See also:

Horn
Press near or on the horn symbols on your steering wheel pad to sound the horn. ...

Using the Universal Remote System
Press and hold the appropriate Universal Remote system button for at least half of a second. The indicator light will come on while the signal is being transmitted. ...

OnStar Personal Identification Number (PIN)
A PIN is needed to access some of the OnStar services, like Remote Door Unlock and Stolen Vehicle Assistance. You will be prompted to change the PIN the first time when speaking with an Advi ...