Year: 1988-91 S1 TRUCKS Some 1988-91 S truck (two wheel drive) and 2 door utility models equipped with 4.3L engines and either automatic or manual transmissions, may experience an idle shake or vibration. This condition is most noticeable at engine speeds below 1500 RPM. Page 398 - Diagnostic Chart Code 64. Page 3252 Knock Sensor: Description and Operation Knock Sensor Operation ESC Wiring Diagram The Electronic Spark Control (ESC) system is comprised of a knock sensor, the ESC module, and the ECM. As the knock sensor detects engine knock, it sends a voltage signal to the ECM. The ECM responds by retarding the ignition timing until the knocking ceases. As detonation is reduced, the ECM advances the timing again in small increments back to the pre-programmed point for that engine speed and load. Generator Light - Flickers During Pulse Wiper Use Diode: Customer Interest Generator Light - Flickers During Pulse Wiper Use Number: 90-84-8A Section: 8A Date: November 1989 Corporate Bulletin No: 966402 Subject: GENERATOR LIGHT FLICKER DURING PULSE WIPER OPERATION Model and Year: 1988-89 S, T TRUCKS WITH 2.8L OR 4.3L (VIN CODES R, Z) ENGINES TO: ALL CHEVROLET DEALERS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 89-219-8A, DATED JULY 1989. THE 1990 MODEL S/T VEHICLES ARE INCLUDED IN THE LATEST BULLETIN ALONG WITH A CORRECTION TO THE ELECTRICAL CONNECTOR NUMBER. ALL COPIES OF 89-219-8A SHOULD BE DISCARDED. The generator light flicker condition during pulse wiper switch operation in the 1988, 1989 and 1990 S/T instrument panel, with standard cluster, can be caused by negative voltage transients from the wiper motor. There is no possibility of a system failure as a result of this condition. The effect of this condition is that the generator light will turn on for 80 milliseconds (if gages, the voltage drop on the voltmeter lasts 2.5 seconds). This causes no harm to the generator or other electrical components. Subject condition can be eliminated by installing a diode (industry part number 1N4003) or diode/connector kit (diode kit part number 12085207) in the brown wire at the generator connector (circuit 25 at connector C118). See the following pages in the 1988, 89 and 90 S/T Electrical Wiring Diagrams for circuit 25, connector C118 locations: 1988 4.3L: Section C - Page 24 1988 2.8L: Section C - Page 22 1989 4.3L: Page 40 1989 2.8L: Page 39 1990 2.8L: Page 44 1990 4.3L: Page 45 PARTS INFORMATION: Quantity Part Number Description 1 12085207 Diode ----OR---1 *1N4003 Diode * This part available locally. Parts are currently available from GMSPO. INSTALLATION PROCEDURE: 1. Disconnect the battery. 2. Remove the connector from the generator. 3. Peel back the black plastic conduit covering the wires. 4. If installing diode 1N4003: cut out a section of the brown wire that matches the length of the diode. 4A. A diode/connector kit is also available (GMSPO diode kit part number 12085207). If using the kit cut out approximately four inches of the brown wire, following crimping and soldering instructions in the kit. Spiral tape the solder joints and tuck the wire back into the conduit away from the generator. Secure the diode/connector to the outside of the conduit with electrical tape. 5. Solder in diode with the banded end toward the generator. A/T - Buzzing Noise at Idle Fluid Pressure Sensor/Switch: All Technical Service Bulletins A/T - Buzzing Noise at Idle Number: 93-29-7A Section: 7A Date: OCT. 1992 Corporate Bulletin No.: 277142 ASE No.: A2 Subject: BUZZING NOISE AT IDLE Model and Year: 1982-93 CAPRICE, CAMARO AND CORVETTE 1982-93 C/K, R/V, S/T, M/L AND G TRUCKS WTIH 4L60 AUTOMATIC TRANSMISSION TRANSMISSION APPLICATIONS: 1982-1993 HYDRA-MATIC 4L60 (MD8) TRANSMISSION MODELS: All SUBJECT: Pressure Regulator Valve Buzz VEHICLE APPLICATIONS: B, D, F, Y - Cars C/K, R/V, S/T Trucks G, M, L - Vans CONDITION: Some 1982-1993 vehicles equipped with a HYDRA-MATIC 4L60 transmission may have a buzzing noise coming from the transmission when the vehicle is at idle. The buzzing noise may be noticed more when the vehicle is in reverse at idle. CAUSE: The buzzing noise may be a result of pressure regulator valve oscillating due to oil pressure instability at lower idle RPM. CORRECTION: Page 7941 Numerous & Various Size Drops of Water Collecting on the Inside Surface of the Lamp Lens After the Vehicle Has Been Exposed to Rain or a Car Washing Environment - A condition that covers more than half the surface of the lamp lens. - An accumulation of water in the bottom of the lamp assembly. - A condition that WON'T clear when the vehicle is parked in a dry environment, or when the vehicle is driven with the lights ON. - A comparison of the equivalent lamp on the opposing side of the vehicle indicates a different performance. Any of the above conditions would indicate the need to service the lens or lamp assembly. Disclaimer Specifications Voltage Regulator: Specifications System Operating Voltage System Operating Voltage Voltage Setting 13.5-16.0 V Page 347 Headlamp Switch: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. Figure 21 Figure 22 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. Page 2975 Disclaimer Brakes - Change In Brake Feel After Rotor Refinishing Brake Rotor/Disc: All Technical Service Bulletins Brakes - Change In Brake Feel After Rotor Refinishing Number: 91-133-5 5 Section: 5 Date: December 1990 Corporate Bulletin No.: 075003R Subject: CHANGE IN BRAKE EFFECTIVENESS AFTER DISC BRAKE ROTOR REFINISHING/PAD REPLACEMENT Model and Year: ALL PASSENGER CARS ALL LIGHT DUTY TRUCKS TO: ALL CHEVROLET DEALERS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 90-316-5, DATED AUGUST 1990. INFORMATION HAS BEEN ADDED REGARDING HUB AND ROTOR CLEANING, PROPER TORQUING TECHNIQUE, REVISED MACHINING TABLE, CHANGE SPECIFICATION FOR MAXIMUM SCORINGING DEPTH. THE 1991 MODEL YEAR WAS ALSO ADDED. ALL COPIES OF 90-316-5 SHOULD BE DISCARDED. Some comments have been received about a change in preceived braking effectiveness which occurs after rotors have been refinished and/or disc brake pads have been replaced. New lining materials have been formulated for increased lining life and to reduce brake squeal. Also, Federal regulations currently prohibit the use of asbestos in Original Equipment Manufactured (O.E.M.) front disc brake linings, and will totally ban asbestos from all O.E.M. brake linings in the near future. Due to these changes, initial rotor surface finish is more critical than in the past, and is required for good brake performance. Following are some recommended actions/procedures to assure proper performance of the brake systems on all vehicles after rotor and/or pad service has been performed: 1 . When performing routine brake maintenance such as replacing worn disc brake pads or shoes, DO NOT refinish disc brake rotors or drums unless: A. There is a brake pulsation condition present, and this pulsation is found to be caused by the brake rotors or drums, or B. The rotors and/or drums are excessively scored. Surface scoring that does not exceed 1.2 MM (0.050 in.) on rotors or drums should not affect brake operation. Before removing rotors from the hub assembly, mark the rotor and on wheel stud so that the rotor may be re-installed in the same position. If rotors are removed, it is very important that rust and scale be removed from the rotor and hub mating surfaces. Failure to do so may introduce excessive lateral runout when the rotor is mounted on the brake lathe, or when the rotor is re-installed to the hub. 2. When refinishing disc brake rotors, it is important that the brake lathe be in good operating condition and that all tools or bits are sharp. Recommended vibration dampeners and/or adaptors should be used and should be clean and free of nicks (remember, 1988-91 W models require the use of an adaptor, J37160, because of the two-piece design). The following table shows the recommended procedure for rotor machining: ROUGH CUT FINISH CUT Spindle Speed 150 RPM 150 RPM Depth of Cut (per side) 0.127 mm (0.005") 0.051 mm (0.002") Tool Cross Feed per Rev 0.152 mm - 0.254 mm 0.051 mm (0.002")Max (0.006" - 0.010") Vibration Damper Yes Yes Sand Rotors-Final Finish No Yes It is important that a rough and a finish cut be made. All brake lathes use a single-point cutting tool which is not capable of giving the necessary surface finish. A SECONDARY FINISHING OPERATION MUST BE PERFORMED TO OBTAIN THE NECESSARY SURFACE FINISH. Page 5769 D. Lower tank sufficiently to disconnect sender unit connector, fuel lines, and ground terminal. E. Remove fuel tank. F. Remove front bolts from tank upper straps and move straps to rear out of the way. Figure 2 - Shock Absorber Installation 5. Remove shock absorbers (Figure 2). A. Remove shock absorber to tower bolts and nuts. B. Remove shock absorber to anchor plate nut and washer. C. Remove shock absorber from vehicle. 6. Remove rear frame crossmember and towers (Figure 2). A. Cut three crossmember to frame rivet heads off on each side of vehicle. Use air chisel, cutting wheel, or grinding wheel. B. Remove and discard crossmember and tower assembly. Before discarding, remove the two spring mounted nuts for the tank straps and install the nuts in the new crossmember. 7. Install new frame crossmember and tower assembly (Figure 2). A. Install three bolts, nuts, and six washers on each side of frame crossmember and torque nuts to 40-51 N-m (29-37 lbs.ft. or torque bolts to 45-60 N-m (33-44 lbs.ft.). B. Reinstall shock absorber and torque anchor plate nut to 20-26 N-m (15-19 lbs.ft.). C. Bolt shock to tower and torque nuts to 58-70 N-m (43-50 lbs.ft.). Page 6369 J 5403 Snap Ring Pliers J 33011 O-ring Seal Installer 1. O-ring seals (44) to the switch cavity with J 33011. ^ Dip the O-ring seals into clean 525 refrigerant oil. 2. Switches (3) and (4). 3. Retainers (45). Page 4357 Flex Plate: Specifications THM180 & 180 C Automatic Trans Flexplate to Converter ......................................................................................................................... ................................................................ 30-40 ft lbs Specifications Oil Pressure Sender: Specifications Oil Pressure Switch 10 ft.lb Page 928 Parts Information Parts are currently available from GMSPO. Page 3099 Fuel Pump Relay: Description and Operation Fuel Pump Relay 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). - 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. Drive Axle (Front) - Will Not Disengage Transfer Case Actuator: All Technical Service Bulletins Drive Axle (Front) - Will Not Disengage Number: 91-476-4C Section: 4C Date: JAN. 1992 Corporate Bulletin No.: 167402 ASE No.: A3 Subject: FRONT AXLE WILL NOT DISENGAGE Model and Year: 1983-1991 T TRUCKS Owners of some 1983-1991 T vehicles may comment about inappropriate front axle disengagement. This condition may be due to a corroded transfer case vacuum actuator switch. To correct this condition a revised switch (P/N 15664811), constructed of noncorrosive stainless steel, should be installed. SERVICE PROCEDURE: The vacuum switch is located on the left upper side of the transfer case (Figure 1). 1. Raise the vehicle and support with suitable safety stands. 2. Remove the vacuum lines from the switch. 3. Remove the corroded switch from the transfer case. 4. Install a revised switch (P/N 15664811), coat the threads with thread sealant. 5. Connect the vacuum lines. 6. Lower the vehicle. 7. Check for oil leaks at the threads and vacuum leaks around the vacuum lines. Page 7147 - An alternative in some geographic areas may be plastic media blasting such as may be provided by members of: - Dry Stripping Facilities Network 1-800-634-9185 * * 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. Important Additional time or payment beyond established allowances in this bulletin will not be allowed. - The use of a razor blade on large flat surfaces is not recommended because of the potential to chip. gouge or otherwise damage the primer surface. If razor blade technique is used, the application of a "guide coat" prior to wet sanding should also be used. Note: Chemical stripping is not recommended because of negative impact to moldings, non-metal components, ELPO and environmental concerns. 4. Blow off with air to remove all dirt and sanding residue from cracks and vehicle surface. 5. Clean sanded surface with an appropriate wax and grease remover. 6. Tack wipe entire area to be primed. 7. Spray entire prepared area with a coat of anti-corrosion primer to ensure maximum adhesion and corrosion resistance. Be sure to cover any bare metal surfaces exposed during the sanding operations. Follow manufacturer's instructions and recommended dry times. Typical materials for this application would be: DuPont 615S/616S, BASE DE17/PR8O/DA18, PPG DP4O/DP401, or equivalent. V.O.C. materials would be: DuPont 615S/616S, BASF DE15/PA16/PRB0, PPG DCP21/DCX211 or equivalent. 8. Apply two to three medium wet coats of primer surfacer to the primed surface of the vehicle, following the manufacturer's instructions for application and film build requirements. Important Failure to apply primer surfacer will likely result in future delamination. Typical materials for this application would be: DuPont 1120S/1130S/1125S, BASF DP20/PR80/PH36, PPG K36/DT870/K201, or equivalent. V.O.C. materials would be: DuPont 210S, BASF HP400, PPG DCP21/DCX211, or equivalent. 9. After allowing adequate drying time, wet sand with 400 grit (or finer) or dry sand with 320 grit (or finer) sandpaper. 10. Repeat steps 4 through 6. 11. Apply a medium coat of corrosion resistant primer sealer (tintable base) to the entire surface to be refinished. This will provide maximum adhesion, uniform color coating and corrosion protection to areas "sanded through" during wet sanding. Follow manufacturer's instructions and recommended dry times. Typical materials for this application would be: DuPont 2610S/2605S, BASF DP21/DH6O/PR80, PPG DP40/DP402 or equivalent. V.O.C. materials for this application would be: DuPont 21255, PPG DPW1834 or equivalent. 12. Apply two to three medium wet coats of color (or until primer color is hidden). Follow manufacturer's instructions and recommended dry times. 13. If vehicle has basecoat/clearcoat paint, apply clearcoat. Follow manufacturer's instructions and recommended dry times. 14. After sufficient air or force dry time, unmask the vehicle. 15. Finesse/polish as required. 16. Reinstall all previously removed items. 17. Wash and prepare the vehicle for delivery. HARDWARE ITEMS REMOVAL LIST Drive Axle (Front) - Will Not Disengage Transfer Case Actuator: All Technical Service Bulletins Drive Axle (Front) - Will Not Disengage Number: 91-476-4C Section: 4C Date: JAN. 1992 Corporate Bulletin No.: 167402 ASE No.: A3 Subject: FRONT AXLE WILL NOT DISENGAGE Model and Year: 1983-1991 T TRUCKS Owners of some 1983-1991 T vehicles may comment about inappropriate front axle disengagement. This condition may be due to a corroded transfer case vacuum actuator switch. To correct this condition a revised switch (P/N 15664811), constructed of noncorrosive stainless steel, should be installed. SERVICE PROCEDURE: The vacuum switch is located on the left upper side of the transfer case (Figure 1). 1. Raise the vehicle and support with suitable safety stands. 2. Remove the vacuum lines from the switch. 3. Remove the corroded switch from the transfer case. 4. Install a revised switch (P/N 15664811), coat the threads with thread sealant. 5. Connect the vacuum lines. 6. Lower the vehicle. 7. Check for oil leaks at the threads and vacuum leaks around the vacuum lines. A/T - Buzzing Noise at Idle Fluid Pressure Sensor/Switch: All Technical Service Bulletins A/T - Buzzing Noise at Idle Number: 93-29-7A Section: 7A Date: OCT. 1992 Corporate Bulletin No.: 277142 ASE No.: A2 Subject: BUZZING NOISE AT IDLE Model and Year: 1982-93 CAPRICE, CAMARO AND CORVETTE 1982-93 C/K, R/V, S/T, M/L AND G TRUCKS WTIH 4L60 AUTOMATIC TRANSMISSION TRANSMISSION APPLICATIONS: 1982-1993 HYDRA-MATIC 4L60 (MD8) TRANSMISSION MODELS: All SUBJECT: Pressure Regulator Valve Buzz VEHICLE APPLICATIONS: B, D, F, Y - Cars C/K, R/V, S/T Trucks G, M, L - Vans CONDITION: Some 1982-1993 vehicles equipped with a HYDRA-MATIC 4L60 transmission may have a buzzing noise coming from the transmission when the vehicle is at idle. The buzzing noise may be noticed more when the vehicle is in reverse at idle. CAUSE: The buzzing noise may be a result of pressure regulator valve oscillating due to oil pressure instability at lower idle RPM. CORRECTION: Page 7151 Diagram Information and Instructions Power Locks: Diagram Information and Instructions 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 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. Page 1082 Controlled Idle Speed / IAC Counts Idle Speed: Specifications Controlled Idle Speed / IAC Counts Controlled Idle Speed / IAC Counts Idle Speed IAC Counts Note: Let engine idle until proper fuel control status is Note: Add 2 counts for engines with less than 500 miles. closed loop. Add 2 count for every 1000 ft above sea level. Manual Transmission Neutral 500-550 rpm 2-12 Auto Transmission Drive 500-550 rpm 2-20 Page 1213 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. Suspension (Front) - Squeaking Noise Coil Spring Insulator: All Technical Service Bulletins Suspension (Front) - Squeaking Noise Number: 91-330-3C Section: 3C Date: MAY 1991 Corp. Bulletin No.: 063306R Subject: FRONT SUSPENSION SQUEAK Model and Year: 1982-91 S1 TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 91-168-3C, DATED JANUARY 1991. THE LABOR OPERATION HAS BEEN CHANGED. ALL COPIES OF 91-168-3C SHOULD BE DISCARDED. Some S1 trucks may experience a squeaking noise from the front suspension. Spraying of lubricant in the spring pocket areas may help for a short time but the squeak usually returns. The usual cause of this squeak is contact between the spring and the frame pocket or control arm. An insulator is installed in production between the spring and upper frame pocket, but this insulator will occasionally be pushed aside allowing metal to metal contact. An insulator was not installed in production between the control arm and the spring. To fix the squeak, the existing upper insulator should be removed and M-Van insulators installed at both ends of the spring; that is, between the spring and the upper frame pocket and between the spring and the lower control arm. VEHICLES INVOLVED 1982 - 1991 S trucks. SERVICE PROCEDURE: REMOVE 1. Lower control arm and spring. 2. Insulator from top end of spring. - Clean excess paint and adhesive from both ends of spring. INSTALL 1. New insulators to spring ends. - Apply a full bead of weatherstrip adhesive to the diameter of the spring insulator contact area. - Be sure upper and lower insulators are installed to respective ends of the spring. - Allow weatherstrip adhesive to cure enough to hold the insulators in place before reinstalling springs. 2. Spring. Tape should be on lower end and gripper notch on top. - Position end of lower spring coil to cover one lower control arm inspection drain hole and expose the other 3. Lower control arm. Refer to S/T Service Manual, Section 3C - Front Suspension for complete coil spring replacement procedure. SERVICE PARTS INFORMATION Quantity Part Number Description Required Diagram Information and Instructions Headlamp Switch: Diagram Information and Instructions 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 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. Page 5105 Neutral Safety Switch: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. Figure 21 Figure 22 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. Page 6802 Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Description Labor Op. Striker and/or Support - Replace (RH) B5820 Striker and/or Support - Replace (LH) B5821 Page 8219 Wiper Switch: Testing and Inspection Fig. 3 Permanent Magnet Type Windshield Wiper Motor W/Pulse Wipers 1. Disconnect electrical connectors from wiper motor. 2. Check switch voltage using a digital voltmeter with ignition switch in the On position. If readings are not as specified at between various switch positions and ground, replace switch. Page 7333 Fig. 3 Module Test (Part 3 of 4) Door Locks - Binding or Sticking or Key Hard to Insert Door Lock Cylinder: All Technical Service Bulletins Door Locks - Binding or Sticking or Key Hard to Insert Number: 93-133-10 Section: 10 Date: MARCH 1993 Corporate Bulletin No.: 1341070R ASE No.: B1 Subject: DOOR LOCK CYLINDERS (RECOMMENDED LUBRICATION) Model and Year: ALL 1993 AND PREVIOUS MODEL CARS AND TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN 92-41-10, DATED NOV. 1991. THE 1993 MODEL YEAR HAS BEEN ADDED AS WELL AS A NOTE. PLEASE DISCARD ALL COPIES OF 92-41-10. Customer comments of binding/sticking door lock cylinders, or keys that are hard to insert or extract may be corrected in many cases by applying the proper lubrication. The recommended materials for lubricating these components are (in order of preference): - GM # 12345120 Multi purpose lubricant (9 oz. spray) or # 12345121 (12 oz.). - 5 W 30 Motor Oil - GM # 1052276 or 1052277 spray type Silicone (4.5 oz. or 12 oz. cans). Penetrating oil type lubricants (such as GM # 1052949 or 1052950, WD-40 lubricants) ARE NOT RECOMMENDED because they wash out the original lubrication and eventually evaporate, leaving little or no lubricating material. However, if these type materials are used to "unfreeze" or loosen lock cylinder components, refer to steps 2 through 4 listed below for the proper methods of lubricating. NOTE: DO NOT REPLACE THE DOOR LOCK CYLINDERS UNTIL AFTER THE LUBRICATING MATERIALS HAVE BEEN USED AND THE CYLINDER REMAINS FROZEN/BOUND. If door lock cylinders require replacement for any reason, apply a coating of GM # 12345120 Multi purpose Lubricant to the inside of the lock case and the cylinder keyway prior to assembling and installing the cylinder. Parts are currently available from GMSPO. Frozen cylinders due to cold weather may be repaired using the following procedure: 1. Apply heat to the cylinder area with a heat gun while being careful not to damage the painted surfaces. 2. Hold the shutter door open with a paper clip (or similar item) and force air into the cylinder using compressed air and a blow gun attachment. 3. While holding the shutter door open, inject a small amount of lubricant (see above recommendations) into the cylinder. 4. Work the key into the cylinder several times and wipe any excess lubrication residue from the key. Use applicable Labor Time Number and Time allowance. Page 579 Alignment: Specifications (Figure 1) Front End Alignment Specifications NOTE: Vehicle must be jounced three times before checking alignment to eliminate false geometry readings. (A) Front suspension "Z" dimension and rear suspension "D" dimension are held as indicated in Adjustments / Curb Trim Heights. See: Service and Repair/Ride/Trim Height Measurement and Adjustment Front end alignment specifications are indicated in (Figure 1). (B) Left and right side to be equal within 0.50 degree. (C) Left and right side to be equal within 1.0 degree. (D) Toe-in-left and right side to be set separately per wheel and steering wheel must be held in straight ahead position within ± 5.0 degree. Interior - Proper Use of Floor Mats Carpet: Technical Service Bulletins Interior - Proper Use of Floor Mats INFORMATION Bulletin No.: 10-08-110-001 Date: March 30, 2010 Subject: Information on Proper Use of Floor Mats Models: 2011 and Prior GM Passenger Cars and Trucks (Including Saturn) 2003-2009 HUMMER H2 2006-2010 HUMMER H3, H3T 2005-2009 Saab 9-7X GM's carpeted and all-weather (rubber) floor mats are especially designed for use in specific GM vehicles. Using floor mats that were not designed for the specific vehicle or using them incorrectly may cause interference with the accelerator or brake pedal. Please review the following safety guidelines regarding proper driver's side floor mat usage with the customer. Warning If a floor mat is the wrong size or is not properly installed, it can interfere with the accelerator pedal and/or brake pedal. Interference with the pedals can cause unintended acceleration and/or increased stopping distance which can cause a crash and injury. Make sure the floor mat does not interfere with the accelerator or brake pedal. - Do not flip the driver's floor mat over (in an effort to keep the floor mat clean) - Do not place anything on top of the driver's floor mat (e.g. carpet remnant, towel) - Do not place another mat on top of the driver's floor mat (e.g. do not place all-weather rubber mats over carpeted floor mats) - Only use floor mats that are designed specifically for your vehicle - When using replacement mats, make certain the mats do not interfere with the accelerator or brake pedal before driving the vehicle If your vehicle is equipped with a floor mat retaining pin(s) or clip(s), make certain the mat is installed correctly and according to the instructions. 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 Page 2770 Oxygen Sensor: Specifications Oxygen Sensor 30 ft.lb Body - Vehicle Glass Distortion Information Front Corner Window Glass: Technical Service Bulletins Body - Vehicle Glass Distortion Information INFORMATION Bulletin No.: 00-08-48-005D Date: September 10, 2010 Subject: Distortion in Outer Surface of Vehicle Glass Models: 2011 and Prior GM Passenger Cars and Trucks 2009 and Prior HUMMER H2 2010 and Prior HUMMER H3 2005-2009 Saab 9-7X 2010 and Prior Saturn Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 00-08-48-005C (Section 08 - Body and Accessories). Distortion in the outer surface of the windshield glass, door glass or backlite glass may appear after the vehicle has: - Accumulated some mileage. - Been frequently washed in automatic car washes, particularly "touchless" car washes. This distortion may look like a subtle orange peel pattern, or may look like a drip or sag etched into the surface of the glass. Some car wash solutions contain a buffered solution of hydrofluoric acid which is used to clean the glass. This should not cause a problem if used in the correct concentration. However, if not used correctly, hydrofluoric acid will attack the glass, and over time, will cause visual distortion in the outer surface of the glass which cannot be removed by scraping or polishing. If this condition is suspected, look at the area of the windshield under the wipers or below the belt seal on the side glass. The area of the glass below the wipers or belt seal will not be affected and what looks like a drip or sag may be apparent at the edge of the wiper or belt seal. You may also see a line on the glass where the wiper blade or the belt seal contacts the glass. Important The repair will require replacing the affected glass and is not a result of a defect in material or workmanship. Therefore, is not covered by New Vehicle Warranty. Disclaimer Service and Repair EGR Electronic Vacuum Regulator Solenoid: Service and Repair EVRV Filter Replacment The EVRV filter should be replaced every 30,000 miles. 1. Grasp and pull filter "OFF" with a rocking motion. 2. Push new filter "ON", making sure cut-out for wires is properly aligned. Page 6226 6. Remove blower motor switch. (Figure 2) 7. Remove the 2 control base plate mounting screws. (Figure 2) 8. Remove the control baseplate. 9. Remove the 4 housing to bezel mounting screws. (Figure 3) 10. Discard the broken housing. 11. Apply a small amount of GM silicone grease, P/N 12345579, or its equivalent to areas of the new housing where the mode and temperature levers protrude through the housing slots. (Figure 3) NOTE: Do not use petroleum based lubricants. Petroleum based lubricant causes the housing material to become brittle and generate a repeat failure. 12. Reassemble using the reverse procedure. Use care when assembling the base plate to the housing and bezel. The mode control lever must be 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. Page 5106 e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors Do Not require all the steps shown. Skip the steps that Do Not apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. 1. Separate connector halves (see Figures 2 through 6). Figure 2 Figure 3 Page 6186 Removing Or Installing The Shaft Seal Seat Retainer 2. Shaft seal retainer ring using J 5403. ^ Clean the compressor neck area around the shaft (38), the exposed part of the shaft seal (29) and the O-ring seal groove. Removing Or Installing The Shaft Seal 3. Shaft lip seal using J 23128-A. ^ Insert J 23128-A into the shaft lip seal, tighten and remove lip seal. Page 6365 Refrigerant Pressure Sensor / Switch: Locations Pressure Cycling Switch Pressure Cycling Switch Location The Pressure Cycling Switch is located on the Accumulator. Locations Fuel Pump And Sender Assembly (Typical) Page 5064 The hydraulic pushrod operates against the master cylinder piston. A split system (tandem piston) type master cylinder is incorporated into some units. The front half of the master cylinder in the split system operates the rear brakes while the rear half of the master cylinder operates the front brakes. A vacuum check valve, attached to the front vacuum chamber and connected to the intake manifold, traps vacuum in the power unit at the highest level of vacuum. OPERATION As the brakes are applied by the driver, the valve operating rod and control piston move forward in the power piston assembly to compress the valve return spring and bring the poppet valve into contact with the vacuum valve seat in the valve housing to close the vacuum post. Any additional movement of the valve operating rod in the applied direction moves the control valve away from the poppet valve to open the atmospheric port and admit air through the air filter and passages to the chamber at the right of the vacuum power piston assembly. With vacuum on the left side of the diaphragm and atmospheric pressure on the right side of the diaphragm, a force is developed to move the vacuum power piston assembly, hydraulic pushrod, and hydraulic piston to the left to close the compensating port and force hydraulic fluid under pressure through the residual check valve and brake tubes into the brake wheel cylinders. Page 3164 Distributor: Description and Operation Typical Distributor Components The distributor has a separate coil which connects to the rotor through a high tension wire. The distributor uses a magnetic pick-up assembly located inside the distributor consists of a permanent magnet, a pole piece with internal teeth, and a pick-up coil. When the teeth of the timer core, rotating inside the pole piece, line up with the teeth of the pole piece, an induced voltage in the pick-up coil signals the electronic module to trigger the coil primary circuit. The primary current decreases and a high voltage of 35,000 volts is induced in the ignition coil secondary winding which is directed through the rotor and secondary leads to fire the spark plugs. The capacitor in the distributor is for radio noise suppression. This distributor also features a longer spark duration, made possible by the higher amount of energy that is stored in the coil. This is desirable for firing leaner mixtures. Page 5770 Figure 1 - Fuel Tank Installation 8. Reinstall fuel tank (Figure 1). A. Raise tank sufficiently to install fuel tank sending unit hoses, electrical connector, and ground strap. Route strap 1 under hoses and wiring. B. Raise tank fully and install tank supports (5). Torque front strap nuts (9) to 27-47 N-m (20-35 lbs.ft.). Torque support nuts (7) to 40-50 N-m (29-37 lbs.ft.). C. Reinstall tank shield and torque screws to 9-13 N-m (80-115 lb.in.). 9. Lower vehicle, refill fuel, connect battery negative ground cable. 10. Start engine and check for fuel leaks. SERVICE PARTS INFORMATION Part Number Description Quantity 15674914 Rear Frame Crossmember and Shock Tower 1 Assembly 11504596 Bolt, Crossmember Mounting, 6 11501033 Nut, Crossmember Mounting, 6 15531204 Washer, 12 Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: T7186 Labor Time: 2.5 hrs. Trouble Code: 92 NOTE: Labor Operation is coded to base vehicle coverage in the warranty system. Page 5785 Figure 16 1. Loosen bolts (90) attaching the axle tube bracket (5) to the frame bracket (6). 2. Tighten nuts (94) to 75 N-m (55 lbs.ft.). This should cause the axle assembly to move toward the driver's side approximately 1/8" to 1/4". If the axle does not move it may be pried toward the driver's side with a bar. Position bar against the frame and the end of the shaft (1). 3. Tighten bolts (90) to 75 N-m (55 lbs.ft.). Seal Replacement: After checking the shock absorber installation and front axle location, smaller profile tripot seals may be installed. These smaller seals can be identified by their visibly smaller profile and by the number 26027961 which is molded onto the seal. Required Tools: J 28733 Axle Remover J 24319-01 Tie Rod Puller J 8059 Snap Ring Pliers J 35910 Seal Clamp Tool J 34026 Ball Joint Separator Drive Axle Removal: Figure 1 - Prevent Shaft From Turning 1. Raise vehicle and support it with suitable safety stands. 2. Remove the wheel and tire assembly. 3. Insert a drift or large screwdriver through brake caliper into one of the brake rotor vanes to prevent halfshaft from turning (Figure 1). Figure 2 - Hub Nut and Washer Removal 4. Remove halfshaft cotter pin, retainer, nut, and washer (Figure 2). Page 2595 Center Of Dash Panel (engine Compartment) Page 350 Figure 8 Figure 9 Figure 10 Figure 11 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). Wipers - Intermittent Phantom Wipe (No Driver Input) Wiper Switch: All Technical Service Bulletins Wipers - Intermittent Phantom Wipe (No Driver Input) Number: 90-266-8E Section: 8E Date: May 1990 Corp. Bulletin No.: 968302 Subject: WINDSHIELD WIPER PHANTOM WIPE Model and Year: 1985-90 S/T/M TRUCK AND 1990 L TRUCK THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 90-171-8E, DATED FEBRUARY 1990. THE LABOR TIMES HAVE BEEN UPDATED. ALL COPIES OF 90-171-8E SHOULD BE DISCARDED. Some 1985-1990 M vans, 1990 L Vans and S/T model trucks may exhibit intermittent phantom wipe - occasional wiper sweep of the windshield with no driver input. A new steering column wiper switch has been developed with an internal resistor to correct this condition. The following parts can be installed to repair intermiftent phantom wipe. They will service subject M/L vans and S/T trucks. SERVICE PARTS INFORMATION Part Number Description 26020403 Switch (Standard) 26020404 Switch (Tilt Wheel) Parts are currently available through GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Time Labor Time Labor Operation Models (standard) (tilt wheel) N2610 S/T M/L 1.2 hrs 1.0 hrs. Page 1659 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 Page 3568 NOTE: In the overhaul repair kits for the HYDRA-MATIC 4L60 there are two (2) sets of 3rd and 4th clutch fiber plates. The two 3rd and 4th clutch fiber plates are calibration sensitive and interchanging the wrong plates may cause premature failure. The chart shows which models should use the plates labeled "2050" Figure 3. 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. Page 2318 Wiring Diagram For Chart C-5 - Electronic Spark Control System Check CHART C-5 - ELECTRONIC SPARK CONTROL SYSTEM CHECK Circuit Description: Electronic spark control is accomplished with a module that sends a voltage signal to the ECM. As the knock sensor detects engine knock, the voltage from the ESC module to the ECM is shut "OFF" and this signals the ECM to retard timing, if engine RPM is over about 900. Test Description: Numbers below refer to circled numbers on the diagnostic chart. 1. If A Code 43 is not set, but a knock signal is indicated while running at 1500 RPM, listen for an internal engine noise. Under a no load condition there should not be any detonation, and if knock is indicated, an internal engine problem may exist. 2. Usually a knock signal can be generated by tapping on the right exhaust manifold. This test can also be performed at idle. Test number 1 was run at 1500 RPM to determine if a constant knock signal was present, which would affect engine performance. 3. This tests whether the knock signal is due to the sensor, a basic engine problem, or the ESC module. 4. If the module ground circuit is faulty, the ESC module will not function correctly. The test light should light indicating the ground circuit is OK. 5. Contacting CKT 496, with a test light to 12 volts, should generate a knock signal to determine whether the knock sensor is faulty, or the ESC module can't recognize a knock signal. Diagnostic Aids: "Scan" tools have two positions to diagnose the ESC system. The knock signal can be monitored to see if the knock sensor is detecting a knock condition and if the ESC module is functioning, knock signal should display "yes", whenever detonation is present. The knock retard position on the "Scan" displays the amount of spark retard the ECM is commanding. The ECM can retard the timing up to 20 degrees. This check should be used after other causes of spark knock have been checked such as engine timing, EGR systems, engine temperature or excessive engine noise. Specifications Distributor: Specifications Distributor Hold-down Clamp Bolt ............................................................................................................................................................. 27 Nm (20 lb-ft) Page 3756 Service Manual References: Reference the Automatic Transmission Unit Repair Section of the appropriate service manual for retaining ring installation information. Page 2584 Idle Speed/Throttle Actuator - Electronic: Description and Operation IAC Valve Operation And Fuel Pressure Regulation Engine idle speed is computer controlled by signals to the Idle Air Control (IAC) valve mounted on the throttle body. The IAC valve regulates idle speed by moving a pintle valve in and out, varying air flow through a passage bypassing the throttle valve. The more air that is allowed to bypass the throttle valve, the faster the idle speed. The ECM sends voltage pulses to the IAC motor windings causing the IAC motor shaft to move a given distance for each pulse, (referred to as IAC counts). The number of IAC counts can be read on a Scan tool display. 0 counts corresponds to fully closed passage, while 140 counts or more (depending on application) corresponds to full flow. The ECM monitors idle speed and increases the IAC counts if the idle speed is too slow. If the idle speed is too fast, IAC counts will be decreased. Page 5377 For vehicles repaired under warranty, use the table. Disclaimer Specifications TEMPERATURE SENSORS Page 4304 Figure 11 - Snap Ring and Spider Removal 5. To remove the spider assembly (also required for seal replacement), spread the spacer ring with tool J8059 or equivalent and slide the ring and spider assembly up on the shaft (Figure 11). This will provide access to the shaft retaining ring in the groove at the end of the shaft. Remove the retaining ring, spider assembly, spacer ring, and seal. Figure 12 - Small Retaining Clamp Installation 6. Clean the shaft. If rust is present in the seal mounting area (grooves), wire brush this area (Figure 12). 7. Slide the new small seal clamp and seal onto the shaft to the proper position. 8. Secure the clamp with tool J35910, breaker bar and torque wrench. Torque small clamp to 136 N-m (100 lbs.ft.). Check clamp ear gap dimension (Figure 12). Page 7084 Customers should be urged to wash and dry their vehicles frequently and garage them, or at least cover them with a quality car cover when not in use. Vehicles in dealer inventories should be kept clean and dry. A vehicle that sits unattended, especially after the sun has dried any water on the body surface, is a target for acid rain damage. MATERIALS DESCRIBED IN THIS BULLETIN* WAX AND GREASE REMOVER - USE BELOW OR EQUIVALENT Dupont # 3919S, PPG # DX440, BASF # 900, SIKKENS # 6041 FINESSE POLISHES - USE BELOW OR EQUIVALENT Dupont # 1500S, 3000S; BASF # 563-808, 560-1502; PPG # DRX10; 3M PERFECT-IT * USE V.O.C. EQUIVALENTS IN STATES WITH V.O.C. RESTRICTIONS RAIL DUST REMOVER - USE BELOW OR EQUIVALENT Industrial Fallout Remover # 5029 Zep Corporation Atlanta, GA. Telephone # 404-352-1680 Stain Away # HBY 0160 Hornby Chemical Milwaukee, WI. Telephone # 414-462-2833 If the rail dust remover is not available in your area, call one of the numbers listed above for a distributor near your location. PAINT GAGES - USE BELOW OR EQUIVALENT Elcometer Inc. 1893 Rochester Ind. Drive Rochester Hills, MI. 48309 (800) 521-0635 or (313) 650-0500 Zelcro, Ltd./Zormco 8520 Garfield Rd. Cleveland, OH 44125 (216) 441-6102 Delfesko Corp. 410 Cedar St. Ogdensburg, NY 13669 (800) 267-0607 or (613) 925-5987 Pro Motorcar Products Inc. 22025 US-19 North Clearwater, FL 34625 (800) 323-1090 (813) 726-9225 "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." Page 4985 Brake Proportioning/Combination Valve: Description and Operation These vehicles use either a two function or three function combination valve. Some vehicles use a height sensitive proportioning valve in addition to the combination valve. The two function combination valve consists of a metering valve and a brake failure warning switch. The hydraulic brake lines are routed through this valve to the wheel cylinders or calipers. The metering portion of this valve assists in providing balanced front to rear braking by delaying full hydraulic fluid pressure to the front disc brakes until the rear drum brakes overcome return spring tension and the linings contact the drums. The brake failure warning switch portion of the valve activates the brake warning lamp when there is a loss of pressure in either the front or the rear braking system. The three function combination valve consists of a metering valve, a brake failure warning switch, and a proportioning valve. The metering valve and brake failure warning switch operate the same as those in the two function combination valve previously described. The proportioning section of the valve proportions outlet pressure to the rear brakes after a certain rear input pressure has been reached, preventing rear wheel lock-up. The height sensitive proportioning valve provides ideal brake balance according to weight at rear axle. This valve is mounted on the frame and responds to changes in vehicle trim height in relation to rear axle load. Mechanical linkage connects the valve to a bracket attached to the rear axle. Belt Tension - Used BELT TENSION Page 895 - In commercial service (taxi or police use). ^ If the vehicle has been operated under these conditions, shut the engine off and allow the vehicle to "cool" for thirty (30) minutes. After the cooldown period, restart the vehicle and continue from step "2" above. Page 352 When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 5mm (3/16") of insulation from wire. e. Crimp a new terminal to the wire. f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. Figure 17 To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Figure 18 Figure 19 Page 2821 LH Side Of Steering Column Behind Instrument Cluster Page 6526 Some Chevrolet models may exhibit a condition of poor AM or FM radio reception. This may be caused by a poor contact on the female terminal of the antenna coaxial cable lead. The illustration contains a four-step procedure to test and repair the female terminal. The opening in the female terminal should range from .120" to .125" in diameter. If the gage passes through freely, the terminal should be repaired as illustrated. Gage sets are available from Kent Moore, tool number J26900-14. For warranty purposes use Labor Operation T6369 at .5 hour for all carlines. Engine - Vibration On Acceleration Catalytic Converter: Customer Interest Engine - Vibration On Acceleration Number: 88-270-6F Section: 6F Date: JULY, 1988 Subject VIBRATION ON ACCELERATION Model and Year 1988 S/T TRUCK W/4.3L (VIN CODE Z) ENGINE TO: ALL CHEVROLET DEALERS Some 1988 S/T Trucks equipped with 4.3L engines may experience a vibration that can be felt in the floor pan area near the shifter, in the right hand passenger seat foot area, or on the steering column. These conditions may be caused by the following items: 1. The shifter rod that goes from the steering column to the transmission equalizer lever (#340 and #338 in Figure 36 page 7A-45 of the 1988 S/T Manual) hitting the exhaust crossover pipe and/or the equalizer lever making firm contact at the shift lever (T-truck only). 2. The exhaust pipe to catalytic converter clamp (Figure 7, page 6F-6 of the 1988 S/T Manual) hitting the catalytic converter heat shield. 3. The exhaust pipe to converter installation allows the exhaust pipe to contact the transmission crossmember. To repair these conditions, use the following procedures: 1. A. Raise vehicle on hoist. B. Check Transmission linkage for correct adjustment. C. Check exhaust pipe for shifter rod interference (shiny spot on pipe). D. If linkage hits pipe, remove 15 mm (5/8 in) from bottom of rod. E. Put transmission into low gear and mark exhaust pipe area near linkage. F. Put transmission in park. Using a hammer, lightly dimple exhaust pipe for additional clearance. Page 5165 Fig. 11 Diagnosis Chart (Part 3 of 3) When diagnosing Delco-Remy starter motors, refer to Fig. 11. There is no provision for adjusting pinion clearance on this type motor, but should be checked after motor reassembly on all models except the 28 MT, which is not serviceable. When the shift lever mechanism is correctly assembled, the pinion clearance should fall within the limits of .010 to .140 inch on 1987 models and .010-.160 inch on 1988-91 models. When the clearance is not within these limits, it may indicate excessive wear of the solenoid linkage or shift lever yoke buttons. Fig. 13 Connections For Checking Pinion Clearance Fig. 14 Checking Pinion Clearance Pinion clearance should be checked as follows: Page 128 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 Page 410 Oxygen Sensor: Locations The oxygen sensor is located in the LH exhaust manifold just above the flange. Specifications Exhaust Manifold: Specifications Exhaust Manifold Bolts Center Two Bolts 36 ft.lb All others 28 ft.lb Page 7869 Brake Light Switch: Locations Stop Lamp Switch LH Side Of Steering Column Behind Instrument Cluster Page 5560 Tighten Tighten to 8 Nm (71 lb in). Note The repair area MUST BE properly refinished to maintain a secure, stable and corrosion-free electrical ground. 12. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 13. Verify proper system operation. M8 Weld Nut Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M8 weld nut electrical ground location is accessible from both sides of the panel, a M8 conductive bolt and a M8 conductive nut may be used to secure the electrical ground wire terminal. Refer to the Parts Information section of this bulletin. 2. Select a location adjacent the M8 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the new electrical ground site. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the ground location and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 10 mm (0.40 in) diameter hole through the panel. 5. Remove paint and primer from the area surrounding the 10 mm (0.40 in) hole until bare metal is visible. 6. Select a M8 conductive bolt. Refer to the Parts Information section of this bulletin. 7. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M8 conductive bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 8. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 9. Install the electrical ground wire terminal and the M8 conductive bolt to the ground location. 10. Select a M8 conductive nut. Refer to the Parts Information section of this bulletin. 11. Install the M8 conductive nut to the bolt and: Tighten Tighten to 22 Nm (16 lb ft). Note The repair area MUST BE properly refinished to maintain a secure, stable and corrosion-free electrical ground. 12. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 13. Verify proper system operation. M8 Weld Nut Alternative Repair Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M8 weld nut electrical ground location is not accessible from both sides of the panel, a M6 conductive rivet stud and a M6 conductive nut may be used to secure the electrical ground wire terminal. 2. Select a location adjacent the damaged M8 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the M6 conductive rivet stud flange. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the repair site and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 10 mm (0.40 in) diameter hole through the panel. Page 3934 than a standard fan. These benefits are possible through the addition of a thermostatic clutch to the fan drive. When the engine is cool 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, 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 engage. However, if the vehicle is pulling a trailer, heavily loaded or operated at high ambient temperatures the thermostatic clutch may cycle on and off as the engine 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 cooling system or transmission parts will not change or reduce the noise level. Attempts to reduce this noise will only give you, the customer, a false sense of vehicle unreliability and the inconvenience of having your vehicle out of service. Page 6046 4WD Without Aluminum Wheels, 6 lug..............................................................................................................................................88 ft/lbs 1987-88 R-, V-Suburban: 2WD...................................................................................................................................................... .............................................103 ft/lbs 4WD With Aluminum Wheels, 6 lug.................................................................................................................................................103 ft/lbs 4WD Without Aluminum Wheels, 6 lug..............................................................................................................................................88 ft/lbs 1987 R-, V-Pickup: 2WD...................................................................................................................................................... ...............................................88 ft/lbs 4WD......................................................................................... ............................................................................................................80 ft/lbs 1987 Van: G10-25.................................................................................................................................................. ...............................................88 ft/lbs G30-35, exc. 8 lug.................................................................... ..........................................................................................................103 ft/lbs G30-35, with 8 lug....... .............................................................................................................................................................. ........125 ft/lbs 1986-87 S-10,15................................................................................................................................... ....................................................................90 ft/lbs 1984-86 C-K Models (Blazer, Jimmy, Suburban): 5 lug (1/2")............................................................................................................................................ .............................................100 ft/lbs 5 lug (9/16")............................................................................. ..........................................................................................................120 ft/lbs 6 lug............................ .............................................................................................................................................................. ...........90 ft/lbs 8 lug............................................................................................................................. ......................................................................140 ft/lbs 1984-86 Van: G10-25.................................................................................................................................................. .............................................100 ft/lbs G30-35 (5 lug).......................................................................... .........................................................................................................120 ft/lbs G30-35 (Dual Rear Wheels, 8 lug)....................................................................................................................................... .............140 ft/lbs 1983-85 S-10, 15: With Standard Wheels.......................................................................................................................... ...............................................81 ft/lbs With Optional Wheels.............................................................. ..........................................................................................................100 ft/lbs 1983 C-K Models (Blazer, Jimmy, Suburban): 5 lug...................................................................................................................................................... .............................................100 ft/lbs 6 lug......................................................................................... ............................................................................................................90 ft/lbs 8 lug............................ .............................................................................................................................................................. .........120 ft/lbs 1983 Van: G10-25.................................................................................................................................................. .............................................100 ft/lbs G30-35 (Single Rear Wheel).................................................... ..........................................................................................................120 ft/lbs G30-35 (Dual Rear W heels).................................................................................................................................................... ..........140 ft/lbs Page 4640 This part number can be found on the identification tag (80) located on the rear case half (Figure 1). Group B: Some 1991 T-Trucks equipped with transfer cases identified by the following part numbers and built before 10/22/90: 15653414 15659232 This part number and build number can be found on the identification tag (80) located on the rear case half (Figure 1). Service Procedure: Group A: These transfer cases require the replacement of the parts indicated in the Group A column of the PARTS INFORMATION section. Group B: These transfer cases require the replacement of the parts indicated in the Group B column of the PARTS INFORMATION section. Remove 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 Locks - Key Code Security Rules and Information Key: Technical Service Bulletins Locks - Key Code Security Rules and Information INFORMATION Bulletin No.: 10-00-89-010 Date: May 27, 2010 Subject: Key Code Security Rules and Information on GM KeyCode Look-Up Application (Canada Only) Models: 2011 and Prior GM Passenger Cars and Trucks 2010 and Prior HUMMER H2, H3 2009 and Prior Saturn and Saab 2002 and Prior Isuzu Attention: This bulletin has been created to address potential issues and questions regarding KeyCode security. This bulletin should be read by all parties involved in KeyCode activity, including dealer operator, partner security coordinator, sales, service and parts departments. A copy of this bulletin should be printed and maintained in the parts department for use as a reference. Important U.S. dealers should refer to Corporate Bulletin Number 10-00-89-009. Where Are Key Codes Located? General Motors provides access to KeyCodes through three sources when a vehicle is delivered to a dealer. Vehicle KeyCodes are located on the original vehicle invoice to the dealership. There is a small white bar coded tag sent with most new vehicles that also has the key code printed on it. Dealerships should make a practice of comparing the tag's keycode numbers to the keycode listed on the invoice. Any discrepancy should be reported immediately to the GM of Canada Key Code Inquiry Desk. Remember to remove the key tag prior to showing vehicles to potential customers. The third source for Key codes is through the GM KeyCode Look-Up feature within the OEConnection D2DLink application. KeyCode Look-Up currently goes back 17 previous model years from the current model year. When a vehicle is received by the dealership, care should be taken to safeguard the original vehicle invoice and KeyCode tag provided with the vehicle. Potential customers should not have access to the invoice or this KeyCode tag prior to the sale being completed. After a sale has been completed, the KeyCode information belongs to the customer and General Motors. Tip Only the original invoice contains key code information, a re-printed invoice does not. GM KeyCode Look-Up Application for GM of Canada Dealers All dealers should review the General Motors of Canada KeyCode Look-Up Policies and Procedures (Service Policy & Procedures Manual Section 3.1.6 "Replacement of VIN plates & keys"). Please note that the KeyCode Access site is restricted. Only authorized users should be using this application. Please see your Parts Manager for site authorized users. KeyCode Look-Up currently goes back 17 years from current model year. Important notes about security: - Users may not access the system from multiple computers simultaneously. - Users may only request one KeyCode at a time. - KeyCode information will only be available on the screen for 2 minutes. - Each user is personally responsible for maintaining and protecting their password. - Never share your password with others. - User Id's are suspended after 6 consecutive failed attempts. - User Id's are disabled if not used for 90 days. - Processes must be in place for regular dealership reviews. - The Parts Manager (or assigned management) must have processes in place for employee termination or life change events. Upon termination individuals access must be turned off immediately and access should be re-evaluated upon any position changes within the dealership. - If you think your password or ID security has been breached, contact Dealer Systems Support at 1-800-265-0573. Page 6988 On a clean surface, at or above room temperature, firmly apply a 2" wide piece of masking tape and pull upward quickly. DO NOT USE duct tape, cloth backed tape or other aggressive tapes. If the colorcoat flakes or peels away from the ELPO (leaving the ELPO intact) the colorcoat is delaminating and the vehicle should be repaired using the "Paint Repair Procedure" contained in this bulletin. This test SHOULD ONLY BE APPLIED TO A VEHICLE SHOWING THE CONDITION, (peeling/delamination) and NOT in areas of stone chipping or other obvious damage. These "other" conditions should be repaired following standard paint repair procedures. CORRECTION Refinish the ENTIRE BODY ABOVE THE BODY SIDE MOLDINGS using the following repair procedure. It is important that ALL surfaces above the body side moldings (including recessed areas around door handles) be refinished, as these surfaces may show the same DELAMINATION (peeling) condition at a later date. Note: Many vehicles have some type of plastic exterior body panels (cowl vent grilles, fascias, front end panels, rear fenders, etc.). These panels are not subject to DELAMINATION and therefore do not require refinishing. If painting of these panels is required for color uniformity, scuff sand and colorcoat only (and clearcoat if basecoat/clearcoat system is used). Note: Two tone lines, feature lines or body side molding treatments near mid-door height are appropriate break lines. If no such convenient break lines are present, the entire panel above the next lower break line must be refinished and the portion of the panel below that break line should be COLORCOATED ONLY (and clearcoated if basecoat/clearcoat system is used) for color uniformity of the repair. Note: Pickup boxes which are covered by caps, bedliners or tonneau covers do not receive direct exposure to sunlight, and normally would not be repaired under this procedure. However, if the inside of the box has been uncovered and experienced DELAMINATION, use the appropriate Labor Operation Number. Note: Certain two tone applications on trucks using the high potential colors (Blues, Grays and Silvers) may require that only portions of the vehicle surface be refinished. Examples would be: Example 1. Blues, Grays and Silvers as "insert colors" on vertical surfaces with other, non-high potential colors above the insert (or break line). Action: Refinish the "insert color" only, between the break line and body side molding (or to the lower feature line on certain vehicles). Example 2. Blues, Grays and Silvers on surfaces above the break line with other, non-high potential colors as "insert colors". Action: Refinish the surfaces above the "insert color" or break line only. Example 3. Blues, Grays and Silvers used as both the primary and "insert colors". Action: Refinish both high potential color surfaces above the body side moldings (or to the lower feature line on certain vehicles). Vehicles should be repaired with the same type materials they were manufactured with; repair basecoat/clearcoat with basecoat/clearcoat materials and monocoat with monocoat. PAINT REPAIR PROCEDURE 1. Some vehicle components will be removed from the vehicle while others will require masking. The list located at the end of this bulletin will establish the removal items. Items not found on the list and non-repair areas are to be masked. 2. Prior to removing the paint finish, clean the area to be refinished with an appropriate wax and grease remover to remove any contaminants. 3. Remove the original finish of paint down to the ELPO primer surface using an orbital D.A. sander, leaving the ELPO surface intact. This can be done in "stages" using 80 grit (or finer) discs to remove the majority of coating, followed with 180 grit (or finer) discs to remove the remainder of material down to the ELPO surface and any chalky residue or degraded ELPO that may remain. Avoid sanding through ELPO to bare metal in order to retain maximum corrosion protection. - An alternative in some geographic areas may be plastic media blasting such as may be provided by members of: - Dry Stripping Facilities Network 1-800-634-9185 * Page 6217 6. Remove blower motor switch. (Figure 2) 7. Remove the 2 control base plate mounting screws. (Figure 2) 8. Remove the control baseplate. 9. Remove the 4 housing to bezel mounting screws. (Figure 3) 10. Discard the broken housing. 11. Apply a small amount of GM silicone grease, P/N 12345579, or its equivalent to areas of the new housing where the mode and temperature levers protrude through the housing slots. (Figure 3) NOTE: Do not use petroleum based lubricants. Petroleum based lubricant causes the housing material to become brittle and generate a repeat failure. 12. Reassemble using the reverse procedure. Use care when assembling the base plate to the housing and bezel. The mode control lever must be Page 3598 situations does the condition occur, whether the condition is more noticeable when the vehicle is hot or cold, or in what gear range does the condition become evident. Figure 3 - Range Reference Chart Before driving the vehicle, check that proper fluid level and correct T.V. cable setting have been maintained. Check minimum and maximum mainline pressures against the transmission pressure charts updated and printed each year in the appropriate Service Manuals. Also, one of the preliminary checks should include making certain that the engine is in proper tune and not contributing to or mistaken for a transmission condition. With all preliminary information collected, the vehicle should then be road tested. During the road test, note when and in what range the condition occurs. By comparing this information with the range reference chart (refer to Figure 3) you can begin to eliminate known good circuits and/or clutches. Through this process of elimination, it is possible to pinpoint the circuit and/or clutch that is causing the condition. Locations Fuel Pump And Sender Assembly (Typical) Page 6871 FIGURE 1 2. Remove the cowl vent panel fasteners (Figure No. 1). Page 6916 e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors Do Not require all the steps shown. Skip the steps that Do Not apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. 1. Separate connector halves (see Figures 2 through 6). Figure 2 Figure 3 Page 7422 Symbol Identification Wire Color Code Identification WIRE COLOR ABBREVIATION BLACK BLK BLUE BLU DARK BLUE DK BLU Page 7809 Parking Lamp: Locations LH Side Of Engine Compartment Lower LH Corner Of Engine Compartment Page 4933 Fig. 8 Adjusting Brake Shoes To Brake Drum Inside Diameter 8. Using suitable brake drum to shoe gauge, Fig. 5, measure brake drum inside diameter. Adjust brake shoes to dimension obtained on outside portion of gauge, Fig. 6. 9. Install brake drum, wheel and tire assembly. 10. If any hydraulic connections have been opened, bleed brake system. 11. Adjust parking brake. 12. Inspect all hydraulic lines and connections for leakage, and repair as necessary. 13. Check master cylinder fluid level and replenish as necessary. 14. Check brake pedal for proper feel and return. 15. Lower vehicle and road test. CAUTION: Do not severely apply brakes immediately after installation of new brake linings or permanent damage may occur to linings, and/or brake drums may become scored. Brakes must be used moderately during first several hundred miles of operation to ensure proper burnishing of linings. 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. Removal and Installation Clutch Slave Cylinder: Service and Repair Removal and Installation REMOVAL 1. Raise and support vehicle. 2. Disconnect hydraulic line from slave cylinder. 3. Remove slave cylinder retaining nuts, then the slave cylinder. INSTALLATION 1. Connect hydraulic line to slave cylinder. 2. Bleed system. 3. Position slave cylinder on bell housing, then install retaining nuts and torque to 10-15 ft lbs. Page 6277 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 With A-6 Compressor High Pressure Safety Valve HVAC: Service and Repair With A-6 Compressor A-6 Compressor Component View The pressure relief valve is located at the rear of the compressor Remove or Disconnect 1. Valve (56). 2. Seal (57). Clean A/C Recirculation Door - Water Leak Hood Hinge: All Technical Service Bulletins A/C Recirculation Door - Water Leak File In Section: 1 - HVAC Bulletin No.: 56-12-04 Date: April, 1995 Subject: Water Leak at the A/C Recirculation Door (Install New Hood Hinge Seal) Models: 1983-93 Chevrolet and GMC Truck S/T Pickups 1983-94 Chevrolet and GMC Truck S/T Utilities 1991-94 Oldsmobile Bravada Built Prior to the Following VIN Breakpoints: Assembly Plant Division (Plant Code) VIN Breakpoint GMC Truck Pontiac West (0) R0525661 Chevrolet Pontiac West (0) R0168567 Oldsmobile Pontiac West (0) R0704953 GMC Truck Moraine (2) All Chevrolet Moraine (2) All Oldsmobile Moraine (2) All CONDITION Some owners may comment that they have a water leak at the kick panel vent when their A/C controls are in the MAX position and it is raining. CAUSE Water is entering the plenum and cowl area by way of the hood hinge. CORRECTION To correct this condition, remove the current hood hinge seal and replace with a redesigned hood hinge seal. The redesigned seal has foam flaps which restrict water entry. Service Procedure 1. Raise and support the hood. 2. Remove the cowl vent grille. Refer to "Cowl Vent Grille Replacement" in Section 2B of the Service Manual. 3. Remove hood hinge bolts from hood (both sides). 4. Remove hood from vehicle. 5. Remove fender nut and bolt from hinge (both sides). 6. Remove hood hinge from vehicle (both sides). 7. Remove hood hinge seals and replace with redesigned hood hinge seals P/N's 15995797 (LH) and 15995798 (RH). Important: Be sure that hood hinge seals are properly seated and sealed or water leakage could recur. 8. Install hood hinges to vehicle. Important: Apply lubricant to the hood hinges around the hinge to fender bolts. 9. Install fender nuts and bolts to hood hinges. 10. Install hood hinges to hood bolts. Tighten the hinge to hood bolts to 25 Nm (18 lb.ft.). Page 5124 Figure 8 Figure 9 Figure 10 Figure 11 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). Page 7584 LIGHT BLUE LT BLU BROWN BRN GRAY GRY GREEN GRN DARK GREEN DK GRN LIGHT GREEN LT GRN ORANGE ORN PINK PNK PURPLE PPL RED RED TAN TAN WHITE WHT YELLOW YEL A/T - Buzzing Noise at Idle Fluid Pressure Sensor/Switch: Customer Interest A/T - Buzzing Noise at Idle Number: 93-29-7A Section: 7A Date: OCT. 1992 Corporate Bulletin No.: 277142 ASE No.: A2 Subject: BUZZING NOISE AT IDLE Model and Year: 1982-93 CAPRICE, CAMARO AND CORVETTE 1982-93 C/K, R/V, S/T, M/L AND G TRUCKS WTIH 4L60 AUTOMATIC TRANSMISSION TRANSMISSION APPLICATIONS: 1982-1993 HYDRA-MATIC 4L60 (MD8) TRANSMISSION MODELS: All SUBJECT: Pressure Regulator Valve Buzz VEHICLE APPLICATIONS: B, D, F, Y - Cars C/K, R/V, S/T Trucks G, M, L - Vans CONDITION: Some 1982-1993 vehicles equipped with a HYDRA-MATIC 4L60 transmission may have a buzzing noise coming from the transmission when the vehicle is at idle. The buzzing noise may be noticed more when the vehicle is in reverse at idle. CAUSE: The buzzing noise may be a result of pressure regulator valve oscillating due to oil pressure instability at lower idle RPM. CORRECTION: Diagram Information and Instructions Heated Glass Element: Diagram Information and Instructions 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 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. Restraints - Extender Availability For Seat Belt Seat Belt Extension: Technical Service Bulletins Restraints - Extender Availability For Seat Belt INFORMATION Bulletin No.: 99-09-40-005F Date: June 23, 2010 Subject: Seat Belt Extender Availability Models: 2011 and Prior GM Passenger Cars and Trucks (Including Saturn) 2009 and Prior HUMMER H2 2010 and Prior HUMMER H3 2005-2009 Saab 9-7X Supercede: This bulletin is being revised to add the 2009‐2011 model years and update the Warranty Information. Please discard Corporate Bulletin Number 99-09-40-005E (Section 09 Restraints). Important: DO NOT use belt extenders when securing a child restraint. The seat and shoulder belt restraint systems used in all General Motors vehicles have sufficient belt length to accommodate most drivers and passengers. Consequently, requests for belt extensions (extenders) should be minimal. Seat belt extenders are available ONLY IN BLACK for most GM passenger cars and trucks produced in recent years. They are available in two different lengths, 23 cm (9 in) and 38 cm (15 in). They are designed to be coupled with the existing belts in each vehicle. When in use, the extender makes the belt arrangement a "custom fit" and use by anyone else or in another vehicle will lessen or nullify the protection offered by the vehicle's restraint system. For this reason, it is extremely important that the correct length extender be used for the vehicle and occupant intended. Important: Do not use an extender just to make it easier to buckle the safety belt. Use an extender only when you cannot buckle the safety belt without using an extender. Parts Information For part numbers, usage and availability of extenders, see Extension Kit in Group 14.875 (cars) or Group 16.714 (trucks) of the appropriate parts catalog. Saturn retailers should refer to the appropriate model year Parts & Illustration catalog for the vehicle. U.S. Saab dealers should contact the Parts Help line. Canadian Saab dealers should fax requests to Partech Canada. Warranty Information ^ Seat belt extenders are a NO CHARGE item to all GM customers who request them for their specific vehicles. ^ Dealers should not be charging part costs since these extenders are supplied by GM to the dealers. ^ Dealers should not be charging labor costs since the extender can be customer installed. Disclaimer Page 3733 R3261 LH mirror R&R; 0.4 Hr. (Time is different than published time in Labor Operation Guide.) Specifications Turbocharger: Specifications Turbocharger Coolant Feed Pipe 26 ft.lb Turbocharger Coolant Return Pipe Fitting 16 ft.lb Turbocharger Mounting Nut 33 ft.lb Turbocharger Oil Feed Hose Fitting 16 ft.lb Turbocharger Oil Return Pipe 5 ft.lb Turbocharger Outlet Pipe Nut 41 ft.lb Turbocharger Outlet Pipe Support Bolt 22 ft.lb 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. Page 7027 Customers should be urged to wash and dry their vehicles frequently and garage them, or at least cover them with a quality car cover when not in use. Vehicles in dealer inventories should be kept clean and dry. A vehicle that sits unattended, especially after the sun has dried any water on the body surface, is a target for acid rain damage. MATERIALS DESCRIBED IN THIS BULLETIN* WAX AND GREASE REMOVER - USE BELOW OR EQUIVALENT Dupont # 3919S, PPG # DX440, BASF # 900, SIKKENS # 6041 FINESSE POLISHES - USE BELOW OR EQUIVALENT Dupont # 1500S, 3000S; BASF # 563-808, 560-1502; PPG # DRX10; 3M PERFECT-IT * USE V.O.C. EQUIVALENTS IN STATES WITH V.O.C. RESTRICTIONS RAIL DUST REMOVER - USE BELOW OR EQUIVALENT Industrial Fallout Remover # 5029 Zep Corporation Atlanta, GA. Telephone # 404-352-1680 Stain Away # HBY 0160 Hornby Chemical Milwaukee, WI. Telephone # 414-462-2833 If the rail dust remover is not available in your area, call one of the numbers listed above for a distributor near your location. PAINT GAGES - USE BELOW OR EQUIVALENT Elcometer Inc. 1893 Rochester Ind. Drive Rochester Hills, MI. 48309 (800) 521-0635 or (313) 650-0500 Zelcro, Ltd./Zormco 8520 Garfield Rd. Cleveland, OH 44125 (216) 441-6102 Delfesko Corp. 410 Cedar St. Ogdensburg, NY 13669 (800) 267-0607 or (613) 925-5987 Pro Motorcar Products Inc. 22025 US-19 North Clearwater, FL 34625 (800) 323-1090 (813) 726-9225 "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." Page 5930 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 Fuse Block - Deforms Hazard Warning Flasher: Customer Interest Fuse Block - Deforms Number: 90-432-8B Section: 8B Date: SEPT. 1991 Corporate Bulletin No.: 168102 ASE No.: A6 Subject: FUSE BLOCK DEFORMS Model and Year: 1988-90 SI (LLV) POSTAL VEHICLES Some 1988 to 1990 LLV postal vehicles built prior to August 3, 1990, may exhibit a condtion where the fuse block is partially deformed due to heat generated by continuous operation of the hazard flasher. This condition may be corrected by the repositioning of the hazard flasher to a remote location. SERVICE PROCEDURE: 1. Disconnect positive battery cable. 2. Remove old flasher. 3. Back out terminals for circuit 140A (orange wire) and circuit 27 (brown wire) using a small flat screwdriver or pick. Using the same tool, raise the locking tang on the back of the terminal. 4. Cut electrical tape used to wrap main wiring harness a sufficient amount to provide 2 to 3 inches of flasher wiring for relocation. 5. Insert terminals of circuits 140A and 27 into new connector (P/N 2973385). 6. Install electronic flasher (P/N 15504673) into the new connector. 7. Using nylon ties, strap the connector and flasher assembly to the wiring harness that runs above the fuse block. Verify that the relocated flasher and all wiring is secured so it does not cause interference with the throttle linkage. 8. Reconnect battery cable. 9. Test operation of hazard flasher system. SERVICE PARTS INFORMATION PART NUMBER DESCRIPTION QTY 2973385 Connector 1 15504673 Flasher (Electronic) 1 NPN Nylon Tie Straps 2 Parts are currently available from GMSPO. Air Inlet Actuator Replace Air Door Actuator / Motor: Service and Repair Air Inlet Actuator Replace Fig. 2 Air inlet actuator assembly. S/T-10/15 S/T-10/15 1. Disconnect battery ground cable. 2. Remove both windshield wiper arm and blade assemblies. 3. Remove cowl and plenum grille, then disconnect actuator linkage, Fig. 2. 4. Remove actuator. 5. Reverse procedure to install. Page 7920 Symbol Identification Backup Lamps/Tailgate Window Release - Inoperative Shift Interlock Switch: Customer Interest Backup Lamps/Tailgate Window Release - Inoperative Number: 91-459-8A Section: 8A Date: DEC. 1991 Corporate Bulletin No.: 168104 ASE No.: A6 Subject: BACKUP LAMPS OR TAILGATE WINDOW RELEASE INOPERATIVE Model and Year: 1980-91 ALL LIGHT DUTY TRUCKS (EXCEPT GEO) Owners of some 1980-1991 C/K, 1982-1991 G, 1985-1991 M/L, 1984-1991 P2,P3, 1987-1991 R/V, 1983- 1991 ST (including LLV) with automatic transmissions may comment on a condition of inoperative back-up lamps or inoperative tailgate window release. This condition occurs when the vehicle's gear shift lever is placed in the "reverse" position, but the back-up lamps do not illuminate. In addition, on the S/T utility vehicles, the electric tailgate window release does not release when the transmission gear shift lever is placed in the "park" or "neutral" position and the endgate window release button is depressed. The park/neutral and back-up lamp switch comes out of adjustment which does not allow for the contact points to remain engaged. To correct these conditions, the contact carrier on the park/neutral and back-up lamp switch has been modified to increase switch carrier travel. SERVICE PROCEDURE: 1. Disconnect the battery ground cable from the battery. 2. Disconnect the switch assembly harness. 3. Place the gear selector in neutral. 4. Squeeze the tangs on the switch together and remove the switch assembly. 5. Install the new switch assembly (P/N 15679680) by: -aligning the actuator with the cutout in the steering column jacket. -inserting the tangs into the rectangular holes and pushing down on the switch assembly. 6. Adjust the switch by moving the gear selector to park. 7. Connect the switch assembly harness. 8. Connect the negative battery cable. 9. Check for proper switch operation. Readjust the switch as necessary. Engine Controls - Aftermarket Accessory Usage Engine Control Module: All 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 Page 6815 Symbol Identification Wire Color Code Identification WIRE COLOR ABBREVIATION BLACK BLK BLUE BLU DARK BLUE DK BLU Page 1347 Refer to the appropriate section of SI for specifications and repair procedures that are related to the vibration concern. Disclaimer Page 6711 Specifications IGNITION COIL Page 2628 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. Brakes - Rotor & Hub Flange Cleaning Tool Revision Brake Rotor/Disc: All Technical Service Bulletins Brakes - Rotor & Hub Flange Cleaning Tool Revision File In Section: 5 - Brakes Bulletin No.: 73-50-37 Date: January, 1998 INFORMATION Subject: Revision to J 42450 Tool; Proper Brake Rotor and Hub Flange Surface Cleaning Models: 1998 and Prior Passenger Cars and Light Duty Trucks - with Disc Brakes (Rotor and Hub Separate) This bulletin is being revised to update the following text. This bulletin is being issued to inform the dealer about a revision to tool J 42450 and reinforce the need for proper hub flange and brake rotor mating surface cleaning during service. Tool J 42450 is a cleaning pad arbor and pad system that fits over the wheel stud and cleans the portion of the hub surface that is very difficult to reach with normal rotary cleaning pads. Tool J 42450 is being revised to J 42450-A to improve the hook and loop material retention. Any dealer experiencing problems with tool J 42450 should contact Kent-Moore at 1-800-345-2233 for a revised arbor at no charge. Anytime the brake rotor has been separated from the hub bearing flange or if rotor machining is necessary, the rotor and hub should be marked to maintain the original position. Clean the hub flange of all dirt and foreign material using special tool J 42450 or J 42450-A. Clean both sides of the brake rotor hub using an aggressive (80 grit) abrasive sanding pad on a rotary disc. Properly cleaning the rotor surfaces before rotor machining or reassembly ensures that dirt and corrosion will not add lateral runout to the rotor. Proper cleaning of the hub flange will also minimize the stack-up of lateral runout. On reassembly, the rotor should be reinstalled aligning the marks made on disassembly. Always use a torque wrench or the appropriate Torque Socket found in J 39544-KIT on an impact wrench when installing the wheel and tire assembly. Torque all wheel nuts using the correct sequence and torque. Refer to the Tire and Wheel Sub-Section in the applicable Service Manual. Excessive torque or torque variation between wheel nuts may cause distortion of the hub and rotor mating surface. This distortion may cause lateral runout and lead to brake pulsation. Page 3227 Fig. 4 Pickup coil test connections PICKUP COIL TEST 1. Remove distributor cap and rotor, and disconnect pickup coil leads from module. 2. Connect ohmmeter as shown in step 1, Fig. 4, and flex pickup coil leads while observing meter. Meter should indicate infinite resistance at all times. If not, pickup coil is defective. 3. Connect ohmmeter as shown in step 2, Fig. 4, and flex pickup coil leads while observing meter. Meter reading should remain constant between 500 and 1500 ohms. If not, replace pickup coil. Page 8156 6. Tape the solder and diode. 7. Reinstall the black plastic conduit. 8. Reconnect connector to the generator. 9. Reconnect battery. This procedure will not affect the operation of the generator light during the bulb check at the beginning of the start cycle. For vehicles repaired under warranty use, Labor Operation Number: T7990 Labor Time: .4 Hr 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. Page 573 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 Modes of Operation Engine Control Module: Description and Operation Modes of Operation Acceleration Mode In the Acceleration Mode, the ECM senses rapid change in throttle position and manifold pressure and provides a corresponding amount of added fuel. Battery Voltage Correction Mode When battery voltage is low, the ECM compensates to maintain acceptable system performance by increasing injector pulses, idle speed and ignition dwell time. Clear Flood Mode (Port and TBI Injection) A flooded engine is cleared by fully depressing the accelerator pedal, which causes the ECM to pulse the injectors at a air/fuel ratio of 20:1. The ECM will maintain this air/fuel ratio as long as the throttle is wide open and engine RPM is less than 600. If throttle position becomes less than 80% of wide open throttle, the ECM returns to "Starting Mode". Deceleration Mode In the Deceleration Mode, the ECM senses changes in throttle position and manifold pressure and reduces fuel delivery. When decelerating very rapidly, the ECM can cut off fuel completely for short periods of time. Electronic Spark Timing (EST) The Electronic Spark Timing (EST) distributor contains no vacuum or centrifugal advance mechanisms. In addition to the connectors normally found on HEI distributors, the HEI-EST distributor also has four wires going to a four terminal connector. A reference pulse, indicating engine RPM and crankshaft position is sent to the ECM. The ECM determines the proper spark advance for the engine operating conditions and sends an "EST" pulse to the distributor. In the case of EST failure, a back-up spark advance system is incorporated in the module. Run Mode The Run Mode consists of two separate operating conditions; open loop and closed loop. The engine operates in open loop when it is first started and RPM is above 400 RPM. During open loop operation, the ECM disregards the oxygen sensor signal and determines air/fuel mixture primarily from the coolant and MAP sensors. The engine will continue to operate in open loop until the following conditions are met: 1. The Oxygen sensor has varying voltage output, indicating it is hot enough to operate properly. 2. The Coolant sensor is above a specified temperature. 3. A specific amount of time has elapsed since the engine was started. The specified values for conditions mentioned above vary from model to model, and are stored in the ECM PROM. When the above conditions are met, the engine goes into closed loop operation. When operating in closed loop, the ECM determines the air/fuel ratio (injector pulse rate) based on signals from the oxygen sensor. This allows the air/fuel mixture to remain close to the optimum 14.7:1 ratio. During idling conditions, the V6-173 and V8-454 engines automatically goes into open loop operation. Starting Mode (Port and TBI Injection) When the ignition switch is rotated to the "On" position, the ECM energizes the fuel pump for two seconds and fuel pressure is built up to the TBI unit. The ECM then checks the coolant temperature sensor, the TPS and determines the proper air/fuel mixture for starting. The ECM controls the air/fuel ratio by changing the length of time the injectors are turned on and off. This is accomplished by "Pulsing" the injectors for short periods of time. Backup Lamps/Tailgate Window Release - Inoperative Shift Interlock Switch: All Technical Service Bulletins Backup Lamps/Tailgate Window Release Inoperative Number: 91-459-8A Section: 8A Date: DEC. 1991 Corporate Bulletin No.: 168104 ASE No.: A6 Subject: BACKUP LAMPS OR TAILGATE WINDOW RELEASE INOPERATIVE Model and Year: 1980-91 ALL LIGHT DUTY TRUCKS (EXCEPT GEO) Owners of some 1980-1991 C/K, 1982-1991 G, 1985-1991 M/L, 1984-1991 P2,P3, 1987-1991 R/V, 1983- 1991 ST (including LLV) with automatic transmissions may comment on a condition of inoperative back-up lamps or inoperative tailgate window release. This condition occurs when the vehicle's gear shift lever is placed in the "reverse" position, but the back-up lamps do not illuminate. In addition, on the S/T utility vehicles, the electric tailgate window release does not release when the transmission gear shift lever is placed in the "park" or "neutral" position and the endgate window release button is depressed. The park/neutral and back-up lamp switch comes out of adjustment which does not allow for the contact points to remain engaged. To correct these conditions, the contact carrier on the park/neutral and back-up lamp switch has been modified to increase switch carrier travel. SERVICE PROCEDURE: 1. Disconnect the battery ground cable from the battery. 2. Disconnect the switch assembly harness. 3. Place the gear selector in neutral. 4. Squeeze the tangs on the switch together and remove the switch assembly. 5. Install the new switch assembly (P/N 15679680) by: -aligning the actuator with the cutout in the steering column jacket. -inserting the tangs into the rectangular holes and pushing down on the switch assembly. 6. Adjust the switch by moving the gear selector to park. 7. Connect the switch assembly harness. 8. Connect the negative battery cable. 9. Check for proper switch operation. Readjust the switch as necessary. Page 7124 Cleveland, OH 44146-0478 708-671-3000 216-439-1200 Can-Am Croix Can-Am Engineered Croix Air Products Products. Inc. 520 Airport Rd./Flemingfield 30850 Industrial Rd. So. St Paul, MN 55074 Livinoia, MI 48150 612-455-1213 313-427-2020 DevilBiss Graco Inc. The Devilbiss Co. P.O. Box 1441 320 Phillips Ave. Minneapolis, MN 55440-1441 P.O. Box 913 1-800-367-4023 Toledo, OH 43962 419-470-2169 Lex-Air Turbine Spray Mattson Lex-Air South 230 West Coleman 5874 Buford Hwy. P.O. Box 132 Doraville, GA 30340 Rice Lake, WI 54868 404-454-8417 715-234-1617 Sata Sharpe Mfg. Sata Spray Equipment 1224 Wall St. P.O. Box 46 Hwy. 16&63 N. P.O. Box 15042 Spring Valley, MN 55975 Los Angeles, CA 90015-0042 507-346-7102 213-749-4368 Xcel Spray Smith Eastern Corporation 5020 Sunnyside Ave. #207 Beltsville, MD 20705 301-937-4548 We believe the sources listed in this bulletin 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 this firm or for any such item which may be available from other sources. Engine - Shake At Low RPM & At Idle, Engine Mount Engine Mount: All Technical Service Bulletins Engine - Shake At Low RPM & At Idle, Engine Mount Group Ref.: Engine Mechanical Bulletin No.: 166102 Date: November, 1993 SUBJECT: ENGINE SHAKE AT LOW SPEEDS AND AT IDLE (MOUNT NEUTRALIZATION PROCEDURE) MODELS: 1988-92 S/T TRUCKS WITH 4.3L ENGINE (RPO LB4) This bulletin is being revised to change the service parts availability information. Previous divisional publication numbers were: Chevrolet 92-353-6 GMC Truck 92-6A-158 CONDITION Owners of some 1988-92 S/T Trucks equipped with a 4.3L engine (VIN Code Z) may comment about excessive engine shake slightly above idle (800-1800 RPM). CAUSE Due to the cylinder arrangement, design, and firing order, the 4.3L engine has inherent natural vibrations. Before attempting to repair any of these disturbances, it is necessary to compare it to another known good vehicle, same model, year, etc. Some engine shake is normal. However, if the engine shake is more than normal, it may be due to powertrain mount and/or exhaust system positioning and/or movement. The following procedure addresses the condition. CORRECTION This diagnosis is designed to identify engine mount ground out. Pay special attention to engine mounts, transmission mounts, and exhaust system hangers. The vibration or ground out location must be isolated. 1. Apply parking brake. 2. Block the front wheels. 3. Place the vehicle in DRIVE (1st gear for standard transmission). 4. Bring engine rpm up to 1500-2000, listen for ground out (knocks or booming noise) and/or increased vibrations. 5. If no ground out is found, repeat step 3 with transmission in REVERSE. CAUTION: DO NOT ACCELERATE AGAINST THE BRAKES FOR LONGER THAN 15 SECONDS. CARE SHOULD BE TAKEN NOT TO OVERHEAT THE ENGINE OR TRANSMISSION. ALSO, CARE SHOULD BE TAKEN DURING DIAGNOSIS DUE TO THE FACT THAT SOME DISTURBANCES MAY BE CREATED DURING BRAKE TORQUE THAT NORMALLY DO NOT EXIST. Note: Pay special attention to engine mounts making hard contact, check for proper clearance at tangs. If ground out or crushed mounts are confirmed, replace worn or torn components as required, refer to the neutralization procedure below. To neutralize the engine and align the exhaust system properly: 1. Allow vehicle to warm up fully. Raise vehicle and support with suitable safety stands. Page 4290 Figure 11 - Snap Ring and Spider Removal 5. To remove the spider assembly (also required for seal replacement), spread the spacer ring with tool J8059 or equivalent and slide the ring and spider assembly up on the shaft (Figure 11). This will provide access to the shaft retaining ring in the groove at the end of the shaft. Remove the retaining ring, spider assembly, spacer ring, and seal. Figure 12 - Small Retaining Clamp Installation 6. Clean the shaft. If rust is present in the seal mounting area (grooves), wire brush this area (Figure 12). 7. Slide the new small seal clamp and seal onto the shaft to the proper position. 8. Secure the clamp with tool J35910, breaker bar and torque wrench. Torque small clamp to 136 N-m (100 lbs.ft.). Check clamp ear gap dimension (Figure 12). Description and Operation Electronic Spark Timing: Description and Operation Varying octane levels in today's gasoline can cause detonation in engines. Detonation is sometimes called spark knock. To control spark knock an Electronic Spark Control (ESC) system has been added. This system is designed to retard spark timing up to 20~ to reduce spark knock in the engine. This allows the engine to use maximum spark advance to improve driveability and fuel economy. The ESC system has three major components: ^ ESC module ^ ESC knock sensor ^ ECM The ESC knock sensor detects abnormal vibration (spark knocking) in the engine. The sensor is mounted in the engine block near the cylinders. The ESC module receives the knock sensor information and sends a signal to the ECM. The ECM then adjusts the timing to reduce spark knocking. The ESC module sends a voltage signal (8 to 10 volts) to the ECM when no spark knocking is detected by the ESC knock sensor, and the ECM provides normal spark advance. When the knock sensor detects spark knock, the module turns "OFF" the circuit to the ECM. The ECM then retards EST to reduce spark knock. Loss of the ESC knock sensor signal or loss of ground at ESC module would cause the signal to the ECM to remain high. This condition would cause the ECM to control EST as if no spark knock were happening. No retard would occur, and spark knocking could become severe under heavy engine load conditions, possibly leading to pre-ignition and severe engine damage. Loss of the ESC signal to the ECM would cause the ECM to constantly retard EST. This could result in sluggish performance and cause a Code 43 to set. Spark retard without the knock sensor connected could indicate a noise signal on the wire to the ESC module or a malfunctioning ESC module. Page 7889 SERVICE PARTS INFORMATION Part Number Application Description 15636850 1988-1991 Plate kit I/P (no switches). (Gray) Switch trim plate (gray) bracket, covers for switch trim plate holes (quantity 2), and 4 bolts/screws. 15636853 1986-1987 Plate kit I/P (no switches). (Black) Switch trim plate (black), bracket, covers for switch trim plate holes (quantity 2), and 4 bolts/screws. Important: Torque 11508898 bolts/screws supplied in kit to 0.4-0.7 N-m. (4-6 lbs.in.). Parts are expected to be available on January 21, 1991. Until then, normal part orders will not be accepted by GMSPO. Only verifiable emergency VIP orders will be accepted. GMSPO will make every effort to obtain parts. All parts will be placed on 400 control to waive VIP surcharges. However, the parts will be shipped premium transportation at dealer's expense. All other order types will be canceled as incorrectly ordered while 400 control is in place. WARRANTY INFORMATION For vehicle repaired under warranty use: Labor Operation: T7101 Labor Time: .3 hr. Trouble Code: 92 NOTE: Labor Operation is coded to base vehicle coverage in the warranty system. Page 3070 Fuel Supply Line: Service and Repair NOTES: a. 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. b. 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. Page 957 - Tighten poppet screw to 31 N-m (23 lbs.ft.). - New poppet plunger P/N 15633556 (70) group A vehicles only. - New poppet spring P/N 15633557 (71) group A vehicles only. - New poppet screw P/N 15633558 (68) group A vehicles only. 23. Vacuum switch (46) and new O-ring P/N 14071849 (47) to the front case housing. - Tighten switch to 24 N-m (17 lbs.ft.). 24. Front output flange (74), rubber sealing washer (75), washer (76) and flange nut (77). - Tighten nut (26) to 149 N-m (110 lbs.ft). 25. New vent pipe P/N 15581915 in new front case half (group A vehicles only). - Lightly coat end of vent pipe with Loctite 609 (R) or equivalent. 26. Transfer case into vehicle. - Refer to section 7D of the appropriate S/T Service Manual for complete transfer case replacement procedure. Service Parts & Warranty Information SERVICE PARTS INFORMATION: The "Easy Shift" package consists of the following parts. Parts must be ordered individually. Required Parts Part Quantity Figure 1 Group A Group B Number Description Required Reference Trucks Trucks 15635347 Front case half 1 45 X 15637215 Sector W/shaft 1 55 X X 15637217 Mode shift fork 1 54 X X 15633556 Poppet plunger 1 70 X 15633557 Poppet spring 1 71 X 15633558 Plug 1 68 X 14071849 O-ring 2 69 & 47 X X 15581915 Vent Pipe 1 N/S X 14095609 Input seal 1 42 X 14037958 Retainer 1 66 X X 14095598 Range sector seal 1 67 X X 15579788 Output front seal 1 72 X 15642511 Adapter gasket 1 N/S X X 15579803 Drive Sprocket 1 20 * * 14071703 Synchronizer 1 28 * * Blocking Ring * These parts required only if damaged or in cases of customer complaint of clash when shifting from 2Hi to 4Hi. Parts are currently available from GMSPO. WARRANTY INFORMATION: For vehicles repaired under warranty use: Labor Labor Operation Truck Time Page 698 Disclaimer Page 1265 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 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 Page 4621 Figure 3 REMOVE (Figures 2 & 3) Tools required: J8092 Drive handle J33790 Bearing installer and remover 1. Transfer case from vehicle. - Refer to Section 7D of the appropriate S/T Service Manual for complete transfer case removal procedure. 2. Front output flange nut (77), washer (76), rubber sealing washer (75) and front output flange (74) from the front output shaft. 3. Vacuum switch (46) and O-ring seal (47). 4. Poppet screw (68), O-ring seal (69), poppet spring (71) and poppet plunger (70). Mainshaft Extension and Oil Pump Housing 5. Rear extension housing bolts (3) and rear extension (4). 6. Bearing retainer (snap ring) (5) from the mainshaft (19). 7. Pump retainer housing bolts (7). 8. Pump retainer housing (8) from the rear case half (17). 9. Speedometer tone wheel (11) from the mainshaft (19). Page 2283 Fuel Pump Relay: Service and Repair Fuel Pump Relay REMOVAL 1. Verify that ignition switch is in the OFF position. 2. Disconnect the wiring harness plug. 3. Remove the fuel pump relay. INSTALLATION 1. Install the new fuel pump relay. 2. Reconnect the wiring harness plug to relay. 3. Verify correct operation to confirm repair. 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 Engine - Serpentine Belt, Worn Idler/Tensioner Pulley Drive Belt Tensioner: All Technical Service Bulletins Engine - Serpentine Belt, Worn Idler/Tensioner Pulley Number: 89-260-6A Section: 6A Date: September 1989 936204 Corporate Bulletin No.: Subject: SERPENTINE BELT WITH WORN IDLER PULLEY OR TENSIONER Model and Year: 1987-89 C, K, R, V, S, T TRUCKS AND M, G VANS WITH 4.3L, 5.0L, 5.7L, 7.4L (VIN CODE Z, H, K, N) ENGINES TO: ALL CHEVROLET DEALERS Some 1987-89 light-duty trucks with 4.3L, 5.0L, 5.7L, and 7.4L engines and equipped with serpentine belt drive may experience a condition where the belt becomes loose and squeals or the belt may come off the engine drive pulleys. This condition may be caused by a worn idler and/or worn belt tensioner pulley (plastic). If this condition exists, the following procedures may be used to repair this condition: IDLER PULLEY ONLY: 1. Using procedures in Section 6B-Engine Cooling, remove and discard the serpentine belt. 2. On trucks with 4.3L, 5.0L, and 5.7L engines, replace the existing idler pulley with a new metal pulley, P/N 10129560. On trucks with 7.4L engines, replace the existing pulley with P/N 10129561. Parts are expected to be available on October 9, 1989. Until then normal part orders will not be accepted by GMSPO. Only verifiable emergency VIP orders will be accepted. SPO will make every effort to obtain parts. All parts will be placed on 400 control to waive VIP surcharges. However, the part will be shipped premium transportation at dealer's expense. All other order types will be canceled as incorrectly ordered while the 400 control is in place. 3. Install new serpentine belt. Page 4343 Fig. 19 Aligning Bearing Cups & Journals Fig. 20 Relieving Binding Condition At Point A Fig. 21 Relieving Binding Condition At Point B Page 5683 Steering Column: Service and Repair Steering Column - Removal and Installation Fig. 3 Steering column removal Removal 1. Disconnect battery ground cable. 2. Disconnect transmission control linkage from column shift tube levers. 3. Remove upper clamp bolt from steering shaft. Mark location of pot joint on steering shaft. Fig. 3. 4. Remove column support bracket, nuts and bolts. 5. Remove column bolts and seal, then steering wheel with suitable steering wheel puller. 6. Disconnect steering column electrical connectors. 7. Rotate column so shift lever clears dash opening and remove. Fig. 4 Pot joint angle Fig. 5 Pot joint angle Installation 1. Lower end of column through dash opening and guide steering shaft into pot joint, lining up marks made at removal. 2. Loosely attach support bracket, nuts and bolts, finger tighten. 3. Install pot joint bolt. Bolt must pass through shaft undercut. Tighten to specifications. 4. Measure pot joint operating angle. a. On Bravada & S/T 10-15, angle must not exceed 12.5°. Refer to Fig. 4. b. On C, K, R and V Models, angle must not exceed 10°. Refer to Fig. 5. 5. Install attaching screws through cover and seal to dash panel. 6. Connect electrical connectors and install steering wheel, then connect transmission linkage and battery ground cable. Page 5700 Steering Gear: Adjustments Saginaw Integral Power Steering Gear Worm Bearing Preload Fig. 12 Adjuster plug nut removal Fig. 4 Adjuster plug removal Fig. 13 Adjuster plug alignment mark Page 6830 After installing floor mats, make certain they cannot move and do not interfere with the accelerator or brake pedals. Disclaimer Locations Accelerator Controls: Locations Accelerator Pedal Assembly Control Cable And Linkage Page 5915 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 Page 6164 R-4 Compressor Component View Remove or Disconnect Tool Required: J 25031 Rotor and Bearing Puller 1. Clutch drive hub (3). 2. Rotor (5) and bearing (6) assembly. 3. Pulley rim mounting screws (9) and washers (10). 4. Pulley rim (11). Install or Connect Tool Required: J 26271-A Rotor and Bearing Installer Clutch Coil, Pulley Rim, Rotor & Bearing Assembly ^ Clutch (7), pulley rim (8), clutch rotor (5) and bearing (6). Page 7175 5. Clean sanded surfaces with grease and wax remover. 6. Spray entire prepared area with a coat of DP40/DP401 anti-corrosion primer (PPG/ Ditzler) or equivalent. Follow manufacturers instructions and recommended dry times. 7. Apply 2 to 3 medium wet coats of primer-surfacer to primed surfaces of truck, making sure to follow manufacturers instructions for application. 8. After allowing adequate drying time, wet sand with 400 grit (or finer) sandpaper or dry sand with 320 grit (or finer) sandpaper. 9. Repeat steps 4 and 5. 10. Apply 1 medium wet coat of primer sealer, following manufacturers instructions. 11. Apply 3 to 4 medium wet coats (or until primer color is well hidden) of Acrylic/Urethane Enamel Color. Follow manufacturers instructions. NOTICE: Reinstall all trim and other items removed in step 2. 12. Final wash and detail vehicle. Claim Information Submit a claim with the information indicated below: * Select times as listed below for "Labor Hours" and material allowances for "Net Amount" as required for appropriate vehicle type and operation performed. Page 2496 Compression Check: Testing and Inspection COMPRESSION CHECK - Disconnect the primary terminal from the ignition coil. - Remove all spark plugs. - Block the throttle plate wide open. - Make sure the battery is fully charged. Starting with the compression gauge at zero, crank the engine through four compression strokes (four "puffs"). - Make the compression check at each cylinder and record each reading. - If some cylinders have low compression, inject 15 ml (one table spoon, or 3 squirts from a pump type oil can) of engine oil into the combustion chamber through the spark plug hole. - Minimum compression recorded in any one cylinder should not be less than 70 percent of the highest cylinder, and no cylinder should read less than 690 kPa (100 psi). Normal Compression: Compression builds up quickly and evenly to specified compression on each cylinder. Piston Rings Leaking: Compression low on first stroke, tends to build up on following strokes, but does not reach normal. Improves considerably with addition of oil. Valves Leaking: Low on first stroke. Does not tend to build up on following strokes. Does not improve much with addition of oil. Head Gasket Leakage: If two adjacent cylinder have lower than normal compression, and injecting oil into cylinders does not increase the compression, the cause may be a head gasket leak between the cylinders. Removal Brake Caliper: Service and Repair Removal For additional information see Removal Notes. See: Fundamentals and Basics 1. Siphon enough brake fluid out of the master cylinder to bring fluid level to 1/3 full to avoid fluid overflow when the caliper piston is pushed back into its bore. 2. Raise vehicle and remove front wheels. Fig. 2 Compressing piston & shoes with C-clamp 3. Using a C-clamp, push piston back into its bore. Fig. 3 Caliper & Mounting Bolts 4. Remove two mounting bolts and lift caliper away from disc. Hang caliper from coil spring with wire. CAUTION: Do not allow caliper to hang from brake hose. Page 3078 Fuel Gauge Sender: Service and Repair Fuel Pump And Sender Assembly (Typical) REMOVAL: 1. Disconnect the negative battery cable. 2. Raise vehicle. 3. Remove fuel tank. Refer to FUEL TANK ASSEMBLY. 4. Remove pump and sending unit assembly by turning the cam lock counterclockwise using tool J-36608 or J-24187 or equivalent. ^ Pull the fuel pump up into the attaching hose while pulling outward from the bottom support. ^ Do not damage the rubber insulator or the strainer. INSPECTION: 1. Inspect the fuel pump attaching hose for signs of deterioration. 2. Inspect the rubber sound insulation at the bottom of the pump for deterioration. INSTALLATION: 1. Install pump assembly into the attaching hose. NOTE: Care should be taken not to fold over or twist the strainer, when installing the sending unit as this will restrict fuel flow. 2. Install sending unit and fuel pump assembly into the fuel tank. (Always use a new O-ring seal). 3. Install the cam lock assembly. Turn the cam lock clockwise to lock it. 4. Install fuel tank assembly. 5. Connect the negative battery cable. 6. START vehicle and check for fuel leaks. Page 7677 Brake Lamp: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. Figure 21 Figure 22 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. Page 4349 Fig. 3 Cross & Roller Type Universal Joints Fig. 4 Cross & Roller Type Universal Joints & Propeller Shaft 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 with relation to the propeller shaft so they may be reassembled in the same relative position. Failure to observe these precautions may produce rough vehicle operation which results in rapid wear and failure of parts, and place 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. Some driveshafts use an injected nylon retainer to hold the bearing cups. When service is necessary, pressing the cups out will sheer the nylon retainer, Fig. 1. Replacement with the conventional steel snap ring type is then necessary, Fig. 2. Figs. 3 and 4 illustrate typical examples of universal joints of this type. They all operate on the same principle and similar service and replacement procedures may be applied to all. Fig. 7 Removing Bearing Cups Using Tool & Adapter Page 1120 - 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 Diagram Information and Instructions Brake Warning Indicator: Diagram Information and Instructions 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 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. Page 7133 Page 3726 R3261 LH mirror R&R; 0.4 Hr. (Time is different than published time in Labor Operation Guide.) Drive Belt - Making Chirp Noise Drive Belt: Customer Interest Drive Belt - Making Chirp Noise Number: 88-291-7A Section: 7A Date: JULY, 1988 Subject: SERPENTINE BELT CHIRP Model and Year: 1988 S/T TRUCKS W/4.3L (VIN CODE Z) ENGINE TO: ALL CHEVROLET DEALERS Some owners of 1988 4.3L S/T trucks may experience a chirping noise from the accessory drive belt. "Belt Chirp" is a short duration, intermittent, high pitched sound and should not be confused with belt "squeal", which is continuous in nature. This condition can be addressed by aligning the power steering pump pulley 3/4 mm plus or minus 1/4 mm (.030" plus or minus .010") forward of flush with the power steering pump shaft (See Illustration). A wheel puller should be used to perform this realignment. Labor Operation Number: T7460 Labor Time : .3 Hours Service and Repair Blower Motor Switch: Service and Repair S/T-10/15 1. Disconnect battery ground cable. 2. Remove instrument panel center bezel. 3. Remove control assembly attaching screws, then pull control assembly outward and remove blower switch. 4. Reverse procedure to install. Electrical - Information For Electrical Ground Repair Wiring Harness: All Technical Service Bulletins Electrical - Information For Electrical Ground Repair INFORMATION Bulletin No.: 10-08-45-001B Date: October 25, 2010 Subject: Information for Electrical Ground Repair - Use New Replacement Fasteners with Conductive Finish 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 the 2011 model year and update the Warranty Information. Please discard Corporate Bulletin Number 10-08-45-001A (Section 08 - Body and Accessories). Electrical Ground Repair Overview Proper electrical system function relies on secure, stable and corrosion-free electrical ground connections. Loose, stripped, or corroded connections increase the possibility of improper system function and loss of module communication. These conditions may also lead to unnecessary repairs and component replacement. In general, electrical ground connections are accomplished using one, or a combination of the following attachment methods: - Welded M6 stud and nut - Welded M6 nut and bolt - Welded M8 nut and bolt Determine which attachment method is used and perform the appropriate or alternative repair as described in this bulletin. M6 Weld Stud Replacement Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. Select a location adjacent the damaged or missing M6 ground stud having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the M6 conductive rivet stud flange. 2. Using GM approved residue-free solvent or equivalent, remove any grease from the repair site and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 3. Drill a 10 mm (0.40 in) diameter hole through the panel. 4. Remove paint and primer from the area surrounding the 10 mm (0.40 in) hole until bare metal is visible. A/T - Updated ATF Fluid Color/Level Check Information Fluid - A/T: All Technical Service Bulletins A/T - Updated ATF Fluid Color/Level Check Information Number: 89-234-7A Section: 7A Date: August 1989 Corporate Bulletin No.: 977126 Subject: AUTOMATIC TRANSMISSION/TRANSAXLE FLUID COLOR/LEVEL CHECK INFORMATION Model and Year: 1987-89 PASSENGER CARS AND TRUCKS WITH AUTOMATIC TRANSMISSIONS TO: ALL CHEVROLET DEALERS THE INFORMATION PROVIDED IN THIS BULLETIN SUPERSEDES THE PUBLISHED INFORMATION PERTAINING TO AUTOMATIC TRANSMISSIONS COVERED ON PAGES 3 AND 4 OF DEALER SERVICE BULLETIN 89-145-08 DATED MAY 1989. PLEASE MARK YOUR COPIES OF 89-145-08 TO INDICATE THE INFORMATION CONTAINED IN THIS BULLETIN. This bulletin provides Service Manual updates for Transmission/Transaxle fluid level and condition information. This information is updated for 1989 service manuals printed prior to June 1989. TRANSMISSION/TRANSAXLE FLUID LEVEL INFORMATION: Checking fluid level and condition (color and odor) at regular intervals will provide early diagnosis information about the transmission. This information may then be used to correct a condition that, if not detected early, could result in major transmission repairs. When adding or changing fluid, use only DEXRONR II. Refer to Maintenance and Lubricaton (Service Manual Section OB) for maintenance information and servicing intervals. NOTICE: Do not overfill. Overfilling will cause foaming, loss of fluid, shift complaints and possible damage to to transmission. ^ Fluid level should only be checked when it reaches a normal operating temperature of 82-93C (180-200F). This temperature is reached after approximately 24 km (15 miles) of driving. ^ Fluid color will be red when new. IMPORTANT: When new, automatic transmission fluid is red in color. The red dye is added so the assembly plant can identify as transmission fluid and distinguish it from engine oil or anti-freeze. The red dye is not an indicator of fluid quality and is not permanent. As the vehicle is driven, the transmission fluid will begin to look darker in color. The color may eventually appear light brown. A dark brown color along with a burnt odor may indicate excessive fluid deterioration and signal a need for fluid change. TRANSMISSION/TRANSAXLE FLUID CHECKING PROCEDURE: 1. Start engine and drive vehicle for a minimum of 24 km (15 miles), or until normal operating temperature is reached. NOTICE: The automatic transmission fluid level must be checked with the vehicle at normal operating temperature, 82-93C (180-200F). Temperature will greatly affect transmission fluid level. If the vehicle is not at normal operating temperature and the proper checking procedures are not followed, the result could be a false reading of the fluid level indicator and an incorrect adjustment of the fluid level. 2. Park vehicle on level ground. 3. Move gear selector to "PARK". 4. Apply parking brake and block wheels. 5. Let vehicle idle for 3 minutes with accessories off. Page 7170 Time Allowance: See Chants NOTE: The time allowances provided on the chart include the hardware removal and installation (as indicated by the list guidelines), the masking and unmasking of the vehicle, stripping of the surface (as indicated by the guidelines), the refinish (and colorcoat when required), mix time for primer/ paint (and clearcoat when required), finesse/polish where required, washing and preparing the vehicle for delivery. OPERATION DESCRIPTION: PAINT COLORCOAT DELAMINATION FROM ELPO PRIMER, REFINISH ENTIRE BODY ABOVE BODY SIDE MOLDINGS. PAINT TERM DEFINITIONS Following are definitions of paint repair terms used in this bulletin: Basecoat: A color topcoat that requires a clear topcoat over it. Break line: A natural dividing line on Fuse Block - Deforms Fuse Block: All Technical Service Bulletins Fuse Block - Deforms Number: 90-432-8B Section: 8B Date: SEPT. 1991 Corporate Bulletin No.: 168102 ASE No.: A6 Subject: FUSE BLOCK DEFORMS Model and Year: 1988-90 SI (LLV) POSTAL VEHICLES Some 1988 to 1990 LLV postal vehicles built prior to August 3, 1990, may exhibit a condtion where the fuse block is partially deformed due to heat generated by continuous operation of the hazard flasher. This condition may be corrected by the repositioning of the hazard flasher to a remote location. SERVICE PROCEDURE: 1. Disconnect positive battery cable. 2. Remove old flasher. 3. Back out terminals for circuit 140A (orange wire) and circuit 27 (brown wire) using a small flat screwdriver or pick. Using the same tool, raise the locking tang on the back of the terminal. 4. Cut electrical tape used to wrap main wiring harness a sufficient amount to provide 2 to 3 inches of flasher wiring for relocation. 5. Insert terminals of circuits 140A and 27 into new connector (P/N 2973385). 6. Install electronic flasher (P/N 15504673) into the new connector. 7. Using nylon ties, strap the connector and flasher assembly to the wiring harness that runs above the fuse block. Verify that the relocated flasher and all wiring is secured so it does not cause interference with the throttle linkage. 8. Reconnect battery cable. 9. Test operation of hazard flasher system. SERVICE PARTS INFORMATION PART NUMBER DESCRIPTION QTY 2973385 Connector 1 15504673 Flasher (Electronic) 1 NPN Nylon Tie Straps 2 Parts are currently available from GMSPO. Page 4260 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. 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. ECM/PCM - Damaged and/or Misdiagnosed Engine Control Module: All Technical Service Bulletins ECM/PCM - Damaged and/or Misdiagnosed Number: 91-384-6E Section: 6E Date: AUGUST 1991 Corporate Bulletin No.: 176503 Subject: DAMAGED ECM/PCM AND/OR MIS-DIAGNOSED ECM/PCM SYMPTOMS DUE TO INCORRECT "TAP-TESTING" PROCEDURES Model and Year: 1982-91 ALL PASSENGER CARS AND TRUCKS CONDITION: Because of the intermittent nature of some Electronic Control Module (ECM) or Powertrain Control Modules (PCM) symptoms, some service technicians have been subjecting the ECM/PCM to vibration and/or shock testing. Commonly known as tap-testing, this procedure involves tapping on the ECM/PCM case, while the engine is running. It is generally accepted that if the engine or ECM/PCM falters due to the tapping, an intermittent internal ECM/PCM defect may be indicated. However, this may not always be true. If too much force is applied to the ECM/PCM during the test the following symptoms may result: ^ Immediate ECM/PCM failure. ^ ECM/PCM suffers damage which may cause a failure at a later date. ^ ECM/PCM Reset (or Glitch), creating a momentary stall, miss Service Engine Soon (SES) light and/or loss of serial data. CAUSE: The ECM/PCM should be tapped using only the fingertips of one hand. Use of the palm, fist, or any type of tool subjects the ECM/PCM to forces that can cause both the circuit board and the outer aluminum case to flex and distort beyond design limits. The Integrated Circuits (IC) used in today's ECM/PCMs are mounted to the circuit board using a mounting process referred to as "surface technology." There are no circuit board holes for IC leads to go through. The IC leads set on pads, (28 pads or 52 pads depending on the IC) and solder is flowed around the leads to make the electrical connection to the circuit board. ^ Any flexing of the circuit board, beyond design limits, places the IC solder connections at risk of damage. Such damage may be apparent immediately, or it may appear at a future date. Circuit board deflection can occur as a result of striking the ECM/PCM, using ONLY THE PALM OF THE HAND. ^ If struck on the bottom side (the side opposite the service label), the ECM/PCM's aluminum outer case may deflect inward far enough to contact the electrical leads attached to the circuit board. Once in contact with the case the ECM/PCM electrical components will be shorted directly to ground. Although such shorting certainly has the potential to damage the ECM/PCM, it may not be permanent damage, depending on which circuit is involved. However, even if permanent damage is avoided, a short on any of the circuits will cause a disruption of normal ECM/PCM operation for the instant that the short occurs. This disruption may cause the ECM/PCM to reset (see "reset" above), creating the false impression that it is vibration sensitive or faulty. Reset is the ECM/PCM's normal way of coping with large voltage spikes. An ECM/PCM reset does not indicate that the ECM/PCM is defective or faulty, only that it is being subjected to abnormal conditions. CORRECTION: 1. TAP THE ECM/PCM ONLY ON THE TOP SIDE (The top side is where the service label is located.) ^ This will minimize the chance of deflecting the ECM/PCM case into the electrical leads on the circuit board. The clearance between the case and the circuit board is closest on the bottom side of the ECM/PCM. 2. TAP THE ECM/PCM USING ONLY THE FINGERTIPS - NO TOOLS. ^ To avoid excessive case deflection, avoid tapping in the center of the case. Tapping close to the edge of the ECM/PCM, especially in the corners, is best. ^ While using greater force may seem more effective, the test itself may cause the ECM/PCM to fail. Page 7594 Oil Pressure Gauge: Testing and Inspection Gauge Reads ``0'' 1. Check oil level, add if necessary. 2. Remove oil pressure sensor lead at sensor, gauge should read ``80.'' 3. If gauge stays at ``0'' remove sensor lead at gauge, gauge should read ``80.'' If gauge reads ``80'' find short to ground between gauge and sensor. 4. If gauge still reads ``0'' replace cluster. 5. With lead removed at sensor, connect a suitable ohmmeter to sensor. With engine stopped resistance should be one ohm, and approximately 44 ohms with engine running. 6. If sensor reads one ohm with engine running, replace sensor. Page 6832 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 Suspension - Knocking/Rattling Noise Torsion Bar: All Technical Service Bulletins Suspension - Knocking/Rattling Noise Number: 91-362-3C Section: 3C Date: JULY 1991 Corporate Bulletin No.: 163302 Subject: KNOCKING NOISE-TORSION BAR SUPPORT INSULATOR DAMAGED/BROKEN Model and Year: 1988-91 T TRUCKS Some owners of 1988-1991 T trucks may comment about a knocking or rattling sound coming from the underside of their vehicle. This sound can occur if the torsion bar support insulator is damaged or breaks. To correct this condition, a new more durable torsion bar insulator has been released. The new insulator is visually identical to the previous insulator and the installation procedure has not changed (reference S-10 Service Manual, Section 3C). VEHICLES INVOLVED: The new torsion bar support insulators have been installed on vehicles after the following VIN breakpoints. Shreveport 1GDCT14Z9M8801063 Pontiac West 1GCCS14A7M0190577 Moraine 1GCCS19R1M2273070 SERVICE PARTS INFORMATION: Part Number Description 15677665 Insulator, Torsion Bar Support Parts are currently available from GMSPO. WARRANTY INFORMATION: Labor Operation: E3340 Use applicable labor time guide for labor hours. Page 753 Oil Filter: 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. Description and Operation Electronic Spark Timing: Description and Operation Varying octane levels in today's gasoline can cause detonation in engines. Detonation is sometimes called spark knock. To control spark knock an Electronic Spark Control (ESC) system has been added. This system is designed to retard spark timing up to 20~ to reduce spark knock in the engine. This allows the engine to use maximum spark advance to improve driveability and fuel economy. The ESC system has three major components: ^ ESC module ^ ESC knock sensor ^ ECM The ESC knock sensor detects abnormal vibration (spark knocking) in the engine. The sensor is mounted in the engine block near the cylinders. The ESC module receives the knock sensor information and sends a signal to the ECM. The ECM then adjusts the timing to reduce spark knocking. The ESC module sends a voltage signal (8 to 10 volts) to the ECM when no spark knocking is detected by the ESC knock sensor, and the ECM provides normal spark advance. When the knock sensor detects spark knock, the module turns "OFF" the circuit to the ECM. The ECM then retards EST to reduce spark knock. Loss of the ESC knock sensor signal or loss of ground at ESC module would cause the signal to the ECM to remain high. This condition would cause the ECM to control EST as if no spark knock were happening. No retard would occur, and spark knocking could become severe under heavy engine load conditions, possibly leading to pre-ignition and severe engine damage. Loss of the ESC signal to the ECM would cause the ECM to constantly retard EST. This could result in sluggish performance and cause a Code 43 to set. Spark retard without the knock sensor connected could indicate a noise signal on the wire to the ESC module or a malfunctioning ESC module. Removal Wheel Cylinder: Service and Repair Removal For additional information see Notes, Warnings, and Hints. See: Fundamentals and Basics 1. Raise and support vehicle. 2. Remove wheel and tire assembly. 3. Remove drum. 4. Remove brake shoes. 5. Disconnect hydraulic line at wheel cylinder. CAUTION: Do not pull metal line away from cylinder, as this may kink or bend line. Line will separate from cylinder when cylinder is moved away from brake backing plate. 6. Remove wheel cylinder-to-brake plate attaching screws, then the wheel cylinder. Page 6314 - 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. Page 7464 10. Drive the door frame (the second layer of sheet metal) down with a punch approximately 1/4" all the way around the hole. 11. Paint the bare metal edges left from cutting the hole with a zinc rich primer. 12. Completely fill the hole with black RTV, GM P/N 1052917, or equivalent and level for good adhesion and appearance. 13. Follow Steps 6-12 on each side of the vehicle. 14. Reinstall the hood hinge seals in their original position to prevent water leakage into the cowl. If it is necessary, additional adhesive (3M weather strip adhesive P/N 08001 or equivalent) should be used to secure the hood hinge seal. 15. Reinstall the windshield washer hose, cowl vent panel, radio antenna, and windshield wipers, and remove the protective tape from the fender and cowl vent panel. Brakes (ABS) - 'False' or Dropping Pedal Hydraulic Control Assembly - Antilock Brakes: Customer Interest Brakes (ABS) - 'False' or Dropping Pedal Bulletin No. 24 Date November, 1982 Vehicle Make/Model DODGE, FORD and GENERAL MOTORS TRUCKS Equipped with Rear Anti-Lock Brake Systems Ford: RABB (Rear Anti-Lock Brake System) GM & Dodge: RWAL (Rear Wheel Anti-Lock) Topic False or Dropping Pedal Some of the above mentioned vehicles may experience a "false" or dropping pedal condition that may feel very similer to a master cylinder with an excessive amount of by-pass. Upon installation of the replacement master cylinder, there is little or no improvement in pedal feel or height, This condition may be caused by the dump valve in the E-H (Electro Hydraulic) valve being held slightly open by a small particle of foreign material. This allows fluid to flow into the accumulator and create the low or dropping brake pedal. To determine if this is the cause of the dropping pedal, begin by disconnecting the steel line at the master cylinder that serves the rear brakes. Install a solid tubing plug into the outlet that serves the rear brakes. Note: When installing the plug, have an assistent depress the pedal about one inch to purge any air from the outlet. Tighter, the plug while the assistant holds the pedal in this position. After tightening the plug, continue to apply pressure to the pedal. This will prevent damage to the primary cup in the master cylinder as the cup moves across the vent port. If the pedal no longer drops as it did with the rear brakes connected, this would indicate that the problem is in the rearbrakes and not the master cylinder. The next step would be to block off the outlet port of the E-H valve and retest the brake pedal as done previously. If the dropping pedal reappears, the problem is in the E-H valve and most likely caused by fluid leaking into the accumulator of the E-H valve. If this is the case, it will be necessary to change the valve. The E-H valve, including the accumulator and valving, is not serviceable. Note that brake fluid over a period of time absorbs contaminants, therefore, annual flushing and replacement with clean, fresh brake fluid will help to prevent this condition from occurring. Page 2082 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. Page 4622 10. Case bolts (3) from the case halves. - Note the two longer bolts (16) and washers go into doweled case holes (33). - Separate case halves, insert screwdrivers into the slot cast in the case ends and pry apart. Do not attempt to wedge the case halves apart at any point on the mating surfaces. - Be careful not to damage the oil pump (12) (located in the rear case half) while removing the rear case half (17). Internal Components 11. Fork shift spring (52). 12. Mainshaft (19)/drive sprocket 14071703 (20), chain (58) and front output shaft (21) as a unit. Mode shift fork (54) and shift rail (48) will be removed with the mainshaft. INSPECT: The teeth of the synchronizer stop ring (28) and drive sprocket (20) for damage. If they are damaged, or in cases of customer complaint of clash when shifting from 2Hi to 4Hi, follow steps 13, 14 & 15, otherwise skip to step 16. 13. Retainer (snag ring) (83) from the mainshaft (19). 14. Synchronizer assembly (81). 15. Drive sprocket (20) from the mainshaft (19). 16. Range shift fork (51), range shift hub (34) and sector with shaft (55) from the planetary carrier (36). - It is necessary to rotate the sector with shaft (55) to obtain clearance when removing the range fork (51). 17. Plastic washer (retainer) (66) and O-ring seal (67) from the front case half. IMPORTANT: Group B vehicles should complete step 17 and skip to INSTALL step 8. 18. Input bearing retainer bolts (43) and input bearing retainer (44) from the front case half (45). 19. Retainer snap ring from the input gear (38). 20. Planetary carrier (36) and the input gear (38) from the annulus gear (62) using a soft hammer. 21. Input bearing retainer (39) and input bearing (40). 22. Front output bearing retainer ring (snap ring) (60). 23. Front output bearing (61) from the front case half (45) using J33790, and J8092. 