Chart 5
- Unique Idle Concerns: Fast Idle
- Diesels/Runs On
NOTE:
If the vehicle runs normally after the ignition key is turned OFF, check for a damaged ignition switch, an IGN RUN circuit short to power, a VPWR circuit short to power, etc. Refer to the appropriate service information article or SYSTEM WIRING DIAGRAMS
.
| SYSTEM/COMPONENT | REFERENCE ( PINPOINT TEST - GASOLINE MODELS unless noted) |
|---|---|
| Base engine 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). | REFER to ENGINE . |
| Verify the engine operates at normal temperature. | Visual. REFER to ENGINE COOLING or the Symptom Index, to diagnose any cooling system concerns that are present. |
| Fast idle concerns: (applications without electronic throttle control) KOEO, 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:
NOTE:
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. Also check for loose/worn throttle plates. If no concern is found, GO to PINPOINT TEST Z . |
| Applications without electronic throttle control: Intake Air System (air leaks) |
GO to PINPOINT TEST HU . |
| Additional Testing | GO to PINPOINT TEST Z . |