Lincoln Nautilus Manuals

Lincoln Nautilus: Rear Seats / Rear Seats. Diagnosis and Testing

Lincoln Nautilus 2018-2024 Service Manual / Body and Paint / Body and Paint / Rear Seats / Rear Seats. Diagnosis and Testing

Symptom Chart(s)

Symptom Chart: Rear Seats

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
Both heated rear seats are inoperative
  • Refer to the Pinpoint Test
  • GO to Pinpoint Test A
The LH heated rear seat is inoperative
  • Refer to the Pinpoint Test
  • GO to Pinpoint Test B
The RH heated rear seat is inoperative
  • Refer to the Pinpoint Test
  • GO to Pinpoint Test C
The LH heated rear seat heats correctly but the indicator does not illuminate when activated
  • Refer to the Pinpoint Test
  • GO to Pinpoint Test D
The RH heated rear seat heats correctly but the indicator does not illuminate when activated
  • Refer to the Pinpoint Test
  • GO to Pinpoint Test E
The LH heated rear seat indicator is always on
  • Wiring, terminals or connectors
  • Heated seat module
  • DISCONNECT the heated rear seat module electrical connector.
    • If the LH heated rear seat indicator turns off when the heated rear seat module is disconnected, INSTALL a new heated rear seat module.
      REFER to: Heated Rear Seat Module (501-10B Rear Seats, Removal and Installation).
    • If the LH heated rear seat indicator remains on when the heated rear seat module is disconnected, REPAIR the LH heated rear seat module indicator circuits for a short to voltage.
The RH heated rear seat indicator is always on
  • Wiring, terminals or connectors
  • Heated seat module
  • DISCONNECT the heated rear seat module electrical connector.
    • If the RH heated rear seat indicator turns off when the heated rear seat module is disconnected, INSTALL a new heated rear seat module.
      REFER to: Heated Rear Seat Module (501-10B Rear Seats, Removal and Installation).
    • If the RH heated rear seat indicator remains on when the heated rear seat module is disconnected, REPAIR the RH heated rear seat module indicator circuits for a short to voltage.
Both rear power fold seats are inoperative
  • Refer to the Pinpoint Test
  • GO to Pinpoint Test F
The LH rear power fold seat is inoperative
  • Refer to the Pinpoint Test
  • GO to Pinpoint Test G
The RH rear power fold seat is inoperative
  • Refer to the Pinpoint Test
  • GO to Pinpoint Test H

Pinpoint Tests

Both Heated Rear Seats are Inoperative


Refer to Wiring Diagrams Cell 119 for schematic and connector information.

Normal Operation and Fault Conditions


REFER to: Rear Seats (501-10 Rear Seats) .

Possible Causes

  • Fuse
  • Wiring, terminals or connectors
  • Heated seat module

Visual Inspection and Diagnostic Pre-checks

  • Verify BCM fuse 36 (15A) is OK.
  • Verify BJB fuse 73 (20A) is OK.

PINPOINT TEST A: BOTH HEATED REAR SEATS ARE INOPERATIVE
A1 CHECK FOR VOLTAGE TO THE HEATED REAR SEAT MODULE
  • Disconnect Heated Rear Seat Module C3304B .
  • Ignition ON.
  • Measure:
    Click to display connectors
    Positive Lead Measurement / Action Negative Lead
      C3304B-1   Ground
      C3304B-2   Ground

Are the voltages greater than 11 volts?
Yes GO to A2
No VERIFY BJB fuse 73 (20A) and BCM fuse 36 (15A) are OK. If OK, REPAIR the circuit in question. If not OK, REFER to the Wiring Diagrams manual to identify the possible causes of the circuit short.

A2 CHECK THE HEATED REAR SEAT MODULE GROUND CIRCUIT FOR AN OPEN
  • Ignition OFF.
  • Measure:
    Click to display connectors
    Positive Lead Measurement / Action Negative Lead
      C3304B-5   Ground

Is the resistance less than 3 ohms?
Yes GO to A3
No REPAIR the circuit.

A3 VERIFY THE HEATED REAR SEAT SWITCH IS PROVIDING A GROUND INPUT SIGNAL TO THE HEATED SEAT MODULE
  • Disconnect Heated Rear Seat Module C3304A .
  • While pressing and releasing the LH heated rear seat switch, measure:
    Click to display connectors
    Positive Lead Measurement / Action Negative Lead
      C3304A-2   Ground

Is the resistance less than 3 ohms when the switch is pressed and greater than 10,000 ohms when released?
Yes GO to A5
No GO to A4

A4 CHECK THE HEATED REAR SEAT SWITCH GROUND CIRCUIT FOR AN OPEN
  • Disconnect Heated Rear Seat Switch C3182 .
  • Measure:
    Click to display connectors
    Positive Lead Measurement / Action Negative Lead
      C3182-8   Ground

Is the resistance less than 3 ohms?
Yes INSTALL a new heated rear seat switch.
REFER to: Heated Rear Seat Switch (501-10B Rear Seats, Removal and Installation).
No REPAIR the circuit.

