Engine Controls - Self Diagnostics - 8.1L: Introduction

To properly diagnose and repair this vehicle, follow DIAGNOSTIC STARTING POINT - ENGINE CONTROLS  under SELF-DIAGNOSTIC SYSTEM. If no Diagnostic Trouble Codes (DTC) are present and a no-start condition exists, proceed to NO-START DIAGNOSIS in BASIC DIAGNOSTIC PROCEDURES - 8.1L AVALANCHE, SIERRA, SILVERADO, SUBURBAN & YUKON XL article. If no DTCs are present and a driveability condition exists, diagnosis by symptom (i.e., ROUGH IDLE, ENGINE STALLS, etc.). Proceed to SYMPTOMS in TROUBLE SHOOTING - NO CODES - 8.1L AVALANCHE, SIERRA, SILVERADO, SUBURBAN & YUKON XL article.