Diagnostic Aids

Inspect for the following conditions:

• High resistance in an IAC valve control circuit.
• Correct Positive Crankcase Ventilation (PCV) valve, properly installed and proper operation of PCV valve (if equipped).
• Proper operation and installation of all air intake components.
• Proper installation and operation of the Mass Airflow (MAF) sensor, if equipped.
• Tampered with or damaged throttle stop screw.
• A misadjusted throttle cable.
• A skewed high Throttle Position (TP) sensor.
• Excessive deposits in the IAC passage or on the IAC pintle.
• Excessive deposits in the throttle bore or on the throttle plate.
• Vacuum leaks.
• A high or unstable idle condition could be caused by a non-IAC system condition that can not be overcome by the IAC valve.
• If the condition is determined to be intermittent, see INTERMITTENTS in TROUBLE SHOOTING - NO CODES - 2.2L ION article.