A5 CHECK THE TEMPERATURE SENSOR CIRCUIT FOR SHORT TO VOLTAGE
  • Ignition ON.
  • Measure:
    Click to display connectors
    Positive Lead Measurement / Action Negative Lead
      C3304A-3   Ground

Is any voltage present?
Yes REPAIR the circuit.
No GO to A6

A6 CHECK THE TEMPERATURE SENSOR RETURN CIRCUIT FOR AN OPEN
  • Ignition OFF.
  • Measure:
    Click to display connectors
    Positive Lead Measurement / Action Negative Lead
      C3304A-3   C3304A-12

Is the resistance between 300 and 300K ohms?
Yes INSTALL a new heated rear seat module.
REFER to: Heated Rear Seat Module (501-10B Rear Seats, Removal and Installation).
No REPAIR the circuit.


The LH Heated Rear Seat is Inoperative


Refer to Wiring Diagrams Cell 119 for schematic and connector information.

Normal Operation and Fault Conditions


REFER to: Rear Seats (501-10 Rear Seats) .

Possible Causes

  • Wiring, terminals or connectors
  • Heater mat
  • Heated seat switch
  • Heated seat module

PINPOINT TEST B: THE LH (LEFT-HAND) HEATED REAR SEAT IS INOPERATIVE
B1 CHECK THE HEATED SEAT SWITCH INPUT
  • Ignition OFF.
  • Disconnect Heated Rear Seat Module C3304A .
  • While pressing and releasing the LH heated rear seat switch, measure:
    Click to display connectors
    Positive Lead Measurement / Action Negative Lead
      C3304A-2   Ground

Is the resistance less than 3 ohms when the switch is pressed and greater than 10,000 ohms when released?
Yes GO to B3
No GO to B2

B2 CHECK THE HEATED SEAT SWITCH CIRCUIT FOR AN OPEN OR SHORT TO GROUND
  • Disconnect Heated Rear Seat Switch C3182 .
  • Measure:
    Click to display connectors
    Positive Lead Measurement / Action Negative Lead
      C3182-2   C3304A-2
      C3182-2   Ground

Are the resistances less than 3 ohms between the heated seat switch and heated seat module, and greater than 10,000 ohms between the heated seat switch and ground?
Yes INSTALL a new heated rear seat switch.
REFER to: Heated Rear Seat Switch (501-10B Rear Seats, Removal and Installation).
No REPAIR the circuit.

B3 CHECK FOR VOLTAGE TO THE HEATED SEAT MODULE
  • Disconnect Heated Rear Seat Module C3304B .
  • Measure:
    Click to display connectors
    Positive Lead Measurement / Action Negative Lead
      C3304B-1   Ground

Is the voltage greater than 11 volts?
Yes GO to B4
No REPAIR the circuit.

B4 CHECK THE HEATER CIRCUITS AND HEATER MATS FOR AN OPEN
  • Measure:
    Click to display connectors
    Positive Lead Measurement / Action Negative Lead
      C3304B-4   Ground

Is the resistance between 2.5 and 4.5 ohms?
Yes GO to B9
No GO to B5

B5 CHECK THE HEATER MAT GROUND CIRCUIT FOR AN OPEN
  • Disconnect LH Rear Backrest Heater Mat C3168 .
  • Measure:
    Click to display connectors
    Positive Lead Measurement / Action Negative Lead
      C3168-2   Ground

Is the resistance less than 3 ohms?
Yes GO to B6
No REPAIR the circuit.

B6 CHECK THE HEATER CIRCUIT FOR AN OPEN OR SHORT TO GROUND
  • Disconnect LH Rear Cushion Heater Mat C3167 .
  • Measure:
    Click to display connectors
    Positive Lead Measurement / Action Negative Lead
      C3304B-4   C3167-1
  • Measure:
    Click to display connectors
    Positive Lead Measurement / Action Negative Lead
      C3304B-4 Ground

Are the resistances less than 3 ohms between the heated seat module and the LH rear cusion heater mat, and greater than 10,000 ohms between the heated seat module and ground?
Yes GO to B7
No REPAIR the circuit.

