ECO mode INFINITI QX56 2010 Factory Workshop Manual

4WD SYSTEMDLN-15
< FUNCTION DIAGNOSIS > [ATX14B]
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TRANSFER FLUID TEMPERATURE SENSOR
The transfer fluid temperature sensor detects the trans fer fluid temperature and sends a signal to the transfer
control unit.
TRANSFER MOTOR
• The transfer motor drives the sub-oil pump to provi de proper lubrication and oil pressure control when the
vehicle is at standstill, during low-speed operations or is being driven in reverse.
• The main oil pump is operated by the driving force of t he mainshaft. In other words, sufficient oil pressure
buildup does not occur when the vehicle is at standsti ll or during low-speed operations. While the vehicle is
being driven in reverse, the main oil pump rotates in the reverse direction. Therefore the main oil pump does
not discharge oil pressure. During any of the above vehi cle operations, the transfer motor drives the sub-oil
pump to compensate for insufficient oil pressure.
• The transfer motor operates as follows:
- The motor relay turns OFF in the 2WD mode.
- The motor relay operates as described in the table below in modes other than the 2WD mode.
• 4WD shift switch, transmission range switch, Neutral-4LO switch, vehicle speed sensor and throttle position
sensor are used in conjunction with the transfer motor.
Transfer Motor Relay Operation
*: After 2.5 seconds have elapsed.
CLUTCH PRESSURE SOLENOID VALVE
The clutch pressure solenoid valve distributes front and rear torque in AUTO mode.
2-4WD SHIFT SOLENOID VALVE
The 2-4WD shift solenoid valve operates to apply oil pressure to the wet-multiplate clutch, depending on the
drive mode. The driving force is transmitted to the front wheels through the clutch so the vehicle is set in the
4WD mode. Setting the vehicle in the 2WD mode requires no pressure buildup. In other words, pressure force
applied to the wet-multiplate clutch becomes zero.
TRANSFER CONTROL DEVICE
Integrates actuator motor and actuator position switch.
4WD shift switch A/T selector lever position Vehicle speed
(VSS) Accelerator pedal position Motor relay drive
command
2WD ———OFF
4H (LOCK) and 4LO N position
0— ON
P position 00 - 0.07/8
OFF*
0.07/8 - 1/8 HOLD
1/8 - MAX ON
Other than R position 0 < VSS ≤
50 km/h (31 MPH)
— ON
50 km/h (31 MPH) < VSS < 55 km/h (34 MPH) HOLD
55 km/h (34 MPH) ≤ VSS OFF
R position —— ON
R position —— ON
AUTO P or N position 0
0 - 0.07/8
OFF*
0.07/8 - 1/8 HOLD
1/8 - MAX ON
0 < VSS ≤ 50 km/h (31 MPH)
— ON
50 km/h (31 MPH) < VSS < 55 km/h (34 MPH) HOLD
55 km/h (34 MPH) ≤ VSS OFF
Other than R, P and N posi-
tion 0 < VSS ≤
50 km/h (31 MPH)
— ON
50 km/h (31 MPH) < VSS < 55 km/h (34 MPH) HOLD
55 km/h (34 MPH) ≤ VSS OFF
Revision: April 20092010 QX56

DLN-20
< FUNCTION DIAGNOSIS >[ATX14B]
DIAGNOSIS SYSTEM (T
RANSFER CONTROL UNIT)
4L SW [On/Off] ×–×4WD shift switch status is displayed.
(4L means 4LO of 4WD shift switch.)
N POSI SW TF [On/Off] ×–×Neutral-4LO switch signal status is displayed.
ATP SWITCH [On/Off] ×–×ATP switch signal status is displayed.
WAIT DETCT SW [On/Off] ×–×Wait detection switch status is displayed.
LINE PRES SW [On/Off] ×–×Line pressure switch status is displayed.
CL PRES SW [On/Off] ×–×Clutch pressure switch status is displayed.
N POSI SW AT [On/Off] ×–×N position signal of transmission range switch
status is displayed.
Signal input with CAN communication line.
R POSI SW AT [On/Off] ×–×R position signal of transmission range switch
status is displayed.
Signal input with CAN communication line.
P POSI SW AT [On/Off] ×–×P position signal of transmission range switch
status is displayed.
Signal input with CAN communication line.
ABS OPER SW [On/Off] ×–×ABS operation signal status is displayed.
Signal input with CAN communication line.
VDC OPER SW [On/Off] ×–×VDC operation signal status is displayed.
Signal input with CAN communication line.
TCS OPER SW [On/Off] ×–×TCS operation signal status is displayed.
Signal input with CAN communication line.
THROTTLE POSI [0.0/8] –×× Thottle position status is displayed.
Signal input with CAN communication line.
4WD MODE [AUTO/LOCK/2WD/4L] – ××Control status of 4WD recognized by transfer
control unit. (AUTO, 4H, 2WD or 4LO)
VHCL/S COMP [km/h] or [mph] –×× Vehicle speed recognized by transfer control
unit.
COMP CL TORQ [kgm] –×× Calculated torque recognized by transfer con-
trol unit.
DUTY SOLENOID [%] –×× Control value of clutch pressure solenoid.
2-4WD SOL [On/Off] –×× Output condition to 2-4WD solenoid.
2-4WD SOL MON [On/Off] ––×Check signal for transfer control unit signal
output.
MOTOR RELAY [On/Off] –×× Transfer motor relay signal status is dis-
played.
MOTOR RELAY MON [On/Off] ––×Check signal for transfer control unit signal
ou
t