24. Seal (42) from the input bearing retainer (44) if it shows signs of damage. Install Engine - Improved Head Gasket Cylinder Head Gasket: Customer Interest Engine - Improved Head Gasket Number: 89-283-6A Section: 6A Date: December 1989 Corporate Bulletin No.: 836537 Subject: REVISED CYLINDER HEAD GASKET Model and Year: 1987-89 PASSENGER CARS AND LIGHT DUTY TRUCKS TO: ALL CHEVROLET DEALERS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 89-06-6A, DATED SEPTEMBER 1988. THE 4.3L ENGINE APPLICATION AND PART NUMBER HAS BEEN ADDED. ALL COPIES OF 89-06-6A SHOULD BE DISCARDED. A cylinder head gasket with improved sealing characteristics is now available for service use on all 4.3L, 5.0L and 5.7L engine applications. The applicable part numbers are listed below: Application Cylinder Head Gasket P/N 4.3L Engines 10105110 5.0L Engines 10105115 5.7L Engines 10105117 These parts are currently available from GMSPO. When replacing head gaskets on vehicles under warranty, use: Labor Operation Numbers: J0500 - Right Bank J0501 - Left Bank J0507 - Both Banks Refer to Labor Time Guide for applicable labor times for various models. Paint - Identification/Repair of Colorcoat Delamination Paint: All Technical Service Bulletins Paint - Identification/Repair of Colorcoat Delamination BULLETIN NUMBER: 92-1O-134A SECTION: 10 Body NUMBER: 4 CORPORATE REFERENCE NUMBER: 231054R DATE: July 1993 SUBJECT: SERVICE PROCEDURES FOR IDENTIFICATION AND REPAIR OF PAINT COLORCOAT DELAMINATION FROM ELPO PRIMER MODELS: 1988-92 TRUCKS THIS BULLETIN CANCELS AND REPLACES TRUCK SERVICE BULLETIN 92-10-134 (CORP # 231054R), DATED OCTOBER 1992. IT IS BEING REVISED TO REMOVE THE COVER LETTER PORTION AND SUBJECT STATEMENT NOW INCLUDES NOTE FOR TRUCKS AND REVISES THE MONOCOAT MATERIAL ALLOWANCES ON "G", "S/T" AND SOME "R/V" MODELS. THE ALLOWANCE FOR "ADD FOR TWO-TONE" ON G AND S/T TRUCKS HAS BEEN CHANGED. ALL COPIES OF 92-10-134 SHOULD BE DISCARDED. The revisions are the result of changes to the MONOCOAT (ENAMEL) material allowance charts published in June, 1993. Six (6) of the "G" model revisions use Basecoat/Clearcoat material allowance codes. THESE ARE TO BE USED AS DOLLAR REFERENCES ONLY, AND ARE MARKED WITH A # INDICATOR. Continue to repair these vehicles with monocoat materials. DO NOT repair these vehicles with Basecoat/Clearcoat products. Use the latest (June, 1993) material allowance charts when submitting claims. SUBJECT: Service procedures for the repair of paint colorcoat delamination from elpo primer (repaint entire body above the body side moldings, except trucks as noted). APPLICATION: 1988-1992 LIGHT DUTY TRUCKS (C/K, R/V, S/T, M/L AND G) This bulletin cancels and supersedes service procedures and time allowances on all previous bulletins regarding paint DELAMINATION. Due to the use of new procedures, add times for optional equipment, and designating specific hardware items for removal, the published labor times will not be the same as previously published. CONDITION This bulletin is being issued to assure that the correct procedure is followed to repair a condition known as DELAMINATION. Some of the above listed passenger cars, light duty trucks, and vans may have DELAMINATION (peeling) of the paint color-coat from the ELPO primer depending upon variable factors including prolonged exposure to sunlight and humidity. Blues, Grays, Silvers and Black Metallics are the colors that have the highest potential for this condition. On rare occasions, other colors may be involved. Important DELAMINATION is different than other paint conditions and/or damage. A proper problem identification is necessary, and the service procedure that follows is specific to the proper repair of DELAMINATION and must be followed. The information in this bulletin covers Paint DELAMINATION of the colorcoat from the ELPO primer ONLY. It does not address any other paint conditions. Procedures for the repair of other paint conditions (stone chips, scratches, environmental damage, clearcoat peeling, runs, dirt, fading, etc.) will not effectively repair DELAMINATION and customer dissatisfaction will result. CAUSE This condition may occur on vehicles produced in plants where the paint process does not call for application of a primer surfacer. Under certain conditions, ultraviolet light can penetrate the colorcoat, sometimes causing a reaction and separation of portions of the colorcoat from the ELPO (electrocoat) primer. PROBLEM IDENTIFICATION: Page 5183 When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 5mm (3/16") of insulation from wire. e. Crimp a new terminal to the wire. f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. Figure 17 To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Figure 18 Figure 19 Page 7599 Oil Pressure Sender: Locations Engine Harness Top rear of engine Page 4021 Transmission Pressure Test Port: Specifications 4L60 - 700R4 Transmission Pressure Plugs (1/8 - 27) ..................................................................................................................... ...................................................................... 8 ft. lbs. Pressure Plugs (1/4 - 18) ................................ ......................................................................................................................................................... 18 ft. lbs. Radio - Popping Noise Due to Spark Plugs Radio/Stereo: All Technical Service Bulletins Radio - Popping Noise Due to Spark Plugs Number: 88-107-6E Section: 6E Date: JAN., 1988 Subject: RADIO POPPING NOISE DUE TO SPARK PLUGS Model and Year: 1988 LIGHT DUTY TRUCKS WITH 4.3L, 5.0L AND 5.7L ENGINES (VIN CODES Z, H AND K) TO: ALL CHEVROLET DEALERS Some 1988 trucks with 4.3L, 5.0L and 5.7L engines may experience a popping noise in the radio due to the use of AC CR43TS spark plugs. This condition can be repaired by replacing the CR43TS plugs with R43TS plugs (P/N 5613325). R43TS plugs entered production with engines produced since August 30, 1987. Spark plug gap specification is 0.035". Wiper Blades - Chattering on Windshield Windshield: All Technical Service Bulletins Wiper Blades - Chattering on Windshield Number: 91-126-8E Section: 8E Date: November 1990 Corporate Bulletin No.: 031066 Subject: CHATTERING WIPER BLADES OR BLADE WIPEABILITY Model and Year: ALL PASSENGER CARS AND TRUCKS TO: ALL CHEVROLET DEALERS Condition: Chattering and poor wipeability comments may be due to the windshield glass and/or wiper blades becoming contaminated by insect residue, dirt, road grime, carwax etc. Correction: 1. Clean the windshield glass with GM # 1050011 (Bon Ami) glass cleaner or equivalent. Important: The glass is clean when rinse water does not "bead-up," but "sheets" across the entire glass surface. Multiple cleanings may be required to remove all contaminants. 2. Clean the wiper blades by using a cloth that has been saturated with full strength washer solution and wipe vigorously. Rinse the blades with water after cleaning. Engine Controls - Idle Speed/Minumum Idle Air Rate Specs Idle Speed: Technical Service Bulletins Engine Controls - Idle Speed/Minumum Idle Air Rate Specs GMC NUMBER: 88-T-55 GROUP: 6E - Engine Emissions DATE: November, 1987 CORPORATE NUMBER: 836302 SUBJECT: TRUCK ENGINE CONTROLLED IDLE SPEED AND MINIMUM IDLE AIR RATE SPECIFICATIONS MODELS: 1987 AND 1988 TRUCKS (ALL GASOLINE ENGINES) WITH THROTTLE BODY INJECTION (TBI) This bulletin defines the controlled idle speed and minimum idle air rate specifications for 1987 and 1988 model year trucks for all engine applications with TBI. Additionally, step by step procedures are provided for performing the controlled idle speed check and the minimum idle air rate check. It is important that these procedures and specifications be adhered to. An incorrect readjustment with a high minimum air rate will cause the Idle Air Control (IAC) valve pintle to constantly bottom on its seat and may result in early IAC valve failure. A minimum air rate that is too low may result in a no-start condition in cold weather, a stall after start or a stall during deceleration, because of poor air/fuel distribution through the throttle bore. NOTICE: THESE SPECIFICATIONS AND PROCEDURES SUPERSEDE THOSE PROCEDURES DEFINED IN THE 1987 FUEL AND DRIVEABILITY MANUAL, X-8736. Controlled Idle Speed Check Before performing this check there should be no codes displayed, idle air control system has been checked and ignition timing correct. The procedures to check the idle air control system can be found in the Light Duty Truck Fuel and Emissions service manual at the following locations: All Truck Engines Except 2.5L Page 4-11 2.5L Truck Engines Page 3-61 1. Set parking brake and block drive wheels. 2. Connect a "SCAN" tool to the Assembly Line Data Link (ALDL) connector with tool in Open Mode. 3. Start engine and bring it to normal operating temperature. 4. Check for correct state of Park/Neutral switch on "Scan" tool. 5. Check specifications chart at the end of this bulletin for controlled idle speed and IAC valve pintle position (counts). 6. If within specifications, the idle speed is being correctly controlled by the Electronic Control Module (ECM). 7. If not within specifications, refer to "Rough, Unstable or Incorrect Idle, Stalling" in Section "2" of the Fuel and Driveability Manual X-8736 and review information at the beginning of this check. MINIMUM IDLE AIR RATE CHECK 1. Check controlled idle speed and perform idle air control system check first. 2. Set parking brake and block drive wheels. 3. Start engine and bring it to normal operating temperatures (85-100 degrees Celsius). Turn engine "OFF". 4. Remove air cleaner, adapter and gaskets. On S/T series vehicles, leave THERMAC hose connected. Check that the throttle lever is not being bound by the throttle, Throttle Valve (TV) or cruise control cables. 5. With IAC valve connected, ground the diagnostic terminal (ALDL connector). 6. Turn "ON" ignition, do not start engine. Wait at least 10 seconds (this allows IAC valve pintle to extend and seat in throttle body). 7. With ignition "ON", engine stopped, test terminal still grounded, disconnect IAC valve electrical connector. (This disables IAC valve in seated position). Remove ground from diagnostic terminal. 8. Connect a "Scan" tool to the ALDL connector and place in open mode. If a tool is not available connect a tachometer to the engine. 9. Start engine. With transmission in neutral, allow engine rpm to stabilize. NOTICE: ON 2.5L ENGINES A SERVICE ENGINE SOON LIGHT WILL COME ON AND A CODE 35 WILL BE SET. 10. Check rpm against specifications at the end of this bulletin. Disregard IAC counts on "Scan tool with the IAC disconnected. If the engine has less than 500 miles or is checked at altitudes above 1500 feet, the idle rpm with a seated IAC valve should be lower than values in chart. 11. If the minimum idle air rate is within specifications, no further check is required. 12. If the minimum idle air rate is not within specifications, perform the following procedures: 13. If present, remove stop screw plug by piercing it with an awl, then applying leverage. The screw is covered to discourage unauthorized adjustments. Compact Disc Players - CD Changer Loading Procedures Compact Disc Player (CD): Customer Interest Compact Disc Players - CD Changer Loading Procedures File In Section: 9 - Accessories Bulletin No.: 64-96-01 Date: January, 1997 INFORMATION Subject: Compact Disc Players - Procedures for Correct Use and Maintenance Models: 1997 and Prior Passenger Cars and Trucks CD Changer Loading Procedures Because of differences in CD changer loading procedures, some confusion exists regarding this issue. Although correct loading procedures are included with each changer's Owner's Manual, often this information is not available to the dealer service personnel. Verify proper loading when evaluating customer concerns of "CD inoperative". Delco Electronics Product Type Loading Procedure Radio w/intergral CD label side up 6 disc changer (LLAI) label side up 10 disc changer (FMI) label side up 12 disc changer (LLAI) label side down Important: Failure to load magazine/player correctly will disable the operation. Important: Only the 12 disc changer is to be loaded with the label side down. CD Cleaners Avoid use of commercially available CD cleaners. The use of CD cleaners is not recommended and can damage the player's CD mechanism. Locations Brake Fluid Pressure Sensor/Switch: Locations LH Side Of Engine Compartment At Master Cylinder Drive Axle (Front) - Will Not Disengage Transfer Case Actuator: Customer Interest Drive Axle (Front) - Will Not Disengage Number: 91-476-4C Section: 4C Date: JAN. 1992 Corporate Bulletin No.: 167402 ASE No.: A3 Subject: FRONT AXLE WILL NOT DISENGAGE Model and Year: 1983-1991 T TRUCKS Owners of some 1983-1991 T vehicles may comment about inappropriate front axle disengagement. This condition may be due to a corroded transfer case vacuum actuator switch. To correct this condition a revised switch (P/N 15664811), constructed of noncorrosive stainless steel, should be installed. SERVICE PROCEDURE: The vacuum switch is located on the left upper side of the transfer case (Figure 1). 1. Raise the vehicle and support with suitable safety stands. 2. Remove the vacuum lines from the switch. 3. Remove the corroded switch from the transfer case. 4. Install a revised switch (P/N 15664811), coat the threads with thread sealant. 5. Connect the vacuum lines. 6. Lower the vehicle. 7. Check for oil leaks at the threads and vacuum leaks around the vacuum lines. Page 1329 *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 4L60 - 700R4 Transmission Fluid Pump: Specifications 4L60 - 700R4 Transmission Pump Assembly To Case .................................................................................................................... .................................................................... 18 ft. lbs. Pump Cover To Body ...................................... ....................................................................................................................................................... 18 ft. lbs. 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 Page 180 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 module's 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 flexible ducting 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. Page 4825 This results in the piston seals again being dragged across the layer of corrosion and deposits. Calipers which are not rebuilt or replaced have a higher probability of sticking or leaking. - Check to ensure the bleeder screw is not frozen prior to reinstalling caliper. Freeing a stuck bleeder screw is much easier with the caliper removed from the vehicle. Page 8195 Wiper Motor: Service and Repair FRONT 1. Disconnect battery ground cable. 2. Remove windshield wiper arms. 3. Remove cowl vent and grille. 4. Loosen, but do not remove transmission drive link to motor crank arm attaching nuts, then disconnect drive link from motor crank arm. 5. Disconnect motor electrical connector and remove attaching bolts. 6. Remove motor by rotating up and outward. 7. Reverse procedure to install. Torque motor attaching bolts to 49-75 inch lbs. Fig. 11 Windshield Wiper Motor Removal (Rear) REAR Refer to Fig. 11, for wiper motor replacement. 1. Disconnect battery ground cable. 2. Remove three retainer screws and cover from wiper motor. 3. Remove three roof trim panel screws, then the trim panel. 4. Disconnect washer hose and electrical connector at wiper motor. 5. Remove wiper arm assembly from wiper motor. 6. Support glass on right side. 7. Remove nut, spacer and flat seal from wiper motor. 8. Remove wiper motor hinge bolt from hinge assembly, then the wiper motor. 9. Reverse procedure to install noting the following: a. Torque wiper motor hinge bolt to 54 inch lbs. b. Torque wiper motor nut to 54 inch lbs. Page 3069 NOTE: If a fuel filler cap requires replacement, only a cap with the same features should be used. Failure to use the correct cap can result in a serious malfunction of the system. FUEL AND VAPOR PIPES The fuel feed and return pipes extend from the fuel pump/gauge sending unit to the engine compartment. The pipes are secured to the underbody with clip and screw assemblies. Both fuel feed pipes and return pipe must be properly routed and retained, and should be inspected occasionally for leaks, kinks, or dents. If evidence of dirt is found in the fuel injector assembly or fuel filter during disassembly, the pipes should be disconnected and blown out. Check the fuel strainer on the fuel pump/fuel gauge assembly for damage or omission. The vapor pipe extends from the fuel pump/gauge assembly to the canister. However, it does not follow the same route as the fuel feed pipe. Due to the fact that the fuel pipes/hoses are under high pressure on fuel injected systems these systems require special consideration for service. NOTE: All fuel feed and return line attachments in the system are screw type fittings. Always use a backup wrench when loosening or tightening the fittings. Screw fittings used on the two systems utilize O-rings for the fuel feed and return pipes and the two sizes of O-rings are not interchangeable. Any time that the fuel or return pipes are disconnected, inspect the O-rings for cuts or other type of damage and replace as necessary. The flare used on these fuel pipes is not compatible with the flare used on other fuel pipes. FUEL LINE O-RINGS The fuel line O-rings used are made of Viton. They are brown in color. Viton is less affected than rubber by the additives used in many fuels. Therefore, rubber should not be used. Page 2094 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 Page 4340 Fig. 1. Replacement with the conventional steel snap ring type is then necessary, Fig. 2. Fig. 11 Bearing Cup Removal Sequence Fig. 12 Alignment Punch Marks Fig. 13 Cross Press Being Used In Place Of Socket Page 4644 Figure 2 Capacity Specifications Fluid - A/T: Capacity Specifications 3L30 (180C) Transmission Fluid Capacity Pan Capacity ............................................................................................................... ........................................................................................... 1.5 Qts. Total Capacity ............................ .............................................................................................................................................................. ............. 2.3 Qts. 4L60 - 700R4 Transmission Fluid Capacity Pan Capacity ....................................................................................................................................... ......................................................................... 5.0 qts Overhaul Capacity ......................................... ............................................................................................................................................................ 11.5 qts Page 320 Brake Light Switch: Locations Stop Lamp Switch LH Side Of Steering Column Behind Instrument Cluster Page 3742 Fluid Pump: Technical Service Bulletins A/T - Updated Oil Pump Assemblies Number: 88-56 Section: 7A Date: Sept., 1987 Subject: NEW PUMP ASSEMBLY VANE RINGS THM 700-R4 THM 200-4R Model and Year: 1981-88 PASSENGER CARS AND L.D. TRUCKS EQUIPPED WITH EITHER THM 700-R4 OR THM 200-4R TRANSMISSIONS TO: ALL CHEVROLET DEALERS New transmission oil pump assemblies with Nodular Iron Vane Rings entered production April 28, 1987 (Julian date 118) on THM 700-R4 transmissions. This change also applies to SRTA. FIGURE 1 - THM 200-4R AND THM 700-R4 TRANSMISSION IDENTIFICATION INFORMATION Beginning June 17, 1987 (Julian date 168) all THM 200-4R began production with the new rings. (Refer to Figure 1) Page 359 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. Diagram Information and Instructions Starter Solenoid: Diagram Information and Instructions 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 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. Page 1189 Coolant Level Indicator Lamp: Service and Repair This lamp will be illuminated when engine coolant level in the radiator drops below a pre-determined level. To turn lamp "OFF," check cooling system, then add coolant to bring system to proper level. Page 6329 - 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. Page 7073 PAINT air dry only Note: Only items marked with an asterisk are "add" conditions to the Major Operation being performed. Removal time for all other items listed is included in the refinish time. LIGHT DUTY TRUCKS C/K TRUCKS Grille Front bumper filler panel Antenna Tail lamps Door edge guards Metal wheel opening moldings *Roof marker lamps "Luggage rack *West coast style mirrors "Stripes Emblems/decals if necessary Swing out windows/seals Tail gate handle bezel S/T TRUCKS Windshield molding Bumper filler panels, Ft./Rr. Wiper arms Antenna Wheel opening moldings Cowl vent grille Door edge guards Side view mirrors Tail lamps *Wind deflector Rear Window (Jimmy) *Luggage rack *Stripes Emblems/decals if necessary Swing out windows/seals *Spare tire carrier and latch-external mount (Jimmy) M/L VANS Windshield molding Wheel opening moldings Headlamp bezels Antenna Tail lamps Door edge guards *Luggage rack *Stripes Emblems/decals if necessary R/V TRUCKS Wiper arms Cowl vent grille Antenna Tail lamps Hood ornaments Wheel opening moldings Side view mirrors Grille and headlamp bezels Page 3569 Backup Lamps/Tailgate Window Release - Inoperative Shift Interlock Switch: All Technical Service Bulletins Backup Lamps/Tailgate Window Release Inoperative Number: 91-459-8A Section: 8A Date: DEC. 1991 Corporate Bulletin No.: 168104 ASE No.: A6 Subject: BACKUP LAMPS OR TAILGATE WINDOW RELEASE INOPERATIVE Model and Year: 1980-91 ALL LIGHT DUTY TRUCKS (EXCEPT GEO) Owners of some 1980-1991 C/K, 1982-1991 G, 1985-1991 M/L, 1984-1991 P2,P3, 1987-1991 R/V, 1983- 1991 ST (including LLV) with automatic transmissions may comment on a condition of inoperative back-up lamps or inoperative tailgate window release. This condition occurs when the vehicle's gear shift lever is placed in the "reverse" position, but the back-up lamps do not illuminate. In addition, on the S/T utility vehicles, the electric tailgate window release does not release when the transmission gear shift lever is placed in the "park" or "neutral" position and the endgate window release button is depressed. The park/neutral and back-up lamp switch comes out of adjustment which does not allow for the contact points to remain engaged. To correct these conditions, the contact carrier on the park/neutral and back-up lamp switch has been modified to increase switch carrier travel. SERVICE PROCEDURE: 1. Disconnect the battery ground cable from the battery. 2. Disconnect the switch assembly harness. 3. Place the gear selector in neutral. 4. Squeeze the tangs on the switch together and remove the switch assembly. 5. Install the new switch assembly (P/N 15679680) by: -aligning the actuator with the cutout in the steering column jacket. -inserting the tangs into the rectangular holes and pushing down on the switch assembly. 6. Adjust the switch by moving the gear selector to park. 7. Connect the switch assembly harness. 8. Connect the negative battery cable. 9. Check for proper switch operation. Readjust the switch as necessary. Specifications A/C Hose Or Line Torque Specifications Page 5615 (Figure 2) Caster/Camber Adjustment - 4WD Models Caster and camber adjustments are made by cam mounted upper control arm attaching bolts, refer to (Figure 2). To adjust caster and/or camber, loosen upper control arm to frame attaching bolt nut, then rotate cam by turning bolt head. When proper alignment settings are established, torque upper control arm to frame attaching bolt nuts to 95 Nm (70 ft lbs). Caster To increase positive caster, move front cam lobe inward and rear cam lobe outward. Camber To increase positive camber, move both front and rear cam lobes inward. Front Toe Adjustment Page 6266 Hose/Line HVAC: Service and Repair 1. Discharge system refrigerant. 2. Disconnect hose pipe assembly at accumulator outlet, condenser inlet and compressor head. 3. Remove mounting straps and remove assembly from vehicle. 4. Reverse procedure to install. Description and Operation Transmission Position Switch/Sensor: Description and Operation The park/neutral switch indicates to the ECM when the transmission is in park or neutral. This information is used by the ECM for ignition timing, IAC operation and transmission Torque Converter Clutch (TCC) operation. Do not drive vehicle with park/neutral switch disconnected, as idle quality may be affected. Page 7907 Light Switch Details (Part 3 Of 3) Page 7721 Courtesy & Dome (W/Cargo Lamp) Page 402 Manifold Pressure/Vacuum Sensor: Testing and Inspection Chart C-1D - Manifold Absolute Pressure (MAP) Output Check Diagram Information and Instructions Brake Warning Indicator: Diagram Information and Instructions 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 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. Page 356 Light Switch Details (Part 1 Of 3) Page 2918 Disclaimer Page 7950 Symbol Identification Page 252 Oil Pressure Sender: Locations Engine Harness Top rear of engine With Power Windows Window Regulator: Service and Repair With Power Windows Door Armrest Replacement Front Door Trim Panel REMOVE OR DISCONNECT 1. Screws securing the armrest to the door trim. 2. Armrest from the door trim. ^ Slide the armrest towards the rear of the door, and then, lift the armrest from the door. INSTALL OR CONNECT 1. Armrest to the door trim. ^ Place the armrest retaining clips in the slots on the door panel. ^ Slide the armrest toward the front of the door unit the holes in the armrest align with the holes in the door trim. 2. Screws securing the armrest to the door trim. Door Trim Panel Replacement Page 473 Symbol Identification Wire Color Code Identification WIRE COLOR ABBREVIATION BLACK BLK BLUE BLU DARK BLUE DK BLU Page 2836 FIGURE 1(T-TRUCK ONLY) G. (T-truck only) Check equalizer lever for firm contact at the shift lever inboard side of the guide slot. (See Figure 1) H. If firm contact is evident, add an additional washer (#10 in Figure #1) P/N 14074908 to adjust equalizer lever outboard toward the center of the guide slot to eliminate contact. 2. A. Raise vehicle on hoist. B. Note location of clamp rotation on pipe. Some clamps are located with the lower lock ring (nuts) pointed towards the transmission. If the clamp is located in such a manner, loosen clamp and rotate it down so the nuts point toward the ground and retighten to 58 N-m (43 ft/lbs.) 3. A. Loosen converter clamp until it will rotate around the pipe. Using a suitable pry bar, move exhaust system rearward to obtain a minimum of 5/8 in. clearance between any point on the exhaust system and the transmission crossmember. For repairs performed under warranty, use the following labor operations and times: Labor Operation Labor Time Exhaust/muffler clamp L2020 .3 Hr Exhaust system align L2004 .3 Hr Shift Linkage (shorten) K5244 .3 Hr Page 2338 Manifold Pressure/Vacuum Sensor: Service and Repair Fig. 337 MAP Sensor Removal (V6 Models Similar) The MAP sensor unit is not serviceable and must be replaced as a unit. 1. Disconnect vacuum hose from MAP sensor, then remove top of air cleaner assembly. 2. Remove MAP sensor unit retaining clip, then the sensor, Fig. 337. 3. Reverse procedure to install. Page 4400 Mainshaft: Specifications Warner 83 mm 4 Speed Main drive gear bearing retainer bolts ................................................................................................. ................................................................... 18 ft. lbs. Page 1409 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 Page 2694 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 Page 598 14. With engine at normal operating temperature (85-100 degrees C), adjust stop screw to obtain nominal rpm per specifications with seated IAC valve. 15. Turn ignition "OFF" and reconnect IAC valve electrical connector. 16. Disconnect "Scan" tool or tachometer. 17. Use silicon sealant or equivalent to cover stop screw hole. 18. Install air cleaner, adapter and gasket. 19. On 2.5L engines, clear Code 35 that has been set. 1987 AND 1988 MODEL YEAR TRUCKS CONTROLLED IDLE SPEED 1987 AND 1988 MODEL YEAR TRUCKS MINIMUM IDLE AIR RATE Page 721 Drive Belt: Service and Repair Fig. 20 Serpentine Drive Belt Routing 1. Remove belt tensioner pulley retaining bolt. 2. Remove belt tensioner pulley. then the belt. 3. Reverse procedure to install, refer to Fig. 20 for belt routing. Page 7715 Figure 4 Figure 5 Figure 6 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 7 Detonation Sensor LH Rear Of Engine, At Rear Of Cylinder Head With A-6 Compressor Compressor Clutch: Service and Repair With A-6 Compressor Clutch Plate and Hub Assembly Remove or Disconnect Tools Required: J 9396 Compressor Holding Fixture J 9399 Compressor Shaft Nut Socket J 9401-A Hub Drive Plate Remover J 25030 Clutch Hub Holding Tool ^ Clamp J 9396 in a vise. Removing The Shaft Nut ^ Compressor to J 9396. Secure with thumb screws. 1. Shaft nut (1) with J 9399. ^ Hold the clutch plate and hub assembly (2) with J 25030. Page 4895 For more information on how to use a disc brake micrometer see Fundamentals and Basics. See: Fundamentals and Basics PARALLELISM Parallelism is the measurement of the thickness of the rotor at 12 or more points around the circumference of the rotor. All measurements must be made at the same distance in from the edge of the rotor. Lack Of Parallelism Lack Of Parallelism The rotor thickness must not vary more than 0.013 mm (0.0005-inch) from point to point. Page 1024 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) 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. Backup Lamps/Tailgate Window Release - Inoperative Backup Lamp Switch: All Technical Service Bulletins Backup Lamps/Tailgate Window Release Inoperative Number: 91-459-8A Section: 8A Date: DEC. 1991 Corporate Bulletin No.: 168104 ASE No.: A6 Subject: BACKUP LAMPS OR TAILGATE WINDOW RELEASE INOPERATIVE Model and Year: 1980-91 ALL LIGHT DUTY TRUCKS (EXCEPT GEO) Owners of some 1980-1991 C/K, 1982-1991 G, 1985-1991 M/L, 1984-1991 P2,P3, 1987-1991 R/V, 1983- 1991 ST (including LLV) with automatic transmissions may comment on a condition of inoperative back-up lamps or inoperative tailgate window release. This condition occurs when the vehicle's gear shift lever is placed in the "reverse" position, but the back-up lamps do not illuminate. In addition, on the S/T utility vehicles, the electric tailgate window release does not release when the transmission gear shift lever is placed in the "park" or "neutral" position and the endgate window release button is depressed. The park/neutral and back-up lamp switch comes out of adjustment which does not allow for the contact points to remain engaged. To correct these conditions, the contact carrier on the park/neutral and back-up lamp switch has been modified to increase switch carrier travel. SERVICE PROCEDURE: 1. Disconnect the battery ground cable from the battery. 2. Disconnect the switch assembly harness. 3. Place the gear selector in neutral. 4. Squeeze the tangs on the switch together and remove the switch assembly. 5. Install the new switch assembly (P/N 15679680) by: -aligning the actuator with the cutout in the steering column jacket. -inserting the tangs into the rectangular holes and pushing down on the switch assembly. 6. Adjust the switch by moving the gear selector to park. 7. Connect the switch assembly harness. 8. Connect the negative battery cable. 9. Check for proper switch operation. Readjust the switch as necessary. Page 2511 Coolant Temperature Sensor/Switch (For Computer): Service and Repair The coolant sensor must be handled carefully. If sensor is damaged, fuel injection operation will be affected. 1. Disconnect battery ground cable. 2. Drain coolant from radiator so level is below sensor. 3. Disconnect coolant sensor electrical connector. 4. Carefully back out coolant sensor and remove. 5. Reverse procedure to install. Page 4288 Figure 9 - Disconnecting the Upper Ball Joint 17. Tip the knuckle out and toward the rear of the vehicle. Suspend the knuckle to prevent straining the brake line (Figure 9). Important: Cover the shock mounting bracket and the ball stud on the lower control arm with a shop towel to prevent possible halfshaft seal damage during removal and installation. Figure 8 - Splined Shank and Knuckle Separation 18. Install J28733 on brake rotor and separate outer C/V joint splined shank from knuckle hub (Figure 8). Figure 3 - Inboard Flange Bolt Removal 19. Remove six bolts (loosened earlier) from inboard joint flange (Figure 3). 20. Support inboard end of halfshaft. Free splined shank from hub and remove halfshaft from vehicle. Important: Wipe the wheel bearing seal area on the knuckle clean. Check the seal for cuts or tears. Page 1803 Note The rivet stud and surrounding panel area MUST BE properly refinished PRIOR to the installation of the electrical ground wire terminal and conductive nut to maintain a secure, stable and corrosion-free electrical ground. 11. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 12. Allow the refinished repair area to cure sufficiently before removing the protective material applied to the rivet stud threads. 13. Remove the painters tape or equivalent from the rivet stud threads. 14. Using GM approved residue-free solvent or equivalent, thoroughly clean the rivet stud threads to remove any adhesive and allow to dry. 15. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive rivet stud. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 16. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 17. Install the electrical ground wire terminal to the M6 conductive rivet stud. 18. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 19. Install the M6 conductive nut to the rivet stud and: Tighten Tighten to 8 Nm (71 lb in) 20. Verify proper system operation. Parts Information Warranty Information (excluding Saab Models) For vehicles repaired under warranty, use: Warranty Information (Saab Models) Page 3875 FIGURE 2 - THM 700-R4 WIRING DIAGRAM DATE OF PRODUCTION CHANGE: (Figure 1) On April 20, 1988 (Julian Date 111), the 1988 THM 700-R4, THM and TLM models were built with the new Type 18 Solenoid Assembly and Wiring Harness. Beginning May 9, 1988 (Julian Date 130), the remaining 1988 THM 700-R4 models listed above were built using the new Type 18 Solenoid Assembly. SERVICE NOTES: Any 1988 THM 700-R4 transmission models built with the Type 18 Solenoid Assembly, refer to models and Julian Dates listed above, must be serviced with the Type 18 Solenoid Assembly and Wiring Harness Complete listed under "Service Parts Information". Any 1988 THM 700-R4 transmission model built with a Type 15 Solenoid Assembly may be serviced with the new Type 18 assembly; however, there will be no wire connection for the 4-3 pulse switch. The 4-3 pulse switch, which can be left installed, will then function as a plug. SERVICE PARTS INFORMATION: Part No. Description 10478100 Type 18 Solenoid Assembly - Complete 8654415 Type 15 Solenoid Assembly - Complete Parts are currently available from GMSPO. SERVICE MANUAL REFERENCE: Please update the 1988 THM 700-R4 Hydraulic Diagnosis section of your service manual accordingly. Page 3297 SERVICE PARTS INFORMATION Part Number Description 15664811 Vacuum Actuator Switch Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: K4120 Use applicable labor time guide for labor hours. Page 5568 Warranty Information (excluding Saab U.S. Models) For vehicles repaired under warranty, use the appropriate labor operation for the source of the water leak Warranty Information (Saab U.S. Models) For vehicles repaired under warranty, use the table. Disclaimer Engine - Serpentine Belt, Worn Idler/Tensioner Pulley Drive Belt Tensioner: Customer Interest Engine - Serpentine Belt, Worn Idler/Tensioner Pulley Number: 89-260-6A Section: 6A Date: September 1989 936204 Corporate Bulletin No.: Subject: SERPENTINE BELT WITH WORN IDLER PULLEY OR TENSIONER Model and Year: 1987-89 C, K, R, V, S, T TRUCKS AND M, G VANS WITH 4.3L, 5.0L, 5.7L, 7.4L (VIN CODE Z, H, K, N) ENGINES TO: ALL CHEVROLET DEALERS Some 1987-89 light-duty trucks with 4.3L, 5.0L, 5.7L, and 7.4L engines and equipped with serpentine belt drive may experience a condition where the belt becomes loose and squeals or the belt may come off the engine drive pulleys. This condition may be caused by a worn idler and/or worn belt tensioner pulley (plastic). If this condition exists, the following procedures may be used to repair this condition: IDLER PULLEY ONLY: 1. Using procedures in Section 6B-Engine Cooling, remove and discard the serpentine belt. 2. On trucks with 4.3L, 5.0L, and 5.7L engines, replace the existing idler pulley with a new metal pulley, P/N 10129560. On trucks with 7.4L engines, replace the existing pulley with P/N 10129561. Parts are expected to be available on October 9, 1989. Until then normal part orders will not be accepted by GMSPO. Only verifiable emergency VIP orders will be accepted. SPO will make every effort to obtain parts. All parts will be placed on 400 control to waive VIP surcharges. However, the part will be shipped premium transportation at dealer's expense. All other order types will be canceled as incorrectly ordered while the 400 control is in place. 3. Install new serpentine belt. Page 3424 [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. Page 4274 - 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.). Page 2305 Coolant Temperature Sensor/Switch (For Computer): Service and Repair The coolant sensor must be handled carefully. If sensor is damaged, fuel injection operation will be affected. 1. Disconnect battery ground cable. 2. Drain coolant from radiator so level is below sensor. 3. Disconnect coolant sensor electrical connector. 4. Carefully back out coolant sensor and remove. 5. Reverse procedure to install. Engine - Drive Belt Misalignment Diagnostics Drive Belt: All 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. Page 7076 Page 1074 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 Page 581 Thrust Angle Description WHEEL ALIGNMENT DEFINITIONS Wheel alignment refers to the angular relationship between a vehicles wheels, suspension attaching points, and the ground. Vehicles with properly aligned front and rear suspensions handle predictably, and provide good straight line stability on the highway with minimal tire wear. In real world driving conditions, wheel alignment settings change over time due to suspension component wear or damage; they must be periodically checked and adjusted as necessary. TOE IN/OUT Toe is a measure of how far a wheel is turned in or out from the straight ahead direction. When the front of a wheel is turned in, the toe is positive. When turned out, the toe is negative. CAMBER Camber is a measure of wheel tilt from the vertical direction, when the wheel is viewed from the front or rear of the vehicle. Camber is negative when the top of the wheel tilts inward and positive when the top of the wheel tilts outward. CASTER Caster is a measure of the angle between the steering axis and vertical when viewed from the side of the vehicle with the wheel in the straight ahead position. The steering axis is determined by the location of the lower control arm ball joint and the center of the strut-to-body attachment. A line drawn through the center of the ball joint and the strut-to-body joint represents the steering axis. When the center point of the strut-to-body attachment is rearward of the ball joint, the caster is positive. When the center of the strut-to-body attachment is forward of the ball joint, the caster is negative. THRUST ANGLE Thrust angle is the angle between the geometric centerline of the vehicle and the direction that the rear wheels track. Ideally, the thrust angle is equal to zero. Diagram Information and Instructions Trailer Adapter Kit: Diagram Information and Instructions 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 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. Page 6296 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 Removal Notes Brake Caliper: Fundamentals and Basics Removal Notes When Removing the Caliper, Remember... - Prior to removing the calipers, remove/siphon brake fluid from master-cylinder until the reservoir is only 1/3 full. - Brake fluid will remove paint and damage electrical connections. Use a drip pan and fender covers to protect the vehicle's finish and electrical system. - Always replace all brake linings on an axle. Never replace only one wheel. Unequal lining thickness between wheels on the same axle will result in a strong steering pull when the brakes are applied. - Work on one side at a time. If you forget how to reassemble the parts you can always use the other side as a model. - When forcing the piston back into the caliper, open the bleeder valve first. Corrosion and other deposits accumulate inside of the caliper. If the bleeder valve is not opened when the piston is forced back into the caliper, these deposits will be forced back through the brake lines and into the master-cylinder. When pushing the pistons back into the caliper with the bleeder screw open, a stream of brake fluid will be expelled from the bleeder screw for 2-3 feet. Use a drip pan and be careful not to "shoot" brake fluid onto the vehicle's finish. A cleaner method is to use a piece of clear plastic hose and a glass or plastic jar to catch the expelled fluid. - Upon removal, Do Not allow the calipers to hang by the flexible brake hoses. The brake hoses can be damaged easily by this practice. These hoses are double walled, damage to the interior pressure hose will not be visible. - Do not depress the brake pedal with either caliper removed from the rotor. The caliper pistons will be inadvertently expelled from the caliper. If this occurs rebuild or replace the caliper, do not attempt to insert the piston back into the caliper. Tires - Proper Rotation and Warranty Coverage Tires: All Technical Service Bulletins Tires - Proper Rotation and Warranty Coverage GMC NUMBER: 88-T-66 GROUP: 3E - Wheels & Tires DATE: December, 1987 CORPORATE NUMBER: 893504R SUBJECT: GM DEALER'S RESPONSIBILITY CONCERNING TIRE WARRANTIES, INCLUDING IRREGULAR/PREMATURE WEAR MODELS: ALL LIGHT DUTY TRUCKS As in the past, tires continue to be warranted by the tire manufacturer against defects in material or workmanship. Details of this limited warranty may be found in each tire company warranty booklet, which is part of the glove box material. The GM Warranty and Owner Assistance Booklet also now states that the GM dealer will assist the customer in obtaining a tire adjustment if necessary. Tire conditions caused by vehicle defects are warranted by General Motors. This statement is now included in the GM Warranty and Owner Assistance Booklet. This applies during the basic coverage period, which is 12 Months/ 12,000 Miles, and should be applied to all past and current models. Examples of tire conditions that fall within GM's responsibility may include tire damage during vehicle assembly, tire damage due to tire-to-vehicle interference, and irregular/premature tire wear. Tire wear due to abusive driving is not covered by warranty. FIGURE 1 Page 7768 Headlamp Switch: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. Figure 21 Figure 22 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. Page 2907 Accelerator Controls: Service and Repair ACCELERATOR PEDAL: When performing service on the accelerator pedal, observe the following: Accelerator Pedal Assembly Control Cable And Linkage ^ 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 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. Page 4940 Brake Shoe: Fundamentals and Basics Notes, Warnings, and Hints PRIOR TO REMOVING THE SHOES - Clean the shoes, hardware, and backing-plate thoroughly for the following reasons. Initially the springs will appear black (from brake dust). The springs are actually color coded and it is very important to reinstall the springs in the correct location. - The shoes and hardware will need to be cleaned to determine if an overheating condition has occurred (discolored bluish-purple). - Inhaling brake dust is VERY HAZARDOUS TO YOUR HEALTH. WARNING: Do not use compressed air to clean the brake assembly. - Verify the Leading and Trailing shoes are installed in the correct relationship. - Verify the new brake components exactly match the old ones. DURING REMOVAL - If there is any possibility that the shoes may reused, remove any drip pans that may be under the brake assembly and handle the shoes carefully when removing. NOTE: WORK ON ONE SIDE AT A TIME (unless you are very familiar with the system). The other side may then be used as a model for reassembling. INSTALLATION - Clean and lubricate the backing-plate contact pads with a high temperature silicone lubricant. 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 Cowl - Popping/Tapping Noise Cowl: All Technical Service Bulletins Cowl - Popping/Tapping Noise Number: 91-351-10 Section: 10 Date: JUNE 1991 Corporate Bulletin No.: 162001R Subject: COWL "POP"/TAPPING NOISE Model and Year: 1983-91 S/T TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 86-58, DATED APRIL 1986. THE SERVICE PROCEDURE HAS BEEN UPDATED AND THE 1987-91 MODEL YEARS ADDED. ALL COPIES OF 86-58 SHOULD BE DISCARDED. Some 1983-1991 S/T pickup and utility vehicles may experience a "popping" noise from the cowl area (at the base of the "A" pillar in front of the speaker grills). The sound may emanate from either side of the vehicle. The exact cause of this condition is currently unknown. Cowl "pop" is defined as a tapping noise at the lower corner of the windshield or base of the "A" pillar that usually, but not always, occurs when the vehicle is cold (below 45 degrees F). The sound is simiiar to the noise made when tapping a pencil point on the windshield. Some success has been achieved in correcting this condition by trimming areas of hood flange that may contact the cowl vent panel, by relieving any stress that may be created by the front fender mounting sequence, and by loosening the # 1 body mount and/or shimming one or both front body mounts. SERVICE PROCEDURE: NOTE: Typically this condition occurs only when the vehicle sheet metal is at a temperature below 45 degrees F. The condition may temporarily disappear if vehicle evaluation is performed after a vehicle has been in a warm environment. REMOVAL OF HOOD FLANGE MATERIAL: Some ST vehicles experiencing a cowl "pop" tapping noise may be corrected by trimming the back edge of the hood flange. On a small number of vehicles, excess material on the rear edge of the hood flange contacts the front of the cowl vent panel causing a tapping noise when the vehicle goes over a bump. 1. Visually inspect for witness marks in the painted area of the cowl vent panel to determine if the hood flange contacts any cowl panel surfaces. 2. If witness marks are not present, it is not necessary to perform Steps 3 and 4. Continue to "Relieving Fender Mounting Stress" Section. If witness marks are present, trim off approximately 1/8" of the hood flange only in the areas contacting the cowl vent panel using Jilson Tool 1451 SS or equivalent. 3. Refinish the bare metal on the trimmed areas and on matching cowl vent panel areas to prevent corrosion. RELIEVING FENDER MOUNTING STRESS: Some success has been achieved in correcting the cowl "pop" tapping condition by relieving the stress caused by the front fender mounting sequence. 1. Remove windshield wiper arms using Kent-Moore Tool J-8966 Remover and Installer, or equivalent. 2. Remove cowl vent panel assembly. 3. Loosen the four rear fender mounting bolts to zero torque. (One of the upper fender mounting bolts is located underneath the hood hinge seal.) 4. Retorque the two lower fender bolts to 20-34 N-m (15-25 Lbs.Ft.). 5. The upper hinge mounting bolt should be left at zero torque. Apply Loctite 242 thread locking compound (GM P/N 12345382), or equivalent, to hold in place. Retorque the remaining upper fender bolt to 20-34 N-m (15-25 Lbs.Ft.). 6. Reinstall cowl vent panel assembly and windshield wiper arms. Page 4224 Parts Information Parts are currently available from GMSPO. Body - Polypropylene Energy Absorber Replacement Rear Bumper Reinforcement: Technical Service Bulletins Body - Polypropylene Energy Absorber Replacement Bulletin No.: 07-08-63-001 Date: April 17, 2007 INFORMATION Subject: Information on Repair of Polypropylene Energy Absorbers Models: 2007 and Prior GM Passenger Cars and Trucks (including Saturn) 2007 and Prior HUMMER H2, H3 2005-2007 Saab 9-7X Supercede: This bulletin is being revised to change the repair information. Please discard Corporate Bulletin Number 63-20-02 (Section 8 - Body and Accessories). Because the energy absorbers are relatively low in cost to replace, it is now more cost efficient to replace the energy absorbers whenever they are damaged. Disclaimer Page 3418 [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. 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. Page 1685 Oil Pressure & Temperature Gauge (Gauges Cluster) Engine Controls - ECM May Contain Wrong PROM PROM - Programmable Read Only Memory: All Technical Service Bulletins Engine Controls - ECM May Contain Wrong PROM Number: 88-42 Section: 6E Date: Sept., 1987 Subject: SERVICE REPLACEMENT ELECTRONIC MODULES (ECM) WITH PROM INSTALLED Model and Year: 1981-88 ALL MODELS TO: ALL CHEVROLET DEALERS It has been brought to our attention that some service replacement electronic control modules (ECM's) have contained a PROM. A PROM should not have been included in a replacement ECM as it may not be the correct PROM for the vehicle. When this situation is encountered, the PROM should be removed from the replacement ECM and the PROM from the vehicle should be installed. Transfer Case - High Shift Effort When Shifting Fluid - Transfer Case: Customer Interest Transfer Case - High Shift Effort When Shifting Number: 91-165-7A Section: 7A Date: January 1991 Corporate Bulletin No.: 967402R Subject: HIGH TRANSFER CASE SHIFT EFFORT Model and Year: 1983-91 T1 TRUCKS 1988-91 K TRUCKS TO: ALL CHEVROLET DEALERS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 91-128-7A, DATED NOVEMBER 1990. THE BULLETIN NUMBER HAS BEEN CORRECTED IN THE FIRST PARAGRAPH. ALL COPIES OF 91-128-7A SHOULD BE DISCARDED. Some four wheel drive K and T trucks may experience high transfer case shift effort and/ or total blockouts when "SHIFTING ON THE FLY" from 2H to 4H under cold weather conditions (usually 25 degrees or less). In order to shift to 4H the speed of the front propshaft must be increased to allow proper engagement of front axles. As the transfer case shift lever is moved into 4H the front propshaft begins rotating to synchronize the front axle assembly. In cold weather conditions regular production lube has high viscosity which may delay or prohibit the synchronizing of the front propshaft and axle resulting in high transfer case shift effort. To reduce high shift effort, regular production front axle gear lube may be replaced with a 75W-90 synthetic gear lube which maintains a lower viscosity under cold weather conditions. This synthetic gear lube is now available in one quart containers from GMSPO. Before installing, it is important to drain and flush the front axle with clean mineral based (non synthetic) axle lube. The front axle should then be refilled to the level of the filler hole with synthetic lube listed below. Front Axle Lube Capacities: K1, K2 - 1.66 liter (1.75 qts) K3 - 2.13 Liter (2.2 qts) T1 - 1.20 liter (1.3 qts) SERVICE PARTS INFORMATION P/N DESCRIPTION 12345836 SAE 75W-90 synthetic gear lube, 1 qt. bottle Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation Number: T7980 Labor Time: .4 hr Trouble Code: 92 NOTE: Labor Operation is coded to base vehicle coverage in the warranty system. Turbo Hydra-Matic 3L30 (180C) Fluid - A/T: Testing and Inspection Turbo Hydra-Matic 3L30 (180C) Check fluid at regular intervals. Noticing a change in color, odor or fluid level can serve as a warning of possible transmission problems. To check fluid level, bring fluid to operating temperature of 200°F. With vehicle on a level surface and engine idling in Park and parking brake applied, the level on the dipstick should be at the Full mark. To bring the fluid level from the Add mark to the Full mark requires one pint of fluid. If additional fluid is required, use only Dexron II or Dexron IIE automatic transmission fluid. When adding fluid, do not overfill, as foaming and loss of fluid through the vent may occur as the fluid heats up. Also, if fluid level is too low, complete loss of drive may occur especially when cold, which can cause transmission failure. The oil should be drained, the oil pan removed, the screen cleaned and fresh fluid added every 30,000 miles for trucks under 8600 lbs. GVWR or every 24,000 miles for vehicles over 8600 GVWR. For vehicles subjected to more severe use such as heavy city traffic especially in hot weather, prolonged periods of idling or as a tow vehicle this maintenance should be performed every 15,000 miles for trucks under 8600 GVWR, or every 12,000 miles for trucks over 8600 GVWR. Page 3531 Bell Housing: Specifications THM180 & 180 C Automatic Trans Application ........................................................................................................................................... ................................................................... Ft. Lbs. Lower Cover To Converter Housing: 180 ............................................................................................ .................................................................................................................................. 8-12 180C ......... .............................................................................................................................................................. ........................................................ 15 Converter Housing To Cylinder Block ................................... ...................................................................................................................................... 20-30 Converter Housing To Case ................................................................................................................ .......................................................................... 24-26 Converter Housing To Oil Pump .................... .............................................................................................................................................................. 13-15 Page 2313 Center Of Dash Panel (engine Compartment) Page 1823 Intake Manifold Gasket: Technical Service Bulletins Intake Manifold Gasket - Correct Installation GMC NUMBER: 90-T-02 GROUP: 6A - Engine Mechanical DATE: June, 1989 CORPORATE NUMBER: 966104 SUBJECT: CORRECT INTAKE MANIFOLD GASKET INSTALLATION MODELS: 1987-90 LIGHT DUTY TRUCKS WITH 4.3L, 5.0L, 5.7L TBI FUEL INJECTED ENGINES (VIN CODES Z, H, AND K) Electrical Connectors - Service Procedure Multiple Junction Connector: All Technical Service Bulletins Electrical Connectors - Service Procedure Number: 91-85-8A Section: 8A Date: October 1990 Corp. Bulletin No.: 018115 Subject: PROCEDURE FOR CHECKING CONNECTOR TERMINAL CONTACT Model and Year: 1982-91 PASSENGER CARS AND TRUCKS Figure 1 TO: ALL CHEVROLET DEALERS Locations Brake Fluid Pressure Sensor/Switch: Locations LH Side Of Engine Compartment At Master Cylinder Page 1455 Compression Check: Testing and Inspection COMPRESSION CHECK - Disconnect the primary terminal from the ignition coil. - Remove all spark plugs. - Block the throttle plate wide open. - Make sure the battery is fully charged. Starting with the compression gauge at zero, crank the engine through four compression strokes (four "puffs"). - Make the compression check at each cylinder and record each reading. - If some cylinders have low compression, inject 15 ml (one table spoon, or 3 squirts from a pump type oil can) of engine oil into the combustion chamber through the spark plug hole. - Minimum compression recorded in any one cylinder should not be less than 70 percent of the highest cylinder, and no cylinder should read less than 690 kPa (100 psi). Normal Compression: Compression builds up quickly and evenly to specified compression on each cylinder. Piston Rings Leaking: Compression low on first stroke, tends to build up on following strokes, but does not reach normal. Improves considerably with addition of oil. Valves Leaking: Low on first stroke. Does not tend to build up on following strokes. Does not improve much with addition of oil. Head Gasket Leakage: If two adjacent cylinder have lower than normal compression, and injecting oil into cylinders does not increase the compression, the cause may be a head gasket leak between the cylinders. Page 179 Engine Control Module: Component Tests and General Diagnostics Chart C-9A - ECM QDR Check Procedure Checking Control Module For Bad Solder Joints Some control module's 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 Differential - Growl Noise Differential Axle Housing: All Technical Service Bulletins Differential - Growl Noise Number: 8-416-4C Section: 4C Date: May, 1989 Subject: FRONT AXLE GROWL NOISE Model and Year: 1983-88 T1 TRUCKS Figure 1 TO ALL CHEVROLET DEALERS: Beginning with start of production 1989, the material in the thrust washers in the front axle tube of T Model Trucks was changed to reduce thrust washer wear. The washers involved are # 7, # 20 and # 24 as shown in Figure # 1. When worn, the metal in the washer will be smeared from slipping. Number 24 may also be dished. Page 6183 Removing The Shaft Seal With J 23128-A ^ Engage J 23138-A into the recessed portion of the seal by turning with a hand motion. ^ Lift the seal with a rotary-pulling motion. Removing And Installing The Shaft Seal 4. Seal (O-ring) (13) with J 9553-01. Install or Connect Tool Required: J 33011 "O" Ring Installer Installing The Seal 1. Seal (O-ring) (14) to the shaft (22). 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 Page 1036 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 Page 5948 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. Brakes (ABS) - 'False' or Dropping Pedal Hydraulic Control Assembly - Antilock Brakes: All Technical Service Bulletins Brakes (ABS) 'False' or Dropping Pedal Bulletin No. 24 Date November, 1982 Vehicle Make/Model DODGE, FORD and GENERAL MOTORS TRUCKS Equipped with Rear Anti-Lock Brake Systems Ford: RABB (Rear Anti-Lock Brake System) GM & Dodge: RWAL (Rear Wheel Anti-Lock) Topic False or Dropping Pedal Some of the above mentioned vehicles may experience a "false" or dropping pedal condition that may feel very similer to a master cylinder with an excessive amount of by-pass. Upon installation of the replacement master cylinder, there is little or no improvement in pedal feel or height, This condition may be caused by the dump valve in the E-H (Electro Hydraulic) valve being held slightly open by a small particle of foreign material. This allows fluid to flow into the accumulator and create the low or dropping brake pedal. To determine if this is the cause of the dropping pedal, begin by disconnecting the steel line at the master cylinder that serves the rear brakes. Install a solid tubing plug into the outlet that serves the rear brakes. Note: When installing the plug, have an assistent depress the pedal about one inch to purge any air from the outlet. Tighter, the plug while the assistant holds the pedal in this position. After tightening the plug, continue to apply pressure to the pedal. This will prevent damage to the primary cup in the master cylinder as the cup moves across the vent port. If the pedal no longer drops as it did with the rear brakes connected, this would indicate that the problem is in the rearbrakes and not the master cylinder. The next step would be to block off the outlet port of the E-H valve and retest the brake pedal as done previously. If the dropping pedal reappears, the problem is in the E-H valve and most likely caused by fluid leaking into the accumulator of the E-H valve. If this is the case, it will be necessary to change the valve. The E-H valve, including the accumulator and valving, is not serviceable. Note that brake fluid over a period of time absorbs contaminants, therefore, annual flushing and replacement with clean, fresh brake fluid will help to prevent this condition from occurring. A/T TCC - MIL ON/False Code 32 Set Diagnostics Torque Converter Clutch Solenoid: Technical Service Bulletins A/T TCC - MIL ON/False Code 32 Set Diagnostics Number: 91-149-6E Section: 6E Date: January 1991 Corporate Bulletin No.: 066502R Subject: "SERVICE ENGINE SOON" LIGHT POSSIBLE FALSE CODE 32 Model and Year: ALL 1987-91 TRUCKS WITH 4L60 AUTOMATIC TRANSMISSION (700-R4) TO: ALL CHEVROLET DEALERS Some 1987-91 light duty trucks equipped with 4L60 transmissions may experience a possible false Code 32 - EGR System Malfunction. The customer may not experience a change in performance or driveability with a Code 32 set. If normal EGR diagnostics do not reveal the cause for Code 32, the following steps should be taken to correct the condition: Check the TCC (Torque Converter Clutch) engagement solenoid/wiring harness for a short-circuit. 1. Disconnect the TCC harness connector from the left side of the transmission. 2. Measure resistance between TCC transmission connector terminals "A" and "D" with a Digital Volt Ohmmeter (DVOM). Solenoid resistance must measure 20 - 25 ohms at 20 degrees C (68 degrees F). Resistance will be slightly higher if the transmission is at operating temperature. If the resistance is less than 20 ohms the TCC solenoid diode or wiring is shorted and the solenoid must be replaced. 3. With key on, using a DVOM check for voltage at pin "D" of the TCC wiring harness. Voltage greater than one volt should not be found. If voltage exceeding one volt is present, circuit 422 is shorted to voltage and the short must be repaired. Refer to the appropriate service manual for circuit 422 diagnosis and repair. Test operation of the TCC through the use of a scan tool connected to the vehicle ALDL connector. The following conditions must be satisfied when testing TCC operation. ^ Clear stored trouble codes. ^ Engine at normal operating temperature (above 65 degrees C, 149 degrees F) and in closed loop. ^ Constant throttle position. TPS voltage = 1.3 V (minimum = 1.1 V, maximum = 1.5 V). ^ Vehicle speed = 45 mph (minimum = 35 mph, maximum = 55 mph). ^ Brake switch closed (brake pedal not applied). ^ 3rd or 4th gear. Confirmation The scan tool will display the ECM command for TCC engagement when the above conditions are satisfied. When the TCC engages there should be a decrease in engine speed by a minimum of 100 RPM. If TCC operation is normal, it is not necessary to replace the solenoid assembly. After verification of TCC operation, check for stored trouble codes. If TCC fails to engage consult Section 10, Transmission Controls located in Fuel and Emissions Manual and section 7A of the appropriate service manual. Diagram Information and Instructions Headlamp Switch: Diagram Information and Instructions 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 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. Page 7818 Figure 4 Figure 5 Figure 6 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 7 Page 4168 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: Adjustments Ride Height Sensor: Adjustments When repair or adjustment procedures require that vehicle be raised on a hoist, it is important that the rear axle assembly remains in the normal trim height position at all times. When a frame contact hoist is used, two additional jack stands should be used to support the rear axle or control arms in the normal trim height position. Fig. 21 Adjusting Height Sensor The link should be properly attached to the sensor arm and track bar, when making this adjustment. 1. Loosen lock bolt that secures metal arm to height sensor plastic arm, Fig. 21. 2. To raise vehicle trim height, move plastic arm upward and tighten lock bolt. If no adjustment remains, refer to FRONT SUSPENSION/SPECIFICATIONS/VEHICLE TRIM HEIGHT. 3. To lower vehicle trim height, follow step 1 and move plastic arm down. 4. If adjustment cannot be made, check for correct sensor. Page 7585 Oil Pressure Gauge: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. Figure 21 Figure 22 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. Page 3584 Page 3718 A new pressure regulator valve (III. 218) has been made which will improve the oil pressure stability at lower RPM. SERVICE PARTS INFORMATION: Description Part Number Valve, Pressure Regulator (III. 218) 8684048 Part numbers are for Reference Only. Check with your Parts Department for latest information. Page 3453 Shift Solenoid: Specifications 4L60 - 700R4 Transmission Pressure Control Solenoid To Valve Body .............................................................................................................................................................. 8 ft. lbs. Solenoid Assembly To Case .................................................................................................. .................................................................................. 18 ft. lbs. Solenoid Assembly To Pump ............ .............................................................................................................................................................. .......... 8 ft. lbs. Page 5604 Frame Angle Measurement (Express / Savana Only) ........ 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 Page 6394 Refrigerant Pressure Sensor / Switch: Service and Repair High-Side-High Pressure Cut Off Switch R-4 COMPRESSOR R-4 Compressor Component View Remove or Disconnect Tools Required: J 5403 Snap Ring Pliers J 9553 O-Ring Remover 1. Protective cap (28). 2. Retainer ring (27) with J 5403. 3. Valve (26). 4. Seal (25) with J 9553-01. Clean ^ Remove any dirt from the valve cavity. Install or Connect 1. New seal (O-ring) (25) to the cavity. ^ Dip the new seal in clean 525 viscosity refrigerant oil. 2. Pressure relief valve (26). 3. Retainer ring (27) with J 5403-A. 4. Cap (28). Page 4648 T7251 Group A 3.2 hr. T7261 Group B 2.8 hr. NOTE: Labor Operation is coded to base vehicle coverage in the warranty system. Capacity Specifications Fluid - Differential: Capacity Specifications Standard & Locking.............................................................................................................................. ................................................80W, 80W-90*, GL-5 *For vehicles normally operated in Canada, 80W only CAPACITY, Refill: Front- Astro, Safari, Bravada.................................................................. ...............................................................................................1.7 Liters 3.5 Pints Front- S-series........ .............................................................................................................................................................. ..................1.2 Liters 2.6 Pints Rear- Bravada..................................................................................... ....................................................................................................1.7 Liters 3.5 Pints Rear- Astro, Safari, S-Series.................................................................................................................................... ...........................1.9‡ Liters 3.9‡ Pints ‡Fill to 3/8" (9.5 mm) below fill plug hole Page 2406 Man. N 500-550 2-12 CL Auto D 500-550 2-20 CL [1] Add 2 counts for engines with less than 500 miles. Add 2 counts for every 1000 ft. above sea level. [2] Let engine idle until proper fuel control status is reached (OPEN/CLOSED LOOP). MINIMUM IDLE AIR RATE Transmission Gear Engine Speed OPEN/CLOSED LOOP [1] Man. N 450 +/- 50 CL Auto. N 475 +/- 50 CL [1] Let engine idle until proper fuel control status (OPEN/CLOSED LOOP) is reached. Page 1736 Oil Pressure Gauge: Testing and Inspection Gauge Reads ``0'' 1. Check oil level, add if necessary. 2. Remove oil pressure sensor lead at sensor, gauge should read ``80.'' 3. If gauge stays at ``0'' remove sensor lead at gauge, gauge should read ``80.'' If gauge reads ``80'' find short to ground between gauge and sensor. 4. If gauge still reads ``0'' replace cluster. 5. With lead removed at sensor, connect a suitable ohmmeter to sensor. With engine stopped resistance should be one ohm, and approximately 44 ohms with engine running. 6. If sensor reads one ohm with engine running, replace sensor. Backup Lamps/Tailgate Window Release - Inoperative Shift Interlock Switch: All Technical Service Bulletins Backup Lamps/Tailgate Window Release Inoperative Number: 91-459-8A Section: 8A Date: DEC. 1991 Corporate Bulletin No.: 168104 ASE No.: A6 Subject: BACKUP LAMPS OR TAILGATE WINDOW RELEASE INOPERATIVE Model and Year: 1980-91 ALL LIGHT DUTY TRUCKS (EXCEPT GEO) Owners of some 1980-1991 C/K, 1982-1991 G, 1985-1991 M/L, 1984-1991 P2,P3, 1987-1991 R/V, 1983- 1991 ST (including LLV) with automatic transmissions may comment on a condition of inoperative back-up lamps or inoperative tailgate window release. This condition occurs when the vehicle's gear shift lever is placed in the "reverse" position, but the back-up lamps do not illuminate. In addition, on the S/T utility vehicles, the electric tailgate window release does not release when the transmission gear shift lever is placed in the "park" or "neutral" position and the endgate window release button is depressed. The park/neutral and back-up lamp switch comes out of adjustment which does not allow for the contact points to remain engaged. To correct these conditions, the contact carrier on the park/neutral and back-up lamp switch has been modified to increase switch carrier travel. SERVICE PROCEDURE: 1. Disconnect the battery ground cable from the battery. 2. Disconnect the switch assembly harness. 3. Place the gear selector in neutral. 4. Squeeze the tangs on the switch together and remove the switch assembly. 5. Install the new switch assembly (P/N 15679680) by: -aligning the actuator with the cutout in the steering column jacket. -inserting the tangs into the rectangular holes and pushing down on the switch assembly. 6. Adjust the switch by moving the gear selector to park. 7. Connect the switch assembly harness. 8. Connect the negative battery cable. 9. Check for proper switch operation. Readjust the switch as necessary. Page 6842 movement. Refer to Dealer Service Bulletin Number 91-181-10, Dated February 1991. Page 1022 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. Body - Stain/Film On Windshield Glass Perimeter Windshield: Customer Interest Body - Stain/Film On Windshield Glass Perimeter TECHNICAL Bulletin No.: 09-08-48-006 Date: September 18, 2009 Subject: Clear Stain or Film on Inside Perimeter of Windshield Glass (Clean/Polish Glass) Models: 2010 and Prior Passenger Cars and Trucks (Including Saturn and Saab) 2010 and Prior HUMMER H2, H3 Condition Some customers may comment on a clear stain or film on the inside of the windshield glass. This condition appears along the outer edges of the glass along the top, bottom or A-pillar areas. Normal glass cleaning procedures will not remove the stain. Cause The assembly plant uses a clear sealer/primer on the outer edge of the windshield glass to improve adhesion to the urethane adhesive that bonds the windshield glass to the vehicle body. Excess sealer/primer may drip or flow onto the windshield and cause a stain. Once the sealer/primer dries, it may appear to have etched the glass. Correction Note A "white" type of toothpaste is recommended for this repair. Gel-type toothpaste may provide less satisfactory results. Use a small amount of toothpaste on a soft, cotton cloth to polish the stained area. It may be necessary to wrap the cloth around a paint stir stick or a similar tool to reach the lower corners of the windshield glass. After polishing the glass, clean the inside of the windshield glass with a clean, damp, cotton cloth and verify all of the stain is removed. Do not use any cleaners or solvents - use only clean warm water. Warranty Information (excluding Saab U.S. Models) For vehicles repaired under warranty, use: Warranty Information (Saab U.S. Models) For vehicles repaired under warranty, use the table. Page 5660 Power Steering Pump: Testing and Inspection Using Power Steering Gauge No. J-5176-D All tests are made with engine idling at normal operating temperature. Check idle speed adjustment and, if necessary, adjust to correct specification. 1. Place a container under steering gear or pump. 2. With engine Off, disconnect pressure hose at steering gear or power steering pump, then install J-5176-D to both hoses using adapter fitting No. J-5176-20 or equivalent. Gauge must be installed between shutoff valve and pump. 3. Open shutoff valve. 4. Remove filler cap from pump reservoir and check fluid level. fill pump reservoir with power steering fluid to full mark on dipstick. Start engine and, momentarily holding steering wheel against stop, check connections for leakage. Do not hold wheel against stop for more than five seconds as pump can be damaged internally. 5. Bleed power steering system. 6. Insert thermometer No. J-5421-02 or equivalent in reservoir filler opening. Move steering wheel from stop to stop several times until thermometer indicates that hydraulic fluid in reservoir has reached a temperature Of 150-170 °F. To prevent flat spotting tires, do not turn steering wheel more than five times without rolling vehicle to change tire to floor contact area. 7. Check pump fluid level. Add fluid if required. 8. When engine is at normal operating temperature, the initial pressure on gauge (valve open) should be within 80-125 psi. If pressure is in excess of 200 psi., check hoses for restrictions and poppet valve for proper assembly. 9. Open and close gauge valve fully three times. Do not leave valve closed for more than five seconds as pump could be damaged internally. 10. Record highest pressures attained each time. a. If pressures recorded are within specifications, and range of readings is within 50 psi., pump is functioning within specification. b. If pressures recorded are constant but more than 100 psi., below minimum specification, replace flow control valve and recheck. If pressures are still low, replace rotating group in pump. c. If pressure recorded are high, but do not repeat within 50 psi., flow control valve is sticking. Remove and clean valve. Remove any burrs using crocus cloth or fine hone. If system contains some dirt, flush system. If it is exceptionally dirty, both pump and gear must be completely disassembled, cleaned, flushed and reassembled before further use. 11. If pump checks within specifications, leave valve open and turn steering wheel to both stops. Record highest pressures and compare with maximum pump pressure recorded. If maximum pressure cannot be reached in either (or one) side of gear, gear is leaking internally and must be disassembled and repaired. 12. Turn engine Off, remove testing gauge, reconnect pressure hose, check fluid level and/or make needed repairs. 13. If problem still exists, steering and from suspension must be thoroughly examined. Page 7462 FIGURE 2 3. Place tape on the fender edge and cowl panel edge to prevent paint damage (Figure No. 2) . 4. Disconnect the windshield washer hose from the nozzle. 5. Remove the cowl panel, being careful not to scrape the cowl on the inner hood edge or fender. 6. Pull back the hood hinge seal to expose the windshield frame and close the hood. Page 2572 ECM Connector Terminal Identification & Voltage Specifications. Page 7515 Fuel Gauge: Electrical Diagrams Fuel, Tachometer & Voltmeter (Gauge Cluster) Page 6052 Accumulator HVAC: Service and Repair When removing an accumulator that will be reused, or when installing a new accumulator, ensure inlet and outlet openings of unit are protected from exposure to the atmosphere. If openings are not sealed, moisture contamination will result, rendering unit inoperative. New units are supplied with caps for this purpose, and plastic sheet and elastic bands may be used on units removed from vehicles. ASTRO, SAFARI & S/T-10/15 1. Disconnect battery ground cable, then discharge system refrigerant. 2. Disconnect inlet and outlet lines. Plug open connections. 3. Remove accumulator mounting bracket screws and remove accumulator. 4. Reverse procedure to install. When installing new unit on vehicle, measure amount of oil present in old unit at time of removal. Add this amount plus 2 fluid ounces of fresh 525 viscosity refrigerant oil to new unit prior to installation. Engine Controls - Aftermarket Accessory Usage Engine Control Module: All 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 Removal Notes Brake Caliper: Fundamentals and Basics Removal Notes When Removing the Caliper, Remember... - Prior to removing the calipers, remove/siphon brake fluid from master-cylinder until the reservoir is only 1/3 full. - Brake fluid will remove paint and damage electrical connections. Use a drip pan and fender covers to protect the vehicle's finish and electrical system. - Always replace all brake linings on an axle. Never replace only one wheel. Unequal lining thickness between wheels on the same axle will result in a strong steering pull when the brakes are applied. - Work on one side at a time. If you forget how to reassemble the parts you can always use the other side as a model. - When forcing the piston back into the caliper, open the bleeder valve first. Corrosion and other deposits accumulate inside of the caliper. If the bleeder valve is not opened when the piston is forced back into the caliper, these deposits will be forced back through the brake lines and into the master-cylinder. When pushing the pistons back into the caliper with the bleeder screw open, a stream of brake fluid will be expelled from the bleeder screw for 2-3 feet. Use a drip pan and be careful not to "shoot" brake fluid onto the vehicle's finish. A cleaner method is to use a piece of clear plastic hose and a glass or plastic jar to catch the expelled fluid. - Upon removal, Do Not allow the calipers to hang by the flexible brake hoses. The brake hoses can be damaged easily by this practice. These hoses are double walled, damage to the interior pressure hose will not be visible. - Do not depress the brake pedal with either caliper removed from the rotor. The caliper pistons will be inadvertently expelled from the caliper. If this occurs rebuild or replace the caliper, do not attempt to insert the piston back into the caliper. Adjustments Brake Switch (Cruise Control): Adjustments With brake or clutch pedal depressed, push valve or switch fully into tubular clip until seated. Pull brake or clutch pedal rearward until pedal is against stop. Valve or switch will travel in tubular clip to provide proper adjustment. A/T - Buzzing Noise at Idle Fluid Pressure Sensor/Switch: All Technical Service Bulletins A/T - Buzzing Noise at Idle Number: 93-29-7A Section: 7A Date: OCT. 1992 Corporate Bulletin No.: 277142 ASE No.: A2 Subject: BUZZING NOISE AT IDLE Model and Year: 1982-93 CAPRICE, CAMARO AND CORVETTE 1982-93 C/K, R/V, S/T, M/L AND G TRUCKS WTIH 4L60 AUTOMATIC TRANSMISSION TRANSMISSION APPLICATIONS: 1982-1993 HYDRA-MATIC 4L60 (MD8) TRANSMISSION MODELS: All SUBJECT: Pressure Regulator Valve Buzz VEHICLE APPLICATIONS: B, D, F, Y - Cars C/K, R/V, S/T Trucks G, M, L - Vans CONDITION: Some 1982-1993 vehicles equipped with a HYDRA-MATIC 4L60 transmission may have a buzzing noise coming from the transmission when the vehicle is at idle. The buzzing noise may be noticed more when the vehicle is in reverse at idle. CAUSE: The buzzing noise may be a result of pressure regulator valve oscillating due to oil pressure instability at lower idle RPM. CORRECTION: Page 4872 FIGURE 1 - WHEEL NUT TIGHTENING WHEEL BOLT TORQUE: Overtorqued wheel nuts or torquing wheel nuts without alternating the tightening sequence, especially on aluminum wheels, can also create a rotor runout condition. Refer to Figure 1. The use of a torque wrench when tightening wheel nuts is necessary to prevent distortion of the rotor, hub or wheel. The wheel nuts should be tightened in two steps to assure an even clamp load. FIGURE 2 - CALL TO BRACKET CLEARANCE CALIPER DRAG: Caliper drag is usually caused by interference between the caliper to knuckle interface or a caliper bolt binding on the caliper bolt bushing. Caliper to knuckle clearance is important. Clearance should be checked with the caliper in position and the caliper mounting bolts properly torqued. If excessive clearance exists, a clunking noise may occur on each brake apply. Too little clearance can cause caliper drag. The desired clearance is .005 - .012 in. at each caliper to knuckle bracket interface, or a total of .010 - .024 in. The caliper bracket stops can be filed -to obtain proper clearance. Refer to Figure 2. Engine - Rough/Unstable/Incorrect Idle Engine Mount: All Technical Service Bulletins Engine - Rough/Unstable/Incorrect Idle Number: 88-269-6E Section: 6E Date: JUNE, 1988 Subject: SERVICE MANUAL UPDATE ROUGH, UNSTABLE OR INCORRECT IDLE Model and Year: 1981-88 CHEVROLET PASSENGER CARS AND LIGHT DUTY TRUCKS TO: ALL CHEVROLET DEALERS When diagnosing Rough, Unstable, or Incorrect Idle, make sure to check the motor mounts for damage, grounding out on the frame, or mispositioned, etc. Engine - Vibration On Acceleration Muffler: All Technical Service Bulletins Engine - Vibration On Acceleration Number: 88-270-6F Section: 6F Date: JULY, 1988 Subject VIBRATION ON ACCELERATION Model and Year 1988 S/T TRUCK W/4.3L (VIN CODE Z) ENGINE TO: ALL CHEVROLET DEALERS Some 1988 S/T Trucks equipped with 4.3L engines may experience a vibration that can be felt in the floor pan area near the shifter, in the right hand passenger seat foot area, or on the steering column. These conditions may be caused by the following items: 1. The shifter rod that goes from the steering column to the transmission equalizer lever (#340 and #338 in Figure 36 page 7A-45 of the 1988 S/T Manual) hitting the exhaust crossover pipe and/or the equalizer lever making firm contact at the shift lever (T-truck only). 2. The exhaust pipe to catalytic converter clamp (Figure 7, page 6F-6 of the 1988 S/T Manual) hitting the catalytic converter heat shield. 3. The exhaust pipe to converter installation allows the exhaust pipe to contact the transmission crossmember. To repair these conditions, use the following procedures: 1. A. Raise vehicle on hoist. B. Check Transmission linkage for correct adjustment. C. Check exhaust pipe for shifter rod interference (shiny spot on pipe). D. If linkage hits pipe, remove 15 mm (5/8 in) from bottom of rod. E. Put transmission into low gear and mark exhaust pipe area near linkage. F. Put transmission in park. Using a hammer, lightly dimple exhaust pipe for additional clearance. Page 6246 For vehicles repaired under warranty, use the table. Disclaimer Page 7381 Symbol Identification A/T - New Case Assembly, Removal of Pressure Taps Clutch: All Technical Service Bulletins A/T - New Case Assembly, Removal of Pressure Taps Number: 89-116-7A Section: 7A Date: MARCH, 1989 Subject: NEW CASE ASSEMBLY - REMOVAL OF 2ND, 3RD, AND 4TH CLUTCH PRESSURE TAPS Model and Year: 1982-89 B, F, Y CARS WITH 700-R4 TRANSMISSION 1982-89 C, G, K, M, R, S, T, V TRUCKS WITH 700-R4 TRANSMISSION Figure 1 - Removal Of 2nd, 3rd And 4th Clutch Pressure Taps Figure 2 - THM 700-R4 / HYDRA-MATIC 4L60 Transmission Identification Information TO: ALL CHEVROLET DEALERS This bulletin covers service information for new THM 700-R4/HYDRA-MATIC 4L60 Case assemblies (Figure 1). Starting December 2, 1988 (Julian Date 337) (Figure 2) all THM 700-R4/HYDRA-MATIC 4L60 transmissions were built without drilling and tapping the 2nd, 3rd, or 4th clutch pressure taps. The case bosses will be removed through normal die maintenance. Mainline pressure tap remains unchanged. The clutch pressure taps require case bosses to bring the channeling to the exterior of the case and provide an area to tap and plug the pressure ports. The casting process necessary to provide the case bosses and channeling increase the chance of case porosity in those areas. By removing the clutch pressure taps, the casting can be changed to reduce incidences of case porosity and leaks. Even though individual clutch pressure readings are no longer available, use of basic diagnostic procedures, as outlined in the Service Manuals, will result in successful diagnosis of an automatic transmission concern. The first step in systematic transmission diagnosis is to obtain a complete description of the condition from the vehicle owner. Gather as much information from the owner as they can provide. As an example, under what driving Page 7323 Note the difference between the wire exit openings of the new multi-functional lever and the old lever (Figure 1). Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Op. Description E7060 Multi-functional lever, replace Use applicable labor time guide for labor hours. Endgate Window - Will Not Release/Opens Without Key Trunk / Liftgate Latch: All Technical Service Bulletins Endgate Window - Will Not Release/Opens Without Key Number: 91-504-10 Section: 10 Date: MAY 1992 Corporate Bulletin No.: 161506 ASE No.: B1 Subject: ENDGATE WINDOW LATCH NOT RELEASING OR ENDGATE OPENS WITHOUT KEY Model and Year: 1983-91 S/T TRUCKS Some owners of 1983-1991 S/T utility vehicles may experience difficulty releasing the rear endgate window latch and/or the endgate may be opened without a key. These conditions may be caused by an endgate window latch which has dirt contamination, a deformed spring leg, a missing or broken spring, a bent release lever, a bent frame or a latch which is misadjusted. To correct this condition, it is necessary to properly adjust the endgate window latch assembly and/or replace it. ADJUSTMENT PROCEDURE: 1. Check for proper window latch assembly adjustment by performing the following steps: NOTICE: To open the end gate, insert the key into the lock assembly and rotate the handle COUNTERCLOCKWISE. Turning the key/handle clockwise and exerting excessive force may result in a broken lock assembly. * Hold the window/glass handle and try to move the glass in and out. If the latch is misaligned to the striker, a rattle condition will exist. * Inspect the endgate glass for a snug fit against the top and sides of the body opening. Engine Controls - ECM May Contain Wrong PROM Engine Control Module: All Technical Service Bulletins Engine Controls - ECM May Contain Wrong PROM Number: 88-42 Section: 6E Date: Sept., 1987 Subject: SERVICE REPLACEMENT ELECTRONIC MODULES (ECM) WITH PROM INSTALLED Model and Year: 1981-88 ALL MODELS TO: ALL CHEVROLET DEALERS It has been brought to our attention that some service replacement electronic control modules (ECM's) have contained a PROM. A PROM should not have been included in a replacement ECM as it may not be the correct PROM for the vehicle. When this situation is encountered, the PROM should be removed from the replacement ECM and the PROM from the vehicle should be installed. Page 4802 LIGHT BLUE LT BLU BROWN BRN GRAY GRY GREEN GRN DARK GREEN DK GRN LIGHT GREEN LT GRN ORANGE ORN PINK PNK PURPLE PPL RED RED TAN TAN WHITE WHT YELLOW YEL Page 4948 Wheel Cylinder: Fundamentals and Basics REMOVAL - Wheel cylinder retaining bolts, brake line fittings, and bleeder screws are often heavily corroded. Prior to starting the job you should spray these with a penetrating oil. - A line (flare nut) wrench should be used when loosening the brake line fittings. These fittings round off easily. OVERHAUL - Light amounts of corrosion within the cylinder bore and on the piston may be removed with crocus cloth. - Pitting and heavy corrosion should be removed with a hone. When honing the hone should be inserted and withdrawn quickly to achieve a 45 degree crosshatch. - Closely inspect the areas of the cylinder where the pistons seals contact. It is very important these areas are absolutely free of deposits, corrosion, or pitting. - Remove the bleeder screw and verify that the passage is clear. - Leave the bleeder open when installing pistons and cups into the cylinder bore. If the bleeder is closed a large amount of air will be forced into the brake lines. - Use brake assembly lubricant to coat the cylinder bore, pistons, and cups. Clean brake fluid is an acceptable lubricant when assemblying the wheel-cylinder but brake assembly lubricant is much slicker and minimizes the chance that the cups will be damaged. WARNING: Do not use a petroleum based grease or oil to lubricate the wheel-cylinder components. This will cause the seals and cups to swell and deteriorate. - When reassemblying the wheel-cylinder it is helpful to follow this sequence: 1. Rear cup (verify the cup is inserted properly, flat side towards the piston, concave side towards the center) 2. Rear piston 3. Rear dust cap (this prevents the rear cup and piston from popping back out when the spring and front components are installed). 4. Spring 5. Front cup 6. Front piston 7. Front dust cap INSTALLATION Attach the brake fluid line fitting loosely to the wheel-cylinder prior to inserting and tightening the retaining bolts. The brake fluid line fitting is much easier to attach and start turning with the wheel-cylinder loose. WARNING: Don't forget to tighten the brake line fitting after the retaining bolts are tightened. - Leave the wheel-cylinder bleeder screw open and place a drip pan under the rear brake assembly. Refill the master-cylinder with new brake fluid and let the fluid gravity bleed through the open bleeder screw. When brake fluid begins to drip from the bleeder, close the bleeder screw. NOTE: The brake system will still need to be flushed and bled, but this makes starting the process much easier. Service and Repair Turn Signal Switch: Service and Repair Fig. 6 Compressing Lock Plate 1. Disconnect battery ground cable. 2. Remove steering wheel as outlined under STEERING SUSPENSION CHASSIS AND BODY COMPONENTS/STEERING/COMPONENT REPLACEMENT AND REPAIR PROCEDURES/STEERING WHEEL & HORN SOUNDER. 3. Using a screwdriver, pry cover from lock plate. 4. Using lock plate compressing tool No. J-23653, compress lock plate and pry retaining ring from groove on shaft, Fig. 6. Slowly release lock plate compressing tool, 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. Page 3199 Spark Plug Wire: Locations Spark Plug Wire Routing Page 1792 - 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 Locations Htr-A/C, Pwr Wdo Circuit Breaker Page 2374 Oil Pressure Switch (For Fuel Pump): Service and Repair REMOVAL: 1. Disconnect negative battery cable from battery. 2. Remove sensor or switch connectors. 3. Remove sensor or switch. INSTALLATION: 1. Install sensor or switch. 2. Connect sensor or switch. 3. Reconnect negative battery cable. Page 6652 Trailer Adapter Kit: Electrical Diagrams Trailer Adapter Wiring Circuit (W/Heavy Duty Suspension) Turbo Hydra-Matic 3L30 (180C) Fluid - A/T: Service and Repair Turbo Hydra-Matic 3L30 (180C) Draining Bottom Pan 1. Raise and support vehicle. 2. Position a suitable drain pan below transmission oil pan. 3. Remove front and side oil pan bolts. 4. Loosen rear bolts and gently pry the pan down to allow fluid to drain. 5. Remove remaining bolts and pull pan away from case carefully, as there will still be fluid contained in the pan. 6. Drain remaining fluid from pan, then remove gasket, oil filter retaining bolts, oil filter and seal. 7. Using solvent, thoroughly clean oil pan and gasket surfaces, then air dry. 8. Install new oil seal and filter into case. Torque attaching bolts to 13-15 ft. lbs. 9. Install oil pan with new gasket and torque bolts to 7-10 ft. lbs. 10. Add transmission fluid, then with engine idling and brakes applied, move selector lever through each gear range and return selector lever to Park. 11. Bring fluid to proper operating temperature and check fluid level, adding as required to bring level to the Full mark. Adding Fluid to A Dry Transmission 1. Add transmission fluid. 2. With transmission in Park, start engine and let engine idle (carburetor off fast idle cam.) 3. Apply brakes and move shifter lever through each gear range, then with transmission in Park, add additional fluid as required to bring the level up to Full mark on dipstick. A/T - New Servo Apply Pin Band Apply Servo: Technical Service Bulletins A/T - New Servo Apply Pin GMC NUMBER: 88-T-44 GROUP: 7A - Automatic Transmission DATE: September, 1987 CORPORATE NUMBER: 867105 SUBJECT: NEW SERVO APPLY PIN MODELS: 1982 - 88 LIGHT DUTY MODELS EQUIPPED WITH THM 700-R4 AUTOMATIC TRANSMISSIONS BULLETIN COVERS: This bulletin covers changes to the second servo apply pin that eliminated the two ring seals. This change reduces the potential for seal damage during assembly. Testing has shown that any potential leakage in this area with the new design pin will not affect transmission performance. FIGURE 1 - THM 700-R4 TRANSMISSION IDENTIFICATION INFORMATION Page 4817 Brake Caliper: Service and Repair Rebuild Caliper Assembly DISASSEMBLY 1. Remove caliper. 2. Disconnect hose from steel line, remove U-shaped retainer and withdraw hose from frame support bracket. 3. After cleaning outside of caliper, remove brake hose and discard copper gasket. 4. Drain brake fluid from caliper. Removing Piston 5. Pad caliper interior with clean shop towels and use compressed air to remove piston. Use just enough air pressure to ease piston out of bore. Do not blow piston out of bore. WARNING: Do not place fingers in front of piston in an attempt to catch or protect it when applying compressed air. This could result in serious injury. Saginaw 3 Speed Extension Housing: Specifications Saginaw 3 Speed Extension housing to case bolts .......................................................................................................... ...................................................................... 45 ft.lbs. Page 2095 For vehicles repaired under warranty, use the table. Disclaimer Page 3406 [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. Page 1290 FIGURE 2 Irregular/premature tire wear is aggravated by excessive toe-in (or toe-out). Excessive camber can also be a contributor, as can operating conditions, such as city driving with alot of cornering. Irregular tire wear usually occurs on non-drive axles, such as the front wheel positions of rear drive vehicles. An early indication may be an increase in tire noise. In most cases, modified "X" tire rotation, which is a scheduled maintenance at 7500 miles, will equalize tire wear (see Figure 1). Some amount of wear is expected and should be considered normal. Only when the cross grooves in the tread disappear within 12,000 miles should the tires be replaced under warranty (see Figure 2). Even when these grooves disappear, however, the tire is normally only half worn in this area. Whenever tires are replaced for this reason, alignment should be checked and reset to specification, if necessary. If tires are needed for any of the above conditions, they should be purchased from your local tire outlet. If tires are not readily available, each tire manufacturer has a toll-free assistance line for car and truck dealers. These numbers have been previously provided. The tire invoice amount should be entered as a net item on the warranty claim. Labor code E0420, replace wheel and/or tire, should be used. Figure 1 modified "X" tire rotation, front wheel drive, rear wheel drive. This rotation pattern eventually gets each tire on all four positions. It gets those tires on the non-drive axle, which are most prone to irregular wear, to turn in the opposite direction. This will equalize wear quickest, and tire noise related to tread wear will actually become quieter after a few thousand miles. Figure 2 evaluating tire wear. Typical all-season tire. Tire should be replaced only if these grooves are no longer visible within first 12,000 miles. Page 1649 1. Mounting to crossmember nut(s) and washer(s). 2. Mounting to transmission bolts and washers. -Raise the rear of the engine only enough to permit removal of the mounting. 3. Mounting. Install or Connect 1. Mounting. -Lower the rear of the engine. 2. Mounting to transmission bolts and washers. NOTICE: When fasteners are removed, always reinstall them at the same location from which they were removed. If a fastener needs to be replaced, use the correct part number fastener for that application. If the correct part number fastener is not available, a fastener of equal size and strength (or stronger) may be used. Fasteners that are not reused and those requiring thread locking compound will be called out. The correct torque value must be used when installing fasteners that require it. If the above condition are not followed, parts or system damage could result. 3. Mounting to crossmember nut(s) and washer(s). -Tighten fasteners to specifications as shown in the image. Page 6139 Installing The Pulley Rotor Bearing 1. Pulley (26) on J 35372. NOTICE: Do not support the rotor by resting the pulley rim on a flat surface during bearing installation or the rotor face will be bent. 2. Pulley bearing (25) into the hub using J 29886, J 9481-A and J 35372. ^ J 33019 in the pulley bore. Staking The Pulley Bearing In The Pulley Bore ^ Seat the pulley and bearing assembly on J 35372 to support to the hub under the staking pin location. ^ Strike the staking pin with a hammer until a metal stake, similar to the original, is formed down to, but not touching the bearing. - Position the stake pin after striking. - The staked metal should not contact the outer race of the bearing to prevent the possibility of bending the outer race. Page 951 Figure 2 A/T - New Trans Fluid, Dexron IIE Fluid - A/T: All Technical Service Bulletins A/T - New Trans Fluid, Dexron IIE Number: 92-26-7A Section: 7A Date: OCT. 1991 Corporate Bulletin No.: 177125 ASE No.: A2 Subject: DEXRON-IIE AUTOMATIC TRANSMISSION/TRANSAXLE FLUID Model and Year: 1976-92 ALL TRUCKS WITH AUTOMATIC TRANSMISSION TRANSMISSION APPLICATIONS: SUBJECT: All Automatic Transmissions DEXRON-IIE Automatic Transmission/Transaxle Fluid TRANSMISSION MODELS: VEHICLE APPLICATIONS: All All HYDRA-MATIC Automatic Transmissions/Transaxles Bulletin Covers: General Motors Corporation has developed a new service fill automatic transmission/transaxle fluid which is designated DEXRON-IIE. This fluid is the preferred fluid for all HYDRA-MATIC automatic transmission/transaxles and will eventually replace DEXRON II. DEXRON-IIE is acceptable for use wherever DEXRON II was previously specified. DEXRON II is acceptable for use when DEXRON-IIE is not available. DEXRON-IIE can be used in both electronically and hydraulically controlled transmissions/transaxles. DEXRON-IIE Advantages: ^ Has better anti-foaming characteristics. ^ Improved low temperature flow characteristics (low temperature viscosity) and improved high temperature oxidation stability. ^ DEXRON-IIE and DEXRON II can be mixed in any ratio. No draining or flushing of system is required. ^ DEXRON-IIE is back serviceable to 1949 for all General Motors automatic transmission/transaxles. ^ No change in transmission/transaxle calibration or reduction in transmission/transaxle durability will occur as a result of using DEXRON-IIE. Service Parts Information: PART NUMBER DESCRIPTION 12345881 1 quart container 12345882 1 gallon container 12345883 55 gallon drum Parts are currently available from GMSPO. Page 6562 Page 6115 the body several turns, remove J 9480-B and check that the shaft key (36) is properly in place in the keyway. ^ Air gap between contact surfaces of the clutch plate and hub assembly (2) and the pulley (6) should be 0.56-1.34 mm (0.022-0.057-inch). ^ Remove J 9480-B. Inspect ^ Position of the shaft (39) (even with or slightly above the clutch hub). 3. Shaft nut (1). ^ Use J 9396 to hold the clutch plate and hub assembly (2). Tighten ^ Shaft nut (1) to 27 N.m (20 ft. lbs.) with J 9399. ^ Hand spin the pulley (6) to check for free rotation. Pulley and Bearing Assembly Page 3856 Transmission Speed Sensor: Service and Repair 1. Disconnect battery ground cable. 2. Raise and support vehicle, then disconnect sensor electrical connector. 3. Remove sensor retaining bolt, then the sensor. 4. Reverse procedure to install. Page 2578 Engine Control Module: Component Tests and General Diagnostics Chart C-9A - ECM QDR Check Procedure Checking Control Module For Bad Solder Joints Some control module's 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 Page 3687 FIGURE 1(T-TRUCK ONLY) G. (T-truck only) Check equalizer lever for firm contact at the shift lever inboard side of the guide slot. (See Figure 1) H. If firm contact is evident, add an additional washer (#10 in Figure #1) P/N 14074908 to adjust equalizer lever outboard toward the center of the guide slot to eliminate contact. 2. A. Raise vehicle on hoist. B. Note location of clamp rotation on pipe. Some clamps are located with the lower lock ring (nuts) pointed towards the transmission. If the clamp is located in such a manner, loosen clamp and rotate it down so the nuts point toward the ground and retighten to 58 N-m (43 ft/lbs.) 3. A. Loosen converter clamp until it will rotate around the pipe. Using a suitable pry bar, move exhaust system rearward to obtain a minimum of 5/8 in. clearance between any point on the exhaust system and the transmission crossmember. For repairs performed under warranty, use the following labor operations and times: Labor Operation Labor Time Exhaust/muffler clamp L2020 .3 Hr Exhaust system align L2004 .3 Hr Shift Linkage (shorten) K5244 .3 Hr Page 7702 Brake Light Switch: Locations Stop Lamp Switch LH Side Of Steering Column Behind Instrument Cluster 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 Windshield Washer Bottle - Cracking Windshield Washer Reservoir: Customer Interest Windshield Washer Bottle - Cracking Number: 91-31-8E Section: 8E Date: July 1990 Corp. Bulletin No.: 061010 Subject: WASHER BOTTLES CRACKING Model and Year: 1988-91 S/T TRUCKS TO: ALL CHEVROLET DEALERS Some 1988 - 1991 S/T trucks may be experiencing a condition of windshield wiper washer bottles cracking and then leaking washer fluid. This condition can be caused by an increased amount of pressure exerted by the two fastening nuts and screws. This increase of pressure causes the screws to cut into the plastic and initiate cracks. To correct the situation new parts have been released with a wider flange, and the torque requirement has also been revised. The new torque requirement is now 5-8 N-m (3.7 - 5.9 lbs. ft.) instead of the old 8-11 N-m (5.9 - 8.1 lbs. ft.). When ordering a new washer bottle be sure and order new bolts and nuts with the revised flanges. SERVICE PARTS INFORMATION Part Number Description Usage 11509005 nut 2 per bottle 15653669 bolt 2 per vehicle 22072762 container and grommet 1 per vehicle Parts are currently available through GMSPO. WARRANTY INFORMATION For vehicle repaired under warranty use: Labor Operation: N3750 Labor Time: .2 hr. Page 477 Figure 4 Figure 5 Figure 6 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 7 Page 2753 - Diagnostic Chart Code 33. Diagram Information and Instructions Parking Lamp: Diagram Information and Instructions 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 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. Page 5273 Important The M6 conductive rivet stud as shown, can accommodate a panel thickness range of 0.7-4.2 mm (0.03-0.17 in). If there are layers of sheet metal, they should be touching without any air gaps to ensure a good ground. 5. Select a M6 conductive rivet stud. Refer to the Parts Information section of this bulletin. Note Use the GE-50317 rivet stud tool kit. 6. Place the M6 conductive rivet stud (1) in the 10 mm (0.40 in) hole. Assemble the rivet stud tool (2) with the groove and flare side facing the rivet stud, then the washer and the M6 nut (3). 7. Using a wrench on the rivet stud tool, and a socket on the M6 nut, secure the M6 conductive rivet stud. 8. Ensure the rivet stud is securely fastened, WITHOUT ANY detectable movement. 9. Completely wrap the threads of the rivet stud with painters tape or equivalent. Note The rivet stud and surrounding panel area MUST BE properly refinished PRIOR to the installation of the ground wire terminal and conductive nut to maintain a secure, stable and corrosion-free electrical ground. 10. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 11. Allow the refinished repair area to cure sufficiently before removing the protective material applied to the rivet stud threads. 12. Remove the painters tape or equivalent from the rivet stud threads. 13. Using GM approved residue-free solvent or equivalent, thoroughly clean the rivet stud threads to remove any adhesive and allow to dry. 14. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive rivet stud. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. Page 6603 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 Page 7235 Pontiac West: 1GNCT18ZOM0101419 Moraine: 1GNDT13Z6M2115163 Warranty Information For vehicles repaired under warranty use: Labor Operation: T7026 Labor Time: .4 hr. FAILURE CODE: 92 Add: .1 hr. to replace tire carrier striker Add .4 hr. to replace tire carrier arm NOTE: Labor Operation is coded to base vehicle coverage in the warranty system. Page 113 Electronic Spark Timing: Testing and Inspection Chart C-5 - Electronic Spark Control System Check Paint - Removal of Minor Imperfections Paint: All Technical Service Bulletins Paint - Removal of Minor Imperfections Number: 88-135-10 Section: 10 Date: Jan., 1988 Subject: REMOVAL OF "CHEMICAL SPOTTING" AND OTHER MINOR PAINT IMPERFECTIONS WITHOUT REPAINTING Model and Year: ALL MODELS WITH BASECOAT/CLEARCOAT PAINT TO: ALL CHEVROLET DEALERS This bulletin cancels and supersedes Chevrolet Dealer Service Bulletin 87-166 (Section 10) dated June 1987. This bulletin provides new materials which are available for use on basecoat/clearcoat systems. Some Chevrolet models equipped with basecoat/clearcoat paint applications may experience a condition of small etched spots on horizontal surfaces of the paint finish. This condition is referred to as chemical spotting and may be caused by industrial fallout (acid rain). FIGURE 1 Chemical spotting along with other minor paint imperfections on basecoat/clearcoat finishes, such as sand scratches, dirt in paint, sags and orange peel may be repaired without paint application. Examples of these imperfections are shown in Figure 1. To repair these conditions use the following procedures: Bleeding Procedure Hydraulic Brake Booster: Service and Repair Bleeding Procedure Hydro-Boost 1. Fill oil reservoir to proper level and let stand at least two minutes. 2. Start engine and run momentarily. 3. Add oil as necessary. 4. Repeat above procedure until oil level remains constant after running engine. 5. Raise and support front of vehicle. 6. Turn wheels left and right, lightly contacting stops. 7. Add oil as necessary. 8. Lower vehicle. 9. Start engine and depress brake pedal several times while rotating steering wheel from stop to stop. 10. Turn engine off, then pump brake pedal four or five times to deplete accumulator pressure. 11. Check oil level, filling as necessary. 12. If oil is extremely foamy, allow vehicle to stand several minutes with engine off, then repeat entire procedure. Hydro-Boost II 1. Fill power steering pump until fluid level is at base of pump reservoir neck. 2. Disconnect 12 volt wire from injection pump or distributor, then crank engine for several seconds. Do not start engine. 3. Check fluid level, adding as necessary. 4. Connect 12 volt wire and start engine. 5. Turn steering wheel from stop to stop, then turn off engine. 6. Depress brake pedal four or five times to deplete accumulator vacuum. 7. Check fluid level, adding as necessary. 8. Start engine, turn steering wheel from stop to stop. Turn engine off, and check fluid level. 9. If fluid is extremely foamy, stop engine and let vehicle stand for one hour, then check fluid level, adding as necessary. Specifications Idle/Throttle Speed Control Unit: Specifications IDLE SPEED CONTROL Measured between terminals A& B and C & D. Page 2353 Throttle Position Sensor: Description and Operation Typical Throttle Position Sensor (TPS) Wiring The Throttle Position Sensor (TPS), is mounted on the side of the throttle body opposite the throttle lever assembly. Its function is to sense the current throttle valve position and relay that information to the ECM. Throttle position information allows the ECM to generate the required injector control signals (base pulse). If the TPS senses a wide open throttle, a voltage signal indicating this condition is sent to the ECM. The ECM then increases the injector pulse width, permitting increased fuel flow. As the throttle valve rotates in response to movement of the accelerator pedal, the throttle shaft transfers this rotation to the TPS. A potentiometer (variable resistor) within the TPS assembly changes its resistance (and voltage drop) in proportion to throttle movement. By applying a reference voltage (5.0 volts) to the TPS input, a varying voltage (reflecting throttle position) is available at the TPS output. For example, approximately 2.5 volts results from a 50% throttle valve opening (depending on TPS calibration). The voltage output from the TPS assembly is routed to the ECM for use in determining throttle position. Page 6202 DA-V5 Compressor Component View Remove or Disconnect Tools Required: J 5403 Snap Ring Pliers J 9553-01 O-ring Seal Remover 1. Retainer ring with J 5403. 2. O-ring seal (44) with J 9553-01. 3. Valve (5). Install or Connect Tools Required: J 5403 Snap Ring Pliers J 33011 O-ring Seal Installer Ignition Firing Order Firing Order: Specifications Ignition Firing Order Firing Order ......................................................................................................................................... ............................................................... 1-6-5-4-3-2 Page 2180 Figure 1 Some 1988-1991 S/T vehicles with a 4.3L engine may experience exhaust manifold heat shield rattle. This condition can occur if the heat shield is improperly installed. To correct this condition, it is necessary to reposition the heat shield and bend its rear tab for proper fit throughout the mounting bracket. It may also be necessary to bend the mounting bracket slightly. SERVICE PROCEDURE: 1. Raise the vehicle on a hoist following proper lift procedures. 2. Allow the exhaust manifold and catalytic converter to cool. CAUTION: Exhaust manifold and/or catalytic converter may be extremely hot. Allow them to cool to avoid personal injury. 3. Reposition the exhaust manifold heat shield rearward insuring the full length of the rear tab is completely through the mounting bracket slot (Figure 1). The rear tab is "folded". This "fold" should extend approximately 1/2 in. (12.7 mm) beyond mounting bracket slot. 4. Slide the heat shield inboard as far as possible within the mounting bracket slot. 5. Bend the accessible portion of the rear tab down to limit up and down movement of the shield. 6. Check heat shield for possible side movement and/or rattle. 7. If the heat shield can be moved and/or rattles, bend the mounting bracket toward the front of the vehicle and slightly upward snugging the mounting bracket against the heat shield. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: L2280 Use applicable labor time guide for labor hours. Page 6142 Removing The Clutch Coil Assembly ^ Install J 8433-1 with J 33025. ^ Tighten J 8433-3 forcing screw against J 33025. Inspect ^ Clutch coil assembly (27). Replace as necessary. Install or Connect Tools Required: J 8433-1 Puller Bar J 33024 Clutch Coil Installer Adapter 1. Clutch coil assembly (27) onto the front head (33) with the terminals positioned at the "marked" location. Installing The Clutch Coil Assembly ^ J 33024 over the internal opening of the clutch coil assembly (27). Page 4473 Labor operation T7990 Labor time .4 Hr Page 6994 Time Allowance: See Chants NOTE: The time allowances provided on the chart include the hardware removal and installation (as indicated by the list guidelines), the masking and unmasking of the vehicle, stripping of the surface (as indicated by the guidelines), the refinish (and colorcoat when required), mix time for primer/ paint (and clearcoat when required), finesse/polish where required, washing and preparing the vehicle for delivery. OPERATION DESCRIPTION: PAINT COLORCOAT DELAMINATION FROM ELPO PRIMER, REFINISH ENTIRE BODY ABOVE BODY SIDE MOLDINGS. PAINT TERM DEFINITIONS Following are definitions of paint repair terms used in this bulletin: Basecoat: A color topcoat that requires a clear topcoat over it. Break line: A natural dividing line on Page 5117 Symbol Identification Page 5142 Disclaimer Page 4605 - Tighten poppet screw to 31 N-m (23 lbs.ft.). - New poppet plunger P/N 15633556 (70) group A vehicles only. - New poppet spring P/N 15633557 (71) group A vehicles only. - New poppet screw P/N 15633558 (68) group A vehicles only. 23. Vacuum switch (46) and new O-ring P/N 14071849 (47) to the front case housing. - Tighten switch to 24 N-m (17 lbs.ft.). 24. Front output flange (74), rubber sealing washer (75), washer (76) and flange nut (77). - Tighten nut (26) to 149 N-m (110 lbs.ft). 25. New vent pipe P/N 15581915 in new front case half (group A vehicles only). - Lightly coat end of vent pipe with Loctite 609 (R) or equivalent. 26. Transfer case into vehicle. - Refer to section 7D of the appropriate S/T Service Manual for complete transfer case replacement procedure. Service Parts & Warranty Information SERVICE PARTS INFORMATION: The "Easy Shift" package consists of the following parts. Parts must be ordered individually. Required Parts Part Quantity Figure 1 Group A Group B Number Description Required Reference Trucks Trucks 15635347 Front case half 1 45 X 15637215 Sector W/shaft 1 55 X X 15637217 Mode shift fork 1 54 X X 15633556 Poppet plunger 1 70 X 15633557 Poppet spring 1 71 X 15633558 Plug 1 68 X 14071849 O-ring 2 69 & 47 X X 15581915 Vent Pipe 1 N/S X 14095609 Input seal 1 42 X 14037958 Retainer 1 66 X X 14095598 Range sector seal 1 67 X X 15579788 Output front seal 1 72 X 15642511 Adapter gasket 1 N/S X X 15579803 Drive Sprocket 1 20 * * 14071703 Synchronizer 1 28 * * Blocking Ring * These parts required only if damaged or in cases of customer complaint of clash when shifting from 2Hi to 4Hi. Parts are currently available from GMSPO. WARRANTY INFORMATION: For vehicles repaired under warranty use: Labor Labor Operation Truck Time Page 7228 Figure No. 2 Page 5663 Power Steering Pump: Service and Repair Disassembly/Assembly Flushing Power Steering System 1. Raise front end of vehicle off ground until wheels are free to turn. 2. Remove fluid return hose at pump inlet connector and plug connector port on pump. Position hose in large container. 3. While an assistant is filling reservoir with new power steering fluid, run engine at idle. turn steering wheel from stop to stop. Do not contact wheel stops or hold wheel in a corner as fluid will stop and pump will be in pressure relief mode. A sudden overflow from reservoir may develop if wheel is held at a stop. 4. Install all pipes and hoses. Fill system with new power steering fluid and bleed system as outlined under SYSTEM BLEEDING. 5. Operate engine for 15 minutes. 6. Remove pump return hose at pump inlet and plug connection on pump. While refilling reservoir, check draining fluid for contamination. If foreign material is still evident, replace all hoses, disassemble and clean or replace power steering system components. Do not reuse any drained power steering fluid. Disassembly Fig. 2 Exploded view of power steering pump Refer to Fig. 2, when servicing pump. Before disassembly of pump, remove filler cap and drain fluid. If broken components or foreign materials are found during disassembly, hydraulic system should be disassembled, inspected, cleaned and flushed before servicing is complete. 1. Clean exterior of pump with solvent and crocus cloth. 2. Remove bolt and fitting from rear of pump reservoir, then the reservoir and seals. 3. Remove end plate retaining ring using a screwdriver and punch. 4. Remove end plate and pressure plate spring, then the O-ring, control valve and control valve spring by inverting housing. 5. Tap lightly on driveshaft with a rubber mallet to remove pressure plate. 6. Pull out pump ring and vanes, then remove shaft retaining ring, pump rotor and thrust plate. 7. Remove driveshaft key from slot in shaft, then with end of shaft pointed downward, press down until shaft is free. 8. Remove seals, dowel pins and O-rings. Inspection 1. Clean all parts with solvent and blow dry. 2. Check vane tips for scoring or wear. Vanes must fit snugly but slide freely in slots of rotor. Examine rotor slots for burrs and excessive wear at thrust faces. 3. Check inner surface of pump ring for scoring or wear and thrust plate and pressure plate for wear on plate surfaces. 4. If heavy wear is evident in any of above components, replace entire rotating group. 5. Inspect seal for leakage, cracking or swelling, if evident replace seal. 6. Check driveshaft for excessive burning or scoring. 7. Control valve must move smoothly in the valve bore. Assembly Page 6593 - 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 Page 6494 Disclaimer Page 6151 - Stake 3 places 120 degrees apart. 3. Pulley (5) on the front head. Installing The Pulley Bearing Assembly ^ Position J 33017 and J 33023-A over the inner race of the bearing. ^ Position J 8433-1 on J 33023-A and assemble the through bolts and washers through the puller bar slots and thread them into J 33026. The thread of the through bolts should engage the full thickness of J 33026. ^ Tighten the center screw in J 8433-1 to force the pulley and bearing assembly onto the compressor front head (11). Should J 33017 become misaligned with the inner race of the bearing, back off J 8433-1 and relocate center, then continue installation. Removing The Pulley Rotor & Bearing Retaining Ring 4. Pulley bearing retainer (3) using J 6083. 5. Clutch plate and hub assembly (2). Clutch Coil and Housing Assembly Page 5677 Steering Column: Description and Operation The energy absorbing function of the steering column allows the column to collapse at a controlled rate during a severe collision. The collapsing action reduces the possibility of the steering wheel being driven rearward towards the driver. If the driver is thrown forward into the steering wheel, the column can collapse even further at the same controlled rate, thereby reducing the force of impact. Several designs of steering column jackets are used: The slip-tube design which is held together with plastic inserts or rivets that shear upon impact and allow the column to collapse, and the slotted or corrugated mesh design and bellows type which shorten in length during impact. The shift tube is a two piece design which is held together by injections of plastic that form the interconnecting inserts and shear pins. Under impact, there is a gradual paring away of the inserts by the knife-like edge in the adjoining tube section. The steering shaft is a two piece assembly. The upper piece is solid and has a double flattened lower end. The lower piece is hollow and formed to fit over the double flattened section of the upper piece. The purpose of the double flattened section is to provide continued steering action even though the shaft is completely collapsed. Upon impact, the shear pins break off and the shaft gradually telescopes against resistance provided by the plastic injections. The steering column mounting bracket prevents the column from being shifted towards the driver during impact. It uses two breakaway capsules that allow the mounting bracket to slip off its attaching points, allowing the steering column to compress or yield in a forward direction under a severe impact from the driver's end. Page 1851 Fuel Pressure: Testing and Inspection NOTE: A fuel system pressure test is part of several of the Diagnostic Charts and Symptom Checks. To perform this test, follow this procedure: FUEL PRESSURE TEST 1. Turn engine OFF to relieve system pressure. 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. - The constant bleed feature relieves fuel pump system pressure when the engine is turned "OFF". 2. Uncouple fuel supply flexible hose in engine compartment. Install fuel pressure gauge between steel line and flexible hose. 3. Tighten gauge in line to insure no leaks occur during testing. 4. Connect negative battery terminal and START engine and observe fuel pressure reading. It should be 62-90 kPa (9-13 psi). If not, refer to DIAGNOSTIC CHARTS/FUEL SYSTEM PRESSURE TEST (CHART A-6). 5. Turn engine OFF to relieve system pressure. 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. - The constant bleed feature relieves fuel pump system pressure when the engine is turned "OFF". 6. Remove fuel pressure gauge. 7. Reinstall fuel line. 8. Connect negative battery terminal and START engine and check for fuel leaks. 9. Install air cleaner assembly. Page 3222 Wiring Diagram For Chart C-5 - Electronic Spark Control System Check CHART C-5 - ELECTRONIC SPARK CONTROL SYSTEM CHECK Circuit Description: Electronic spark control is accomplished with a module that sends a voltage signal to the ECM. As the knock sensor detects engine knock, the voltage from the ESC module to the ECM is shut "OFF" and this signals the ECM to retard timing, if engine RPM is over about 900. Test Description: Numbers below refer to circled numbers on the diagnostic chart. 1. If A Code 43 is not set, but a knock signal is indicated while running at 1500 RPM, listen for an internal engine noise. Under a no load condition there should not be any detonation, and if knock is indicated, an internal engine problem may exist. 2. Usually a knock signal can be generated by tapping on the right exhaust manifold. This test can also be performed at idle. Test number 1 was run at 1500 RPM to determine if a constant knock signal was present, which would affect engine performance. 3. This tests whether the knock signal is due to the sensor, a basic engine problem, or the ESC module. 4. If the module ground circuit is faulty, the ESC module will not function correctly. The test light should light indicating the ground circuit is OK. 5. Contacting CKT 496, with a test light to 12 volts, should generate a knock signal to determine whether the knock sensor is faulty, or the ESC module can't recognize a knock signal. Diagnostic Aids: "Scan" tools have two positions to diagnose the ESC system. The knock signal can be monitored to see if the knock sensor is detecting a knock condition and if the ESC module is functioning, knock signal should display "yes", whenever detonation is present. The knock retard position on the "Scan" displays the amount of spark retard the ECM is commanding. The ECM can retard the timing up to 20 degrees. This check should be used after other causes of spark knock have been checked such as engine timing, EGR systems, engine temperature or excessive engine noise. Locations Blower Motor Resistor: Locations Blower Resistors Location. The Blower Resistors are located at the RH front of the dash on the blower module. Page 6960 R3261 LH mirror R&R; 0.4 Hr. (Time is different than published time in Labor Operation Guide.) Page 6285 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 Page 1482 Connecting Rod Bearing: Service and Repair Main bearings are available in standard size and undersizes of .001, .002, .009, .010 and .020 inch. Connecting rod bearings are available in standard size and .001 and .002 inch undersize for use with new and used standard size crankshafts and .010 and .020 inch undersize for use with reconditioned crankshafts. Page 613 Disclaimer Page 4479 6. Tape the solder and diode. 7. Reinstall the black plastic conduit. 8. Reconnect connector to the generator. 9. Reconnect battery. This procedure will not affect the operation of the generator light during the bulb check at the beginning of the start cycle. For vehicles repaired under warranty use, Labor Operation Number: T7990 Labor Time: .4 Hr Page 5375 5. Remove paint and primer from the area surrounding the 10 mm (0.40 in) until bare metal is visible. Important The M6 conductive rivet stud as shown, can accommodate a panel thickness range of 0.7-4.2 mm (0.03-0.17 in). If there are layers of sheet metal, they should be touching without any air gaps to ensure a good ground. 6. Select a M6 conductive rivet stud. Refer to the Parts Information section of this bulletin. Note Use the GE-50317 rivet stud tool kit. 7. Place the M6 conductive rivet stud (1) in the 10 mm (0.40 in) hole. Assemble the rivet stud tool (2) with the groove and flare side facing the rivet stud, then the washer and the M6 nut (3). 8. Using a wrench on the rivet stud tool, and a socket on the M6 nut, secure the M6 conductive rivet stud. 9. Ensure the new rivet stud is securely fastened, WITHOUT ANY detectable movement. 10. Completely wrap the threads of the rivet stud with painters tape or equivalent. Page 6145 Removing The Shaft Nut ^ Clamp J 33026 in a vise and attach the compressor to the holding fixture with thumb screws. 1. Shaft nut (1) using J 33022. ^ Hold the clutch plate and hub assembly (2) steady using J 25030. 2. Clutch plate and hub assembly (2). ^ Thread J 33013-B into the clutch plate and hub assembly (2). Removing The Clutch Plate & Hub Assembly ^ Hold the body of J 33013-B with a wrench and tighten the center screw into the remover body. 3. Shaft key (21). ^ Retain shaft key (21) if usable. Inspect ^ All parts and replace as necessary. Install or Connect Tools Required: Page 3831 Labor Operation No.: K6550 Valve, Pressure Regulator-R&R; or Replace Use the appropriate labor time in the labor time guide. Parts are currently available from GMSPO. Page 4924 Brake Drum: Fundamentals and Basics Notes, Warnings, and Hints DRUM REMOVAL The drum should just slide off however it will often bind or stick for the following reasons: Excessive Grooves or Scoring - The interlocking grooves prevent the drum from sliding off. Uneven Wear - Uneven wear across the surface of the shoe creates a wedge which prevents the drum from sliding off. Lip or Edge - Commonly there will be a lip worn at the edge of the drum where the shoe to drum contact stops. NOTE: If both drums are stuck tightly, verify the parking brake is released. To remove a drum which is stuck you should retract the shoes by backing off the automatic adjuster. If the drum still will not slide off there may be corrosion between the drum and hub. A few sharp blows from a mallet or hammer along the front flat surface of the drum will usually free the drum. CAUTION: Prying off a stuck drum with a puller or pry bar can damage the springs or hardware. Always attempt to withdraw the shoes with the automatic adjuster first. Once the drum is removed a layer of brake dust will remain in the bottom of the drum. This dust should be thoroughly soaked with water or brake cleaner and then removed from the drum. WARNING: Inhaling brake dust is extremely hazardous to your health. DRUM INSTALLATION - Prior to installing the drum verify the automatic adjuster operates properly and that the tools you are intending to use to adjust the brakes will be able to reach the adjuster. - With the drum off, practice operating the adjuster through the access hole in the backing-plate. This will make adjusting the brakes much easier once the drum is installed. Ensure the shoes/linings are centered on the backing-plate (top to bottom and side to side). The drum will be very difficult to slide on if the shoes/linings are not centered. A/T - THM 700-R4 New Harness/Solenoid Assembly Shift Solenoid: Technical Service Bulletins A/T - THM 700-R4 New Harness/Solenoid Assembly Number: 88-335-7A Section: 7A Date: SEPT., 1988 Subject: SERVICE MANUAL UPDATE: NEW SOLENOID ASSEMBLY AND WIRING HARNESS Model and Year: 1988 C, K, R, V, S, T, G SERIES TRUCKS WITH THM 700-R4 TO: ALL CHEVROLET DEALERS This bulletin covers the introduction of a new Solenoid Assembly and Wiring Harness (Type 18) and new Control Valve Assembly for some 1988 THM 700-R4 models (refer to models listed below). Transmission Models: MAM, MDM, MFM, MKM, MLM, MPM, MRM MWM, MXM, MZM, THM, TJM, TKM, TLM TUM, TXM The new control valve assembly uses a plug in place of the 4-3 pulse switch. The function of the 4-3 pulse switch, to momentarily release the torque converter clutch during a 4-3 downshift, was programmed into the ECM for the 1988 model year. These models had previously used a Type 15 Solenoid Assembly. FIGURE 1 - THM 700-R4 TRANSMISSION IDENTIFICATION INFORMATION Page 2156 Exhaust Manifold: Service and Repair EXCEPT TURBO 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. TURBO Left 1. Disconnect battery ground cable, then remove air cleaner and duct assembly. 2. Remove turbocharger air inlet elbow and upper fan shroud. 3. Loosen fan nuts, then remove serpentine drive belt. 4. Remove fan and pulley assembly, then the power steering pump pulley. 5. Remove rear brace at generator, then raise and support vehicle. 