GM Service Manual Online
For 1990-2009 cars only

Vehicles Equipped With Content Theft Deterrent (UA6)

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

    • The identification of the control modules which command the system.
    • 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.

Vehicles Not Equipped With Content Theft Deterrent (UA6)

Begin the system diagnosis by reviewing the system Description and Operation. Reviewing the Description and Operation information will help you determine the correct symptom diagnostic procedure when a malfunction exists. Reviewing the Description and Operation information will also help you determine if the condition described by the customer is normal operation. Refer to Symptoms - Horns in order to identify the correct procedure for diagnosing the system and where the procedure is located.