INFINITI QX56 2011 Factory Service Manual

PREPARATIONDLN-9
< PREPARATION > [TRANSFER: ATX90A]
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Drift
a: 63 mm (2.48 in) dia.
b: 59 mm (2.32 in) dia. Installing front oil seal
Power tool Loosening bolts and nuts
Tool name
Description
ZZA1003D
PBIC0190E
Revision: 2010 May2011 QX56

DLN-10
< SYSTEM DESCRIPTION >[TRANSFER: ATX90A]
COMPONENT PARTS
SYSTEM DESCRIPTION
COMPONENT PARTS
Component Parts LocationINFOID:0000000006222214
1. ECM
Refer to EC-16, "
Component Parts
Location". 2. ABS actuator and electric unit (con-
trol unit)
Refer to BRC-10, "Component Parts
Location". 3. Steering angle sensor
Refer to BRC-10, "
Component Parts
Location".
4. Control valve & TCM Refer to TM-10, "
A/T CONTROL
SYSTEM : Compon ent Parts Loca-
tion". 5. Transfer control unit 6. 4WD switch assembly
7. Transfer lock position sensor 8. Transfer Hi-Lo position sensor 9. Transfer rotary position sensor
10. Transfer control actuator 11. Transfer fluid temperature sensor
A. Back of glove box assembly B. 4WD indicator lamp, 4WD warning lamp, ATP warning lamp (in combina-
tion meter)C. Console assembly
D. Transfer assembly upper side E. Transfer assembly under side
JPDIE0270GB
Revision: 2010 May2011 QX56

COMPONENT PARTSDLN-11
< SYSTEM DESCRIPTION > [TRANSFER: ATX90A]
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Component DescriptionINFOID:0000000006222215
Transfer Control UnitINFOID:0000000006222216
 Transfer control unit operates transfer control act uator, 4WD warning lamp and 4WD mode indicator lamp
according to input signal from 4WD shift switch and each sensor and control unit.
 When 4WD system is malfunctioning, 4WD warning la mp turns ON and fail-safe status activates.
 When protection is necessary, 4WD warning la mp blinks and protection status activates.
Transfer Control ActuatorINFOID:0000000006222217
Transfer control actuator integrates transfer motor, transfer internal position sensor, and transfer motor tem-
perature sensor, and switches 4WD mode (AUTO ⇔4H ⇔4L).
TRANSFER MOTOR
Transfer motor operates according to signal from transfer control unit and switches 4WD mode
(AUTO ⇔4H ⇔4L). It also performs front and rear distri bution of traction force during AUTO mode.
TRANSFER INTERNAL SPEED SENSOR
Transfer internal speed sensor detects rotation status of transfer motor and transmits signal to transfer control
unit.
TRANSFER MOTOR TEMPERATURE SENSOR
 Transfer motor temperature sensor m easures temperature of transfer motor.
Component parts Reference/Function
Transfer control unit DLN-11, "
Transfer Control Unit"
Transfer control actua-
torTransfer motor
DLN-11, "
Transfer Control Actuator"
Transfer internal speed
sensorDLN-11, "Transfer Control Actuator"
Transfer motor temper-
ature sensor
DLN-11, "Transfer Control Actuator"
Transfer Hi-Lo position sensor
DLN-12, "Transfer Hi-Lo Position Sensor"
Transfer rotary position sensorDLN-12, "Transfer Rotary Position Sensor"
Transfer lock position sensorDLN-12, "Transfer Lock Position Sensor"
Transfer fluid temperature sensorDLN-12, "Transfer Fluid Temperature Sensor"
4WD mode switchDLN-18, "4WD SYSTEM : System Description"
4WD indicator lampDLN-18, "4WD SYSTEM : System Description"
4WD warning lampDLN-18, "4WD SYSTEM : System Description"
AT P w a r n i n g l a m pDLN-18, "4WD SYSTEM : System Description"
ABS actuator and electric unit (control unit)Transmits the following signals via CAN communication line to transfer control unit.
 Vehicle speed signal (ABS)
 Stop lamp switch signal (brake signal)
 ABS operation signal
 VDC operation signal
 TCS operation signal
Steering angle sensor Transmits the following signals via CAN communication line to transfer control unit.
 Steering angle sensor signal
ECM Transmits the following signals via CAN communication line to transfer control unit.
 Accelerator pedal position signal
 Engine speed signal
 Engine torque signal
TCM Transmits the following signals via CAN communication line to transfer control unit.
 Shift position signal
 Gear position signal
 Output shaft revolution signal
Revision: 2010 May2011 QX56

