See also:

How to Detect a Tamper Condition
If  is pressed and the horn sounds, an attempted break-in occurred while the system was armed. If the alarm has been activated, a message will appear on the DIC. See Anti-theft Alarm ...

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

Ignition Transmission Lock Check
While parked, and with the parking brake set, try to turn the ignition to LOCK/OFF in each shift lever position. • The ignition should turn to LOCK/OFF only when the shift lever is in P ( ...