GM Service Manual Online
For 1990-2009 cars only

Performing Diagnostic System Check

To enter the Diagnostic System Check, perform the following procedure:

  1. Turn the ignition to ACC, with the engine OFF.
  2. Turn the radio ON and insert the map disc.
  3. Press and hold the "TA" button on the navigation radio while turning the exterior lights ON and OFF 3 times.
  4. The System Check is performed and the check result is displayed.

Important: The following information lists the results of the System Check and the appropriate action for that result.

    • The System Check Mode results in an "OK" output. Refer to Symptoms - Navigation Systems .
    • The System Check Mode results in a "Check" output. Highlight and select the "Check" result. The Unit Check Mode Screen will appear and the DTC codes will be displayed. Refer to Diagnostic Trouble Code (DTC) List .

Clearing DTC Codes From Memory

After a repair select "Code CLR" and hold for 3 seconds to delete DTC codes from diagnosis memory. The Diagnostic System Check may then be performed by selecting "Recheck".

Exiting the Diagnostic System Check

To exit the Diagnostic System Check turn the ignition to OFF.