Ford Fusion: Horn / Horn - System Operation and Component Description. Description and Operation
System Operation
System Diagram

| Item |
Description |
| 1 |
BJB |
| 2 |
Horn Relay |
| 3 |
Horn Switch |
| 4 |
Clockspring |
| 5 |
SCCM |
| 6 |
BCM |
| 7 |
Horn |
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 airbag 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 and BCM. The BCM grounds the horn relay coil to energize the integrated relay in the BJB. When energized, the horn relay provides voltage to the horn, enabling the horn to sound.
DTC Chart
Diagnostics in this manual assume a certain skill level and knowledge of Ford-specific diagnostic practices. REFER to: Diagnostic Methods (100-00 General Information, Description and Operation)...
Other information:
DTC Charts
Diagnostics in this manual assume a certain skill level and knowledge of Ford-specific diagnostic practices. REFER to: Diagnostic Methods (100-00 General Information, Description and Operation).
HUD DTC Chart
DTC
Description
Action
U0104:00
Lost Communication With Cruise Control Module: No Sub Type Information
&..
Removal
NOTE:
Removal steps in this procedure may contain installation details.
NOTICE:
Do not service the brake pedal or brake booster
without first removing the stoplamp switch. This switch must be removed
with the brake pedal in the at-rest position. The switch plunger must be
compressed for the switch to rotate in the bracket. Attempting to
remove the switch when the plunger ..