See also:

Lamps
Properly working headlamps, taillamps, and brake lamps are important to see and be seen on the road. • Signs that the headlamps need attention include dimming, failure to light, cracking, or damage ...

Door Ajar Messages
DRIVER DOOR OPEN This message displays and a chime sounds if the driver door is not fully closed and the vehicle is shifted out of P (Park). Stop and turn off the vehicle, check the door for obstruct ...

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 ...