GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2005 🢒 Express 🢒 Engine 🢒 Engine Controls - 4.3L 🢒 Idle Air Control Valve Replacement

Removal Procedure
  1. Turn OFF the ignition.
  2. Remove the engine cover. Refer to Engine Cover Replacement .

    3. Object Number: 12886 Size: SH
  3. Disconnect the harness connector from the idle air control (IAC) valve.

    4. Object Number: 12909 Size: SH
  4. Remove the IAC valve attaching fasteners.

    5. Notice: If the IAC valve has been in service: DO NOT push or pull on the IAC valve pintle. The force required to move the pintle may damage the threads on the worm drive. Also, DO NOT soak the IAC valve in any liquid cleaner or solvent, as damage may result.


    Object Number: 12910 Size: SH
  5. Remove the IAC valve assembly.
  6. Remove the O-ring.

Cleaning and Inspection Procedure

    Object Number: 17065 Size: SH
  1. Clean the IAC valve O-ring sealing surface, the pintle valve seat, and the air passage.
    2. • Use a carburetor cleaner and a parts cleaning brush in order to remove any carbon deposits. Follow the instructions on the container.
    • Do not use a cleaner that contains methyl ethyl ketone (MEK). MEK is an extremely strong solvent and not necessary for this type of deposit.
    • Shiny spots on the pintle or seat are normal and do not indicate misalignment or a bent pintle shaft.
    • If the air passage has heavy deposits, remove the throttle body for a complete cleaning. Refer to Throttle Body Assembly Replacement .
  2. Inspect the IAC valve O-ring for cuts, cracks, or distortion. Replace the O-ring if damaged.

Installation Procedure

    Object Number: 12910 Size: SH

    Important: If you are installing a new IAC valve, replace the valve with an identical part. The IAC valve pintle shape and diameter are designed for the specific application.

  1. Measure the distance between tip of the IAC valve pintle and the mounting flange.

    2. If the distance is more than 28 mm (1.10 in), use finger pressure in order to slowly retract the pintle. The force required to retract the pintle of a new valve will not cause damage to the valve.

  2. Lubricate the IAC valve O-ring with clean engine oil.
  3. Install the IAC valve assembly.

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


    Object Number: 12909 Size: SH
  4. Install the attaching fasteners.

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


    Object Number: 12886 Size: SH
  5. Connect the IAC harness connector.
  6. Install the engine cover. Refer to Engine Cover Replacement .
  7. Reset the IAC valve pintle position.

IAC Valve Reset Procedure
  1. Turn ON the ignition for 20 seconds.
  2. Turn OFF the ignition for 10 seconds.
  3. Start the engine.
  4. Check for the proper idle speed.