GM Service Manual Online
For 1990-2009 cars only

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

    â€¢ The identification of the control module or modules which command the system.
    â€¢ The ability of the control module or modules to communicate through the serial data circuit.
    â€¢ The identification of any stored diagnostic trouble codes (DTCs) and the status of the codes.

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