For 1990-2009 cars only
Begin the system diagnosis with Diagnostic System Check - Retained Accessory Power . The Diagnostic System Check will provide the following information:
| • | The identification of the control module that commands the system. |
| • | The ability of the control module 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.
