2008 INFINITI FX35 warning

AWD SYSTEMTF-11
< SERVICE INFORMATION >
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AWD SYSTEM
Power Transfer DiagramINFOID:0000000001327431
System DescriptionINFOID:0000000001327432
DESCRIPTION
 Electronic control allows optimal distribution of torque to front/rear wheels to match road conditions.
 Makes possible stable driving, with no wheel sp in, 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 conditi on, 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 becom es too high and AWD warning lamp flashes rapidly.
(When AWD warning lamp flashes, vehicle changes to r ear-wheel drive conditions.) Also, optional distribu-
tion 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 ther e is a significant difference in diameter of the tires.
At this time, vehicle performance is not fully avail able 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.
ELECTRIC CONTROLLED COUPLING
Operation Principle
SDIA1611E
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TF-12
< SERVICE INFORMATION >
AWD SYSTEM
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 accordingto 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 sen-
sors.
 Self-diagnosis can be done with CONSULT-III.
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
SDIA2270E
SDIA1844E
SDIA2273E
Condition AWD warning lamp
Lamp check Turns ON when ignition switch is turned ON. Turns OFF ap-
prox. 1 second after engine start.
AWD system malfunction ON
Protection function is activated due to heavy load to electric controlled
coupling. (AWD system is not malfunctioning and AWD system chang-
es 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
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AWD SYSTEMTF-13
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SchematicINFOID:0000000001327433
COMPONENTS FUNCTION DESCRIPTION
CAN CommunicationINFOID:0000000001327434
SYSTEM DESCRIPTION
CAN (Controller Area Network) is a serial communication li ne 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.
For details, refer to LAN-43, "
CAN System Specification Chart".
SDIA2160E
Component parts Function
AWD control unit  Controls driving force distribution by signals from each sensor and switch from rear wheel driving
mode (0:100) to AWD mode (50:50).
 2WD mode is available by fail-safe function if malfunction is detected in AWD system.
Wheel sensors Detects wheel speed.
AWD solenoid Controls electric controlled coupling by command current from AWD control unit.
Electric controlled coupling Transmits driving force to front final drive.
AWD warning lamp  Illuminates if malfunction is detected in electrical system of AWD 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.
ABS actuator and electric unit
(control unit) Transmits the following signals via CAN communication to AWD control unit.
 Vehicle speed signal
 Stop lamp switch signal (brake signal)
ECM Transmits the following signals via CAN communication to AWD control unit.
 Accelerator pedal position signal
 Engine speed signal
Unified meter and A/C amp. Transmits conditions of parking brake switch via CAN communication to AWD control unit.
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TF-14
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
TROUBLE DIAGNOSIS
Fail-Safe FunctionINFOID:0000000001327435
 If any malfunction occurs in AWD electrical system, and control unit detects the malfunction, AWD warning
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 DiagnosisINFOID:0000000001327436
BASIC CONCEPT
 To perform trouble diagnosis, it is the most import ant to have understanding about vehicle systems (control
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 cus-
tomer.
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 inter-
view 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 without any symp-
tom diagnosis, you cannot judge if malfunctions have actually been
eliminated.
 After completing diagnosis, always erase diagnostic memory. Refer to TF-21, "
CONSULT-III Function (ALL MODE AWD/4WD)".
 For intermittent malfunctions, move harness or harness connector by hand. Then check for poor contact or reproduced open circuit.
SEF233G
SEF234G
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TF-20
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
Trouble Diagnosis Chart by Symptom
INFOID:0000000001327440
If AWD warning lamp turns ON, perform self-diagnosis. Refer to TF-21, "CONSULT-III Function (ALL MODE AWD/4WD)".
NOTE:
Light tight-corner braking symptom may occur depending on driving conditions. This is not malfunction.
AWD Control Unit Input/Output Signal Reference ValueINFOID:0000000001327441
AWD CONTROL UNIT INSPECTION TABLE
Specifications with CONSULT-III
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: ONCAN communication line
TF-30
Unified meter and A/C amp.
Unified meter control unit
AWD warning lamp does not turn OFF sev-
eral seconds after engine started. Engine runningCAN communication line
TF-30
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-32
Accelerator 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 drivingAWD solenoid
TF-33
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 drivingProtection 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-33
While driving, AWD 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 more Tire size is different between front and
rear of vehicle.
