2006 INFINITI QX56 4WD

POWER STEERING GEAR AND LINKAGEPS-15
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Revision: November 2009 2006 QX56
POWER STEERING GEAR AND LINKAGEPFP:49001
Removal and InstallationEGS000UH
CAUTION:
Spiral cable may snap due to steering operation if steering column is separated from steering gear
assembly. Therefore secure steering wheel to avoid turning.
REMOVAL
1. Turn wheels to the straight-ahead position.
2. Remove tires from vehicle using power tool.
3. Remove undercover using power tool.
4. On 4WD model, remove front final drive, then support drive shafts with wire. Refer to FFD-12, "
Removal
and Installation" .
5. Remove cotter pin at steering outer socket and discard, then loosen nut.
6. Remove steering outer socket from steering knuckle using Tool. Be careful not to damage ball joint boot.
CAUTION:
Temporarily tighten mounting nut to prevent damage to
threads and to prevent Tool from coming off.
7. On 2WD model, remove stabilizer bar mounting bolts and reposition stabilizer bar. Refer to FSU-12,
"Removal and Installation" .
1. Cotter pin2. Mounting bracket3. Mounting insulator
4. Steering gear assembly 5. Washer
WGIA0127E
Tool number : HT72520000 (J-25730-A)
SDIA1434E

RFD-32
SERVICE DATA AND SPECIFICATIONS (SDS)
Revision: November 20092006 QX56
SERVICE DATA AND SPECIFICATIONS (SDS)PFP:00030
General SpecificationsEDS0044V
Inspection and AdjustmentEDS0044W
DRIVE GEAR RUNOUT
Unit: mm (in)
SIDE GEAR CLEARANCE
Unit: mm (in)
PRELOAD TORQUE
Unit: N·m (kg-m, in-lb)
BACKLASH
Unit: mm (in)
COMPANION FLANGE RUNOUT
Unit: mm (in)
SELECTIVE PARTS
Side Gear Thrust Washer
Unit: mm (in)
*: Always check with the Parts Department for the latest parts information. Applied model
VK56DE
2WD 4WD
Final drive model R230
Gear ratio 2.9373.357
Number of teeth (Drive gear/Drive pinion) 47 / 1647 / 14
Oil capacity (Approx.) 1.75 (3 3/4 US pt, 3 1/8 Imp pt)
Number of pinion gears 2
Drive pinion adjustment spacer type Collapsible
ItemRunout limit
Drive gear back face 0.05 (0.0020) or less
ItemSpecification
Side gear back clearance
(Clearance limit between side gear and differential case for adjusting
side gear backlash) 0.20 (0.0079) or less
(Each gear should rotate smoothly without excessive resis- tance during differential motion.)
Item Specification
Drive pinion bearing preload torque 1.77 − 2.64 N·m (0.18 − 0.26 kg−m, 16 − 23 in-lb)
Side bearing preload torque (reference value determined by drive
gear bolt pulling force) 0.20
− 0.52 N·m (0.02 − 0.05 kg −m, 2 − 4 in-lb)
Drive gear bolt pulling force (by spring gauge) 34.2 − 39.2 N (3.5 − 4 kg, 7.7 − 8.8 lb)
Total preload torque
(Total preload torque = drive pinion bearing preload torque + Side
bearing preload torque) 2.05
− 4.11 N·m (0.21 − 0.42 kg −m, 19 − 36 in-lb)
Item Specification
Drive gear to drive pinion gear 0.13 − 0.18 (0.0051 − 0.0070)
Item Runout limit
Outer side of the companion flange 0.08 (0.0031) or less
ThicknessPart number*
1.75 (0.0688)
1.80 (0.0708)
1.85 (0.0728) 38424 7S000
38424 7S001
38424 7S002

SERVICE DATA AND SPECIFICATIONS (SDS)RSU-49
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Revision: November 2009 2006 QX56
Wheelarch Height (Unladen*1 )EES001HV
Unit: mm (in)
*1: Fuel, engine coolant and engine oil full. Spare tire, jack, hand tools and mats in designated positions.
*2: Verify the vehicle height. If vehicle height is not within ± 10 mm (0.39 in) of the specification, perform the control unit initialization pro-
cedure. Refer to RSU-47, "
Initialization Procedure" .
Suspension type
Air leveling*
2
Applied model2WD 4WD
Front wheelarch height (Hf) 913
(35.94) 931
(36.65)
Rear wheelarch height (Hr) 912
(35.91) 932
(36.69)
LEIA0085E

