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:
Reverse Gear Wipes
If the rear wiper control is off, the rear wiper will automatically operate continuously
when the shift lever is in R (Reverse), and the front windshield wiper is performing
low or high speed wipe ...
Global Positioning System (GPS)
• Obstruction of the GPS can occur in a large city with tall buildings; in parking garages; around airports; in tunnels, underpasses, or parking garages; or in an area with very dense trees. If GPS ...
Trip/Fuel Menu Items (with DIC Buttons)
(Trip/Fuel): Press this button to scroll through the following menu items: ...