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).
BCM
DTC Chart
DTC
Description
Action
B1315:11
Backlighting (Non Reflective Controls) Illumination Output: Circuit ..
Materials
Name
Specification
Motorcraft® MERCON® LV Automatic Transmission FluidXT-10-QLVC
WSS-M2C938-AMERCON® LV,
Check
Connect the diagnostic scan tool to the vehicle. Monitor the TFT
PID.
With the engine running in PARK on a level surface make
sure the transmission is at normal operating temperature 85-93° C
(185-200° F). If necessary, drive ..