put.
4WD FAIL LAMP [On/Off] –×× Control status of 4WD warning lamp is dis-
played.
2WD IND [On/Off] ––×Control status of 4WD shift indicator lamp
(2WD indicator lamp) is displayed.
AUTO IND [On/Off] ––×Control status of 4WD shift indicator lamp
(2WD and AUTO indicator lamp) is displayed.
LOCK IND [On/Off] ––×Control status of 4WD shift indicator lamp
(2WD, AUTO and Lock indicator) is displayed.
4L IND [On/Off] ––×Control status of 4LO indicator lamp is dis-
played.
Monitored item (Unit)
Monitor item selection
Remarks
ECU INPUT
SIGNALS MAIN
SIGNALS SELEC-
TION FROM
MENU
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DLN-22
< COMPONENT DIAGNOSIS >[ATX14B]
P1811 POWER SUPPLY CIRCUIT
FOR TRANSFER CONTROL UNIT
COMPONENT DIAGNOSIS
P1811 POWER SUPPLY CIRCUIT FOR TRANSFER CONTROL UNIT
DescriptionINFOID:0000000005148775
Power supply to transfer control unit is abnormally low while driving.
DTC LogicINFOID:0000000005148776
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON.
2. Perform self-diagnosis.
Is DTC P1811 detected?
YES >> Perform diagnosis procedure. Refer to DLN-22, "Diagnosis Procedure".
NO >> Inspection End.
Diagnosis ProcedureINFOID:0000000005148777
Regarding Wiring Diagram information, refer to DLN-89, "Wiring Diagram - ALL-MODE 4WD SYSTEM -".
1.CHECK POWER SUPPLY
1. Turn ignition switch OFF. (Stay for at least 5 seconds.)
2. Connect transfer control unit harness connector.
3. Check voltage between transfer control unit harness connector terminals and ground.
4. Turn ignition switch ON. (Do not start engine.)
5. Check voltage between transfer control unit harness connector terminals and ground.
DTC CONSULT-III Diagnostic item is detected when... Reference
[ P 1 8 11 ] B AT T E R Y V O LTA G E Power supply voltage for transfer control
unit is abnormally low while driving.Refer to
DLN-22
.
Connector Terminal Voltage (Approx.)
E142 16 - Ground
0V
22 - Ground
E143 29 - Ground
30 - Ground
Battery voltage
47 - Ground
WDIA0165E
Connector Terminal Voltage (Approx.)
E142 16 - Ground
Battery voltage
22 - Ground
E143 29 - Ground
30 - Ground
0V
47 - Ground Battery voltage
WDIA0166E
Revision: April 20092010 QX56

P1802 – P1804, P1809 TRANSFER CONTROL UNIT
DLN-25
< COMPONENT DIAGNOSIS > [ATX14B]
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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.
Revision: April 20092010 QX56

P1819 TRANSFER CONTROL DEVICEDLN-49
< COMPONENT DIAGNOSIS > [ATX14B]
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P1819 TRANSFER CONTROL DEVICE
DescriptionINFOID:0000000005148811
The transfer control device integrates the actuator motor and actuator position switch. DTC P1819 will set if
either of the following conditions exist:
• Malfunction occurs in transfer control device actuator circuit.
• Malfunction is detected in the transfer shut off relay.
DTC LogicINFOID:0000000005148812
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON.
2. Perform self-diagnosis.
Is DTC P1819 detected?
YES >> Perform diagnosis procedure. Refer to DLN-49, "Diagnosis Procedure".
NO >> Inspection End.
Diagnosis ProcedureINFOID:0000000005148813
Regarding Wiring Diagram information, refer to DLN-89, "Wiring Diagram - ALL-MODE 4WD SYSTEM -".
1.CHECK POWER SUPPLY
1. Turn ignition switch OFF. (Stay for at least 5 seconds.)
2. Connect transfer control unit harness connector.
3. Check voltage between transfer control unit harness connector terminal and ground.
DTC CONSULT-III Diagnostic item is detected when... Reference
[P1819] SHIFT ACT CIR • Transfer control device actuator circuit
is shorted or open. (Malfunctions are
detected when transfer shift relay cir-
cuit is open/shorted or relay monitor
circuit is open/shorted.)
• Malfunction occurs in transfer control device drive circuit.
• Malfunction is detected in transfer shut off relay. Refer to DLN-49
.
Connector
Terminal Voltage (Approx.)
E142 16 - Ground
0V
22 - Ground
E143 30 - Ground Battery voltage
SDIA2834E
Revision: April 20092010 QX56

