GM Service Manual Online
For 1990-2009 cars only

Tools Required

J 39400-A Halogen Leak Detector

Removal Procedure

  1. Remove the HVAC module - auxiliary assembly. Refer to Auxiliary HVAC Module Replacement .
  2. Remove the heater core - auxiliary. Refer to Auxiliary Heater Core Replacement .
  3. Remove the inverted TORX studs from the evaporator block - auxiliary.

  4. Object Number: 814580  Size: SH
  5. Remove the backing plate (1) from the evaporator core.

  6. Object Number: 814581  Size: SH
  7. Remove the screws from the blower motor control processor - auxiliary.
  8. Remove the blower motor control processor - auxiliary.
  9. Remove the screws from the HVAC module - auxiliary case sump (2).
  10. Remove the HVAC module - auxiliary case sump (2).

  11. Object Number: 814587  Size: SH
  12. Remove the evaporator core (3) from the HVAC module - auxiliary (1).
  13. Carefully remove the foam insulator (2) from around the evaporator core - auxiliary (3).

Installation Procedure

  1. If replacing the evaporator core, add the proper amount of refrigerant oil to the evaporator. Refer to Refrigerant System Capacities for the capacity information.

  2. Object Number: 814587  Size: SH
  3. Transfer the foam insulator (2) to the replacement evaporator core-auxiliary (3).
  4. Transfer the thermal expansion valve-auxiliary to the replacement evaporator core - auxiliary.
  5. Install the evaporator core - auxiliary (3) to the rear HVAC module - auxiliary (1).


    Object Number: 814581  Size: SH
  6. Install the HVAC module - auxiliary case sump (2).
  7. Notice: Refer to Fastener Notice in the Preface section.

  8. Install the screws to the HVAC module - auxiliary case sump.
  9. Tighten
    Tighten the screws to 2 N·m (18 lb in).

  10. Install the blower motor control processor - auxiliary.

  11. Object Number: 814580  Size: SH
  12. Install the backing plate (1) to the evaporator core - auxiliary.
  13. Install the evaporator block - auxiliary.
  14. Install the inverted TORX studs to the evaporator block - auxiliary.
  15. Tighten
    Tighten the TORX studs to 2 N·m (18 lb in).

  16. Install the heater core-auxiliary. Refer to Auxiliary Heater Core Replacement .
  17. Install the HVAC module - auxiliary assembly. Refer to Auxiliary HVAC Module Replacement .
  18. Leak test the fittings of the component using the J 39400-A .