2004 INFINITI QX56 lock

SRS-48
SPIRAL CABLE
Revision: August 20072004 QX56
6. Remove wiper washer switch connector, then pinch the tabs at
wiper and washer switch base and slide switch away from steer-
ing column to remove.
7. While pressing tabs, pull lighting and turn signal switch toward
driver door and disconnect from base.
8. Remove the screws, release the clip, and remove the spiral
cable.
CAUTION:

Do not disassemble spiral cable.

Do not apply lubricant to the spiral cable.
9. Remove the spiral cable connectors.
CAUTION:
With the steering linkage disconnected, the spiral cable may snap by turning the steering wheel
beyond the limited number of turns. The spiral cable can be turned counterclockwise about 2.5
turns from the neutral position.
INSTALLATION
Installation is in the reverse order of removal.

Align spiral cable correctly when installing steering wheel. Make
sure that the spiral cable is in the neutral position. The neutral
position is detected by turning left 2.6 revolutions from the right
end position and ending with the knob at the top.

If equipped with VDC, refer to BRC-62, "Adjustment of Steering
Angle Sensor Neutral Position" for steering angle sensor
adjustment.

After the work is completed, perform self-diagnosis to make sure
no malfunction is detected. Refer to SRS-20, "
SRS Operation
Check" .
LHIA0034E
LHIA0035E
LHIA0036E
WGIA0038E

SPIRAL CABLE
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CAUTION:

The spiral cable may snap due to steering operation if the
cable is not installed in the correct position.

With the steering linkage disconnected, the cable may snap
by turning the steering wheel beyond the limited number of
turns. The spiral cable can be turned counterclockwise
about 2.5 turns from the neutral position.
PHIA0275E
Steering wheel center nut : Refer to PS-10, "STEERING COLUMN"

SRS-50
FRONT PASSENGER AIR BAG MODULE
Revision: August 20072004 QX56
FRONT PASSENGER AIR BAG MODULEPFP:K8515
Removal and InstallationEHS000WN
The passenger air bag module originally installed in the vehicle uses direct-connect style harness connectors.
Service replacement passenger air bag modules use tab-locking style harness connectors. If the passenger
air bag module is replaced or if the direct-connect harness connectors are damaged, the vehicle wiring har-
ness must be modified to allow connection of the service replacement passenger air bag module. Refer to
SRS-51, "
WIRING HARNESS MODIFICATION" for wiring harness modification procedure.
REMOVAL
CAUTION:

Do not attempt to repair or replace damaged direct-connect front passenger air bag module con-
nectors. If a direct-connect harness connector is damaged, the front passenger air bag must be
replaced and the wiring harness modified.

Before servicing SRS, turn the ignition switch off, disconnect both battery cables and wait at least
3 minutes.

Always work from the side of or under front passenger air bag module.
1. Remove the glove box. Refer to IP-10, "
INSTRUMENT PANEL ASSEMBLY" .
2. Remove 2 nuts (through glove box opening) retaining front pas-
senger air bag module to instrument panel crossmember.
3. Disconnect the air bag module electrical connectors.

For removal/installation of the direct-connect SRS connec-
tors, refer to SRS-7, "
Direct-connect SRS Component Con-
nectors" .
4. Remove the instrument panel assembly from the vehicle. Refer
to IP-10, "
INSTRUMENT PANEL ASSEMBLY" .
5. Remove front passenger air bag module nuts and remove air
bag module from the instrument panel assembly.
CAUTION:

When servicing the SRS, do not work from directly in front
of air bag module.

Always place front passenger air bag module with caution
label side facing upward.

Do not insert any foreign objects (screwdriver, etc.) into air
bag module or harness connectors.

Do not disassemble air bag module.

Do not use old nuts after removal; replace with new nuts.

Do not expose the front passenger air bag module to tem-
peratures exceeding 90°C (194°F).

Replace the air bag module if it has been dropped or sus-
tained an impact.

Do not allow oil, grease or water to come in contact with the
air bag module.

For removal/installation of the direct-connect SRS connec-
tors, refer to SRS-7, "
Direct-connect SRS Component Con-
nectors" .
INSTALLATION
Original Passenger Air Bag Module
To install, reverse the removal procedure.
WHIA0110E
W H I A 0111 E
SBF 8 14 E

FRONT PASSENGER AIR BAG MODULE
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For removal/installation of the direct-connect SRS connectors, refer to SRS-7, "Direct-connect SRS Com-
ponent Connectors" .
CAUTION:

Always work from the side of or under front passenger air bag module.

