Ford Explorer: Exterior Lighting / Diagnosis and Testing - Autolamps

Ford Explorer 2020-2026 Service Manual / Electrical / Lighting / Exterior Lighting / Diagnosis and Testing - Autolamps

Diagnostic Trouble Code (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).


  Diagnostic Trouble Code Chart


Module   DTC Description Action
  BCM B1A85:11 Ambient Light Sensor: Circuit Short To Ground   GO to Pinpoint Test A
  BCM B1A85:13 Ambient Light Sensor:Circuit 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

Symptom Chart: Autolamps

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).

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

Pinpoint Tests


PINPOINT TEST A : THE AUTOLAMPS ARE INOPERATIVE OR DO NOT OPERATE CORRECTLY

Refer to Wiring Diagrams Cell 86 for schematic and connector information.

Normal Operation and Fault Conditions

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

DTC Description Fault Trigger Condition
BCM B1A85:11 Ambient Light Sensor: Circuit Short To Ground A continuous memory and on-demand DTC that sets when the BCM detects a short to ground from the light sensor input circuit.
BCM B1A85:13 Ambient Light Sensor: Circuit Open An on-demand DTC that sets when the BCM detects an open from the light sensor input circuit.

Possible Sources

  • Light sensor
  • Wiring, terminals or connectors
  • BCM

Visual Inspection and Pre-checks

  • Inspect the headlamp switch for damage.
  • Inspect the light sensor for damage.
A1 CHECK THE MANUAL HEADLAMP OPERATION
  • Place the headlamp switch in the HEADLAMPS and then OFF positions.

Do the headlamps operate correctly?
Yes GO to A2
No
REFER to: Headlamps (417-01 Exterior Lighting, Diagnosis and Testing).

A2 CHECK FOR VOLTAGE TO THE LIGHT SENSOR
  • Ignition OFF.
  • Disconnect: Autolamp/Sunload Sensor C286.
  • Ignition ON.
  • Place the headlamp switch in the AUTOLAMPS position.
  • Measure:
    Click to display connectors
    Positive Lead Measurement / Action Negative Lead
      C286-2   Ground

Is the voltage approximately 5 volts?
Yes GO to A3
No If the voltage is low, GO to A5
If the voltage is high, GO to A7

A3 CHECK THE LIGHT SENSOR FOR GROUND
  • Measure:
    Click to display connectors
    Positive Lead Measurement / Action Negative Lead
      C286-2   C286-4

Is the voltage approximately 5 volts?
Yes INSTALL a new autolamp/sunload sensor.
REFER to: Light Sensor (417-01 Exterior Lighting, Removal and Installation).
No GO to A4

A4 CHECK THE LIGHT SENSOR GROUND CIRCUIT FOR AN OPEN
  • Ignition OFF.
  • Disconnect: BCM C2280B.
  • Measure:
    Click to display connectors
    Positive Lead Measurement / Action Negative Lead
      C286-4   C2280B-22

Is the resistance less than 3 ohms?
Yes GO to A8
No REPAIR the circuit.

A5 CHECK THE LIGHT SENSOR INPUT CIRCUIT FOR A SHORT TO GROUND
  • Ignition OFF.
  • Disconnect: BCM C2280B.
  • Measure:
    Click to display connectors
    Positive Lead Measurement / Action Negative Lead
      C286-2   Ground

Is the resistance greater than 10,000 ohms?
Yes GO to A6
No REPAIR the circuit.

A6 CHECK THE LIGHT SENSOR INPUT CIRCUIT FOR AN OPEN
  • Measure:
    Click to display connectors
    Positive Lead Measurement / Action Negative Lead
      C286-2   C2280B-24

Is the resistance less than 3 ohms?
Yes GO to A8
No REPAIR the circuit.

A7 CHECK THE LIGHT SENSOR INPUT CIRCUIT FOR A SHORT TO VOLTAGE
  • Ignition OFF.
  • Disconnect: BCM C2280B.
  • Ignition ON.
  • Measure:
    Click to display connectors
    Positive Lead Measurement / Action Negative Lead
      C286-2   Ground

Is any voltage present?
Yes REPAIR the circuit.
No GO to A8

A8 CHECK FOR CORRECT BCM (BODY CONTROL MODULE) OPERATION
  • Disconnect and inspect all BCM and all related in-line 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 and all related in-line 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 service articles: TSB, GSB, SSM or FSA. If a service article exists for this concern, DISCONTINUE this test and FOLLOW the service article instructions. If no service articles address this concern, INSTALL a new BCM.
REFER to: Body Control Module (BCM) (419-10 Multifunction Electronic Modules, Diagnosis and Testing).
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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