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 vehicle is equipped with the Tire Pressure Monitoring
System. If a diagnostics check is needed between e-mails, press
, and an Advisor can run a check.
Connections
OnStar Additional InformationService Vehicle Messages
SERVICE AC SYSTEM
This message displays if there is a problem with the air conditioning system.
Take the vehicle to your dealer for service.
SERVICE POWER STEERING
This message displays if there is a problem with the power steering system. Take
the vehicle to your dealer for service.
SERVICE ...
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 ...
Battery Disconnect Warning
Warning: Unless directed otherwise, the ignition and start switch
must be in the OFF or LOCK position, and all electrical loads must be
OFF before servicing any electrical component. Disconnect the negative battery
cable to prevent an electrical spark should a tool or
equipment come in contact ...