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 vehicle is equipped with the Tire Pressure Monitoring System.
If a diagnostics check is needed between e-mails, push 
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Advisor can run a check.
See also:
Airbag System Messages
SERVICE AIR BAG
This message displays when there
is a problem with the airbag system.
Have the vehicle serviced by your
dealer immediately. See Airbag
Readiness Light for
more information. ...
Manual Rearview Mirror
Adjust the inside rearview mirror for a clear view of the area behind your
vehicle. To avoid glare of the headlamps from behind, push the tab forward for
daytime and pull it for nighttime use.
Ve ...
Treadwear
The treadwear grade is a comparative rating based on the wear rate of the tire
when tested under controlled conditions on a specified government test course. For
example, a tire graded 150 would w ...