Section 420 (Engine Control System Self-Diagnostics - 3.8L): Introduction
WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2003 Pontiac Grand Prix, 2003 Pontiac Bonneville, 2003 Chevrolet Monte Carlo, 2003 Chevrolet Impala, and 2003 Buick Regal. However, it is still accessible from the selected car via links, so may be relevant.
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 appropriate NO-START DIAGNOSIS in BASIC DIAGNOSTIC PROCEDURES - 3.8L BONNEVILLE, GRAND PRIX, IMPALA, LE SABRE, MONTE CARLO, PARK AVENUE & REGAL article. If no DTCs are present and a driveability condition exists, diagnose by symptom, see SYMPTOMS in TROUBLE SHOOTING - NO CODES - 3.8L BONNEVILLE, GRAND PRIX, IMPALA, LESABRE, MONTE CARLO, PARK AVENUE & REGAL article.