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NO.9 FAST IDLE/RUNS ON [L8, LF, L3]

id0103a1801500

9 | FAST IDLE/RUNS ON
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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 pedal position sensor misadjustment • Cruise control system operation improperly • Improper load signal input • Improper operation of electronic throttle control system

Diagnostic procedure

STEP | INSPECTION | RESULTS | ACTION
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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. Turn the ignition switch to the ON position (Engine off). Retrieve any DTCs. Are there any DTCs displayed? | Yes | DTC is displayed: Go to the appropriate DTC inspection. (See DTC TABLE [L8, LF, L3].)
No | No DTC is displayed: Go to the next step.
3 | Connect the WDS or equivalent to DLC-2 Access ACSW, COLP, CPP/PNP, TR and PSP PIDs. Monitor each PID. (See PCM INSPECTION [L8, LF, L3].) Are PIDs value okay? | Yes | Go to the next step.
No | ACSW PID is not specified: Inspect A/C switch, refrigerant pressure switch and fan switch. COLP PID is not specified: Inspect refrigerant pressure switch (middle pressure). CPP PID is not specified: Inspect clutch switch (MTX). CPP/PNP PID: Inspect neutral switch (MTX). TR PID: TR switch (ATX). PSP PID: Inspect P/S pressure switch.
4 | Is there air leakage felt or heard at intake-air system components while racing engine to higher speed? | Yes | Repair or replace parts if necessary.
No | Inspect the following: • Electronic throttle control system operation • Accelerator pedal position sensor
5 | • Verify test results. - If normal, return to diagnostic index to service any additional symptoms. (See ENGINE SYMPTOM TROUBLESHOOTING [L8, LF, L3].) - If malfunction remains, inspect related Service Information and perform repair or diagnosis. • If vehicle is repaired, troubleshooting completed. • If vehicle is not repaired or additional diagnostic information is not available, replace the PCM. (See PCM REMOVAL/INSTALLATION [L8, LF, L3].)