Engine Controls - Tests W/Codes - 1.8L: Introduction: Notes

Most engine control problems result from mechanical failures, poor electrical connections, or damaged vacuum hoses. Before condemning the computer system, perform basic diagnostic procedures in BASIC TESTING - 1.8L article. Failure to do so may result in lost diagnostic time.

If no faults were found while performing basic diagnostic procedures, proceed with self-diagnostics. If no Diagnostic Trouble Codes (DTCs) are present, and driveability problems exist, proceed to TESTS W/O CODES article for diagnosis by symptom (i.e., ROUGH IDLE, NO START, etc.). If only intermittent DTCs are present, also see TESTS W/O CODES article.