GM Service Manual Online
For 1990-2009 cars only

Removal Procedure


    Object Number: 154945  Size: SH

    Important: The hardware used to attach the Throttle Position (TP) sensor and Idle Air Control (IAC) valve is coated with thread-locking adhesive. If these parts are removed for service, inspect the attaching screw threads. There should be enough thread-locking material (adhesive or compound) on the threads to insure proper re-locking. If not, clean the threads and apply Loctite® 262, GM Part No. 1052624, or equivalent, to the threads before re-assembly.

  1. Remove the IAC electrical connector (1) from the IAC valve (8).

  2. Object Number: 18398  Size: SH
  3. Remove the two IAC valve attaching screws (4) from the IAC valve (1).
  4. Remove the IAC valve (1) from the throttle body.
  5. Remove the IAC valve O-ring from the IAC valve.

Installation Procedure


    Object Number: 18398  Size: SH

    Notice: The IAC valve may be damaged if installed with the cone (pintle) extended more than 28 mm (1-1/8 in). Measure the distance that the valve is extended before installing a new valve. The distance from the idle air control valve motor housing to the end of the idle air control valve pintle should be less than 28 mm (1-1/8 in). Manually compress the pintle until the extension is less than 28 mm (1-1/8 in).

  1. Install the new IAC O-ring.
  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.

  3. Install the IAC valve (1) to the throttle body and tighten the screws (4).
  4. Tighten
    Tighten the screws to 3 N·m (27 lb in).


    Object Number: 154945  Size: SH
  5. Connect the IAC valve electrical connector (1) to the IAC valve (8).