Code 35, IAC Idle Speed Error Using Tech I: Notes

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

1. The Tech 1 RPM control mode is used to extend and retract the 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. 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.
2. This test uses the Tech 1 to command the IAC controlled idle speed. The control module issues commands to obtain the requested idle speed. 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.