GM Service Manual Online
For 1990-2009 cars only

Diagnostic Starting Point - Engine Controls Petrol

Begin the system diagnosis with Diagnostic System Check - Vehicle. 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 DTCs and the codes status.

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