GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2007 🢒 STS 🢒 HVAC 🢒 Heating, Ventilation, and Air Conditioning 🢒 HVAC Module Assembly Replacement

Tools Required

J 39400-A Halogen Leak Detector

Removal Procedure
  1. Recover the refrigerant. Refer to Refrigerant Recovery and Recharging .
  2. Drain the coolant. Refer to Cooling System Draining and Filling .
  3. Disconnect the heater inlet hose from the heater core. Refer to Heater Inlet Hose Replacement .
  4. Disconnect the heater outlet hose from the heater core. Refer to Heater Outlet Hose Replacement .
  5. At the evaporator core, disconnect and remove the A/C quick connect fittings from the suction hose and the liquid line. Refer to Air Conditioning Line/Tube Connector Removal/Replacement .
  6. Separate the suction hose and liquid line from the evaporator core.
  7. Remove and discard the O-rings.

    8. Object Number: 756222 Size: SH
  8. Remove the instrument panel (I/P) carrier. Refer to Instrument Panel Carrier Replacement .
  9. Remove the air inlet assembly.
  10. Disconnect the HVAC module electrical connector.
  11. Disconnect the HVAC module drain tube (2) from the floor.

    12. Object Number: 756232 Size: SH
  12. Remove the lower left HVAC module mounting nut (1).

    13. Object Number: 756237 Size: SH
  13. Remove the upper left HVAC module mounting nut (1).
  14. Remove the HVAC module from the vehicle.

    15. Object Number: 817511 Size: SH
  15. Remove the foam from the A/C lines.
  16. Remove the foam from around the heater pipes.

Installation Procedure

    Object Number: 819805 Size: SH
  1. Install the thick foam packing (1) on the heater core pipes.
  2. Install the thin foam packing (2) on the heater core pipes.

    3. Object Number: 819804 Size: SH
  3. Install the thick foam packing (1) on the A/C lines.
  4. Install the thin foam packing (2) on the A/C lines.

    5. Object Number: 756237 Size: SH
  5. Install the HVAC module into the vehicle.

    6. Notice: Refer to Fastener Notice in the Preface section.

  6. Install the upper left HVAC module mounting nut (1).

    7. Tighten
    Tighten the nut to 9 N·m (80 lb in).


    Object Number: 756232 Size: SH
  7. Install the lower left HVAC module mounting nut (1).

    8. Tighten
    Tighten the nut to 9 N·m (80 lb in).

  8. Connect the drain tube to the bottom of the HVAC module.

    9. Object Number: 756222 Size: SH
  9. Connect the drain tube (2) to the floor.
  10. Connect the HVAC electrical connector.
  11. Install the air inlet assembly.
  12. Install the I/P carrier. Refer to Instrument Panel Carrier Replacement .
  13. Install new O-rings to the suction hose and liquid line. Refer to O-Ring Replacement .
  14. Connect the suction hose and liquid line to the evaporator core.
  15. Install the A/C quick connect fittings to the suction hose and liquid line. Refer to Air Conditioning Line/Tube Connector Removal/Replacement .
  16. Connect the heater inlet hose to the heater core. Refer to Heater Inlet Hose Replacement .
  17. Connect the heater outlet hose to the heater core. Refer to Heater Outlet Hose Replacement .
  18. Fill the coolant. Refer to Cooling System Draining and Filling .
  19. Evacuate and recharge the AC system. Refer to Refrigerant Recovery and Recharging .
  20. Leak test the fittings of the component using J 39400-A .