6. Remove left front tire and wheel assembly, then the left wheelhouse panel. 7. Disconnect power steering inlet and outlet hoses from pump. 8. Remove oil filter lines bracket from power steering pump, then the steering column intermediate shaft. 9. Disconnect exhaust crossover pipe from left exhaust manifold. 10. Disconnect power steering pump and rear brace as an assembly from front bracket. 11. Disconnect spark plug wires from plugs, then remove spark plugs. 12. Remove exhaust manifold attaching bolts and studs. 13. Remove manifold lock tabs, washers and heat shields, then the manifold. 14. Reverse procedure to install. Right 1. Disconnect both battery cables, then drain engine coolant from radiator. 2. Remove battery tray and vacuum tank. 3. Remove turbocharger oil feed hose and coolant return pipe. 4. Disconnect oxygen sensor electrical connector, then raise and support vehicle. 5. Remove right front tire and wheel assembly, then the wheelhouse panel. 6. Disconnect exhaust system from catalytic converter. 7. Remove catalytic converter support bolts, then lower vehicle. 8. Remove turbocharger as described in TURBOCHARGER. 9. Remove exhaust crossover pipe from exhaust manifold. 10. Disconnect spark plug wires from plugs, then remove spark plugs. 11. Remove charge air cooler lower supports, exhaust manifold attaching bolts and studs, lock tabs, washers and heat shields. 12. Remove exhaust manifold. 13. Reverse procedure to install. Page 7583 Symbol Identification Wire Color Code Identification WIRE COLOR ABBREVIATION BLACK BLK BLUE BLU DARK BLUE DK BLU Page 7681 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 4. Make repair. Page 3229 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. Frame Crossmember, Rear - Rattle Noise Suspension Strut / Shock Absorber: All Technical Service Bulletins Frame Crossmember, Rear Rattle Noise Number: 90-403-10 Section: 10 Date: March 1991 Corp. Bulletin No.: 062001 Subject: RATTLE NOISE FROM REAR FRAME CROSSMEMBER Model and Year: 1988-90 T1 TRUCKS Separation of the rear shock absorber tower from the frame crossmember in 1988-90 T Utility Vehicles may result in the driver noticing a rattle noise coming from the rear of the vehicle over bumps. If the rear shock tower separates from the frame crossmember, the entire rear frame crossmember and tower assembly should be replaced using the following parts and service procedures. The new crossmember has reinforced shock absorber towers. Service Procedures: 1. Disconnect battery ground cable. 2. Raise vehicle on hoist. 3. Remove the six bolts holding the fuel tank protective shield on and remove shield. Figure 1 - Fuel Tank Installation 4. Remove fuel tank (Figure 1). A. Drain fuel from tank through the filler neck using a hand pump or energize in-tank fuel pump and drain from fuel feed line. See service manual for proper procedures and safety precautions. B. Remove lines and disconnect fuel fill hose and vent hose. C. Support fuel tank and remove tank supports (5). Brakes - Poor Rotor Finish/Hard Pedal Feel Brake Rotor/Disc: All Technical Service Bulletins Brakes - Poor Rotor Finish/Hard Pedal Feel Number: 90-293-5 Section: 5 Date: July 1990 Corp. Bulletin No.: 005003 Subject: BRAKE ROTOR REFINISH Model and Year: 1981-90 ALL PASSENGER CARS AND TRUCKS TO: ALL CHEVROLET DEALERS Comments have been received of poor brake rotor finish and/or hard brake pedal feel after refinishing brake rotors using the On-Vehicle Brake Lathe (VGB 320/366, Kent-Moore 38- 070400) sold through GM Dealer Equipment program. CAUSE: This condition results from using non-original cutting tips. Only original equipment replacement tips should be used. CORRECTION: When replacing the original cutting tips for an On-Vehicle Brake Lathe, use only replacement tips ordered from Kent-Moore Tool and Equipment Division. The replacement cutting tips can be ordered from Kent-Moore (1-800-GM-TOOLS) as follows: Part Number: J-37704-13 Cufting Tips (Box of Ten) 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 this firm or for any such items which may be available from other sources. 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. Ignition System - Diagnosis Precautions Spark Plug Wire: All Technical Service Bulletins Ignition System - Diagnosis Precautions Number: 88-138-6D Section: 6D Date: Feb., 1988 Subject: ENGINE MISS, HESITATION, OR ROUGHNESS DUE TO PIERCED SECONDARY IGNITION COMPONENTS Model and Year: ALL MODELS WITH GASOLINE ENGINE TO: ALL CHEVROLET DEALERS During the diagnosis procedures for an engine miss, hesitation, or roughness condition, a spark plug or spark plug wire condition may be suspected. Several types of commercial or homemade diagnostic equipment require the secondary ignition boots or wire to be pierced. This is normally done to check for spark plug firing or to perform a cylinder balance test. Similarly, the use of pliers or other such tools to disengage a spark plug boot may pierce or damage the boot or wire. NOTICE: SECONDARY IGNITION COMPONENTS SHOULD NOT BE PIERCED FOR ANY REASON. Piercing a spark plug wire and/or distributor or direct fire module nipple may create a failure condition that will not be immediately apparent. Over time, the hole in the pierced boot may allow a ground path to develop, creating a plug misfire condition. Heavily moisture-laden air in the vicinity of the pierced boot may accelerate this effect. Piercing a secondary ignition wire creates a gap in the wire's conductive core. This gap is a point of high resistance. The current flow in the wire will increase to compensate for the higher wire resistance. Over time, the wire may fail, creating a plug misfire condition. The time required for the condition to appear depends upon the extent of damage to the conductive core. To help prevent future customer comments that are spark plug wire related, do not pierce or otherwise damage any secondary ignition component. Only use diagnostic equipment containing an inductive pick-up to check for spark plug firing or to perform cylinder balance tests. When disengaging a spark plug boot from the spark plug, twist the flanged boot 1/2 turn, then pull only on the boot to remove the wire. Page 7143 Page 3577 Page 6688 Loosen and Shim # 1 Body Mount: 1. Loosen the # 1 body mount to zero torque. 2. Raise the body off the mount to obtain clearance between the floor and the top of the body mount. 3. Cut a 4" x 4" square of 1/32 inch thick teflon or nylon (obtain locally) and drill a 5/8" hole through the center. Insert this between the floor pan and the body mount and lower the body. An alternative material is three washer pump shields, P/N 22063244. If three washer pump shields are used, cut three shields (sheets) to size and locate a 5/8" hole in the center of each shield. Place the three shields between the floor pan and mount, then lower the body on the mount. 4. Apply Loctite 242 thread locking compound (GM P/N 12345382), or equivalent, to the body mount, bolt and retorque to 60-80 N-m (44-59 Lbs.Ft.). NOTE: Some insulating materials may compress over time resulting in a loss of torque to the body mount bolt. For this reason, nylon or teflon 1/32" thick and the thread locking compound on the bolt are being specified. Parts are currently available from GMSPO. WARRANTY INFORMATION: For vehicles repaired under warranty use: Labor Operation: T7276 Labor Time: 0.8 hr. Trouble Code: 92 NOTE: Labor Operation is coded to base vehicle coverage in the warranty system. Page 7346 Note the difference between the wire exit openings of the new multi-functional lever and the old lever (Figure 1). Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Op. Description E7060 Multi-functional lever, replace Use applicable labor time guide for labor hours. Page 5524 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 4. Make repair. Page 3068 Fuel Supply Line: Description and Operation Fuel Tank Assembly FUEL TANK The fuel tank is located under the left rear of the vehicle and is the fuel reservoir. The tank has a vertical baffle installed to prevent fuel slosh. The fuel pump and fuel level sending unit assembly are mounted in the fuel tank as one assembly. The fuel tank assembly also consists of the fuel filler neck and filler cap. Fuel Filler Neck FUEL FILLER NECK To help prevent refueling with leaded fuel, the fuel filler neck has a built-in restrictor and deflector. The opening of the restrictor will accept only the smaller unleaded gasoline nozzle which must be fully inserted to bypass the deflector. Attempted refueling with a leaded fuel nozzle will result in fuel splashing back out of the filler neck. FUEL TANK FILLER CAP The fuel tank filler neck is equipped with a screw type cap. The threaded part of the cap requires several turns counterclockwise to remove. The long threaded area was designed to allow any remaining fuel tank pressure to escape during the cap removal operation. A ratchet type torque limiting device prevents over-tightening. To install, turn the cap clockwise until a clicking noise is heard. This signals that the correct torque has been reached and the cap is fully seated. Cruise Control - Works Intermittently Cruise Control Switch: All Technical Service Bulletins Cruise Control - Works Intermittently Number: 92-195-9B Section: 9B Date: MAY 1992 Corporate Bulletin No.: 268102R ASE No.: A8 Subject: CRUISE CONTROL WORKS INTERMITTENTLY Model and Year: 1985-92 M VANS 1990-92 L VANS 1986-92 S/T TRUCKS Some owners of 1985-1992 WL vehicles or 1986-1992 S/T vehicles with cruise control (RPO K34) may comment that their cruise control operates intermittently. This condition may be caused by the wires becoming pinched as they exit the multi-functional lever. These wires may ground out on the lever rod and short the cruise function. To correct this condition in production, the wiring harness that exits the lever has been rerouted and the opening in the multi-functional lever has been redesigned to allow the wires more clearance. The diagnostic procedures in the applicable Service Manual should be followed before replacing the multi-functional lever. If the multi-functional lever requires replacement, the following procedure should be performed: SERVICE PROCEDURE: 1. Disconnect the wire harness connector. 2. Remove the harness protector cover. 3. Attach a long piece of mechanic's wire to the end of the harness connector. 4. Remove the multi-functional lever from the turn signal switch. 5. Gently pull the harness up and out so the mechanic's wire can be used to install the new unit. 6. Attach the upper end of the mechanic's wire to the new harness connector. Gently pull the mechanic's wire at the lower end of the column, feeding the harness into the proper location in the column. 7. Install a redesigned multi-functional lever (P/N 25111290) into the turn signal switch. 8. Disconnect the mechanic's wire from the harness connector. 9. Install the harness protector cover. 10. Reconnect the wire harness connector. SERVICE PARTS INFORMATION Part Number Description 25111290 Multi-functional Lever Use applicable labor time guide for labor hours. Important: The new Part Number (P/N 25111290) should be used when correcting this condition in the above listed vehicles. Page 7902 Headlamp Switch: Electrical Diagrams Light Switch Details (Part 1 Of 3) 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 Brakes - ECU Software Improvement Electronic Brake Control Module: Technical Service Bulletins Brakes - ECU Software Improvement Number: 91-101-5 Section: 5 Date: November 1990 Corp. Bulletin No.: 065021 Subject: INTRODUCTION OF CODES 6, 9 AND 10 AS SOFT CODES Model and Year: 1988-91 C/K, S/T, R/V, G AND M TRUCKS WITH RWAL TO: ALL CHEVROLET DEALERS Beginning in August 1990, a software change was made to the Electronic Control Units on all RWAL equipped vehicles. This software improvement will change codes 6, 9, and 10 to "Soft Codes." The conditions which set these codes remain the same, as well as the diagnostics technicians should follow to determine the root cause. Codes 6 and 9 will light the brake light when a fault is detected and the applicable code will be stored in memory. The brake light will remain on until the next ignition cycle at which time if the fault is not present, the brake light will remain off. The code, will still remain in memory as a "Soft Code." If the code should reoccur, the brake light will again be illuminated for the duration of that ignition cycle. A code 10 will set if the brake pedal is depressed or the brake switch circuit is opened and remains open until vehicle speed passes approximately 38 MPH. This soft code differs from codes 6 and 9 in that the red brake light will be illuminated only while the fault is detected. Code 10 will remain stored in the ECU memory after the light has been turned off. IMPORTANT: Technicians MUST use a Tech One scan tool to read codes. This is because soft codes will be erased by grounding terminals A to H and a false code 9 could be set if this is attempted. The new ECUs can be identified by the code printed on the bottom of the longer of two bar code labels on the module. Older ECUs will have a fifteen digit alphanumeric code beginning with 912349K. New ECUs with the soft code software will have a code that begins with 919220K. Transfer Case - Increased Shift Effort From 2H to 4H Technical Service Bulletin # 914047A Date: 910801 Transfer Case - Increased Shift Effort From 2H to 4H Number: 91-404-7A Section: 7A Date: AUGUST 1991 Corporate Bulletin No.: 167401 ASE No.: A2 Subject: HIGH TRANSFER CASK SHIFT EFFORT Model and Year: 1988-91 T1 TRUCKS Some 1988-91 T-Trucks may experience high transfer case shift effort or total blockouts when "shifting on the fly" from 2H to 4H under cold weather conditions. This condition may be corrected by the installation of the synthetic 75W90 gear lube described in Dealer Service Bulletin No. 91-128-7A. This fluid maintains a more constant viscosity under cold weather conditions allowing quicker front axle synchronization and easier transfer case engagement. If the installation of the synthetic fluid does not result in a satisfactory shift effort, an "Easy Shift" package may be installed in the transfer case. This package features a roller pin (53) rather than a solid pin on the mode shift fork (54) and revised ramp angles on the sector (55) to reduce engagement forces. This package was installed in the 1991 model year and will provide reduced transfer case shift effort under cold weather conditions. Figure 1 VEHICLES INVOLVED: Group A: Some 1988-91 T-Trucks equipped with transfer cases identified by the following part numbers: 15568078 15627441 15568079 15627442 15568597 15653450 Page 2151 NOTICE: When jacking or lifting vehicle from frame side rails, be certain lift pads do not contact catalytic converter or damage to converter may result. 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. This device sometimes requires the use of heat shields, due to its high operating temperatures. The heat shields are necessary to protect chassis components, passenger compartment and other areas from heat related damage. 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. A small diameter fuel tank filler tube 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. Page 1608 Labor Operation No.: K6550 Valve, Pressure Regulator-R&R; or Replace Use the appropriate labor time in the labor time guide. Parts are currently available from GMSPO. Modes of Operation Engine Control Module: Description and Operation Modes of Operation Acceleration Mode In the Acceleration Mode, the ECM senses rapid change in throttle position and manifold pressure and provides a corresponding amount of added fuel. Battery Voltage Correction Mode When battery voltage is low, the ECM compensates to maintain acceptable system performance by increasing injector pulses, idle speed and ignition dwell time. Clear Flood Mode (Port and TBI Injection) A flooded engine is cleared by fully depressing the accelerator pedal, which causes the ECM to pulse the injectors at a air/fuel ratio of 20:1. The ECM will maintain this air/fuel ratio as long as the throttle is wide open and engine RPM is less than 600. If throttle position becomes less than 80% of wide open throttle, the ECM returns to "Starting Mode". Deceleration Mode In the Deceleration Mode, the ECM senses changes in throttle position and manifold pressure and reduces fuel delivery. When decelerating very rapidly, the ECM can cut off fuel completely for short periods of time. Electronic Spark Timing (EST) The Electronic Spark Timing (EST) distributor contains no vacuum or centrifugal advance mechanisms. In addition to the connectors normally found on HEI distributors, the HEI-EST distributor also has four wires going to a four terminal connector. A reference pulse, indicating engine RPM and crankshaft position is sent to the ECM. The ECM determines the proper spark advance for the engine operating conditions and sends an "EST" pulse to the distributor. In the case of EST failure, a back-up spark advance system is incorporated in the module. Run Mode The Run Mode consists of two separate operating conditions; open loop and closed loop. The engine operates in open loop when it is first started and RPM is above 400 RPM. During open loop operation, the ECM disregards the oxygen sensor signal and determines air/fuel mixture primarily from the coolant and MAP sensors. The engine will continue to operate in open loop until the following conditions are met: 1. The Oxygen sensor has varying voltage output, indicating it is hot enough to operate properly. 2. The Coolant sensor is above a specified temperature. 3. A specific amount of time has elapsed since the engine was started. The specified values for conditions mentioned above vary from model to model, and are stored in the ECM PROM. When the above conditions are met, the engine goes into closed loop operation. When operating in closed loop, the ECM determines the air/fuel ratio (injector pulse rate) based on signals from the oxygen sensor. This allows the air/fuel mixture to remain close to the optimum 14.7:1 ratio. During idling conditions, the V6-173 and V8-454 engines automatically goes into open loop operation. Starting Mode (Port and TBI Injection) When the ignition switch is rotated to the "On" position, the ECM energizes the fuel pump for two seconds and fuel pressure is built up to the TBI unit. The ECM then checks the coolant temperature sensor, the TPS and determines the proper air/fuel mixture for starting. The ECM controls the air/fuel ratio by changing the length of time the injectors are turned on and off. This is accomplished by "Pulsing" the injectors for short periods of time. Page 501 A new pressure regulator valve (III. 218) has been made which will improve the oil pressure stability at lower RPM. SERVICE PARTS INFORMATION: Description Part Number Valve, Pressure Regulator (III. 218) 8684048 Part numbers are for Reference Only. Check with your Parts Department for latest information. 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. Page 7712 LIGHT BLUE LT BLU BROWN BRN GRAY GRY GREEN GRN DARK GREEN DK GRN LIGHT GREEN LT GRN ORANGE ORN PINK PNK PURPLE PPL RED RED TAN TAN WHITE WHT YELLOW YEL Body - TPO Fascia Cleaning Prior to Painting Paint: All Technical Service Bulletins Body - TPO Fascia Cleaning Prior to Painting INFORMATION Bulletin No.: 08-08-51-002 Date: March 12, 2008 Subject: New Primer For TPO Fascias and Affected Cleaning Process of Painting Operation Models: 2009 and Prior Passenger Cars and Trucks 2009 and Prior HUMMER H2, H3 The purpose of this bulletin is to inform the technician that General Motors has made a change in the primer it uses for TPO plastic for service parts. This new primer comes in several different colors from five different suppliers. This change affects the cleaning process of the painting operation. The new process is as follows. 1. Wash with soap and water. 2. Clean with a 50% mix of isopropyl alcohol and water (or a waterborne cleaner). Check with your paint supplier for product recommendations. 3. Scuff sand per your paint suppliers recommendations. Note: The use of a solvent-type cleaner will soften, or begin to dissolve the primer. Base coats do not have any affect on this primer. 4. Reclean with a 50% mix of isopropyl alcohol and water (or a waterborne cleaner). All fascias, with the exception of the Corvette, Camaro, and Cadillac XLR, are made of TPO. You may find other TPO parts with this primer. If the technician has a question as to the type of plastic they are painting, inspect the back of the part for the plastic symbol (TPO). Disclaimer Page 5941 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 Page 6621 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) Page 1585 BELT TENSION Page 3977 Transmission Cooler: Technical Service Bulletins A/T - Cooler Replacement/Flushing BULLETIN NO: 93-7A-97 SECTION: 7A Automatic Transmission NUMBER: 14 CORPORATE REFERENCE NO: 367102R DATE: July, 1993 SUBJECT: Information on Automatic Transmission Cooler Replacement MODELS: 1993 and Prior Light Duty Trucks Equipped with Automatic Transmissions When inspection of an inoperative automatic transmission reveals metal material in the oil pan, the transmission oil cooler (located in the radiator end tank) must be replaced. The cooler lines must also be flushed to prevent any debris from entering the transmission oil cooler or the transmission. If inspection reveals friction material or fluid contamination (but no metal), the transmission cooler must be flushed and a flow check MUST be performed. It is essential to flush the cooler after SRTA installation, major overhaul, in the case of pump or torque converter replacement, or when fluid contamination is suspected. Use Kent-Moore tool J35944 and solvent J35944-20 to flush the cooler. Follow the instructions published in each Service Manual, Section 7A, On Vehicle Service, Transmission Cooler Flushing. SERVICE PARTS INFORMATION Refer to section 4.128 of the appropriate GMSPO parts catalog for transmission oil cooler applications. WARRANTY INFORMATION For vehicles repaired under warranty, use: Note: If transmission is to be replaced with SRTA, do not use ADD condition H (To Replace Transmission Oil Cooler - 0.7 hr). Labor Operation K7000 (Transmission Assembly Replace) already includes 0.7 hr (for transmission cooler flush). Page 7282 Loosen and Shim # 1 Body Mount: 1. Loosen the # 1 body mount to zero torque. 2. Raise the body off the mount to obtain clearance between the floor and the top of the body mount. 3. Cut a 4" x 4" square of 1/32 inch thick teflon or nylon (obtain locally) and drill a 5/8" hole through the center. Insert this between the floor pan and the body mount and lower the body. An alternative material is three washer pump shields, P/N 22063244. If three washer pump shields are used, cut three shields (sheets) to size and locate a 5/8" hole in the center of each shield. Place the three shields between the floor pan and mount, then lower the body on the mount. 4. Apply Loctite 242 thread locking compound (GM P/N 12345382), or equivalent, to the body mount, bolt and retorque to 60-80 N-m (44-59 Lbs.Ft.). NOTE: Some insulating materials may compress over time resulting in a loss of torque to the body mount bolt. For this reason, nylon or teflon 1/32" thick and the thread locking compound on the bolt are being specified. Parts are currently available from GMSPO. WARRANTY INFORMATION: For vehicles repaired under warranty use: Labor Operation: T7276 Labor Time: 0.8 hr. Trouble Code: 92 NOTE: Labor Operation is coded to base vehicle coverage in the warranty system. Page 8031 Front Door Trim Panel Components NOTE: Images shown are for manual windows, power windows are similar. Tool Required: J-21104 Trim Pad Remover. REMOVE OR DISCONNECT 1. Door pillar molding. 2. Armrest. 3. Power window switch. 4. Trim panel. Pry the fasteners from their seats using J-21104. INSTALL OR CONNECT 1. Trim panel to the door. 2. Armrest. 3. Power window switch. 4. Door pillar molding. Door Inner Panel Water Deflector Replacement Page 6814 Symbol Identification Page 552 6. Tape the solder and diode. 7. Reinstall the black plastic conduit. 8. Reconnect connector to the generator. 9. Reconnect battery. This procedure will not affect the operation of the generator light during the bulb check at the beginning of the start cycle. For vehicles repaired under warranty use, Labor Operation Number: T7990 Labor Time: .4 Hr Page 1775 Note The rivet stud and surrounding panel area MUST BE properly refinished PRIOR to the installation of the electrical ground wire terminal and conductive nut to maintain a secure, stable and corrosion-free electrical ground. 11. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 12. Allow the refinished repair area to cure sufficiently before removing the protective material applied to the rivet stud threads. 13. Remove the painters tape or equivalent from the rivet stud threads. 14. Using GM approved residue-free solvent or equivalent, thoroughly clean the rivet stud threads to remove any adhesive and allow to dry. 15. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive rivet stud. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 16. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 17. Install the electrical ground wire terminal to the M6 conductive rivet stud. 18. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 19. Install the M6 conductive nut to the rivet stud and: Tighten Tighten to 8 Nm (71 lb in) 20. Verify proper system operation. Parts Information Warranty Information (excluding Saab Models) For vehicles repaired under warranty, use: Warranty Information (Saab Models) Locations Power Window Switch: Locations Behind Instrument Cluster Page 7158 ** Refer to the applicable labor time guide for paint mix time allowance and include in "Other Hours." *** Select corresponding material allowances to combine with proper "Above Belt Line" material allowance in "Net Amount" as required for appropriate vehicle type and operations performed. Reimbursement Customer claims for reimbursement on previously paid repairs to correct paint topcoat delamination (peeling) are to be submitted according to the forms and instructions included in this bulletin (additional copies to be reproduced locally). Owners must submit original documentation that reasonably confirms the amount of unreimbursed repair expenses, a description of the repair, the date of the repair, and the person or entity performing the repair. Page 6913 Symbol Identification Wire Color Code Identification WIRE COLOR ABBREVIATION BLACK BLK BLUE BLU DARK BLUE DK BLU Page 5311 Symbol Identification Wire Color Code Identification WIRE COLOR ABBREVIATION BLACK BLK BLUE BLU DARK BLUE DK BLU Page 4267 Pinion Gear: Service and Repair Corporate and Eaton 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. Page 5573 Disclaimer Page 1677 Symbol Identification Wire Color Code Identification WIRE COLOR ABBREVIATION BLACK BLK BLUE BLU DARK BLUE DK BLU Page 4703 SERVICE PARTS INFORMATION Part Number Description 15664811 Vacuum Actuator Switch Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: K4120 Use applicable labor time guide for labor hours. Page 1688 Oil Pressure Gauge: Testing and Inspection Gauge Reads ``0'' 1. Check oil level, add if necessary. 2. Remove oil pressure sensor lead at sensor, gauge should read ``80.'' 3. If gauge stays at ``0'' remove sensor lead at gauge, gauge should read ``80.'' If gauge reads ``80'' find short to ground between gauge and sensor. 4. If gauge still reads ``0'' replace cluster. 5. With lead removed at sensor, connect a suitable ohmmeter to sensor. With engine stopped resistance should be one ohm, and approximately 44 ohms with engine running. 6. If sensor reads one ohm with engine running, replace sensor. Page 4625 8. New O-ring seal P/N 14095598 (67) and new plastic washer (retainer) P/N 14037958 (66) into the front case half. 9. New sector with shaft P/N 15637215 (55) into the front case half. 10. Range shift fork (51), range shift hub (34) into the planetary carrier (36). - It is necessary to rotate the sector with shaft (55) to obtain clearance when installing the range fork (51). INSPECT: The teeth of the synchronizer stop ring (28) and drive sprocket (20) for damage. If the parts are to be replaced due to damage or in cases of customer complaint of clash when shifting from 2Hi to 4Hi, follow steps 11, 12, & 13, otherwise skip to step 14. 11. New drive sprocket P/N 15579803 (20) to the main shaft (19). 12. New synchronizer stop ring P/N 14071703 (28) to the drive sprocket (20). 13. Synchronizer assembly (81) to the main shaft. 14. Mainshaft (19)/drive sprocket (20), chain (58) and front output shaft (21) as a unit. Mode shift fork (54) and shift rail (48) will be installed with the mainshaft. 15. Fork shift spring (52). Mainshaft Extension and Oil Pump 16. Rear case (17) over mainshaft (19) and onto the front case half (45). - Clean case mating surfaces and apply RTV sealer or equivalent to the mating surfaces. - Transfer dowels from old case half to new case half if necessary. IMPORTANT: Be careful not to damage the oil pump (12) while installing the rear case half (Figure 7). 17. Case bolts (3) into case halves. - Apply Loctite 242 (R) or equivalent on pump housing bolt threads. - The two longer bolts and washers into the doweled case holes (33). - Tighten bolts to 31 N-m (23 lbs.ft.). 18. Speedometer tone wheel (11) to the main shaft (19). 19. Pump retainer housing (8) and pump housing bolts (7) to the rear case half (17). - Clean mating surfaces and apply RTV sealer or equivalent to the mating surfaces. - Apply Loctite (R) or equivalent on pump housing threads. - Pump housing bolts are shouldered (7). - Tighten bolts to 41 N-m (30 lbs.ft.). 20. Output bearing retainer (snap ring) (5), to the main shaft (19). 21. Rear extension housing (4) and extension housing bolts (3) to the pump retainer housing (8). - Clean mating surfaces and apply RTV sealer or equivalent to the mating surfaces. - Apply Loctite 242 (R) or equivalent on the extension housing bolts. - Tighten bolts to 31 N-m (23 lbs.ft.). External Components 22. Poppet plunger (70), poppet spring (71), new O-ring seal P/N 14071849 (69), and poppet screw (68) to the front case half (45). A/T - Updated ATF Fluid Color/Level Check Information Fluid - A/T: All Technical Service Bulletins A/T - Updated ATF Fluid Color/Level Check Information Number: 89-234-7A Section: 7A Date: August 1989 Corporate Bulletin No.: 977126 Subject: AUTOMATIC TRANSMISSION/TRANSAXLE FLUID COLOR/LEVEL CHECK INFORMATION Model and Year: 1987-89 PASSENGER CARS AND TRUCKS WITH AUTOMATIC TRANSMISSIONS TO: ALL CHEVROLET DEALERS THE INFORMATION PROVIDED IN THIS BULLETIN SUPERSEDES THE PUBLISHED INFORMATION PERTAINING TO AUTOMATIC TRANSMISSIONS COVERED ON PAGES 3 AND 4 OF DEALER SERVICE BULLETIN 89-145-08 DATED MAY 1989. PLEASE MARK YOUR COPIES OF 89-145-08 TO INDICATE THE INFORMATION CONTAINED IN THIS BULLETIN. This bulletin provides Service Manual updates for Transmission/Transaxle fluid level and condition information. This information is updated for 1989 service manuals printed prior to June 1989. TRANSMISSION/TRANSAXLE FLUID LEVEL INFORMATION: Checking fluid level and condition (color and odor) at regular intervals will provide early diagnosis information about the transmission. This information may then be used to correct a condition that, if not detected early, could result in major transmission repairs. When adding or changing fluid, use only DEXRONR II. Refer to Maintenance and Lubricaton (Service Manual Section OB) for maintenance information and servicing intervals. NOTICE: Do not overfill. Overfilling will cause foaming, loss of fluid, shift complaints and possible damage to to transmission. ^ Fluid level should only be checked when it reaches a normal operating temperature of 82-93C (180-200F). This temperature is reached after approximately 24 km (15 miles) of driving. ^ Fluid color will be red when new. IMPORTANT: When new, automatic transmission fluid is red in color. The red dye is added so the assembly plant can identify as transmission fluid and distinguish it from engine oil or anti-freeze. The red dye is not an indicator of fluid quality and is not permanent. As the vehicle is driven, the transmission fluid will begin to look darker in color. The color may eventually appear light brown. A dark brown color along with a burnt odor may indicate excessive fluid deterioration and signal a need for fluid change. TRANSMISSION/TRANSAXLE FLUID CHECKING PROCEDURE: 1. Start engine and drive vehicle for a minimum of 24 km (15 miles), or until normal operating temperature is reached. NOTICE: The automatic transmission fluid level must be checked with the vehicle at normal operating temperature, 82-93C (180-200F). Temperature will greatly affect transmission fluid level. If the vehicle is not at normal operating temperature and the proper checking procedures are not followed, the result could be a false reading of the fluid level indicator and an incorrect adjustment of the fluid level. 2. Park vehicle on level ground. 3. Move gear selector to "PARK". 4. Apply parking brake and block wheels. 5. Let vehicle idle for 3 minutes with accessories off. Page 1215 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 Page 7214 Seat Cover: 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. Page 7908 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. Engine - Noise/Damage Oil Filter Application Importance Oil Filter: 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 Page 1271 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 Page 6978 6. Spray entire prepared area with a coat of DP40/DP401 anti-corrosion primer (PPG/ Ditzler) or equivalent. Follow manufacturers instructions and recommended dry times. 7. Apply 2 to 3 medium wet coats of primer-surfacer to primed surfaces of truck, making sure to follow manufacturers instructions for application. 8. After allowing adequate drying time, wet sand with 400 grit (or finer) sandpaper or dry sand with 320 grit (or finer) sandpaper. 9. Repeat steps 4 and 5. 10. Apply 1 medium wet coat of primer sealer, following manufacturers instructions. 11. Apply 3 to 4 medium wet coats (or until primer color is well hidden) of Acrylic/Urethane Enamel Color. Follow manufacturers instructions. NOTICE: Reinstall all trim and other items removed in step 2. 12. Final wash and detail vehicle. Claim Information Submit a claim with the information indicated below: * Select times as listed below for "Labor Hours" and material allowances for "Net Amount" as required for appropriate vehicle type and operation performed. Coolant - Used Anti-Freeze Policy Coolant: Technical Service Bulletins Coolant - Used Anti-Freeze Policy Number: 91-09-0A Section: OA Date: April 1990 Corporate Bulletin No.: 976202 Subject: INFORMATION REGARDING RECONSTITUTED ANTI-FREEZE COOLANT TESTING AND THE USE OF A REFRACTOMETER Model and Year: ALL MODELS AND YEARS TO: ALL CHEVROLET DEALERS RECONSTITUTED ANTIFREEZE At present, three types of recycling systems are available: 1) chemical addition to coolant; 2) filtration and addition of supplemental additives; and 3) separation of pure glycol from used coolant and reinhibition. 1) Chemical Addition-NOT RECOMMENDED With chemical addition, chemicals are added to the used engine coolant in an attempt to "clean up" the coolant. This system is the easiest since the only work involved is the addition of chemicals to the radiator. Most of these types of recycling systems use a strong acid to change precipitated corrosion products into a more soluble form. However, in addition to dissolving the corrosion products, the strong acid also attacks and corrodes the metals of the cooling system. 2) Filtration and Addition of Supplemental Additives-NOT RECOMMENDED In this type of system, the used coolant is either taken out of the vehicle or a flush-type unit is connected to the cooling system. The current technology consists simply of filtration and reinhibition of the spent coolant. While this does remove suspended solids, filtration does nothing to remove harmful degradation and corrosion products that are soluble in glycol solution. The reinhibition step used in current recycling systems may fail to produce a coolant which adequately protects all metals including aluminum in the most critical heat transfer applications, such as occurs in the cylinder heads and blocks. 3) Separation of Pure Glycol and InhibitionThe separation of pure glycol and the addition of fresh inhibitors is the ideal method for recycling coolants. Unfortunately, this method is expensive from both a collection standpoint and the technology available to economically extract pure ethylene glycol from used coolant. At this time, General Motors does not endorse these practices or equipment. Due to a worldwide shortage of ethylene glycol in 1988, some coolant manufacturers have started to mix other types of glycol in their coolant formulations; propylene glycol is the most common new ingredient. A hydrometer will not provide a correct measurement of freeze protection when anything other than ethylene glycol and water is being tested. The degree of inaccuracy will vary depending on the proportion of other glycols present in the coolant. Hydrometers test the amount of glycol in a mixture by measuring the specific gravity of the mixture; the more ethylene glycol, the higher the float balls go, and the better the freeze protection. Because ethylene glycol and propylene glycol do not have the same specific gravities, hydrometer readings of mixtures containing propylene glycol give incorrect values. As the shortage of ethylene glycol continues and/or worsens, more and more variations in antifreeze formulas will be marketed. It is, therefore, recommended that you purchase a "refractometer" and encourage your technicians to use it. Refractometers test for the amount of glycol in a coolant mixture by measuring the speed of light as it passes through the fluid and are not affected by the specific gravity of the glycol. The freeze protection of solutions of ethylene glycol in water, solutions of propylene glycol in water, and solutions of mixtures of propylene glycol and ethylene glycol in water may all be tested with sufficient accuracy using a refractometer. The following refractometers are available from Kent Moore: J 23688 Farenheit scale, measures to -50 F J 26568 Centigrade scale, measures to -45.5 C J 38633 Farenheit scale, measures to -84 F (For extreme cold weather regions) Diagram Information and Instructions Oil Pressure Gauge: Diagram Information and Instructions 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 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. Page 3253 Knock Sensor: Testing and Inspection Chart C-5 - Electronic Spark Control System Check Page 576 Frame Angle Measurement (Express / Savana Only) ........ Page 6120 J 6435 Snap Ring Pliers 1. Clutch plate and hub assembly (2). 2. Pulley (6). ^ Mark or scribe the location of the clutch coil (8) to terminal on the compressor front head (16). 3. Clutch coil assembly (8). ^ Coil housing retaining ring (7) with J 6435. ^ Using a large screwdriver or small pry bar, pry the clutch coil away from the front head. If necessary, hand impact a blow to the screwdriver handle or pry bar to break the adhesive bond of the clutch coil to the front head. Clean ^ Adhesive from the coil by scraping with a putty knife. ^ Remove any adhesive around the three locator hole areas of the front head and around the three clutch coil locator protrusions at the rear of the clutch coil housing. ^ Use a suitable solvent to clean the coil. Important ^ After applying Loctite Depend, Loctite Trim and Detail Adhesive or equivalent to the coil, install all the clutch parts to the compressor Allow 30 minutes for the adhesive to set. Install or Connect Tool Required: J 6435 Snap Ring Pliers Adhesive Fill Guide 1. Adhesive to the clutch coil (8). ^ Place the clutch coil "face down" and apply the adhesive in a circular bead around the three coil locator protrusions. Page 914 Fluid - M/T: Fluid Type Specifications Tremec 3 Speed Fluid Type ............................................................................................................................................ ........................................................... 80W Gear Oil Saginaw 3 Speed Fluid Type ............................................................................................................................................ ........................................................... 80W Gear Oil Saginaw (76 mm) 4 Speed Fluid Type ............................................................................................................................................ ...................................................... 80W-90 Gear Oil Warner 83 mm 4 Speed Fluid Type ............................................................................................................................................ ........................................................... 80W Gear Oil Warner T-4C 4 Speed Fluid Types .......................................................................................................................................... ......................................................... Dextron II ATF Muncie CH & SM-465 4 Speed Fluid Types .......................................................................................................................................... ....................................................... 80W-90 Gear Oil Warner T-5 (77MM) 5 Speed Lubricant Type ..................................................................................................................................... ......................................................... Dextron II ATF MUNCIE 5LM60 (HM-290) 4 & 5 Speed Lubricant Type ..................................................................................................................................... ................................ Syncromesh Trans Fluid T2850 Page 5441 - 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 Page 2149 Whenever it is determined that one washer is worn, all three thrust washers should be replaced with kit P/N 26018721, that contains all three thrust washers. Parts are currently available from GMSPO. The kit should be used to resolve T Model front axle growl noise conditions. For vehicles under warranty, use: Labor Operations: F2115 Labor Time: 1.4 Hrs (plus applicable "adds") Diagram Information and Instructions Multiple Junction Connector: Diagram Information and Instructions 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 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. Page 7794 e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors Do Not require all the steps shown. Skip the steps that Do Not apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. 1. Separate connector halves (see Figures 2 through 6). Figure 2 Figure 3 Page 2711 ECM Connector Terminal Identification & Voltage Specifications. Page 3987 11501033 Nut 1 Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: K2283 (Manual Trans.) Labor Time: 0.4 Hrs. Labor Operation: K6723 (Automatic Trans.) Labor Time: 0.4 Hrs. Specifications Valve Clearance: Specifications All ......................................................................................................................................................... ................................................................ E-I-E-I-I-E A/T - DEXRON(R)-VI Fluid Information Fluid - A/T: All 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. Page 6144 Compressor Clutch: Service and Repair With HR-6 Compressor Clutch Plate and Hub Assembly HR-6 Component View Clean ^ The compressor assembly with solvent and blow dry with dry air. Remove or Disconnect Tools Required: J 33026 Compressor Holding Fixture J 33027 Clutch Hub Holding Tool J 33022 6-Point 13 mm Socket J 33013-B Hub and Drive Plate Remover and Installer Page 4094 ^ Harsh N-D, P-D Shifts ^ Slipping on Hard Accelerations ^ Forward Clutch Distress ^ No Upshift ^ 1-2 Tie-Up/Lo-Rev Clutch Distress and 2-4 Band Distress Page 1802 5. Remove paint and primer from the area surrounding the 10 mm (0.40 in) until bare metal is visible. Important The M6 conductive rivet stud as shown, can accommodate a panel thickness range of 0.7-4.2 mm (0.03-0.17 in). If there are layers of sheet metal, they should be touching without any air gaps to ensure a good ground. 6. Select a M6 conductive rivet stud. Refer to the Parts Information section of this bulletin. Note Use the GE-50317 rivet stud tool kit. 7. Place the M6 conductive rivet stud (1) in the 10 mm (0.40 in) hole. Assemble the rivet stud tool (2) with the groove and flare side facing the rivet stud, then the washer and the M6 nut (3). 8. Using a wrench on the rivet stud tool, and a socket on the M6 nut, secure the M6 conductive rivet stud. 9. Ensure the new rivet stud is securely fastened, WITHOUT ANY detectable movement. 10. Completely wrap the threads of the rivet stud with painters tape or equivalent. Page 2611 - Diagnostic Chart Code 33. Page 1628 For vehicles repaired under warranty, use: Warranty - Recycled Engine Coolant Policy 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. Page 4932 Brake Shoe: Service and Repair Installation For additional information see Notes, Warnings, and Hints. See: Fundamentals and Basics Exploded View 1. Lubricate parking brake lever fulcrum with suitable brake lube, then attach lever to brake shoe. Ensure lever operates smoothly. 2. Connect brake shoes with adjusting screw spring, then position adjusting screw. Ensure adjusting screw star wheel does not contact adjusting screw spring after installation, and also ensure right hand thread adjusting screw is installed on left side of vehicle and lefthand thread adjusting screw is installed on right side of vehicle. When brake shoe installation is completed, ensure star-wheel lines up with adjusting hole in backing plate. 3. Lightly lubricate backing plate shoe contact surfaces with suitable brake lube, then the area where parking brake cable contacts backing plate. 4. Install brake shoes on backing plate while engaging wheel cylinder links with shoe webbing. Connect parking brake cable to parking brake lever. The primary shoe (short lining) faces towards front of vehicle. NOTE: For additional information see Brake Spring Removal and Installation Notes. See: Fundamentals and Basics 5. Install actuating levers, actuating link and return spring. 6. Install hold-down springs with suitable tool. 7. Install primary and secondary shoe return springs using brake spring pliers or equivalent. Fig. 7 Measuring Brake Drum Inside Diameter Page 4238 for models with 8-1/2 or 8-7/8 inch ring gear, Figs. 16 and 17, or suitable equivalents. On models with 8-7/8 inch ring gear, substitute cloverleaf gauge plate J-21777-36 for plate J-21777-29. Follow all tool manufacturer's recommendations when installing gauge assembly. 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 that bearings are properly seated. d. Hold preload stud and tighten nut until 20 inch lbs. torque are required to rotate stud. Tighten nut in small increments, checking rotating torque after each adjustment, to prevent damaging bearings. 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 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 drive shaft 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. 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 Page 1689 Oil Pressure Gauge: Testing and Inspection Gauge Reads ``80'' or Above 1. Disconnect lead from sensor, then ground lead. 2. Gauge should read ``0'' psi. If gauge read ``0'' replace replace sensor, and if gauge reads ``80'' psi, check for short between sensor and gauge. Engine Controls - Idle Speed/Minumum Idle Air Rate Specs Idle Speed: Technical Service Bulletins Engine Controls - Idle Speed/Minumum Idle Air Rate Specs GMC NUMBER: 88-T-55 GROUP: 6E - Engine Emissions DATE: November, 1987 CORPORATE NUMBER: 836302 SUBJECT: TRUCK ENGINE CONTROLLED IDLE SPEED AND MINIMUM IDLE AIR RATE SPECIFICATIONS MODELS: 1987 AND 1988 TRUCKS (ALL GASOLINE ENGINES) WITH THROTTLE BODY INJECTION (TBI) This bulletin defines the controlled idle speed and minimum idle air rate specifications for 1987 and 1988 model year trucks for all engine applications with TBI. Additionally, step by step procedures are provided for performing the controlled idle speed check and the minimum idle air rate check. It is important that these procedures and specifications be adhered to. An incorrect readjustment with a high minimum air rate will cause the Idle Air Control (IAC) valve pintle to constantly bottom on its seat and may result in early IAC valve failure. A minimum air rate that is too low may result in a no-start condition in cold weather, a stall after start or a stall during deceleration, because of poor air/fuel distribution through the throttle bore. NOTICE: THESE SPECIFICATIONS AND PROCEDURES SUPERSEDE THOSE PROCEDURES DEFINED IN THE 1987 FUEL AND DRIVEABILITY MANUAL, X-8736. Controlled Idle Speed Check Before performing this check there should be no codes displayed, idle air control system has been checked and ignition timing correct. The procedures to check the idle air control system can be found in the Light Duty Truck Fuel and Emissions service manual at the following locations: All Truck Engines Except 2.5L Page 4-11 2.5L Truck Engines Page 3-61 1. Set parking brake and block drive wheels. 2. Connect a "SCAN" tool to the Assembly Line Data Link (ALDL) connector with tool in Open Mode. 3. Start engine and bring it to normal operating temperature. 4. Check for correct state of Park/Neutral switch on "Scan" tool. 5. Check specifications chart at the end of this bulletin for controlled idle speed and IAC valve pintle position (counts). 6. If within specifications, the idle speed is being correctly controlled by the Electronic Control Module (ECM). 7. If not within specifications, refer to "Rough, Unstable or Incorrect Idle, Stalling" in Section "2" of the Fuel and Driveability Manual X-8736 and review information at the beginning of this check. MINIMUM IDLE AIR RATE CHECK 1. Check controlled idle speed and perform idle air control system check first. 2. Set parking brake and block drive wheels. 3. Start engine and bring it to normal operating temperatures (85-100 degrees Celsius). Turn engine "OFF". 4. Remove air cleaner, adapter and gaskets. On S/T series vehicles, leave THERMAC hose connected. Check that the throttle lever is not being bound by the throttle, Throttle Valve (TV) or cruise control cables. 5. With IAC valve connected, ground the diagnostic terminal (ALDL connector). 6. Turn "ON" ignition, do not start engine. Wait at least 10 seconds (this allows IAC valve pintle to extend and seat in throttle body). 7. With ignition "ON", engine stopped, test terminal still grounded, disconnect IAC valve electrical connector. (This disables IAC valve in seated position). Remove ground from diagnostic terminal. 8. Connect a "Scan" tool to the ALDL connector and place in open mode. If a tool is not available connect a tachometer to the engine. 9. Start engine. With transmission in neutral, allow engine rpm to stabilize. NOTICE: ON 2.5L ENGINES A SERVICE ENGINE SOON LIGHT WILL COME ON AND A CODE 35 WILL BE SET. 10. Check rpm against specifications at the end of this bulletin. Disregard IAC counts on "Scan tool with the IAC disconnected. If the engine has less than 500 miles or is checked at altitudes above 1500 feet, the idle rpm with a seated IAC valve should be lower than values in chart. 11. If the minimum idle air rate is within specifications, no further check is required. 12. If the minimum idle air rate is not within specifications, perform the following procedures: 13. If present, remove stop screw plug by piercing it with an awl, then applying leverage. The screw is covered to discourage unauthorized adjustments. Tools - Introduction Of The Fuel Injector Tester Fuel Injector: All 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. Page 1679 Oil Pressure Gauge: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. Figure 21 Figure 22 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. Page 6915 Power Locks: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. Figure 21 Figure 22 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. Coolant Temperature Sensor Radiator Cooling Fan Temperature Sensor / Switch: Locations Coolant Temperature Sensor Center Of Dash Panel (engine Compartment) Center Front Of Engine Applicable to: V6-262/4.3L Engine Page 1034 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 Interior - Tapping Noise In Corner of Dash Dashboard / Instrument Panel: All Technical Service Bulletins Interior - Tapping Noise In Corner of Dash Number: 89-101-10 Section: 10 Date: MARCH, 1989 Subject: TAPPING NOISE IN CORNER OF DASH Model and Year: 1987-89 S/T TRUCKS TO: ALL CHEVROLET DEALERS Some 1987-89 S/T Trucks may experience a noise from the cowl area located around either of the front dash speakers. The noise has been described as a tapping or creaking noise similar to tapping a pencil lead on the windshield. This condition occurs primarily at ambient temperatures below 45 degrees Fahrenheit. Therefore, vehicles which sit inside a heated facility during repair should be "cold soaked" prior to verifying the repair. Repair Procedure Apply repair procedure exactly as described in Chevrolet Bulletin 86-58 (Section 10) dated April, 1986, which has been reproduced in this bulletin for your convenience. IMPORTANT: Windshield replacement will not resolve the situation. For repairs to vehicles under warranty, use: Labor Op: T7230 1983-86 Models - Labor Time: .6 Hr per side 1987-89 Models - Labor Time: .8 Hr. per side NOTE: On 87-89 vehicles, the location of the one inch hole will encompass a small weld. Additional time has been added to the labor operation to take this into account. Be sure to cut through only the first layer of sheet metal as specified in Step 9 on the bulletin. IMPORTANT: Dealers who have vehicles that are not repaired by this procedure should contact Technical Assistance for further assistance. Subject: COWL POPPING NOISE Model and Year: 1983-86 S/T TRUCKS Number: 86-58 Section: 10 Date: APR., 1986 TO: ALL CHEVROLET DEALERS On some S/T Trucks operating in low ambient temperatures, a condition may exist where a snapping or "popping" noise is heard coming from the cowl. This noise is caused by an "oil can" effect between the windshield frame and the door frame. The service procedure for eliminating the noise is as follows: 1. Remove the windshield wipers and radio antenna. Page 2781 Throttle Position Sensor: Adjustments The TPS is not adjustable. The ECM utilizes the IAC position reading at idle for its zero reading, therefore no adjustment is necessary. Locations Power Window Switch: Locations Behind Instrument Cluster Door Side Glass, Front - Binding/Track Disengagement Window Frame: All Technical Service Bulletins Door Side Glass, Front - Binding/Track Disengagement Number: 93-89-10 Section: 10 Date: JAN. 1993 Corporate Bulletin No.: 261614 ASE No.: B1 Subject: FRONT DOOR SIDE GLASS BINDING/TRACK DISENGAGEMENT Model and Year: 1982-93 S/T TRUCKS Owners of some 1982-1993 S/T vehicles may comment about the side front door glass binding during operation or the glass disengaging from the window track. These conditions may occur if the glass binds against the run assembly weatherstrip, and/or the plastic window guide separates from the glass due to improper seating during installation and/or breaks. To correct, it is necessary to replace the following items: - The side door glass with glass that has the lower rear corner rounded off. The new glass reduces binding between the glass and run assembly weatherstrip during window operation. - The run assembly weatherstrip with a weatherstrip that has additional flocking (Figure 1, Section A-A). The additional flocking helps eliminate friction between the glass and channel providing smoother window operation. Page 384 Wiring Diagram For Chart C-5 - Electronic Spark Control System Check CHART C-5 - ELECTRONIC SPARK CONTROL SYSTEM CHECK Circuit Description: Electronic spark control is accomplished with a module that sends a voltage signal to the ECM. As the knock sensor detects engine knock, the voltage from the ESC module to the ECM is shut "OFF" and this signals the ECM to retard timing, if engine RPM is over about 900. Test Description: Numbers below refer to circled numbers on the diagnostic chart. 1. If A Code 43 is not set, but a knock signal is indicated while running at 1500 RPM, listen for an internal engine noise. Under a no load condition there should not be any detonation, and if knock is indicated, an internal engine problem may exist. 2. Usually a knock signal can be generated by tapping on the right exhaust manifold. This test can also be performed at idle. Test number 1 was run at 1500 RPM to determine if a constant knock signal was present, which would affect engine performance. 3. This tests whether the knock signal is due to the sensor, a basic engine problem, or the ESC module. 4. If the module ground circuit is faulty, the ESC module will not function correctly. The test light should light indicating the ground circuit is OK. 5. Contacting CKT 496, with a test light to 12 volts, should generate a knock signal to determine whether the knock sensor is faulty, or the ESC module can't recognize a knock signal. Diagnostic Aids: "Scan" tools have two positions to diagnose the ESC system. The knock signal can be monitored to see if the knock sensor is detecting a knock condition and if the ESC module is functioning, knock signal should display "yes", whenever detonation is present. The knock retard position on the "Scan" displays the amount of spark retard the ECM is commanding. The ECM can retard the timing up to 20 degrees. This check should be used after other causes of spark knock have been checked such as engine timing, EGR systems, engine temperature or excessive engine noise. Description and Operation Oil Pressure Warning Lamp/Indicator: Description and Operation Many trucks utilize 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. Page 1658 - 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 A/T - THM 700-R4 TCC Applies During 1 to 2 Gear Shift Valve Body: Customer Interest A/T - THM 700-R4 TCC Applies During 1 to 2 Gear Shift Number: 88-449-7A Section: 7A Date: JULY 1991 Corporate Bulletin No.: 177112R Subject: TCC APPLIES DURING 1-2 SHIFT Model and Year: 1988 G2, R1, S1 AND T1 TRUCKS WITH 700-R4 SERVICE REPLACEMENT TRANSMISSION ASSEMBLY Figure 1 - Control Valve Body Bulletin Covers: Some 1988 Service Replacement Transmission Assemblies (SRTA) may have been built with a bore plug in the TCC valve bore. The 8MHM, 8TAM, 8TBM, and 8TNM models should have the TCC shift valve lineup in this bore instead of the bore plug. If the bore plug is present, TCC will apply during the 1-2 shift. Service Information: If the control valve assembly contains a bore plug in place of the TCC shift valve lineup, the control valve assembly must be replaced. Service Parts Information: Reference the GMSPO Service Parts Catalog for the correct control valve assembly part number. Service Manual Reference: Refer to the THM 700-R4 Automatic Transmission Unit Repair Section of the appropriate Service Manual for instructions on replacing the control valve assembly. Interior - Itch Noise From Windshield Pillar Area Instrument Cluster / Carrier: All Technical Service Bulletins Interior - Itch Noise From Windshield Pillar Area Number: 92-286-10 Section: 10 Date: SEPT. 1992 Corporate Bulletin No.: 261610 ASE No.: B1 Subject: ITCH NOISE FROM WINDSHIELD PILLAR AREA Model and Year: 1986-92 S/T TRUCKS Some 1986-1992 S/T utility trucks may exhibit a plastic to metal or plastic to plastic "itch" noise from the left or right windshield pillar area. This noise may be caused by the instrument panel pad rubbing against the cowl or dash support panel. An adhesive backed felt tape has been released to insulate the dash pad outer corners from the dash support panel. This tape may also be used on the non-visible surfaces of other trim panels as necessary to eliminate itch noises. The felt tape, P/N 12541499, is released in a 10 ft. x 30 mm x 1 mm roll to provide the technician sufficient material to insulate numerous trim panels. SERVICE PROCEDURE: Prior to installing the felt tape, it should be determined if the IP pad to dash support panel is the area that is generating the noise. Refer to the Squeak and Rattle Diagnosis and Correction Manual to identify other possible sources such as ECM Mounting Bracket or Air Vent. If it is determined the IP pad is the source of the noise: 1. Remove the instrument panel radio speaker(s) to obtain better access to the metal ledge on which the instrument panel pad rests. 2. Remove the 4 IP upper retaining screws located in the defroster duct openings and pull the pad back slightly. NOTICE: Do not remove the dash pad any further than necessary to perform the repair. The possibility exists that additional noises may be generated due to the wiring and HVAC ducts being mispositioned upon reinstallation. 3. Cut a strip of felt tape 6 inches long, remove the protective backing and apply the tape to the top of the metal ledges in front of the speaker openings where the instrument panel pad rests. NOTICE: Installation is easier if 2 screwdrivers are wedged between instrument panel pad and the cowl panel to raise the IP pad. 4. Push the IP pad forward and reinstall the retaining screws and speakers. 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 Page 4947 Wheel Cylinder: Service and Repair Rebuild For additional information see Notes, Warnings, and Hints. See: Fundamentals and Basics Fig. 8 Disassembled View Of Wheel Cylinder (typical) 1. Remove boots, pistons, springs and cups from the wheel cylinder. 2. Clean all parts with brake fluid. 3. Inspect cylinder bore. A scored bore may be honed as long as the diameter is not increased by more than 0.127 mm (0.005 inch). Replace worn or damaged parts as necessary. 4. Ensure hands are clean before proceeding with assembly. Lubricate cylinder wall and rubber cups with brake fluid, then install springs, cups, pistons and boots in housing. 5. Install wheel cylinder. Specifications Shifter Detent Spring: Specifications Detent Spring Cover Bolts ................................................................................................................... ..................................................................... 7 ft. lbs. 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. Tremec 3 Speed Case: Specifications Tremec 3 Speed Case attaching screws ........................................................................................................................ .................................................................. 30-36 ft lbs Page 4160 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 Page 7304 Cruise Control Servo: Description and Operation Fig. 2 Servo Assembly The servo, Fig. 2, consists of a vacuum operated diaphragm, a normally open solenoid valve to vent the diaphragm, a normally closed solenoid valve connecting the diaphragm chamber to the vacuum source, and a variable inductance position sensor that provides the module with servo position data. The servo operates the throttle in response to control module commands as follows: When the system is engaged and operating at a steady rate of speed, both solenoid valves are closed. Vacuum is trapped in the diaphragm chamber exerting a constant force on the diaphragm and the throttle position remains fixed. When the vehicle is losing speed due to increased load, or when the operator seeks to increase speed through the control switch assembly, the module energizes the vacuum valve solenoid. This increases the force exerted on the diaphragm, which in turn increases the throttle opening. When vehicle speed increases above the pre-set cruise speed, or when the operator seeks to decrease speed through the control switch assembly, the module de-energizes the diaphragm vent valve solenoid. This opens the valve, decreases force on the diaphragm, and allows the throttle return spring to decrease the throttle opening. During normal operation, the module will pulse the operation of the vent or vacuum valves, as needed, to maintain the set cruise speed. The average duration of each pulse is 10 milliseconds. If vehicle speed drops 5 mph below set cruise speed, the module will hold the vacuum valve in the completely open (energized) position. If vehicle speed exceeds set cruise speed by 3 mph or more, then module will hold the vent valve in the open (de-energized) position. The module will hold the valves open until the vehicle speed matches the set cruise speed. The diaphragm vent valve will also remain in the fully open position if the brake or clutch pedal is depressed, the ignition is switched off, or if an open circuit exists in the system feed circuit or in the servo position sensor. Page 258 Oil Pressure Switch (For Fuel Pump): Service and Repair REMOVAL: 1. Disconnect negative battery cable from battery. 2. Remove sensor or switch connectors. 3. Remove sensor or switch. INSTALLATION: 1. Install sensor or switch. 2. Connect sensor or switch. 3. Reconnect negative battery cable. Page 6138 Removing The Bearing From The Pulley Rotor Assembly 4. Pulley bearing (25) from the pulley (26) using J 9398-A and J 8092. ^ Remove the forcing screw from J 33020 and with the puller fangs still in place in the pulley slots, turn the assembly upside down onto a flat surface. ^ When removing the old pulley bearing (25) allow the staking to remain, then file away the old staked metal for proper fit when installing a new bearing (25) in the pulley bore. Install or Connect Tools Required: J 6083 Snap Ring Pliers J 8433-1 Puller Bar J 9481 Pulley Bearing Installer J 29886 Threaded Driver Handle J 33017 Pulley and Bearing Assembly Installer J 33019 Bearing Staking Tool (with staking pin and retaining band) J 33023-A Puller Pilot J 33026 Compressor Holding Fixture J 35372 Compressor Support Block Page 3397 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. Engine Controls - Idle Speed/Minumum Idle Air Rate Specs Idle Speed: Technical Service Bulletins Engine Controls - Idle Speed/Minumum Idle Air Rate Specs GMC NUMBER: 88-T-55 GROUP: 6E - Engine Emissions DATE: November, 1987 CORPORATE NUMBER: 836302 SUBJECT: TRUCK ENGINE CONTROLLED IDLE SPEED AND MINIMUM IDLE AIR RATE SPECIFICATIONS MODELS: 1987 AND 1988 TRUCKS (ALL GASOLINE ENGINES) WITH THROTTLE BODY INJECTION (TBI) This bulletin defines the controlled idle speed and minimum idle air rate specifications for 1987 and 1988 model year trucks for all engine applications with TBI. Additionally, step by step procedures are provided for performing the controlled idle speed check and the minimum idle air rate check. It is important that these procedures and specifications be adhered to. An incorrect readjustment with a high minimum air rate will cause the Idle Air Control (IAC) valve pintle to constantly bottom on its seat and may result in early IAC valve failure. A minimum air rate that is too low may result in a no-start condition in cold weather, a stall after start or a stall during deceleration, because of poor air/fuel distribution through the throttle bore. NOTICE: THESE SPECIFICATIONS AND PROCEDURES SUPERSEDE THOSE PROCEDURES DEFINED IN THE 1987 FUEL AND DRIVEABILITY MANUAL, X-8736. Controlled Idle Speed Check Before performing this check there should be no codes displayed, idle air control system has been checked and ignition timing correct. The procedures to check the idle air control system can be found in the Light Duty Truck Fuel and Emissions service manual at the following locations: All Truck Engines Except 2.5L Page 4-11 2.5L Truck Engines Page 3-61 1. Set parking brake and block drive wheels. 2. Connect a "SCAN" tool to the Assembly Line Data Link (ALDL) connector with tool in Open Mode. 3. Start engine and bring it to normal operating temperature. 4. Check for correct state of Park/Neutral switch on "Scan" tool. 5. Check specifications chart at the end of this bulletin for controlled idle speed and IAC valve pintle position (counts). 6. If within specifications, the idle speed is being correctly controlled by the Electronic Control Module (ECM). 7. If not within specifications, refer to "Rough, Unstable or Incorrect Idle, Stalling" in Section "2" of the Fuel and Driveability Manual X-8736 and review information at the beginning of this check. MINIMUM IDLE AIR RATE CHECK 1. Check controlled idle speed and perform idle air control system check first. 2. Set parking brake and block drive wheels. 3. Start engine and bring it to normal operating temperatures (85-100 degrees Celsius). Turn engine "OFF". 4. Remove air cleaner, adapter and gaskets. On S/T series vehicles, leave THERMAC hose connected. Check that the throttle lever is not being bound by the throttle, Throttle Valve (TV) or cruise control cables. 5. With IAC valve connected, ground the diagnostic terminal (ALDL connector). 6. Turn "ON" ignition, do not start engine. Wait at least 10 seconds (this allows IAC valve pintle to extend and seat in throttle body). 7. With ignition "ON", engine stopped, test terminal still grounded, disconnect IAC valve electrical connector. (This disables IAC valve in seated position). Remove ground from diagnostic terminal. 8. Connect a "Scan" tool to the ALDL connector and place in open mode. If a tool is not available connect a tachometer to the engine. 9. Start engine. With transmission in neutral, allow engine rpm to stabilize. NOTICE: ON 2.5L ENGINES A SERVICE ENGINE SOON LIGHT WILL COME ON AND A CODE 35 WILL BE SET. 10. Check rpm against specifications at the end of this bulletin. Disregard IAC counts on "Scan tool with the IAC disconnected. If the engine has less than 500 miles or is checked at altitudes above 1500 feet, the idle rpm with a seated IAC valve should be lower than values in chart. 11. If the minimum idle air rate is within specifications, no further check is required. 12. If the minimum idle air rate is not within specifications, perform the following procedures: 13. If present, remove stop screw plug by piercing it with an awl, then applying leverage. The screw is covered to discourage unauthorized adjustments. Page 4623 Figure 2 Page 4285 Figure 16 1. Loosen bolts (90) attaching the axle tube bracket (5) to the frame bracket (6). 2. Tighten nuts (94) to 75 N-m (55 lbs.ft.). This should cause the axle assembly to move toward the driver's side approximately 1/8" to 1/4". If the axle does not move it may be pried toward the driver's side with a bar. Position bar against the frame and the end of the shaft (1). 3. Tighten bolts (90) to 75 N-m (55 lbs.ft.). Seal Replacement: After checking the shock absorber installation and front axle location, smaller profile tripot seals may be installed. These smaller seals can be identified by their visibly smaller profile and by the number 26027961 which is molded onto the seal. Required Tools: J 28733 Axle Remover J 24319-01 Tie Rod Puller J 8059 Snap Ring Pliers J 35910 Seal Clamp Tool J 34026 Ball Joint Separator Drive Axle Removal: Figure 1 - Prevent Shaft From Turning 1. Raise vehicle and support it with suitable safety stands. 2. Remove the wheel and tire assembly. 3. Insert a drift or large screwdriver through brake caliper into one of the brake rotor vanes to prevent halfshaft from turning (Figure 1). Figure 2 - Hub Nut and Washer Removal 4. Remove halfshaft cotter pin, retainer, nut, and washer (Figure 2). Page 2866 Electronic Vacuum Regulator Valve (EVRV): Description and Operation To regulate EGR flow, an ECM controlled Electronic Vacuum Regulator Valve (EVRV) solenoid is used in the vacuum line. The ECM uses information from the following sensors to regulate the solenoid: ^ Coolant Temperature ^ Throttle Position (TPS) ^ P/N switch ^ Distributor (RPM Signal) The EGR vacuum control has an EVRV solenoid that uses "pulse width modulation". This means the ECM turns the solenoid "ON" and "OFF" many times a second and varies the amount of "ON" time ("pulse width") to vary the amount of EGR. A/T - Evaluating Peened Spacer Plates Valve Body: All Technical Service Bulletins A/T - Evaluating Peened Spacer Plates Number: 91-396-7A Section: 7A Date: AUGUST 1991 Corporate Bulletin No.: 177120 Subject: EVALUATING PEENED SPACER PLATES Model and Year: 1982-91 ALL PASSENGER CARS AND TRUCKS WITH AUTOMATIC TRANSAXLES AND TRANSMISSIONS (EXCEPT GEO) TRANSMISSIONS APPLICATIONS: All HYDRA-MATIC Automatic Transmissions and Transaxles SUBJECT: Evaluating Peened Spacer Plates (Service Information) TRANSMISSION MODELS: All VEHICLE APPLICATIONS: All Vehicles Using HYDRA-MATIC Automatic Transmissions and Transaxles Bulletin Covers: Some spacer plate peening is considered acceptable and preferred because it can help seat the check ball. This bulletin will help you decide if a spacer plate needs to be replaced due to a peening condition. Service Procedure: The following two procedures can help determine if the spacer plate can be reused. The following must be performed at all check-ball locations. Figure 1 1. The spacer plate must be inspected 100% for raised material on the opposite side of the check-ball seat (see Figure 1). If the material on the opposite side is raised, the peening is too severe and the spacer plate must be replaced. Page 738 Disclaimer Page 5709 Fig. 9 Recirculating ball installation Fig. 2 Rack piston plug removal Fig. 10 Ball guide installation Fig. 11 Needle bearing installation Page 5151 Symbol Identification 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". Page 7524 Fuel Gauge Sender: Service and Repair Fuel Pump And Sender Assembly (Typical) REMOVAL: 1. Disconnect the negative battery cable. 2. Raise vehicle. 3. Remove fuel tank. Refer to FUEL TANK ASSEMBLY. 4. Remove pump and sending unit assembly by turning the cam lock counterclockwise using tool J-36608 or J-24187 or equivalent. ^ Pull the fuel pump up into the attaching hose while pulling outward from the bottom support. ^ Do not damage the rubber insulator or the strainer. INSPECTION: 1. Inspect the fuel pump attaching hose for signs of deterioration. 2. Inspect the rubber sound insulation at the bottom of the pump for deterioration. INSTALLATION: 1. Install pump assembly into the attaching hose. NOTE: Care should be taken not to fold over or twist the strainer, when installing the sending unit as this will restrict fuel flow. 2. Install sending unit and fuel pump assembly into the fuel tank. (Always use a new O-ring seal). 3. Install the cam lock assembly. Turn the cam lock clockwise to lock it. 4. Install fuel tank assembly. 5. Connect the negative battery cable. 6. START vehicle and check for fuel leaks. Page 3736 Fluid Pressure Sensor/Switch: Specifications 4L60 - 700R4 Transmission Pressure Switches ............................................................................................................................... ....................................................................... 8 ft. lbs. Page 5356 For vehicles repaired under warranty, use the table. Disclaimer Page 5202 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 wire ends to protect the diode from excess heat. Follow the manufacturers instructions for the solderin equipment you are using. 5. Install terminal(s) into the connector body if previously removed in step number 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. NOTE: A universal diode with a 3 amp, 400 PIV (Peak Inverse Voltage) rating can be used in all of the previously mentioned applications. The following 1993 Service Manuals will need to be updated with the correct part numbers and rating changes. Carline Page All J, L, W, and UO 8A-5-12 Heat sink, part number 276-1567, can be obtained from Radio Shack. We believe the diodes and heat sink listed in this article as well as their manufacturer to be reliable. There may be additional manufacturers or equivalent products. General Motors does not endorse, indicate any preference for or assume any responsibility for the products from these firms or for any such items which may be available from other sources. Page 7799 License Plate Lamp: Electrical Diagrams License, Stop, Tail & Turn Lamps (Part 3 Of 4, W/Trailer Tow Package) Cooling - Cold Start Fan Noise Fan Clutch: All Technical Service Bulletins Cooling - Cold Start Fan Noise BULLETIN NUMBER: 92-66-56A SECTION: 6B Engine Cooling NUMBER: 2 CORPORATE REFERENCE NUMBER: 1662O3R DATE: May 1993 SUBJECT: COLD START FAN NOISE (INSTALL REVISED "QUICK DUMP" FAN CLUTCH) MODELS: 1987-92 M-VANS WITH 4.3L ENGINE 1990-92 L-VANS WITH 4.3L ENGINE 1988-92 S/T TRUCKS WITH 4.3L ENGINE THIS BULLETIN CANCELS AND REPLACES GMC TRUCK BULLETIN 92-6B-56. IT IS BEING REVISED TO INCLUDE M/L VANS, AND TO SERVICE PARTS INFORMATION AND RPO DEFINITIONS. ALL COPIES OF 92-6B-56 SHOULD BE DISCARDED. CONDITION Some owners of 1987-92 M-vans, 1990-92 L-vans, and 1988-92 S/T vehicles with a 4.3L engine (RPO LB4, LU2, or L35) and air conditioning (RPO C60) may experience higher than normal fan noise upon cold start up (usually fan noise extended beyond 90 seconds after start up). CAUSE This condition may be due to an extended engagement of the fan clutch. CORRECTION The condition may be corrected by installing a revised fan clutch which reduces the fan clutch engagement cycle. Vehicles built after the following VIN breakpoints have the new fan clutch installed in production: Plant VIN Moraine N2514836 Shreveport N8512403 Pontiac West N0508347 Baltimore NB534465 SERVICE PROCEDURE Refer to section 6B1 "FAN CLUTCH REPLACEMENT" in the appropriate Service Manual for removal and installation of the fan clutch. Page 8158 Wiper Switch: Service and Repair Fig. 8 Windshield Wiper Switch Removal (Front). Except Tilt Column Fig. 9 Windshield Wiper Switch Removal (Front). Tilt Column FRONT 1. Remove turn signal switch. Refer to Vehicle Lighting/Turn Signals/Turn Signal Switch/Service and Repair procedure. 2. Refer to Figs. 8 and 9 for wiper switch replacement. Page 7590 When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 5mm (3/16") of insulation from wire. e. Crimp a new terminal to the wire. f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. Figure 17 To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Figure 18 Figure 19 Locations Throttle Position Sensor: Locations Center Of Dash Panel (engine Compartment) Center Rear Of Engine Applicable to: V6-262/4.3L Engine Page 7480 FIGURE 1 2. Remove the cowl vent panel fasteners (Figure No. 1). 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. Page 4627 T7251 Group A 3.2 hr. T7261 Group B 2.8 hr. NOTE: Labor Operation is coded to base vehicle coverage in the warranty system. 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. Page 7075 Tools - Revised Brake Booster Push Rod Height Gage Vacuum Brake Booster: Technical Service Bulletins Tools - Revised Brake Booster Push Rod Height Gage Number: 89-132-5 Section: 5 Date: APRIL, 1989 Subject: REVISED BRAKE BOOSTER PUSH ROD HEIGHT GAGE Model and Year: 1982-89 C/K, S/T, R/V AND M TRUCKS FIGURE 1 TO: ALL CHEVROLET DEALERS A new brake booster push rod height gage (J37839) has been approved by Delco Moraine. The new gage is an essential tool and replaces tool J22647, which should be scrapped. The new gage will be shipped to dealers in the April-May 1989 time frame. The reason for the new gage is twofold: 1. The new gage locates on the chamfered sides of the booster push rod rather than the top of the rod. This is a more accurate reference point because the push rod sides initiate the contact with the master cylinder primary piston (See Figure 1). 2. The maximum and minimum push rod length tolerance was revised to reduce push rod free travel. IMPORTANT: These design changes were made for all 1989 Delco Moraine vacuum boosters. The new gage can be used on all pre-1989 models with Delco Moraine vacuum boosters. Gage Procedure: 1. With master cylinder removed and the brake booster still attached to the vehicle, gage the booster with 85.0 kPa (25 In. Hg.) vacuum or maximum engine vacuum. IMPORTANT: Booster can be gaged without being installed on the vehicle, if a suitable vacuum source is available. 2. Position gage (J37839) over piston rod as shown in Figure 1. 3. Check for both the maximum and minimum rod length. 4. If the rod length does not fall between the maximum and minimum dimensions, replace with adjustable push rod P/N 5469384. Parts are currently available from GMSPO. Page 1030 Page 2712 Engine Control Module: Locations Figure 1 Located under the passenger side hush panel, under the dash. Page 7841 Backup Lamp Switch: Locations LH Side Of Manual Transmission LH Side Of Transmission Page 8125 Note the difference between the wire exit openings of the new multi-functional lever and the old lever (Figure 1). Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Op. Description E7060 Multi-functional lever, replace Use applicable labor time guide for labor hours. Page 431 Vehicle Speed Sensor: Locations LH Side Of I/P Behind Instrument Cluster Endgate Window - Will Not Release/Opens Without Key Trunk / Liftgate Latch: All Technical Service Bulletins Endgate Window - Will Not Release/Opens Without Key Number: 91-504-10 Section: 10 Date: MAY 1992 Corporate Bulletin No.: 161506 ASE No.: B1 Subject: ENDGATE WINDOW LATCH NOT RELEASING OR ENDGATE OPENS WITHOUT KEY Model and Year: 1983-91 S/T TRUCKS Some owners of 1983-1991 S/T utility vehicles may experience difficulty releasing the rear endgate window latch and/or the endgate may be opened without a key. These conditions may be caused by an endgate window latch which has dirt contamination, a deformed spring leg, a missing or broken spring, a bent release lever, a bent frame or a latch which is misadjusted. To correct this condition, it is necessary to properly adjust the endgate window latch assembly and/or replace it. ADJUSTMENT PROCEDURE: 1. Check for proper window latch assembly adjustment by performing the following steps: NOTICE: To open the end gate, insert the key into the lock assembly and rotate the handle COUNTERCLOCKWISE. Turning the key/handle clockwise and exerting excessive force may result in a broken lock assembly. * Hold the window/glass handle and try to move the glass in and out. If the latch is misaligned to the striker, a rattle condition will exist. * Inspect the endgate glass for a snug fit against the top and sides of the body opening. Audio - Radio Frequency Interference (RFI) Diagnosis/ID Technical Service Bulletin # 349212R Date: 930701 General Information Bulletin Number: 93-9-10 Reference Number: 349212R Publish Date: 7/93 Subject: RADIO FREQUENCY INTERFERENCE IDENTIFICATION AND DIAGNOSIS Models Affected: 1993 AND PRIOR ALL MODELS The purpose of this information is to help in the identification and diagnosis of Radio Frequency Interference (RFI). RFI symptoms may include noises, interference, static, whines, pops. and poor reception of stations normally receivable by the radio system. These symptoms may also apply to any two-way communications radio installed in the vehicle including HAM, police, fire, business band and cellular phones. Radio Frequency Interference is the undesirable disturbance of an electrical system or device with another electrical system or device. The following charts will help identify: 1. If the symptoms are related to RFI, and 2. The source of the interference. It may be helpful to obtain a copy of the Delco Electronics Audio Systems Diagnostics Guide 1992 edition. This is a manual aimed at identifying, diagnosing, and repairing the radio system. This manual is available from STG; item # 19007.03-1. You may also want to consult your division's service bulletin concerning Radio Telephone Installation Guidelines. This information will identify the proper methods and routing for all installations of two-way communications devices. Questionnaire To begin diagnosing RFI, it is important to understand the nature of the condition and the elements that may be involved. The following questionnaire will help determine vital pieces of information for the diagnostic process. 1. Is the vehicle equipped with any non-factory installed electronics? (This includes: radar detectors, scanners, and hand held communications devices.) 2. If the condition occurs with a non-factory installed radio or telephone, have the Radio Installation Guidelines been followed? 3. Identify the frequencies affected. 4. If the concern is with the entertainment radio, is the tape or CD affected. 5. Identify when the condition occurs: Key off, Key in accessory, Key on engine not running, Engine running, Other - describe. 6. Is the condition intermittent or related to the operation of another electrical device in the vehicle? 7. If the condition is related to a fleet vehicle answer the following: a. Who installed the radio(s)? b. Were the GM installation guidelines followed? c. Is this the only vehicle that demonstrates this condition? d. Do similar vehicles have different antennas? e. Are the antennas mounted in the same location? See RFI Diagnostic Charts that follow. RFI Determination and Identifying Chart This chart is to be used along with the diagnostic charts to help determine if the condition is RFI related, and to help identify what electronic device in the vehicle is interfering with the radio. Make sure the information in the questionnaire is as accurate as possible. You MUST be able to duplicate the customer's condition to diagnose RFI concerns. The process of identifying RFI and the source of an interference is simply the process of elimination. When the source of the interference is disconnected from power, the radio will work properly. 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 Windshield - Wind Noise Windshield: Customer Interest Windshield - Wind Noise Number: 91-83-10 Section: 10 Date: October 1990 Corp. Bulletin No.: 061007 Subject: WINDNOISE AT DASH Model and Year: 1982-91 S/T TRUCKS AND UTILITY VEHICLES TO: ALL CHEVROLET DEALERS Some owners of 1982 - 1991 S/T pickup and utility vehicles may experience a condition described as wind noise near the windshield. SERVICE PROCEDURE: This condition may result from a sealer gap or a light application of the sealer to the seam between the windshield and the cab frame. This light application can separate and create a gap for air to pass through. To determine if either of these conditions have occurred perform the following steps. Page 2645 Oxygen Sensor: Service and Repair 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. 1. Disconnect electrical connector from oxygen sensor. 2. Using suitable wrench, carefully remove sensor from exhaust manifold or pipe. The oxygen sensor may be difficult to remove when engine temperature is below 120°F. Use caution, since excessive force may damage threads in exhaust manifold or pipe. 3. If new sensor is being used, install sensor into manifold or pipe. 4. If old sensor is being reused, coat threads with anti-seize compound, Part No. 5613695 or equivalent, then install into manifold or pipe. 5. Torque oxygen sensor to 30 ft. lbs., then reconnect electrical connector. Page 114 Wiring Diagram For Chart C-5 - Electronic Spark Control System Check CIRCUIT DESCRIPTION: Electronic spark control is accomplished with a module that sends a voltage signal to the ECM. As the knock sensor detects engine knock, the voltage from the ESC module to the ECM is shut "OFF" and this signals the ECM to retard timing, if engine RPM is over about 900. TEST DESCRIPTION: Numbers below refer to circled numbers on the diagnostic chart. 1. If A Code 43 is not set, but a knock signal is indicated while running at 1500 RPM, listen for an internal engine noise. Under a no load condition there should not be any detonation, and if knock is indicated, an internal engine problem may exist. 2. Usually a knock signal can be generated by tapping on the right exhaust manifold. This test can also be performed at idle. Test number 1 was run at 1500 RPM to determine if a constant knock signal was present, which would affect engine performance. 3. This tests whether the knock signal is due to the sensor, a basic engine problem, or the ESC module. 4. If the module ground circuit is faulty, the ESC module will not function correctly. The test light should light indicating the ground circuit is OK. 5. Contacting CKT 496, with a test light to 12 volts, should generate a knock signal to determine whether the knock sensor is faulty, or the ESC module can't recognize a knock signal. DIAGNOSTIC AIDS: "Scan" tools have two positions to diagnose the ESC system. The knock signal can be monitored to see if the knock sensor is detecting a knock condition and if the ESC module is functioning, knock signal should display "yes", whenever detonation is present. The knock retard position on the "Scan" displays the amount of spark retard the ECM is commanding. The ECM can retard the timing up to 20 degrees. This check should be used after other causes of spark knock have been checked such as engine timing, EGR systems, engine temperature or excessive engine noise. Page 5712 Fig. 3 Retaining ring & dust cover removal 1. Remove adjuster plug lock nut from adjuster plug, Fig. 2. 2. Remove adjuster plug, spring and rack bearing. 3. Remove retaining ring from valve bore of housing and dust cover from bottom, Fig. 3. 4. While holding stub shaft, remove hex lock nut from pinion and valve assembly. Stub shaft must be held to prevent damage to pinion teeth. 5. Use an arbor press on threaded end of pinion until it is possible to remove dust seal, shaft seal and bearing assembly. Do not hammer or pound on pinion and valve assembly. Do not remove pinion and valve assembly from housing. press only far enough to allow bearing and seal removal. 6. Reverse procedure to install, noting the following: a. Lubricate seals, stub shaft and dust seal area with multi-purpose grease. b. Lubricate rack bearing, adjuster spring and adjuster plug with lithium grease. c. With rack center in gear assembly, turn adjuster plug clockwise until it bottoms in gear assembly, then back off 50-70 degrees (approximately one flat). Check rotational torque on pinion. Maximum pinion preload torque is 16 inch lbs. Generator Light - Flickers During Pulse Wiper Use Wiper Switch: Customer Interest Generator Light - Flickers During Pulse Wiper Use Number: 90-84-8A Section: 8A Date: November 1989 Corporate Bulletin No: 966402 Subject: GENERATOR LIGHT FLICKER DURING PULSE WIPER OPERATION Model and Year: 1988-89 S, T TRUCKS WITH 2.8L OR 4.3L (VIN CODES R, Z) ENGINES TO: ALL CHEVROLET DEALERS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 89-219-8A, DATED JULY 1989. THE 1990 MODEL S/T VEHICLES ARE INCLUDED IN THE LATEST BULLETIN ALONG WITH A CORRECTION TO THE ELECTRICAL CONNECTOR NUMBER. ALL COPIES OF 89-219-8A SHOULD BE DISCARDED. The generator light flicker condition during pulse wiper switch operation in the 1988, 1989 and 1990 S/T instrument panel, with standard cluster, can be caused by negative voltage transients from the wiper motor. There is no possibility of a system failure as a result of this condition. The effect of this condition is that the generator light will turn on for 80 milliseconds (if gages, the voltage drop on the voltmeter lasts 2.5 seconds). This causes no harm to the generator or other electrical components. Subject condition can be eliminated by installing a diode (industry part number 1N4003) or diode/connector kit (diode kit part number 12085207) in the brown wire at the generator connector (circuit 25 at connector C118). See the following pages in the 1988, 89 and 90 S/T Electrical Wiring Diagrams for circuit 25, connector C118 locations: 1988 4.3L: Section C - Page 24 1988 2.8L: Section C - Page 22 1989 4.3L: Page 40 1989 2.8L: Page 39 1990 2.8L: Page 44 1990 4.3L: Page 45 PARTS INFORMATION: Quantity Part Number Description 1 12085207 Diode ----OR---1 *1N4003 Diode * This part available locally. Parts are currently available from GMSPO. INSTALLATION PROCEDURE: 1. Disconnect the battery. 2. Remove the connector from the generator. 3. Peel back the black plastic conduit covering the wires. 4. If installing diode 1N4003: cut out a section of the brown wire that matches the length of the diode. 4A. A diode/connector kit is also available (GMSPO diode kit part number 12085207). If using the kit cut out approximately four inches of the brown wire, following crimping and soldering instructions in the kit. Spiral tape the solder joints and tuck the wire back into the conduit away from the generator. Secure the diode/connector to the outside of the conduit with electrical tape. 5. Solder in diode with the banded end toward the generator. Page 479 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 4. Make repair. Paint - Manufacturer Codes Paint: All Technical Service Bulletins Paint - Manufacturer Codes Number: 88-67-10 Section: 10 Date: October, 1987 SUBJECT: 1988 PAINT CODES MODELS: ALL 1988 TRUCK MODELS The following is a list of paint code numbers from various suppliers for the 1988 model year. These colors can be obtained locally. DuPont refinish paints are available in: ^ L - Lucite - Acrylic Lacquer ^ A - Centari - Acrylic Enamel ^ D - Dulux -Enamel ^ 355S - Flexible Additive ^ 1234 Vinyl Lacquer - Chip resistant NOTE: Vinyl Resin must be added to the base color when painting interior components. DuPont Vinyl Resin #304 -Instrument Panel DuPont Vinyl Resin #305 - All Remaining Interior Parts Except Seats DuPont Vinyl Resin #306 - Seats and Vinyl Roofs When ordering DuPont paint, use "L", "A", "D", 355S or 1234 with the appropriate DuPont code. Ditzler refinish paints are available in: ^ DDL - Duracryl - Acrylic Lacquer ^ DBU - Deltron - Acrylic B/C ^ DAR -Delstar -Acrylic Enamel ^ DAU - Deltron - Acrylic Urethane ^ DIA - Interior Lacquer ^ UCV -Vinyl Colors ^ DX-369 - Flexative - Flexible Finishes ^ DX-54 Roadguard - Road Abrasion Protection When ordering PPG paint use "DDL", "DBU", "DAR", "DAU", "UCV", "DX-369", or "DX-54" with appropriate Ditzler code. Sherwin-Williams, Acme/Rogers, and MartinSenour are available in acrylic lacquer or acrylic enamel. S-W use: prefix 34, J4, or L10 for acrylic lacquer prefix 35, J5, or F10 for acrylic enamel Acme use: prefix 84 for acrylic lacquer prefix 85 for acrylic enamel Rogers use: prefix 94 for acrylic lacquer prefix 95 for acrylic enamel Martin-Senour: jobber will interchange number shown when acrylic lacquer is needed 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. Detonation Sensor LH Rear Of Engine, At Rear Of Cylinder Head Fuse Block - Deforms Fuse Block: All Technical Service Bulletins Fuse Block - Deforms Number: 90-432-8B Section: 8B Date: SEPT. 1991 Corporate Bulletin No.: 168102 ASE No.: A6 Subject: FUSE BLOCK DEFORMS Model and Year: 1988-90 SI (LLV) POSTAL VEHICLES Some 1988 to 1990 LLV postal vehicles built prior to August 3, 1990, may exhibit a condtion where the fuse block is partially deformed due to heat generated by continuous operation of the hazard flasher. This condition may be corrected by the repositioning of the hazard flasher to a remote location. SERVICE PROCEDURE: 1. Disconnect positive battery cable. 2. Remove old flasher. 3. Back out terminals for circuit 140A (orange wire) and circuit 27 (brown wire) using a small flat screwdriver or pick. Using the same tool, raise the locking tang on the back of the terminal. 4. Cut electrical tape used to wrap main wiring harness a sufficient amount to provide 2 to 3 inches of flasher wiring for relocation. 5. Insert terminals of circuits 140A and 27 into new connector (P/N 2973385). 6. Install electronic flasher (P/N 15504673) into the new connector. 7. Using nylon ties, strap the connector and flasher assembly to the wiring harness that runs above the fuse block. Verify that the relocated flasher and all wiring is secured so it does not cause interference with the throttle linkage. 8. Reconnect battery cable. 9. Test operation of hazard flasher system. SERVICE PARTS INFORMATION PART NUMBER DESCRIPTION QTY 2973385 Connector 1 15504673 Flasher (Electronic) 1 NPN Nylon Tie Straps 2 Parts are currently available from GMSPO. Paint - Acid Rain Damage to Base Coat/Clear Coat Paint: All Technical Service Bulletins Paint - Acid Rain Damage to Base Coat/Clear Coat Number: 92-33-10 Section: 10 Date: NOV. 1991 Corporate Bulletin No.: 131060 ASE No.: B2 Subject: INDUSTRIAL FALLOUT/RAIL DUST DAMAGE TO BASE COAT/CLEAR COAT Model and Year: 1983-92 ALL PASSENGER CARS AND TRUCKS Application: 1992 (and previous) models with Base Coat/Clear Coat Paint The following information regards the use of finesse type repairs to environmental (industrial fallout) and rail dust damage of base coat/clear coat paint finishes. Since the severity of the condition varies from area to area, PROPER DIAGNOSIS of the damage extent is CRITICAL TO THE SUCCESS OF REPAIRS. Diagnosis should be performed under high intensity fluorescent lighting, on horizontal surfaces (hood, roof, decklid) after they have been properly cleaned. INDUSTRIAL FALLOUT (ACID RAIN) There are three basic types of acid rain damage: Surface level contamination, - may be repaired by simply washing the vehicle, cleaning the surface with a wax and grease remover, neutralizing acidic residue and finesse polishing. - Clearcoat etching, - slight etching still noticeable after the above washing and finesse polishing procedure. - Basecoat etching, - severe etching beyond the clearcoat into the basecoat. PROCEDURES FOR SURFACE LEVEL CONTAMINATION REPAIRS 1. Wash the vehicle with standard car detergent and water and dry thoroughly. 2. Clean the affected area with a wax and grease remover. 3. Neutralize any left over acidic residue by cleaning the damaged areas with a mixture of baking soda and water (one tablespoon per quart of water), rinse THOROUGHLY and dry the panels completely. 4. Apply a finesse type polish with a foam pad. CLEAN AND INSPECT THE SURFACE A. If the damage has been repaired, remove any swirl marks with a dual action orbital polisher and foam pad. B. If some damage remains, proceed to step 5. SLIGHT CLEARCOAT DAMAGE - WET SANDING, FINESSE POLISHING 5. Select a small test area on a damaged panel. 6. Wet sand the damaged area with an American Grade ultra fine sandpaper of 1,500 to 2,000 grit and a rubber sponge sanding block. During the wet sand process; a. Use ample amounts of water b. Go slow to prevent removing too much clearcoat. Note: Be sure to use American Sandpaper. European Sandpaper has a "P" before the grit number and European grits do not align with American grits the majority of the time. 7. Remove the excess water with a rubber squeegee and inspect the area. A. If this has repaired the damage, continue the sanding procedure on the entire panel, apply a finesse type polish with a foam pad and remove any swirl marks with a dual action orbital polisher and foam pad. B. If (during the repair) it is suspected or observed that; - etching has penetrated into the base coat OR - too much clearcoat has been removed during sanding OR - base color is transferred to pad during polishing, Cowl - Popping/Tapping Noise Cowl: Customer Interest Cowl - Popping/Tapping Noise Number: 91-351-10 Section: 10 Date: JUNE 1991 Corporate Bulletin No.: 162001R Subject: COWL "POP"/TAPPING NOISE Model and Year: 1983-91 S/T TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 86-58, DATED APRIL 1986. THE SERVICE PROCEDURE HAS BEEN UPDATED AND THE 1987-91 MODEL YEARS ADDED. ALL COPIES OF 86-58 SHOULD BE DISCARDED. Some 1983-1991 S/T pickup and utility vehicles may experience a "popping" noise from the cowl area (at the base of the "A" pillar in front of the speaker grills). The sound may emanate from either side of the vehicle. The exact cause of this condition is currently unknown. Cowl "pop" is defined as a tapping noise at the lower corner of the windshield or base of the "A" pillar that usually, but not always, occurs when the vehicle is cold (below 45 degrees F). The sound is simiiar to the noise made when tapping a pencil point on the windshield. Some success has been achieved in correcting this condition by trimming areas of hood flange that may contact the cowl vent panel, by relieving any stress that may be created by the front fender mounting sequence, and by loosening the # 1 body mount and/or shimming one or both front body mounts. SERVICE PROCEDURE: NOTE: Typically this condition occurs only when the vehicle sheet metal is at a temperature below 45 degrees F. The condition may temporarily disappear if vehicle evaluation is performed after a vehicle has been in a warm environment. REMOVAL OF HOOD FLANGE MATERIAL: Some ST vehicles experiencing a cowl "pop" tapping noise may be corrected by trimming the back edge of the hood flange. On a small number of vehicles, excess material on the rear edge of the hood flange contacts the front of the cowl vent panel causing a tapping noise when the vehicle goes over a bump. 1. Visually inspect for witness marks in the painted area of the cowl vent panel to determine if the hood flange contacts any cowl panel surfaces. 2. If witness marks are not present, it is not necessary to perform Steps 3 and 4. Continue to "Relieving Fender Mounting Stress" Section. If witness marks are present, trim off approximately 1/8" of the hood flange only in the areas contacting the cowl vent panel using Jilson Tool 1451 SS or equivalent. 3. Refinish the bare metal on the trimmed areas and on matching cowl vent panel areas to prevent corrosion. RELIEVING FENDER MOUNTING STRESS: Some success has been achieved in correcting the cowl "pop" tapping condition by relieving the stress caused by the front fender mounting sequence. 1. Remove windshield wiper arms using Kent-Moore Tool J-8966 Remover and Installer, or equivalent. 2. Remove cowl vent panel assembly. 3. Loosen the four rear fender mounting bolts to zero torque. (One of the upper fender mounting bolts is located underneath the hood hinge seal.) 4. Retorque the two lower fender bolts to 20-34 N-m (15-25 Lbs.Ft.). 5. The upper hinge mounting bolt should be left at zero torque. Apply Loctite 242 thread locking compound (GM P/N 12345382), or equivalent, to hold in place. Retorque the remaining upper fender bolt to 20-34 N-m (15-25 Lbs.Ft.). 6. Reinstall cowl vent panel assembly and windshield wiper arms. Page 5659 Fig. 1 Troubleshooting power steering system Page 7822 Front Hazard Marker, Park & Turn Lamps (Part 2 Of 4) Page 6360 Refrigerant Oil: Fluid Type Specifications REFRIGERANT OIL TYPE ^ R-12 refrigerant oil, 525 viscosity (See Note). NOTE: If vehicle has been converted to R-134a use PAG (Polyalkaline Glycol) synthetic refrigerant oil (GM Part No. 12345923) or equivalent. Engine - Miss, Hesitation, or Roughness Spark Plug Wire: Customer Interest Engine - Miss, Hesitation, or Roughness Number: 93-35-6D Section: 6D Date: OCT. 1992 Corporate Bulletin No.: 716404R ASE No.: A1, A8 Subject: ENGINE MISS HESITATION OR ROUGHNESS DUE TO PIERCED SECONDARY IGNITION COMPONENTS Model and Year: 1980-93 ALL PASSENGER CARS AND TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 87-121, DATED MAY 1987. THE 1989-93 MODEL YEARS HAVE BEEN ADDED. ALL COPIES OF 87-121 SHOULD BE DISCARDED. During the diagnosis procedure for an engine miss, hesitation or roughness, a spark plug or spark plug wire condition may be suspected. Several types of commercial or homemade diagnostic equipment required the secondary ignition boots or wire to be pierced. This is normally done to check for spark plug firing or to perform a cylinder balance test. Similarly the use of pliers or other such tools to disengage a spark plug boot may pierce or damage the boot or wire. Secondary ignition components should not be pierced for any reason. Piercing a spark plug wire and/or distributor boot may create a condition that will not be immediately apparent. Over time, the hole in the pierced boot may allow a ground path to develop creating a plug misfire condition. Heavily moisture laden air in the vicinity of the pierced boot may accelerate this effect. Piercing a secondary ignition wire creates a gap in the wire's conductive core. This gap is a point of high resistance. The current flow in the wire will increase to compensate for the higher wire resistance. Over time, the wire may fail creating a plug misfire condition. The time required for the condition to appear depends upon the extent of damage to the conductive core. To help prevent future condition that are spark plug wire related, do not pierce or otherwise damage any secondary ignition component. Only use diagnostic equipment containing an inductive pick-up to check for spark plug firing or to perform cylinder balance tests. When disengaging a spark plug boot from the spark plug, twist the flanged boot 1/2 turn then pull on the boot only to remove the wire. Page 5697 Steering Gear: Component Tests and General Diagnostics 1. Disconnect pressure hose at pump. Use small container to catch any fluid which might leak. 2. Connect spare pressure hose to pump. 3. Connect pressure gauge J-5176-D to both hoses. Adapter J-38049-38 is required for 3.8L (VIN L) engine. 4. Open valve on gauge. 5. Start engine. Allow system to reach operating temperature, then check fluid level and add fluid if required. 6. when engine is at normal operating temperature, pressure reading on gauge (valve open) should be 80-125 psi. If pressure is more than 200 psi., check hoses for restrictions and poppet valve on steering gear for proper assembly. 7. Fully close valve three times. Do not leave valve fully closed for more than five seconds, as pump could be damaged.. Record pressure reading each time valve is closed. Three readings should be within 50 psi. of each other. a. If pressure readings are high enough, and are within 50 psi. of each other, pump is functioning properly. b. If pressure readings are high enough, but are not within 50 psi. of each other, flow control valve in pump is sticking. Remove and clean valve. Remove any burrs using crocus cloth or fine hone. If system contains some dirt, flush system. If system is exceptionally dirty, both pump and steering gear must be completely disassembled, cleaned and reassembled. 8. If pump checks to specifications, leave valve open and turn steering wheel to both stops. Record highest pressures and compare with highest pump pressure recorded. If pressure at both stops is not the same as maximum pressure, steering gear is leaking internally and must be disassembled and repaired. 9. Turn engine Off, then remove testing gauge and spare hose. Reconnect pressure hose, check fluid level or make needed repairs. Page 4893 Brake Rotor/Disc: Testing and Inspection PURPOSE In the manufacturing of the brake rotor all the tolerances regarding surface finish, parallelism, and lateral runout are held very closely. The maintenance of these tolerances provide the surface necessary to prevent brake roughness. Light scoring of the rotor surface not in excess of 01.5 mm (0.060-inch) in depth is normal. This condition does not affect the brake operation. Some discoloration or wear of the disc surface is normal and does not require re-surfacing when linings are replaced. SPECIFICATIONS - See: Specifications LATERAL RUNOUT Lateral runout is the movement of the rotor from side to side as it rotates on the spindle. This could also be referred to as "rotor wobble". This movement causes the brake pad and piston to be knocked back into it's bore. This results in additional pedal travel and a vibration during braking. Checking Lateral Runout 1. Tighten the wheel bearings to eliminate all freeplay. 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 Page 7766 Symbol Identification Wire Color Code Identification WIRE COLOR ABBREVIATION BLACK BLK BLUE BLU DARK BLUE DK BLU Page 1871 Disclaimer Page 6116 A-6 Compressor Component View Remove or Disconnect Tools Required: J 0435 Snap Ring Pliers J 8092 Driver Handle J 8433 Heavy Duty Pulley Puller J 9395 Pulley Puller Adapter J 9398-A Pulley Bearing Remover J 9481-A Pulley Bearing and Pulley Installer J 24092 Pulley Hub Adapter Set 1. Clutch plate and hub assembly (2). Page 6772 Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Description Labor Op. Striker and/or Support - Replace (RH) B5820 Striker and/or Support - Replace (LH) B5821 Page 4896 MACHINING Since accurate control of the rotor tolerances is necessary for proper performance of the disc brakes, machining of the rotor should be done only with precision equipment. NOTE: 1 inch = 25.4mm, so if your micrometer measures in inches and the specified thickness on the disc is in millimeters, convert millimeters to inches by dividing the specified number of millimeters by 25.4. Example: Specification on disc is 17.8 mm. Dividing 17.8mm by 25.4mm/in = 17.8/25.4 = 0.70 inches. Page 6340 Warner T-4C 4 Speed Mainshaft Bearing/Bushing: Specifications Warner T-4C 4 Speed Front bearing cap attaching bolts ........................................................................................................ .................................................................... 15 ft. lbs. Page 6230 Figure 6 - Heater Functional Test - Deluxe Heater Page 7250 Figure No. 5 With the tailgate closed and the tailgate window lowered, look down the vertical side of the tailgate on both ends. What you should see is the tailgate wedges, shown in Figure 5, displacing the spring loaded body mounted wedges shown in Figure 3. If one or both of the body mounted wedges are not displaced, shim the tailgate mounted wedge(s) with 1 mm or 2 mm shims (P/N 15659205 1 mm, P/N 20093974 2 mm). If both spring loaded wedges are displaced then do nothing to this area. To shim the wedges: 1) Locate the wedges shown on Figure 5. 2) Remove the wedges and retain existing shims. Begin with 1 mm shims to prevent excess shimming and insert the width of shims necessary to slightly displace wedge(s). Service Procedure 4 Page 5021 Wheel Cylinder: Fundamentals and Basics REMOVAL - Wheel cylinder retaining bolts, brake line fittings, and bleeder screws are often heavily corroded. Prior to starting the job you should spray these with a penetrating oil. - A line (flare nut) wrench should be used when loosening the brake line fittings. These fittings round off easily. OVERHAUL - Light amounts of corrosion within the cylinder bore and on the piston may be removed with crocus cloth. - Pitting and heavy corrosion should be removed with a hone. When honing the hone should be inserted and withdrawn quickly to achieve a 45 degree crosshatch. - Closely inspect the areas of the cylinder where the pistons seals contact. It is very important these areas are absolutely free of deposits, corrosion, or pitting. - Remove the bleeder screw and verify that the passage is clear. - Leave the bleeder open when installing pistons and cups into the cylinder bore. If the bleeder is closed a large amount of air will be forced into the brake lines. - Use brake assembly lubricant to coat the cylinder bore, pistons, and cups. Clean brake fluid is an acceptable lubricant when assemblying the wheel-cylinder but brake assembly lubricant is much slicker and minimizes the chance that the cups will be damaged. WARNING: Do not use a petroleum based grease or oil to lubricate the wheel-cylinder components. This will cause the seals and cups to swell and deteriorate. - When reassemblying the wheel-cylinder it is helpful to follow this sequence: 1. Rear cup (verify the cup is inserted properly, flat side towards the piston, concave side towards the center) 2. Rear piston 3. Rear dust cap (this prevents the rear cup and piston from popping back out when the spring and front components are installed). 4. Spring 5. Front cup 6. Front piston 7. Front dust cap INSTALLATION Attach the brake fluid line fitting loosely to the wheel-cylinder prior to inserting and tightening the retaining bolts. The brake fluid line fitting is much easier to attach and start turning with the wheel-cylinder loose. WARNING: Don't forget to tighten the brake line fitting after the retaining bolts are tightened. - Leave the wheel-cylinder bleeder screw open and place a drip pan under the rear brake assembly. Refill the master-cylinder with new brake fluid and let the fluid gravity bleed through the open bleeder screw. When brake fluid begins to drip from the bleeder, close the bleeder screw. NOTE: The brake system will still need to be flushed and bled, but this makes starting the process much easier. Page 5002 Brake Master Cylinder: Testing and Inspection INSPECTION Inspect for Leakage NOTE: The master-cylinder should be cleaned thoroughly prior to inspection (several days preferably). Spilled brake fluid can be easily confused with leakage. Piston Seals Leakage around the piston seals will seep out from the end of the cylinder and leak down the outside of the brake booster. - Inspect for signs of seepage or bubbled paint on the brake booster. - If any leakage is detected the master-cylinder should be replaced or overhauled Brake Line Fittings While someone is applying pressure to the brake pedal, inspect the brake line fittings on the master-cylinder for leakage. - If the fittings are leaking they should be disassembled and inspected. Reservoir to Cylinder Gasket Inspect the gasket for signs of leakage or hardening and cracking. Overhaul or replace the master-cylinder if any leakage is indicated. Inspect for Oil Contamination. - Inspect the rubber gasket on the inside of the master-cylinder lid. If the gasket is swollen or bloated, the brake fluid is contaminated with oil. - Siphon or scoop a small amount of brake fluid out of the master-cylinder and place into a styrofoam cup filled 2/3 of the way with water. Brake fluid will mix with the water while oil contaminants will float on the surface and dissolve the styrofoam. NOTE: If any oil contamination is present ALL brake components containing rubber seals will need to be replaced or overhauled. This includes the master-cylinder, both front calipers, both rear wheel cylinders, and all flexible brake hoses. Verify Hold-Down Bolts Are Tight - While someone is applying and releasing pressure to the brake pedal, verify the the master-cylinder is tightly secured to the brake booster. Retighten hold-down bolts if necessary. Functional Checks WARNING: Always bleed the entire brake system and verify the rear brakes are properly adjusted prior to diagnosing a master-cylinder as defective. For additional information on master-cylinder / brake pedal relationship see Fundamentals and Basics. See: Fundamentals and Basics Check Related Systems - Check for proper brake booster operation 1. With the engine "OFF", depress and release the brake pedal 4-5 times (this bleeds off the vacuum reserve in the booster). 2. Depress the brake pedal firmly and start the engine. If the pedal goes down slightly the brake booster is assisting in brake operation. If the pedal does not go down slightly the brake booster is not assisting in brake operation and should be diagnosed for problems. - Check and adjust rear brakes. - Check all brake lines and brake assemblies for leakage. Repair all deficiencies with related systems prior to diagnosing the master-cylinder as defective. Check Brake Pedal Travel (Non-Antilock Brake Systems Only) Fully depress the brake pedal and check for the following: The pedal should have a 75% reserve. Page 2933 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"). Page 732 Disclaimer Page 3976 Disclaimer ECM - Intermittent Connection Engine Control Module: Customer Interest ECM - Intermittent Connection Number: 88-251-8A Section: 8A Date: JUNE, 1988 Subject: INTERMITTENT CONNECTION TO THE ECM Model and Year: 1988 CHEVROLET PASSENGER CARS AND LIGHT DUTY TRUCKS TO: ALL CHEVROLET DEALERS A condition may exist in which the female terminals in the connector to the ECM do not make a solid connection to the male pins in the ECM (see illustration). This can result in an intermittent condition, in any circuit operated by the ECM. The Service Manuals direct a check of connections any time an intermittent condition is found, and this may be the cause of some of these conditions. Visually inspect the terminal using a flashlight, or use a .95 mm pin gauge. The gauge should not pass freely through the female terminal. Do not probe the terminal with anything other than the pin gauge, as probing could damage the terminal. If the female terminal does not grip properly, replace the terminal with P/N 12020757. General directions on wiring repair are shown in Section 8A of the service Manual. Page 7451 movement. Refer to Dealer Service Bulletin Number 91-181-10, Dated February 1991. Page 6614 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 Page 2404 Idle Speed: Specifications Minimum Idle Air Rate Minimum Idle Air Rate Engine Speed Note: Let engine idle until proper fuel control status is closed loop. Manual Transmission Neutral 450 +/- 50 rpm Auto Transmission Drive 400 +/- 50 rpm Neutral 475 +/- 50 rpm Page 1339 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 Transmission Mount - Idle Shake or Vibration Transmission Mount: Customer Interest Transmission Mount - Idle Shake or Vibration Number: 91-16-7A Section: 7A Date: May 1990 Corp. Bulletin No: 066101 Subject: IDLE SHAKE OR VIBRATION Model and Year: 1988-91 S1 TRUCKS Some 1988-91 S truck (two wheel drive) and 2 door utility models equipped with 4.3L engines and either automatic or manual transmissions, may experience an idle shake or vibration. This condition is most noticeable at engine speeds below 1500 RPM. 3L30 (THM180/180C) Automatic Transmission Installing Check Balls (3L30) Page 7901 When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 5mm (3/16") of insulation from wire. e. Crimp a new terminal to the wire. f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. Figure 17 To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Figure 18 Figure 19 Page 3512 The new band is interchangeable with the previous band and should be used for service whenever possible. As soon as the previous bands are used up, the new bands will become available. Part Name Previous Part Number New Part Number Band Assembly - 2/4 8654144 8673175 Parts are currently available from GMSPO. Refer to the HYDRA-MATIC 4L60 Unit Repair section of the appropriate Service Manual for removal and installation of the 2-4 band. Connecting Rod/Bearing Dimensions Connecting Rod: Specifications Pin Clearance 0.0008-0.0016 in Note: Interference fit. Side Clearance 0.006-0.014 in Page 4088 Valve Body: Locations 4L60 (THM 700-R4) Automatic Transmission Case Checkballs GMC NUMBER: 88-T-16 GROUP:7A - Automatic Transmission DATE: May, 1987 CORPORATE NUMBER: 867103 SUBJECT: PROPER LOCATION OF THE FORWARD CLUTCH CHECKBALL MODELS: ALL 1987 LIGHT DUTY MODELS AND 1988 C/K MODELS WITH THM 700-R4 AUTOMATIC TRANSMISSIONS FIGURE 1 - CHECKBALL LOCATIONS ON TRANSMISSIONS WITH AUXILIARY VALVE BODIES BULLETIN COVERS: Service information on the correct location of the forward clutch checkball (#12-Figure No. 1) and the possible effects of installing the checkball in the wrong location. Page 6294 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: Frame Crossmember, Rear - Rattle Noise Suspension Strut / Shock Absorber: Customer Interest Frame Crossmember, Rear - Rattle Noise Number: 90-403-10 Section: 10 Date: March 1991 Corp. Bulletin No.: 062001 Subject: RATTLE NOISE FROM REAR FRAME CROSSMEMBER Model and Year: 1988-90 T1 TRUCKS Separation of the rear shock absorber tower from the frame crossmember in 1988-90 T Utility Vehicles may result in the driver noticing a rattle noise coming from the rear of the vehicle over bumps. If the rear shock tower separates from the frame crossmember, the entire rear frame crossmember and tower assembly should be replaced using the following parts and service procedures. The new crossmember has reinforced shock absorber towers. Service Procedures: 1. Disconnect battery ground cable. 2. Raise vehicle on hoist. 3. Remove the six bolts holding the fuel tank protective shield on and remove shield. Figure 1 - Fuel Tank Installation 4. Remove fuel tank (Figure 1). A. Drain fuel from tank through the filler neck using a hand pump or energize in-tank fuel pump and drain from fuel feed line. See service manual for proper procedures and safety precautions. B. Remove lines and disconnect fuel fill hose and vent hose. C. Support fuel tank and remove tank supports (5). Page 1212 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 Page 6595 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 Removal Wheel Cylinder: Service and Repair Removal For additional information see Notes, Warnings, and Hints. See: Fundamentals and Basics 1. Raise and support vehicle. 2. Remove wheel and tire assembly. 3. Remove drum. 4. Remove brake shoes. 5. Disconnect hydraulic line at wheel cylinder. CAUTION: Do not pull metal line away from cylinder, as this may kink or bend line. Line will separate from cylinder when cylinder is moved away from brake backing plate. 6. Remove wheel cylinder-to-brake plate attaching screws, then the wheel cylinder. ECM/PCM - Damage Prevention Engine Control Module: All Technical Service Bulletins ECM/PCM - Damage Prevention Number: 91-318-6E Section: 6E Date: MAY 1991 Corp. Bulletin No.: 176502R Subject: DAMAGE TO ECM/PCM CIRCUIT BOARD WHEN INSTALLING A MEM-CAL Model and Year: 1986-91 ALL PASSENGER CARS AND TRUCKS CONDITION: When installing a service replacement ECM/PCM, the use of incorrect MEMCAL installation procedures may cause the ECM/PCM to fail before it can be installed in the vehicle. This condition may appear as if the ECM/PCM were defective when it was shipped to the dealership, when in fact it was damaged while being installed. In addition this condition may also occur when installing an "updated" service MEM-CAL into the vehicles original equipment ECM/PCM. CAUSE: Excessive vertical force may be applied to the MEM-CAL resulting in flexing of the circuit board and damage to the connections between the circuit board and attached components. Excessive verticle force may be generated in two ways. 1. Incorrect MEM-CAL installation procedure. 2. Interference between MEM-CAL and cover. CORRECTION: Use the following procedure. Service Procedure: Important: This procedure supersedes any instructions regarding MEM-CAL installation dated prior to September 1990. 1. Inspect the MEM-CAL to determine if a cork spacer is glued to the top side of the MEM-CAL assembly. If so, remove it prior to installation. 2. Align small notches with matching notches in the ECM/PCM MEM-CAL socket. 3. VERY GENTLY press down on the ends of the MEM-CAL until the locking levers are rotated toward the sides of the MEM-CAL. Notice: To avoid ECM/PCM damage, do not press on the ends of the MEM-CAL until the levers snap into place. Do not use any vertical force beyond the minimum required to engage the MEM-CAL into its socket. 4. While continuing light pressure on the ends of MEM-CAL, use your index fingers to press the locking levers inward until they are snapped into place. Listen for click. 5. Install MEM-CAL cover and install ECM/PCM in vehicle. Backup Lamps/Tailgate Window Release - Inoperative Shift Interlock Switch: All Technical Service Bulletins Backup Lamps/Tailgate Window Release Inoperative Number: 91-459-8A Section: 8A Date: DEC. 1991 Corporate Bulletin No.: 168104 ASE No.: A6 Subject: BACKUP LAMPS OR TAILGATE WINDOW RELEASE INOPERATIVE Model and Year: 1980-91 ALL LIGHT DUTY TRUCKS (EXCEPT GEO) Owners of some 1980-1991 C/K, 1982-1991 G, 1985-1991 M/L, 1984-1991 P2,P3, 1987-1991 R/V, 1983- 1991 ST (including LLV) with automatic transmissions may comment on a condition of inoperative back-up lamps or inoperative tailgate window release. This condition occurs when the vehicle's gear shift lever is placed in the "reverse" position, but the back-up lamps do not illuminate. In addition, on the S/T utility vehicles, the electric tailgate window release does not release when the transmission gear shift lever is placed in the "park" or "neutral" position and the endgate window release button is depressed. The park/neutral and back-up lamp switch comes out of adjustment which does not allow for the contact points to remain engaged. To correct these conditions, the contact carrier on the park/neutral and back-up lamp switch has been modified to increase switch carrier travel. SERVICE PROCEDURE: 1. Disconnect the battery ground cable from the battery. 2. Disconnect the switch assembly harness. 3. Place the gear selector in neutral. 4. Squeeze the tangs on the switch together and remove the switch assembly. 5. Install the new switch assembly (P/N 15679680) by: -aligning the actuator with the cutout in the steering column jacket. -inserting the tangs into the rectangular holes and pushing down on the switch assembly. 6. Adjust the switch by moving the gear selector to park. 7. Connect the switch assembly harness. 8. Connect the negative battery cable. 9. Check for proper switch operation. Readjust the switch as necessary. Page 7510 e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors Do Not require all the steps shown. Skip the steps that Do Not apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. 1. Separate connector halves (see Figures 2 through 6). Figure 2 Figure 3 Page 7427 Figure 8 Figure 9 Figure 10 Figure 11 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). Page 5079 Vacuum Pump: Testing and Inspection GEAR DRIVEN PUMP 1. Start engine, then attach hose and vacuum gauge to pump. Gauge should read at least 20 inches Hg. 2. Shut off engine. Vacuum level should remain above 19 inches Hg. for at least 1-1/2 seconds. BELT DRIVEN PUMP Fig. 1 Vacuum Chart 1. Block wheels, apply parking brake, and place gear shift lever in P or N. 2. Connect vacuum gauge to vacuum pump inlet (lower port). 3. Disconnect outlet hose from outlet tube (upper port) and plug end of hose. Do not plug vacuum pump outlet tube. 4. Start engine and run at idle. Vacuum should read as shown, Fig. 1, within 30 seconds. 5. If vacuum is within specifications, proceed to step 8. 6. If vacuum is below specification or gauge reading fluctuates, proceed as follows: a. Check gauge and connections for leaks, correcting as necessary. b. Check belt tension and pulley fit to pump, repairing or replacing as necessary. c. Check idle speed and correct as necessary. 7. If vacuum is still below specifications or gauge still fluctuates, replace vacuum pump and repeat steps 1 through 6. 8. If vacuum was within specifications in step 5 or step 7, proceed as follows: a. Remove plug from outlet hose and connect hose to pump outlet tube. b. Connect vacuum inlet hose to pump with a T-fitting and vacuum gauge located near pump inlet. c. Start engine and run at idle for one minute. d. If vacuum is three inches Hg. lower than in step four, vacuum pump is not defective. e. If vacuum is more than three inches Hg. lower than in step four, check all attaching hoses for leaks, correcting as necessary. f. If vacuum is still too low, check all vacuum accessories for leaks, repairing or replacing as necessary. Page 6819 Figure 4 Figure 5 Figure 6 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 7 Page 2716 Engine Control Module: Description and Operation Throttle Body Fuel Injection Engine Control Module Fig. 5 ECM Unit (Showing PROM & CALPAK Locations) The Electronic Control Module (ECM), located in the passenger compartment, is the control center of the fuel injection system. The ECM continually monitors and processes the input information and generates output commands to the various systems affecting vehicle performance. A removable calibration unit (PROM) enables the ECM to recognize and adjust for vehicle variations (vehicle weight, axle ratio, etc.). There are specific ECM/PROM combinations for each specific vehicle which are not interchangeable, Fig. 4. On V6 models, a CALPAK is also installed in the ECM. The CALPAK allows fuel delivery in the case that other parts of the ECM are damaged, Fig. 5. The ECM also performs the diagnostic function of the fuel injection system. When the ECM senses an operational problem, it will illuminate the "Check Engine" or "Service Engine Soon" light and store the appropriate code(s) to identify the problem area. Page 3128 3. Install fuel meter cover gasket on fuel meter cover. 4. Install fuel meter cover. Ensure pressure regulator seal and cover gaskets are properly installed. Apply suitable thread locking compound to meter cover-to-meter body attaching screws and install. Torque screws to 28 inch lbs. When applying thread locking compound to screw threads, use GM 1052624, Loctite 262 or equivalent. Use of a higher strength locking compound is not recommended as it may prevent attaching screw removal or screw head breakage if screws are removed again. Page 4834 1. Wedge a flat chisel between the brake pad and rotor hat so that there is maximum clearance between the shoe tab and caliper casting ear (Figure 1). 