Nissan Pathfinder (2009 year). Manual - part 215

DLN-202

< COMPONENT DIAGNOSIS >

[TRANSFER: TX15B]

P1801, P1811 POWER SUPPLY CIRCUIT FOR TRANSFER CONTROL UNIT

COMPONENT DIAGNOSIS

P1801, P1811 POWER SUPPLY CIRCUIT FOR TRANSFER CONTROL
UNIT

Description

INFOID:0000000003937323

The transfer control unit controls the transfer control device which controls shifts between 4H and 4LO and
between 2WD and 4WD.  When the vehicle battery is removed, the power supply to the transfer control unit is
interupted, and self-diagnosis memory function is suspended.  These DTC's may also set when the power
supply voltage for the transfer control unit is abnormally low while driving.

DTC Logic

INFOID:0000000003937324

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

DTC CONFIRMATION PROCEDURE

1.

Turn ignition switch ON.

2.

Perform self-diagnosis.

Are DTC's “P1801 or P1811 detected?

YES

>> Perform diagnosis procedure. Refer to 

DLN-202, "Diagnosis Procedure"

.

NO

>> Inspection End.

Diagnosis Procedure

INFOID:0000000003937325

1.

CHECK POWER SUPPLY

1.

Turn ignition switch “OFF”.  (Stay for at least 5 seconds.)

2.

Disconnect transfer control unit harness connector.

3.

Check voltage between transfer control unit harness connector
terminals and ground.

DTC

CONSULT-III

Diagnostic item is detected when...

Reference

[P1801]

*INITIAL START*

Due to removal of battery which cuts off 
power supply to transfer control unit, 
self-diagnosis memory function is sus-
pended.

DLN-202

[P1811]

BATTERY VOLTAGE

Power supply voltage for transfer control 
unit is abnormally low while driving.

Connector

Terminal

Voltage (Approx.)

M165

19 - Ground

Battery voltage

25 - Ground

0V

M166

40 - Ground

Battery voltage

44 - Ground

0V

45 - Ground

SDIA3360E

2009 Pathfinder

P1801, P1811 POWER SUPPLY CIRCUIT FOR TRANSFER CONTROL UNIT

DLN-203

< COMPONENT DIAGNOSIS >

[TRANSFER: TX15B]

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4.

Turn ignition switch “ON”. (Do not start engine.)

5.

Check voltage between transfer control unit harness connector
terminals and ground.

Is there voltage?

YES

>> GO TO 2.

NO

>>

Check the following. If any items are damaged, repair or replace damaged parts.

• 40A fuse (No. j, located in the fuse and fusible link box).
• 10A fuses (No. 21, located in the fuse block (J/B) and Nos. 60 and 61 located in the fuse and

relay box).

• Harness for short or open between battery and transfer control unit harness connector M165

terminal 19.

• Harness for short or open between battery and transfer shut off relay 2 harness connector E157

terminal 1 and 3.

• Harness for short or open between battery and transfer shut off relay 1 harness connector E156

terminal 3.

• Harness for short or open between ignition switch and transfer control unit harness connector

M165 terminal 25.

• Harness for short or open between ignition switch and transfer shut off relay 1 harness connec-

tor E156 terminal 1.

• Harness for short or open between transfer shut off relay 2 harness connector E157 terminal 5

and transfer control unit harness connector M166 terminals 44, 45.

• Harness for short or open between transfer shut off relay 1 harness connector E156 terminal 5

and transfer control unit harness connector M166 terminals 44, 45.

• Harness for short or open between transfer shut off relay 2 harness connector E157 terminal 2

and transfer control unit harness connector M166 terminal 40.

• Harness for open between transfer shut off relay 1 harness connector E156 terminal 2 and

ground.

• Battery and ignition switch.
• Transfer shut off relay 1, 2. Refer to 

DLN-204, "Component Inspection"

.

2.

CHECK GROUND CIRCUIT

1.

