Fast Idle

DETECTION CONDITION AND POSSIBLE CAUSE

5	FAST IDLE
DESCRIPTION	Engine speed continues at fast idle after engine warm-up

FAST IDLE INSPECTION

STEP	INSPECTION		ACTION
1	VERIFY ENGINE OPERATES AT NORMAL OPERATING TEMPERATURE NOTE: If vehicle runs normally after the ignition key is turned off, check for damaged ignition switch, IGN RUN circuit short to power, VPWR circuit short to power, etc. The ECT PID at normal operating temperature should read between.35 volt (112°C/232°F) and.75 volt (82°C/180°F). Does engine appear to be either overheating or not reaching normal operating temperature?	Yes	See ENGINE COOLING SYMPTOM CHART .
1		No	Go to step 2.
2	PRELIMINARY CHECKS Perform the following preliminary checks: Vacuum leaks. Throttle plate and linkage. Cruise control linkage binding/sticking. Intake air tube (leaks). Proper sealing of intake manifold and components attached to intake air (such as the EGR valve or IAC valve). Are all checks OK?	Yes	Go to step 3.
2		No	Service as necessary. Verify symptom no longer exists.
3	PERFORM PCM QUICK TEST Are any DTCs displayed during Continuous Memory, Key ON, Engine OFF (KOEO) or Key ON, Engine Running (KOER) Self Tests?	Yes	Check for cause. See DIAGNOSTIC TROUBLE CODE NUMBERS .
3		No	Go to step 4.
4	CHECK FOR BASE ENGINE AIR LEAKS Check for base engine air leaks (such as intake manifold gasket air leaks), See ENGINE COMPONENT TESTS . Is a fault indicated?	Yes	Service as required.
4		No	Go to step 5.
5	Verify test results. If OK, See DIAGNOSTIC INDEX to service any additional symptoms