NO.9 FAST IDLE/RUNS ON [LF, L3]


id0103b2801500

9

FAST IDLE/RUNS ON

DESCRIPTION

• The engine speed continues at fast idle after warm-up.
• The engine runs after the ignition switch is turned off.

POSSIBLE CAUSE

• ECT sensor malfunction
• Air leakage from intake-air system
• Throttle body malfunction
• Accelerator cable free play 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 engine to normal operating temperature.
Is ECT PID 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 appropriate 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, CPP (MTX), CPP/PNP (MTX), TR (ATX) and PSP PIDs.
Monitor each PID.
Are PIDs normal?
Yes
Go to the next step.
No

AC_REQ PID:

Inspect the A/C switch, refrigerant pressure switch and the fan switch.

CPP PID:

Inspect the clutch pedal position switch.

CPP/PNP PID:

Inspect neutral switch.

TR PID:

Inspect the TR switch.

PSP PID:

Inspect PSP switch.
4
Is there air leakage felt or heard at the intake-air system components while racing engine to higher speed?
Yes
Repair or replace part 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, inspect related Service information perform repair or diagnosis.
- If vehicle repaired, troubleshooting completed.
- If vehicle not repaired or additional diagnostic information not available, replace the PCM.
(See PCM REMOVAL/INSTALLATION [LF, L3].)