Component Tests and General Diagnostics

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:
^ Adjust the idle speed.
^ Air conditioning signal
^ Alternator FR signal
^ A/T gear position signal
^ Starter switch signal
^ Brake switch signal
^ PSP switch signal
^ Fast idle thermo valve.
^ Starting Air Valve
^ Hoses and connections
^ 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.
^ 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 ECM and recheck. If symptom goes away, replace the original ECM.