2004 INFINITI QX56 warning

COLLISION DIAGNOSIS
SRS-61
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SRS
Revision: August 20072004 QX56
For Side CollisionEHS0 00 W X
Check the SRS components using the following table.

After the work is completed, perform self-diagnosis to check that no malfunction is detected. Refer to
SRS-20, "
SRS Operation Check" .
WHEN SRS IS ACTIVATED IN THE SIDE COLLISION
1. Replace the following components:
–Front seat back assembly (on the side on which side air bag is activated)
–Diagnosis sensor unit
–(LH or RH) side air bag (satellite) sensor (on the side on which side air bag is activated)
2. Check the SRS components and the related parts using the following table.
–Replace any SRS components and the related parts showing visible signs of damage (dents, cracks,
deformation).
3. Conduct self-diagnosis using CONSULT-II and “AIR BAG” warning lamp. Refer to SRS-20, "
SRS Opera-
tion Check" for details. Ensure entire SRS operates properly.
WHEN SRS IS NOT ACTIVATED IN THE SIDE COLLISION
1. Check the SRS components and the related parts using the following table.
–If the front seat back assembly is damaged, the front seat back assembly must be replaced.
2. Conduct self-diagnosis using CONSULT-II and “AIR BAG” warning lamp. Refer to SRS-20, "
SRS Opera-
tion Check" for details. Ensure entire SRS operates properly.
SRS INSPECTION (FOR SIDE COLLISION)
Harness and connec-
tors1. Check connectors for poor connection, damage, and terminals for deformities.
2. Check harness for binding, chafing, cuts, or deformities.
3. If no damage is found, reinstall the harness and connectors.
4. If damaged—REPLACE the damaged harness. Do not attempt to repair, splice or modify any SRS harness.
Instrument panel
REPLACE the instru-
ment panel assembly.1. Visually check instrument panel for damage.
2. If no damage is found, reinstall the instrument panel.
3. If damaged—REPLACE the instrument panel. Part SRS is activated SRS is NOT activated
Part SRS is activated SRS is NOT activated
(LH or RH) side cur-
tain air bag moduleReplace the side cur-
tain air bag module.
(Repair the center pil-
lar inner, etc. before
installing new one if
damaged.)1. Check for visible signs of damage (dents, tears, deformation) of the center pillar on
the collision side.
2. If damaged—Remove the side curtain air bag module.
3. Check for visible signs of damaged (tears etc.) of the side curtain air bag module.
4. Check harness and connectors for damage, and terminals for deformities.
5. If no damage is found, reinstall the side curtain air bag module with new fasteners.
6. If damaged—REPLACE the side curtain air bag module with new fasteners.
Front (LH or RH) side
air bag moduleREPLACE front seat-
back assembly.1. Check for visible signs of damage (dents, tears, deformation) of the seat back on
the collision side.
2. Check harness and connectors for damage, and terminals for deformities.
3. If damaged—REPLACE the front seatback assembly.
(LH or RH) side air
bag (satellite) sensor REPLACE the side
air bag (satellite) sen-
sor on the collision
side with new fasten-
ers.
(Repair the center pil-
lar inner, etc. before
installing new one if
damaged.)1. Remove the side air bag (satellite) sensor on the collision side. Check harness
connectors for damage, terminals for deformities, and harness for binding.
2. Check for visible signs of damage (dents, cracks, deformation) of the side air bag
(satellite) sensor.
3. Install the side air bag (satellite) sensor to check fit.
4. If no damage is found, reinstall the side sir bag (satellite) sensor with new fasten-
ers.
5. If damaged—REPLACE the side air bag (satellite) sensor with new fasteners.

SRS-62
COLLISION DIAGNOSIS
Revision: August 20072004 QX56
For RolloverEHS001BC
Check the SRS components using the following table.

