Begin the system diagnosis with Powertrain On Board Diagnostic (OBD) System Check . The Powertrain On Board Diagnostic (OBD) System Check 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 diagnostic trouble codes (DTCs) and their status |
The use of the Powertrain On Board System Check (OBD) System Check will identify the correct procedure for diagnosing the system and where the procedure is located.