See also:

Parade Dimming
This feature automatically prohibits the dimming of the instrument panel displays in daylight while the headlamps are on so that the displays are still able to be seen. ...

Fast Idle System
If the vehicle has this feature it is available only with cruise control. The manual fast idle switch is operated using the cruise control buttons located on the left hand side of the steering wheel. ...

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 access to all of ...