GM Service Manual Online
For 1990-2009 cars only

Tools Required

J 39400-A Halogen Leak Detector

Removal Procedure

  1. Recover the refrigerant. Refer to Refrigerant Recovery and Recharging .
  2. Remove the left rear quarter trim panel. Refer to Rear Quarter Lower Trim Panel Replacement in Interior Trim.
  3. Drain the cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.
  4. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
  5. Remove the level ride air compressor. Refer to Air Compressor Replacement in Automatic Level Control.

  6. Object Number: 400659  Size: SH
  7. Remove the auxiliary A/C line block fitting bolt.
  8. Important: Cap or tape the open A/C refrigerant lines immediately.

  9. Disconnect the A/C line block fitting, remove and discard the sealing washers and cap or tape the lines to prevent contamination of the system.

  10. Object Number: 400657  Size: SH
  11. Disconnect the auxiliary heater hoses from the heater core pipes.
  12. Lower the vehicle.

  13. Object Number: 812955  Size: SH
  14. Remove the air distribution duct mounting bolts.
  15. Disconnect the air distribution duct from the HVAC module.
  16. Disconnect the auxiliary blower motor electrical connector.
  17. Disconnect the auxiliary blower motor resistor electrical connector.
  18. Disconnect the auxiliary temperature actuator electrical connector.

  19. Object Number: 791058  Size: SH
  20. Remove the HVAC module assembly mounting bolts and nut.
  21. Disconnect the left PSD module from the mounting bracket and reposition aside.
  22. Remove the HVAC module assembly from the vehicle.
  23. Remove and discard the HVAC module assembly to body seals.

Installation Procedure

  1. Install new HVAC module assembly to body seals.

  2. Object Number: 791058  Size: SH
  3. Install the HVAC module assembly to the vehicle.
  4. Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

  5. Install the HVAC module assembly mounting bolts and the nut.
  6. Tighten
    Tighten the bolts and the nut to 10 N·m (89 lb in).

  7. Connect the left PSD module to the mounting bracket.

  8. Object Number: 812955  Size: SH
  9. Connect the auxiliary temperature actuator electrical connector.
  10. Connect the electrical connector to the auxiliary blower motor resistor.
  11. Connect the auxiliary blower motor electrical connector.
  12. Connect the auxiliary air distribution duct to the HVAC module assembly .
  13. Install the auxiliary air distribution duct mounting bolts.
  14. Tighten
    Tighten the bolts to 10 N·m (89 lb in).

  15. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.

  16. Object Number: 400657  Size: SH
  17. Connect the auxiliary heater hoses to the heater core pipes.
  18. Remove the cap or tape from the A/C lines.
  19. Using a lint-free clean, dry cloth, carefully clean the sealing surfaces of the A/C lines.
  20. Important: Flat washer type seals do not require lubrication.

  21. Slide the new sealing washers onto the A/C line until seated.

  22. Object Number: 400659  Size: SH
  23. Install the auxiliary A/C line block fitting bolt.
  24. Tighten
    Tighten the bolt to 20 N·m (15 lb ft).

  25. Install the level ride air compressor. Refer to Air Compressor Replacement in Automatic Level Control.
  26. Lower the vehicle.
  27. Fill the cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.
  28. Evacuate and recharge the A/C system. Refer to Refrigerant Recovery and Recharging .
  29. Leak test the fittings of the component using J 39400-A .
  30. Install the left rear quarter trim panel. Refer to Rear Quarter Lower Trim Panel Replacement in Interior Trim.