TF-34
TROUBLE DIAGNOSIS
Revision: October 20052005 QX56
CRUISE TEST
1. CHECK INPUT SIGNAL
1. Warm up engine to normal operating temperature.
2. Park vehicle on flat surface.
3. Move A/T selector lever to “P” position.
4. Set 4WD shift switch to “AUTO” position.
5. Start engine.
6. Drive vehicle for at least 30 seconds at a speed higher than 20 km/h (12 MPH).
Check 4WD warning lamp turned ON?
On steady>>Perform the self-diagnosis. Refer to TF-50, "SELF-DIAGNOSTIC PROCEDURE (WITH CON-
SULT-II)" (with CONSULT-II) or TF-50, "SELF-DIAGNOSTIC PROCEDURE (WITHOUT CON-
SULT-II)" (without CONSULT-II).
Flash rapidly>>GO TO TF-128, "
4WD Warning Lamp Flashes Rapidly" .
Flash slowly>>GO TO TF-129, "
4WD Warning Lamp Flashes Slowly" .
NO >> GO TO 2.
2. CHECK TIGHT CORNER BRAKING SYMPTOM (1)
1. Set 4WD shift switch to “AUTO” position.
2. Drive vehicle at speed lower than 20 km/h (12 MPH) with steering wheel fully turned.
Does tight corner braking symptom occur?
YES >> GO TO TF-130, "Heavy Tight-corner Braking Symptom Occurs" .
NO >> GO TO 3.
3. CHECK TIGHT CORNER BRAKING SYMPTOM (2)
1. Set 4WD shift switch to “4HI” position.
2. Drive vehicle at speed lower than 20 km/h (12 MPH) with steering wheel fully turned.
Does tight corner braking symptom occur?
YES >> Inspection End.
NO >> GO TO TF-131, "
4WD System Does Not Operate" .
Trouble Diagnosis Chart for SymptomsEDS002HI
If 4WD warning lamp turns ON, perform self-diagnosis. Refer to TF-50, "Self-diagnostic Procedure" .
Symptom Condition Check item Reference page
4WD shift indicator lamp and 4LO indicator
lamp do not turn ON
(4WD shift indicator lamp and 4LO indicator
lamp check)Ignition switch: ONPower supply and ground for transfer
control unit
TF-117
Transfer shut off relay
Combination meter
4WD warning lamp does not turn ON
(4WD warning lamp check)Ignition switch: ONPower supply and ground for transfer
control unit
TF-121
Transfer shut off relay
Combination meter
TROUBLE DIAGNOSIS
TF-35
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Revision: October 20052005 QX56
NOTE:
Light tight-corner braking symptom may occur depending on driving conditions in AUTO mode. This is not
a malfunction.
Heavy tight-corner braking symptom occurs when vehicle is driven in the following conditions: 4WD shift
switch is "4H" or "4LO", steering wheel is turned fully to either side.
4WD shift indicator lamp or 4LO indicator
lamp does not changeEngine running4WD shift switch
TF-123
Wait detection switch
Neutral-4LO switch
ATP switch
2-4WD solenoid
Transfer control device
Actuator motor
Actuator position switch
Transfer inner parts
ATP warning lamp turns ON Engine runningCAN communication line
TF-125
4WD shift switch
PNP switch signal
ATP switch
Combination meter
Transfer inner parts
4LO indicator lamp repeats flashing Engine runningWait detection switch
TF-127
Neutral-4LO switch
Transfer inner parts
4WD warning lamp flashes rapidly (2 times/
second)While drivingTransfer fluid temperature
TF-128
Tire size is different between front and
rear of vehicle
4WD warning lamp flashes slowly
(1 time/2 seconds)While drivingTire size is different between front and
rear of vehicle.
TF-129
Transfer fluid temperature
Clutch pressure switch
Heavy tight-corner braking symptom occurs
(See NOTE.)