2. Using a brass punch and hammer, carefully drive the upper brake pad tab down against the caliper ear. Repeat this step for the lower tab (Figure 1). 3. Push on back of pad with your thumb to insure clinch is tight. Pads should not move (Figure 2). NOTICE: Do not attempt to clinch inboard pads as they must be allowed to freely move in the brake caliper. Page 4845 Caliper Knuckle Clearances 8. Measure the clearance between the caliper and the steering knuckle. The clearance at each end of the caliper should be measured individually and added together. this total should be between 0.26-0.60 mm (0.010-0.024 inch). 9. Install tire and wheel assembly. 10. Lower the vehicle. WARNING: Before moving vehicle, pump brake pedal several times to be sure it is firm. Do not move vehicle until a firm pedal is obtained. Page 7790 Symbol Identification Page 6594 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) Locations Power Steering Pressure Switch: Locations LH Fender Apron LH Front Corner Of Engine Compartment Page 446 Throttle Position Sensor: Service and Repair REMOVAL: 1. Disconnect electrical connectors. 2. Remove the TPS attaching screw assemblies and retainer, (if applicable). 3. Remove TPS from throttle body assembly. NOTE: The TPS is an electrical component and must not be soaked in any liquid cleaner or solvent, as damage may result. INSTALLATION: 1. Install TPS to throttle body assembly, while lining up TPS lever with TPS drive lever on throttle body. 2. Install the two attaching screw assemblies. Tighten screw assemblies to 2.0 Nm (18.0 lb-in). 3. Install electrical connector to TPS. 4. Check for TPS output as follows: a. Connect an ALDL scanner to read TPS output voltage. b. With ignition ON and engine stopped, TPS voltage should be less than 1.25 volts. If more than 1.25 volts, replace TPS. Page 5759 Figure 9 - Disconnecting the Upper Ball Joint 17. Tip the knuckle out and toward the rear of the vehicle. Suspend the knuckle to prevent straining the brake line (Figure 9). Important: Cover the shock mounting bracket and the ball stud on the lower control arm with a shop towel to prevent possible halfshaft seal damage during removal and installation. Figure 8 - Splined Shank and Knuckle Separation 18. Install J28733 on brake rotor and separate outer C/V joint splined shank from knuckle hub (Figure 8). Figure 3 - Inboard Flange Bolt Removal 19. Remove six bolts (loosened earlier) from inboard joint flange (Figure 3). 20. Support inboard end of halfshaft. Free splined shank from hub and remove halfshaft from vehicle. Important: Wipe the wheel bearing seal area on the knuckle clean. Check the seal for cuts or tears. Tire - Tread Chunking/Torn bead Tires: All Technical Service Bulletins Tire - Tread Chunking/Torn bead Number: 91-171-3E Section: 3E Date: January 1991 Corp. Bulletin No.: 993501R Subject: TIRE DAMAGE CAUSED IN GM ASSEMBLY PLANTS - TREAD CHUNKING TORN BEAD Model and Year: 1988-91 PASSENGER CARS AND TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 90-52-3E, DATED OCTOBER 1989. THE 1991 MODEL YEAR HAS BEEN ADDED. ALL COPIES OF 90-52-3E SHOULD BE DISCARDED. Isolated incidents of the following types of tire damage have recently been reported from the field. Any such damage would be present at time of delivery to the dealer. The probable cause of some of this damage has been traced to the assembly plant. Since such tire conditions are usually not the fault of the tire manufacturer, any tires requiring replacement for these reasons should be considered GM's responsibility. Assembly plant damage should not be confused with transportation damage, which continues to be the responsibility of the transportation company. The purpose of this bulletin is to help identify assembly plant tire damage. Tread Chunking This condition is identified by small pieces of tread rubber torn or "chunked" out of the tire. This usually occurs in one area of the tread, although more than one area is possible. The missing tread rubber should be apparent upon visual inspection. It can also usually be detected as a once-per-rev tire noise upon road testing. This condition can happen in the assembly plant during the end of line line roll test. Hard braking such that the tire locks up on the roll could be the cause, although other variables during the roll test can also be factors. Other types of tire tread damage noted at delivery should be considered transportation damage. Torn Bead Rubber This condition is usually not visible unless the tire is dismounted from the wheel and, therefore, may not be detected during new vehicle inspection. Depending on the extent of the tear, the condition may later be detected as a slow air loss, or a slight sidewall bulge. If the tire is dismounted from the wheel and bead rubber is torn, it is possible that this damage occurred in the assembly plant during tire mounting. If it happened in the plant, the tear will usually be on the inboard (blackwall) side of the tire. There should also be evidence of two tears, about 90 degrees apart, although one is usually much Page 4503 A new pressure regulator valve (III. 218) has been made which will improve the oil pressure stability at lower RPM. SERVICE PARTS INFORMATION: Description Part Number Valve, Pressure Regulator (III. 218) 8684048 Part numbers are for Reference Only. Check with your Parts Department for latest information. Body - Stain/Film On Windshield Glass Perimeter Windshield: All Technical Service Bulletins Body - Stain/Film On Windshield Glass Perimeter TECHNICAL Bulletin No.: 09-08-48-006 Date: September 18, 2009 Subject: Clear Stain or Film on Inside Perimeter of Windshield Glass (Clean/Polish Glass) Models: 2010 and Prior Passenger Cars and Trucks (Including Saturn and Saab) 2010 and Prior HUMMER H2, H3 Condition Some customers may comment on a clear stain or film on the inside of the windshield glass. This condition appears along the outer edges of the glass along the top, bottom or A-pillar areas. Normal glass cleaning procedures will not remove the stain. Cause The assembly plant uses a clear sealer/primer on the outer edge of the windshield glass to improve adhesion to the urethane adhesive that bonds the windshield glass to the vehicle body. Excess sealer/primer may drip or flow onto the windshield and cause a stain. Once the sealer/primer dries, it may appear to have etched the glass. Correction Note A "white" type of toothpaste is recommended for this repair. Gel-type toothpaste may provide less satisfactory results. Use a small amount of toothpaste on a soft, cotton cloth to polish the stained area. It may be necessary to wrap the cloth around a paint stir stick or a similar tool to reach the lower corners of the windshield glass. After polishing the glass, clean the inside of the windshield glass with a clean, damp, cotton cloth and verify all of the stain is removed. Do not use any cleaners or solvents - use only clean warm water. Warranty Information (excluding Saab U.S. Models) For vehicles repaired under warranty, use: Warranty Information (Saab U.S. Models) For vehicles repaired under warranty, use the table. Page 4646 8. New O-ring seal P/N 14095598 (67) and new plastic washer (retainer) P/N 14037958 (66) into the front case half. 9. New sector with shaft P/N 15637215 (55) into the front case half. 10. Range shift fork (51), range shift hub (34) into the planetary carrier (36). - It is necessary to rotate the sector with shaft (55) to obtain clearance when installing the range fork (51). INSPECT: The teeth of the synchronizer stop ring (28) and drive sprocket (20) for damage. If the parts are to be replaced due to damage or in cases of customer complaint of clash when shifting from 2Hi to 4Hi, follow steps 11, 12, & 13, otherwise skip to step 14. 11. New drive sprocket P/N 15579803 (20) to the main shaft (19). 12. New synchronizer stop ring P/N 14071703 (28) to the drive sprocket (20). 13. Synchronizer assembly (81) to the main shaft. 14. Mainshaft (19)/drive sprocket (20), chain (58) and front output shaft (21) as a unit. Mode shift fork (54) and shift rail (48) will be installed with the mainshaft. 15. Fork shift spring (52). Mainshaft Extension and Oil Pump 16. Rear case (17) over mainshaft (19) and onto the front case half (45). - Clean case mating surfaces and apply RTV sealer or equivalent to the mating surfaces. - Transfer dowels from old case half to new case half if necessary. IMPORTANT: Be careful not to damage the oil pump (12) while installing the rear case half (Figure 7). 17. Case bolts (3) into case halves. - Apply Loctite 242 (R) or equivalent on pump housing bolt threads. - The two longer bolts and washers into the doweled case holes (33). - Tighten bolts to 31 N-m (23 lbs.ft.). 18. Speedometer tone wheel (11) to the main shaft (19). 19. Pump retainer housing (8) and pump housing bolts (7) to the rear case half (17). - Clean mating surfaces and apply RTV sealer or equivalent to the mating surfaces. - Apply Loctite (R) or equivalent on pump housing threads. - Pump housing bolts are shouldered (7). - Tighten bolts to 41 N-m (30 lbs.ft.). 20. Output bearing retainer (snap ring) (5), to the main shaft (19). 21. Rear extension housing (4) and extension housing bolts (3) to the pump retainer housing (8). - Clean mating surfaces and apply RTV sealer or equivalent to the mating surfaces. - Apply Loctite 242 (R) or equivalent on the extension housing bolts. - Tighten bolts to 31 N-m (23 lbs.ft.). External Components 22. Poppet plunger (70), poppet spring (71), new O-ring seal P/N 14071849 (69), and poppet screw (68) to the front case half (45). Page 3570 Page 5517 Symbol Identification Door Locks - Binding or Sticking or Key Hard to Insert Door Lock Cylinder: Customer Interest Door Locks - Binding or Sticking or Key Hard to Insert Number: 93-133-10 Section: 10 Date: MARCH 1993 Corporate Bulletin No.: 1341070R ASE No.: B1 Subject: DOOR LOCK CYLINDERS (RECOMMENDED LUBRICATION) Model and Year: ALL 1993 AND PREVIOUS MODEL CARS AND TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN 92-41-10, DATED NOV. 1991. THE 1993 MODEL YEAR HAS BEEN ADDED AS WELL AS A NOTE. PLEASE DISCARD ALL COPIES OF 92-41-10. Customer comments of binding/sticking door lock cylinders, or keys that are hard to insert or extract may be corrected in many cases by applying the proper lubrication. The recommended materials for lubricating these components are (in order of preference): - GM # 12345120 Multi purpose lubricant (9 oz. spray) or # 12345121 (12 oz.). - 5 W 30 Motor Oil - GM # 1052276 or 1052277 spray type Silicone (4.5 oz. or 12 oz. cans). Penetrating oil type lubricants (such as GM # 1052949 or 1052950, WD-40 lubricants) ARE NOT RECOMMENDED because they wash out the original lubrication and eventually evaporate, leaving little or no lubricating material. However, if these type materials are used to "unfreeze" or loosen lock cylinder components, refer to steps 2 through 4 listed below for the proper methods of lubricating. NOTE: DO NOT REPLACE THE DOOR LOCK CYLINDERS UNTIL AFTER THE LUBRICATING MATERIALS HAVE BEEN USED AND THE CYLINDER REMAINS FROZEN/BOUND. If door lock cylinders require replacement for any reason, apply a coating of GM # 12345120 Multi purpose Lubricant to the inside of the lock case and the cylinder keyway prior to assembling and installing the cylinder. Parts are currently available from GMSPO. Frozen cylinders due to cold weather may be repaired using the following procedure: 1. Apply heat to the cylinder area with a heat gun while being careful not to damage the painted surfaces. 2. Hold the shutter door open with a paper clip (or similar item) and force air into the cylinder using compressed air and a blow gun attachment. 3. While holding the shutter door open, inject a small amount of lubricant (see above recommendations) into the cylinder. 4. Work the key into the cylinder several times and wipe any excess lubrication residue from the key. Use applicable Labor Time Number and Time allowance. Page 7958 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 4. Make repair. Page 1715 Intake Manifold: Service and Repair VIN Z Turbo Engine 1. Disconnect battery ground cable. 2. Remove air cleaner and duct assembly. 3. Drain engine and charge air cooler radiators. 4. Remove charge air cooler clamps ducts and hoses. 5. Remove charge air cooler from supports, then disconnect electrical connections and hoses from EVRV solenoid, ignition coil and MAP sensor located on multi-use bracket. 6. Remove multi-use bracket from lower intake manifold. 7. Remove upper intake manifold electrical connectors and hoses. 8. Remove throttle body, gasket, bolts and cable bracket from upper intake manifold. 9. Remove upper intake manifold bolts, then the upper intake manifold. 10. Disconnect heater hose at lower intake manifold. 11. Remove charge air cooler coolant inlet pipe by disconnecting clamp and hose from radiator. 12. Disconnect fuel injector electrical connectors, then the fuel pipes from fuel rail. 13. Remove A/C compressor rear brace, then the turbocharger coolant return line. 14. Disconnect upper radiator hose and ground strap from lower intake manifold. 15. Disconnect coolant sensor electrical connector, then the spark plug wires from distributor. 16. Remove two screws from sides of distributor cap. 17. Scribe a mark on distributor shaft in line with rotor. 18. Scribe a mark on engine in line with distributor rotor. 19. Note position of distributor housing in relation to engine, then remove distributor. 20. Remove lower intake manifold bolts and studs, then the manifold gasket from cylinder block. 21. Reverse procedure to install, tighten bolts and nuts to specifications. Page 3348 Transmission Position Switch/Sensor: Testing and Inspection Chart C-1A - Park/Neutral Switch Diagnosis Page 4654 Figure 2 - Transfer Case Linkage Adjustment Service Procedure: Check to assure that the transfer case is fully engaged into the 4-High position. If hopout occurs, perform the following service procedure: 1. Inspect the transfer case upper boot and verify that the lower convolute is not trapped beneath the console (Figure 1). Correct the boot installation as required. 2. Inspect the transfer case shift linkage (Figure 1). Use the following procedure to properly adjust the transfer case shift linkage (See Figure 2). A. Remove the console (48). B. Raise the shift lever boot up the shift lever. C. Loosen bolt (44). D. Loosen bolt (47). E. Place the shift lever (40) in 4-High position. F. Install a suitable bolt (A) at the shift lever on the transfer case as shown. This will lock the transfer case in 4-High. G. Insert an 8 mm (5/16-inch) diameter gage pin or drill bit through the hole in the shift lever into the upper corner of the switch detent bracket (49). This aligns the switch assembly in the 4-High position. H. Tighten bolt (47) to 130 N-m (95 ft.lbs.). I. Tighten bolt (44) to 40 N-m (30 ft.lbs.). J. Remove the lock bolt (A) and gage pin or drill bit (B). K. Install the console and boot. Check for proper illumination of the display indicator when in each shift position. When properly adjusted, and in the 4-High position, the shift lever should have approximately 2-4 mm of rearward play at the knob before hitting the 4-High detent stop. Oxygen Sensors - Silica Contamination Oxygen Sensor: 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. Fuse Link A Fusible Link: Locations Fuse Link A Center Of Dash Panel (engine Compartment) At Rear Of Generator Applicable to: V6-262/4.3L Engine Backup Lamps/Tailgate Window Release - Inoperative Backup Lamp Switch: Customer Interest Backup Lamps/Tailgate Window Release - Inoperative Number: 91-459-8A Section: 8A Date: DEC. 1991 Corporate Bulletin No.: 168104 ASE No.: A6 Subject: BACKUP LAMPS OR TAILGATE WINDOW RELEASE INOPERATIVE Model and Year: 1980-91 ALL LIGHT DUTY TRUCKS (EXCEPT GEO) Owners of some 1980-1991 C/K, 1982-1991 G, 1985-1991 M/L, 1984-1991 P2,P3, 1987-1991 R/V, 1983- 1991 ST (including LLV) with automatic transmissions may comment on a condition of inoperative back-up lamps or inoperative tailgate window release. This condition occurs when the vehicle's gear shift lever is placed in the "reverse" position, but the back-up lamps do not illuminate. In addition, on the S/T utility vehicles, the electric tailgate window release does not release when the transmission gear shift lever is placed in the "park" or "neutral" position and the endgate window release button is depressed. The park/neutral and back-up lamp switch comes out of adjustment which does not allow for the contact points to remain engaged. To correct these conditions, the contact carrier on the park/neutral and back-up lamp switch has been modified to increase switch carrier travel. SERVICE PROCEDURE: 1. Disconnect the battery ground cable from the battery. 2. Disconnect the switch assembly harness. 3. Place the gear selector in neutral. 4. Squeeze the tangs on the switch together and remove the switch assembly. 5. Install the new switch assembly (P/N 15679680) by: -aligning the actuator with the cutout in the steering column jacket. -inserting the tangs into the rectangular holes and pushing down on the switch assembly. 6. Adjust the switch by moving the gear selector to park. 7. Connect the switch assembly harness. 8. Connect the negative battery cable. 9. Check for proper switch operation. Readjust the switch as necessary. Page 6033 Description and Operation Transmission Position Switch/Sensor: Description and Operation The park/neutral switch indicates to the ECM when the transmission is in park or neutral. This information is used by the ECM for ignition timing, IAC operation and transmission Torque Converter Clutch (TCC) operation. Do not drive vehicle with park/neutral switch disconnected, as idle quality may be affected. Page 8159 Fig. 10 Windshield Wiper Switch Removal (Rear) REAR Refer to Fig. 10, for wiper switch replacement. 1. Disconnect battery ground cable. 2. Remove switch trim plate and screws from instrument panel. 3. Disconnect electrical connector, then remove switch. 4. Reverse procedure to install. Locations Throttle Position Sensor: Locations Center Of Dash Panel (engine Compartment) Center Rear Of Engine Applicable to: V6-262/4.3L Engine A/T - Proper Fluid Level Checking Procedure Fluid - A/T: All Technical Service Bulletins A/T - Proper Fluid Level Checking Procedure Number: 88-41 Section: 7A Date: AUG., 1987 Subject: PROPER TRANSMISSION FLUID LEVEL CHECKING PROCEDURE Model and Year: 1987-88 CHEVROLET VEHICLES WITH THM 125C, 200-4R, 400, 440-T4, AND 700-R4 TRANSMISSIONS TO: ALL CHEVROLET DEALERS This bulletin outlines proper hot and cold fluid level checking procedures for the transmissions and transaxles listed above. A. "COLD" CHECK PROCEDURE: 1. Start vehicle and let idle in Park for 3 minutes. Note for THM 440-T4: Start vehicle and cycle range selector through 1, 2, D, OD, and R for approximately 3 seconds in eash range. Complete check preparation by letting vehicle idle in Park for 3 minutes. 2. With vehicle level, accessories turned off, and engine idling in Park, check fluid level as outlined below. FIGURE 1 ^ THM 200-4R, 400, 700-R4 (Refer to Figure 1): When cold, 27 Degrees C (80 Degrees F), a full transmission will show the fluid level below the "Add" mark on the indicator. As the transmission warms to normal operating temperature, the fluid expands, raising the level to within the cross-hatched area. 3L30 (180C) Transmission Shift Solenoid: Specifications 3L30 (180C) Transmission Component .......................................................................................................................................... .................................................................... Ft. Lbs. Solenoid ............................................................. .............................................................................................................................................................. .. 14 Page 3711 A new pressure regulator valve (III. 218) has been made which will improve the oil pressure stability at lower RPM. SERVICE PARTS INFORMATION: Description Part Number Valve, Pressure Regulator (III. 218) 8684048 Part numbers are for Reference Only. Check with your Parts Department for latest information. Page 3732 4. Remove the retention spring from the mirror bracket (Figure 2, Item A). 5. Drill and tap the retention spring, on the rear side wing, so that it will accept a 6.0 mm X 1.0 mm (diameter X thread pitch) set screw fastener (Figure 3, Item A) (procured locally). The approximate fastener length should be 10 mm. NOTE: The hole must be drilled perpendicular to the flat surface of the retention spring's wing. 6. Reinstall the retention spring in the mirror bracket. 7. Reinstall the mirror head and arm to the mirror bracket. 8. Reinstall the mirror assembly to the door. 9. Install the 6.0 mm X 1.0 mm headed fastener, adjusting it to obtain the original pressure against the mirror arm. DO NOT over-torque this fastener. 10. Reinstall the screws which secure the mirror cover to the door. WARRANTY INFORMATION For vehicles repaired under warranty, use: Labor Description Labor Time Operation R3260 RH mirror R&R; 0.4 Hr. 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. Locations Quad Driver: Locations Quad/Output drivers are hard wired onto the ECM/PCM/VCM. Suspension - Knocking/Rattling Noise Torsion Bar: Customer Interest Suspension - Knocking/Rattling Noise Number: 91-362-3C Section: 3C Date: JULY 1991 Corporate Bulletin No.: 163302 Subject: KNOCKING NOISE-TORSION BAR SUPPORT INSULATOR DAMAGED/BROKEN Model and Year: 1988-91 T TRUCKS Some owners of 1988-1991 T trucks may comment about a knocking or rattling sound coming from the underside of their vehicle. This sound can occur if the torsion bar support insulator is damaged or breaks. To correct this condition, a new more durable torsion bar insulator has been released. The new insulator is visually identical to the previous insulator and the installation procedure has not changed (reference S-10 Service Manual, Section 3C). VEHICLES INVOLVED: The new torsion bar support insulators have been installed on vehicles after the following VIN breakpoints. Shreveport 1GDCT14Z9M8801063 Pontiac West 1GCCS14A7M0190577 Moraine 1GCCS19R1M2273070 SERVICE PARTS INFORMATION: Part Number Description 15677665 Insulator, Torsion Bar Support Parts are currently available from GMSPO. WARRANTY INFORMATION: Labor Operation: E3340 Use applicable labor time guide for labor hours. Page 5788 Figure 9 - Disconnecting the Upper Ball Joint 17. Tip the knuckle out and toward the rear of the vehicle. Suspend the knuckle to prevent straining the brake line (Figure 9). Important: Cover the shock mounting bracket and the ball stud on the lower control arm with a shop towel to prevent possible halfshaft seal damage during removal and installation. Figure 8 - Splined Shank and Knuckle Separation 18. Install J28733 on brake rotor and separate outer C/V joint splined shank from knuckle hub (Figure 8). Figure 3 - Inboard Flange Bolt Removal 19. Remove six bolts (loosened earlier) from inboard joint flange (Figure 3). 20. Support inboard end of halfshaft. Free splined shank from hub and remove halfshaft from vehicle. Important: Wipe the wheel bearing seal area on the knuckle clean. Check the seal for cuts or tears. Page 5020 Wheel Cylinder: Service and Repair Rebuild For additional information see Notes, Warnings, and Hints. See: Fundamentals and Basics Fig. 8 Disassembled View Of Wheel Cylinder (typical) 1. Remove boots, pistons, springs and cups from the wheel cylinder. 2. Clean all parts with brake fluid. 3. Inspect cylinder bore. A scored bore may be honed as long as the diameter is not increased by more than 0.127 mm (0.005 inch). Replace worn or damaged parts as necessary. 4. Ensure hands are clean before proceeding with assembly. Lubricate cylinder wall and rubber cups with brake fluid, then install springs, cups, pistons and boots in housing. 5. Install wheel cylinder. Page 4025 Transmission Speed Sensor: Service and Repair 1. Disconnect battery ground cable. 2. Raise and support vehicle, then disconnect sensor electrical connector. 3. Remove sensor retaining bolt, then the sensor. 4. Reverse procedure to install. Engine - Rough/Unstable/Incorrect Idle Engine Mount: All Technical Service Bulletins Engine - Rough/Unstable/Incorrect Idle Number: 88-269-6E Section: 6E Date: JUNE, 1988 Subject: SERVICE MANUAL UPDATE ROUGH, UNSTABLE OR INCORRECT IDLE Model and Year: 1981-88 CHEVROLET PASSENGER CARS AND LIGHT DUTY TRUCKS TO: ALL CHEVROLET DEALERS When diagnosing Rough, Unstable, or Incorrect Idle, make sure to check the motor mounts for damage, grounding out on the frame, or mispositioned, etc. Brakes - Light Brake Drag While Driving Brake Light Switch: Customer Interest Brakes - Light Brake Drag While Driving Number: 89-262-5 Section: 5 Date: September 1989 Corporate Bulletin No.: 915002 Subject: LIGHT BRAKE DRAG - BRAKE SWITCH ADJUSTMENT Model and Year: 1980-89 A, B, F, G, J, L, X, Y 1980-89 ALL TRUCKS Figure 1 TO: ALL CHEVROLET DEALERS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 89-178-5, DATED JUNE 1989, IN ORDER THAT WE MAY CORRECTLY IDENTIFY THE SWITCH REQUIRING ADJUSTMENT. ALL COPIES OF 89-178-5 SHOULD BE DISCARDED. Some vehicles may experience a condition of light brake drag while driving. These conditions have been found to be more noticeable on vehicles which have an anti-lock brake system. This may be caused by improper brake switch adjustment. If the brake switch is not adjusted properly, the switch may push on the brake pedal and cause the brake to remain partially applied. If a vehicle exhibits any of the above conditions, perform the following functional brake switch adjustment check: Passenger Cars Only: The following steps should be used to check brake switch adjustment: 1. Remove the driver-side hush panel (refer to Figure 1). 2. Gently pull back on the brake pedal until no audible clicks are heard. The switch will be moved in the tubular retainer providing adjustment. 3. Replace the hush panel. 4. Verify that the brake drag condition is no longer present and that the cruise control and brake lights function properly. Page 509 Labor Operation No.: K6550 Valve, Pressure Regulator-R&R; or Replace Use the appropriate labor time in the labor time guide. Parts are currently available from GMSPO. 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 Page 7434 Page 3578 Locations Power Steering Pressure Switch: Locations LH Fender Apron LH Front Corner Of Engine Compartment Page 3420 [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. Page 3741 A. Use a micrometer to measure the original pump rotor and slide thickness accurately (Figure 3). To obtain the most accurate reading, measure on flat undamaged surfaces. The oil pump rotor and slides for the THM 200-4R and the THM 700-R4 transmissions are the same. B. Using the original part measurement, order replacement parts according to the selective charts. Note The replacement part will provide the same clearance that the oil pump assembly was originally built with. The proper end clearance specification is 0.020 to 0.050 mm. or (.0008") to (.002") for the 200-4R and the 700-R4. C. Hone both sides of the replacement rotor and slide to remove any burrs, and measure the replacement parts with a micrometer to assure proper selection. Note Incorrect rotor selection could result in a damaged oil pump assembly, and/or low oil pressure. Incorrect slide selection could result in incorrect line pressure. Page 1307 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. Page 4582 Figure 3 REMOVE (Figures 2 & 3) Tools required: J8092 Drive handle J33790 Bearing installer and remover 1. Transfer case from vehicle. - Refer to Section 7D of the appropriate S/T Service Manual for complete transfer case removal procedure. 2. Front output flange nut (77), washer (76), rubber sealing washer (75) and front output flange (74) from the front output shaft. 3. Vacuum switch (46) and O-ring seal (47). 4. Poppet screw (68), O-ring seal (69), poppet spring (71) and poppet plunger (70). Mainshaft Extension and Oil Pump Housing 5. Rear extension housing bolts (3) and rear extension (4). 6. Bearing retainer (snap ring) (5) from the mainshaft (19). 7. Pump retainer housing bolts (7). 8. Pump retainer housing (8) from the rear case half (17). 9. Speedometer tone wheel (11) from the mainshaft (19). Page 6719 A/T - 700R4 New 3-4 Clutch Apply Package Clutch: All Technical Service Bulletins A/T - 700R4 New 3-4 Clutch Apply Package SIL 88-13 (Mar) THM 700-R4 SUBJECT: New 3-4 Clutch Apply Package TRANSMISSION MODELS: All Models CHANGE TO ASSEMBLY COMPONENTS: NOTICE Certain transmissions ("A" Models, Figure 14) will have two steel plates stacked together in two places (one in the middle) to provide the same stack-up as a six plate clutch assembly and to draw heat away from the fiber plates. When assemblying the 3-4 clutch, refer to Figures 13, 13A and 14 for proper assembly Page 5312 LIGHT BLUE LT BLU BROWN BRN GRAY GRY GREEN GRN DARK GREEN DK GRN LIGHT GREEN LT GRN ORANGE ORN PINK PNK PURPLE PPL RED RED TAN TAN WHITE WHT YELLOW YEL 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". A/T - Water Or Coolant Contamination Information Fluid - A/T: All 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. Locations Compressor Clutch Relay: Locations A/C Cutout Relay The A/C Cutout Relay is located at the LH front of the dash on the relay bracket. Page 6818 e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors Do Not require all the steps shown. Skip the steps that Do Not apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. 1. Separate connector halves (see Figures 2 through 6). Figure 2 Figure 3 Page 8032 Front Inner Panel Water Deflector NOTE: Waterproof deflectors are used to seal the door inner panel, and to prevent water from entering into the body. The deflector is secured by a strip of adhesive between the deflector and the door, as well as waterproof sealing tape. REMOVE OR DISCONNECT 1. Door trim panel. 2. Plastic fasteners (when used). 3. Armrest bracket. 4. Water deflector. ^ Pull the waterproof sealing tape from the deflector. ^ Break the bond between the sealer and the door with a flat-bladed tool. INSTALL OR CONNECT 1. Water deflector strip caulking as a sealant between the deflector and the door, If needed. 2. Plastic fasteners (when used). 3. Waterproof tape. 4. Armrest bracket. 5. Door trim panel. Window Regulator Replacement Page 3925 Torque Converter: Testing and Inspection 1. Converter clutch pressure plate damaged. 2. Check ball on end of turbine shaft damaged. 3. Sticking converter clutch shift valve in valve body. 4. Sticking converter clutch apply valve in valve body. 5. Restricted converter clutch apply passage. 6. Low oil or oil pressure. 7. Engine not tuned properly. Master Cylinder Installation Brake Master Cylinder: Service and Repair Master Cylinder Installation Master Cylinder 1. Bench bleed master cylinder. 2. Install master cylinder, combination valve bracket and mounting bolts. 3. Connect brake lines to master cylinder. 4. Connect all wire connectors to master cylinder (if equipped). 5. On models with manual brakes, connect master cylinder push rod to brake pedal. 6. On all models, Bleed brakes. For additional information see Notes, Warnings, and Hints. See: Fundamentals and Basics A/T - THM 700-R4 TCC Applies During 1 to 2 Gear Shift Torque Converter Clutch: Customer Interest A/T - THM 700-R4 TCC Applies During 1 to 2 Gear Shift Number: 88-449-7A Section: 7A Date: JULY 1991 Corporate Bulletin No.: 177112R Subject: TCC APPLIES DURING 1-2 SHIFT Model and Year: 1988 G2, R1, S1 AND T1 TRUCKS WITH 700-R4 SERVICE REPLACEMENT TRANSMISSION ASSEMBLY Figure 1 - Control Valve Body Bulletin Covers: Some 1988 Service Replacement Transmission Assemblies (SRTA) may have been built with a bore plug in the TCC valve bore. The 8MHM, 8TAM, 8TBM, and 8TNM models should have the TCC shift valve lineup in this bore instead of the bore plug. If the bore plug is present, TCC will apply during the 1-2 shift. Service Information: If the control valve assembly contains a bore plug in place of the TCC shift valve lineup, the control valve assembly must be replaced. Service Parts Information: Reference the GMSPO Service Parts Catalog for the correct control valve assembly part number. Service Manual Reference: Refer to the THM 700-R4 Automatic Transmission Unit Repair Section of the appropriate Service Manual for instructions on replacing the control valve assembly. Diagram Information and Instructions Oil Pressure Gauge: Diagram Information and Instructions 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 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. Page 3496 Shift Solenoid: Specifications 4L60 - 700R4 Transmission Pressure Control Solenoid To Valve Body .............................................................................................................................................................. 8 ft. lbs. Solenoid Assembly To Case .................................................................................................. .................................................................................. 18 ft. lbs. Solenoid Assembly To Pump ............ .............................................................................................................................................................. .......... 8 ft. lbs. Description and Operation Electronic Spark Timing: Description and Operation Varying octane levels in today's gasoline can cause detonation in engines. Detonation is sometimes called spark knock. To control spark knock an Electronic Spark Control (ESC) system has been added. This system is designed to retard spark timing up to 20~ to reduce spark knock in the engine. This allows the engine to use maximum spark advance to improve driveability and fuel economy. The ESC system has three major components: ^ ESC module ^ ESC knock sensor ^ ECM The ESC knock sensor detects abnormal vibration (spark knocking) in the engine. The sensor is mounted in the engine block near the cylinders. The ESC module receives the knock sensor information and sends a signal to the ECM. The ECM then adjusts the timing to reduce spark knocking. The ESC module sends a voltage signal (8 to 10 volts) to the ECM when no spark knocking is detected by the ESC knock sensor, and the ECM provides normal spark advance. When the knock sensor detects spark knock, the module turns "OFF" the circuit to the ECM. The ECM then retards EST to reduce spark knock. Loss of the ESC knock sensor signal or loss of ground at ESC module would cause the signal to the ECM to remain high. This condition would cause the ECM to control EST as if no spark knock were happening. No retard would occur, and spark knocking could become severe under heavy engine load conditions, possibly leading to pre-ignition and severe engine damage. Loss of the ESC signal to the ECM would cause the ECM to constantly retard EST. This could result in sluggish performance and cause a Code 43 to set. Spark retard without the knock sensor connected could indicate a noise signal on the wire to the ESC module or a malfunctioning ESC module. Page 2762 Manifold Pressure/Vacuum Sensor: Description and Operation MAP Sensor The Manifold Absolute Pressure (MAP) sensor measures changes in the intake manifold pressure resulting from engine load and speed changes and converts this to a voltage output, Fig. 7. The ECM sends a 5 volt reference signal to the MAP sensor. As pressure changes in the intake manifold occur, the electrical resistance of the MAP sensor also changes. By monitoring the sensor output voltage, the ECM can determine the MAP. The higher the MAP, the lower the engine vacuum and the higher the sensor output, which requires more fuel. The lower the MAP, the higher the engine vacuum and the lower the sensor output, which requires less fuel. Page 471 Symbol Identification A/T - Paint Flakes In Fluid Fluid - A/T: Customer Interest A/T - Paint Flakes In Fluid Number: 88-400-7A Section: 7A Date: APRIL, 1989 Subject: EVIDENCE OF PAINT FLAKES IN TRANSMISSION FLUID Model and Year: 1988 PASSENGER CARS WITH AUTOMATIC TRANSAXLES TO: ALL CHEVROLET DEALERS Black paint flakes may be found in the transaxle fluid, bottom pan, fluid level indicator and filter assembly as the result of paint peeling from inside the transaxle fill tube. After the paint peels the unprotected areas of the fill tubes can corrode (interior and exterior), leaving corrosion on the fluid level indicator and the fill tube. The fill tube paints used on the interior and exterior of the tube may not withstand temperatures over 260 degrees Fahrenheit. Transaxle durability should not be affected in vehicles equipped with these fill tubes, but paint flakes can cause filter clogging over a period of time. DATE OF PRODUCTION CHANGE: The suspect fill tubes may be found in vehicles produced between October 17, 1987 (Julian Date 289) through June 30, 1988 (Julian Date 184). SERVICE ACTION: If vehicles are found with flaking paint fill tubes they should be changed along with Transaxle Fluid, Filter and Fluid Level Indicator. Labor Operation Number: T5181 Labor Time: .9 SERVICE MANUAL REFERENCE: Refer to the On-Car Section of your Service Manual whenever service of the Fluid Level Indicator and Fill Tube is necessary. Page 2610 Page 1071 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. Page 5196 6. Tape the solder and diode. 7. Reinstall the black plastic conduit. 8. Reconnect connector to the generator. 9. Reconnect battery. This procedure will not affect the operation of the generator light during the bulb check at the beginning of the start cycle. For vehicles repaired under warranty use, Labor Operation Number: T7990 Labor Time: .4 Hr Specifications Valve Cover: Specifications Rocker Arm Cover Bolts 7.5 ft.lb Fuel - Feed/Return Pipe Repair Fuel Supply Line: Technical Service Bulletins Fuel - Feed/Return Pipe Repair Number: 89-31-6C Section: 6C Date: NOV., 1988 Subject: FUEL FEED AND/OR RETURN PIPE REPAIR Model and Year: 1984-89 CHEVROLET PASSENGER AND LIGHT DUTY TRUCK VEHICLES TO: ALL CHEVROLET DEALERS When making any repairs to the fuel system, it is IMPORTANT that the following procedures be adhered to: A minimum of 13.0 mm (1/2") clearance must be maintained around sharp edges such as flanges, pinch weld, etc., to prevent contact and chaffing. A minimum of 19 mm (3/4") clearance must be maintained around any moving parts. ^ When rubber hose is used to replace pipe, use only reinforced fuel-resistant hose which is identified with the word "Fluorelastomer" or "GM6163-M" on the hose. Hose inside diameter must match pipe outside diameter. ^ Do not use rubber hose within 100 mm (4") of any part of the exhaust system or within 254 mm (10") of the catalytic converter. ^ In the repairable areas, cut a piece of fuel hose 100 mm (4") longer than portion of the line removed. If more than a 6 inch length of pipe is removed, use a combination of steel pipe and hose so that the total hose lengths, including the 100 mm (4") additional length will not be more than 254 mm (10") long. Follow the same routing as the original pipe. ^ Cut ends of pipe remaining on car square with a tube cutter. Using the first step of a double flaring tool, form a bead on the end of both pipe sections. If 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 screw-type hose clamp No. 2494772 or equivalent. Slide clamps onto pipe and push hose 51 mm (2") onto each portion of fuel pipe. Tighten clamps on each side of repair. A/T - Buzzing Noise at Idle Fluid Pressure Sensor/Switch: All Technical Service Bulletins A/T - Buzzing Noise at Idle Number: 93-29-7A Section: 7A Date: OCT. 1992 Corporate Bulletin No.: 277142 ASE No.: A2 Subject: BUZZING NOISE AT IDLE Model and Year: 1982-93 CAPRICE, CAMARO AND CORVETTE 1982-93 C/K, R/V, S/T, M/L AND G TRUCKS WTIH 4L60 AUTOMATIC TRANSMISSION TRANSMISSION APPLICATIONS: 1982-1993 HYDRA-MATIC 4L60 (MD8) TRANSMISSION MODELS: All SUBJECT: Pressure Regulator Valve Buzz VEHICLE APPLICATIONS: B, D, F, Y - Cars C/K, R/V, S/T Trucks G, M, L - Vans CONDITION: Some 1982-1993 vehicles equipped with a HYDRA-MATIC 4L60 transmission may have a buzzing noise coming from the transmission when the vehicle is at idle. The buzzing noise may be noticed more when the vehicle is in reverse at idle. CAUSE: The buzzing noise may be a result of pressure regulator valve oscillating due to oil pressure instability at lower idle RPM. CORRECTION: Page 6187 Removing The Shaft Seal Seat O-Ring 4. O-ring seal using J 9553-01. Inspect ^ Make sure the compressor neck area is clean. ^ All parts. Replace as necessary. Install or Connect Tools Required: J 5403 Snap Ring Pliers J 23128-A Seal Seat Remover and Installer J 33011 O-Ring Seal Installer J 34614 Shaft Seal Protector ^ Dip the new O-ring seal in clean 525 viscosity refrigerant oil. 1. J 34614 onto the shaft (38). Installing The Shaft Seal Seat O-Ring 2. O-ring seal using J 33011. ^ Insert J 33011 into the compressor neck until the installer "bottoms." ^ Lower the movable slide of J 33011, releasing the O-ring seal into the lower groove. ^ Rotate J 33011 to seat the O-ring seal and remove J 33011. 3. Shaft lip seal using J 23128-A. ^ Dip the shaft lip seal in clean 525 viscosity refrigerant oil and install the shaft lip seal on J 23128-A. ^ Bottom the shaft lip seal into the compressor neck area using J 23128-A. 4. Shaft seal retainer ring using J 5403. ^ Install the flat side of the shaft seal retainer ring against the lip seal. ^ Remove J 34614. Important ^ Leak test the compressor. Clean ^ Shaft (38) and inside the compressor neck area. 5. Clutch plate and hub assembly (22). Page 6117 Removing The Pulley Bearing 2. Pulley bearing retainer (2) with J 6435. 3. Pulley (6). Removing The Pulley And Bearing ^ Install J 9395 over the end of the compressor shaft (38). Important ^ Use J 9395 puller pilot to prevent internal damage to the compressor when removing the pulley. Do not use the pulley directly against the end of the shaft. ^ Place J 8433 over J 9395 for the regular V-groove pulley. ^ Place J 24092 over J 9395 for the multi-groove pulley. ^ Turn the screw on J 8433 to remove the pulley (6). Important ^ When using J 24092, the puller arms must extend around to the rear side of the pulley. Do not attempt to pull the pulley off by engaging the puller arms in a multi-groove pulley. Page 4655 IMPORTANT: Do not depress the detent button when checking rearward play. Figure 3 - Detent Spring/Screw Replacement 3. Replace the transfer case detent poppet spring (P/N 15547384) with P/N 15580210. Replace the transfer case detent spring retaining screw (P/N 3975717) with P/N 15580211. This will increase the detent spring load (Figure 3). Parts are currently available from GMSPO. NOTICE: Both the detent poppet spring and detent poppet screw must be replaced together. Interchanging the old and new parts may cause shifting problems (i.e. an inability to shift the transfer case). Transfer case oil must be drained to perform the above part change. Refill with Dexron II upon completion. Page 1383 Specifications TEMPERATURE SENSORS Page 3690 Fluid - A/T: Fluid Type Specifications 3L30 (180C) Transmission Lubricant Types ................................................................................................................................... ................................................................... Dexron II 4L60 - 700R4 Transmission Lubricant Type ..................................................................................................................................... ......................................................... Dextron II ATF Electrical - MIL ON/DTC's Set By Various Control Modules Wiring Harness: 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 Page 4653 Figure 1 - Transfer Case Linkage And Boot Page 6278 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. Page 6075 e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors Do Not require all the steps shown. Skip the steps that Do Not apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. 1. Separate connector halves (see Figures 2 through 6). Figure 2 Figure 3 Page 7129 Figure No. 1 NOTICE: For two tone vehicles, it is only necessary to refinish surfaces painted Galaxy Blue, Aspen Blue or Steel Gray. Other colors should not be affected by this condition. The front bumper filler panel and all surfaces painted with affected colors above the belt line (Fig. 1, page 3) must be refinished according to the procedure listed below (regardless of previous paint repairs). If surfaces below the belt line and the interior of the pickup box (on pickup models) appear to be in good condition, the dealer should scuff sand, seal and color coat those painted surfaces rather than refinish. However, if any peeling or topcoat delamination is evident, or If scuff sanding produces any topcoat delamination, it will be necessary to refinish these surfaces as well, according to the procedures. It should not be necessary to paint inside of door jambs, or underneath exterior moldings or decals (sunshine stripes), as these areas are not normally subjected to continued ultraviolet exposure. 2. Sand original finish coat of paint down to electro-coat (Elpo) primer, making sure factory pretreatment and Elpo primer are still intact for good corrosion protection. DO NOT USE CHEMICALS TO REMOVE PAINT AS THIS MAY DAMAGE THE ELPO PRIMER. NOTICE: Rough tape vehicle as necessary (window glass, etc.), and remove nameplates, weatherstrips, and reveal moldings as needed to properly refinish all surfaces as required. 3. Finish sand exposed Elpo primer with 240 grit sandpaper to assure removal of any chalky residue or degraded Elpo primer that may remain as a result of overbaking the primer. NOTICE: Avoid sanding through Elpo to bare metal when possible. 4. Use an air gun to remove all dirt from cracks and surfaces of truck. 5. Clean sanded surfaces with grease and wax remover. Page 7426 Figure 4 Figure 5 Figure 6 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 7 Page 2335 Manifold Pressure/Vacuum Sensor: Description and Operation MAP Sensor The Manifold Absolute Pressure (MAP) sensor measures changes in the intake manifold pressure resulting from engine load and speed changes and converts this to a voltage output, Fig. 7. The ECM sends a 5 volt reference signal to the MAP sensor. As pressure changes in the intake manifold occur, the electrical resistance of the MAP sensor also changes. By monitoring the sensor output voltage, the ECM can determine the MAP. The higher the MAP, the lower the engine vacuum and the higher the sensor output, which requires more fuel. The lower the MAP, the higher the engine vacuum and the lower the sensor output, which requires less fuel. Page 7074 Door edge guards Bumper filler panel, Frt./Rr. Front side marker lamps *Roof marker lamps *West coast style mirrors *Stripes Emblems/decals if necessary G VANS Wiper arms Cowl vent grille Grille and headlamp bezels Front bumper filler panel Antenna Side view mirrors Side marker lamps Tail lamps Door edge guards Wheel opening moldings *Roof marker lamps *West coast style mirrors *Stripes Emblems/decals if necessary Swing out windows/seals WARRANTY INFORMATION For vehicles repaired under warranty. and for customer satisfaction. use: Labor Op (Labor Operations include mix time) A6100 Refinish the entire exterior body surface ABOVE THE BODY SIDE MOLDING AND INSERT COLOR on two tone vehicles if equipped. A6101 Refinish the entire exterior body surface INSERT COLOR only. A61O2 Refinish the PICKUP BOX LOAD FLOOR AND INNER FENDERS when applicable. A61O3 On units with an insert color, included is the entire exterior body surface ABOVE THE BREAKLINE. (If the insert color and the entire body surface above the break-line requires refinishing, use A6100). Page 478 Figure 8 Figure 9 Figure 10 Figure 11 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). Electrical - Intermittent MIL/DTC P2138/Reduced Power Multiple Junction Connector: All Technical Service Bulletins Electrical - Intermittent MIL/DTC P2138/Reduced Power TECHNICAL Bulletin No.: 07-06-04-019D Date: June 28, 2010 Subject: Intermittent Malfunction Indicator Lamp (MIL) Illuminated, DTC P2138 with Reduced Engine Power (Repair Instrument Panel (IP) to Body Harness Connector) Models: 2005-2011 GM Passenger Cars and Light Duty Trucks (Including Saturn) 2005-2009 HUMMER H2 2006-2010 HUMMER H3 2005-2009 Saab 9-7X Supercede: This bulletin is being revised to update the model years and warranty information. Please discard Corporate Bulletin Number 07-06-04-019C (Section 06 - Engine/Propulsion System) Condition - Some customers may comment on an intermittent malfunction indicator lamp (MIL) being Illuminated with a message or an indicator that displays Reduced Engine Power. - The technician may observe on a scan tool DTC P2138 - Accelerator Pedal Position (APP) Sensor 1-2 Correlation set as Current or in History. Cause This condition may be caused by water intrusion into the instrument panel (IP) to body harness connector, which carries the APP sensor signals to the ECM/PCM. This water intrusion results in a voltage difference between APP Sensor 1 and APP Sensor 2 that exceeds a predetermined value for more than a calibrated period of time, setting P2138. Correction Note Aftermarket equipment can generate DTC P2138 and/or other DTCs. 1. Verify that aftermarket equipment is not electrically connected to any of the APP sensor signal or low reference circuits or to any other ECM/PCM 5V reference or low reference circuits. Refer to Checking Aftermarket Accessories in SI. 2. Perform the Diagnostic System Check - Vehicle. ‹› If any 5V reference DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle. ‹› If any 5V reference DTCs are not set, proceed to Step 3. 3. Locate the IP to body harness connector, which may be located in and around the left hand kick panel area or inside the IP. Depending on the vehicle and model year, refer to Wiring Systems or Power and Signal Distribution in SI. Note Some examples of potential water leaks are: A-pillar seals, sunroof drain lines (if equipped) and windshield/cowl sealing. 4. Inspect for a water leak in the area. If necessary use a water hose to determine the source of the leak. Refer to General Information > Water Leaks in SI. ‹› If a water leak is observed, repair as necessary. Verify the effectiveness of the repair. 5. Inspect the IP to body harness connector terminals for corrosion and debris. Refer to Testing for Intermittent Conditions and Poor Connections in SI. ‹› If any corrosion and/or debris is observed, repair as necessary. 6. After completing the repair, verify the proper operation of the system. Depending on the vehicle and model year, perform the Diagnostic Repair Verification procedure or refer to Diagnostic Trouble Code (DTC) List - Vehicle in SI. Description and Operation Cruise Controller: Description and Operation The module monitors mode control switch position, signals from the speed sensor, servo position and release switch operation, then operates vacuum valves within the servo unit to control servo operation and vehicle speed. The module also contains a speed limiting function which prevents system operation at speeds below approximately 25 mph. Page 697 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. Page 6578 Box 1 Verify that the condition is present, then disconnect any non-factory add-on electronics, (not including the radio) Box 2 If the condition goes away when a particular device is disconnected, reconnect the device to verify it as the source of the interference. If the condition is related to non-factory add-on electronics, consult the GM installation guidelines (See Box 6) as an example of how to add an electronic component to the vehicle's electrical system. Box 3 If the condition is ONLY present with the engine running, disconnect electrical components that are active only with the engine running. The charging system, various solenoids, and relays may be intermittently disconnected while observing the condition. In some cases a component cannot be disconnected while the engine is running. In these cases, the component can be tested independent of the vehicle (i.e. fuel injectors). For further tips on engine noise diagnostics refer to the Delco Sound Service Guide, Engine Noise Chart. Box 4 If the condition can be eliminated and the interference isolated to a component, determine if a bulletin has been published concerning this particular condition. Contact your Technical Assistance Group for additional information if no bulletins are found. Box 5 If the concern cannot be eliminated by testing in any key position and by disconnecting fuses and components, the condition most likely is not RFI. Refer to the Delco Sound Service Guide or the vehicle service manual for further diagnostic tips and check for any published bulletins. If the concern cannot be identified or eliminated, contact your Technical Assistance Group for further assistance. Box 6 The "Installation Guidelines for Aftermarket Accessories" for all model years and all trucks and carlines are located in the following Service Bulletin 91-8-2. Also, there may be separate installation guidelines for cellular phones. A search for service bulletins may be necessary to find these. Wheels - Sealing Leaking Cast Aluminum Wheels: All Technical Service Bulletins Wheels - Sealing Leaking Cast Aluminum Bulletin Number: 93-3-16 Reference Number: 393504 Publish Date: 7/93 Subject: LEAKING CAST ALUMINUM WHEELS (REPAIR WITH ADHESIVE SEALANT) Models Affected: 1985-1993 ALL MODELS Should a vehicle equipped with cast aluminum wheels exhibit a slow leak due to a porous condition existing in the wheel, the wheel can be repaired by using Dow Corning Silastic 732 RTV, p/n 1052366 or equivalent, as described in the following procedure: 1. Remove tire-wheel assembly from vehicle. 2. Locate leaking area by inflating tire to 40 psi and dipping tire-wheel assembly in water bath. 3. If air bubbles are observed, mark leak area and remove tire from wheel. 4. Scuff INSIDE rim surface at leak area with # 80 grit paper and clean area with general purpose cleaner, such as 3M # 08984. 5. Apply 1/8" thick layer of adhesive/sealant to leak area on INSIDE of rim and allow six hours of drying time. 6. Mount tire on wheel, pressurizing to 40 psi and check for leaks. NOTICE: Caution must be used when mounting the tire so as not to damage the sealer. 7. Adjust tire pressure to meet placard specification. 8. Balance tire-wheel assembly, using proper coated weights. 9. Water test wheel again. 10. Reinstall tire-wheel assembly on vehicle. Parts are currently available from GMSPO. WARRANTY INFORMATION: Labor Operation Number: E0420 Fuse Block - Deforms Fuse Block: Customer Interest Fuse Block - Deforms Number: 90-432-8B Section: 8B Date: SEPT. 1991 Corporate Bulletin No.: 168102 ASE No.: A6 Subject: FUSE BLOCK DEFORMS Model and Year: 1988-90 SI (LLV) POSTAL VEHICLES Some 1988 to 1990 LLV postal vehicles built prior to August 3, 1990, may exhibit a condtion where the fuse block is partially deformed due to heat generated by continuous operation of the hazard flasher. This condition may be corrected by the repositioning of the hazard flasher to a remote location. SERVICE PROCEDURE: 1. Disconnect positive battery cable. 2. Remove old flasher. 3. Back out terminals for circuit 140A (orange wire) and circuit 27 (brown wire) using a small flat screwdriver or pick. Using the same tool, raise the locking tang on the back of the terminal. 4. Cut electrical tape used to wrap main wiring harness a sufficient amount to provide 2 to 3 inches of flasher wiring for relocation. 5. Insert terminals of circuits 140A and 27 into new connector (P/N 2973385). 6. Install electronic flasher (P/N 15504673) into the new connector. 7. Using nylon ties, strap the connector and flasher assembly to the wiring harness that runs above the fuse block. Verify that the relocated flasher and all wiring is secured so it does not cause interference with the throttle linkage. 8. Reconnect battery cable. 9. Test operation of hazard flasher system. SERVICE PARTS INFORMATION PART NUMBER DESCRIPTION QTY 2973385 Connector 1 15504673 Flasher (Electronic) 1 NPN Nylon Tie Straps 2 Parts are currently available from GMSPO. Specifications Idle/Throttle Speed Control Unit: Specifications IDLE SPEED CONTROL Measured between terminals A& B and C & D. Service and Repair Axle Beam: Service and Repair Fig. 5 Rear Suspension (Left Side) 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 and drums then disconnect shock absorbers from anchor plates. 3. Scribe reference marks between driveshaft and pinion flange for use during reassembly, then disconnect driveshaft and position aside. 4. Disconnect brake lines from junction block and backing plates, then remove junction block attaching bolt and position aside. 5. Remove backing plates. 6. Remove U-bolts and anchor plates, Fig. 5. 7. On 1988-93 models, disconnect vent hose from axle housing. 8. Lower rear axle assembly, then remove lower spring shackle bolts. 9. Remove rear axle assembly. 10. Reverse procedure to install. Torque shock absorber nut, U-bolt nuts and lower spring shackle bolts to specification. Electrical - VSS Connector Mislabeled Vehicle Speed Sensor: Technical Service Bulletins Electrical - VSS Connector Mislabeled GMC NUMBER: 88-T-145 GROUP: 6D-Engine Electrical DATE: August, 1988 CORPORATE NUMBER: 818107 SUBJECT: CONNECTOR MISLABELED MODELS: 1985-88 G, S, R, AND M VEHICLES FIGURE NO. 1VEHICLE SPEED SENSOR BUFFER CORRECT CONNECTOR LABEL Some 1985-88 vehicles may have an electrical connector at the vehicle speed sensor (VSS), which is improperly labeled. The connector will work properly but could cause confusion if electrical troubleshooting is necessary. Figure No. 1 shows a properly labeled connector. The improperly labeled connectors have the "A" and "C" reversed. All Service Manual terminal call-outs use the labeling as shown in Figure No. 1. Drivetrain - Evaluating Driveline Vibration Technical Service Bulletin # 891994A Date: 890601 Drivetrain - Evaluating Driveline Vibration Number: 89-199-4A Section: 4A Date: June 1989 Subject: EVALUATING DRIVELINE VIBRATION Model and Year: 1980-89 LIGHT DUTY TRUCKS TO: ALL CHEVROLET DEALERS The purpose of this bulletin is to provide a logical approach to evaluating vehicles for driveline generated vibrations and imbalance occurring between 50-62 mph. The following diagnosis tree is designed to be used as a guide, and when utilized properly can help isolate and identify causes of driveline disturbances. Procedure: Prior to road test, determine if disturbance is engine related by following the procedure below: 1. With engine at operating temperature and vehicle parked, set parking brake and place transmission shift lever in neutral. 2. Slowly accelerate engine from idle to 4000 RPM (diesels 3200 RPM), noting RPM at which vibration is felt (if any). 3. If vibration is felt, disregard use of this bulletin and isolate and repair responsible engine component (transmission, clutch/flywheel, torque converter, engine accessory, etc.). Road test vehicle on a smooth level road to verify customer comment. It is usually beneficial to road test the vehicle with the customer present. Note the speeds and conditions at which the disturbance is most noticeable. Refer to Remark A in this bulletin for diagnosis information. Page 7780 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. A/C - Refrigerant Loss Prevention Service Port HVAC: All Technical Service Bulletins A/C - Refrigerant Loss Prevention Number: 91-284-1A Section: 1A Date: APRIL 1991 Corp. Bulletin No.: 971202R Subject: AIR CONDITIONING REFRIGERANT LOSS DUE TO LOOSE OR MISSING ACCESS FITTING CAPS Model and Year: 1980-91 PASSENGER CARS AND TRUCKS All GM air conditioning Hi side and Low side access fittings are supplied with a black plastic cap and seal assembly which provides the primary refrigerant seal for the service fittings. If the cap and seal assembly is missing or loose, a significant amount of refrigerant may leak through the valve core located in the access fitting, which could result in poor A/C performance or failure. When servicing any vehicle's A/C system, make sure all access fitting cap seals (refer to Figure) are in place and tight. Caps should be threaded on until contact with the "O" ring seal is made and then tightened another 1/4 - 1/2 turn to ensure proper sealing. High Side Low Side Valve - Cap and Seal Valve - Cap and Seal P/N 52451233 P/N 6551640 Parts are currently available from GMSPO. Page 1577 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. Page 317 If the functional brake switch adjustment check does not repair the condition, refer to Section 5 of the appropriate Service Information Manual for aid in diagnosing other causes. For warranty purposes use: Labor Operation Number: N2440 Labor Time: .3 hour TRUCK ONLY: Service Procedure: 1. Depress the brake pedal and press the switch in until it is firmly seated in the clip. * Audible "clicks" can be heard as the threaded portion of the switch is pushed through the clip. 2. Pull the brake pedal against the pedal stop until the audible "click" can no longer be heard. For stop lamp switch adjustments on vehicles repaired under warranty use: Labor Operation Number: T7945 Labor Time: .2 Hr. Page 3921 Throttle Valve Cable/Linkage: Adjustments 1. Stop engine. 2. Depress and hold down readjust tab, move slider through fitting, away from lever assembly, until slider stops against fitting. 3. Release readjust tab, then open throttle lever to its full throttle position to automatically adjust cable. 4. Release throttle lever and check cable for sticking or binding. The cable may appear to function properly with engine stopped and cold. Recheck cable with engine at normal operating temperature. 5. Road test vehicle. Page 3964 Wiring Diagram For Chart C-8 - Transmission Converter Clutch (TCC) (Under 8500 GVW) CHART C-8 - TRANSMISSION CONVERTER CLUTCH (UNDER 8500 GVW) Circuit Description: The purpose of the automatic transmission torque converter clutch feature is to eliminate the power loss of the torque converter stage when the vehicle is in a cruise condition. This allows the convenience of the automatic transmission and the fuel economy of a manual transmission. Fused battery ignition is supplied to the TCC solenoid through the TCC brake switch. The ECM will engage TCC by grounding CKT 422 to energize the solenoid. TCC will engage when: - Vehicle speed above 30 mph (48 km/h). - Engine at normal operating temperature (above 65~C) (149~F). - Throttle position sensor output not changing, indicating a steady road speed. - Brake switch closed. - 3rd or 4th gears. Test Description: Numbers below refer to circled numbers on the diagnostic chart. 1. A test light on indicates battery voltage and continuity through the TCC solenoid is OK. 2. Checks for vehicle speed sensor signal to ECM using a "Scan" tool. 3. Checks for 4th gear signal to ECM. This signal will not prevent TCC engagement, but could cause a change in the engage and disengage speed points. Diagnostic Aids: Solenoid coil resistance must measure more than 20 ohms. less resistance will cause early failure of the ECM "Driver". Refer to ECM QDR check. Using an ohmmeter, check the solenoid coil resistance of all ECM controlled solenoids and relays before installing a replacement ECM. Replace any solenoid or relay that measures less than 20 ohms resistance. Page 5052 Fig. 5 Bracket Removal & Installation Page 3604 8667423 3-4 Clutch Apply Plate 8667661 Input Housing and Shaft Assembly (621) (used with 245 mm converter) 8667659 Input Housing and Shaft Assembly (621) (used with 298 mm converter) 8667660 Input Housing and Shaft Assembly (621) (used with 298 mm converter MHM model only) 8663636 Internal Retaining Ring 8663639 Input Internal Gear 3-4 Clutch Backing Plate Selection Procedure (Figure 15) 1. With the input housing and shaft assembly fully assembled, use a feeler gage to measure for correct backing plate travel (Figure 15). 2. Select the proper backing plate to obtain the specified travel (Figure 15). Borg Warner Pinion Gear: Adjustments Borg Warner 2 - Pinion Fig. 8 Pinion gauge plate installation Fig. 9 Checking pinion depth Page 5561 5. Remove paint and primer from the area surrounding the 10 mm (0.40 in) until bare metal is visible. Important The M6 conductive rivet stud as shown, can accommodate a panel thickness range of 0.7-4.2 mm (0.03-0.17 in). If there are layers of sheet metal, they should be touching without any air gaps to ensure a good ground. 6. Select a M6 conductive rivet stud. Refer to the Parts Information section of this bulletin. Note Use the GE-50317 rivet stud tool kit. 7. Place the M6 conductive rivet stud (1) in the 10 mm (0.40 in) hole. Assemble the rivet stud tool (2) with the groove and flare side facing the rivet stud, then the washer and the M6 nut (3). 8. Using a wrench on the rivet stud tool, and a socket on the M6 nut, secure the M6 conductive rivet stud. 9. Ensure the new rivet stud is securely fastened, WITHOUT ANY detectable movement. 10. Completely wrap the threads of the rivet stud with painters tape or equivalent. Paint - Acid Rain Damage to Base Coat/Clear Coat Paint: All Technical Service Bulletins Paint - Acid Rain Damage to Base Coat/Clear Coat Number: 92-33-10 Section: 10 Date: NOV. 1991 Corporate Bulletin No.: 131060 ASE No.: B2 Subject: INDUSTRIAL FALLOUT/RAIL DUST DAMAGE TO BASE COAT/CLEAR COAT Model and Year: 1983-92 ALL PASSENGER CARS AND TRUCKS Application: 1992 (and previous) models with Base Coat/Clear Coat Paint The following information regards the use of finesse type repairs to environmental (industrial fallout) and rail dust damage of base coat/clear coat paint finishes. Since the severity of the condition varies from area to area, PROPER DIAGNOSIS of the damage extent is CRITICAL TO THE SUCCESS OF REPAIRS. Diagnosis should be performed under high intensity fluorescent lighting, on horizontal surfaces (hood, roof, decklid) after they have been properly cleaned. INDUSTRIAL FALLOUT (ACID RAIN) There are three basic types of acid rain damage: Surface level contamination, - may be repaired by simply washing the vehicle, cleaning the surface with a wax and grease remover, neutralizing acidic residue and finesse polishing. - Clearcoat etching, - slight etching still noticeable after the above washing and finesse polishing procedure. - Basecoat etching, - severe etching beyond the clearcoat into the basecoat. PROCEDURES FOR SURFACE LEVEL CONTAMINATION REPAIRS 1. Wash the vehicle with standard car detergent and water and dry thoroughly. 2. Clean the affected area with a wax and grease remover. 3. Neutralize any left over acidic residue by cleaning the damaged areas with a mixture of baking soda and water (one tablespoon per quart of water), rinse THOROUGHLY and dry the panels completely. 4. Apply a finesse type polish with a foam pad. CLEAN AND INSPECT THE SURFACE A. If the damage has been repaired, remove any swirl marks with a dual action orbital polisher and foam pad. B. If some damage remains, proceed to step 5. SLIGHT CLEARCOAT DAMAGE - WET SANDING, FINESSE POLISHING 5. Select a small test area on a damaged panel. 6. Wet sand the damaged area with an American Grade ultra fine sandpaper of 1,500 to 2,000 grit and a rubber sponge sanding block. During the wet sand process; a. Use ample amounts of water b. Go slow to prevent removing too much clearcoat. Note: Be sure to use American Sandpaper. European Sandpaper has a "P" before the grit number and European grits do not align with American grits the majority of the time. 7. Remove the excess water with a rubber squeegee and inspect the area. A. If this has repaired the damage, continue the sanding procedure on the entire panel, apply a finesse type polish with a foam pad and remove any swirl marks with a dual action orbital polisher and foam pad. B. If (during the repair) it is suspected or observed that; - etching has penetrated into the base coat OR - too much clearcoat has been removed during sanding OR - base color is transferred to pad during polishing, Service and Repair Condenser HVAC: Service and Repair Figure 29 - Condenser Replacement REMOVE OR DISCONNECT (Figure 29) 1. Refrigerant from the system. 2. Upper fan shroud. 3. Radiator. 4. Shields at either side of the radiator support. 5. Condenser retainers (121) and insulators (120). 6. Condenser lines (110 and 111). 7. Condenser (21). INSTALL OR CONNECT (Figure 29) 1. Condenser (2). 2. Condenser retainers (121) and insulators (120). ^ Tighten-Mounting bolts (122) to 6 Nm (62 in. lbs.). 3. Condenser lines (110 and 111) to the condenser (2). ^ Tighten-Nuts (110 and 111) to 24 Nm (18 ft. lbs.). 4. Radiator. 5. Upper fan shroud. 6. Refrigerant to the system. 7. Evacuate, charge and leak test. Fuel - Injector Wires Trapped Under Air Cleaner Fuel Injector: Customer Interest Fuel - Injector Wires Trapped Under Air Cleaner Number: 93-86A-6C Section: 6C Date: MAY 1993 Corporate Bulletin No.: 266402R ASE No.: A1, A8 Subject: FUEL INJECTOR WIRES MAY BECOME TRAPPED WHEN REINSTALLING THE AIR CLEANER (TWIST WIRES ONCE) Model and Year: 1988-93 LIGHT DUTY TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 93-8-6C, DATED JAN. 1993. CALL LIGHT DUTY TRUCKS HAVE BEEN ADDED AS WELL AS THE REFERENCED ARTWORK REVISED. CONDITION: When an air cleaner is removed on 1988-93 Light duty trucks, the potential for trapping the injector wires between the air cleaner and the throttle body or between the extension ring and throttle body is present during reinstallation (Figure 1). CORRECTION: Interior - Tapping Noise In Corner of Dash Dashboard / Instrument Panel: Customer Interest Interior - Tapping Noise In Corner of Dash Number: 89-101-10 Section: 10 Date: MARCH, 1989 Subject: TAPPING NOISE IN CORNER OF DASH Model and Year: 1987-89 S/T TRUCKS TO: ALL CHEVROLET DEALERS Some 1987-89 S/T Trucks may experience a noise from the cowl area located around either of the front dash speakers. The noise has been described as a tapping or creaking noise similar to tapping a pencil lead on the windshield. This condition occurs primarily at ambient temperatures below 45 degrees Fahrenheit. Therefore, vehicles which sit inside a heated facility during repair should be "cold soaked" prior to verifying the repair. Repair Procedure Apply repair procedure exactly as described in Chevrolet Bulletin 86-58 (Section 10) dated April, 1986, which has been reproduced in this bulletin for your convenience. IMPORTANT: Windshield replacement will not resolve the situation. For repairs to vehicles under warranty, use: Labor Op: T7230 1983-86 Models - Labor Time: .6 Hr per side 1987-89 Models - Labor Time: .8 Hr. per side NOTE: On 87-89 vehicles, the location of the one inch hole will encompass a small weld. Additional time has been added to the labor operation to take this into account. Be sure to cut through only the first layer of sheet metal as specified in Step 9 on the bulletin. IMPORTANT: Dealers who have vehicles that are not repaired by this procedure should contact Technical Assistance for further assistance. Subject: COWL POPPING NOISE Model and Year: 1983-86 S/T TRUCKS Number: 86-58 Section: 10 Date: APR., 1986 TO: ALL CHEVROLET DEALERS On some S/T Trucks operating in low ambient temperatures, a condition may exist where a snapping or "popping" noise is heard coming from the cowl. This noise is caused by an "oil can" effect between the windshield frame and the door frame. The service procedure for eliminating the noise is as follows: 1. Remove the windshield wipers and radio antenna. A/T - 700R4 Valve Body Modification Valve Body: All Technical Service Bulletins A/T - 700R4 Valve Body Modification SIL 85-21 SUBJECT: 700-R4 For start of production 1985, the converter clutch shift valve train was eliminated on units where the converter clutch is controlled by the computer. Page 5061 Vacuum Brake Booster: Technical Service Bulletins Brakes - Replacement Booster Push Rod Height Gage GMC NUMBER: 89-T-51 GROUP: 5 - Brakes DATE: April, 1989 CORPORATE NUMBER: 965005 SUBJECT: BRAKE BOOSTER PUSH ROD HEIGHT GAGE MODELS: 1982-89 LIGHT DUTY TRUCKS A new brake booster push rod height gage (J37839) has been approved by Delco Moraine. The new gage is an essential tool and replaces tool J22647, which should be scrapped. The new gage will be shipped to dealers in the April-May 1989 time frame. FIGURE 1 The reason for the new gage is twofold 1. The new gage locates on the chamfered sides of the booster push rod rather then the top of the rod. This is a more accurate reference point because the push rod sides initiate the contact with the master cylinder primary piston (See Figure 1). 2. The maximum and minimum push rod length tolerance was revised to reduce push rod free travel. IMPORTANT: These design change were made for all 1989 Delco Moraine vacuum boosters. The new gage can be used on all pre-1989 models with Delco Moraine vacuum boosters. Gage Procedure 1. With master cylinderr removed and the brake booster still attached to the vehicle, gage the booster with 85.0 kPa (25 In. Hg.) vacuum or maximum engine vacuum. IMPORTANT: Booster can be gaged without being installed on the vehicle, if a suitable vacuum source is available. 2. Position gage (J37839) over piston rod as shown in Figure 1. 3. Check for both the maximum and minimum rod length. 4. If the rod length does not fall between the maxand minimum dimensions, replace with adjustable push rod P/N 5469384. Parts are currently available from GMSPO. Page 3205 Ignition Coil: Service and Repair REMOVAL: 1. Disconnect the negative battery cable. 2. Disconnect the engine control switch and tachometer connectors at the coil, if equipped. 3. Disconnect coil to distributor lead at the coil. 4. Remove screws holding the coil bracket and coil to the engine. 5. Remove coil bracket and coil. 6. Drill out rivets holding the coil to the coil bracket. 7. Remove coil from coil bracket. INSTALLATION: 1. Install coil to coil bracket. 2. Install screws to hold coil to coil bracket. 3. Install coil and coil bracket to engine. Tighten screws to 22 N-m (16 lb. ft.). 4. Connect coil to distributor lead. 5. Connect engine control switch and tachometer connectors at the coil, if equipped. 6. Connect negative battery cable. Page 8034 Front Door Trim Panel Components Front Inner Panel Water Deflector A/C - Erratic HVAC Operation & Self Diagnostic Blinks Air Conditioning Indicator Lamp: 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). Page 4348 Fig. 6 Installing Bearing Cups Into Driveshaft Yoke Assembly 1. If old parts are to be reassembled, pack bearing cups with universal joint grease. Do not fill cups completely or use excessive amounts as over-lubrication may damage seals during reassembly. Use new seals if available. 2. If new parts are being installed, check new bearings for adequate grease before assembling. 3. With the pusher (smaller) socket, press one bearing cup part way into driveshaft. Position spider into the partially installed cup. Place second bearing cup into driveshaft. Fasten driveshaft in vise so that cups are in contact with faces of vise jaws, Fig. 6. Some spiders are provided with locating lugs which must face toward driveshaft when installed. 4. Press bearing cups all the way into position and install snap rings or retainer plates. 5. Install bearing cups in yoke in same manner. When installation is completed, check U-joint for binding or roughness. If free movement is impeded, correct the condition before installation in vehicle. Without Joint Replacement 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) ECM/PCM - Damaged and/or Misdiagnosed Engine Control Module: All Technical Service Bulletins ECM/PCM - Damaged and/or Misdiagnosed Number: 91-384-6E Section: 6E Date: AUGUST 1991 Corporate Bulletin No.: 176503 Subject: DAMAGED ECM/PCM AND/OR MIS-DIAGNOSED ECM/PCM SYMPTOMS DUE TO INCORRECT "TAP-TESTING" PROCEDURES Model and Year: 1982-91 ALL PASSENGER CARS AND TRUCKS CONDITION: Because of the intermittent nature of some Electronic Control Module (ECM) or Powertrain Control Modules (PCM) symptoms, some service technicians have been subjecting the ECM/PCM to vibration and/or shock testing. Commonly known as tap-testing, this procedure involves tapping on the ECM/PCM case, while the engine is running. It is generally accepted that if the engine or ECM/PCM falters due to the tapping, an intermittent internal ECM/PCM defect may be indicated. However, this may not always be true. If too much force is applied to the ECM/PCM during the test the following symptoms may result: ^ Immediate ECM/PCM failure. ^ ECM/PCM suffers damage which may cause a failure at a later date. ^ ECM/PCM Reset (or Glitch), creating a momentary stall, miss Service Engine Soon (SES) light and/or loss of serial data. CAUSE: The ECM/PCM should be tapped using only the fingertips of one hand. Use of the palm, fist, or any type of tool subjects the ECM/PCM to forces that can cause both the circuit board and the outer aluminum case to flex and distort beyond design limits. The Integrated Circuits (IC) used in today's ECM/PCMs are mounted to the circuit board using a mounting process referred to as "surface technology." There are no circuit board holes for IC leads to go through. The IC leads set on pads, (28 pads or 52 pads depending on the IC) and solder is flowed around the leads to make the electrical connection to the circuit board. ^ Any flexing of the circuit board, beyond design limits, places the IC solder connections at risk of damage. Such damage may be apparent immediately, or it may appear at a future date. Circuit board deflection can occur as a result of striking the ECM/PCM, using ONLY THE PALM OF THE HAND. ^ If struck on the bottom side (the side opposite the service label), the ECM/PCM's aluminum outer case may deflect inward far enough to contact the electrical leads attached to the circuit board. Once in contact with the case the ECM/PCM electrical components will be shorted directly to ground. Although such shorting certainly has the potential to damage the ECM/PCM, it may not be permanent damage, depending on which circuit is involved. However, even if permanent damage is avoided, a short on any of the circuits will cause a disruption of normal ECM/PCM operation for the instant that the short occurs. This disruption may cause the ECM/PCM to reset (see "reset" above), creating the false impression that it is vibration sensitive or faulty. Reset is the ECM/PCM's normal way of coping with large voltage spikes. An ECM/PCM reset does not indicate that the ECM/PCM is defective or faulty, only that it is being subjected to abnormal conditions. CORRECTION: 1. TAP THE ECM/PCM ONLY ON THE TOP SIDE (The top side is where the service label is located.) ^ This will minimize the chance of deflecting the ECM/PCM case into the electrical leads on the circuit board. The clearance between the case and the circuit board is closest on the bottom side of the ECM/PCM. 2. TAP THE ECM/PCM USING ONLY THE FINGERTIPS - NO TOOLS. ^ To avoid excessive case deflection, avoid tapping in the center of the case. Tapping close to the edge of the ECM/PCM, especially in the corners, is best. ^ While using greater force may seem more effective, the test itself may cause the ECM/PCM to fail. 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. Page 1994 The toll free number for Kent Moore is 1-800-345-2233. Portions of this article were reprinted with permission, from Dow Chemical Canada, Inc., P.O. Box 1012, Sarnia, Ontario N7T 7K7. Page 1801 Tighten Tighten to 8 Nm (71 lb in). Note The repair area MUST BE properly refinished to maintain a secure, stable and corrosion-free electrical ground. 12. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 13. Verify proper system operation. M8 Weld Nut Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M8 weld nut electrical ground location is accessible from both sides of the panel, a M8 conductive bolt and a M8 conductive nut may be used to secure the electrical ground wire terminal. Refer to the Parts Information section of this bulletin. 2. Select a location adjacent the M8 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the new electrical ground site. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the ground location and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 10 mm (0.40 in) diameter hole through the panel. 5. Remove paint and primer from the area surrounding the 10 mm (0.40 in) hole until bare metal is visible. 6. Select a M8 conductive bolt. Refer to the Parts Information section of this bulletin. 7. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M8 conductive bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 8. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 9. Install the electrical ground wire terminal and the M8 conductive bolt to the ground location. 10. Select a M8 conductive nut. Refer to the Parts Information section of this bulletin. 11. Install the M8 conductive nut to the bolt and: Tighten Tighten to 22 Nm (16 lb ft). Note The repair area MUST BE properly refinished to maintain a secure, stable and corrosion-free electrical ground. 12. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 13. Verify proper system operation. M8 Weld Nut Alternative Repair Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M8 weld nut electrical ground location is not accessible from both sides of the panel, a M6 conductive rivet stud and a M6 conductive nut may be used to secure the electrical ground wire terminal. 2. Select a location adjacent the damaged M8 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the M6 conductive rivet stud flange. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the repair site and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 10 mm (0.40 in) diameter hole through the panel. Page 5332 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) Warranty - Recycled Engine Coolant Policy 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. Page 2803 Throttle Position Sensor: Adjustments The TPS is not adjustable. The ECM utilizes the IAC position reading at idle for its zero reading, therefore no adjustment is necessary. Page 1942 SPARK PLUGS Locations Oil Pressure Switch Specifications Engine Oil Pressure: Specifications Normal Oil Pressure 30-35 psi Page 1055 - 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. Page 2143 Whenever it is determined that one washer is worn, all three thrust washers should be replaced with kit P/N 26018721, that contains all three thrust washers. Parts are currently available from GMSPO. The kit should be used to resolve T Model front axle growl noise conditions. For vehicles under warranty, use: Labor Operations: F2115 Labor Time: 1.4 Hrs (plus applicable "adds") Engine Controls - ECM May Contain Wrong PROM Engine Control Module: All Technical Service Bulletins Engine Controls - ECM May Contain Wrong PROM Number: 88-42 Section: 6E Date: Sept., 1987 Subject: SERVICE REPLACEMENT ELECTRONIC MODULES (ECM) WITH PROM INSTALLED Model and Year: 1981-88 ALL MODELS TO: ALL CHEVROLET DEALERS It has been brought to our attention that some service replacement electronic control modules (ECM's) have contained a PROM. A PROM should not have been included in a replacement ECM as it may not be the correct PROM for the vehicle. When this situation is encountered, the PROM should be removed from the replacement ECM and the PROM from the vehicle should be installed. 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. Page 6077 Figure 8 Figure 9 Figure 10 Figure 11 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). Page 5310 Symbol Identification Page 7172 Section: 10 Date: Jan., 1988 Subject: REMOVAL OF "CHEMICAL SPOTTING" AND OTHER MINOR PAINT IMPERFECTIONS WITHOUT REPAINTING Model and Year: ALL MODELS WITH BASECOAT/CLEARCOAT PAINT TO: ALL CHEVROLET DEALERS This bulletin cancels and supersedes Chevrolet Dealer Service Bulletin 87-166 (Section 10) dated June 1987. This bulletin provides new materials which are available for use on basecoat/clearcoat systems. Some Chevrolet models equipped with basecoat/clearcoat paint applications may experience a condition of small etched spots on horizontal surfaces of the paint finish. This condition is referred to as chemical spotting and may be caused by industrial fallout (acid rain). FIGURE 1 Chemical spotting along with other minor paint imperfections on basecoat/clearcoat finishes, such as sand scratches, dirt in paint, sags and orange peel may be repaired without paint application. Examples of these imperfections are shown in Figure 1. To repair these conditions use the following procedures: 1. Wash the subject panel with water to remove any foreign material such as dirt, grit, etc. 2. Wet sand subject panel with 3M Micro fine 1500 grit sandpaper, P/N 2023 or equivalent. Wrap the sandpaper around a 3M rubber sponge back up Page 4345 Fig. 24 Lubrication Fittlng Adapter & Fitting Location Fig. 25 Lubrication Fitting Locations Lubrication of the constant velocity joints should not be overlooked during the regular service intervals recommended by the manufacturer. During lubrication, use only the type of lubricant recommended by the manufacturer. This lubricant is usually lithium type chassis grease. Lubrication fitting adapters and locations of the lubrication fittings are shown in Figs. 23, 24 and 25. Page 4884 An acceptable finish can be obtained using the Ammco Model 8350 Safe Swirl Disc Rotor Grinder, or equivalent, using 120 grit sandpaper and sanding each rotor surface with moderate pressure for a minimum of 60 seconds with the rotor turning at 150 RPM. An alternate method is to use a sanding block with 150 grit sandpaper. With the rotor turning at approximately 150 RPM, sand each side for a minimum of 60 seconds using moderate pressure. After the rotor has been sanded, the surfaces must be cleaned with a solvent such as brake cleaning, denatured alcohol, or equivalent. THE FINISHED ROTOR SURFACE SHOULD BE AS CLOSE TO THAT OF A NEW ROTOR AS POSSIBLE. FAILURE TO OBTAIN THE BEST POSSIBLE ROTOR FINISH WILL AFFECT INITIAL BRAKING PERFORMANCE. CAUTION: ROTORS OR DRUMS SHOULD ALWAYS BE REPLACED IF TURNING WILL RESULT IN A ROTOR OR DRUM THAT DOES NOT MEET MANUFACTURER SPECIFICATIONS FOR MINIMUM ROTOR THICKNESS OR MAXIMUM DRUM DIAMETER. NOTICE: When re-installing tire and wheel assemblies, it is very important that proper procedures be followed when installing and torquing the wheel nuts: A. Finger start all wheel nuts. B. Tighten wheel nuts to specified torque (use the "star," or alternating nut pattern) using a torque wrench. DO NOT USE AN IMPACT WRENCH. UNEVEN AND/OR EXCESSIVE TORQUING OF THE WHEEL NUTS HAS BEEN FOUND TO DISTORT ROTORS, RESULTING IN PREMATURE CUSTOMER COMEBACKS FOR BRAKE PULSATION 3. After brake pads have been replaced and/or rotors have been refinished, it is recommended that the new braking surfaces be broken in, or burnished, to properly seat them. This can be accomplished by making 20 stops from 30 mph, using medium to firm pressure. Take care to avoid overheating the brakes. 4. It is strongly recommended that the correct, specified General Motors replacement part(s) be used when servicing G.M. vehicles. General Motors does not test non-G.M. parts for proper performance on G.M. vehicles. Therefore, the use of non-G.M. parts may result in unacceptable vehicle performance. It is also important that the correct G.M. part(s) be used in the correct G.M. application. For example, some "A" model disc brake pads ("A" Heavy) will fit on "C" and "H" models, but will not provide the same performance as the pads specified for use on C and H vehicles. It may seem preferable to stock fewer brake pad part numbers, but customer dissatisfaction may result if vehicle performance is affected. Initial Inspection and Diagnostic Overview Blower Motor: Initial Inspection and Diagnostic Overview Troubleshooting Hints ^ If the Blower Motor does not operate in any speed, check the A/C HEATER FUSE, the Blower motor and all connections at the Blower Motor. ^ If the Blower Motor only operates in high speed, check the blower resistors. ^ If the Blower Motor does not operate in High Speed check the High Blower Relay and the (2) RED wire at the High Blower Relay. - Go to A/C system check for a guide to normal operation. See: Testing and Inspection - Go to System Check Table for a guide to normal Blower Operations. See: With Air Conditioning/System Check Table System Check Table Page 1408 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 Page 1340 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 Page 7429 When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 5mm (3/16") of insulation from wire. e. Crimp a new terminal to the wire. f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. Figure 17 To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Figure 18 Figure 19 Page 6992 A/T TCC - MIL ON/False Code 32 Set Diagnostics Torque Converter Clutch Solenoid: Technical Service Bulletins A/T TCC - MIL ON/False Code 32 Set Diagnostics Number: 91-149-6E Section: 6E Date: January 1991 Corporate Bulletin No.: 066502R Subject: "SERVICE ENGINE SOON" LIGHT POSSIBLE FALSE CODE 32 Model and Year: ALL 1987-91 TRUCKS WITH 4L60 AUTOMATIC TRANSMISSION (700-R4) TO: ALL CHEVROLET DEALERS Some 1987-91 light duty trucks equipped with 4L60 transmissions may experience a possible false Code 32 - EGR System Malfunction. The customer may not experience a change in performance or driveability with a Code 32 set. If normal EGR diagnostics do not reveal the cause for Code 32, the following steps should be taken to correct the condition: Check the TCC (Torque Converter Clutch) engagement solenoid/wiring harness for a short-circuit. 1. Disconnect the TCC harness connector from the left side of the transmission. 2. Measure resistance between TCC transmission connector terminals "A" and "D" with a Digital Volt Ohmmeter (DVOM). Solenoid resistance must measure 20 - 25 ohms at 20 degrees C (68 degrees F). Resistance will be slightly higher if the transmission is at operating temperature. If the resistance is less than 20 ohms the TCC solenoid diode or wiring is shorted and the solenoid must be replaced. 3. With key on, using a DVOM check for voltage at pin "D" of the TCC wiring harness. Voltage greater than one volt should not be found. If voltage exceeding one volt is present, circuit 422 is shorted to voltage and the short must be repaired. Refer to the appropriate service manual for circuit 422 diagnosis and repair. Test operation of the TCC through the use of a scan tool connected to the vehicle ALDL connector. The following conditions must be satisfied when testing TCC operation. ^ Clear stored trouble codes. ^ Engine at normal operating temperature (above 65 degrees C, 149 degrees F) and in closed loop. ^ Constant throttle position. TPS voltage = 1.3 V (minimum = 1.1 V, maximum = 1.5 V). ^ Vehicle speed = 45 mph (minimum = 35 mph, maximum = 55 mph). ^ Brake switch closed (brake pedal not applied). ^ 3rd or 4th gear. Confirmation The scan tool will display the ECM command for TCC engagement when the above conditions are satisfied. When the TCC engages there should be a decrease in engine speed by a minimum of 100 RPM. If TCC operation is normal, it is not necessary to replace the solenoid assembly. After verification of TCC operation, check for stored trouble codes. If TCC fails to engage consult Section 10, Transmission Controls located in Fuel and Emissions Manual and section 7A of the appropriate service manual. 3L30 (180C) Transmission Shift Solenoid: Specifications 3L30 (180C) Transmission Component .......................................................................................................................................... .................................................................... Ft. Lbs. Solenoid ............................................................. .............................................................................................................................................................. .. 14 Page 586 Alignment: Service and Repair Front Wheel Alignment Front Caster and Camber Adjustment NOTE: Before checking or adjusting caster and camber angles, jounce vehicle at least 3 times to prevent false geometric readings. 4 X 2 MODELS (Figure 1) Caster & camber adjustment. 4 x 2 models Caster and camber adjustments are made by shims inserted between upper control arm shaft and frame bracket, refer to (Figure 1). Add, subtract, or transfer shims to change readings as noted below: To adjust caster and/or camber, loosen upper control arm shaft to frame nuts, then add or subtract shims as necessary and torque upper control arm shaft to frame nuts to 88 Nm (65 ft lbs). After adjustment, the shim pack should have at least two threads of bolt exposed beyond the nut. The difference between front and rear shim packs must not exceed 10 mm (0.40 inch). Caster Transfer shims from front to rear, or rear to front. The transfer of shims from rear to front bolt will decrease positive caster. Camber Change shims at both front and rear of shaft. Adding an equal amount of shims at both front and rear locations will decrease positive camber. 4 X 4 MODELS Specifications Piston: Specifications Piston Diameter Standard 3.9988-4.0008 in Note: Measured at 90 degree angle to piston pin. Piston Clearance Desired 0.0007-0.0017 in Service Limit 0.0027 in Description and Operation Transmission Position Switch/Sensor: Description and Operation The park/neutral switch indicates to the ECM when the transmission is in park or neutral. This information is used by the ECM for ignition timing, IAC operation and transmission Torque Converter Clutch (TCC) operation. Do not drive vehicle with park/neutral switch disconnected, as idle quality may be affected. Head Lamp Switch Trim Plate - Cracked Headlamp Switch: All Technical Service Bulletins Head Lamp Switch Trim Plate - Cracked Number: 91-109-10 Section: 10 Date: January 1991 Corporate Bulletin No.: 061605 Subject: CRACKED PLASTIC HEAD LAMP SWITCH TRIM PLATE Model and Year: 1986-91 S/T TRUCKS TO: ALL CHEVROLET DEALERS Figure 1-Plate Assembly-Instrument Panel Switch Trim Some 1986-1991 S/T trucks may experience a cracked plastic head lamp switch trim plate. This may result in the inaccessibility of the rheostat assembly (dimmer switch) and/or the switch assembly (head lamp/park lamp switch) (Figure 1). Previously, it was necessary to replace the complete head lamp switch trim plate assembly. The complete assembly includes the rheostat assembly part number 01995293 (instrument panel dimmer switch), switch assembly part number 01995313 (head lamp/ parking lamp switch) and the switch trim plate (Figure 1), and the switch trim plate hole covers. A new trim plate kit is now available which does not contain the rheostat assembly or the head lamp switch. This kit replaces the complete head lamp switch trim plate assembly when the switch trim plate is cracked and the rheostat assembly or the head lamp switches do not need replacing. This new kit includes; a switch trim plate, bracket for switch mounting, covers for the switch trim plate holes and four bolts/screws. Page 5942 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 Paint - Assembly Plant Identification Paint: All Technical Service Bulletins Paint - Assembly Plant Identification GMC NUMBER: 88-T-72 GROUP: 10 - Body Section DATE: January, 1988 CORPORATE NUMBER: 851701R SUBJECT: PAINT IDENTIFICATION - ASSEMBLY PLANT MODELS: ALL 1988 LIGHT AND MEDIUM DUTY TRUCK MODELS Attached is a current listing of the various assembly plants and their paint suppliers. It should be noted, however, that paint suppliers are subject to change at any given time. Page 6852 FIGURE 1 2. Remove the cowl vent panel fasteners (Figure No. 1). Page 6281 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. Page 6368 DA-V5 Compressor Component View Remove or Disconnect Tool Required: J 9553-01 O-ring Remover 1. Retainers (44) from switches (3) and (4). 2. Switches (3) and (4). 3. O-ring seals (44) from the switch cavities with J 9553-01. Clean ^ Switch cavity and O-ring seal groove. Install or Connect Tools Required: Page 1031 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 Page 3646 Disclaimer Page 2587 Idle Speed/Throttle Actuator - Electronic: Service and Repair IAC Thread Mounted 10mm Pintle NOTES: a. 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. b. 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. REMOVAL: 1. Disconnect electrical connector. 2. Remove IAC valve, use a 32 mm (1 1/4") wrench. 3. Remove IAC gasket and discard. 4. Clean old gasket material from surface of throttle body assembly to insure seal of new gasket. Idle Air Control Valve Pintle Retraction (Manually) NOTES: a. 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). Before installing a IAC valve, measure the distance between the tip of the valve pintle and the mounting surface. If the dimension is greater than 28.0 mm (1.10 inches), the valve pintle must be retracted to prevent damage to the 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. b. 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. INSTALLATION: 1. Install the IAC valve into the throttle body with new gasket. NOTE: New IAC valves have been reset at the factory and should be installed in the throttle body in an "as is" condition, without any adjustment. 2. Tighten IAC valve assembly to 18.0 Nm (13.0 lb-ft). 3. Reconnect electrical connector to IAC valve. 4. START engine and allow it to reach operating temperature. Page 4807 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 4. Make repair. A/T - THM 700-R4 New Harness/Solenoid Assembly Shift Solenoid: Technical Service Bulletins A/T - THM 700-R4 New Harness/Solenoid Assembly Number: 88-335-7A Section: 7A Date: SEPT., 1988 Subject: SERVICE MANUAL UPDATE: NEW SOLENOID ASSEMBLY AND WIRING HARNESS Model and Year: 1988 C, K, R, V, S, T, G SERIES TRUCKS WITH THM 700-R4 TO: ALL CHEVROLET DEALERS This bulletin covers the introduction of a new Solenoid Assembly and Wiring Harness (Type 18) and new Control Valve Assembly for some 1988 THM 700-R4 models (refer to models listed below). Transmission Models: MAM, MDM, MFM, MKM, MLM, MPM, MRM MWM, MXM, MZM, THM, TJM, TKM, TLM TUM, TXM The new control valve assembly uses a plug in place of the 4-3 pulse switch. The function of the 4-3 pulse switch, to momentarily release the torque converter clutch during a 4-3 downshift, was programmed into the ECM for the 1988 model year. These models had previously used a Type 15 Solenoid Assembly. FIGURE 1 - THM 700-R4 TRANSMISSION IDENTIFICATION INFORMATION Diagram Information and Instructions Headlamp Switch: Diagram Information and Instructions 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 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. Page 3254 Wiring Diagram For Chart C-5 - Electronic Spark Control System Check CHART C-5 - ELECTRONIC SPARK CONTROL SYSTEM CHECK Circuit Description: Electronic spark control is accomplished with a module that sends a voltage signal to the ECM. As the knock sensor detects engine knock, the voltage from the ESC module to the ECM is shut "OFF" and this signals the ECM to retard timing, if engine RPM is over about 900. Test Description: Numbers below refer to circled numbers on the diagnostic chart. 1. If A Code 43 is not set, but a knock signal is indicated while running at 1500 RPM, listen for an internal engine noise. Under a no load condition there should not be any detonation, and if knock is indicated, an internal engine problem may exist. 2. Usually a knock signal can be generated by tapping on the right exhaust manifold. This test can also be performed at idle. Test number 1 was run at 1500 RPM to determine if a constant knock signal was present, which would affect engine performance. 3. This tests whether the knock signal is due to the sensor, a basic engine problem, or the ESC module. 4. If the module ground circuit is faulty, the ESC module will not function correctly. The test light should light indicating the ground circuit is OK. 5. Contacting CKT 496, with a test light to 12 volts, should generate a knock signal to determine whether the knock sensor is faulty, or the ESC module can't recognize a knock signal. Diagnostic Aids: "Scan" tools have two positions to diagnose the ESC system. The knock signal can be monitored to see if the knock sensor is detecting a knock condition and if the ESC module is functioning, knock signal should display "yes", whenever detonation is present. The knock retard position on the "Scan" displays the amount of spark retard the ECM is commanding. The ECM can retard the timing up to 20 degrees. This check should be used after other causes of spark knock have been checked such as engine timing, EGR systems, engine temperature or excessive engine noise. Specifications Distributor Pickup Page 6742 11. Install cowl vent grille. Refer to "Cowl Vent Grille Replacement" in Section 2B of the Service Manual. PARTS INFORMATION Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty, use: Labor Operation Description Labor Time B1717 Replace Use Published Labor Hood Hinge Operation Time Page 2898 14. With engine at normal operating temperature (85-100 degrees C), adjust stop screw to obtain nominal rpm per specifications with seated IAC valve. 15. Turn ignition "OFF" and reconnect IAC valve electrical connector. 16. Disconnect "Scan" tool or tachometer. 17. Use silicon sealant or equivalent to cover stop screw hole. 18. Install air cleaner, adapter and gasket. 19. On 2.5L engines, clear Code 35 that has been set. 1987 AND 1988 MODEL YEAR TRUCKS CONTROLLED IDLE SPEED 1987 AND 1988 MODEL YEAR TRUCKS MINIMUM IDLE AIR RATE Ignition System - Spark Plug Usage Change Spark Plug: Technical Service Bulletins Ignition System - Spark Plug Usage Change GMC NUMBER: 88-T-64 GROUP: 6D - Engine Electrical DATE: December, 1987 CORPORATE NUMBER: 836402R SUBJECT: SPARK PLUG USAGE CHANGE MODELS: 1988 LIGHT DUTY TRUCKS WITH 4.3L, 5.0L AND 5.7L ENGINES (VIN CODES Z, H AND K) This bulletin is to advise dealers that there has been a spark plug usage change in production for 1988 trucks with the 4.3L, 5.0L and 5.7L engines. Engines built through August 30, 1987, have spark plugs AC CR43TS, P/N 5614029. Engines built starting August 31, 1987, have spark plugs AC R43TS, P/N 5613325. Due to design differences between the CR43TS and R43TS spark plugs, a radio popping noise may be encountered in vehicles equipped with CR43TS spark plugs. This condition can be repaired by replacing CR43TS spark plugs with R43TS spark plugs. Spark plug gap is 0.035". Page 3912 new driven gear is required. Use (gray) 22 tooth driven gear (GM Part Number 3987922) if vehicle is equipped with L38 and GU6. Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: # T1612 Labor Time: 1.0 hr. FAILURE CODE: 92 Aluminum Wheels - New Coated Wheel Weights Wheels: All Technical Service Bulletins Aluminum Wheels - New Coated Wheel Weights Number: 91-35-3E Section: 3E Date: August 1990 Corporate Bulletin No.: 003502 Subject: COATED WHEEL WEIGHTS FOR ALUMINUM WHEELS Model and Year: 1985-91 MODELS WITH CAST ALUMINUM WHEELS TO: ALL CHEVROLET DEALERS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 89-65-3E, DATED JANUARY 1989. POLYESTER COATED WHEEL WEIGHTS NOW AVAILABLE FROM GMSPO. THE 1990-91 MODEL YEARS HAVE ALSO BEEN ADDED. ALL COPIES OF 89-65-3E SHOULD BE DISCARDED. Vehicles with cast aluminum wheels use a coated clip on wheel weight. The coating has recently changed from nylon to polyester, giving a more natural appearance that more closely matches the wheel. Coated balance weights are used on both the inboard and outboard rim flanges. They will not discolor, corrode or damage the appearance of the wheel as may have been the case in the past with uncoated clip on weights. These coated weights will fit most GM cast aluminum wheels. There are two types of coated wheel weights available to fit the GM vehicles (see illustration). Both types of weights are available from GMSPO in 1/4 ounce increments. See usage chart below to determine which type weight is correct for the vehicle. "MC" Type Weight Used On: 1990-1991 "W" Car 1988-1990 "Y" Car "AW" Type Weight 1989-1991 "L" Car Used On All Other 1991 "B" Car, "U" Van Series Vehicles 1/4 oz. P/N 9591670 P/N 9591669 1/2 oz. 9591584 9591582 3/4 oz. 9591585 9591583 1-1/4 oz. 9591378 9591362 1-1/2 oz. 9591379 9591363 1-3/4 oz. 9591380 9591364 2 oz. 9591381 9591365 "MC" Type Weight Used On: Page 7077 Time Allowance: See Chants NOTE: The time allowances provided on the chart include the hardware removal and installation (as indicated by the list guidelines), the masking and unmasking of the vehicle, stripping of the surface (as indicated by the guidelines), the refinish (and colorcoat when required), mix time for primer/ paint (and clearcoat when required), finesse/polish where required, washing and preparing the vehicle for delivery. OPERATION DESCRIPTION: PAINT COLORCOAT DELAMINATION FROM ELPO PRIMER, REFINISH ENTIRE BODY ABOVE BODY SIDE MOLDINGS. PAINT TERM DEFINITIONS Following are definitions of paint repair terms used in this bulletin: Basecoat: A color topcoat that requires a clear topcoat over it. Break line: A natural dividing line on Page 4091 ^ Harsh N-D, P-D Shifts ^ Slipping on Hard Accelerations ^ Forward Clutch Distress ^ No Upshift ^ 1-2 Tie-Up/Lo-Rev Clutch Distress and 2-4 Band Distress Control Valve Body Checkballs GMC NUMBER: 88-T-16 GROUP:7A - Automatic Transmission DATE: May, 1987 CORPORATE NUMBER: 867103 SUBJECT: PROPER LOCATION OF THE FORWARD CLUTCH CHECKBALL MODELS: ALL 1987 LIGHT DUTY MODELS AND 1988 C/K MODELS WITH THM 700-R4 AUTOMATIC TRANSMISSIONS FIGURE 1 - CHECKBALL LOCATIONS ON TRANSMISSIONS WITH AUXILIARY VALVE BODIES BULLETIN COVERS: Service information on the correct location of the forward clutch checkball (#12-Figure No. 1) and the possible effects of installing the checkball in the wrong location. Interior - Itch Noise From Windshield Pillar Area Instrument Cluster / Carrier: All Technical Service Bulletins Interior - Itch Noise From Windshield Pillar Area Number: 92-286-10 Section: 10 Date: SEPT. 1992 Corporate Bulletin No.: 261610 ASE No.: B1 Subject: ITCH NOISE FROM WINDSHIELD PILLAR AREA Model and Year: 1986-92 S/T TRUCKS Some 1986-1992 S/T utility trucks may exhibit a plastic to metal or plastic to plastic "itch" noise from the left or right windshield pillar area. This noise may be caused by the instrument panel pad rubbing against the cowl or dash support panel. An adhesive backed felt tape has been released to insulate the dash pad outer corners from the dash support panel. This tape may also be used on the non-visible surfaces of other trim panels as necessary to eliminate itch noises. The felt tape, P/N 12541499, is released in a 10 ft. x 30 mm x 1 mm roll to provide the technician sufficient material to insulate numerous trim panels. SERVICE PROCEDURE: Prior to installing the felt tape, it should be determined if the IP pad to dash support panel is the area that is generating the noise. Refer to the Squeak and Rattle Diagnosis and Correction Manual to identify other possible sources such as ECM Mounting Bracket or Air Vent. If it is determined the IP pad is the source of the noise: 1. Remove the instrument panel radio speaker(s) to obtain better access to the metal ledge on which the instrument panel pad rests. 2. Remove the 4 IP upper retaining screws located in the defroster duct openings and pull the pad back slightly. NOTICE: Do not remove the dash pad any further than necessary to perform the repair. The possibility exists that additional noises may be generated due to the wiring and HVAC ducts being mispositioned upon reinstallation. 3. Cut a strip of felt tape 6 inches long, remove the protective backing and apply the tape to the top of the metal ledges in front of the speaker openings where the instrument panel pad rests. NOTICE: Installation is easier if 2 screwdrivers are wedged between instrument panel pad and the cowl panel to raise the IP pad. 4. Push the IP pad forward and reinstall the retaining screws and speakers. Page 3249 Center Of Dash Panel (engine Compartment) Page 8017 Front Door Window Glass: Technical Service Bulletins Body - Side Window Chipping Information INFORMATION Bulletin No.: 06-08-64-001B Date: October 20, 2009 Subject: Information on Side Door Window Glass Chipping Caused by Hanging Vehicle Key Lock Box 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 add vehicles and model years and to include all types of door window glass. Please discard Corporate Bulletin Number 06-08-64-001A (Section 08 - Body & Accessories). - In several warranty parts review cases, side door window glass was observed with a chip or chips on the top side of the window glass. Dealer contacts confirmed that they use a vehicle key lock box on the front side door window glass. - A random selection of side door glass returns will be conducted to confirm adherence. If a side door glass is discovered with a chip or chips in the location previously described, the side door glass will be returned to the dealership for debit. Example of Side Door Glass - DO NOT place a vehicle key lock box on a side door window glass. Page 4082 Valve Body: Specifications THM180 & 180 C Automatic Trans Application ........................................................................................................................................... ................................................................... Ft. Lbs. Valve Body To Case ............................................................................................................................ ......................................................................... 13-15 Transfer Plate To Valve Body ......................... .............................................................................................................................................................. ... 6-8 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. Page 1732 When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 5mm (3/16") of insulation from wire. e. Crimp a new terminal to the wire. f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. Figure 17 To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Figure 18 Figure 19 Page 5600 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 Page 3436 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. Odometer/Speedometer - ACDelco Service Center Locations Speedometer Head: 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) Page 5278 For vehicles repaired under warranty, use the table. Disclaimer Page 3165 Distributor: Service and Repair INSTALLATION: REMOVAL: 1. Disconnect the negative battery terminal. 2. Disconnect the wiring connectors at the side of the distributor cap. 3. Remove the distributor cap and move it out of the way. a. Scribe a mark on the engine in line with the rotor. b. Note the position of the distributor housing in relation to the engine. 4. Remove the distributor hold-down nut and clamp. 5. Remove the distributor. INSTALLATION: NOTE: a. To ensure correct timing of the distributor, the distributor must be installed with the rotor correctly positioned as noted. If the engine was accidentally cranked after the distributor was removed, the following procedure can be used for installing. a. Remove the number 1 spark plug. b. Place finger over the number 1 spark plug hole and crank engine slowly until compression is felt. c. Align timing mark on pulley to "0" on engine timing indicator. d. Turn rotor to point to the 1 spark plug tower on the distributor cap. b. If the distributor shaft will not drop down flush with the engine, it may be necessary to rotate the oil pump drive shaft to align it with the slot on the bottom of the distributor drive gear. Insert a screwdriver into the distributor hole in the engine and turn the oil pump drive shaft slightly to allow alignment. 1. Install the distributor. 2. Install the distributor hold-down clamp and retaining nut. 3. Install the distributor cap. 4. Connect the wiring harness connector at the side of the distributor cap. 5. Connect the negative battery cable. 6. Set ignition timing to specification. Page 7714 e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors Do Not require all the steps shown. Skip the steps that Do Not apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. 1. Separate connector halves (see Figures 2 through 6). Figure 2 Figure 3 Page 6184 ^ Dip the seal in clean 525 viscosity refrigerant oil. ^ Seal (O-ring) to J 33011. ^ Insert J 33011 over the shaft and down until it reaches the bottom of the shaft. ^ Tower the slide on J 33011 to release the seal (O-ring) into its groove. ^ Rotate J 21508-A to seat the seal (O-ring). 2. Shift seal (12). ^ Shaft seal to J 23128-A. ^ J 23128-A and shaft seal to the shaft. ^ Slide J 23128-A over and down the shaft until it stops. ^ Disengage J 23128-A from the shaft seal with a reverse hand twisting motion. 4. Retainer ring (11). 5. Clutch drive hub (3). Page 189 Fuel Pump Relay: Description and Operation Fuel Pump Relay 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). - 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. Page 6620 - 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 Page 776 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 3L30 (180C) Transmission Band Apply Servo: Specifications 3L30 (180C) Transmission Component .......................................................................................................................................... .................................................................... Ft. Lbs. Servo Adjusting Bolt Locknut ............................................................................................................... ............................................................................. 14 Locking Differential - Chattering on Turns Fluid - Differential: All Technical Service Bulletins Locking Differential - Chattering on Turns Number: 91-370-0B Section: 0B Date: JULY 1991 Corporate Bulletin No.: 964201R Subject: LOCKING DIFFERENTIAL LUBRICANT Model and Year: 1982-91 ALL TRUCKS WITH G80 REAR AXLE THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 90-139-4A, DATED JANUARY 1990. CONDITION DESCRIPTION AND CORRECTION HAVE BEEN ADDED AS WELL AS THE 1991 MODEL YEAR. ALL COPIES OF 90-139-4A SHOULD BE DISCARDED. Some light duty trucks equipped with locking rear axles (G80) may exhibit rear axle chatter, especially when turning a corner from a stop. This condition of alternate engagement and disengagement of the clutches in the differential assembly is usually caused by contaminated axle lubricant. To correct this condition, drain and refill the rear axle with SAE 80W-90 GL5 (P/N 1052271). The use of any additive in locking rear axles (G80) is not recommended. Rear axle additives are designed for use in limited slip differentials which are normally installed in cars. All light duty trucks equipped with RPO G80 make use of a locking differential and the use of additives will delay the engagement of the locking mechanism and may decrease axle life. VEHICLES/COMPONENTS INVOLVED: Some light duty trucks equipped with locking rear axles, RPO G80. SERVICE PARTS INFORMATION: Part Number Description 1052271 Lubricant, Rear Axle (24 oz.) See Appropriate Parts Manual Gasket, Rear Axle Housing Cover Parts are currently available through GMSPO. WARRANTY INFORMATION: As specified in Light Duty Truck Maintenance Schedules, locking rear axle fluid drain and refill is required owner maintenance at the first engine oil change. Failure to drain and refill the rear axle as specified may contribute to a later axle chatter condition. Refer to the appropriate Light Duty Truck Maintenance Schedule or service manual, section 0B, for further details on change intervals. For those vehicles repaired under warranty, which have had the axle fluid changed at the first oil change and have experienced rear axle chatter use: Labor Operation: F2010 Use applicable labor time guide for labor hours. Page 7956 Figure 4 Figure 5 Figure 6 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 7 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 Electrical - Intermittent MIL/DTC P2138/Reduced Power Multiple Junction Connector: Customer Interest Electrical - Intermittent MIL/DTC P2138/Reduced Power TECHNICAL Bulletin No.: 07-06-04-019D Date: June 28, 2010 Subject: Intermittent Malfunction Indicator Lamp (MIL) Illuminated, DTC P2138 with Reduced Engine Power (Repair Instrument Panel (IP) to Body Harness Connector) Models: 2005-2011 GM Passenger Cars and Light Duty Trucks (Including Saturn) 2005-2009 HUMMER H2 2006-2010 HUMMER H3 2005-2009 Saab 9-7X Supercede: This bulletin is being revised to update the model years and warranty information. Please discard Corporate Bulletin Number 07-06-04-019C (Section 06 - Engine/Propulsion System) Condition - Some customers may comment on an intermittent malfunction indicator lamp (MIL) being Illuminated with a message or an indicator that displays Reduced Engine Power. - The technician may observe on a scan tool DTC P2138 - Accelerator Pedal Position (APP) Sensor 1-2 Correlation set as Current or in History. Cause This condition may be caused by water intrusion into the instrument panel (IP) to body harness connector, which carries the APP sensor signals to the ECM/PCM. This water intrusion results in a voltage difference between APP Sensor 1 and APP Sensor 2 that exceeds a predetermined value for more than a calibrated period of time, setting P2138. Correction Note Aftermarket equipment can generate DTC P2138 and/or other DTCs. 1. Verify that aftermarket equipment is not electrically connected to any of the APP sensor signal or low reference circuits or to any other ECM/PCM 5V reference or low reference circuits. Refer to Checking Aftermarket Accessories in SI. 2. Perform the Diagnostic System Check - Vehicle. ‹› If any 5V reference DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle. ‹› If any 5V reference DTCs are not set, proceed to Step 3. 3. Locate the IP to body harness connector, which may be located in and around the left hand kick panel area or inside the IP. Depending on the vehicle and model year, refer to Wiring Systems or Power and Signal Distribution in SI. Note Some examples of potential water leaks are: A-pillar seals, sunroof drain lines (if equipped) and windshield/cowl sealing. 4. Inspect for a water leak in the area. If necessary use a water hose to determine the source of the leak. Refer to General Information > Water Leaks in SI. ‹› If a water leak is observed, repair as necessary. Verify the effectiveness of the repair. 5. Inspect the IP to body harness connector terminals for corrosion and debris. Refer to Testing for Intermittent Conditions and Poor Connections in SI. ‹› If any corrosion and/or debris is observed, repair as necessary. 6. After completing the repair, verify the proper operation of the system. Depending on the vehicle and model year, perform the Diagnostic Repair Verification procedure or refer to Diagnostic Trouble Code (DTC) List - Vehicle in SI. Page 938 Parts Information Parts are currently available from GMSPO. Wipers - Intermittent Phantom Wipe (No Driver Input) Wiper Switch: Customer Interest Wipers - Intermittent Phantom Wipe (No Driver Input) Number: 90-266-8E Section: 8E Date: May 1990 Corp. Bulletin No.: 968302 Subject: WINDSHIELD WIPER PHANTOM WIPE Model and Year: 1985-90 S/T/M TRUCK AND 1990 L TRUCK THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 90-171-8E, DATED FEBRUARY 1990. THE LABOR TIMES HAVE BEEN UPDATED. ALL COPIES OF 90-171-8E SHOULD BE DISCARDED. Some 1985-1990 M vans, 1990 L Vans and S/T model trucks may exhibit intermittent phantom wipe - occasional wiper sweep of the windshield with no driver input. A new steering column wiper switch has been developed with an internal resistor to correct this condition. The following parts can be installed to repair intermiftent phantom wipe. They will service subject M/L vans and S/T trucks. SERVICE PARTS INFORMATION Part Number Description 26020403 Switch (Standard) 26020404 Switch (Tilt Wheel) Parts are currently available through GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Time Labor Time Labor Operation Models (standard) (tilt wheel) N2610 S/T M/L 1.2 hrs 1.0 hrs. Page 6563 Tires - Slipping on Rim Wheels: Customer Interest Tires - Slipping on Rim Number: 93-169-3E Section: 3E Date: APRIL 1993 Corporate Bulletin No.: 393501 ASE No.: A4 Subject: TIRES SLIPPING ON WHEELS (USE PROPER TIRE MOUNTING PROCEDURE) Model and Year: 1988-93 ALL PASSENGER CARS AND LIGHT DUTY TRUCKS Some incidents of tires slipping (rotating) on wheels have been reported on 1988-93 passenger cars and light duty trucks. Most incidents have occurred when driven aggressively immediately after tire mounting. Hard acceleration and/or braking is usually required. This condition will affect wheel balance, which could result in a vibration. To reduce the chance of tires rotating on their wheels, any excess lube should be wiped from the tire and rim after tire mounting, but before inflating to seat the bead. (Never exceed 40 psi to seat the bead.) Also, the vehicle should not be driven aggressively for at least four hours after tire mounting to allow the lube to dry. GM Goodwrench Rubber Lubricant, p/n 12345884, is the recommended lube for tire mounting. Page 2814 Vehicle Speed Sensor: Locations LH Side Of I/P Behind Instrument Cluster Page 6703 Backup Lamps/Tailgate Window Release - Inoperative Shift Interlock Switch: Customer Interest Backup Lamps/Tailgate Window Release - Inoperative Number: 91-459-8A Section: 8A Date: DEC. 1991 Corporate Bulletin No.: 168104 ASE No.: A6 Subject: BACKUP LAMPS OR TAILGATE WINDOW RELEASE INOPERATIVE Model and Year: 1980-91 ALL LIGHT DUTY TRUCKS (EXCEPT GEO) Owners of some 1980-1991 C/K, 1982-1991 G, 1985-1991 M/L, 1984-1991 P2,P3, 1987-1991 R/V, 1983- 1991 ST (including LLV) with automatic transmissions may comment on a condition of inoperative back-up lamps or inoperative tailgate window release. This condition occurs when the vehicle's gear shift lever is placed in the "reverse" position, but the back-up lamps do not illuminate. In addition, on the S/T utility vehicles, the electric tailgate window release does not release when the transmission gear shift lever is placed in the "park" or "neutral" position and the endgate window release button is depressed. The park/neutral and back-up lamp switch comes out of adjustment which does not allow for the contact points to remain engaged. To correct these conditions, the contact carrier on the park/neutral and back-up lamp switch has been modified to increase switch carrier travel. SERVICE PROCEDURE: 1. Disconnect the battery ground cable from the battery. 2. Disconnect the switch assembly harness. 3. Place the gear selector in neutral. 4. Squeeze the tangs on the switch together and remove the switch assembly. 5. Install the new switch assembly (P/N 15679680) by: -aligning the actuator with the cutout in the steering column jacket. -inserting the tangs into the rectangular holes and pushing down on the switch assembly. 6. Adjust the switch by moving the gear selector to park. 7. Connect the switch assembly harness. 8. Connect the negative battery cable. 9. Check for proper switch operation. Readjust the switch as necessary. Removal Brake Drum: Service and Repair Removal Rear Drum Assembly 1. Raise and support vehicle. 2. Remove tire and wheel assembly. 3. Remove brake drum. If brake lining is dragging on brake drum, back off brake adjustment by rotating adjustment screw. If brake drum is rusted or corroded to axle flange and cannot be removed, lightly tap axle flange to drum mounting surface with a suitable hammer. NOTE: For additional information see Notes, Warnings, and Hints. See: Fundamentals and Basics IP Dimmer Control - Proper Setting Instrument Cluster / Carrier: All 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 Diagram Information and Instructions Brake Lamp: Diagram Information and Instructions 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 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. Page 6218 inserted through the mode indicator. (Fig.3) 13. Torque the housing, baseplate and blower switch mounting screws to 6-10 lbs.in. 14. If necessary, install new knobs on mode, temperature, and blower controls to ensure proper retention. SERVICE PARTS INFORMATION Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: LABOR OPERATION DESCRIPTION D0362 R & R HVAC control ADD: Replace housing Use applicable labor time guide for labor hours. Page 4620 Figure 2 Cruise Control - Works Intermittently Cruise Control Switch: Customer Interest Cruise Control - Works Intermittently Number: 92-195-9B Section: 9B Date: MAY 1992 Corporate Bulletin No.: 268102R ASE No.: A8 Subject: CRUISE CONTROL WORKS INTERMITTENTLY Model and Year: 1985-92 M VANS 1990-92 L VANS 1986-92 S/T TRUCKS Some owners of 1985-1992 WL vehicles or 1986-1992 S/T vehicles with cruise control (RPO K34) may comment that their cruise control operates intermittently. This condition may be caused by the wires becoming pinched as they exit the multi-functional lever. These wires may ground out on the lever rod and short the cruise function. To correct this condition in production, the wiring harness that exits the lever has been rerouted and the opening in the multi-functional lever has been redesigned to allow the wires more clearance. The diagnostic procedures in the applicable Service Manual should be followed before replacing the multi-functional lever. If the multi-functional lever requires replacement, the following procedure should be performed: SERVICE PROCEDURE: 1. Disconnect the wire harness connector. 2. Remove the harness protector cover. 3. Attach a long piece of mechanic's wire to the end of the harness connector. 4. Remove the multi-functional lever from the turn signal switch. 5. Gently pull the harness up and out so the mechanic's wire can be used to install the new unit. 6. Attach the upper end of the mechanic's wire to the new harness connector. Gently pull the mechanic's wire at the lower end of the column, feeding the harness into the proper location in the column. 7. Install a redesigned multi-functional lever (P/N 25111290) into the turn signal switch. 8. Disconnect the mechanic's wire from the harness connector. 9. Install the harness protector cover. 10. Reconnect the wire harness connector. SERVICE PARTS INFORMATION Part Number Description 25111290 Multi-functional Lever Use applicable labor time guide for labor hours. Important: The new Part Number (P/N 25111290) should be used when correcting this condition in the above listed vehicles. Page 6821 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 4. Make repair. Page 4079 When the converter clutch valve train has been eliminated, there will be a sleeve and plug installed as illustrated. Page 6072 Symbol Identification Wire Color Code Identification WIRE COLOR ABBREVIATION BLACK BLK BLUE BLU DARK BLUE DK BLU Testing and Inspection Page 4624 Figure 3 INSTALL (Figures 2 & 3) Tools required: J8092 Drive handle J33790 Bearing installer and remover J33833 Bearing installer and remover 1. Front output bearing (61) to the new front case half P/N 15635347 (45) using J 8092 and J 33833. 2. New front output shaft seal P/N 15579788 (72) to the new front case half (45). 3. Front output bearing retainer ring (snap ring) (60) to the new case half. 4. New input seal P/N 14095609 (42) into retainer (44) if it was removed in step 24 above. 5. Input bearing (40) and input bearing retainer (39) to the new case half using J 36372. 6. Planetary carrier (36) and the input gear (38) to the annulus gear (62) using a soft hammer. 7. Retainer snap ring to the input gear (38). Input bearing retainer (44) and input bearing retainer bolts (43) to the front case half (45). - Clean mating surfaces and apply RTV or equivalent on bearing retainer mating surfaces. NOTE Do not block oil feed hole from case to bearing retainer. - Apply Loctite 242 (R) or equivalent on bearing retainer bolts. - Tighten bolts to 19 N-m (14 lbs.ft.). Page 4844 Brake Pad: Service and Repair Installation Caliper Assembly 1. Lubricate new sleeves, rubber bushings, bushing grooves and mounting bolt ends with Delco Silicone Lube or equivalent. 2. Install new bushings and sleeves on caliper ears. Position the sleeve so that the end toward the pad is flush with the machined surface of the ear. 3. Install pad retaining spring on inner pad. 4. Position inner pad in caliper so spring ends centrally contact pad edge. Initially, this will place the pad on an angle. Push upper edge of pad down until pad is flat against caliper. When properly seated, spring ends will not extend past pad more than 2.4 mm (0.1 inch). 5. Position outer pad in caliper with pad ears over caliper ears and tab at bottom of pad engaged in caliper cutout. 