2008 INFINITI QX56 oil

DLN-4
Commercial Service Tool ......................................191
SYMPTOM DIAGNOSIS ............................192
NOISE, VIBRATION, AND HARSHNESS
(NVH) TROUBLESHOOTING ......................... .
192
NVH Troubleshooting Chart ................................ ..192
ON-VEHICLE REPAIR ...............................193
PROPELLER SHAFT ..................................... .193
On-Vehicle Service .............................................. ..193
REMOVAL AND INSTALLATION ..............194
PROPELLER SHAFT ..................................... .194
Removal and Installation ..................................... ..194
DISASSEMBLY AND ASSEMBLY ............197
PROPELLER SHAFT ..................................... .197
Disassembly and Assembly ................................. ..197
SERVICE DATA AND SPECIFICATIONS
(SDS) ........................................................ ..
199
SERVICE DATA AND SPECIFICATIONS
(SDS) ............................................................... .
199
General Specification .......................................... ..199
Snap Ring ..............................................................200
FRONT FINAL DRIVE: M205
PRECAUTION .............. ..............................
201
PRECAUTIONS .............................................. .201
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" .............................................................. ..
201
Precaution Necessary for Steering Wheel Rota-
tion After Battery Disconnect .................................
201
Precaution for Servicing Front Final Drive .............202
PREPARATION ..........................................203
PREPARATION .............................................. .203
Special Service Tool ............................................ ..203
Commercial Service Tool ......................................205
SYMPTOM DIAGNOSIS ............................206
NOISE, VIBRATION AND HARSHNESS
(NVH) TROUBLESHOOTING ......................... .
206
NVH Troubleshooting Chart ................................ ..206
ON-VEHICLE MAINTENANCE ..................207
DIFFERENTIAL GEAR OIL ............................ .207
Changing Differential Gear Oil ...............................207
Checking Differential Gear Oil ............................. ..207
ON-VEHICLE REPAIR ...............................208
SIDE OIL SEAL .............................................. ..208
Removal and Installation .......................................208
FRONT OIL SEAL ............................................209
Removal and Installation .......................................209
CARRIER COVER .......................................... ..211
Removal and Installation .......................................211
REMOVAL AND INSTALLA TION .............212
FRONT FINAL DRIVE .................................... ..212
Removal and Installation .......................................212
DISASSEMBLY AND ASSEMBLY ...........214
FRONT FINAL DRIVE .................................... ..214
Disassembly and Assembly ................................. .214
SERVICE DATA AND SPECIFICATIONS
(SDS) ........ .................................................
231
SERVICE DATA AND SPECIFICATIONS
(SDS) .............................................................. ..
231
General Specification ........................................... .231
Inspection and Adjustment ....................................231
REAR FINAL DRIVE: R230
PRECAUTION ............... ............................
233
PRECAUTIONS .............................................. ..233
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" .............................................................. .
233
Precaution Necessary for Steering Wheel Rota-
tion After Battery Disconnect ................................
233
Precaution for Servicing Rear Final Drive .............234
PREPARATION .........................................235
PREPARATION .............................................. ..235
Special Service Tool ............................................ .235
Commercial Service Tool ......................................239
SYMPTOM DIAGNOSIS ...........................240
NOISE, VIBRATION AND HARSHNESS
(NVH) TROUBLESHOOTING ......................... ..
240
NVH Troubleshooting Chart ..................................240
DESCRIPTION ................................................ ..241
Cross-Sectional View ........................................... .241
ON-VEHICLE MAINTENANCE .................242
DIFFERENTIAL GEAR OIL ..............................242
Changing Differential Gear Oil ............................. .242
Checking Differential Gear Oil ..............................242
ON-VEHICLE REPAIR ..............................243
FRONT OIL SEAL ............................................243
Revision: March 2010 2008 QX56

