See also:

SERVICE BRAKE ASSIST
This message may be displayed when there is a problem with the brake boost assist system. When this message is displayed, the brake boost assist motor might be heard operating and you might ...

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 c ...

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 acce ...