Page 4214 of 4366

TF-10
AWD SYSTEM
Revision: 2006 July 2007 FX35/FX45
AWD SYSTEMPFP:41650
Power Transfer DiagramNDS0009U
System DescriptionNDS0009V
DESCRIPTION
Electronic control allows optimal distribution of torque to front/rear wheels to match road conditions.
Makes possible stable driving, with no wheel spin, on snowy roads or other slippery surfaces.
On roads which do not require AWD, it contributes to improved fuel economy by driving in conditions close
to rear-wheel drive.
Sensor inputs determine the vehicle's turning condition, and in response tight cornering/braking are con-
trolled by distributing optimum torque to front wheels.
NOTE:
When driving, if there is a large difference between front and rear wheel speed which continues for a long
time, fluid temperature of drive system parts becomes too high and AWD warning lamp flashes rapidly.
(When AWD warning lamp flashes, vehicle changes to rear-wheel drive conditions.) Also, optional distri-
bution of torque sometimes becomes rigid before lamp flashes rapidly, but it is not malfunction.
If AWD warning lamp is flashing rapidly, stop vehicle and allow it to idle for some time. Flashing will stop
and AWD system will be restored.
When driving, AWD warning lamp may flash slowly if there is a significant difference in diameter of the
tires. At this time, vehicle performance is not fully available and cautious driving is required. (Continues
until engine is turned OFF.)
If 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.
When the difference of revolution speed between the front and rear wheel mode the shift occasionally
changes to direct 4-wheel driving conditions automatically. This is not malfunction.
SDIA1611E
Page 4215 of 4366
AWD SYSTEM TF-11
C E F
G H
I
J
K L
M A
B
TF
Revision: 2006 July 2007 FX35/FX45
ELECTRIC CONTROLLED COUPLING
Operation Principle
1. AWD control unit supplies command current to electric controlled coupling (AWD solenoid).
2. 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. Main clutch transmits torque to front wheels according to pressing power.
Transmission torque to front wheels is determined according
to command current.
AWD CONTROL UNIT
Controls distribution of drive power between rear-wheel drive
(0:100) and AWD (50:50) conditions according to signals from
sensors.
Self-diagnosis can be done with CONSULT-II.
SDIA2270E
SDIA1844E
SDIA2273E
Page 4216 of 4366

TF-12
AWD SYSTEM
Revision: 2006 July 2007 FX35/FX45
AWD WARNING LAMP
Turns ON when there is a malfunction in AWD system. It indicates that fail-safe mode is engaged and vehicle
change to rear-wheel drive or shifting driving force-AWD (Front-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.
AWD Warning Lamp Indication
System DiagramNDS0009W
Condition AWD warning lamp
Lamp check Turns ON when ignition switch is turned ON. Turns OFF
approx. 1 second after engine start.
AWD system malfunction ON
Protection function is activated due to heavy load to electric con-
trolled coupling. (AWD system is not malfunctioning and AWD system
changes to 2WD mode.) Rapid flashing: 2 times/second
(Flashing in approx. 1 minute and then turning OFF.)
Large difference in diameter of front/rear tires Slow flashing: 1 time/2 seconds
(Continuing to flash until turning ignition switch OFF)
Other than above (system normal) OFF
SDIA2160E
Page 4218 of 4366

TF-14
TROUBLE DIAGNOSIS
Revision: 2006 July 2007 FX35/FX45
TROUBLE DIAGNOSISPFP:00004
Fail-Safe FunctionNDS0009Y
If any malfunction occurs in AWD electrical system, and control unit detects the malfunction, AWD warn-
ing lamp on combination meter turns ON to indicate system malfunction.
When AWD warning lamp is ON, vehicle changes to rear-wheel drive or shifting driving force-AWD (Front-
wheels still have some driving torque).
How to Perform Trouble DiagnosisNDS0009Z
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-23, "
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
Page 4224 of 4366

