Engine Controls Self-Diagnostics - 5.7L - Bi-Fuel: Introduction

This article should be used in conjunction with the SELF-DIAGNOSTICS - 5.0L & 5.7L CHEVY EXPRESS & SAVANA article. This article covers only the Alterative Fuels Engine Control Module (AF ECM) self-diagnostics. To properly diagnose and repair this vehicle, follow DIAGNOSTIC PROCEDURE  under SELF-DIAGNOSTIC SYSTEM. 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, proceed to appropriate TROUBLE SHOOTING - NO CODES article for diagnosis by symptom (i.e., ROUGH IDLE, ENGINE STALLS, etc.).