B7 CHECK THE CUSHION HEATER MAT FOR AN OPEN
  • Measure the component side resistance between:
    Positive Lead Measurement / Action Negative Lead
    C3167-1, Component Side C3167-4, Component Side

Is the resistance between 1.5 and 2.5 ohms?
Yes GO to B8
No INSTALL a new cushion heater mat.
REFER to: Seat Heater Mat Removal (501-10A Front Seats, General Procedures).

B8 CHECK FOR AN OPEN OR A SHORT TO GROUND BETWEEN THE HEATER MATS
  • Measure:
    Click to display connectors
    Positive Lead Measurement / Action Negative Lead
      C3167-4   C3168-1
  • Measure:
    Click to display connectors
    Positive Lead Measurement / Action Negative Lead
      C3167-4 Ground

Are the resistances less than 3 ohms between the cushion heater mat and backrest heater mat, and greater than 10,000 ohms between cushion heater mat and ground?
Yes INSTALL a new backrest heater mat.
REFER to: Seat Heater Mat Removal (501-10A Front Seats, General Procedures).
No REPAIR the circuit.

B9 CHECK THE TEMPERATURE SENSOR CIRCUIT FOR A SHORT TO VOLTAGE
  • Ignition ON.
  • Measure:
    Click to display connectors
    Positive Lead Measurement / Action Negative Lead
      C3304A-3 Ground

Is any voltage present?
Yes REPAIR the circuit.
No GO to B10

B10 CHECK THE TEMPERATURE SENSOR CIRCUIT FOR A SHORT TO GROUND
  • Ignition OFF.
  • Measure:
    Click to display connectors
    Positive Lead Measurement / Action Negative Lead
      C3304A-3 Ground

Is the resistance greater than 10,000 ohms?
Yes GO to B11
No REPAIR the circuit.

B11 CHECK THE TEMPERATURE SENSOR AND CIRCUITS FOR AN OPEN
  • Measure:
    Click to display connectors
    Positive Lead Measurement / Action Negative Lead
      C3304A-3   C3304A-12

Is the resistance between 300 and 300K ohms?
Yes INSTALL a new heated rear seat module.
REFER to: Heated Rear Seat Module (501-10B Rear Seats, Removal and Installation).
No GO to B12

B12 CHECK THE TEMPERATURE SENSOR FOR AN OPEN WITH THE HEATER MAT DISCONNECTED
  • Disconnect LH Rear Cushion Heater Mat C3167 .
  • Measure:
    Click to display connectors
    Positive Lead Measurement / Action Negative Lead
      C3304A-3   C3167-2
      C3304A-12   C3167-3

Are the resistances less than 3 ohms?
Yes INSTALL a new cushion heater mat.
REFER to: Seat Heater Mat Removal (501-10A Front Seats, General Procedures).
No REPAIR the circuit in question.


The RH Heated Rear Seat is Inoperative


Refer to Wiring Diagrams Cell 119 for schematic and connector information.

Normal Operation and Fault Conditions


REFER to: Rear Seats (501-10 Rear Seats) .

Possible Causes

  • Wiring, terminals or connectors
  • Heater mat
  • Heated seat switch
  • Heated seat module

PINPOINT TEST C: THE RH (RIGHT-HAND) HEATED REAR SEAT IS INOPERATIVE
C1 CHECK THE HEATED SEAT SWITCH INPUT
  • Ignition OFF.
  • Disconnect Heated Rear Seat Module C3304A .
  • While pressing and releasing the RH heated rear seat switch, measure:
    Click to display connectors
    Positive Lead Measurement / Action Negative Lead
      C3304A-8   Ground

Is the resistance less than 3 ohms when the switch is pressed and greater than 10,000 ohms when released?
Yes GO to C3
No GO to C2

C2 CHECK THE HEATED SEAT SWITCH CIRCUIT FOR AN OPEN OR SHORT TO GROUND
  • Disconnect Heated Rear Seat Switch C3182 .
  • Measure:
    Click to display connectors
    Positive Lead Measurement / Action Negative Lead
      C3182-3   C3304A-8
      C3182-3   Ground

Are the resistances less than 3 ohms between the heated rear seat switch and heated rear seat module, and greater than 10,000 ohms between the heated rear seat switch and ground?
Yes INSTALL a new heated rear seat switch.
REFER to: Power Fold Seat Control Switch (501-10B Rear Seats, Removal and Installation).
No REPAIR the circuit.