While driving
AUTO mode
Steering wheel is
turned fully to either
sideCAN communication line
TF-130
4WD shift switch
Accelerator pedal position signal
Clutch pressure solenoid
Transfer inner parts
4WD system does not operate While driving4WD shift switch
TF-131
Clutch pressure switch
Transfer inner parts Symptom Condition Check item Reference page
TF-44
TROUBLE DIAGNOSIS
Revision: October 20052005 QX56
CONSULT-II Function (ALL MODE AWD/4WD)EDS002HK
FUNCTION
CONSULT-II can display each diagnostic item using the diagnostic test modes shown following.
CONSULT-II SETTING PROCEDURE
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.
NOTE:
For details, refer to the separate “CONSULT-II Operations Manual”.
1. Turn ignition switch “OFF”.
2. Connect CONSULT-II and CONSULT-II CONVERTER to data
link connector on vehicle.
3. Turn ignition switch “ON”.
4. Touch “START (NISSAN BASED VHCL)”.
5. Touch “ALL MODE AWD/4WD”.
If “ALL MODE AWD/4WD” is not indicated, go to GI-39, "
CON-
SULT-II Data Link Connector (DLC) Circuit" .
6. Perform each diagnostic test mode according to each service
procedure.
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
TROUBLE DIAGNOSIS
TF-45
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SELF-DIAG RESULT MODE
Operation Procedure
1. Perform “CONSULT-II SETTING PROCEDURE”. Refer to TF-44, "CONSULT-II SETTING PROCEDURE"
.
2. With engine at idle, touch “SELF-DIAG RESULTS”.
Display shows malfunction experienced since the last erasing
operation.
NOTE:
The details for “TIME” are as follow:
–“0”: Error currently detected with transfer control unit.
–Except for “0”: Error detected in the past and memorized
with transfer control unit.
Detects frequency of driving after DTC occurs (frequency
of turning ignition switch “ON/OFF”).
Display Item List
SDIA2687E
Items (CONSULT-II screen
terms)Diagnostic item is detected when... Check item
CONTROL UNIT 1
[P1802]
Malfunction is detected in the memory (RAM) system of transfer
control unit.TF-57, "Transfer Control Unit"
CONTROL UNIT 2
[P1803]Malfunction is detected in the memory (ROM) system of transfer
control unit.TF-57, "Transfer Control Unit"
CONTROL UNIT 3
[P1804]Malfunction is detected in the memory (EEPROM) system of
transfer control unit.TF-57, "Transfer Control Unit"
VHCL SPEED SEN·AT
[P1807]Malfunction is detected in output shaft revolution signal that is
output from TCM through CAN communication.
Improper signal is input while driving.TF-58, "
Output Shaft Revolution
Signal (TCM)"
VHCL SPEED SEN·ABS
[P1808]
Malfunction is detected in vehicle speed signal that is output from
ABS actuator and electric unit (control unit) through CAN commu-
nication.
Improper signal is input while driving.TF-58, "
Vehicle Speed Sensor
(ABS)"
CONTROL UNIT 4
[P1809]AD converter system of transfer control unit is malfunctioning.TF-57, "Transfer Control Unit"
4L POSI SW TF
[P1810]Improper signal from neutral-4LO switch is input due to open or
short circuit.TF-59, "Neutral-4LO Switch"
BATTERY VOLTAGE
[P1811]Power supply voltage for transfer control unit is abnormally low
while driving.TF-54, "Power Supply Circuit For
Transfer Control Unit"
4WD MODE SW
[P1813]More than two switch inputs are simultaneously detected due to
short circuit of 4WD shift switch.TF-62, "4WD Shift Switch"
4WD DETECT SWITCH
[P1814]Improper signal from wait detection switch is input due to open or
short circuit.TF-66, "Wait Detection Switch"
PNP SW/CIRC
[P1816]When A/T PNP switch signal is malfunction or communication
error between the vehicles.TF-69, "PNP Switch Signal
(TCM)"
SHIFT ACTUATOR
[P1817]
Motor does not operate properly due to open or short circuit in
actuator motor.
