2004 INFINITI QX56 Revers

CRASH ZONE SENSOR
SRS-55
C
D
E
F
G
I
J
K
L
MA
B
SRS
Revision: August 20072004 QX56
CRASH ZONE SENSORPFP:98531
Removal and InstallationEHS000WQ
REMOVAL
CAUTION:

Before servicing the SRS, turn the ignition switch off, disconnect both battery cables and wait at
least 3 minutes.
1. Open hood.
2. Disconnect the crash zone sensor harness connector.
3. Remove crash zone sensor nuts.
CAUTION:

Replace crash zone sensor if it has been dropped or sustained an impact.

Do not disassemble crash zone sensor.
INSTALLATION
To install, reverse the removal procedure.

After the work is complete, perform self-diagnosis to check that no malfunction is detected. Refer to SRS-
20, "SRS Operation Check" .
LHIA0056E

SRS-56
SIDE AIR BAG (SATELLITE) SENSOR
Revision: August 20072004 QX56
SIDE AIR BAG (SATELLITE) SENSORPFP:98830
Removal and InstallationEHS000WR
REMOVAL
CAUTION:

Before servicing the SRS, turn the ignition switch off, disconnect both battery cables and wait at
least 3 minutes.
1. Remove seat belt pre-tensioner. Refer to SB-3, "
Removal and
Installation of Front Seat Belt" .
2. Remove side air bag (satellite) sensor nuts.
3. Disconnect the side air bag (satellite) sensor harness connector.
CAUTION:

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

Check side air bag (satellite) sensor to ensure it is free of deformities, dents, cracks or rust. If it
shows any visible signs of damage, replace it with new one.

Do not disassemble side air bag (satellite) sensor.

Replace side air bag (satellite) sensor if it has been dropped or sustained an impact.
INSTALLATION
To install, reverse the removal procedure.

After the work is completed, perform self-diagnosis to check that no malfunction is detected. Refer to
SRS-20, "
SRS Operation Check" .
LHIA0057E

SRS-58
DIAGNOSIS SENSOR UNIT
Revision: August 20072004 QX56
DIAGNOSIS SENSOR UNITPFP:28556
Removal and InstallationEHS0 00 W T
REMOVAL
CAUTION:

Before servicing the SRS, turn the ignition switch off, disconnect both battery cables and wait at
least 3 minutes.
1. Disconnect the harness connectors for each air bag module and seat belt pre-tensioner.
2. Remove center console. Refer to IP-10, "
INSTRUMENT PANEL ASSEMBLY" .
3. Disconnect diagnosis sensor unit harness connectors.
4. Remove fixing bolts from the diagnosis sensor unit.
CAUTION:

Do not use old bolts; replace with new bolts.

Check diagnosis sensor unit bracket to ensure it is free of deformities, dents, cracks or rust. If it
shows any visible signs of damage, replace with new one.

Replace diagnosis sensor unit if it has been dropped or sustained an impact.
INSTALLATION
To install, reverse the removal procedure.

After the work is completed, perform self-diagnosis to check that no malfunction is detected. Refer to
SRS-20, "
SRS Operation Check" .
CAUTION:

The diagnosis sensor unit must always be installed with the arrow mark "⇐" pointing toward the
front of the vehicle for proper operation.
ECU DISCRIMINATED NO.
After replacing the diagnosis sensor unit, confirm that the diagnosis sensor unit identification is correct for the
vehicle as equipped. Refer to SRS-18, "
CONSULT-II Function (AIR BAG)" .
LHIA0053E

