Lincoln Navigator Manuals

Lincoln Navigator: Exterior Lighting / Fog Lamps. Diagnosis and Testing

Lincoln Navigator 2018-2025 Workshop Manual / Lighting / Exterior Lighting / Fog Lamps. Diagnosis and Testing

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).


Module DTC Description Action
BCM B1147:11 Left Front Fog Lamps: Circuit Short To Ground GO to Pinpoint Test A
BCM B1147:15 Left Front Fog Lamps: Circuit Short To Battery Or Open GO to Pinpoint Test A
BCM B1148:11 Right Front Fog Lamps: Circuit Short To Ground GO to Pinpoint Test A
BCM B1148:15 Right Front Fog Lamps: Circuit Short To Battery Or Open GO to Pinpoint Test A
BCM B1A79:11 Rear Fog Lamp: Circuit Short To Ground GO to Pinpoint Test B
BCM B1A79:15 Rear Fog Lamp: Circuit Short To Battery Or Open GO to Pinpoint Test B

Global Customer Symptom Code (GCSC) 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).


Symptom Action
Lighting/Glass/Vision > Exterior Lighting > Fog/Auxiliary > Inoperative GO to Pinpoint Test A
Lighting/Glass/Vision > Exterior Lighting > Fog/Auxiliary > Inoperative GO to Pinpoint Test B
Lighting/Glass/Vision > Exterior Lighting > Fog/Auxiliary > Inoperative GO to Pinpoint Test C
Lighting/Glass/Vision > Exterior Lighting > Fog/Auxiliary > Stays On GO to Pinpoint Test A
Lighting/Glass/Vision > Exterior Lighting > Fog/Auxiliary > Stays On GO to Pinpoint Test B

Symptom Chart

Symptom Chart: Fog Lamps

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
A module does not respond to the diagnostic scan tool
  • Fuse
  • Wiring, terminals or connectors
  • Module
 
REFER to: Controller Area Network (CAN) Module Communications Network (418-00A Controller Area Network (CAN) Module Communications Network, Diagnosis and Testing).
An individual front fog lamp is inoperative or always on Refer to the Pinpoint Test   GO to Pinpoint Test A
Both rear fog lamps are inoperative or always on Refer to the Pinpoint Test   GO to Pinpoint Test B
An individual rear fog lamp is inoperative Refer to the Pinpoint Test   GO to Pinpoint Test C

Pinpoint Tests


PINPOINT TEST A: AN INDIVIDUAL FRONT FOG LAMP IS INOPERATIVE OR ALWAYS ON

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

Normal Operation and Fault Conditions

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

DTC Fault Trigger Conditions

DTC Description Fault Trigger Condition
BCM B1147:11 Left Front Fog Lamps: Circuit Short To Ground A continuous memory and on-demand DTC that sets when the BCM detects a short to ground from the LH fog lamp output circuit.
BCM B1147:15 Left Front Fog Lamps: Circuit Short To Battery Or Open A continuous memory and on-demand DTC that sets when the BCM detects an open from the LH fog lamp output circuit.
BCM B1148:11 Right Front Fog Lamps: Circuit Short To Ground A continuous memory and on-demand DTC that sets when the BCM detects a short to ground from the RH fog lamp output circuit.
BCM B1148:15 Right Front Fog Lamps: Circuit Short To Battery Or Open A continuous memory and on-demand DTC that sets when the BCM detects an open from the RH fog lamp output circuit.

Possible Sources

  • Fog lamp assembly
  • Wiring, terminals or connectors
  • LDCM
  • BCM

Visual Inspection and Pre-checks

  • Inspect the fog lamp assembly for damage.
A1 CHECK FOR BCM (BODY CONTROL MODULE) DIAGNOSTIC TROUBLE CODES (DTCS)
  • Ignition ON.
  • Using a diagnostic scan tool, perform the BCM self-test.

