See also:

Ignition Transmission Lock Check
While parked, and with the parking brake set, try to turn the ignition to LOCK/OFF in each shift lever position. The ignition should turn to LOCK/OFF only when the shift lever is in P (Park). ...

Competitive Driving Mode
To select this optional handling mode, press the TCS/StabiliTrak button quickly two times and STABILITRAK COMPETITIVE MODE displays in the Driver Information Center (DIC). While in the Sta ...

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 ...