C3 CHECK FOR VOLTAGE TO THE HEATED SEAT MODULE
  • Disconnect Heated Rear Seat Module C3304B .
  • Measure:
    Click to display connectors
    Positive Lead Measurement / Action Negative Lead
      C3304B-3   Ground

Is the voltage greater than 11 volts?
Yes GO to C4
No REPAIR the circuit.

C4 CHECK THE HEATER CIRCUITS AND HEATER MATS FOR AN OPEN
  • Measure:
    Click to display connectors
    Positive Lead Measurement / Action Negative Lead
      C3304B-6   Ground

Is the resistance between 2.5 and 4.5 ohms?
Yes GO to C9
No GO to C5

C5 CHECK THE HEATER MAT GROUND CIRCUIT FOR AN OPEN
  • Disconnect RH Rear Backrest Heater Mat C3169 .
  • Measure:
    Click to display connectors
    Positive Lead Measurement / Action Negative Lead
      C3169-2   Ground

Is the resistance less than 3 ohms?
Yes GO to C6
No REPAIR the circuit.

C6 CHECK THE HEATER CIRCUIT FOR AN OPEN OR SHORT TO GROUND
  • Disconnect RH Rear Cushion Heater Mat C3045 .
  • Measure:
    Click to display connectors
    Positive Lead Measurement / Action Negative Lead
      C3304B-6   C3045-1
  • Measure:
    Click to display connectors
    Positive Lead Measurement / Action Negative Lead
      C3304B-6 Ground

Are the resistances less than 3 ohms between the heated rear seat module and rear seat cushion heater mat, and greater than 10,000 ohms between the heated rear seat module and ground?
Yes GO to C7
No REPAIR the circuit.

C7 CHECK THE CUSHION HEATER MAT FOR AN OPEN
  • Measure the component side resistance between:
    Positive Lead Measurement / Action Negative Lead
    C3045-1, Component Side C3045-4, Component Side

Is the resistance between 1.5 and 2.5 ohms?
Yes GO to C8
No INSTALL a new cushion heater mat.
REFER to: Seat Heater Mat Removal (501-10A Front Seats, General Procedures).

C8 CHECK FOR AN OPEN OR A SHORT TO GROUND BETWEEN THE HEATER MATS
  • Measure:
    Click to display connectors
    Positive Lead Measurement / Action Negative Lead
      C3045-4   C3169-1
  • Measure:
    Click to display connectors
    Positive Lead Measurement / Action Negative Lead
      C3045-4 Ground

Are the resistances less than 3 ohms between the rear seat cushion heater mat and rear seat backrest heater mat, and greater than 10,000 ohms between the rear seat cushion heater mat and ground?
Yes INSTALL a new backrest heater mat.
REFER to: Seat Heater Mat Removal (501-10A Front Seats, General Procedures).
No REPAIR the circuit.

C9 CHECK THE TEMPERATURE SENSOR CIRCUIT FOR A SHORT TO VOLTAGE
  • Ignition ON.
  • Measure:
    Click to display connectors
    Positive Lead Measurement / Action Negative Lead
      C3304A-9 Ground

Is any voltage present?
Yes REPAIR the circuit.
No GO to C10

C10 CHECK THE TEMPERATURE SENSOR CIRCUIT FOR A SHORT TO GROUND
  • Ignition OFF.
  • Measure:
    Click to display connectors
    Positive Lead Measurement / Action Negative Lead
      C3304A-9 Ground

Is the resistance greater than 10,000 ohms?
Yes GO to C11
No REPAIR the circuit.

C11 CHECK THE TEMPERATURE SENSOR AND CIRCUITS FOR AN OPEN
  • Measure:
    Click to display connectors
    Positive Lead Measurement / Action Negative Lead
      C3304A-9   C3304A-12

Is the resistance between 300 and 300K ohms?
Yes INSTALL a new heated rear seat module.
REFER to: Heated Rear Seat Module (501-10B Rear Seats, Removal and Installation).
No GO to C12

C12 CHECK THE TEMPERATURE SENSOR FOR AN OPEN WITH THE HEATER MAT DISCONNECTED
  • Disconnect RH Rear Cushion Heater Mat C3045 .
  • Measure:
    Click to display connectors
    Positive Lead Measurement / Action Negative Lead
      C3304A-9   C3045-2
      C3304A-12   C3045-3

Are the resistances less than 3 ohms?
Yes INSTALL a new backrest heater mat.
REFER to: Seat Heater Mat Removal (501-10A Front Seats, General Procedures).
No REPAIR the circuit in question.


