KE12 - Check For Problems Affecting Proper Engine Speed

- Check throttle linkage and/or speed control linkage for binding.

- Inspect throttle body for proper operation.

- Check engine vacuum hoses. Refer to Emission Control Systems/Diagrams.

- Check for vacuum leaks around intake components (i.e. gaskets, Idle Air Control (IAC) solenoid, Exhaust Gas Recirculation (EGR) valve, etc.).

- Are all the above checks OK?

Yes -- Remove IAC solenoid and Inspect for contamination. If contamination is present, determine if solenoid is a type that can be cleaned.

Hitachi Idle Air Control (IAC) Valve And Solenoid:

Hitachi
This type of IAC solenoid is serviceable and may be removed and cleaned of sludge deposits that accumulate within the valve.

Hitachi Idle Air Control (IAC) Valve And Solenoid:

Hitachi With Vent/Filter
This type of IAC solenoid is not serviceable and cannot be cleaned.

No contamination present or solenoid cannot be cleaned: Replace IAC solenoid. Rerun quick test. Quick Test Appendix (Detailed Testing Instructions)

Solenoid is contaminated and can be cleaned: Clean as necessary. Rerun quick test. If Diagnostic Trouble Code (DTC)/symptom is still present, replace IAC solenoid.

No -- Service as necessary. Remove breakout box. Reconnect Powertrain Control Module (PCM). Rerun quick test. Quick Test Appendix (Detailed Testing Instructions)