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

Diagnostic procedure

• Do the PCM idle learn procedure .
• Check the idle speed .
• Check the fuel pressure .
• Do the carbon accumulation check .
• Troubleshoot the A/C signal circuit .
• Check the A/C refrigerant amount .

  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

• Incorrect valve adjustment
• Intake air leaks