For 1990-2009 cars

Important:

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 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.

### Visual/Physical Inspection

• | Inspect for aftermarket devices which may affect the operation of the Radio/Audio System. Refer to Checking Aftermarket Accessories.

• | 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.

### Symptom List

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

• | Radio Poor Reception

• | Digital Radio Poor or No Reception

• | Radio Displays LOC, LOCKED, or CODE

• | iPod Audio Distorted or Inoperative - One or More Speakers

• | Radio Does Not Interface with iPod

• | Speakers Inoperative - One or More