4WD NISSAN X-TRAIL 2003 Service Owner's Manual
[x] Cancel search | Manufacturer: NISSAN, Model Year: 2003, Model line: X-TRAIL, Model: NISSAN X-TRAIL 2003Pages: 4179, PDF Size: 87.27 MB
Page 2579 of 4179
PRECAUTIONS
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PRECAUTIONSPFP:00001
Precautions for Supplemental Restraint System (SRS) “AIR BAG” and “SEAT
BELT PRE-TENSIONER”
EDS001W1
The Supplemental Restraint System such as “AIR BAG” and “SEAT BELT PRE-TENSIONER”, used along
with a front seat belt, helps to reduce the risk or severity of injury to the driver and front passenger for certain
types of collision. Information necessary to service the system safely is included in the SRS and SB section of
this Service Manual.
WARNING:
To avoid rendering the SRS inoperative, which could increase the risk of personal injury or death
in the event of a collision which would result in air bag inflation, all maintenance must be per-
formed by an authorized NISSAN/INFINITI dealer.
Improper maintenance, including incorrect removal and installation of the SRS, can lead to per-
sonal injury caused by unintentional activation of the system. For removal of Spiral Cable and Air
Bag Module, see the SRS section.
Do not use electrical test equipment on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harnesses can be identified by yellow and/or orange harnesses or
harness connectors.
PrecautionsEDS001V6
Before connecting or disconnecting the 4WD control unit
harness connector, turn ignition switch “OFF” and discon-
nect battery ground cable. Because battery voltage is
applied to 4WD control unit even if ignition switch is turned
“OFF”.
When connecting or disconnecting pin connectors into or
from 4WD control unit, take care not to damage pin termi-
nals (bend or break).
When connecting pin connectors, make sure that there are
no bends or breaks on 4WD control unit pin terminal.
Before replacing 4WD control unit, perform 4WD control
unit input/output signal inspection and make sure whether
4WD control unit functions properly or not. Refer to TF-28,
"4WD Control Unit Input/Output Signal Reference Values" .
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TF-10
ALL MODE 4X4 SYSTEM
ALL MODE 4X4 SYSTEMPFP:47850
Power Transfer DiagramEDS001VA
System DescriptionEDS001VB
ELECTRIC CONTROLLED COUPLING
Operation Principle
1. The 4WD control unit supplies command current to electric con-
trolled coupling (4WD solenoid).
2. The control clutch is engaged by electromagnet and torque is
detected in control clutch.
3. The cam operates in response to control clutch torque and
applies pressure to main clutch.
4. The main clutch transmits torque to front wheels according to
pressing power.
Transmission torque to the rear wheels is determined accord-
ing to command current.
4WD CONTROL UNIT
4WD controls distribution of drive power between front-wheel
drive (100:0) and 4WD (50:50) conditions according to signals
from sensors.
Self-diagnosis can be done with CONSULT-II.
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Page 2587 of 4179
ALL MODE 4X4 SYSTEM
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4WD MODE SWITCH
AUTO Mode
Electronic control allows optimal distribution of torque to front/rear wheels to match road conditions.
4WD mode makes possible stable driving, with no wheel spin, on snowy roads or other slippery surfaces.
On roads which do not require 4WD, AUTO mode contributes to improved fuel economy by driving in con-
ditions close to front-wheel drive.
Sensor inputs determine the vehicle's turning condition, and tight cornering/braking are controlled by dis-
tributing optimum torque to rear wheels.
LOCK Mode
Front/rear wheel torque distribution is fixed, ensuring stable driving when climbing slopes.
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.
LOCK mode will change to AUTO mode automatically, when the vehicle speed exceeds approx. 30 km/h
(19 MPH). The LOCK indicator light keeps illuminating.
NOTE:
If there is a significant difference in pressure or wear between tires, full vehicle performance is not available.
LOCK mode may be prohibited, or speeds at which LOCK mode is enabled may be restricted detecting tire
conditions.
2WD Mode
Vehicle is in front-wheel drive.
NOTE:
If front wheels are slipping in 2WD mode, do not switch to AUTO or LOCK. This can cause difficulties for
the system.
Even if the 4WD mode switch is in 2WD mode, the 4WD control unit occasionally automatically change to
AUTO mode depending on the driving condition (For example; Depressing the acceleration firmly). This is
not malfunction. However, 4WD indicator lamp dose not illuminate.
4WD INDICATOR LAMP AND LOCK INDICATOR LAMP
The following is the indications of indicator lamp.
4WD WARNING LAMP
Turns ON when there is a malfunction in 4WD system. It indicates that the vehicle is in fail-safe mode and
change to front-wheel drive or shifting driving force-4WD (Rear-wheels still have some driving torque).
Also turns ON when ignition switch is turned ON, for purpose of lamp check. Turns OFF approximately for 1
seconds after the engine starts if system is normal.
4WD Warning Lamp Indication
Condition 4WD indicator lamp LOCK indicator lamp
AUTO mode ON OFF
LOCK mode ON ON
2WD mode OFF OFF
Lamp check Turns ON for approx. 1 second when ignition switch is turned ON.
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Condition 4WD warning lamp
Lamp checkTurns ON when ignition switch is turned ON. Turns OFF
approx. 1 seconds after engine start.
4WD system malfunctionON
Protection function is activated due to heavy load to electric con-
trolled coupling. (4WD system is not malfunctioning and 4WD system
changes to 2WD mode.)Rapid flashing: 2 times/second
(Flashing in approx. 1 minute and then turning OFF.)
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TF-12
ALL MODE 4X4 SYSTEM
System DiagramEDS001VC
Large difference in diameter of front/rear tiresSlow flashing: 1 time/2 seconds
(Continuing to flash until turning ignition switch OFF)
Other than above (system normal) OFFCondition 4WD warning lamp
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ALL MODE 4X4 SYSTEM
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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.
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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
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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
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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
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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
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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
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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
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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.
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