Horn
Press 
on the steering wheel pad to sound the horn.
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.
...
Customer Satisfaction Procedure (U.S. and
Canada)
Your satisfaction and goodwill are important to your dealer and to GMC. Normally, any concerns with the sales transaction or the operation of the vehicle will be resolved by your dealer's sales or ser ...
Instrument Cluster
English Light Duty Premium Shown. Metric, Uplevel, Base and Heavy Duty
Similar.
For vehicles with a DURAMAX® Diesel engine, see the DURAMAX® Diesel Supplement for more information.
For vehicle ...