Diagnostic Starting Point
WARNING: This page does not describe the selected car, but rather 12 other vehicles, including the 2003 GMC Yukon XL, 2003 GMC Yukon, 2003 GMC Sierra, 2003 GMC Cab & Chassis Sierra, and 2003 Chevrolet Tahoe. However, it is still accessible from the selected car via links, so may be relevant.
Begin the system diagnosis with the ENGINE ELECTRICAL DIAGNOSTIC SYSTEM CHECK . The Diagnostic System Check will provide the following information:
- The identification of the control module(s) which command the system.
- The ability of the control module(s) to communicate through the serial data circuit.
- The identification of any stored diagnostic trouble codes (DTCs) and their status.