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 boils 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 could 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.
See also:
Diagnostics
OnStar Vehicle Diagnostics will perform a vehicle check every month. It will
check the engine, transmission, antilock brakes, and major vehicle systems. It also
checks the tire pressures, if the v ...
Driver Information Center (DIC)
The Driver Information Center (DIC)
provides status of many vehicle
systems. The DIC displays warning/
status messages. The DIC display
is at the bottom of the instrument
panel cluster. The ...
Navigation System
If the vehicle has a navigation
system, use of the system may
result in the storage of destinations,
addresses, telephone numbers, and
other trip information. Refer to the
navigation manual ...






