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:
Door Locks
WARNING
Unlocked doors can be dangerous.
○ Passengers, especially children, can easily open the doors and fall out of
a moving vehicle. The chance of being thrown out of the vehicle in a cra ...
Vehicle Symbol Chart
Here are some additional symbols that may be found on the vehicle and what they mean. For more information on the symbol, refer to the Index.
Airbag Readiness Light
Air Conditioning
...
Transfer Case
Refer to the Maintenance Schedule to determine how often to check the lubricant
and when to change it. See Maintenance Schedule on page 11‑3. ...