TF-1
TRANSFER
D DRIVELINE/AXLE
CONTENTS
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Revision: November 2009 2006 QX56
PRECAUTIONS .....................................................
..... 4
Precautions for Supplemental Restraint System
(SRS) “AIR BAG” and “SEAT BELT PRE-TEN-
SIONER” ............................................................. ..... 4
Precautions for Transfer Assembly and Transfer
Control Unit Replacement ................................... ..... 4
METHOD FOR POSITION ADJUSTMENT ...... ..... 4
Precautions ......................................................... ..... 4
Service Notice .......................................................... 5
PREPARATION ...................................................... ..... 6
Special Service Tools .......................................... ..... 6
Commercial Service Tools ................................... ..... 9
NOISE, VIBRATION AND HARSHNESS (NVH)
TROUBLESHOOTING ........................................... ... 10
NVH Troubleshooting Chart ................................ ... 10
TRANSFER FLUID ................................................ ....11
Replacement ....................................................... .... 11
DRAINING ........................................................ .... 11
FILLING ............................................................ .... 11
Inspection ............................................................ .... 11
FLUID LEAKAGE AND FLUID LEVEL ............. .... 11
ALL-MODE 4WD SYSTEM ................................... ... 12
Cross-section View ............................................. ... 12
Power Transfer .................................................... ... 13
POWER TRANSFER DIAGRAM ..................... ... 13
POWER TRANSFER FLOW ............................ ... 14
System Description ............................................. ... 15
CONTROL SYSTEM ........................................ ... 15
TRANSFER MOTOR ....................................... ... 16
WAIT DETECTION SWITCH ........................... ... 17
NEUTRAL-4LO SWITCH ................................. ... 17
ATP SWITCH ................................................... ... 17
2-4WD SHIFT SOLENOID VALVE ................... ... 17
CLUTCH PRESSURE SOLENOID VALVE ...... ... 18
LINE PRESSURE SWITCH ............................. ... 18
CLUTCH PRESSURE SWITCH ....................... ... 18
TRANSFER FLUID TEMPERATURE SENSOR ... 18
TRANSFER CONTROL UNIT .......................... ... 18
TRANSFER CONTROL DEVICE ..................... ... 18
4WD SHIFT SWITCH AND INDICATOR LAMP ... 184WD WARNING LAMP ....................................
... 19
ATP WARNING LAMP ...................................... ... 19
System Diagram ..................................................... 19 COMPONENTS FUNCTION ............................ ... 20
CAN Communication .............................................. 20 SYSTEM DESCRIPTION ................................. ... 20
TROUBLE DIAGNOSIS ......................................... ... 21
How to Perform Trouble Diagnosis ...................... ... 21
BASIC CONCEPT ............................................ ... 21
Location of Electrical Parts .................................. ... 22
Circuit Diagram ....................................................... 23
Wiring Diagram — T/F — .................................... ... 24
Inspections Before Trouble Diagnosis ................. ... 32
TRANSFER FLUID CHECK ............................. ... 32
PREPARATION FOR ROAD TEST .................. ... 32
CHECK BEFORE ENGINE IS STARTED ........ ... 32
CHECK AT IDLE ............................................... ... 32
CRUISE TEST ..................................................... 33
Trouble Diagnosis Chart for Symptoms ............... ... 34
Transfer Control Unit Input/Output Signal Refer-
ence Values ......................................................... ... 35
TRANSFER CONTROL UNIT INSPECTION
TABLE .............................................................. ... 35
CONSULT-II Function (ALL MODE AWD/4WD) .. ... 44
FUNCTION ....................................................... ... 44
CONSULT-II SETTING PROCEDURE ............. ... 44
SELF-DIAG RESULT MODE ............................ ... 45
DATA MONITOR MODE ................................... ... 47
WORK SUPPORT ............................................ ... 49
Self-diagnostic Procedure ................................... ... 50
SELF-DIAGNOSTIC PROCEDURE (WITH
CONSULT-II) .................................................... ... 50
SELF-DIAGNOSTIC PROCEDURE (WITHOUT
CONSULT-II) .................................................... ... 50
ERASE SELF-DIAGNOSIS .............................. ... 53
TROUBLE DIAGNOSIS FOR SYSTEM ................. ... 54
Power Supply Circuit For Transfer Control Unit ... ... 54
CONSULT-II REFERENCE VALUE IN DATA
MONITOR MODE ............................................. ... 54
TRANSFER CONTROL UNIT TERMINALS AND