Malfunction is detected in the actuator motor. (When 4WD shift
switch is operated and actuator motor is not operated)
Malfunction is detected in transfer shift high relay and transfer
shift low relay.TF-70, "
Actuator Motor"
SHIFT ACT POSI SW
[P1818]Improper signal from actuator position switch is input due to open
or short circuit.
Malfunction is detected in the actuator position switch.TF-77, "
Actuator Position
Switch"
TROUBLE DIAGNOSIS
TF-51
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Revision: October 20052005 QX56
Diagnostic Procedure
1. Warn up engine.
2. Move A/T selector lever to “P” position.
3. Turn 4WD shift switch to “2WD” position.
4. Turn ignition switch “ON” and “OFF” at least twice, and then turn ignition switch “OFF”.
5. Turn 4WD shift switch to “AUTO” position.
6. Turn ignition switch “ON”. (Do not start engine.)
7. 4WD warning lamp ON.
If 4WD warning lamp does not turn ON, refer to TF-121, "
4WD Warning Lamp Does Not Turn ON" .
8. Move A/T selector lever to “R” position.
9. Turn 4WD shift switch to “2WD”, “AUTO” and “2WD” in order.
10. Move A/T selector lever to “D” position.
11. Turn 4WD shift switch to “LOCK”, “AUTO” and “LOCK” in order.
12. Move A/T selector lever to “N” position.
13. Turn 4WD shift switch to “AUTO” position.
14. Move A/T selector lever to “P” position.
15. Read the flickering of 4WD warning lamp.
Refer to TF-51, "
Judgement Self-diagnosis" .
Judgement Self-diagnosis
When a malfunction is detected, the malfunction route is indicated by flickering of the 4WD warning lamp.
PDIA0227E
Flickering pattern or
flickering conditionItems Malfunction Check items
2Output shaft revolution
signal (from TCM)
Malfunction is detected in output shaft revolution signal
that is output from TCM through CAN communication.
Improper signal is input while driving.TF-58, "
Output Shaft
Revolution Signal
(TCM)"
3Clutch pressure sole-
noid signalProper voltage is not applied to clutch pressure solenoid
valve due to open or short circuit.TF-86, "Clutch Pres-
sure Solenoid"
4 2-4WD solenoid signalProper voltage is not applied to 2-4WD solenoid valve
due to open or short circuit.TF-91, "2-4WD Sole-
noid"
5 Transfer motorMotor does not operate properly due to open or short cir-
cuit in transfer motor or motor relay.TF-95, "Tran s fe r Mo to r"
6Vehicle speed signal
(from ABS)
Malfunction is detected in vehicle speed signal that is
output from ABS actuator and electric unit (control unit)
through CAN communication.
Improper signal is input while driving.TF-58, "
Vehicle Speed
Sensor (ABS)"
7 CAN communicationMalfunction has been detected from CAN communica-
tion line.TF-113, "CAN Commu-
nication Line"
8 AD converterAD converter system of transfer control unit is malfunc-
tioning.TF-54, "Power Supply
Circuit For Transfer
Control Unit"
TROUBLE DIAGNOSIS
TF-53
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Revision: October 20052005 QX56
CAUTION:
If “CAN communication” is displayed with other DTCs, first perform the trouble diagnosis for CAN communication line.
If “ABS operation signal”, “VDC operation signal" or “TCS operation signal" is displayed, first perform the trouble diag-
nosis for ABS system.
If “Output shaft revolution signal” is displayed, first perform the trouble diagnosis for A/T system.
NOTE:
If "actuator position switch" or “actuator circuit” is displayed, first erase self-diagnostic results. ("Actuator position switch" or “actua-
tor circuit” may be displayed after installing transfer control unit or transfer assembly.)
If “clutch pressure switch” or “line pressure switch” is displayed 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.
ERASE SELF-DIAGNOSIS
In order to make it easier to find the cause of hard-to-duplicate malfunctions, malfunction information is
stored into the control unit as necessary during use by the user. This memory is not erased no matter how
many times the ignition switch is turned ON and OFF.