TF-33
Monitored item [Unit] Content Condition Display value
FR RH SENSOR [km/h] or [mph] Wheel speed (Front wheel
right)Vehicle stopped 0.00 km/h (0.00 mph)
Vehicle running
CAUTION:
Check air pressure of tire under
standard condition.
Approximately equal to
the indication on speed-
ometer (Inside of
±10%)
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TROUBLE DIAGNOSISTF-21
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*: The values are changed by throttle opening and engine speed.
CONSULT-III Function (ALL MODE AWD/4WD)INFOID:0000000001327442
FUNCTION
CONSULT-III can display each diagnostic item using the diagnostic test modes shown following.
FR LH SENSOR [km/h] or [mph] Wheel speed (Front wheel
left)Vehicle stopped 0.00 km/h (0.00 mph)
Vehicle running
CAUTION:
Check air pressure of tire under
standard condition.
Approximately equal to
the indication on speed-
ometer (Inside of
±10%)
RR RH SENSOR [km/h] or [mph] Wheel speed (Rear wheel
right)Vehicle stopped 0.00 km/h (0.00 mph)
Vehicle running
CAUTION:
Check air pressure of tire under
standard condition.
Approximately equal to
the indication on speed-
ometer (Inside of
±10%)
RR LH SENSOR [km/h] or [mph] Wheel speed (Rear wheel left) Vehicle stopped 0.00 km/h (0.00 mph)
Vehicle running
CAUTION:
Check air pressure of tire under
standard condition.Approximately equal to
the indication on speed-
ometer (Inside of
±10%)
BATTERY VOLT [V] Power supply voltage for AWD
control unitIgnition switch: ON Battery voltage
THRTL POS SEN [%] Throttle opening condition When depressing accelerator pedal
(Value rises gradually in response to
throttle position.)0 - 100%
ETS SOLENOID [A] Monitored value of current at
AWD solenoidEngine running
 At idle speed
Approx. 0.000A
Engine running
 When depressing accelerator ped- al Approx. 0.000 - 2.400A*
STOP LAMP SW [ON/OFF] Condition of brake pedal oper-
ationBrake pedal: Depressed ON
Brake pedal: Released OFF
ENG SPEED SIG [RUN/STOP] Condi tion of engine runningEngine stopped
(Engine speed: Less than 400 rpm)
STOP
Engine running
(Engine speed: 400 rpm or more) RUN
ETS ACTUATOR [ON/OFF] Operating condition of AWD
actuator relay (integrated in
AWD control unit)Engine stopped (Ignition
switch: ON)
OFF
Engine running ON
4WD WARN LAMP [ON/OFF] AWD warning lamp conditionAWD warning lamp: ON ON
AWD warning lamp: OFF OFF
4WD MODE MON [AUTO] Control status of AWD Engine running AUTO
DIS-TIRE MONI [mm] Improper size tire installed
conditionVehicle running with normal size tire
installed
0-4 mm
Vehicle running with improper size
tire installed (Front /rear tire size dif-
ference, wear condition) 4-8 mm, 8- mm
P BRAKE SW [ON/OFF] Condition of parking brake Parking brake operated ON
Parking brake not operated OFF
Monitored item [Unit] Content Condition Display value
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TF-22
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
SELF-DIAG RESULT MODE
Drive at 30 km/h or more for approximately 1 minute before performing the self-diagnosis.
Display Item List
CAUTION:
 If “CAN COMM CIRCUIT [U1000]” is displayed with other DTCs, first perform the trouble diagnosis for CAN communication
line.
 Make sure that ABS warning lamp turns OFF by driving for a minute at vehicle speed of 30 km/h (19 MPH) or more after turn- ing ignition switch “OFF” if AWD warning lamp turns ON with system malfunction of “ABS SYSTEM [C1203]”. AWD warning
lamp may not turn OFF if it is normal unless ignition switch turns OFF at once and engine restarts after that.
How to Erase Self-Diagnostic Results
Before erasing DTC memory, start the engine and drive at 30 km/h or more for approximately 1 minute.
Checkthat ABS warning lamp turns OFF.
NOTE:
Make sure that ABS warning lamp turns OFF by driv ing for a minute at vehicle speed of 30 km/h (19
MPH) or more after turning ignition switch “OFF ” if AWD warning lamp turns ON with system malfunc-
tion of “ABS SYSTE M [C1203]”. AWD warning lamp may not turn OFF if it is normal unless ignition
switch turns OFF at once and engine restarts after that.
