NISSAN X-TRAIL 2003 Electronic Repair Manual

ALL MODE 4X4 SYSTEM
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ALL MODE 4X4 SYSTEMPFP:47850
PrecautionsEDS000IV
lThis section describes ESP/TCS/ABS model.
lRefer to the BRC section for model without ESP/TCS/ABS.Refer toBRC-6, "ALL MODE 4X4 SYSTEM"
System ComponentEDS000IJ
System DescriptionEDS000IK
ERECTRONIC COUPLING
lIn response to command current from 4WD control unit, control
clutch pull-in force is generated at the electromagnet and torque
is generated at the control clutch.
lThe cam operates in response to control clutch torque and
applies pressure to main clutch.
lMain clutch transmits torque from input shaft to output shaft,
according to the amount of pressure.
lThe actual amount of torque transfer is determined by control
current as shown in figure below (I-T characteristics figure).
4WD CONTROL UNIT
lControls distribution of drive power between front-wheel drive
(100:0) and 4WD (50:50) conditions circuit according to signals
from sensors.
lIf malfunction occurs in 4WD system, 4WD warning lamp turns
ON and vehicle changes to front-wheel drive.
lSelf-diagnosis can be done with CONSULT-II.
SFIA0283E
SFIA0284E
SFIA0285E
SFIA0286E

TF-32
ALL MODE 4X4 SYSTEM
4WD MODE SWITCT
AUTO mode (AUTO indicator lamp ON)
lElectronic control allows optimal distribution of torque to front/rear wheels to match road conditions.
lMakes possible stable driving, with no wheel spin, on snowy roads or other slippery surfaces.
lOn roads which do not require 4WD, it contributes to improved fuel economy by driving in conditions close
to front-wheel drive.
lSensors determine the vehicle's turning condition, and in response tight cornering/braking are controlled
by distributing optimum torque to rear wheels.
NOTE:
lWhen driving in AUTO mode or LOCK mode, if there is a large difference between front and rear wheel
speed which continues for a long time, oil temperature of drive system parts becomes too high and 4WD
warning lamp flashes rapidly. (When 4WD warning lamp flashes, vehicle changes to front-wheel drive
conditions.)
lWhen driving in AUTO mode, 4WD warning lamp may flash slowly if there is a significant difference in
pressure or wear between tires. At this time, vehicle performance is not fully available and cautious driving
is required. (Continues until engine is turned OFF.)
lIf 4WD warning lamp is flashing rapidly, stop vehicle and allow it to idle for some time. Flashing will stop
and AUTO mode will be restored.
lIf the warning lamp flashes slowly during driving but remains OFF after engine is restarted, the system is
normal. If it again flashes slowly after driving for some time, vehicle must be inspected.
lWhen the difference of revolution speed between the front and rear wheel with AUTO mode the shift
switch occasionally changes to LOCK mode automatically. This is not malfunction.
LOCK mode (LOCK indicator lamp and AUTO indicator lamp ON)
lFront/rear wheel torque distribution is fixed, ensuring stable driving when climbing slopes.
lWhen LOCK mode is selected, vehicle will switch automatically to AUTO mode if vehicle speed increases.
If vehicle speed then decreases, the vehicle automatically returns to direct 4-wheel driving conditions.
NOTE:
If there is a significant difference in pressure or wear between tires, full vehicle performance is not available.
Tire conditions are detected, and LOCK mode may be prohibited, or else speeds at which LOCK mode is
enabled may be restricted.
2WD mode (indicator lamps OFF)
Vehicle is in front-wheel drive.
NOTE:
lIf front wheels are slipping in 2WD mode, do not switch to AUTO or LOCK. This can cause difficulties for
the system.
lThe shift switch even if the shift switch is in 2WD mode, the sift switch occasionally automatically change
to 4WD mode depending on the driving condition (For example; Depressing the acceleration firmly). this is
not malfunction. How ever, 4WD mode indicator lamp dose not illuminate.
4WD WARNING LAMP
Turns ON when there is a malfunction in 4WD system. It indicates that fail-safe mode is engaged and vehicle
is in 2WD.
Also turns ON when ignition switch is turned ON, for purpose of bulb check. Turns OFF approximately for 3
seconds after the engine starts if system is normal.
4WD waning lamp indiction
Condition Display 4WD warning lamp
Self-diagnosisWhen self-diagnosis is performed, indicates location of
malfunction by number of flashes.-
Lamp checkTurns ON when engine is started to check for burned-out
lamps.Turns ON when ignition switch
is turned ON. Turns OFF
approximately 3 seconds after
engine start.
4WD system malfunction Turns ON if there is malfunction in 4WD system. ON

