Diagnostic Starting Point - Doors for Cadillac CTS 2005

Begin the system diagnosis with the Diagnostic System Check - Vehicle in Vehicle DTC Information. The Diagnostic System Check - Vehicle will provide the following information:

•	The identification of the control modules which command the system

•	The ability of the control modules to communicate through the serial data circuit

•	The identification of any stored diagnostic trouble codes (DTCs) and their status

The use of the Diagnostic System Check - Vehicle will identify the correct procedure for diagnosing the system and where the procedure is located.