wheel INFINITI QX56 2011 Factory Service Manual

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

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

DLN-20
< SYSTEM DESCRIPTION >[TRANSFER: ATX90A]
SYSTEM
4WD Warning Lamp
 Turns ON when there is a malfunction in 4WD system. 4W
D warning lamp indicates the vehicle is in fail-safe
mode.
 Also turns ON when ignition switch is turned ON, fo r the purpose of lamp check. Turns OFF approximately
for 1 second after the engine starts if system is normal.
ATP Warning Lamp
When the A/T shift selector is in P position, the vehicle may move if the transfer case in neutral. ATP warning
lamp is turned on to indicate this condition to the driver.
CONDITION FOR OPERATE WARNING BUZZER
For preventing an incorrect operation during 4H ⇔4L switching, warning buzzer sounds from inside of transfer
control unit and warns the driver, when certain conditions are satisfied.
4WD SYSTEM : Fail-SafeINFOID:0000000006303692
 If any malfunction occurs in 4WD electrical system, and control unit detects the malfunction, 4WD warning
lamp on combination meter turns ON to indicate system malfunction.
 When 4WD warning lamp is ON, vehicle changes to rear-wheel drive or shifts to 4-wheel drive (front-wheels
still have some driving torque).
Condition 4WD warning lamp
Lamp check Turns ON when ignition switch is turned ON. Turns OFF ap-
prox. 1 second after the engine start.
4WD system malfunction ON
Protection function is activated due to heavy load to transfer assem-
bly. (4WD system is not malfunctioning.) Quick blinking: 2 times/second
(Blinking in approx. 1 minute and then turning OFF)
Large difference in diameter of front/rear tires Slow blinking: 1 time/2 seconds
(Continuing to blink until turning ignition switch OFF)
Other than above (system normal) OFF
Condition Warning buzzer
4WD shift status A/T shift selector Engine speed
4H⇔4L N range 350
− 1.600 rpm OFF
Under 350 rpm or over 1.600 rpm ON
Except N range Always
Revision: 2010 May2011 QX56

DLN-22
< SYSTEM DESCRIPTION >[TRANSFER: ATX90A]
DIAGNOSIS SYSTEM (T
RANSFER CONTROL UNIT)
ABS OPER [On/Off] X ABS operation status via CAN communication
line is displayed.
SAND MODE IND [On/Off] This indicator is not equipped, but it is dis-
played.
ROCK MODE IND [On/Off] This indicator is not equipped, but it is dis-
played.
SNOW MODE IND [On/Off] This indicator is not equipped, but it is dis-
played.
ONROAD MODE IND [On/Off] This indicator is not equipped, but it is dis-
played.
SAND MODE SW [On/Off] X This switch is not equipped, but it is displayed.
ROCK MODE SW [On/Off] X This switch is not equipped, but it is displayed.
SNOW MODE SW [On/Off] X This switch is not equipped, but it is displayed.
ONROAD MODE SW [On/Off] X This switch is not equipped, but it is displayed.
HI/LO POSI SEN 3 [On/Off] X Transfer Hi-Lo position sensor (3) status is dis-
played.
HI/LO POSI SEN 1 [On/Off] X Transfer Hi-Lo position sensor (1) status is dis-
played.
LOCK POSI SEN [OPEN/LOCK/BAT/UNLEAN/HI
TEMP/ERROR/GND] X
Transfer lock position sensor signal is dis-
played.
ATP IND [On/Off] Control status of ATP warning lamp is dis-
played.
4WD FAILLAMP [On/Off] X Control status of ATP warning lamp is dis-
played.
4WD MODE IND [4L/LOCK/AUTO] X Control status of 4WD mode indicator lamp is
displayed.
(LOCK means 4H of 4WD mode)
MOTOR DRIVE B [HI/LO/PWM] X Driving status of transfer motor is displayed.
(Reverse side)
MOTOR DRIVE A [HI/LO/PWM] X Driving status of transfer motor is displayed.
(Drive side)
FLUID TEMP SEN [V] X Temperature of transfer fluid is displayed.
MOTOR TEMP [V] X Temperature of transfer motor is displayed.
C/U POWER SUP [V] X Power supply voltage value of transfer control
unit is displayed.
MOTOR POWER SUP [V] X Power supply voltage value of transfer motor
unit is displayed.
ROTARY POSI SEN [%] X Transfer rotary position sensor signal is dis-
played.
THRTL POSI SEN [%] X X Throttle opening status via CAN communica-
tion line is displayed.
AT R SPEED [km/h] X Output shaft revolution speed via CAN commu-
nication line is displayed.
T/M GEAR [0 - 7] X Current transmission gear via CAN communi-
cation line is displayed.
COMPR VHCL SPEED [km/h] X Vehicle speed calculated by transfer control
unit is displayed.
VHCL/S SEN-FR [km/h] X Wheel speed (front) average calculated by
transfer control.
Monitor item (Unit)
SELECT MONITOR ITEM
Remarks
ECU INPUT
SIGNALS MAIN SIG-
NALS
Revision: 2010 May2011 QX56

