GM Service Manual Online
For 1990-2009 cars only

Removal Procedure


    Object Number: 1646796  Size: SH
  1. Remove the driver knee bolster. Refer to Driver Knee Bolster Replacement .
  2. Remove the communication interface module, if equipped. Refer to Communication Interface Module Replacement .
  3. Disconnect the electrical connector from the mode actuator.
  4. Remove the mode actuator screws from the evaporator case assembly.
  5. Remove the mode actuator from the evaporator case assembly.

  6. Object Number: 1646798  Size: SH
  7. Remove the screws retaining the mode cam bracket (1) to the evaporator case assembly.
  8. Remove the mode cam bracket (1) from the evaporator case assembly.
  9. Remove the mode cam (2) and the mode cam levers (3) from the evaporator case assembly.

Installation Procedure


    Object Number: 1646798  Size: SH
  1. Install the mode cam levers (3) to the evaporator case assembly.
  2. Align and install the mode cam (2) to the mode cam levers (3). Rotate the mode cam (2) to verify mode door operation.
  3. Install the mode cam bracket (1) to the evaporator case assembly.
  4. Notice: Refer to Fastener Notice in the Preface section.

  5. Install the mode cam bracket screws to the evaporator case assembly.
  6. Tighten
    Tighten the screws to 1.5 N·m (13 lb in).


    Object Number: 1646796  Size: SH
  7. Install the mode actuator to the evaporator case assembly.
  8. Install the mode actuator screws to the evaporator case assembly.
  9. Tighten
    Tighten the screws to 1.5 N·m (13 lb in).

  10. Connect the electrical connector to the mode actuator.
  11. Install the communication interface module, if equipped. Refer to Communication Interface Module Replacement .
  12. Install the driver knee bolster. Refer to Driver Knee Bolster Replacement .
  13. Important: Any time a mode actuator or the HVAC control module is replaced, the HVAC control module must be calibrated to ensure proper air distribution.

  14. Calibrate the actuators. Refer to Actuator Recalibration .
  15. Cycle the ignition and verify proper operation.

Removal Procedure


    Object Number: 1646796  Size: SH
  1. Remove the driver knee bolster. Refer to Driver Knee Bolster Replacement.
  2. Remove the communication interface module, if equipped. Refer to Communication Interface Module Replacement.
  3. Disconnect the electrical connector from the mode actuator.
  4. Remove the mode actuator screws from the evaporator case assembly.
  5. Remove the mode actuator from the evaporator case assembly.

  6. Object Number: 1646798  Size: SH
  7. Remove the screws retaining the mode cam bracket (1) to the evaporator case assembly.
  8. Remove the mode cam bracket (1) from the evaporator case assembly.
  9. Remove the mode cam (2) and the mode cam levers (3) from the evaporator case assembly.

Installation Procedure


    Object Number: 1646798  Size: SH
  1. Install the mode cam levers (3) to the evaporator case assembly.
  2. Align and install the mode cam (2) to the mode cam levers (3). Rotate the mode cam (2) to verify mode door operation.
  3. Install the mode cam bracket (1) to the evaporator case assembly.
  4. Caution: Refer to Fastener Caution in the Preface section.

  5. Install the mode cam bracket screws to the evaporator case assembly and tighten the screws to 1.5 N·m (13 lb in).

  6. Object Number: 1646796  Size: SH
  7. Install the mode actuator to the evaporator case assembly.
  8. Install the mode actuator screws to the evaporator case assembly and tighten the screws to 1.5 N·m (13 lb in).
  9. Connect the electrical connector to the mode actuator.
  10. Install the communication interface module, if equipped. Refer to Communication Interface Module Replacement.
  11. Install the driver knee bolster. Refer to Driver Knee Bolster Replacement.
  12. Note: Any time a mode actuator or the HVAC control module is replaced, the HVAC control module must be calibrated to ensure proper air distribution.

  13. Calibrate the actuators. Refer to Actuator Recalibration.
  14. Cycle the ignition and verify proper operation.