INFINITI QX56 2009 Factory Service Manual

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Changing Differential Gear Oil ............................
..
244
Checking Differential Gear Oil ...............................244
ON-VEHICLE REPAIR ...............................245
FRONT OIL SEAL .......................................... ..245
Removal and Installation ..................................... ..245
SIDE OIL SEAL ................................................247
Removal and Installation ..................................... ..247
CARRIER COVER .......................................... ..249
Removal and Installation ..................................... ..249
REMOVAL AND INSTALLATION .............250
REAR FINAL DRIVE .......................................250
Removal and Installation ..................................... ..250
DISASSEMBLY AND ASSEMBLY ............253
REAR FINAL DRIVE .......................................253
Disassembly and Assembly ................................. ..253
SERVICE DATA AND SPECIFICATIONS
(SDS) ............... ...........................................
270
SERVICE DATA AND SPECIFICATIONS
(SDS) ...............................................................
270
General Specification .......................................... ..270
Inspection and Adjustment ....................................270
Revision: December 20092009 QX56

DLN-6
< BASIC INSPECTION >[ATX14B]
DIAGNOSIS AND REPAIR WORKFLOW
BASIC INSPECTION
DIAGNOSIS AND REPAIR WORKFLOW
Work FlowINFOID:0000000003772073
WORK FLOW
DETAILED FLOW
1.CUSTOMER INFORMATION
Interview the customer to obtain detailed information about the symptom.
>> GO TO 2
2.PRELIMINARY CHECK
Perform preliminary check. Refer to DLN-7, "Preliminary Check"
.
>> GO TO 3
3.SELF-DIAGNOSIS
Perform self-diagnosis. Refer to DLN-18, "CONSULT-III Function (ALL MODE AWD/4WD)"
.
AWNIA1592GB
Revision: December 20092009 QX56

DIAGNOSIS AND REPAIR WORKFLOWDLN-7
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>> GO TO 4
4.SYMPTOM
Check for symptoms. Refer to DLN-102, "Symptom Table"
.
>> GO TO 5
5.MALFUNCTIONING PARTS
Repair or replace the applicable parts.
>> GO TO 6
6.SYSTEM OPERATION
Check system operation.
>> GO TO 7
7.SELF-DIAGNOSIS
Perform self-diagnosis.
Are any DTC's displayed?
YES >> GO TO 5
NO >> Inspection End
Preliminary CheckINFOID:0000000003772074
TRANSFER FLUID CHECK
Check for leaks and fluid level. Refer to DLN-129, "Inspection".
PREPARATION FOR ROAD TEST
The purpose of the test is to determine overall performance of trans-
fer case and analyze causes of malfunctions.
When a malfunction is found in any part of transfer, perform the road
test to locate the malfunction area and repair the malfunction parts.
The road test consists of the following three parts.
1. CHECK BEFORE ENGINE IS STARTED
2. CHECK AT IDLE
3. CRUISE TEST
CHECK BEFORE ENGINE IS STARTED
1.CHECK 4WD SHIFT INDICATOR LAMP
1. Park vehicle on flat surface.
2. Turn ignition switch to OFF position.
3. Move A/T selector lever to P position.
4. Set 4WD shift switch to 2WD position.
5. Turn ignition switch to ON position. (Do not start engine.)
Does 4WD shift indicator lamp turn ON for approximately 1 second?
YES >> GO TO 2.
NO >> GO TO DLN-103, "Diagnosis Procedure"
.
2.CHECK 4WD WARNING LAMP
1. Turn ignition switch to OFF position.
2. Move A/T selector lever to P position.
3. Set 4WD shift switch to 2WD position.
4. Turn ignition switch to ON position. (Do not start engine.)
SMT089D
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DLN-8
< BASIC INSPECTION >[ATX14B]
DIAGNOSIS AND REPAIR WORKFLOW
Does 4WD warning lamp turn ON?
YES >> GO TO CHECK AT IDLE.
NO >> GO TO
DLN-105, "Diagnosis Procedure"
.
CHECK AT IDLE
1.CHECK 4WD SHIFT INDICATOR LAMP
1. Park vehicle on flat surface and engage the parking brake.
2. Turn ignition switch to OFF position.
3. Move A/T selector lever to P position.
4. Set 4WD shift switch to 2WD position.
5. Start engine.
Does 4WD shift indicator lamp turn ON?
YES >> GO TO 3.
NO >> GO TO 2.
2.CHECK 4WD WARNING LAMP
Check 4WD warning lamp state.
Is 4WD warning lamp turned ON?
YES >> Perform the self-diagnosis. Refer to DLN-18, "CONSULT-III Function (ALL MODE AWD/4WD)".
NO >> Refer to DLN-107, "Diagnosis Procedure"
.
3.CHECK 4WD SHIFT INDICATOR AND 4LO INDICATOR OPERATION
1. Brake pedal depressed.
2. Move A/T selector lever to N position.
3. Set 4WD shift switch to 2WD, AUTO, 4H, 4LO, 4H, AUTO and 2WD in order. (Stay at each switch position for at least 1 sec-
ond.)
Do 4WD shift indicator and 4LO indicator lamps change properly?
Does buzzer sound?
YES >> GO TO CRUISE TEST.
NO >> GO TO DLN-107, "Diagnosis Procedure"
.
CRUISE TEST
1.CHECK INPUT SIGNAL
1. Warm up engine to normal operating temperature.
2. Park vehicle on flat surface.
3. Move A/T selector lever to P position.
4. Set 4WD shift switch to AUTO position.
5. Start engine.
6. Drive vehicle for at least 30 seconds at a speed higher than 20 km/h (12 MPH).
Is 4WD warning lamp turned ON?
On steady>>Perform the self-diagnosis. Refer to DLN-18, "CONSULT-III Function (ALL MODE AWD/4WD)".
WDIA0136E
Revision: December 20092009 QX56

