For 1990-2009 cars only
Always begin the diagnosis by reviewing the system Description and Operation. Reviewing the Description and Operation will help you determine the correct symptom diagnostic procedure when a malfunction exists. Reviewing the Description and Operation will also help you determine if the condition described by the customer is normal operation.
Begin diagnosis with the Diagnostic System Check - Vehicle in Vehicle DTC Information. 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 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.
