See also:

Horn
Pressa on the steering wheel pad to sound the horn. ...

Radio Data System (RDS)
The Radio Data System (RDS) feature is available for use only on FM stations that broadcast RDS information. This system relies upon receiving specific information from these stations and only works w ...

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 ...