Turn ignition switch “OFF”.

2.

Disconnect transfer control unit harness connector.

3.

Check continuity between transfer control unit harness connec-
tor M165 terminals 6 and 18, and M166 terminal 32 and ground.

Also check harness for short to power.

Do you have continuity?

YES

>> GO TO 3.

NO

>> Repair open circuit or short to power in harness or con-

nectors.

3.

CHECK TRANSFER CONTROL UNIT

Check transfer control unit input/output signal. Refer to 

DLN-233, "Reference Value"

.

Are the inspection results normal?

YES

>> GO TO 4.

Connector

Terminal

Voltage (Approx.)

M165

19 - Ground

Battery voltage

25 - Ground

M166

40 - Ground

44 - Ground

45 - Ground

SDIA3361E

Continuity should exist.

SDIA3362E

2009 Pathfinder

DLN-204

< COMPONENT DIAGNOSIS >

[TRANSFER: TX15B]

P1801, P1811 POWER SUPPLY CIRCUIT FOR TRANSFER CONTROL UNIT

NO

>> Check transfer control unit pin terminals for damage or loose connection with harness connector.

If any items are damaged, repair or replace damaged parts.

4.

CHECK DTC

Drive vehicle and then perform Self-diagnosis.

Do DTC's P1801 or P1811 display?

YES

>> Replace transfer control unit.  Refer to 

DLN-271, "Removal and Installation"

.

NO

>> Inspection End.

Component Inspection

INFOID:0000000003937326

1.

Turn ignition switch “OFF”.  (Stay for at least 5 seconds.)

2.

Remove transfer shut off relay 1 and transfer shut off relay 2. Refer to 

DLN-194, "Component Parts Loca-

tion"

.

3.

Apply 12V direct current between transfer shut off relay termi-
nals 1 and 2.

4.

Check continuity between relay terminals 3 and 5.

5.

If inspection results are not normal, replace the transfer shut off
relay 1 or 2.

Condition

Continuity

12V direct current supply between terminals 1 and 2

Yes

OFF

No

SCIA1245E

2009 Pathfinder

P1802 – P1804, P1809 TRANSFER CONTROL UNIT

DLN-205

< COMPONENT DIAGNOSIS >

[TRANSFER: TX15B]

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P1802 – P1804, P1809 TRANSFER CONTROL UNIT

Description

INFOID:0000000003937327

The transfer control unit controls the transfer control device which controls shifts between 4H and 4LO and
between 2WD and 4WD.  A DTC may set when any of the following occur:
• Malfunction is detected in the memory (RAM) system of transfer control unit.
• Malfunction is detected in the memory (ROM) system of transfer control unit.
• Malfunction is detected in the memory (EEPROM) system of transfer control unit.
• AD converter system of transfer control unit is malfunctioning.

DTC Logic

INFOID:0000000003937328

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

DTC CONFIRMATION PROCEDURE

1.

Turn ignition switch ON.

2.

Perform self-diagnosis.

Are DTC's “P1802 - P1804 or P1809 detected?

YES

>> Perform diagnosis procedure. Refer to 

DLN-205, "Diagnosis Procedure"

.

NO

>> Inspection End.

Diagnosis Procedure

INFOID:0000000003937329

1.

INSPECTION START

Do you have CONSULT-III?

YES or NO

YES

>> GO TO 2.

NO

>> GO TO 3.

2.

PERFORM SELF-DIAGNOSIS (WITH CONSULT-III)

1.

Turn ignition switch “ON”.

2.

Select “SELF-DIAG RESULTS” mode for “ALL MODE AWD/4WD” with CONSULT-III.

3.

Touch “ERASE”.

4.

Turn ignition switch “OFF” and wait at least 10 seconds.

5.

Perform the self-diagnosis again.

Is the “CONTROL UNIT 1 [P1802]”, “CONTROL UNIT 2 [P1803]”, “CONTROL UNIT 3 [P1804]” or CONTROL
UNIT 4 [P1809]” displayed?

