System Description
The horn system consists of the following components:
| • | Inflatable restraint steering wheel coil |
| • | Body Control Module (BCM) |
System Operation
The vehicle horns are activated under the following conditions:
| • | The horn switch is depressed. |
| • | The body control module commands the horns on. The BCM commands
the horns on under any of the following conditions: |
| - | When the OnStar® system is used to sound the horns, if equipped.
For further information refer to
OnStar Description and Operation
in Cellular Communications. |
| - | 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. The body control module 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.
