See also:

Shifting In or Out of Four-Wheel Drive Low
Notice: Shifting the transfer case into Four-Wheel-Drive Low while moving at speeds faster than 5 km/h (3 mph) may cause premature wear to the transfer case, and may cause the gears to grind. To avoid ...

Antilock Brake System (ABS) Warning Light
For vehicles with the Antilock Brake System (ABS), this light comes on briefly when the engine is started. If it does not, have the vehicle serviced by your dealer. If the system is working normall ...

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 ...