NO.7 SLOW RETURN TO IDLE [AJ] (VIN: JMZ LW19J7*# 300001-, JM0 LW10J300 300001-301405, JM6 LW10J300 300001-, JM8 LW28J**# 300001-301513)


BME010300103212

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

Diagnostic procedure

STEP

INSPECTION

ACTION

1
• Connect the WDS or equivalent to the DLC-2.
• Turn the ignition switch to the ON position (Engine off).
• Retrieve any DTCs.
• Is "PASSED" displayed?
Yes
No DTC is displayed:
• Go to the next step.
No
DTC is displayed:
• Go to the applicable DTC inspection.
2
• Remove the thermostat and inspect the operation.
• Is the thermostat normal?
Yes
The ECT and the thermostat are normal.
Go to the next step.
No
Access ECT PID.
Inspect for both ECT PID and the temperature gauge on the instrument cluster readings.
• If the temperature gauge on the instrument cluster indicates normal range but ECT PID is not the same as the temperature gauge reading, inspect the ECT sensor.
• If the temperature gauge on the instrument cluster indicates cold range but 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 the intake-air system components while racing the engine to higher speed.
No
Clean or replace the throttle body.
4
• Verify test results.
- If normal, return to diagnostic index to service any additional symptoms.
- If malfunction remains, inspect related Service Information and perform repair or diagnosis.
• If vehicle is repaired, troubleshooting completed.
• If vehicle is not repaired or additional diagnostic information is not available, replace or reprogram the PCM.