See also:

Four-Wheel Drive
If the vehicle has Four-Wheel Drive, you can send the engine's driving power to all four wheels for extra traction. ...

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 ...

Tire Messages
SERVICE TIRE MONITOR SYSTEM If the vehicle has the Tire Pressure Monitor System (TPMS), this message displays if a part on the system is not working properly. The tire pressure light also flashes and ...