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:
Roadside Assistance Program
U.S.: 1-888-881-3302
TTY Users (U.S.): 1-888-889-2438
Canada: 1-800-268-6800
Mexico: 01-800-466-0801
As the owner of a new GMC, you are automatically enrolled in the Roadside Assistance program.
...
Radio Data System (RDS)
The Radio Data System (RDS) feature is available for use only on FM stations that broadcast RDS information. This system relies upon receiving specific information from these stations and only works w ...
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. ...





