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

1. Perform 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 modules can communicate via the serial data link.

2. Review the system operation in order to familiarize yourself with the system functions. Refer to Radio/Audio System Description and Operation.

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

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom: