IDLE SPEED FLUCTUATES (MIL works OK, no DTCs set)

Diagnostic procedure

1. Do the PCM Idle Learn procedure.
2. Check the Idle Speed .
3. Do the Carbon Accumulation Check .
4. Troubleshoot the A/C signal circuit - Refer to:
A/C Signal Circuit Troubleshooting, or

A/C Signal Circuit Troubleshooting (9-Speed A/T) (2019 2020 2021) .
5. Check the A/C refrigerant amount - Go to: A/C Refrigerant Recovery/Evacuation/Charging (1234yf)
NOTE: Turning the A/C to ON under the conditions that the A/C refrigerant amount is out of specification (excessive or too little) may cause the idle speed fluctuation.

Also check for