Ford Explorer Quiz
Electrical

Diagnosis and Testing - Back-Up Lamps

In this manual: Electrical
General Information — 41Chassis — 173Powertrain — 250Electrical — 303Body and Paint — 331
~7min read

Diagnostic Trouble Code (DTC) Chart

The diagnosis in this manual assumes a certain level of skill and knowledge of Ford-approved diagnostic procedures.
REFER TO: Diagnostic Methods (100-00 General Information, Description and Operation).


Diagnostic Trouble Code Chart


Module Trouble Code Description Action
BCM B1277:11 Back-up lamp: short to ground GO to Pinpoint Test A
BCM B1277:15 Back-up lamp: short to battery or open GO to Pinpoint Test A
BCM — All Other BCM Diagnostic Trouble Codes (DTCs)
REFER TO: Body Control Module (BCM) (419-10 Multifunction Electronic Modules, Diagnosis and Testing).

Symptom Charts

The diagnosis in this manual assumes a certain level of skill and knowledge of Ford-approved diagnostic procedures.
REFER TO: Diagnostic Methods (100-00 General Information, Description and Operation).

Symptom Chart: Back-Up Lamps


Condition Possible Sources Action
Module Does Not Respond to Diagnostic Scan Tool
  • Fuse
  • Wiring, Terminals or Connectors
  • Module
REFER TO: Communication Network (418-00 Communication Network, Diagnosis and Testing).
Both back-up lamps inoperative or always on Refer to Pinpoint Test GO to Pinpoint Test A
Individual back-up lamp inoperative Refer to Pinpoint Test GO to Pinpoint Test B

Pinpoint Tests


DIAGNOSTIC TEST A: BOTH BACK-UP LAMPS INOPERATIVE OR ALWAYS ON

For wiring diagrams and connectors, refer to Wiring Diagrams, Cell 93.

Normal Operation and Fault Symptoms

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

DTC Fault Trigger Conditions

Trouble Code Description Fault Trigger Condition
BCM B1277:11 Back-up lamp: short to ground Continuous memory and on-demand DTC set when the BCM detects a short to ground in the back-up lamp output circuit.
BCM B1277:15 Back-up lamp: short to battery or open Continuous memory and on-demand DTC set when the BCM detects an open or short to voltage supply in the back-up lamp output circuit.

Possible Sources

  • Wiring, Terminals or Connectors
  • Gear Range Concern
  • BCM
A1 CHECK THE PCM (POWERTRAIN CONTROL MODULE) GEAR RANGE PID (PARAMETER IDENTIFICATION)
  • Apply the parking brake.
  • The ignition is on.

  • Access PCM and monitor TR_CORRECTED (0) PID

  • Place the gear selector in each gear position.

Does the PID indicate the correct value when each gear is selected?
Yes If both back-up lamps do not work, GO to A2.
If both back-up lamps are constantly on, GO to A5.
No CHECK for a transmission range concern. REFER TO: Symptom Diagnosis (307-01A Automatic Transmission - 10-Speed Automatic Transmission - 10R60, Diagnosis and Testing).
REFER TO: Symptom Diagnosis (307-01B Automatic Transmission - 10-Speed Automatic Transmission - 10R80, Diagnosis and Testing).
REFER TO: Symptom Diagnosis (307-01C Automatic Transmission - 10-Speed Automatic Transmission - 10R80 MHT, Diagnosis and Testing).
A2 CHECK THE BACK-UP LAMP VOLTAGE CIRCUIT FOR A SHORT TO GROUND
  • Move the shift lever to PARK (P).
  • Ignition OFF.
  • Disconnect: Left rear lamp C414 and right rear lamp C417.
  • Disconnect: BCM C2280C.
  • Action:
    Click to display the connectors
    Positive lead Measurement/Action Negative lead
    C2280C-11 Ground

Is the resistance greater than 10000 Ohms?
Yes If not equipped with inside rearview mirror with automatic dimming, police package or Class III trailer tow, GO to A4.
If equipped with inside rearview mirror with automatic dimming, police package or Class III trailer tow, GO to A3.
No REPAIR the faulty circuit. After repair:
If no diagnostic trouble codes (DTCs) are present, CHECK the system for normal operation.
If DTC U1000:00 is present, CLEAR the DTCs and REPEAT the self-test (required to enable the lamp output driver if DTC U1000:00 is present).
If DTC U3000:49 is present, INSTALL a new BCM.
REFER TO: Body Control Module (BCM) (419-10 Multifunction Electronic Modules, Diagnosis and Testing).
A3 CHECK REVERSE OUTPUT CIRCUIT FOR SHORT TO GROUND
  • Move the shift lever to PARK (P).
  • Ignition OFF.
  • Disconnect: BCM C2280G.
  • Disconnect: Inside rearview mirror with automatic dimming C9012 (if equipped).
  • Disconnect: BCMC C1035B (if equipped with Class III trailer tow).
  • Disconnect: TRM C2498C (if equipped with police package).
  • Action:
    Click to display the connectors
    Positive lead Measurement/Action Negative lead
    C2280G-19 Ground