ALL MODE 4X4 SYSTEM
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FAIL- SAFE FUNCTION
lIf a malfunction occurs in 4WD electrical system, and control unit detects the malfunction, 4WD warning
lamp on gauge turns ON to inform driver of system malfunction.
lWhen 4WD warning lamp is ON, vehicle is in 2WD.
System DiagramEDS000IL
CAN CommunicationEDS000IP
SYSTEM DESCRIPTION
CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle mul-
tiplex communication line with high data communication speed and excellent error detection ability. Many elec-
tronic control units are equipped onto a vehicle, and each control unit shares information and links with other
control units during operation (not independent). In CAN communication, control units are connected with 2
communication lines (CAN H line, CAN L line) allowing a high rate of information transmission with less wiring.
Each control unit transmits/receives data but selectively reads required data only.
SYSTEM DIAGRAM
Largedifferenceindiameteroffront/
rear tires4WD warning lamp flashes slowly. Flashes once every 2 seconds.
Difference in front/rear wheel speed
continues and oil temperature of
drive system has increased.4WD warning lamp flashes rapidly. Flashes twice each second.
Other than above (system normal) OFF OFFCondition Display 4WD warning lamp
SFIA0287E
SKIA0885E

TF-34
ALL MODE 4X4 SYSTEM
INPUT/OUTPUT SIGNAL
T: Transmit R: Receive
Signals ECMSteering wheel
angle sensor4WD control unitESP/ TCS / ABS
control unit
Engine speed signal T R R
Accelerator pedal position signal T R
ESP operation signal R R T
TCS operation signal R R T
ABS operation signal R R T
Stop lamp switch signalRT
Steering wheel angle sensor signal T R
ESP-OFFSW signalRT
Wheel speed sensor signalRT
4WD Mode signalTR

ALL MODE 4X4 SYSTEM
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Circuit DiagramEDS000IM
TDWA0001E

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ALL MODE 4X4 SYSTEM
Wiring Diagram
EDS000IN
TDWA0002E

ALL MODE 4X4 SYSTEM
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TDWA0003E

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ALL MODE 4X4 SYSTEM
TDWA0004E

ALL MODE 4X4 SYSTEM
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TDWA0005E

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TROUBLE DIAGNOSIS
TROUBLE DIAGNOSIS
PFP:00004
Fail-safe functionEDS000H4
lIf a malfunction occurs in 4WD electrical system, and control unit detects the malfunction, 4WD warning
lamp on gauge turns ON to inform driver of system malfunction.
lWhen 4WD warning lamp is ON, the vehicle is in 2WD.
How to proceed with trouble diagnosisEDS000H5
BASIC CONCEPT
lThe most important point to perform trouble diagnosis is to understand vehicle systems (control and
mechanism) thoroughly.
lIt is also important to clarify customer complaints before inspec-
tion.
First of all, reproduce symptom, and understand it fully.
Ask customer about his/her complaints carefully. In some cases,
it will be necessary to check symptoms by driving vehicle with
customer.
CAUTION:
Customers are not professional. It is dangerous to make an
easy guess like "maybe the customer means that...," or
"maybe the customer mentions this symptom".
lIt is essential to check symptoms right from the beginning in
order to repair a malfunction completely.
For intermittent malfunction, reproduce symptom based on inter-
view with customer and past examples. Do not perform inspec-
tion on ad hoc basis. Most intermittent malfunctions are caused
by poor contacts. In this case, it will be effective to shake sus-
pected harness or connector by hand. When repairing without
any symptom diagnosis, you cannot judge if malfunction has
actually been eliminated.
lAfter completing diagnosis, always erase diagnostic memory.
Refer toTF-45, "
Operation procedure".
lFor intermittent malfunction, move harness or harness connector by hand. Then check poor contact or
false open circuit.
SEF234G
SEF233G