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![INFINITI QX56 2010 Factory Service Manual P1811 POWER SUPPLY CIRCUIT FOR TRANSFER CONTROL UNIT
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Are the inspection results normal?
YES >> GO TO 2.
NO >> Check the followi INFINITI QX56 2010 Factory Service Manual P1811 POWER SUPPLY CIRCUIT FOR TRANSFER CONTROL UNIT
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Are the inspection results normal?
YES >> GO TO 2.
NO >> Check the followi](/manual-img/42/57032/w960_57032-1104.png)
P1811 POWER SUPPLY CIRCUIT FOR TRANSFER CONTROL UNIT
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Are the inspection results normal?
YES >> GO TO 2.
NO >> Check the following. If any items are damaged, repair or replace damaged parts. • 10A fuses No. 26 located in fuse and fusible link box and No. 59 located in the fuse and relaybox.
• 20A fuse No. 53 located in the IPDM E/R.
• Harness for short or open between battery and transfer control unit harness connector terminals
47.
• Harness for short or open between battery and transfer control unit harness connector terminal
29.
• Harness for short or open between battery and transfer shut off relay harness connector E69 terminal 1, and 5.
• Harness for short or open between transfer shut off relay harness connector E69 terminal 2 and
transfer control unit harness connector terminal 30.
• Harness for short or open between transfer shut off relay harness connector E69 terminal 3 and transfer control unit harness connector terminals 16 and 22.
• Battery and ignition switch.
• Transfer shut off relay. Refer to DLN-23, "
Component Inspection".
2.CHECK GROUND CIRCUIT
1. Turn ignition switch OFF. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connector.
3. Check continuity between transfer control unit harness connec- tor E142 terminals 3, 6, E143 terminal 45 and ground.
Also check harness for short to ground and short to power.
Are the inspection results normal?
YES >> GO TO 3.
NO >> Repair open circuit or short to ground or short to power in harness or connectors.
3.CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Refer to DLN-81, "
Reference Value".
Are the inspection results normal?
YES >> GO TO 4.
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
Perform the self-diagnosis, after driving a vehicle for a while.
Are the inspection results normal?
YES >> Inspection End.
NO >> Replace transfer control unit. Refer to DLN-130, "
Removal and Installation".
Component InspectionINFOID:0000000005148778
1. Turn ignition switch OFF. (Stay for at least 5 seconds.)
2. Remove transfer shut off relay. Refer to DLN-16, "
Component Parts Location".
Continuity should exist.
SDIA2691E
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DLN-24
< COMPONENT DIAGNOSIS >[ATX14B]
P1811 POWER SUPPLY CIRCUIT
FOR TRANSFER CONTROL UNIT
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 abnormal replace the transfer shut off relay.
Condition Continuity
12V direct current supply between terminals 1 and 2 Yes
OFF No
SCIA1245E
Revision: April 20092010 QX56
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![INFINITI QX56 2010 Factory Service Manual P1802 – P1804, P1809 TRANSFER CONTROL UNIT
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P1802 – P1804, P1809 TRANSFER CONTROL UNIT
DescriptionINFOID:0000000005148779
Th INFINITI QX56 2010 Factory Service Manual P1802 – P1804, P1809 TRANSFER CONTROL UNIT
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P1802 – P1804, P1809 TRANSFER CONTROL UNIT
DescriptionINFOID:0000000005148779
Th](/manual-img/42/57032/w960_57032-1106.png)
P1802 – P1804, P1809 TRANSFER CONTROL UNIT
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P1802 – P1804, P1809 TRANSFER CONTROL UNIT
DescriptionINFOID:0000000005148779
The transfer control unit controls the transfer control device which controls shifts between AUTO, 4H and 4LO
and between 2WD and 4WD. A DTC may se t 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 LogicINFOID:0000000005148780
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-25, "Diagnosis Procedure".
NO >> Inspection End.
Diagnosis ProcedureINFOID:0000000005148781
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)
With CONSULT-III
1. Turn ignition switch ON. (Do not start engine.)
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-130, "Removal and Installation".
NO >> Inspection End.
3.PERFORM SELF-DIAGNOSIS (WITHOUT CONSULT-III)
DTCCONSULT-III Diagnostic item is detected when... Reference
[P1802] CONTROL UNIT 1 Malfunction is detected in the memory
(RAM) system of transfer control unit.
Refer to DLN-25
.
[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.
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P1802 – P1804, P1809 TRANSFER CONTROL UNIT
Without CONSULT-III
1. Perform the self-diagnosis and then erase self-diagnostic results. Refer to DLN-18, "CONSULT-III Func-
tion (ALL MODE AWD/4WD)".
2. Perform the self-diagnosis again.
Do the self-diagnostic results indicate AD converter?
YES >> Replace transfer control unit. Refer to DLN-130, "Removal and Installation".
NO >> Inspection End.
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![INFINITI QX56 2010 Factory Service Manual P1807 VEHICLE SPEED SENSOR (A/T)DLN-27
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P1807 VEHICLE SPEED SENSOR (A/T)
DescriptionINFOID:0000000005148782
The transmission control mo INFINITI QX56 2010 Factory Service Manual P1807 VEHICLE SPEED SENSOR (A/T)DLN-27
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P1807 VEHICLE SPEED SENSOR (A/T)
DescriptionINFOID:0000000005148782
The transmission control mo](/manual-img/42/57032/w960_57032-1108.png)
P1807 VEHICLE SPEED SENSOR (A/T)DLN-27
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P1807 VEHICLE SPEED SENSOR (A/T)
DescriptionINFOID:0000000005148782
The transmission control module (TCM) transmits the out put shaft revolution signal via CAN communication to
Transfer control unit. DTC P1807 will set when a malfunc tion is detected in the output shaft revolution signal
or an improper signal is input while driving.
DTC LogicINFOID:0000000005148783
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-27, "Diagnosis Procedure".
NO >> Inspection End.
Diagnosis ProcedureINFOID:0000000005148784
1.CHECK DTC WITH TCM
Perform self-diagnosis with TCM. Refer to TM-32, "
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-81, "
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 the vehicle and then perform self-diagnosis.
Are the inspection results normal?
YES >> Inspection End.
NO >> Perform self-diagnosis with TCM again.
DTC CONSULT-III Diagnostic item is detected when... Reference
[P1807] VHCL SPEED SEN·AT • Malfunction is detected in output shaft
revolution signal that is output from
TCM through CAN communication.
• Improper signal is input while driving. Refer to DLN-27
.
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![INFINITI QX56 2010 Factory Service Manual DLN-28
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P1808 VEHICLE SPEED
SENSOR (ABS)
P1808 VEHICLE SPEED SENSOR (ABS)
DescriptionINFOID:0000000005148785
The ABS actuator and electric unit (control unit) tr ansmit INFINITI QX56 2010 Factory Service Manual DLN-28
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P1808 VEHICLE SPEED
SENSOR (ABS)
P1808 VEHICLE SPEED SENSOR (ABS)
DescriptionINFOID:0000000005148785
The ABS actuator and electric unit (control unit) tr ansmit](/manual-img/42/57032/w960_57032-1109.png)
DLN-28
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P1808 VEHICLE SPEED
SENSOR (ABS)
P1808 VEHICLE SPEED SENSOR (ABS)
DescriptionINFOID:0000000005148785
The ABS actuator and electric unit (control unit) tr ansmits 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 elec tric unit (control unit) or an improper signal is input while driving.
DTC LogicINFOID:0000000005148786
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-28, "Diagnosis Procedure".
NO >> Inspection End.
Diagnosis ProcedureINFOID:0000000005148787
1.CHECK DTC WITH ABS ACTUATOR AN D ELECTRIC UNIT (CONTROL UNIT)
Perform self-diagnosis with ABS actuator and electric unit (control unit). Refer to BRC-23, "
CONSULT-III
Function (ABS)".
Is any malfunction detec ted 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-81, "
Reference Value".
Are the inspection results normal?
YES >> GO TO 3.
NO >> Check transfer control unit pin terminals fo r damage or loose connection with harness connector.
If any items are damaged, repair or replace damaged parts.
3.CHECK DTC
Perform the self-diagnosis, after driving a vehicle for a while.
Are the inspection results normal?
YES >> Inspection End.
NO >> Perform self-diagnosis with ABS actuator and electric unit (control unit) again.
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. Refer to
DLN-28
.
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![INFINITI QX56 2010 Factory Service Manual P1810 NEUTRAL-4LO SWITCHDLN-29
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P1810 NEUTRAL-4LO SWITCH
DescriptionINFOID:0000000005148788
The neutral-4LO switch detects that the tra INFINITI QX56 2010 Factory Service Manual P1810 NEUTRAL-4LO SWITCHDLN-29
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The neutral-4LO switch detects that the tra](/manual-img/42/57032/w960_57032-1110.png)
P1810 NEUTRAL-4LO SWITCHDLN-29
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P1810 NEUTRAL-4LO SWITCH
DescriptionINFOID:0000000005148788
The neutral-4LO switch detects that the transfer case is in neutral or 4LO range. DTC P1810 will set when an
improper signal from the neutral-4LO switch is input due to an open or short circuit.
DTC LogicINFOID:0000000005148789
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-29, "Diagnosis Procedure".
NO >> Inspection End.
Diagnosis ProcedureINFOID:0000000005148790
Regarding Wiring Diagram information, refer to DLN-89, "Wiring Diagram - ALL-MODE 4WD SYSTEM -".
1.CHECK 4LO POSITION SWITCH SIGNAL
With CONSULT-III1. Start engine.
2. Select DATA MONITOR mode for ALL MODE AWD/4WD with CONSULT-III.
3. Read out the value of N POSI SW TF.
Without CONSULT-III
1. Start engine.
DTCCONSULT-III Diagnostic item is detected when... Reference
[P1810] 4L POSI SW TF Improper signal from neutral-4LO switch
is input due to open or short circuit.Refer to DLN-29
.
Condition
Display value
• Vehicle stopped
• Engine running
• A/T selector lever N position
• Brake pedal depressed 4WD shift switch: 2WD,
AUTO or 4H
OFF
4WD shift switch: 4H to
4LO (While actuator mo-
tor is operating.) OFF
→ ON
4WD shift switch: 4LO to
4H (While actuator motor
is operating.) ON
→ OFF
4WD shift switch: 4LO ON
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![INFINITI QX56 2010 Factory Service Manual DLN-30
< COMPONENT DIAGNOSIS >[ATX14B]
P1810 NEUTRAL-4LO SWITCH
2. Check voltage between transfer control unit harness connector
terminal and ground.
Are inspection results normal?
YES >> GO TO 5.
NO INFINITI QX56 2010 Factory Service Manual DLN-30
< COMPONENT DIAGNOSIS >[ATX14B]
P1810 NEUTRAL-4LO SWITCH
2. Check voltage between transfer control unit harness connector
terminal and ground.
Are inspection results normal?
YES >> GO TO 5.
NO](/manual-img/42/57032/w960_57032-1111.png)
DLN-30
< COMPONENT DIAGNOSIS >[ATX14B]
P1810 NEUTRAL-4LO SWITCH
2. Check voltage between transfer control unit harness connector
terminal and ground.
Are inspection results normal?
YES >> GO TO 5.
NO >> GO TO 2.
2.CHECK HARNESS BETWEEN TRANSFER CO NTROL UNIT AND NEUTRAL-4LO SWITCH
1. Turn ignition switch OFF. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connecto r and the neutral-4LO switch harness connector.
3. Check continuity between transfer control unit harness connec-
tor E143 terminal 25 and neutral-4LO switch harness connector
F60 terminal 13.
Also check harness for short to ground and short to power.
Are inspection results normal?
YES >> GO TO 3.
NO >> Repair or replace damaged parts.
3.CHECK GROUND CIRCUIT
1. Turn ignition switch OFF. (Stay for at least 5 seconds.)
2. Disconnect neutral-4LO switch harness connector.
3. Check continuity between neutral-4LO switch harness connec- tor F60 terminal 12 and ground.
Also check harness for short to ground and short to power.
Are inspection results normal?
YES >> GO TO 4.
NO >> Repair open circuit or short to ground or short to power in harness or connectors.
4.CHECK 4LO SWITCH
1. Turn ignition switch OFF.
2. Disconnect neutral-4LO switch harness connector.
3. Remove neutral-4LO switch.
Connector Te r m i n a l
(Wire col- or) Condition
Voltage
(Approx.)
E143 25 -
Ground • Vehicle stopped
• Engine running
• A/T selector lever
N position
• Brake pedal de-
pressed 4WD shift switch:
2WD, AUTO or 4H
Battery
voltage
4WD shift switch: 4H to
4LO (While actuator
motor is operating.) Battery
voltage
→ 0V
4WD shift switch: 4LO
to 4H (While actuator
motor is operating.) 0V
→
Battery
voltage
4WD shift switch: 4LO 0V
SDIA2693E
Continuity should exist.
SDIA2694E
Continuity should exist.
SDIA2695E
Revision: April 20092010 QX56