Cannot Adjust Idle Speed To Specification

1. When the idle speed is out of specification and the Malfunction Indicator Lamp (MIL) does not blink Diagnostic Trouble Code (DTC) 14, check the following items:

NOTE: On Canadian models the MALFUNCTION INDICATOR WARNING LAMP is the CHECK ENGINE LAMP.

- Adjust the idle speed.
- Air conditioning signal
- Alternator FR signal
- A/T gear position signal
- M/T clutch switch signal
- Starter switch signal
- Brake switch signal
- Power Steering Pressure switch signal
- Fast idle thermo valve
- Hoses and connections
- Idle Air Control (IAC) Valve and its mounting 0-rings

2. If the above items are normal, substitute a known-good IAC Valve and readjust the idle speed.

3. If the idle speed still cannot be adjusted to specification (and the MIL does not blink code 14) after IAC Valve replacement, substitute a known-good Engine Control Module (ECM) and recheck. If symptom goes away, replace the original ECM.