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:
Maintenance When Trailer Towing
The vehicle needs service more often when pulling a trailer.
See Maintenance Schedule on page 11‑3. Things that are especially important in trailer operation are automatic transmission fluid, e ...
Replacing Brake System Parts
The braking system on a vehicle is complex. Its many parts have to be of top
quality and work well together if the vehicle is to have really good braking. The
vehicle was designed and tested with ...
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 vehic ...





