See also:

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 v ...

Transmission Messages
SERVICE 4 WHEEL DRIVE If the vehicle has four-wheel drive, this message may display if a problem occurs with the four-wheel-drive system. If this message appears, stop as soon as possible and turn of ...

Headlamp Aiming
Headlamp aim has been preset and should need no further adjustment. If the vehicle is damaged in a crash, the headlamp aim may be affected. If adjustment to the headlamps is necessary, see your deal ...