Section 405 (Engine Controls - Self Diagnostics - 6.6L): Summary
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.
If no Diagnostic Trouble Codes (DTCs) 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.). See SYMPTOMS in TROUBLE SHOOTING - NO CODES - 6.6L SIERRA & SILVERADO - DIESEL article.