Automatic Headlamp System
When it is dark enough outside, the headlamps come on automatically.

Do not cover the light sensor on top of the instrument panel or the headlamps will come on when they are not needed.
The system may also turn on the headlamps when driving through a parking garage or tunnel.
See also:
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 ...
Underbody Maintenance
Use plain water to flush dirt and debris from the vehicle's underbody. Your dealer
or an underbody car washing system can do this. If not removed, rust and corrosion
can develop. ...
XM Messages
XL (Explicit Language Channels): These channels, or any others, can be blocked
by request, by calling 1-800-929-2100 in the U.S. and 1-877-438-9677 in Canada.
XM Updating: The encryption code in th ...





