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: 791031  Size: SH
  3. Remove the auxiliary thermal expansion valve (TXV) line clamp screws.
  4. Remove the auxiliary TXV line clamp from the HVAC module assembly.

  5. Object Number: 791034  Size: SH
  6. Remove the TXV insulation.
  7. Remove the bolt from the auxiliary TXV line block fitting.
  8. Disconnect the A/C lines from the auxiliary TXV.
  9. Remove and discard the sealing washers.
  10. Important: Cap or tape the open A/C lines immediately to prevent system contamination.

  11. Cap or tape the A/C lines.

  12. Object Number: 882523  Size: SH
  13. Remove the auxiliary TXV to auxiliary evaporator core bolts.
  14. Remove the auxiliary TXV from the auxiliary evaporator core.
  15. Remove and discard the sealing washers.

  16. Object Number: 791361  Size: SH
  17. Remove the auxiliary temperature actuator screws.
  18. Remove the auxiliary temperature actuator from the auxiliary HVAC module.

  19. Object Number: 882516  Size: SH
  20. Remove the auxiliary blower motor housing screws.
  21. Remove the auxiliary blower motor housing from the HVAC module.
  22. Remove the auxiliary HVAC module case screws.
  23. Separate the auxiliary HVAC module case halves.
  24. 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: Refer to Fastener Notice in the Preface section.

  5. Install the auxiliary HVAC module case screws.
  6. Tighten
    Tighten the screws to 1.6 N·m (14 lb in).


    Object Number: 882516  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: 791361  Size: SH
  10. Install the auxiliary temperature actuator to the auxiliary HVAC module.
  11. Install the auxiliary temperature actuator screws.
  12. Tighten
    Tighten the screws to 1.6 N·m (14 lb in).

  13. Install new sealing washers to the auxiliary evaporator core. Refer to Sealing Washer Replacement .
  14. Remove cap or tape from the A/C lines.

  15. Object Number: 882523  Size: SH
  16. Install the auxiliary TXV to the auxiliary evaporator core.
  17. Install the auxiliary TXV to the auxiliary evaporator core mounting bolts.
  18. Tighten
    Tighten the bolts to 3.5 N·m (31 lb in).

  19. Install new sealing washers onto the auxiliary TXV line block fitting. Refer to Sealing Washer Replacement .

  20. Object Number: 791034  Size: SH
  21. Connect the auxiliary TXV line block fitting to the auxiliary evaporator core.
  22. Install the auxiliary TXV line block fitting retaining bolt.
  23. Tighten
    Tighten the bolt to 11 N·m (97 lb in).

  24. Install the new TXV insulation.
  25. Install the auxiliary TXV line clamp to the HVAC module assembly.

  26. Object Number: 791031  Size: SH
  27. Install the auxiliary TXV line clamp screws.
  28. Tighten
    Tighten the screws to 1.6 N·m (14 lb in).

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