After the work is completed, perform self-diagnosis to check that no malfunction is detected. Refer to
SRS-20, "
SRS Operation Check" .
WHEN SRS IS ACTIVATED IN THE ROLLOVER
1. Replace the following components:
–Diagnosis sensor unit
–(LH or RH) side air bag (satellite) sensor (on the side on which side air bag is activated)
2. Check the SRS components and the related parts using the following table.
–Replace any SRS components and the related parts showing visible signs of damage (dents, cracks,
deformation).
3. Conduct self-diagnosis using CONSULT-II and “AIR BAG” warning lamp. Refer to SRS-20, "
SRS Opera-
tion Check" for details. Ensure entire SRS operates properly.
WHEN SRS IS NOT ACTIVATED IN THE ROLLOVER
1. Check the SRS components and the related parts using the following table.
–If the front seat back assembly is damaged, the front seat back assembly must be replaced.
2. Conduct self-diagnosis using CONSULT-II and “AIR BAG” warning lamp. Refer to SRS-20, "
SRS Opera-
tion Check" for details. Ensure entire SRS operates properly.
Diagnosis sensor unit REPLACE the diag-
nosis sensor unit with
new fasteners.1. Check case and bracket for dents, cracks or deformities.
2. Check connectors for damage, and terminals for deformities.
3. If no damage is found, reinstall the diagnosis sensor unit with new fasteners.
4. If damaged—REPLACE the diagnosis sensor unit with new fasteners.
Seat belt pre-ten-
sioner assembly and
seat belt buckle pre-
tensioner assembly1. Check if the seat belt can be extended smoothly.
If the seat belt cannot be extended smoothly,
–Check for deformities of the center pillar inner.
–If the center pillar inner has no damage, REPLACE the seat belt pre-tensioner assembly.
2. Remove the seat belt pre-tensioner assembly and the seat belt buckle pre-tensioner assembly on the colli-
sion side. Check harness cover and connectors for damage, terminals for deformities, and harness for bind-
ing.
3. Check for visible signs of damage (dents, cracks, deformation) of the seat belt pre-tensioner assembly and
the seat belt buckle pre-tensioner assembly.
4. Check seat belt adjuster for damage.
5. If no damage is found, reinstall the seat belt pre-tensioner assembly and the seat belt buckle pre-tensioner
assembly.
6. If damaged—REPLACE the seat belt pre-tensioner assembly or the seat belt buckle pre-tensioner assem-
bly with new fasteners.
Seat (with front side
air bag)REPLACE front seat-
back assembly.1. Visually check the seat on the collision side.
2. Remove the seat on the collision side and check the following for damage and
deformities.
–Harness, connectors and terminals
–Frame and recliner (for front and rear seat), and also adjuster and slides (for front
seat)
3. If no damage is found, reinstall the seat.
4. If damaged—REPLACE the damaged seat parts using new fasteners. If the front
seat back is damaged, the front seat back assembly must be replaced.
Center inner pillar 1. Check the center inner pillar on the collision side for damage (dents, cracks, deformation).
2. If damaged—REPAIR the center inner pillar.
Trim/headlining 1. Check for visible signs of damage (dents, cracks, deformation) of the interior trim on the collision side.
2. If damaged—REPLACE the damaged trim parts. Part SRS is activated SRS is NOT activated

