Warranty
OnStar equipment may be warranted as part of the new-vehicle limited warranty. The manufacturer of the vehicle furnishes detailed warranty information.
See also:
Horn
Press on the steering wheel pad to sound the horn. ...
Recommended Fuel
Use regular unleaded gasoline with a posted octane rating of 87 or higher. If the octane rating is less than 87, an audible knocking noise, commonly referred to as spark knock, might be heard when dri ...
Customer Assistance Offices (U.S. and Canada)
GMC encourages customers to call the toll-free number for assistance.
However, if a customer wishes to write or e-mail GMC, the letter should be addressed to:
United States
GMC Customer Assistance ...