GM Service Manual Online
For 1990-2009 cars only

Intake Air Heater Relay Replacement Federal

Removal Procedure

Important: The intake air heater (IAH) relay is a part of the glow plug controller on vehicles equipped with federal emissions.


    Object Number: 658266  Size: SH
  1. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.
  2. Remove the upper intake manifold sight shield using the following procedure:
  3. 2.1. Remove the retaining bolt in the front of the shield.
    2.2. Lift up on the front of the shield.
    2.3. Lift the shield off the rear bracket.

    Object Number: 1177261  Size: SH
  4. Using a flat bladed screwdriver, disengage the glow plug controller cover clips.

  5. Object Number: 1177263  Size: SH
  6. Remove the glow plug controller cover.

  7. Object Number: 1177264  Size: SH
  8. Remove the glow plug controller nuts.

  9. Object Number: 1177266  Size: SH
  10. Lift the glow plug controller off the studs.

  11. Object Number: 1177273  Size: SH
  12. Separate the intake heater relay from the glow plug controller housing by inserting a small screwdriver between them while prying the relay assembly outward.

  13. Object Number: 1177274  Size: SH
  14. Slide the intake heater relay outward to disengage it from the glow plug controller housing.

  15. Object Number: 1177276  Size: SH
  16. Using a flat bladed screwdriver, disengage the intake heater relay clip.

  17. Object Number: 1177277  Size: SH
  18. Remove the intake heater relay.

Installation Procedure


    Object Number: 1177277  Size: SH
  1. Install the intake heater relay.

  2. Object Number: 1177274  Size: SH
  3. Slide the intake heater relay inward to engage it to the glow plug controller housing.

  4. Object Number: 1177266  Size: SH
  5. Place the glow plug controller onto the studs.

  6. Object Number: 1177264  Size: SH

    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.

  7. Install the glow plug controller nuts.
  8. Tighten
    Tighten the nuts to 42 N·m (31 lb ft).


    Object Number: 1177263  Size: SH
  9. Install the glow plug controller cover.

  10. Object Number: 658266  Size: SH
  11. Install the upper intake manifold sight shield.
  12. Tighten
    Tighten the bolt to 9 N·m (80 lb in).

  13. Connect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.

Intake Air Heater Relay Replacement California

Removal Procedure


    Object Number: 813243  Size: SH
  1. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.
  2. Loosen the outlet duct clamp at the upper intake manifold cover.
  3. Remove he upper intake manifold cover from the outlet duct.
  4. Remove the upper intake manifold cover.

  5. Object Number: 757209  Size: SH
  6. Disconnect the engine harness electrical connector (2).
  7. Disconnect the intake air heater (IAH) relay electrical connector (3)

  8. Object Number: 1198931  Size: SH
  9. Reposition the battery cable boots (1).

  10. Object Number: 1198934  Size: SH
  11. Remove the battery cable nuts and cables from the IAH relay controller. Reposition the cables.
  12. Remove the IAH relay controller bolts (2).
  13. Remove the IAH relay controller.

  14. Object Number: 1198936  Size: SH
  15. Remove the IAH relay controller cover.

  16. Object Number: 1198938  Size: SH
  17. Remove the IAH relay controller nuts and washers.

  18. Object Number: 1198939  Size: SH
  19. Using 2 screwdrivers, disengage the IAH relay assembly from the controller housing.

  20. Object Number: 1198940  Size: SH
  21. Remove the IAH relay assembly from the housing.

  22. Object Number: 1198942  Size: SH
  23. Remove the IAH relay.

Installation Procedure


    Object Number: 1198942  Size: SH
  1. Install the IAH relay.

  2. Object Number: 1198940  Size: SH
  3. Install the IAH relay assembly to the housing.

  4. Object Number: 1198938  Size: SH

    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.

  5. Install the IAH relay controller nuts and washers.
  6. Tighten
    Tighten the nuts to 5 N·m (44 lb in).


    Object Number: 1198936  Size: SH
  7. Install the IAH relay controller cover.

  8. Object Number: 1198934  Size: SH
  9. Install the IAH relay controller.
  10. Install the IAH relay controller bolts (2).
  11. Tighten
    Tighten the bolts to 20 N·m (15 lb ft).

  12. Install the battery cables and nuts to the IAH relay controller.
  13. Tighten
    Tighten the nuts to 5 N·m (44 lb in).


    Object Number: 1198931  Size: SH
  14. Reposition the battery cable boots (1).

  15. Object Number: 757209  Size: SH
  16. Connect the IAH relay electrical connector (3).
  17. Connect the engine harness connector (2).

  18. Object Number: 813243  Size: SH
  19. Install the upper intake manifold cover.
  20. Install the upper intake manifold cover to the outlet duct.
  21. Tighten the outlet duct clamp at the upper intake manifold cover.
  22. Tighten
    Tighten the clamp to 6 N·m (53 lb in).

  23. Connect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.