DIAGNOSIS SYSTEM (TRANSFER CONTROL UNIT)
DLN-23
< SYSTEM DESCRIPTION > [TRANSFER: ATX90A]
C
EF
G H
I
J
K L
M A
B
DLN
N
O P
WORK SUPPORT
*: “LOCK SLEEVE SENSOR” means transfer lock position sensor.
VHCL/S SEN-RR [km/h] X Wheel speed (rear) average calculated by
transfer control.
ENG SPEED [rpm] X Engine status via CAN communication line is
displayed.
INTERNL SPEED SEN [count] X Transfer internal speed sensor status is dis-
played.
TRANSFER TORQUE [Nm] X Commanded transfer communication torque is
displayed.
UNIT PARAMETER [A1 - A9, B1 - B9, C1 - C9, D1
- D9, E1 - E9, F1 - F9, G1 - G9, H1 - H9, J1 - J9] Unit parameter of transfer recognized by trans-
fer control unit is displayed.
Monitor item (Unit)
SELECT MONITOR ITEM
Remarks
ECU INPUT
SIGNALS MAIN SIG-
NALS
Function Description
UNIT CHARACTERISTIC WRITE Writes the unit parameter of transfer to transfer control unit.
START CALIBRATION Perform initial calibration of transfer control unit.
LOCK SLEEVE SENSOR
* INITIALIZE Format learning the transfer lock position sensor written to transfer control unit.
LOCK SLEEVE SENSOR
* LEARNING Perform learning the transfer lock position sensor.
OIL DETERIORATION INFO RESET Format the transfer fl uid viscosity written to transfer control unit.
Revision: 2010 May2011 QX56

DLN-28
< ECU DIAGNOSIS INFORMATION >[TRANSFER: ATX90A]
TRANSFER CONTROL UNIT
CAUTION:
When using circuit tester to measure voltage for in
spection, be sure not to extend forcibly any con-
nector terminals.
Fail-SafeINFOID:0000000006222228
 If any malfunction occurs in 4WD electrical system, and control unit detects the malfunction, 4WD warning
lamp on combination meter turns ON to indicate system malfunction.
 When 4WD warning lamp is ON, vehicle changes to rear-wheel drive or shifts to 4-wheel drive (front-wheels
still have some driving torque).
29
(LG/R) Ground Hi-Lo position sensor 2
Input/
Output Engine
running
(Never
drive the
vehicle.)
Always 0 V
30
(R/B) Ground Transfer lock position
sensor (GND) —Always 0 V
31
(L/O) Ground Transfer internal speed
sensor (DIR)
Input IGN ONWhen changing the trans-
fer motor rota
tion direc-
tion.
32
(BR/R) Ground IGN SW Input IGN ON Battery voltage
IGN OFF 0V
35
(R) Ground 4WD shift SW (4H) Input IGN ON 4WD shift switch: 4H Battery voltage
4WD shift switch: Except
4H
0 V
36
(L/R) Ground Transfer fluid tempera-
ture sensor (GND)
—Always 0 V
38
(G/O) Ground
Transfer lock position
sensor signal Input IGN ON
39
(R/W) Ground Transfer internal speed
sensor power supply
InputIGN ON 8 V
IGN OFF 0V
41
(W/R) Ground Transfer control actuator
power supply Input Always Battery voltage
43
(G/R) Ground Motor drive B Input/
Output Transfer motor driving 0V - Battery voltage
44
(B) Ground GND — Always 0 V
45
(G/Y) Ground Motor drive A Input/
Output Transfer motor driving 0V - Battery voltage
46
(B) Ground Transfer control actuator
(GND)
—Always 0 V
Te r m i n a l N o .
(Wire color) Description
Condition Value (Approx.)
+ - Signal name Input/
Output
JPDIE0269GB
JPDIE0268GB
Revision: 2010 May2011 QX56

