For 1990-2009 cars only
Begin the 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 Diagnostic System Check - Vehicle , in order to identify the correct procedure for diagnosing the system and where the procedure is located.
The Diagnostic 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. |
