Driving on Grades

Reduce speed and shift to a lower gear before starting down a long or steep downgrade. If the transmission is not shifted down, the brakes might have to be used so much that they would get hot and no longer work well.

The vehicle can tow in D (Drive). Use a lower gear if the transmission shifts too often.

When towing at high altitude on steep uphill grades, engine coolant will boil at a lower temperature than at normal altitudes. If the engine is turned off immediately after towing at high altitude on steep uphill grades, the vehicle may show signs similar to engine overheating. To avoid this, let the engine run while parked, preferably on level ground, with the transmission in P (Park) for a few minutes before turning the engine off. If the overheat warning comes on, see Engine Overheating on page 10‑20.

    See also:

    Roadside Assistance Program
    U.S.: 1-888-881-3302 TTY Users (U.S.): 1-888-889-2438 Canada: 1-800-268-6800 Mexico: 01-800-466-0801 As the owner of a new GMC, you are automatically enrolled in the Roadside Assistance program. ...

    Manual Operation of Power Liftgate
    To change the liftgate to manual operation, turn the mode switch to the OFF position. With the power liftgate disabled and all of the doors unlocked, the liftgate can be manually opened and closed. ...

    Symbols
    The navigation system may have a feature that lets the driver view symbols on the navigation screen while using the rear vision camera. The Ultrasonic Rear Park Assist (URPA) system must not be disab ...