Is DTC B1533:02, B1533:08, B1533:49 or B1533:56 present?
Yes
REFER to: Headlamps (417-01 Exterior Lighting, Diagnosis and Testing).
No GO to A2

A2 CHECK FOR LDCMA (LIGHTING DRIVER CONTROL MODULE A) ( LH (LEFT-HAND) HEADLAMP) OR LDCMB (LIGHTING DRIVER CONTROL MODULE B) ( RH (RIGHT-HAND) HEADLAMP) DIAGNOSTIC TROUBLE CODES (DTCS)
  • Ignition ON.
  • Using a diagnostic scan tool, perform the LDCMA ( LH headlamp) or LDCMB ( RH headlamp) self-test.

Are any LDCMA or LDCMB Diagnostic Trouble Codes (DTCs) present?
Yes REFER to the Master DTC Chart.
No GO to A3

A3 CHECK THE FRONT FOG LAMP OPERATION
  • Ignition ON.
  • While observing the front fog lamps, place the headlamp switch in the PARKLAMPS position and engage the front fog lamp switch.
  • While observing the front fog lamps, disengage the front fog lamp switch.

Does either front fog lamp stay on?
Yes GO to A4
No GO to A5

A4 CHECK THE FOG LAMP SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE
  • Ignition OFF.
  • Disconnect: For LH fog lamp, LH Headlamp C1758.
  • Disconnect: For RH fog lamp, RH Headlamp C1759.
  • Ignition ON.

Does the fog lamp continue to illuminate?
Yes REPAIR the circuits.
No GO to A13

A5 CHECK FOR SUPPLY VOLTAGE TO THE INOPERATIVE FOG LAMP
  • Ignition OFF.
  • Disconnect: Inoperative LH Fog Lamp C1322 or RH Fog Lamp C1323.
  • Ignition ON.
  • Measure:
    Click to display connectors

      LH Fog Lamp


    Positive Lead Measurement / Action Negative Lead
      C1322-1   Ground

    Click to display connectors

      RH Fog Lamp


    Positive Lead Measurement / Action Negative Lead
      C1323-1   Ground

Is the voltage greater than 11 volts?
Yes GO to A9
No GO to A6

A6 REPEAT THE ON-DEMAND SELF-TEST AND CHECK FOR SUPPLY VOLTAGE TO THE FOG LAMP
  • Using a diagnostic scan tool, perform the BCM self-test.
  • Clear the Diagnostic Trouble Codes (DTCs) and repeat the self-test (required to enable the lamp output driver if DTC U1000:00 is present).
  • Measure:
    Click to display connectors

      LH Fog Lamp


    Positive Lead Measurement / Action Negative Lead
      C1322-1   Ground

    Click to display connectors

      RH Fog Lamp


    Positive Lead Measurement / Action Negative Lead
      C1323-1   Ground

Is the voltage greater than 11 volts?
Yes INSTALL a new front fog lamp.
REFER to: Front Fog Lamp (417-01 Exterior Lighting, Removal and Installation).
No GO to A7

A7 CHECK FOG LAMP VOLTAGE SUPPLY CIRCUIT FOR A SHORT TO GROUND
  • Ignition OFF.
  • Disconnect: BCM C2280G.
  • Measure:
    Click to display connectors

      LH Fog Lamp


    Positive Lead Measurement / Action Negative Lead
      C1322-1   Ground

    Click to display connectors

      RH Fog Lamp


    Positive Lead Measurement / Action Negative Lead
      C1323-1   Ground

Is the resistance greater than 10,000 ohms?
Yes GO to A8
No REPAIR the circuit in question. After the repair:
If no Diagnostic Trouble Codes (DTCs) are present, TEST the system for normal operation.
If DTC U1000:00 is present, CLEAR the Diagnostic Trouble Codes (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, Removal and Installation).

