2003 NISSAN X-TRAIL 4WD

ALL MODE 4X4 SYSTEM
TF-13
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COMPONENTS FUNCTION DESCRIPTION
CAN CommunicationEDS0027K
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.
CAN COMMUNICATION UNIT (M/T MODELS WITHOUT ESP)
System diagram
Component parts Function
4WD control unit

Controls driving force distribution by signals from each sensor and switch from front wheel driving
mode (100:0) to 4WD mode (50:50).

2WD mode is available by fail-safe function if malfunction is detected in electrical system.
Wheel sensors Detects wheel speed.
4WD solenoid Controls electric controlled coupling by operation signal from 4WD control unit.
Electric controlled coupling Transmits driving force to rear final drive.
4WD mode switch Able to select from 2WD, AUTO or LOCK mode.
4WD warning lamp

Illuminates if malfunction is detected in electrical system of 4WD system.

There is 1 blink in 2 seconds if rotation difference of front wheels and rear wheels is large.

There are 2 blinks in 1 second if load is still applied to driving parts.
4WD indicator lamp Indicate operation with optimal distribution of torque to front/rear wheels.
LOCK indicator lamp Indicate that 4WD system is under direct 4-wheel driving mode.
ABS actuator and electric unit
(control unit) (without ESP) or
ESP/TCS/ABS control unit (with
ESP)Transmits the following signals via CAN communication to 4WD control unit.

Vehicle speed signal

Stop lamp switch signal (brake signal)
ECMTransmits the following signals via CAN communication to 4WD control unit.

Accelerator pedal position signal

Engine speed signal
Unified meter control unit Transmits conditions of parking brake switch via CAN communication to 4WD control unit.
PKIA6458E

TF-14
ALL MODE 4X4 SYSTEM

Input/output signal chart
T: Transmit R: Receive
CAN COMMUNICATION UNIT (A/T MODELS WITHOUT ESP)
System diagram
Input/output signal chart
T: Transmit R: Receive Signals ECMABS actuator and
electric unit
(control unit)4WD control unit Combination meter
Stop lamp switch signal T R
Engine speed signal T R R
Engine coolant temperature signal T R
Accelerator pedal position signal T R
A/C compressor feedback signal T R
Vehicle speed signalTRR
RT
ABS warning lamp signal T R
4WD warning lamp signalTR
4WD mode indicator lamp signal T R
Parking brake switch signalRT
MI signal T R
PKIA6457E
Signals ECM TCMABS actuator
and electric unit
(control unit)4WD control
unitCombination
meter
Stop lamp switch signalRT
TR
P·N range signal R T
A/T position indicator lamp signal T R
Overdrive control switch signal R T
O/D OFF indicator signal T R
Closed throttle position signal T R
Wide open throttle position signal T R

ALL MODE 4X4 SYSTEM
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CAN COMMUNICATION UNIT (M/T MODELS WITH ESP)
System diagram
Input/output signal chart
T: Transmit R: Receive Engine speed signal T R R
Engine coolant temperature signal TR
Accelerator pedal position signal T R
Output shaft revolution signal R T
A/C compressor feedback signal TR
Vehicle speed signalTRR
RT
ABS warning lamp signal T R
4WD warning lamp signalTR
4WD mode indicator lamp signalTR
Parking brake switch signalRT
MI signal TR
Engine A/T integrated control signalTR
RT
A/T self-diagnosis signal R TSignals ECM TCMABS actuator
and electric unit
(control unit)4WD control
unitCombination
meter
PKIA6459E
Signals ECMESP/TCS/ABS
control unitSteering angle
sensor4WD control
unitCombination
meter
Stop lamp switch signal T R
Engine speed signal T R R R
Engine coolant temperature signal TR
Accelerator pedal position signal T R R
A/C switch signal*
1RT
A/C compressor feedback signal*
2TR

TF-16
ALL MODE 4X4 SYSTEM

*1: YD engine models only
*2: QR engine models only
CAN COMMUNICATION UNIT (A/T MODELS WITH ESP)
System diagram
Input/output signal chart
T: Transmit R: Receive Vehicle speed signalTRR
RT
ABS warning lamp signal T R
Brake warning lamp signal T R
SLIP indicator lamp signal T R
ESP OFF indicator lamp signal T R
4WD warning lamp signalTR
4WD mode indicator lamp signalTR
Parking brake switch signalRT
MI signal TR
Glow indicator lamp signal*
1TR
Steering angle sensor signal R TSignals ECMESP/TCS/ABS
control unitSteering angle
sensor4WD control
unitCombination
meter
PKIA6460E
Signals ECM TCMESP/TCS/
ABS control
unitSteering
angle sensor4WD control
unitCombination
meter
Stop lamp switch signalRT
TR
P·N range signal R T
A/T position indicator lamp signal T R R
O/D OFF indicator signal T R
Overdrive control switch signal R T
Closed throttle position signal T R
Wide open throttle position signal T R

