The Idle Air Control (IAC) valve adjusts the engine idle speed. The valve is located on the side of the throttle body. The valve is controlled by a duty cycle signal from the PCM and allows air to bypass the throttle plate in order to maintain the proper idle speed.
Do not attempt to clean the IAC valve. Carburetor tune-up cleaners or any type of solvent cleaners will damage the internal components of the valve.
See Figure 1
- Turn the ignition switch to the OFF position.
- Disconnect the wiring harness from the IAC valve.
- Measure the resistance between the terminals of the valve.
Due to the diode in the solenoid, place the ohmmeter positive lead on the VPWR terminal and the negative lead on the ISC terminal.
- Resistance should be 6-13 ohms.
- If resistance is not within specification, the valve may be faulty.
REMOVAL & INSTALLATION
- Disconnect the negative battery cable.
- Detach the IAC solenoid connector.
- Remove the 2 retaining bolts and remove the IAC solenoid and gasket from the throttle body.
- Installation is the reverse of the removal procedure. Use a new gasket and tighten the retaining bolts to 71-97 inch lbs. (8-11 Nm).
If scraping is necessary to remove old gasket material, be careful not to damage the IAC solenoid or the throttle body gasket surfaces or drop material into the throttle body.
See Figure 2