413-06 Horn 2013 - 2014 MKZ
Diagnosis and Testing Procedure revision date: 05/15/2013

Horn

DTC Chart(s)

DTC Chart: Horn

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).



  Body Control Module (BCM) DTC Chart


  DTC Description Actions
B1323:11 Horn Switch: Circuit Short To Ground   GO to Pinpoint Test B
B1C55:12 Horn Relay: Circuit Short to Battery   GO to Pinpoint Test A
B1C55:14 Horn Relay: Circuit Short to Ground or Open   GO to Pinpoint Test A


Symptom Chart(s)

Symptom Chart: Horn

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).



  Symptom Chart


Condition Possible Sources Actions
The horn is inoperative Refer to Pinpoint Test   GO to Pinpoint Test A
The horn is always on Refer to Pinpoint Test   GO to Pinpoint Test B


Pinpoint Tests

The Horn Is Inoperative


Refer to Wiring Diagrams Cell 44 for schematic and connector information.

Normal Operation and Fault Conditions


REFER to: Horn - System Operation and Component Description (413-06 Horn, Description and Operation).



  DTC Chart


  DTC Description Fault Trigger Condition
B1C55:12 Horn Relay: Circuit Short to Battery A Continuous Memory Diagnostic Trouble Code (CMDTC) that sets when the BCM detects a short to voltage on the horn relay control circuit. The BCM disables the horn when this DTC is set.
B1C55:14 Horn Relay: Circuit Short to Ground or Open A Continuous Memory Diagnostic Trouble Code (CMDTC) that sets when the BCM detects a short to ground or an open on the horn relay control circuit.


Possible Sources

Visual Inspection and Diagnostic Pre-checks

Verify the BJB fuse 48 (20A) is OK.


PINPOINT TEST A : THE HORN IS INOPERATIVE
A1   CHECK THE BCM (BODY CONTROL MODULE) OUTPUT
  • Ignition ON.
  • Using a diagnostic scan tool, view BCM Parameter Identifications (PIDs).
  • Select the active command BCM HORN Parameter Identification (PID) and command the horn ON and then OFF.

Does the horn sound when commanded on?

Yes GO to A2
No VERIFY the BJB fuse 48 (20A) is OK. If OK, GO to A8 If not OK, REFER to the Wiring Diagrams manual to identify the possible causes of the circuit short.


A2   CHECK HORN OPERATION WITH HORN SWITCH CIRCUITS ISOLATED

NOTE: Test is carried out with jumper at female (harness) side of connector.

  • WARNING: Turn the ignition OFF and wait one minute to deplete the backup power supply. Failure to follow this instruction may result in serious personal injury or death in the event of an accidental deployment.

    Ignition OFF and wait one minute.
  • Remove the driver airbag module.
    REFER to: Driver Airbag (501-20B Supplemental Restraint System, Removal and Installation).
  • Disconnect SCCM C2414A .
  • Disconnect SCCM C2414D .
  • Connect a fused jumper wire:


    Positive Lead Measurement / Action Negative Lead
      C2414A-1   C2414D-4



Does the horn sound?

Yes REMOVE the fused jumper wire. GO to A6
No REMOVE the fused jumper wire. GO to A3


A3   CHECK THE HORN CIRCUIT FOR A SHORT TO VOLTAGE
  • Ignition OFF.
  • Disconnect: BCM C2280G
  • Ignition ON.
  • Measure:


    Positive Lead Measurement / Action Negative Lead
      C2414A-1   Ground



Is any voltage present?

Yes REPAIR the circuit.
No GO to A4


A4   CHECK THE HORN CIRCUIT FOR AN OPEN
  • Ignition OFF.
  • Measure:


    Positive Lead Measurement / Action Negative Lead
      C2414A-1   C2280G-18



Is the resistance less than 3 ohms?

Yes GO to A5
No REPAIR the circuit.


A5   CHECK THE HORN SWITCH GROUND CIRCUIT FOR AN OPEN
  • Measure:


    Positive Lead Measurement / Action Negative Lead
      C2414A-1   Ground



Is the resistance less than 3 ohms?

Yes GO to A15
No REPAIR the circuit.


A6   CHECK HORN OPERATION WITH CLOCKSPRING ISOLATED

NOTE: Test is carried out with jumper at male (clockspring) side of connector.

