July 1: So it begins. Don't worry, this is not in the correct legal jurisdiction!

Engine Controls - Tests W/Codes - 7.4L: Summary

If no hard fault codes are present, driveability symptoms exist or intermittent DTC(s) exist, proceed to TESTS W/O CODES - 7.4L article for diagnosis by symptom (i.e., ROUGH IDLE, NO START, etc.) or intermittent diagnostic procedures.