Self-Diagnostic System: 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.

NOTE: Always clear DTCs once repairs are complete. See CLEARING DIAGNOSTIC TROUBLE CODES . Road test vehicle and retrieve DTCs to determine if complaint or DTC is repaired.

If no hard DTCs are present, and driveability symptoms or intermittent DTCs exist, attempt diagnosis by symptom, or by testing individual components related to system fault. See TROUBLE SHOOTING . If no problem is found, verify proper electronic control system circuit operation.