Section 231 (Engine Controls - Trouble Shooting - No Codes - 6.6L): Introduction

WARNING: This page is about a different car, the 2003 GMC Sierra, 2003 GMC Cab & Chassis Sierra, 2003 Chevrolet Silverado, and 2003 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Unless indicated otherwise, Sierra and Silverado includes Cab & Chassis Sierra and Cab & Chassis Silverado.

Before diagnosing symptoms or intermittent faults, follow proper workflow. See DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - 6.6L SIERRA & SILVERADO - DIESEL article. If no Diagnostic Trouble Codes (DTC) are present and a no-start condition exists, proceed to NO-START DIAGNOSIS in BASIC DIAGNOSTIC PROCEDURES - 6.6L SIERRA & SILVERADO - DIESEL article. If no DTCs are present and a driveability condition exists, diagnosis by symptom (i.e., ROUGH IDLE, ENGINE STALLS, etc.).

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 soft (intermittent) trouble code was present but no problem was found during self-diagnostic testing.

NOTE: For specific testing procedures, see SYSTEM & COMPONENT TESTING - 6.6L SIERRA & SILVERADO - DIESEL article. For specifications, see ON-VEHICLE ADJUSTMENT - TRUCKS - EXCEPT TRACKER or SERVICE & ADJUSTMENT SPECIFICATIONS - 6.6L SIERRA & SILVERADO - DIESEL article.