After the work is completed, perform self-diagnosis to check that no malfunction is detected.
Refer to SRS-20, "
SRS Operation Check" .
Service Replacement Passenger Air Bag Module
1. Install the front passenger air bag module to the instrument
panel pad assembly.
2. Install the instrument panel assembly. Refer to IP-10, "
INSTRUMENT PANEL ASSEMBLY" .
3. Connect the front passenger air bag module harness connector to yellow 4-pin service replacement air
bag connector and fasten connector to mounting bracket.
CAUTION:

Always work from the side of or under front passenger air bag module.

After the work is completed, perform self-diagnosis to check that no malfunction is detected.
Refer to SRS-20, "
SRS Operation Check" .
WIRING HARNESS MODIFICATION
The passenger air bag module originally installed in the vehicle uses direct-connect style harness connectors.
Service replacement passenger air bag modules use tab-locking style harness connectors. If the passenger
air bag module is replaced or if the direct-connect harness connectors are damaged, the vehicle wiring har-
ness must be modified to allow connection of the service replacement passenger air bag module.
NOTE:
The wiring harness modification is to be performed only if the vehicle is equipped with the original passenger
air bag which uses direct-connect harness connectors. If the passenger air bag is to be replaced in a vehicle
that has already had the service replacement passenger air bag installed, the wiring harness modification is
not required.
CAUTION:

Do not attempt to repair or replace damaged direct-connect front passenger air bag module con-
nectors. If a direct-connect harness connector is damaged, the front passenger air bag must be
replaced and the wiring harness modified.

Before servicing SRS, turn the ignition switch off, disconnect both battery cables and wait at least
3 minutes.

Always work from the side of or under front passenger air bag module.

After the work is completed, perform self-diagnosis to check that no malfunction is detected.
Refer to SRS-20, "
SRS Operation Check" .
1. Locate the yellow and orange direct-connect passenger air bag module harness connectors.
2. Use wire cutters to cut back both previously used direct-connect passenger air bag module harness con-
nectors from the vehicle wiring harness approximately 50 mm (1.9 in) from the connectors.
3. Remove approximately 150 mm (5.9 in) of the vehicle harness covering from the cut end.
WHIA0110E

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

ALL-MODE 4WD SYSTEM
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Description of Electrical PartsEDS0017R
TRANSFER MOTOR
1. The transfer motor drives the sub-oil pump to provide proper lubrication and oil pressure control when the
vehicle is at standstill, during low-speed operations or is being driven in reverse.
2. The main oil pump is operated by the driving force of the mainshaft. In other words, sufficient oil pressure
buildup does not occur when the vehicle is at standstill 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 vehicle operations, the transfer motor drives the
sub-oil pump to compensate for insufficient oil pressure.
3. The transfer motor operates as follows:
1. The motor relay turns OFF in the 2WD mode.
2. The motor relay operates as described in the table below in modes other than the 2WD mode.
Ta b l e 1
Ta b l e 2
NOTE:
OFF (after 2.5 seconds have elapsed.)
4. 4WD shift switch, PNP switch, Neutral-4LO switch, vehicle speed sensor and throttle position sensor are
used in conjunction with the transfer motor.
WAIT DETECTION SWITCH
1. The wait detection switch releases the “booming” torque produced in the propeller shaft. After the release
of the “booming” torque, the wait detection switch helps provide the 4WD lock gear (clutch drum) shifts. A
difference may occur between the operation (“4LO” to “4H” shift only) of the 4WD shift switch and actual
drive mode. At this point, the wait detection switch senses an actual drive mode.
2. The wait detection switch operates as follows:
4WD lock gear (clutch drum) locked: ON
4WD lock gear (clutch drum) released: OFF
3. The wait detection switch senses an actual drive mode and the 4WD shift indicator lamp indicates the
vehicle drive 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 when 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.
PNP switch “R” position VFF (Vehicle speed) A/T position Motor relay drive command
ON — R ON
OFF0Positions other than the “P” or
“N” positionsON
—“P” or “N” position (See Table
2.)—
0 < VFF ≤ 50 km/h (31 MPH) — ON
50 km/h (31 MPH) < VFF < 55
km/h (34 MPH)—HOLD
55 km/h (34 MPH) ≤ VFF — OFF
A/T position N-4L SW 4WD modeThrottle position
0 - 0.07/8 0.07/8 - 1/8 1/8 - MAX
NOFFLOCK (4H) ON ON ON
Positions other than
the LOCK position
(2WD or AUTO)See NOTE. HOLD ON
ON — See NOTE. HOLD ON
P——See NOTE.HOLDON

ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
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Revision: August 20072004 QX56
7. Touch “ECU INPUT SIGNALS” or “MAIN SIGNALS”.
8. Select “Numerical Display”, “Bar Chart Display” or “Line Graph
Display”.
9. Touch “SETTING” to set record conditions.
10. Touch “AUTO TRIG” or “MANU TRIG”.
11. Return to “SELECT MONITOR ITEM” on “DATA MONITOR”
screen and touch “START”.
12. Monitored data are displayed.
DATA MONITOR ITEMS
: Standard : Option
WDIA0084E
SAT9 7 3J
SMT963D
Item [Unit]Monitor item
Remarks ECU
INPUT
SIGNALSMAIN
SIGNALSSELEC-
TION
FROM
MENU
VHCL/SEN-FR [km/h], [MPH]Indicates average vehicle speed of ABS
front left/right wheel.
VHCL/SEN-RR [km/h], [MPH]Indicates average vehicle speed of ABS
rear left/right wheel.
Engine speed [rpm]—
Throttle position sensor—
Transfer fluid temperature sensor
[V]—
Battery voltage [V]—
2WD switch [ON-OFF] 2WD switch of 4WD shift switch
AUTO switch [ON-OFF] AUTO switch of 4WD shift switch
Lock switch [ON-OFF] 4H switch of 4WD shift switch
4L switch [ON-OFF] 4LO switch of 4WD shift switch

TF-36
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
Revision: August 20072004 QX56
N position switch TF [ON-OFF] N position switch of transfer
Line pressure switch [ON-OFF] Line pressure switch
Clutch pressure switch [ON-OFF] Clutch pressure switch
ATP switch [ON-OFF]—
N position switch AT [ON-OFF] “N” position on A/T PNP switch
R position switch AT [ON-OFF] “R” position on A/T PNP switch
P position switch AT [ON-OFF] “P” position on A/T PNP switch
ABS operation switch [ON-OFF] ABS operation switch
Wait detection switch [ON-OFF] —
Throttle positionThrottle opening recognized by transfer
control unit
4WD-mode4WD-mode recognized by transfer control
unit (2WD, AUTO, 4H & 4LO)
Vehicle speed comp [km/h (MPH)]Vehicle speed recognized by transfer con-
trol unit
*Control torque [N·m (kg-m, ft.-lb.)]Calculated torque recognized by transfer
control unit
Duty solenoid valve [%]
(Transfer 4WD solenoid valve)—
2-4WD shift solenoid valve [ON-
OFF]
Control signal outputs of transfer control
unit Transfer motor relay [ON-OFF]
Shift activating 1 [ON-OFF]
Shift activating 2 [ON-OFF]
2-4WD shift solenoid valve monitor
[ON-OFF]
Check signal (re-input signal) of transfer
control unit control signal output is dis-
played. If circuit is shorted or open, ON/OFF
state does not change. Transfer motor relay monitor [ON-
OFF]
Shift activating monitor 1 [ON-OFF]
Shift activating monitor 2 [ON-OFF]
4WD fail lamp [ON-OFF]Transfer control unit control signal output for
4WD warning lamp (left)
Shift position switch 1 [ON-OFF] —
Shift position switch 2 [ON-OFF] —
2WD indicator lamp [ON-OFF]Transfer control unit control signal output for
4WD shift indicator lamp (rear)
AUTO indicator lamp [ON-OFF]Transfer control unit control signal output for
4WD shift indicator lamp (front & rear)
LOCK indicator lamp [ON-OFF]Transfer control unit control signal output for
4WD shift indicator lamp (center)
4LO indicator lamp [ON-OFF]Transfer control unit control signal output for
4WD shift indicator lamp (right) Item [Unit]Monitor item
Remarks ECU
INPUT
SIGNALSMAIN
SIGNALSSELEC-
TION
FROM
MENU