Engine Controls - Self-Diagnostics: Introduction

If no faults were found while performing preliminary inspection, proceed with ENTERING SELF-DIAGNOSTICS. If no fault codes or only pass codes are present, proceed to TROUBLE SHOOTING - NO CODES (ENGINE 112) article for diagnosis by symptom (i.e., ROUGH IDLE, NO START, etc.).

NOTE: All voltage tests should be performed with a Digital Volt-Ohmmeter (DVOM) with a minimum 10-megohm input impedance, unless specifically stated different in testing procedures.