The LH Heated Rear Seat Heats Correctly But The Indicator Does Not Illuminate When Activated


Refer to Wiring Diagrams Cell 119 for schematic and connector information.

Normal Operation and Fault Conditions

With the ignition and heated seat on, the heated seat module supplies voltage to the indicator circuit(s) to illuminate the appropriate switch indicator. The first button press puts the seat heater on low. A second button press operates the seat heater on high. The heated seat and indicator deactivates with a third button press.

Possible Causes

  • Wiring, terminals or connectors
  • Heated rear seat switch
  • Heated rear seat module

Visual Inspection and Diagnostic Pre-checks

  • Inspect for a damaged heated rear seat switch.

PINPOINT TEST D: THE LH (LEFT-HAND) HEATED REAR SEAT HEATS CORRECTLY BUT THE INDICATOR DOES NOT ILLUMINATE WHEN ACTIVATED
D1 CHECK THE HEATED SEAT INDICATOR CIRCUITS FOR A SHORT TO GROUND
  • Ignition OFF.
  • Disconnect Heated Rear Seat Module C3304A .
  • Disconnect Heated Rear Seat Switch C3182 .
  • Measure:
    Click to display connectors
    Positive Lead Measurement / Action Negative Lead
      C3304A-4 Ground
      C3304A-5 Ground

Are the resistances greater than 10,000 ohms?
Yes GO to D2
No REPAIR the circuit in question.

D2 CHECK THE HEATED SEAT INDICATOR CIRCUITS FOR AN OPEN
  • Measure:
    Click to display connectors
    Positive Lead Measurement / Action Negative Lead
      C3304A-4   C3182-6
      C3304A-5   C3182-7

Are the resistances less than 3 ohms?
Yes GO to D3
No REPAIR the circuit in question.

D3 CHECK THE HIGH HEAT INDICATOR
  • Disconnect Heated Rear Seat Module C3304B .
  • Connect Heated Rear Seat Switch C3182 .
  • Connect:
    Click to display connectors
    Positive Lead Measurement / Action Negative Lead
      C3304A-5   C3304B-1

Does the indicator illuminate?
Yes REMOVE the fused jumper wire. GO to D4
No REMOVE the fused jumper wire. INSTALL a new heated rear seat switch.
REFER to: Heated Rear Seat Switch (501-10B Rear Seats, Removal and Installation).

D4 CHECK THE LOW HEAT INDICATOR
  • Connect:
    Click to display connectors
    Positive Lead Measurement / Action Negative Lead
      C3304A-4   C3304B-1

Does the indicator illuminate?
Yes REMOVE the fused jumper wire. INSTALL a new heated rear seat module.
REFER to: Heated Rear Seat Module (501-10B Rear Seats, Removal and Installation).
No REMOVE the fused jumper wire. INSTALL a new heated rear seat switch.
REFER to: Heated Rear Seat Switch (501-10B Rear Seats, Removal and Installation).


The RH Heated Rear Seat Heats Correctly But The Indicator Does Not Illuminate When Activated


Refer to Wiring Diagrams Cell 119 for schematic and connector information.

Normal Operation and Fault Conditions

With the ignition and heated seat on, the heated seat module supplies voltage to the indicator circuit(s) to illuminate the appropriate switch indicator. The first button press puts the seat heater on low. A second button press operates the seat heater on high. The heated seat and indicator deactivates with a third button press.

Possible Causes

  • Wiring, terminals or connectors
  • Heated rear seat switch
  • Heated rear seat module

Visual Inspection and Diagnostic Pre-checks

  • Inspect for a damaged heated rear seat switch.

PINPOINT TEST E: THE RH (RIGHT-HAND) HEATED REAR SEAT HEATS CORRECTLY BUT THE INDICATOR DOES NOT ILLUMINATE WHEN ACTIVATED
E1 CHECK THE HEATED SEAT INDICATOR CIRCUITS FOR A SHORT TO GROUND
  • Ignition OFF.
  • Disconnect Heated Rear Seat Module C3304A .
  • Disconnect Heated Rear Seat Switch C3182 .
  • Measure:
    Click to display connectors
    Positive Lead Measurement / Action Negative Lead
      C3304A-10 Ground
      C3304A-11 Ground

Are the resistances greater than 10,000 ohms?
Yes GO to E2
No REPAIR the circuit in question.

E2 CHECK THE HEATED SEAT INDICATOR CIRCUITS FOR AN OPEN
  • Measure:
    Click to display connectors
    Positive Lead Measurement / Action Negative Lead
      C3304A-10   C3182-4
      C3304A-11   C3182-5

Are the resistances less than 3 ohms?
Yes GO to E3
No REPAIR the circuit in question.