TF-1
TRANSFER
D DRIVELINE/AXLE
CONTENTS
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SECTION TF
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B
TF
Revision: August 20072004 QX56 PREPARATION ........................................................... 4
Special Service Tools ............................................... 4
Commercial Service Tools ........................................ 7
PRECAUTIONS .......................................................... 8
Precautions for Supplemental Restraint System
(SRS) “AIR BAG” and “SEAT BELT PRE-TEN-
SIONER” .................................................................. 8
Precautions .............................................................. 8
Service Notice .......................................................... 9
Wiring Diagrams and Trouble Diagnosis .................. 9
ALL-MODE 4WD SYSTEM ...................................... 10
Cross-sectional View .............................................. 10
Control System ........................................................11
ALL-MODE 4WD TRANSFER BASIC CONTROL
... 12
HYDRAULIC CONTROL CIRCUITS ................... 12
OUTLINE ............................................................. 12
CONTROL SYSTEM DIAGRAM ......................... 13
INDICATIONS OF 4WD WARNING LAMP ......... 13
CAN Communication .............................................. 13
SYSTEM DESCRIPTION .................................... 13
Location of Electrical Parts ..................................... 14
Description of Electrical Parts ................................ 15
TRANSFER MOTOR .......................................... 15
WAIT DETECTION SWITCH .............................. 15
2-4WD SHIFT SOLENOID VALVE ...................... 15
LINE PRESSURE SWITCH ................................ 16
Circuit Diagram for Quick Pinpoint Check .............. 17
Wiring Diagram — T/F — ....................................... 18
ON BOARD DIAGNOSTIC SYSTEM DESCRIP-
TION .......................................................................... 27
Trouble Diagnosis without CONSULT-II ................. 27
DESCRIPTION .................................................... 27
SELF-DIAGNOSTIC PROCEDURE .................... 28
INDICATIONS OF 4WD WARNING LAMP ......... 28CONSULT-II Function (ALL MODE AWD/4WD) ..... 31
Trouble Diagnosis with CONSULT-II ...................... 31
SELF-DIAGNOSIS .............................................. 31
SELF-DIAGNOSTIC ITEMS ................................ 32
DATA MONITOR ................................................. 34
DATA MONITOR ITEMS ..................................... 35
REFERENCE VALUE IN DATA MONITOR MODE
... 38
WORK SUPPORT ............................................... 41
CLUTCH FORCE RELEASE LIMIT ADJUST-
MENT .................................................................. 42
TROUBLE DIAGNOSIS — INTRODUCTION ........... 44
Introduction ............................................................. 44
DESCRIPTION .................................................... 44
DIAGNOSTIC WORKSHEET .............................. 44
Work Flow ............................................................... 46
HOW TO PERFORM TROUBLE DIAGNOSES
FOR QUICK AND ACCURATE REPAIR ............. 46
TROUBLE DIAGNOSIS — BASIC INSPECTION .... 47
Listen to Customer Complaints .............................. 47
Transfer Fluid Check .............................................. 47
Road Test ............................................................... 47
PREPARATION FOR ROAD TEST ..................... 47
1. CHECK BEFORE ENGINE IS STARTED ....... 48
2. CHECK AT IDLE .............................................. 49
3. CRUISE TEST ................................................. 53
TROUBLE DIAGNOSIS — GENERAL DESCRIP-
TION .......................................................................... 55
Transfer Control Unit Terminals and Reference
Value ....................................................................... 55
TRANSFER CONTROL UNIT HARNESS CON-
NECTOR LAYOUT .............................................. 55
TRANSFER CONTROL UNIT INSPECTION
TABLE ................................................................. 55
DTC U1000, U1001 CAN COMMUNICATION LINE ... 59
CAN Communication System Inspection ................ 59
4WD SOLENOID VALVE .......................................... 60
Diagnostic Procedure ............................................. 60
2-4WD SHIFT SOLENOID VALVE AND 4WD SHIFT

