Engine Controls - Tests W/Codes - Introduction: Introduction

NOTE: Engine Control Module (ECM) is used on vehicles equipped with a manual transmission. Powertrain Control Module (PCM) is used on vehicles equipped with an automatic transmission. ECM will be referred to as PCM.

If no faults were found while performing BASIC DIAGNOSTIC PROCEDURES, proceed with self-diagnostics. If no Diagnostic Trouble Codes (DTCs) or only pass codes exist after entering self-diagnostics, proceed to TESTS W/O CODES article for diagnosis by symptom (i.e., ROUGH IDLE, NO START, etc.).