Is the resistance greater than 10000 Ohms?
Yes GO to A4
No REPAIR the faulty circuit. After repair:
If no diagnostic trouble codes (DTCs) are present, CHECK the system for normal operation.
If DTC U1000:00 is present, CLEAR the DTCs and REPEAT the self-test (required to enable the lamp output driver if DTC U1000:00 is present).
If DTC U3000:49 is present, INSTALL a new BCM.
REFER TO: Body Control Module (BCM) (419-10 Multifunction Electronic Modules, Diagnosis and Testing).
A4 CHECK BACK-UP LAMP VOLTAGE CIRCUITS FOR OPEN
  • Action:
    Click to display the connectors
    Positive lead Measurement/Action Negative lead
    C414-4 C2280C-11

Is the resistance less than 3 ohms?
Yes GO to A7
No REPAIR the faulty circuit.
A5 CHECK BACK-UP LAMP VOLTAGE SUPPLY CIRCUIT FOR SHORT TO VOLTAGE
  • Ignition OFF.
  • Disconnect: BCM C2280C.
  • The ignition is on.

Do the back-up lamps remain on?
Yes REPAIR the circuit.
No If not equipped with inside rearview mirror with automatic dimming, police package or Class III trailer tow, GO to A7.
If equipped with inside rearview mirror with automatic dimming, police package or Class III trailer tow, GO to A6.
A6 CHECK REVERSE OUTPUT POWER SUPPLY CIRCUIT FOR SHORT TO VOLTAGE
  • Ignition OFF.
  • Connect: BCM C2280C.
  • Disconnect: BCM C2280G.
  • Disconnect: Inside rearview mirror with automatic dimming C9012 (if equipped).
  • Disconnect: BCMC C1035B (if equipped with Class III trailer tow).
  • Disconnect: TRM C2498C (if equipped with police package).
  • The ignition is on.
  • Action:
    Click to display the connectors
    Positive lead Measurement/Action Negative lead
    C2280G-19 Ground

Is there voltage present?
Yes REPAIR the circuit.
No GO to A7
A7 CHECK THE 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
    • backed-out pins - install new pins as necessary
  • Reconnect the BCM connectors. Make sure they are fully seated and locked.
  • Operate the system and determine if the concern is still present.

Is the concern still present?
Yes CHECK OASIS for any applicable service articles: TSB, GSB, SSM or FSA. If a service article exists for this concern, STOP this test and FOLLOW the service article instructions. If no service articles apply, INSTALL a new BCM.
REFER to: Body Control Module (BCM) (419-10 Multifunction Electronic Modules, Diagnosis and Testing).
No The system is currently operating correctly. The concern may have been caused by module connections. ADDRESS the root cause of any connector or terminal issues.
DIAGNOSTIC TEST B: ONE BACK-UP LAMP INOPERATIVE

For wiring diagrams and connectors, refer to Wiring Diagrams, Cell 93.

Normal Operation and Fault Symptoms

REFER TO: Exterior Lighting - Overview (417-01 Exterior Lighting, Description and Operation).
REFER TO: Exterior Lighting - Overview (417-01 Exterior Lighting, Description and Operation).

Possible Sources

  • Wiring, Terminals or Connectors
  • Back-Up Lamp Assembly

Visual Inspection and Pre-checks

  • Inspect the back-up lamp assembly for damage.
B1 BACK-UP LAMP VOLTAGE CHECK
  • Ignition OFF.
  • Apply the parking brake.
  • Disconnect: Left rear lamp C414 or right rear lamp C417 not working.
  • The ignition is on.
  • Place the gear selector in REVERSE (R).
  • Action:
    Click to display the connectors

    Left Back-Up Lamp


    Positive lead Measurement/Action Negative lead
    C414-4 Ground

    Click to display the connectors

    Right Back-Up Lamp


    Positive lead Measurement/Action Negative lead
    C417-4 Ground

Is the voltage greater than 11 volts?
Yes GO to B2
No REPAIR the back-up lamp voltage supply circuit for an open.
B2 CHECK THE BACK-UP LAMP GROUND CIRCUIT FOR AN OPEN
  • Action:
    Click to display the connectors

    Left Back-Up Lamp


    Positive lead Measurement/Action Negative lead
    C414-4 C414-1

    Click to display the connectors

    Right Back-Up Lamp


    Positive lead Measurement/Action Negative lead
    C417-4 C417-1

Is the voltage greater than 11 volts?
Yes INSTALL a new back-up lamp.
REFER TO: Back-Up Lamp (417-01 Exterior Lighting, Removal and Installation).
No REPAIR the faulty circuit.

Test yourself

A quick Ford Explorer quiz: every answer comes with an explanation and a link to the manual page.