See also:

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

Underbody Maintenance
Use plain water to flush dirt and debris from the vehicle's underbody. Your dealer or an underbody car washing system can do this. If not removed, rust and corrosion can develop. ...

Place a Call Using a Stored Number
1. Push . System responds: “OnStar ready.”. 2. Say “Call <name tag>.” System responds: “OK, calling <name tag>.” ...