GM Service Manual Online
For 1990-2009 cars only

Special Tools

J 39400-A Halogen Leak Detector

Removal Procedure


    Object Number: 1224339  Size: SH
  1. Remove the HVAC module. Refer to HVAC Module Assembly Replacement.
  2. Remove and discard the HVAC module assembly foam seal.

  3. Object Number: 1226246  Size: SH
  4. Remove the TXV mounting bolts.
  5. Remove the TXV from the evaporator core.
  6. Remove and discard the sealing washers.

  7. Object Number: 1226250  Size: SH
  8. Disconnect the discharge temperature management (DTM) sensor electrical connectors.
  9. Disconnect the HVAC module wiring harness retainer pin (2) from the HVAC module.
  10. Disconnect the wiring harness from the heater core cover wire harness retainer (1) and reposition the wiring harness aside.
  11. Disconnect the wiring harness from the heater core cover wire harness retainer (3) and reposition the wiring harness aside.

  12. Object Number: 1224370  Size: SH
  13. Remove the heater cover screws.
  14. Remove the heater cover from the HVAC module.

  15. Object Number: 1224297  Size: SH
  16. Remove the heater core from the HVAC module.

  17. Object Number: 1224373  Size: SH
  18. Remove the HVAC module case retaining screws.

  19. Object Number: 1224310  Size: SH
  20. Separate the HVAC module upper case from the HVAC module lower case.

  21. Object Number: 1224311  Size: SH
  22. Remove the evaporator core from the HVAC module.

Installation Procedure

  1. If replacing the evaporator core, add the specified amount of PAG oil directly to the evaporator core. Refer to Refrigerant System Capacities.

  2. Object Number: 1224314  Size: SH

    Note: Line the evaporator core side seal up with the corners of the evaporator core.

  3. Install a new side seal to the evaporator core.

  4. Object Number: 1224315  Size: SH
  5. Install a new upper seal to the evaporator core.

  6. Object Number: 1224316  Size: SH

    Note: Locate the seals at the outer corners of the evaporator core.

  7. Install 2 new lower seals to the evaporator core.

  8. Object Number: 1224311  Size: SH
  9. Install the evaporator core to the HVAC module.

  10. Object Number: 1224310  Size: SH
  11. Install the HVAC module upper case to the HVAC module lower case.
  12. Caution: Refer to Fastener Caution in the Preface section.


    Object Number: 1224373  Size: SH
  13. Install the HVAC module case retaining screws and tighten to 1.6 N·m (14 lb in).

  14. Object Number: 1224308  Size: SH
  15. Install a new foam seal to the heater core.

  16. Object Number: 1224297  Size: SH
  17. Install the heater core to the HVAC module.
  18. Install the heater cover to the HVAC module.

  19. Object Number: 1224370  Size: SH
  20. Install the heater cover screws and tighten to 1.6 N·m (14 lb in).

  21. Object Number: 1226250  Size: SH
  22. Reposition the HVAC wiring harness and connect the wiring harness to the heater core cover wiring harness retainer (1).
  23. Reposition the HVAC wiring harness and connect the wiring harness to the heater core cover wiring harness retainer (3).
  24. Connect the HVAC module wiring harness retainer pin (2) to the HVAC module.
  25. Connect the discharge temperature management (DTM) sensor electrical connectors.

  26. Object Number: 1226246  Size: SH
  27. Install new sealing washers to the evaporator core. Refer to Sealing Washer Replacement.
  28. Install the TXV to the evaporator core.
  29. Install the TXV to mounting bolts and tighten to 7 N·m (62 lb in).
  30. Install the HVAC module. Refer to HVAC Module Assembly Replacement.