DLN-12
< SYSTEM DESCRIPTION >[TRANSFER: ATX90A]
COMPONENT PARTS
 This sensor uses a thermistor and its electrical resi
stance varies as the temperature varies. The electrical
resistance decreases as the temperature increases.
Transfer Hi-Lo Position SensorINFOID:0000000006222218
Transfer Hi-Lo position sensor detects engagement status of Hi-Lo sleeve and transmits signal to transfer con-
trol unit.
Transfer Rotary Position SensorINFOID:0000000006222219
Transfer rotary position sensor detects rotation status of actuator shaft and transmits signal to transfer control
unit.
Transfer Lock Position SensorINFOID:0000000006222220
Transfer lock position sensor detects engagement status of lock sleeve and transmits signal to transfer control
unit.
Transfer Fluid Temperature SensorINFOID:0000000006222221
 Transfer fluid temperature sensor m easures temperature of transfer fluid.
 This sensor uses a thermistor and its electrical resi stance varies as the temperature varies. The electrical
resistance decreases as the temperature increases.
Revision: 2010 May2011 QX56

STRUCTURE AND OPERATIONDLN-13
< SYSTEM DESCRIPTION > [TRANSFER: ATX90A]
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STRUCTURE AND OPERATION
Sectional ViewINFOID:0000000006222222
Torque Split MechanismINFOID:0000000006222223
CONTROL DIAGRAM
1. Rear companion flange 2. Main shaft 3. Rear case
4. Ball ramp lever 5. Ball lamp lever 6. Piston
7. Clutch 8. Sprocket 9. Lock sleeve
10. Hi-Lo sleeve 11. Sun gear 12. Front case
13. Planetary carrier assembly 14. Internal gear 15. Shift fork
16. Transfer rotary position sensor 17. Front shaft flange 18. Drive chain
19. Actuator shaft 20. Cam 21. Transfer control actuator
JPDIE0277ZZ
Revision: 2010 May2011 QX56

DLN-14
< SYSTEM DESCRIPTION >[TRANSFER: ATX90A]
STRUCTURE AND OPERATION
DESCRIPTION
 Ball ramp lever operates in the direction of main shaft axis according to rotation of actuator shaft and
presses piston. Pressure is applied to each clutch and torque is transmitted.
 Shift fork operates in the direction of main shaft axis according to rotation of actuator shaft and performs
engagement and disengagement to Hi-Lo sleeve and lock sleev e of main shaft. Mode is switched between
4H ⇔4L.
AUTO MODE
 The optimum torque distribution is electronically performed for front and rear wheels according to road con-
ditions.
 Stable start without wheel spin is possible on slippery road conditions, such as on a snowy road.
 When road condition does not require 4WD driving, the st atus becomes close to rear wheel drive, which
results in better fuel efficiency and prov ides FR-like steering characteristics.
 The vehicle cornering status is judged according to information from each sensor, and the optimum torque is
distributed to front wheels for prev enting tight-corner braking symptom.
NOTE:
When there is a difference of revolution speed between the front and rear wheel the shift occasionally changes
to direct 4-wheel driving conditions aut omatically. This is not a malfunction.
4H MODE
 Torque distribution for front and rear wheels is fixed and stable start is achieved while driving on an rough,
sandy or snowy road.
4L MODE
 Large traction force is obtained due to low gear. High running ability and escaping ability are achieved.
 Switching from 4H mode to 4L mode is not possible w hen the vehicle is not stopped and A/T shift selector is
not in the neutral position.
TORQUE DISTRIBUTION DIAGRAM
JPDIE0256GB
Revision: 2010 May2011 QX56

