Lincoln Navigator: Horn / Horn - System Operation and Component Description. Description and Operation

System Operation

System Diagram

Horn Operation

The horn switch consists of 2 sets of contacts separated by springs. The lower set is connected to ground and the upper set is connected to the horn signal circuit. When the driver air bag module is pressed, it pushes down on the upper set of contacts, collapsing the springs and allowing the contacts to touch. When the contacts touch, it completes the circuit and provides the ground signal which is routed through the clockspring to the SCCM . The SCCM sends a signal to the BCM . The BCM then energizes the horn relay sending voltage to the horn(s), enabling the horn(s) to sound.

Component Description

Horn(s)

The horn(s) consists of different notes (high and low) attached to a bracket.

Clockspring

The clockspring is the interface between the SCCM and the horn switch contacts. It allows the steering wheel to rotate while maintaining circuit integrity with the electrically monitored/activated components mounted to the steering wheel.

SCCM

The SCCM controls the horn activation based on input from the clockspring and the horn switch contacts..

The SCCM requires PMI when replaced.

BCM

The BCM controls the horn activation based on input from the SCCM .

The BCM requires PMI when replaced. Additionally, carry out the parameter reset procedure and program at least 2 keys.