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:
Express-Up/Express-Down Windows
A window with the express-up/down feature allows it to be raised or lowered without holding the switch.
Press or pull the window switch fully and release it to activate the express feature. The expre ...
How to Reset the Engine Oil Life System
Reset the system whenever the engine oil is changed so that the system can calculate the next engine oil change. To reset the system:
If the vehicle does not have Driver Information Center (DIC) butt ...
How to Check
Use a good quality pocket-type gauge to check tire pressure.
Proper tire inflation cannot be determined by looking at the tire.
Check the tire inflation pressure when the tires are cold, meaning the ...