GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2005 🢒 Terraza 🢒 HVAC 🢒 Heating, Ventilation and Air Conditioning 🢒 HVAC Module Assembly Replacement

Tools Required

J 39400-A Halogen Leak Detector

Removal Procedure

    Object Number: 1547627 Size: SH
  1. Recover the refrigerant from the air conditioning (A/C) system. Refer to Refrigerant Recovery and Recharging .
  2. Drain the cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.

    3. Important: The defroster door must be closed to allow clearance during defroster duct removal.

  3. Set the heating, ventilation and air conditioning (HVAC) controls in the vent setting to close the defroster door.
  4. Remove the blower motor. Refer to Blower Motor Replacement .
  5. Disconnect the electrical connector from the blower motor resistor.
  6. Disconnect the electrical connector from the evaporator temperature sensor.
  7. Disconnect all of the HVAC actuator electrical connectors.
  8. Remove the instrument panel (I/P) carrier. Refer to Instrument Panel Carrier Replacement in Instrument Panel, Gages, and Console.
  9. Remove the evaporator outlet tube nut.
  10. Disconnect the evaporator outlet tube and evaporator inlet tube from the thermal expansion valve (TXV).
  11. Remove and discard the sealing washers.

    12. Object Number: 656207 Size: SH
  12. Remove the heater inlet and outlet hoses. Refer to Heater Inlet Hose/Pipe and Heater Outlet Hose/Pipe Replacement .
  13. Remove the HVAC module nuts.

Installation Procedure

Important: Ensure proper alignment of the HVAC module and drain tube through the cowl.

  1. Install the HVAC module.

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


    Object Number: 656207 Size: SH
  2. Instal the HVAC module to dash panel sound barrier nuts.

    3. Tighten
    Tighten the nuts to 10 N·m (89 lb in).

  3. Install the heater inlet and outlet hoses. Refer to Heater Inlet Hose/Pipe and Heater Outlet Hose/Pipe Replacement .

    4. Object Number: 1547627 Size: SH
  4. Install NEW sealing washers.
  5. Connect the evaporator inlet and outlet tube block to the TXV.
  6. Install the evaporator tube block nut.

    7. Tighten
    Tighten the nut to 16 N·m (12 lb ft).

  7. Install the I/P carrier. Refer to Instrument Panel Carrier Replacement in Instrument Panel, Gages, and Console.
  8. Connect all of the HVAC actuator electrical connectors.
  9. Connect the electrical connector to the evaporator temperature sensor.
  10. Connect the electrical connector to the blower motor resistor.
  11. Install the blower motor. Refer to Blower Motor Replacement .
  12. Fill the cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.
  13. Evacuate and recharge the A/C system. Refer to Refrigerant Recovery and Recharging .
  14. Leak test the fittings using the J 39400-A .