GM Service Manual Online
For 1990-2009 cars only

Tools Required

J 39400-A Halogen Leak Detector

Removal Procedure

  1. Remove the auxiliary HVAC module assembly. Refer to Auxiliary HVAC Module Replacement .

  2. Object Number: 791035  Size: SH
  3. Remove the auxiliary TXV to auxiliary evaporator core bolts.
  4. Remove the auxiliary TXV from the auxiliary evaporator core.

  5. Object Number: 791062  Size: SH
  6. Remove the auxiliary blower motor housing screws.
  7. Remove the auxiliary blower motor housing from the HVAC module.
  8. Remove the auxiliary HVAC module case screws.
  9. Separate the auxiliary HVAC module case halves.
  10. Remove the auxiliary evaporator core from the lower HVAC module case.

Installation Procedure

  1. If replacing the auxiliary evaporator core add the specified amount of PAG oil directly to the auxiliary evaporator core. Refer to Refrigerant System Capacities .
  2. Install the auxiliary evaporator core into the lower HVAC module case.
  3. Assemble the auxiliary HVAC module case halves.
  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 auxiliary HVAC module case screws.
  6. Tighten
    Tighten the screws to 1.6 N·m (14 lb in).


    Object Number: 791062  Size: SH
  7. Install the auxiliary blower motor housing to the HVAC module.
  8. Install the auxiliary blower motor housing screws.
  9. Tighten
    Tighten the screws to 1.6 N·m (14 lb in).


    Object Number: 791035  Size: SH
  10. Install the auxiliary TXV to the auxiliary evaporator core.
  11. Install the auxiliary TXV to the auxiliary evaporator core mounting bolts.
  12. Tighten
    Tighten the bolts to 3.5N·m (31 lb in).

  13. Install the auxiliary HVAC module assembly. Refer to Auxiliary HVAC Module Replacement .
  14. Leak test the fittings of the component using J 39400-A .