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 
, and an Advisor can run a check.
See also:
Shifting out of Park
To shift out of P (Park):
1. Apply the brake pedal.
2. Turn the ignition to ON/RUN.
3. Press the shift lever button.
4. Move the shift lever.
If you still are unable to shift out of P (Park):
1. ...
Tire Pressure Monitor
This vehicle may have a Tire Pressure Monitor System (TPMS).
The TPMS warning light alerts you to a significant loss in pressure of one of
the vehicle's tires. If the warning light comes on, ...
Rear Safety Belt Comfort Guides
This vehicle may have rear shoulder belt comfort guides. If not, they are available
through your dealer. The guides may provide added safety belt comfort for older
children who have outgrown boost ...