TF-2Revision: August 20072004 QX56 SWITCH ..................................................................... 62
Diagnostic Procedure ............................................. 62
TRANSFER MOTOR AND TRANSFER MOTOR
RELAY ....................................................................... 64
Diagnostic Procedure ............................................. 64
TRANSFER FLUID TEMPERATURE SENSOR ....... 66
Diagnostic Procedure ............................................. 66
ATP SWITCH, WAIT DETECTION SWITCH AND
NEUTRAL-4LO SWITCH .......................................... 69
Diagnostic Procedure ............................................. 69
CLUTCH PRESSURE SWITCH ................................ 72
Diagnostic Procedure ............................................. 72
LINE PRESSURE SWITCH ....................................... 74
Diagnostic Procedure ............................................. 74
DATA ERASE/DISPLAY ............................................ 76
Diagnostic Procedure ............................................. 76
SHIFT ACTUATOR ................................................... 77
Diagnostic Procedure ............................................. 77
SHIFT ACTUATOR POSITION SWITCH .................. 80
Diagnostic Procedure ............................................. 80
SHIFT ACTUATOR CIRCUIT .................................... 82
Diagnostic Procedure ............................................. 82
TROUBLE DIAGNOSES FOR SYMPTOMS ............. 85
Symptom 1. 4WD Shift Indicator Lamp Does Not
Turn ON (Although the ignition switch is turned ON,
all the 4WD indicator lamps do not turn ON for 1
second) ................................................................... 85
Symptom 2. 4WD Warning Lamp Does Not Turn ON
(Although the ignition switch is turned ON, the 4WD
warning lamp does not turn ON) ............................. 87
Symptom 3. 4WD Shift Indicator Lamp Does Not
Turn OFF (When 4WD shift switch is set from 4H
to 4LO, all the 4WD shift indicator lamps do not turn
off) ........................................................................... 88
Symptom 4. ATP Warning Lamp Does Not Turn ON
(When 4WD shift switch is set from 4H to 4LO with
the A/T selector lever in P position, the ATP warning
lamp does not turn on) ............................................ 89
Symptom 5. 4LO Indicator Lamp Does Not Turn ON
(When 4WD shift switch is set from 4H to 4LO posi-
tion, 4LO indicator lamp does not turn ON) ............ 90
Symptom 6. 4WD Shift Indicator Lamp Does Not
Indicate “LOCK” (When 4WD shift switch is set to
“4H”, 4WD shift indicator lamp does not indicate
“LOCK”) .................................................................. 91
Symptom 7. 4WD Shift Indicator Lamp Repeats
Flickering (4WD Shift Indicator Lamp Keeps Flick-
ering) ...................................................................... 92
Symptom 8. Tight Corner Braking Symptom (Tight
Corner Braking Symptom Occurs-Hydraulic Sys-
tem Failure) ............................................................ 93
Symptom 9. 4WD System Does Not Operate (The
Vehicle Cannot Be Put Into 4WD Mode-Hydraulic
System Failure) ...................................................... 94
Component Inspection ............................................ 95
4WD SHIFT SWITCH .......................................... 95
2-4WD SHIFT SOLENOID VALVE AND TRANS-
FER FLUID TEMPERATURE SENSOR .............. 95
4WD SOLENOID VALVE, CLUTCH PRESSURE SWITCH AND LINE PRESSURE SWITCH .........95
TRANSFER DROPPING RESISTOR ..................96
ATP SWITCH, NEUTRAL-4LO SWITCH AND
WAIT DETECTION SWITCH ...............................96
TRANSFER MOTOR ...........................................96
TRANSFER MOTOR RELAY ...............................97
TRANSFER SHIFT RELAY (HIGH & LOW) .........97
ACTUATOR AND ACTUATOR POSITION
SWITCH ...............................................................97
TRANSFER CONTROL UNIT ...................................98
Removal and Installation .........................................98
REMOVAL ............................................................98
INSTALLATION ....................................................98
FRONT OIL SEAL .....................................................99
Removal and Installation .........................................99
REMOVAL ............................................................99
INSTALLATION .................................................. 100
REAR OIL SEAL ..................................................... 101
Removal and Installation ....................................... 101
REMOVAL .......................................................... 101
INSTALLATION .................................................. 101
SIDE OIL SEAL ....................................................... 103
Removal and Installation ....................................... 103
REMOVAL .......................................................... 103
INSTALLATION .................................................. 103
TRANSFER CONTROL DEVICE ............................ 104
Removal and Installation ....................................... 104
AIR BREATHER HOSE ........................................... 105
Removal and Installation ....................................... 105
TRANSFER MOTOR ............................................... 106
Removal and Installation ....................................... 106
REMOVAL .......................................................... 106
INSTALLATION ..................................................... 106
TRANSFER OIL FILTER ......................................... 107
Removal and Installation ....................................... 107
REMOVAL .......................................................... 107
INSTALLATION .................................................. 107
REMOVAL AND INSTALLATION ............................ 109
Removal ................................................................ 109
Installation ............................................................. 109
OVERHAUL .............................................................110
Transfer Components ...........................................110
REAR CASE ............................................................112
Disassembly ..........................................................112
CENTER CASE .......................................................113
Disassembly ..........................................................113
FRONT DRIVE SHAFT AND DRIVE CHAIN .....115
MAINSHAFT AND CLUTCH DRUM ..................116
CLUTCH PISTON ..............................................118
CONTROL VALVE .............................................119
MAINSHAFT REAR BEARING .......................... 122
MAIN OIL PUMP ................................................ 122
SUB OIL PUMP ................................................. 123
OIL FILTER ........................................................ 124
FRONT CASE .......................................................... 125
Disassembly .......................................................... 125
SHIFT ROD COMPONENTS ............................. 125
PLANETARY CARRIER, SUN GEAR AND
INTERNAL GEAR .............................................. 127

