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:
Automatic Headlamp System
When it is dark enough outside, the headlamps come on automatically.
Do not cover the light sensor on top of the instrument panel or the headlamps
will come on when they are not needed.
The syst ...
Security Light
The immobilizer light should come on briefly as the engine is started. If it
does not come on, have the vehicle serviced by your dealer. If the system is working
normally, the indicator light tu ...
Cellular and GPS Antennas
Avoid placing items over or near the antenna to prevent blocking cellular and GPS signal reception. Cellular reception is required for OnStar to send remote signals to the vehicle. ...