P1808 WHEEL SPEED SENSORDLN-53
< DTC/CIRCUIT DIAGNOSIS > [TRANSFER: ATX90A]
C
EF
G H
I
J
K L
M A
B
DLN
N
O P
P1808 WHEEL SPEED SENSOR
DTC LogicINFOID:0000000006222248
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.DTC REPRODUCTION PROCEDURE
With CONSULT-III
1. Start the engine and drive at 30 km/h (19 MPH) or more for approximately 1minute.
2. Perform self-diagnosis for “ALL MODE AWD/4WD”.
Is DTC
“P1808” detected?
YES >> Proceed to diagnosis procedure. Refer to DLN-53, "DTC Logic".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006222249
1.PERFORM ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT) SELF-DIAGNOSIS
With CONSULT-III
Perform self-diagnosis for “ABS”.
Is any DTCs detected?
YES >> Check the DTCs.
NO >> GO TO 2.
2.ERASE SELF-DIAGNOSTIC RESULT
With CONSULT-III
1. Erase self-diagnostic results for “ALL MODE AWD/4WD”.
2. Start the engine and drive vehicle at 30 km/h (19 MPH) or more.
3. Check that ABS warning lamp turns OFF.
Does ABS warning lamp turn OFF?
YES >> GO TO 3.
NO >> Refer to BRC-122, "
Diagnosis Procedure".
3.CHECK TERMINALS AND HARNESS CONNECTORS
Check transfer control unit pin terminals for damage or loose connection with harness connector.
Is inspection result normal?
YES >> After turning the ignition switch OFF, perform DTC confirmation procedure again. When DTC
"P1808" is detected, 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
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.  Harness or connector (CAN communi-
cation line)
 Malfunction of ABS actuator and elec-
tric unit (control unit)
- Malfunction of ABS actuator and elec-
tric unit (control unit) circuit error
- Vehicle speed signal error
Revision: 2010 May2011 QX56