6. Install caliper. See Brake Caliper / Service and Repair. See: Brake Caliper/Service and Repair CAUTION: Make sure that the brake hose is not twisted or kinked since damage to the hose could result. Compressing The Pad Ears 7. Compress the pad ears to the caliper. Page 2758 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 Page 7792 LIGHT BLUE LT BLU BROWN BRN GRAY GRY GREEN GRN DARK GREEN DK GRN LIGHT GREEN LT GRN ORANGE ORN PINK PNK PURPLE PPL RED RED TAN TAN WHITE WHT YELLOW YEL Page 5482 Tighten Tighten to 8 Nm (71 lb in). Note The repair area MUST BE properly refinished to maintain a secure, stable and corrosion-free electrical ground. 12. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 13. Verify proper system operation. M8 Weld Nut Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M8 weld nut electrical ground location is accessible from both sides of the panel, a M8 conductive bolt and a M8 conductive nut may be used to secure the electrical ground wire terminal. Refer to the Parts Information section of this bulletin. 2. Select a location adjacent the M8 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the new electrical ground site. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the ground location and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 10 mm (0.40 in) diameter hole through the panel. 5. Remove paint and primer from the area surrounding the 10 mm (0.40 in) hole until bare metal is visible. 6. Select a M8 conductive bolt. Refer to the Parts Information section of this bulletin. 7. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M8 conductive bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 8. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 9. Install the electrical ground wire terminal and the M8 conductive bolt to the ground location. 10. Select a M8 conductive nut. Refer to the Parts Information section of this bulletin. 11. Install the M8 conductive nut to the bolt and: Tighten Tighten to 22 Nm (16 lb ft). Note The repair area MUST BE properly refinished to maintain a secure, stable and corrosion-free electrical ground. 12. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 13. Verify proper system operation. M8 Weld Nut Alternative Repair Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M8 weld nut electrical ground location is not accessible from both sides of the panel, a M6 conductive rivet stud and a M6 conductive nut may be used to secure the electrical ground wire terminal. 2. Select a location adjacent the damaged M8 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the M6 conductive rivet stud flange. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the repair site and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 10 mm (0.40 in) diameter hole through the panel. Page 3349 Wiring Diagram For Chart C-1A - Park/Neutral Switch Diagnosis CHART C-1A - PARK/NEUTRAL SWITCH DIAGNOSIS Circuit Description: The Park/Neutral Switch contacts are closed to ground in park or neutral and open in drive ranges. The ECM supplies ignition voltage, through a current limiting resistor, to CKT 434 and senses a closed switch, when the voltage on CKT 434 drops to less than one volt. The ECM uses the P/N signal as one of the inputs to control: Idle Air Control VSS Diagnostics EGR Test Description: Numbers below refer to circled numbers on the diagnostic chart. 1. Checks for a closed switch to ground in park position. Different makes of "Scan" tools will read P/N differently. Refer to operators manual for type of display used for a specific tool. 2. Checks for an open switch in drive or reverse range. 3. Be sure "Scan" indicates drive, even while wiggling shifter to test for an intermittent or misadjusted switch in drive range. Diagnostic Aids: If CKT 434 indicates PIN (grounded), while in drive range, the EGR would be inoperative, resulting in possible detonation. If CKT 434 always indicates drive (open), a drop in the idle may exist when the gear selector is moved into drive range. Page 3603 - New 3-4 clutch apply plate "stepped" replacing a "flat" apply plate (Fig. 13) - Input housing and shaft assembly revised with longer housing splines for using the new 3-4 clutch apply plate. - New input internal gear with longer splines on outside diameter. - Eliminate usage of longer 3-4 clutch apply ring (now only using short 3-4 clutch apply ring on all models. - New 3-4 backing plates, (material and thickness) - New internal retaining ring (thinner) and end configuration changed for identification. SERVICE ACTION: The new 3-4 clutch apply plate or the new input housing and shaft assembly cannot be used on transmissions built prior to February 9, 1987 (Julian date 040). SERVICE PARTS INFORMATION: PART NUMBER DESCRIPTION 8642173 Plate, 3-4 clutch Ignition System - Spark Plug Usage Change Spark Plug: Technical Service Bulletins Ignition System - Spark Plug Usage Change GMC NUMBER: 88-T-64 GROUP: 6D - Engine Electrical DATE: December, 1987 CORPORATE NUMBER: 836402R SUBJECT: SPARK PLUG USAGE CHANGE MODELS: 1988 LIGHT DUTY TRUCKS WITH 4.3L, 5.0L AND 5.7L ENGINES (VIN CODES Z, H AND K) This bulletin is to advise dealers that there has been a spark plug usage change in production for 1988 trucks with the 4.3L, 5.0L and 5.7L engines. Engines built through August 30, 1987, have spark plugs AC CR43TS, P/N 5614029. Engines built starting August 31, 1987, have spark plugs AC R43TS, P/N 5613325. Due to design differences between the CR43TS and R43TS spark plugs, a radio popping noise may be encountered in vehicles equipped with CR43TS spark plugs. This condition can be repaired by replacing CR43TS spark plugs with R43TS spark plugs. Spark plug gap is 0.035". Page 3533 Bell Housing: Specifications 4L60 - 700R4 Transmission Bellhousing To Case ........................................................................................................................... .................................................................... 55 ft. lbs. Page 3427 3491 6185 ADUK 16076184 2251 16082083 3501 6196 ADUL 16076195 2261 16082087 3511 1163 AKSJ 16121162 4741 16154688 Chevrolet 88-424-6E Rough idle. GMC Truck 88-T-213 3521 1167 AKSK 16121166 4751 16154689 Chevrolet 88-424-6E Rough idle. GMC Truck 88-T-213 3521 6202 ADUN 16076201 7271 16087029 Chevrolet 88-235-6E High emissions, exhaust odor, starting and driveability problems (G046). 3531 1171 AKSL 16121170 5701 16155648 Chevrolet 88-424-6E Rough idle. GMC Truck 88-T-213 3531 6206 ADUP 16076205 Running change. 3541 1199 AKSM 16121198 Chevrolet 88-424-6E Rough idle. GMC Truck 88-T-213 3541 6216 ADUR 16076215 8961 16079238 3551 1175 AKSN 16121174 5691 16155647 Chevrolet 88-424-6E Rough idle. GMC Truck 88-T-213 3551 6221 ADUS 16076220 2251 16082083 3561 0723 AKSP 16120722 Chevrolet 88-255-6E Exhaust odor, requires Y-pipe and plug (G046). Chevrolet 88-306-6E GMC Truck 88-T-126 GMC Truck 88-T-153 3561 6225 ADUT 16076224 8351 16088362 Chevrolet 88-235-6E High emissions, exhaust odor, starting and driveability problems (G046). 3571 0728 AKSR 16120727 Chevrolet 88-255-6E Exhaust odor, requires Y-pipe and plug (G046). Chevrolet 88-306-6E GMC Truck 88-T-126 GMC Truck 88-T-153 3571 6243 ADUU 16076242 8401 16088400 3581 6471 ADUW 16076470 2291 16082103 3591 6475 ADUX 16076474 7261 16087025 3641 6247 ADWB 16076246 7251 16087020 3651 6252 ADWC 16076251 2261 16082087 3661 6256 ADWD 16076255 8351 16088362 4511 4747 AFCK 16074746 4761 16083464 4521 4753 AFCL 16074752 4771 16083468 4731 4786 AWDM 16154687 Chevrolet 90-320-6E Idle rise between shifts. GMC Truck 90-6E-93 4741 4789 AWDN 16154688 Chevrolet 90-320-6E Idle rise between shifts. GMC Truck 90-6E-93 Page 7574 Locations Power Steering Pressure Switch: Locations LH Fender Apron LH Front Corner Of Engine Compartment Electrical - Information For Electrical Ground Repair Wiring Harness: All Technical Service Bulletins Electrical - Information For Electrical Ground Repair INFORMATION Bulletin No.: 10-08-45-001B Date: October 25, 2010 Subject: Information for Electrical Ground Repair - Use New Replacement Fasteners with Conductive Finish 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 the 2011 model year and update the Warranty Information. Please discard Corporate Bulletin Number 10-08-45-001A (Section 08 - Body and Accessories). Electrical Ground Repair Overview Proper electrical system function relies on secure, stable and corrosion-free electrical ground connections. Loose, stripped, or corroded connections increase the possibility of improper system function and loss of module communication. These conditions may also lead to unnecessary repairs and component replacement. In general, electrical ground connections are accomplished using one, or a combination of the following attachment methods: - Welded M6 stud and nut - Welded M6 nut and bolt - Welded M8 nut and bolt Determine which attachment method is used and perform the appropriate or alternative repair as described in this bulletin. M6 Weld Stud Replacement Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. Select a location adjacent the damaged or missing M6 ground stud having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the M6 conductive rivet stud flange. 2. Using GM approved residue-free solvent or equivalent, remove any grease from the repair site and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 3. Drill a 10 mm (0.40 in) diameter hole through the panel. 4. Remove paint and primer from the area surrounding the 10 mm (0.40 in) hole until bare metal is visible. Page 1083 Service and Repair Front Crankshaft Seal: Service and Repair Fig. 16 Installing Front Oil Seal 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. Ensure not to 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. Page 5406 6. Tape the solder and diode. 7. Reinstall the black plastic conduit. 8. Reconnect connector to the generator. 9. Reconnect battery. This procedure will not affect the operation of the generator light during the bulb check at the beginning of the start cycle. For vehicles repaired under warranty use, Labor Operation Number: T7990 Labor Time: .4 Hr Page 7234 Figure No. 7 1) Replace the Spare tire carrier arm with part number 15659234. This arm has a new adjustable bumper that will take up the additional play that the striker assembly could not remove (See Figure 7). 2) If the striker, shown in Figure 1, was not replaced during service procedure 1 then do so now. This is done because the adjustment outlined below will push the spare tire carrier arm away from the smaller rubber bumper on the old style striker plate. The resultant gap will continue to allow a rattle condition. 3) To adjust the rubber bumper begin by removing the spare tire, and closing the spare tire carrier. Loosen adjustable nut shown in Figure 7. Turn the bumper screw until the bumper contacts the the surface of the tailgate. Open the carrier arm and turn the bumper screw 1 and 1/2 turns to the left (counter clockwise). This will move the rubber bumper closer to the striker plate. Tighten adjustable nut and close carrier making sure that latching mechanisms are securely latched. Check to be sure that carrier arm sleeve rests against the striker plate's rubber bumper. If this is not the case then move the adjustable rubber bumper until contact results. IMPORTANT: The rubber bumper will cause the tailgate to close hard for a couple of weeks. Eventually the rubber will take a permanent set and the carrier will close with reasonable effort. NOTE: If the subject vehicle was manufactured after the following break points then Service Procedure 5 will not be required as the material called out was incorporated in production. Shreveport: 1GNCS18ZXM8104025 Page 2755 - Diagnostic Chart Code 34. Locations Throttle Position Sensor: Locations Center Of Dash Panel (engine Compartment) Center Rear Of Engine Applicable to: V6-262/4.3L Engine Page 1773 Tighten Tighten to 8 Nm (71 lb in). Note The repair area MUST BE properly refinished to maintain a secure, stable and corrosion-free electrical ground. 12. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 13. Verify proper system operation. M8 Weld Nut Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M8 weld nut electrical ground location is accessible from both sides of the panel, a M8 conductive bolt and a M8 conductive nut may be used to secure the electrical ground wire terminal. Refer to the Parts Information section of this bulletin. 2. Select a location adjacent the M8 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the new electrical ground site. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the ground location and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 10 mm (0.40 in) diameter hole through the panel. 5. Remove paint and primer from the area surrounding the 10 mm (0.40 in) hole until bare metal is visible. 6. Select a M8 conductive bolt. Refer to the Parts Information section of this bulletin. 7. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M8 conductive bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 8. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 9. Install the electrical ground wire terminal and the M8 conductive bolt to the ground location. 10. Select a M8 conductive nut. Refer to the Parts Information section of this bulletin. 11. Install the M8 conductive nut to the bolt and: Tighten Tighten to 22 Nm (16 lb ft). Note The repair area MUST BE properly refinished to maintain a secure, stable and corrosion-free electrical ground. 12. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 13. Verify proper system operation. M8 Weld Nut Alternative Repair Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M8 weld nut electrical ground location is not accessible from both sides of the panel, a M6 conductive rivet stud and a M6 conductive nut may be used to secure the electrical ground wire terminal. 2. Select a location adjacent the damaged M8 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the M6 conductive rivet stud flange. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the repair site and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 10 mm (0.40 in) diameter hole through the panel. Page 1614 A new pressure regulator valve (III. 218) has been made which will improve the oil pressure stability at lower RPM. SERVICE PARTS INFORMATION: Description Part Number Valve, Pressure Regulator (III. 218) 8684048 Part numbers are for Reference Only. Check with your Parts Department for latest information. Page 6873 FIGURE 1 7. Measure 1 1/4" down from the bottom of the windshield and make a horizontal mark on the windshield frame inboard of the cowl screen lock tab (Figure No. 1). 8. Measure 7/8" inboard from the cowl screen lock tab and make a vertical mark through the line made in the previous step. 9. Center punch the windshield frame at the point the lines intersect. Use a one inch hole saw to cut a hole in the windshield frame (cut through only the first layer of sheet metal) and remove the circular piece of metal that remains from cutting the hole. DO NOT CUT THE SECOND LAYER PANEL. Page 1266 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 Page 7719 Courtesy Lamp: Electrical Diagrams Ashtray, Glove Box, Engine Compartment & Lighted Rearview Mirror Locations Power Steering Pressure Switch: Locations LH Fender Apron LH Front Corner Of Engine Compartment Page 3744 FIGURE 3 - 700-R4 PUMP BODY ASSEMBLY The new design vane rings (item 212, Figures 2 and 3) will reduce the possibility of vane ring distress and can be used on any 1982 through 1987 THM 700-R4 transmission or any 1981 through 1987 THM 200-4R transmission, and it is recommended that the new iron pump vane rings be used when replacement of the vane rings becomes necessary. PARTS INFORMATION: THM 700-R4 transmission only: 8657531 Pump Vane Ring (2 required) THM 200-4R transmission only: 8657692 Pump Vane Ring (2 required) Page 6175 Removing Or Installing The Shaft Lip Seal Retaining Ring 2. Shaft seal retainer ring using J 5403. ^ Clean the compressor neck area around the shaft (20), the exposed part of the shaft seal (8) and the O-ring seal groove. Removing Or Installing The Shaft Tip Seal 3. Shaft lip seal using J 23128-A. ^ Insert J 23128-A into the shaft lip seal, tighten and remove lip seal. Removing The Shaft Seal Seat O-Ring 4. O-Ring seal using J 9553-01. High-Side Pressure & High-Side Low Pressure Cutoff Switches Refrigerant Pressure Sensor / Switch: Service and Repair High-Side Pressure & High-Side Low Pressure Cutoff Switches DA-V5 COMPRESSOR Rear Head Details Page 5837 Light Duty truck tire rotation recommendations are pictured on the following page. Rotation Guidelines for Tires used on Light Duty Trucks: Tires used on Pickups, Vans and Utility vehicles should be rotated at the first 6,000 miles for Schedule 1 or 7,500 miles for Schedule 2 and then every 15,000 miles thereafter. NOTE: Earlier rotation may be required should irregular wear pafterns develop due to harsh service use - the following rotation patterns are recommended for the various vehicle types and tire combinations. Generator Light - Flickers During Pulse Wiper Use Wiper Switch: Customer Interest Generator Light - Flickers During Pulse Wiper Use Number: 90-84-8A Section: 8A Date: November 1989 Corporate Bulletin No: 966402 Subject: GENERATOR LIGHT FLICKER DURING PULSE WIPER OPERATION Model and Year: 1988-89 S, T TRUCKS WITH 2.8L OR 4.3L (VIN CODES R, Z) ENGINES TO: ALL CHEVROLET DEALERS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 89-219-8A, DATED JULY 1989. THE 1990 MODEL S/T VEHICLES ARE INCLUDED IN THE LATEST BULLETIN ALONG WITH A CORRECTION TO THE ELECTRICAL CONNECTOR NUMBER. ALL COPIES OF 89-219-8A SHOULD BE DISCARDED. The generator light flicker condition during pulse wiper switch operation in the 1988, 1989 and 1990 S/T instrument panel, with standard cluster, can be caused by negative voltage transients from the wiper motor. There is no possibility of a system failure as a result of this condition. The effect of this condition is that the generator light will turn on for 80 milliseconds (if gages, the voltage drop on the voltmeter lasts 2.5 seconds). This causes no harm to the generator or other electrical components. Subject condition can be eliminated by installing a diode (industry part number 1N4003) or diode/connector kit (diode kit part number 12085207) in the brown wire at the generator connector (circuit 25 at connector C118). See the following pages in the 1988, 89 and 90 S/T Electrical Wiring Diagrams for circuit 25, connector C118 locations: 1988 4.3L: Section C - Page 24 1988 2.8L: Section C - Page 22 1989 4.3L: Page 40 1989 2.8L: Page 39 1990 2.8L: Page 44 1990 4.3L: Page 45 PARTS INFORMATION: Quantity Part Number Description 1 12085207 Diode ----OR---1 *1N4003 Diode * This part available locally. Parts are currently available from GMSPO. INSTALLATION PROCEDURE: 1. Disconnect the battery. 2. Remove the connector from the generator. 3. Peel back the black plastic conduit covering the wires. 4. If installing diode 1N4003: cut out a section of the brown wire that matches the length of the diode. 4A. A diode/connector kit is also available (GMSPO diode kit part number 12085207). If using the kit cut out approximately four inches of the brown wire, following crimping and soldering instructions in the kit. Spiral tape the solder joints and tuck the wire back into the conduit away from the generator. Secure the diode/connector to the outside of the conduit with electrical tape. 5. Solder in diode with the banded end toward the generator. Page 6256 1. Pressure relief valve (32). 2. O-ring seal (33). Install or Connect ^ Lubricate the threads of the pressure relief valve (32) and new seal with 525 viscosity refrigerant oil. 1. Pressure relief valve (32) with new seal. Tighten ^ Pressure relief valve (32) to 9 N.m (84 in. lbs.). Important ^ Leak test the compressor Page 5714 Steering Gear: Service and Repair Removal/Installation 1. On models equipped with power steering, disconnect pressure and return hoses from steering gear housing, then plug hose ends and gear housing ports to prevent entry of dirt. 2. On all models, disconnect battery ground cable and remove coupling shield if so equipped. 3. Remove retaining nuts, lock washers and bolts at steering coupling to steering shaft flange. 4. Remove pitman arm nut and washer from pitman shaft and mark relation of arm position to shaft, then remove pitman arm using a puller. 5. On turbocharged models, raise and support vehicle. 6. Remove charge air cooler radiator. 7. Lower vehicle, then remove intermediate shaft assembly at steering gear. 8. Remove attaching bolt and nut to pot joint coupling. Ensure alignment marks line up. 9. On all models, remove screws securing steering gear to frame and remove gear from vehicle. 10. Reverse procedure to install. Page 2043 IMPORTANT: To maintain a balanced fan assembly, align the yellow paint mark on the fan clutch with the yellow paint mark on the water pump hub. SERVICE PARTS INFORMATION Part Number Description 15672779 Fan Clutch Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Page 6286 Page 5847 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 Page 2524 Electronic Spark Timing: Testing and Inspection Chart C-5 - Electronic Spark Control System Check Page 3120 Throttle Body Assembly (Exploded View) Capacity Specifications Fluid - Differential: Capacity Specifications Standard & Locking.............................................................................................................................. ................................................80W, 80W-90*, GL-5 *For vehicles normally operated in Canada, 80W only CAPACITY, Refill: Front- Astro, Safari, Bravada.................................................................. ...............................................................................................1.7 Liters 3.5 Pints Front- S-series........ .............................................................................................................................................................. ..................1.2 Liters 2.6 Pints Rear- Bravada..................................................................................... ....................................................................................................1.7 Liters 3.5 Pints Rear- Astro, Safari, S-Series.................................................................................................................................... ...........................1.9‡ Liters 3.9‡ Pints ‡Fill to 3/8" (9.5 mm) below fill plug hole Page 971 10. Case bolts (3) from the case halves. - Note the two longer bolts (16) and washers go into doweled case holes (33). - Separate case halves, insert screwdrivers into the slot cast in the case ends and pry apart. Do not attempt to wedge the case halves apart at any point on the mating surfaces. - Be careful not to damage the oil pump (12) (located in the rear case half) while removing the rear case half (17). Internal Components 11. Fork shift spring (52). 12. Mainshaft (19)/drive sprocket 14071703 (20), chain (58) and front output shaft (21) as a unit. Mode shift fork (54) and shift rail (48) will be removed with the mainshaft. INSPECT: The teeth of the synchronizer stop ring (28) and drive sprocket (20) for damage. If they are damaged, or in cases of customer complaint of clash when shifting from 2Hi to 4Hi, follow steps 13, 14 & 15, otherwise skip to step 16. 13. Retainer (snag ring) (83) from the mainshaft (19). 14. Synchronizer assembly (81). 15. Drive sprocket (20) from the mainshaft (19). 16. Range shift fork (51), range shift hub (34) and sector with shaft (55) from the planetary carrier (36). - It is necessary to rotate the sector with shaft (55) to obtain clearance when removing the range fork (51). 17. Plastic washer (retainer) (66) and O-ring seal (67) from the front case half. IMPORTANT: Group B vehicles should complete step 17 and skip to INSTALL step 8. 18. Input bearing retainer bolts (43) and input bearing retainer (44) from the front case half (45). 19. Retainer snap ring from the input gear (38). 20. Planetary carrier (36) and the input gear (38) from the annulus gear (62) using a soft hammer. 21. Input bearing retainer (39) and input bearing (40). 22. Front output bearing retainer ring (snap ring) (60). 23. Front output bearing (61) from the front case half (45) using J33790, and J8092. 24. Seal (42) from the input bearing retainer (44) if it shows signs of damage. Install Page 5757 Figure 3 - Inboard Flange Bolt Removal 5. Loosen (do not remove at this time) six bolts securing inboard C/V joint drive flange to output shaft companion flange (Figure 3). Figure 4 - Brake Line Bracket Removal 6. Remove brake line support bracket from upper control arm to allow extra travel of knuckle (Figure 4). 7. Remove cotter pin and nut from the outer tie rod. Figure 5 - Disconnecting the Tie Rod 8. Separate the outer tie rod ball stud from the steering knuckle using J24319-01 (Figure 5). Notice: Do not attempt to disengage the joint by driving a wedge-type tool between the joint and the knuckle because the seal may be damaged. 9. Push linkage to opposite side of the vehicle and secure outer tie rod up and out of the way. This will provide the needed clearance to remove the halfshaft. Page 2334 Manifold Pressure/Vacuum Sensor: Locations Center Of Dash Panel (engine Compartment) Center Rear Of Engine Applicable to: V6-262/4.3L Engine Page 7516 Fuel Gauge & Illumination (Standard Cluster) Page 775 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). Page 2599 Knock Sensor: Testing and Inspection Chart C-5 - Electronic Spark Control System Check Page 6129 - Stake 3 places 120 degrees apart. Installing The Pulley Bearing Assembly 3. Pulley (5) on the front head. ^ Position J 33017 and J 33023-A over the inner race of the bearing. ^ Position J 8433-1 on J 33023-A and assembly the through bolts and washers through the puller bar slots and thread them into J 33026. The thread of the through bolts should engage the full thickness of J 33026. ^ Tighten the center screw in J 8433-1 to force the pulley bearing assembly onto the compressor front head (11). Should J 33017 become misaligned with the inner race of the bearing, back off J 8433-1 and relocate center, then continue installation. 4. Pulley bearing retainer (3) using J 6083. 5. Clutch plate and hub assembly (2). Clutch Coil and Housing Assembly Page 1526 INSTALLATION - RIGHT SIDE Install or Connect 1. Rocker arm cover and new gasket. 2. Rocker arm cover bolts and washers. Tighten Rocker arm cover bolts to 10.2 Nm (90 in. lbs.) 3. Dipstick tube bracket. 4. Spark plug wires to the clips. 5. Wiring harnesses to the clips. 6. Emissions relays with bracket. 7. Heater pipe. 8. PCV valve. 9. Air cleaner. 10. Battery negative cable. INSTALLATION - LEFT SIDE Install or Connect 1. Rocker arm cover and new gasket. 2. Rocker arm cover bolts and washers. Tighten Rocker arm cover bolts to 10.2 Nm (90 in. lbs.). 3. Power brake vacuum line. 4. Spark plugs to the clips. 5. Generator rear bracket. 6. Fuel pipes. 7. Crankcase ventilation pipe. 8. Air cleaner and heat stove tube. 9. Battery negative cable. Page 6779 Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Description Labor Op. Striker and/or Support - Replace (RH) B5820 Striker and/or Support - Replace (LH) B5821 Service and Repair Turn Signal Switch: Service and Repair Fig. 6 Compressing Lock Plate 1. Disconnect battery ground cable. 2. Remove steering wheel as outlined under STEERING SUSPENSION CHASSIS AND BODY COMPONENTS/STEERING/COMPONENT REPLACEMENT AND REPAIR PROCEDURES/STEERING WHEEL & HORN SOUNDER. 3. Using a screwdriver, pry cover from lock plate. 4. Using lock plate compressing tool No. J-23653, compress lock plate and pry retaining ring from groove on shaft, Fig. 6. Slowly release lock plate compressing tool, 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. 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. Page 1607 A new pressure regulator valve (III. 218) has been made which will improve the oil pressure stability at lower RPM. SERVICE PARTS INFORMATION: Description Part Number Valve, Pressure Regulator (III. 218) 8684048 Part numbers are for Reference Only. Check with your Parts Department for latest information. Page 587 (Figure 2) Caster/Camber Adjustment - 4WD Models Caster and camber adjustments are made by cam mounted upper control arm attaching bolts, refer to (Figure 2). To adjust caster and/or camber, loosen upper control arm to frame attaching bolt nut, then rotate cam by turning bolt head. When proper alignment settings are established, torque upper control arm to frame attaching bolt nuts to 95 Nm (70 ft lbs). Caster To increase positive caster, move front cam lobe inward and rear cam lobe outward. Camber To increase positive camber, move both front and rear cam lobes inward. Front Toe Adjustment 3L30 (180C) Transmission Flex Plate: Specifications 3L30 (180C) Transmission Component .......................................................................................................................................... .................................................................... Ft. Lbs. Flexplate To Converter ........................................................................................................................ .............................................................................. 35 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 Page 5908 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 Throttle Body Injection (TBI) Unit Throttle Body: Service and Repair Throttle Body Injection (TBI) Unit Throttle Body Assembly (Exploded View) REMOVAL: 1. Remove the TBI assembly from vehicle. 2. Remove the fuel meter body attaching screw assemblies. 3. Remove the fuel meter body assembly. 4. Remove the throttle body to fuel meter body gasket and discard. DISASSEMBLE: Remove the TPS from the old throttle body, for use on the new throttle body. (The IAC valve does not have to be removed, since a new one comes with the replacement throttle body.) ASSEMBLE: 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. Page 6000 *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 Description and Operation Transmission Position Switch/Sensor: Description and Operation The park/neutral switch indicates to the ECM when the transmission is in park or neutral. This information is used by the ECM for ignition timing, IAC operation and transmission Torque Converter Clutch (TCC) operation. Do not drive vehicle with park/neutral switch disconnected, as idle quality may be affected. Backup Lamps/Tailgate Window Release - Inoperative Shift Interlock Switch: All Technical Service Bulletins Backup Lamps/Tailgate Window Release Inoperative Number: 91-459-8A Section: 8A Date: DEC. 1991 Corporate Bulletin No.: 168104 ASE No.: A6 Subject: BACKUP LAMPS OR TAILGATE WINDOW RELEASE INOPERATIVE Model and Year: 1980-91 ALL LIGHT DUTY TRUCKS (EXCEPT GEO) Owners of some 1980-1991 C/K, 1982-1991 G, 1985-1991 M/L, 1984-1991 P2,P3, 1987-1991 R/V, 1983- 1991 ST (including LLV) with automatic transmissions may comment on a condition of inoperative back-up lamps or inoperative tailgate window release. This condition occurs when the vehicle's gear shift lever is placed in the "reverse" position, but the back-up lamps do not illuminate. In addition, on the S/T utility vehicles, the electric tailgate window release does not release when the transmission gear shift lever is placed in the "park" or "neutral" position and the endgate window release button is depressed. The park/neutral and back-up lamp switch comes out of adjustment which does not allow for the contact points to remain engaged. To correct these conditions, the contact carrier on the park/neutral and back-up lamp switch has been modified to increase switch carrier travel. SERVICE PROCEDURE: 1. Disconnect the battery ground cable from the battery. 2. Disconnect the switch assembly harness. 3. Place the gear selector in neutral. 4. Squeeze the tangs on the switch together and remove the switch assembly. 5. Install the new switch assembly (P/N 15679680) by: -aligning the actuator with the cutout in the steering column jacket. -inserting the tangs into the rectangular holes and pushing down on the switch assembly. 6. Adjust the switch by moving the gear selector to park. 7. Connect the switch assembly harness. 8. Connect the negative battery cable. 9. Check for proper switch operation. Readjust the switch as necessary. Page 5034 Parking Brake Cable: Testing and Inspection Inspect parking brake cable end for kinks, fraying and elongation, and replace as necessary. Use a small hose clamp to compress clamp where it enters backing plate to remove. Specifications Transmission Speed Sensor: Specifications Electronic Speed Sensor Retainer Bolt ............................................................................................... ...................................................................... 7 ft. lbs. Page 2479 Spark Plug Wire: Locations Spark Plug Wire Routing Page 3581 Ignition System - Spark Plug Usage Change Spark Plug: Technical Service Bulletins Ignition System - Spark Plug Usage Change GMC NUMBER: 88-T-64 GROUP: 6D - Engine Electrical DATE: December, 1987 CORPORATE NUMBER: 836402R SUBJECT: SPARK PLUG USAGE CHANGE MODELS: 1988 LIGHT DUTY TRUCKS WITH 4.3L, 5.0L AND 5.7L ENGINES (VIN CODES Z, H AND K) This bulletin is to advise dealers that there has been a spark plug usage change in production for 1988 trucks with the 4.3L, 5.0L and 5.7L engines. Engines built through August 30, 1987, have spark plugs AC CR43TS, P/N 5614029. Engines built starting August 31, 1987, have spark plugs AC R43TS, P/N 5613325. Due to design differences between the CR43TS and R43TS spark plugs, a radio popping noise may be encountered in vehicles equipped with CR43TS spark plugs. This condition can be repaired by replacing CR43TS spark plugs with R43TS spark plugs. Spark plug gap is 0.035". Page 7399 6. Tape the solder and diode. 7. Reinstall the black plastic conduit. 8. Reconnect connector to the generator. 9. Reconnect battery. This procedure will not affect the operation of the generator light during the bulb check at the beginning of the start cycle. For vehicles repaired under warranty use, Labor Operation Number: T7990 Labor Time: .4 Hr 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 Page 4794 Brake Bleeding: Fundamentals and Basics BENCH BLEEDING Why A master-cylinder will develop little or no pressure if air is trapped in cylinder bore. Normal brake bleeding will not remove air trapped within the master-cylinder. How Clamp the master-cylinder securely in a vice. It is usually best to clamp the side of the vice onto the flat surface that is used to secure the master-cylinder to the brake booster. There are two basic methods for bleeding master-cylinder, one utilizes stroking the master-cylinder to expel air from the cylinder bore while the other utilizes a large syringe to backflush fluid from the outlet ports to the reservoir. Stroking Fill the master-cylinder with clean brake fluid. - The brake line fittings on the master-cylinder should be capped or plugged. NOTE: Special "bench bleeding" plastic fittings are available which allow for recirculating the brake fluid back into the reservoir. - Using a dull object, slowly stroke the master-cylinder piston, air and brake fluid will be expelled from the brake line fittings. Prior to releasing the piston plug or cap the outlet ports. - Repeat this procedure 8-10 times or until no air is emitted from the outlet ports. - When finished, cap the outlet ports and install the master-cylinder. Syringe Fill the syringe (one especially designed for brake bleeding) with clean brake fluid. - Insert the end of the syringe into one of the outlet ports on the master-cylinder. - Slowly compress the syringe and back flush the brake fluid through the master-cylinder. - A combination of air and brake fluid will be emitted from the inlet port in the fluid reservoir. - Repeat this procedure until only brake fluid is emitted into the reservoir. Cap the outlet ports and install the master-cylinder. Page 7032 Cleveland, OH 44146-0478 708-671-3000 216-439-1200 Can-Am Croix Can-Am Engineered Croix Air Products Products. Inc. 520 Airport Rd./Flemingfield 30850 Industrial Rd. So. St Paul, MN 55074 Livinoia, MI 48150 612-455-1213 313-427-2020 DevilBiss Graco Inc. The Devilbiss Co. P.O. Box 1441 320 Phillips Ave. Minneapolis, MN 55440-1441 P.O. Box 913 1-800-367-4023 Toledo, OH 43962 419-470-2169 Lex-Air Turbine Spray Mattson Lex-Air South 230 West Coleman 5874 Buford Hwy. P.O. Box 132 Doraville, GA 30340 Rice Lake, WI 54868 404-454-8417 715-234-1617 Sata Sharpe Mfg. Sata Spray Equipment 1224 Wall St. P.O. Box 46 Hwy. 16&63 N. P.O. Box 15042 Spring Valley, MN 55975 Los Angeles, CA 90015-0042 507-346-7102 213-749-4368 Xcel Spray Smith Eastern Corporation 5020 Sunnyside Ave. #207 Beltsville, MD 20705 301-937-4548 We believe the sources listed in this bulletin 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 this firm or for any such item which may be available from other sources. Page 1794 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 Page 5485 For vehicles repaired under warranty, use the table. Disclaimer Page 3415 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. Page 5538 - 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 Instrument Panel - Upper Surface Reflection Instrument Cluster / Carrier: All Technical Service Bulletins Instrument Panel - Upper Surface Reflection File In Section: 08 - Body and Accessories Bulletin No.: 99-08-49-006 Date: April, 1999 INFORMATION Subject: Cleaning of Upper Instrument Panel Surfaces Models: 1999 and Prior Passenger Cars and Light Duty Trucks Comments on a reflection of the upper instrument panel pad into the windshield, when driving in direct sunlight, may be received. This condition, sometimes referred to as a "veiling reflection", may be aggravated by the use of wax or silicone based products when cleaning the surface. Advise customers, technicians and new car prep or make ready personnel, that products containing wax or silicone should not be used to clean the top instrument panel pad. A warm water and mild soap solution such as saddle soap, oil soap or an equivalent, should be used whenever the top instrument panel pad needs cleaning. If a customer requests that a protectant type product be applied, ONLY USE THOSE THAT LEAVE A FLAT OR SATIN FINISH. Do NOT apply products that leave a glossy finish or those that Increase the shine level above the original production level. Cowl - Popping/Tapping Noise Cowl: All Technical Service Bulletins Cowl - Popping/Tapping Noise Number: 91-351-10 Section: 10 Date: JUNE 1991 Corporate Bulletin No.: 162001R Subject: COWL "POP"/TAPPING NOISE Model and Year: 1983-91 S/T TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 86-58, DATED APRIL 1986. THE SERVICE PROCEDURE HAS BEEN UPDATED AND THE 1987-91 MODEL YEARS ADDED. ALL COPIES OF 86-58 SHOULD BE DISCARDED. Some 1983-1991 S/T pickup and utility vehicles may experience a "popping" noise from the cowl area (at the base of the "A" pillar in front of the speaker grills). The sound may emanate from either side of the vehicle. The exact cause of this condition is currently unknown. Cowl "pop" is defined as a tapping noise at the lower corner of the windshield or base of the "A" pillar that usually, but not always, occurs when the vehicle is cold (below 45 degrees F). The sound is simiiar to the noise made when tapping a pencil point on the windshield. Some success has been achieved in correcting this condition by trimming areas of hood flange that may contact the cowl vent panel, by relieving any stress that may be created by the front fender mounting sequence, and by loosening the # 1 body mount and/or shimming one or both front body mounts. SERVICE PROCEDURE: NOTE: Typically this condition occurs only when the vehicle sheet metal is at a temperature below 45 degrees F. The condition may temporarily disappear if vehicle evaluation is performed after a vehicle has been in a warm environment. REMOVAL OF HOOD FLANGE MATERIAL: Some ST vehicles experiencing a cowl "pop" tapping noise may be corrected by trimming the back edge of the hood flange. On a small number of vehicles, excess material on the rear edge of the hood flange contacts the front of the cowl vent panel causing a tapping noise when the vehicle goes over a bump. 1. Visually inspect for witness marks in the painted area of the cowl vent panel to determine if the hood flange contacts any cowl panel surfaces. 2. If witness marks are not present, it is not necessary to perform Steps 3 and 4. Continue to "Relieving Fender Mounting Stress" Section. If witness marks are present, trim off approximately 1/8" of the hood flange only in the areas contacting the cowl vent panel using Jilson Tool 1451 SS or equivalent. 3. Refinish the bare metal on the trimmed areas and on matching cowl vent panel areas to prevent corrosion. RELIEVING FENDER MOUNTING STRESS: Some success has been achieved in correcting the cowl "pop" tapping condition by relieving the stress caused by the front fender mounting sequence. 1. Remove windshield wiper arms using Kent-Moore Tool J-8966 Remover and Installer, or equivalent. 2. Remove cowl vent panel assembly. 3. Loosen the four rear fender mounting bolts to zero torque. (One of the upper fender mounting bolts is located underneath the hood hinge seal.) 4. Retorque the two lower fender bolts to 20-34 N-m (15-25 Lbs.Ft.). 5. The upper hinge mounting bolt should be left at zero torque. Apply Loctite 242 thread locking compound (GM P/N 12345382), or equivalent, to hold in place. Retorque the remaining upper fender bolt to 20-34 N-m (15-25 Lbs.Ft.). 6. Reinstall cowl vent panel assembly and windshield wiper arms. Page 1838 Oil Pressure Switch (For Fuel Pump): Testing and Inspection Refer to DIAGNOSTIC CHARTS/FUEL PUMP RELAY CIRCUIT DIAGNOSIS (CHART A-5), for fuel related oil pressure switch problems. Page 7324 Cruise Control Switch: Description and Operation Fig. 1 Cruise Control Switch The mode control assembly, Fig. 1, consists of a 3 position slide-type switch and a set/coast switch button. To operate the system, the slide switch must be in on position and vehicle speed must be above 25 mph. The system is engaged at the desired speed by fully depressing, then releasing the set/coast button. Cruise speed can be increased from set position by accelerating vehicle to desired speed, then pressing and releasing button. In order to decrease speed, the set/coast button is held in the fully depressed position (disengaging system), then released when the desired speed is reached. The system can be disengaged at any time by depressing the brake or clutch pedal, or by moving the slide switch to off position. If the system is disengaged by depressing the brake or clutch pedal, the last set speed will be retained in the module memory until the slide switch or ignition switch is moved to off position. Momentarily moving the slide switch to the resume/accel position will cause the vehicle to accelerate to the last set speed and maintain that speed. If the slide switch is held in the resume/accel position, the vehicle will continue to accelerate until the switch is released. When the switch is released, the speed that the vehicle accelerated to becomes the new set speed. The slide switch also allows a tap-up function to increase cruise set speed in 1 mph increments. With the cruise control engaged and operating, tapping-up is done by pressing the slide switch to the resume position, then quickly releasing it. This procedure can be repeated 10 times before the system must be reset to a new speed in the conventional manner. Service and Repair Turn Signal Switch: Service and Repair Fig. 6 Compressing Lock Plate 1. Disconnect battery ground cable. 2. Remove steering wheel as outlined under STEERING SUSPENSION CHASSIS AND BODY COMPONENTS/STEERING/COMPONENT REPLACEMENT AND REPAIR PROCEDURES/STEERING WHEEL & HORN SOUNDER. 3. Using a screwdriver, pry cover from lock plate. 4. Using lock plate compressing tool No. J-23653, compress lock plate and pry retaining ring from groove on shaft, Fig. 6. Slowly release lock plate compressing tool, 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. Page 6485 Another condition that may occur is the belt not extending when desired. This is often caused by the belt, after having been in the ratchet mode, not being retracted all the way back to the stop. Usually aiding the belt back to the stop by wiggling, removing obstructions, pulling releasing, etc. will allow the belt to once again extend. This condition frequently happens when the shoulder portion of the belt fully retracts before the lap portion of the belt reaches the stop. All the conditions described above are part of the normal operation of belts equipped with the child hold out mechanism, and will not be eliminated by replacing the belt. Page 1094 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 Fuel Gauge Inaccurate Fuel Gauge: Testing and Inspection Fuel Gauge Inaccurate 1. Ensure terminals are clean and terminal connections are tight. 2. Remove sender, using a suitable ohmmeter test sender. At empty position reading should be 1 ohm, at 1/2 full 44 ohms, and 88 ohms at full position. 3. Disconnect front body connector, connect tester J 33431-A or equivalent. 4. Turn ignition switch to On position, if gauge responds accurately, check wiring between rear compartment and front body connector. 5. If gauge reads between one fourth and one half with tester set at 90 ohms, replace cluster. Description and Operation Cruise Controller: Description and Operation The module monitors mode control switch position, signals from the speed sensor, servo position and release switch operation, then operates vacuum valves within the servo unit to control servo operation and vehicle speed. The module also contains a speed limiting function which prevents system operation at speeds below approximately 25 mph. Page 8030 Tools Front Door Trim Panel Page 7227 Figure No. 1 Before beginning this procedure, make sure that the spare tire carrier striker latch is double latched in order to assure that the following check is accurate. Grasp the carrier arm where the release handle is located and move the arm in a forward and backward direction relative to the vehicle. If a metallic sound is heard or if the arm moves easily then replace the striker plate with a new revised striker plate (P/N 15659235). This new striker plate has a thickened rubber bumper to reduce the movement of the carrier arm as well as an additional reinforcement bracket to absorb the additional force on the striker as a result of the thickened bumper. Old and new bumper sizes as well as the reinforcement bracket are shown in Figure 1. Note: If the subject vehicle was manufactured after the following breakpoints then Service Procedure 1 will not be required as the latest design striker was used in production. Shreveport: 1GNCT18Z9M8104384 Pontiac West: 1GNCT18Z4MO103321 Moraine: 1GNDT13Z6M2115163 Service Procedure 2 Page 3409 [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). Locations Compressor Clutch Relay: Locations A/C Cutout Relay The A/C Cutout Relay is located at the LH front of the dash on the relay bracket. Page 4327 Figure 2 Companion Flange Compensation Weights Figure 3 This "compensation" weight was originally installed to compensate for the effect of offsetting 1/2 the mass of the propshaft because of companion flange runout. Missing or improperly located weights may worsen the driveline disturbance. Refer to Figure 2 for companion flange and compensation weight specifications. Page 2478 Spark Plug Wire: 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. Page 64 - 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 Page 1432 Page 4793 Brake Bleeding: Service and Repair Master Cylinder Bleeding THIS PROCEDURE CAN BE PERFORMED WITH MASTER CYLINDER ON OR OFF VEHICLE. 1. Disconnect brake lines at master cylinder, if necessary. 2. Connect suitable lengths of brake lines to master cylinder and immerse other ends of lines in master cylinder reservoirs. 3. Apply master cylinder pushrod or brake pedal with full strokes until air bubbles have disappeared in reservoirs. It may require 20-30 applications to fully eliminate air bubbles. 4. Remove bleeding lines from master cylinder, then install master cylinder on vehicle, if necessary, and connect brake lines. 5. Fill the reservoir. Normal bleeding procedures should be followed after the master cylinder is installed. For additional information see Bench Bleeding Notes. See: Hydraulic System/Brake Master Cylinder/Fundamentals and Basics Symptom Related Diagnostic Procedures Steering Gear: Symptom Related Diagnostic Procedures Fig. 1 Troubleshooting power steering system Page 1035 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: Body - Marks/Stains on Windshield When Wet Windshield: Customer Interest Body - Marks/Stains on Windshield When Wet TECHNICAL Bulletin No.: 09-08-48-002A Date: March 19, 2009 Subject: Marks/Stains on Windshield When Wet (Clean Windshield) Models: 2010 and Prior Passenger Cars and Trucks (Including Saturn and Saab) 2010 and Prior HUMMER H2, H3 Supercede: This bulletin is being revised to update the models and model years. Please discard Corporate Bulletin Number 09-08-48-002 (Section 08 - Body and Accessories). Condition Some owners may comment that marks/stains appear on the windshield when the windshield is wet. Cause This condition may be caused by contact between the windshield and the vacuum hoses or other tools used in the assembly process. This contact may leave a residue that creates a water repellent surface on the glass which, in wet conditions, appear as marks/stains on the surface. Correction Important DO NOT REPLACE THE WINDSHIELD FOR THIS CONDITION. To clean the windshield, use Eastwood Glass Polishing Compound*. Follow the manufacturer's directions for product use. Use only hand tools. DO NOT USE POWER TOOLS. Parts Information Eastwood Glass Polishing Compound 1-800-343-9353 (for overseas inquiries: +1-610-705-2200) http://www.eastwoodco.com/ *We believe this source 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 from this firm or for any such items which may be available from other sources. Warranty Information For vehicles repaired under warranty, use the table above. Disclaimer Removal and Installation Clutch Master Cylinder: Service and Repair Removal and Installation Description REMOVAL 1. Remove sound absorbing panel from upper left side foot well. 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 10-15 ft lbs. 2. Connect master cylinder push rod to clutch pedal and install retaining clip. 3. Install sound absorbing panel. 4. Connect reservoir hose and slave cylinder hydraulic line to master cylinder. 5. Bleed system. Page 6759 1. Disconnect the negative battery cable. 2. Open the endgate to the horizontal position. 3. Remove the inner trim panel. 4. Remove the bolts retaining the endgate inner panel reinforcement and remove the reinforcement (Figure 1, Item 2). 5. Disconnect the right and left endgate lock rods from the endgate window latch assembly (Figure 2). 6. Remove the adjusting nuts securing the window latch assembly to the endgate. (Figure 1, Item 4) 7. Disconnect the power window release actuator cable, if equipped. 8. Remove the window latch assembly from the endgate and discard. 9. Preassemble the lock rods to the new endgate window latch assembly (P/N 20367780) and install. DO NOT force the lock rods into position. The lock rods should line up with the attaching hole or stud on the window latch lever. NOTE: The temporary lock md positioning fastener must be in place for this procedure. (Figure 2, Item 4) If the rods do not align with the attaching hole or stud, adjust the rod(s) by turning to either lengthen or shorten as required. 10. Remove and discard the temporary lock rod positioning fastener 11. Reconnect the power window release actuator cable, if equipped. 12. Check for proper endgate operation. If necessary, readjust the lock rods. 13. Reattach the endgate inner panel reinforcement. 14. Adjust the latch assembly as described in steps 1-3 of the "Adjusting Procedure". 15. Reinstall the inner trim panel. 16. Reconnect the negative battery cable. SERVICE PARTS INFORMATION PART NUMBER DESCRIPTION QUANTITY 20367780 Window Latch Assembly 1 Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: B5880 Use applicable labor time guide for labor hours. Differential - Growl Noise Differential Axle Housing: All Technical Service Bulletins Differential - Growl Noise Number: 8-416-4C Section: 4C Date: May, 1989 Subject: FRONT AXLE GROWL NOISE Model and Year: 1983-88 T1 TRUCKS Figure 1 TO ALL CHEVROLET DEALERS: Beginning with start of production 1989, the material in the thrust washers in the front axle tube of T Model Trucks was changed to reduce thrust washer wear. The washers involved are # 7, # 20 and # 24 as shown in Figure # 1. When worn, the metal in the washer will be smeared from slipping. Number 24 may also be dished. Page 5157 Figure 8 Figure 9 Figure 10 Figure 11 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). Page 7892 Symbol Identification Page 6980 ** Refer to the applicable labor time guide for paint mix time allowance and include in "Other Hours." *** Select corresponding material allowances to combine with proper "Above Belt Line" material allowance in "Net Amount" as required for appropriate vehicle type and operations performed. Reimbursement Customer claims for reimbursement on previously paid repairs to correct paint topcoat delamination (peeling) are to be submitted according to the forms and instructions included in this bulletin (additional copies to be reproduced locally). Owners must submit original documentation that reasonably confirms the amount of unreimbursed repair expenses, a description of the repair, the date of the repair, and the person or entity performing the repair. Page 3035 S Series with 2.5L Engine 72267 S Series with 2.8L Engine 23911 Service Action For vehicles exhibiting third gear vibration that were built prior to the production incorporation of the new lever, the shift lever should be replaced with the new design lever. Reference Section 7B-3 of the Service Manual for replacement procedure. The new design shift lever P/N is 15618925. IMPORTANT: After shift lever replacement, assure that the boot assembly is positioned to ride as high as possible on the shift lever to reduce transmission noise into the cab. For vehicles repaired under warranty, use the following Labor Operations and Times: Labor Operation: K1060 Labor Time: .3 Hr Page 1772 15. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 16. Install the electrical ground wire terminal to the rivet stud. 17. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 18. Install the M6 conductive nut to the rivet stud and: Tighten Tighten to 8 Nm (71 lb in). 19. Verify proper system operation. M6 Weld Nut Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M6 weld nut at the electrical ground location is damaged or stripped, a M7 conductive self-threading bolt may be used to secure the ground wire terminal. 2. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the weld nut and allow to dry. 3. Remove any loose metal particles from the damaged or stripped weld nut with a stiff brush. 4. Select a M7 conductive self-threading bolt. Refer to the Parts Information section of this bulletin 5. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M7 conductive self-threading bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 6. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 7. Install the electrical ground wire terminal to the M7 conductive self-threading bolt. 8. Install the M7 conductive self-threading bolt and: Tighten Tighten to 9 Nm (80 lb in). 9. Verify proper system operation. M6 Weld Nut Alternative Repair Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the electrical ground location is accessible from both sides of the panel, a M6 conductive bolt and a M6 conductive nut may be used to secure the electrical ground wire terminal. Refer to the Parts Information section of this bulletin. 2. Select a location adjacent the damaged M6 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the new electrical ground site. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the ground location and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 8.5 mm (0.33 in) diameter hole through the panel. 5. Remove paint and primer from the area surrounding the 8.5 mm (0.33 in) hole until bare metal is visible. 6. Select a M6 conductive bolt. Refer to the Parts Information section of this bulletin. 7. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 8. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 9. Install the electrical ground wire terminal and the M6 conductive bolt to the ground location. 10. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 11. Install the M6 conductive nut to the bolt and: Page 7718 When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 5mm (3/16") of insulation from wire. e. Crimp a new terminal to the wire. f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. Figure 17 To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Figure 18 Figure 19 Page 7325 Cruise Control Switch: Service and Repair Fig. 40 Mode control replacement 1. Remove steering wheel, lower steering column covers and steering lock plate cover, if equipped. 2. Disconnect mode control connector from main harness connector and attach a suitable length of flexible wire to mode control harness. 3. Tape joint between wire and control harness to aid removal, then remove control assembly as shown in Fig. 40. 4. Reverse procedure to install. Page 2938 - An updated engine control calibration, or service procedure, may be available to make the engine less susceptible to low volatility fuels. 3. If basic checks do not reveal a vehicle fault, then advise the customer that fuel quality may be an issue. Recommend the following actions: Change brands of fuel - Use 87 octane gasoline, unless the vehicle is designed for premium gasoline. - Try to empty the fuel tank as much as practical before refilling. - Run a minimum of three tanks of new fuel before returning for service. 4. If above steps are ineffective, do not proceed with additional vehicle diagnosis and/or parts replacement until the fuel tank has been drained and refilled with a known good quality gasoline AT THE DEALERSHIP. 5. If the problem remains refer to service manual, service bulletins and/or technical assistance. Page 3276 Shift Solenoid: Specifications 4L60 - 700R4 Transmission Pressure Control Solenoid To Valve Body .............................................................................................................................................................. 8 ft. lbs. Solenoid Assembly To Case .................................................................................................. .................................................................................. 18 ft. lbs. Solenoid Assembly To Pump ............ .............................................................................................................................................................. .......... 8 ft. lbs. MAP - Revised Check Chart for DTC's 33, 34, 63, 64 Manifold Pressure/Vacuum Sensor: Technical Service Bulletins MAP - Revised Check Chart for DTC's 33, 34, 63, 64 Number: 90-199-6E Section: 6E Date: March 1990 Corporate Bulletin No.: 016510 Subject: REVISED CHART C-1D, CODE 33, 34, 63, 64 Model and Year: 1980-90 PASSENGER CARS AND TRUCKS TO: ALL CHEVROLET DEALERS This bulletin revises the Manifold Absolute Pressure (MAP) Output Check Chart C-1D and updates Code 33, Code 34, Code 63, and Code 64 in the Service Manual section on "Driveability And Emissions" (Section 6E1, 6E2, and 6E3). This information applies to all MAP Sensors on 1980-1990 vehicles with gasoline engines (except turbocharged) with green (standard) MAP sensor electrical connector insert or the solid black MAP sensor electrical connector insert. The revised chart information: Restraints - Seat Belt Warning Lamp On/Buckling Issues Seat Belt Buckle: All Technical Service Bulletins Restraints - Seat Belt Warning Lamp On/Buckling Issues INFORMATION Bulletin No.: 09-09-40-001A Date: February 02, 2011 Subject: Seat Belt Buckle Latching Issues and/or Seat Belt Warning Lights Illuminated Models: 2011 and Prior GM Passenger Cars and Trucks (Including Saturn) 2010 and Prior HUMMER H2, H3 2009 and Prior Saab 9-7 X Supercede: This bulletin is being revised to add the 2011 model year. Please discard Corporate Bulletin Number 09-09-40-001 (Section 09 - Restraints). This bulletin is being published to advise dealers about seat belt buckles not operating and/or seat belt warning light illumination, as well as difficulty latching and unlatching the buckle or the buckle release button sticking. Analysis of warranty data has determined that this condition may be caused by sticky beverages being spilled onto or into the seat belt buckle assembly. Foreign debris from food, candy wrappers, paper and coins can also contribute to this condition. Important If foreign material (debris) or sticky liquids are the cause of the concern, show the customer the condition of the component (buckle assembly) and explain how it is affecting the function of the restraint system. Strongly recommend that the component be replaced. Point out the fact that this is not a manufacturing defect and is not covered by the new vehicle warranty. If the customer declines to have parts replaced, the service department management must make a notation on the service record that the lack of functionality of seating position with an inoperative buckle was fully explained to the customer. The service department management must advise the customer that having a non-functioning buckle in a seating position voids ability to use that seating position (no one should ride in the seat). Also make the customer aware that it may be against the law to ride in a vehicle without wearing a restraint system. Important Never insert anything other than the seat belt latch plate into the buckle assembly. Do not attempt to dig anything out of a buckle with a tool. Never try to wash out a buckle to remove a spilled liquid as this may damage the buckle. Use the following steps to determine the cause of the concern. 1. Inspect the buckle assembly with a light shining on the latch plate insertion area. Look for any debris or foreign objects in the buckle. 2. If any debris or foreign objects are observed, try to vacuum out the item. After the foreign material is removed, latch and unlatch the seat belt. If the system functions properly, do not replace the seat belt buckle assembly. 3. If the condition has not been corrected, inspect the buckle assembly for any sticky residue. If sticky residue is found, inform the customer that a substance was spilled on the seat belt buckle assembly causing the malfunction. The buckle assembly will need to be replaced at the customer's expense. 4. Refer to SI for seat belt component replacement. Important If foreign material (debris) or sticky liquids are the cause of the concern, show the customer the condition of the component (buckle assembly) and explain how it is affecting the function of the restraint system. Strongly recommend that the component be replaced at the customer's expense. Point out the fact that this is not a manufacturing defect and is not covered by the new vehicle warranty. If the customer declines to have parts replaced, the service department management must make a notation on the service record that the lack of functionality of seating position with an inoperative buckle was fully explained to the customer. The service department management must advise customer that having a non-functioning buckle in a seating position voids ability to use that seating position (no one should ride in the seat). Also make the customer aware that it may be against the law to ride in a vehicle without wearing a restraint system. 5. If further restraint diagnosis is required, refer to Seat Belt System Operational and Functional Checks in SI. Page 5019 Wheel Cylinder: Service and Repair Installation For additional information see Notes, Warnings, and Hints. See: Fundamentals and Basics 1. Wipe end of hydraulic line to remove any foreign matter, then place wheel cylinder in position. Enter tubing into cylinder and start threads on fitting. 2. Install wheel cylinder bolts and tighten to backing plate. 3. Tighten brake line. 4. Install brake shoes. 5. Install brake drum. 6. Install wheel and tire assembly. 7. Bleed the brake system. 8. Adjust parking brake. Page 2107 Radiator Cooling Fan Temperature Sensor / Switch: Locations Coolant Temperature Switch Center Of Dash Panel (engine Compartment) Lower RH Side Of Engine Applicable to: V6-262/4.3L Engine 3L30 (180C) Transmission Fluid Pressure Sensor/Switch: Specifications 3L30 (180C) Transmission Component .......................................................................................................................................... .................................................................... Ft. Lbs. Governor Pressure Switch ................................................................................................................... ................................................................................. 7 Page 7104 Page 5512 Multiple Junction Connector: Locations Center Of Dash Panel (engine Compartment) Head Lamp Switch Trim Plate - Cracked Headlamp Switch: Customer Interest Head Lamp Switch Trim Plate - Cracked Number: 91-109-10 Section: 10 Date: January 1991 Corporate Bulletin No.: 061605 Subject: CRACKED PLASTIC HEAD LAMP SWITCH TRIM PLATE Model and Year: 1986-91 S/T TRUCKS TO: ALL CHEVROLET DEALERS Figure 1-Plate Assembly-Instrument Panel Switch Trim Some 1986-1991 S/T trucks may experience a cracked plastic head lamp switch trim plate. This may result in the inaccessibility of the rheostat assembly (dimmer switch) and/or the switch assembly (head lamp/park lamp switch) (Figure 1). Previously, it was necessary to replace the complete head lamp switch trim plate assembly. The complete assembly includes the rheostat assembly part number 01995293 (instrument panel dimmer switch), switch assembly part number 01995313 (head lamp/ parking lamp switch) and the switch trim plate (Figure 1), and the switch trim plate hole covers. A new trim plate kit is now available which does not contain the rheostat assembly or the head lamp switch. This kit replaces the complete head lamp switch trim plate assembly when the switch trim plate is cracked and the rheostat assembly or the head lamp switches do not need replacing. This new kit includes; a switch trim plate, bracket for switch mounting, covers for the switch trim plate holes and four bolts/screws. End Gate Lock Cylinder - Rattles Trunk / Liftgate Lock Cylinder: All Technical Service Bulletins End Gate Lock Cylinder - Rattles Number: 91-507-10 Section: 10 Date: AUGUST 1992 Corporate Bulletin No.: 261003 ASE No.: B1 Subject: END GATE LOCK CYLINDER ASSEMBLY RATTLE Model and Year: 1982-91 S/T TRUCKS Some owners of 1982-1991 S/T utility vehicles may experience a rattling sound emanating from the rear of the truck. This condition may occur if the end gate lock cylinder assembly is loose. To correct this condition, it is necessary to bend the ends of the spring within the lock cylinder assembly eliminating any clearance between the pawl assembly and cylinder housing. SERVICE PROCEDURE: 1. Open the end gate to the horizontal position and remove the inner trim panel. Engine Controls - Aftermarket Accessory Usage Engine Control Module: All 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 Page 7808 Numerous & Various Size Drops of Water Collecting on the Inside Surface of the Lamp Lens After the Vehicle Has Been Exposed to Rain or a Car Washing Environment - A condition that covers more than half the surface of the lamp lens. - An accumulation of water in the bottom of the lamp assembly. - A condition that WON'T clear when the vehicle is parked in a dry environment, or when the vehicle is driven with the lights ON. - A comparison of the equivalent lamp on the opposing side of the vehicle indicates a different performance. Any of the above conditions would indicate the need to service the lens or lamp assembly. Disclaimer Page 7078 panel(s) that can be used as a starting/ stopping point when making a repair. Clearcoat: A clear topcoat required to cover a color basecoat. DELAMINATION: Loss of adhesion between one coat of paint to succeeding coats or coatings. Ultraviolet DELAMINATION is between the E coat (ELPO) and color topcoat(s). ELPO: (Electrocoating or "E" coat): The process by which electrically charged primer is plated on conductive surfaces of an opposite charge. This process provides outstanding corrosion resistance. Guidecoat: A light coat (almost overspray) of color applied over primer surfacer prior to wetsanding to highlight any low spots. Insert Color: The secondary two-tone color between the break line and body side molding. Monocoat: A color topcoat that does not require a clearcoat. Primer: The coating applied to a properly prepared substrate (bare metal) to give adhesion, corrosion and chemical resistance. Primer Sealer: An undercoat that provides maximum adhesion. color coating and corrosion protection. Primer Surfacer: An undercoat used to fill imperfections, with primer qualities, that must be sanded. Refinish: The act of replacing a painted surface, usually undercoat and topcoat. Scuff Sand: A method of sanding a painted surface using a fine grit sandpaper to promote paint adhesion. Topcoat: A finish material over an undercoat material. Ultraviolet Light: The portion of the spectrum of light which can cause fading of paint. It is located below the visible part of the spectrum. V.O.C.: "Volatile Organic Compound" or "Volatile Organic Content" relates to certain emission requirements in specific areas of the country. Electrical - MIL ON/DTC's Set By Various Control Modules Wiring Harness: 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 Page 7171 panel(s) that can be used as a starting/ stopping point when making a repair. Clearcoat: A clear topcoat required to cover a color basecoat. DELAMINATION: Loss of adhesion between one coat of paint to succeeding coats or coatings. Ultraviolet DELAMINATION is between the E coat (ELPO) and color topcoat(s). ELPO: (Electrocoating or "E" coat): The process by which electrically charged primer is plated on conductive surfaces of an opposite charge. This process provides outstanding corrosion resistance. Guidecoat: A light coat (almost overspray) of color applied over primer surfacer prior to wetsanding to highlight any low spots. Insert Color: The secondary two-tone color between the break line and body side molding. Monocoat: A color topcoat that does not require a clearcoat. Primer: The coating applied to a properly prepared substrate (bare metal) to give adhesion, corrosion and chemical resistance. Primer Sealer: An undercoat that provides maximum adhesion. color coating and corrosion protection. Primer Surfacer: An undercoat used to fill imperfections, with primer qualities, that must be sanded. Refinish: The act of replacing a painted surface, usually undercoat and topcoat. Scuff Sand: A method of sanding a painted surface using a fine grit sandpaper to promote paint adhesion. Topcoat: A finish material over an undercoat material. Ultraviolet Light: The portion of the spectrum of light which can cause fading of paint. It is located below the visible part of the spectrum. V.O.C.: "Volatile Organic Compound" or "Volatile Organic Content" relates to certain emission requirements in specific areas of the country. Technical Service Bulletin # 881351010 Date: 880101 Paint - Removal of Minor Imperfections Number: 88-135-10 Page 3547 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 Aluminum Wheels - New Coated Wheel Weights Wheels: All Technical Service Bulletins Aluminum Wheels - New Coated Wheel Weights Number: 91-35-3E Section: 3E Date: August 1990 Corporate Bulletin No.: 003502 Subject: COATED WHEEL WEIGHTS FOR ALUMINUM WHEELS Model and Year: 1985-91 MODELS WITH CAST ALUMINUM WHEELS TO: ALL CHEVROLET DEALERS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 89-65-3E, DATED JANUARY 1989. POLYESTER COATED WHEEL WEIGHTS NOW AVAILABLE FROM GMSPO. THE 1990-91 MODEL YEARS HAVE ALSO BEEN ADDED. ALL COPIES OF 89-65-3E SHOULD BE DISCARDED. Vehicles with cast aluminum wheels use a coated clip on wheel weight. The coating has recently changed from nylon to polyester, giving a more natural appearance that more closely matches the wheel. Coated balance weights are used on both the inboard and outboard rim flanges. They will not discolor, corrode or damage the appearance of the wheel as may have been the case in the past with uncoated clip on weights. These coated weights will fit most GM cast aluminum wheels. There are two types of coated wheel weights available to fit the GM vehicles (see illustration). Both types of weights are available from GMSPO in 1/4 ounce increments. See usage chart below to determine which type weight is correct for the vehicle. "MC" Type Weight Used On: 1990-1991 "W" Car 1988-1990 "Y" Car "AW" Type Weight 1989-1991 "L" Car Used On All Other 1991 "B" Car, "U" Van Series Vehicles 1/4 oz. P/N 9591670 P/N 9591669 1/2 oz. 9591584 9591582 3/4 oz. 9591585 9591583 1-1/4 oz. 9591378 9591362 1-1/2 oz. 9591379 9591363 1-3/4 oz. 9591380 9591364 2 oz. 9591381 9591365 "MC" Type Weight Used On: Page 7980 3. Regulator lift arm roller to the window mount sash. 4. Wire harness to the motor. 5. Water deflector. 6. Armrest bracket. 7. Door trim panel. 8. Battery ground cable. Page 6271 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. Engine Controls - Idle Speed/Minumum Idle Air Rate Specs Idle Speed: Technical Service Bulletins Engine Controls - Idle Speed/Minumum Idle Air Rate Specs GMC NUMBER: 88-T-55 GROUP: 6E - Engine Emissions DATE: November, 1987 CORPORATE NUMBER: 836302 SUBJECT: TRUCK ENGINE CONTROLLED IDLE SPEED AND MINIMUM IDLE AIR RATE SPECIFICATIONS MODELS: 1987 AND 1988 TRUCKS (ALL GASOLINE ENGINES) WITH THROTTLE BODY INJECTION (TBI) This bulletin defines the controlled idle speed and minimum idle air rate specifications for 1987 and 1988 model year trucks for all engine applications with TBI. Additionally, step by step procedures are provided for performing the controlled idle speed check and the minimum idle air rate check. It is important that these procedures and specifications be adhered to. An incorrect readjustment with a high minimum air rate will cause the Idle Air Control (IAC) valve pintle to constantly bottom on its seat and may result in early IAC valve failure. A minimum air rate that is too low may result in a no-start condition in cold weather, a stall after start or a stall during deceleration, because of poor air/fuel distribution through the throttle bore. NOTICE: THESE SPECIFICATIONS AND PROCEDURES SUPERSEDE THOSE PROCEDURES DEFINED IN THE 1987 FUEL AND DRIVEABILITY MANUAL, X-8736. Controlled Idle Speed Check Before performing this check there should be no codes displayed, idle air control system has been checked and ignition timing correct. The procedures to check the idle air control system can be found in the Light Duty Truck Fuel and Emissions service manual at the following locations: All Truck Engines Except 2.5L Page 4-11 2.5L Truck Engines Page 3-61 1. Set parking brake and block drive wheels. 2. Connect a "SCAN" tool to the Assembly Line Data Link (ALDL) connector with tool in Open Mode. 3. Start engine and bring it to normal operating temperature. 4. Check for correct state of Park/Neutral switch on "Scan" tool. 5. Check specifications chart at the end of this bulletin for controlled idle speed and IAC valve pintle position (counts). 6. If within specifications, the idle speed is being correctly controlled by the Electronic Control Module (ECM). 7. If not within specifications, refer to "Rough, Unstable or Incorrect Idle, Stalling" in Section "2" of the Fuel and Driveability Manual X-8736 and review information at the beginning of this check. MINIMUM IDLE AIR RATE CHECK 1. Check controlled idle speed and perform idle air control system check first. 2. Set parking brake and block drive wheels. 3. Start engine and bring it to normal operating temperatures (85-100 degrees Celsius). Turn engine "OFF". 4. Remove air cleaner, adapter and gaskets. On S/T series vehicles, leave THERMAC hose connected. Check that the throttle lever is not being bound by the throttle, Throttle Valve (TV) or cruise control cables. 5. With IAC valve connected, ground the diagnostic terminal (ALDL connector). 6. Turn "ON" ignition, do not start engine. Wait at least 10 seconds (this allows IAC valve pintle to extend and seat in throttle body). 7. With ignition "ON", engine stopped, test terminal still grounded, disconnect IAC valve electrical connector. (This disables IAC valve in seated position). Remove ground from diagnostic terminal. 8. Connect a "Scan" tool to the ALDL connector and place in open mode. If a tool is not available connect a tachometer to the engine. 9. Start engine. With transmission in neutral, allow engine rpm to stabilize. NOTICE: ON 2.5L ENGINES A SERVICE ENGINE SOON LIGHT WILL COME ON AND A CODE 35 WILL BE SET. 10. Check rpm against specifications at the end of this bulletin. Disregard IAC counts on "Scan tool with the IAC disconnected. If the engine has less than 500 miles or is checked at altitudes above 1500 feet, the idle rpm with a seated IAC valve should be lower than values in chart. 11. If the minimum idle air rate is within specifications, no further check is required. 12. If the minimum idle air rate is not within specifications, perform the following procedures: 13. If present, remove stop screw plug by piercing it with an awl, then applying leverage. The screw is covered to discourage unauthorized adjustments. Diagnostic Trouble Code Descriptions Engine Control Module: Diagnostic Trouble Code Descriptions For information regarding B, C, P, U and Manufacturer Code Descriptions - Page 4195 Whenever it is determined that one washer is worn, all three thrust washers should be replaced with kit P/N 26018721, that contains all three thrust washers. Parts are currently available from GMSPO. The kit should be used to resolve T Model front axle growl noise conditions. For vehicles under warranty, use: Labor Operations: F2115 Labor Time: 1.4 Hrs (plus applicable "adds") 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. Page 1206 Light Duty truck tire rotation recommendations are pictured on the following page. Rotation Guidelines for Tires used on Light Duty Trucks: Tires used on Pickups, Vans and Utility vehicles should be rotated at the first 6,000 miles for Schedule 1 or 7,500 miles for Schedule 2 and then every 15,000 miles thereafter. NOTE: Earlier rotation may be required should irregular wear pafterns develop due to harsh service use - the following rotation patterns are recommended for the various vehicle types and tire combinations. Page 456 Knock Sensor: Testing and Inspection Chart C-5 - Electronic Spark Control System Check Page 5525 When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 5mm (3/16") of insulation from wire. e. Crimp a new terminal to the wire. f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. Figure 17 To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Figure 18 Figure 19 Page 6989 * 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. Important Additional time or payment beyond established allowances in this bulletin will not be allowed. - The use of a razor blade on large flat surfaces is not recommended because of the potential to chip. gouge or otherwise damage the primer surface. If razor blade technique is used, the application of a "guide coat" prior to wet sanding should also be used. Note: Chemical stripping is not recommended because of negative impact to moldings, non-metal components, ELPO and environmental concerns. 4. Blow off with air to remove all dirt and sanding residue from cracks and vehicle surface. 5. Clean sanded surface with an appropriate wax and grease remover. 6. Tack wipe entire area to be primed. 7. Spray entire prepared area with a coat of anti-corrosion primer to ensure maximum adhesion and corrosion resistance. Be sure to cover any bare metal surfaces exposed during the sanding operations. Follow manufacturer's instructions and recommended dry times. Typical materials for this application would be: DuPont 615S/616S, BASE DE17/PR8O/DA18, PPG DP4O/DP401, or equivalent. V.O.C. materials would be: DuPont 615S/616S, BASF DE15/PA16/PRB0, PPG DCP21/DCX211 or equivalent. 8. Apply two to three medium wet coats of primer surfacer to the primed surface of the vehicle, following the manufacturer's instructions for application and film build requirements. Important Failure to apply primer surfacer will likely result in future delamination. Typical materials for this application would be: DuPont 1120S/1130S/1125S, BASF DP20/PR80/PH36, PPG K36/DT870/K201, or equivalent. V.O.C. materials would be: DuPont 210S, BASF HP400, PPG DCP21/DCX211, or equivalent. 9. After allowing adequate drying time, wet sand with 400 grit (or finer) or dry sand with 320 grit (or finer) sandpaper. 10. Repeat steps 4 through 6. 11. Apply a medium coat of corrosion resistant primer sealer (tintable base) to the entire surface to be refinished. This will provide maximum adhesion, uniform color coating and corrosion protection to areas "sanded through" during wet sanding. Follow manufacturer's instructions and recommended dry times. Typical materials for this application would be: DuPont 2610S/2605S, BASF DP21/DH6O/PR80, PPG DP40/DP402 or equivalent. V.O.C. materials for this application would be: DuPont 21255, PPG DPW1834 or equivalent. 12. Apply two to three medium wet coats of color (or until primer color is hidden). Follow manufacturer's instructions and recommended dry times. 13. If vehicle has basecoat/clearcoat paint, apply clearcoat. Follow manufacturer's instructions and recommended dry times. 14. After sufficient air or force dry time, unmask the vehicle. 15. Finesse/polish as required. 16. Reinstall all previously removed items. 17. Wash and prepare the vehicle for delivery. HARDWARE ITEMS REMOVAL LIST Note: Some technicians may apply a small cord (wire, plastic tube, etc.) behind or underneath moldings that remain on the vehicle to improve sanding and painting. If the vehicle paint system is baked with cord in place, damage to some moldings may occur. If this technique is used, DO NOT BAKE Page 1027 Audio - Poor AM or FM Radio Reception Antenna, Radio: Customer Interest Audio - Poor AM or FM Radio Reception Number: 89-108-9A Section: 9A Date: MARCH, 1989 Subject: POOR AM OR FM RADIO RECEPTION Model and Year: 1980-89 CHEVROLET VEHICLES TO: ALL CHEVROLET DEALERS Page 5372 Important The M6 conductive rivet stud as shown, can accommodate a panel thickness range of 0.7-4.2 mm (0.03-0.17 in). If there are layers of sheet metal, they should be touching without any air gaps to ensure a good ground. 5. Select a M6 conductive rivet stud. Refer to the Parts Information section of this bulletin. Note Use the GE-50317 rivet stud tool kit. 6. Place the M6 conductive rivet stud (1) in the 10 mm (0.40 in) hole. Assemble the rivet stud tool (2) with the groove and flare side facing the rivet stud, then the washer and the M6 nut (3). 7. Using a wrench on the rivet stud tool, and a socket on the M6 nut, secure the M6 conductive rivet stud. 8. Ensure the rivet stud is securely fastened, WITHOUT ANY detectable movement. 9. Completely wrap the threads of the rivet stud with painters tape or equivalent. Note The rivet stud and surrounding panel area MUST BE properly refinished PRIOR to the installation of the ground wire terminal and conductive nut to maintain a secure, stable and corrosion-free electrical ground. 10. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 11. Allow the refinished repair area to cure sufficiently before removing the protective material applied to the rivet stud threads. 12. Remove the painters tape or equivalent from the rivet stud threads. 13. Using GM approved residue-free solvent or equivalent, thoroughly clean the rivet stud threads to remove any adhesive and allow to dry. 14. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive rivet stud. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. Page 4227 Fluid - Differential: Fluid Type Specifications 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. Page 7898 Figure 4 Figure 5 Figure 6 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 7 Page 7716 Figure 8 Figure 9 Figure 10 Figure 11 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). Page 2792 Vehicle Speed Sensor: Locations LH Side Of I/P Behind Instrument Cluster Tailgate - Latch Rattle, Revised Striker & Latch Trunk / Liftgate Latch: All Technical Service Bulletins Tailgate - Latch Rattle, Revised Striker & Latch Number: 92-153-10 Section: 10 Date: APRIL 1992 Corporate Bulletin No.: 161514 ASE No.: B1 Subject: END GATE LATCH RATTLE Model and Year: 1983-92 S/T TRUCKS Owners of some 1983-1992 S/T 2 and 4 door utility vehicles may comment that their end gate latch rattles. One possible cause of this condition is the end gate latch fork bolts contacting the striker assembly (metal-tometal) causing a rattle. To correct this condition, it is necessary to install a new striker assembly that has a urethane sleeve over the striker post. The urethane sleeve preventsmetal-to-metal contact and may eliminate the rattle. SERVICE PROCEDURE: Page 999 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. Compressor Low Side Cut-Off Switch Refrigerant Pressure Sensor / Switch: Locations Compressor Low Side Cut-Off Switch A/C Low Charge Pressure Switch The A/C Low Charge Protection Switch is located at the rear of the compressor. Page 5562 Note The rivet stud and surrounding panel area MUST BE properly refinished PRIOR to the installation of the electrical ground wire terminal and conductive nut to maintain a secure, stable and corrosion-free electrical ground. 11. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 12. Allow the refinished repair area to cure sufficiently before removing the protective material applied to the rivet stud threads. 13. Remove the painters tape or equivalent from the rivet stud threads. 14. Using GM approved residue-free solvent or equivalent, thoroughly clean the rivet stud threads to remove any adhesive and allow to dry. 15. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive rivet stud. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 16. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 17. Install the electrical ground wire terminal to the M6 conductive rivet stud. 18. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 19. Install the M6 conductive nut to the rivet stud and: Tighten Tighten to 8 Nm (71 lb in) 20. Verify proper system operation. Parts Information Warranty Information (excluding Saab Models) For vehicles repaired under warranty, use: Warranty Information (Saab Models) Electrical - Intermittent MIL/DTC P2138/Reduced Power Wiring Harness: All Technical Service Bulletins Electrical - Intermittent MIL/DTC P2138/Reduced Power TECHNICAL Bulletin No.: 07-06-04-019D Date: June 28, 2010 Subject: Intermittent Malfunction Indicator Lamp (MIL) Illuminated, DTC P2138 with Reduced Engine Power (Repair Instrument Panel (IP) to Body Harness Connector) Models: 2005-2011 GM Passenger Cars and Light Duty Trucks (Including Saturn) 2005-2009 HUMMER H2 2006-2010 HUMMER H3 2005-2009 Saab 9-7X Supercede: This bulletin is being revised to update the model years and warranty information. Please discard Corporate Bulletin Number 07-06-04-019C (Section 06 - Engine/Propulsion System) Condition - Some customers may comment on an intermittent malfunction indicator lamp (MIL) being Illuminated with a message or an indicator that displays Reduced Engine Power. - The technician may observe on a scan tool DTC P2138 - Accelerator Pedal Position (APP) Sensor 1-2 Correlation set as Current or in History. Cause This condition may be caused by water intrusion into the instrument panel (IP) to body harness connector, which carries the APP sensor signals to the ECM/PCM. This water intrusion results in a voltage difference between APP Sensor 1 and APP Sensor 2 that exceeds a predetermined value for more than a calibrated period of time, setting P2138. Correction Note Aftermarket equipment can generate DTC P2138 and/or other DTCs. 1. Verify that aftermarket equipment is not electrically connected to any of the APP sensor signal or low reference circuits or to any other ECM/PCM 5V reference or low reference circuits. Refer to Checking Aftermarket Accessories in SI. 2. Perform the Diagnostic System Check - Vehicle. ‹› If any 5V reference DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle. ‹› If any 5V reference DTCs are not set, proceed to Step 3. 3. Locate the IP to body harness connector, which may be located in and around the left hand kick panel area or inside the IP. Depending on the vehicle and model year, refer to Wiring Systems or Power and Signal Distribution in SI. Note Some examples of potential water leaks are: A-pillar seals, sunroof drain lines (if equipped) and windshield/cowl sealing. 4. Inspect for a water leak in the area. If necessary use a water hose to determine the source of the leak. Refer to General Information > Water Leaks in SI. ‹› If a water leak is observed, repair as necessary. Verify the effectiveness of the repair. 5. Inspect the IP to body harness connector terminals for corrosion and debris. Refer to Testing for Intermittent Conditions and Poor Connections in SI. ‹› If any corrosion and/or debris is observed, repair as necessary. 6. After completing the repair, verify the proper operation of the system. Depending on the vehicle and model year, perform the Diagnostic Repair Verification procedure or refer to Diagnostic Trouble Code (DTC) List - Vehicle in SI. Page 6171 Page 2974 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/. Page 6293 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 Page 1534 Cylinder Head, Valve Guides & Valve Seats Engine - Rough Idle/Stall After Cold Start PROM - Programmable Read Only Memory: All Technical Service Bulletins Engine - Rough Idle/Stall After Cold Start Number: 91-44-6E Section: 6E Date: August 1990 Corp. Bulletin No.: 036511 Subject: ROUGH IDLE/STALL AFTER COLD START Model and Year: 1988-91 S/T TRUCKS WITH 4.3L (VIN CODE Z) ENGINE AND AUTOMATIC TRANSMISSION 4L60 TO: ALL CHEVROLET DEALERS APPLICATION: 1988-91 4.3L Auto. S/T Truck W / Calif. Emission (NB2) 1988-90 4.3L Auto. S/T Truck W / Federal Emission (NA5) CONDITION: Some of the above trucks may exhibit a rough idle, sag or stalling condition after cold start-up at intermediate ambient temperatures of 30-70 degrees F. This condition may be most noticeable while performing a Park to Drive/Reverse shift. The condition improves as the engine reaches normal operating temperature. CAUSE: The condition is due to low idle speeds and/or lean air/fuel ratios after cold start-up. CORRECTION: To correct this condition install a new service calibration PROM which revises warm-up idle speeds. The new PROM will also raise the normal controlled idle speed from 500 RPM to 525 RPM in drive. Reference the chart below for the proper PROM application. Note: These PROMs were released to production as follows: The Federal PROM is in all 1991 models. The California PROM will go into production in August 1990 for 1991 models. Parts are currently available from GMSPO. Labor Operation: T0500 Labor Time: 0.8 Hrs. Page 3398 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). 3L30 (180C) Transmission Shift Solenoid: Specifications 3L30 (180C) Transmission Component .......................................................................................................................................... .................................................................... Ft. Lbs. Solenoid ............................................................. .............................................................................................................................................................. .. 14 Page 5481 15. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 16. Install the electrical ground wire terminal to the rivet stud. 17. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 18. Install the M6 conductive nut to the rivet stud and: Tighten Tighten to 8 Nm (71 lb in). 19. Verify proper system operation. M6 Weld Nut Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M6 weld nut at the electrical ground location is damaged or stripped, a M7 conductive self-threading bolt may be used to secure the ground wire terminal. 2. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the weld nut and allow to dry. 3. Remove any loose metal particles from the damaged or stripped weld nut with a stiff brush. 4. Select a M7 conductive self-threading bolt. Refer to the Parts Information section of this bulletin 5. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M7 conductive self-threading bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 6. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 7. Install the electrical ground wire terminal to the M7 conductive self-threading bolt. 8. Install the M7 conductive self-threading bolt and: Tighten Tighten to 9 Nm (80 lb in). 9. Verify proper system operation. M6 Weld Nut Alternative Repair Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the electrical ground location is accessible from both sides of the panel, a M6 conductive bolt and a M6 conductive nut may be used to secure the electrical ground wire terminal. Refer to the Parts Information section of this bulletin. 2. Select a location adjacent the damaged M6 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the new electrical ground site. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the ground location and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 8.5 mm (0.33 in) diameter hole through the panel. 5. Remove paint and primer from the area surrounding the 8.5 mm (0.33 in) hole until bare metal is visible. 6. Select a M6 conductive bolt. Refer to the Parts Information section of this bulletin. 7. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 8. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 9. Install the electrical ground wire terminal and the M6 conductive bolt to the ground location. 10. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 11. Install the M6 conductive nut to the bolt and: Electronic Spark Control (ESC) Knock Sensor: Description and Operation Electronic Spark Control (ESC) Electronic Spark Control (ESC) is used on some models. The ESC system is used in conjunction with the EST system to provide additional spark retard during engine detonation. A knock sensor signals a separate ESC controller to retard the timing when it senses engine knock. The ESC controller signals the ECM which reduces spark advance until no more signals are received from the knock sensor. Drive Axle (Front) - Will Not Disengage Transfer Case Actuator: Customer Interest Drive Axle (Front) - Will Not Disengage Number: 91-476-4C Section: 4C Date: JAN. 1992 Corporate Bulletin No.: 167402 ASE No.: A3 Subject: FRONT AXLE WILL NOT DISENGAGE Model and Year: 1983-1991 T TRUCKS Owners of some 1983-1991 T vehicles may comment about inappropriate front axle disengagement. This condition may be due to a corroded transfer case vacuum actuator switch. To correct this condition a revised switch (P/N 15664811), constructed of noncorrosive stainless steel, should be installed. SERVICE PROCEDURE: The vacuum switch is located on the left upper side of the transfer case (Figure 1). 1. Raise the vehicle and support with suitable safety stands. 2. Remove the vacuum lines from the switch. 3. Remove the corroded switch from the transfer case. 4. Install a revised switch (P/N 15664811), coat the threads with thread sealant. 5. Connect the vacuum lines. 6. Lower the vehicle. 7. Check for oil leaks at the threads and vacuum leaks around the vacuum lines. 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 Page 4386 Fluid - M/T: Fluid Type Specifications Tremec 3 Speed Fluid Type ............................................................................................................................................ ........................................................... 80W Gear Oil Saginaw 3 Speed Fluid Type ............................................................................................................................................ ........................................................... 80W Gear Oil Saginaw (76 mm) 4 Speed Fluid Type ............................................................................................................................................ ...................................................... 80W-90 Gear Oil Warner 83 mm 4 Speed Fluid Type ............................................................................................................................................ ........................................................... 80W Gear Oil Warner T-4C 4 Speed Fluid Types .......................................................................................................................................... ......................................................... Dextron II ATF Muncie CH & SM-465 4 Speed Fluid Types .......................................................................................................................................... ....................................................... 80W-90 Gear Oil Warner T-5 (77MM) 5 Speed Lubricant Type ..................................................................................................................................... ......................................................... Dextron II ATF MUNCIE 5LM60 (HM-290) 4 & 5 Speed Lubricant Type ..................................................................................................................................... ................................ Syncromesh Trans Fluid T2850 Page 7819 Figure 8 Figure 9 Figure 10 Figure 11 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). Door Side Glass, Front - Binding/Track Disengagement Window Frame: Customer Interest Door Side Glass, Front - Binding/Track Disengagement Number: 93-89-10 Section: 10 Date: JAN. 1993 Corporate Bulletin No.: 261614 ASE No.: B1 Subject: FRONT DOOR SIDE GLASS BINDING/TRACK DISENGAGEMENT Model and Year: 1982-93 S/T TRUCKS Owners of some 1982-1993 S/T vehicles may comment about the side front door glass binding during operation or the glass disengaging from the window track. These conditions may occur if the glass binds against the run assembly weatherstrip, and/or the plastic window guide separates from the glass due to improper seating during installation and/or breaks. To correct, it is necessary to replace the following items: - The side door glass with glass that has the lower rear corner rounded off. The new glass reduces binding between the glass and run assembly weatherstrip during window operation. - The run assembly weatherstrip with a weatherstrip that has additional flocking (Figure 1, Section A-A). The additional flocking helps eliminate friction between the glass and channel providing smoother window operation. Page 4111 Clutch Master Cylinder: Service and Repair Clutch Master Cylinder Replace Fig. 1 Clutch master cylinder REMOVE OR DISCONNECT 1. Negative battery cable. 2. Sound absorbing panel from upper left side foot well. 3. Lower left side A/C duct (if equipped). 4. Master cylinder pushrod from clutch pedal. 5. Reservoir hose and slave cylinder hydraulic line from master cylinder. 6. Master cylinder retaining nuts. 7. Clutch master cylinder and gasket. INSTALL OR CONNECT 1. New gasket and master cylinder, then install retaining nuts and torque to 14-20 Nm (10-15 ft lbs). 2. Connect reservoir hose and slave cylinder hydraulic line to master cylinder. 3. Connect master cylinder pushrod to clutch pedal and install retaining clip. 4. Lower left side A/C duct (if equipped). 5. Install sound absorbing panel. 6. Negative battery cable. 7. Fill reservoir and bleed system. Interior - Tapping Noise In Corner of Dash Dashboard / Instrument Panel: Customer Interest Interior - Tapping Noise In Corner of Dash Number: 89-101-10 Section: 10 Date: MARCH, 1989 Subject: TAPPING NOISE IN CORNER OF DASH Model and Year: 1987-89 S/T TRUCKS TO: ALL CHEVROLET DEALERS Some 1987-89 S/T Trucks may experience a noise from the cowl area located around either of the front dash speakers. The noise has been described as a tapping or creaking noise similar to tapping a pencil lead on the windshield. This condition occurs primarily at ambient temperatures below 45 degrees Fahrenheit. Therefore, vehicles which sit inside a heated facility during repair should be "cold soaked" prior to verifying the repair. Repair Procedure Apply repair procedure exactly as described in Chevrolet Bulletin 86-58 (Section 10) dated April, 1986, which has been reproduced in this bulletin for your convenience. IMPORTANT: Windshield replacement will not resolve the situation. For repairs to vehicles under warranty, use: Labor Op: T7230 1983-86 Models - Labor Time: .6 Hr per side 1987-89 Models - Labor Time: .8 Hr. per side NOTE: On 87-89 vehicles, the location of the one inch hole will encompass a small weld. Additional time has been added to the labor operation to take this into account. Be sure to cut through only the first layer of sheet metal as specified in Step 9 on the bulletin. IMPORTANT: Dealers who have vehicles that are not repaired by this procedure should contact Technical Assistance for further assistance. Subject: COWL POPPING NOISE Model and Year: 1983-86 S/T TRUCKS Number: 86-58 Section: 10 Date: APR., 1986 TO: ALL CHEVROLET DEALERS On some S/T Trucks operating in low ambient temperatures, a condition may exist where a snapping or "popping" noise is heard coming from the cowl. This noise is caused by an "oil can" effect between the windshield frame and the door frame. The service procedure for eliminating the noise is as follows: 1. Remove the windshield wipers and radio antenna. Page 7507 Symbol Identification Wire Color Code Identification WIRE COLOR ABBREVIATION BLACK BLK BLUE BLU DARK BLUE DK BLU Page 5690 Steering Gear: Description and Operation Saginaw Integral Power Steering Gear Fig. 1 Exploded view of power steering gear The power steering gear has a recirculating ball system which acts as a rolling thread between the worm shaft and the rack piston, Fig. 1. The worm shaft is supported by a thrust bearing preload and two conical thrust races at the lower end, and a bearing assembly in the adjuster plug at the upper end. The control valve in the steering gear directs the power steering fluid to either side of the rack piston. The rack piston converts the hydraulic pressure into a mechanical force. If the steering system loses hydraulic pressure, the vehicle can be controlled manually. When the worm shaft is turned right, the rack piston moves up in the gear while turning left moves the rack piston down in the gear. The rack piston teeth mesh with the pitman shaft sector. Turning the worm shaft turns the pitman shaft, which turns the wheels through the steering linkage. Generator Light - Flickers During Pulse Wiper Use Wiper Switch: Customer Interest Generator Light - Flickers During Pulse Wiper Use Number: 90-84-8A Section: 8A Date: November 1989 Corporate Bulletin No: 966402 Subject: GENERATOR LIGHT FLICKER DURING PULSE WIPER OPERATION Model and Year: 1988-89 S, T TRUCKS WITH 2.8L OR 4.3L (VIN CODES R, Z) ENGINES TO: ALL CHEVROLET DEALERS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 89-219-8A, DATED JULY 1989. THE 1990 MODEL S/T VEHICLES ARE INCLUDED IN THE LATEST BULLETIN ALONG WITH A CORRECTION TO THE ELECTRICAL CONNECTOR NUMBER. ALL COPIES OF 89-219-8A SHOULD BE DISCARDED. The generator light flicker condition during pulse wiper switch operation in the 1988, 1989 and 1990 S/T instrument panel, with standard cluster, can be caused by negative voltage transients from the wiper motor. There is no possibility of a system failure as a result of this condition. The effect of this condition is that the generator light will turn on for 80 milliseconds (if gages, the voltage drop on the voltmeter lasts 2.5 seconds). This causes no harm to the generator or other electrical components. Subject condition can be eliminated by installing a diode (industry part number 1N4003) or diode/connector kit (diode kit part number 12085207) in the brown wire at the generator connector (circuit 25 at connector C118). See the following pages in the 1988, 89 and 90 S/T Electrical Wiring Diagrams for circuit 25, connector C118 locations: 1988 4.3L: Section C - Page 24 1988 2.8L: Section C - Page 22 1989 4.3L: Page 40 1989 2.8L: Page 39 1990 2.8L: Page 44 1990 4.3L: Page 45 PARTS INFORMATION: Quantity Part Number Description 1 12085207 Diode ----OR---1 *1N4003 Diode * This part available locally. Parts are currently available from GMSPO. INSTALLATION PROCEDURE: 1. Disconnect the battery. 2. Remove the connector from the generator. 3. Peel back the black plastic conduit covering the wires. 4. If installing diode 1N4003: cut out a section of the brown wire that matches the length of the diode. 4A. A diode/connector kit is also available (GMSPO diode kit part number 12085207). If using the kit cut out approximately four inches of the brown wire, following crimping and soldering instructions in the kit. Spiral tape the solder joints and tuck the wire back into the conduit away from the generator. Secure the diode/connector to the outside of the conduit with electrical tape. 5. Solder in diode with the banded end toward the generator. Page 1930 Spark Plug Wire: Locations Spark Plug Wire Routing A/C - R12 Loss From Loose or Missing Access Fitting Caps Service Port HVAC: Customer Interest A/C - R12 Loss From Loose or Missing Access Fitting Caps Number: 89-127-1B Section: 1B Date: APRIL, 1989 Subject: A/C REFRIGERANT LOSS DUE TO LOOSE OR MISSING ACCESS FITTING CAPS Model and Year: 1980-89 CHEVROLET MODELS WITH A/C FIGURE 1 TO: ALL CHEVROLET DEALERS All Chevrolet air conditioning Hi side and Low side access fittings are supplied with a black plastic cap and seal assembly which provides the primary refrigerant seal for the service fittings. If the cap and seal assembly is missing or loose, a significant amount of refrigerant may leak through the valve core located in the access fitting, which could result in poor A/C performance or failure. When servicing any vehicle's A/C system, make sure all access fitting cap seals (refer to Figure 1) are in place and tight. Caps should be threaded on until contact with the O-ring seal is made and then tightened another 1/4 - 1/2 turn to ensure proper sealing. High Side Low Side Valve - Cap and Seal Valve - Cap and Seal P/N 3033974 P/N 6551640 Parts are currently available from GMSPO. Page 3042 Fuel Injector Part Number Location NOTE: a. The TBI unit has two different fuel injectors (with two different flow rates). Injectors having part number 5235134 (color coded Orange and Green) should be installed on the throttle lever side. Those with part number 5235342 (color coded Pink and Brown) go on the TPS side. b. 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. Fuel Injector Installation INSTALLATION: 1. Lubricate new lower (small) O-rings with automatic transmission fluid and push on nozzle end of injector until it presses against injector fuel filter. 2. Install steel injector back up washer in counterbore of fuel meter body. 3. Lubricate new upper (large) O-rings with automatic transmission fluid 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. 4. Install 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). 5. Install fuel meter cover gasket. 6. Install fuel meter cover. 7. Reconnect electrical connectors to fuel injectors. 8. With engine OFF and ignition ON, check for fuel leaks. Page 2435 4. Remove the retention spring from the mirror bracket (Figure 2, Item A). 5. Drill and tap the retention spring, on the rear side wing, so that it will accept a 6.0 mm X 1.0 mm (diameter X thread pitch) set screw fastener (Figure 3, Item A) (procured locally). The approximate fastener length should be 10 mm. NOTE: The hole must be drilled perpendicular to the flat surface of the retention spring's wing. 6. Reinstall the retention spring in the mirror bracket. 7. Reinstall the mirror head and arm to the mirror bracket. 8. Reinstall the mirror assembly to the door. 9. Install the 6.0 mm X 1.0 mm headed fastener, adjusting it to obtain the original pressure against the mirror arm. DO NOT over-torque this fastener. 10. Reinstall the screws which secure the mirror cover to the door. WARRANTY INFORMATION For vehicles repaired under warranty, use: Labor Description Labor Time Operation R3260 RH mirror R&R; 0.4 Hr. Page 6724 Front Door Panel: Service and Repair Door Trim Panel Replacement Front Door Trim Panel Page 1730 Figure 8 Figure 9 Figure 10 Figure 11 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). Page 2372 Oil Pressure Switch (For Fuel Pump): Description and Operation As a back-up system to the fuel pump relay, the fuel pump can also be turned ON by the oil pressure switch. The oil pressure switch is a normally open switch which closes when oil pressure reaches about 28.0 kPa (4.0 psi). If the fuel pump relay fails, the oil pressure switch will power the fuel pump. Page 7709 Symbol Identification Specifications Distributor: Specifications Distributor Hold-down Clamp Bolt ............................................................................................................................................................. 27 Nm (20 lb-ft) Steering/Suspension - Wheel Alignment Specifications Alignment: 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. Page 5810 Suspension Strut / Shock Absorber: Service and Repair Fig. 6 Shock Absorber Mounting 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. Disconnect shock absorber from upper mounting location, Fig. 6. 3. Disconnect shock absorber attaching nut from spring anchor plate. 4. Remove shock absorber. 5. Reverse procedure to install. Torque upper and lower mounting nuts to specifications. Coolant - Specification/Usage Coolant: Technical Service Bulletins Coolant - Specification/Usage Number: 91-62-6B Section: 6B Date: August 1990 Corp. Bulletin No.: 066202 Subject: COOLANT USAGE Model and Year: ALL 1988-91 PASSENGER CARS AND TRUCKS TO: ALL CHEVROLET DEALERS THIS INFORMATION SUPERSEDES INFORMATION PROVIDED BY GMSPO IN PARTS AND ACCESSORIES BULLETINS IB NO. 90-55 AND 90-60 AND INFORMATION PROVIDED IN VARIOUS TRUCK SERVICE AND OWNERS MANUALS AND SHOULD BE USED TO DETERMINE CORRECT COOLANT USAGE IN LIGHT AND MEDIUM DUTY TRUCK APPLICATIONS. GM coolant specification 6038-M or 1899-M (P/N 1052103) is for use in all light duty trucks with gasoline or diesel engines. This coolant features a low silicate formulation and is intended only for use in engines that have cylinder heads and cylinder blocks made of cast iron. GM coolant specification 1825-M or 6043-M (P/N 1052753) which until recently has been the recommended coolant for light duty trucks has been superseded by GM coolant 6038-M or 1899-M (P/N 1052103) in cast iron truck engines. GM coolant specification 1825-M has a higher silicate formulation which is recommended for all passenger car engines with cylinder heads or cylinder blocks made of aluminum. Locations Wiper Motor: Locations Rear LH Corner Of Engine Compartment. LH Side Of Firewall Applicable to: V6-262/4.3L Engine Page 2615 - Diagnostic Chart Code 63. Page 4765 Wiring Diagram For Chart C-1A - Park/Neutral Switch Diagnosis CHART C-1A - PARK/NEUTRAL SWITCH DIAGNOSIS Circuit Description: The Park/Neutral Switch contacts are closed to ground in park or neutral and open in drive ranges. The ECM supplies ignition voltage, through a current limiting resistor, to CKT 434 and senses a closed switch, when the voltage on CKT 434 drops to less than one volt. The ECM uses the P/N signal as one of the inputs to control: Idle Air Control VSS Diagnostics EGR Test Description: Numbers below refer to circled numbers on the diagnostic chart. 1. Checks for a closed switch to ground in park position. Different makes of "Scan" tools will read P/N differently. Refer to operators manual for type of display used for a specific tool. 2. Checks for an open switch in drive or reverse range. 3. Be sure "Scan" indicates drive, even while wiggling shifter to test for an intermittent or misadjusted switch in drive range. Diagnostic Aids: If CKT 434 indicates PIN (grounded), while in drive range, the EGR would be inoperative, resulting in possible detonation. If CKT 434 always indicates drive (open), a drop in the idle may exist when the gear selector is moved into drive range. 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 Page 5098 Neutral Safety Switch: Locations Manual Trans. LH Side Of I/P Behind Instrument Cluster Page 8131 Note the difference between the wire exit openings of the new multi-functional lever and the old lever (Figure 1). Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Op. Description E7060 Multi-functional lever, replace Use applicable labor time guide for labor hours. Capacity Specifications Fluid - M/T: Capacity Specifications Tremec 3 Speed Fluid capacities .................................................................................................................................... ........................................................................ 3.5 Pts Saginaw 3 Speed Fluid Capacities ................................................................................................................................... ........................................................................ 3.0 Pts Saginaw (76 mm) 4 Speed Fluid Capacities ................................................................................................................................... ........................................................................ 3.2 Pts Warner 83 mm 4 Speed Fluid Capacities ................................................................................................................................... .............................................................................. 3.0 Warner T-4C 4 Speed Fluid Capacities ................................................................................................................................... ........................................................................ 4.0 Pts Warner T-5 (77MM) 5 Speed Fluid Capacity ...................................................................................................................................... ...................................................................... 4.2 Pts. Muncie CH & SM-465 4 Speed Fluid Capacities ................................................................................................................................... ........................................................................ 8.2 Pts 4 Speed Fluid Capacity ...................................................................................................................................... ...................................................................... 4.2 Pts. 5 Speed Fluid Capacity ...................................................................................................................................... ...................................................................... 3.0 Pts. Page 2325 Page 502 Labor Operation No.: K6550 Valve, Pressure Regulator-R&R; or Replace Use the appropriate labor time in the labor time guide. Parts are currently available from GMSPO. Diagram Information and Instructions Neutral Safety Switch: Diagram Information and Instructions 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 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. M/T - Shift Lever Vibration/Rattle In Third Gear Shifter M/T: All Technical Service Bulletins M/T - Shift Lever Vibration/Rattle In Third Gear Number: 89-169-7B Section: 7B Date: May, 1989 Subject: THIRD GEAR SHIFT LEVER VIBRATION/RATTLE Model and Year: 1986-89 S/T TRUCKS W/BORG WARNER FIVE SPEED MAN TRANSMISSION Figure 1 - Identification Tag Explanation Chart TO: ALL CHEVROLET DEALERS Some 1986-89 S/T Trucks may experience a shift lever vibration while the vehicle is in third gear. This condition may also be described as a rattle. The vibration may be most prominent on a coast down (deceleration) while in third gear. Production Change A new design shift lever was put Into production during the 1989 model year. Vehicles which have the new design lever can be identified by the serial number on the transmission identification tag. An example of the tag and its location on the transmission is shown in Figure 1. Vehicles with transmission serial numbers equal to or higher than those given below have the new design lever. Vehicle Serial Number Breakpoint T Series 21564 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 Page 1729 Figure 4 Figure 5 Figure 6 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 7 IP Dimmer Control - Proper Setting Instrument Cluster / Carrier: All 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 Page 2038 SERVICE PARTS INFORMATION RPO DEFINITIONS: C60 - AIR CONDITIONER, FRONT, MANUAL CONTROLS C41 - HEATER, OUTSIDE AIR W/FAN AND DEFROSTER C42 - HEATER, DELUXE GU2 - AXLE REAR 2.73 RATIO GU4 - AXLE REAR 3.08 RATIO GU5 - AXLE REAR 3.23 RATIO GU6 - AXLE REAR 3.42 RATIO GT4 - AXLE REAR 3.73 RATIO K01 - FAN CLUTCH DRIVE L84 - ENGINE, 4.3L, (4.3Z) V6 LU2 - ENGINE, 4.3B, (4.3B) V6 HI-OUTPUT TBI L35 - ENGINE, 4.3L, (4.3W) CENTRAL PORT INJECTION V6 90 DEG WARRANTY INFORMATION For vehicles repaired under warranty, use: Labor Op: J3390 Labor Time: See Applicable Labor Time Guide Specifications Idle/Throttle Speed Control Unit: Specifications IDLE SPEED CONTROL Measured between terminals A& B and C & D. Page 5805 Do Not Replace coil-over shock absorbers displaying condition 1 or 2 levels of seepage. 1. Oil or fluid residue only on the bottom of the lower shock absorber tube or the coil-over shock absorber components and not originating from the shaft seal (located at the top of the coil-over shock tube). 2. Light film/residue on the shock absorber tube, but not on the spring seat and originating from the shaft seal. Replace coil-over shock absorbers displaying conditions 3 and 4 levels of leaks. 3. Oil drip or trail down the lower shock tube and originating from the shaft seal. 4. An extreme, wet film of oil covering the shock absorber tube and pooling in the spring seat and originating from the shaft seal. Struts Do Not Replace Struts displaying condition 1 or 2 levels of seepage. 1. Oil or fluid residue only on the bottom of the strut tube or on other strut components and not originating from the shaft seal. 2. Light film/residue on the strut tube, but not on the spring seat and originating from the shaft seal. Replace Struts displaying conditions 3 and 4 levels of leaks. 3. Oil drip or trail down the strut tube and originating from the shaft seal (located at the top of the strut tube). 4. Extreme wet film of oil covering the strut tube and pooling in the spring seat and originating from the shaft seal. Correction Use the information published in SI for diagnosis and repair. Use the applicable published labor operation. Disclaimer Page 3660 Figure 1 TRANSMISSION FLUID CHECKING PROCEDURE: 1. Start engine and drive vehicle for a minimum of 24 km (15 miles), or until normal operating temperature is reached. NOTICE: The automatic transmission fluid level must be checked with the vehicle at normal operating temperature, 82-93C (180- 200F). Temperature will greatly affect transmission fluid level. If the vehicle is not at normal operating temperature and the proper checking procedures are not followed, the result could be a false reading of the fluid level indicator and an incorrect adjustment of the fluid level. 2. Park vehicle on level ground. 3. Move gear selector to "PARK". 4. Apply parking brake and block wheels. 5. Let vehicle idle for 3 minutes with accessories off. 6. Check fluid level, color and condition (refer to Figure 1). * Inaccurate fluid level readings win result if the fluid is checked immediately after the vehicle has been operated under certain conditions: - In high ambient temperature above 32C (90F). - At sustained high speeds. - In heavy city traffic during hot weather - As a towing vehicle. - In commercial service (taxi or police use). * If the vehicle has been operated under these conditions, shut the engine off and allow the vehicle to "cool" for thirty (30) minutes. After the cooldown period, restart the vehicle and continue from step "2" above. Page 7975 Power Window Motor: Service and Repair Door Trim Panel Front Door Trim Panel Page 1130 - 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 Notes, Warnings, and Hints Brake Master Cylinder: Fundamentals and Basics Notes, Warnings, and Hints REMOVAL WARNING: DOT 3 or DOT 4 brake fluid is very corrosive to your vehicles finish. Removing master cylinders can be a messy process. To prevent or minimize any possible damage perform the following: Siphon all brake fluid from the master-cylinder reservoir prior to removal. - Use a fender cover to protect the vehicles finish. - Use a drip pan to catch all fluid that leaks from the master-cylinder during removal. - Any brake fluid which contacts the vehicles finish should be washed off immediately. - Any brake fluid which drips onto electrical connections should be immediately removed (aerosol brake cleaner works well for this). After the brake lines have been disconnected from the master-cylinder place vacuum caps over ends of the lines to prevent further leakage or contamination. Once the master-cylinder has been removed place it in a drip pan. Although the reservoir is empty, brake fluid trapped within the cylinder bore will continue to slowly leak out. OVERHAUL WARNING: Never hone aluminum cylinders, if deposits cannot be removed with crocus cloth the cylinder should be replaced. Check the cylinder bore for excessive clearance. With the piston installed you should not be able to install a 0.006 inch feeler gauge between piston and cylinder. If the clearance is greater than 0.006 inches the cylinder should be replaced. When installing the piston and seals into the cylinder always use clean brake fluid or assembly lubricant to lubricate the components. INSTALLATION Prior to installation the master-cylinder should be bench bled (this can be done on the vehicle but it is much easier on a workbench. NOTE: Normal brake bleeding procedures will not remove air which is trapped in the cylinder bore area of a master-cylinder. Attach the brake line fittings prior to snugging down the master-cylinder retaining bolts. The fittings are much easier to start turning when the master-cylinder is still loose. WARNING: Remember to tighten the retaining bolts after the brake lines are installed and tightened. When snugging down the retaining bolts, alternately tighten them in small increments. This prevents the master-cylinder or push rod from becoming cocked. Upon installing the master-cylinder the entire brake system (front and rear) will need to be bled. Air enters the brake system as soon as the brake lines are removed. It only requires a very small amount of air in the system to create a soft brake pedal. WARNING: Never test drive a vehicle after a master-cylinder replacement until a firm brake pedal with a 75% reserve is established. Specifications Water Pump: Specifications Water Outlet Bolts 21 ft.lb Water Pump Bolts 30 ft.lb Engine - Rough Idle/Stall After Cold Start PROM - Programmable Read Only Memory: Customer Interest Engine - Rough Idle/Stall After Cold Start Number: 91-44-6E Section: 6E Date: August 1990 Corp. Bulletin No.: 036511 Subject: ROUGH IDLE/STALL AFTER COLD START Model and Year: 1988-91 S/T TRUCKS WITH 4.3L (VIN CODE Z) ENGINE AND AUTOMATIC TRANSMISSION 4L60 TO: ALL CHEVROLET DEALERS APPLICATION: 1988-91 4.3L Auto. S/T Truck W / Calif. Emission (NB2) 1988-90 4.3L Auto. S/T Truck W / Federal Emission (NA5) CONDITION: Some of the above trucks may exhibit a rough idle, sag or stalling condition after cold start-up at intermediate ambient temperatures of 30-70 degrees F. This condition may be most noticeable while performing a Park to Drive/Reverse shift. The condition improves as the engine reaches normal operating temperature. CAUSE: The condition is due to low idle speeds and/or lean air/fuel ratios after cold start-up. CORRECTION: To correct this condition install a new service calibration PROM which revises warm-up idle speeds. The new PROM will also raise the normal controlled idle speed from 500 RPM to 525 RPM in drive. Reference the chart below for the proper PROM application. Note: These PROMs were released to production as follows: The Federal PROM is in all 1991 models. The California PROM will go into production in August 1990 for 1991 models. Parts are currently available from GMSPO. Labor Operation: T0500 Labor Time: 0.8 Hrs. 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 Rearview Mirror, Outside - Vibration Mirrors: All Technical Service Bulletins Rearview Mirror, Outside - Vibration Group Ref.: Body Bulletin No.: 461001 Date: April, 1994 SUBJECT: OUTSIDE REAR VIEW MIRROR VIBRATION (INSTALL SET SCREW FASTENER) MODELS: 1982-93 CHEVROLET AND GMC TRUCK S/T PICKUPS 1983-94 CHEVROLET AND GMC TRUCK S/T UTILITIES WITH D44 OR D45 MIRRORS CONDITION: Some owners may comment that their outside rear view mirrors vibrate. CAUSE: Force is applied against the mirror arm by a retention spring wedged between the mirror bracket and mirror arm to prevent mirror rotation. Over time, this spring force decreases allowing the mirror arm to move or vibrate. CORRECTION: This condition can be corrected by drilling and tapping a hole in the retention spring to accept a set screw fastener. The fastener can be adjusted to force the spring against the mirror arm, restoring the original pressure. SERVICE PROCEDURE: 1. From outside the vehicle, remove the screws which secure the mirror cover and the mirror assembly to the door (Figure 1). 2. Remove the mirror assembly from the door. 3. Remove the mirror head and arm from the mirror bracket. Campaign - Paint Delamination Policy Adjustment Technical Service Bulletin # 8931810 Date: 900901 Campaign - Paint Delamination Policy Adjustment Number: 89-318-10 Section: 10 Date: September, 1990 Corp. Bulletin No.: SPECIAL Subject: SPECIAL POLICY ADJUSTMENT PAINT DELAMINATION (PEELING) Model and Year: 1988-89 CHEVROLET S/T PICKUPS AND S/T BLAZERS (SHREVEPORT ASSEMBLY PLANT ONLY - PLANT CODE "8") TO: ALL CHEVROLET DEALERS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 89-305-10, DATED APRIL 1990. ALL COPIES OF 89-305-10 SHOULD BE DISCARDED AS THIS BULLETIN CONTAINS AN EXPANDED SERVICE PROCEDURE. General Motors has determined that some 1988-89 Chevrolet S/T pickups and S/T Blazers built at the Shreveport Assembly Plant may exhibit a delamination (peeling) of the paint on exterior surfaces due to continued ultraviolet exposure. If one of these vehicles should require repairs for a paint peeling condition, all exterior surfaces painted with affected colors should be refinished even though the peeling may be evident in only a few places. VEHICLES INVOLVED Involved are certain 1988-89 Chevrolet S/T model trucks painted Galaxy Blue (paint code 28), Aspen Blue (paint code 24) or Steel Gray (paint code 90) and built at the Shreveport Assembly Plant within the following VIN breakpoints: SPECIAL POLICY ADJUSTMENT This special policy covers the condition described above on 1988 involved vehicles for 12 months from the date of this bulletin. 