  • Ignition OFF.
  • Connect SCCM C2414A .
  • Connect SCCM C2414D .
  • Disconnect Clockspring C218B .
  • Connect a fused jumper wire:


    Positive Lead Measurement / Action Negative Lead
      C218B-4   C218B-11



Does the horn sound?

Yes REMOVE the fused jumper wire. GO to A7
No INSTALL a new clockspring.
REFER to: Clockspring (501-20B Supplemental Restraint System, Removal and Installation).


A7   CHECK HORN OPERATION WITH STEERING WHEEL HARNESS ISOLATED

NOTE: Switch harness may be temporarily removed from airbag assembly for test purposes.

  • Ignition OFF.
  • Connect Clockspring C218B .
  • Disconnect Horn Switch C217A .
  • Disconnect Horn Switch C217B .
  • Connect a fused jumper wire:


    Positive Lead Measurement / Action Negative Lead
      C217A-1   C217B-1



Does the horn sound?

Yes INSTALL a new driver airbag module.
REFER to: Driver Airbag (501-20B Supplemental Restraint System, Removal and Installation).
No INSTALL a new steering wheel.
REFER to: Steering Wheel (211-04 Steering Column, Removal and Installation).


A8   CHECK THE HORN RELAY
  • Ignition OFF.
  • Remove the horn relay.
  • Carry out the relay component test.
    Refer to Wiring Diagrams Cell 149 for schematic and connector information.

Did the relay pass the component test?

Yes GO to A9
No INSTALL a new horn relay.


A9   CHECK THE HORN OPERATION WITH RELAY CONTROL ISOLATED
  • Connect a fused jumper wire:


    Positive Lead Measurement / Action Negative Lead

    Pin socket 3

    Pin socket 5



Does the horn sound?

Yes REMOVE the fused jumper wire. GO to A10
No REMOVE the fused jumper wire. GO to A12


A10   CHECK THE HORN OPERATION WITH BCM (BODY CONTROL MODULE) ISOLATED
  • Ignition OFF.
  • Install the horn relay.
  • Disconnect BCM C2280C .
  • Connect a fused jumper wire:


    Positive Lead Measurement / Action Negative Lead
      C2280C-20   Ground



Does the horn sound?

Yes REMOVE the fused jumper wire. GO to A15
No REMOVE the fused jumper wire. GO to A11


A11   CHECK THE HORN RELAY VOLTAGE SUPPLY CIRCUIT FOR VOLTAGE
  • Remove the horn relay.
  • Measure:


    Positive Lead Measurement / Action Negative Lead

    Pin socket 2     		  Ground



Is the voltage greater than 11 volts?

Yes REPAIR circuit CRH02 (BU/WH).
No REPAIR the horn relay voltage supply circuit.


A12   CHECK THE HORN RELAY LOAD CIRCUIT FOR VOLTAGE
  • Measure:


    Positive Lead Measurement / Action Negative Lead

    Pin socket 3     		  Ground



Is the voltage greater than 11 volts?

Yes GO to A13
No REPAIR the circuit.


A13   CHECK FOR VOLTAGE AT THE HORN
  • Install the horn relay.
  • Disconnect Horn C131 .
  • Press and hold the horn switch.
  • Measure:


    Positive Lead Measurement / Action Negative Lead
      C131-2   Ground



Is the voltage greater than 11 volts?

Yes GO to A14
No REPAIR the circuit.


A14   CHECK THE HORN GROUND CIRCUIT FOR AN OPEN
  • Press and hold the horn switch.
  • Measure:


    Positive Lead Measurement / Action Negative Lead
      C131-2   C131-1



Is the voltage greater than 11 volts?

Yes INSTALL a new horn.
REFER to: Horn (413-06 Horn, Removal and Installation).
No REPAIR the circuit.


A15   CHECK FOR CORRECT BCM (BODY CONTROL MODULE) OPERATION
  • Ignition OFF.
  • Disconnect and inspect the BCM connectors.
  • Repair:
    • corrosion (install new connector or terminals – clean module pins)
    • damaged or bent pins – install new terminals/pins
    • pushed-out pins – install new pins as necessary
  • Reconnect the BCM connectors. Make sure they seat and latch correctly.
  • Operate the system and determine if the concern is still present.

Is the concern still present?

