GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2007 🢒 Corvette 🢒 HVAC 🢒 Heating, Ventilation, and Air Conditioning 🢒 Mode Valve Assembly Replacement

Removal Procedure

    Object Number: 1224374 Size: SH
  1. Remove the HVAC module. Refer to HVAC Module Assembly Replacement .
  2. Disconnect the left-hand (LH) air temperature actuator electrical connector.
  3. Remove the LH actuator retaining screws.
  4. Remove the LH actuator.

    5. Object Number: 1224325 Size: SH
  5. Disconnect the mode actuator electrical connector.
  6. Disconnect the right-hand (RH) air temperature actuator electrical connector.
  7. Remove the actuator support bracket retaining screws.
  8. Remove the actuator support bracket and actuators.

    9. Notice: Do not remove the TORX screws from the mode valve assembly. Misalignment can cause damage to the film valve.


    Object Number: 1224372 Size: SH
  9. Remove the mode valve assembly retaining screws.

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

    13. Object Number: 1224370 Size: SH
  13. Remove the heater core cover screws.
  14. Remove the heater core cover.

    15. Object Number: 1224371 Size: SH
  15. Remove the mode valve assembly.

Installation Procedure

    Notice: Do not tamper, adjust or disassemble the mode valve assembly. The proper setting of the pretensions on the springs is critical to the film valve function.


    Object Number: 1224371 Size: SH
  1. Install the mode valve assembly.
  2. Install the heater core cover.

    3. Object Number: 1224370 Size: SH

    Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

  3. Install the heater core cover screws.

    4. Tighten
    Tighten the screws to 1.6 N·m (14 lb in).

  4. Connect the wiring harness to the heater core cover wire harness retainer (2).

    5. Object Number: 1226250 Size: SH
  5. Connect the HVAC module wiring harness retainer pin (1) to the HVAC module.
  6. Connect the DTM sensor electrical connectors.

    7. Object Number: 1224372 Size: SH
  7. Install the mode valve assembly retaining screws.

    8. Tighten
    Tighten the screws to 1.6 N·m (14 lb in).


    Object Number: 1224325 Size: SH

    Important: It may be necessary to gently rotate the RH temperature door to align the actuator support bracket and actuators.

  8. Install the actuator support bracket and actuators to the HVAC module.
  9. Install the actuator support bracket retaining screws.

    10. Tighten
    Tighten the screws to 1.6 N·m (14 lb in).

  10. Connect the RH air temperature actuator electrical connector.
  11. Connect the mode actuator electrical connector.
  12. Install the LH actuator.
  13. Install the LH actuator retaining screws.
  14. Connect the LH air temperature actuator electrical connector.

    15. Object Number: 1224374 Size: SH
  15. Install the HVAC module. Refer to HVAC Module Assembly Replacement .