download
Subject: Operating Characteristics of the Electro-Viscous (EV) Fan Clutch and Diagnostic Tips for Cooling Fan Noise, Delayed Transmission Shifts and/or Engine Revving Too High Models: 2004-2006 Buick Rainier 2002-2006 Chevrolet TrailBlazer, TrailBlazer EXT 2006 Chevrolet TrailBlazer SS 2002-2006 GMC Envoy, Envoy XL 2004-2005 GMC Envoy XUV 2002-2004 Oldsmobile Bravada 2005-2006 Saab 9-7X with 4.2L I-6, 5.3L V-8 or 6.0L V-8 Engine (VINs S, P, M, H – RPOs LL8, LM4, LH6, LS2) Date/VIN Breakpoints for Vehicles with New EV Fan Clutch Vehicles built after and including the Date or VIN Breakpoints listed in the table shown are equipped with the new electro-viscous (EV) fan clutch. Vehicles of any model year listed in “Models Affected” with labor code J3390 (claimed after June 8, 2005) with P/N 15293048 in Claim History may also be equipped with this new EV fan clutch.

download
1. Open the rear liftgate.2. Remove the two screws that attach both the left and right tail lamp assemblies and remove the lamps from the body. 3. Inspect the part number on both the left and right tail lamp circuit boards. Chevrolet – New P/N 16532713 Chevrolet Export – New P/N 16532714 Buick and Oldsmobile – New P/N 16532715 GMC – New P/N 16532716 • If the part number printed on a circuit boards IS one of the part number listed above, then the circuit board is the new design and does NOT need to be replaced. • If the part number printed on a circuit board is NOT one of the part numbers listed above, then the circuit boards is the old design and MUST BE REPLACED. Proceed to the next step if either circuit board needs to be replaced. 4. Turn on the tail lamps, directional signals, etc. and determine if there are any bulbs that require replacement. 5. Disconnect the electrical connector from the circuit board being replaced. 6. Remove the three screws attaching the circuit board to the tail lamp and remove the circuit board. 7. Install a NEW stop lamp bulb in a NEW circuit board. • On Chevrolet, Buick and Oldsmobile vehicles, the stop lamp bulb is located in the UPPER (top) socket in the circuit boards. • On GMC vehicles, the stop lamp bulb is located in the LOWER (bottom) socket in the circuit board. Important: This special policy will cover the cost of replacing the stop lamp bulb(s). All other bulbs that require replacement are to be submitted under the normal warranty operation, if applicable. 8. Transfer the remaining bulbs from the old circuit board to the new circuit board. Replace any burned out bulbs. 9. Connect the electrical connector to the new circuit board(s). 10. Turn on the tail lamps, directional signals, etc. and verify that all bulbs are functional. 11. Install the circuit board to the tail lamp and install the three screws.

download
1. Remove the idle air control (IAC) valve connector. 2. Remove the IAC valve attaching screws (1). NOTE: If the IAC valve has been in service: DO NOT push or pull on the IAC valve pintle. The force required to move the pintle may damage the threads on the worm drive. Also, DO NOT soak the IAC valve in any liquid cleaner or solvent, as damage may result. 3. Remove the IAC valve assembly (2). ^ Clean the IAC valve O-ring sealing surface, the pintle valve seat, and the air passage. ^ The IAC valve may be cleaned. Use a shop towel or parts cleaning brush to remove any heavy deposits. ^ Any shiny spots on the pintle or seat are normal and do not indicate misalignment or a bent pintle shaft. ^ If the air passage have heavy deposits, remove the throttle body for a complete cleaning. ^ Inspect the IAC valve O-ring for cuts, cracks, or distortion. Replace the O-rings if necessary. ^ When installing a new IAC valve, be sure to replace the valve with an identical part. The IAC valve pintle shape and diameter are designed for a specific application. MEASUREMENT PROCEDURE This procedure is only for installing a new IAC valve. IMPORTANT: If installing a new IAC valve, replace the IAC valve with an identical part. The IAC valve pintle shape and diameter are designed for the specific application. Measure the distance between tip of the IAC valve pintle and the mounting flange. If the distance is more than 28 mm (1.1 in), use finger pressure to slowly retract the pintle. The force required to retract the pintle of a new valve will not cause damage to the valve. INSTALLATION PROCEDURE

download
Important: The front and rear sections of the cooler lines can be serviced separately. Refer to the appropriate steps when servicing individual lines. Perform the following procedure when removing the cooler lines from the quick connect fittings. 1. Pull the plastic cap back from the quick connect fining and down along the cooler line about 5 cm (2 inch) . 2. Using a bent-tip screwdriver, pull on one of the open ends of the retaining ring in order to rotate the retaining ring around the quick connect fining until the retaining ring is out of position and can be completely removed. 3. Remove the retaining ring from the quick connect fitting. 4. Discard the retaining ring. 5. Pull the cooler line straight out from the quick connect fitting. Installation Procedure Important: Do not reuse any of existing fittings if there is excessive corrosion. Do not reuse any of the existing retaining rings that were removed from the existing quick connect fittings. All retaining rings being installed must be new. Ensure the following procedures are performed when installing the new retaining rings onto the fittings.

download
Tool Required J 41240 Fan Clutch Wrench Removal Procedure 1. Drain the coolant. 2. Remove the fan and shroud. 3. Remove the drive belt. 4. Using the J 41240, secure the water pump pulley and remove the water pump pulley bolts. 5. Remove the J 41240. 6. Remove the water pump pulley. 7. Loosen and remove the water pump bolts. 8. Remove the water pump. 9. Clean and inspect the water pump. 10. Discard and replace the gasket. Installation Procedure 1. Install a new water pump gasket. NOTICE: Refer to Fastener Notice in Service Precautions. See: Service Precautions\Vehicle Damage Warnings\Fastener Notice 2. Install the water pump and secure the water pump with the bolts. Tighten On the initial pass, tighten the bolts to 4 Nm (35 lb in). On the final pass, tighten the bolts to 10 Nm (89 lb in). 3. Install the water pump pulley. 4. Install the water pump pulley bolts.