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 get hot and no longer work well.
Vehicles can tow in D (Drive). Shift the transmission to a lower gear if the transmission shifts too often under heavy loads and/or hilly conditions.
The Tow/Haul Mode may be used if the transmission shifts too often.
See Tow/Haul Mode on page 9‑42.
When towing at high altitude on steep uphill grades, consider the following: 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 automatic transmission in P (Park) for a few minutes before turning the engine off. If the overheat warning comes on, see Engine Overheating on page 10‑23.
See also:
Engine Overheating
If the vehicle has the Duramax® Diesel engine, see the Duramax Diesel Supplement for more information.
The vehicle has several indicators to warn of engine overheating.
There is a coolant temperatu ...
Listing All Paired and Connected Phones
The system can list all cell phones paired to it. If a paired cell phone is also connected to the vehicle, the system responds with “is connected” after that phone name.
1. Press and hold for tw ...
Exiting the Feature Settings Menu
The feature settings menu will be exited when any of the following occurs:
• The vehicle is shifted out of P (Park).
• The vehicle is no longer in ON/RUN.
• The trip/fuel or vehicle informati ...





