NO.7 SLOW RETURN TO IDLE [LF]

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NO.7 SLOW RETURN TO IDLE [LF]

B3E010318881W09

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 | RESULTS | ACTION
--- | --- | --- | ---
1 | Connect the WDS or equivalent to the DLC-2. Retrieve any continuous memory, KOEO and KOER DTCs using WDS or equivalent. Are there DTCs displayed? | Yes | DTC is displayed: Go to the appropriate DTC inspection. (See DTC TABLE [LF].)
No | No DTC is displayed: Go to the next step.
2 | Remove thermostat and inspect operation. (See THERMOSTAT REMOVAL/INSTALLATION [LF].) (See THERMOSTAT INSPECTION [LF].) Is thermostat normal? | Yes | ECT sensor and thermostat are normal. Go to the next step.

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 throttle body free of contaminations? | Yes | Inspect for air leakage from the intake-air system components while racing 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.
(See ENGINE SYMPTOM TROUBLESHOOTING [LF].)
• If malfunction remains, inspect related Service information perform repair or diagnosis.

  - If vehicle repaired, troubleshooting completed.
  - If vehicle not repaired or additional diagnostic information not available, replace the PCM.
  (See PCM REMOVAL/INSTALLATION [LF].)