1989 involved vehicles will be covered for a period of 3 years from the date of original vehicle purchase regardless of ownership with no deductible. Correction, at no charge to the customer, will consist of refinishing exterior surfaces painted with affected colors on involved vehicles. Customers may also be eligible for reimbursement of previous repairs with supporting documentation. NOTICE: Only exterior surface areas painted Galaxy Blue, Aspen Blue or Steel Gray should be refinished. If peeling of colors other than those described above should occur, handle as described in the Chevrolet Claims Processing Manual, Section XIII, Warranty Management System. This "Special Policy Adjustment Bulletin" should be filed in the three ring binder previously furnished to dealers by General Motors. PARTS INFORMATION No parts are required to complete this special policy. Paint supplies should be obtained through normal supplier. Service Procedure 1. After washing vehicle, verify that condition is delamination of topcoat by applying a 2 inch width piece of masking tape firmly over suspect area, pulling upward quickly. If topcoat and/or clear coat flake or peel away from primer, leaving primer intact, the topcoat is delaminating and the following service procedure should be performed. Page 6319 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. Page 6070 Symbol Identification Tires - Slipping on Rim Tires: Customer Interest Tires - Slipping on Rim Number: 93-169-3E Section: 3E Date: APRIL 1993 Corporate Bulletin No.: 393501 ASE No.: A4 Subject: TIRES SLIPPING ON WHEELS (USE PROPER TIRE MOUNTING PROCEDURE) Model and Year: 1988-93 ALL PASSENGER CARS AND LIGHT DUTY TRUCKS Some incidents of tires slipping (rotating) on wheels have been reported on 1988-93 passenger cars and light duty trucks. Most incidents have occurred when driven aggressively immediately after tire mounting. Hard acceleration and/or braking is usually required. This condition will affect wheel balance, which could result in a vibration. To reduce the chance of tires rotating on their wheels, any excess lube should be wiped from the tire and rim after tire mounting, but before inflating to seat the bead. (Never exceed 40 psi to seat the bead.) Also, the vehicle should not be driven aggressively for at least four hours after tire mounting to allow the lube to dry. GM Goodwrench Rubber Lubricant, p/n 12345884, is the recommended lube for tire mounting. Page 7960 Rear Window Defogger Wiring Circuit Page 1032 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 Page 3328 Labor Operation No.: K6550 Valve, Pressure Regulator-R&R; or Replace Use the appropriate labor time in the labor time guide. Parts are currently available from GMSPO. Page 2003 Coolant Level Indicator Lamp: Service and Repair This lamp will be illuminated when engine coolant level in the radiator drops below a pre-determined level. To turn lamp "OFF," check cooling system, then add coolant to bring system to proper level. Page 4903 Brake Rotor/Disc: Fundamentals and Basics Wheel Bearing Inspection and Repacking WHEEL BEARING INSPECTION Inspect the wheel bearing closely for the following: Fatigue Spalding Look for small flakes of shiny metal (babbit) embedded in the grease. This can easily be done by dragging the bearing across a clean shop towel. Any metal flakes will be readily visible in the grease deposited on the shop towel. If any flakes are found the wheel bearing should be replaced. Brinelling Look for a series of vertical indentations on the races. This is caused by impact loading or vibration while the bearing is not rotating. Replace the bearing if the indentations are severe or the bearing is noisy. Heat Discoloration Heat discoloration can range from faint yellow to dark blue. This results from the bearing being adjusted too tightly or an insufficient amount of lubricant/grease. Excessive heat can cause the races and rollers to soften. To check for a loss of temper on the races or rollers a simple file test may be performed. A file drawn lightly over a race or roller which has lost its case hardening will grab and cut metal, whereas a file drawn lightly over a hardened part will glide readily without scratching the metal. Replace the bearing and race if softening is indicated. Cracked Outer Race Cracked races often result from the race being driven in cocked or at an angle. Replace the bearing and race and be careful to drive the new race in evenly. Loose Outer Race Check to see that the race is tight and secure in the hub. If there is any evidence of movement or slippage, replace both the hub assembly and the bearing. Bent or Damaged Cage Verify that the cage has not been bent or distorted. Bent or damaged cages are often the result of improper bearing and grease seal removal techniques. When removing the inner wheel bearing use a seal puller to remove the grease seal. The inner bearing should then just slide out of the hub. Borg Warner Pinion Bearing: Adjustments Borg Warner 2 - Pinion Fig. 8 Pinion gauge plate installation Fig. 9 Checking pinion depth Page 2764 Wiring Diagram For Chart C-1D - Manifold Absolute Pressure (MAP) Output Check CHART C-1D - MANIFOLD ABSOLUTE PRESSURE (MAP) OUTPUT CHECK Circuit Description: The Manifold Absolute Pressure (MAP) sensor measures manifold pressure (vacuum) and sends that signal to the ECM. The MAP sensor is mainly used for fuel calculation, when the ECM is running in the throttle body backup mode. The MAP sensor is also used to determine the barometric pressure and to help calculate fuel delivery. Test Description: Numbers below refer to circled numbers on the diagnostic chart. 1. Checks MAP sensor output voltage to the ECM. This voltage, without engine running, represents a barometer reading to the ECM. 2. Applying 34 kPa (10" Hg.) vacuum to the MAP sensor should cause the voltage to be 1.2 - 2.3 volts less than the voltage at Step 1. 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 no other vacuum devices are connected tot he MAP hose. Page 3082 Idle Speed/Throttle Actuator - Electronic: Description and Operation IAC Valve Operation And Fuel Pressure Regulation Engine idle speed is computer controlled by signals to the Idle Air Control (IAC) valve mounted on the throttle body. The IAC valve regulates idle speed by moving a pintle valve in and out, varying air flow through a passage bypassing the throttle valve. The more air that is allowed to bypass the throttle valve, the faster the idle speed. The ECM sends voltage pulses to the IAC motor windings causing the IAC motor shaft to move a given distance for each pulse, (referred to as IAC counts). The number of IAC counts can be read on a Scan tool display. 0 counts corresponds to fully closed passage, while 140 counts or more (depending on application) corresponds to full flow. The ECM monitors idle speed and increases the IAC counts if the idle speed is too slow. If the idle speed is too fast, IAC counts will be decreased. Page 1837 Oil Pressure Switch (For Fuel Pump): Description and Operation As a back-up system to the fuel pump relay, the fuel pump can also be turned ON by the oil pressure switch. The oil pressure switch is a normally open switch which closes when oil pressure reaches about 28.0 kPa (4.0 psi). If the fuel pump relay fails, the oil pressure switch will power the fuel pump. Electrical - Intermittent MIL/DTC P2138/Reduced Power Multiple Junction Connector: All Technical Service Bulletins Electrical - Intermittent MIL/DTC P2138/Reduced Power TECHNICAL Bulletin No.: 07-06-04-019D Date: June 28, 2010 Subject: Intermittent Malfunction Indicator Lamp (MIL) Illuminated, DTC P2138 with Reduced Engine Power (Repair Instrument Panel (IP) to Body Harness Connector) Models: 2005-2011 GM Passenger Cars and Light Duty Trucks (Including Saturn) 2005-2009 HUMMER H2 2006-2010 HUMMER H3 2005-2009 Saab 9-7X Supercede: This bulletin is being revised to update the model years and warranty information. Please discard Corporate Bulletin Number 07-06-04-019C (Section 06 - Engine/Propulsion System) Condition - Some customers may comment on an intermittent malfunction indicator lamp (MIL) being Illuminated with a message or an indicator that displays Reduced Engine Power. - The technician may observe on a scan tool DTC P2138 - Accelerator Pedal Position (APP) Sensor 1-2 Correlation set as Current or in History. Cause This condition may be caused by water intrusion into the instrument panel (IP) to body harness connector, which carries the APP sensor signals to the ECM/PCM. This water intrusion results in a voltage difference between APP Sensor 1 and APP Sensor 2 that exceeds a predetermined value for more than a calibrated period of time, setting P2138. Correction Note Aftermarket equipment can generate DTC P2138 and/or other DTCs. 1. Verify that aftermarket equipment is not electrically connected to any of the APP sensor signal or low reference circuits or to any other ECM/PCM 5V reference or low reference circuits. Refer to Checking Aftermarket Accessories in SI. 2. Perform the Diagnostic System Check - Vehicle. ‹› If any 5V reference DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle. ‹› If any 5V reference DTCs are not set, proceed to Step 3. 3. Locate the IP to body harness connector, which may be located in and around the left hand kick panel area or inside the IP. Depending on the vehicle and model year, refer to Wiring Systems or Power and Signal Distribution in SI. Note Some examples of potential water leaks are: A-pillar seals, sunroof drain lines (if equipped) and windshield/cowl sealing. 4. Inspect for a water leak in the area. If necessary use a water hose to determine the source of the leak. Refer to General Information > Water Leaks in SI. ‹› If a water leak is observed, repair as necessary. Verify the effectiveness of the repair. 5. Inspect the IP to body harness connector terminals for corrosion and debris. Refer to Testing for Intermittent Conditions and Poor Connections in SI. ‹› If any corrosion and/or debris is observed, repair as necessary. 6. After completing the repair, verify the proper operation of the system. Depending on the vehicle and model year, perform the Diagnostic Repair Verification procedure or refer to Diagnostic Trouble Code (DTC) List - Vehicle in SI. Page 4394 Mainshaft Bearing/Bushing: Specifications Saginaw 3 Speed Main drive gear bearing ....................................................................................................................... ................................................................... 15 ft. lbs. Page 1137 If the spring breaks while bending, it will be necessary to replace the lock cylinder assembly 7. Reinstall the spring in the lock assembly. Next, shake the assembly to check for looseness. If loose, replace the lock cylinder assembly. 8. Reinstall the gasket, lock cylinder and retainer (Figure 3, Items 3, 4 and 2). 9. Reconnect the end gate lock rods (Figure 2, Items 1 and 2). 10. Reinstall the end gate inner panel reinforcement to the end gate (Figure 1, Item 1). 11. Reinstall the inner trim panel. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Op: B5810 Use applicable labor time guide for labor hours. Description and Operation Brake Master Cylinder: Description and Operation Master Cylinder The master cylinder is designed for a system using low drag calipers. In addition to the standard master cylinder functions, a quick take up feature is included on models with a vacuum booster. This provides a large volume of low pressure fluid to the wheels with the initial brake application. The large volume of fluid helps overcome the clearance created by the caliper pistons and rear brake shoes retracting. Page 4320 Figure 2 Procedure 1. Measure runout of companion flange, as described in Figure 2. Indicate high point with a mark. 2. Remove companion flange as described in Section 4B of the Service Manual. 3. Measure runout of pinion stem at radius between nut thread and spline. Mark low point. 4. Reinstall pinion companion flange with marks aligned. Tighten pinion nut to specification torque. Refer to Section 4B of the Service Manual. 5. Remeasure companion flange runout. If excessive runout still exists, do Step 6. 6. Additional reindexing of the companion flange to the pinion stem splines by one or two teeth may further reduce runout Remarks A. Verify concern. Drive on smooth road up to 65 mph as speed limits permit. Note speeds and severity of disturbance. Assure that disturbance is not engine or transmission related. Refer to Section OC "Vibration Diagnosis Chart" in the 1989 Service Manual. If disturbance is determined to be engine/transmission related, disregard use of this bulletin. Page 6944 If the functional brake switch adjustment check does not repair the condition, refer to Section 5 of the appropriate Service Information Manual for aid in diagnosing other causes. For warranty purposes use: Labor Operation Number: N2440 Labor Time: .3 hour TRUCK ONLY: Service Procedure: 1. Depress the brake pedal and press the switch in until it is firmly seated in the clip. * Audible "clicks" can be heard as the threaded portion of the switch is pushed through the clip. 2. Pull the brake pedal against the pedal stop until the audible "click" can no longer be heard. For stop lamp switch adjustments on vehicles repaired under warranty use: Labor Operation Number: T7945 Labor Time: .2 Hr. Page 7166 8. Apply two to three medium wet coats of primer surfacer to the primed surface of the vehicle, following the manufacturer's instructions for application and film build requirements. Important Failure to apply primer surfacer will likely result in future delamination. Typical materials for this application would be: DuPont 1120S/1130S/1125S, BASF DP20/PR80/PH36, PPG K36/DT870/K201, or equivalent. V.O.C. materials would be: DuPont 210S, BASF HP400, PPG DCP21/DCX211, or equivalent. 9. After allowing adequate drying time, wet sand with 400 grit (or finer) or dry sand with 320 grit (or finer) sandpaper. 10. Repeat steps 4 through 6. 11. Apply a medium coat of corrosion resistant primer sealer (tintable base) to the entire surface to be refinished. This will provide maximum adhesion, uniform color coating and corrosion protection to areas "sanded through" during wet sanding. Follow manufacturer's instructions and recommended dry times. Typical materials for this application would be: DuPont 2610S/2605S, BASF DP21/DH6O/PR80, PPG DP40/DP402 or equivalent. V.O.C. materials for this application would be: DuPont 21255, PPG DPW1834 or equivalent. 12. Apply two to three medium wet coats of color (or until primer color is hidden). Follow manufacturer's instructions and recommended dry times. 13. If vehicle has basecoat/clearcoat paint, apply clearcoat. Follow manufacturer's instructions and recommended dry times. 14. After sufficient air or force dry time, unmask the vehicle. 15. Finesse/polish as required. 16. Reinstall all previously removed items. 17. Wash and prepare the vehicle for delivery. HARDWARE ITEMS REMOVAL LIST Note: Some technicians may apply a small cord (wire, plastic tube, etc.) behind or underneath moldings that remain on the vehicle to improve sanding and painting. If the vehicle paint system is baked with cord in place, damage to some moldings may occur. If this technique is used, DO NOT BAKE PAINT air dry only Note: Only items marked with an asterisk are "add" conditions to the Major Operation being performed. Removal time for all other items listed is included in the refinish time. LIGHT DUTY TRUCKS C/K TRUCKS Grille Front bumper filler panel Antenna Tail lamps Door edge guards Metal wheel opening moldings *Roof marker lamps "Luggage rack *West coast style mirrors "Stripes Emblems/decals if necessary Swing out windows/seals Tail gate handle bezel S/T TRUCKS Page 5413 1. Disconnect the negative battery cable. 2. Open the endgate to the horizontal position. 3. Remove the inner trim panel. 4. Remove the bolts retaining the endgate inner panel reinforcement and remove the reinforcement (Figure 1, Item 2). 5. Disconnect the right and left endgate lock rods from the endgate window latch assembly (Figure 2). 6. Remove the adjusting nuts securing the window latch assembly to the endgate. (Figure 1, Item 4) 7. Disconnect the power window release actuator cable, if equipped. 8. Remove the window latch assembly from the endgate and discard. 9. Preassemble the lock rods to the new endgate window latch assembly (P/N 20367780) and install. DO NOT force the lock rods into position. The lock rods should line up with the attaching hole or stud on the window latch lever. NOTE: The temporary lock md positioning fastener must be in place for this procedure. (Figure 2, Item 4) If the rods do not align with the attaching hole or stud, adjust the rod(s) by turning to either lengthen or shorten as required. 10. Remove and discard the temporary lock rod positioning fastener 11. Reconnect the power window release actuator cable, if equipped. 12. Check for proper endgate operation. If necessary, readjust the lock rods. 13. Reattach the endgate inner panel reinforcement. 14. Adjust the latch assembly as described in steps 1-3 of the "Adjusting Procedure". 15. Reinstall the inner trim panel. 16. Reconnect the negative battery cable. SERVICE PARTS INFORMATION PART NUMBER DESCRIPTION QUANTITY 20367780 Window Latch Assembly 1 Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: B5880 Use applicable labor time guide for labor hours. Page 3100 Fuel Pump Relay: Service and Repair Fuel Pump Relay REMOVAL 1. Verify that ignition switch is in the OFF position. 2. Disconnect the wiring harness plug. 3. Remove the fuel pump relay. INSTALLATION 1. Install the new fuel pump relay. 2. Reconnect the wiring harness plug to relay. 3. Verify correct operation to confirm repair. Drive Axle (Front) - Will Not Disengage Transfer Case Actuator: Customer Interest Drive Axle (Front) - Will Not Disengage Number: 91-476-4C Section: 4C Date: JAN. 1992 Corporate Bulletin No.: 167402 ASE No.: A3 Subject: FRONT AXLE WILL NOT DISENGAGE Model and Year: 1983-1991 T TRUCKS Owners of some 1983-1991 T vehicles may comment about inappropriate front axle disengagement. This condition may be due to a corroded transfer case vacuum actuator switch. To correct this condition a revised switch (P/N 15664811), constructed of noncorrosive stainless steel, should be installed. SERVICE PROCEDURE: The vacuum switch is located on the left upper side of the transfer case (Figure 1). 1. Raise the vehicle and support with suitable safety stands. 2. Remove the vacuum lines from the switch. 3. Remove the corroded switch from the transfer case. 4. Install a revised switch (P/N 15664811), coat the threads with thread sealant. 5. Connect the vacuum lines. 6. Lower the vehicle. 7. Check for oil leaks at the threads and vacuum leaks around the vacuum lines. Page 758 Hose/Line HVAC: Service and Repair 1. Discharge system refrigerant. 2. Disconnect hose pipe assembly at accumulator outlet, condenser inlet and compressor head. 3. Remove mounting straps and remove assembly from vehicle. 4. Reverse procedure to install. Page 4083 Valve Body: Specifications 4L60 - 700R4 Transmission Auxiliary Valve Body To Case ............................................................................................................. .................................................................... 8 ft. lbs. Detent Spring To Valve Body ............................ ..................................................................................................................................................... 18 ft. lbs. Pressure Control Solenoid To Valve Body .............................................................................................................................................................. 8 ft. lbs. Spacer Plate Support To Case .............................................................................................. ..................................................................................... 8 ft. lbs. Valve Body To Case ........................ .............................................................................................................................................................. ........... 8 ft. lbs. Page 6078 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 4. Make repair. Body - Vehicle Glass Distortion Information Front Door Window Glass: Technical Service Bulletins Body - Vehicle Glass Distortion Information INFORMATION Bulletin No.: 00-08-48-005D Date: September 10, 2010 Subject: Distortion in Outer Surface of Vehicle Glass Models: 2011 and Prior GM Passenger Cars and Trucks 2009 and Prior HUMMER H2 2010 and Prior HUMMER H3 2005-2009 Saab 9-7X 2010 and Prior Saturn Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 00-08-48-005C (Section 08 - Body and Accessories). Distortion in the outer surface of the windshield glass, door glass or backlite glass may appear after the vehicle has: - Accumulated some mileage. - Been frequently washed in automatic car washes, particularly "touchless" car washes. This distortion may look like a subtle orange peel pattern, or may look like a drip or sag etched into the surface of the glass. Some car wash solutions contain a buffered solution of hydrofluoric acid which is used to clean the glass. This should not cause a problem if used in the correct concentration. However, if not used correctly, hydrofluoric acid will attack the glass, and over time, will cause visual distortion in the outer surface of the glass which cannot be removed by scraping or polishing. If this condition is suspected, look at the area of the windshield under the wipers or below the belt seal on the side glass. The area of the glass below the wipers or belt seal will not be affected and what looks like a drip or sag may be apparent at the edge of the wiper or belt seal. You may also see a line on the glass where the wiper blade or the belt seal contacts the glass. Important The repair will require replacing the affected glass and is not a result of a defect in material or workmanship. Therefore, is not covered by New Vehicle Warranty. Disclaimer Page 5947 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 Page 1487 Connecting Rod: Specifications Connecting Rod cap Nuts 45 ft.lb Windshield/A Pillar - Pop Noise Diagnosis Windshield: All Technical Service Bulletins Windshield/A Pillar - Pop Noise Diagnosis Number: 93-25-10 Section: 10 Date: OCT. 1992 Corporate Bulletin No.: 262001 ASE No.: B1 Subject: POP NOISE FROM WINDSHIELD PILLAR AREA Model and Year: 1983-93 S/T TRUCKS REFERENCE COWL "POP" TAPPING NOISE CHEVROLET DEALER SERVICE BULLETIN NUMBER 91-351-10, DATED JUNE 1991. Owners of some 1983-1993 S/T Pickups and Utilities may comment on a cowl "pop" noise transmitted through the "A" pillar. It has been determined that sections other than the windshield cowl area may produce a sound which imitates cowl "pop". PRIOR TO PERFORMING ANY CORRECTION FOR COWL "POP" TAPPING NOISES, VERIFY THE SOURCE OF THE NOISE(S) TO DETERMINE IF IT IS A VALID COWL "POP" CONDITION. Possible noise areas to check are: ^ Instrument panel "pop"/noise. ^ Loose door lock rods. ^ Loose wires/harnesses contacting the wall of the engine/passenger compartment (cowl). ^ A lack of door hinge lubrication. ^ An Electronic Control Module (ECM) bracket "pop". ^ An ash tray rattle. ^ An air vent squeak. ^ Hood hinge "flutter"/rattle. INFORMATION: 1. INSTRUMENT PANEL (I/P) "POP"/NOISE sound at the front edge of the I/P may occur if the I/P pad rubs against the cowl/dash support panel. Refer to "Instrument Panel Pad to Cowl Panel "Pop" Noise" Chevrolet Dealer Service Bulletin Number 92-286-10, dated Sept. 1992. 2. LOOSE DOOR LOCK RODS may vibrate during vehicle operation creating a rattle type noise. Refer to "Front Door Lock Rod Rattle" Chevrolet Dealer Service Bulletin No. 91-406-10, dated August 1991. 3. THE ELECTRONIC CONTROL MODULE (ECM) WIRING HARNESS CLIP may not be properly attached at the transmission bellhousing bolt allowing contact with the floor pan/front of dash area. This sound may be amplified by the HVAC ductwork. 4. LOOSE WIRES/HARNESSES maybe tapping against the engine/passenger compartment wall (cowl). 5. LACK OF DOOR HINGE LUBRICATION - Insufficient lubrication may create a binding/squeaking condition. 6. AN ECM BRACKET "POP" sound may occur if the ECM moves within its mounting bracket. 7. AN ASH TRAY BRACKET RATTLE coming from the ash tray or radio area of the instrument panel may occur if the bracket is loose and vibrating against the I/P. 8. AN AIR VENT "POP" may occur if the louvered vent and A/C duct rub together. 9. HOOD "FLUTTER"/RATTLE may occur if there is movement in the hood hinge attachment to the truck frame. Sound may accompany the hood Page 6602 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) Restraints - Driver/Passenger Seat Head Rest Information Head Restraint System: Technical Service Bulletins Restraints - Driver/Passenger Seat Head Rest Information INFORMATION Bulletin No.: 10-08-50-003A Date: March 24, 2011 Subject: Information on Driver or Passenger Seat Head Restraint Concerns with Comfort, Custom Upholstery or Other Comfort Enhancing Devices Models: 2012 and Prior GM Passenger Cars and Trucks Equipped with Adjustable Head Restraints Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 10-08-50-003 (Section 08 - Body and Accessories). Important ON A GM VEHICLE EQUIPPED WITH ADJUSTABLE HEAD RESTRAINTS, USE THE HEAD RESTRAINT COVERS, FOAM AND OTHER SEAT-RELATED EQUIPMENT AS RELEASED BY GM FOR THAT VEHICLE. DO NOT ALTER OR REPOSITION THE HEAD RESTRAINT SYSTEM. ANY ALTERATIONS TO HEAD RESTRAINTS DEFEATS THE INTENDED DESIGN OF THE SYSTEM. GM WILL NOT BE LIABLE FOR ANY PROBLEMS CAUSED BY USE OF SUCH IMPROPER DESIGN ALTERATIONS, INCLUDING ANY WARRANTY REPAIRS INCURRED. You may have a customer with a concern that the head restraint is uncomfortable or sits too far forward. The front driver and passenger seats are equipped with head restraints that have been designed to help minimize injuries while still providing comfort to the occupants. Each GM vehicle has its own specifically designed head restraint. The head restraints should only be used in the vehicle for which they were designed. The head restraint will not operate to its design intent if the original foam is replaced (1) by non-GM foam or head restraint, (2) by GM foam or head restraint designed for a different vehicle, (3) by GM foam or head restraint that has been altered by a trim shop or (4) if any object, such as an aftermarket comfort enhancing pad or device, is installed. Never modify the design of the head restraint or remove the head restraint from the vehicle as this may interfere with the operation of the seating and restraint systems and may prevent proper positioning of the passenger within the vehicle. Disclaimer Page 4892 Brake Rotor/Disc: Specifications Front Nominal Thickness 1.03 in Minimum Thickness 0.98 in Thickness Variation (Parallelism) 0.0005 in Run Out (TIR) 0.004 in Finish --- A/T - DEXRON III Fluid Introduction Fluid - A/T: All 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 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. Oxygen Sensors - Silica Contamination Oxygen Sensor: 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. Page 5382 Disclaimer Page 7629 AC Delco Service Centers Page 4645 Figure 3 INSTALL (Figures 2 & 3) Tools required: J8092 Drive handle J33790 Bearing installer and remover J33833 Bearing installer and remover 1. Front output bearing (61) to the new front case half P/N 15635347 (45) using J 8092 and J 33833. 2. New front output shaft seal P/N 15579788 (72) to the new front case half (45). 3. Front output bearing retainer ring (snap ring) (60) to the new case half. 4. New input seal P/N 14095609 (42) into retainer (44) if it was removed in step 24 above. 5. Input bearing (40) and input bearing retainer (39) to the new case half using J 36372. 6. Planetary carrier (36) and the input gear (38) to the annulus gear (62) using a soft hammer. 7. Retainer snap ring to the input gear (38). Input bearing retainer (44) and input bearing retainer bolts (43) to the front case half (45). - Clean mating surfaces and apply RTV or equivalent on bearing retainer mating surfaces. NOTE Do not block oil feed hole from case to bearing retainer. - Apply Loctite 242 (R) or equivalent on bearing retainer bolts. - Tighten bolts to 19 N-m (14 lbs.ft.). Page 6047 Wheel Fastener: Specifications Wheel Fastener Tightening Sequence Lug Nut Torque Patterns IMPORTANT Check all parts, including rims, lug studs, lug nuts, and mating surfaces of hubs and tire rims for rust, damage, or dirt. Clean mating surfaces with a wire brush to remove any foreign material. Replace any damaged parts as needed. Careless installation of tire/rim assemblies in a vehicle is a major cause of tire installation problems. Proper installation, including fastener torque, is essential to economical, safe and trouble free service. Use only the proper sizes and types of fasteners for safe and proper service. Tighten the fasteners a quarter turn at a time using the tightening sequence diagram as a guide. This is very important to prevent misalignment of the wheel. Continue tightening the fasteners in sequence until the fasteners are tightened to the proper torque (See WHEEL FASTENER TORQUE). CAUTION: Improper torque or tightening sequence can cause distortion, fatigue cracks, or alignment problems. After driving the vehicle for a short distance, recheck the wheel fastener torque. Parts will usually seat naturally, reducing the torque on the fasteners. Retorque all fasteners to the proper torque. Page 176 Engine Control Module: Description and Operation Throttle Body Fuel Injection Engine Control Module Fig. 5 ECM Unit (Showing PROM & CALPAK Locations) The Electronic Control Module (ECM), located in the passenger compartment, is the control center of the fuel injection system. The ECM continually monitors and processes the input information and generates output commands to the various systems affecting vehicle performance. A removable calibration unit (PROM) enables the ECM to recognize and adjust for vehicle variations (vehicle weight, axle ratio, etc.). There are specific ECM/PROM combinations for each specific vehicle which are not interchangeable, Fig. 4. On V6 models, a CALPAK is also installed in the ECM. The CALPAK allows fuel delivery in the case that other parts of the ECM are damaged, Fig. 5. The ECM also performs the diagnostic function of the fuel injection system. When the ECM senses an operational problem, it will illuminate the "Check Engine" or "Service Engine Soon" light and store the appropriate code(s) to identify the problem area. ECM - Intermittent Connection Engine Control Module: Customer Interest ECM - Intermittent Connection Number: 88-251-8A Section: 8A Date: JUNE, 1988 Subject: INTERMITTENT CONNECTION TO THE ECM Model and Year: 1988 CHEVROLET PASSENGER CARS AND LIGHT DUTY TRUCKS TO: ALL CHEVROLET DEALERS A condition may exist in which the female terminals in the connector to the ECM do not make a solid connection to the male pins in the ECM (see illustration). This can result in an intermittent condition, in any circuit operated by the ECM. The Service Manuals direct a check of connections any time an intermittent condition is found, and this may be the cause of some of these conditions. Visually inspect the terminal using a flashlight, or use a .95 mm pin gauge. The gauge should not pass freely through the female terminal. Do not probe the terminal with anything other than the pin gauge, as probing could damage the terminal. If the female terminal does not grip properly, replace the terminal with P/N 12020757. General directions on wiring repair are shown in Section 8A of the service Manual. Page 6520 Some Chevrolet models may exhibit a condition of poor AM or FM radio reception. This may be caused by a poor contact on the female terminal of the antenna coaxial cable lead. The illustration contains a four-step procedure to test and repair the female terminal. The opening in the female terminal should range from .120" to .125" in diameter. If the gage passes through freely, the terminal should be repaired as illustrated. Gage sets are available from Kent Moore, tool number J26900-14. For warranty purposes use Labor Operation T6369 at .5 hour for all carlines. Page 906 Fluid - A/T: Testing and Inspection Turbo Hydra-Matic 4L60 (700-R4) Check fluid at regular intervals. Noticing a change in color, odor or fluid level can serve as a warning of possible transmission problems. To check fluid level, bring fluid to operating temperature of 200°F. With vehicle on a level surface, engine idling in park and parking brake applied, the level on the dipstick should be at the Full mark. To bring the fluid level from the Add mark to the Full mark requires one pint of fluid. If additional fluid is required, use only Dexron II or Dexron IIE automatic transmission fluid. When adding fluid, do not overfill, as foaming and loss of fluid through the vent may occur as the fluid heats up. Also, If fluid level is too low, complete loss of drive may occur especially when cold, Which can cause transmission failure. Every 100,000 miles, the oil should be drained, the pan removed, the screen should be cleaned or replaced if applicable, and fresh fluid added. For vehicles subjected to more severe use such as heavy city traffic especially in hot weather, prolonged periods of idling or use as a tow vehicle, this maintenance should be performed every 15,000 miles. Page 5028 FIGURE 1 - PARKING BRAKE ADJUSTMENT SERVICE PROCEDURE A (See Figure No. 1) 1. Block the front wheels. 2. Raise and support the rear axle with suitable safety stands. 3. Fully apply parking brake. 4. Remove all brake adjustment by turning adjusting knob (#7) on parking brake lever counter-clockwise until the snap-over-center, when the brake is applied, disappears. Number 1 Cylinder Location Number One Cylinder: Locations Number 1 Cylinder Location NUMBER ONE CYLINDER LOCATION Page 2802 Throttle Position Sensor: Description and Operation Typical Throttle Position Sensor (TPS) Wiring The Throttle Position Sensor (TPS), is mounted on the side of the throttle body opposite the throttle lever assembly. Its function is to sense the current throttle valve position and relay that information to the ECM. Throttle position information allows the ECM to generate the required injector control signals (base pulse). If the TPS senses a wide open throttle, a voltage signal indicating this condition is sent to the ECM. The ECM then increases the injector pulse width, permitting increased fuel flow. As the throttle valve rotates in response to movement of the accelerator pedal, the throttle shaft transfers this rotation to the TPS. A potentiometer (variable resistor) within the TPS assembly changes its resistance (and voltage drop) in proportion to throttle movement. By applying a reference voltage (5.0 volts) to the TPS input, a varying voltage (reflecting throttle position) is available at the TPS output. For example, approximately 2.5 volts results from a 50% throttle valve opening (depending on TPS calibration). The voltage output from the TPS assembly is routed to the ECM for use in determining throttle position. Body - Vehicle Glass Distortion Information Quarter Window Glass: Technical Service Bulletins Body - Vehicle Glass Distortion Information INFORMATION Bulletin No.: 00-08-48-005D Date: September 10, 2010 Subject: Distortion in Outer Surface of Vehicle Glass Models: 2011 and Prior GM Passenger Cars and Trucks 2009 and Prior HUMMER H2 2010 and Prior HUMMER H3 2005-2009 Saab 9-7X 2010 and Prior Saturn Supercede: This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 00-08-48-005C (Section 08 - Body and Accessories). Distortion in the outer surface of the windshield glass, door glass or backlite glass may appear after the vehicle has: - Accumulated some mileage. - Been frequently washed in automatic car washes, particularly "touchless" car washes. This distortion may look like a subtle orange peel pattern, or may look like a drip or sag etched into the surface of the glass. Some car wash solutions contain a buffered solution of hydrofluoric acid which is used to clean the glass. This should not cause a problem if used in the correct concentration. However, if not used correctly, hydrofluoric acid will attack the glass, and over time, will cause visual distortion in the outer surface of the glass which cannot be removed by scraping or polishing. If this condition is suspected, look at the area of the windshield under the wipers or below the belt seal on the side glass. The area of the glass below the wipers or belt seal will not be affected and what looks like a drip or sag may be apparent at the edge of the wiper or belt seal. You may also see a line on the glass where the wiper blade or the belt seal contacts the glass. Important The repair will require replacing the affected glass and is not a result of a defect in material or workmanship. Therefore, is not covered by New Vehicle Warranty. Disclaimer Page 5638 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. Page 1244 Light Duty truck tire rotation recommendations are pictured on the following page. Rotation Guidelines for Tires used on Light Duty Trucks: Tires used on Pickups, Vans and Utility vehicles should be rotated at the first 6,000 miles for Schedule 1 or 7,500 miles for Schedule 2 and then every 15,000 miles thereafter. NOTE: Earlier rotation may be required should irregular wear pafterns develop due to harsh service use - the following rotation patterns are recommended for the various vehicle types and tire combinations. Page 1254 FIGURE 2 Irregular/premature tire wear is aggravated by excessive toe-in (or toe-out). Excessive camber can also be a contributor, as can operating conditions, such as city driving with a lot of cornering. Irregular tire wear usually occurs on non-drive axles, such as the front wheel positions of rear drive vehicles. An early indication may be an increase in tire noise. In most cases, modified "X" tire rotation, which is a scheduled maintenance at 7500 miles, will equalize tire wear (See Figure No. 1). Some amount of wear is expected and should be considered normal. To determine if questionable tires meet the replacement criteria, follow the particular service procedure outlined for that brand tire. Whenever tires are replaced due to vehicle caused premature wear, alignment should be checked and reset to specification if necessary. FIRESTONE AND GOODYEAR IF WITHIN THE NEW VEHICLE WARRANTY PERIOD (12/12): A. Outer shoulder wear has progressed to the point that the outer shoulder is smooth (no tread visible), replace both front tires. B. The outer shoulder tread is visible, use a tread depth gauge (such as provided with Truck Service Bulletin 86-B-94) to determine the extent of the wear. Measurements must be made in a full depth tread groove shown in Figure No. 2. If tread depth is 5/32" or less, tire replacement will be necessary. It should be noted that at 5/32" tread depth the tire is normally only half worn in this area. If greater than 5/32", the tires should be rotated using the modified "X" pattern (See Figure No. 1). This method will best equalize wear after a few thousand miles. Specifications Oil Pan: Specifications Oil Pan Bolts 8.3 ft.lb Oil Pan Nuts 16.5 ft.lb Oil Pan Studs To Oil Seal Retainer Or Crankcase 1-2 ft.lb Page 6874 10. Drive the door frame (the second layer of sheet metal) down with a punch approximately 1/4" all the way around the hole. 11. Paint the bare metal edges left from cutting the hole with a zinc rich primer. 12. Completely fill the hole with black RTV, GM P/N 1052917, or equivalent and level for good adhesion and appearance. 13. Follow Steps 6-12 on each side of the vehicle. 14. Reinstall the hood hinge seals in their original position to prevent water leakage into the cowl. If it is necessary, additional adhesive (3M weather strip adhesive P/N 08001 or equivalent) should be used to secure the hood hinge seal. 15. Reinstall the windshield washer hose, cowl vent panel, radio antenna, and windshield wipers, and remove the protective tape from the fender and cowl vent panel. A/T - Buzzing Noise at Idle Fluid Pressure Sensor/Switch: All Technical Service Bulletins A/T - Buzzing Noise at Idle Number: 93-29-7A Section: 7A Date: OCT. 1992 Corporate Bulletin No.: 277142 ASE No.: A2 Subject: BUZZING NOISE AT IDLE Model and Year: 1982-93 CAPRICE, CAMARO AND CORVETTE 1982-93 C/K, R/V, S/T, M/L AND G TRUCKS WTIH 4L60 AUTOMATIC TRANSMISSION TRANSMISSION APPLICATIONS: 1982-1993 HYDRA-MATIC 4L60 (MD8) TRANSMISSION MODELS: All SUBJECT: Pressure Regulator Valve Buzz VEHICLE APPLICATIONS: B, D, F, Y - Cars C/K, R/V, S/T Trucks G, M, L - Vans CONDITION: Some 1982-1993 vehicles equipped with a HYDRA-MATIC 4L60 transmission may have a buzzing noise coming from the transmission when the vehicle is at idle. The buzzing noise may be noticed more when the vehicle is in reverse at idle. CAUSE: The buzzing noise may be a result of pressure regulator valve oscillating due to oil pressure instability at lower idle RPM. CORRECTION: Page 5102 Symbol Identification Page 1107 Brake Bleeding: Fundamentals and Basics BENCH BLEEDING Why A master-cylinder will develop little or no pressure if air is trapped in cylinder bore. Normal brake bleeding will not remove air trapped within the master-cylinder. How Clamp the master-cylinder securely in a vice. It is usually best to clamp the side of the vice onto the flat surface that is used to secure the master-cylinder to the brake booster. There are two basic methods for bleeding master-cylinder, one utilizes stroking the master-cylinder to expel air from the cylinder bore while the other utilizes a large syringe to backflush fluid from the outlet ports to the reservoir. Stroking Fill the master-cylinder with clean brake fluid. - The brake line fittings on the master-cylinder should be capped or plugged. NOTE: Special "bench bleeding" plastic fittings are available which allow for recirculating the brake fluid back into the reservoir. - Using a dull object, slowly stroke the master-cylinder piston, air and brake fluid will be expelled from the brake line fittings. Prior to releasing the piston plug or cap the outlet ports. - Repeat this procedure 8-10 times or until no air is emitted from the outlet ports. - When finished, cap the outlet ports and install the master-cylinder. Syringe Fill the syringe (one especially designed for brake bleeding) with clean brake fluid. - Insert the end of the syringe into one of the outlet ports on the master-cylinder. - Slowly compress the syringe and back flush the brake fluid through the master-cylinder. - A combination of air and brake fluid will be emitted from the inlet port in the fluid reservoir. - Repeat this procedure until only brake fluid is emitted into the reservoir. Cap the outlet ports and install the master-cylinder. Page 2622 Wiring Diagram For Chart C-1D - Manifold Absolute Pressure (MAP) Output Check CHART C-1D - MANIFOLD ABSOLUTE PRESSURE (MAP) OUTPUT CHECK Circuit Description: The Manifold Absolute Pressure (MAP) sensor measures manifold pressure (vacuum) and sends that signal to the ECM. The MAP sensor is mainly used for fuel calculation, when the ECM is running in the throttle body backup mode. The MAP sensor is also used to determine the barometric pressure and to help calculate fuel delivery. Test Description: Numbers below refer to circled numbers on the diagnostic chart. 1. Checks MAP sensor output voltage to the ECM. This voltage, without engine running, represents a barometer reading to the ECM. 2. Applying 34 kPa (10" Hg.) vacuum to the MAP sensor should cause the voltage to be 1.2 - 2.3 volts less than the voltage at Step 1. 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 no other vacuum devices are connected tot he MAP hose. Generator Light - Flickers During Pulse Wiper Use Charge Lamp/Indicator: Customer Interest Generator Light - Flickers During Pulse Wiper Use Number: 90-84-8A Section: 8A Date: November 1989 Corporate Bulletin No: 966402 Subject: GENERATOR LIGHT FLICKER DURING PULSE WIPER OPERATION Model and Year: 1988-89 S, T TRUCKS WITH 2.8L OR 4.3L (VIN CODES R, Z) ENGINES TO: ALL CHEVROLET DEALERS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 89-219-8A, DATED JULY 1989. THE 1990 MODEL S/T VEHICLES ARE INCLUDED IN THE LATEST BULLETIN ALONG WITH A CORRECTION TO THE ELECTRICAL CONNECTOR NUMBER. ALL COPIES OF 89-219-8A SHOULD BE DISCARDED. The generator light flicker condition during pulse wiper switch operation in the 1988, 1989 and 1990 S/T instrument panel, with standard cluster, can be caused by negative voltage transients from the wiper motor. There is no possibility of a system failure as a result of this condition. The effect of this condition is that the generator light will turn on for 80 milliseconds (if gages, the voltage drop on the voltmeter lasts 2.5 seconds). This causes no harm to the generator or other electrical components. Subject condition can be eliminated by installing a diode (industry part number 1N4003) or diode/connector kit (diode kit part number 12085207) in the brown wire at the generator connector (circuit 25 at connector C118). See the following pages in the 1988, 89 and 90 S/T Electrical Wiring Diagrams for circuit 25, connector C118 locations: 1988 4.3L: Section C - Page 24 1988 2.8L: Section C - Page 22 1989 4.3L: Page 40 1989 2.8L: Page 39 1990 2.8L: Page 44 1990 4.3L: Page 45 PARTS INFORMATION: Quantity Part Number Description 1 12085207 Diode ----OR---1 *1N4003 Diode * This part available locally. Parts are currently available from GMSPO. INSTALLATION PROCEDURE: 1. Disconnect the battery. 2. Remove the connector from the generator. 3. Peel back the black plastic conduit covering the wires. 4. If installing diode 1N4003: cut out a section of the brown wire that matches the length of the diode. 4A. A diode/connector kit is also available (GMSPO diode kit part number 12085207). If using the kit cut out approximately four inches of the brown wire, following crimping and soldering instructions in the kit. Spiral tape the solder joints and tuck the wire back into the conduit away from the generator. Secure the diode/connector to the outside of the conduit with electrical tape. 5. Solder in diode with the banded end toward the generator. Page 5053 Fig. 6 Spool Valve, Power Piston/Accumulator & Seal, Assembly & Disassembly Refer to Figs. 5 and 6 for disassembly and assembly of Hydro-Boost II unit. or accumulator service, refer to HYRO-BOOST ACCUMULATOR. CLEANING/INSPECTION Keep all disassembled parts clean until assembly. Lubricate all seals and metal friction points with power steering fluid. When unit is disassembled, all seals and tube inserts should be replaced. These parts are available in replacement kits. If any accumulator valve components are damaged or lost, replace all valve components. 1. Inspect spool valve and spool valve bore for corrosion, nicks, scoring or other damage. Discoloration of the spool or bore, particularly in the groove areas, is not harmful and replacement is not necessary. 2. If spool valve or bore has nicks or scoring that can be felt with a fingernail, the entire booster should be replaced as an assembly. The clearance between the spool valve and the spool valve bore is important. Because of this clearance, the spool valve and the housing make up a selective assembly. The spool valve is selected to match the spool valve bore. 3. Inspect piston for scratches and nicks. If scratches on the outside surface can be felt with a fingernail, replace piston. Page 7769 e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors Do Not require all the steps shown. Skip the steps that Do Not apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. 1. Separate connector halves (see Figures 2 through 6). Figure 2 Figure 3 Page 584 Alignment: Service and Repair Ride/Trim Height Measurement and Adjustment Measuring "Z" Height - 2WD Models Measuring "Z" Height - 4WD Models "Z" Height Adjustment - 4WD Models Locations Rear LH Corner Of Engine Compartment. Page 3108 Oil Pressure Switch (For Fuel Pump): Description and Operation As a back-up system to the fuel pump relay, the fuel pump can also be turned ON by the oil pressure switch. The oil pressure switch is a normally open switch which closes when oil pressure reaches about 28.0 kPa (4.0 psi). If the fuel pump relay fails, the oil pressure switch will power the fuel pump. Page 8157 Wiper Switch: Testing and Inspection Fig. 3 Permanent Magnet Type Windshield Wiper Motor W/Pulse Wipers 1. Disconnect electrical connectors from wiper motor. 2. Check switch voltage using a digital voltmeter with ignition switch in the On position. If readings are not as specified at between various switch positions and ground, replace switch. Specifications Lifter / Lash Adjuster: Specifications Vin Z, Lifter Dimensions Vin Z, Lifter Dimensions Lifter Diameter 0.8420-0.8427 in Lifter To Bore Clearance 0.0008-0.0025 in 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. Page 7176 * Select applicable additional "Labor Hours" and add to above "Labor Hours" as needed. Page 5694 Fig. 1 Troubleshooting power steering system Page 8072 Figure 2 Page 5852 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 Page 2391 Wiring Diagram For Chart C-5 - Electronic Spark Control System Check CHART C-5 - ELECTRONIC SPARK CONTROL SYSTEM CHECK Circuit Description: Electronic spark control is accomplished with a module that sends a voltage signal to the ECM. As the knock sensor detects engine knock, the voltage from the ESC module to the ECM is shut "OFF" and this signals the ECM to retard timing, if engine RPM is over about 900. Test Description: Numbers below refer to circled numbers on the diagnostic chart. 1. If A Code 43 is not set, but a knock signal is indicated while running at 1500 RPM, listen for an internal engine noise. Under a no load condition there should not be any detonation, and if knock is indicated, an internal engine problem may exist. 2. Usually a knock signal can be generated by tapping on the right exhaust manifold. This test can also be performed at idle. Test number 1 was run at 1500 RPM to determine if a constant knock signal was present, which would affect engine performance. 3. This tests whether the knock signal is due to the sensor, a basic engine problem, or the ESC module. 4. If the module ground circuit is faulty, the ESC module will not function correctly. The test light should light indicating the ground circuit is OK. 5. Contacting CKT 496, with a test light to 12 volts, should generate a knock signal to determine whether the knock sensor is faulty, or the ESC module can't recognize a knock signal. Diagnostic Aids: "Scan" tools have two positions to diagnose the ESC system. The knock signal can be monitored to see if the knock sensor is detecting a knock condition and if the ESC module is functioning, knock signal should display "yes", whenever detonation is present. The knock retard position on the "Scan" displays the amount of spark retard the ECM is commanding. The ECM can retard the timing up to 20 degrees. This check should be used after other causes of spark knock have been checked such as engine timing, EGR systems, engine temperature or excessive engine noise. Page 7952 Symbol Identification Wire Color Code Identification WIRE COLOR ABBREVIATION BLACK BLK BLUE BLU DARK BLUE DK BLU Wheels - Sealing Leaking Cast Aluminum Wheels: All Technical Service Bulletins Wheels - Sealing Leaking Cast Aluminum Bulletin Number: 93-3-16 Reference Number: 393504 Publish Date: 7/93 Subject: LEAKING CAST ALUMINUM WHEELS (REPAIR WITH ADHESIVE SEALANT) Models Affected: 1985-1993 ALL MODELS Should a vehicle equipped with cast aluminum wheels exhibit a slow leak due to a porous condition existing in the wheel, the wheel can be repaired by using Dow Corning Silastic 732 RTV, p/n 1052366 or equivalent, as described in the following procedure: 1. Remove tire-wheel assembly from vehicle. 2. Locate leaking area by inflating tire to 40 psi and dipping tire-wheel assembly in water bath. 3. If air bubbles are observed, mark leak area and remove tire from wheel. 4. Scuff INSIDE rim surface at leak area with # 80 grit paper and clean area with general purpose cleaner, such as 3M # 08984. 5. Apply 1/8" thick layer of adhesive/sealant to leak area on INSIDE of rim and allow six hours of drying time. 6. Mount tire on wheel, pressurizing to 40 psi and check for leaks. NOTICE: Caution must be used when mounting the tire so as not to damage the sealer. 7. Adjust tire pressure to meet placard specification. 8. Balance tire-wheel assembly, using proper coated weights. 9. Water test wheel again. 10. Reinstall tire-wheel assembly on vehicle. Parts are currently available from GMSPO. WARRANTY INFORMATION: Labor Operation Number: E0420 Page 4318 Page 5008 Brake Master Cylinder: Tools and Equipment BASIC SERVICE (Removal and Installation) - Fender cover (servicing and bleeding a master-cylinder can be a messy process) CAUTION: DOT 3 or 4 brake fluid is very corrosive to the vehicles finish and electrical connections. - Drip pan. - Complete set of combination wrenches or sockets. - Bleeding device: - Pressure bleeder or - Vacuum bleeder or - One-man brake bleeder kit or - Length of clear plastic hose (3/16 inch ID) and a glass jar. Brake Bleeding Setup - Small ruler or depth gauge (for adjusting the pushrod) - Brake adjusting tool (rear brake adjustment should be checked) - Clean shop towels. OPTIONAL - Master Cylinder bleeding kit (contains plastic fittings and hoses used for bleeding master cylinders) - Suction bulb (for removing brake fluid from reservoir) IF MASTER-CYLINDER IS OVERHAULED - Snap-ring pliers - Small pry bar (for separating the reservoir from the cylinder) - Cylinder hone (cast iron cylinders only) - Feeler gauges (for checking piston to cylinder clearance). Specifications Harmonic Balancer - Crankshaft Pulley: Specifications Torsional Damper Bolt 70 ft.lb Page 3517 FIGURE 2 DATE OF PRODUCTION CHANGE: (Figure No. 1) Beginning January 5, 1987 (Julian date 005) THM 700-R4 transmissions were built with the new servo apply pin (Figure No. 2). SERVICE ACTION: The new second servo apply piston pin (Figure No. 2) can be used on all 1982-1988 THM 700-R4 transmissions. NOTICE: If a past design second servo apply pin is used on a THM 700-R4 transmission, seal rings must be installed. SERVICE PARTS INFORMATION: SECOND SERVO APPLY PIN PART NUMBER DESCRIPTION PIN LENGTH 8667571 Pin Second Apply 66.37-66.67 mm (2.61" - 2.62") (2 IDENTIFICATION RINGS) 8667572 Pin Second Apply 66.74-68.04 mm (2.67" - 2.68") (3 IDENTIFICATION RINGS) 8667573 Pin Second Apply 69.11 -69.41 mm (2.72" - 2.73") (WIDE BAND) Page 1993 Coolant: Technical Service Bulletins Coolant - Used Anti-Freeze Policy Number: 91-09-0A Section: OA Date: April 1990 Corporate Bulletin No.: 976202 Subject: INFORMATION REGARDING RECONSTITUTED ANTI-FREEZE COOLANT TESTING AND THE USE OF A REFRACTOMETER Model and Year: ALL MODELS AND YEARS TO: ALL CHEVROLET DEALERS RECONSTITUTED ANTIFREEZE At present, three types of recycling systems are available: 1) chemical addition to coolant; 2) filtration and addition of supplemental additives; and 3) separation of pure glycol from used coolant and reinhibition. 1) Chemical Addition-NOT RECOMMENDED With chemical addition, chemicals are added to the used engine coolant in an attempt to "clean up" the coolant. This system is the easiest since the only work involved is the addition of chemicals to the radiator. Most of these types of recycling systems use a strong acid to change precipitated corrosion products into a more soluble form. However, in addition to dissolving the corrosion products, the strong acid also attacks and corrodes the metals of the cooling system. 2) Filtration and Addition of Supplemental Additives-NOT RECOMMENDED In this type of system, the used coolant is either taken out of the vehicle or a flush-type unit is connected to the cooling system. The current technology consists simply of filtration and reinhibition of the spent coolant. While this does remove suspended solids, filtration does nothing to remove harmful degradation and corrosion products that are soluble in glycol solution. The reinhibition step used in current recycling systems may fail to produce a coolant which adequately protects all metals including aluminum in the most critical heat transfer applications, such as occurs in the cylinder heads and blocks. 3) Separation of Pure Glycol and InhibitionThe separation of pure glycol and the addition of fresh inhibitors is the ideal method for recycling coolants. Unfortunately, this method is expensive from both a collection standpoint and the technology available to economically extract pure ethylene glycol from used coolant. At this time, General Motors does not endorse these practices or equipment. Due to a worldwide shortage of ethylene glycol in 1988, some coolant manufacturers have started to mix other types of glycol in their coolant formulations; propylene glycol is the most common new ingredient. A hydrometer will not provide a correct measurement of freeze protection when anything other than ethylene glycol and water is being tested. The degree of inaccuracy will vary depending on the proportion of other glycols present in the coolant. Hydrometers test the amount of glycol in a mixture by measuring the specific gravity of the mixture; the more ethylene glycol, the higher the float balls go, and the better the freeze protection. Because ethylene glycol and propylene glycol do not have the same specific gravities, hydrometer readings of mixtures containing propylene glycol give incorrect values. As the shortage of ethylene glycol continues and/or worsens, more and more variations in antifreeze formulas will be marketed. It is, therefore, recommended that you purchase a "refractometer" and encourage your technicians to use it. Refractometers test for the amount of glycol in a coolant mixture by measuring the speed of light as it passes through the fluid and are not affected by the specific gravity of the glycol. The freeze protection of solutions of ethylene glycol in water, solutions of propylene glycol in water, and solutions of mixtures of propylene glycol and ethylene glycol in water may all be tested with sufficient accuracy using a refractometer. The following refractometers are available from Kent Moore: J 23688 Farenheit scale, measures to -50 F J 26568 Centigrade scale, measures to -45.5 C J 38633 Farenheit scale, measures to -84 F (For extreme cold weather regions) Page 976 T7251 Group A 3.2 hr. T7261 Group B 2.8 hr. NOTE: Labor Operation is coded to base vehicle coverage in the warranty system. Page 1499 Crankshaft: Specifications Bearing Clearance Bearing Clearance Main Bearings Production Front 0.0008-0.0020 in Intermediate 0.0011-0.0023 in Rear 0.0017-0.0032 in Service Front 0.0010-0.0015 in Intermediate 0.0010-0.0025 in Rear 0.0025-0.0035 in Connecting Rod Bearings Production 0.0013-0.0035 in Service 0.0020-0.0030 in Thrust Bearing 0.002-0.007 in Page 6010 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 Locations Timing Connector-In Pass Comp Behind Carpet, Below Heater Page 720 BELT TENSION Fuel - Use of Gasoline Containing 15 Percent MTBE Fuel: All Technical Service Bulletins Fuel - Use of Gasoline Containing 15 Percent MTBE Number: 89-268-08 Section: 0B Date: October 1989 Corporate Bulletin No.: 930108 Subject: USE OF GASOLINE CONTAINING 15 PERCENT MTBE Model and Year: ALL 1980-89 PASSENGER CARS AND LIGHT DUTY TRUCKS TO: ALL CHEVROLET DEALERS In August of the U.S. Environmental Protection Agency approved the use of methyltertiary-butyl ether (MTBE) in gasolines at concentrations of 15 percent or Prior to that time, the legal limit was 11 percent; Generai Motors owners manuals stated that the use of gasolines containing 11 percent or less MTBE should not adversely affect the operation of the vehicle and would be covered by the New Vehicle and Emission Control Systems Warranties. The use of 15 percent MTBE in gasoline should also not adversely affect the operation of 1989 and earlier model vehicles and therefore, will not void any warranties covering those vehicles. In the interest of contributing to cleaner air, General Motors recommends that all model year vehicles use such fuels whenever available. The 1990 and future owners manuals will reflect this position. Page 2842 FIGURE 1(T-TRUCK ONLY) G. (T-truck only) Check equalizer lever for firm contact at the shift lever inboard side of the guide slot. (See Figure 1) H. If firm contact is evident, add an additional washer (#10 in Figure #1) P/N 14074908 to adjust equalizer lever outboard toward the center of the guide slot to eliminate contact. 2. A. Raise vehicle on hoist. B. Note location of clamp rotation on pipe. Some clamps are located with the lower lock ring (nuts) pointed towards the transmission. If the clamp is located in such a manner, loosen clamp and rotate it down so the nuts point toward the ground and retighten to 58 N-m (43 ft/lbs.) 3. A. Loosen converter clamp until it will rotate around the pipe. Using a suitable pry bar, move exhaust system rearward to obtain a minimum of 5/8 in. clearance between any point on the exhaust system and the transmission crossmember. For repairs performed under warranty, use the following labor operations and times: Labor Operation Labor Time Exhaust/muffler clamp L2020 .3 Hr Exhaust system align L2004 .3 Hr Shift Linkage (shorten) K5244 .3 Hr Page 1106 Brake Bleeding: Service and Repair Master Cylinder Bleeding THIS PROCEDURE CAN BE PERFORMED WITH MASTER CYLINDER ON OR OFF VEHICLE. 1. Disconnect brake lines at master cylinder, if necessary. 2. Connect suitable lengths of brake lines to master cylinder and immerse other ends of lines in master cylinder reservoirs. 3. Apply master cylinder pushrod or brake pedal with full strokes until air bubbles have disappeared in reservoirs. It may require 20-30 applications to fully eliminate air bubbles. 4. Remove bleeding lines from master cylinder, then install master cylinder on vehicle, if necessary, and connect brake lines. 5. Fill the reservoir. Normal bleeding procedures should be followed after the master cylinder is installed. For additional information see Bench Bleeding Notes. See: Brakes and Traction Control/Hydraulic System/Brake Master Cylinder/Fundamentals and Basics A/T - DEXRON(R)-VI Fluid Information Fluid - A/T: All 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. Page 3125 Throttle Body: Service and Repair Fuel Meter Body Fuel Meter Body Assembly REMOVAL: 1. Disconnect electrical connections to fuel injectors. (Squeeze plastic tabs and pull straight up.) 2. Remove fuel meter cover assembly, refer to FUEL METER COVER ASSEMBLY. 3. Remove fuel injectors, refer to FUEL INJECTOR ASSEMBLIES. 4. Disconnect fuel inlet and outlet lines. Discard O-rings. 5. Remove fuel inlet and outlet nuts and gaskets from the fuel meter body assembly. Discard gaskets. NOTE: Note locations of nuts, for proper reassembly later. Inlet nut has a larger passage than outlet nut. 6. Remove fuel meter body to throttle body attaching screw assemblies. 7. Remove fuel meter body assembly from throttle body assembly. 8. Remove throttle body to fuel meter body gasket and discard. INSTALLATION: 1. Install new throttle body to fuel meter gasket. Match cut-out portions in gasket with openings in throttle body. 2. Install fuel meter body assembly on throttle body assembly. 3. Install fuel meter body-to-throttle body attaching screw assemblies, precoated with appropriate locking compound. Tighten screw assemblies to 4.0 Nm (30.0 lb-in). 4. Install fuel inlet and outlet nuts with new gaskets to fuel body assembly. Tighten inlet nut to 40.0 Nm (30.0 lb-ft)., outlet nut to 29.0 Nm (21.0 lb-ft). 5. Reconnect fuel inlet and return lines and new O-rings. (Use back-up wrench to keep TBI nuts from turning. Tighten fuel lines to 23.0 Nm (21.0 lb-ft). 6. Install injectors, with new upper and lower O-rings in fuel meter body assembly. 7. Install fuel meter cover gasket, fuel meter outlet gasket, and pressure regulator seal. 8. Install fuel meter cover assembly. 9. Install long and short fuel meter cover attaching screw assemblies, coated with appropriate compound. Tighten screw assemblies to 3.0 Nm (27.0 lb-in). Page 6921 Power Door Locks Wiring Circuit Page 5293 Warranty Information (excluding Saab U.S. Models) For vehicles repaired under warranty, use the appropriate labor operation for the source of the water leak Warranty Information (Saab U.S. Models) For vehicles repaired under warranty, use the table. Disclaimer Page 4069 Figure 2 2. To verify that the spacer plate is peening evenly and the ball is sealing correctly, seat the check-ball on the spacer plate. Shine a beam of light on the opposite side and inspect for light between the spacer plate and check-ball (see Figure 2). No trace of light should be present. If light can be seen, a proper seal does not exist, and the spacer plate must be replaced. Service Manual Reference: Refer to the HYDRA-MATIC Automatic Transaxle/Transmission Diagnosis or Unit Repair section of your service manual for proper check-ball locations and functions. Door Locks - Binding or Sticking or Key Hard to Insert Door Lock Cylinder: All Technical Service Bulletins Door Locks - Binding or Sticking or Key Hard to Insert Number: 93-133-10 Section: 10 Date: MARCH 1993 Corporate Bulletin No.: 1341070R ASE No.: B1 Subject: DOOR LOCK CYLINDERS (RECOMMENDED LUBRICATION) Model and Year: ALL 1993 AND PREVIOUS MODEL CARS AND TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN 92-41-10, DATED NOV. 1991. THE 1993 MODEL YEAR HAS BEEN ADDED AS WELL AS A NOTE. PLEASE DISCARD ALL COPIES OF 92-41-10. Customer comments of binding/sticking door lock cylinders, or keys that are hard to insert or extract may be corrected in many cases by applying the proper lubrication. The recommended materials for lubricating these components are (in order of preference): - GM # 12345120 Multi purpose lubricant (9 oz. spray) or # 12345121 (12 oz.). - 5 W 30 Motor Oil - GM # 1052276 or 1052277 spray type Silicone (4.5 oz. or 12 oz. cans). Penetrating oil type lubricants (such as GM # 1052949 or 1052950, WD-40 lubricants) ARE NOT RECOMMENDED because they wash out the original lubrication and eventually evaporate, leaving little or no lubricating material. However, if these type materials are used to "unfreeze" or loosen lock cylinder components, refer to steps 2 through 4 listed below for the proper methods of lubricating. NOTE: DO NOT REPLACE THE DOOR LOCK CYLINDERS UNTIL AFTER THE LUBRICATING MATERIALS HAVE BEEN USED AND THE CYLINDER REMAINS FROZEN/BOUND. If door lock cylinders require replacement for any reason, apply a coating of GM # 12345120 Multi purpose Lubricant to the inside of the lock case and the cylinder keyway prior to assembling and installing the cylinder. Parts are currently available from GMSPO. Frozen cylinders due to cold weather may be repaired using the following procedure: 1. Apply heat to the cylinder area with a heat gun while being careful not to damage the painted surfaces. 2. Hold the shutter door open with a paper clip (or similar item) and force air into the cylinder using compressed air and a blow gun attachment. 3. While holding the shutter door open, inject a small amount of lubricant (see above recommendations) into the cylinder. 4. Work the key into the cylinder several times and wipe any excess lubrication residue from the key. Use applicable Labor Time Number and Time allowance. Page 6245 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 Page 2389 Knock Sensor: Description and Operation Knock Sensor Operation ESC Wiring Diagram The Electronic Spark Control (ESC) system is comprised of a knock sensor, the ESC module, and the ECM. As the knock sensor detects engine knock, it sends a voltage signal to the ECM. The ECM responds by retarding the ignition timing until the knocking ceases. As detonation is reduced, the ECM advances the timing again in small increments back to the pre-programmed point for that engine speed and load. Page 6297 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 Page 5120 LIGHT BLUE LT BLU BROWN BRN GRAY GRY GREEN GRN DARK GREEN DK GRN LIGHT GREEN LT GRN ORANGE ORN PINK PNK PURPLE PPL RED RED TAN TAN WHITE WHT YELLOW YEL Specifications Distributor: Specifications Distributor Hold-down Clamp Bolt ............................................................................................................................................................. 27 Nm (20 lb-ft) Page 1680 e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors Do Not require all the steps shown. Skip the steps that Do Not apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. 1. Separate connector halves (see Figures 2 through 6). Figure 2 Figure 3 A/T - Buzzing Noise at Idle Fluid Pressure Sensor/Switch: Customer Interest A/T - Buzzing Noise at Idle Number: 93-29-7A Section: 7A Date: OCT. 1992 Corporate Bulletin No.: 277142 ASE No.: A2 Subject: BUZZING NOISE AT IDLE Model and Year: 1982-93 CAPRICE, CAMARO AND CORVETTE 1982-93 C/K, R/V, S/T, M/L AND G TRUCKS WTIH 4L60 AUTOMATIC TRANSMISSION TRANSMISSION APPLICATIONS: 1982-1993 HYDRA-MATIC 4L60 (MD8) TRANSMISSION MODELS: All SUBJECT: Pressure Regulator Valve Buzz VEHICLE APPLICATIONS: B, D, F, Y - Cars C/K, R/V, S/T Trucks G, M, L - Vans CONDITION: Some 1982-1993 vehicles equipped with a HYDRA-MATIC 4L60 transmission may have a buzzing noise coming from the transmission when the vehicle is at idle. The buzzing noise may be noticed more when the vehicle is in reverse at idle. CAUSE: The buzzing noise may be a result of pressure regulator valve oscillating due to oil pressure instability at lower idle RPM. CORRECTION: Page 3170 Wiring Diagram For Chart C-5 - Electronic Spark Control System Check CIRCUIT DESCRIPTION: Electronic spark control is accomplished with a module that sends a voltage signal to the ECM. As the knock sensor detects engine knock, the voltage from the ESC module to the ECM is shut "OFF" and this signals the ECM to retard timing, if engine RPM is over about 900. TEST DESCRIPTION: Numbers below refer to circled numbers on the diagnostic chart. 1. If A Code 43 is not set, but a knock signal is indicated while running at 1500 RPM, listen for an internal engine noise. Under a no load condition there should not be any detonation, and if knock is indicated, an internal engine problem may exist. 2. Usually a knock signal can be generated by tapping on the right exhaust manifold. This test can also be performed at idle. Test number 1 was run at 1500 RPM to determine if a constant knock signal was present, which would affect engine performance. 3. This tests whether the knock signal is due to the sensor, a basic engine problem, or the ESC module. 4. If the module ground circuit is faulty, the ESC module will not function correctly. The test light should light indicating the ground circuit is OK. 5. Contacting CKT 496, with a test light to 12 volts, should generate a knock signal to determine whether the knock sensor is faulty, or the ESC module can't recognize a knock signal. DIAGNOSTIC AIDS: "Scan" tools have two positions to diagnose the ESC system. The knock signal can be monitored to see if the knock sensor is detecting a knock condition and if the ESC module is functioning, knock signal should display "yes", whenever detonation is present. The knock retard position on the "Scan" displays the amount of spark retard the ECM is commanding. The ECM can retard the timing up to 20 degrees. This check should be used after other causes of spark knock have been checked such as engine timing, EGR systems, engine temperature or excessive engine noise. Page 5608 Alignment: Description and Operation Toe In/Out Description Camber Description Caster Description Page 5764 15. Insert a drift-through brake caliper to prevent drive axle from turning and torque inboard flange bolts to 80 N-m (60 lbs.ft.). 16. Torque hub nut to 220-270 N-m (162-199 lbs.ft.). 17. Attach retainer. 18. Align cotter pin hole with retainer slot by rotating retainer. Important: DO NOT back off or tighten hub nut more than specified to install cotter pin. 19. Install new cotter pin. Cotter pin must be bent so retainer is held snugly to prevent rattling. 20. Remove drift, install wheels, and lower vehicle. Service Parts Information: Part Number Description Quantity Required 26027964 Seal Kit, Tripot 1 per side Parts are expected to be available on June 17, 1991. Until then, normal part orders will not be accepted by GMSPO. Only verifiable emergency VIP orders will be accepted. GMSPO will make every effort to obtain parts. All parts will be placed on 400 control to waive VIP surcharges. However, the parts will be shipped premium transportation at dealer's expense. All other order types will be cancelled as incorrectly ordered while 400 control is in place. Warranty Information: For Vehicle repaired under warranty use: Labor Operation: T7271 Labor Time: 1.6 hrs. each side Trouble Code: 92 Page 2483 Distributor: Description and Operation Typical Distributor Components The distributor has a separate coil which connects to the rotor through a high tension wire. The distributor uses a magnetic pick-up assembly located inside the distributor consists of a permanent magnet, a pole piece with internal teeth, and a pick-up coil. When the teeth of the timer core, rotating inside the pole piece, line up with the teeth of the pole piece, an induced voltage in the pick-up coil signals the electronic module to trigger the coil primary circuit. The primary current decreases and a high voltage of 35,000 volts is induced in the ignition coil secondary winding which is directed through the rotor and secondary leads to fire the spark plugs. The capacitor in the distributor is for radio noise suppression. This distributor also features a longer spark duration, made possible by the higher amount of energy that is stored in the coil. This is desirable for firing leaner mixtures. Page 2642 Oxygen Sensor: Specifications Oxygen Sensor 30 ft.lb Page 4254 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. Page 3110 Oil Pressure Switch (For Fuel Pump): Service and Repair REMOVAL: 1. Disconnect negative battery cable from battery. 2. Remove sensor or switch connectors. 3. Remove sensor or switch. INSTALLATION: 1. Install sensor or switch. 2. Connect sensor or switch. 3. Reconnect negative battery cable. Page 2185 FIGURE 1(T-TRUCK ONLY) G. (T-truck only) Check equalizer lever for firm contact at the shift lever inboard side of the guide slot. (See Figure 1) H. If firm contact is evident, add an additional washer (#10 in Figure #1) P/N 14074908 to adjust equalizer lever outboard toward the center of the guide slot to eliminate contact. 2. A. Raise vehicle on hoist. B. Note location of clamp rotation on pipe. Some clamps are located with the lower lock ring (nuts) pointed towards the transmission. If the clamp is located in such a manner, loosen clamp and rotate it down so the nuts point toward the ground and retighten to 58 N-m (43 ft/lbs.) 3. A. Loosen converter clamp until it will rotate around the pipe. Using a suitable pry bar, move exhaust system rearward to obtain a minimum of 5/8 in. clearance between any point on the exhaust system and the transmission crossmember. For repairs performed under warranty, use the following labor operations and times: Labor Operation Labor Time Exhaust/muffler clamp L2020 .3 Hr Exhaust system align L2004 .3 Hr Shift Linkage (shorten) K5244 .3 Hr Page 512 Fluid Pressure Sensor/Switch: Specifications 4L60 - 700R4 Transmission Pressure Switches ............................................................................................................................... ....................................................................... 8 ft. lbs. Diagram Information and Instructions License Plate Lamp: Diagram Information and Instructions 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 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. Page 6284 ^ 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. Page 3582 Page 7051 1. Wash the subject panel with water to remove any foreign material such as dirt, grit, etc. 2. Wet sand subject panel with 3M Micro fine 1500 grit sandpaper, P/N 2023 or equivalent. Wrap the sandpaper around a 3M rubber sponge back up pad, P/N 5530, to prevent leaving finger marks in the clearcoat. NOTE: Always sand the length of the panel and use a mild dish soap detergent in the wet sand operation for sandpaper lubricant. 3. Wheel compound sanded panel with 3M Finesse it II, P/N 5928, polishing compound and 3M Super Buff Polishing Pad, P/N 5705 or equivalent. 4. Swirl marks, left in the clearcoat, can be removed by rebuffing the affected area with a non-directional, dual action (D.A.) orbital sander. A clean terry cloth polishing bonnet and 3M Finesse II compound should be used. CAUTION: Buffing wheels are not recommended for routine new car pre-delivery preparation of basecoat/ clearcoat finishes. 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. A/T - THM 700-R4 New Harness/Solenoid Assembly Shift Solenoid: Technical Service Bulletins A/T - THM 700-R4 New Harness/Solenoid Assembly Number: 88-335-7A Section: 7A Date: SEPT., 1988 Subject: SERVICE MANUAL UPDATE: NEW SOLENOID ASSEMBLY AND WIRING HARNESS Model and Year: 1988 C, K, R, V, S, T, G SERIES TRUCKS WITH THM 700-R4 TO: ALL CHEVROLET DEALERS This bulletin covers the introduction of a new Solenoid Assembly and Wiring Harness (Type 18) and new Control Valve Assembly for some 1988 THM 700-R4 models (refer to models listed below). Transmission Models: MAM, MDM, MFM, MKM, MLM, MPM, MRM MWM, MXM, MZM, THM, TJM, TKM, TLM TUM, TXM The new control valve assembly uses a plug in place of the 4-3 pulse switch. The function of the 4-3 pulse switch, to momentarily release the torque converter clutch during a 4-3 downshift, was programmed into the ECM for the 1988 model year. These models had previously used a Type 15 Solenoid Assembly. FIGURE 1 - THM 700-R4 TRANSMISSION IDENTIFICATION INFORMATION 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 Cooling System - Reconstituted Anti-Freeze Information Coolant: Technical Service Bulletins Cooling System - Reconstituted Anti-Freeze Information Number: 90-49-6B Section: 6B Date: August 1989 Corporate Bulletin No.: 930107 Subject: RECONSTITUTED ANTI-FREEZE Model and Year: ALL MODELS, ALL MODEL YEARS TO: ALL CHEVROLET DEALERS This bulletin provides information on "reconstituted anti-freeze". It has been brought to our attention that a number of manufacturers claim to have the capability of reconstituting engine coolant on site. At this time, General Motors does not endorse this practice or any equipment. Anti-freeze recycling is a very complex issue. In use as an engine coolant, ethylene glycol becomes oxidized producing a very degraded and deteriorated substance. Contamination by other automotive fluids during draining, handling and storage is also a major detriment to the reclaiming process. There is no additive we are aware of that can be merely put into used coolant that will restore it to an acceptable state. Typically, a multi-million dollar facility, utilizing sophisticated technology with distillation capabilities along with appropriate quality control would be required to adequately process used coolant to bring it to GM specifications. Disposal of all chemical products should be done in accordance with all applicable federal, state and local laws and regulations. Review engine coolant substitutes Dealer Service Bulletin No. 89-57-6B, dated January 1989. 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. M/T - Shift Lever Vibration/Rattle In Third Gear Shifter M/T: All Technical Service Bulletins M/T - Shift Lever Vibration/Rattle In Third Gear Number: 89-169-7B Section: 7B Date: May, 1989 Subject: THIRD GEAR SHIFT LEVER VIBRATION/RATTLE Model and Year: 1986-89 S/T TRUCKS W/BORG WARNER FIVE SPEED MAN TRANSMISSION Figure 1 - Identification Tag Explanation Chart TO: ALL CHEVROLET DEALERS Some 1986-89 S/T Trucks may experience a shift lever vibration while the vehicle is in third gear. This condition may also be described as a rattle. The vibration may be most prominent on a coast down (deceleration) while in third gear. Production Change A new design shift lever was put Into production during the 1989 model year. Vehicles which have the new design lever can be identified by the serial number on the transmission identification tag. An example of the tag and its location on the transmission is shown in Figure 1. Vehicles with transmission serial numbers equal to or higher than those given below have the new design lever. Vehicle Serial Number Breakpoint T Series 21564 Locations Parking Brake Warning Switch: Locations LH Side Of I/P Behind Instrument Cluster Page 3450 FIGURE 2 - THM 700-R4 WIRING DIAGRAM DATE OF PRODUCTION CHANGE: (Figure 1) On April 20, 1988 (Julian Date 111), the 1988 THM 700-R4, THM and TLM models were built with the new Type 18 Solenoid Assembly and Wiring Harness. Beginning May 9, 1988 (Julian Date 130), the remaining 1988 THM 700-R4 models listed above were built using the new Type 18 Solenoid Assembly. SERVICE NOTES: Any 1988 THM 700-R4 transmission models built with the Type 18 Solenoid Assembly, refer to models and Julian Dates listed above, must be serviced with the Type 18 Solenoid Assembly and Wiring Harness Complete listed under "Service Parts Information". Any 1988 THM 700-R4 transmission model built with a Type 15 Solenoid Assembly may be serviced with the new Type 18 assembly; however, there will be no wire connection for the 4-3 pulse switch. The 4-3 pulse switch, which can be left installed, will then function as a plug. SERVICE PARTS INFORMATION: Part No. Description 10478100 Type 18 Solenoid Assembly - Complete 8654415 Type 15 Solenoid Assembly - Complete Parts are currently available from GMSPO. SERVICE MANUAL REFERENCE: Please update the 1988 THM 700-R4 Hydraulic Diagnosis section of your service manual accordingly. Page 5232 - 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 Page 3766 Service Manual References: Reference the Automatic Transmission Unit Repair Section of the appropriate service manual for retaining ring installation information. Page 2333 Manifold Pressure/Vacuum Sensor: Specifications MANIFOLD ABSOLUTE, VACUUM AND BAROMETRIC PRESSURE SENSORS Engines may use one, or a combination of these sensors. All sensors appear the same. Manifold Absolute Pressure sensors have a vacuum line connected between the unit and manifold vacuum. On Barometric Pressure sensors, the line is not used and the connector is either open or has a filter installed over it. Pressure sensors also have a vacuum line between the sensor and intake manifold and only appear on carburetted models. Barometric Pressure Sensors: Measure voltage with ignition on and engine off. Manifold Absolute Pressure Sensors: Measure voltage with ignition on and engine off. Start engine and apply 10 in./ 250 mm Hg to unit, voltage should be 1.2-2.3 volts less. Pressure Sensors: Measure voltage as indicated. Page 562 6. Tape the solder and diode. 7. Reinstall the black plastic conduit. 8. Reconnect connector to the generator. 9. Reconnect battery. This procedure will not affect the operation of the generator light during the bulb check at the beginning of the start cycle. For vehicles repaired under warranty use, Labor Operation Number: T7990 Labor Time: .4 Hr A/T - New Wave Plate Now Available Clutch: All Technical Service Bulletins A/T - New Wave Plate Now Available Number: 91-186-7A Section: 7A Date: February 1991 Corporate Bulletin No.: 077148 Subject: LOW AND REVERSE CLUTCH Model and Year: 1987-91 CAPRICE, CAMARO, CORVETTE AND 1987-91 C/K, R/V, S/T TRUCKS, G, M VANS AND 1990-91 L VAN WITH 4L60 AUTOMATIC TRANSMISSION Figure 2 - Lo And Reverse Clutch Waved Plate SERVICE INFORMATION: (Figure 2) Low and Reverse Clutch failure can be caused by case casting flash interfering with clutch plate travel. A new wave plate is now available which will alleviate this condition. This new plate can be used to service any Hydra-matic 4L60 transmission produced after February 9, 1987 (Julian Date 040). When installing the new wave plate, check for any case flash that may be present in the low and reverse grooves, and use a metal file to remove. See Figure 2 for case location information. SERVICE PARTS INFORMATION: Description New Part Plate - Low and Reverse (wave) 8676362 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. Drivetrain - Recommended Axle Lubricant Fluid - Differential: All 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. Instrument Panel - Upper Surface Cleaning Instrument Cluster / Carrier: All Technical Service Bulletins Instrument Panel - Upper Surface Cleaning Number: 91-285-0A Section: 0A Date: APRIL 1991 Corporate Bulletin No.: 101003 Subject: CLEANING OF UPPER INSTRUMENT PANEL SURFACES Model and Year: ALL PASSENGER CARS AND TRUCKS ALL YEARS Comments on reflection into the windshield of the upper instrument panel may be received. The condition of instrument panel reflection into the windshield in direct sunlight may be aggravated by dealers and owners applying a wax or silicone base material to the pad surface. The higher gloss of such application results in a "veiling reflection" in the windshield. Advise customers and new car make ready area that materials containing wax or silicone should not be used to clean the instrument panel pad. A warm water and mild soap solution such as saddle soap, oil soap, or an equivalent should be used whenever the instrument panel pad needs cleaning. Page 7995 - The split post guide clips with new solid post guide clips (Figure 2, Views A and B). The material in the new clip has been changed and the post redesigned. The material change is not evident, but provides additional strength in the clip hinge area. The new post is solid instead of split providing better fastening characteristics (Figure 2, View A). The purpose of the guide clips is to keep the glass parallel to the door frame when the glass is cycled. SERVICE PROCEDURE: 1. Remove the window glass. Follow the "Front Door Window Replacement" instructions in "Section 10A1-Door" of the applicable Service Manual. 2. Install new redesigned guide clips on the new glass. Glass P/N's 15960877-LH and 15960878-RH for non-export vehicles or P/N's 15962245-LH and 15962246-RH for export vehicles (RPO A26). - Align the clips with the holes in the glass and carefully snap together securely at each fastener location. The clips attach to the rear upper edge and front lower edge of the front door glass through holes in the glass (Figure 2, View B). 3. Remove three screws from the weatherstrip in the run assembly and remove the weatherstrip (Figure 1). 4. Install a new low friction run assembly weatherstrip, P/N 15960867-LH or 15960868-RH (Figure 1, Section A-A). Torque the fastening screws to 1.6 - 2.2 N-m (13 - 18 lbs.in.). Ensure the weatherstrip is properly seated in the door run channels. (Special care should be taken to ensure the weatherstrip below the door daylight opening is also properly seated). Apply silicone spray lubricant to the lower portion of the run assembly as indicated in illustration. 5. Install the new glass assembly (with new guide clips). Follow "Front Door Window Replacement" instructions in "Section 10A1-Doors" in the applicable Service Manual. 6. Check for proper window operation. Page 1648 3. Engine mounting through-bolts. -Tighten through-bolts or nuts to 70 Nm (52 ft.lbs) -Lower the vehicle. Fig. 2 Rear Engine Mount Installation. Except Bravada Fig. 3 Rear Engine Mount Installation. Bravada REAR MOUNTING REPLACEMENT Remove or Disconnect -Support the rear of the engine to relieve the weight on the rear mountings. Page 4347 Fig. 4 Cross & Roller Type Universal Joints & Propeller Shaft 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 with relation to the propeller shaft so they may be reassembled in the same relative position. Failure to observe these precautions may produce rough vehicle operation which results in rapid wear and failure of parts, and place 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. Some driveshafts use an injected nylon retainer to hold the bearing cups. When service is necessary, pressing the cups out will sheer the nylon retainer, Fig. 1. Replacement with the conventional steel snap ring type is then necessary, Fig. 2. Figs. 3 and 4 illustrate typical examples of universal joints of this type. They all operate on the same principle and similar service and replacement procedures may be applied to all. Fig. 5 Removing Bearing Cups From Yoke Disassembly 1. Place driveshaft into a vise using care not to damage it. 2. Remove snap rings (or retainer plates) that retain bearing cups in yoke and driveshaft. 3. Select a socket with an outside diameter slightly smaller than the bearing cup. Select another socket with an inside diameter slightly larger than the bearing cup. 4. Place the sockets at opposite ends of the yoke so that the smaller socket becomes a cup pusher and the larger socket becomes a cup receiver and reposition in vise as shown Fig. 5. Close vise jaws until both cups are free of yoke. Remove cups from the cross or spider and remove yoke. 5. If bearing cups will not come all the way out, close the vise until the cup in receiver socket protrudes from yoke as much as possible without using excessive force. Then remove from vise and place that portion of the cup which protrudes from yoke between vise jaws. Tighten vise to hold cup and drive yoke off with a soft hammer. 6. To remove opposite bearing cup from yoke, replace in vise with pusher socket in exposed cross journal and receiver socket over bearing cup, then tighten vise jaws to press cup through yoke into receiving socket. If bearing cup will not come all the way out, place protruding portion of cup between vise jaws, then tighten vise to hold cup while driving yoke off cup with soft hammer. 7. Turn spider or cross 1/4 turn and repeat procedure to press cups out of driveshaft. Specifications Fuel Pressure: Specifications FUEL PRESSURE: Ignition ON Engine OFF ...................................................................................................................... ................................................. 62-90 kPa (9-13 psi) Page 21 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) Page 5494 Warranty Information (excluding Saab U.S. Models) For vehicles repaired under warranty, use the appropriate labor operation for the source of the water leak Warranty Information (Saab U.S. Models) For vehicles repaired under warranty, use the table. Disclaimer Single Diaphragm Type Vacuum Brake Booster: Description and Operation Single Diaphragm Type Fig. 1 Exploded View Of Delco-Moraine Single Diaphragm Power Brake Unit Fig. 2 Exploded View Of Delco-Moraine Single Diaphragm Power Piston Assembly DESCRIPTION These power brake units, Figs. 1 and 2, are a combination vacuum-hydraulic brake booster of the vacuum suspended type which use engine intake manifold vacuum and atmospheric pressure for its power. These units consist of a vacuum power section and an hydraulic master cylinder section. The vacuum power section contains a power piston with rolling diaphragm mechanism and power piston return spring. The control valve is made up of an air valve and floating vacuum control valve assembly. The reaction mechanism consists of an hydraulic piston, reaction plate and a series of levers. The valve operating rod, which operates the air valve, projects from the power section and is connected to the brake pedal linkage. Specifications TEMPERATURE SENSORS Page 3906 new driven gear is required. Use (gray) 22 tooth driven gear (GM Part Number 3987922) if vehicle is equipped with L38 and GU6. Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: # T1612 Labor Time: 1.0 hr. FAILURE CODE: 92 ECM - Packard 32 Way Connector Identification Engine Control Module: All Technical Service Bulletins ECM - Packard 32 Way Connector Identification Number: 90-56-8 Section: 8 Date: September 1989 Corporate Bulletin No.: 916521R Subject: PACKARD 32 WAY CONNECTOR IDENTIFICATION Model and Year: 1980-90 A, B, F, G, J, L, W, Y CARS AND ALL TRUCKS WITH GMP4 ECM APPLICATIONS TO: ALL CHEVROLET DEALERS This bulletin serves to clarify the labeling of the Packard 32 way connectors used on the GMP4 under dash ECMS. Currently a common strain relief is used in both the C-D 32 pin and the E-F 32 pin connectors. To properly identify these connectors, the strain reliefs must be removed. Use the lettering on the connector as shown on figure. The colors used at this time for the 32 pin E-F connector are yellow, mint green or orange. This updates any previous information released concerning identification that indicates any of these colors as being C & D connectors, found in the 6E and 8D Sections of the affected Service Manuals. Engine Controls - Aftermarket Accessory Usage Engine Control Module: All 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 Page 2804 Throttle Position Sensor: Service and Repair REMOVAL: 1. Disconnect electrical connectors. 2. Remove the TPS attaching screw assemblies and retainer, (if applicable). 3. Remove TPS from throttle body assembly. NOTE: The TPS is an electrical component and must not be soaked in any liquid cleaner or solvent, as damage may result. INSTALLATION: 1. Install TPS to throttle body assembly, while lining up TPS lever with TPS drive lever on throttle body. 2. Install the two attaching screw assemblies. Tighten screw assemblies to 2.0 Nm (18.0 lb-in). 3. Install electrical connector to TPS. 4. Check for TPS output as follows: a. Connect an ALDL scanner to read TPS output voltage. b. With ignition ON and engine stopped, TPS voltage should be less than 1.25 volts. If more than 1.25 volts, replace TPS. Page 3029 S Series with 2.5L Engine 72267 S Series with 2.8L Engine 23911 Service Action For vehicles exhibiting third gear vibration that were built prior to the production incorporation of the new lever, the shift lever should be replaced with the new design lever. Reference Section 7B-3 of the Service Manual for replacement procedure. The new design shift lever P/N is 15618925. IMPORTANT: After shift lever replacement, assure that the boot assembly is positioned to ride as high as possible on the shift lever to reduce transmission noise into the cab. For vehicles repaired under warranty, use the following Labor Operations and Times: Labor Operation: K1060 Labor Time: .3 Hr Page 389 Page 5711 Steering Gear: Service and Repair Saginaw Rack & Pinion Power Steering Gear Service Note To prevent damage to the rack and pinion boot seal during removal, the following should be noted. Slide the small end of the boot toward the rack until the groove is exposed. Place a small rubber band in the groove, then slide the small end of the boot over the rubber band and off the threaded end of the tie rod. Lip seals, which seal rotating shafts, require special treatment. This type of seal is used on the steering gear at the pinion shaft and on the pump drive shaft. When a leak occurs in these areas, always inspect and thoroughly clean sealing surface before replacing. Replace seals only if severe pitting is found. If lip seal contact zone corrosion is slight, clean the surface of the shaft with crocus cloth. Replace only if the leakage cannot be stopped by smoothing with crocus cloth first. System Flushing 1. Raise front end of vehicle off ground until wheels are free to turn. 2. Remove fluid return line at pump reservoir inlet connector, then plug inlet connector port on pump reservoir. 3. Position fluid return line in large container. 4. While a second person fills reservoir with power steering fluid, start engine at idle. 5. Turn steering wheel from stop to stop. Do not hold wheel against stops while flushing system. Holding steering wheel against stops will cause high system pressure, overheating and damage to pump and/or gear. 6. Continue draining until all old fluid is cleared from power steering system. The addition of approximately one quart of new fluid will be required to flush system. 7. Unplug pump reservoir inlet and reconnect return line. 8. Turn engine Off, and fill reservoir to Full Cold mark. 9. Bleed system as outlined under SYSTEM BLEEDING. System Bleeding If system has been serviced, an accurate fluid level reading cannot be obtained unless air is bled from system. Any air in the system may cause pump cavitation noise and may cause pump damage over time. 1. With engine off, front wheels off ground and wheels turned to far left, add power steering fluid to FULL COLD mark. 2. Bleed system by turning wheels several times from side to side without hitting stops. Add fluid if necessary. 3. Fluid with air has a light tan appearance. Air must be removed before normal steering can be obtained. 4. Start engine, recheck fluid level and add if necessary. 5. Return wheels to center position. Lower vehicle to ground and continue running engine for 2-3 minutes. 6. Road test vehicle to ensure steering functions properly and is free from noise. check fluid level and add if necessary. Pinion Seal, Dust Seal & Bearing Fig. 2 Bearing adjustment Page 2798 Wiring Diagram For Chart C-8B - Manual Transmission Shift Light Check (Below 8500 GVW) CHART C-8B - MAN. TRANS. SHIFT LIGHT CHECK (VEHICLES BELOW 8500 GVW) Circuit Description: The ECM uses information from the following inputs to control the shift light: ^ Coolant temperature ^ TPS ^ VSS ^ RPM The ECM uses the measured RPM and the vehicle speed to calculate what gear the vehicle is in. It's this calculation that determines when the shift light should be turned on. Test Description: Numbers below refer to circled numbers on the diagnostic chart. 1. This should not turn "ON" the shift light. If the light "ON", there is a short to ground in CKT 456 wiring, or a fault in the ECM. 2. This should turn "ON" the shift light. 3. This checks for an open in the shift light circuit, or a faulty ECM. Engine - Vibration On Acceleration Muffler: Customer Interest Engine - Vibration On Acceleration Number: 88-270-6F Section: 6F Date: JULY, 1988 Subject VIBRATION ON ACCELERATION Model and Year 1988 S/T TRUCK W/4.3L (VIN CODE Z) ENGINE TO: ALL CHEVROLET DEALERS Some 1988 S/T Trucks equipped with 4.3L engines may experience a vibration that can be felt in the floor pan area near the shifter, in the right hand passenger seat foot area, or on the steering column. These conditions may be caused by the following items: 1. The shifter rod that goes from the steering column to the transmission equalizer lever (#340 and #338 in Figure 36 page 7A-45 of the 1988 S/T Manual) hitting the exhaust crossover pipe and/or the equalizer lever making firm contact at the shift lever (T-truck only). 2. The exhaust pipe to catalytic converter clamp (Figure 7, page 6F-6 of the 1988 S/T Manual) hitting the catalytic converter heat shield. 3. The exhaust pipe to converter installation allows the exhaust pipe to contact the transmission crossmember. To repair these conditions, use the following procedures: 1. A. Raise vehicle on hoist. B. Check Transmission linkage for correct adjustment. C. Check exhaust pipe for shifter rod interference (shiny spot on pipe). D. If linkage hits pipe, remove 15 mm (5/8 in) from bottom of rod. E. Put transmission into low gear and mark exhaust pipe area near linkage. F. Put transmission in park. Using a hammer, lightly dimple exhaust pipe for additional clearance. Instruments - Reduced PRNDL Display Visibility Transmission Shift Position Indicator Lamp: Technical Service Bulletins Instruments - Reduced PRNDL Display Visibility Bulletin No.: 02-08-42-004A Date: March 30, 2007 INFORMATION Subject: PRNDL Display Reduced Visibility For Approximately One Minute Models: 2007 and Prior Passenger Cars and Trucks (Including Saturn) 2007 and Prior HUMMER H2, H3 2005-2007 Saab 9-7X with Automatic Headlamp Control and Vacuum Fluorescent PRNDL Indicator Instrument Panel Cluster Supercede: This bulletin is being revised to include additional models and model years. Please discard Corporate Bulletin Number 02-08-42-0004 (Section 08 - Body and Accessories). After backing the vehicle out of a garage or dark environment into a daylight environment, the PRNDL display has reduced visibility for approximately one minute. While the vehicle is parked in a dark environment, the sensor for the automatic headlamp/driving lamps senses that it is dark. When the key is turned to the run/start position, the automatic headlamp module will turn all driving lamps, the instrument panel cluster and PRNDL display ON in the night-time mode. The night-time mode intensity of the instrument panel lamps and PRNDL display is controlled by the automatic headlamp module and can be dimmed further by the customer using the dimming control of the headlamp switch. When the customer then moves the vehicle from the dark environment into the bright sunlight, it will take approximately one minute before the headlamp control module recognizes this as true daylight and not just a bright overhead street lamp shining on the sensor. The headlamp control module will then turn the headlamps off and restore the instrument panel and PRNDL display to full brilliance. Without the time delay, the automatic headlamp control module would switch to the night mode (turn on all driving lamps, instrument panel lamps and PRNDL display would dim) each time the vehicle was driven under an overpass or other darkened environment. This is a normal condition and no repair should be attempted. Ensure the instrument panel backlighting control is in the full bright position. This will help alleviate the condition. You may demonstrate to the customer what happens by placing a repair order over the automatic headlamp control light sensor, which will cause the automatic headlamp control module to switch to the night mode in approximately one minute. All driving lamps will come ON, the instrument panel backlight will be dim, and the PRNDL display will also dim to the night setting in conjunction with the position of the headlamp switch dimming control. Demonstrate to the customer the variance in the instrument panel backlighting and PRNDL display while adjusting the headlamp switch dimming control to both ends of its allowable range. Advise the customer to keep the headlight switch dimming control in the highest position to allow viewing of the PRNDL display in a bright environment. Disclaimer Service and Repair Compressor Fitting HVAC: Service and Repair DA-V5 COMPRESSOR Rear Head Details 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. Page 6766 1. Disconnect the negative battery cable. 2. Open the endgate to the horizontal position. 3. Remove the inner trim panel. 4. Remove the bolts retaining the endgate inner panel reinforcement and remove the reinforcement (Figure 1, Item 2). 5. Disconnect the right and left endgate lock rods from the endgate window latch assembly (Figure 2). 6. Remove the adjusting nuts securing the window latch assembly to the endgate. (Figure 1, Item 4) 7. Disconnect the power window release actuator cable, if equipped. 8. Remove the window latch assembly from the endgate and discard. 9. Preassemble the lock rods to the new endgate window latch assembly (P/N 20367780) and install. DO NOT force the lock rods into position. The lock rods should line up with the attaching hole or stud on the window latch lever. NOTE: The temporary lock md positioning fastener must be in place for this procedure. (Figure 2, Item 4) If the rods do not align with the attaching hole or stud, adjust the rod(s) by turning to either lengthen or shorten as required. 10. Remove and discard the temporary lock rod positioning fastener 11. Reconnect the power window release actuator cable, if equipped. 12. Check for proper endgate operation. If necessary, readjust the lock rods. 13. Reattach the endgate inner panel reinforcement. 14. Adjust the latch assembly as described in steps 1-3 of the "Adjusting Procedure". 15. Reinstall the inner trim panel. 16. Reconnect the negative battery cable. SERVICE PARTS INFORMATION PART NUMBER DESCRIPTION QUANTITY 20367780 Window Latch Assembly 1 Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: B5880 Use applicable labor time guide for labor hours. Starter Models 1998440 - 9000735 Starter Solenoid: Specifications Hold-In Windings And Pull-In Windings Amperes Hold-In Windings And Pull-In Windings Amperes Hold-In Windings Pull-In Windings Starter Identification Number 1998440 13-18 A 11-18 A 1998559 13-19 A 23-30 A 1998583 13-19 A 23-30 A 1998584 13-19 A 23-30 A 1998588 14-18 A 26-30 A 1998589 14-18 A 26-30 A 9000735 13-15 A 31-36 A Page 1804 For vehicles repaired under warranty, use the table. Disclaimer Page 6709 Parts Information Parts required to complete this special coverage are to be obtained from General Motors Service and Parts Operations (GMSPO). Customer Notification General Motors will notify customers of this special coverage on their vehicles. Service Procedure Replacement of interior door handle assembly(s) Provide the customer with one or two interior front door handle assemblies. The customer is to self-install the assemblies or pay the dealer for the installation. Application of Lithium Grease Apply lithium based lubricant to the door handle springs. The lubricant should be applied so that it works into and between the spring coils, allowing the coils to move past each other freely. Claim Information Due to the age of the vehicles involved in this program, most involved VINs will be added to GMVIS to allow submission of claims. However, there are a few VINs that were not legible and could not be loaded into GMVIS. If a customer presents a letter authorizing repairs but the VIN is not found in GMVIS, H-route the claim to your AVM for approval. Page 1050 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 Page 346 LIGHT BLUE LT BLU BROWN BRN GRAY GRY GREEN GRN DARK GREEN DK GRN LIGHT GREEN LT GRN ORANGE ORN PINK PNK PURPLE PPL RED RED TAN TAN WHITE WHT YELLOW YEL Page 2579 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 module's 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 flexible ducting 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. Page 3038 Fuel Injector: Specifications J-39021 Injector Tester Kent-Moore Fuel Injector Tester, tool J-39021, has the capability of performing injector balance and coil tests on all GM and many non-GM fuel injection systems. In addition to the familiar fuel pressure drop test, the injector coil test is a new test whereby the injector's resistance is measured during normal operation by feeding a fixed current through the injector and measuring the voltage drop across the injector. Injector coil failures are more accurately detected using this method than by simply measuring the injector's resistance with an ohmmeter. Refer to the instructions included with the tool. For further information, refer to TSB 93-6E-14, dated June 1993. (Corp. Ref. No.: 316501R) NOTE: Measuring injector resistance is not a fool-proof method of determining the condition of the injectors. A Fuel Injector Balance Test will more accurately determine the mechanical condition of the injector, while the injector resistance will determine the electrical condition of the injector. If available, use applicable C-Charts at Computers and Control Systems, Testing and Inspection. You should also start at Diagnostic System Check if you have not already done so. See: Computers and Control Systems/Testing and Inspection Page 7586 e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors Do Not require all the steps shown. Skip the steps that Do Not apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. 1. Separate connector halves (see Figures 2 through 6). Figure 2 Figure 3 Page 7442 Coolant Level Indicator Lamp: Service and Repair This lamp will be illuminated when engine coolant level in the radiator drops below a pre-determined level. To turn lamp "OFF," check cooling system, then add coolant to bring system to proper level. Page 3975 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. 3L30 (180C) Transmission Governor Pressure Switch: Specifications 3L30 (180C) Transmission Component .......................................................................................................................................... .................................................................... Ft. Lbs. Governor Body To Governor Hub ........................................................................................................ ............................................................................... 6 Governor Pressure Switch ................................ .............................................................................................................................................................. ...... 7 A/C - Use of R-22 Refrigerant Not Recommended Refrigerant: Technical Service Bulletins A/C - Use of R-22 Refrigerant Not Recommended GMC NUMBER: 88-T-65 GROUP: 1B - Air Conditioning DATE: December, 1987 CORPORATE NUMBER: 861201 SUBJECT: R-22 REFRIGERANT MODELS: ALL TRUCK MODELS Use of R-22 refrigerant in any GMC truck A/C system is not recommended. R-22 refrigerant will not mix with the compressor lubricant currently used. Any mixture of R-12 and R-22 may cause the following to occur: ^ A/C compressor relief valve to blow at idle due to the build up of head pressures. ^ Loss of A/C system charge due to R-22 seeping through A/C hoses. ^ Compressor failure due to insufficient lubrication. R-12 is the only refrigerant that should be used in GMC truck A/C systems. Compressor Low Side Cut-Off Switch Refrigerant Pressure Sensor / Switch: Locations Compressor Low Side Cut-Off Switch A/C Low Charge Pressure Switch The A/C Low Charge Protection Switch is located at the rear of the compressor. Page 6189 Removing Or Installing The Shaft Lip Seal Retaining Ring 2. Shaft seal retainer ring using J 5403. ^ Clean the compressor neck area around the shaft (20). the exposed part of the shaft seal (8) and the O-ring seal groove. Removing Or Installing The Shaft Tip Seal 3. Shaft lip seal using J 23128-A. ^ Insert J 23128-A into the shaft lip seal, tighten and remove lip seal. Removing The Shaft Seal Seat O-Ring 4. O-Ring seal using J 9553-01. Inspect ^ Make sure the compressor neck area is clean. Page 6341 Testing and Inspection Page 6127 Removing The Pulley Bearing ^ Hold J 33020 in place and tighten the puller screw against J 33023-A puller pilot to remove the pulley (5). 4. Pulley bearing (4) from the pulley (5) using J 9398-A and J 8092. ^ Remove the forcing screw from J 33020 and with the puller tangs still in place in the pulley slots, turn the assembly upside down onto a flat surface. ^ When removing the old pulley bearing (5) allow the staking to remain, then file away the old staked metal for proper fit when installing a new bearing (5) in the pulley bore. Install or Connect Tools Required: J 21352-A Compressor Support Block J 9481-A Pulley Bearing Installer J 33019 Bearing Staking Tool (with staking pin and retaining band) J 33017 Pulley and Bearing Assembly Installer J 33023-A Puller Pilot J 8433-1 Puller Bar J 33026 Compressor Holding Fixture J 6083 Snap Ring Pliers 1. Pulley (5) on J 21352-A. NOTICE: Do not support the rotor by resting the pulley rim on a flat surface during bearing installation or the rotor face will be bent. Page 7098 1. Wash the subject panel with water to remove any foreign material such as dirt, grit, etc. 2. Wet sand subject panel with 3M Micro fine 1500 grit sandpaper, P/N 2023 or equivalent. Wrap the sandpaper around a 3M rubber sponge back up pad, P/N 5530, to prevent leaving finger marks in the clearcoat. NOTE: Always sand the length of the panel and use a mild dish soap detergent in the wet sand operation for sandpaper lubricant. 3. Wheel compound sanded panel with 3M Finesse it II, P/N 5928, polishing compound and 3M Super Buff Polishing Pad, P/N 5705 or equivalent. 4. Swirl marks, left in the clearcoat, can be removed by rebuffing the affected area with a non-directional, dual action (D.A.) orbital sander. A clean terry cloth polishing bonnet and 3M Finesse II compound should be used. CAUTION: Buffing wheels are not recommended for routine new car pre-delivery preparation of basecoat/ clearcoat finishes. 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. Page 7959 When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 5mm (3/16") of insulation from wire. e. Crimp a new terminal to the wire. f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. Figure 17 To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Figure 18 Figure 19 Page 4097 Valve Body: Service and Repair Turbo Hydra-Matic 4L60 (700-R4) Auxiliary Valve Body Replace 1. Raise and support vehicle, then drain transmission fluid. 2. Remove transmission oil pan and filter. Valve Body 3. Remove two bolts that attach auxiliary accumulator valve tube to control valve assembly and accumulator valve body assembly. 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. Control Valve Assembly Replace 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. Page 1467 Lifter / Lash Adjuster: Service and Repair Fig. 13 Hydraulic Lifters & Retainer REMOVAL 1. Remove rocker arm cover and pushrods as described under ROCKER ARM & PUSHRODS 2. Remove intake manifold as described under INTAKE MANIFOLD. 3. Remove retainer-to-engine attaching bolts, retainer and restrictors, Fig. 13. 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 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 oil. 6. Install metering valve, pushrod seat and seat retainer. 7. Depress pushrod seat with pushrod and remove 1/16 inch punch from lifter body. Page 1072 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 Page 4346 Universal Joint: Service and Repair Cross & Roller Type With Joint Replacement 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) Fig. 3 Cross & Roller Type Universal Joints Page 5986 A. Obtain a straight edge approximately 8-9 inches long and, while holding it in two hands, as shown in the attached illustration, place it on the inboard mounting surface of the wheel and try to rock it up and down. B. Repeat the above procedure on three or four different positions on the wheel inboard mounting surface. C. The outer ring of the mounting surface is normally raised above everything inside it. If a wheel mounting surface has been bent on a tire changer, it will be raised above the outer ring and the straight edge will rock on this "raised" portion. D. If a bent wheel is found, it must be replaced. Page 3852 Wiring Diagram For Chart C-1A - Park/Neutral Switch Diagnosis CHART C-1A - PARK/NEUTRAL SWITCH DIAGNOSIS Circuit Description: The Park/Neutral Switch contacts are closed to ground in park or neutral and open in drive ranges. The ECM supplies ignition voltage, through a current limiting resistor, to CKT 434 and senses a closed switch, when the voltage on CKT 434 drops to less than one volt. The ECM uses the P/N signal as one of the inputs to control: Idle Air Control VSS Diagnostics EGR Test Description: Numbers below refer to circled numbers on the diagnostic chart. 1. Checks for a closed switch to ground in park position. Different makes of "Scan" tools will read P/N differently. Refer to operators manual for type of display used for a specific tool. 2. Checks for an open switch in drive or reverse range. 3. Be sure "Scan" indicates drive, even while wiggling shifter to test for an intermittent or misadjusted switch in drive range. Diagnostic Aids: If CKT 434 indicates PIN (grounded), while in drive range, the EGR would be inoperative, resulting in possible detonation. If CKT 434 always indicates drive (open), a drop in the idle may exist when the gear selector is moved into drive range. Page 3019 To reduce the possibility of such an occurrence, especially if the reason for removing the air cleaner is a pinched wire, carefully remove the injector wires. Route the green and white wire under the blue and red wire and carefully twist once (Figure 2). Reconnect injector wires. One twist will reduce the slack in the injector wires so that there is less chance of them being trapped between the mating surfaces during assembly. Page 2336 Manifold Pressure/Vacuum Sensor: Testing and Inspection Chart C-1D - Manifold Absolute Pressure (MAP) Output Check Detonation Sensor LH Rear Of Engine, At Rear Of Cylinder Head Page 8039 Front Door Trim Panel Components Tools Page 4261 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. Page 2600 Wiring Diagram For Chart C-5 - Electronic Spark Control System Check CHART C-5 - ELECTRONIC SPARK CONTROL SYSTEM CHECK Circuit Description: Electronic spark control is accomplished with a module that sends a voltage signal to the ECM. As the knock sensor detects engine knock, the voltage from the ESC module to the ECM is shut "OFF" and this signals the ECM to retard timing, if engine RPM is over about 900. Test Description: Numbers below refer to circled numbers on the diagnostic chart. 1. If A Code 43 is not set, but a knock signal is indicated while running at 1500 RPM, listen for an internal engine noise. Under a no load condition there should not be any detonation, and if knock is indicated, an internal engine problem may exist. 2. Usually a knock signal can be generated by tapping on the right exhaust manifold. This test can also be performed at idle. Test number 1 was run at 1500 RPM to determine if a constant knock signal was present, which would affect engine performance. 3. This tests whether the knock signal is due to the sensor, a basic engine problem, or the ESC module. 4. If the module ground circuit is faulty, the ESC module will not function correctly. The test light should light indicating the ground circuit is OK. 5. Contacting CKT 496, with a test light to 12 volts, should generate a knock signal to determine whether the knock sensor is faulty, or the ESC module can't recognize a knock signal. Diagnostic Aids: "Scan" tools have two positions to diagnose the ESC system. The knock signal can be monitored to see if the knock sensor is detecting a knock condition and if the ESC module is functioning, knock signal should display "yes", whenever detonation is present. The knock retard position on the "Scan" displays the amount of spark retard the ECM is commanding. The ECM can retard the timing up to 20 degrees. This check should be used after other causes of spark knock have been checked such as engine timing, EGR systems, engine temperature or excessive engine noise. A/T - 700R4 Valve Body Modification Valve Body: All Technical Service Bulletins A/T - 700R4 Valve Body Modification SIL 85-21 SUBJECT: 700-R4 For start of production 1985, the converter clutch shift valve train was eliminated on units where the converter clutch is controlled by the computer. Specifications A/C Hose Or Line Torque Specifications Specifications Oil Pressure Sender: Specifications Oil Pressure Switch 10 ft.lb Page 7791 Symbol Identification Wire Color Code Identification WIRE COLOR ABBREVIATION BLACK BLK BLUE BLU DARK BLUE DK BLU Tire - Tread Chunking/Torn bead Tires: All Technical Service Bulletins Tire - Tread Chunking/Torn bead Number: 91-171-3E Section: 3E Date: January 1991 Corp. Bulletin No.: 993501R Subject: TIRE DAMAGE CAUSED IN GM ASSEMBLY PLANTS - TREAD CHUNKING TORN BEAD Model and Year: 1988-91 PASSENGER CARS AND TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 90-52-3E, DATED OCTOBER 1989. THE 1991 MODEL YEAR HAS BEEN ADDED. ALL COPIES OF 90-52-3E SHOULD BE DISCARDED. Isolated incidents of the following types of tire damage have recently been reported from the field. Any such damage would be present at time of delivery to the dealer. The probable cause of some of this damage has been traced to the assembly plant. Since such tire conditions are usually not the fault of the tire manufacturer, any tires requiring replacement for these reasons should be considered GM's responsibility. Assembly plant damage should not be confused with transportation damage, which continues to be the responsibility of the transportation company. The purpose of this bulletin is to help identify assembly plant tire damage. Tread Chunking This condition is identified by small pieces of tread rubber torn or "chunked" out of the tire. This usually occurs in one area of the tread, although more than one area is possible. The missing tread rubber should be apparent upon visual inspection. It can also usually be detected as a once-per-rev tire noise upon road testing. This condition can happen in the assembly plant during the end of line line roll test. Hard braking such that the tire locks up on the roll could be the cause, although other variables during the roll test can also be factors. Other types of tire tread damage noted at delivery should be considered transportation damage. Torn Bead Rubber This condition is usually not visible unless the tire is dismounted from the wheel and, therefore, may not be detected during new vehicle inspection. Depending on the extent of the tear, the condition may later be detected as a slow air loss, or a slight sidewall bulge. If the tire is dismounted from the wheel and bead rubber is torn, it is possible that this damage occurred in the assembly plant during tire mounting. If it happened in the plant, the tear will usually be on the inboard (blackwall) side of the tire. There should also be evidence of two tears, about 90 degrees apart, although one is usually much Locations Power Steering Pressure Switch: Locations LH Fender Apron LH Front Corner Of Engine Compartment Description and Operation Electronic Spark Timing: Description and Operation Varying octane levels in today's gasoline can cause detonation in engines. Detonation is sometimes called spark knock. To control spark knock an Electronic Spark Control (ESC) system has been added. This system is designed to retard spark timing up to 20~ to reduce spark knock in the engine. This allows the engine to use maximum spark advance to improve driveability and fuel economy. The ESC system has three major components: ^ ESC module ^ ESC knock sensor ^ ECM The ESC knock sensor detects abnormal vibration (spark knocking) in the engine. The sensor is mounted in the engine block near the cylinders. The ESC module receives the knock sensor information and sends a signal to the ECM. The ECM then adjusts the timing to reduce spark knocking. The ESC module sends a voltage signal (8 to 10 volts) to the ECM when no spark knocking is detected by the ESC knock sensor, and the ECM provides normal spark advance. When the knock sensor detects spark knock, the module turns "OFF" the circuit to the ECM. The ECM then retards EST to reduce spark knock. Loss of the ESC knock sensor signal or loss of ground at ESC module would cause the signal to the ECM to remain high. This condition would cause the ECM to control EST as if no spark knock were happening. No retard would occur, and spark knocking could become severe under heavy engine load conditions, possibly leading to pre-ignition and severe engine damage. Loss of the ESC signal to the ECM would cause the ECM to constantly retard EST. This could result in sluggish performance and cause a Code 43 to set. Spark retard without the knock sensor connected could indicate a noise signal on the wire to the ESC module or a malfunctioning ESC module. Page 6035 A. Obtain a straight edge approximately 8-9 inches long and, while holding it in two hands, as shown in the attached illustration, place it on the inboard mounting surface of the wheel and try to rock it up and down. B. Repeat the above procedure on three or four different positions on the wheel inboard mounting surface. C. The outer ring of the mounting surface is normally raised above everything inside it. If a wheel mounting surface has been bent on a tire changer, it will be raised above the outer ring and the straight edge will rock on this "raised" portion. D. If a bent wheel is found, it must be replaced. End Gate Lock Cylinder - Rattles Trunk / Liftgate Lock Cylinder: Customer Interest End Gate Lock Cylinder - Rattles Number: 91-507-10 Section: 10 Date: AUGUST 1992 Corporate Bulletin No.: 261003 ASE No.: B1 Subject: END GATE LOCK CYLINDER ASSEMBLY RATTLE Model and Year: 1982-91 S/T TRUCKS Some owners of 1982-1991 S/T utility vehicles may experience a rattling sound emanating from the rear of the truck. This condition may occur if the end gate lock cylinder assembly is loose. To correct this condition, it is necessary to bend the ends of the spring within the lock cylinder assembly eliminating any clearance between the pawl assembly and cylinder housing. SERVICE PROCEDURE: 1. Open the end gate to the horizontal position and remove the inner trim panel. Page 3433 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. Page 7793 License Plate Lamp: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. Figure 21 Figure 22 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. Electronic Vacuum Regulator Valve Electronic Vacuum Regulator Valve (EVRV): Locations Electronic Vacuum Regulator Valve Center Of Dash Panel (engine Compartment) RH Side Of Engine Applicable to: V6-262/4.3L Engine Page 6110 Compressor Clutch: Specifications Tightening Specifications With A-6 Compressor Rear Head to Shell Stud Nuts ............................................................................................................. ................................................... 34 N.m (25 ft. lbs.) Shaft Mounting Nut .............................................................................................................................. ................................................. 27 N.m (20 ft. lbs.) Pressure Relief Valve .......................................................................................................................... ................................................... 19 N.m (14 ft. lbs.) Oil Drain Screw .................................................................................................................................... ................................................. 20 N.m (15 ft. lbs.) With DA-6 Compressor Through Bolts ...................................................................................................................................... .................................................... 9 N.m (84 in. lbs.) Shaft Nut .............................................................................................................................................. .................................................. 16 N.m (12 ft. lbs.) Pressure Relief Valve .......................................................................................................................... .................................................... 9 N.m (84 in. lbs.) Compressor Suction & Discharge Connector Bolt ................................................................................................................................. 24 N.m (18 ft. lbs.) With R-4 Compressor Oil Drain Screw .................................................................................................................................... ................................................. 17 N.m (13 ft. lbs.) Cycling Pressure Switch ...................................................................................................................... .................................................. 10 N.m (7.5 ft. lbs.) Shaft Nut .............................................................................................................................................. .................................................. 17 N.m (13 ft. lbs.) Pressure Relief Valve .......................................................................................................................... ................................................... 17 N.m (13 ft. lbs.) Front Head Bolts .................................................................................................................................. .................................................. 27 N.m (20 ft. lbs.) Rim Mounting Screws .......................................................................................................................... ............................................... 11 N.m (100 in. lbs.) With DA-V5 Compressor Shaft Nut .............................................................................................................................................. .................................................. 17 N.m (12 ft. lbs.) Pressure Relief Valve .......................................................................................................................... .................................................... 9 N.m (80 in. lbs.) Through Bolts ...................................................................................................................................... .................................................... 9 N.m (80 in. lbs.) Oil Drain Plug ...................................................................................................................................... .................................................. 16 N.m (12 ft. lbs.) Suction and Discharge Connector Bolt .................................................................................................................................................. 34 N.m (25 ft. lbs.) With HR-6 Compressor Shaft Nut .............................................................................................................................................. .................................................. 