DLN-52
< COMPONENT DIAGNOSIS >[ATX14B]
P1819 TRANSFER CONTROL DEVICE
7.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 SHIFT ACT CIR [P1819] displayed?
YES >> Replace transfer control unit. Refer to
DLN-130, "Removal and Installation".
NO >> Inspection End.
8.PERFORM SELF-DIAGNOSIS (WITHOUT CONSULT-III)
Without CONSULT-III1. 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 transfer control device?
YES >> Replace transfer control unit.
NO >> Inspection End.
Revision: April 20092010 QX56

DLN-102
< SYMPTOM DIAGNOSIS >[ATX14B]
4WD SYSTEM SYMPTOMS
SYMPTOM DIAGNOSIS
4WD SYSTEM SYMPTOMS
Symptom TableINFOID:0000000005148856
If 4WD warning lamp turns ON, perform self-diagnosis. Refer to DLN-18, "CONSULT-III Function (ALL MODE AWD/4WD)".
NOTE:
• Light tight-corner braking symptom may occur depending on driving conditions in AUTO mode. This is not a
malfunction.
• Heavy tight-corner braking symptom occurs when vehicle is driven in the following conditions: 4WD shift
switch is 4H or 4LO, steering wheel is turned fully to either side.
Symptom ConditionReference page
4WD shift indicator lamp and 4LO indicator lamp do not turn ON
(4WD shift indicator lamp and 4LO indicator lamp check) Ignition switch: ON
DLN-103
4WD warning lamp does not turn ON
(4WD warning lamp check) Ignition switch: ON
DLN-105
4WD shift indicator lamp or 4LO indicator lamp does not change Engine runningDLN-107
ATP warning lamp does not turn ON Engine runningDLN-109
4WD shift indicator lamp keeps flashing Engine runningDLN-111
4WD warning lamp flashes rapidly (2 times/second) While drivingDLN-112
4WD warning lamp flashes slowly
(1 time/2 seconds) While driving
DLN-113
Heavy tight-corner braking symptom occurs
(See NOTE.) • While driving
•AUTO mode
• Steering wheel is turned fully
to either side DLN-114
ATP switch does not operate
Engine runningDLN-116
4WD system does not operate While drivingDLN-118
Revision: April 20092010 QX56

4WD SHIFT INDICATOR LAMP AND 4LO INDICATOR LAMP DO NOT TURN ON
DLN-103
< SYMPTOM DIAGNOSIS > [ATX14B]
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4WD SHIFT INDICATOR LAMP AND 4LO INDICATOR LAMP DO NOT
TURN ON
DescriptionINFOID:0000000005148857
4WD shift indicator lamp and 4LO indicator lamp do not turn ON for approx. 1 second when turning ignition
switch to ON.
Diagnosis ProcedureINFOID:0000000005148858
Regarding Wiring Diagram information, refer to DLN-89, "Wiring Diagram - ALL-MODE 4WD SYSTEM -".
1.CHECK TRANSFER CONTROL UNIT POWER SUPPLY AND GROUND CIRCUITS
Refer to DLN-22, "
Diagnosis Procedure".
Are the inspection results normal?
YES >> GO TO 2.
NO >> Repair as necessary.
2.CHECK COMBINATION METER POWER SUPPLY AND GROUND CIRCUITS
Refer to MWI-28, "
COMBINATION METER : Diagnosis Procedure".
Are the inspection results normal?
YES >> GO TO 3.
NO >> Perform repairs as necessary.
3.CHECK HARNESS BETWEEN TR ANSFER CONTROL UNIT AND COMBINATION METER
1. Turn ignition switch OFF. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connector.
3. Check continuity between the following terminals.
- Transfer control unit harness connector E142 (B) terminal 2 and combination meter harness connector M24 (A) terminal 38.
- Transfer control unit harness connector E142 (B) terminal 11 and combination meter harness connector M24 (A) terminal 29.
- Transfer control unit harness connector E142 (B) terminal 12 and combination meter harness connector M24 (A) terminal 39.
- Transfer control unit harness connector E142 (B) terminal 21
and combination meter harness connector M24 (A) terminal 28.
Also check harness for short to ground and short to power.
Are the inspection results normal?
YES >> GO TO 4.
NO >> Repair or replace damaged parts.
4.CHECK INDICATOR LAMP CIRCUIT
1. Connect combination meter harness connector.
2. Turn ignition switch ON. Continuity should exist.
AWDIA0184ZZ
Revision: April 20092010 QX56