TF-2Revision: November 20092006 QX56
REFERENCE VALUE .......................................
... 54
DIAGNOSTIC PROCEDURE ........................... ... 55
COMPONENT INSPECTION ........................... ... 57
Transfer Control Unit ........................................... ... 57
DIAGNOSTIC PROCEDURE ........................... ... 57
Output Shaft Revolution Signal (TCM) ................ ... 58
DIAGNOSTIC PROCEDURE ........................... ... 58
Vehicle Speed Sensor (ABS) ............................... ... 58
DIAGNOSTIC PROCEDURE ........................... ... 58
Neutral-4LO Switch ................................................ 59 CONSULT-II REFERENCE VALUE IN DATA
MONITOR MODE ............................................. ... 59
TRANSFER CONTROL UNIT TERMINALS AND
REFERENCE VALUE ....................................... ... 59
DIAGNOSTIC PROCEDURE ........................... ... 60
COMPONENT INSPECTION ........................... ... 62
4WD Shift Switch ................................................. ... 62
CONSULT-II REFERENCE VALUE IN DATA
MONITOR MODE ............................................. ... 62
TRANSFER CONTROL UNIT TERMINALS AND
REFERENCE VALUE ....................................... ... 62
DIAGNOSTIC PROCEDURE ........................... ... 63
COMPONENT INSPECTION ........................... ... 66
Wait Detection Switch .......................................... ... 66
CONSULT-II REFERENCE VALUE IN DATA
MONITOR MODE ............................................. ... 66
TRANSFER CONTROL UNIT TERMINALS AND
REFERENCE VALUE ....................................... ... 66
DIAGNOSTIC PROCEDURE ........................... ... 67
COMPONENT INSPECTION ........................... ... 69
PNP Switch Signal (TCM) ................................... ... 69
DIAGNOSTIC PROCEDURE ........................... ... 69
Actuator Motor ..................................................... ... 70
CONSULT-II REFERENCE VALUE IN DATA
MONITOR MODE ............................................. ... 70
TRANSFER CONTROL UNIT TERMINALS AND
REFERENCE VALUE ....................................... ... 70
DIAGNOSTIC PROCEDURE ........................... ... 71
COMPONENT INSPECTION ........................... ... 76
Actuator Position Switch ...................................... ... 77
CONSULT-II REFERENCE VALUE IN DATA
MONITOR MODE ............................................. ... 77
TRANSFER CONTROL UNIT TERMINALS AND
REFERENCE VALUE ....................................... ... 77
DIAGNOSTIC PROCEDURE ........................... ... 78
COMPONENT INSPECTION ........................... ... 80
Transfer Control Device ....................................... ... 81
CONSULT-II REFERENCE VALUE IN DATA
MONITOR MODE ............................................. ... 81
TRANSFER CONTROL UNIT TERMINALS AND
REFERENCE VALUE ....................................... ... 81
DIAGNOSTIC PROCEDURE ........................... ... 82
Engine Speed Signal (ECM) ................................ ... 85
DIAGNOSTIC PROCEDURE ........................... ... 85
Clutch Pressure Solenoid .................................... ... 86
CONSULT-II REFERENCE VALUE IN DATA
MONITOR MODE ............................................. ... 86
TRANSFER CONTROL UNIT TERMINALS AND
REFERENCE VALUE ....................................... ... 86DIAGNOSTIC PROCEDURE ............................
... 87
COMPONENT INSPECTION ............................ ... 90
2-4WD Solenoid ................................................... ... 91
CONSULT-II REFERENCE VALUE IN DATA
MONITOR MODE ............................................. ... 91
TRANSFER CONTROL UNIT TERMINALS AND
REFERENCE VALUE ....................................... ... 91
DIAGNOSTIC PROCEDURE ............................ ... 91
COMPONENT INSPECTION ............................ ... 94
Transfer Motor ...................................................... ... 95
CONSULT-II REFERENCE VALUE IN DATA
MONITOR MODE ............................................. ... 95
TRANSFER CONTROL UNIT TERMINALS AND
REFERENCE VALUE ....................................... ... 96
DIAGNOSTIC PROCEDURE ............................ ... 97
COMPONENT INSPECTION ............................ .102
Transfer Fluid Temperature .................................. .102
CONSULT-II REFERENCE VALUE IN DATA
MONITOR MODE ............................................. .102
TRANSFER CONTROL UNIT TERMINALS AND
REFERENCE VALUE ....................................... .102
DIAGNOSTIC PROCEDURE ............................ .103
COMPONENT INSPECTION ............................ .104
Clutch Pressure Switch ........................................ .105
CONSULT-II REFERENCE VALUE IN DATA
MONITOR MODE ............................................. .105
TRANSFER CONTROL UNIT TERMINALS AND
REFERENCE VALUE ....................................... .105
DIAGNOSTIC PROCEDURE ............................ .106
COMPONENT INSPECTION ............................ .107
Line Pressure Switch ........................................... .108
CONSULT-II REFERENCE VALUE IN DATA
MONITOR MODE ............................................. .108
TRANSFER CONTROL UNIT TERMINALS AND
REFERENCE VALUE ....................................... .108
DIAGNOSTIC PROCEDURE ............................ .109
COMPONENT INSPECTION ............................ .110
Throttle Position Signal (ECM) ............................. . 111
DIAGNOSTIC PROCEDURE ............................ . 111
ABS Operation Signal (ABS) ............................... . 111
DIAGNOSTIC PROCEDURE ............................ . 111
VDC Operation Signal (ABS) ............................... .112
DIAGNOSTIC PROCEDURE ............................ .112
TCS Operation Signal (ABS) ............................... .112
DIAGNOSTIC PROCEDURE ............................ .112
CAN Communication Line .................................... .113
DIAGNOSTIC PROCEDURE ............................ .113
ATP Switch ........................................................... .113
CONSULT-II REFERENCE VALUE IN DATA
MONITOR MODE ............................................. .113
TRANSFER CONTROL UNIT TERMINALS AND
REFERENCE VALUE ....................................... .113
DIAGNOSTIC PROCEDURE ............................ .114
COMPONENT INSPECTION ............................ .115
TROUBLE DIAGNOSIS FOR SYMPTOMS ........... .117
4WD Shift Indicator Lamp and 4LO Indicator Lamp
Do Not Turn ON ................................................... .117
SYMPTOM: ....................................................... .117
DIAGNOSTIC PROCEDURE ............................ .117

