See also:

Turn Signal Indicator
The vehicle may also have a turn signal indicator on the mirror. An arrow on the mirror flashes in the direction of the turn or lane change. ...

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 ...

Antilock Brake System (ABS) Warning Light
The ABS warning light comes on briefly when the ignition key is turned to ON/RUN. This is normal. If the light does not come on then, have it fixed so it will be ready to warn you if there is a pro ...