4WD WARNING LAMP DOES NOT TURN ONDLN-105
< SYMPTOM DIAGNOSIS > [ATX14B]
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4WD WARNING LAMP DOES NOT TURN ON
DescriptionINFOID:0000000005148859
4WD warning lamp does not turn ON when turning ignition switch to ON.
Diagnosis ProcedureINFOID:0000000005148860
Regarding Wiring Diagram information, refer to DLN-89, "Wiring Diagram - ALL-MODE 4WD SYSTEM -".
1.CHECK TRANSFER CONTROL UNIT POWER SUPPLY AND GROUND CIRCUITS
Refer to DLN-22, "
Diagnosis Procedure".
Are the inspection results normal?
YES >> GO TO 2.
NO >> Repair as necessary.
2.CHECK COMBINATION METER POWER SUPPLY AND GROUND CIRCUITS
Refer to MWI-28, "
COMBINATION METER : Diagnosis Procedure".
Are the inspection results normal?
YES >> GO TO 3.
NO >> Perform repairs as necessary.
3.CHECK HARNESS BETWEEN TR ANSFER CONTROL UNIT AND COMBINATION METER
1. Turn ignition switch OFF. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit and combination meter harness connectors.
3. Check continuity between the following terminals.
- Transfer control unit harness connector E142 (A) terminal 5 and combination meter harness connector M23 (B) terminal 49.
Also check harness for short to ground and short to power.
Are the inspection results normal?
YES >> GO TO 4.
NO >> Repair or replace damaged parts.
4.CHECK INDICATOR LAMP CIRCUIT
1. Connect combination meter harness connector.
2. Turn ignition switch ON. (Do not start engine.)
3. Ground the following terminal using suitable wiring.
- Transfer control unit harness connector E142 terminal 5 and ground.
Does 4WD warning lamp turn on?
YES >> GO TO 5.
NO >> Replace combination meter. Refer to MWI-100,
"Removal and Installation".
5.SYMPTOM CHECK
Check again.
Are the inspection results normal?
YES >> Inspection End. Continuity should exist.
AWDIA0187ZZ
SDIA2774E
Revision: April 20092010 QX56

ATP WARNING LAMP DOES NOT TURN ONDLN-109
< SYMPTOM DIAGNOSIS > [ATX14B]
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ATP WARNING LAMP DOES NOT TURN ON
DescriptionINFOID:0000000005148863
ATP warning lamp does not turn ON when the transfer case is switched in or out of 4LO with the A/T selector
lever in N position.
Diagnosis ProcedureINFOID:0000000005148864
Regarding Wiring Diagram information, refer to DLN-89, "Wiring Diagram - ALL-MODE 4WD SYSTEM -".
1.CHECK SYSTEM FOR CAN COMMUNICATION LINE
Perform self-diagnosis. Refer to DLN-18, "
CONSULT-III Function (ALL MODE AWD/4WD)".
Do the self-diagnostic results indicate CAN communication?
YES >> Perform trouble diagnosis for CAN communication line.
NO >> GO TO 2.
2.CHECK SYSTEM FOR 4WD SHIFT SWITCH
Perform trouble diagnosis for 4WD shift switch system. Refer to DLN-32, "
Diagnosis Procedure".
Are the inspection results normal?
YES >> GO TO 3.
NO >> Repair or replace damaged parts.
3.CHECK SYSTEM FOR TRANSMIS SION RANGE SWITCH SIGNAL
Perform trouble diagnosis for transmission range switch signal system. Refer to DLN-39, "
Diagnosis Proce-
dure".
Are the inspection results normal?
YES >> GO TO 4.
NO >> Repair or replace damaged parts.
4.CHECK SYSTEM FOR ATP SWITCH
Perform trouble diagnosis for ATP switch system. Refer to DLN-116, "
Diagnosis Procedure".
Are the inspection results normal?
YES >> GO TO 5.
NO >> Repair or replace damaged parts.
5.CHECK HARNESS BETWEEN TR ANSFER CONTROL UNIT AND COMBINATION METER
1. Turn ignition switch OFF. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connector and combination meter harness connector.
3. Check continuity between the following terminals.
- Transfer control unit harness connector E142 (B) terminal 15 and combination meter harness connector M23 (A) terminal 43.
Continuity should exist.
AWDIA0185ZZ
Revision: April 20092010 QX56