DLN-5
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Removal and Installation
.......................................
243
SIDE OIL SEAL .............................................. ..245
Removal and Installation .......................................245
CARRIER COVER .......................................... ..247
Removal and Installation .......................................247
REMOVAL AND INSTALLA TION .............248
REAR FINAL DRIVE ...................................... ..248
Removal and Installation .......................................248
DISASSEMBLY AND AS SEMBLY ............251
REAR FINAL DRIVE .......................................251
Disassembly and Assembly ................................. ..251
SERVICE DATA AND SPECIFICATIONS
(SDS) ............... .......................................... .
268
SERVICE DATA AND SPECIFICATIONS
(SDS) ...............................................................
268
General Specification .......................................... ..268
Inspection and Adjustment ....................................268
Revision: March 2010 2008 QX56

DLN-10
< FUNCTION DIAGNOSIS >[ATX14B]
4WD SYSTEM
FUNCTION DIAGNOSIS
4WD SYSTEM
System DiagramINFOID:0000000001737096
COMPONENT DESCRIPTION
WDIA0164E
Components
Function
Transfer control unit Controls transfer control device, control valves and shifts between 2WD/4WD and 4H/4LO.
Transfer control device Integrates actuator motor and actuator position switch.
2-4WD shift solenoid valve Controls oil pressure and allows shifting between 2WD and 4WD.
Clutch pressure solenoid valve Controls oil pressure and distributes torque between front and rear tires.
Line pressure switch Detects line pressure.
Clutch pressure switch Detects clutch pressure.
Transfer fluid temperature sensor Detects transfer fluid temperature.
Actuator motor Moves shift rods when signaled by transfer control unit.
Actuator position switch Detects actuator motor position.
Wait detection switch Detects whether or not 4WD lock gear is locked.
4LO switch Detects if transfer case is in 4LO.
ATP switch Detects if transfer case is in neutral.
4WD shift switch Allows driver to select from 2WD/4WD, 4H/4LO and AUTO.
4WD warning lamp • Illuminates if malfunction is detected in 4WD system.
• Flashes (1 flash / 2 seconds) if large difference in diameter of front and rear tires.
• Flashes (2 flashes / 1 second) if high transfer fluid temperature is detected.
AT P w a r n i n g l a m p Indicates that A/T parking mechanism does not operate when A/T selector lever is in P position
because transfer case is in neutral.
4WD shift indicator lamp Displays driving range selected by 4WD shift switch.
4LO indicator lamp Displays 4LO range.
Revision: March 2010 2008 QX56

DLN-14
< FUNCTION DIAGNOSIS >[ATX14B]
4WD SYSTEM
• Displays 4LO condition while engine is running. 4LO indicator lamp flashes if transfer gear does not shift
completely under 2WD, AUTO, 4H ⇔4LO. (When 4WD warning lamp is turned on, 4LO indicator lamp is
turned off.)
• Turns ON for approximately 1 second when ignition switch is turned ON, for purpose of lamp check.
4WD WARNING LAMP
Turns on or flashes when there is a malfunction in 4WD system.
Also turns on when ignition switch is turned ON, for purpose of lamp che\
ck. Turns OFF approximately 1 sec-
ond after the engine starts if system is normal.
4WD Warning Lamp Indication
ATP WARNING LAMP
When the A/T selector lever is in P position, the vehicle may move if the transfer case is in neutral. ATP warn-
ing lamp is turned on to indicate this condition to the driver.
LINE PRESSURE SWITCH
• With the transfer system design, control of the oil pressure provides the transmission of drive torque to the
front wheels. The main pressure to control the oil pressure is referred to as the line pressure.
• The line pressure switch determines whether or not adequate line pressure has built up under different oper- ating conditions.
• The line pressure switch closes when line pressure is produced.
• The line pressure switch senses line pressure abnormalities and turns the 4WD warning lamp ON.
CLUTCH PRESSURE SWITCH
• The clutch pressure switch determines whether or not adequate clutch pressure has built up under different
operating conditions.
• The clutch pressure switch closes when clutch pressure is produced.
• The clutch pressure switch senses clutch pressure abnormalities and turns the 4WD warning lamp ON.
WAIT DETECTION SWITCH
• The wait detection switch operates when there is circulating torque produced in the propeller shaft (L→H) or
when there is a phase difference between 2-4 sleeve and clutch drum (H →L). After the release of the circu-
lating torque, the wait detection switch helps provi de the 4WD lock gear (clutch drum) shifts. A difference
may occur between the operation of the 4WD shift swit ch and actual drive mode. At this point, the wait
detection switch senses an actual drive mode.
• The wait detection switch operates as follows.
- 4WD lock gear (clutch drum) locked: ON
- 4WD lock gear (clutch drum) released: OFF
• The wait detection switch senses an actual drive mode and the 4WD shift indicator lamp indicates the vehi-
cle drive mode.
ATP SWITCH
ATP switch detects if transfer case is in neutral by the position of the L-H shift fork.
NOTE:
Transfer case may be in neutral when shifting between 4H-4LO.
NEUTRAL-4LO SWITCH
The neutral-4LO switch detects that transfer gear is in neutral or 4LO (or shifting from neutral to 4LO) condi-
tion by L-H shift fork position.
Condition 4WD warning lamp
System normal OFF
Lamp check Turns ON when ignition switch is turned ON.
Turns OFF after engine start.
4WD system malfunction ON
During self-diagnosis Flashes malfunction mode.
Large difference in diameter of front/
rear tires Flashes slow (1 flash / 2 seconds)
(Continues to flash until the ignition switch is turned OFF)
High fluid temperature in transfer case Flashes rapidly (2 flashes / 1 second)
(Continues to flash until fluid temperature returns to normal)
Revision: March 2010 2008 QX56