16 N.m (12 ft. lbs.) Pressure Relief Valve .......................................................................................................................... .................................................... 9 N.m (84 in. lbs.) Through Bolts ...................................................................................................................................... .................................................... 9 N.m (84 in. lbs.) Suction and Discharge Connector ........................................................................................................................................................ 24 N.m (18 ft. lbs.) Page 4462 11501033 Nut 1 Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: K2283 (Manual Trans.) Labor Time: 0.4 Hrs. Labor Operation: K6723 (Automatic Trans.) Labor Time: 0.4 Hrs. Page 6086 Test C Blower Motor Does Not Operate In High Page 5426 1. Disconnect the negative battery cable. 2. Open the endgate to the horizontal position. 3. Remove the inner trim panel. 4. Remove the bolts retaining the endgate inner panel reinforcement and remove the reinforcement (Figure 1, Item 2). 5. Disconnect the right and left endgate lock rods from the endgate window latch assembly (Figure 2). 6. Remove the adjusting nuts securing the window latch assembly to the endgate. (Figure 1, Item 4) 7. Disconnect the power window release actuator cable, if equipped. 8. Remove the window latch assembly from the endgate and discard. 9. Preassemble the lock rods to the new endgate window latch assembly (P/N 20367780) and install. DO NOT force the lock rods into position. The lock rods should line up with the attaching hole or stud on the window latch lever. NOTE: The temporary lock md positioning fastener must be in place for this procedure. (Figure 2, Item 4) If the rods do not align with the attaching hole or stud, adjust the rod(s) by turning to either lengthen or shorten as required. 10. Remove and discard the temporary lock rod positioning fastener 11. Reconnect the power window release actuator cable, if equipped. 12. Check for proper endgate operation. If necessary, readjust the lock rods. 13. Reattach the endgate inner panel reinforcement. 14. Adjust the latch assembly as described in steps 1-3 of the "Adjusting Procedure". 15. Reinstall the inner trim panel. 16. Reconnect the negative battery cable. SERVICE PARTS INFORMATION PART NUMBER DESCRIPTION QUANTITY 20367780 Window Latch Assembly 1 Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: B5880 Use applicable labor time guide for labor hours. Page 815 Coolant: Technical Service Bulletins Coolant - Specification/Usage Number: 91-62-6B Section: 6B Date: August 1990 Corp. Bulletin No.: 066202 Subject: COOLANT USAGE Model and Year: ALL 1988-91 PASSENGER CARS AND TRUCKS TO: ALL CHEVROLET DEALERS THIS INFORMATION SUPERSEDES INFORMATION PROVIDED BY GMSPO IN PARTS AND ACCESSORIES BULLETINS IB NO. 90-55 AND 90-60 AND INFORMATION PROVIDED IN VARIOUS TRUCK SERVICE AND OWNERS MANUALS AND SHOULD BE USED TO DETERMINE CORRECT COOLANT USAGE IN LIGHT AND MEDIUM DUTY TRUCK APPLICATIONS. GM coolant specification 6038-M or 1899-M (P/N 1052103) is for use in all light duty trucks with gasoline or diesel engines. This coolant features a low silicate formulation and is intended only for use in engines that have cylinder heads and cylinder blocks made of cast iron. GM coolant specification 1825-M or 6043-M (P/N 1052753) which until recently has been the recommended coolant for light duty trucks has been superseded by GM coolant 6038-M or 1899-M (P/N 1052103) in cast iron truck engines. GM coolant specification 1825-M has a higher silicate formulation which is recommended for all passenger car engines with cylinder heads or cylinder blocks made of aluminum. Electronic Spark Control (ESC) Knock Sensor: Description and Operation Electronic Spark Control (ESC) Electronic Spark Control (ESC) is used on some models. The ESC system is used in conjunction with the EST system to provide additional spark retard during engine detonation. A knock sensor signals a separate ESC controller to retard the timing when it senses engine knock. The ESC controller signals the ECM which reduces spark advance until no more signals are received from the knock sensor. Service and Repair Timing Chain: Service and Repair Fig. 28 Valve timing marks 1. Remove Front Cover. 2. Remove crankshaft oil slinger. 3. Crank engine until 0.0 marks on sprockets are in alignment, Fig. 8. 4. Remove three camshaft to sprocket bolts. 5. Remove camshaft sprocket and timing chain together. Sprocket is a light press fit on camshaft for approximately 1/8 inch. If sprocket does not come off easily, a light blow with a plastic hammer on the lower edge of the sprocket should dislodge it. 6. If crankshaft sprocket is to be replaced, remove it with a gear puller. Install new sprocket, aligning key and keyway. 7. Install chain onto camshaft sprocket. Hold sprocket with chain hanging vertically, then align marks on sprockets as shown, Fig. 8. The valve timing marks shown in Fig. 8 do not indicate TDC compression stroke for No. 1 cylinder, which is used during distributor installation. If distributor was removed, install timing chain and sprockets, aligning timing marks, Fig. 8, then rotate engine until No. 1 cylinder is on compression and camshaft timing mark is 180 degrees from valve timing position shown in Fig. 8. 8. Align dowel in camshaft with dowel hole in sprocket and install sprocket on camshaft. Do not attempt to drive sprocket on camshaft, as welch plug at rear of engine can be dislodged. 9. Draw sprocket onto camshaft, using the three mounting bolts. Tighten to specifications. 10. Lubricate timing chain and install cover. A/T - Evaluating Peened Spacer Plates Valve Body: All Technical Service Bulletins A/T - Evaluating Peened Spacer Plates Number: 91-396-7A Section: 7A Date: AUGUST 1991 Corporate Bulletin No.: 177120 Subject: EVALUATING PEENED SPACER PLATES Model and Year: 1982-91 ALL PASSENGER CARS AND TRUCKS WITH AUTOMATIC TRANSAXLES AND TRANSMISSIONS (EXCEPT GEO) TRANSMISSIONS APPLICATIONS: All HYDRA-MATIC Automatic Transmissions and Transaxles SUBJECT: Evaluating Peened Spacer Plates (Service Information) TRANSMISSION MODELS: All VEHICLE APPLICATIONS: All Vehicles Using HYDRA-MATIC Automatic Transmissions and Transaxles Bulletin Covers: Some spacer plate peening is considered acceptable and preferred because it can help seat the check ball. This bulletin will help you decide if a spacer plate needs to be replaced due to a peening condition. Service Procedure: The following two procedures can help determine if the spacer plate can be reused. The following must be performed at all check-ball locations. Figure 1 1. The spacer plate must be inspected 100% for raised material on the opposite side of the check-ball seat (see Figure 1). If the material on the opposite side is raised, the peening is too severe and the spacer plate must be replaced. Page 7684 License, Stop, Tail & Turn Lamps (Part 4 Of 4) Page 4167 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. Page 5886 FIGURE 3 FIGURE 1 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 Page 6824 Trailer Adapter Wiring Circuit (W/Light Duty Suspension) Roof Rack - Wind Noise Roof Rack Frame: Customer Interest Roof Rack - Wind Noise Number: 91-70-10 Section: 10 Date: September 1990 Corp. Bulletin No.: 061003 Subject: ROOF RACK HOWL WIND NOISE Model and Year: ALL S/T UTILITY VEHICLES WITH ROOF RACK Page 5651 The illustration presents a pictorial illustration of the bleed procedure. This new procedure replaces previous steering system bleed procedures. Testing and Inspection Starter Drive/Bendix: Testing and Inspection Fig. 11 Diagnosis Chart (Part 1 of 3) Fig. 11 Diagnosis Chart (Part 2 of 3) Page 7720 Courtesy & Dome (Less Cargo Lamp) Generator Light - Flickers During Pulse Wiper Use Charge Lamp/Indicator: All Technical Service Bulletins Generator Light - Flickers During Pulse Wiper Use Number: 90-84-8A Section: 8A Date: November 1989 Corporate Bulletin No: 966402 Subject: GENERATOR LIGHT FLICKER DURING PULSE WIPER OPERATION Model and Year: 1988-89 S, T TRUCKS WITH 2.8L OR 4.3L (VIN CODES R, Z) ENGINES TO: ALL CHEVROLET DEALERS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 89-219-8A, DATED JULY 1989. THE 1990 MODEL S/T VEHICLES ARE INCLUDED IN THE LATEST BULLETIN ALONG WITH A CORRECTION TO THE ELECTRICAL CONNECTOR NUMBER. ALL COPIES OF 89-219-8A SHOULD BE DISCARDED. The generator light flicker condition during pulse wiper switch operation in the 1988, 1989 and 1990 S/T instrument panel, with standard cluster, can be caused by negative voltage transients from the wiper motor. There is no possibility of a system failure as a result of this condition. The effect of this condition is that the generator light will turn on for 80 milliseconds (if gages, the voltage drop on the voltmeter lasts 2.5 seconds). This causes no harm to the generator or other electrical components. Subject condition can be eliminated by installing a diode (industry part number 1N4003) or diode/connector kit (diode kit part number 12085207) in the brown wire at the generator connector (circuit 25 at connector C118). See the following pages in the 1988, 89 and 90 S/T Electrical Wiring Diagrams for circuit 25, connector C118 locations: 1988 4.3L: Section C - Page 24 1988 2.8L: Section C - Page 22 1989 4.3L: Page 40 1989 2.8L: Page 39 1990 2.8L: Page 44 1990 4.3L: Page 45 PARTS INFORMATION: Quantity Part Number Description 1 12085207 Diode ----OR---1 *1N4003 Diode * This part available locally. Parts are currently available from GMSPO. INSTALLATION PROCEDURE: 1. Disconnect the battery. 2. Remove the connector from the generator. 3. Peel back the black plastic conduit covering the wires. 4. If installing diode 1N4003: cut out a section of the brown wire that matches the length of the diode. 4A. A diode/connector kit is also available (GMSPO diode kit part number 12085207). If using the kit cut out approximately four inches of the brown wire, following crimping and soldering instructions in the kit. Spiral tape the solder joints and tuck the wire back into the conduit away from the generator. Secure the diode/connector to the outside of the conduit with electrical tape. 5. Solder in diode with the banded end toward the generator. Page 2436 R3261 LH mirror R&R; 0.4 Hr. (Time is different than published time in Labor Operation Guide.) Page 2721 Engine Control Module: Service and Repair Figure 1 *** THIS PROCEDURE HAS BEEN UPDATED BY TSB # 88-42, dated 9/87 Some replacement ECM's may come with a replacement PROM already installed in them. If this situation occurs, remove prom from old ECM and install in rebuilt ECM. When replacing a production ECM with a service ECM, transfer the broadcast code and production number from the production unit to the service unit. Also, during replacement, the PROM, and if equipped, the CALPAK must be removed from the ECM being replaced and transferred to the new unit. Refer to "PROM, REPLACE" and "CALPAK, REPLACE" for procedure. 1. Disconnect battery ground cable. 2. Locate ECM on passenger side under the instrument panel hush panel. (see figure 1.). 3. Remove ECM mounting hardware. 4. Remove ECM from passenger compartment. 5. Reverse procedure to install. Page 3618 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". Page 4526 S Series with 2.5L Engine 72267 S Series with 2.8L Engine 23911 Service Action For vehicles exhibiting third gear vibration that were built prior to the production incorporation of the new lever, the shift lever should be replaced with the new design lever. Reference Section 7B-3 of the Service Manual for replacement procedure. The new design shift lever P/N is 15618925. IMPORTANT: After shift lever replacement, assure that the boot assembly is positioned to ride as high as possible on the shift lever to reduce transmission noise into the cab. For vehicles repaired under warranty, use the following Labor Operations and Times: Labor Operation: K1060 Labor Time: .3 Hr Page 6154 Installing The Clutch Coil Assembly ^ Thread through bolts into J 33026 to full fixture thickness. ^ Be sure J 8433-1 and the clutch coil assembly (6) stay "in line" during installation. Staking The Clutch Coil Assembly To The Coil Head ^ When the clutch coil assembly (6) is seated on the front head (11), use a 3 mm (1/8-inch) diameter drift punch to stake the head (11) at 3 places, 120 degrees apart to assure the clutch coil assembly (6) remains in position. Clutch Coil Staking Locations - Stake size should be one half the area of the punch tip and 0.25-0.35 mm (0.010-0.015-inch) deep. 3. Pulley (5). 4. Clutch plate and hub assembly (2). Page 4273 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. Page 6622 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 Page 6087 Electrical System Diagnostic Chart Part 1 Of 2 Page 5667 1. Clean all parts with solvent and blow dry. 2. Inspect rotating components as follows: a. Vane tips for scoring or wear. b. Fit of vanes in rotor. Vanes must fit properly in slots without sticking or excessive play. c. Rotor slots for burrs and excessive wear at thrust faces. d. Inner surface of pump ring for scoring or wear. e. Thrust plate and pressure plate for wear on plate surfaces. f. If heavy wear is present, or parts are faulty, replace entire rotating group. 3. Inspect bearing for rough or looseness and bearing seal for leakage, cracking or swelling. 4. Check driveshaft and bearing bore for excessive burning or scoring. 5. Control valve must move smoothly in the valve bore. Assembly Fig. 9 Dowel pin installation Fig. 10 Pressure Plate Alignment Fig. 11 Thrust plate compression 1. Press sleeve into housing using a suitable socket and press. 2. Install dowel pin, seal and pressure plate spring. Fig. 9. 3. Install O-ring seal, pressure plate and dowel pins. Mark top of pressure plate where pin enters from underneath to ease alignment with dowel pin during assembly, Fig. 10. 4. Lubricate O-ring, pump ring, rotor and vanes with power steering fluid. Install vanes and rotor with rounded edge facing away from rotor. Ensure counterbore of rotor faces driveshaft end of housing. 5. Install pump ring with identification marks facing up, then install O-ring seal and thrust plate. Thrust plate dimples must line up with bolt holes in housing and plate must engage pump ring dowel pins. 6. Using a press to compress thrust plate, install retaining plate with the center opening of ring with bolt hole nearest the access hole, Fig. 11. 7. Using a suitable socket and press, install driveshaft seal into housing until it bottoms. Page 3693 Fluid - A/T: Testing and Inspection Turbo Hydra-Matic 4L60 (700-R4) Check fluid at regular intervals. Noticing a change in color, odor or fluid level can serve as a warning of possible transmission problems. To check fluid level, bring fluid to operating temperature of 200°F. With vehicle on a level surface, engine idling in park and parking brake applied, the level on the dipstick should be at the Full mark. To bring the fluid level from the Add mark to the Full mark requires one pint of fluid. If additional fluid is required, use only Dexron II or Dexron IIE automatic transmission fluid. When adding fluid, do not overfill, as foaming and loss of fluid through the vent may occur as the fluid heats up. Also, If fluid level is too low, complete loss of drive may occur especially when cold, Which can cause transmission failure. Every 100,000 miles, the oil should be drained, the pan removed, the screen should be cleaned or replaced if applicable, and fresh fluid added. For vehicles subjected to more severe use such as heavy city traffic especially in hot weather, prolonged periods of idling or use as a tow vehicle, this maintenance should be performed every 15,000 miles. Page 2750 Page 3580 Page 7977 Tools Tool Required: J-21104 Trim Pad Remover. REMOVE OR DISCONNECT 1. Door pillar molding. 2. Armrest. 3. Power window switch. 4. Trim panel. Pry the fasteners from their seats using J-21104. INSTALL OR CONNECT 1. Trim panel to the door. 2. Armrest. 3. Power window switch. 4. Door pillar molding. Page 1262 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 Page 2327 Page 4092 FIGURE 2 DATE OF PRODUCTION CHANGE: By October 6, 1986 (Julian Date 279) (Figure No. 2) all 1987 THM 700-R4 transmissions were produced with an auxiliary valve body for an improved drive engagement shift feel. As part of this change, the lo and reverse #5 checkball located in the valve body assembly (Figure No. 3) was eliminated, and a new forward clutch checkball (#12-Figure No. 1) was added to the Auxiliary Valve Body. All 1987 Service Replacement Transmission Assembly (SRTA) units have this change. FIGURE 1 - CHECKBALL LOCATIONS ON TRANSMISSIONS WITH AUXILIARY VALVE BODIES NOTICE: 1987 Service Manuals refer to the forward clutch checkball (#55B) in the auxiliary valve body as #5. To avoid confusion with the lo and reverse #5 checkball in a THM 700-R4 transmission produced without an auxiliary valve body (#55B-Figure No. 3), the forward clutch checkball has been changed to #12 (#55B-Figure No. 1). Page 7217 Seat Cover: 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. Page 2416 Disclaimer Page 6153 Removing The Clutch Coil Assembly ^ Install J 8433-1 with J-33025. ^ Tighten J 8433-1 forcing screw against J 33025-A. Inspect ^ Clutch coil assembly (6). Replace as necessary. Install or Connect Tools Required: J 8433-1 Puller Bar J 33024 Clutch Coil Installer Adapter J 33026 Compressor Holding Fixture 1. Compressor assembly on J 33026. 2. Clutch coil assembly (6) onto the front head (11) with the terminals positioned at the "marked" location. ^ J 33024 over the internal opening of the clutch coil assembly (6). ^ J 8433-1 with through bolts, washers and forcing screw over J 33024. Page 530 Wiring Diagram For Chart C-1A - Park/Neutral Switch Diagnosis CHART C-1A - PARK/NEUTRAL SWITCH DIAGNOSIS Circuit Description: The Park/Neutral Switch contacts are closed to ground in park or neutral and open in drive ranges. The ECM supplies ignition voltage, through a current limiting resistor, to CKT 434 and senses a closed switch, when the voltage on CKT 434 drops to less than one volt. The ECM uses the P/N signal as one of the inputs to control: Idle Air Control VSS Diagnostics EGR Test Description: Numbers below refer to circled numbers on the diagnostic chart. 1. Checks for a closed switch to ground in park position. Different makes of "Scan" tools will read P/N differently. Refer to operators manual for type of display used for a specific tool. 2. Checks for an open switch in drive or reverse range. 3. Be sure "Scan" indicates drive, even while wiggling shifter to test for an intermittent or misadjusted switch in drive range. Diagnostic Aids: If CKT 434 indicates PIN (grounded), while in drive range, the EGR would be inoperative, resulting in possible detonation. If CKT 434 always indicates drive (open), a drop in the idle may exist when the gear selector is moved into drive range. Page 5013 - Brake fluid which is contaminated with air or water will significantly add to the amount of pedal travel. - Pure DOT 3 (or 4) brake fluid is incompressible (allowing for a solid, firm pedal). A small amount of air trapped in the brake fluid will require extra effort from the master-cylinder to compress it, resulting in a soft and spongy pedal. - During prolonged or severe braking the brake fluid temperature can rapidly rise above 212 degrees F. When this occurs any water in the brake fluid will boil into steam (which is compressable) and create a soft and spongy pedal. Rear Brake Shoe Adjustment Drum brake system utilize return springs to pull the shoes away from the drums when not in use. The amount of distance the shoes have to extend to meet the drums greatly affects the amount of pedal travel. - Shoes/Linings which are badly out of adjustment can by themselves result in a brake pedal sinking all the way to the floor NOTE: Improperly adjusted rear shoes/linings also affect the parking brake. Calipers Excessive rotor wobble caused by a warped rotor or loose/worn wheel bearings can knock the caliper piston further inward from its normal resting position. This results in additional pedal travel required to extend the piston and apply the brakes. Drum Expansion Drums which are worn past their "Discard" thickness are prone to expanding outwards into an oval shape during heavy braking. This drum expansion results in additional brake pedal travel. Brake Fade During prolonged or severe braking, the amount of pedal effort/travel required to slow the vehicle increases as the ability of the brakes to dissipate heat decreases. - As the brake linings heat up, their "coefficient of friction" is reduced (they become slicker). As the coefficient of friction is reduced, more hydraulic pressure is required to stop the vehicle. More hydraulic pressure results in more heat which then results in more pedal fade. - As the brake linings, rotors, and drums begin to wear, their ability to absorb and release heat is reduced significantly. This makes worn brakes more prone to "pedal fade". NOTE: Prior to replacing a master-cylinder, verify the entire brake system is functioning properly. C/V Boot - Contacts Front Shock Technical Service Bulletin # 913114C Date: 910501 C/V Boot - Contacts Front Shock Number: 91-311-4C Section: 4C Date: MAY 1991 Corporate Bulletin No.: 164301R Subject: FRONT AXLE INNER C/V BOOT CONTACTS FRONT SHOCK Model and Year: 1985-91 T TRUCKS Some 1985-91 T trucks may experience a condition of the front axle tripot seals (commonly referred to as the inner C/V boots) contacting the front shock absorbers. This contact usually occurs during suspension operation and may be evidenced as torn seals, premature wear on the outer edges of the seal convolutes or grooves worn into the body of the shock absorber. This condition can be relieved by correcting problems with shock absorber or axle installation and installing smaller profile tripot seals. VEHICLES INVOLVED: 1985-91 T trucks. SERVICE PROCEDURE: The following items should be checked and verified to provide the greatest amount of clearance for the tripot seals. - The shock absorbers are installed correctly with the fluid reservoir on the bottom and the shield on the top. - If aftermarket shock absorbers have been installed, their diameter must measure 50.4 mm (1.98") or less. - The output shaft retaining ring is in place. To check, pull outward on the output shaft. Outward movement should measure 5 mm (.200") or less. IMPORTANT: DO NOT cut or relocate shock absorber mounting brackets. If the contact between the tripot joint and shock absorber is occurring on the passenger side of the vehicle, the axle assembly may be shifted in the frame too far toward the passenger side. To correct this condition the procedure below should be followed: Figure 16 - Carrier Assembly Installation Page 4683 Shift Solenoid: 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. Page 2713 ECM Connector Terminal Identification & Voltage Specifications. Page 3651 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. Page 5668 Fig. 6 Driveshaft & bearing removal Fig. 5 Driveshaft retaining ring removal 8. Install bearing onto driveshaft, Fig. 6, then slide assembly into housing while rotating driveshaft so shaft serrations engage with rotor. 9. Insert retaining ring ensuring large tab of ring is properly located. Refer to Fig. 5. 10. Install flow control spring, control valve, O-ring seal and O-ring. 11. Install reservoir or return tube, then clips if equipped. System Bleeding 1. Fill pump fluid reservoir to proper level and let fluid settle for at least two minutes. 2. Start and run engine for a few seconds. Do not turn steering wheel. 3. Turn engine Off. Check fluid level, add fluid if necessary. 4. Repeat above procedure until fluid level remains constant after running engine. 5. Raise front end of vehicle so wheels are off ground. 6. Start engine. Slowly turn steering wheel in both directions, lightly contacting wheel stops. 7. Add power steering fluid, if necessary. 8. Lower vehicle and turn steering wheel slowly from lock to lock. 9. Stop engine. Check fluid level and refill as required. 10. If fluid is extremely foamy, allow vehicle to stand a few minutes and repeat above procedure. Page 4921 Brake Drum: Service and Repair Installation Rear Drum Assembly Fig. 7 Measuring Brake Drum Inside Diameter Fig. 8 Adjusting Brake Shoes To Brake Drum Inside Diameter 1. If brake shoes have been replaced or the adjusting screw has been moved the shoes should be adjusted. To do this use a suitable brake drum to shoe gauge, measure brake drum inside diameter. Adjust brake shoes to dimension obtained on outside portion of gauge. 2. Install the brake drum. 3. Install the tire and wheel assembly 4. Lower vehicle. NOTE: For additional information see Notes, Warnings, and Hints. See: Fundamentals and Basics Description and Operation Electronic Spark Timing: Description and Operation Varying octane levels in today's gasoline can cause detonation in engines. Detonation is sometimes called spark knock. To control spark knock an Electronic Spark Control (ESC) system has been added. This system is designed to retard spark timing up to 20~ to reduce spark knock in the engine. This allows the engine to use maximum spark advance to improve driveability and fuel economy. The ESC system has three major components: ^ ESC module ^ ESC knock sensor ^ ECM The ESC knock sensor detects abnormal vibration (spark knocking) in the engine. The sensor is mounted in the engine block near the cylinders. The ESC module receives the knock sensor information and sends a signal to the ECM. The ECM then adjusts the timing to reduce spark knocking. The ESC module sends a voltage signal (8 to 10 volts) to the ECM when no spark knocking is detected by the ESC knock sensor, and the ECM provides normal spark advance. When the knock sensor detects spark knock, the module turns "OFF" the circuit to the ECM. The ECM then retards EST to reduce spark knock. Loss of the ESC knock sensor signal or loss of ground at ESC module would cause the signal to the ECM to remain high. This condition would cause the ECM to control EST as if no spark knock were happening. No retard would occur, and spark knocking could become severe under heavy engine load conditions, possibly leading to pre-ignition and severe engine damage. Loss of the ESC signal to the ECM would cause the ECM to constantly retard EST. This could result in sluggish performance and cause a Code 43 to set. Spark retard without the knock sensor connected could indicate a noise signal on the wire to the ESC module or a malfunctioning ESC module. Page 391 Page 2980 - 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 Hydraulic System Bleeding Brake Bleeding: Service and Repair Hydraulic System Bleeding Manual Bleeding 1. If vehicle is equipped with power brakes, remove vacuum reserve by applying brakes several times with engine off. 2. Fill master cylinder reservoirs with suitable brake fluid. Be sure to always keep master cylinder reservoirs at least half full during entire bleeding procedure. 3. If master cylinder is suspected to have air in the bore, it must be bled first, as follows: a. Disconnect forward brake pipe connection at master cylinder. b. Allow brake fluid to fill master cylinder bore until it begins to flow from forward pipe connector port. c. Connect and tighten forward brake pipe at master cylinder. d. Depress brake pedal slowly one time and hold, then loosen forward brake pipe connection at master cylinder to purge air from bore. Tighten connection, then release brake pedal slowly. Wait 15 seconds, then repeat sequence, including 15 second wait, until all air is purged from bore. e. Bleed rear bore of master cylinder as front bore was bled. 4. Bleed right rear brake as follows: a. Depress brake pedal slowly one time and hold. b. Loosen bleeder valve to purge air from brake, then tighten bleeder valve and slowly release pedal. c. Wait 15 seconds, then repeat sequence, including 15 second wait, until all air is purged. 5. Bleed left rear, right front, and left front brakes, in that order, using same method as for right rear brake. 6. Check brake operation and ensure pedal is firm. Also check master cylinder fluid level and add fluid as necessary. 7. Turn off brake warning light by applying moderate pressure to brake pedal several times. 8. Road test vehicle. Fig. 1 Installing Pressure Bleeder Adapter Pressure Bleeding 1. Loosen, then slightly retighten bleeder valves at all four wheels. Repair any broken, stripped or frozen valves at this time. 2. Using a diaphragm type pressure bleeder, install suitable bleeder adapter to master cylinder, Fig. 1. 3. Charge bleeder ball to 20-25 psi, then depress and hold valve stem on combination valve. 4. Connect pressure bleeder line to adapter. 5. Open line valve on pressure bleeder, then depress bleed-off valve on adapter until a small amount of brake fluid is released. 6. Raise and support vehicle. 7. Bleed right rear, left rear, right front and left front brakes, in that order. 8. Place transparent tube over bleeder valve, then allow tube to hang down into transparent container. Ensure end of tube is submerged in clean brake fluid. 9. Open bleeder valve 1/2 to 3/4 turn and allow fluid to flow into container until all air is purged from line. Flushing Hydraulic System If brake fluid is old, rusty or contaminated, or whenever new parts are installed in the hydraulic system, the system must be flushed. Bleed brakes, allowing at least one quart of clean brake fluid to pass through system. Any rubber parts in hydraulic system which were exposed to contaminated fluid must be replaced. Page 5331 - 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 Page 2211 FIGURE 1(T-TRUCK ONLY) G. (T-truck only) Check equalizer lever for firm contact at the shift lever inboard side of the guide slot. (See Figure 1) H. If firm contact is evident, add an additional washer (#10 in Figure #1) P/N 14074908 to adjust equalizer lever outboard toward the center of the guide slot to eliminate contact. 2. A. Raise vehicle on hoist. B. Note location of clamp rotation on pipe. Some clamps are located with the lower lock ring (nuts) pointed towards the transmission. If the clamp is located in such a manner, loosen clamp and rotate it down so the nuts point toward the ground and retighten to 58 N-m (43 ft/lbs.) 3. A. Loosen converter clamp until it will rotate around the pipe. Using a suitable pry bar, move exhaust system rearward to obtain a minimum of 5/8 in. clearance between any point on the exhaust system and the transmission crossmember. For repairs performed under warranty, use the following labor operations and times: Labor Operation Labor Time Exhaust/muffler clamp L2020 .3 Hr Exhaust system align L2004 .3 Hr Shift Linkage (shorten) K5244 .3 Hr Page 4801 Symbol Identification Wire Color Code Identification WIRE COLOR ABBREVIATION BLACK BLK BLUE BLU DARK BLUE DK BLU Locations Blower Motor: Locations RH Side Of Cowl RH Side Of Firewall Tires - Proper Rotation and Warranty Coverage Tires: All Technical Service Bulletins Tires - Proper Rotation and Warranty Coverage GMC NUMBER: 88-T-66 GROUP: 3E - Wheels & Tires DATE: December, 1987 CORPORATE NUMBER: 893504R SUBJECT: GM DEALER'S RESPONSIBILITY CONCERNING TIRE WARRANTIES, INCLUDING IRREGULAR/PREMATURE WEAR MODELS: ALL LIGHT DUTY TRUCKS As in the past, tires continue to be warranted by the tire manufacturer against defects in material or workmanship. Details of this limited warranty may be found in each tire company warranty booklet, which is part of the glove box material. The GM Warranty and Owner Assistance Booklet also now states that the GM dealer will assist the customer in obtaining a tire adjustment if necessary. Tire conditions caused by vehicle defects are warranted by General Motors. This statement is now included in the GM Warranty and Owner Assistance Booklet. This applies during the basic coverage period, which is 12 Months/ 12,000 Miles, and should be applied to all past and current models. Examples of tire conditions that fall within GM's responsibility may include tire damage during vehicle assembly, tire damage due to tire-to-vehicle interference, and irregular/premature tire wear. Tire wear due to abusive driving is not covered by warranty. FIGURE 1 Adjustments Air Door Cable: Adjustments S/T-10/15 The temperature cable incorporates a slider type self-adjust feature. As the control head temperature lever is moved through its full range of travel, the cable clip will assume a position assuring that the temperature door will seat in the full hot and full cold positions. Page 3824 Labor Operation No.: K6550 Valve, Pressure Regulator-R&R; or Replace Use the appropriate labor time in the labor time guide. Parts are currently available from GMSPO. 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. Page 1439 1990-1991 "W" Car 1988-1990 "Y" Car "AW" Type Weight 1989-1991 "L" Car Used On All Other 1991 "B" Car, "U" Van Series Vehicles 2-1/4 oz. 9591382 9591366 2-1/2 oz. 9591383 9591367 3oz. 9591385 9591369 Parts are currently available from GMSPO. Dealers should make sure they have a supply of both types weights for balancing GM aluminum wheels. When installing the coated weights, care must be taken so that the coating does not crack. It is recommended that a Teflon tipped hammer be used, such as 85403 Nicholson Industrial Hammer, their part number CAS 3340551, available through the Charles Strelinger Company, Warren, Mi (313-268-4100), or equivalent. Page 6831 Carpet: 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. Page 6644 Symbol Identification Wire Color Code Identification WIRE COLOR ABBREVIATION BLACK BLK BLUE BLU DARK BLUE DK BLU Isolation Diodes - Replacement Information Diode: All Technical Service Bulletins Isolation Diodes - Replacement Information Number: 93-163-8A Section: 8A Date: MAY 1993 Corporate Bulletin No.: 178201R ASE No.: A6 Subject: ISOLATION DIODES REPLACEMENT INFORMATION Model and Year: 1993 AND PRIOR YEAR PASSENGER CARS AND TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 92-47-8A, DATED NOV. 1991. THE 1993 MODEL YEAR HAS BEEN ADDED AS WELL AS PART NUMBERS HAVE BEEN REVISED. THIS WILL ALSO UPDATE CERTAIN SERVICE MANUALS. ALL COPIES OF 92-47-8A SHOULD BE DISCARDED. Many of the electrical systems on our vehicles use a diode to isolate certain circuits and protect them from voltage spikes. Some of the circuits which may use such a diode are listed below: A/C Compressor Clutch ABS/4WAL NOTE: The ABS diode on the Delco Moraine system is hidden inside of an electrical connector under the carpet at the right kick panel. Wiper Charging System (hidden in wire harness) Parking Brake (vehicles with ABS) Relays Solenoids Diesel Glow Plug Circuit Day Time Running Lights Obtaining replacement diodes can sometimes be a problem. A universal diode, that meets the specifications in the chart below, may be used for the applications listed above. Since certain diode applications have specific part numbers, always reference the applicable GM parts catalogue before installing one of the universal diodes listed in this bulletin. When installing the new diode, use the following procedures to obtain a lasting repair: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to current flow direction, remove inoperative 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 needed to attach the new diode. 4. Check current flow direction of the new diode, being sure to install the diode with correct bias. Reference the appropriate service manual wiring schematic to obtain the correct diode installation position. Reference Figure 1 for replacement diode symbols and current flow explanations. Page 674 SPARK PLUGS Service and Repair Vacuum Reservoir HVAC: Service and Repair 1. Remove vacuum lines from tank fittings. 2. Remove tank retaining screws. 3. Reverse procedure to install. MAP - Revised Check Chart for DTC's 33, 34, 63, 64 Manifold Pressure/Vacuum Sensor: Technical Service Bulletins MAP - Revised Check Chart for DTC's 33, 34, 63, 64 Number: 90-199-6E Section: 6E Date: March 1990 Corporate Bulletin No.: 016510 Subject: REVISED CHART C-1D, CODE 33, 34, 63, 64 Model and Year: 1980-90 PASSENGER CARS AND TRUCKS TO: ALL CHEVROLET DEALERS This bulletin revises the Manifold Absolute Pressure (MAP) Output Check Chart C-1D and updates Code 33, Code 34, Code 63, and Code 64 in the Service Manual section on "Driveability And Emissions" (Section 6E1, 6E2, and 6E3). This information applies to all MAP Sensors on 1980-1990 vehicles with gasoline engines (except turbocharged) with green (standard) MAP sensor electrical connector insert or the solid black MAP sensor electrical connector insert. The revised chart information: Page 5846 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 Page 353 Headlamp Switch: Electrical Diagrams Light Switch Details (Part 1 Of 3) Page 1256 FIGURE 4 GENERAL AND UNIROYAL IF WITHIN THE NEW VEHICLE WARRANTY PERIOD (12/12): A. If only slight cupping is noticed, and the cross grooves in the tire's outside shoulder are still visible (See Figure No. 3), the tires should be rotated. The modified "X" pattern should be used (See Figure No. 1). This method will best equalize wear after a few thousand miles. B. The cupping or wear is severe, and the cross grooves in the outside shoulder are not visible, tire replacement will be necessary (See Figure No. 4). It should be noted, however, that even when these grooves disappear, the tire is normally only half worn in this area. If tires are needed for any of the previous conditions, they should be purchased from your local tire outlet. If tires are not readily available, contact the manufacturers toll-free assistance number provided below. Firestone - 1-800-638-4730 General - 1-800-Tire-FIX - 1-800-426-4889 (Ohio) Goodyear - 1-800-321-2136 Uniroyal - 1-800-231-5893 (Except Texas) - 1-800-833-5906 (Texas) The tire invoice amount should be entered as a net item on the warranty claim using the E0420 labor operation code for wheel and/or tire replacement. Labor Op E0420 - Wheel and/or Tire-Replace Replace One - .6 hr. Each Additional Tire - .4 hr. Page 4507 Fluid Pressure Sensor/Switch: Specifications 4L60 - 700R4 Transmission Pressure Switches ............................................................................................................................... ....................................................................... 8 ft. lbs. Page 8073 Figure 1, 3 Note: If performing the above procedure does not appear to correct the condition, a gap at the back of the dash, where the dash and cowl assembly come together with the windshield frame and plenum assembly, may be the cause (see Figure 2). When these two pieces are welded together in production a gap may be created on the vehicle. After the welding process this gap, as well as the rest of the joint, is sealed. If this gap is not sealed properly a howl condition can occur. To eliminate this condition the entire joint will have to be resealed. This can be done at the same time as procedure 1 (see Figure 3). 1) Using Bowman Distribution black caulking part number 19023 or equivalent it is possible to seal the area where the dash meets the plenum assembly through the exposed cowl vent windows located on the plenum assembly. 2) Remove caulking from package and apply through the exposed cowl vent grille. Firmly push the caulking into the area where the dash and cowl assembly meet the plenum assembly. To insure proper seal it is necessary to install the caulking the full length of the windshield (3.5 Page 3303 15522278 Insulator, Front Spring Upper 2 15522279 Insulator, Front Spring Lower 2 12345097 Adhesive, Weatherstrip, 5 oz. 1 Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: E3907 Use applicable labor time guide for labor hours. Page 358 Light Switch Details (Part 3 Of 3) Locations Parking Brake Warning Switch: Locations LH Side Of I/P Behind Instrument Cluster Page 4643 10. Case bolts (3) from the case halves. - Note the two longer bolts (16) and washers go into doweled case holes (33). - Separate case halves, insert screwdrivers into the slot cast in the case ends and pry apart. Do not attempt to wedge the case halves apart at any point on the mating surfaces. - Be careful not to damage the oil pump (12) (located in the rear case half) while removing the rear case half (17). Internal Components 11. Fork shift spring (52). 12. Mainshaft (19)/drive sprocket 14071703 (20), chain (58) and front output shaft (21) as a unit. Mode shift fork (54) and shift rail (48) will be removed with the mainshaft. INSPECT: The teeth of the synchronizer stop ring (28) and drive sprocket (20) for damage. If they are damaged, or in cases of customer complaint of clash when shifting from 2Hi to 4Hi, follow steps 13, 14 & 15, otherwise skip to step 16. 13. Retainer (snag ring) (83) from the mainshaft (19). 14. Synchronizer assembly (81). 15. Drive sprocket (20) from the mainshaft (19). 16. Range shift fork (51), range shift hub (34) and sector with shaft (55) from the planetary carrier (36). - It is necessary to rotate the sector with shaft (55) to obtain clearance when removing the range fork (51). 17. Plastic washer (retainer) (66) and O-ring seal (67) from the front case half. IMPORTANT: Group B vehicles should complete step 17 and skip to INSTALL step 8. 18. Input bearing retainer bolts (43) and input bearing retainer (44) from the front case half (45). 19. Retainer snap ring from the input gear (38). 20. Planetary carrier (36) and the input gear (38) from the annulus gear (62) using a soft hammer. 21. Input bearing retainer (39) and input bearing (40). 22. Front output bearing retainer ring (snap ring) (60). 23. Front output bearing (61) from the front case half (45) using J33790, and J8092. 24. Seal (42) from the input bearing retainer (44) if it shows signs of damage. Install Page 3262 Spark Plug: Description and Operation Resistor type, copper core, tapered seat quantum spark plugs are used on all engines. No gasket is used on these tapered seat plugs. A dot before the spark plug code or the letter C after the number in the code indicates that the plug has a copper core. For the correct gap information refer to the Vehicle Emissions Control Information label under the hood or refer to SPECIFICATIONS/ELECTRICAL AND ELECTRONIC SPECIFICATIONS. Normal or average service is assumed to be a mixture of idling, slow speed, and high speed operation with some of each making up the daily total driving. Occasional or intermittent high-speed driving is essential to good spark plug performance as it provides increased and sustained combustion heat that burns away any excess deposits or carbon or oxides that may have accumulated from frequent idling or continual stop and go or slow speed driving. Spark plugs are protected by an insulating boot made of special heat-resistant material which covers the spark plug terminal and extends over a portion of the plug insulator. These boots prevent flash-over with resultant missing of the engine, even though a film is allowed to accumulate on the exposed portion of the plug porcelains. Do not mistake corona discharge for flash-over or a shorted insulator. Corona is a steady blue light appearing around the insulator, just above the shell crimp. It is the visible evidence of a high-tension field, and has no effect on ignition performance. Usually it can be detected only in the darkness. This discharge may repel dust particles, leaving a clear ring on the insulator just above the shell. This ring is sometimes mistakenly regarded as evidence that combustion gases have blown out between the shell and the insulator. Page 6227 inserted through the mode indicator. (Fig.3) 13. Torque the housing, baseplate and blower switch mounting screws to 6-10 lbs.in. 14. If necessary, install new knobs on mode, temperature, and blower controls to ensure proper retention. SERVICE PARTS INFORMATION Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: LABOR OPERATION DESCRIPTION D0362 R & R HVAC control ADD: Replace housing Use applicable labor time guide for labor hours. Page 3589 Figure 1 - HYDRA-MATIC 4L60 Transmission Identification Information Part is currently available from GMSPO. DATE OF PRODUCTION CHANGE: (Figure 1) Beginning March 28, 1990 (Julian Date 087), all HYDRA-MATIC 4L60 transmissions were built using the new low and reverse clutch wave plate. SERVICE MANUAL REFERENCE: Refer to the Automatic Transmission Unit Repair Section of the appropriate service manual for low and reverse clutch plate removal and installation information. Page 7042 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 Page 2614 Page 2071 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 Page 2873 EGR Valve: Testing and Inspection CAUTION: Do Not wash any EGR valve in solvents or degreaser, as permanent damage may result, Also, sand blasting of the valve is not recommended, since this can affect the operation of the valve. Wear approved eye protection for this cleaning procedure, to avoid possible injury to the eyes. Use the following cleaning instructions for all EGR valves except the digital EGR valve used on VIN C 3800 engines. 1. With a wire wheel, buff the exhaust deposits from the mounting surface and around the valve. 2. Look for exhaust deposits in the valve outlet. Remove deposit buildup with a screwdriver. 3. Clean mounting surfaces of intake manifold and valve assembly. 4. Install valve assembly using new gasket. Page 2386 Center Of Dash Panel (engine Compartment) Page 5616 (Figure 1) Tie rod clamp & sleeve positioning NOTE: Tie rod adjuster parts often become rusted in service. If the torque required to remove the nut from the bolt after breakaway exceeds 9 Nm (7 ft Lbs), discard the nuts and bolts. Apply penetrating oil between the clamp and tube and rotate the clamps until they move freely and install new bolts and nuts. PROCEDURE Toe-in can be increased or decreased by changing the length of the tie rods. A threaded sleeve is provided for this purpose. When the tie rods are mounted ahead of the steering knuckle they must be: ^ Decreased in length to increase toe-in. ^ Increased in length to decrease toe-in. To adjust, loosen clamp bolts at each end of steering tie rod adjustable sleeves. With steering wheel in straight ahead position, turn tie rod adjusting sleeves to obtain proper adjustment. - After adjusting, check that number of threads showing on each end of sleeve are equal to within 3 threads and that the tie rod end housings are at the right angles to steering arm. - Position tie rod clamps and sleeves, refer to (Figure 1) and torque nuts to 15 ft. lbs. Page 2822 Vehicle Speed Sensor Signal Buffer: Locations Vehicle Speed Sensor Buffer LH Side Of I/P Behind Instrument Cluster Page 4970 This results in the piston seals again being dragged across the layer of corrosion and deposits. Calipers which are not rebuilt or replaced have a higher probability of sticking or leaking. - Check to ensure the bleeder screw is not frozen prior to reinstalling caliper. Freeing a stuck bleeder screw is much easier with the caliper removed from the vehicle. Specifications TEMPERATURE SENSORS Page 5529 Courtesy & Dome Page 4012 Wiring Diagram For Chart C-1A - Park/Neutral Switch Diagnosis CHART C-1A - PARK/NEUTRAL SWITCH DIAGNOSIS Circuit Description: The Park/Neutral Switch contacts are closed to ground in park or neutral and open in drive ranges. The ECM supplies ignition voltage, through a current limiting resistor, to CKT 434 and senses a closed switch, when the voltage on CKT 434 drops to less than one volt. The ECM uses the P/N signal as one of the inputs to control: Idle Air Control VSS Diagnostics EGR Test Description: Numbers below refer to circled numbers on the diagnostic chart. 1. Checks for a closed switch to ground in park position. Different makes of "Scan" tools will read P/N differently. Refer to operators manual for type of display used for a specific tool. 2. Checks for an open switch in drive or reverse range. 3. Be sure "Scan" indicates drive, even while wiggling shifter to test for an intermittent or misadjusted switch in drive range. Diagnostic Aids: If CKT 434 indicates PIN (grounded), while in drive range, the EGR would be inoperative, resulting in possible detonation. If CKT 434 always indicates drive (open), a drop in the idle may exist when the gear selector is moved into drive range. Page 6148 Removing The Pulley Rotor & Bearing Retaining Ring 2. Pulley bearing retainer (3) using J 6083. 3. Pulley (5). Installing The Puller Pilot & Pulley Rotor Slot Location ^ Install J 33023-A to the front head. Installing J-33020 In The Pulley Rotor Slots ^ Install J 33020 tangs into the inner circle of slots in the pulley (5) contact surface. Rotate J 33020 clockwise so the tangs will lock into the segments between the slots. Page 5521 e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors Do Not require all the steps shown. Skip the steps that Do Not apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. 1. Separate connector halves (see Figures 2 through 6). Figure 2 Figure 3 Page 1038 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 Coolant - Information on Propylene Glycol Usage 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. Page 3321 Labor Operation No.: K6550 Valve, Pressure Regulator-R&R; or Replace Use the appropriate labor time in the labor time guide. Parts are currently available from GMSPO. Page 6149 Removing The Puller Bearing ^ Hold J 33020 in place and tighten the puller screw against J 33023-A puller pilot to remove the pulley (5). 4. Pulley bearing (4) from the pulley (5) using J 9398-A and J 29886. ^ When removing the old pulley bearing (5) allow the staking to remain, then file away the old staked metal for proper fit when installing a new bearing (5) in the pulley bore. Install or Connect Tools Required: J 2f352-A Compressor Support Block J 9481-A Pulley Bearing Installer J 33019 Bearing Staking Tool (with staking pin and retaining band) J 33017 Pulley and Bearing Assembly Installer J 33023-A Puller Pilot J 8433-1 Puller Bar J 33026 Compressor Holding Fixture J 6083 Snap Ring Pliers 1. Pulley (5) on J 21352-A. NOTICE: Do not support the rotor by resting the pulley rim on a flat surface during bearing installation or the rotor face will be bent. Page 7384 Brake Warning Indicator: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. Figure 21 Figure 22 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. Page 5451 - 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 Page 952 Figure 3 REMOVE (Figures 2 & 3) Tools required: J8092 Drive handle J33790 Bearing installer and remover 1. Transfer case from vehicle. - Refer to Section 7D of the appropriate S/T Service Manual for complete transfer case removal procedure. 2. Front output flange nut (77), washer (76), rubber sealing washer (75) and front output flange (74) from the front output shaft. 3. Vacuum switch (46) and O-ring seal (47). 4. Poppet screw (68), O-ring seal (69), poppet spring (71) and poppet plunger (70). Mainshaft Extension and Oil Pump Housing 5. Rear extension housing bolts (3) and rear extension (4). 6. Bearing retainer (snap ring) (5) from the mainshaft (19). 7. Pump retainer housing bolts (7). 8. Pump retainer housing (8) from the rear case half (17). 9. Speedometer tone wheel (11) from the mainshaft (19). Page 6650 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 4. Make repair. Page 997 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". Head Lamp Switch Trim Plate - Cracked Headlamp Switch: Customer Interest Head Lamp Switch Trim Plate - Cracked Number: 91-109-10 Section: 10 Date: January 1991 Corporate Bulletin No.: 061605 Subject: CRACKED PLASTIC HEAD LAMP SWITCH TRIM PLATE Model and Year: 1986-91 S/T TRUCKS TO: ALL CHEVROLET DEALERS Figure 1-Plate Assembly-Instrument Panel Switch Trim Some 1986-1991 S/T trucks may experience a cracked plastic head lamp switch trim plate. This may result in the inaccessibility of the rheostat assembly (dimmer switch) and/or the switch assembly (head lamp/park lamp switch) (Figure 1). Previously, it was necessary to replace the complete head lamp switch trim plate assembly. The complete assembly includes the rheostat assembly part number 01995293 (instrument panel dimmer switch), switch assembly part number 01995313 (head lamp/ parking lamp switch) and the switch trim plate (Figure 1), and the switch trim plate hole covers. A new trim plate kit is now available which does not contain the rheostat assembly or the head lamp switch. This kit replaces the complete head lamp switch trim plate assembly when the switch trim plate is cracked and the rheostat assembly or the head lamp switches do not need replacing. This new kit includes; a switch trim plate, bracket for switch mounting, covers for the switch trim plate holes and four bolts/screws. Page 7169 Page 2346 Oxygen Sensor: Service and Repair 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. 1. Disconnect electrical connector from oxygen sensor. 2. Using suitable wrench, carefully remove sensor from exhaust manifold or pipe. The oxygen sensor may be difficult to remove when engine temperature is below 120°F. Use caution, since excessive force may damage threads in exhaust manifold or pipe. 3. If new sensor is being used, install sensor into manifold or pipe. 4. If old sensor is being reused, coat threads with anti-seize compound, Part No. 5613695 or equivalent, then install into manifold or pipe. 5. Torque oxygen sensor to 30 ft. lbs., then reconnect electrical connector. Page 5710 Fig. 4 Adjuster plug removal 1. Install connectors using valve connector installer tool J-6217 or equivalent, Fig. 8. 2. Lubricate 24 balls with power steering fluid, then install alternately by color into rack piston, Fig. 9. Use ball retainer tool J-21552 or equivalent, Fig. 2, to hold balls inside. 3. Install balls in ball guide alternately by color, retain in guide with petroleum jelly. Fig. 10. 4. Connect ball guide, clamp and screws to rack piston. 5. Lubricate stub shaft, valve spool and seals with power steering fluid, then install into valve body. 6. Connect valve body, seal, worm shaft, races and roller bearing. 7. Install seal on adjuster plug, then needle bearing in adjuster plug using J-8524-1 and J-7079-2 or equivalent. Fig. 11. 8. Install seal, washer and retaining ring in adjuster plug. Retainer projections must not extend beyond washer when retainer ring is seated. Washer must rotate freely. 9. Install worm shaft and valve assembly into gear housing. 10. Install adjuster plug into gear housing using spanner wrench tool J-7624 or equivalent, Fig. 4. Page 1345 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 Page 1988 The toll free number for Kent Moore is 1-800-345-2233. Portions of this article were reprinted with permission, from Dow Chemical Canada, Inc., P.O. Box 1012, Sarnia, Ontario N7T 7K7. Engine - Miss, Hesitation, or Roughness Spark Plug Wire: All Technical Service Bulletins Engine - Miss, Hesitation, or Roughness Number: 93-35-6D Section: 6D Date: OCT. 1992 Corporate Bulletin No.: 716404R ASE No.: A1, A8 Subject: ENGINE MISS HESITATION OR ROUGHNESS DUE TO PIERCED SECONDARY IGNITION COMPONENTS Model and Year: 1980-93 ALL PASSENGER CARS AND TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 87-121, DATED MAY 1987. THE 1989-93 MODEL YEARS HAVE BEEN ADDED. ALL COPIES OF 87-121 SHOULD BE DISCARDED. During the diagnosis procedure for an engine miss, hesitation or roughness, a spark plug or spark plug wire condition may be suspected. Several types of commercial or homemade diagnostic equipment required the secondary ignition boots or wire to be pierced. This is normally done to check for spark plug firing or to perform a cylinder balance test. Similarly the use of pliers or other such tools to disengage a spark plug boot may pierce or damage the boot or wire. Secondary ignition components should not be pierced for any reason. Piercing a spark plug wire and/or distributor boot may create a condition that will not be immediately apparent. Over time, the hole in the pierced boot may allow a ground path to develop creating a plug misfire condition. Heavily moisture laden air in the vicinity of the pierced boot may accelerate this effect. Piercing a secondary ignition wire creates a gap in the wire's conductive core. This gap is a point of high resistance. The current flow in the wire will increase to compensate for the higher wire resistance. Over time, the wire may fail creating a plug misfire condition. The time required for the condition to appear depends upon the extent of damage to the conductive core. To help prevent future condition that are spark plug wire related, do not pierce or otherwise damage any secondary ignition component. Only use diagnostic equipment containing an inductive pick-up to check for spark plug firing or to perform cylinder balance tests. When disengaging a spark plug boot from the spark plug, twist the flanged boot 1/2 turn then pull on the boot only to remove the wire. 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. Page 274 J 5403 Snap Ring Pliers J 33011 O-ring Seal Installer 1. O-ring seals (44) to the switch cavity with J 33011. ^ Dip the O-ring seals into clean 525 refrigerant oil. 2. Switches (3) and (4). 3. Retainers (45). Page 4149 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 Page 5126 When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 5mm (3/16") of insulation from wire. e. Crimp a new terminal to the wire. f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. Figure 17 To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Figure 18 Figure 19 Locations Combination Switch: Locations LH Side Of Steering Column Behind Instrument Cluster Page 7795 Figure 4 Figure 5 Figure 6 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 7 Adjustments Brake Switch (Cruise Control): Adjustments With brake or clutch pedal depressed, push valve or switch fully into tubular clip until seated. Pull brake or clutch pedal rearward until pedal is against stop. Valve or switch will travel in tubular clip to provide proper adjustment. Page 5361 Warranty Information (excluding Saab U.S. Models) For vehicles repaired under warranty, use the appropriate labor operation for the source of the water leak Warranty Information (Saab U.S. Models) For vehicles repaired under warranty, use the table. Disclaimer Page 774 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 Page 6966 4. Remove the retention spring from the mirror bracket (Figure 2, Item A). 5. Drill and tap the retention spring, on the rear side wing, so that it will accept a 6.0 mm X 1.0 mm (diameter X thread pitch) set screw fastener (Figure 3, Item A) (procured locally). The approximate fastener length should be 10 mm. NOTE: The hole must be drilled perpendicular to the flat surface of the retention spring's wing. 6. Reinstall the retention spring in the mirror bracket. 7. Reinstall the mirror head and arm to the mirror bracket. 8. Reinstall the mirror assembly to the door. 9. Install the 6.0 mm X 1.0 mm headed fastener, adjusting it to obtain the original pressure against the mirror arm. DO NOT over-torque this fastener. 10. Reinstall the screws which secure the mirror cover to the door. WARRANTY INFORMATION For vehicles repaired under warranty, use: Labor Description Labor Time Operation R3260 RH mirror R&R; 0.4 Hr. Page 6121 Installing The Coil Housing 2. Clutch coil (8) to the front head (16). ^ Align the coil and housing assembly on the compressor front head (16) 50 that the electrical terminals line up the marks scribed on the compressor ^ Align the coil locator projections on the coil housing with the holes in the front head (16). 3. Coil and housing retainer ring (7) with J 6435. Clean ^ Remove any excess adhesive. 4. Pulley and bearing assembly (5 and 6). 5. Clutch plate and hub assembly (2). Page 4177 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. 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 Page 6146 J 33026 Compressor Holding Fixture J 33027 Clutch Hub Holding Tool J 33022 6-Point 13 mm Socket J 33013-B Hub and Drive Plate Remover and Installer 1. Shaft key (1). Positioning The Shaft Key, Clutch Plate & Hub Assembly ^ Allow the shaft key (21) to extend 3.2 mm (118-inch) out of the bottom of the hub keyway. ^ The shaft key is curved slightly to give an interference fit in the groove. Important ^ Do not drive or pound on the clutch hub or the shaft (20). Internal damage to the compressor may result. Installing The Clutch Plate & Hub Assembly 2. Clutch plate and hub assembly (2). ^ Make sure the contact surfaces of the clutch plate (2) and the pulley (5) are clean. ^ Remove the forcing screw tip from J 33013-B and reverse the body direction on the center screw. ^ Install J 33013-B with bearing. ^ Back off J 33013-B body enough to allow the center screw to be threaded against the end of the compressor shaft. ^ Hold the center screw with a wrench and tighten the hex portion of J 33013-B body while pressing the hub onto the shaft. After tightening the Locations Fuel Filler Neck Engine - Generator Belt Tension Drive Belt: All Technical Service Bulletins Engine - Generator Belt Tension GMC NUMBER: 88-T-36 GROUP: 6D - Engine Electrical DATE: September, 1987 CORPORATE NUMBER: 866403 SUBJECT: GENERATOR BELT TENSIONING - CS-130 GENERATORS MODELS: 1986 - 1988 LIGHT DUTY MODELS EQUIPPED WITH CS-130 GENERATORS Some 1986-1988 Light Duty models are equipped with CS-130 Delcotron generators and without automatic belt tensioning equipment. On these applications, the generator belt tension is adjusted by forcing the generator against the belt until the belt tension specification is reached. FIGURE 1 As with several other Delcotron models, the CS-Series housing includes an adjustment lug on the drive end frame (see Figure No. 1) which should be used to push the generator against the belt while the adjustment bolt is tightened. A 3/4" wrench (or equivalent) should be used when holding the generator by this lug. If the vehicle configuration does not permit use of the adjustment lug, pressure may be applied to the side of the drive end frame to tighten the belt. If pressure cannot be applied directly to the drive end frame, a block of wood should be inserted between the prying instrument and the side of the generator to distribute the force to a wider area which includes the drive end frame. Do not pry directly against the stator or slip ring end frame. Rearview Mirror, Outside - Vibration Mirrors: All Technical Service Bulletins Rearview Mirror, Outside - Vibration Group Ref.: Body Bulletin No.: 461001 Date: April, 1994 SUBJECT: OUTSIDE REAR VIEW MIRROR VIBRATION (INSTALL SET SCREW FASTENER) MODELS: 1982-93 CHEVROLET AND GMC TRUCK S/T PICKUPS 1983-94 CHEVROLET AND GMC TRUCK S/T UTILITIES WITH D44 OR D45 MIRRORS CONDITION: Some owners may comment that their outside rear view mirrors vibrate. CAUSE: Force is applied against the mirror arm by a retention spring wedged between the mirror bracket and mirror arm to prevent mirror rotation. Over time, this spring force decreases allowing the mirror arm to move or vibrate. CORRECTION: This condition can be corrected by drilling and tapping a hole in the retention spring to accept a set screw fastener. The fastener can be adjusted to force the spring against the mirror arm, restoring the original pressure. SERVICE PROCEDURE: 1. From outside the vehicle, remove the screws which secure the mirror cover and the mirror assembly to the door (Figure 1). 2. Remove the mirror assembly from the door. 3. Remove the mirror head and arm from the mirror bracket. Page 667 Distributor: Service and Repair INSTALLATION: REMOVAL: 1. Disconnect the negative battery terminal. 2. Disconnect the wiring connectors at the side of the distributor cap. 3. Remove the distributor cap and move it out of the way. a. Scribe a mark on the engine in line with the rotor. b. Note the position of the distributor housing in relation to the engine. 4. Remove the distributor hold-down nut and clamp. 5. Remove the distributor. INSTALLATION: NOTE: a. To ensure correct timing of the distributor, the distributor must be installed with the rotor correctly positioned as noted. If the engine was accidentally cranked after the distributor was removed, the following procedure can be used for installing. a. Remove the number 1 spark plug. b. Place finger over the number 1 spark plug hole and crank engine slowly until compression is felt. c. Align timing mark on pulley to "0" on engine timing indicator. d. Turn rotor to point to the 1 spark plug tower on the distributor cap. b. If the distributor shaft will not drop down flush with the engine, it may be necessary to rotate the oil pump drive shaft to align it with the slot on the bottom of the distributor drive gear. Insert a screwdriver into the distributor hole in the engine and turn the oil pump drive shaft slightly to allow alignment. 1. Install the distributor. 2. Install the distributor hold-down clamp and retaining nut. 3. Install the distributor cap. 4. Connect the wiring harness connector at the side of the distributor cap. 5. Connect the negative battery cable. 6. Set ignition timing to specification. Specifications Absolute Pressure Sensor: Specifications MANIFOLD ABSOLUTE, VACUUM AND BAROMETRIC PRESSURE SENSORS Engines may use one, or a combination of these sensors. All sensors appear the same. Manifold Absolute Pressure sensors have a vacuum line connected between the unit and manifold vacuum. On Barometric Pressure sensors, the line is not used and the connector is either open or has a filter installed over it. Pressure sensors also have a vacuum line between the sensor and intake manifold and only appear on carburetted models. Barometric Pressure Sensors: Measure voltage with ignition on and engine off. Manifold Absolute Pressure Sensors: Measure voltage with ignition on and engine off. Start engine and apply 10 in./ 250 mm Hg to unit, voltage should be 1.2-2.3 volts less. Pressure Sensors: Measure voltage as indicated. Page 440 Oil Pressure Switch (For Fuel Pump): Service and Repair REMOVAL: 1. Disconnect negative battery cable from battery. 2. Remove sensor or switch connectors. 3. Remove sensor or switch. INSTALLATION: 1. Install sensor or switch. 2. Connect sensor or switch. 3. Reconnect negative battery cable. Page 4089 FIGURE 2 DATE OF PRODUCTION CHANGE: By October 6, 1986 (Julian Date 279) (Figure No. 2) all 1987 THM 700-R4 transmissions were produced with an auxiliary valve body for an improved drive engagement shift feel. As part of this change, the lo and reverse #5 checkball located in the valve body assembly (Figure No. 3) was eliminated, and a new forward clutch checkball (#12-Figure No. 1) was added to the Auxiliary Valve Body. All 1987 Service Replacement Transmission Assembly (SRTA) units have this change. FIGURE 1 - CHECKBALL LOCATIONS ON TRANSMISSIONS WITH AUXILIARY VALVE BODIES NOTICE: 1987 Service Manuals refer to the forward clutch checkball (#55B) in the auxiliary valve body as #5. To avoid confusion with the lo and reverse #5 checkball in a THM 700-R4 transmission produced without an auxiliary valve body (#55B-Figure No. 3), the forward clutch checkball has been changed to #12 (#55B-Figure No. 1). Service and Repair Crankshaft Main Bearing Seal: Service and Repair Fig. 17 Installing Rear Main Oil Seal 1. Remove transmission. 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 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. Page 5222 - 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 Page 6613 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) Drive Belt - Making Chirp Noise Drive Belt: Customer Interest Drive Belt - Making Chirp Noise Number: 88-291-7A Section: 7A Date: JULY, 1988 Subject: SERPENTINE BELT CHIRP Model and Year: 1988 S/T TRUCKS W/4.3L (VIN CODE Z) ENGINE TO: ALL CHEVROLET DEALERS Some owners of 1988 4.3L S/T trucks may experience a chirping noise from the accessory drive belt. "Belt Chirp" is a short duration, intermittent, high pitched sound and should not be confused with belt "squeal", which is continuous in nature. This condition can be addressed by aligning the power steering pump pulley 3/4 mm plus or minus 1/4 mm (.030" plus or minus .010") forward of flush with the power steering pump shaft (See Illustration). A wheel puller should be used to perform this realignment. Labor Operation Number: T7460 Labor Time : .3 Hours Page 7821 When using a new terminal: a. Slip cable seal away from terminal (if seal exist). b. Cut wire as close to terminal as possible. c. Slip a new cable seal onto wire (if necessary). d. Strip 5mm (3/16") of insulation from wire. e. Crimp a new terminal to the wire. f. Solder with rosin core solder. g. Slide cable seal toward terminal (if equipped with a seal). h. Crimp cable seal and insulation (if equipped with a seal). i. Apply grease to connectors outside the passenger compartment where the connector originally was equipped with grease. Figure 17 To re-use a terminal or lead assembly, see previous steps c through i for repairs. Be sure to keep cable seal (if equipped) on terminal side of splice. 5. Insert lead from the back until it catches. 6. Install TPA's, CPA's and/or secondary locks, if equipped (see Figures 18 & 19). Figure 18 Figure 19 Page 6847 Page 5609 Thrust Angle Description WHEEL ALIGNMENT DEFINITIONS Wheel alignment refers to the angular relationship between a vehicles wheels, suspension attaching points, and the ground. Vehicles with properly aligned front and rear suspensions handle predictably, and provide good straight line stability on the highway with minimal tire wear. In real world driving conditions, wheel alignment settings change over time due to suspension component wear or damage; they must be periodically checked and adjusted as necessary. TOE IN/OUT Toe is a measure of how far a wheel is turned in or out from the straight ahead direction. When the front of a wheel is turned in, the toe is positive. When turned out, the toe is negative. CAMBER Camber is a measure of wheel tilt from the vertical direction, when the wheel is viewed from the front or rear of the vehicle. Camber is negative when the top of the wheel tilts inward and positive when the top of the wheel tilts outward. CASTER Caster is a measure of the angle between the steering axis and vertical when viewed from the side of the vehicle with the wheel in the straight ahead position. The steering axis is determined by the location of the lower control arm ball joint and the center of the strut-to-body attachment. A line drawn through the center of the ball joint and the strut-to-body joint represents the steering axis. When the center point of the strut-to-body attachment is rearward of the ball joint, the caster is positive. When the center of the strut-to-body attachment is forward of the ball joint, the caster is negative. THRUST ANGLE Thrust angle is the angle between the geometric centerline of the vehicle and the direction that the rear wheels track. Ideally, the thrust angle is equal to zero. Page 7167 Windshield molding Bumper filler panels, Ft./Rr. Wiper arms Antenna Wheel opening moldings Cowl vent grille Door edge guards Side view mirrors Tail lamps *Wind deflector Rear Window (Jimmy) *Luggage rack *Stripes Emblems/decals if necessary Swing out windows/seals *Spare tire carrier and latch-external mount (Jimmy) M/L VANS Windshield molding Wheel opening moldings Headlamp bezels Antenna Tail lamps Door edge guards *Luggage rack *Stripes Emblems/decals if necessary R/V TRUCKS Wiper arms Cowl vent grille Antenna Tail lamps Hood ornaments Wheel opening moldings Side view mirrors Grille and headlamp bezels Door edge guards Bumper filler panel, Frt./Rr. Front side marker lamps *Roof marker lamps *West coast style mirrors *Stripes Emblems/decals if necessary G VANS Wiper arms Cowl vent grille Grille and headlamp bezels Front bumper filler panel Antenna Side view mirrors Side marker lamps Tail lamps Door edge guards Wheel opening moldings *Roof marker lamps *West coast style mirrors *Stripes Emblems/decals if necessary Swing out windows/seals Page 5352 15. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 16. Install the electrical ground wire terminal to the rivet stud. 17. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 18. Install the M6 conductive nut to the rivet stud and: Tighten Tighten to 8 Nm (71 lb in). 19. Verify proper system operation. M6 Weld Nut Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M6 weld nut at the electrical ground location is damaged or stripped, a M7 conductive self-threading bolt may be used to secure the ground wire terminal. 2. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the weld nut and allow to dry. 3. Remove any loose metal particles from the damaged or stripped weld nut with a stiff brush. 4. Select a M7 conductive self-threading bolt. Refer to the Parts Information section of this bulletin 5. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M7 conductive self-threading bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 6. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 7. Install the electrical ground wire terminal to the M7 conductive self-threading bolt. 8. Install the M7 conductive self-threading bolt and: Tighten Tighten to 9 Nm (80 lb in). 9. Verify proper system operation. M6 Weld Nut Alternative Repair Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the electrical ground location is accessible from both sides of the panel, a M6 conductive bolt and a M6 conductive nut may be used to secure the electrical ground wire terminal. Refer to the Parts Information section of this bulletin. 2. Select a location adjacent the damaged M6 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the new electrical ground site. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the ground location and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 8.5 mm (0.33 in) diameter hole through the panel. 5. Remove paint and primer from the area surrounding the 8.5 mm (0.33 in) hole until bare metal is visible. 6. Select a M6 conductive bolt. Refer to the Parts Information section of this bulletin. 7. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 8. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 9. Install the electrical ground wire terminal and the M6 conductive bolt to the ground location. 10. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 11. Install the M6 conductive nut to the bolt and: Page 5954 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 Specifications Fuel Pressure: Specifications FUEL PRESSURE: Ignition ON Engine OFF ...................................................................................................................... ................................................. 62-90 kPa (9-13 psi) Wheels (Steel) - Damage Due to Improper Mounting Wheels: All Technical Service Bulletins Wheels (Steel) - Damage Due to Improper Mounting Number: 92-232-3E Section: 3E Date: JUNE 1992 Corporate Bulletin No.: 233002 ASE No.: A4 Subject: AVOIDING DAMAGE TO STEEL WHEELS FROM IMPROPER WHEEL/TIRE CHANGING TECHNIQUES Model and Year: 1983-92 ALL PASSENGER CARS AND TRUCKS WITH STEEL WHEELS It is important to use proper procedures to prevent damage to either the tire mounting surface or the wheel mounting holes. Damage can result from the improper wheel attachment or tire mounting techniques on vehicles with steel wheels. 1. IMPROPER TIRE CHANGING TECHNIQUES: It takes about 70 seconds for the air to completely exhaust from a large tire. If the technician doesn't wait this amount of time after removing the valve core, the bead breaker on the tire change could put enough force on the tire to bend the wheel at the mounting surface. Such damage can result in vibration, shimmy, and under severe usage (i.e. police vehicle) lead to cracking. 2. OVER TORQUING OF THE WHEEL NUTS: The service specification for wheel nuts is listed in the Service Manuals. Some wheels have been observed with wheel nuts that were over torqued by as much as 50 percent. This may damage the wheel mounting holes and may also lead to cracks. I. PROPER TIRE CHANGING TECHNIQUES: Completely deflate the tire before attempting to break the tire bead loose. MOUNTING SURFACE CHECKING PROCEDURE Page 5175 Symbol Identification Page 6215 Owners of some 1986-92 S/T Trucks equipped with air conditioning may comment on loose or binding temperature control or HVAC mode selection levers. These conditions may be caused by broken housing bosses at the plate mounting screws on the A/C control (Figure 3). The result may be inability to actuate certain HVAC modes or obtain maximum heating or cooling. Previously it was necessary to replace the complete A/C control assembly to correct this condition. The control assembly included the valves, switches, bezel and lighting. The housing, P/N 16074394, is now available allowing this condition to be corrected when other parts of the control are operating properly. Partial disassembly of the A/C control is required. SERVICE PROCEDURE: 1. Remove the A/C control assembly from the instrument panel. Page 953 10. Case bolts (3) from the case halves. - Note the two longer bolts (16) and washers go into doweled case holes (33). - Separate case halves, insert screwdrivers into the slot cast in the case ends and pry apart. Do not attempt to wedge the case halves apart at any point on the mating surfaces. - Be careful not to damage the oil pump (12) (located in the rear case half) while removing the rear case half (17). Internal Components 11. Fork shift spring (52). 12. Mainshaft (19)/drive sprocket 14071703 (20), chain (58) and front output shaft (21) as a unit. Mode shift fork (54) and shift rail (48) will be removed with the mainshaft. INSPECT: The teeth of the synchronizer stop ring (28) and drive sprocket (20) for damage. If they are damaged, or in cases of customer complaint of clash when shifting from 2Hi to 4Hi, follow steps 13, 14 & 15, otherwise skip to step 16. 13. Retainer (snag ring) (83) from the mainshaft (19). 14. Synchronizer assembly (81). 15. Drive sprocket (20) from the mainshaft (19). 16. Range shift fork (51), range shift hub (34) and sector with shaft (55) from the planetary carrier (36). - It is necessary to rotate the sector with shaft (55) to obtain clearance when removing the range fork (51). 17. Plastic washer (retainer) (66) and O-ring seal (67) from the front case half. IMPORTANT: Group B vehicles should complete step 17 and skip to INSTALL step 8. 18. Input bearing retainer bolts (43) and input bearing retainer (44) from the front case half (45). 19. Retainer snap ring from the input gear (38). 20. Planetary carrier (36) and the input gear (38) from the annulus gear (62) using a soft hammer. 21. Input bearing retainer (39) and input bearing (40). 22. Front output bearing retainer ring (snap ring) (60). 23. Front output bearing (61) from the front case half (45) using J33790, and J8092. 24. Seal (42) from the input bearing retainer (44) if it shows signs of damage. Install Page 4821 Caliper Knuckle Clearances 5. Measure the clearance between the caliper and the steering knuckle. The clearance at each end of the caliper should be measured individually and added together. this total should be between 0.26-0.60 mm (0.010-0.024 inch). 6. If brake hose was removed, reconnect it and bleed the brakes. 7. Install wheels and tires, lower vehicle and add brake fluid to master cylinder to bring level to 1/4 inch from top. WARNING: Before moving vehicle, pump brake pedal several times to be sure it is firm. Do not move vehicle until a firm pedal is obtained. Exhaust Manifold Heat Shield - Rattles Heat Shield: Customer Interest Exhaust Manifold Heat Shield - Rattles Number: 91-421-6F Section: 6F Date: SEPT. 1991 Corporate Bulletin No.: 166604 ASE No.: A8 Subject: EXHAUST HEAT SHIELD RATTLE Model and Year: 1988-91 S1/T1 TRUCKS WITH 4.3L ENGINE Windshield Washer Bottle - Cracking Windshield Washer Reservoir: All Technical Service Bulletins Windshield Washer Bottle - Cracking Number: 91-31-8E Section: 8E Date: July 1990 Corp. Bulletin No.: 061010 Subject: WASHER BOTTLES CRACKING Model and Year: 1988-91 S/T TRUCKS TO: ALL CHEVROLET DEALERS Some 1988 - 1991 S/T trucks may be experiencing a condition of windshield wiper washer bottles cracking and then leaking washer fluid. This condition can be caused by an increased amount of pressure exerted by the two fastening nuts and screws. This increase of pressure causes the screws to cut into the plastic and initiate cracks. To correct the situation new parts have been released with a wider flange, and the torque requirement has also been revised. The new torque requirement is now 5-8 N-m (3.7 - 5.9 lbs. ft.) instead of the old 8-11 N-m (5.9 - 8.1 lbs. ft.). When ordering a new washer bottle be sure and order new bolts and nuts with the revised flanges. SERVICE PARTS INFORMATION Part Number Description Usage 11509005 nut 2 per bottle 15653669 bolt 2 per vehicle 22072762 container and grommet 1 per vehicle Parts are currently available through GMSPO. WARRANTY INFORMATION For vehicle repaired under warranty use: Labor Operation: N3750 Labor Time: .2 hr. Page 855 - In commercial service (taxi or police use). ^ If the vehicle has been operated under these conditions, shut the engine off and allow the vehicle to "cool" for thirty (30) minutes. After the cooldown period, restart the vehicle and continue from step "2" above. Page 3574 Page 7770 Figure 4 Figure 5 Figure 6 2. Release terminal using proper pick or removal tool. Gently pull cable and terminal out the back of the connector (see Figures 7 through 11). Figure 7 Page 4306 Figure 15 - Large Retaining Clamp Installation 13. Secure the large metal clamp and seal to the housing with tool J35910, breaker bar and torque wrench. Torque the large clamp to 176 N-m (130 lbs.ft.). Check clamp ear gap dimension (Figure 15). Halfshaft Installation: 1. Prior to halfshaft installation, cover shock mounting bracket, lower control arm ball stud, and all other sharp edges with shop towels so that the seal is not damaged during assembly. 2. Remove convolute retainer. 3. Insert and draw up outer C/V joint splined shank into knuckle hub; then secure inboard C/V joint flange to companion flange with bolts (do not tighten). Install hub nut washer and nut. Seat shank splines in hub. 4. Connect the upper ball joint to the steering knuckle. 5. Attach the stud nut and torque 83 N-m (61 lbs.ft.). 6. Install new cotter pin. 7. Lubricate the upper ball joint until grease appears at the seal. 8. Remove floor jack or stand from beneath lower control arm, if used. 9. Connect the shock absorber to the lower shock mounting bracket. 10. Attach the shock mounting bolt and nut. Torque the nut and bolt to 73 N-m (54 lbs.ft.). 11. Attach outer tie rod to steering knuckle. 12. Install tie rod nut and torque to 47 N-m (35 lbs.ft.). Important: Advance the nut to align the nut slot with the cotter pin hole. Never back the nut off to align the cotter pin hole. 13. Install new cotter pin and spread the ends to secure. 14. Attach the brake line support bracket to the upper control arm. Torque to 17 N-m (13 lbs.ft.). Important: Make sure that the brake hose is not twisted or kinked or damage to the hose could result. Diagram Information and Instructions Oil Pressure Gauge: Diagram Information and Instructions 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 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. Page 5844 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. Page 6701 Parts Information Parts required to complete this special coverage are to be obtained from General Motors Service and Parts Operations (GMSPO). Customer Notification General Motors will notify customers of this special coverage on their vehicles. Service Procedure Replacement of interior door handle assembly(s) Provide the customer with one or two interior front door handle assemblies. The customer is to self-install the assemblies or pay the dealer for the installation. Application of Lithium Grease Apply lithium based lubricant to the door handle springs. The lubricant should be applied so that it works into and between the spring coils, allowing the coils to move past each other freely. Claim Information Due to the age of the vehicles involved in this program, most involved VINs will be added to GMVIS to allow submission of claims. However, there are a few VINs that were not legible and could not be loaded into GMVIS. If a customer presents a letter authorizing repairs but the VIN is not found in GMVIS, H-route the claim to your AVM for approval. Page 2782 Throttle Position Sensor: Service and Repair REMOVAL: 1. Disconnect electrical connectors. 2. Remove the TPS attaching screw assemblies and retainer, (if applicable). 3. Remove TPS from throttle body assembly. NOTE: The TPS is an electrical component and must not be soaked in any liquid cleaner or solvent, as damage may result. INSTALLATION: 1. Install TPS to throttle body assembly, while lining up TPS lever with TPS drive lever on throttle body. 2. Install the two attaching screw assemblies. Tighten screw assemblies to 2.0 Nm (18.0 lb-in). 3. Install electrical connector to TPS. 4. Check for TPS output as follows: a. Connect an ALDL scanner to read TPS output voltage. b. With ignition ON and engine stopped, TPS voltage should be less than 1.25 volts. If more than 1.25 volts, replace TPS. Page 4606 T7251 Group A 3.2 hr. T7261 Group B 2.8 hr. NOTE: Labor Operation is coded to base vehicle coverage in the warranty system. Page 986 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 IP Dimmer Control - Proper Setting Instrument Cluster / Carrier: All 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 Locations Idle Speed/Throttle Actuator - Electronic: Locations Center Of Dash Panel (engine Compartment) Center Rear Of Engine Applicable to: V6-262/4.3L Engine Page 1839 Oil Pressure Switch (For Fuel Pump): Service and Repair REMOVAL: 1. Disconnect negative battery cable from battery. 2. Remove sensor or switch connectors. 3. Remove sensor or switch. INSTALLATION: 1. Install sensor or switch. 2. Connect sensor or switch. 3. Reconnect negative battery cable. 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. Page 3507 Accumulator: Specifications Accumulator Cover To Case ............................................................................................................... ...................................................................... 8 ft. lbs. Electrical - MIL ON/DTC's Set By Various Control Modules Wiring Harness: 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 Page 7425 e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors Do Not require all the steps shown. Skip the steps that Do Not apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. 1. Separate connector halves (see Figures 2 through 6). Figure 2 Figure 3 Number 1 Cylinder Location Number One Cylinder: Locations Number 1 Cylinder Location NUMBER ONE CYLINDER LOCATION Page 2137 FIGURE 1(T-TRUCK ONLY) G. (T-truck only) Check equalizer lever for firm contact at the shift lever inboard side of the guide slot. (See Figure 1) H. If firm contact is evident, add an additional washer (#10 in Figure #1) P/N 14074908 to adjust equalizer lever outboard toward the center of the guide slot to eliminate contact. 2. A. Raise vehicle on hoist. B. Note location of clamp rotation on pipe. Some clamps are located with the lower lock ring (nuts) pointed towards the transmission. If the clamp is located in such a manner, loosen clamp and rotate it down so the nuts point toward the ground and retighten to 58 N-m (43 ft/lbs.) 3. A. Loosen converter clamp until it will rotate around the pipe. Using a suitable pry bar, move exhaust system rearward to obtain a minimum of 5/8 in. clearance between any point on the exhaust system and the transmission crossmember. For repairs performed under warranty, use the following labor operations and times: Labor Operation Labor Time Exhaust/muffler clamp L2020 .3 Hr Exhaust system align L2004 .3 Hr Shift Linkage (shorten) K5244 .3 Hr Page 2032 DISCLAIMER Page 7433 Check Gauges Lamp: Testing and Inspection Page 6344 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 Page 7713 Courtesy Lamp: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. Figure 21 Figure 22 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. Page 6185 Compressor Shaft Seal: Service and Repair With DA-V5 Compressor DA-V5 Compressor Component View Remove or Disconnect Tools Required: J 5403 Snap Ring Pliers J 9553-01 O-Ring Seal Remover J 23128-A Seal Remover and installer J 34614 Shaft Seal Protector 1. Clutch plate and hub assembly (22). ^ Install J 34614 over the threaded end of the shaft (38). Tires (Front) - Irregular Wear Tires: Customer Interest Tires (Front) - Irregular Wear Number: 91-26-3E Section: 3E Date: June 1990 Corp. Bulletin No: 053501 Subject: FRONT TIRE WEAR Model and Year: 1982-91 LIGHT DUTY TRUCKS (REAR WHEEL DRIVE) THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 91-12-3E. THE KILOMETERS HAVE BEEN TRANSLATED INTO MILES. ALL COPIES OF 91-12-3E SHOULD BE DISCARDED. Rear wheel drive trucks, equipped with All Season and/or On-Off road tires may exhibit irregular wear of; the front tires. Small amounts of irregular wear is considered normal and is not necessarily a result of incorrect alignment. Incorrect alignment (especially toe) may result in premature wear of the front tires, however agressive cornering may also have a similar effect. Drive axle tires are much less prone to irregular wear, therefore they should not be considered for comparison of wear to non-drive axle tires. The rate of irregular wear is also dependent upon the depth of tread. New tires are more prone to irregular wear, so it is essential that tires are rotated at the proper intervals to normalize the wear. Page 2373 Oil Pressure Switch (For Fuel Pump): Testing and Inspection Refer to DIAGNOSTIC CHARTS/FUEL PUMP RELAY CIRCUIT DIAGNOSIS (CHART A-5), for fuel related oil pressure switch problems. Instruments - Generator Light Flickers, Pulse Wipers ON Charge Lamp/Indicator: All Technical Service Bulletins Instruments - Generator Light Flickers, Pulse Wipers ON GMC NUMBER: 89-T-85 GROUP: 6D - Engine Electrical DATE: July, 1989 CORPORATE NUMBER: 966402R SUBJECT: GENERATOR LIGHT FLICKER DURING PULSE WIPER OPERATION MODELS: 1988-89 S/T WITH 2.8L OR 4.3L ENGINE The generator light flicker condition in the 1988 and 1989 S/T instrument panel during pulse wiper switch operation can be caused by negative voltage transients from the wiper motor There is no possibility of a system failure as a result of this condition. The effect of this condition is that the generator light will turn on for 80 milliseconds (if gages, the voltage drop on the voltmeter lasts 2.5 seconds). This causes no harm to the generator or other electrical components. Subject condition can be eliminated by installing a diode (industry part number 1N4003) or diode/connector kit (diode kit part number 12085207) in the brown wire at the generator connector (circuit 25 at connector C118). See the following pages in the 1988 and 1989 S/T Electrical Wiring Diagrams for circuit 25, connector C188 locations: 1988 4.3L: Section C - Page 24 1988 2.8L: Section C - Page 22 1989 4.3L: Page 40 1989 2.8L: Page 39 PARTS INFORMATION: Quantity Part Number Description 1 12085207 Diode OR 1 *1N4003 Diode *This part available locally. Parts are currently available from GMSPO. INSTALLATION PROCEDURE: 1. Disconnect the battery. 2. Remove the connector from the generator. 3. Peel back the black plastic conduit covering the wires. 4. If installing diode 1N4003: cut out a section of the brown wire that matches the length of the diode. 4A. A diode/connector kit is also available (GMSPO diode kit part number 12085207). If using the kit cut out approximately four inches of the brown wire, following crimping and soldering instructions in the kit. Spiral tape the solder joints and tuck the wire back into the conduit away from the generator Secure the diode/connector to the outside of the conduit with electrical tape. 5. Solder in diode with the banded end toward the generator. 6. Tape the solder and diode. 7. Reinstall the black plastic conduit. 8. Reconnect connector to the generator. 9. Reconnect battery. This procedure will not affect the operation of the generator light during the bulb check at the beginning of the start cycle. For vehicles repaired under warranty use Page 6133 Compressor Clutch: Service and Repair With DA-V5 Compressor Clutch Plate and Hub Assembly Clean ^ The compressor assembly with solvent and blow dry with dry air. Remove or Disconnect Tools Required: J 33013-B Hub and Drive Plate Remover and Installer J 33022 6-Point 13 mm Socket J 33027 Clutch Hub Holding Tool J 34992 Compressor Holding Fixture ^ Clamp J 34992 in a vise and attach the compressor to the holding fixture with thumb screws. Removing The Shaft Nut 1. Shaft nut (21) using J 33022. ^ Hold the clutch plate and hub assembly (22) steady using J 33027. 2. Clutch plate and hub assembly (22). ^ Thread J 33013-B into the clutch plate and hub assembly (22). Windshield/A Pillar - Pop Noise Diagnosis Dashboard / Instrument Panel: Customer Interest Windshield/A Pillar - Pop Noise Diagnosis Number: 93-25-10 Section: 10 Date: OCT. 1992 Corporate Bulletin No.: 262001 ASE No.: B1 Subject: POP NOISE FROM WINDSHIELD PILLAR AREA Model and Year: 1983-93 S/T TRUCKS REFERENCE COWL "POP" TAPPING NOISE CHEVROLET DEALER SERVICE BULLETIN NUMBER 91-351-10, DATED JUNE 1991. Owners of some 1983-1993 S/T Pickups and Utilities may comment on a cowl "pop" noise transmitted through the "A" pillar. It has been determined that sections other than the windshield cowl area may produce a sound which imitates cowl "pop". PRIOR TO PERFORMING ANY CORRECTION FOR COWL "POP" TAPPING NOISES, VERIFY THE SOURCE OF THE NOISE(S) TO DETERMINE IF IT IS A VALID COWL "POP" CONDITION. Possible noise areas to check are: ^ Instrument panel "pop"/noise. ^ Loose door lock rods. ^ Loose wires/harnesses contacting the wall of the engine/passenger compartment (cowl). ^ A lack of door hinge lubrication. ^ An Electronic Control Module (ECM) bracket "pop". ^ An ash tray rattle. ^ An air vent squeak. ^ Hood hinge "flutter"/rattle. INFORMATION: 1. INSTRUMENT PANEL (I/P) "POP"/NOISE sound at the front edge of the I/P may occur if the I/P pad rubs against the cowl/dash support panel. Refer to "Instrument Panel Pad to Cowl Panel "Pop" Noise" Chevrolet Dealer Service Bulletin Number 92-286-10, dated Sept. 1992. 2. LOOSE DOOR LOCK RODS may vibrate during vehicle operation creating a rattle type noise. Refer to "Front Door Lock Rod Rattle" Chevrolet Dealer Service Bulletin No. 91-406-10, dated August 1991. 3. THE ELECTRONIC CONTROL MODULE (ECM) WIRING HARNESS CLIP may not be properly attached at the transmission bellhousing bolt allowing contact with the floor pan/front of dash area. This sound may be amplified by the HVAC ductwork. 4. LOOSE WIRES/HARNESSES maybe tapping against the engine/passenger compartment wall (cowl). 5. LACK OF DOOR HINGE LUBRICATION - Insufficient lubrication may create a binding/squeaking condition. 6. AN ECM BRACKET "POP" sound may occur if the ECM moves within its mounting bracket. 7. AN ASH TRAY BRACKET RATTLE coming from the ash tray or radio area of the instrument panel may occur if the bracket is loose and vibrating against the I/P. 8. AN AIR VENT "POP" may occur if the louvered vent and A/C duct rub together. 9. HOOD "FLUTTER"/RATTLE may occur if there is movement in the hood hinge attachment to the truck frame. Sound may accompany the hood Page 3309 15522278 Insulator, Front Spring Upper 2 15522279 Insulator, Front Spring Lower 2 12345097 Adhesive, Weatherstrip, 5 oz. 1 Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: E3907 Use applicable labor time guide for labor hours. Brakes - Light Brake Drag While Driving Brake Light Switch: All Technical Service Bulletins Brakes - Light Brake Drag While Driving Number: 89-262-5 Section: 5 Date: September 1989 Corporate Bulletin No.: 915002 Subject: LIGHT BRAKE DRAG - BRAKE SWITCH ADJUSTMENT Model and Year: 1980-89 A, B, F, G, J, L, X, Y 1980-89 ALL TRUCKS Figure 1 TO: ALL CHEVROLET DEALERS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 89-178-5, DATED JUNE 1989, IN ORDER THAT WE MAY CORRECTLY IDENTIFY THE SWITCH REQUIRING ADJUSTMENT. ALL COPIES OF 89-178-5 SHOULD BE DISCARDED. Some vehicles may experience a condition of light brake drag while driving. These conditions have been found to be more noticeable on vehicles which have an anti-lock brake system. This may be caused by improper brake switch adjustment. If the brake switch is not adjusted properly, the switch may push on the brake pedal and cause the brake to remain partially applied. If a vehicle exhibits any of the above conditions, perform the following functional brake switch adjustment check: Passenger Cars Only: The following steps should be used to check brake switch adjustment: 1. Remove the driver-side hush panel (refer to Figure 1). 2. Gently pull back on the brake pedal until no audible clicks are heard. The switch will be moved in the tubular retainer providing adjustment. 3. Replace the hush panel. 4. Verify that the brake drag condition is no longer present and that the cruise control and brake lights function properly. 3L30 (180C) Transmission Transmission Pressure Test Port: Specifications 3L30 (180C) Transmission Component .......................................................................................................................................... .................................................................... Ft. Lbs. Fluid Pressure Check Plug .................................................................................................................. ................................................................................. 6 Page 1678 LIGHT BLUE LT BLU BROWN BRN GRAY GRY GREEN GRN DARK GREEN DK GRN LIGHT GREEN LT GRN ORANGE ORN PINK PNK PURPLE PPL RED RED TAN TAN WHITE WHT YELLOW YEL Page 7216 Disclaimer A/T - Revised 3-4 Clutch Clutch: All Technical Service Bulletins A/T - Revised 3-4 Clutch Number: 93-143-7A Section: 7A Date: MARCH 1993 Corporate Bulletin No.: 377117 ASE No.: A2 Subject: TRANSMISSION UNIT REPAIR UPDATE 3-4 CLUTCH Model and Year: 1987-93 CAPRICE, CAMARO AND CORVETTE 1987-93 G AND M VAN 1987-93 C/K, R/V AND S/T TRUCKS 1990-93 L VAN WITH 4L60 AND 4L60-E AUTOMATIC TRANSMISSION SERVICE UPDATE BULLETIN COVERS: New Product Information for 1993 HYDRA-MATIC 4L60 and 4L60-E transmissions. This information has been updated since publication of the 1993 Service Manual and should be noted accordingly. Be certain to familiarize yourself with these updates to properly repair the 1993 HYDRA-MATIC 4L60 and 4L60-E transmissions. DATE OF PRODUCTION CHANGE: On January 05, 1993 (Julian Date 005) HYDRA-MATIC 4L60 and 4L60-E transmissions were built with an improved design 3-4 clutch. The improved design consisted of combining the 3rd and 4th clutch ring retainer plate (III. 652), the 3rd and 4th clutch apply (stepped) plate (III. 653) and the 3rd and 4th clutch (steel) plate (III. 654C) into one 3rd and 4th clutch apply plate (III. 653) Figure 1. The 3rd and 4th clutch steel plates are also thicker and the backing plate selection has changed as noted in Figure 2. Wipers - Intermittent Phantom Wipe (No Driver Input) Wiper Switch: All Technical Service Bulletins Wipers - Intermittent Phantom Wipe (No Driver Input) Number: 90-266-8E Section: 8E Date: May 1990 Corp. Bulletin No.: 968302 Subject: WINDSHIELD WIPER PHANTOM WIPE Model and Year: 1985-90 S/T/M TRUCK AND 1990 L TRUCK THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 90-171-8E, DATED FEBRUARY 1990. THE LABOR TIMES HAVE BEEN UPDATED. ALL COPIES OF 90-171-8E SHOULD BE DISCARDED. Some 1985-1990 M vans, 1990 L Vans and S/T model trucks may exhibit intermittent phantom wipe - occasional wiper sweep of the windshield with no driver input. A new steering column wiper switch has been developed with an internal resistor to correct this condition. The following parts can be installed to repair intermiftent phantom wipe. They will service subject M/L vans and S/T trucks. SERVICE PARTS INFORMATION Part Number Description 26020403 Switch (Standard) 26020404 Switch (Tilt Wheel) Parts are currently available through GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Time Labor Time Labor Operation Models (standard) (tilt wheel) N2610 S/T M/L 1.2 hrs 1.0 hrs. Page 340 SERVICE PARTS INFORMATION Part Number Application Description 15636850 1988-1991 Plate kit I/P (no switches). (Gray) Switch trim plate (gray) bracket, covers for switch trim plate holes (quantity 2), and 4 bolts/screws. 15636853 1986-1987 Plate kit I/P (no switches). (Black) Switch trim plate (black), bracket, covers for switch trim plate holes (quantity 2), and 4 bolts/screws. Important: Torque 11508898 bolts/screws supplied in kit to 0.4-0.7 N-m. (4-6 lbs.in.). Parts are expected to be available on January 21, 1991. Until then, normal part orders will not be accepted by GMSPO. Only verifiable emergency VIP orders will be accepted. GMSPO will make every effort to obtain parts. All parts will be placed on 400 control to waive VIP surcharges. However, the parts will be shipped premium transportation at dealer's expense. All other order types will be canceled as incorrectly ordered while 400 control is in place. WARRANTY INFORMATION For vehicle repaired under warranty use: Labor Operation: T7101 Labor Time: .3 hr. Trouble Code: 92 NOTE: Labor Operation is coded to base vehicle coverage in the warranty system. Hydraulic System Bleeding Brake Bleeding: Service and Repair Hydraulic System Bleeding Manual Bleeding 1. If vehicle is equipped with power brakes, remove vacuum reserve by applying brakes several times with engine off. 2. Fill master cylinder reservoirs with suitable brake fluid. Be sure to always keep master cylinder reservoirs at least half full during entire bleeding procedure. 3. If master cylinder is suspected to have air in the bore, it must be bled first, as follows: a. Disconnect forward brake pipe connection at master cylinder. b. Allow brake fluid to fill master cylinder bore until it begins to flow from forward pipe connector port. c. Connect and tighten forward brake pipe at master cylinder. d. Depress brake pedal slowly one time and hold, then loosen forward brake pipe connection at master cylinder to purge air from bore. Tighten connection, then release brake pedal slowly. Wait 15 seconds, then repeat sequence, including 15 second wait, until all air is purged from bore. e. Bleed rear bore of master cylinder as front bore was bled. 4. Bleed right rear brake as follows: a. Depress brake pedal slowly one time and hold. b. Loosen bleeder valve to purge air from brake, then tighten bleeder valve and slowly release pedal. c. Wait 15 seconds, then repeat sequence, including 15 second wait, until all air is purged. 5. Bleed left rear, right front, and left front brakes, in that order, using same method as for right rear brake. 6. Check brake operation and ensure pedal is firm. Also check master cylinder fluid level and add fluid as necessary. 7. Turn off brake warning light by applying moderate pressure to brake pedal several times. 8. Road test vehicle. Fig. 1 Installing Pressure Bleeder Adapter Pressure Bleeding 1. Loosen, then slightly retighten bleeder valves at all four wheels. Repair any broken, stripped or frozen valves at this time. 2. Using a diaphragm type pressure bleeder, install suitable bleeder adapter to master cylinder, Fig. 1. 3. Charge bleeder ball to 20-25 psi, then depress and hold valve stem on combination valve. 4. Connect pressure bleeder line to adapter. 5. Open line valve on pressure bleeder, then depress bleed-off valve on adapter until a small amount of brake fluid is released. 6. Raise and support vehicle. 7. Bleed right rear, left rear, right front and left front brakes, in that order. 8. Place transparent tube over bleeder valve, then allow tube to hang down into transparent container. Ensure end of tube is submerged in clean brake fluid. 9. Open bleeder valve 1/2 to 3/4 turn and allow fluid to flow into container until all air is purged from line. Flushing Hydraulic System If brake fluid is old, rusty or contaminated, or whenever new parts are installed in the hydraulic system, the system must be flushed. Bleed brakes, allowing at least one quart of clean brake fluid to pass through system. Any rubber parts in hydraulic system which were exposed to contaminated fluid must be replaced. Tires (Front) - Irregular Wear Tires: Customer Interest Tires (Front) - Irregular Wear Number: 91-26-3E Section: 3E Date: June 1990 Corp. Bulletin No: 053501 Subject: FRONT TIRE WEAR Model and Year: 1982-91 LIGHT DUTY TRUCKS (REAR WHEEL DRIVE) THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 91-12-3E. THE KILOMETERS HAVE BEEN TRANSLATED INTO MILES. ALL COPIES OF 91-12-3E SHOULD BE DISCARDED. Rear wheel drive trucks, equipped with All Season and/or On-Off road tires may exhibit irregular wear of; the front tires. Small amounts of irregular wear is considered normal and is not necessarily a result of incorrect alignment. Incorrect alignment (especially toe) may result in premature wear of the front tires, however agressive cornering may also have a similar effect. Drive axle tires are much less prone to irregular wear, therefore they should not be considered for comparison of wear to non-drive axle tires. The rate of irregular wear is also dependent upon the depth of tread. New tires are more prone to irregular wear, so it is essential that tires are rotated at the proper intervals to normalize the wear. 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 Page 580 Alignment: Description and Operation Toe In/Out Description Camber Description Caster Description Page 3204 Ignition Coil: Testing and Inspection Ignition Coil Testing PROCEDURE: 1. Disconnect the distributor lead and wiring from the coil. 2. Connect an ohmmeter as shown in step 1 of the image above. Use the high scale. The reading should be infinite. If not replace coil. 3. Connect an ohmmeter as shown in step 2 of the image above. Use the low scale. The reading should be very low or zero. If not, replace coil. 4. Connect an ohmmeter as shown in step 3 of the image above. Use the high scale. The meter should NOT read infinite. If it does, replace the coil. 5. Reconnect the distributor lead and wiring to the coil. Windshield Washer Bottle - Cracking Windshield Washer Reservoir: All Technical Service Bulletins Windshield Washer Bottle - Cracking Number: 91-31-8E Section: 8E Date: July 1990 Corp. Bulletin No.: 061010 Subject: WASHER BOTTLES CRACKING Model and Year: 1988-91 S/T TRUCKS TO: ALL CHEVROLET DEALERS Some 1988 - 1991 S/T trucks may be experiencing a condition of windshield wiper washer bottles cracking and then leaking washer fluid. This condition can be caused by an increased amount of pressure exerted by the two fastening nuts and screws. This increase of pressure causes the screws to cut into the plastic and initiate cracks. To correct the situation new parts have been released with a wider flange, and the torque requirement has also been revised. The new torque requirement is now 5-8 N-m (3.7 - 5.9 lbs. ft.) instead of the old 8-11 N-m (5.9 - 8.1 lbs. ft.). When ordering a new washer bottle be sure and order new bolts and nuts with the revised flanges. SERVICE PARTS INFORMATION Part Number Description Usage 11509005 nut 2 per bottle 15653669 bolt 2 per vehicle 22072762 container and grommet 1 per vehicle Parts are currently available through GMSPO. WARRANTY INFORMATION For vehicle repaired under warranty use: Labor Operation: N3750 Labor Time: .2 hr. Specifications Adjustment Specifications End Gate Lock Cylinder - Rattles Trunk / Liftgate Lock Cylinder: Customer Interest End Gate Lock Cylinder - Rattles Number: 91-507-10 Section: 10 Date: AUGUST 1992 Corporate Bulletin No.: 261003 ASE No.: B1 Subject: END GATE LOCK CYLINDER ASSEMBLY RATTLE Model and Year: 1982-91 S/T TRUCKS Some owners of 1982-1991 S/T utility vehicles may experience a rattling sound emanating from the rear of the truck. This condition may occur if the end gate lock cylinder assembly is loose. To correct this condition, it is necessary to bend the ends of the spring within the lock cylinder assembly eliminating any clearance between the pawl assembly and cylinder housing. SERVICE PROCEDURE: 1. Open the end gate to the horizontal position and remove the inner trim panel. Electrical - Intermittent MIL/DTC P2138/Reduced Power Wiring Harness: Customer Interest Electrical - Intermittent MIL/DTC P2138/Reduced Power TECHNICAL Bulletin No.: 07-06-04-019D Date: June 28, 2010 Subject: Intermittent Malfunction Indicator Lamp (MIL) Illuminated, DTC P2138 with Reduced Engine Power (Repair Instrument Panel (IP) to Body Harness Connector) Models: 2005-2011 GM Passenger Cars and Light Duty Trucks (Including Saturn) 2005-2009 HUMMER H2 2006-2010 HUMMER H3 2005-2009 Saab 9-7X Supercede: This bulletin is being revised to update the model years and warranty information. Please discard Corporate Bulletin Number 07-06-04-019C (Section 06 - Engine/Propulsion System) Condition - Some customers may comment on an intermittent malfunction indicator lamp (MIL) being Illuminated with a message or an indicator that displays Reduced Engine Power. - The technician may observe on a scan tool DTC P2138 - Accelerator Pedal Position (APP) Sensor 1-2 Correlation set as Current or in History. Cause This condition may be caused by water intrusion into the instrument panel (IP) to body harness connector, which carries the APP sensor signals to the ECM/PCM. This water intrusion results in a voltage difference between APP Sensor 1 and APP Sensor 2 that exceeds a predetermined value for more than a calibrated period of time, setting P2138. Correction Note Aftermarket equipment can generate DTC P2138 and/or other DTCs. 1. Verify that aftermarket equipment is not electrically connected to any of the APP sensor signal or low reference circuits or to any other ECM/PCM 5V reference or low reference circuits. Refer to Checking Aftermarket Accessories in SI. 2. Perform the Diagnostic System Check - Vehicle. ‹› If any 5V reference DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle. ‹› If any 5V reference DTCs are not set, proceed to Step 3. 3. Locate the IP to body harness connector, which may be located in and around the left hand kick panel area or inside the IP. Depending on the vehicle and model year, refer to Wiring Systems or Power and Signal Distribution in SI. Note Some examples of potential water leaks are: A-pillar seals, sunroof drain lines (if equipped) and windshield/cowl sealing. 4. Inspect for a water leak in the area. If necessary use a water hose to determine the source of the leak. Refer to General Information > Water Leaks in SI. ‹› If a water leak is observed, repair as necessary. Verify the effectiveness of the repair. 5. Inspect the IP to body harness connector terminals for corrosion and debris. Refer to Testing for Intermittent Conditions and Poor Connections in SI. ‹› If any corrosion and/or debris is observed, repair as necessary. 6. After completing the repair, verify the proper operation of the system. Depending on the vehicle and model year, perform the Diagnostic Repair Verification procedure or refer to Diagnostic Trouble Code (DTC) List - Vehicle in SI. Instruments - Generator Light Flickers, Pulse Wipers ON Charge Lamp/Indicator: Customer Interest Instruments - Generator Light Flickers, Pulse Wipers ON GMC NUMBER: 89-T-85 GROUP: 6D - Engine Electrical DATE: July, 1989 CORPORATE NUMBER: 966402R SUBJECT: GENERATOR LIGHT FLICKER DURING PULSE WIPER OPERATION MODELS: 1988-89 S/T WITH 2.8L OR 4.3L ENGINE The generator light flicker condition in the 1988 and 1989 S/T instrument panel during pulse wiper switch operation can be caused by negative voltage transients from the wiper motor There is no possibility of a system failure as a result of this condition. The effect of this condition is that the generator light will turn on for 80 milliseconds (if gages, the voltage drop on the voltmeter lasts 2.5 seconds). This causes no harm to the generator or other electrical components. Subject condition can be eliminated by installing a diode (industry part number 1N4003) or diode/connector kit (diode kit part number 12085207) in the brown wire at the generator connector (circuit 25 at connector C118). See the following pages in the 1988 and 1989 S/T Electrical Wiring Diagrams for circuit 25, connector C188 locations: 1988 4.3L: Section C - Page 24 1988 2.8L: Section C - Page 22 1989 4.3L: Page 40 1989 2.8L: Page 39 PARTS INFORMATION: Quantity Part Number Description 1 12085207 Diode OR 1 *1N4003 Diode *This part available locally. Parts are currently available from GMSPO. INSTALLATION PROCEDURE: 1. Disconnect the battery. 2. Remove the connector from the generator. 3. Peel back the black plastic conduit covering the wires. 4. If installing diode 1N4003: cut out a section of the brown wire that matches the length of the diode. 4A. A diode/connector kit is also available (GMSPO diode kit part number 12085207). If using the kit cut out approximately four inches of the brown wire, following crimping and soldering instructions in the kit. Spiral tape the solder joints and tuck the wire back into the conduit away from the generator Secure the diode/connector to the outside of the conduit with electrical tape. 5. Solder in diode with the banded end toward the generator. 6. Tape the solder and diode. 7. Reinstall the black plastic conduit. 8. Reconnect connector to the generator. 9. Reconnect battery. This procedure will not affect the operation of the generator light during the bulb check at the beginning of the start cycle. For vehicles repaired under warranty use Page 5178 Starter Solenoid: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. Figure 21 Figure 22 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. Page 4214 Parts Information Parts are currently available from GMSPO. 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 Page 6601 - 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 Page 3897 Transmission Vacuum Regulator Valve: Service and Repair 1. Raise and support vehicle. 2. Remove vacuum line from modulator. 3. Using vacuum modulator wrench J-23100 remove modulator, seal and modulator plunger. 4. Then remove modulator valve and sleeve. 5. Clean all parts with soapy water and air dry. 6. Check modulator and vacuum line for kinks, cracks and dry rot damage. 7. Reverse procedure to install using new seal. Add transmission fluid as necessary. Page 3454 Shift Solenoid: 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. Page 1143 2. Remove the end gate inner panel reinforcement from the end gate (Figure 1, Item 1). 3. Disconnect the end gate lock rods (Figure 2, Items 1 and 2). 4. Remove the lock cylinder retainer (Figure 3, Item 2). 5. Working through the access hole, remove the lock cylinder and gasket (Figure 3, Items 4 and 3) through the outer panel. 6. Remove the spring (located on the lock assembly) and carefully bend the spring ends just far enough to eliminate any clearance between the lock pawl assembly and the lock cylinder housing (Figure 3, Items 6 and 4). Note: Page 3916 Speedometer Gear, A/T: Service and Repair Turbo Hydra-Matic 4L60 (700-R4) 1. Disconnect speedometer cable. 2. Remove retainer bolt, retainer, speedometer driven gear, and O-ring seal. 3. Reverse procedure to install, using new O-ring and adjusting fluid level. Page 3809 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 Page 6392 DA-V5 Compressor Component View Remove or Disconnect Tool Required: J 9553-01 O-ring Remover 1. Retainers (44) from switches (3) and (4). 2. Switches (3) and (4). 3. O-ring seals (44) from the switch cavities with J 9553-01. Clean ^ Switch cavity and O-ring seal groove. Install or Connect Tools Required: Turbo Hydra-Matic 3L30 (180C) Fluid - A/T: Service and Repair Turbo Hydra-Matic 3L30 (180C) Draining Bottom Pan 1. Raise and support vehicle. 2. Position a suitable drain pan below transmission oil pan. 3. Remove front and side oil pan bolts. 4. Loosen rear bolts and gently pry the pan down to allow fluid to drain. 5. Remove remaining bolts and pull pan away from case carefully, as there will still be fluid contained in the pan. 6. Drain remaining fluid from pan, then remove gasket, oil filter retaining bolts, oil filter and seal. 7. Using solvent, thoroughly clean oil pan and gasket surfaces, then air dry. 8. Install new oil seal and filter into case. Torque attaching bolts to 13-15 ft. lbs. 9. Install oil pan with new gasket and torque bolts to 7-10 ft. lbs. 10. Add transmission fluid, then with engine idling and brakes applied, move selector lever through each gear range and return selector lever to Park. 11. Bring fluid to proper operating temperature and check fluid level, adding as required to bring level to the Full mark. Adding Fluid to A Dry Transmission 1. Add transmission fluid. 2. With transmission in Park, start engine and let engine idle (carburetor off fast idle cam.) 3. Apply brakes and move shifter lever through each gear range, then with transmission in Park, add additional fluid as required to bring the level up to Full mark on dipstick. Locations Vacuum Restrictor: Locations RH Side Of Cowl Center Of Firewall Page 5119 Symbol Identification Wire Color Code Identification WIRE COLOR ABBREVIATION BLACK BLK BLUE BLU DARK BLUE DK BLU Page 6351 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 Page 1136 2. Remove the end gate inner panel reinforcement from the end gate (Figure 1, Item 1). 3. Disconnect the end gate lock rods (Figure 2, Items 1 and 2). 4. Remove the lock cylinder retainer (Figure 3, Item 2). 5. Working through the access hole, remove the lock cylinder and gasket (Figure 3, Items 4 and 3) through the outer panel. 6. Remove the spring (located on the lock assembly) and carefully bend the spring ends just far enough to eliminate any clearance between the lock pawl assembly and the lock cylinder housing (Figure 3, Items 6 and 4). Note: Page 7071 On a clean surface, at or above room temperature, firmly apply a 2" wide piece of masking tape and pull upward quickly. DO NOT USE duct tape, cloth backed tape or other aggressive tapes. If the colorcoat flakes or peels away from the ELPO (leaving the ELPO intact) the colorcoat is delaminating and the vehicle should be repaired using the "Paint Repair Procedure" contained in this bulletin. This test SHOULD ONLY BE APPLIED TO A VEHICLE SHOWING THE CONDITION, (peeling/delamination) and NOT in areas of stone chipping or other obvious damage. These "other" conditions should be repaired following standard paint repair procedures. CORRECTION Refinish the ENTIRE BODY ABOVE THE BODY SIDE MOLDINGS using the following repair procedure. It is important that ALL surfaces above the body side moldings (including recessed areas around door handles) be refinished, as these surfaces may show the same DELAMINATION (peeling) condition at a later date. Note: Many vehicles have some type of plastic exterior body panels (cowl vent grilles, fascias, front end panels, rear fenders, etc.). These panels are not subject to DELAMINATION and therefore do not require refinishing. If painting of these panels is required for color uniformity, scuff sand and colorcoat only (and clearcoat if basecoat/clearcoat system is used). Note: Two tone lines, feature lines or body side molding treatments near mid-door height are appropriate break lines. If no such convenient break lines are present, the entire panel above the next lower break line must be refinished and the portion of the panel below that break line should be COLORCOATED ONLY (and clearcoated if basecoat/clearcoat system is used) for color uniformity of the repair. Note: Pickup boxes which are covered by caps, bedliners or tonneau covers do not receive direct exposure to sunlight, and normally would not be repaired under this procedure. However, if the inside of the box has been uncovered and experienced DELAMINATION, use the appropriate Labor Operation Number. Note: Certain two tone applications on trucks using the high potential colors (Blues, Grays and Silvers) may require that only portions of the vehicle surface be refinished. Examples would be: Example 1. Blues, Grays and Silvers as "insert colors" on vertical surfaces with other, non-high potential colors above the insert (or break line). Action: Refinish the "insert color" only, between the break line and body side molding (or to the lower feature line on certain vehicles). Example 2. Blues, Grays and Silvers on surfaces above the break line with other, non-high potential colors as "insert colors". Action: Refinish the surfaces above the "insert color" or break line only. Example 3. Blues, Grays and Silvers used as both the primary and "insert colors". Action: Refinish both high potential color surfaces above the body side moldings (or to the lower feature line on certain vehicles). Vehicles should be repaired with the same type materials they were manufactured with; repair basecoat/clearcoat with basecoat/clearcoat materials and monocoat with monocoat. PAINT REPAIR PROCEDURE 1. Some vehicle components will be removed from the vehicle while others will require masking. The list located at the end of this bulletin will establish the removal items. Items not found on the list and non-repair areas are to be masked. 2. Prior to removing the paint finish, clean the area to be refinished with an appropriate wax and grease remover to remove any contaminants. 3. Remove the original finish of paint down to the ELPO primer surface using an orbital D.A. sander, leaving the ELPO surface intact. This can be done in "stages" using 80 grit (or finer) discs to remove the majority of coating, followed with 180 grit (or finer) discs to remove the remainder of material down to the ELPO surface and any chalky residue or degraded ELPO that may remain. Avoid sanding through ELPO to bare metal in order to retain maximum corrosion protection. - An alternative in some geographic areas may be plastic media blasting such as may be provided by members of: - Dry Stripping Facilities Network 1-800-634-9185 * Instrument Panel - Upper Surface Reflection Instrument Cluster / Carrier: All Technical Service Bulletins Instrument Panel - Upper Surface Reflection File In Section: 08 - Body and Accessories Bulletin No.: 99-08-49-006 Date: April, 1999 INFORMATION Subject: Cleaning of Upper Instrument Panel Surfaces Models: 1999 and Prior Passenger Cars and Light Duty Trucks Comments on a reflection of the upper instrument panel pad into the windshield, when driving in direct sunlight, may be received. This condition, sometimes referred to as a "veiling reflection", may be aggravated by the use of wax or silicone based products when cleaning the surface. Advise customers, technicians and new car prep or make ready personnel, that products containing wax or silicone should not be used to clean the top instrument panel pad. A warm water and mild soap solution such as saddle soap, oil soap or an equivalent, should be used whenever the top instrument panel pad needs cleaning. If a customer requests that a protectant type product be applied, ONLY USE THOSE THAT LEAVE A FLAT OR SATIN FINISH. Do NOT apply products that leave a glossy finish or those that Increase the shine level above the original production level. Page 2654 Wiring Diagram For Chart C-5 - Electronic Spark Control System Check CIRCUIT DESCRIPTION: Electronic spark control is accomplished with a module that sends a voltage signal to the ECM. As the knock sensor detects engine knock, the voltage from the ESC module to the ECM is shut "OFF" and this signals the ECM to retard timing, if engine RPM is over about 900. TEST DESCRIPTION: Numbers below refer to circled numbers on the diagnostic chart. 1. If A Code 43 is not set, but a knock signal is indicated while running at 1500 RPM, listen for an internal engine noise. Under a no load condition there should not be any detonation, and if knock is indicated, an internal engine problem may exist. 2. Usually a knock signal can be generated by tapping on the right exhaust manifold. This test can also be performed at idle. Test number 1 was run at 1500 RPM to determine if a constant knock signal was present, which would affect engine performance. 3. This tests whether the knock signal is due to the sensor, a basic engine problem, or the ESC module. 4. If the module ground circuit is faulty, the ESC module will not function correctly. The test light should light indicating the ground circuit is OK. 5. Contacting CKT 496, with a test light to 12 volts, should generate a knock signal to determine whether the knock sensor is faulty, or the ESC module can't recognize a knock signal. DIAGNOSTIC AIDS: "Scan" tools have two positions to diagnose the ESC system. The knock signal can be monitored to see if the knock sensor is detecting a knock condition and if the ESC module is functioning, knock signal should display "yes", whenever detonation is present. The knock retard position on the "Scan" displays the amount of spark retard the ECM is commanding. The ECM can retard the timing up to 20 degrees. This check should be used after other causes of spark knock have been checked such as engine timing, EGR systems, engine temperature or excessive engine noise. Page 2773 Oxygen Sensor: Service and Repair 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. 1. Disconnect electrical connector from oxygen sensor. 2. Using suitable wrench, carefully remove sensor from exhaust manifold or pipe. The oxygen sensor may be difficult to remove when engine temperature is below 120°F. Use caution, since excessive force may damage threads in exhaust manifold or pipe. 3. If new sensor is being used, install sensor into manifold or pipe. 4. If old sensor is being reused, coat threads with anti-seize compound, Part No. 5613695 or equivalent, then install into manifold or pipe. 5. Torque oxygen sensor to 30 ft. lbs., then reconnect electrical connector. Locations Fuel Filler Neck Drive Belt - Making Chirp Noise Drive Belt: All Technical Service Bulletins Drive Belt - Making Chirp Noise Number: 88-291-7A Section: 7A Date: JULY, 1988 Subject: SERPENTINE BELT CHIRP Model and Year: 1988 S/T TRUCKS W/4.3L (VIN CODE Z) ENGINE TO: ALL CHEVROLET DEALERS Some owners of 1988 4.3L S/T trucks may experience a chirping noise from the accessory drive belt. "Belt Chirp" is a short duration, intermittent, high pitched sound and should not be confused with belt "squeal", which is continuous in nature. This condition can be addressed by aligning the power steering pump pulley 3/4 mm plus or minus 1/4 mm (.030" plus or minus .010") forward of flush with the power steering pump shaft (See Illustration). A wheel puller should be used to perform this realignment. Labor Operation Number: T7460 Labor Time : .3 Hours A/T - Click or Whine in Third or Fourth Gear Clutch: All Technical Service Bulletins A/T - Click or Whine in Third or Fourth Gear Number: 93-228-7A Section: 7A Date: JUNE 1993 Corporate Bulletin No.: 277121R ASE No.: A2 Subject: CLICK/WHINE IN THIRD/FOURTH GEAR Model and Year: 1988-93 CAPRICE, CAMARO AND CORVETTE 1988-93 C/K, RN, S/T, M AND G TRUCKS 1990-93 L VAN THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 92-157-7A, DATED APRIL 1992. THE 1993 MODEL YEAR HAS BEEN ADDED, AS WELL AS A NOTE IN THE CORRECTION SECTION. ALSO THE SERVICE PARTS INFORMATION HAS BEEN CHANGED. ALL COPIES OF 92-157-7A SHOULD BE DISCARDED. CONDITION: Some 1988-93 vehicles with HYDRA-MATIC 4L60 or 4L60-E transmissions built before November 19, 1992 (Julian Date 324) may exhibit a clicking or whining noise in third and fourth gear. A customer may also describe it as a ticking or rattle noise. CAUSE: The clicking noise is caused by transmission fluid passing over the friction plates of the low and reverse clutch. The fluid causes them to vibrate when the low and reverse clutch is not applied (third and fourth gear). CORRECTION: Install five new fiber plates in the low and reverse clutch. The new plates have a non-groove configuration. NOTE: All HYDRA-MATIC 4L60 and 4L60-E transmissions built on or after November 19,1992 (Julian Date 324) have been assembled with the new low and reverse clutch fiber plates. SERVICE PARTS INFORMATION: Parts are expected to be available on 6/07/93. Detonation Sensor LH Rear Of Engine, At Rear Of Cylinder Head Page 5558 Important The M6 conductive rivet stud as shown, can accommodate a panel thickness range of 0.7-4.2 mm (0.03-0.17 in). If there are layers of sheet metal, they should be touching without any air gaps to ensure a good ground. 5. Select a M6 conductive rivet stud. Refer to the Parts Information section of this bulletin. Note Use the GE-50317 rivet stud tool kit. 6. Place the M6 conductive rivet stud (1) in the 10 mm (0.40 in) hole. Assemble the rivet stud tool (2) with the groove and flare side facing the rivet stud, then the washer and the M6 nut (3). 