2004 INFINITI QX56 display

TROUBLE DIAGNOSIS
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Trouble Diagnosis: “AIR BAG” Warning Lamp Does Not Turn OffEHS000WJ
DIAGNOSTIC PROCEDURE 6
1. CHECK CONDITION OF AIR BAG MODULE
Inspect for deployed air bag modules or seat belt pre-tensioners.
Are air bag modules or seat belt pre-tensioners deployed?
Yes >> Refer to SRS-60, "COLLISION DIAGNOSIS" .
No >> GO TO 2.
2. CHECK THE AIR BAG FUSE
Check 10A fuse [No. 13, located in the fuse block (J/B)].
Refer to PG-4, "
POWER SUPPLY ROUTING CIRCUIT" .
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3. CHECK AIR BAG FUSE AGAIN
Replace 10A fuse [No. 13, located in the fuse block (J/B)] and turn ignition switch ON.
Does the fuse blow again?
Yes >> Repair harness.
No >> Inspection End.
4. CHECK AIR BAG DIAGNOSIS SENSOR UNIT
Connect CONSULT-II and touch “START”.
Is
“AIR BAG” displayed on CONSULT-II?
Yes >> GO TO 5.
No >> Visually inspect the air bag diagnosis sensor unit har-
ness connections. If the connections are OK, replace
the air bag diagnosis sensor unit. Refer to SRS-58,
"Removal and Installation" .
5. CHECK HARNESS CONNECTION
Check for loose connections between the combination meter and the air bag diagnosis sensor unit.
OK or NG
OK >> Replace air bag diagnosis sensor unit. Refer to SRS-58, "Removal and Installation" .
NG >> Properly connect the combination meter and air bag diagnosis sensor unit harness connectors. If
“AIR BAG” warning lamp still does not turn off, replace the wiring harness.
BCIA0030E

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

ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
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CONSULT-II Function (ALL MODE AWD/4WD)EDS002G7
CONSULT-II can display each diagnostic item using the diagnostic test modes shown following.
Trouble Diagnosis with CONSULT-IIEDS0017V
SELF-DIAGNOSIS
CONSULT-II Setting Procedure
1. Turn ignition switch to “OFF” position.
CAUTION:
If CONSULT-II is used with no connection of CONSULT-II CONVERTER, malfunctions might be
detected in self-diagnosis depending on control unit which carry out CAN communication.
2. Connect CONSULT-II and CONSULT-II CONVERTER to data
link connector.
3. Start engine.
4. On CONSULT-II screen, touch “START (NISSAN BASED
VHCL)”.
5. Touch “ALL MODE AWD/4WD” on SELECT SYSTEM screen.
If "ALL MODE AWD/4WD" is not indicated, refer to GI-39,
"CONSULT-II Data Link Connector (DLC) Circuit" .
ALL MODE AWD/4WD diag-
nostic modeDescription
SELF-DIAG RESULTS Displays transfer control unit self-diagnosis results.
DATA MONITOR Displays transfer control unit input/output data in real time.
WORK SUPPORTSupports inspections and adjustments. Commands are transmitted to the transfer control unit for set-
ting the status suitable for required operation, input/output signals are received from the transfer con-
trol unit and received data is displayed.
CAN DIAG SUPPORT
MNTRThe results of transmit/receive diagnosis of CAN communication can be read.
ECU PART NUMBER Transfer control unit part number can be read.
BBIA0369E
BCIA0029E
BCIA0030E

TF-32
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
Revision: August 20072004 QX56
6. Touch “SELF-DIAG RESULTS” on SELECT DIAG MODE
screen.
7. Self-diagnostic results are displayed.
SELF-DIAGNOSTIC ITEMS
BCIA0031E
Detected items
(Screen terms for CONSULT-II,
“SELF-DIAG RESULT” mode)Malfunction is detected when... Check items
Revolution sensor (rear)
(VHCL SPEED SEN·RR)

Signal from vehicle speed sensor 1 (installed on A/T) is
not input due to open circuit.

Improper signal is input while driving.Refer to AT- 11 2 , "
DTC P0720
VEHICLE SPEED SENSOR A/T
(REVOLUTION SENSOR)" .
4WD solenoid valve
(DUTY SOLENOID)

Proper voltage is not applied to solenoid valve due to
open or short circuit.Refer to TF-60, "
Diagnostic Proce-
dure" .
2-4WD shift solenoid valve
(2-4WD SOLENOID)Refer to TF-62, "
Diagnostic Proce-
dure" .
Tran s fe r mo to r re lay
(MOTOR RELAY)

Motor does not operate properly due to open or short cir-
cuit in transfer motor or motor relay.Refer to TF-64, "Diagnostic Proce-
dure" .
Transfer fluid temperature sensor
(FLUID TEMP SENSOR)

Signal voltage from fluid temperature sensor is abnor-
mally high (T/F fluid temperature is abnormally low)
while driving.Refer to TF-66, "Diagnostic Proce-
dure" .
Neutral-4LO switch
(N POSI SW TF)

Improper signal is input while driving.Refer to TF-69, "Diagnostic Proce-
dure" .
Clutch pressure
(CLUTCH PRESSURE)

Improper signal is input due to open or short circuit.

Malfunction occurs in clutch pressure hydraulic circuit.(*1) Refer to TF-72, "
Diagnostic
Procedure" .
Line pressure
(LINE PRESSURE)

Improper signal is input due to open or short circuit.

Malfunction occurs in line pressure hydraulic circuit.(*1) Refer to TF-74, "
Diagnostic
Procedure" .
Engine speed signal (Note 1)
(ENGINE SPEED SIG)

Engine speed is abnormally low while driving.Refer to AT- 11 5 , "DTC P0725
ENGINE SPEED SIGNAL" .
Throttle position sensor
(THRTL POSI SEN)

Signal voltage from throttle position sensor is abnormally
high.

