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:
Feature Settings Menu Items
The following are customization
features that allow you to program
settings to the vehicle.
Display In English
This feature will only display if a
language other than English has
been set. T ...
Underbody Maintenance
Use plain water to flush dirt and debris from the vehicle's underbody. Your dealer
or an underbody car washing system can do this. If not removed, rust and corrosion
can develop. ...
What to Use
Refer to Recommended Fluids and Lubricants to determine what kind
of lubricant to use. ...