Engine Controls - Tests W/Codes - 1.8L: Summary
- If no DTCs are present, and driveability symptoms exist, proceed to ADJUSTMENTS - 1.8L article. If idle speed and IAC duty are within specifications, go to step 3). If idle speed is high and IAC duty is low, or idle speed is low and IAC duty is high, go to next step. If idle speed and IAC duty are high, or idle speed and IAC duty are low, replace PCM. Retest system.
- Adjust idle speed and IAC duty. If adjustments can be made with idle air adjusting screw, go to next step. If adjustments cannot be made with idle air adjusting screw, go to step 4).
- If idle speed remains within specification as headlights are turned on, check for an intermittent problem. See appropriate TESTS W/O CODES article for diagnosis by symptom (i.e., ROUGH IDLE, NO START, etc.).