Diagnostic Aids

Inspect IAC valve connector for proper connection. Inspect throttle linkage for signs of binding or excessive wear. A slow or unstable idle may be caused by one of the following:

• Fuel system too rich or too lean.
• Foreign material in throttle body bore or in air induction system.
• Leaking or restricted intake manifold.
• Excessive engine overloading.
• Too high a viscosity engine oil.

Reviewing FAIL RECORDS vehicle mileage since diagnostic test last failed may help determine how often condition that caused DTC to be set occurs.