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:
Dome Lamp Override
The dome lamp override button is next to the exterior lamps control.
DOME OFF: Press the top of the button in and the dome lamps remain off when a door is opened.
An indicator light on the button ...
Door Locks
WARNING
Unlocked doors can be dangerous.
○ Passengers, especially children, can easily open the doors and fall out of
a moving vehicle. The chance of being thrown out of the vehicle in a cra ...
Footnotes — Maintenance Schedule Additional Required Services — Severe
a) Or every two years, whichever comes first.
b) Check all fuel and vapor lines and hoses for proper hook-up, routing, and condition. Check that the purge valve, if the vehicle has one, works properl ...