Signal voltage from throttle position sensor is abnormally
low when closed throttle position switch is OFF.Refer to EC-351, "
DTC P0605
ECM" .
Transfer control unit (ADC)
C/U (ADC)/THRTL SEN

Power supply voltage for A/D converter system of trans-
fer control unit is malfunctioning.Refer to EC-351, "DTC P0605
ECM" .
Battery voltage (Note 1)
(BATTERY VOLTAGE)

Power supply voltage for transfer control unit is abnor-
mally low while driving.Refer to TF-18, "Wiring Diagram —
T/F —" .
4WD shift switch
(4WD MODE SW)

More than two switch inputs are simultaneously detected
due to short circuit of 4WD shift switch.Refer to TF-62, "Diagnostic Proce-
dure" .
ABS operation signal (Note 4)
(ABS OPER SIGNAL)

When a malfunction signal due to disconnection or
shorting is detected.

When a defect signal is entered from the ABS control
unit.Refer to BRC-54, "
CAN Communi-
cation System Inspection" .
Wait detection switch (Note 2)
(WAIT DETECT SWITCH)

Improper signal is input due to open or short circuit.(*2) Refer to TF-69, "Diagnostic
Procedure" .

ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
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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

ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
TF-35
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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

ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
TF-37
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*: This item is indicated as “COMP CL TORQ”.Clutch limit [N·m (kg-m, ft.-lb.)]Clutch force release limit value set in
WORK SUPPORT
Voltage [V]Value measured by voltage probe is dis-
played.
Frequency [Hz]Value measured by pulse probe is dis-
played. If measurement is impossible, “#”
sign is displayed. “#” sign is also displayed
at the final data value until the measure-
ment result is obtained.
DUTY-HI
Duty cycle value for measurement probe is
displayed.
DUTY-LOW
PLS WIDTH-HI
Measured pulse width of measurement
probe is displayed.
PLS WIDTH-LOW
FR/RR G-SEN [G] Displayed, but do not use.
TF F SPEED [km/h], [MPH] Displayed, but do not use.
AT R SPEED [km/h], [MPH] Indicates A/T rear vehicle speed.
A/T actual gear position Indicates A/T actual gear position.
VDC OPER SW [ON-OFF] Indicates VDC operation switch.
TCS OPER SW [ON-OFF] Indicates TCS operation switch.
AT P L A M P [O N - O F F ]Indicates C/U control signal output of ATP
lamp. Item [Unit]Monitor item
Remarks ECU
INPUT
SIGNALSMAIN
SIGNALSSELEC-
TION
FROM
MENU

TF-38
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
Revision: August 20072004 QX56
REFERENCE VALUE IN DATA MONITOR MODE
Indicated items
(Screen terms for CONSULT-II, “DATA
MONITOR” mode)Display Conditions
Throttle position sensor
(THRTL POS SEN) 0.0/8 - 8.0/8 Throttle valve fully closed to fully open
Transfer fluid temperature sensor
(FLUID TEMP SE)Approx. 1.5 - 0.5V Transfer fluid temperature approx. 20 - 80°C (68 - 176°F)
ABS operation switch
(ABS OPER SW)OFF ABS is not operating.
ON ABS is operating.
2WD position
(2WD SWITCH)ON 4WD shift switch is in “2WD”.
OFF Except the above condition
Lock position
(LOCK SWITCH)ON 4WD shift switch is in “4H”.
OFF Except the above condition
Neutral-4LO switch
(N POSI SW TF)
AT P s w i tc h
(ATP SWITCH)
Wait detection switch
(WAIT DETCT SW)4WD shift switch position2WD,
AUTO, 4H(N) 4LO
AT P s w i t c h O F F O N O F F
Neutral-4LO switch/Wait detec-
tion switch See Note.OFF ON
Note: When shifting into or out of “4LO” the switches turn ON when “Wait” function is oper-
ating and they turn OFF when “Wait” function is canceled.
Tran s fe r mo to r re lay
(MOTOR RELAY)
Transfer motor relay monitor
(MOTOR RELAY MON)Throttle valve4WD
shift
switchA/T selector
leverMotor relay/
Motor relay
monRemarks
Fully closed2WD — OFF —
AUTO,
4LOP, N O F F
ON for approx. 2 sec. after
shifting to “P” and “N”
Others ON
4HPOFF
ON for approx. 2 sec. after
shifting to “P”
Others ON
Line pressure switch
(LINE PRES SW)OFFThe vehicle has been left at room temperature for 5 min-
utes and more with ignition switch in “OFF” position.
ONIgnition switch in “ON”, and 4WD shift switch in “AUTO” or
“4H” and A/T selector lever in “D”.
Clutch pressure switch
(CL PRES SW)OFFIgnition switch in “ON”, and 4WD shift switch in “2WD”.
(“Wait” function is not operating.)
ONIgnition switch in “ON”, and 4WD shift switch in “AUTO” or
“4H” and A/T selector lever in “D”. (“Wait” function is not
operating.)
Vehicle speed
(VHCL/S COMP)0 km/h (0 MPH) — —
Control torque
(COMP CL TORQ)0 kg-m
4WD shift switch
(“Wait” function is not oper-
ating.)In “2WD” position
39 - 1,353 N·m
(4 - 138 kg-m, 29 - 998 ft.-lb.)In “AUTO” position
1,353 N·m
(138 kg-m, 998 ft.-lb.)In “4H” or “4LO” position
4WD solenoid
(DUTY SOLENOID)4% In “2WD” position
96 - 4% In “AUTO” position
4% In “4H” or “4LO” position