Engine Controls - Trouble Shooting - No Codes - Except Coupe: Introduction

Before diagnosing symptoms or intermittent faults, follow proper workflow. See DIAGNOSTIC PROCEDURE under SELF-DIAGNOSTIC SYSTEM in appropriate SELF-DIAGNOSTICS article. If no Diagnostic Trouble Codes (DTC) are present and a no-start condition exists, proceed to appropriate BASIC DIAGNOSTIC PROCEDURES article. If no DTCs are present and a driveability condition exists, diagnose by symptom (i.e., ROUGH IDLE, ENGINE STALLS, etc.).

Symptom checks direct technician to malfunctioning component(s) for further diagnosis. A symptom should lead to a specific component, system test or an adjustment.

Use intermittent test procedures to locate driveability problems that do not occur when the vehicle is being tested. These test procedures should also be used if a DTC code is present, but no problem is found during self-diagnostic testing.

NOTE: For specific testing procedures, see appropriate SYSTEM & COMPONENT TESTING article. For specifications, see appropriate ON-VEHICLE ADJUSTMENTS or appropriate SERVICE & ADJUSTMENT SPECIFICATIONS article.