GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2009 🢒 XLR 🢒 Engine 🢒 Engine Cooling 🢒 Heater Core Replacement

Removal Procedure

    Object Number: 1224339 Size: SH
  1. Remove the HVAC module. Refer to HVAC Module Assembly Replacement.
  2. Remove and discard the HVAC module assembly foam seal.

    3. Object Number: 1226250 Size: SH
  3. Disconnect the discharge temperature management (DTM) sensor electrical connectors.
  4. Disconnect the HVAC module wiring harness retainer pin (2) from the HVAC module.
  5. Disconnect the wiring harness from the heater core cover wire harness retainer (1) and reposition the wiring harness aside.
  6. Disconnect the wiring harness from the heater core cover wire harness retainer (3) and reposition the wiring harness aside.

    7. Object Number: 1224370 Size: SH
  7. Remove the heater cover screws.
  8. Remove the heater cover from the HVAC module.

    9. Object Number: 1224297 Size: SH
  9. Remove the heater core from the HVAC module.

Installation Procedure

    Note: Always install new heater core seals onto the heater core.


    Object Number: 1224308 Size: SH
  1. Install a new foam seal to the heater core.

    2. Object Number: 1224297 Size: SH
  2. Install the heater core to the HVAC module.

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

  3. Install the heater cover to the HVAC module.

    4. Object Number: 1224370 Size: SH
  4. Install the heater cover screws and tighten to 1.6 N·m (14 lb in).

    5. Object Number: 1226250 Size: SH
  5. Reposition the HVAC wiring harness and connect the wiring harness to the heater core cover wiring harness retainer (1).
  6. Reposition the HVAC wiring harness and connect the wiring harness to the heater core cover wiring harness retainer (3).
  7. Connect the HVAC module wiring harness retainer pin (2) to the HVAC module.
  8. Connect the discharge temperature management (DTM) sensor electrical connectors.
  9. Install the HVAC module. Refer to HVAC Module Assembly Replacement.