GM Service Manual Online
For 1990-2009 cars only

Begin the IP or DIC system diagnosis with Diagnostic System Check - Instrument Cluster , the HUD system diagnosis with Diagnostic System Check - Head Up Display , or the audible warning system diagnosis with Diagnostic System Check - Audible Warnings . 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.

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