Engine Control System Self Diagnostics: Introduction

NOTE: Before performing testing procedures, check for any related Technical Service Bulletins (TSBs).

To properly diagnosis and repair this vehicle, follow TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM. If no diagnostic trouble codes (DTC) are present and a no start condition exists, proceed to BASIC DIAGNOSTIC PROCEDURES - 4-CYL 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.).