Description And Operation: Operation
The system for the horns receives a power supply via the horn relay in the Auxiliary Power Distribution Center (PDC) which receives direct current from the battery via a fuse in the Front PDC. The coil for the relay is energized with a ground signal when the horn switch on the steering wheel is pressed. It is connected to the wire harness via the clockspring, which is part of the Steering Column Control Module (SCCM). The clockspring in the SCCM sends a control signal to the Body Control Module (BCM), which energizes the horn relay in the Aux PDC, which in turn powers the high and low tone horns.
The BCM receives direct battery power via the circuit protected by a maxi fuse in the Battery Distribution Unit (BDU) on the battery. The BCM receives an ignition-operated power supply (INT) from the Radio Frequency Hub (RFH) Module.
The horn as well as the hardwired input circuit for the horn may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate wiring information.