See also:

Lamp Messages
TURN SIGNAL ON This message displays and a chime sounds if a turn signal is left on for 1.2 km (0.75 mile). Move the turn signal/multifunction lever to the off position. ...

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 ...

Flash-to-Pass
This feature lets you use the high-beam headlamps to signal a driver in front of you that you want to pass. It works even if the headlamps are in the automatic position. To use it, pull the turn sign ...