NO.7 SLOW RETURN TO IDLE [13B-MSP]

id0103f2801300

7

SLOW RETURN TO IDLE

DESCRIPTION

The engine takes more time than normal to return to idle speed.

POSSIBLE CAUSE

•  ECT sensor malfunction

•  The thermostat is stuck open.

•  Throttle body malfunction

•  Air leakage from intake-air system

•  Eccentric shaft bypass valve stuck open

7	SLOW RETURN TO IDLE
DESCRIPTION	The engine takes more time than normal to return to idle speed.
POSSIBLE CAUSE	• ECT sensor malfunction • The thermostat is stuck open. • Throttle body malfunction • Air leakage from intake-air system • Eccentric shaft bypass valve stuck open

Diagnostic procedure

STEP	INSPECTION	RESULTS	ACTION
1	Connect the M-MDS to the DLC-2. Turn the ignition switch to the ON position (Engine off). Retrieve any DTCs. Are there any DTCs displayed?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [13B-MSP].)
1		No	Go to the next step.
2	Remove the thermostat and inspect operation. (See THERMOSTAT REMOVAL/INSTALLATION [13B-MSP].) (See THERMOSTAT INSPECTION [13B-MSP].) Is the thermostat normal?	Yes	The ECT and the thermostat are normal. Go to the next step.
2		No	Access the ECT PID on the M-MDS. Inspect the readings on both ECT PID and the temperature gauge on the instrument cluster. If the temperature gauge on the instrument cluster indicates the normal range but the ECT PID is not the same as the temperature gauge reading, inspect the ECT sensor. (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION [13B-MSP].) If the temperature gauge on the instrument cluster indicates the cold range but the ECT PID is normal, inspect the temperature gauge and the sending unit. (See INSTRUMENT CLUSTER INSPECTION.)
3	Is the throttle body free of contamination?	Yes	Go to the next step.
3	Is the throttle body free of contamination?	No	Clean or replace the throttle body.
4	Inspect for air leakage from the intake-air system components while racing the engine to a higher speed. Is there air leakage from intake-air system?	Yes	Repair or replace the malfunctioning parts according to the inspection results.
4		No	Inspect the eccentric shaft bypass valve.
5	• Verify test results. ― If normal, return to the diagnostic index to service any additional symptoms. ― If the malfunction remains, inspect the related Service Bulletins and/or the On-line Repair Information and perform the repair or diagnosis.