Chart 5

Unique Idle Concerns: Fast Idle
Diesels/Runs On

NOTE: If the vehicle runs normally with the key in the OFF position, check for a damaged ignition switch, an IGN RUN circuit short to voltage, a VPWR circuit short to voltage. Refer to the applicable SYSTEM WIRING DIAGRAMS or service information article.

SYSTEM/COMPONENT	REFERENCE (PINPOINT TESTS -- GASOLINE MODELS unless noted)
Base Engine Check for air leaks, including proper sealing of intake manifold and components/vacuum lines attached to intake air (such as the PCV, EGR or IAC valve/vacuum lines).	Visual. REFER to the appropriate ENGINE article .
Verify the engine operates at normal temperature.	Visual. REFER to the appropriate ENGINE COOLING article or STEP 2: NO DIAGNOSTIC TROUBLE CODES (DTCS) PRESENT SYMPTOM CHART INDEX , to diagnose any cooling system concerns that are present.
Fast idle concerns (for vehicles equipped with an IAC valve) With the key ON, engine OFF monitor the TP MODE PID while wiggling the TP sensor circuits. The TP MODE PID can also be monitored during vehicle drive. With the throttle closed, the TP MODE PID must be C/T (closed throttle).	TP MODE PID is not C/T with the throttle closed: At vehicle start, the TPREL begins at about 1.25 volts and counts down to the lowest TP V value seen since engine start. If the TP V value goes below the normal range, then increases again, TPREL sets to the lower voltage. If TP V is about 0.04 volts greater than the TPREL value at closed throttle, the PCM goes into part throttle mode. MONITOR the TP V and TPREL PIDs for sudden changes while checking for intermittent TP circuit/connector concerns. CHECK for loose or worn throttle plates. If no concern is found, GO to Pinpoint Test Z .
Intake Air System Leaks (for vehicles equipped with an IAC valve)	GO to Pinpoint Test HU .
Additional Testing	GO to Pinpoint Test Z .