NO.7 SLOW RETURN TO IDLE [WITH WU-TWC]


7	SLOW RETURN TO IDLE
DESCRIPTION	The engine takes more time than normal to return to the 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 DLC-2. Retrieve any continuous memory, KOEO and KOER DTCs. (See KOEO/KOER SELF-TEST.) Are there DTCs displayed?	Yes	DTC is displayed: Go to the appropriate DTC test.
1		No	No DTC is displayed: Go to the next step.
2	Remove the thermostat and inspect the operation. Is the thermostat normal?	Yes	The ECT and thermostat are normal. Go to the next step.
2		No	Access the ECT PID on the WDS or equivalent. Inspect both the ECT PID and temperature gauge in the instrument cluster readings. • If the temperature gauge in the instrument cluster indicates a normal range but the ECT PID is not the same as the temperature gauge reading, inspect the ECT sensor. • If the temperature gauge in the instrument cluster indicates a cold range but the ECT PID is normal, inspect the temperature gauge and heat gauge unit.
3	Is the throttle body free of contaminations?	Yes	Inspect for air leakage from intake-air system components while racing the engine to a higher speed.
3	Is the throttle body free of contaminations?	No	Clean or replace the throttle body.
4	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.