Engine Controls - Basic Testing - 4.0L: Summary

If no faults were found while performing BASIC DIAGNOSTIC PROCEDURES, proceed to TESTS W/CODES - 4.0L article. If no trouble codes found in self-diagnostics, proceed to TESTS W/O CODES - 4.0L article for diagnosis by symptom (i.e., ROUGH IDLE, NO START, etc.) or intermittent diagnostic procedures.