TF-3
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Revision: November 2009 2006 QX56
4WD Warning Lamp Does Not Turn ON .............
. 121
SYMPTOM: ...................................................... . 121
DIAGNOSTIC PROCEDURE ........................... . 121
4WD Shift Indicator Lamp or 4LO Indicator Lamp
Does Not Change ................................................ . 123
SYMPTOM: ...................................................... . 123
DIAGNOSTIC PROCEDURE ........................... . 124
ATP Warning Lamp Turns ON ............................. . 125
SYMPTOM: ...................................................... . 125
DIAGNOSTIC PROCEDURE ........................... . 125
4LO Indicator Lamp Repeats Flashing ................ . 127
SYMPTOM: ...................................................... . 127
DIAGNOSTIC PROCEDURE ........................... . 127
4WD Warning Lamp Flashes Rapidly ................. . 128
SYMPTOM: ...................................................... . 128
DIAGNOSTIC PROCEDURE ........................... . 128
4WD Warning Lamp Flashes Slowly ................... . 129
SYMPTOM: ...................................................... . 129
DIAGNOSTIC PROCEDURE ........................... . 129
Heavy Tight-corner Braking Symptom Occurs .... . 130
SYMPTOM: ...................................................... . 130
DIAGNOSTIC PROCEDURE ........................... . 130
4WD System Does Not Operate ......................... . 131
SYMPTOM: ...................................................... . 131
DIAGNOSTIC PROCEDURE ........................... . 131
TRANSFER CONTROL UNIT ................................ . 132
Removal and Installation ..................................... . 132
REMOVAL ........................................................ . 132
INSTALLATION ................................................ . 132
FRONT OIL SEAL ................................................. . 133
Removal and Installation ..................................... . 133
REMOVAL ........................................................ . 133
INSTALLATION ................................................ . 134
REAR OIL SEAL ................................................... . 135
Removal and Installation ..................................... . 135
REMOVAL ........................................................ . 135
INSTALLATION ................................................ . 135SIDE OIL SEAL ......................................................
.137
Removal and Installation ..................................... .137
REMOVAL ........................................................ .137
INSTALLATION ................................................ .137
TRANSFER CONTROL DEVICE ........................... .138
Removal and Installation ..................................... .138
AIR BREATHER HOSE ......................................... .139
Removal and Installation ..................................... .139
TRANSFER MOTOR .............................................. .142
Removal and Installation ..................................... .142
REMOVAL ........................................................ .142
INSTALLATION ................................................ .142
TRANSFER OIL FILTER ........................................ .143
Removal and Installation ..................................... .143
REMOVAL ........................................................ .143
INSTALLATION ................................................ .143
TRANSFER ASSEMBLY ....................................... .145
Removal and Installation ..................................... .145
REMOVAL ........................................................ .145
INSTALLATION ................................................ .145
Disassembly and Assembly ................................. .146
COMPONENTS ................................................ .146
DISASSEMBLY ................................................ .148
INSPECTION AFTER DISASSEMBLY ............. .163
ASSEMBLY ...................................................... .167
SERVICE DATA AND SPECIFICATIONS (SDS) ... .183
General Specifications ......................................... .183
Inspection and Adjustment .................................. .183
CLEARANCE BETWEEN INNER GEAR AND
OUTER GEAR .................................................. .183
CLUTCH ........................................................... .183
PINION GEAR END PLAY ............................... .183
CLEARANCE BETWEEN SHIFT FORK AND
SLEEVE ........................................................... .183
SELECTIVE PARTS ......................................... .183

