Horn
Pressa 
on the steering wheel pad
to sound the horn.
See also:
Power Steering Fluid
The power steering fluid reservoir is located under the engine cover on the passenger side of the vehicle.
See Engine Compartment Overview on page 10‑6 for reservoir location. ...
Accessories and Modifications
Adding non-dealer accessories or making modifications to the vehicle can affect vehicle performance and safety, including such things as airbags, braking, stability, ride and handling, emissions syste ...
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.
...