See also:

Dual Tone Multi-Frequency (DTMF) Tones
The in-vehicle Bluetooth system can send numbers during a call. This is used when calling a menu-driven phone system. For Radio with CD: 1. Turn or press the TUNE/MENU knob and select Enter Number ...

Your Responsibility
Increase the volume of the radio if the OnStar Advisor cannot be heard. If the light next to the OnStar buttons is red, the system may not be functioning properly. Push and request a vehicle diagnos ...

Additives
To provide cleaner air, all gasolines in the United States are now required to contain additives that help prevent engine and fuel system deposits from forming, allowing the emission control sys ...