Fast Idle
FAST IDLE DESCRIPTION
| PINPOINT TEST 5 |
FAST IDLE |
| DESCRIPTION |
- Engine speed continues at fast idle after engine warm-up
|
FAST IDLE - PINPOINT TEST REFERENCE
| PINPOINT TEST 5 |
FAST IDLE |
| 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 0.35 volt (112°C/232°F) and 0.75 volt (82°C/180°F).
- Does engine appear to be either overheating or not reaching normal operating temperature?
|
Yes |
See
SYMPTOM TROUBLESHOOTING CHART - ENGINE COOLING
. |
| No |
Go to next step. |
| 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 exhaust gas recirculation (EGR) valve or idle air control (IAC) valve
- Are all checks OK?
|
Yes |
Go to next step. |
| 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 (DTC) INDEX - POWERTRAIN CONTROL MODULE (PCM)
. |
| No |
Go to next step. |
| 4 |
CHECK FOR BASE ENGINE AIR LEAKS
- Check for base engine air leaks (such as intake manifold gasket air leaks). See
ENGINE COMPONENT TEST
. See vacuum test.
- Is a fault indicated?
|
Yes |
Service as required. |
| No |
Verify test results. If OK, See
SYMPTOM TROUBLESHOOTING CHART- ENGINE DRIVEABILITY
to service any additional symptoms. |