For 1990-2009 cars

### System Description

The horn system consists of the following components:

• | HORN fuse

• | THEFT HORN fuse

• | Horn relay

• | Horn switch

• | Left Horn

• | Right Horn

• | Theft Deterrent Alarm Siren

• | Body control module (BCM)

### System Operation

• | The vehicle horns are activated whenever the horn switch is depressed.

• | The BCM commands the horns ON under any of the following conditions:

- | When the immobilizer detects a vehicle intrusion.

- | When the keyless entry system is used to lock the vehicle, a horn chirp may sound to notify the driver that the vehicle has been locked. The notification feature may be enabled or disabled through personalization. For further information refer to Keyless Entry System Description and Operation.

- | When the panic button is pressed on the key fob. For further information refer to Keyless Entry System Description and Operation.

### Circuit Operation

Battery positive voltage is applied at all times to the horn relay coil and the horn relay switch. Pressing the horn switch applies ground to the horn relay control circuit or when the body control module (BCM) receives a request to sound the horns, it to will provide a ground to the horn relay control circuit. When the horn relay control circuit is grounded, the horn relay is energized and battery positive voltage is applied to the horns through the horn control circuit. The horns sound as long as ground is applied to the horn relay control circuit

The theft deterrent alarm siren shares the same control circuit as the left and right horns, but the theft deterrent alarm has it's own 10A fuse so that if the HORN fuse is open while the BCM is commanding the theft deterrent alarm, the theft deterrent alarm siren will still sound independently of the left and right horns.