However, this information is erased by turning ignition switch “OFF” after performing self-diagnostics or by
erasing the memory using the CONSULT-II.
24PNP switch signal
(from TCM)When A/T PNP switch signal is malfunctioning or com-
munication error between the vehicles.TF-69, "PNP Switch
Signal (TCM)"
Repeats flickering
every 2 to 5 sec.— Circuits that the self-diagnosis covers have no malfunction. —
Repeats flickering
every 0.25 sec.Data erase display
Power supply failure of memory back-up.
Battery performance is poor.TF-54, "
Power Supply
Circuit For Transfer
Control Unit"
No flickeringPNP switch or 4WD
shift switchPNP switch or 4WD shift switch circuit is shorted or
open.TF-69, "PNP Switch
Signal (TCM)", TF-62,
"4WD Shift Switch"
Flickering pattern or
flickering conditionItems Malfunction Check items
TF-56
TROUBLE DIAGNOSIS FOR SYSTEM
Revision: October 20052005 QX56
2. CHECK GROUND CIRCUIT
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connector.
3. Check continuity between transfer control unit harness connec-
tor E142 terminals 3 (B), 6 (B), E143 terminal 45 (B) and ground.
Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 3.
NG >> Repair open circuit or short to ground or short to power
in harness or connectors.
3. CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Refer to TF-36, "
Transfer Control Unit Input/Output Signal Ref-
erence Values" .
OK or NG
OK >> GO TO 4.
NG >> Check transfer control unit pin terminals for damage or loose connection with harness connector.
If any items are damaged, repair or replace damaged parts.
4. CHECK DTC
Perform the self-diagnosis, after driving a vehicle for a while.
OK or NG
OK >> Inspection End.
NG >> Replace transfer control unit. Refer to TF-132, "
Removal and Installation" . Continuity should exist.
SDIA2691E
TF-60
TROUBLE DIAGNOSIS FOR SYSTEM
Revision: October 20052005 QX56
DIAGNOSTIC PROCEDURE
1. CHECK 4LO POSITION SWITCH SIGNAL
With CONSULT-II
1. Start engine.
2. Select “DATA MONITOR” mode for “ALL MODE AWD/4WD” with CONSULT-II.
3. Read out the value of “N POSI SW TF”.
Without CONSULT-II
1. Start engine.
2. Check voltage between transfer control unit harness connector
terminal and ground.
OK or NG
OK >> GO TO 5.
NG >> GO TO 2.
2. CHECK HARNESS BETWEEN TRANSFER CONTROL UNIT AND NEUTRAL-4LO SWITCH
1. Turn ignition switch “OFF”. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connector and the neutral-4LO switch harness connector.
3. Check continuity between transfer control unit harness connec-
tor E143 terminal 25 (V) and neutral-4LO switch harness con-
nector F60 terminal 13 (V).
Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace damaged parts.
Condition Display value
Vehicle stopped
Engine running
A/T selector lever “N” position
Brake pedal depressed4WD shift switch: 2WD,
AUTO or 4HOFF
4WD shift switch: 4H to
4LO (While actuator
motor is operating.)OFF → ON
4WD shift switch: 4LO to
4H (While actuator motor
is operating.)ON → OFF
4WD shift switch: 4LO ON
SDIA2692E
ConnectorTe r m i n a l
(Wire
color)ConditionVoltage
(Approx.)
E143 25 (V) -
Ground
Vehicle stopped
Engine running
A/T selector lever
“N” position
Brake pedal
depressed4WD shift switch:
2WD, AUTO or 4HBattery
voltage
4WD shift switch: 4H
to 4LO (While actuator
motor is operating.)Battery
voltage
→ 0V
4WD shift switch: 4LO
to 4H (While actuator
motor is operating.)0V →
Battery
voltage
4WD shift switch: 4LO 0V
SDIA2693E
Continuity should exist.
SDIA2694E