E3 CHECK THE HIGH HEAT INDICATOR
  • Disconnect Heated Rear Seat Module C3304B .
  • Connect Heated Rear Seat Switch C3182 .
  • Connect:
    Click to display connectors
    Positive Lead Measurement / Action Negative Lead
      C3304A-11   C3304B-3

Does the indicator illuminate?
Yes REMOVE the fused jumper wire. GO to E4
No REMOVE the fused jumper wire. INSTALL a new heated rear seat switch.
REFER to: Heated Rear Seat Switch (501-10B Rear Seats, Removal and Installation).

E4 CHECK THE LOW HEAT INDICATOR
  • Connect:
    Click to display connectors
    Positive Lead Measurement / Action Negative Lead
      C3304A-10   C3304B-3

Does the indicator illuminate?
Yes REMOVE the fused jumper wire. INSTALL a new heated rear seat module.
REFER to: Heated Rear Seat Module (501-10B Rear Seats, Removal and Installation).
No REMOVE the fused jumper wire. INSTALL a new heated rear seat switch.
REFER to: Heated Rear Seat Switch (501-10B Rear Seats, Removal and Installation).


Both Rear Power Fold Seats Are Inoperative


Refer to Wiring Diagrams Cell 120 for schematic and connector information.

Normal Operation and Fault Conditions


REFER to: Rear Seats (501-10 Rear Seats) .

Possible Causes

  • Fuse
  • Wiring, terminals or connectors
  • Demand lighting system concern
  • Second row seat control switch
  • BCM

Visual Inspection and Diagnostic Pre-checks

  • Verify BJB fuse 1 (30A) is OK.

PINPOINT TEST F: BOTH REAR POWER FOLD SEATS ARE INOPERATIVE
F1 CHECK THE DEMAND LIGHTING OPERATION
  • Ignition ON.
  • Verify the demand lighting (map/reading lights, vanity mirror lamps) operates.

Do the demand lighting lamps operate?
Yes GO to F2
No Diagnose the inoperative demand lighting system.
REFER to: Interior Lighting (417-02 Interior Lighting) .

F2 CHECK FOR BATTERY VOLTAGE TO THE SECOND ROW SEAT RELEASE LH (LEFT-HAND) RELAY
  • Ignition OFF.
  • Disconnect Second Row Seat Release LH Relay.
  • Measure:
    Positive Lead Measurement / Action Negative Lead
    Second Row Seat Relase LH Relay, socket pin 3   Ground

Is the voltage greater than 11 volts?
Yes GO to F3
No VERIFY BJB fuse 1 (30A) is OK. If OK, REPAIR the circuit. If not OK, REFER to the Wiring Diagrams manual to identify the possible causes of the circuit short.

F3 CHECK THE ENABLE CIRCUIT FOR VOLTAGE TO THE SECOND ROW SEAT RELEASE LH (LEFT-HAND) RELAY
  • Ignition ON.
  • Measure:
    Positive Lead Measurement / Action Negative Lead
    Second Row Seat Relase LH Relay, socket pin 1   Ground

Is the voltage greater than 11 volts?
Yes GO to F5
No GO to F4

F4 CHECK THE ENABLE CIRCUIT FOR AN OPEN
  • Ignition OFF.
  • Disconnect BCM C2280D .
  • Measure:
    Positive Lead Measurement / Action Negative Lead
    Second Row Seat Relase LH Relay, socket pin 1   C2280D-11

Is the resistance less than 3 ohms?
Yes GO to F6
No REPAIR the circuit.

F5 CHECK THE SECOND ROW SEAT CONTROL SWITCH GROUND CIRCUIT FOR AN OPEN
  • Ignition OFF.
  • Disconnect Second Row Seat Control Switch C3343 .
  • Ignition ON.
  • Measure:
    Click to display connectors
    Positive Lead Measurement / Action Negative Lead
      C3343-3   Ground

Is the resistance less than 3 ohms?
Yes INSTALL a new second row seat control switch.
REFER to: Power Fold Seat Control Switch (501-10B Rear Seats, Removal and Installation).
No REPAIR the circuit.

F6 CHECK FOR CORRECT BCM (BODY CONTROL MODULE) MODULE OPERATION
  • Ignition OFF.
  • Disconnect and inspect all the BCM connectors.
  • Repair:
    • corrosion (install new connector or terminals - clean module pins)
    • damaged or bent pins - install new terminals/pins as necessary
    • pushed-out pins - install new pins as necessary
  • Reconnect the BCM connectors and all previously disconnected system 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 the appropriate Removal and Installation procedure in Section 419-10.
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 LH Rear Power Fold Seat Is Inoperative


Refer to Wiring Diagrams Cell 120 for schematic and connector information.

