Pull out the IAC idle control knob fully using the IAC actuator.
Start the engine. If the idle speed is above 800 rpm:
- find and repair a vacuum leak;
- check for throttle sticking or insufficiently tight closing;
- check that the basic idle speed settings are correct.
Inspect the IAC piping for blockages.
Measure the resistance between these IAC valve terminals. Resistance between terminals C and D. A and B must be equal to (40 to 80 ohm).
Check for an open or short in the wiring between the following terminals:
- IAC valve connector D terminal and ECM connector terminal A28;
- terminal C of the IAC valve and terminal AZO of the ECM connector;
- terminal B of the IAC valve connector and terminal A13 of the ECM connector;
- terminal A of the IAC valve connector and terminal A29 of the ECM connector.
