OnStar Services

See also:

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 ...

New Vehicle Break-In
Notice: The vehicle does not need an elaborate break-in. But it will perform better in the long run if you follow these guidelines: • If you have all-wheel drive, keep your speed at 88 km/h (55 mp ...

The Inside
Here's where GM has really outdone itself in its new SUVs. Like the Tahoe, the Yukon shows off one of the best interiors GM has ever mustered in a mass-marketed vehicle. All the buttons are of abo ...