See also:

TTY Users
OnStar has the ability to communicate to the deaf, hard–of–hearing, or speech–impaired customers while in the vehicle. The available dealer–installed TTY system can provide in-vehicle acces ...

Transferring a Call
Audio can be transferred between the in-vehicle Bluetooth system and the cell phone. The cell phone must be paired and connected with the Bluetooth system before a call can be transferred. ...

Audio System
When using the in-vehicle Bluetooth system, sound comes through the vehicle's front audio system speakers and over-rides the audio system. Use the audio system volume knob, during a call, to ...