Overview
The horn output is controlled by the BCM. The BCM energizes the horn relay and sounds the horn.
Scheme 1
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 BCM. The BCM grounds the horn relay coil to energize the relay. When energized, the horn relay provides voltage to the horn, enabling the horn to sound.
Diagnostic Overview
Diagnostics in this information assume a certain skill level and knowledge of Ford-specific diagnostic practices. Refer to Diagnostic Methods in SERVICE INFORMATION for information about these practices.
Refer to the SYSTEM WIRING DIAGRAMS - Horn/Cigar Lighter .
Normal Operation and Fault Conditions
Refer to HORN .
| DTC | Description | Fault Trigger Conditions |
|---|---|---|
| B1C55:13 | Horn Relay: Circuit Open | A continuous DTC that sets when the BCM detects an open on the horn relay control circuit. |
| B1C55:19 | Horn Relay: Circuit Current Above Threshold | A continuous DTC that sets when the BCM detects a high current condition on the horn relay control circuit. The BCM disables the horn when this DTC is set. |
DTC FAULT TRIGGER CONDITIONS
Diagnostics in this information assume a certain skill level and knowledge of Ford-specific diagnostic practices. Refer to Diagnostic Methods in SERVICE INFORMATION for information about these practices.
Refer to the SYSTEM WIRING DIAGRAMS - Horn/Cigar Lighter .
Refer to HORN .
| DTC | Description | Fault Trigger Conditions |
|---|---|---|
| B1323:11 | Horn Switch: Circuit Short to Ground | A continuous DTC that sets when the BCM detects a short to ground on the horn signal circuit. |
| B1323:23 | Horn Switch: Signal Stuck Low | An on-demand DTC that sets when the BCM detects a short to ground on the horn signal circuit. |
| B1C55:11 | Horn Relay: Circuit Short to Ground | A continuous DTC that sets when the BCM detects a short to ground on the horn relay control circuit. |
DTC FAULT TRIGGER CONDITIONS
See also:
• SUPPLEMENTAL RESTRAINT SYSTEM