See also:

Compass Calibration
The compass can be manually calibrated. Only calibrate the compass in a magnetically clean and safe location, such as an open parking lot, where driving the vehicle in circles is not a dange ...

CALIBRATING DRIVE IN CIRCLES
This message displays when calibrating the compass. Drive the vehicle in circles at less than 8 km/h (5 mph) to complete the calibration. See Compass for more information. ...

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 ...