NO.7 SLOW RETURN TO IDLE [YF (2.0L Zetec)]


7	SLOW RETURN TO IDLE
DESCRIPTION	Engine takes more time than normal to return to idle speed.
POSSIBLE CAUSE	• ECT sensor malfunction • Thermostat is stuck open. • Throttle body malfunction • Air leakage from intake-air system


STEP	INSPECTION	RESULTS	ACTION
1	Connect the WDS or equivalent to the DLC-2. Retrieve any continuous memory, KOEO and KOER DTCs using the WDS or equivalent. Are any DTCs displayed?	Yes	DTC is displayed: Go to the appropriate DTC inspection. (See DTC TABLE [YF (2.0L Zetec)].)
1		No	No DTC is displayed: Go to the next step.
2	Remove thermostat and inspect operation. (See THERMOSTAT INSPECTION [YF (2.0L Zetec), AJ (3.0L Duratec)].) Is the thermostat normal?	Yes	ECT sensor and thermostat are normal. Go to the next step.
2		No	Access ECT PID on the WDS or equivalent. Inspect for both ECT PID and temperature gauge on instrument cluster readings. • If temperature gauge on instrument cluster indicates normal range but ECT PID is not same as temperature gauge reading, inspect ECT sensor. • If temperature gauge on instrument cluster indicates cold range but ECT PID is normal, inspect temperature gauge and heat gauge unit.
3	Is the throttle body free of contamination?	Yes	Inspect for air leakage from the intake-air system components while racing engine to a higher speed.
3	Is the throttle body free of contamination?	No	Clean or replace the throttle body.
4	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)].)