See also:

OnStar®
If equipped, this vehicle has a comprehensive, in-vehicle system that can connect to a live Advisor for Emergency, Security, Navigation, Connection, and Diagnostic Services. See OnStar Overview. ...

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 ...

How to Check Lubricant
To get an accurate reading, the vehicle should be on a level surface. For Two-Wheel-Drive vehicles, the proper level is from 15mm to 40mm (0.6 in to 1.6 in) below the bottom of the filler plu ...