Vehicle and Power Issues
OnStar services require a vehicle electrical system, wireless service, and GPS satellite technologies to be available and operating for features to function properly. These systems may not operate if the battery is discharged or disconnected.
See also:
Horn
Pressa on the steering wheel pad
to sound the horn. ...
Rear Seats (All Split Bench and Hybrid Full Bench)
Folding Rear Seat
Either side of the rear seat can be folded for added cargo space.
Notice: Folding a rear seat with the safety belts still fastened may cause damage to the seat or the safety belts. ...
Customer Assistance for Text Telephone (TTY) Users (U.S. and Canada)
To assist customers who are deaf, hard of hearing, or speech impaired and who use Text Telephones (TTYs), GMC has TTY equipment available at its Customer Assistance Center. Any TTY user can communicat ...