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.
Vehicles with an automatic transmission can tow in D (Drive) but M (Manual Mode) is recommended. Shift the transmission to a lower gear if the transmission shifts too often under heavy loads and/or hilly conditions.
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 .
See also:
How OnStar Service Works
: This blue button connects you
to a specially
trained OnStar advisor to verify your account information
and to answer questions.
: Push this red emergency button to
get priority help
fro ...
High-Beam On Light
This light comes on when the
high-beam headlamps are in use.
See Headlamp High/Low-Beam
Changer for more
information. ...
When to Inspect the Engine Air
Cleaner/Filter
Inspect the air cleaner/filter at the
scheduled maintenance intervals
and replace it at the first oil change
after each 80 000 km (50,000 mi)
interval. See Maintenance Schedule for more inform ...