TF-12
ALL-MODE 4WD SYSTEM
Revision: August 20072004 QX56
ALL-MODE 4WD TRANSFER BASIC CONTROL
HYDRAULIC CONTROL CIRCUITS
OUTLINE
All-mode 4WD transfer is controlled by the transfer control unit and sensors.
If a malfunction occurs in the all-mode 4WD system, the 4WD warning lamp lights up to indicate the system
malfunction. There are two ways to identify the cause of the malfunction.
1. Performing the self-diagnosis. (The 4WD warning lamp will indicate what kind of malfunction has occurred
by flickering.)
2. Performing diagnosis using CONSULT-II.
LDIA0055E
WDIA0056E

ALL-MODE 4WD SYSTEM
TF-13
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Revision: August 20072004 QX56
CONTROL SYSTEM DIAGRAM
INDICATIONS OF 4WD WARNING LAMP
*: When 4WD warning lamp is ON, all the 4WD shift indicator lamps turn OFF.
CAN CommunicationEDS0017P
SYSTEM DESCRIPTION
Refer to LAN-5, "CAN COMMUNICATION" .
WDIA0075E
Condition Content 4WD warning lamp
During self-diagnosis Indicates the malfunction position by number of flickers. Flickers at malfunction mode.
Lamp check*Checks the lamp by turning ON during engine starting. After
engine starts, it turns OFF if there are no malfunctions.ON
Malfunction in 4WD system*Turns ON to indicate malfunction. When ignition switch is
turned to “OFF” or the malfunction is corrected, it turns OFF.ON
When vehicle is driven with different
diameters of front and rear tiresFlickers once every 2 seconds.
Turns OFF when ignition switch is “OFF”.Flickers once every 2 sec-
onds.
High fluid temperature in transfer unitWhen fluid temperature is high or fluid temperature sensor cir-
cuit is shorted, it flickers twice every second.
It turns OFF when fluid temperature becomes normal.Flickers twice a second.
Other than above (System is nor-
mal.)Lamp is OFF. OFF

TF-16
ALL-MODE 4WD SYSTEM
Revision: August 20072004 QX56
LINE PRESSURE SWITCH
1. 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
operating conditions.
2. The line pressure switch turns ON when line pressure is produced.
3. The line pressure switch senses line pressure abnormalities and turns the 4WD warning lamp ON.

ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
TF-27
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Revision: August 20072004 QX56
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONPFP:00000
Trouble Diagnosis without CONSULT-IIEDS0017U
DESCRIPTION
If the engine starts when there is something wrong with the all-mode 4WD system, the 4WD warning lamp
turns ON or flickers in the combination meter. When the system functions properly, the warning lamp turns ON
when the ignition switch is turned to ON, and it turns OFF after engine starts.
To locate the cause of a problem, start the self-diagnosis function. The 4WD warning lamp in the combination
meter will indicate the problem area by flickering according to the self-diagnostic results. As for the details of
the 4WD warning lamp flickering patterns, refer to TF-28
.