See also:

OnStar®
For vehicles with an active OnStar subscription, OnStar uses several innovative technologies and live Advisors to provide a wide range of safety, security, navigation, diagnostics, and calling servi ...

Horn
Press on the steering wheel pad to sound the horn. ...

If the Off Indicator is Lit for an Adult-Size Occupant
If a person of adult-size is sitting in the right front passenger seat, but the off indicator is lit, it could be because that person is not sitting properly in the seat. If this happens, use the fo ...