Yes CHECK OASIS for any applicable Technical Service Bulletins (TSBs). If a TSB exists for this concern, DISCONTINUE this test and FOLLOW TSB instructions. If no Technical Service Bulletins (TSBs) address this concern, INSTALL a new BCM .
REFER to: Body Control Module (BCM) (419-10 Multifunction Electronic Modules, Removal and Installation).
No The system is operating correctly at this time. The concern may have been caused by module connections. ADDRESS the root cause of any connector or pin issues.



The Horn Is Always On


Refer to Wiring Diagrams Cell 44 for schematic and connector information.

Normal Operation and Fault Conditions


REFER to: Horn - System Operation and Component Description (413-06 Horn, Description and Operation).



  DTC Chart


  DTC Description Fault Trigger Condition
B1323:11 Horn Switch: Circuit Short to Ground A Continuous Memory Diagnostic Trouble Code (CMDTC) that sets when the BCM detects a short to ground on the horn signal circuit.


Possible Sources


PINPOINT TEST B : THE HORN IS ALWAYS ON
B1   ISOLATE THE HORN RELAY
  • Remove the horn relay.

Does the horn continue to sound?

Yes DISCONNECT the horn to prevent damage from continuous operation. REPAIR the short in circuit CRH04 (VT/GN).
No GO to B2


B2   CHECK THE HORN RELAY
  • Carry out the relay component test.
    Refer to Wiring Diagrams Cell 149 for schematic and connector information.

Did the relay pass the component test?

Yes GO to B3
No INSTALL a new horn relay.


B3   ISOLATE THE BCM (BODY CONTROL MODULE) HORN OUTPUT CIRCUIT
  • Install the horn relay.
  • Disconnect BCM C2280C .

Does the horn continue to sound?

Yes REPAIR the short in circuit CRH02 (BU/WH).
No GO to B4


B4   ISOLATE THE BCM (BODY CONTROL MODULE) HORN INPUT CIRCUIT
  • Connect BCM C2280C .
  • Disconnect BCM C2280G .

Does the horn continue to sound?

Yes GO to B8
No GO to B5


B5   CHECK THE HORN SWITCH INPUT FOR A SHORT TO GROUND
  • Connect BCM C2280C .
  • Disconnect SCCM C2414A .

Does the horn continue to sound?

Yes REPAIR the short in circuit RRH02 (GN/WH).
No GO to B6


B6   CHECK THE CLOCKSPRING FOR A SHORT TO GROUND
  • Connect SCCM C2414A .
  • WARNING: Turn the ignition OFF and wait one minute to deplete the backup power supply. Failure to follow this instruction may result in serious personal injury or death in the event of an accidental deployment.

    Ignition OFF and wait one minute.
  • Remove the driver airbag.
    REFER to: Driver Airbag (501-20B Supplemental Restraint System, Removal and Installation).
  • Disconnect Clockspring C218B .

Does the horn continue to sound?

Yes INSTALL a new clockspring.
REFER to: Clockspring (501-20B Supplemental Restraint System, Removal and Installation).
No GO to B7


B7   CHECK THE HORN SWITCH
  • Connect Clockspring C218B .
  • Disconnect Horn Switch C217A .

Does the horn continue to sound?

Yes INSTALL a new steering wheel.
REFER to: Steering Wheel (211-04 Steering Column, Removal and Installation).
No INSTALL a new driver airbag module.
REFER to: Driver Airbag (501-20B Supplemental Restraint System, Removal and Installation).


B8   CHECK FOR CORRECT BCM (BODY CONTROL MODULE) OPERATION
  • Ignition OFF.
  • Disconnect and inspect the BCM connectors.
  • Repair:
    • corrosion (install new connector or terminals – clean module pins)
    • damaged or bent pins – install new terminals/pins
    • pushed-out pins – install new pins as necessary
  • Reconnect the BCM connectors. Make sure they seat and latch correctly.
  • Operate the system and determine if the concern is still present.

Is the concern still present?

Yes CHECK OASIS for any applicable Technical Service Bulletins (TSBs). If a TSB exists for this concern, DISCONTINUE this test and FOLLOW TSB instructions. If no Technical Service Bulletins (TSBs) address this concern, INSTALL a new BCM .
REFER to: Body Control Module (BCM) (419-10 Multifunction Electronic Modules, Removal and Installation).
No The system is operating correctly at this time. The concern may have been caused by module connections. ADDRESS the root cause of any connector or pin issues.





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