7. Using a wrench on the rivet stud tool, and a socket on the M6 nut, secure the M6 conductive rivet stud. 8. Ensure the rivet stud is securely fastened, WITHOUT ANY detectable movement. 9. Completely wrap the threads of the rivet stud with painters tape or equivalent. Note The rivet stud and surrounding panel area MUST BE properly refinished PRIOR to the installation of the ground wire terminal and conductive nut to maintain a secure, stable and corrosion-free electrical ground. 10. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 11. Allow the refinished repair area to cure sufficiently before removing the protective material applied to the rivet stud threads. 12. Remove the painters tape or equivalent from the rivet stud threads. 13. Using GM approved residue-free solvent or equivalent, thoroughly clean the rivet stud threads to remove any adhesive and allow to dry. 14. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive rivet stud. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. Page 1076 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. Page 7683 Brake Lamp: Electrical Diagrams License, Stop, Tail & Turn Lamps (Part 3 Of 4, W/Trailer Tow Package) Spare Tire Carrier - Rattle Technical Service Bulletin # 903303E Date: 900801 Spare Tire Carrier - Rattle Number: 90-330-3E Section: 3E Date: August 1990 Corp. Bulletin No.: 061005 Subject: SPARE TIRE CARRIER RATTLE Model and Year: 1986-90 S/T BLAZER TRUCK WITH SPARE TIRE CARRIER (RPO P16) TO: ALL CHEVROLET DEALERS Owners of some 1986 through 1990 S/T Blazers equipped with factory installed spare tire carriers (RPO P16) may comment on a rattle condition coming from the spare tire carrier area. This rattle condition may result from vehicle and road vibrations which are transmitted through the vehicle to the spare tire carrier region. This vibration changes to a rattle in any of the following three locations. TAILGATE Mode of vibration is a side to side motion of the tailgate and is caused by the tailgate not being properly aligned into the opening when closed. SPARE TIRE CARRIER This second form of vibration occurs in a forward and backward motion relative to the vehicle. Again, this is due to the tire carrier not being tightly held in place. This motion creates a rattle between the striker assembly and the carrier latch, and/or the carrier arm and the striker plate. Page 5606 Alignment: Technical Service Bulletins Alignment - The Importance of Four Wheel Alignment Number: 89-01-3A Section: 3A Date: SEPT., 1988 Subject: THE IMPORTANCE OF FOUR WHEEL ALIGNMENT Model and Year: 1979-89 ALL CHEVROLET MODELS TO: ALL CHEVROLET DEALERS In which direction will the vehicle pictured below travel if the steering wheel is straight ahead? The vehicle will track to the left because of the directional forces created by the rear wheels and tires. This directional force is called the "thrust angle". The front wheels aim or steer the vehicle but the rear wheels control tracking and assist in directing the car. What might the driver comment about? In the illustration, the driver may comment about the steering wheel being off center when going straight down the road. This would be true because of the added input required at the steering wheel to offset the thrust angle force caused by the rear wheels not tracking the front wheels to the geometric center line of the vehicle. The driver may also comment about unusual tire wear, not precise handling characteristics and even decreased fuel economy. A four wheel alignment allows the technician to measure the toe of each rear wheel to determine if the rear wheels are tracking the geometric center line of the car. Ideally the geometric center line will be the same as the thrust line. In the example in Figure 1, the thrust line has shifted to the right because the rear wheel toe is not tracking the front wheels. This can occur on both or on one rear wheel. On some vehicles the rear toe is adjustable; other models may require component straightening or replacement or shims. Once the rear toe is properly adjusted or set, the front wheel toe can be set so all four wheels are tracking the geometric center line of the vehicle. This will provide optimum tire wear, handling and fuel economy characteristics for the vehicle. Page 399 Manifold Pressure/Vacuum Sensor: Specifications MANIFOLD ABSOLUTE, VACUUM AND BAROMETRIC PRESSURE SENSORS Engines may use one, or a combination of these sensors. All sensors appear the same. Manifold Absolute Pressure sensors have a vacuum line connected between the unit and manifold vacuum. On Barometric Pressure sensors, the line is not used and the connector is either open or has a filter installed over it. Pressure sensors also have a vacuum line between the sensor and intake manifold and only appear on carburetted models. Barometric Pressure Sensors: Measure voltage with ignition on and engine off. Manifold Absolute Pressure Sensors: Measure voltage with ignition on and engine off. Start engine and apply 10 in./ 250 mm Hg to unit, voltage should be 1.2-2.3 volts less. Pressure Sensors: Measure voltage as indicated. Page 6349 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 Page 421 Throttle Position Sensor: Service and Repair REMOVAL: 1. Disconnect electrical connectors. 2. Remove the TPS attaching screw assemblies and retainer, (if applicable). 3. Remove TPS from throttle body assembly. NOTE: The TPS is an electrical component and must not be soaked in any liquid cleaner or solvent, as damage may result. INSTALLATION: 1. Install TPS to throttle body assembly, while lining up TPS lever with TPS drive lever on throttle body. 2. Install the two attaching screw assemblies. Tighten screw assemblies to 2.0 Nm (18.0 lb-in). 3. Install electrical connector to TPS. 4. Check for TPS output as follows: a. Connect an ALDL scanner to read TPS output voltage. b. With ignition ON and engine stopped, TPS voltage should be less than 1.25 volts. If more than 1.25 volts, replace TPS. 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. Page 783 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). Page 3993 FIGURE 1 If this condition is encountered, and cannot be corrected using normal diagnostics, a newly released rear transmission mount may be installed (see Figure 1). This rear transmission mount is currently in use on 1988-90 Cl, C2, and C3 pickups with 4.3 L engines and 3- speed automatic transmissions (M40). When installing this mount, new service washers (one washer per bolt) are required for retaining mount to transmission. Also install a new nut on the stud when attaching mount to cross member. IMPORTANT: This mount is not for use on 1991 S/T 4 door utility or any 1988-91 T model pickup or utility. PARTS INFORMATION PART NUMBER DESCRIPTION QUANTITY 15567796 Mount 1 15614758 Washer 2 Page 6861 movement. Refer to Dealer Service Bulletin Number 91-181-10, Dated February 1991. Page 4243 Pinion Bearing: Service and Repair Dana/Spicer 9 3/4 Inch Ring Gear Fig. 5 Pinion Setting Chart If original ring gear and pinion assembly are to be reused, measure original shim pack and build a new shim pack to the same dimension. If baffle is in the axle assembly, it is considered part of the shim pack. Ring gears and pinions are supplied in matched sets only. If a new gear is being used, verify numbers on pinion and ring gear before proceeding with assembly. On the button end of the pinion there is a +, - , or 0 number which indicates the best running position for each particular gear set. This position is controlled by shims installed behind the inner bearing cup. If baffles or oil slingers are used, they are considered part of the adjusting shim pack. If a new gear set is being installed, note the plus or minus mark on both old and new pinions and adjust thickness of shim pack to compensate for the difference between these two numbers. Refer to chart, Fig. 5, when determining shim size. 1. Install inner shim pack and, on 9-3/4 inch ring gear axle, the oil slinger in inner or rear cup bore, then drive cup into position using suitable tool. 2. Add or remove an equal amount to the outer shim pack as was added to the inner shim pack. 3. Drive outer cup into carrier bore, then press rear pinion bearing onto pinion shaft. 4. Install drive pinion and bearing into differential carrier. 5. Install shims and outer or front pinion bearing. 6. Install companion flange, then the washer and nut on pinion shaft. 7. Measure rotating torque of pinion shaft. Rotating torque should measure 10-20 inch lbs. with original bearings installed, or 20-40 inch lbs. with new bearings installed, discounting torque required to start turning shaft. 8. If rotating torque is not within specifications, adjust shim pack as necessary. Increase outer shim pack to reduce torque, or decrease shim pack to increase torque. 9. Remove nut, washer and companion flange from pinion shaft. 10. Install oil slinger, gasket (if equipped) and oil seal onto pinion shaft. 11. Install companion flange, washer and nut and torque as described is step 7. Disassembly Fig. 9 Drive Pinion Removal Page 1328 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 Engine - Performance Problems PROM - Programmable Read Only Memory: Customer Interest Engine - Performance Problems Number: 88-193-6E Section: 6E Date: April, 1988 Subject: INCREASED PERFORMANCE Model and Year: 1988 S/T TRUCKS WITH 4.3L (VIN CODE Z) ENGINE AND CALIFORNIA EMISSIONS TO: ALL CHEVROLET DEALERS Customer comments of lack of performance, poor tip-in response, or engine flatness may be received in connection with some early built S/T trucks with a 4.3L engine and California emissions. A new prom was put into production that addresses these concerns. This new prom is now available for trucks built before the following breakpoints: 172008 The new PROM, part number for the LB4 (4.3L) engine is listed below: A/T - New Governor Driven Gear for No Upshift or Erratic Governor Pressure Switch: All Technical Service Bulletins A/T - New Governor Driven Gear for No Upshift or Erratic Number: 88-161-7A Section: 7A Date: MARCH, 1988 Subject: ERRATIC OR NO UPSHIFT - NEW GOVERNOR DRIVEN GEAR Model and Year: 1987-88 VEHICLES WITH THM 400/475 OR THM 700-R4 TRANSMISSIONS FIGURE 2 - "APPLECORED" GOVERNOR DRIVEN GEAR TO: ALL CHEVROLET DEALERS A THM 400/475 or THM 700-R4 transmission with an erratic or no upshift condition may be created by "applecoring" of the governor driven gear. "Applecoring" is pictured in the illustration below. A new governor driven gear with a higher fiberglass content entered production on all THM 400/475 transmissions December 11, 1987 (Julian date 345). THM 700-R4 transmissions were produced with a new gear beginning July 6, 1987 (Julian date 187). "Applecoring" of the governor driven gear may be the result of nicks or burrs present on the output shaft drive gear. Inspection of the output shaft should be performed and if nicks or burrs are present the output shaft should be replaced. The new service part numbers are listed below for each model transmission. Part No. Description 8663995 THM 700-R4 - Governor Driven Gear and Pin Package 8629977 THM 400 - Governor Driven Gear and Pin Package Page 22 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 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). Page 7710 Symbol Identification Page 5599 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. Turbo Hydra-Matic 3L30 (180C) Valve Body: Service and Repair Turbo Hydra-Matic 3L30 (180C) 1. Raise and support vehicle. 2. Drain transmission fluid by removing oil pan attaching bolts, then the oil pan and gasket. 3. Remove oil strainer attaching bolts, then the strainer and gasket. 4. Remove manual detent roller and spring assembly. 5. Disconnect electrical connections from governor pressure switch. 6. Remove solenoid from transfer plate reinforcement. 7. Remove solenoid from solenoid tubes. 8. Remove solenoid tubes from valve body and case. 9. Remove governor pressure switch. 10. Remove transfer plate reinforcement attaching bolts, then the reinforcement. 11. Remove servo cover attaching bolts, then the cover and gasket. 12. Remove valve body attaching bolts, then the valve body and manual link valve, being careful not to lose check balls. Page 3808 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 A/T - Buzzing Noise at Idle Fluid Pressure Sensor/Switch: All Technical Service Bulletins A/T - Buzzing Noise at Idle Number: 93-29-7A Section: 7A Date: OCT. 1992 Corporate Bulletin No.: 277142 ASE No.: A2 Subject: BUZZING NOISE AT IDLE Model and Year: 1982-93 CAPRICE, CAMARO AND CORVETTE 1982-93 C/K, R/V, S/T, M/L AND G TRUCKS WTIH 4L60 AUTOMATIC TRANSMISSION TRANSMISSION APPLICATIONS: 1982-1993 HYDRA-MATIC 4L60 (MD8) TRANSMISSION MODELS: All SUBJECT: Pressure Regulator Valve Buzz VEHICLE APPLICATIONS: B, D, F, Y - Cars C/K, R/V, S/T Trucks G, M, L - Vans CONDITION: Some 1982-1993 vehicles equipped with a HYDRA-MATIC 4L60 transmission may have a buzzing noise coming from the transmission when the vehicle is at idle. The buzzing noise may be noticed more when the vehicle is in reverse at idle. CAUSE: The buzzing noise may be a result of pressure regulator valve oscillating due to oil pressure instability at lower idle RPM. CORRECTION: Page 8119 inches from the inside of the hood opening)(see Figure 3). 3) Test with compressed air to insure all leaks have been eliminated. Once repairs have been made install cowl vent screen, grille and cowl vent screws. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: T7071 Labor Time: .6 hrs FAILURE CODE: 92 NOTE: Labor Operation is coded to base vehicle coverage in the warranty system. Page 7814 Symbol Identification Wire Color Code Identification WIRE COLOR ABBREVIATION BLACK BLK BLUE BLU DARK BLUE DK BLU Page 958 T7251 Group A 3.2 hr. T7261 Group B 2.8 hr. NOTE: Labor Operation is coded to base vehicle coverage in the warranty system. ECM/PCM - Damage Prevention Engine Control Module: All Technical Service Bulletins ECM/PCM - Damage Prevention Number: 91-318-6E Section: 6E Date: MAY 1991 Corp. Bulletin No.: 176502R Subject: DAMAGE TO ECM/PCM CIRCUIT BOARD WHEN INSTALLING A MEM-CAL Model and Year: 1986-91 ALL PASSENGER CARS AND TRUCKS CONDITION: When installing a service replacement ECM/PCM, the use of incorrect MEMCAL installation procedures may cause the ECM/PCM to fail before it can be installed in the vehicle. This condition may appear as if the ECM/PCM were defective when it was shipped to the dealership, when in fact it was damaged while being installed. In addition this condition may also occur when installing an "updated" service MEM-CAL into the vehicles original equipment ECM/PCM. CAUSE: Excessive vertical force may be applied to the MEM-CAL resulting in flexing of the circuit board and damage to the connections between the circuit board and attached components. Excessive verticle force may be generated in two ways. 1. Incorrect MEM-CAL installation procedure. 2. Interference between MEM-CAL and cover. CORRECTION: Use the following procedure. Service Procedure: Important: This procedure supersedes any instructions regarding MEM-CAL installation dated prior to September 1990. 1. Inspect the MEM-CAL to determine if a cork spacer is glued to the top side of the MEM-CAL assembly. If so, remove it prior to installation. 2. Align small notches with matching notches in the ECM/PCM MEM-CAL socket. 3. VERY GENTLY press down on the ends of the MEM-CAL until the locking levers are rotated toward the sides of the MEM-CAL. Notice: To avoid ECM/PCM damage, do not press on the ends of the MEM-CAL until the levers snap into place. Do not use any vertical force beyond the minimum required to engage the MEM-CAL into its socket. 4. While continuing light pressure on the ends of MEM-CAL, use your index fingers to press the locking levers inward until they are snapped into place. Listen for click. 5. Install MEM-CAL cover and install ECM/PCM in vehicle. Page 3523 Band Apply Servo: Specifications THM 180 & 180 C Auto Transmission Servo Cover to Case ........................................................................................................................... ................................................................. 17-19 ft lbs Servo Adjusting Bolt Locknut .......................... ................................................................................................................................................... 12-15 ft lbs Page 6258 High Pressure Safety Valve HVAC: Service and Repair With DA-V5 Compressor Rear Head Details Page 7021 panel(s) that can be used as a starting/ stopping point when making a repair. Clearcoat: A clear topcoat required to cover a color basecoat. DELAMINATION: Loss of adhesion between one coat of paint to succeeding coats or coatings. Ultraviolet DELAMINATION is between the E coat (ELPO) and color topcoat(s). ELPO: (Electrocoating or "E" coat): The process by which electrically charged primer is plated on conductive surfaces of an opposite charge. This process provides outstanding corrosion resistance. Guidecoat: A light coat (almost overspray) of color applied over primer surfacer prior to wetsanding to highlight any low spots. Insert Color: The secondary two-tone color between the break line and body side molding. Monocoat: A color topcoat that does not require a clearcoat. Primer: The coating applied to a properly prepared substrate (bare metal) to give adhesion, corrosion and chemical resistance. Primer Sealer: An undercoat that provides maximum adhesion. color coating and corrosion protection. Primer Surfacer: An undercoat used to fill imperfections, with primer qualities, that must be sanded. Refinish: The act of replacing a painted surface, usually undercoat and topcoat. Scuff Sand: A method of sanding a painted surface using a fine grit sandpaper to promote paint adhesion. Topcoat: A finish material over an undercoat material. Ultraviolet Light: The portion of the spectrum of light which can cause fading of paint. It is located below the visible part of the spectrum. V.O.C.: "Volatile Organic Compound" or "Volatile Organic Content" relates to certain emission requirements in specific areas of the country. Brakes - Trailers Towing Information: Technical Service Bulletins Brakes - Trailers Number: 88-36 Section: OA Date: August, 1987 SUBJECT: TRAILER BRAKES MODELS: ALL LIGHT DUTY MODELS Trailer brakes of adequate size are required on trailers over 1,000 lbs (45 Kg) loaded weight. Follow the instructions of the manufacturer for proper installation and balance. Typically, trailer brake installations require less than 0.02 cubic inches (0.3 cubic centimeters) of fluid from the master cylinder to operate. Systems requiring more than 0.02 cubic inches of fluid must not be installed because the truck brake fluid capacity will NOT be sufficient to operate the truck and trailer brakes under every condition. The brake fluid tap on light duty trucks including the 1988 C/K models equipped with rear wheel anti-lock (RWAL) brakes, must be made to the master cylinder port supplying fluid to rear brakes before the combination valve. On the 1988 C/K, this installation will allow the truck to continue operating with RWAL brakes while the trailer brakes operate independently of the RWAL brake system. Aluminum Wheels - Cosmetic Damage During Balancing Wheels: Customer Interest Aluminum Wheels - Cosmetic Damage During Balancing Number: 93-197-3E Section: 3E Date: MAY 1993 Corporate Bulletin No.: 393502 ASE No.: A4 Subject: INFORMATION ON COSMETIC DAMAGE TO ALUMINUM WHEELS DURING BALANCING Model and Year: 1988-93 C1, K1, G, E/J, L/M, P, S/T, R/V 1990-93 LUMINA APV Some aluminum wheels on GM models may incur cosmetic damage during balancing if proper care and procedures are not used. All aluminum wheels have a clearcoat paint on them that must be cared for like any other painted surface. Some off-car wheel balancer retaining cups used to clamp the wheel to the balancer may put a circular mark into the clearcoat on the face of the wheel. Like any other clearcoat damage, this may be difficult to remove or repair, depending on severity. ALWAYS use balancer retainer cups that are protected with rubber, plastic, or other nonmetallic materials where contact is made with the wheel. Make sure the retainer cup is free from dirt, grease, and gouges. Most wheel balancers now offer this type of protected retainer. DO NOT allow the retainer cup to rotate against the wheel's surface when tightening the wheel to the balancer. DO NOT OVERTIGHTEN. Most balancers use a large "wing nut" design to clamp the retainer against the wheel. Hand tight is sufficient. This procedure will allow accurate balancing using the conventional back cone method. IMPORTANT: Coated balance weights must be used on aluminum wheels to prevent damage to the rim flange. Page 5174 Symbol Identification 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. Page 4809 Brake Warning System Wiring Circuit Page 5516 Symbol Identification Page 1723 Symbol Identification Page 3127 Throttle Body: Service and Repair Fuel Meter Cover REMOVAL The fuel meter cover contains the fuel pressure regulator and is serviced as a complete preset unit. Do not attempt to remove the four pressure regulator-to-fuel meter cover attaching screws as the pressure regulator is spring loaded and, if tension is released, could cause injury. 1. Relieve fuel pressure. Refer to "Fuel Pressure Relief Procedure". 2. Disconnect battery ground cable, then remove air cleaner assembly. 3. Disconnect injector(s) connector by squeezing two tabs together and pulling straight up. 4. Remove five screws securing meter cover-to-meter body. Note locations of two shorter screws. 5. Remove fuel meter cover. Do not immerse fuel meter cover/pressure regulator assembly in parts cleaner, as pressure regulator diaphragms and gaskets could be damaged. Fuel Meter Cover Installation INSTALLATION 1. Install a pressure regulator seal into fuel meter body recess, Fig. 342. 2. Install fuel meter outlet passage gasket on fuel meter cover. Page 1188 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. Page 3085 Idle Speed/Throttle Actuator - Electronic: Service and Repair IAC Thread Mounted 10mm Pintle NOTES: a. 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. b. 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. REMOVAL: 1. Disconnect electrical connector. 2. Remove IAC valve, use a 32 mm (1 1/4") wrench. 3. Remove IAC gasket and discard. 4. Clean old gasket material from surface of throttle body assembly to insure seal of new gasket. Idle Air Control Valve Pintle Retraction (Manually) NOTES: a. 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). Before installing a IAC valve, measure the distance between the tip of the valve pintle and the mounting surface. If the dimension is greater than 28.0 mm (1.10 inches), the valve pintle must be retracted to prevent damage to the 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. b. 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. INSTALLATION: 1. Install the IAC valve into the throttle body with new gasket. NOTE: New IAC valves have been reset at the factory and should be installed in the throttle body in an "as is" condition, without any adjustment. 2. Tighten IAC valve assembly to 18.0 Nm (13.0 lb-ft). 3. Reconnect electrical connector to IAC valve. 4. START engine and allow it to reach operating temperature. Page 7231 Figure No. 5 With the tailgate closed and the tailgate window lowered, look down the vertical side of the tailgate on both ends. What you should see is the tailgate wedges, shown in Figure 5, displacing the spring loaded body mounted wedges shown in Figure 3. If one or both of the body mounted wedges are not displaced, shim the tailgate mounted wedge(s) with 1 mm or 2 mm shims (P/N 15659205 1 mm, P/N 20093974 2 mm). If both spring loaded wedges are displaced then do nothing to this area. To shim the wedges: 1) Locate the wedges shown on Figure 5. 2) Remove the wedges and retain existing shims. Begin with 1 mm shims to prevent excess shimming and insert the width of shims necessary to slightly displace wedge(s). Service Procedure 4 Page 4240 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. Page 4328 Pinion Companion Flange Vectoring (Indexing) Figure 4 Vectoring is a procedure to optimize the mounting and match the high point of the companion flange to the low point of the pinion stem to help reduce flange runout. Fuse Block - Deforms Fuse Block: Customer Interest Fuse Block - Deforms Number: 90-432-8B Section: 8B Date: SEPT. 1991 Corporate Bulletin No.: 168102 ASE No.: A6 Subject: FUSE BLOCK DEFORMS Model and Year: 1988-90 SI (LLV) POSTAL VEHICLES Some 1988 to 1990 LLV postal vehicles built prior to August 3, 1990, may exhibit a condtion where the fuse block is partially deformed due to heat generated by continuous operation of the hazard flasher. This condition may be corrected by the repositioning of the hazard flasher to a remote location. SERVICE PROCEDURE: 1. Disconnect positive battery cable. 2. Remove old flasher. 3. Back out terminals for circuit 140A (orange wire) and circuit 27 (brown wire) using a small flat screwdriver or pick. Using the same tool, raise the locking tang on the back of the terminal. 4. Cut electrical tape used to wrap main wiring harness a sufficient amount to provide 2 to 3 inches of flasher wiring for relocation. 5. Insert terminals of circuits 140A and 27 into new connector (P/N 2973385). 6. Install electronic flasher (P/N 15504673) into the new connector. 7. Using nylon ties, strap the connector and flasher assembly to the wiring harness that runs above the fuse block. Verify that the relocated flasher and all wiring is secured so it does not cause interference with the throttle linkage. 8. Reconnect battery cable. 9. Test operation of hazard flasher system. SERVICE PARTS INFORMATION PART NUMBER DESCRIPTION QTY 2973385 Connector 1 15504673 Flasher (Electronic) 1 NPN Nylon Tie Straps 2 Parts are currently available from GMSPO. Page 3666 - In commercial service (taxi or police use). ^ If the vehicle has been operated under these conditions, shut the engine off and allow the vehicle to "cool" for thirty (30) minutes. After the cooldown period, restart the vehicle and continue from step "2" above. Page 5305 Multiple Junction Connector: Locations Center Of Dash Panel (engine Compartment) Page 7252 Figure No. 1 Page 3425 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 Page 379 Center Of Dash Panel (engine Compartment) Page 3493 FIGURE 2 - THM 700-R4 WIRING DIAGRAM DATE OF PRODUCTION CHANGE: (Figure 1) On April 20, 1988 (Julian Date 111), the 1988 THM 700-R4, THM and TLM models were built with the new Type 18 Solenoid Assembly and Wiring Harness. Beginning May 9, 1988 (Julian Date 130), the remaining 1988 THM 700-R4 models listed above were built using the new Type 18 Solenoid Assembly. SERVICE NOTES: Any 1988 THM 700-R4 transmission models built with the Type 18 Solenoid Assembly, refer to models and Julian Dates listed above, must be serviced with the Type 18 Solenoid Assembly and Wiring Harness Complete listed under "Service Parts Information". Any 1988 THM 700-R4 transmission model built with a Type 15 Solenoid Assembly may be serviced with the new Type 18 assembly; however, there will be no wire connection for the 4-3 pulse switch. The 4-3 pulse switch, which can be left installed, will then function as a plug. SERVICE PARTS INFORMATION: Part No. Description 10478100 Type 18 Solenoid Assembly - Complete 8654415 Type 15 Solenoid Assembly - Complete Parts are currently available from GMSPO. SERVICE MANUAL REFERENCE: Please update the 1988 THM 700-R4 Hydraulic Diagnosis section of your service manual accordingly. Engine - Miss, Hesitation, or Roughness Spark Plug Wire: All Technical Service Bulletins Engine - Miss, Hesitation, or Roughness Number: 93-35-6D Section: 6D Date: OCT. 1992 Corporate Bulletin No.: 716404R ASE No.: A1, A8 Subject: ENGINE MISS HESITATION OR ROUGHNESS DUE TO PIERCED SECONDARY IGNITION COMPONENTS Model and Year: 1980-93 ALL PASSENGER CARS AND TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 87-121, DATED MAY 1987. THE 1989-93 MODEL YEARS HAVE BEEN ADDED. ALL COPIES OF 87-121 SHOULD BE DISCARDED. During the diagnosis procedure for an engine miss, hesitation or roughness, a spark plug or spark plug wire condition may be suspected. Several types of commercial or homemade diagnostic equipment required the secondary ignition boots or wire to be pierced. This is normally done to check for spark plug firing or to perform a cylinder balance test. Similarly the use of pliers or other such tools to disengage a spark plug boot may pierce or damage the boot or wire. Secondary ignition components should not be pierced for any reason. Piercing a spark plug wire and/or distributor boot may create a condition that will not be immediately apparent. Over time, the hole in the pierced boot may allow a ground path to develop creating a plug misfire condition. Heavily moisture laden air in the vicinity of the pierced boot may accelerate this effect. Piercing a secondary ignition wire creates a gap in the wire's conductive core. This gap is a point of high resistance. The current flow in the wire will increase to compensate for the higher wire resistance. Over time, the wire may fail creating a plug misfire condition. The time required for the condition to appear depends upon the extent of damage to the conductive core. To help prevent future condition that are spark plug wire related, do not pierce or otherwise damage any secondary ignition component. Only use diagnostic equipment containing an inductive pick-up to check for spark plug firing or to perform cylinder balance tests. When disengaging a spark plug boot from the spark plug, twist the flanged boot 1/2 turn then pull on the boot only to remove the wire. Page 6333 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 Page 6240 Fig 23. Fitting And Hose Installation REMOVE OR DISCONNECT (Figures 1, 5, and 23) NOTE: Tool Required: J-26549-D Orifice Tube Remover and Extractor 1. Refrigerant from the system. 2. Refrigerant inlet line (108) at the accumulator (4). 3. Orifice from the refrigerant line with J-26549-D. INSTALL OR CONNECT 1. Orifice to the refrigerant inlet line (108). ^ Install the "shorter screen end" first into the expansion tube. 2. Refrigerant line (108) to the accumulator (4). ^ Tighten connection to 24 Nm (18 ft. lbs.). 3. Refrigerant to the system. Page 3747 Fluid Pump: Specifications THM 180 & 180 C Auto Transmission Converter Housing to Oil Pump ........................................................................................................... ................................................................ 13-15 ft lbs Page 2401 14. With engine at normal operating temperature (85-100 degrees C), adjust stop screw to obtain nominal rpm per specifications with seated IAC valve. 15. Turn ignition "OFF" and reconnect IAC valve electrical connector. 16. Disconnect "Scan" tool or tachometer. 17. Use silicon sealant or equivalent to cover stop screw hole. 18. Install air cleaner, adapter and gasket. 19. On 2.5L engines, clear Code 35 that has been set. 1987 AND 1988 MODEL YEAR TRUCKS CONTROLLED IDLE SPEED 1987 AND 1988 MODEL YEAR TRUCKS MINIMUM IDLE AIR RATE Page 4800 Symbol Identification Page 5470 Fuse Block: Locations LH Side Of I/P Behind Instrument Cluster Page 1726 LIGHT BLUE LT BLU BROWN BRN GRAY GRY GREEN GRN DARK GREEN DK GRN LIGHT GREEN LT GRN ORANGE ORN PINK PNK PURPLE PPL RED RED TAN TAN WHITE WHT YELLOW YEL Page 3135 ^ 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. ACCELERATOR CONTROL CABLE: 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 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. Page 7056 Page 2908 ^ 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. ACCELERATOR CONTROL CABLE: 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 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. Page 2623 Manifold Pressure/Vacuum Sensor: Service and Repair Fig. 337 MAP Sensor Removal (V6 Models Similar) The MAP sensor unit is not serviceable and must be replaced as a unit. 1. Disconnect vacuum hose from MAP sensor, then remove top of air cleaner assembly. 2. Remove MAP sensor unit retaining clip, then the sensor, Fig. 337. 3. Reverse procedure to install. Page 7670 Numerous & Various Size Drops of Water Collecting on the Inside Surface of the Lamp Lens After the Vehicle Has Been Exposed to Rain or a Car Washing Environment - A condition that covers more than half the surface of the lamp lens. - An accumulation of water in the bottom of the lamp assembly. - A condition that WON'T clear when the vehicle is parked in a dry environment, or when the vehicle is driven with the lights ON. - A comparison of the equivalent lamp on the opposing side of the vehicle indicates a different performance. Any of the above conditions would indicate the need to service the lens or lamp assembly. Disclaimer Page 7432 Check Gauges Lamp: Description and Operation CHECK GAGES Indicator The Check Gages indicator turns on if the Oil Pressure is low or the Engine Coolant Temperature is high Ignition System - Diagnosis Precautions Spark Plug Wire: All Technical Service Bulletins Ignition System - Diagnosis Precautions Number: 88-138-6D Section: 6D Date: Feb., 1988 Subject: ENGINE MISS, HESITATION, OR ROUGHNESS DUE TO PIERCED SECONDARY IGNITION COMPONENTS Model and Year: ALL MODELS WITH GASOLINE ENGINE TO: ALL CHEVROLET DEALERS During the diagnosis procedures for an engine miss, hesitation, or roughness condition, a spark plug or spark plug wire condition may be suspected. Several types of commercial or homemade diagnostic equipment require the secondary ignition boots or wire to be pierced. This is normally done to check for spark plug firing or to perform a cylinder balance test. Similarly, the use of pliers or other such tools to disengage a spark plug boot may pierce or damage the boot or wire. NOTICE: SECONDARY IGNITION COMPONENTS SHOULD NOT BE PIERCED FOR ANY REASON. Piercing a spark plug wire and/or distributor or direct fire module nipple may create a failure condition that will not be immediately apparent. Over time, the hole in the pierced boot may allow a ground path to develop, creating a plug misfire condition. Heavily moisture-laden air in the vicinity of the pierced boot may accelerate this effect. Piercing a secondary ignition wire creates a gap in the wire's conductive core. This gap is a point of high resistance. The current flow in the wire will increase to compensate for the higher wire resistance. Over time, the wire may fail, creating a plug misfire condition. The time required for the condition to appear depends upon the extent of damage to the conductive core. To help prevent future customer comments that are spark plug wire related, do not pierce or otherwise damage any secondary ignition component. Only use diagnostic equipment containing an inductive pick-up to check for spark plug firing or to perform cylinder balance tests. When disengaging a spark plug boot from the spark plug, twist the flanged boot 1/2 turn, then pull only on the boot to remove the wire. Page 1814 Disclaimer Page 4936 Hold-down Spring Tool Conventional pliers or needle nose locking pliers will work if a brake spring tool is not available. - Grasp the top the the spring with the plier, compress, and rotate. CAUTION: Excessive pressure can easily distort the top of the spring. Any distortion widens the slot which can cause the pin to pop out during normal operation. If the slot appears distorted or widened it must be replaced. Installation While holding the brake shoe against the backing-plate, insert the retaining pin from the rear of the backing-plate through the appropriate hole in the brake shoe webbing. Verify the shoe is resting squarely on the contact pads of the backing-plate. NOTE: A strip of duct tape placed across the backside of the pin and backing-plate will help keep the pin from inadvertently falling falling out and will free up a hand to help steady the shoe during the next step. - Place the hold-down spring and washers over the pin. - With the thumb of one hand hold the shoe steady while reaching around the backing-plate to hold the retaining pin steady. - Use your other hand to simultaneously compress and align the slot of the hold-down spring with the pin. - When the slot and pin are aligned, further compress the spring to clear the tip of the pin and then rotate the spring 90 degrees. - The slot and tip of the pin should now be opposing each other at a 90 degree angle. - Verify the tip of the retaining pin is locked into the indents on the surface of the hold-down spring. This will keep the retaining pin from twisting and inadvertently popping out. Isuzu M-150 (77.5 mm) 4-Speed Mainshaft: Specifications Isuzu M-150 (77.5 mm) 4-Speed Reverse gear to mainshaft nut ............................................................................................................ ..................................................................... 95 ft. lbs. Electrical - MIL ON/DTC's Set By Various Control Modules Wiring Harness: 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 Page 20 - 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 Testing and Inspection Temperature Warning Lamp/Indicator: Testing and Inspection 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. 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. Page 5552 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) Locations Accumulator HVAC: Locations RH Side Of Cowl RH Side Of Firewall Page 4804 e. Solder with rosin core solder. f. Carefully pull on wire to draw terminal into connector body until it locks. Push-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J38125 or equivalent. Figure 1 - Typical Push-To-Seat Connector Follow the steps below to repair Push-To-Seat connectors (Figure 1). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors Do Not require all the steps shown. Skip the steps that Do Not apply. Remove Terminal Position Assurance (TPA) device, Connector Position Assurance (CPA) device and/or secondary lock. 1. Separate connector halves (see Figures 2 through 6). Figure 2 Figure 3 Page 7900 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 4. Make repair. Page 6339 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 Page 3579 Page 5152 Symbol Identification Wire Color Code Identification WIRE COLOR ABBREVIATION BLACK BLK BLUE BLU DARK BLUE DK BLU Page 3401 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. Page 1007 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. Page 2580 Engine Control Module: Service and Repair Figure 1 *** THIS PROCEDURE HAS BEEN UPDATED BY TSB # 88-42, dated 9/87 Some replacement ECM's may come with a replacement PROM already installed in them. If this situation occurs, remove prom from old ECM and install in rebuilt ECM. When replacing a production ECM with a service ECM, transfer the broadcast code and production number from the production unit to the service unit. Also, during replacement, the PROM, and if equipped, the CALPAK must be removed from the ECM being replaced and transferred to the new unit. Refer to "PROM, REPLACE" and "CALPAK, REPLACE" for procedure. 1. Disconnect battery ground cable. 2. Locate ECM on passenger side under the instrument panel hush panel. (see figure 1.). 3. Remove ECM mounting hardware. 4. Remove ECM from passenger compartment. 5. Reverse procedure to install. Page 1856 14. With engine at normal operating temperature (85-100 degrees C), adjust stop screw to obtain nominal rpm per specifications with seated IAC valve. 15. Turn ignition "OFF" and reconnect IAC valve electrical connector. 16. Disconnect "Scan" tool or tachometer. 17. Use silicon sealant or equivalent to cover stop screw hole. 18. Install air cleaner, adapter and gasket. 19. On 2.5L engines, clear Code 35 that has been set. 1987 AND 1988 MODEL YEAR TRUCKS CONTROLLED IDLE SPEED 1987 AND 1988 MODEL YEAR TRUCKS MINIMUM IDLE AIR RATE Page 5799 Figure 1 - Fuel Tank Installation 8. Reinstall fuel tank (Figure 1). A. Raise tank sufficiently to install fuel tank sending unit hoses, electrical connector, and ground strap. Route strap 1 under hoses and wiring. B. Raise tank fully and install tank supports (5). Torque front strap nuts (9) to 27-47 N-m (20-35 lbs.ft.). Torque support nuts (7) to 40-50 N-m (29-37 lbs.ft.). C. Reinstall tank shield and torque screws to 9-13 N-m (80-115 lb.in.). 9. Lower vehicle, refill fuel, connect battery negative ground cable. 10. Start engine and check for fuel leaks. SERVICE PARTS INFORMATION Part Number Description Quantity 15674914 Rear Frame Crossmember and Shock Tower 1 Assembly 11504596 Bolt, Crossmember Mounting, 6 11501033 Nut, Crossmember Mounting, 6 15531204 Washer, 12 Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Operation: T7186 Labor Time: 2.5 hrs. Trouble Code: 92 NOTE: Labor Operation is coded to base vehicle coverage in the warranty system. Page 5256 Disclaimer A/T - Proper Usage of Spacer Plate Gaskets, Overhaul Kit Valve Body: All Technical Service Bulletins A/T - Proper Usage of Spacer Plate Gaskets, Overhaul Kit Number: 89-203-7A Section: 7A Date: July 1989 Subject: PROPER USAGE OF SPACER PLATE GASKETS IN OVERHAUL KIT Model and Year: 1982-89 PASSENGER CAR AND TRUCK MODELS WITH 700R4/4L60 TRANSMISSION Figure 1 - THM 700-R4/HYDRA-MATIC 4L60 Transmission Identification Information Figure 2 - Spacer Plate Gaskets-Transmission Overhaul Kit TO: ALL CHEVROLET DEALERS This bulletin covers instructions for choosing the correct spacer plate gaskets from the transmission overhaul service package. Current information enclosed with the service package may be unclear when explaining which spacer plate gaskets are appropriate for use. SERVICE PROCEDURE: (Figure 2) Two sets of spacer plate gaskets are supplied with each transmission overhaul service kit. One set of gaskets is for use on model years 1982 through 1986, and the other set is for use on model years 1987-89. Page 4379 Extension Housing: Specifications Warner 83 mm 4 Speed Extension housing long bolts ............................................................................................................... ................................................................... 40 ft. lbs. Extension housing short bolts .......................... ........................................................................................................................................................ 25 ft. lbs. Specifications Torque Converter: Specifications Lower Cover to Converter Housing 180 .............................................................................................. ......................................................................................................................... 13-16 ft lbs 180C ....... .............................................................................................................................................................. ....................................................... 7 ft lbs Converter Housing to Case ................................................................................................................. ................................................................. 24-26 ft lbs Page 1296 FIGURE 3 FIGURE 1 Service and Repair Fuel Pressure Release: Service and Repair Before performing any procedure that requires disconnecting fuel lines, relieve fuel system pressure as described below. 1. Remove Fuel Pump fuse from fuse block. 2. Start engine and allow to run out of fuel, then crank engine an additional 3 seconds. 3. Service fuel system as necessary. Page 6158 Removing The Rotor & Bearing Assembly Retainer Ring 2. Snap ring (4) with J 6083. ^ Mark the location of the clutch coil terminals. 3. Rotor (6) and bearing (5) assembly. Important ^ If the clutch rotor and/or rotor bearing are to be replaced, bend the washers (9) away from the pulley rim mounting screws (10). Remove the six mounting screws (10) and washers (9). Installing The Rotor And Bearing Guide ^ Install J 25031 guide over the compressor shaft (22). Removing The Clutch Rotor Assembly Interior - Itch Noise From Windshield Pillar Area Dashboard / Instrument Panel: All Technical Service Bulletins Interior - Itch Noise From Windshield Pillar Area Number: 92-286-10 Section: 10 Date: SEPT. 1992 Corporate Bulletin No.: 261610 ASE No.: B1 Subject: ITCH NOISE FROM WINDSHIELD PILLAR AREA Model and Year: 1986-92 S/T TRUCKS Some 1986-1992 S/T utility trucks may exhibit a plastic to metal or plastic to plastic "itch" noise from the left or right windshield pillar area. This noise may be caused by the instrument panel pad rubbing against the cowl or dash support panel. An adhesive backed felt tape has been released to insulate the dash pad outer corners from the dash support panel. This tape may also be used on the non-visible surfaces of other trim panels as necessary to eliminate itch noises. The felt tape, P/N 12541499, is released in a 10 ft. x 30 mm x 1 mm roll to provide the technician sufficient material to insulate numerous trim panels. SERVICE PROCEDURE: Prior to installing the felt tape, it should be determined if the IP pad to dash support panel is the area that is generating the noise. Refer to the Squeak and Rattle Diagnosis and Correction Manual to identify other possible sources such as ECM Mounting Bracket or Air Vent. If it is determined the IP pad is the source of the noise: 1. Remove the instrument panel radio speaker(s) to obtain better access to the metal ledge on which the instrument panel pad rests. 2. Remove the 4 IP upper retaining screws located in the defroster duct openings and pull the pad back slightly. NOTICE: Do not remove the dash pad any further than necessary to perform the repair. The possibility exists that additional noises may be generated due to the wiring and HVAC ducts being mispositioned upon reinstallation. 3. Cut a strip of felt tape 6 inches long, remove the protective backing and apply the tape to the top of the metal ledges in front of the speaker openings where the instrument panel pad rests. NOTICE: Installation is easier if 2 screwdrivers are wedged between instrument panel pad and the cowl panel to raise the IP pad. 4. Push the IP pad forward and reinstall the retaining screws and speakers. Page 2205 FIGURE 1(T-TRUCK ONLY) G. (T-truck only) Check equalizer lever for firm contact at the shift lever inboard side of the guide slot. (See Figure 1) H. If firm contact is evident, add an additional washer (#10 in Figure #1) P/N 14074908 to adjust equalizer lever outboard toward the center of the guide slot to eliminate contact. 2. A. Raise vehicle on hoist. B. Note location of clamp rotation on pipe. Some clamps are located with the lower lock ring (nuts) pointed towards the transmission. If the clamp is located in such a manner, loosen clamp and rotate it down so the nuts point toward the ground and retighten to 58 N-m (43 ft/lbs.) 3. A. Loosen converter clamp until it will rotate around the pipe. Using a suitable pry bar, move exhaust system rearward to obtain a minimum of 5/8 in. clearance between any point on the exhaust system and the transmission crossmember. For repairs performed under warranty, use the following labor operations and times: Labor Operation Labor Time Exhaust/muffler clamp L2020 .3 Hr Exhaust system align L2004 .3 Hr Shift Linkage (shorten) K5244 .3 Hr Page 5909 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. Page 5520 Multiple Junction Connector: Diagnostic Aids Pull-to-Seat Connectors NOTE: The following general repair procedures can be used to repair most types of connectors. Use the Pick(s) or Tools that apply to your terminal. Use Terminal repair kit J 38125 or equivalent. Figure 20 - Typical Pull-To-Seat Connector Follow the steps below to repair Pull-To-Seat connectors (Figure 20). The steps are illustrated with typical connectors. Your connector may be different, but the repair steps are similar. Some connectors DO NOT require all the steps shown. Skip the steps that DO NOT apply. 1. Separate connector halves. Using the proper pick or removal tool, remove terminal (see Figures 21 & 22). a. Pull lead gently. b. Insert pick from front of connector into canal. c. Pry tab up with tool. d. Push lead to remove. Figure 21 Figure 22 2. If terminal is to be re-used, re-form locking tang. 3. Make repair. a. Pull terminal wire out of connector body. b. Cut wire as close to terminal as possible. c. Strip 5 mm (3/16") of insulation from the wire (see Figure 23). d. Crimp new terminal to wire. Page 433 Vehicle Speed Sensor: Service and Repair 1. Disconnect vehicle speed sensor electrical connector. 2. Remove sensor attaching bolt. 3. Using speed sensor remover and installer, tool No. J 38417, remove sensor, then O-ring seal. 4. Reverse procedure to install, coating the new O-ring seal with transmission fluid. Torque attaching bolt to 97 inch lbs. Page 3626 Extension Housing: Specifications 4L60 - 700R4 Transmission Case Extension To Case ..................................................................................................................... ..................................................................... 26 ft. lbs. Electronic Spark Control (ESC) Knock Sensor: Description and Operation Electronic Spark Control (ESC) Electronic Spark Control (ESC) is used on some models. The ESC system is used in conjunction with the EST system to provide additional spark retard during engine detonation. A knock sensor signals a separate ESC controller to retard the timing when it senses engine knock. The ESC controller signals the ECM which reduces spark advance until no more signals are received from the knock sensor. Page 3944 than a standard fan. These benefits are possible through the addition of a thermostatic clutch to the fan drive. When the engine is cool 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, 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 engage. However, if the vehicle is pulling a trailer, heavily loaded or operated at high ambient temperatures the thermostatic clutch may cycle on and off as the engine 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 cooling system or transmission parts will not change or reduce the noise level. Attempts to reduce this noise will only give you, the customer, a false sense of vehicle unreliability and the inconvenience of having your vehicle out of service. Page 6260 ^ Leak test the compressor. Page 1020 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 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 Engine - Vibration On Acceleration Catalytic Converter: Customer Interest Engine - Vibration On Acceleration Number: 88-270-6F Section: 6F Date: JULY, 1988 Subject VIBRATION ON ACCELERATION Model and Year 1988 S/T TRUCK W/4.3L (VIN CODE Z) ENGINE TO: ALL CHEVROLET DEALERS Some 1988 S/T Trucks equipped with 4.3L engines may experience a vibration that can be felt in the floor pan area near the shifter, in the right hand passenger seat foot area, or on the steering column. These conditions may be caused by the following items: 1. The shifter rod that goes from the steering column to the transmission equalizer lever (#340 and #338 in Figure 36 page 7A-45 of the 1988 S/T Manual) hitting the exhaust crossover pipe and/or the equalizer lever making firm contact at the shift lever (T-truck only). 2. The exhaust pipe to catalytic converter clamp (Figure 7, page 6F-6 of the 1988 S/T Manual) hitting the catalytic converter heat shield. 3. The exhaust pipe to converter installation allows the exhaust pipe to contact the transmission crossmember. To repair these conditions, use the following procedures: 1. A. Raise vehicle on hoist. B. Check Transmission linkage for correct adjustment. C. Check exhaust pipe for shifter rod interference (shiny spot on pipe). D. If linkage hits pipe, remove 15 mm (5/8 in) from bottom of rod. E. Put transmission into low gear and mark exhaust pipe area near linkage. F. Put transmission in park. Using a hammer, lightly dimple exhaust pipe for additional clearance. Page 6990 PAINT air dry only Note: Only items marked with an asterisk are "add" conditions to the Major Operation being performed. Removal time for all other items listed is included in the refinish time. LIGHT DUTY TRUCKS C/K TRUCKS Grille Front bumper filler panel Antenna Tail lamps Door edge guards Metal wheel opening moldings *Roof marker lamps "Luggage rack *West coast style mirrors "Stripes Emblems/decals if necessary Swing out windows/seals Tail gate handle bezel S/T TRUCKS Windshield molding Bumper filler panels, Ft./Rr. Wiper arms Antenna Wheel opening moldings Cowl vent grille Door edge guards Side view mirrors Tail lamps *Wind deflector Rear Window (Jimmy) *Luggage rack *Stripes Emblems/decals if necessary Swing out windows/seals *Spare tire carrier and latch-external mount (Jimmy) M/L VANS Windshield molding Wheel opening moldings Headlamp bezels Antenna Tail lamps Door edge guards *Luggage rack *Stripes Emblems/decals if necessary R/V TRUCKS Wiper arms Cowl vent grille Antenna Tail lamps Hood ornaments Wheel opening moldings Side view mirrors Grille and headlamp bezels Page 5715 Steering Gear: Service and Repair Saginaw Recirculating Ball Manual Steering Gear Service Disassembly Fig. 4 Steering gear assembly 1. Referring to Fig. 4, loosen adjusting screw locknut and remove housing side cover by removing adjusting screw. 2. Loosen locknut and back off worm bearing adjuster several turns, then remove housing end cover and gasket. 3. Remove lower thrust bearing, steering shaft and upper bearing from housing. 4. Remove ball return guide clamps and guides from ball nut. Turn ball nut over and remove ball nut from steering shaft worm. Inspection 1. Clean and inspect all ball and roller bearings and races, including race in housing. 2. Inspect pitman shaft bushings in gear housing and end cover. If bushings are worn excessively, replace. 3. It is advisable to replace pitman shaft grease seal in housing to avoid possible leakage of lubricant. Seal must be installed with feather edge toward inside of housing. 4. Inspect pitman shaft for wear or pits in bearing races, which would require replacement of shaft. 5. Check shaft for straightness. 6. Inspect teeth of ball nut and pitman shaft. If scored or excessively worn it is advisable to replace both parts to insure proper mating of teeth. 7. Check serration of pitman shaft; if twisted replace shaft. 8. Check fit of pitman shaft adjusting screw and shim in slot in end of pitman shaft. With shim in place, screw head must be free to turn in slot with zero to .002 inch end play. If endplay is excessive, selectively fit a new shim, which are available in four different thicknesses. Assembly Lubricate all seals, bushings, bearings and gears with multi-purpose gear lube prior to installation. 1. Position ball nut over worm shaft so that deep side of teeth will be toward side cover when installed in gear housing. 2. Install exactly 1/2 the number of balls in each circuit, rocking worm shaft slightly to aid in installing balls. 3. Place about six balls in each return guide, using grease to hold balls in place. 4. Install return guides, clamp and screw. 5. Rotate worm through its complete travel several times to be sure balls are installed correctly and rotate freely. 6. Place upper bearing on worm shaft and slide worm shaft assembly into housing. 7. Place lower bearing in worm bearing adjuster and install bearing retainer. 8. Install adjuster assembly and locknut in housing. Tighten adjuster only enough to hold worm bearings in place. Final adjustment will be made later. 9. Turn worm shaft until center groove in ball nut lines up with center of pitman shaft bushing. 10. Install pitman shaft and lash adjuster with shim so that center tooth meshes with center groove in ball nut. 11. Install side cover with gasket on lash adjuster by turning adjuster counterclockwise. 12. Install side cover bolts and washers. 13. Turn lash adjuster so that teeth on shaft and ball nut engage but do not bind. Page 813 A new pressure regulator valve (III. 218) has been made which will improve the oil pressure stability at lower RPM. SERVICE PARTS INFORMATION: Description Part Number Valve, Pressure Regulator (III. 218) 8684048 Part numbers are for Reference Only. Check with your Parts Department for latest information. 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. Page 5798 D. Lower tank sufficiently to disconnect sender unit connector, fuel lines, and ground terminal. E. Remove fuel tank. F. Remove front bolts from tank upper straps and move straps to rear out of the way. Figure 2 - Shock Absorber Installation 5. Remove shock absorbers (Figure 2). A. Remove shock absorber to tower bolts and nuts. B. Remove shock absorber to anchor plate nut and washer. C. Remove shock absorber from vehicle. 6. Remove rear frame crossmember and towers (Figure 2). A. Cut three crossmember to frame rivet heads off on each side of vehicle. Use air chisel, cutting wheel, or grinding wheel. B. Remove and discard crossmember and tower assembly. Before discarding, remove the two spring mounted nuts for the tank straps and install the nuts in the new crossmember. 7. Install new frame crossmember and tower assembly (Figure 2). A. Install three bolts, nuts, and six washers on each side of frame crossmember and torque nuts to 40-51 N-m (29-37 lbs.ft. or torque bolts to 45-60 N-m (33-44 lbs.ft.). B. Reinstall shock absorber and torque anchor plate nut to 20-26 N-m (15-19 lbs.ft.). C. Bolt shock to tower and torque nuts to 58-70 N-m (43-50 lbs.ft.). Page 563 Wiper Switch: Testing and Inspection Fig. 3 Permanent Magnet Type Windshield Wiper Motor W/Pulse Wipers 1. Disconnect electrical connectors from wiper motor. 2. Check switch voltage using a digital voltmeter with ignition switch in the On position. If readings are not as specified at between various switch positions and ground, replace switch. Page 1033 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 Rockwell Full Floating Axle Differential Axle Housing: Service and Repair Rockwell Full Floating Axle 1. Raise and support vehicle, then remove rear wheels. 2. Remove the two trunnion bearing U-bolts, then split universal joint and position propeller shaft aside. 3. Remove hub and drum assembly, then disconnect parking brake cable at lever and flange plate. 4. Disconnect brake hose at axle connector, then the shock absorbers at axle brackets. 5. Support axle housing with a suitable jack, remove spring plate U-bolts and remove axle housing from vehicle. 6. Reverse procedure to install. Page 2539 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 Page 2056 11. Install cowl vent grille. Refer to "Cowl Vent Grille Replacement" in Section 2B of the Service Manual. PARTS INFORMATION Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty, use: Labor Operation Description Labor Time B1717 Replace Use Published Labor Hood Hinge Operation Time Page 2360 Wiring Diagram For Chart C-1A - Park/Neutral Switch Diagnosis CHART C-1A - PARK/NEUTRAL SWITCH DIAGNOSIS Circuit Description: The Park/Neutral Switch contacts are closed to ground in park or neutral and open in drive ranges. The ECM supplies ignition voltage, through a current limiting resistor, to CKT 434 and senses a closed switch, when the voltage on CKT 434 drops to less than one volt. The ECM uses the P/N signal as one of the inputs to control: Idle Air Control VSS Diagnostics EGR Test Description: Numbers below refer to circled numbers on the diagnostic chart. 1. Checks for a closed switch to ground in park position. Different makes of "Scan" tools will read P/N differently. Refer to operators manual for type of display used for a specific tool. 2. Checks for an open switch in drive or reverse range. 3. Be sure "Scan" indicates drive, even while wiggling shifter to test for an intermittent or misadjusted switch in drive range. Diagnostic Aids: If CKT 434 indicates PIN (grounded), while in drive range, the EGR would be inoperative, resulting in possible detonation. If CKT 434 always indicates drive (open), a drop in the idle may exist when the gear selector is moved into drive range. Page 7249 Figure No. 4 3) Remove existing weatherstrip and replace with revised weatherstrip (P/N 15659207). The revised weatherstrip will have plugs inserted inside of it. When installing the weather-strip align these plugs so that half of the plug is above the striker and half is below (see Figure 4. This is a friction fit, therefore, no adhesive is required. NOTE: If the subject vehicle was manufactured after the following break points then Service Procedure 2 will not be required as the material called out was incorporated in production. Shreveport: 1GNCS18Z2L8144761 Pontiac West: 1GNCT18Z7L0122931 Moraine: 1GNDT13Z6M2115163 Service Procedure 3 SIR - Operating Vehicle with Warning Light On Malfunction Lamp / Indicator: All Technical Service Bulletins SIR - Operating Vehicle with Warning Light On File In Section: 8 - Chassis/Body Electrical Bulletin No.: 83-81-34 Date: March, 1999 INFORMATION Subject: Operating Vehicle with Supplemental Inflatable Restraint (SIR) Warning Light Illuminated Models: 1999 and Prior Passenger Cars and Light Duty Trucks with SDM Controlled Air Bag System The AIR BAG warning light is the key to driver notification of Supplemental Inflatable Restraint (SIR) system malfunctions. When the warning light remains illuminated or continues to flash, one or more of the following conditions may occur if vehicle operation is continued. ^ Non-deployment of the air bags in the event of a crash. ^ Deployment of the air bags without a crash. ^ Deployment of the air bags in crashes less severe than intended. If an AIR BAG warning light is illuminated or flashing, you should advise the customer of these possibilities and that the vehicle should be serviced right away. Locations Cruise Control Servo: Locations Rear LH Corner Of Engine Compartment LH Rear Corner Of Engine Compartment Page 7537 Page 5030 FIGURE 1 - PARKING BRAKE ADJUSTMENT To obtain adequate parking brake holding ability, the distance between X and Y should be a minimum of 12 mm (1/2 inch). If this distance is less than 12 mm (1/2 inch) the front parking brake cable #4 should be replaced. Removal 1. Disconnect battery. 2. Remove locking screw in adjusting knob (if equipped). 3. With the parking brake lever in the full apply position, remove all adjustment by rotating knob (#7 Figure 1) on the parking brake lover counter clockwise until the "snap-over-center", when the brake is applied, disappears. Page 432 Vehicle Speed Sensor: Description and Operation VSS Buffer Amplifier On vehicles with conventional instrumentation, a vehicle speed sensor (VSS) buffer amplifier is used to supply the vehicle speed signal to the cruise control module. On this type system, a speedometer frame mounted optic head is used to pick up light reflected by a speedometer cable mounted blade. The reflected light is produced by a light emitting diode (L.E.D.). As the speedometer cable mounted blade enters the L.E.D. light beam, the light is reflected into the optic head. From there, the light enters a photocell in the optic head and produces a low power signal. This signal is sent to a buffer for amplification and conditioning, then to the controller. Digital Ratio Adapter Controller On vehicles with electronic instrumentation, a digital ratio adapter controller (DRAC) is used to supply the vehicle speed signal to the cruise control module. On this type system, the DRAC receives vehicle speed signals from a transmission or transfer case mounted vehicle speed sensor. The DRAC is calibrated according to axle ratio and tire combination, and provides 40 electronic pulses per revolution of the transmission or transfer case output shaft. 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. A/T - 4L60 Binding/Inoperative In Reverse Valve Body: All Technical Service Bulletins A/T - 4L60 Binding/Inoperative In Reverse Number: 91-283-7A Section: 7A Date: APRIL 1991 Corp. Bulletin No.: 977143R Subject: BINDING OR INOPERATIVE IN REVERSE - STUCK 4-3 SEQUENCE VALVE AND/OR 2-3 SHIFT VALVE Model and Year: 1982-91 PASSENGER CARS AND TRUCKS WITH 700R4 (4L60) AUTOMATIC TRANSMISSION THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 89-271-7A, DATED OCTOBER 1989. THE 1990-91 MODEL YEARS HAVE BEEN ADDED, AS WELL AS INFORMATION CONCERNING BOLT TIGHTENING PATTERN. ALL COPIES OF 89-271-7A SHOULD BE DISCARDED. Figure 1 - Control Valve Assembly SERVICE PROCEDURE: When servicing a HYDRA-MATIC 4L60 transmission for a binding in reverse condition, remove the control valve assembly and inspect the 4-3 sequence valve and the 2-3 shift valve. Refer to Figure 1. Either valve, if stuck in the upshifted position, will result in a binding condition. To correct this condition, the valve body must be completely disassembled and reconditioned according to procedures contaihed in the HYDRA-MATIC 4L60/THM 700-R4 Unit Repair section of the appropriate Service Manual. Inspect the transmission bottom pan for clutch material or burned fluid. Evidence of this will necessitate further transmission diagnosis. Repairs may include complete transmission reconditioning, inc.luding disassembly and reconditioning of the transmission pump and possible torque converter replacement. Complete the cleaning of the hydraulic circuit by changing the transmission fluid and filter and flushing the transmission cooler and cooler pipes. Page 6702 For vehicles repaired under the terms of this special coverage, submit a claim with the information shown. Customer Reimbursement All customer requests for reimbursement for previous repairs for the special coverage condition will be handled by the Customer Assistance Center, not by dealers. Disclaimer Page 3627 Extension Housing: 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. Page 1092 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 Page 4380 Extension Housing: Specifications MUNCIE 5LM60 (HM-290) 4 & 5 Speed Rear Housing Bolts .............................................................................................................................. ................................................................... 17 ft. lbs. Page 849 Figure 1 TRANSMISSION FLUID CHECKING PROCEDURE: 1. Start engine and drive vehicle for a minimum of 24 km (15 miles), or until normal operating temperature is reached. NOTICE: The automatic transmission fluid level must be checked with the vehicle at normal operating temperature, 82-93C (180- 200F). Temperature will greatly affect transmission fluid level. If the vehicle is not at normal operating temperature and the proper checking procedures are not followed, the result could be a false reading of the fluid level indicator and an incorrect adjustment of the fluid level. 2. Park vehicle on level ground. 3. Move gear selector to "PARK". 4. Apply parking brake and block wheels. 5. Let vehicle idle for 3 minutes with accessories off. 6. Check fluid level, color and condition (refer to Figure 1). * Inaccurate fluid level readings win result if the fluid is checked immediately after the vehicle has been operated under certain conditions: - In high ambient temperature above 32C (90F). - At sustained high speeds. - In heavy city traffic during hot weather - As a towing vehicle. - In commercial service (taxi or police use). * If the vehicle has been operated under these conditions, shut the engine off and allow the vehicle to "cool" for thirty (30) minutes. After the cooldown period, restart the vehicle and continue from step "2" above. Page 7155 Figure No. 1 NOTICE: For two tone vehicles, it is only necessary to refinish surfaces painted Galaxy Blue, Aspen Blue or Steel Gray. Other colors should not be affected by this condition. The front bumper filler panel and all surfaces painted with affected colors above the belt line (Fig. 1, page 3) must be refinished according to the procedure listed below (regardless of previous paint repairs). If surfaces below the belt line and the interior of the pickup box (on pickup models) appear to be in good condition, the dealer should scuff sand, seal and color coat those painted surfaces rather than refinish. However, if any peeling or topcoat delamination is evident, or If scuff sanding produces any topcoat delamination, it will be necessary to refinish these surfaces as well, according to the procedures. It should not be necessary to paint inside of door jambs, or underneath exterior moldings or decals (sunshine stripes), as these areas are not normally subjected to continued ultraviolet exposure. 2. Sand original finish coat of paint down to electro-coat (Elpo) primer, making sure factory pretreatment and Elpo primer are still intact for good corrosion protection. DO NOT USE CHEMICALS TO REMOVE PAINT AS THIS MAY DAMAGE THE ELPO PRIMER. NOTICE: Rough tape vehicle as necessary (window glass, etc.), and remove nameplates, weatherstrips, and reveal moldings as needed to properly refinish all surfaces as required. 3. Finish sand exposed Elpo primer with 240 grit sandpaper to assure removal of any chalky residue or degraded Elpo primer that may remain as a result of overbaking the primer. NOTICE: Avoid sanding through Elpo to bare metal when possible. 4. Use an air gun to remove all dirt from cracks and surfaces of truck. 5. Clean sanded surfaces with grease and wax remover. Description and Operation Volt Meter Gauge: Description and Operation The Voltmeter measures the electrical system's voltage with the Ignition Switch in RUN or START. With the engine stopped, the Voltmeter indicates Battery condition. With the engine running, the Voltmeter indicates Charging System operation. Page 73 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"). Page 1693 Oil Pressure Sender: Locations Engine Harness Top rear of engine Page 5376 Note The rivet stud and surrounding panel area MUST BE properly refinished PRIOR to the installation of the electrical ground wire terminal and conductive nut to maintain a secure, stable and corrosion-free electrical ground. 11. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 12. Allow the refinished repair area to cure sufficiently before removing the protective material applied to the rivet stud threads. 13. Remove the painters tape or equivalent from the rivet stud threads. 14. Using GM approved residue-free solvent or equivalent, thoroughly clean the rivet stud threads to remove any adhesive and allow to dry. 15. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive rivet stud. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 16. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 17. Install the electrical ground wire terminal to the M6 conductive rivet stud. 18. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 19. Install the M6 conductive nut to the rivet stud and: Tighten Tighten to 8 Nm (71 lb in) 20. Verify proper system operation. Parts Information Warranty Information (excluding Saab Models) For vehicles repaired under warranty, use: Warranty Information (Saab Models) A/C - Levers Loose or Binding Control Assembly: All Technical Service Bulletins A/C - Levers Loose or Binding Number: 92-277-1A Section: 1A Date: AUGUST 1992 Corporate Bulletin No.: 261106 ASE No.: A7 Subject: TEMPERATURE CONTROL OR HVAC LEVERS LOOSE OR BINDING Model and Year: 1986-92 S/T TRUCKS Page 2745 Wiring Diagram For Chart C-5 - Electronic Spark Control System Check CHART C-5 - ELECTRONIC SPARK CONTROL SYSTEM CHECK Circuit Description: Electronic spark control is accomplished with a module that sends a voltage signal to the ECM. As the knock sensor detects engine knock, the voltage from the ESC module to the ECM is shut "OFF" and this signals the ECM to retard timing, if engine RPM is over about 900. Test Description: Numbers below refer to circled numbers on the diagnostic chart. 1. If A Code 43 is not set, but a knock signal is indicated while running at 1500 RPM, listen for an internal engine noise. Under a no load condition there should not be any detonation, and if knock is indicated, an internal engine problem may exist. 2. Usually a knock signal can be generated by tapping on the right exhaust manifold. This test can also be performed at idle. Test number 1 was run at 1500 RPM to determine if a constant knock signal was present, which would affect engine performance. 3. This tests whether the knock signal is due to the sensor, a basic engine problem, or the ESC module. 4. If the module ground circuit is faulty, the ESC module will not function correctly. The test light should light indicating the ground circuit is OK. 5. Contacting CKT 496, with a test light to 12 volts, should generate a knock signal to determine whether the knock sensor is faulty, or the ESC module can't recognize a knock signal. Diagnostic Aids: "Scan" tools have two positions to diagnose the ESC system. The knock signal can be monitored to see if the knock sensor is detecting a knock condition and if the ESC module is functioning, knock signal should display "yes", whenever detonation is present. The knock retard position on the "Scan" displays the amount of spark retard the ECM is commanding. The ECM can retard the timing up to 20 degrees. This check should be used after other causes of spark knock have been checked such as engine timing, EGR systems, engine temperature or excessive engine noise. Page 5645 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: Locations Power Window Switch: Locations Behind Instrument Cluster Valve Specifications Valve: Specifications Stem Diameter Standard Intake 0.3410-0.3417 in Exhaust 0.3410-0.3417 in Maximum Tip Refinish Note: Grind only enough lo provide true surface. After grinding valve stems, ensure sufficient clearance remains between rocker arm & valve spring cap or rotator Face Angle 45 deg Margin Intake 0.0315 in Note: Minimum Exhaust 0.0315 in Page 4769 Transmission Speed Sensor: Service and Repair 1. Disconnect battery ground cable. 2. Raise and support vehicle, then disconnect sensor electrical connector. 3. Remove sensor retaining bolt, then the sensor. 4. Reverse procedure to install. Fuel - Use of Gasoline Containing 15 Percent MTBE Fuel: All Technical Service Bulletins Fuel - Use of Gasoline Containing 15 Percent MTBE Number: 89-268-08 Section: 0B Date: October 1989 Corporate Bulletin No.: 930108 Subject: USE OF GASOLINE CONTAINING 15 PERCENT MTBE Model and Year: ALL 1980-89 PASSENGER CARS AND LIGHT DUTY TRUCKS TO: ALL CHEVROLET DEALERS In August of the U.S. Environmental Protection Agency approved the use of methyltertiary-butyl ether (MTBE) in gasolines at concentrations of 15 percent or Prior to that time, the legal limit was 11 percent; Generai Motors owners manuals stated that the use of gasolines containing 11 percent or less MTBE should not adversely affect the operation of the vehicle and would be covered by the New Vehicle and Emission Control Systems Warranties. The use of 15 percent MTBE in gasoline should also not adversely affect the operation of 1989 and earlier model vehicles and therefore, will not void any warranties covering those vehicles. In the interest of contributing to cleaner air, General Motors recommends that all model year vehicles use such fuels whenever available. The 1990 and future owners manuals will reflect this position. Page 3353 Transmission Speed Sensor: Service and Repair 1. Disconnect battery ground cable. 2. Raise and support vehicle, then disconnect sensor electrical connector. 3. Remove sensor retaining bolt, then the sensor. 4. Reverse procedure to install. Page 3056 Fuel Pump Relay: Service and Repair Fuel Pump Relay REMOVAL 1. Verify that ignition switch is in the OFF position. 2. Disconnect the wiring harness plug. 3. Remove the fuel pump relay. INSTALLATION 1. Install the new fuel pump relay. 2. Reconnect the wiring harness plug to relay. 3. Verify correct operation to confirm repair. 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. ECM - Intermittent Connection Engine Control Module: All Technical Service Bulletins ECM - Intermittent Connection Number: 88-251-8A Section: 8A Date: JUNE, 1988 Subject: INTERMITTENT CONNECTION TO THE ECM Model and Year: 1988 CHEVROLET PASSENGER CARS AND LIGHT DUTY TRUCKS TO: ALL CHEVROLET DEALERS A condition may exist in which the female terminals in the connector to the ECM do not make a solid connection to the male pins in the ECM (see illustration). This can result in an intermittent condition, in any circuit operated by the ECM. The Service Manuals direct a check of connections any time an intermittent condition is found, and this may be the cause of some of these conditions. Visually inspect the terminal using a flashlight, or use a .95 mm pin gauge. The gauge should not pass freely through the female terminal. Do not probe the terminal with anything other than the pin gauge, as probing could damage the terminal. If the female terminal does not grip properly, replace the terminal with P/N 12020757. General directions on wiring repair are shown in Section 8A of the service Manual. Page 5880 FIGURE 2 Irregular/premature tire wear is aggravated by excessive toe-in (or toe-out). Excessive camber can also be a contributor, as can operating conditions, such as city driving with alot of cornering. Irregular tire wear usually occurs on non-drive axles, such as the front wheel positions of rear drive vehicles. An early indication may be an increase in tire noise. In most cases, modified "X" tire rotation, which is a scheduled maintenance at 7500 miles, will equalize tire wear (see Figure 1). Some amount of wear is expected and should be considered normal. Only when the cross grooves in the tread disappear within 12,000 miles should the tires be replaced under warranty (see Figure 2). Even when these grooves disappear, however, the tire is normally only half worn in this area. Whenever tires are replaced for this reason, alignment should be checked and reset to specification, if necessary. If tires are needed for any of the above conditions, they should be purchased from your local tire outlet. If tires are not readily available, each tire manufacturer has a toll-free assistance line for car and truck dealers. These numbers have been previously provided. The tire invoice amount should be entered as a net item on the warranty claim. Labor code E0420, replace wheel and/or tire, should be used. Figure 1 modified "X" tire rotation, front wheel drive, rear wheel drive. This rotation pattern eventually gets each tire on all four positions. It gets those tires on the non-drive axle, which are most prone to irregular wear, to turn in the opposite direction. This will equalize wear quickest, and tire noise related to tread wear will actually become quieter after a few thousand miles. Figure 2 evaluating tire wear. Typical all-season tire. Tire should be replaced only if these grooves are no longer visible within first 12,000 miles. Page 5181 Figure 8 Figure 9 Figure 10 Figure 11 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). Page 5603 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. Injector Resistance, Application Chart & J-39021 Tester Values Fuel Injector Resistance, Application & Tester Specifications. Page 2329 Page 1670 Oil Pan: Service and Repair 4X2 1. Drain oil, then remove engine as described under ENGINE. 2. Remove oil pan attaching bolts, nuts and reinforcements. 3. Remove oil pan. Clean sealing surfaces on pan and block. 4. Apply sealer No. 1052080 or equivalent to front cover-to-block joint and rear crankshaft oil seal retainer-to-block joint, extend sealer one inch in both on all four corners. Install pan gasket. 5. Reverse procedure to install. Torque bolts and nuts to specification. 4X4 1. Disconnect battery ground cable. 2. Remove dipstick, then the drive belt splash shield. 3. Raise and support vehicle. 4. Remove front axle shield and transfer case shield. 5. Disconnect brake line clips from crossmember and remove second crossmember. 6. Remove converter hanger attaching bolts and exhaust pipe clamp from converter. 7. Disconnect front propshaft from drive pinion. 8. Remove flywheel cover. 9. Remove starter attaching bolts and position starter aside. 10. Disconnect steering shock absorber from frame bracket. 11. Remove steering gear attaching bolts. 12. Mark position of idler arm and remove idler arm attaching bolts. 13. Remove differential housing mounting bolts from the bracket on the right side and the frame on the left side. 14. Pull steering gear and linkage forward, then move differential housing forward. 15. Remove engine mount through bolts, then raise engine and block in position. 16. Drain oil, then remove oil pan attaching bolts, nuts and reinforcements. 17. Remove oil pan. Clean pan and block sealing surfaces. 18. Apply sealer No. 1052080 or equivalent to front cover-to-block joint and rear crankshaft oil seal retainer-to-block joint, extend sealer one inch in both directions on all four corners. 19. Install gasket and oil pan. Torque bolts and nuts to specification. 20. Reverse steps 1 to 17 to complete installation. Page 7119 Customers should be urged to wash and dry their vehicles frequently and garage them, or at least cover them with a quality car cover when not in use. Vehicles in dealer inventories should be kept clean and dry. A vehicle that sits unattended, especially after the sun has dried any water on the body surface, is a target for acid rain damage. MATERIALS DESCRIBED IN THIS BULLETIN* WAX AND GREASE REMOVER - USE BELOW OR EQUIVALENT Dupont # 3919S, PPG # DX440, BASF # 900, SIKKENS # 6041 FINESSE POLISHES - USE BELOW OR EQUIVALENT Dupont # 1500S, 3000S; BASF # 563-808, 560-1502; PPG # DRX10; 3M PERFECT-IT * USE V.O.C. EQUIVALENTS IN STATES WITH V.O.C. RESTRICTIONS RAIL DUST REMOVER - USE BELOW OR EQUIVALENT Industrial Fallout Remover # 5029 Zep Corporation Atlanta, GA. Telephone # 404-352-1680 Stain Away # HBY 0160 Hornby Chemical Milwaukee, WI. Telephone # 414-462-2833 If the rail dust remover is not available in your area, call one of the numbers listed above for a distributor near your location. PAINT GAGES - USE BELOW OR EQUIVALENT Elcometer Inc. 1893 Rochester Ind. Drive Rochester Hills, MI. 48309 (800) 521-0635 or (313) 650-0500 Zelcro, Ltd./Zormco 8520 Garfield Rd. Cleveland, OH 44125 (216) 441-6102 Delfesko Corp. 410 Cedar St. Ogdensburg, NY 13669 (800) 267-0607 or (613) 925-5987 Pro Motorcar Products Inc. 22025 US-19 North Clearwater, FL 34625 (800) 323-1090 (813) 726-9225 "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." Page 5480 Important The M6 conductive rivet stud as shown, can accommodate a panel thickness range of 0.7-4.2 mm (0.03-0.17 in). If there are layers of sheet metal, they should be touching without any air gaps to ensure a good ground. 5. Select a M6 conductive rivet stud. Refer to the Parts Information section of this bulletin. Note Use the GE-50317 rivet stud tool kit. 6. Place the M6 conductive rivet stud (1) in the 10 mm (0.40 in) hole. Assemble the rivet stud tool (2) with the groove and flare side facing the rivet stud, then the washer and the M6 nut (3). 7. Using a wrench on the rivet stud tool, and a socket on the M6 nut, secure the M6 conductive rivet stud. 8. Ensure the rivet stud is securely fastened, WITHOUT ANY detectable movement. 9. Completely wrap the threads of the rivet stud with painters tape or equivalent. Note The rivet stud and surrounding panel area MUST BE properly refinished PRIOR to the installation of the ground wire terminal and conductive nut to maintain a secure, stable and corrosion-free electrical ground. 10. Refinish the repair area using an anti-corrosion primer. Refer to Anti-Corrosion Treatment and Repair in SI. 11. Allow the refinished repair area to cure sufficiently before removing the protective material applied to the rivet stud threads. 12. Remove the painters tape or equivalent from the rivet stud threads. 13. Using GM approved residue-free solvent or equivalent, thoroughly clean the rivet stud threads to remove any adhesive and allow to dry. 14. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive rivet stud. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. Page 5274 15. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 16. Install the electrical ground wire terminal to the rivet stud. 17. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 18. Install the M6 conductive nut to the rivet stud and: Tighten Tighten to 8 Nm (71 lb in). 19. Verify proper system operation. M6 Weld Nut Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the M6 weld nut at the electrical ground location is damaged or stripped, a M7 conductive self-threading bolt may be used to secure the ground wire terminal. 2. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the weld nut and allow to dry. 3. Remove any loose metal particles from the damaged or stripped weld nut with a stiff brush. 4. Select a M7 conductive self-threading bolt. Refer to the Parts Information section of this bulletin 5. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M7 conductive self-threading bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 6. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 7. Install the electrical ground wire terminal to the M7 conductive self-threading bolt. 8. Install the M7 conductive self-threading bolt and: Tighten Tighten to 9 Nm (80 lb in). 9. Verify proper system operation. M6 Weld Nut Alternative Repair Caution Use only the GM-approved replacement fasteners with conductive finish for electrical ground repair. 1. If the electrical ground location is accessible from both sides of the panel, a M6 conductive bolt and a M6 conductive nut may be used to secure the electrical ground wire terminal. Refer to the Parts Information section of this bulletin. 2. Select a location adjacent the damaged M6 weld nut having 20 mm (0.79 in) clearance behind the panel surface and 20 mm (0.79 in) clearance surrounding the new electrical ground site. 3. Using GM approved residue-free solvent or equivalent, remove any grease from the surface surrounding the ground location and allow to dry. Note Ensure 20 mm (0.79 in) clearance is maintained behind the panel to be drilled. 4. Drill a 8.5 mm (0.33 in) diameter hole through the panel. 5. Remove paint and primer from the area surrounding the 8.5 mm (0.33 in) hole until bare metal is visible. 6. Select a M6 conductive bolt. Refer to the Parts Information section of this bulletin. 7. Using a small brush, apply Dielectric Lubricant GM P/N 12377900 (Canadian P/N 10953529) to the threads of the M6 conductive bolt. Note Fretting corrosion is a build-up of insulating, oxidized wear debris that can form when there is a small motion between electrical contacts. The oxidized wear debris can accumulate at the electrical contact points causing the electrical resistance across the connection to increase. 8. Carefully remove ANY corrosion or contamination that may be present on the electrical ground wire terminal. 9. Install the electrical ground wire terminal and the M6 conductive bolt to the ground location. 10. Select a M6 conductive nut. Refer to the Parts Information section of this bulletin. 11. Install the M6 conductive nut to the bolt and: Page 8041 Front Door Trim Panel Page 4899 Brake Rotor/Disc: Service and Repair Installation Fig. 5 Hub, knuckle & bearing components. 1. Apply an approved high temperature front wheel bearing grease to the spindle at the inner and outer bearing seat, shoulder and seal seat. Also finger apply a small amount of grease inboard of each bearing cup in the hub/disc assembly. Pressure pack the bearings with a grease machine or hand pack them. Ensure grease is worked thoroughly into the rollers, cone and cage. 2. Install inner bearing, (apply an additional quantity of grease outboard of the inner bearing), and seal. 3. Install rotor. 4. Install outer bearing, washer and nut. 5. Torque nut to 13-16 Nm (10-12 ft lb) while turning the wheel assembly forward by hand. 6. Loosen nut to a just loose position, then back nut off until hole in the spindle aligns with a slot in the nut. CAUTION: Do not back the nut off more than 1/2 flat. 7. Install cotter pin and cap. 8. Install caliper. See Brake Caliper / Service and Repair. See: Brake Caliper/Service and Repair 9. Install wheel and tire assembly. 10. Lower vehicle. 11. Depress brake pedal. Page 7926 Figure 8 Figure 9 Figure 10 Figure 11 3. If terminal is to be re-used, re-form locking tang (see Figures 12 through 16). A/T - THM 700-R4 New Harness/Solenoid Assembly Shift Solenoid: Technical Service Bulletins A/T - THM 700-R4 New Harness/Solenoid Assembly Number: 88-335-7A Section: 7A Date: SEPT., 1988 Subject: SERVICE MANUAL UPDATE: NEW SOLENOID ASSEMBLY AND WIRING HARNESS Model and Year: 1988 C, K, R, V, S, T, G SERIES TRUCKS WITH THM 700-R4 TO: ALL CHEVROLET DEALERS This bulletin covers the introduction of a new Solenoid Assembly and Wiring Harness (Type 18) and new Control Valve Assembly for some 1988 THM 700-R4 models (refer to models listed below). Transmission Models: MAM, MDM, MFM, MKM, MLM, MPM, MRM MWM, MXM, MZM, THM, TJM, TKM, TLM TUM, TXM The new control valve assembly uses a plug in place of the 4-3 pulse switch. The function of the 4-3 pulse switch, to momentarily release the torque converter clutch during a 4-3 downshift, was programmed into the ECM for the 1988 model year. These models had previously used a Type 15 Solenoid Assembly. FIGURE 1 - THM 700-R4 TRANSMISSION IDENTIFICATION INFORMATION Engine - Vibration On Acceleration Exhaust Pipe/Muffler Hanger: Customer Interest Engine - Vibration On Acceleration Number: 88-270-6F Section: 6F Date: JULY, 1988 Subject VIBRATION ON ACCELERATION Model and Year 1988 S/T TRUCK W/4.3L (VIN CODE Z) ENGINE TO: ALL CHEVROLET DEALERS Some 1988 S/T Trucks equipped with 4.3L engines may experience a vibration that can be felt in the floor pan area near the shifter, in the right hand passenger seat foot area, or on the steering column. These conditions may be caused by the following items: 1. The shifter rod that goes from the steering column to the transmission equalizer lever (#340 and #338 in Figure 36 page 7A-45 of the 1988 S/T Manual) hitting the exhaust crossover pipe and/or the equalizer lever making firm contact at the shift lever (T-truck only). 2. The exhaust pipe to catalytic converter clamp (Figure 7, page 6F-6 of the 1988 S/T Manual) hitting the catalytic converter heat shield. 3. The exhaust pipe to converter installation allows the exhaust pipe to contact the transmission crossmember. To repair these conditions, use the following procedures: 1. A. Raise vehicle on hoist. B. Check Transmission linkage for correct adjustment. C. Check exhaust pipe for shifter rod interference (shiny spot on pipe). D. If linkage hits pipe, remove 15 mm (5/8 in) from bottom of rod. E. Put transmission into low gear and mark exhaust pipe area near linkage. F. Put transmission in park. Using a hammer, lightly dimple exhaust pipe for additional clearance. Page 7674 Symbol Identification Page 2366 Vehicle Speed Sensor: Description and Operation VSS Buffer Amplifier On vehicles with conventional instrumentation, a vehicle speed sensor (VSS) buffer amplifier is used to supply the vehicle speed signal to the cruise control module. On this type system, a speedometer frame mounted optic head is used to pick up light reflected by a speedometer cable mounted blade. The reflected light is produced by a light emitting diode (L.E.D.). As the speedometer cable mounted blade enters the L.E.D. light beam, the light is reflected into the optic head. From there, the light enters a photocell in the optic head and produces a low power signal. This signal is sent to a buffer for amplification and conditioning, then to the controller. Digital Ratio Adapter Controller On vehicles with electronic instrumentation, a digital ratio adapter controller (DRAC) is used to supply the vehicle speed signal to the cruise control module. On this type system, the DRAC receives vehicle speed signals from a transmission or transfer case mounted vehicle speed sensor. The DRAC is calibrated according to axle ratio and tire combination, and provides 40 electronic pulses per revolution of the transmission or transfer case output shaft. 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. 3L30 (180C) Transmission Extension Housing: Specifications 3L30 (180C) Transmission Component .......................................................................................................................................... .................................................................... Ft. Lbs. Extension Housing To Case ................................................................................................................ ............................................................................... 23 Page 7767 LIGHT BLUE LT BLU BROWN BRN GRAY GRY GREEN GRN DARK GREEN DK GRN LIGHT GREEN LT GRN ORANGE ORN PINK PNK PURPLE PPL RED RED TAN TAN WHITE WHT YELLOW YEL Service and Repair Crankcase Filter: Service and Repair The PCV system should be checked every 15,000 miles and also during regular engine tune-ups. If the PCV system includes a breather filter, located in the air cleaner housing, this filter should be replaced whenever the PCV valve or air cleaner is replaced. When a periodic inspection indicates the PCV is not functioning properly, it should be serviced by replacement only. Testing and Inspection Page 6332 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. Page 3402 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. Ignition System - Diagnosis Precautions Spark Plug Wire: All Technical Service Bulletins Ignition System - Diagnosis Precautions Number: 88-138-6D Section: 6D Date: Feb., 1988 Subject: ENGINE MISS, HESITATION, OR ROUGHNESS DUE TO PIERCED SECONDARY IGNITION COMPONENTS Model and Year: ALL MODELS WITH GASOLINE ENGINE TO: ALL CHEVROLET DEALERS During the diagnosis procedures for an engine miss, hesitation, or roughness condition, a spark plug or spark plug wire condition may be suspected. Several types of commercial or homemade diagnostic equipment require the secondary ignition boots or wire to be pierced. This is normally done to check for spark plug firing or to perform a cylinder balance test. Similarly, the use of pliers or other such tools to disengage a spark plug boot may pierce or damage the boot or wire. NOTICE: SECONDARY IGNITION COMPONENTS SHOULD NOT BE PIERCED FOR ANY REASON. Piercing a spark plug wire and/or distributor or direct fire module nipple may create a failure condition that will not be immediately apparent. Over time, the hole in the pierced boot may allow a ground path to develop, creating a plug misfire condition. Heavily moisture-laden air in the vicinity of the pierced boot may accelerate this effect. Piercing a secondary ignition wire creates a gap in the wire's conductive core. This gap is a point of high resistance. The current flow in the wire will increase to compensate for the higher wire resistance. Over time, the wire may fail, creating a plug misfire condition. The time required for the condition to appear depends upon the extent of damage to the conductive core. To help prevent future customer comments that are spark plug wire related, do not pierce or otherwise damage any secondary ignition component. Only use diagnostic equipment containing an inductive pick-up to check for spark plug firing or to perform cylinder balance tests. When disengaging a spark plug boot from the spark plug, twist the flanged boot 1/2 turn, then pull only on the boot to remove the wire. Page 404 Manifold Pressure/Vacuum Sensor: Service and Repair Fig. 337 MAP Sensor Removal (V6 Models Similar) The MAP sensor unit is not serviceable and must be replaced as a unit. 1. Disconnect vacuum hose from MAP sensor, then remove top of air cleaner assembly. 2. Remove MAP sensor unit retaining clip, then the sensor, Fig. 337. 3. Reverse procedure to install. Specifications Oil Pressure Sender: Specifications Oil Pressure Switch 10 ft.lb Paint - Assembly Plant Identification Paint: All Technical Service Bulletins Paint - Assembly Plant Identification GMC NUMBER: 88-T-72 GROUP: 10 - Body Section DATE: January, 1988 CORPORATE NUMBER: 851701R SUBJECT: PAINT IDENTIFICATION - ASSEMBLY PLANT MODELS: ALL 1988 LIGHT AND MEDIUM DUTY TRUCK MODELS Attached is a current listing of the various assembly plants and their paint suppliers. It should be noted, however, that paint suppliers are subject to change at any given time. Locations Idle Speed/Throttle Actuator - Electronic: Locations Center Of Dash Panel (engine Compartment) Center Rear Of Engine Applicable to: V6-262/4.3L Engine Page 2359 Transmission Position Switch/Sensor: Testing and Inspection Chart C-1A - Park/Neutral Switch Diagnosis Page 5483 5. Remove paint and primer from the area surrounding the 10 mm (0.40 in) until bare metal is visible. Important The M6 conductive rivet stud as shown, can accommodate a panel thickness range of 0.7-4.2 mm (0.03-0.17 in). If there are layers of sheet metal, they should be touching without any air gaps to ensure a good ground. 6. Select a M6 conductive rivet stud. Refer to the Parts Information section of this bulletin. Note Use the GE-50317 rivet stud tool kit. 7. Place the M6 conductive rivet stud (1) in the 10 mm (0.40 in) hole. Assemble the rivet stud tool (2) with the groove and flare side facing the rivet stud, then the washer and the M6 nut (3). 8. Using a wrench on the rivet stud tool, and a socket on the M6 nut, secure the M6 conductive rivet stud. 9. Ensure the new rivet stud is securely fastened, WITHOUT ANY detectable movement. 10. Completely wrap the threads of the rivet stud with painters tape or equivalent. Page 2328 - Diagnostic Chart Code 34. Page 1012 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. Page 239 Note the difference between the wire exit openings of the new multi-functional lever and the old lever (Figure 1). Parts are currently available from GMSPO. WARRANTY INFORMATION For vehicles repaired under warranty use: Labor Op. Description E7060 Multi-functional lever, replace Use applicable labor time guide for labor hours. Page 564 Wiper Switch: Service and Repair Fig. 8 Windshield Wiper Switch Removal (Front). Except Tilt Column Fig. 9 Windshield Wiper Switch Removal (Front). Tilt Column FRONT 1. Remove turn signal switch. Refer to Vehicle Lighting/Turn Signals/Turn Signal Switch/Service and Repair procedure. 2. Refer to Figs. 8 and 9 for wiper switch replacement. Page 4302 Figure 9 - Disconnecting the Upper Ball Joint 17. Tip the knuckle out and toward the rear of the vehicle. Suspend the knuckle to prevent straining the brake line (Figure 9). Important: Cover the shock mounting bracket and the ball stud on the lower control arm with a shop towel to prevent possible halfshaft seal damage during removal and installation. Figure 8 - Splined Shank and Knuckle Separation 18. Install J28733 on brake rotor and separate outer C/V joint splined shank from knuckle hub (Figure 8). Figure 3 - Inboard Flange Bolt Removal 19. Remove six bolts (loosened earlier) from inboard joint flange (Figure 3). 20. Support inboard end of halfshaft. Free splined shank from hub and remove halfshaft from vehicle. Important: Wipe the wheel bearing seal area on the knuckle clean. Check the seal for cuts or tears. Page 830 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 Seat Dimensions Valve Seat: Specifications Seat Angle 46 deg Seat Width Intake 0.031-0.062 in Exhaust 0.062-0.093 in Runout 0.002 in Page 474 LIGHT BLUE LT BLU BROWN BRN GRAY GRY GREEN GRN DARK GREEN DK GRN LIGHT GREEN LT GRN ORANGE ORN PINK PNK PURPLE PPL RED RED TAN TAN WHITE WHT YELLOW YEL Page 7765 Symbol Identification A/T - Paint Flakes In Fluid Fluid - A/T: All Technical Service Bulletins A/T - Paint Flakes In Fluid Number: 88-400-7A Section: 7A Date: APRIL, 1989 Subject: EVIDENCE OF PAINT FLAKES IN TRANSMISSION FLUID Model and Year: 1988 PASSENGER CARS WITH AUTOMATIC TRANSAXLES TO: ALL CHEVROLET DEALERS Black paint flakes may be found in the transaxle fluid, bottom pan, fluid level indicator and filter assembly as the result of paint peeling from inside the transaxle fill tube. After the paint peels the unprotected areas of the fill tubes can corrode (interior and exterior), leaving corrosion on the fluid level indicator and the fill tube. The fill tube paints used on the interior and exterior of the tube may not withstand temperatures over 260 degrees Fahrenheit. Transaxle durability should not be affected in vehicles equipped with these fill tubes, but paint flakes can cause filter clogging over a period of time. DATE OF PRODUCTION CHANGE: The suspect fill tubes may be found in vehicles produced between October 17, 1987 (Julian Date 289) through June 30, 1988 (Julian Date 184). SERVICE ACTION: If vehicles are found with flaking paint fill tubes they should be changed along with Transaxle Fluid, Filter and Fluid Level Indicator. Labor Operation Number: T5181 Labor Time: .9 SERVICE MANUAL REFERENCE: Refer to the On-Car Section of your Service Manual whenever service of the Fluid Level Indicator and Fill Tube is necessary. Page 43 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"). Rocker Arm Studs Replace Rocker Arm Assembly: Service and Repair Rocker Arm Studs Replace Fig. 10 Rocker Arm Stud Removal Fig. 11 Reaming Of Rocker Arm Stud Bore Fig. 12 Installing Rocker Arm Stud Rocker arm studs that have damaged threads or are loose should be replaced with oversize studs. Oversize studs are available in .003 and .013 inch and can be installed after properly reaming the holes as follows: 1. Remove stud using stud reamer tool No. J-5802-01, Fig. 10 or equivalent with a nut and flat washer placed over the tool. 2. Ream hole to proper size using reamer tool No. J-5715, Fig. 11 for .003 inch oversize or reamer tool No. J-6036 for .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. 12. - With Standard Column Fig. 14 Exploded view of standard steering column Page 3428 4751 4792 AWDP 16154689 Chevrolet 90-320-6E Idle rise between shifts. GMC Truck 90-6E-93 4761 3465 AKYD 16083464 Running change. 4771 3469 AKYF 16083468 Running change. 4871 3477 AKZC 16083476 Running change. 4881 3482 AKZD 16083480 Running change. 4891 3486 AKZF 16083485 Running change. 4901 3490 AKZH 16083489 Running change. 5261 5471 AWFT 16155470 5551 4987 ANKB 16124986 9851 16129826 GMC Truck 836515 CORP Poor performance, tip-in response, flatness. Chevrolet 88-193-6E GMC Truck 88-T-113 5691 5758 AWJR 16155647 Chevrolet 90-320-6E Idle rise between shifts. GMC Truck 90-6E-93 5701 5761 AWJS 16155648 Chevrolet 90-320-6E Idle rise between shifts. GMC Truck 90-6E-93 5931 6041 AWLN 16156045 Chevrolet 91-44-6E Rough idle/stall after cold start. GMC Truck 91-6E-17 6201 3590 CCK 16063588 8951 16079234 6391 3751 HYP 16063750 3561 16076224 6391 7046 ABDN 16067045 2271 16082093 6401 7050 ABDP 16067049 8961 16079238 6451 7075 ABDW 16067074 3521 16076201 6461 7079 ABDX 16067078 3531 16076205 6501 7110 ABFB 16067109 3571 16076242 6521 7128 ABFD 16067127 3591 16076474 6615 6537 BHZA 16196536 6925 16206830 6925 6832 BLNN 16206830 Running change. 6935 6837 BLNP 16206836 Running change. 7251 7022 AMBR 16087020 3571 16120727 Chevrolet 88-235-6E High emissions, exhaust odor, starting and driveability problems (G046). 7261 7026 AMBS 16087025 3571 16120727 Chevrolet 88-235-6E Page 472 Symbol Identification Page 172 Engine Control Module: Locations Figure 1 Located under the passenger side hush panel, under the dash. Page 1634 2. Loosen engine mount through bolts (Figure 1, "B") and transmission mount to crossmember bolts and ensure the exhaust flexible hose is free to - move. - Loosen exhaust pipe/converter pipe clamp U-bolt (Figure 3). - Move U-bolt out of position. - Heat the exhaust pipe/converter connection joint to loosen the converter. Page 2405 Idle Speed: Adjustments *** UPDATED BY TSB # 88T556E DATED NOV. 1987 CONTROLLED IDLE SPEED CHECK 1. Set parking brake and block drive wheels. 2. Connect a SCAN tool to the assembly line data link (ALDL) connect with tool in Open Mode. 3. START engine and bring it to normal operating temperature. 4. Check for correct state of PARK/NEUTRAL switch on SCAN tool. 5. Check specifications chart for controlled idle speed and IAC valve pintle position (counts). 6. If within specifications, the idle speed is being correctly controlled by the ECM. 7. If not within specifications, perform MINIMUM IDLE AIR RATE CHECK. If still not within specifications, Refer to Diagnosis By Symptom / No Trouble Codes Stored. MINIMUM IDLE AIR RATE CHECK 1. Check controlled idle speed and perform idle air control check first. 2. Set parking brake and block drive wheels. 3. START engine and bring it to normal operating temperatures 185-212 degrees Fahrenheit (85-100 degrees Celsius). Turn engine OFF. 4. Remove air cleaner, adapter and gaskets. Check that the throttle lever is not being bound by the throttle, throttle valve or cruise control cables. 5. With IAC valve connected, ground the diagnostic terminal (ALDL). 6. Turn ON ignition, DO NOT START engine. Wait at least 10 seconds (this will allow the IAC pintle to extend and seat in the throttle body.). 7. With ignition ON, engine stopped, test terminal still grounded, disconnect IAC valve electrical connector. (This disables the IAC valve in the seated position). Remove the ground from the diagnostic terminal. 8. Connect a SCAN tool to the ALDL connector and place in open mode. If a tool is not available connect a tachometer to the engine. 9. START engine. With transmission in NEUTRAL, allow engine rpm to stabilize. 10. Check rpm against specifications. Disregard IAC counts on SCAN tool with the IAC disconnected. If the engine has less than 500 miles or is checked at altitudes above 1500 feet, the idle rpm with a seated IAC valve should be lower than values in chart. 11. If the minimum idle air rate is within specifications, no further check is required. 12. If the minimum idle air rate is not within specifications, perform the following procedures: 13. If present, remove the stop screw plug by piercing it with an awl, then applying leverage. The screw is covered to discourage unauthorized adjustments. 14. With the engine at normal operating temperature 185-212 degrees Fahrenheit (85-100 degrees Celsius), adjust stop screw to obtain nominal rpm per specifications with seated IAC valve. 15. Turn ignition OFF and reconnect IAC valve electrical connector. 16. Disconnect the SCAN tool or tachometer. 17. Use silicon sealant or equivalent to cover stop screw hole. 18. Install air cleaner, adapter and gasket. CONTROLLED IDLE SPEED Transmission Gear Idle Speed IAC Counts [1] OPEN/CLOSED LOOP [2] Instruments - Generator Light Flickers, Pulse Wipers ON Charge Lamp/Indicator: All Technical Service Bulletins Instruments - Generator Light Flickers, Pulse Wipers ON GMC NUMBER: 89-T-85 GROUP: 6D - Engine Electrical DATE: July, 1989 CORPORATE NUMBER: 966402R SUBJECT: GENERATOR LIGHT FLICKER DURING PULSE WIPER OPERATION MODELS: 1988-89 S/T WITH 2.8L OR 4.3L ENGINE The generator light flicker condition in the 1988 and 1989 S/T instrument panel during pulse wiper switch operation can be caused by negative voltage transients from the wiper motor There is no possibility of a system failure as a result of this condition. The effect of this condition is that the generator light will turn on for 80 milliseconds (if gages, the voltage drop on the voltmeter lasts 2.5 seconds). This causes no harm to the generator or other electrical components. Subject condition can be eliminated by installing a diode (industry part number 1N4003) or diode/connector kit (diode kit part number 12085207) in the brown wire at the generator connector (circuit 25 at connector C118). See the following pages in the 1988 and 1989 S/T Electrical Wiring Diagrams for circuit 25, connector C188 locations: 1988 4.3L: Section C - Page 24 1988 2.8L: Section C - Page 22 1989 4.3L: Page 40 1989 2.8L: Page 39 PARTS INFORMATION: Quantity Part Number Description 1 12085207 Diode OR 1 *1N4003 Diode *This part available locally. Parts are currently available from GMSPO. INSTALLATION PROCEDURE: 1. Disconnect the battery. 2. Remove the connector from the generator. 3. Peel back the black plastic conduit covering the wires. 4. If installing diode 1N4003: cut out a section of the brown wire that matches the length of the diode. 4A. A diode/connector kit is also available (GMSPO diode kit part number 12085207). If using the kit cut out approximately four inches of the brown wire, following crimping and soldering instructions in the kit. Spiral tape the solder joints and tuck the wire back into the conduit away from the generator Secure the diode/connector to the outside of the conduit with electrical tape. 5. Solder in diode with the banded end toward the generator. 6. Tape the solder and diode. 7. Reinstall the black plastic conduit. 8. Reconnect connector to the generator. 9. Reconnect battery. This procedure will not affect the operation of the generator light during the bulb check at the beginning of the start cycle. For vehicles repaired under warranty use 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. Page 998 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: Page 5843 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 Engine - Blue Smoke On Start-Up Valve Guide Seal: Technical Service Bulletins Engine - Blue Smoke On Start-Up Group Ref.: Engine Fuel & Emission Bulletin No.: 376514 Date: December, 1993 SUBJECT: BLUE SMOKE ON START-UP (REPLACE VALVE STEM SEALS) MODELS: 1985-93 CHEVROLET CAPRICE WITH 4.3L (LB4) ENGINE 1985-86 PONTIAC PARISIENNE, GRAND PRIX AND BONNEVILLE WITH 4.3L (LB4) ENGINE 1985-93 CHEVROLET AND GMC C/K, G, M/L, S/T, AND P TRUCKS WITH 4.3L ENGINE 1991-93 OLDSMOBILE BRAVADA WITH 4.3L ENGINE CONDITION: Some owners may comment that they observe blue smoke coming from the tailpipe of their vehicle immediately after they start their engine. The condition generally occurs after the vehicle has been parked for several hours. CAUSE: Oil leaking down the valve stem(s) into the cylinder(s) after the engine is shutdown. When the engine is restarted, the oil that has leaked into the cylinder is ignited, causing the blue smoke. CORRECTION: Replace all intake and exhaust valve stem seals. Use the V8 umbrella style exhaust valve stem seal. The umbrella style seal is recommended for service because it is easier to install than the O-ring style exhaust valve stem seal used in production. Barrel style seals continue to be used on the intake valve (same as production). Follow the procedure published in the appropriate service manual for valve stem seal replacement. WARNING: Improper seal installation may cause a condition worse than the original concern. PARTS INFORMATION: Parts are currently available from GMPSO. WARRANTY INFORMATION: For vehicles repaired under warranty, use: Labor Operation: J0547 Labor Time: Use published labor operation time. Page 3116 Throttle Position Sensor: Service and Repair REMOVAL: 1. Disconnect electrical connectors. 2. Remove the TPS attaching screw assemblies and retainer, (if applicable). 3. Remove TPS from throttle body assembly. NOTE: The TPS is an electrical component and must not be soaked in any liquid cleaner or solvent, as damage may result. INSTALLATION: 1. Install TPS to throttle body assembly, while lining up TPS lever with TPS drive lever on throttle body. 2. Install the two attaching screw assemblies. Tighten screw assemblies to 2.0 Nm (18.0 lb-in). 3. Install electrical connector to TPS. 4. Check for TPS output as follows: a. Connect an ALDL scanner to read TPS output voltage. b. With ignition ON and engine stopped, TPS voltage should be less than 1.25 volts. If more than 1.25 volts, replace TPS. Page 452 Center Of Dash Panel (engine Compartment) Page 4938 NOTE: Carefully note the color of the spring and which hole it came out of. Liquid typewriting eraser or nail polish can be very useful in marking the appropriate hole for later installation. Installation Install the spring into the brake shoe webbing first. The two 90 degree bends should slide into the hole and lie flat, locking the spring to the webbing. - Slide the brake spring tool through the looped end of the spring and then hook the notched end of the tool over the anchor pin. - Pivot the tool upwards to stretch the spring over the anchor pin (a light film of grease on the backside of the brake tool will help the spring slide over and onto the anchor pin). - Be careful not to over-extend the spring. WARNING: Do not attempt to help the spring over the anchor pin with your fingers. Should the return spring slip off the tool it could seriously lacerate your hand. Shoe-to-Shoe Return Springs Removal Note the color and relationship of the spring and the holes in the brake shoe webbing it is attached to. - Using a pair of brake spring pliers, slide the hooked end of the pliers around and under one end of the spring. Page 4351 Universal Joint: Service and Repair Double Cardan 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) 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 with relation to the propeller shaft so they may be reassembled in the same relative position. Failure to observe these precautions may produce rough vehicle operation which results in rapid wear and failure of parts, and place 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. Some driveshafts use an injected nylon retainer to hold the bearing cups. When service is necessary, pressing the cups out will sheer the nylon retainer, Fig. 1. Replacement with the conventional steel snap ring type is then necessary, Fig. 2. Fig. 9 Double Cardan Universal Joint Exploded View The double cardan type joint, Fig. 9, incorporates two universal joints, a centering socket yoke, and center yoke at one end of the shaft. A single universal joint is used at the other end. Page 7919 Symbol Identification Page 4600 Figure 3 REMOVE (Figures 2 & 3) Tools required: J8092 Drive handle J33790 Bearing installer and remover 1. Transfer case from vehicle. - Refer to Section 7D of the appropriate S/T Service Manual for complete transfer case removal procedure. 2. Front output flange nut (77), washer (76), rubber sealing washer (75) and front output flange (74) from the front output shaft. 3. Vacuum switch (46) and O-ring seal (47). 4. Poppet screw (68), O-ring seal (69), poppet spring (71) and poppet plunger (70). Mainshaft Extension and Oil Pump Housing 5. Rear extension housing bolts (3) and rear extension (4). 6. Bearing retainer (snap ring) (5) from the mainshaft (19). 7. Pump retainer housing bolts (7). 8. Pump retainer housing (8) from the rear case half (17). 9. Speedometer tone wheel (11) from the mainshaft (19). Page 4352 DISASSEMBLY 1. Remove all bearing cup retainers. 2. Mark bearing cups, spiders, propeller shaft yoke, link yoke and socket yoke for assembly alignment reference, Fig. 9. 3. Remove bearing cups attaching from spider to propeller shaft yoke as follows: a. Use a 5/8 inch socket to drive the bearing cup and a 1-1/16 inch socket to receive the opposite bearing cup as it is driven out. b. Place 5/8 inch socket on one bearing cup and 1-1/16 inch socket on opposite bearing cup. c. Position assembly in vise so vise jaws bear directly against sockets. d. Tighten vise to press first bearing cup out of link yoke. e. Loosen vise, reposition sockets and press opposite bearing cup out of link yoke. 4. Disengage propeller shaft yoke from link yoke. 5. Remove bearing cups attaching front spider to propeller shaft as described in step 3 above. 6. Remove front spider from yoke. 7. Remove bearing cups attaching rear spider to link yoke as outlined in step 3 above and remove spider and socket yoke from link yoke. 8. Clean and inspect assembly for damage or wear. If any component is worn or damaged, the entire assembly must be replaced. ASSEMBLY When assembling universal joint, make sure to align spiders and yokes according to marks made during disassembly. 1. Lubricate all bearings and contact surfaces with lithium base chassis grease. 2. Install bearing cups on yoke ends of rear spider and secure cups with tape, Fig. 9. 3. Assemble socket yoke and rear spider. 4. Position rear spider in link yoke and install bearing cups. Press cups into yoke using 5/8 inch socket until bearing cup retainer grooves are exposed. 5. Install rear spider-to-link yoke bearing cup retainers. 6. Position front spider in propeller shaft yoke and install bearing cups. Press cups into yoke using a 5/8 inch socket until bearing cup retainer grooves are exposed. 7. Install front spider-to-propeller shaft yoke bearing cup retainers. 8. Install thrust washer and socket spring in ball socket bearing bore, if removed. 9. Install thrust washer on ball socket bearing boss (located on propeller shaft yoke), if removed. 10. Align ball socket bearing boss on propeller shaft yoke with ball socket bearing bore and insert boss into bore. 11. Align front spider with link yoke bearing cup bores and install bearing cups. Press cups into yoke using a 5/8 inch socket until bearing cup retainer grooves are exposed. 12. Install front spider-to-link yoke bearing cup retainers. Page 1084 Page 6259 DA-V5 Compressor Component View Remove or Disconnect ^ Be sure the compressor has no charge. 1. Pressure relief valve (2). 2. O-ring seal (46). Install or Connect ^ Lubricate the threads of the pressure relief valve (2) and new O-ring seal with 525 viscosity refrigerant oil. 1. Pressure relief valve (2) with new O-ring seal. Tighten ^ Pressure relief valve (2) to 9 N.m (84 in. lbs.). Important Suspension - Knocking/Rattling Noise Torsion Bar: All Technical Service Bulletins Suspension - Knocking/Rattling Noise Number: 91-362-3C Section: 3C Date: JULY 1991 Corporate Bulletin No.: 163302 Subject: KNOCKING NOISE-TORSION BAR SUPPORT INSULATOR DAMAGED/BROKEN Model and Year: 1988-91 T TRUCKS Some owners of 1988-1991 T trucks may comment about a knocking or rattling sound coming from the underside of their vehicle. This sound can occur if the torsion bar support insulator is damaged or breaks. To correct this condition, a new more durable torsion bar insulator has been released. The new insulator is visually identical to the previous insulator and the installation procedure has not changed (reference S-10 Service Manual, Section 3C). VEHICLES INVOLVED: The new torsion bar support insulators have been installed on vehicles after the following VIN breakpoints. Shreveport 1GDCT14Z9M8801063 Pontiac West 1GCCS14A7M0190577 Moraine 1GCCS19R1M2273070 SERVICE PARTS INFORMATION: Part Number Description 15677665 Insulator, Torsion Bar Support Parts are currently available from GMSPO. WARRANTY INFORMATION: Labor Operation: E3340 Use applicable labor time guide for labor hours. Oxygen Sensors - Silica Contamination Oxygen Sensor: 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. Page 6088 Electrical System Diagnostic Chart Part 2 Of 2 Without Air Conditioning Page 6247 Heater Core: Service and Repair HEATER CORE REPLACEMENT Page 5526 Multiple Junction Connector: Electrical Diagrams Ashtray, Glove Box, Engine Compartment & Lighted Rearview Mirror Brakes - Front Pad Noise, Revised Tab Clinch Procedure Brake Pad: Customer Interest Brakes - Front Pad Noise, Revised Tab Clinch Procedure Number: 89-164-5 Section: 5 Date: May, 1989 Subject: FRONT BRAKE NOISE Model and Year: 1983-89 M, G, S/T, R/V, P TRUCKS (EXC G3 W/RPO JB8) TO ALL CHEVROLET DEALERS: Some front brake noise (clicking, popping and squealing) can be caused by insufficiently clinch outboard brake pad tabs. Loose outboard pads can move within the caliper generating noise. The outboard brake pad clinch can be checked by pushing on the back of the pad with your thumb. The pad should not move. If any movement is felt, the pad should be re-clinched. Pad tab clinching must be checked whenever pads are removed or replaced. All future light duty service manuals will be updated with the following revised brake pad clinch procedure. Figure No. 1 Figure No. 2 Revised Service Procedure Page 6330 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. 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). Page 2073 Heater Core: Service and Repair HEATER CORE REPLACEMENT Specifications Transmission Speed Sensor: Specifications Electronic Speed Sensor Retainer Bolt ............................................................................................... ...................................................................... 7 ft. lbs. Page 7676 LIGHT BLUE LT BLU BROWN BRN GRAY GRY GREEN GRN DARK GREEN DK GRN LIGHT GREEN LT GRN ORANGE ORN PINK PNK PURPLE PPL RED RED TAN TAN WHITE WHT YELLOW YEL Page 4255 Pinion Gear: Adjustments Dana/Spicer Fig. 5 Pinion setting chart If original ring gear and pinion assembly are to be reused, measure original shim pack and build a new shim pack to the same dimension. If baffle is in the axle assembly, it is considered part of the shim pack. Ring gears and pinions are supplied in matched sets only. If a new gear is being used, verify numbers on pinion and ring gear before proceeding with assembly. On the button end of the pinion there is a ``+'', `` - '', or ``0'' number which indicates the best running position for each particular gear set. This position is controlled by shims installed behind the inner bearing cup. If baffles or oil slingers are used, they are considered part of the adjusting shim pack. If a new gear set is being installed, note the plus or minus mark on both old and new pinions and adjust thickness of shim pack to compensate for the difference between these two numbers. Refer to chart, Fig. 5, when determining shim size. 1. Install inner shim pack and, on 9-3/4 inch ring gear axle, the oil slinger in inner or rear cup bore, then drive cup into position using suitable tool. 2. Add or remove an equal amount to the outer shim pack as was added to the inner shim pack. 3. Drive outer cup into carrier bore, then press rear pinion bearing onto pinion shaft. 4. Install drive pinion and bearing into differential carrier. 5. Install shims and outer or front pinion bearing. 6. Install companion flange, then the washer and nut on pinion shaft. Torque nut to 250 ft. lbs. with a suitable holding bar in place. 7. Remove holding bar, then measure rotating torque of pinion shaft. Rotating torque should measure 10-20 inch lbs. with original bearings installed, or 20-40 inch lbs. with new bearings installed, discounting torque required to start turning shaft. 8. If rotating torque is not within specifications, adjust shim pack as necessary. Increase outer shim pack to reduce torque, or decrease shim pack to increase torque. 9. Remove nut, washer and companion flange from pinion shaft. 10. Install oil slinger, gasket (if equipped) and oil seal onto pinion shaft. 11. Install companion flange, washer and nut and torque nut to 250 ft. lbs. Page 4264 Pinion Gear: Service and Repair Dana/Spicer Fig. 5 Pinion Setting Chart If original ring gear and pinion assembly are to be reused, measure original shim pack and build a new shim pack to the same dimension. If baffle is in the axle assembly, it is considered part of the shim pack. Ring gears and pinions are supplied in matched sets only. If a new gear is being used, verify numbers on pinion and ring gear before proceeding with assembly. On the button end of the pinion there is a +, - , or 0 number which indicates the best running position for each particular gear set. This position is controlled by shims installed behind the inner bearing cup. If baffles or oil slingers are used, they are considered part of the adjusting shim pack. If a new gear set is being installed, note the plus or minus mark on both old and new pinions and adjust thickness of shim pack to compensate for the difference between these two numbers. Refer to chart, Fig. 5, when determining shim size. 1. Install inner shim pack and, on 9-3/4 inch ring gear axle, the oil slinger in inner or rear cup bore, then drive cup into position using suitable tool. 2. Add or remove an equal amount to the outer shim pack as was added to the inner shim pack. 3. Drive outer cup into carrier bore, then press rear pinion bearing onto pinion shaft. 4. Install drive pinion and bearing into differential carrier. 5. Install shims and outer or front pinion bearing. 6. Install companion flange, then the washer and nut on pinion shaft. 7. Measure rotating torque of pinion shaft. Rotating torque should measure 10-20 inch lbs. with original bearings installed, or 20-40 inch lbs. with new bearings installed, discounting torque required to start turning shaft. 8. If rotating torque is not within specifications, adjust shim pack as necessary. Increase outer shim pack to reduce torque, or decrease shim pack to increase torque. 9. Remove nut, washer and companion flange from pinion shaft. 10. Install oil slinger, gasket (if equipped) and oil seal onto pinion shaft. 11. Install companion flange, washer and nut and torque as described is step 7. Page 3392 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 Turbo Hydra-Matic 3L30 (180C) Fluid - A/T: Testing and Inspection Turbo Hydra-Matic 3L30 (180C) Check fluid at regular intervals. Noticing a change in color, odor or fluid level can serve as a warning of possible transmission problems. To check fluid level, bring fluid to operating temperature of 200°F. With vehicle on a level surface and engine idling in Park and parking brake applied, the level on the dipstick should be at the Full mark. To bring the fluid level from the Add mark to the Full mark requires one pint of fluid. If additional fluid is required, use only Dexron II or Dexron IIE automatic transmission fluid. When adding fluid, do not overfill, as foaming and loss of fluid through the vent may occur as the fluid heats up. Also, if fluid level is too low, complete loss of drive may occur especially when cold, which can cause transmission failure. The oil should be drained, the oil pan removed, the screen cleaned and fresh fluid added every 30,000 miles for trucks under 8600 lbs. GVWR or every 24,000 miles for vehicles over 8600 GVWR. For vehicles subjected to more severe use such as heavy city traffic especially in hot weather, prolonged periods of idling or as a tow vehicle this maintenance should be performed every 15,000 miles for trucks under 8600 GVWR, or every 12,000 miles for trucks over 8600 GVWR. Isolation Diodes - Replacement Information Diode: All Technical Service Bulletins Isolation Diodes - Replacement Information Number: 93-163-8A Section: 8A Date: MAY 1993 Corporate Bulletin No.: 178201R ASE No.: A6 Subject: ISOLATION DIODES REPLACEMENT INFORMATION Model and Year: 1993 AND PRIOR YEAR PASSENGER CARS AND TRUCKS THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 92-47-8A, DATED NOV. 1991. THE 1993 MODEL YEAR HAS BEEN ADDED AS WELL AS PART NUMBERS HAVE BEEN REVISED. THIS WILL ALSO UPDATE CERTAIN SERVICE MANUALS. ALL COPIES OF 92-47-8A SHOULD BE DISCARDED. Many of the electrical systems on our vehicles use a diode to isolate certain circuits and protect them from voltage spikes. Some of the circuits which may use such a diode are listed below: A/C Compressor Clutch ABS/4WAL NOTE: The ABS diode on the Delco Moraine system is hidden inside of an electrical connector under the carpet at the right kick panel. Wiper Charging System (hidden in wire harness) Parking Brake (vehicles with ABS) Relays Solenoids Diesel Glow Plug Circuit Day Time Running Lights Obtaining replacement diodes can sometimes be a problem. A universal diode, that meets the specifications in the chart below, may be used for the applications listed above. Since certain diode applications have specific part numbers, always reference the applicable GM parts catalogue before installing one of the universal diodes listed in this bulletin. When installing the new diode, use the following procedures to obtain a lasting repair: 1. If the diode is taped to the harness, remove all of the tape. 2. Paying attention to current flow direction, remove inoperative 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 needed to attach the new diode. 4. Check current flow direction of the new diode, being sure to install the diode with correct bias. Reference the appropriate service manual wiring schematic to obtain the correct diode installation position. Reference Figure 1 for replacement diode symbols and current flow explanations. Page 3743 FIGURE 2 - 200-4R PUMP BODY ASSEMBLY Locations Windshield Washer Pump: Locations LH Side Of Engine Compartment LH Rear Corner Of Engine Compartment Page 5166 1. Disconnect motor field coil connector from solenoid motor terminal, then insulate end carefully. 2. Connect one battery lead to solenoid switch terminal, then the other lead to the solenoid frame, Fig. 13. 3. Using a jumper lead connected to the solenoid motor terminal. Momentarily flash the lead to the solenoid frame. This will shift the pinion into the cranking position until the battery is disconnected. 4. Push the pinion back toward the commutator end as far as possible to take up any slack movement, then check the clearance with feeler gauge, Fig. 14.