System Diagnosis
- Determine type of audio complaint.
- Make sure that the customer does not have an aftermarket mobile electronic component, such as a cellular telephone, that has been removed before the vehicle was left for service. This is extremely important, because that component may be emitting the frequency(s) that is (are) causing the complaint.
- OnStar equipment directly affects the audio system. It is designed to use the vehicle speakers for incoming communications. The audio system, OnStar system, or both, may be contributing to the audio complaint. Refer to the information in this section, and the OnStar system in this service manual.
- Try to duplicate condition (listen to AM or FM, start vehicle, put in a good CD or cassette, test switches, etc.).