YES

>> Replace transfer control unit. Refer to 

DLN-271, "Removal and Installation"

.

NO

>> Inspection End.

3.

PERFORM SELF-DIAGNOSIS (WITHOUT CONSULT-III)

1.

Perform the self-diagnosis and then erase self-diagnostic results. Refer to 

DLN-198, "CONSULT-III Func-

tion (ALL MODE AWD/4WD)"

.

2.

Perform the self-diagnosis again.

DTC

CONSULT-III

Diagnostic item is detected when...

Reference

[P1802]

CONTROL UNIT 1

Malfunction is detected in the memory 
(RAM) system of transfer control unit.

DLN-205

[P1803]

CONTROL UNIT 2

Malfunction is detected in the memory 
(ROM) system of transfer control unit.

[P1804]

CONTROL UNIT 3

Malfunction is detected in the memory 
(EEPROM) system of transfer control 
unit.

[P1809]

CONTROL UNIT 4

AD converter system of transfer control 
unit is malfunctioning.

2009 Pathfinder

DLN-206

< COMPONENT DIAGNOSIS >

[TRANSFER: TX15B]

P1802 – P1804, P1809 TRANSFER CONTROL UNIT

Do the self-diagnostic results indicate AD converter?

YES

>> Replace transfer control unit. Refer to 

DLN-271, "Removal and Installation"

.

NO

>> Inspection End.

2009 Pathfinder

P1807 VEHICLE SPEED SENSOR (A/T)

DLN-207

< COMPONENT DIAGNOSIS >

[TRANSFER: TX15B]

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P1807 VEHICLE SPEED SENSOR (A/T)

Description

INFOID:0000000003937330

The transmission control module (TCM) transmits the output shaft revolution signal via CAN communication to
Transfer control unit.  DTC P1807 will set when a malfunction is detected in the output shaft revolution signal
or an improper signal is input while driving.

DTC Logic

INFOID:0000000003937331

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

DTC CONFIRMATION PROCEDURE

1.

Turn ignition switch ON.

2.

Perform self-diagnosis.

Is DTC P1807 detected?

YES

>> Perform diagnosis procedure. Refer to 

DLN-207, "Diagnosis Procedure"

.

NO

>> Inspection End.

Diagnosis Procedure

INFOID:0000000003937332

1.

CHECK DTC WITH TCM

Perform self-diagnosis with TCM. Refer to 

TM-36, "CONSULT-III Function (TRANSMISSION)"

.

Is any malfunction detected by self-diagnosis?

YES

>> Check the malfunctioning system.

NO

>> GO TO 2.

2.

CHECK TRANSFER CONTROL UNIT

Check transfer control unit input/output signal. Refer to 

DLN-233, "Reference Value"

.

Are the inspection results normal?

YES

>> GO TO 3.

NO

>> Check transfer control unit pin terminals for damage or loose connection with harness connector.

If any items are damaged, repair or replace damaged parts.

3.

CHECK DTC

Drive vehicle and then perform Self-diagnosis.
Is DTC P1807 displayed?

YES

>> Perform self-diagnosis with TCM again.

NO

>> Inspection End.

DTC

CONSULT-III

Diagnostic item is detected when...

Reference

[P1807]

VHCL SPEED SEN·AT

• Malfunction is detected in output shaft 

revolution signalthat is output from 
TCM through CAN communication.

• Improper signal is input while driving.

DLN-207

2009 Pathfinder

DLN-208

< COMPONENT DIAGNOSIS >

[TRANSFER: TX15B]

P1808 VEHICLE SPEED SENSOR (ABS)

P1808 VEHICLE SPEED SENSOR (ABS)

Description

INFOID:0000000003937333

The ABS actuator and electric unit (control unit) transmits a vehicle speed signal via CAN communication to
the transfer control unit.  DTC P1808 sets when a malfunction is detected in the vehicle speed signal that is
output from the ABS actuator and electric unit (control unit) or an improper signal is input while driving.

