NO.9 FAST IDLE/RUNS ON [L3]


BME010300103247

9

FAST IDLE/RUNS ON

DESCRIPTION

• Engine speed continues at fast idle after warm up.
• Engine runs after ignition switch is turned off.

POSSIBLE CAUSE

• ECT sensor malfunction
• Air leakage from intake-air system
• Throttle body malfunction
• Accelerator cable free play misadjustment
• Cruise control cable misadjustment
• Improper load signal input

Diagnostic procedure

STEP

INSPECTION

RESULTS

ACTION

1
Connect the WDS or equivalent to the DLC-2.
Access ECT PID.
Start and warm up the engine to normal operating temperature.
Is ECT PID reading between 82-112°C {180-234°F}?
Yes
Go to the next step.
No

ECT PID is higher than 112°C {234°F}:

Go to symptom troubleshooting "No.17 Cooling system concerns - Overheating".

ECT PID is less than 82°C {180°F}:

Go to symptom troubleshooting "No.18 Cooling system concerns - Runs cold".
2
Connect the WDS or equivalent to the DLC-2.
Retrieve any continuous memory DTCs.
Are there any DTCs displayed?
Yes

DTC is displayed:

Go to the applicable DTC inspection.
No

No DTC is displayed:

Go to the next step.
3
Connect the WDS or equivalent to the DLC-2.
Access AC_REQ, COLP, CPP, CPP/PNP and PSP PIDs.
Monitor each PID.
Are PIDs normal?
Yes
Go to the next step.
No
AC_REQ PID: Inspect the A/C switch, the refrigerant pressure switch and the fan switch.
COLP PID: Inspect the refrigerant pressure switch (middle pressure).
CPP PID: Inspect the clutch pedal position switch.
CPP/PNP PID: Inspect the neutral switch.
PSP PID: Inspect the P/S pressure switch.
4
Is there air leakage felt or heard at the intake-air system components while racing the engine to higher speed?
Yes
Repair or replace the parts if necessary.
No
Verify the accelerator cable free play.
5
Verify test results.
• If normal, return to diagnostic index to service any additional symptoms.
• If malfunction remains, replace PCM.