A8 CHECK FOG LAMP VOLTAGE SUPPLY CIRCUIT FOR AN OPEN
  • Measure:
    Click to display connectors

      LH Fog Lamp


    Positive Lead Measurement / Action Negative Lead
      C1322-1   C2280G-12

    Click to display connectors

      RH Fog Lamp


    Positive Lead Measurement / Action Negative Lead
      C1323-1   C2280G-5

Is the resistance less than 3 ohms?
Yes GO to A15
No REPAIR the circuit.

A9 CHECK THE INOPERATIVE FOG LAMP GROUND CIRCUIT FOR AN OPEN
  • Measure:
    Click to display connectors

      LH Fog Lamp


    Positive Lead Measurement / Action Negative Lead
      C1322-1   C1322-3

    Click to display connectors

      RH Fog Lamp


    Positive Lead Measurement / Action Negative Lead
      C1323-1   C1323-3

Is the voltage greater than 11 volts?
Yes GO to A10
No REPAIR the circuit.

A10 CHECK FOR SIGNAL VOLTAGE TO THE INOPERATIVE FOG LAMP
  • Place the headlamp switch in the PARKLAMPS position and engage the front fog lamp switch.
  • Measure:
    Click to display connectors

      LH Fog Lamp


    Positive Lead Measurement / Action Negative Lead
      C1322-2   Ground

    Click to display connectors

      RH Fog Lamp


    Positive Lead Measurement / Action Negative Lead
      C1323-2   Ground

Is the voltage greater than 11 volts?
Yes INSTALL a new front fog lamp.
REFER to: Front Fog Lamp (417-01 Exterior Lighting, Removal and Installation).
No GO to A11

A11 CHECK FOG LAMP SIGNAL CIRCUIT FOR A SHORT TO GROUND
  • Ignition OFF.
  • Disconnect: For inoperative LH fog lamp, LH Headlamp C1758.
  • Disconnect: For inoperative RH fog lamp, RH Headlamp C1759.
  • Measure:
    Click to display connectors

      LH Fog Lamp


    Positive Lead Measurement / Action Negative Lead
      C1322-2   Ground

    Click to display connectors

      RH Fog Lamp


    Positive Lead Measurement / Action Negative Lead
      C1323-2   Ground

Is the resistance greater than 10,000 ohms?
Yes GO to A12
No REPAIR the circuit.

A12 CHECK FOG LAMP SIGNAL CIRCUIT FOR AN OPEN
  • Measure:
    Click to display connectors

      LH Fog Lamp


    Positive Lead Measurement / Action Negative Lead
      C1322-2   C1758-13

    Click to display connectors

      RH Fog Lamp


    Positive Lead Measurement / Action Negative Lead
      C1323-2   C1759-13

Is the resistance less than 3 ohms?
Yes GO to A13
No REPAIR the circuit.

A13 CHECK THE HEADLAMP
  • Place the headlamp switch in the OFF position.
  • Ignition OFF.
  • Substitute the known good headlamp assembly from the opposite side of the vehicle.
  • Ignition ON.
  • CLEAR the Diagnostic Trouble Codes (DTCs), REPEAT the self-test (required to enable the lamp output driver) and cycle the ignition OFF and ON. REPEAT the self-test.
  • Place the headlamp switch in the HEADLAMPS position.
  • Observe the system and determine if the concern is still present.

Is the concern still present or do the Diagnostic Trouble Codes (DTCs) return?
Yes GO to A15
No GO to A14

A14 CHECK THE LDCM (LIGHTING DRIVER CONTROL MODULE)
  • Place the headlamp switch in the OFF position.
  • Ignition OFF.
  • Reinstall the original headlamp assembly for the inoperative side of the vehicle.
  • INSTALL a new LDCM on the suspect headlamp.
    REFER to: Light Sensor (417-01 Exterior Lighting, Removal and Installation).
  • Ignition ON.
  • Using a diagnostic scan tool, complete the PMI process for the LDCMA ( LH headlamp) or for the LDCMB ( RH headlamp) following the on-screen instructions.
  • CLEAR the Diagnostic Trouble Codes (DTCs), REPEAT the self-test (required to enable the lamp output driver) and cycle the ignition OFF and ON. REPEAT the self-test.
  • Place the headlamp switch in the HEADLAMPS position.
  • Observe the system and determine if the concern is still present.

