Code 35: Idle Speed Error (W Body): Notes

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

1. Continue with test even if engine will not idle properly. If idle is too low, "Scan" tester will display 80 or more counts or steps. If idle is high it will display zero counts. Occasionally, an erratic or unstable idle may occur. Engine speed may vary 200 RPM or more up and down. Disconnect IAC. If condition is unchanged, IAC is not at fault.
2. When engine was stopped, IAC valve retracted (more air) to a fixed position to provide increased airflow during next engine start. During next engine start, a "Scan" should display 100 or more counts.
3. Disconnect IAC valve prior to this test. The test light will confirm the ECM signals by a steady or flashing light on all circuits.
4. There is a remote possibility one of the circuits is shorted to voltage, which would have been indicated by a steady light. Disconnect ECM, turn ignition on and probe terminals with a DVOM to check for this condition.