Horn Operation

WARNING: This page is about a different car, the 2018 Ford EcoSport. However, it is still accessible from the selected car via links, so may be relevant.

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 BCM. The BCM then energizes the horn relay sending voltage to the horn, enabling the horn to sound.

Component Description

Horn

The left and right horns consists of different notes (high and low) attached to a bracket.

Clockspring

The clockspring is the interface between the BCM 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.

BCM

The BCM controls the horn activation based on input from horn switch contacts and other features.

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