System Description
The horn system consists of the following components:
| (The horn switch is part of the inflatable restraint steering wheel
module.) |
• | The body control module (BCM) |
• | The vehicle interface unit (VIU) |
System Operation
The vehicle horn system is activated under the following conditions:
• | The horn switch is depressed. |
• | On vehicles equipped with content theft deterrent (UA6), the body
control module may command 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. |
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. On vehicles equipped with UA6, 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.