ALL MODE 4X4 SYSTEM
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Engine speed signal T R R R
Engine coolant temperature signal TR
Accelerator pedal position signal T R R
Output shaft revolution signal R T
A/C compressor feedback signal TR
Vehicle speed signalTRR
RT
ABS warning lamp signal T R
Brake warning lamp signal T R
SLIP indicator lamp signal T R
ESP OFF indicator lamp signal T R
4WD warning lamp signalTR
4WD mode indicator lamp signalTR
Parking brake switch signalRT
MI signal TR
Steering angle sensor signal R T
Engine and A/T integratedTR
RT
A/T self-diagnosis signal R TSignals ECM TCMESP/TCS/
ABS control
unitSteering
angle sensor4WD control
unitCombination
meter

TF-18
TROUBLE DIAGNOSIS

TROUBLE DIAGNOSISPFP:00004
Fail-safe FunctionEDS001VE

If any malfunction occurs in 4WD electrical system, and control unit detects the malfunction, 4WD warning
lamp on combination meter turns ON to indicate system malfunction.

When 4WD warning lamp is ON, vehicle changes to front-wheel drive or shifting driving force-4WD (Rear-
wheels still have some driving torque).
How to Perform Trouble DiagnosisEDS001VF
BASIC CONCEPT

To perform trouble diagnosis, it is the most important to have understanding about vehicle systems (con-
trol and mechanism) thoroughly.

It is also important to clarify customer complaints before inspec-
tion.
First of all, reproduce symptoms, and understand them 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".

It is essential to check symptoms right from the beginning in
order to repair malfunctions completely.
For intermittent malfunctions, reproduce symptoms based on
interview with customer and past examples. Do not perform
inspection on ad hoc basis. Most intermittent malfunctions are
caused by poor contacts. In this case, it will be effective to shake
suspected harness or connector by hand. When repairing with-
out any symptom diagnosis, you cannot judge if malfunctions
have actually been eliminated.

After completing diagnosis, always erase diagnostic memory.
Refer to TF-31, "
How to Erase Self-diagnostic Results" .

For intermittent malfunctions, move harness or harness connec-
tor by hand. Then check for poor contact or reproduced open circuit.
SEF233G
SEF234G

TROUBLE DIAGNOSIS
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Wiring Diagram — 4WD —EDS001VI
LHD MODELS
TDWB0011E

TROUBLE DIAGNOSIS
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Trouble Diagnosis Chart for SymptomsEDS001VJ
If 4WD warning lamp turns ON, perform self-diagnosis. Refer to TF-30, "SELF-DIAG RESULT MODE" .
NOTE:

Light tight-corner braking symptom may occur depending on driving conditions in AUTO mode. This is not malfunction.

Heavy tight-corner braking symptom occurs when vehicle is driven in the following conditions: LOCK mode, steering
wheel is turned fully to either sides, and accelerator pedal was depressed.Symptom Condition Check item Reference page
4WD indicator lamp and LOCK indicator
lamp do not turn ON for approx. 1 second
when the ignition switch is turned to ON.
(4WD indicator lamp and LOCK indicator
lamp check)Ignition switch: ONCAN communication line
TF-44
Power supply and ground for 4WD con-
trol unit
Unified meter control unit
4WD warning lamp does not turn ON when
the ignition switch is turned to ON.
(4WD warning lamp check)Ignition switch: ONCAN communication line
TF-45
Unified meter control unit
4WD warning lamp does not turn OFF sev-
eral seconds after engine started.Engine runningCAN communication line
TF-46
Power supply and ground for 4WD con-
trol unit
Unified meter control unit
4WD solenoid
4WD actuator relay (integrated in 4WD
control unit)
Wheel sensor
4WD mode cannot be switched after engine
is started.Engine running4WD mode switch
TF-47
CAN communication line
Unified meter control unit
Heavy tight-corner braking symptom occurs
when the vehicle is driven in AUTO mode
and the steering wheel is turned fully to
either side after the engine is started. (See
NOTE.)

While driving

AUTO mode

Steering wheel is
turned fully to either
sidesCAN communication line
TF-48
4WD mode switch
Accelerator pedal position signal
4WD solenoid
Mechanical malfunction of electric con-
trolled coupling (clutch sticking etc.)
Vehicle does not enter 4WD mode even
though 4WD warning lamp turned to OFF.Vehicle speed: 10 km/h
(6 MPH) or less4WD solenoid
TF-49
Mechanical malfunction of electric con-
trolled coupling (Mechanical engage-
ment of clutch is not possible.)
Vehicle speed: 10 km/h
(6 MPH) or moreOperating condition of parking brake
4WD solenoid
Mechanical malfunction of electric con-
trolled coupling (Mechanical engage-
ment of clutch is not possible.)
While driving, 4WD warning lamp flashes
rapidly. (When flashing in approx. 1 minute
and then turning OFF.)
Rapid flashing: 2 times/second

While driving

AUTO mode and
LOCK modeProtection function is activated due to
heavy load to electric controlled cou-
pling. (4WD system is not malfunction-
ing.)TF-50
While driving, 4WD warning lamp flashes
slowly. (When continuing to flash until turn-
ing ignition switch OFF)
Slow flashing: 1 time/2 seconds
While driving

Vehicle speed: 20 km/h
(12 MPH) or moreTire size is different between front and
rear of vehicle.TF-51