Horn
Press 
on the steering wheel
pad to sound the horn.
See also:
Windshield Washer
(Windshield Washer): To
spray washer fluid
on the windshield, press the windshield washer
paddle. The wipers will clear the window and then
either stop or return to your preset speed.
CAUTION:
...
Storing Name Tags
The system can store up to 30 phone numbers as name tags that are shared between the Bluetooth and OnStar systems.
The system uses the following commands to store and retrieve phone numbers:
► ...
Hazard Warning Flashers
Hazard Warning Flasher: Press this button located on the instrument panel above the audio system, to make the front and rear turn signal lamps flash on and off.
Press again to turn the flashe ...