Idle Speed Fluctuates (MIL Works OK, No DTCs Set)

Idle speed fluctuates (MIL works OK, no DTCs set)

Diagnostic Procedure:

1. Do the ECM idle learn procedure. ECM Idle Learn Procedure

2. Check the idle speed. Testing and Inspection

3. Do the carbon accumulation check. Testing and Inspection

4. Troubleshoot the A/C signal circuit. A/C Signal Circuit Troubleshooting

Also check for:

- Incorrect valve timing or clearance adjustment