For 1990-2009 cars

Important:

1. Perform the OnStar System Check before using the symptom tables in order to verify that all of the following 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. Refer to OnStar Operation

### Visual/Physical Inspection

• | Inspect for aftermarket devices which could affect the operation of the power windows, power door locks, or power mirrors. Refer to Checking Aftermarket Accessories in Wiring Systems.

• | Inspect the easily accessible or visible system components for obvious damage or conditions which could 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 in Wiring Systems.

### Symptom List

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

• | No (or Noisy) OnStar Audio

• | OnStar One or More Buttons Inoperative

• | OnStar Call Center Lock/Unlock Commands Inoperative

• | OnStar Call Center Exterior Lamp Command Inoperative

• | OnStar Call Center Horn Command Inoperative

• | OnStar Call Center Unable to Locate Vehicle

• | OnStar Operator Unable to Hear Caller

• | OnStar Will Not Power Up

• | Unable to Contact OnStar Call Center

• | OnStar Call Center Unable to Configure OnStar (R) System

• | OnStar Button LED Inoperative