DTC Logic

INFOID:0000000003937334

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

DTC CONFIRMATION PROCEDURE

1.

Turn ignition switch ON.

2.

Perform self-diagnosis.

Is DTC “P1808 displayed?

YES

>> Perform diagnosis procedure. Refer to 

DLN-208, "Diagnosis Procedure"

.

NO

>> Inspection End.

Diagnosis Procedure

INFOID:0000000003937335

1.

CHECK DTC WITH ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)

Perform self-diagnosis with ABS actuator and electric unit (control unit) for specific BRC system type.

Is any malfunction detected by self-diagnosis?

YES

>> Check the malfunctioning system.

NO

>> GO TO 2.

2.

CHECK TRANSFER CONTROL UNIT

Check transfer control unit input/output signal. Refer to 

DLN-233, "Reference Value"

.

Are the inspection results normal?

YES

>> GO TO 3.

NO

>> Check transfer control unit pin terminals for damage or loose connection with harness connector.

If any items are damaged, repair or replace damaged parts.

3.

CHECK DTC

Drive vehicle and then perform Self-diagnosis.

Is DTC P1808 displayed?

YES

>> Perform self-diagnosis with ABS actuator and electric unit (control unit) for specific BRC system

type.

NO

>> Inspection End.

DTC

CONSULT-III

Diagnostic item is detected when...

Reference

[P1808]

VHCL SPEED SEN·ABS

• Malfunction is detected in vehicle 

speed signal that is output from ABS 
actuator and electric unit (control unit) 
through CAN communication.

• Improper signal is input while driving.

DLN-208

2009 Pathfinder

P1810 4 LO SWITCH

DLN-209

< COMPONENT DIAGNOSIS >

[TRANSFER: TX15B]

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P1810 4 LO SWITCH

Description

INFOID:0000000003937336

The 4LO switch detects that the transfer case is in 4LO range.  DTC P1810 will set when an improper signal
from the 4LO switch is input due to an open or short circuit.

DTC Logic

INFOID:0000000003937337

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

DTC CONFIRMATION PROCEDURE

1.

Turn ignition switch ON.

2.

Perform self-diagnosis.

Is DTC P1810 displayed?

YES

>> Perform diagnosis procedure. Refer to 

DLN-209, "Diagnosis Procedure"

.

NO

>> Inspection End.

Diagnosis Procedure

INFOID:0000000003937338

1.

CHECK 4LO POSITION SWITCH SIGNAL

 With CONSULT-III

1.

Start engine.

2.

Select “DATA MONITOR” mode for “ALL MODE AWD/4WD” with CONSULT-III.

3.

Read out the value of “4L POSI SW”.

 Without CONSULT-III

1.

Start engine.

2.

Check voltage between transfer control unit harness connector
terminal and ground.

Are the inspection results normal?

YES 

>> GO TO 5.

NO

>> GO TO 2.

2.

CHECK HARNESS BETWEEN TRANSFER CONTROL UNIT AND 4LO SWITCH

1.

Turn ignition switch “OFF”.  (Stay for at least 5 seconds.)

DTC

CONSULT-III

Diagnostic item is detected when...

Reference

[P1810]

4L POSI SW TF

Improper signal from 4LO switch is input 
due to open or short circuit.

DLN-209

Condition

Display value

• Vehicle stopped
• Engine running
• A/T selector lever “N” position
• Brake pedal depressed

4WD shift switch: 4LO

ON

Except the above

OFF

Connector

Terminal

Condition

Voltage 

(Approx.)

M165

 24 - 

Ground

• Vehicle stopped
• Engine running
• A/T selector lever 

“N” position

• Brake pedal de-

pressed

4WD shift switch: 4LO

0V

Except the above

Battery 
voltage

SDIA3363E

2009 Pathfinder