GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Saturn 🢒 2003 🢒 ION 🢒 HVAC 🢒 HVAC Systems - Manual 🢒 Heater Assembly Replacement

Removal Procedure
  1. Remove the HVAC module from the vehicle. Refer to HVAC Module Assembly Replacement .

    2. Object Number: 877660 Size: SH
  2. Remove the heater core cover fasteners and cover.

    3. Object Number: 872606 Size: SH
  3. Remove the heater core.

    4. Object Number: 877661 Size: SH
  4. Remove the lower HVAC case screws.

    5. Object Number: 877662 Size: SH
  5. Unsnap and open the passenger compartment filter door.
  6. Remove the lower HVAC case.

Installation Procedure

    Object Number: 877662 Size: SH

    Important: Make certain that the orifice plate is correctly positioned in the HVAC module. Make certain that the lower HVAC case is properly positioned and is fully seated on the HVAC module before installing the screws. Be sure to install all lower HVAC case screws.

  1. Install the lower HVAC case.

    2. Notice: Refer to Fastener Notice in the Preface section.


    Object Number: 877661 Size: SH
  2. Install the lower HVAC case screws.

    3. Tighten
    Tighten the screws to 1.8 N·m (15 lb in).

  3. Close and secure the passenger compartment filter door.

    4. Object Number: 872606 Size: SH
  4. Inspect the foam heater core seal on the lower HVAC case. If damaged, replace using Kent Industries adhesive black foam tape P/N 46480 or equivalent.
  5. Install the heater core into the HVAC module.

    6. Object Number: 877660 Size: SH

    Important: Make certain that the heater core cover is properly positioned and is fully seated on the HVAC module before installing the screws. Be sure to install all heater core cover screws.

  6. Install the heater core cover and fasteners.

    7. Tighten
    Tighten the screws to 1.8 N·m (15 lb in).


    Object Number: 872602 Size: SH
  7. Replace the drain tube seal.

    8. Object Number: 873734 Size: SH
  8. Replace the front of dash seal.
  9. Inspect and replace the HVAC module seals if damaged:
    10. • The defrost duct seal
    • The HVAC module to cross car duct seal
    • The center air outlet duct seal
    • The center floor air outlet duct seal
    • The air inlet seal
  10. Install the HVAC module in the vehicle. Refer to HVAC Module Assembly Replacement .
  11. Fill the cooling system. Refer to Cooling System Draining and Filling .