ALL-MODE 4WD SYSTEM
TF-15
C
E
F
G
H
I
J
K
L
MA
B
TF
Revision: August 20072004 QX56
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
TF-33
C
E
F
G
H
I
J
K
L
MA
B
TF
Revision: August 20072004 QX56
Note 1: When a malfunction occurs, it is only displayed and not stored in the memory.
Note 2: When the wait detection switch has been properly fixed, malfunction information is erased from the memory.
Note 3: If 4WD shift switch is left between 4H and 4LO for a while, this indication may be displayed.
(*1): If the malfunction is detected only while driving in reverse, check the continuity of “R” position on A/T PNP switch. When there is
nothing wrong with the electrical system, check the hydraulic system.
(*2): If a revolution sensor malfunction is detected at the same time, check the revolution sensor circuit first.
Note 4: When this malfunction is detected with the ABS warning lamp off, first check for disconnection or shorting in the harness
between the transfer control unit and the ABS control unit.
Note 5: When several systems including CAN communication system indicate malfunctions, perform diagnosis of the CAN communica-
tion first.Shift actuator abnormal
(SHIFT ACT)Transfer control device actuator motor is malfunctioning.
(Malfunctions are detected when actuator motor fails to
operate while shifting from “4H” to “4LO” or vice versa.) Refer to TF-77, "
Diagnostic Proce-
dure" or TF-82, "Diagnostic Pro-
cedure" .
Shift actuator position switch
abnormal
(SHIFT ACT P/S)Transfer control device actuator motor arm position sens-
ing switch is malfunctioning.Refer to TF-80, "
Diagnostic Proce-
dure" or TF-82, "Diagnostic Pro-
cedure" .
Shift actuator circuit abnormal
(SHIFT ACT CIR)Transfer control device actuator circuit is shorted or open.
(Malfunctions are detected when motor relay circuit is
open/shorted or relay monitor circuit is open/shorted.)Refer to TF-77, "
Diagnostic Proce-
dure" , TF-80, "Diagnostic Proce-
dure"TF-82, "Diagnostic
Procedure" .
Memory power supply stop

Due to removal of battery which cuts off power supply to
transfer control unit, self-diagnosis memory function is
suspended.Refer to TF-76, "Diagnostic Proce-
dure" .
Transfer control unit (RAM)
[CONTROL UNIT (RAM)]

Malfunction is detected in the memory (RAM) system of
transfer control unit.—
Transfer control unit (ROM)
[CONTROL UNIT (ROM)]

Malfunction is detected in the memory (ROM) system of
transfer control unit.—
Transfer control unit (EEPROM)
[CONTROL UNIT (EEPROM)]

Malfunction is detected in the memory (EEPROM) sys-
tem of transfer control unit.—
Longitudinal G-sensor Displayed, but do not use. —
ABS VHL SPD SEN

ABS vehicle speed sensor signal is not input due to an
open circuit.

An unexpected signal is input when vehicle is being
driven.Refer to ABS vehicle speed sensor
diagnosis.
STEERING ANGLE SENSOR Displayed, but do not use. —
VDC OPER SIGIf VDC operation signal is being input because of VDC
malfunction or communication error within the vehicle.Refer to BRC-40, "
ABS/TCS/VDC
Control Unit Inspection" .
TCS OPER SIGIf TCS operation signal is being input because of TCS mal-
function or communication error within the vehicle.Refer to BRC-40, "
ABS/TCS/VDC
Control Unit Inspection" .
CAN COMM (Note 5) Malfunction is detected in CAN communication.Refer to LAN-5, "
CAN COMMUNI-
CATION" .
A/T POSITION SIGNALWhen AT PNP switch circuit is malfunction or communica-
tion error between the vehiclesRefer to AT-109, "
DTC P0705
PARK/NEUTRAL POSITION
SWITCH" . Detected items
(Screen terms for CONSULT-II,
“SELF-DIAG RESULT” mode)Malfunction is detected when... Check items

TF-72
CLUTCH PRESSURE SWITCH
Revision: August 20072004 QX56
CLUTCH PRESSURE SWITCHPFP:00000
Diagnostic ProcedureEDS00188
1. CHECK MALFUNCTION
Is this malfunction detected only while driving in reverse?
Ye s o r N o
Yes >> Check A/T PNP switch "R" position.

