GM Service Manual Online
For 1990-2009 cars only

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

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

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