See also:

How OnStar Service Works
Automatic Crash Response, Emergency Services, Crisis Assist, Stolen Vehicle Assistance, Vehicle Diagnostics, Remote Door Unlock, Roadside Assistance, Turn-by-Turn Navigation, and Hands-Free ...

When to Check
Check the tires once a month or more. Do not forget the compact spare tire, if the vehicle has one. The cold compact spare should be at 420 kPa (60 psi). For additional information regarding the c ...

Malfunction Indicator Lamp
A computer system called OBD II (On-Board Diagnostics-Second Generation) monitors the operation of the vehicle to ensure emissions are at acceptable levels, to produce a cleaner environment. ...