System Description
The horn system consists of the following components:
| • | Inflatable restraint steering wheel coil |
| • | Body control module (BCM) |
| • | Steering wheel radio control switch |
System Operation
The vehicle horn system is activated under the following conditions:
| • | The horn switch is depressed. |
| • | The body control module (BCM) commands the horns on. The BCM commands
the horns on under any of the following conditions: |
| - | 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
in Keyless Entry. |
| - | When the OnStar® system is used to sound the horns if equipped. For
further information, refer to
OnStar Description and Operation
in Cellular Communications. |
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. The BCM may also apply ground to the horn relay control circuit as described
above. 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.
