GM Service Manual Online
For 1990-2009 cars only

Tools Required

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: 1224374  Size: SH
  4. Disconnect the LH air temperature actuator electrical connector.
  5. Remove the LH air temperature actuator screws.
  6. Remove the LH air temperature actuator.

  7. Object Number: 1224318  Size: SH
  8. Disconnect the RH air temperature actuator electrical connector.
  9. Remove the RH air temperature actuator screws.
  10. Remove the RH air temperature actuator.

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

  16. Object Number: 1224370  Size: SH
  17. Remove the heater cover screws.
  18. Remove the heater cover from the HVAC module.

  19. Object Number: 1224297  Size: SH
  20. Remove the heater core from the HVAC module.

  21. Object Number: 1224373  Size: SH
  22. Remove the HVAC module case retaining screws.

  23. Object Number: 1224310  Size: SH
  24. Separate the HVAC module upper case from the HVAC module lower case.

  25. Object Number: 1230235  Size: SH
  26. Lift up on the LH and RH air temperature doors to disconnect from one another.

  27. Object Number: 1230229  Size: SH
  28. Remove the LH air temperature door from the HVAC module.

Installation Procedure


    Object Number: 1230229  Size: SH
  1. Install the LH air temperature door to the HVAC module.

  2. Object Number: 1230235  Size: SH
  3. Lift up on the LH and RH air temperature doors to connect to one another.

  4. Object Number: 1224310  Size: SH
  5. Install the HVAC module upper case to the HVAC module lower case.
  6. Notice: Refer to Fastener Notice in the Preface section.


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


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

  10. Object Number: 1224297  Size: SH
  11. Install the heater core to the HVAC module.
  12. Install the heater cover to the HVAC module.

  13. Object Number: 1224370  Size: SH
  14. Install the heater cover screws.
  15. Tighten
    Tighten the screws to 1.6 N·m (14 lb in).


    Object Number: 1226250  Size: SH
  16. Reposition the HVAC wiring harness and connect the wiring harness to the heater core cover wiring harness retainer (1).
  17. Reposition the HVAC wiring harness and connect the wiring harness to the heater core cover wiring harness retainer (3).
  18. Connect the HVAC module wiring harness retainer pin (2) to the HVAC module.
  19. Connect the discharge temperature management (DTM) sensor electrical connectors.
  20. Install the RH air temperature actuator.
  21. Install the RH air temperature actuator screws.
  22. Tighten
    Tighten the screws to 1.6 N·m (14 lb in).


    Object Number: 1224318  Size: SH
  23. Connect the RH air temperature actuator electrical connector.
  24. Install the LH air temperature actuator.
  25. Install the LH air temperature actuator screws.
  26. Tighten
    Tighten the screws to 1.6 N·m (14 lb in).


    Object Number: 1224374  Size: SH
  27. Connect the LH air temperature actuator electrical connector.
  28. Install the HVAC module. Refer to HVAC Module Assembly Replacement .