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NO.9 FAST IDLE/RUNS ON

BHE010300103W11

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 (stuck open) • APP sensor malfunction • Cruise control system operation improperly • Improper load signal input • Improper operation of drive-by-wire control system

Diagnostic procedure

STEP | INSPECTION | RESULTS | ACTION
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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 higher than 112°C {234°F}: Go to the symptom troubleshooting "No.17 Cooling system concerns - Overheating". (See 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". (See NO.18 COOLING SYSTEM CONCERNS-RUNS COLD.)
2 | Connect the WDS or equivalent to the DLC-2. Retrieve any continuous memory DTCs for PCM, TCM, ABS HU/CU, DSC HU/CU and EPS CM. Are there any DTCs displayed? | Yes | DTC is displayed: Go to the applicable DTC inspection. (See DTC TABLE.)
No | No DTC is displayed: Go to the next step.
3 | Connect the WDS or equivalent to the DLC-2. Access ACSW, COLP, CPP (MT), CPP/PNP (MT) and TR (AT) PIDs. Monitor each PID. (See PCM INSPECTION.) Are the PIDs normal? | Yes | Go to the next step.
No | ACSW PID: Inspect the A/C switch, the refrigerant pressure switch and the fan switch. (See REFRIGERANT PRESSURE SWITCH INSPECTION.) (See CLIMATE CONTROL UNIT INSPECTION.) COLP PID: Inspect the refrigerant pressure switch (medium pressure). (See REFRIGERANT PRESSURE SWITCH INSPECTION.) CPP PID: Inspect the CPP switch (MT). (See CLUTCH PEDAL POSITION (CPP) SWITCH INSPECTION.) CPP/PNP PID: Inspect the neutral switch (MT). (See NEUTRAL SWITCH INSPECTION.) TR PID: Inspect the TR switch (AT) and the communication line (PCM-TCM). (See TRANSMISSION RANGE (TR) SWITCH INSPECTION.)
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 | Inspect the following: • Drive-by-wire control system operation (See Drive-by-wire Control System Inspection.) • APP sensor
5 | Verify test results. • If normal, return to the diagnostic index to service any additional symptoms. • If the malfunction remains, inspect the related Service Information and perform the repair or diagnosis.