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 ...

Transferring Service
Push to request account transfer eligibility information. The Advisor can assist in canceling or removing account information. If OnStar receives information that vehicle ownership has changed, ...

Engine Cooling System Messages
ENGINE HOT A/C (Air Conditioning) OFF This message displays when the engine coolant becomes hotter than the normal operating temperature. See Engine Coolant Temperature Gauge on page 5‑14. To ...