GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2009 🢒 Avalanche - 4WD 🢒 HVAC 🢒 Heating, Ventilation, and Air Conditioning 🢒 HVAC Module Assembly Replacement

HVAC Module Assembly Replacement Non-HP2

Special Tools

J 43181 Heater Line QC Release Tool

Removal Procedure
  1. Drain the engine coolant. Refer to Cooling System Draining and Filling.

    2. Object Number: 362171 Size: SH
  2. Using the J 43181 disconnect the inlet heater hose from the heater core.
    3. 2.1. Install the J 43181 to the heater core pipe.
    2.2. Close the tool around the heater core pipe.
    2.3. Firmly pull the tool into the quick connect end of the heater hose.
    2.4. Firmly grasp the heater hose. Pull the heater hose forward in order to disengage the inlet hose from the heater core.
  3. Using the J 43181 disconnect the surge tank outlet hose from the heater core.
    4. 3.1. Install the J 43181 to the heater core pipe.
    3.2. Close the tool around the heater core pipe.
    3.3. Firmly pull the tool into the quick connect end of the heater hose.
    3.4. Firmly grasp the heater hose. Pull the heater hose forward in order to disengage the surge tank outlet hose from the heater core.
  4. Remove the upper intake manifold sight shield. Refer to Upper Intake Manifold Sight Shield Replacement.
  5. Remove the battery. Refer to Battery Replacement.
  6. Remove the accumulator. Refer to Air Conditioning Accumulator Replacement.
  7. Remove the instrument panel to the service position. Refer to Instrument Panel Service Positioning.
  8. Remove the HVAC module drain hose.
  9. Disconnect the electrical harnesses and the ground connections from the HVAC module.

    10. Object Number: 1704876 Size: SH

    Note: Ensure that any wiring harness does not interfere with the drilling process of the rear engine cover.

  10. Locate the rear engine cover (1) on rear of intake manifold.

    11. Object Number: 1704878 Size: SH
  11. Reposition the acoustic foam (if applicable) down from the access location (1).

    12. Note: Drill an 25.4 mm (1 in.) diameter hole in the rear engine cover (1) to access the HVAC module retaining nut located behind rear engine cover.


    Object Number: 1698730 Size: SH
  12. Remove the nuts (2) from the HVAC module (3).
  13. Remove the bolts (1) from the HVAC module (3).
  14. Remove the HVAC module (3).

Installation Procedure

    Object Number: 1698730 Size: SH
  1. If replacing the HVAC module, transfer the components from the old HVAC module as necessary.
  2. Install the HVAC module (3).

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

  3. Install the nuts (2) to the HVAC module (3) and tighten to 9 N·m (80 lb in).
  4. Install the bolts (1) to the HVAC module (3) and tighten to 4 N·m (35 lb in).
  5. Reposition acoustic foam (if applicable) to original position or cover access hole with equivalent foam tape (1).
  6. Connect the electrical harness and the ground connections.
  7. Install the HVAC module drain hose.
  8. Install the instrument panel. Refer to Instrument Panel Service Positioning.
  9. Install the upper intake manifold sight shield. Refer to Upper Intake Manifold Sight Shield Replacement.
  10. Install the battery. Refer to Battery Replacement.
  11. Install the accumulator. Refer to Air Conditioning Accumulator Replacement.

    12. Object Number: 362171 Size: SH
  12. Install the surge tank outlet hose to the heater core.

    13. Firmly push the quick connect onto the heater core pipe until you hear an audible click.

  13. Install the inlet heater hose to the heater core.

    14. Firmly push the quick connect onto the heater core pipe until you hear an audible click.

  14. Fill the engine coolant. Refer to Cooling System Draining and Filling.

HVAC Module Assembly Replacement HP2

Special Tools

J 43181 Heater Line QC Release Tool

Removal Procedure
  1. Drain the engine coolant. Refer to Cooling System Draining and Filling.

    2. Object Number: 362171 Size: SH
  2. Using the J 43181 disconnect the inlet heater hose from the heater core.
    3. 2.1. Install the J 43181 to the heater core pipe.
    2.2. Close the tool around the heater core pipe.
    2.3. Firmly pull the tool into the quick connect end of the heater hose.
    2.4. Firmly grasp the heater hose. Pull the heater hose forward in order to disengage the inlet hose from the heater core.
  3. Using the J 43181 disconnect the surge tank outlet hose from the heater core.
    4. 3.1. Install the J 43181 to the heater core pipe.
    3.2. Close the tool around the heater core pipe.
    3.3. Firmly pull the tool into the quick connect end of the heater hose.
    3.4. Firmly grasp the heater hose. Pull the heater hose forward in order to disengage the surge tank outlet hose from the heater core.
  4. Remove the upper intake manifold sight shield. Refer to Upper Intake Manifold Sight Shield Replacement.
  5. Remove the drive motor generator control module assembly. Refer to Drive Motor Generator Control Module Assembly Replacement.
  6. Remove the battery. Refer to Battery Replacement.
  7. Remove the accumulator. Refer to Air Conditioning Accumulator Replacement.
  8. Remove the instrument panel to the service position. Refer to Instrument Panel Service Positioning.
  9. Remove the HVAC module drain hose.
  10. Disconnect the electrical harnesses and the ground connections from the HVAC module.

    11. Object Number: 1704876 Size: SH
  11. Locate the rear engine cover (1) on rear of intake manifold.

    12. Note: Ensure that any wiring harness does not interfere with the drilling process of the rear engine cover.


    Object Number: 1704878 Size: SH
  12. Reposition the acoustic foam (if applicable) down from the access location (1).

    13. Note: Drill an 25.4 mm (1 in.) diameter hole in the rear engine cover (1) to access the HVAC module retaining nut located behind rear engine cover.


    Object Number: 1698730 Size: SH
  13. Remove the nuts (2) from the HVAC module (3).
  14. Remove the bolts (1) from the HVAC module (3).
  15. Remove the HVAC module (3).

Installation Procedure

    Object Number: 1698730 Size: SH
  1. If replacing the HVAC module, transfer the components from the old HVAC module as necessary.
  2. Install the HVAC module (3).

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

  3. Install the nuts (2) to the HVAC module (3) and tighten to 9 N·m (80 lb in).
  4. Install the bolts (1) to the HVAC module (3) and tighten to 4 N·m (35 lb in).
  5. Reposition acoustic foam (if applicable) to original position or cover access hole with equivalent foam tape (1).
  6. Connect the electrical harness and the ground connections.
  7. Install the HVAC module drain hose.
  8. Install the instrument panel. Refer to Instrument Panel Service Positioning.
  9. Install the upper intake manifold sight shield. Refer to Upper Intake Manifold Sight Shield Replacement.
  10. Install the drive motor generator control module assembly. Refer to Drive Motor Generator Control Module Assembly Replacement.
  11. Install the battery. Refer to Battery Replacement.
  12. Install the accumulator. Refer to Air Conditioning Accumulator Replacement.

    13. Object Number: 362171 Size: SH
  13. Install the surge tank outlet hose to the heater core.

    14. Firmly push the quick connect onto the heater core pipe until you hear an audible click.

  14. Install the inlet heater hose to the heater core.

    15. Firmly push the quick connect onto the heater core pipe until you hear an audible click.

  15. Fill the engine coolant. Refer to Cooling System Draining and Filling.