Diagnostic Aids

Check air intake system for blockage. Check IAC passage or throttle bore for blockage, excessive deposits in IAC passage and IAC pintle. Check for excessive deposits in throttle bore and throttle blade. Ensure vacuum hoses are routed correctly and no vacuum leaks are present.

Ensure engine is idling at normal operating temperature and all electrical accessories are off. Using scan tool, ensure IAC duty cycle is 27-43 percent and that there is no electric load and A/C is commanded off.

An intermittent condition may be caused by poor connection, rubbed-through insulation, or a broken wire inside insulation. Check PCM harness connectors for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals, or poor terminal-to-wire connections before component replacement.