Is the concern still present or does any Diagnostic Trouble Codes (DTCs) return?
Yes REMOVE the known good LDCM control module. INSTALL a new headlamp assembly.
REFER to: Headlamp Assembly (417-01 Exterior Lighting, Removal and Installation).
No The system is operating correctly at this time. The concern may was caused by the LDCM .

A15 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, 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.

PINPOINT TEST B: BOTH REAR FOG LAMPS ARE INOPERATIVE OR ALWAYS ON

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

Normal Operation and Fault Conditions

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

DTC Fault Trigger Conditions

DTC Description Fault Trigger Condition
BCM B1A79:11 Rear Fog Lamp: Circuit Short To Ground A continuous memory and on-demand DTC that sets when the BCM detects a short to ground from the rear fog lamp output circuit.
BCM B1A79:15 Rear Fog Lamp: Circuit Short To Battery Or Open A continuous memory and on-demand DTC that sets when the BCM detects an open from the rear fog lamp output circuit.

Possible Sources

  • Wiring, terminals or connectors
  • Rear fog lamp
  • BCM

Visual Inspection and Pre-checks

  • Inspect the headlamp switch for damage.
B1 CHECK FOR BCM (BODY CONTROL MODULE) DIAGNOSTIC TROUBLE CODES (DTCS)
  • Ignition ON.
  • Using a diagnostic scan tool, perform the BCM self-test.

Is DTC B1533:02, B1533:08, B1533:49 or B1533:56 present?
Yes
REFER to: Headlamps (417-01 Exterior Lighting, Diagnosis and Testing).
No GO to B2

B2 CHECK THE REAR LAMP OPERATION
  • Ignition ON.
  • While observing the rear fog lamps, place the headlamp switch in the PARKLAMPS position and engage the rear fog lamp switch.
  • While observing the rear fog lamps, disengage the rear fog lamp switch.

Do the rear fog lamps stay on?
Yes GO to B3
No GO to B4

B3 CHECK THE REAR FOG LAMP VOLTAGE SUPPLY CIRCUIT FOR A SHORT TO VOLTAGE
  • Disconnect: BCM C2280C.
  • Ignition ON.

Do the rear fog lamps continue to illuminate?
Yes REPAIR the circuit.
No GO to B9

B4 CHECK FOR VOLTAGE TO THE REAR FOG LAMPS
  • Ignition OFF.
  • Disconnect: LH Rear Fog Lamp C437.
  • Ignition ON.
  • Place the headlamp switch in the PARKLAMPS position and engage the rear fog lamp switch.
  • Measure:
    Click to display connectors
    Positive Lead Measurement / Action Negative Lead
      C437-1   Ground

Is the voltage greater than 11 volts?
Yes REPAIR the rear fog lamps ground circuit for an open.
No GO to B5

B5 REPEAT THE ON-DEMAND SELF-TEST AND CHECK FOR VOLTAGE TO THE REAR FOG LAMPS
  • Place the headlamp switch in the OFF position.
  • Using a diagnostic scan tool, perform the BCM self-test.
  • Clear the Diagnostic Trouble Codes (DTCs) and repeat the self-test (required to enable the lamp output driver if DTC U1000:00 is present).
  • Ignition OFF.
  • Ignition ON.
  • Place the headlamp switch in the PARKLAMPS position and engage the rear fog lamp switch.
  • Measure:
    Click to display connectors
    Positive Lead Measurement / Action Negative Lead
      C437-1   Ground

Is the voltage greater than 11 volts?
Yes INSTALL a new LH rear fog lamp.
REFER to: Rear Fog Lamp (417-01 Exterior Lighting, Removal and Installation).
No GO to B6