Normal Operation and Fault Conditions


REFER to: Rear Seats (501-10 Rear Seats) .

Possible Causes

  • Wiring, terminals or connectors
  • Second row seat control switch
  • Second row rear seat motor

PINPOINT TEST G: THE LH (LEFT-HAND) REAR POWER FOLD SEAT IS INOPERATIVE
G1 CHECK FOR VOLTAGE TO THE SECOND ROW SEAT RELEASE LH (LEFT-HAND) RELAY
  • Ignition OFF.
  • Disconnect Second Row Seat Release LH Relay.
  • Ignition ON.
  • Measure:
    Positive Lead Measurement / Action Negative Lead
    Second Row Seat Relase LH Relay, socket pin 3   Ground
    Second Row Seat Relase LH Relay, socket pin 1   Ground

Are the voltages greater than 11 volts?
Yes GO to G2
No REPAIR the circuit in question.

G2 CHECK FOR SECOND ROW SEAT CONTROL SWITCH INPUT TO THE LH (LEFT-HAND) RELAY

NOTICE: The following step uses a test lamp to simulate normal circuit loads. Use only a Rotunda Test Lamp (SGT27000) or 250- 300mA incandescent bulb test lamp. To avoid connector terminal damage, use the Rotunda Flex Probe kit for the test lamp probe connection to the vehicle. Do not use the test lamp probe directly on any connector.

  • Connect:
    Positive Lead Measurement / Action Negative Lead
    Second Row Seat Relase LH Relay, socket pin 1 Second Row Seat Relase LH Relay, socket pin 2
  • Press and release the LH second row seat control switch while observing the test lamp.

Did the test lamp illuminate on and off when the seat control switch was pressed and released?
Yes GO to G4
No GO to G3

G3 CHECK THE SECOND ROW REAR SEAT CONTROL SWITCH CIRCUIT FOR AN OPEN OR SHORT TO GROUND
  • Ignition OFF.
  • Disconnect Second Row Seat Control Switch C3343 .
  • Measure:
    Positive Lead Measurement / Action Negative Lead
      C3343-4 Second Row Seat Relase LH Relay, socket pin 2
      C3343-4   Ground

Is the resistance less than 3 ohms between the switch and the relay, and greater than 10,000 ohms between the switch and ground?
Yes INSTALL a new second row seat control switch.
REFER to: Power Fold Seat Control Switch (501-10B Rear Seats, Removal and Installation).
No REPAIR the circuit.

G4 CHECK THE SECOND ROW SEAT RELEASE LH (LEFT-HAND) RELAY
  • Ignition OFF.
  • Disconnect Second Row Seat Release RH Relay.
  • Install the RH second row seat release relay in the LH second row seat release relay socket.
  • Ignition ON.
  • Attempt to operate the second row seat.

Does the seat operate correctly when the RH second row seat release relay is installed in the LH second row seat release relay socket?
Yes INSTALL a new relay.
No GO to G5

G5 CHECK THE SECOND ROW REAR SEAT MOTOR GROUND
  • Ignition OFF.
  • Disconnect LH Second Row Rear Seat Motor C3345 .
  • Measure:
    Click to display connectors
    Positive Lead Measurement / Action Negative Lead
      C3345-2   Ground

Is the resistance less than 3 ohms?
Yes GO to G6
No REPAIR the circuit.

G6 CHECK THE SECOND ROW REAR SEAT MOTOR CIRCUIT FOR AN OPEN
  • Measure:
    Positive Lead Measurement / Action Negative Lead
      C3345-1 Second Row Seat Relase LH Relay, socket pin 5

Is the resistance less than 3 ohms?
Yes INSTALL a new LH second row seat motor.
REFER to: Power Fold Seat Motor (501-10 Rear Seats) .
No REPAIR the circuit.


The RH Rear Power Fold Seat Is Inoperative


Refer to Wiring Diagrams Cell 120 for schematic and connector information.

Normal Operation and Fault Conditions


REFER to: Rear Seats (501-10 Rear Seats) .

