See also:

If the System Needs Service
If the navigation system needs service and the steps listed here have been followed but there are still problems, see your dealer for assistance. ...

Selective Ride Control
The vehicle may have a ride control system called Selective Ride Control. The setting can be changed at any time. Based on road conditions, steering wheel angle, and the vehicle speed, the system au ...

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 v ...