System Operation

WARNING: This page is about a different car, the 2004 Pontiac Grand Prix. However, it is still accessible from the selected car via links, so may be relevant.

The body control module (BCM) commands the horns on. The BCM commands the horns on under any of the following conditions:

When the horn switch is depressed.
When the panic button is depressed on the remote control door lock transmitter. For further information refer to Keyless Entry System Description and Operation in Keyless Entry.
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.