OnStar Services

See also:

TPMS Malfunction Light and Message
The TPMS will not function properly if one or more of the TPMS sensors are missing or inoperable. When the system detects a malfunction, the low tire pressure warning light flashes for about one m ...

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 ...

When the Light Is On Steady
This indicates that one or more of the tires are significantly underinflated. A Driver Information Center (DIC) tire pressure message may also display. See Vehicle Messages on page 5‑42 for mor ...