GM Service Manual Online
For 1990-2009 cars only

Removal Procedure


    Object Number: 870546  Size: SH
  1. Turn the ignition OFF.
  2. Remove the air induction tubing from the throttle body to the air cleaner.
  3. Disconnect the IAC valve harness connector.
  4. Disconnect the throttle position (TP) sensor harness connector.
  5. Disconnect the manifold absolute pressure (MAP) sensor harness connector.
  6. Notice: The IAC valve is an electrical component and must not be soaked in any liquid solvent, otherwise damage could result.

  7. Remove the IAC valve attachment screws and IAC valve.
  8. Remove the O-ring from the IAC valve and discard.

Installation Procedure


    Object Number: 870546  Size: SH
  1. Clean the IAC valve seating surfaces on the throttle body to assure proper seal of the new O-ring and contact of the IAC valve flange.
  2. Important: Before installing a new IAC valve, retract the pintle using the scan tool. Refer to the scan tool user guide.

    Important: Normal wear of the IAC pintle, characterized by a ring around the cone, is not an indication of a bad IAC valve.

  3. Lubricate the new O-ring with clean engine oil and install on the IAC valve.

  4. Object Number: 870576  Size: SH

    Important: If replacement is necessary, be sure to replace with an identical part. IAC valve pintle shape and diameter are designed for specific applications.

  5. Insert the IAC valve in the throttle body.
  6. Notice: Refer to Fastener Notice in the Preface section.

  7. Install the IAC valve attachment screws using thread coating, Saturn P/N 21485277 (LOCTITE 242® Threadlocker or equivalent).
  8. Tighten
    Tighten the idle air control valve to 3 N·m (27 lb in).

  9. Connect the IAC valve harness connector. Push in the connector until a click is heard and pull back to confirm a positive engagement.
  10. Connect the MAP sensor harness connector. Push in the connector until a click is heard and pull back to confirm a positive engagement.
  11. Connect the TP sensor harness connector. Push in the connector until a click is heard and pull back to confirm a positive engagement.
  12. Important: The powertrain control module (PCM) will have to go through an IAC relearn process once the new valve is installed. The vehicle should be run at normal operating temperature while varying the engine RPM slowly between 3,500 RPM and idle 2 or 3 times.

  13. Install the air induction tubing from the throttle body to the air cleaner.