Horn
Pressaon 
the steering wheel pad
to sound the horn.
See also:
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 v ...
Rear Vision Camera (RVC)
If available, the Rear Vision Camera (RVC) system displays part of the scene
behind the vehicle.
The RVC system does not display pedestrians, bicyclists, animals, or any other
object located outs ...
Recommended Fluids and Lubricants
Fluids and lubricants identified below by name, part number, or specification
can be obtained from your dealer.
...