TF-4
PRECAUTIONS
Revision: November 20092006 QX56
PRECAUTIONSPFP:00001
Precautions for Supplemental Restraint System (SRS) “AIR BAG” and “SEAT
BELT PRE-TENSIONER”
EDS002H3
The Supplemental Restraint System such as “AIR BAG” and “SEAT BELT PRE-TENSIONER ”, used along
with a front seat belt, helps to reduce the risk or severity of injury to the driver and front passenger for certain
types of collision. This system includes seat belt switch inputs and dual stage front air bag modules. The SRS
system uses the seat belt switches to determine the front air bag deployment, and may only deploy one front
air bag, depending on the severity of a collision and whether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the SRS and SB section of this Service Man-
ual.
WARNING:

To avoid rendering the SRS inoperative, which could increase the risk of personal injury or death
in the event of a collision which would result in air bag inflation, all maintenance must be per-
formed by an authorized NISSAN/INFINITI dealer.

Improper maintenance, including incorrect removal and installation of the SRS, can lead to per-
sonal injury caused by unintentional activation of the system. For removal of Spiral Cable and Air
Bag Module, see the SRS section.

Do not use electrical test equipment on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harnesses can be identified by yellow and/or orange harnesses or
harness connectors.
Precautions for Transfer Assembly and Transfer Control Unit ReplacementEDS002H4
When replacing transfer assembly or transfer control unit, check the 4WD shift indicator lamp as follows.
1. Turn ignition switch “ON ”.
2. Check 4WD shift indicator lamp is turned ON for approx. 1 second.

If OK, the position between transfer assembly and transfer control unit is correct.

If NG, the position is different between transfer assembly and transfer control unit.
Adjust the position between transfer assembly and transfer control unit. Refer to TF-4, "
METHOD FOR
POSITION ADJUSTMENT" .
METHOD FOR POSITION ADJUSTMENT
1. Start engine. Run the engine for at least 10 seconds.
2. Stop vehicle and move A/T selector lever to “N” position with brake pedal depressed. Stay in "N" for at
least 2 seconds.
3. Turn 4WD shift switch to “2WD ” position. Stay in "2WD" for at least 2 seconds.
4. Turn ignition switch “ OFF”.
5. Start engine.
6. Erase self-diagnosis. Refer to TF-47, "
How to Erase Self-diagnostic Results" (with CONSULT-II) or TF-
53, "ERASE SELF-DIAGNOSIS" (without CONSULT-II).
7. Check 4WD shift indicator lamp. Refer to TF-32, "
CHECK BEFORE ENGINE IS STARTED" .
If 4WD shift indicator lamp does not indicate "2WD", install new transfer control unit and retry the above
check.
PrecautionsEDS002H5

Before connecting or disconnecting the transfer control
unit harness connector, turn ignition switch “OFF” and dis-
connect battery ground cable. Failure to do so may damage
the transfer control unit. Battery voltage is applied to trans-
fer control unit even if ignition switch is turned “OFF”.
SEF289H

TF-12
ALL-MODE 4WD SYSTEM
Revision: November 20092006 QX56
ALL-MODE 4WD SYSTEMPFP:00000
Cross-section ViewEDS002H8
1. Center case2. Front case 3. Internal gear
4. Planetary carrier assembly 5. Sun gear assembly 6. Main shaft
7. L-H sleeve 8. L-H fork 9. Shift rod
10. 2-4 sleeve 11. 2-4 fork 12. Drive chain
13. Front drive shaft 14. Control valve assembly 15. Transfer motor
16. Rear case 17. Clutch piston 18. Press flange
19. Multiple disc clutch 20. Clutch hub assembly 21. Clutch drum assembly
WDIA0202E