Engine Performance: System: Self-Diagnostics: Introduction

NOTE: The Electronic Control Module (ECM) may also be referred to as the Powertrain Control Module (PCM).

To properly diagnose and repair this vehicle, follow TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM. If component testing procedure is not covered in DTC Self-Diagnostics article, for component testing, see SYSTEM & COMPONENT TESTING article. If no Diagnostic Trouble Codes (DTC) are present and a no-start condition exists, proceed to BASIC DIAGNOSTIC PROCEDURES article. If no DTCs are present and a driveability condition exists, proceed to TROUBLE SHOOTING - NO CODES article for diagnosis by symptom (i.e., ROUGH IDLE, ENGINE STALLS, etc.).