GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2003 🢒 Astro - 4WD 🢒 HVAC 🢒 Heating, Ventilation and Air Conditioning 🢒 Auxiliary Heater Module Replacement

Removal Procedure
  1. Drain the engine coolant. Refer to Cooling System Draining and Filling in Engine Cooling.
  2. Remove the body side front lower trim panel. Refer to Body Side Front Lower Trim Panel Replacement in Interior Trim.

    3. Object Number: 280251 Size: SH
  3. Remove the auxiliary heater module cover retaining screws.
  4. Remove the auxiliary heater module cover.
  5. Remove the auxiliary heater pipe clamps.
  6. Disconnect the auxiliary heater pipes from the auxiliary heater module.

    7. Object Number: 280250 Size: SH
  7. Remove the bolts retaining the auxiliary heater module to the floor.

    8. Important: Before removing the auxiliary heater module from the vehicle, be sure to place a protective cover on the floor in order to prevent coolant from leaking onto the carpet.

  8. Remove the auxiliary heater module from the vehicle.

Installation Procedure

    Object Number: 280250 Size: SH
  1. Install the auxiliary heater module.

    2. 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.

  2. Install the bolts that retain the auxiliary heater module to the floor.

    3. Tighten
    Tighten the bolts to 5 N·m (44 lb in).

  3. Connect the auxiliary heater pipes to the auxiliary heater module.
  4. Install the auxiliary heater pipe clamps.

    5. Object Number: 280251 Size: SH
  5. Install the auxiliary heater module cover.
  6. Install the auxiliary heater module cover retaining screws.

    7. Tighten
    Tighten the screws to 5 N·m (44 lb in).

  7. Install the body side front lower trim panel. Refer to Body Side Front Lower Trim Panel Replacement in Interior Trim.
  8. Refill the cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.