Refer to AT-109, "DTC P0705 PARK/NEUTRAL POSITION SWITCH" .
No >> GO TO 2.
2. CHECK OTHER MALFUNCTION
Are other malfunctions also detected by self-diagnosis and CONSULT-II?
Refer to TF-27, "
Trouble Diagnosis without CONSULT-II" and TF-31, "Trouble Diagnosis with CONSULT-II" .
Ye s o r N o
Yes >> Check for other malfunctions.

(When other malfunctions are eliminated, clutch pressure switch malfunction display may dis-
appear.)
No >> GO TO 3.
3. CHECK 2-4WD SHIFT SOLENOID VALVE AND 4WD SHIFT SWITCH CIRCUITS
Check 2-4WD shift solenoid valve and 4WD shift switch circuits.
OK or NG
OK >> GO TO 4.
NG >> Check, repair or replace faulty parts.
4. CHECK INPUT SIGNAL
Do you have CONSULT-II?
Ye s o r N o ?
Yes >> GO TO 5.
No >> GO TO 6.

TF-74
LINE PRESSURE SWITCH
Revision: August 20072004 QX56
LINE PRESSURE SWITCHPFP:00000
Diagnostic ProcedureEDS00189
1. CHECK MALFUNCTION
Is this malfunction detected only while driving in reverse?
Ye s o r N o
Yes >> Check A/T PNP switch “R” position.

Refer to AT-109, "DTC P0705 PARK/NEUTRAL POSITION SWITCH" .
No >> GO TO 2.
2. CHECK OTHER MALFUNCTIONS
Are other malfunctions also detected by self-diagnosis and CONSULT-II?
Refer to TF-27, "
Trouble Diagnosis without CONSULT-II" and TF-31, "Trouble Diagnosis with CONSULT-II" .
Ye s o r N o
Yes >> Check for other malfunctions.

(When other malfunctions are eliminated, line pressure switch malfunction display may disap-
pear.)
No >> GO TO 3.
3. CHECK INPUT SIGNAL
Do you have CONSULT-II?
Ye s o r N O
Yes >> GO TO 4.
No >> GO TO 5.
4. CHECK INPUT SIGNAL
With CONSULT-II
1. Select “ECU INPUT SIGNALS” in Data Monitor.
2. Put A/T selector lever in D.
3. Turn the 4WD shift switch to 4H and back to 2WD while reading
out ON/OFF status of "LINE PRES SW".
OK or NG
OK >> GO TO 6.
NG >> Check the following.

Continuity between transfer control unit and transfer
terminal cord assembly harness connector

Line pressure switch
Refer to TF-95, "
4WD SOLENOID VALVE, CLUTCH
PRESSURE SWITCH AND LINE PRESSURE
SWITCH" .
SMT790D
WDIA0087E

TF-98
TRANSFER CONTROL UNIT
Revision: August 20072004 QX56
TRANSFER CONTROL UNITPFP:33084
Removal and InstallationEDS00314
REMOVAL
1. Set transfer state as 2WD when 4WD shift switch is at 2WD, or as AUTO when 4WD shift switch is at
AUTO.
CAUTION:
When removing transfer control unit, transfer state must be at 2WD or AUTO.
2. Turn the ignition switch OFF and disconnect negative battery terminal.
3. Remove the glove box assembly. Refer to IP-14, "
Instrument Lower Cover RH and Glove Box" .
4. Disconnect the two transfer control unit connectors.
5. Remove the transfer control unit bolts.
6. Remove the transfer control unit.
INSTALLATION
Installation is in the reverse order of removal.

When installing the transfer control unit, tighten bolts to the specified torque.
CAUTION:

Do not connect harness connector to transfer control unit when 4WD shift switch is at 4LO.

After the installation, check perform self-diagnosis. Refer to TF-28, "SELF-DIAGNOSTIC PROCEDURE"
. If NG, adjust position between transfer assembly and transfer control unit.
BDIA0014E
Transfer control unit bolts : 5.1 N·m (0.52 kg-m, 45 in-lb)