TF-20
TROUBLE DIAGNOSIS
Revision: 2006 July 2007 FX35/FX45
Trouble Diagnosis Chart for SymptomsNDS000A3
If AWD warning lamp turns ON, perform self-diagnosis. Refer to TF-22, "SELF-DIAG RESULT MODE" .
NOTE:
Light tight-corner braking symptom may occur depending on driving conditions. This is not malfunction. Symptom Condition Check item Reference page
AWD warning lamp does not turn ON when
the ignition switch is turned to ON.
(AWD warning lamp check) Ignition switch: ON CAN communication line
TF-33
Unified meter and A/C amp.
Unified meter control unit
AWD warning lamp does not turn OFF sev-
eral seconds after engine started. Engine running CAN communication line
TF-33
Power supply and ground for AWD con-
trol unit
Unified meter and A/C amp.
Unified meter control unit
AWD solenoid
AWD actuator relay (integrated in AWD
control unit)
Wheel sensor
Heavy tight-corner braking symptom occurs
when the vehicle is driven and the steering
wheel is turned fully to either side after the
engine is started. (See NOTE.)
While driving
Steering wheel is
turned fully to either
sides CAN communication line
TF-35Accelerator pedal position signal
AWD solenoid
Mechanical malfunction of electric con-
trolled coupling (clutch sticking etc.)
Vehicle does not enter AWD mode even
though AWD warning lamp turned to OFF. While driving AWD solenoid
TF-36
Mechanical malfunction of electric con-
trolled coupling (Mechanical engage-
ment of clutch is not possible.)
While driving, AWD warning lamp flashes
rapidly. (When flashing in approx. 1 minute
and then turning OFF.)
Rapid flashing: 2 times/second While driving Protection function is activated due to
heavy load to electric controlled cou-
pling. (AWD system is not malfunction-
ing. Also, optional distribution of torque
sometimes becomes rigid before lamp
flashes rapidly, but it is not malfunction.) TF-37
While driving, AWD warning lamp flashes
slowly. (When continuing to flash until turn-
ing ignition switch OFF)
Slow flashing: 1 time/2 secondsWhile driving
Vehicle speed: 20 km/h
(12 MPH) or more Tire size is different between front and
rear of vehicle. TF-37
Page 4274 of 4366

WT-10
ROAD WHEEL TIRE ASSEMBLY
Revision: 2006 July 2007 FX35/FX45
d. If calculated balance weight value exceeds 50 g (1.76 oz), install
two balance weight sheets in line with each other as shown in
the figure.
CAUTION:
Do not install one balance weight sheet on top of another.
3. Start tire balance machine again.
4. Install drive-in balance weight on inner side of road wheel in the tire balance machine indication position (angle).
CAUTION:
Do not install more than two balance weights.
5. Start tire balance machine. Make sure that inner and outer resid- ual unbalance values are 5 g (0.2 oz) each or below.
6. If either residual unbalance value exceeds 5 g (0.2 oz), repeat installation procedures.
Tire RotationNES000KZ
1. Follow the maintenance schedule for tire rotation service intervals. Refer to MA-7, "Introduction of Peri-
odic Maintenance" .
2. Do not include the spare tire when rotating the tires.
3. When installing the wheel, tighten wheel nuts to the specified torque.
CAUTION:
When installing wheels, tighten them diagonally by dividing the work two to three times in order
to prevent the wheels from developing any distortion.
Be careful not to tighten wheel nut at torque exceeding the criteria for preventing strain of disc
rotor.
4. Perform the ID registration, after tire rotation. Refer to WT-20, "
ID Registration Procedure" .
Wheel balance Dynamic (At rim flange) Static (At rim flange)
Maximum allowable
unbalance 5 g (0.2 oz) (one side) 20 g (0.7 oz)
SMA056D
Wheel nuts : 108 N·m (11 kg-m, 80 ft-lb)