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

Removal Procedure
  1. Disconnect the battery negative cable. Refer to Battery Negative Cable Disconnection and Connection.
  2. Remove the instrument panel (I/P) trim pad. Refer to Instrument Panel Trim Pad Replacement.
  3. Remove the bolt from the accessory wiring junction block.
  4. Disengage the junction block tabs from the passenger knee bolster. Remove the junction block from the knee bolster.
  5. Remove the booster push rod from the brake pedal.
  6. Remove the brake pedal bolt. Remove the brake pedal.
  7. Remove the brake pedal brace bolts from the I/P carrier cross car beam.
  8. Lower the body control module (BCM) away from the I/P carrier.
  9. Disconnect any ground wires, as necessary.
  10. Reposition the I/P wiring harness out of the way.

    11. Object Number: 1273425 Size: SH
  11. Remove the bracket bolts from the HVAC module assembly lower support (1).
  12. Remove the bracket bolts from the HVAC module assembly RH support (2).

    13. Object Number: 1197447 Size: SH
  13. Remove the bracket bolts from the HVAC module upper support
  14. Remove the right and the left I/P carrier bolts.
  15. Remove the I/P carrier.

    16. Object Number: 1194938 Size: SH
  16. Remove the two rearward retaining screws (1) from the recirculation housing.

    17. Object Number: 1194936 Size: SH
  17. Remove the retaining screws from the mode valve assembly.
  18. Remove the three heat stakes from the mode valve assembly using a small chisel.
  19. Remove the screws from the mode valve actuator.
  20. Remove the mode valve actuator from the HVAC module assembly.

    21. Note: The right front edge of the mode valve assembly is under the recirculation housing.

  21. Slowly lift the rearward side of the mode valve assembly up and to the left to remove the mode valve assembly.

Installation Procedure
  1. From the inside of the mode valve assembly, drill the dimples adjacent to the heat stakes using a 5.5 mm (7/32 in) drill bit.
  2. Install the right front edge of the mode valve assembly under the recirculation housing.
  3. Install the mode valve assembly to the HVAC module assembly.

    4. Object Number: 1194938 Size: SH
  4. Install the two rearward retaining screws (1) to the recirculation housing.

    5. Object Number: 1194936 Size: SH
  5. Install three new screws in the locations adjacent to the removed heat stakes in the mode valve assembly.
  6. Install the screws that were removed from the mode valve assembly to there original position.

    7. Caution: Refer to Fastener Caution in the Preface section.

  7. Tighten the recirculation housing, mode valve assembly and heat stake replacement screws.

    8. Tighten all the screws to 1.5 N·m (13 lb in).

  8. Position the mode actuator on to the HVAC module assembly.
  9. Install the mode valve actuator bolts and tighten to 1.5 N·m (13 lb in).
  10. Install the I/P carrier to the vehicle. Align the I/P carrier to the HVAC module and the hinge pillars.
  11. Install the bolts to the right and the left I/P carrier and tighten to 25 N·m (18 lb ft).

    12. Object Number: 1197447 Size: SH
  12. Install the bolts to the HVAC module assembly upper support bracket and tighten the bolts to 4 N·m (36 lb in).

    13. Object Number: 1273425 Size: SH
  13. Install the bolts to the HVAC module assembly lower support bracket (1) and tighten to 4 N·m (36 lb in).
  14. Install the bolts to the HVAC module assembly RH support bracket (2) and tighten to 4 N·m (36 lb in).
  15. Position the I/P wiring harness to the original position.
  16. Connect any disconnected ground wires.
  17. Install the BCM.
  18. Install the brake pedal brace bolts to the I/P carrier.
  19. Install the brake pedal and the brake pedal bolt.
  20. Install the booster push rod to the brake pedal.
  21. Seat the bottom junction block tabs and snap the top of the junction block to the passenger knee bolster.
  22. Install the junction block bolt and tighten to 10 N·m (89 lb in).
  23. Install the I/P trim pad. Refer to Instrument Panel Trim Pad Replacement.
  24. Connect the battery negative cable. Refer to Battery Negative Cable Disconnection and Connection.