B6 REPEAT THE ON-DEMAND SELF-TEST AND CHECK FOR VOLTAGE TO THE REAR FOG LAMPS WITH RH (RIGHT-HAND) REAR FOG LAMP DISCONNECTED
  • Place the headlamp switch in the OFF position.
  • Ignition OFF.
  • Ignition ON.
  • Disconnect: RH Rear Fog Lamp C436.
  • Using a diagnostic scan tool, perform the BCM self-test.
  • Clear the Diagnostic Trouble Codes (DTCs) and repeat the self-test (required to enable the lamp output driver if DTC U1000:00 is present).
  • Ignition OFF.
  • Ignition ON.
  • Place the headlamp switch in the PARKLAMPS position and engage the rear fog lamp switch.
  • Measure:
    Click to display connectors
    Positive Lead Measurement / Action Negative Lead
      C437-1   Ground

Is the voltage greater than 11 volts?
Yes INSTALL a new RH rear fog lamp.
REFER to: Rear Fog Lamp (417-01 Exterior Lighting, Removal and Installation).
No GO to B7

B7 CHECK THE REAR FOG LAMP VOLTAGE SUPPLY CIRCUIT FOR A SHORT TO GROUND
  • Place the headlamp switch in the OFF position.
  • Ignition OFF.
  • Disconnect: BCM C2280C.
  • Measure:
    Click to display connectors
    Positive Lead Measurement / Action Negative Lead
      C437-1   Ground

Is the resistance greater than 10,000 ohms?
Yes GO to B8
No REPAIR the circuit in question. After the repair:
If no Diagnostic Trouble Codes (DTCs) are present, TEST the system for normal operation.
If DTC U1000:00 is present, CLEAR the Diagnostic Trouble Codes (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, Removal and Installation).

B8 CHECK THE REAR FOG LAMP VOLTAGE SUPPLY CIRCUIT FOR AN OPEN
  • Measure:
    Click to display connectors
    Positive Lead Measurement / Action Negative Lead
      C437-1   C2280C-25

Is the resistance less than 3 ohms?
Yes GO to B9
No REPAIR the circuit.

B9 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, 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.

PINPOINT TEST C: AN INDIVIDUAL REAR FOG LAMP IS INOPERATIVE

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

Normal Operation and Fault Conditions

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

Possible Sources

  • Wiring, terminals or connectors
  • Rear fog lamp

Visual Inspection and Pre-checks

  • Inspect the rear fog lamp for damage.
C1 CHECK THE INOPERATIVE FOG LAMP VOLTAGE SUPPLY CIRCUIT FOR AN OPEN
  • Ignition OFF.
  • Disconnect: Inoperative LH Fog Lamp C437 or RH Fog Lamp C436.
  • Ignition ON.
  • Place the headlamp switch in the PARKLAMPS position and engage the rear fog lamp switch.
  • Measure:
    Click to display connectors

      LH Fog Lamp


    Positive Lead Measurement / Action Negative Lead
      C437-1   Ground

    Click to display connectors

      RH Fog Lamp


    Positive Lead Measurement / Action Negative Lead
      C436-1   Ground

Is the voltage greater than 11 volts?
Yes GO to C2
No REPAIR the circuit.

C2 CHECK THE INOPERATIVE FOG LAMP GROUND CIRCUIT FOR AN OPEN
  • Measure:
    Click to display connectors

      LH Fog Lamp


    Positive Lead Measurement / Action Negative Lead
      C437-1   C437-2

    Click to display connectors

      RH Fog Lamp


    Positive Lead Measurement / Action Negative Lead
      C436-1   C436-2

Is the voltage greater than 11 volts?
Yes INSTALL a new rear fog lamp.
REFER to: Rear Fog Lamp (417-01 Exterior Lighting, Removal and Installation).
No REPAIR the circuit.


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