GM Service Manual Online
For 1990-2009 cars only

Removal Procedure

  1. Remove the air cleaner outlet resonator. Refer to Air Cleaner Outlet Resonator Replacement .

  2. Object Number: 783168  Size: SH
  3. Disconnect the idle air control (IAC) valve harness connector (1).
  4. Remove the IAC valve screw.
  5. Remove the IAC valve and seal.

Cleaning and Inspection Procedure

    • If using the original IAC valve, perform the following inspection and cleaning procedure:
       - Clean the IAC valve sealing surface, pintle valve seat and air passage in the throttle body.
       - Whenever the air passages have heavy deposits, remove the throttle body for a complete cleaning. Refer to Fuel System Cleaning .
       - The IAC valve may be cleaned by using a shop towel or small parts cleaning brush to remove heavy deposits.
       - Shiny spots on the pintle or seat are normal, and not an indication of a misaligned pintle shaft.
       - Inspect the IAC valve seal for cuts, cracks or distortion. Replace the IAC valve if the seal is damaged.
    • Whenever installing a new IAC valve, replace the valve with an identical part. The IAC valve pintle shape and diameter are specific to this application.
    • Compare the distance between the tip, or the pintle, and the mounting flange of the new and old IAC valves. Use finger pressure to slowly retract the pintle of the new valve to the distance of the old. This will not cause damage to the new IAC valve but is critical for installation.

Installation Procedure

  1. Lubricate the IAC valve seal with clean engine oil.
  2. Install the IAC valve into the throttle body.
  3. 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.

    Important: Install a new screw when replacing the IAC valve.

  4. Install the IAC valve screw.
  5. Tighten
    Tighten the IAC valve screw to 3 N·m (27 lb in).


    Object Number: 783168  Size: SH
  6. Connect the IAC valve harness connector (1).
  7. Install the air cleaner outlet resonator. Refer to Air Cleaner Outlet Resonator Replacement .
  8. Reset the IAC valve pintle using the following procedure:
  9. 6.1. Turn ON the ignition, with the engine OFF.
    6.2. Turn OFF the ignition for 10  seconds.
    6.3. Start the engine and check for proper idle operation.