DIAGNOSIS AND REPAIR WORKFLOWDLN-9
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Flash rapidly>>Refer to DLN-112, "Diagnosis Procedure".
Flash slowly>>Refer to DLN-113, "Diagnosis Procedure"
.
NO >> GO TO 2.
2.CHECK TIGHT CORNER BRAKING SYMPTOM (1)
1. Set 4WD shift switch to AUTO position.
2. Drive vehicle at speed lower than 20 km/h (12 MPH) with steering wheel fully turned.
Does tight corner braking symptom occur?
YES >> GO TO DLN-114, "Diagnosis Procedure".
NO >> GO TO 3.
3.CHECK TIGHT CORNER BRAKING SYMPTOM (2)
1. Set 4WD shift switch to 4HI position.
2. Drive vehicle at speed lower than 20 km/h (12 MPH) with steering wheel fully turned.
Does tight corner braking symptom occur?
YES >> Inspection End.
NO >> GO TO DLN-118, "Diagnosis Procedure"
.
Revision: December 20092009 QX56

DLN-10
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4WD SYSTEM
FUNCTION DIAGNOSIS
4WD SYSTEM
System DiagramINFOID:0000000003772075
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: December 20092009 QX56

4WD SYSTEMDLN-11
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CONTROL SYSTEM
ABS actuator and electric unit
(control unit) Transmits vehicle speed signal via CAN communication to transfer control unit.
TCM Transmits the following signal via CAN communication to transfer control unit.
 Output shaft revolution signal
 A/T position indicator signal (transmission range switch signal)
ECM Transmits the following signals via CAN communication to transfer control unit.
 Engine speed signal
 Accelerator pedal position signal
Components Function
Revision: December 20092009 QX56

DLN-12
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4WD SYSTEM
ALL-MODE 4WD Transfer Basic Control
SDIA3396E
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4WD SYSTEMDLN-13
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Hydraulic Control Circuits
TRANSFER CONTROL UNIT
 Transfer control unit controls transfer control dev
ice and it directs shifts from 4H-4LO and 2WD-4WD.
 Self-diagnosis can be done.
TRANSFER SHIFT HIGH AND LOW RELAYS
Transfer shift high and low relays apply power supply to transfer control device (actuator motor).
TRANSFER SHUT OFF RELAY
Transfer shut off relay applies power supply to transfer motor relay.
4WD SHIFT SWITCH AND INDICATOR LAMPS
4WD Shift Switch
Able to select from 2WD, AUTO, 4H or 4LO.
4WD Shift Indicator Lamp
 Displays driving conditions selected by 4WD shift switch with 2WD, AUTO and 4H indicators while engine is running. (When 4WD warning lamp is turned on, all 4WD shift indicator lamps are turned off.)
 Turns ON for approximately 1 second when ignition switch is turned ON, for purpose of lamp check.
4LO Indicator Lamp
LDIA0055E
WDIA0163E
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DLN-14
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4WD SYSTEM
 Displays 4LO condition while engine is running. 4LO indi
cator 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, cont rol 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 pressu re 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 tr ansfer 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: December 20092009 QX56