Engine Controls - Basic Testing - 4-CYL: Summary

If no faults were found while performing BASIC DIAGNOSTIC PROCEDURES, proceed to TESTS W/CODES - 4-CYL article in the ENGINE PERFORMANCE section. If no hard diagnostic trouble codes are found in self-diagnostics, see TESTS W/O CODES article for diagnosis by symptom (i.e., ROUGH IDLE, NO START, etc.) or intermittent diagnostic procedures.