NO.9 FAST IDLE/RUNS ON [WITH WU-TWC]


id0103008015c5

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
• Steering angle sensor or related circuit malfunction

Diagnostic procedure

STEP

INSPECTION

RESULTS

ACTION

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

ECT PID is more than 112°C {234°F}:

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

ECT PID is less than 82°C {180°F}:

Go to the 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 test.
No

No DTC is displayed:

Go to the next step.
3
Connect the WDS or equivalent to the DLC-2.
Note
• With the ignition switch off, the SWA PID value is cleared to initial value (300 °). If the SWA PID does not move from 300 °, drive the vehicle above 20km/h {12 mph} to set the steering angle sensor to the straight ahead position.
Access the ACSW, A/CL V, CPP, CPP/PNP, SWA, TR and PSP PIDs.
Monitor each PID.
Are PIDs normal?
Yes
Go to the next step.
No

ACSW PID:

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

A/CL V PID:

Inspect the refrigerant pressure switch (middle pressure).

CPP PID:

Inspect the clutch pedal position switch (MTX).

CPP/PNP PID:

Inspect the neutral switch (MTX)

SWA PID:

Inspect the steering angle sensor

TR PID:

Inspect the TR switch (ATX).

PSP PID:

Inspect the PSP switch.
4
Is there air leakage felt or heard at the intake-air system components while racing the engine to a higher speed?
Yes
Repair or replace parts if necessary.
No
Verify the accelerator cable free play.
5
Verify the test results.
• If normal, return to the diagnostic index to service any additional symptoms.
• If the malfunction remains, inspect related Service information and perform repair or diagnosis.
- If the vehicle is repaired, the troubleshooting is completed.
- If the vehicle is not repaired or additional diagnostic information is not available, replace the PCM.