HEAVY TIGHT-CORNER BRAKING SYMPTOM OCCURS
DLN-99
< SYMPTOM DIAGNOSIS > [TRANSFER: ATX90A]
C
EF
G H
I
J
K L
M A
B
DLN
N
O P
SYMPTOM DIAGNOSIS
HEAVY TIGHT-CORNER BRAKING SYMPTOM OCCURS
DescriptionINFOID:0000000006222312
Heavy tight-corner braking symptom o ccurs when the vehicle is driven and the steering wheel is turned fully to
either side after the engine is started.
NOTE:
Light tight-corner braking symptom may occur dependi ng on driving conditions. This is not malfunction.
Diagnosis ProcedureINFOID:0000000006222313
1.PERFORM ECM SELF-DIAGNOSIS
With CONSULT-III
Perform self-diagnosis for “ECM”.
Is any DTC detected?
YES >> Check the DTC. Refer to EC-98, "DTC Index".
NO >> GO TO 2.
2.PERFORM SELF-DIAGNOSIS
With CONSULT-III
Perform self-diagnosis for “ALL MODE AWD/4WD”.
Is any DTC detected?
YES >> Check the DTC. Refer to DLN-29, "DTC Index".
NO >> GO TO 3.
3.CHECK TRANSFER INTERNAL FUNCTION
With CONSULT-III
1. Remove transfer control actuator. Refer to DLN-114, "
Removal and Installation".
2. Turn the actuator shaft. Refer to DLN-114, "
Inspection".
3. Check “ROTARY POSI SEN” of CONSULT-II I “DATA MONITOR” for “ALL MODE AWD/4WD”.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Transfer assembly is mechanical malfunction. Replace transfer assembly. Refer to DLN-121,
"Removal and Installation".
Monitor item Condition Status
ROTARY POSI SEN Turn the actuator shaft. Value is changing
Revision: 2010 May2011 QX56

DLN-100
< SYMPTOM DIAGNOSIS >[TRANSFER: ATX90A]
4WD MODE DOES NOT CHANGE
4WD MODE DOES NOT CHANGE
DescriptionINFOID:0000000006222314
Vehicle does not enter 4-wheel drive mode even though 4WD warning lamp turned to OFF.
Diagnosis ProcedureINFOID:0000000006222315
1.PERFORM SELF-DIAGNOSIS
With CONSULT-III
Perform self-diagnosis for “ALL MODE AWD/4WD”.
Is any DTC detected?
YES >> Check DTC. Refer to DLN-29, "DTC Index".
NO >> GO TO 2.
2.CHECK 4WD MODE INDICATOR LAMP
Check 4WD mode indicator lamp function. Refer to DLN-98, "
Component Function Check".
Is the inspection result normal?
YES >> GO TO 3.
NO >> Proceed to diagnosis procedure. Refer to DLN-98, "
Diagnosis Procedure".
3.CHECK 4WD SHIFT SWITCH
Perform rouble diagnosis of the 4WD shift switch. Refer to DLN-67, "
Diagnosis Procedure".
Is the inspection result normal?
YES >> Transfer assembly is mechanical malfunction. Replace transfer assembly. Refer to DLN-121,
"Removal and Installation".
NO >> Replace 4WD switch assembly. Refer to DLN-108, "
Removal and Installation".
Revision: 2010 May2011 QX56

DLN-126
< SYMPTOM DIAGNOSIS >[FRONT PROPELLER SHAFT: 2F P15]
NOISE, VIBRATION, AND HARSHNESS
(NVH) TROUBLESHOOTING
SYMPTOM DIAGNOSIS
NOISE, VIBRATION, AND HARSHNESS (NVH) TROUBLESHOOTING
NVH Troubleshooting ChartINFOID:0000000006222354
Use the chart below to help you find the cause of the symptom. If necessa ry, repair or replace these parts.
×: ApplicableReference
DLN-127, "
Inspection
"—
—
—
—
DLN-127, "
Inspection
"
DLN-127, "
Inspection
"
NVH of FRONT FINAL DRI VE in this section.
NVH of REAR FINAL DRI VE in this section.
NVH in FAX, RAX, FSU and RSU section.
NVH in WT section.
NVH in WT section.
NVH in FAX and RAX section.
NVH in BR section.
NVH in ST section.
Possible cause an d SUSPECTED PARTS
Uneven rotating torque
Center bearing improper installation
Excessive center bearing axial end play
Center bearing mounting (insulator) cracks, damage or deterioration
Excessive joint angle
Rotation imbalance
Excessive runout
DIFFERENTIAL
AXLE AND SUSPENSION
TIRE
ROAD WHEEL
DRIVE SHAFT
BRAKE
STEERING
Symptom Noise
××××××××××××××
Shake × × ××××××
Vibration ××××××× ×× × ×
Revision: 2010 May2011 QX56