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HOMESERVICE MANUALSCHEVROLET2003TRAILBLAZER 4.2 S, 4WDREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 1443 (HVAC SYSTEMS - GENERAL SERVICING)REPAIR INSTRUCTIONSHVAC MODULE REPLACEMENT - AUXILIARYREMOVAL PROCEDURE
2003 Chevrolet TrailBlazer 4.2 S, 4WD

Removal Procedure

2003 Chevrolet TrailBlazer 4.2 S, 4WDSECTION Removal Procedure
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2004 Oldsmobile Bravada, 2004 GMC Envoy XUV, 2004 GMC Envoy XL, 2004 GMC Envoy, and 2004 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.
  1. Recover the refrigerant. Refer to Refrigerant Recovery and Recharging .
  2. Drain the cooling system. Refer to Draining and Filling Cooling System (LL8) or Draining and Filling Cooling System (LM4) in Engine Cooling.
  3. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
    4. Fig 1: Rear A/C Line Block Fittings
    GM735776Courtesy of GENERAL MOTORS CORP.
  4. Remove the nuts (3) from rear A/C line block fittings.
    5. IMPORTANT: Cap or tape the open A/C refrigerant lines immediately.
  5. Remove the A/C line block fittings and discard the O-ring seals.
    6. Fig 2: Auxiliary Heater Hose Block Fittings
    GM400657Courtesy of GENERAL MOTORS CORP.
  6. Remove the nuts from the heater hoses block fittings.
  7. Remove the heater hoses block fittings from the HVAC module-auxiliary.
  8. Remove the nuts from the HVAC module studs.
  9. Lower the vehicle.
  10. Remove the right side rear quarter trim. Refer to Trim Panel Replacement - Rear Quarter - Right (TrailBlazer, Envoy, Bravada) or Trim Panel Replacement - Rear Quarter - Right (TrailBlazer EXT, Envoy XL) in Interior Trim.
    11. Fig 3: Rear Ducting Views
    GM735895Courtesy of GENERAL MOTORS CORP.
  11. Disconnect the electrical connectors from the HVAC module.
  12. Disconnect the rear compartment air outlet ducts (5) from the HVAC module (3).
    13. Fig 4: Auxiliary HVAC Module
    GM735953Courtesy of GENERAL MOTORS CORP.
  13. Remove the mounting bolts (5) from the HVAC module.
  14. Remove the HVAC module (1).
  15. Remove and discard the HVAC module pass through seal.
RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.