Possible Causes

  • Wiring, terminals or connectors
  • Second row seat control switch
  • Second row rear seat motor

PINPOINT TEST H: THE RH (RIGHT-HAND) REAR POWER FOLD SEAT IS INOPERATIVE
H1 CHECK FOR VOLTAGE TO THE SECOND ROW SEAT RELEASE RH (RIGHT-HAND) RELAY
  • Ignition OFF.
  • Disconnect Second Row Seat Release RH Relay.
  • Ignition ON.
  • Measure:
    Positive Lead Measurement / Action Negative Lead
    Second Row Seat Relase RH Relay, socket pin 3   Ground
    Second Row Seat Relase RH Relay, socket pin 1   Ground

Are the voltages greater than 11 volts?
Yes GO to H2
No REPAIR the circuit in question.

H2 CHECK FOR SECOND ROW SEAT CONTROL SWITCH INPUT TO THE RH (RIGHT-HAND) RELAY

NOTICE: The following step uses a test lamp to simulate normal circuit loads. Use only a Rotunda Test Lamp (SGT27000) or 250- 300mA incandescent bulb test lamp. To avoid connector terminal damage, use the Rotunda Flex Probe kit for the test lamp probe connection to the vehicle. Do not use the test lamp probe directly on any connector.

  • Connect:
    Positive Lead Measurement / Action Negative Lead
    Second Row Seat Relase RH Relay, socket pin 1 Second Row Seat Relase RH Relay, socket pin 2
  • Press and release the RH second row seat control switch while observing the test lamp.

Did the test lamp illuminate on and off when the seat control switch was pressed and released?
Yes GO to H4
No GO to H3

H3 CHECK THE SECOND ROW REAR SEAT CONTROL SWITCH CIRCUIT FOR AN OPEN OR SHORT TO GROUND
  • Ignition OFF.
  • Disconnect Second Row Seat Control Switch C3343 .
  • Measure:
    Positive Lead Measurement / Action Negative Lead
      C3343-2 Second Row Seat Relase RH Relay, socket pin 2
      C3343-2   Ground

Is the resistance less than 3 ohms between the switch and the relay, and greater than 10,000 ohms between the switch and ground?
Yes INSTALL a new second row seat control switch.
REFER to: Power Fold Seat Control Switch (501-10B Rear Seats, Removal and Installation).
No REPAIR the circuit.

H4 CHECK THE SECOND ROW SEAT RELEASE RH (RIGHT-HAND) RELAY
  • Ignition OFF.
  • Disconnect Second Row Seat Release LH Relay.
  • Install the LH second row seat release relay in the RH second row seat release relay socket.
  • Ignition ON.
  • Attempt to operate the second row seat.

Does the seat operate correctly when the LH second row seat release relay is installed in the RH second row seat release relay socket?
Yes INSTALL a new relay.
No GO to H5

H5 CHECK THE SECOND ROW REAR SEAT MOTOR GROUND
  • Ignition OFF.
  • Disconnect RH Second Row Rear Seat Motor C3346 .
  • Measure:
    Click to display connectors
    Positive Lead Measurement / Action Negative Lead
      C3346-2   Ground

Is the resistance less than 3 ohms?
Yes GO to H6
No REPAIR the circuit.

H6 CHECK THE SECOND ROW REAR SEAT MOTOR CIRCUIT FOR AN OPEN
  • Measure:
    Positive Lead Measurement / Action Negative Lead
      C3346-1 Second Row Seat Relase RH Relay, socket pin 5

Is the resistance less than 3 ohms?
Yes INSTALL a new RH second row seat motor.
REFER to: Power Fold Seat Motor (501-10 Rear Seats) .
No REPAIR the circuit.


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    Removal Remove the rear seat cushion. Refer to: Rear Seat Cushion (501-10B Rear Seats, Removal and Installation). Release the seat cushion cover J-clips...

    Other information:

    Lincoln Nautilus 2018-2024 Service Manual: Headlamp Bulb. Removal and Installation


    Removal Remove the headlamp assembly. Refer to: Headlamp Assembly (417-01 Exterior Lighting, Removal and Installation). Remove the screws and position the ballast. Disconnect the electrical connectors and remove the ballast...

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    Special Tool(s) / General Equipment Resistance Spotwelding Equipment Spherical Cutter Hot Air Gun Air Body Saw MIG/MAG Welding Equipment Spot Weld Drill Bit Locking Pliers Materials Name Specification Seam SealerTA-2-B, 3M™ 08308, LORD Fusor® 803DTM -  Flexible Foam Repair3M™ 08463, LORD Fusor® 121 -  Removal R..

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    Replacing the Rear Wiper Blades

    Lincoln Nautilus. Replacing the Rear Wiper Blades

    Lift the wiper arm.

    Note: Do not hold the wiper blade to lift the wiper arm.

    Remove the wiper blade.

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