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: March 2010 2008 QX56

4WD SYSTEMDLN-17
< FUNCTION DIAGNOSIS > [ATX14B]
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CAN CommunicationINFOID:0000000001737099
Refer to LAN-51, "DTC Index".
1. A: Transfer shut off relay E69
B: Transfer shift low relay E47
C: Transfer shift high relay E46 2. A: Actuator
B: Transfer control device F58
C: Actuator lever
D: Transfer case 3. Wait detection switch F59
(View with transfer case removed)
4. A: Clutch pressure switch B: Line pressure switch
C: Transfer fluid temperature sensor
D: 2-4WD shift solenoid valve
E: Clutch pressure solenoid valve
(View with contro l valve removed
from transfer case) 5. A: Neutral 4LO switch F60
B: ATP switch F55
C: Transfer motor F57
D: Transfer terminal cord assembly F56
E: Oil filter 6. Combination meter M23, M24
A: 4WD warning lamp
B: ATP warning lamp
C: 4LO indicator lamp (located in in-
formation display)
D: 4WD shift indicator lamp
7. 4WD shift switch M141 8. Transfer control unit E142, E143 9. Transfer dropping resistor E135
Transfer motor relay E153, E154
(View with battery removed)
Revision: March 2010 2008 QX56

P1826 TRANSFER FLUID TEMPERATUREDLN-67
< COMPONENT DIAGNOSIS > [ATX14B]
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P1826 TRANSFER FLUID TEMPERATURE
DescriptionINFOID:0000000001737155
Signal voltage from the transfer fluid temperature sens or is abnormally high (Transfer fluid temperature is
abnormally low) while driving.
DTC LogicINFOID:0000000001737156
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON.
2. Perform self-diagnosis.
Is DTC P1826 displayed?
YES >> Perform diagnosis procedure. Refer to DLN-67, "Diagnosis Procedure".
NO >> Inspection End.
Diagnosis ProcedureINFOID:0000000001737157
1.CHECK TRANSFER FLUID TE MPERATURE SENSOR SIGNAL
With CONSULT-III
1. Start engine.
2. Select DATA MONITOR mode for ALL MODE AWD/4WD with CONSULT-III.
3. Read out the value of FLUID TEMP SE.
Without CONSULT-III
1. Start engine.
2. Check voltage between transfer control unit harness connector
terminals and ground.
Are inspection results normal?
YES >> GO TO 4.
NO >> GO TO 2.
2.CHECK HARNESS BETWEEN TRANSF ER CONTROL UNIT AND TRANSFER TERMINAL CORD AS-
DTCCONSULT-III Diagnostic item is detected when... Reference
[P1826] OIL TEMP SEN Signal voltage from transfer fluid temper-
ature sensor is abnormally high (Trans-
fer fluid temperature is abnormally low)
while driving.Refer to DLN-67
.
Condition
Display value
(Approx.)
Transfer fluid temperature approx. 20 - 80 °C (68 - 176° F) 1.1 - 0.3V
Connector Terminal ConditionData
(Approx.)
E143 28 -
Ground Always
0V
31 -
Ground Ignition switch:
ON Transfer fluid temperature
approx. 20
°C (68 °F) 1.1V
Transfer fluid temperature
approx. 80 °C (176 °F) 0.3V
SDIA2742E
Revision: March 2010
2008 QX56

