OnStar Vehicle Diagnostics can perform a vehicle check every month. It will check
the engine, transmission, antilock brakes, and other major vehicle systems. It also
checks the tire pressures, if the vehicle is equipped with the Tire Pressure Monitoring
System. If an On-Demand Diagnostics check is needed, press
, and an Advisor can run a check.
Connections
OnStar Additional InformationTire Pressure Light
For vehicles with the Tire Pressure
Monitor System (TPMS), this light comes on briefly when the engine is started. It
provides information about tire pressures and the TPMS.
When the Light Is On Steady
This indicates that one or more of the tires are significantly underinflated.
Stop as soon ...
Hazard Warning Flashers
The hazard warning flasher button is on the center stack.
(Hazard Warning Flasher): Press
to make the front and rear turn signal lamps flash on and off.
This warns others that you are having trouble. Press the button again to turn
the flashers off.
When the hazard warning flashers are on, ...
Brake System Warning Light
The vehicle brake system consists of two hydraulic circuits. If one circuit is
not working, the remaining circuit can still work to stop the vehicle. For normal
braking performance, both circuits need to be working If the warning light comes
on, there is a brake problem. Have the brake system ...