STRUCTURE AND OPERATIONDLN-15
< SYSTEM DESCRIPTION > [TRANSFER: ATX90A]
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TORQUE DISTRIBUTION FLOW
OPERATION PRINCIPLE
AUTO, 4H MODE
1. Main shaft 2. Clutch 3. Sprocket
4. Lock sleeve 5. Hi-Lo sleeve 6. Sun gear
7. Planetary carrier assembly 8. Front shaft flange 9. Drive chain
JPDIE0271GB
JPDIE0257GB
Revision: 2010 May2011 QX56

DLN-16
< SYSTEM DESCRIPTION >[TRANSFER: ATX90A]
STRUCTURE AND OPERATION
1. Transfer control unit supplies command current to transfer motor.
2. Transfer motor operates and actuator shaft rotates clockwise.
3. Shift fork operates according to rotation of actuator shaft. Sun gear and Hi-Lo sleeve are engaged.
4. Ball ramp lever operates in axial direction via cam fixed on actuator shaft according to traction torque of
transfer motor, presses piston, and thrusts multiple plate clutch.
5. Torque is transmitted to front wheels according to thrusting pressure of multiple plate clutch. NOTE:
Torque transmitted to the front wheel is determined according to the command current.
4L MODE
1. Main shaft 2. Ball lamp lever 3. Piston
4. Clutch 5. Hi-Lo sleeve 6. Sun gear
7. Shift fork 8. Actuator shaft 9. Transfer control actuator
JPDIE0278GB
Revision: 2010 May2011 QX56

STRUCTURE AND OPERATIONDLN-17
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1. Transfer control unit supplies command current to transfer motor.
2. Transfer motor operates and actuator shaft rotates counterclockwise.
3. Shift fork operates according to rotation of actuator shaft. Planetary carrier assembly and Hi-Lo sleeve are
engaged.
1. Main shaft 2. Sprocket 3. Lock sleeve
4. Hi-Lo sleeve 5. Sun gear 6. Planetary carrier assembly
7. Internal gear 8. Shift fork 9. Actuator shaft
10. Transfer control actuator
JPDIE0279ZZ
Revision: 2010 May2011 QX56

DLN-18
< SYSTEM DESCRIPTION >[TRANSFER: ATX90A]
SYSTEM
SYSTEM
4WD SYSTEM
4WD SYSTEM : System DescriptionINFOID:0000000006222224
 In AUTO mode, distribution of traction force is cont
rolled from 2WD status (0:100) to 4WD status (50:50)
according to signal from each sensor and switch.
 In accordance with fail-safe function, when system is malfunctioning, 4WD warning lamp on combination meter turns ON and 4WD control stops. For fail-safe function, refer to DLN-20, "
4WD SYSTEM : Fail-Safe".
 When a high load status continues for transfer assembly (transfer control actuator or transfer fluid), 4WD
control temporarily becomes 4H or 2WD status, according to protection function.
NOTE:
4WD system is not malfunctioning.
SYSTEM DIAGRAM
INPUT/OUTPUT SIGNAL
It transmits/receives each signal from the followi ng transfer control unit via CAN communication line.
JPDIE0272GB
Component parts Control signal
ABS actuator and electric unit (control unit) Transmits the following signals via CAN communication line to transfer control unit.
 Vehicle spee
d signal (ABS)
 Stop lamp switch signal (brake signal)
 ABS operation signal
 VDC operation signal
 TCS operation signal
ECM Transmits the following signals via CAN communication line to transfer control unit.
 Accelerator pedal position signal
 Engine speed signal
 Engine torque signal
Revision: 2010 May2011 QX56