417-01 Exterior Lighting 2013 - 2014 MKZ
Diagnosis and Testing Procedure revision date: 07/19/2013

Reversing Lamps

DTC Chart: Body Control Module (BCM)

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
B1277:11 Reverse Lamp: Circuit Short To Ground   GO to Pinpoint Test A
B1277:15 Reverse Lamp: Circuit Short To Battery or Open
For other BCM Diagnostic Trouble Codes (DTCs) -  
REFER to: Body Control Module (BCM) (419-10 Multifunction Electronic Modules, Diagnosis and Testing).


Symptom Chart(s)

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: Reversing Lamps

  Symptom Chart


Condition Possible Sources Actions
A module does not respond to the scan tool
  • Fuse
  • Wiring, terminals or connectors
  • Module
 
REFER to: Communications Network (418-00 Module Communications Network, Diagnosis and Testing).
The reversing lamps are inoperative Refer to the Pinpoint Test   GO to Pinpoint Test A
The reversing lamps are on continuously Refer to the Pinpoint Test   GO to Pinpoint Test B


Pinpoint Tests

The Reversing Lamps Are Inoperative


Refer to Wiring Diagrams Cell 93 for schematic and connector information.

Normal Operation and Fault Conditions


REFER to: Exterior Lighting - System Operation and Component Description (417-01 Exterior Lighting, Description and Operation).



  DTC Fault Trigger Conditions


DTC Description Fault Trigger Conditions
B1277:11 Reverse Lamp: Circuit Short To Ground Sets when the BCM detects a short to ground from the reversing lamps output circuit.
B1277:15 Reverse Lamp: Circuit Short To Battery or Open Sets when the BCM detects an open or short to voltage from the reversing lamps output circuit.


Possible Sources

Visual Inspection and Diagnostic Pre-checks


PINPOINT TEST A : THE REVERSING LAMPS ARE INOPERATIVE
A1   CHECK THE PCM (POWERTRAIN CONTROL MODULE) TRANSMISSION RANGE PID (PARAMETER IDENTIFICATION)
  • Apply the parking brake.
  • Ignition ON.
  • Using a diagnostic scan tool, view PCM Parameter Identifications (PIDs).
  • Monitor the Transmission Range (TR) PID .
  • Place the gear selector lever in the REVERSE (R).

Does the PID indicate the gear range is in reverse?

Yes GO to A2
No DIAGNOSE the transmission range concern.
For 6F50 transmission,
REFER to: External Controls (307-05A Automatic Transmission External Controls - Vehicles With: 6-Speed Automatic Transmission - 6F50, Diagnosis and Testing).

For 6F35 transmission,
REFER to: External Controls (307-05B Automatic Transmission External Controls - Vehicles With: 6-Speed Automatic Transmission - 6F35, Diagnosis and Testing).


A2   CHECK FOR VOLTAGE TO THE REVERSING LAMPS
  • Ignition OFF.
  • Apply the parking brake.
  • Disconnect: Reversing Lamp C451
  • Ignition ON.
  • Place the gear selector lever in REVERSE (R).
  • Measure:


    Positive Lead Measurement / Action Negative Lead
      C451-2   Ground



Is the voltage greater than 11 volts?

Yes GO to A5
No GO to A3


A3   CHECK THE REVERSING LAMP SUPPLY CIRCUIT FOR A SHORT TO GROUND
  • Ignition OFF.
  • Disconnect: BCM C2280F.
  • Measure:


    Positive Lead Measurement / Action Negative Lead
      C451-2   Ground



Is the resistance greater than 10,000 ohms?

Yes GO to A4
No REPAIR the circuit.


A4   CHECK THE REVERSING LAMP SUPPLY CIRCUIT FOR AN OPEN
  • Measure:


    Positive Lead Measurement / Action Negative Lead
      C451-2   C2280F-11



Is the resistance less than 3 ohms?

Yes GO to A6
No REPAIR the circuit.


A5   CHECK THE REVERSING LAMP GROUND CIRCUIT FOR AN OPEN
  • Measure:


    Positive Lead Measurement / Action Negative Lead
      C451-2   C451-4



Is the voltage greater than 11 volts?

Yes INSTALL a new reversing lamp.
REFER to: Reversing Lamp (417-01 Exterior Lighting, Removal and Installation).
No REPAIR the circuit.


A6   CHECK FOR CORRECT BCM (BODY CONTROL MODULE) OPERATION
  • Disconnect and inspect all 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 Reversing Lamps Are On Continuously


Refer to Wiring Diagrams Cell 93 for schematic and connector information.

Normal Operation and Fault Conditions


REFER to: Exterior Lighting - System Operation and Component Description (417-01 Exterior Lighting, Description and Operation).



  DTC Fault Trigger Conditions


DTC Description Fault Trigger Conditions
B1277:15 Reverse Lamp: Circuit Short To Battery or Open Sets when the BCM detects an open or short to voltage from the reversing lamps output circuit.


Possible Sources


PINPOINT TEST B : THE REVERSING LAMPS ARE ON CONTINUOUSLY
B1   CHECK THE PCM (POWERTRAIN CONTROL MODULE) TRANSMISSION RANGE PID (PARAMETER IDENTIFICATION)
  • Apply the parking brake.
  • Ignition ON.
  • Using a diagnostic scan tool, view PCM Parameter Identifications (PIDs).
  • Monitor the Transmission Range (TR) PID .
  • Place the gear selector lever in each position.

Does the PID indicate reverse when the gear selector is not in reverse?

Yes DIAGNOSE the transmission range concern.
For 6F50 transmission,
REFER to: External Controls (307-05A Automatic Transmission External Controls - Vehicles With: 6-Speed Automatic Transmission - 6F50, Diagnosis and Testing).

For 6F35 transmission,
REFER to: External Controls (307-05B Automatic Transmission External Controls - Vehicles With: 6-Speed Automatic Transmission - 6F35, Diagnosis and Testing).
No GO to B2


B2   CHECK THE REVERSING LAMPS SUPPLY CIRCUIT FOR A SHORT TO VOLTAGE
  • Ignition OFF.
  • Disconnect: BCM C2280F.
  • Ignition ON.

Does either reversing lamp continue to illuminate?

Yes REPAIR the affected circuit.
No GO to B3


B3   CHECK FOR CORRECT BCM (BODY CONTROL MODULE) OPERATION
  • Disconnect and inspect all 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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