Code 35, IAC Idle Speed Error: Notes

Code 35 will set when closed throttle engine speed is 150 RPM greater or less than correct idle speed for 20 seconds.

1. IAC driver is used to extend and retract IAC valve. Movement is verified by an engine speed change. If no change in speed occurs, valve can be retested when removed from throttle body.
2. Checks IAC movement quality from step 1). Between 700-1500 RPM, engine speed should change smoothly with each flash of the tester light in both extend and retract. If IAC valve is retracted beyond the control range (about 1500 RPM), it may take many flashes in the extend position before engine speed begins to drop. This is normal on certain engines. Fully extending the IAC may cause engine to stall. This may be normal.
3. Steps 1) and 2) verified proper IAC valve operation while this step checks the IAC circuits. Each light on the node light should flash Red and Green while the IAC valve is cycled. While the sequence of color is not important if either light is off or does not flash Red and Green, check the circuits for faults beginning with poor terminal contacts.