TRANSFER CONTROL UNITDLN-97
< ECU DIAGNOSIS > [ATX14B]
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CAUTION:
• If CAN COMM CIRCUIT [U1000] or CONTROL UNIT (CAN) [U1010] is displayed with other DTCs, first perform the trouble
diagnosis for CAN communication line.
• If ABS OP SIG [P1830], VDC OP SIG [P1831] or TCS OP SIG [P 1832] is displayed, first perform the trouble diagnosis for ABS
system.
• If VHCL SPEED SEN·AT [P1807] is displayed, firs t perform the trouble diagnosis for A/T system.
NOTE:
• If SHIFT ACT POSI SW [P1818] or SHIFT ACT CIR [P1819] is disp layed, first erase self-diagnostic results. (SHIFT ACT POSI SW
[P1818] or SHIFT ACT CIR [P1819] may be displayed after installing transfer control unit or transfer assembly.)
• If CL PRES SW [P1827] or LINE PRES SW [P1828] is displayed only while driving in reverse, check the continuity of R position o n
transmission range switch. When there is no malfunction found in the electrical system, check the hydraulic system.
FLASH CODE CHART
[P1826] OIL TEMP SEN Signal voltage from transfer fluid temperature sen-
sor is abnormally high (Transfer fluid temperature is
abnormally low) while driving. Refer to
DLN-67.
[P1827] CLUTCH PRES SW • Improper signal from clutch pressure switch is in-
put due to open or short circuit.
• Malfunction occurs in clutch pressure switch or
hydraulic circuit. Refer to
DLN-70
.
[P1828] LINE PRES SW • Improper signal from line pressure switch is input
due to open or short circuit.
• Malfunction occurs in line pressure switch or hy-
draulic circuit. Refer to
DLN-73
.
[P1829] THROTTLE POSI SEN • Malfunction is detected in accelerator pedal posi-
tion signal that is output from ECM through CAN
communication.
• Signal voltage from accelerator pedal position sensor is abnormally high or low. Refer to
DLN-76
.
[P1830] ABS OP SIG Malfunction is detected in ABS operation signal that
is output from ABS actuator and electric unit (control
unit) through CAN communication. Refer to
DLN-77
.
[P1831] VDC OP SIG Malfunction is detected in VDC operation signal that
is output from ABS actuator and electric unit (control
unit) through CAN communication.
Refer to
DLN-78
.
[P1832] TCS OP SIG Malfunction is detected in TCS operation signal that
is output from ABS actuator and electric unit (control
unit) through CAN communication. Refer to
DLN-79
.
DTC CONSULT-III Diagnostic item is detected when... Reference
Flashing pattern
ItemDiagnostic item is detected when... Reference
2 Vehicle speed signal
(from A/T) • Malfunction is detected in output speed sensor signal that
is output from TCM through CAN communication.
• Improper signal is input while driving. Refer to DLN-26
.
3 Clutch pressure sole-
noid signal Proper voltage is not applied to clutch pressure solenoid
valve due to open or short circuit.
Refer to DLN-53
.
4 2-4WD solenoid signal Proper voltage is not applied to 2-4WD solenoid valve due
to open or short circuit. Refer to DLN-57
.
5 Transfer motor Transfer motor does not operate properly due to open or
short circuit in transfer motor or transfer motor relay.
Refer to DLN-61
.
6 Vehicle speed signal
(from ABS) • Malfunction is detected in vehicle speed signal that is out-
put from ABS actuator and electric unit (control unit)
through CAN communication.
• Improper signal is input while driving. Refer to DLN-27
.
7 CAN communication Malfunction has been detected from CAN communication
line. Refer to LAN-51
.
8 AD converter AD converter system of transfer control unit is malfunction-
ing. Refer to DLN-24
.
Revision: March 2010
2008 QX56