GM Service Manual Online
For 1990-2009 cars only

Tools Required

    • J 43181 Heater Line Quick Connect Release Tool
    • J 39400-A Halogen Leak Detector

Removal Procedure

  1. Drain the engine coolant. Refer to Cooling System Draining and Filling.
  2. Recover the refrigerant. Refer to Refrigerant Recovery and Recharging .
  3. Remove the instrument panel (I/P) carrier. Refer to Instrument Panel Carrier Replacement.
  4. Reposition the heater hose clamps using J 43181 .
  5. Disconnect the heater hoses from the heater core.

  6. Object Number: 735916  Size: SH
  7. Remove the retaining nut (3) from the accumulator (6) at the evaporator (1).
  8. Disconnect the accumulator (6) from the evaporator (1).
  9. Disconnect the evaporator tube (4) from the evaporator (1).
  10. Disconnect all of the electrical connectors to the HVAC module assembly.
  11. Remove the HVAC module assembly.

Installation Procedure


    Object Number: 735960  Size: SH
  1. If replacing the HVAC module assembly (8), transfer the components from the old HVAC module assembly as necessary.
  2. Install the HVAC module assembly (8).
  3. Connect all of the electrical connectors to the HVAC module assembly.

  4. Object Number: 735916  Size: SH
  5. Connect the heater hoses to the heater core.
  6. Connect the evaporator tube (4) to the evaporator (1).
  7. Install the accumulator (6) to the evaporator (1).
  8. 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.

  9. Tighten the accumulator retaining nut.
  10. Tighten
    Tighten the nut to 4.5 N·m (40 lb in).

  11. Install the I/P carrier. Refer to Instrument Panel Carrier Replacement.
  12. Evacuate and recharge the A/C system. Refer to Refrigerant Recovery and Recharging .
  13. Leak test the fittings of the components using the J 39400-A .
  14. Refill the engine coolant. Refer to Cooling System Draining and Filling.