For 1990-2009 cars

Important: The following steps must be completed before using the symptom tables.

1. Perform the Diagnostic System Check - Vehicle before using the Symptom Tables in order to verify that all of the following conditions are true:

• | There are no DTCs set.

• | The control module(s) can communicate via the serial data link.

2. Review the system operation in order to familiarize yourself with the system functions.

### Visual/Physical Inspection

• | Inspect for aftermarket devices which may affect the operation of the Radio/Audio System.

• | Inspect for easily accessible or visible system components for obvious damage or conditions which may cause the symptom.

### Intermittent

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections .