2011 INFINITI QX56 BATTERY

P1811 POWER SUPPLY CIRCUIT FOR TRANSFER CONTROL UNIT
DLN-65
< DTC/CIRCUIT DIAGNOSIS > [TRANSFER: ATX90A]
C
EF
G H
I
J
K L
M A
B
DLN
N
O P
3.CHECK TRANSFER CONTROL UNIT POWER SUPPLY (3)
1. Turn the ignition switch OFF.
2. Check the voltage between transfer control unit harness connector and ground.
3. Turn the ignition switch ON. CAUTION:
Never start the engine.
4. Check the voltage between transfer control unit harness connector and ground.
Is the inspection result normal?
YES >> GO TO 5.
NO >> GO TO 4.
4.CHECK TRANSFER CONTROL UNIT POWER SUPPLY (4)
1. Turn the ignition switch OFF.
2. Check the 10A fuse (#56).
3. Disconnect IPDM E/R harness connector.
4. Check the continuity between transfer control unit harness connector and IPDM E/R harness connector.
5. Check the continuity between transfer control unit harness connector and the ground.
Is the inspection result normal?
YES >> Perform the trouble diagnosis for ignition power supply circuit. Refer to PG-89, "Wiring Diagram -
IGNITION POWER SUPPLY -".
NO >> Repair or replace error-detected parts.
5.CHECK TRANSFER CONTROL UNIT GROUND
1. Turn the ignition switch OFF.
2. Check the continuity between transfer control unit harness connector and ground.
Is the inspection result normal?
YES >> GO TO 6.
NO >> Repair or replace error-detected parts.
6.CHECK TERMINALS AND HARNESS CONNECTORS
Transfer control unit — Voltage
Connector Terminal
E59 32 Ground 0 V
Transfer control unit — Voltage
Connector Terminal
E59 32 Ground Battery voltage
IPDM E/R Transfer control unit Continuity
Connector Terminal Connector Terminal
E15 58 E59 32 Existed
Transfer control unit —Continuity
Connector Terminal
E59 32 Ground Not existed
Transfer control unit —Continuity
Connector Terminal
E60 46
Ground Existed
44
Revision: 2010 May2011 QX56

DLN-74
< DTC/CIRCUIT DIAGNOSIS >[TRANSFER: ATX90A]
P181B INCOMPLETE SELFSHUT
P181B INCOMPLETE SELFSHUT
DTC LogicINFOID:0000000006222274
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.DTC REPRODUCTION PROCEDURE
With CONSULT-III
1. Turn the ignition switch OFF.
2. Perform self-diagnosis for “ALL MODE AWD/4WD”.
Is DTC
“P181B” detected?
YES >> Proceed to diagnosis procedure. Refer to DLN-74, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006222275
1.CHECK TRANSFER CONTROL UNIT POWER SUPPLY (1)
1. Turn the ignition switch OFF.
2. Disconnect transfer control unit harness connector.
3. Check the voltage between transfer control unit harness connector and ground.
4. Turn the ignition switch ON. CAUTION:
Never start the engine.
5. Check the voltage between transfer control unit harness connector and ground.
Is the inspection result normal?
YES >> GO TO 3.
NO >> GO TO 2.
2.CHECK TRANSFER CONTROL UNIT POWER SUPPLY (2)
1. Turn the ignition switch OFF.
2. Check the 10A fuse (#34).
3. Check the harness for open or short between transfe r control unit harness connector No.20 terminal and
10A (#34).
Is the inspection result normal?
YES >> Perform the trouble diagnosis for power supply circuit. Refer to PG-11, "Wiring Diagram - BAT-
TERY POWER SUPPLY -".
NO >> Repair or replace error-detected parts.
3.CHECK TRANSFER CONTROL UNIT GROUND
1. Turn the ignition switch OFF.
DTC Display item Malfunction detected condition Possible cause
P181B IMCOMP SELFSHUT When ignition switch is OFF and transfer
control unit power su
pply is lower or
higher than normal Self-shut is incomplete.
Transfer control unit
—Voltage
Connector Terminal
E59 20 Ground Battery voltage
Transfer control unit —Voltage
Connector Terminal
E59 20 Ground Battery voltage
Revision: 2010 May2011 QX56

DLN-76
< DTC/CIRCUIT DIAGNOSIS >[TRANSFER: ATX90A]
P181C TRANSFER MOTOR POWER SUPPLY
P181C TRANSFER MO
TOR POWER SUPPLY
DescriptionINFOID:0000000006222276
Supplies power to transfer control actuator (transfer motor).
DTC LogicINFOID:0000000006222277
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.DTC REPRODUCTION PROCEDURE
With CONSULT-III
1. Turn the ignition switch OFF to ON.
2. Perform self-diagnosis for “ALL MODE AWD/4WD”.
Is DTC
“P181C” detected?
YES >> Proceed to diagnosis procedure. Refer to DLN-76, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006222278
1.CHECK TRANSFER MOTOR POWER SUPPLY (2)
Check the voltage between transfer control unit harness connector and ground.
Is the inspection result normal?
YES >> GO TO 3.
NO >> GO TO 2.
2.CHECK TRANSFER MOTOR POWER SUPPLY CIRCUIT (2)
1. Turn the ignition switch OFF.
2. Check the 30A fusible link (J).
3. Check the harness for open or short between transfe r control unit harness connector No.41 terminal and
30A fusible link (J).
Is the inspection result normal?
YES >> Perform the trouble diagnosis for power supply circuit. Refer to PG-11, "Wiring Diagram - BAT-
TERY POWER SUPPLY -".
NO >> Repair or replace error-detected parts.
3.CHECK TERMINALS AND HARNESS CONNECTORS
Check the pin terminals for damage or loose connection with each harness connector.
Is the inspection result normal?
YES >> Replace transfer control unit. Refer to DLN-107, "Removal and Installation".
NO >> Repair or replace error-detected parts.
DTC Display item Malfunction detected condition Possible cause
P181C MOTOR POWER SUPPLY When transfer control actuator power
supply is lower or higher than normalMalfunction of transfer control actuator
(transfer motor) powe
r supply circuit
+ −
Voltag e
Transfer control unit
Connector Terminal E60 41 46 Battery voltage
Revision: 2010 May2011 QX56

P182B TRANSFER LOCK POSITION SENSOR
DLN-85
< DTC/CIRCUIT DIAGNOSIS > [TRANSFER: ATX90A]
C
EF
G H
I
J
K L
M A
B
DLN
N
O P
P182B TRANSFER LOCK POSITION SENSOR
DTC LogicINFOID:0000000006222292
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.DTC REPRODUCTION PROCEDURE
With CONSULT-III
1. Turn the ignition switch OFF to ON.
2. Turn the 4WD shift switch AUTO ⇒4H ⇒4LO ⇒4H ⇒AUTO.
3. Perform self-diagnosis for “ALL MODE AWD/4WD”.
Is DTC
“P182B” detected?
YES >> Proceed to diagnosis procedure. Refer to DLN-85, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006222293
1.CHECK TRANSFER LOCK POSITION SENSOR
With CONSULT-III
1. Start the engine.
2. Turn the 4WD shift switch AUTO ⇒4H ⇒4LO ⇒4H ⇒AUTO.
3. Check “LOCK POSI SEN” of CONSULT-III “DATA MONITOR” for “ALL MODE AWD/4WD”.
What is the item on "DATA MONITOR"?
OPEN >> GO TO 7.
LOCK >> GO TO 7.
UNLEAN>>GO TO 6.
HI TEMP>>GO TO 5.
ERROR>> GO TO 5.
BAT >> GO TO 2.
GND >> GO TO 2.
2.CHECK TRANSFER LOCK POSITION POWER SUPPLY
1. Turn the ignition switch OFF.
2. Disconnect transfer positi on sensor harness connector.
3. Turn the ignition switch ON. CAUTION:
DTC Display item Malfunction detected condition Possible cause
P182B Lock POSITION SEN Malfunction related to transfer lock posi-
tion sensor has been detected. Transfer lock position sensor
- Transfer lock position sensor error
- Malfunction of transfer lock position
sensor circuit
Monitor item Condition Status
LOCK POSI SEN 4WD shift switch: AUTO or 4H OPEN
4WD shift switch: 4L LOCK
When transfer lock position sensor is unlearned. UNLEAN
When the temperature of transfer lock position sensor is
high.
HI TEMP
When transfer lock position sensor is malfunctioning. ERROR
When transfer lock position sensor signal circuit is short.
(Battery short) BAT
When transfer lock position sensor signal circuit is short.
(Ground short) GND
Revision: 2010 May2011 QX56

POWER SUPPLY AND GROUND CIRCUITDLN-93
< DTC/CIRCUIT DIAGNOSIS > [TRANSFER: ATX90A]
C
EF
G H
I
J
K L
M A
B
DLN
N
O P
POWER SUPPLY AND GROUND CIRCUIT
DescriptionINFOID:0000000006222306
Supplies power to 4WD system.
Diagnosis ProcedureINFOID:0000000006222307
1.CHECK TRANSFER CONTROL UNIT POWER SUPPLY (1)
1. Turn the ignition switch OFF.
2. Disconnect transfer control unit harness connector.
3. Check the voltage between transfer control unit harness connector and ground.
4. Turn the ignition switch ON. CAUTION:
Never start the engine.
5. Check the voltage between transfer control unit harness connector and ground.
Is the inspection result normal?
YES >> GO TO 3.
NO >> GO TO 2.
2.CHECK TRANSFER CONTROL UNIT POWER SUPPLY (2)
1. Turn the ignition switch OFF.
2. Check the 10A fuse (#34).
3. Check the harness for open or short between transfe r control unit harness connector No.20 terminal and
10A (#34).
Is the inspection result normal?
YES >> Perform the trouble diagnosis fo r power supply circuit. Refer to PG-11, "Wiring Diagram - BAT-
TERY POWER SUPPLY -".
NO >> Repair or replace error-detected parts.
3.CHECK TRANSFER CONTROL UNIT POWER SUPPLY (3)
1. Turn the ignition switch OFF.
2. Check the voltage between transfer control unit harness connector and ground.
3. Turn the ignition switch ON. CAUTION:
Never start the engine.
4. Check the voltage between transfer control unit harness connector and ground.
Transfer control unit — Voltage
Connector Terminal
E59 20 Ground Battery voltage
Transfer control unit — Voltage
Connector Terminal
E59 20 Ground Battery voltage
Transfer control unit — Voltage
Connector Terminal
E59 32 Ground Approx. 0 V
Transfer control unit — Voltage
Connector Terminal
E59 32 Ground Battery voltage
Revision: 2010 May2011 QX56

DLN-94
< DTC/CIRCUIT DIAGNOSIS >[TRANSFER: ATX90A]
POWER SUPPLY AND GROUND CIRCUIT
Is the inspection result normal?
YES >> GO TO 5.
NO >> GO TO 4.
4.CHECK TRANSFER CONTROL UNIT POWER SUPPLY (4)
1. Turn the ignition switch OFF.
2. Check the 10A fuse (#56).
3. Disconnect IPDM E/R harness connector.
4. Check the continuity between transfer control unit harness connector and IPDM E/R harness connector.
5. Check the continuity between transfer control unit harness connector and the ground.
Is the inspection result normal?
YES >> Perform the trouble diagnosis for ignition power supply circuit. Refer to PG-89, "Wiring Diagram -
IGNITION POWER SUPPLY -".
NO >> Repair or replace error-detected parts.
5.CHECK TRANSFER MOTOR POWER SUPPLY
1. Turn the ignition switch OFF.
2. Check the voltage between transfer control unit harness connector and ground.
3. Turn the ignition switch ON. CAUTION:
Never start the engine.
4. Check the voltage between transfer control unit harness connector and ground.
Is the inspection result normal?
YES >> GO TO 7.
NO >> GO TO 6.
6.CHECK TRANSFER MOTOR POWER SUPPLY CIRCUIT
1. Turn the ignition switch OFF.
2. Check the 30A fusible link (J).
3. Check the harness for open or short between transfe r control unit harness connector No.41 terminal and
30A fusible link (J).
Is the inspection result normal?
YES >> Perform the trouble diagnosis for power supply circuit. Refer to PG-11, "Wiring Diagram - BAT-
TERY POWER SUPPLY -".
NO >> Repair or replace error-detected parts.
7.CHECK 4WD SWITCH ASSEMBLY POWER SUPPLY (1)
1. Turn the ignition switch OFF.
IPDM E/R Transfe r control unit
Continuity
Connector Terminal Connector Terminal
E15 58 E59 32 Existed
Transfer control unit —Continuity
Connector Terminal
E59 32 Ground Not existed
Transfer control unit —Voltage
Connector Terminal
E60 41 Ground Battery voltage
Transfer control unit —Voltage
Connector Terminal
E60 41 Ground Battery voltage
Revision: 2010 May2011 QX56

POWER SUPPLY AND GROUND CIRCUITDLN-95
< DTC/CIRCUIT DIAGNOSIS > [TRANSFER: ATX90A]
C
EF
G H
I
J
K L
M A
B
DLN
N
O P
2. Disconnect 4WD switch assembly harness connector.
3. Check the voltage between 4WD switch assembly harness connector and ground.
4. Turn the ignition switch ON. CAUTION:
Never start the engine.
5. Check the voltage between 4WD switch assembly harness connector and ground.
Is the inspection result normal?
YES >> GO TO 9.
NO >> GO TO 8.
8.CHECK 4WD SWITCH ASSEMBLY POWER SUPPLY (2)
1. Turn the ignition switch OFF.
2. Check the 10A fuse (#13).
3. Disconnect fuse block (J/B) harness connector.
4. Check the continuity between transfer control unit harness connector and IPDM E/R harness connector.
5. Check the continuity between transfer control unit harness connector and the ground.
Is the inspection result normal?
YES >> Perform the trouble diagnosis for ignition power supply circuit. Refer to PG-89, "Wiring Diagram -
IGNITION POWER SUPPLY -".
NO >> Repair or replace error-detected parts.
9.CHECK TRANSFER CONTROL UNIT GROUND
1. Turn the ignition switch OFF.
2. Check the voltage between transfer control unit harness connector and ground.
3. Check the continuity between transfer control unit harness connector and ground.
4WD switch assembly — Voltage
Connector Terminal
M54 12 Ground Approx. 0 V
4WD switch assembly — Voltage
Connector Terminal
M54 12 Ground Battery voltage
Fuse block (J/B) 4WD switch assembly Continuity
Connector Terminal Connector Terminal
M3 10C M54 12 Existed
4WD switch assembly —Continuity
Connector Terminal
M54 12 Ground Not existed
Transfer control unit — Voltage
Connector Terminal
E60 44
Ground Approx. 0 V
46
Transfer control unit —Continuity
Connector Terminal
E60 44
Ground Existed
46
Revision: 2010 May2011 QX56

TRANSFER CONTROL UNITDLN-107
< REMOVAL AND INSTALLATION > [TRANSFER: ATX90A]
C
EF
G H
I
J
K L
M A
B
DLN
N
O P
REMOVAL AND INSTALLATION
TRANSFER CONTROL UNIT
Removal and InstallationINFOID:0000000006222327
REMOVAL
1. Turn the ignition switch OFF.
2. Disconnect negative battery terminal. CAUTION:
Wait for 5 seconds after turning ignition switch OFF.
3. Remove the glove box assembly. Refer to IP-14, "
Removal and Installation".
4. Disconnect the transfer control unit connector.
5. Move instrument lower cover to backward. Refer to IP-14, "
Removal and Installation".
6. Remove the transfer control unit.
INSTALLATION
Note the following, and install in the reverse order of removal.
 When replacing transfer control unit, perform writing unit parameter and initial calibration. Refer to DLN-41,
"Work Procedure".
Revision: 2010 May2011 QX56