NO.9 FAST IDLE/RUNS ON [YF (2.0L Zetec)]


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


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 between 82-112×C {180-234×F}?	Yes	Go to the next step.
1		No	ECT PID is higher than 112×C {234×F}: Go to symptom troubleshooting "No.17 Cooling system concerns - Overheating". (See NO.17 COOLING SYSTEM CONCERNS-OVERHEATING [YF (2.0L Zetec)].) ECT PID is less than 82×C {180×F}: Go to symptom troubleshooting "No.18 Cooling system concerns - Runs cold". (See NO.18 COOLING SYSTEM CONCERNS-RUNS COLD [YF (2.0L Zetec)].)
2	Connect the WDS or equivalent to the DLC-2. Retrieve any continuous memory DTCs. Are any DTCs displayed?	Yes	DTC is displayed: Go to the appropriate DTC inspection. (See DTC TABLE [YF (2.0L Zetec)].)
2		No	No DTC is displayed: Go to the next step.
3	Connect the WDS or equivalent to the DLC-2. Access following PIDs. • AC_REQ • CPP (MTX) • CPP/PNP (MTX) • TR (ATX) • PSP Monitor each PID. (See PCM INSPECTION [YF (2.0L Zetec)].) Are the PIDs normal?	Yes	Go to the next step.
3		No	AC_REQ PID: Inspect the A/C switch, refrigerant pressure switch and the fan switch. CPP PID: (MTX) Inspect the clutch pedal position switch. CPP/PNP PID: (MTX) Inspect the neutral switch. TR PID: (ATX) Inspect the TR switch. (SeeTRANSAXLE RANGE (TR) SWITCH INSPECTION [LA4AX-EL (CD4E)].) PSP PID: Inspect the PSP switch. (See POWER STEERING PRESSURE (PSP) SWITCH INSPECTION [YF (2.0L Zetec)].)
4	Is air leakage felt or heard at the intake-air system components while racing engine to higher speed?	Yes	Repair or replace if necessary.
4		No	Verify the accelerator cable free play.
5	Verify test results. • If normal, return to the diagnostic index to service any additional symptoms. (See ENGINE SYMPTOM TROUBLESHOOTING [YF (2.0L Zetec)].) • If any malfunction remains, inspect related service information and, repair or diagnosis accordingly. - If the vehicle is repaired, troubleshooting completed. - If the vehicle is not repaired or additional diagnostic information is not available, replace the PCM. (See PCM REMOVAL/INSTALLATION [YF (2.0L Zetec)].)