After Warming Up, Idle Speed Is Below Specification Without Load (MIL Works OK, No DTCs Set)

After warming up, idle speed is below specification without load (MIL works OK, no DTCs set)

Diagnostic Procedure:

1. Troubleshoot the alternator FR signal circuit. Alternator FR Signal Circuit Troubleshooting

2. Do the carbon accumulation check. Testing and Inspection

Also check for:

- Incorrect valve timing or clearance adjustment