DATA MONITOR MODE
Display Item List
Diagnostic test mode Function
ECU part number 4WD control unit part number can be read.
Self-diagnostic results Self-diagnostic results can be read and erased quickly.
Data monitor Input/Output data in the 4WD control unit can be read.
Active test Diagnostic Test Mode in which CONSULT-III drives some actuators apart from the 4WD control unit
and also shifts some parameters in a specified range.
Items (CONSULT-III screen
terms) Diagnostic item is detected when... Check item
CONTROLLER FAILURE
[C1201] Malfunction has occurred inside AWD control unit. TF-24, "
DTC C1201 CON-
TROLLER FAILURE"
ABS SYSTEM
[C1203]Malfunction related to wheel sensor
has been detected by ABS actu-
ator and electric unit (control unit). TF-24, "DTC C1203 ABS
SYSTEM"
4WD SOLENOID
[C1204]
Malfunction related to AWD solenoid has been detected.
TF-25, "DTC C1204 4WD
SOLENOID"
4WD ACTUATOR RLY
[C1205]Malfunction has been detected from AWD actuator relay integrated
with AWD control unit, or malfunction related to AWD solenoid has
been detected. TF-27, "
DTC C1205 4WD
ACTUATOR RLY" or
TF-25,
"DTC C1204 4WD SOLE-
NOID"
ENGINE SIGNAL 1
[C1210] Malfunction has been detected from ECM. TF-28, "DTC C1210 EN-
GINE SIGNAL 1"
CAN COMM CIRCUIT
[U1000]When AWD control unit is not transmitting or receiving CAN commu-
nication signal for 2 seconds or more. TF-28, "DTC U1000 CAN
COMM CIRCUIT"
NO DTC IS DETECTED.
FURTHER TESTING MAY BE
REQUIRED.
No NG item has been detected. —
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TROUBLE DIAGNOSISTF-23
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× : Standard : Not applicable
ACTIVE TEST MODE
Description
Use this mode to determine and identify the details of a malfunction based on self-diagnostic results or data
monitor. AWD control unit gives drive signal to actuat or with receiving command from CONSULT-III to check
operation of actuator.
Test Item
CAUTION:
Do not continuously energize for a long time.
Monitored item (Unit) Monitor Menu
Remarks
ECU INPUT
SIGNALS MAIN
SIGNALS
FR RH SENSOR [km/h] or [mph] ××Wheel speed calculated by front wheel sensor
RH signal is displayed.
FR LH SENSOR [km/h] or [mph] ××Wheel speed calculated by front wheel sensor LH
signal is displayed.
RR RH SENSOR [km/h] or [mph] ××Wheel speed calculated by rear wheel sensor RH
signal is displayed.
RR LH SENSOR [km/h] or [mph] ××Wheel speed calculated by rear wheel sensor LH
signal is displayed.
BATTERY VOLT [V] Power supply voltage for AWD control unit
THRTL POS SEN [%] Throttle opening status is displayed.
ETS SOLENOID [A] Monitored value of current at AWD solenoid
STOP LAMP SW [ON/OFF] Stop lamp switch signal status via CAN commu-
nication line is displayed.
ENG SPEED SIG [RUN/STOP] Eng ine status is displayed.
ETS ACTUATOR [ON/OFF] Operating condition of AWD actuator relay (inte-
grated in AWD control unit) is displayed.
4WD WARN LAMP [ON/OFF] Control status of AWD warning lamp is displayed.
4WD MODE SW [AUTO] AWD lock switch is not equipped, but displayed.
4WD MODE MON [AUTO] Control status of AWD is displayed.
DIS-TIRE MONI [mm] Improper size tire installed condition is displayed.
P BRAKE SW [ON/OFF] Parking switch signal status via CAN communi-
cation line is displayed.
Test item Condition Description
ETS S/V
(Detects AWD solenoid valve)  Vehicle stopped
 Engine running
 No DTC detected Change command current value to AWD solenoid, and then change driving
mode. (Monitor value is normal if it is within approximately ±10% of com-
mand value.)
Qu: Increase current value in increments of 0.20A
Qd: Decrease current value in increments of 0.20A
UP: Increase current value in increments of 0.02A
DOWN: Decrease current value in increments of 0.02A
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