INFINITI FX35 2005 Service Manual

TF-8
NOISE, VIBRATION AND HARSHNESS (NVH) TROUBLESHOOTING
Revision: 2005 July 2005 FX
NOISE, VIBRATION AND HARSHNESS (NVH) TROUBLESHOOTINGPFP:00003
NVH Troubleshooting ChartADS000RM
Use the chart below to help you find the cause of the symptom. The numbers indicate the order of the inspec-
tion. If necessary, repair or replace these parts.
Reference pageTF-9TF-45TF-45TF-51TF-51TF-51
SUSPECTED PARTS
(Possible cause)
TRANSFER FLUID (Level low)
TRANSFER FLUID (Wrong)
TRANSFER FLUID (Level too high)
LIQUID GASKET (Damaged)
OIL SEAL (Worn or damaged)
GEAR (Worn or damaged)
BEARING (Worn or damaged)
TRANSFER CASE (Damaged)
Symptom Noise 1 2 3 3 3
Transfer fluid leakage 4 1 2 2 3

TRANSFER FLUID TF-9
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TRANSFER FLUIDPFP:31001
ReplacementADS000RN
DRAINING
1. Run the vehicle to warm up the transfer unit sufficiently.
2. Stop the engine, and remove the drain plug to drain the transfer fluid.
3. Apply sealant to drain plug. Install drain plug on transfer and tighten to the specified torque. Refer to TF-45, "
COMPO-
NENTS" .

Use Genuine Silicone RTV or equivalent. Refer to GI-48,
"Recommended Chemical Products and Sealants" .
FILLING
1. Remove filler plug and add transfer fluid until fluid level reaches
the specified limit near filler plug mounting hole.
CAUTION:
Carefully fill the fluid. (Fill up for approx. 3 minutes.)
2. Leave the vehicle for 3 minutes, and check the fluid level again.
3. Set a new gasket onto filler plug and install it on transfer and tighten to the specified torque. Refer to TF-45, "
COMPO-
NENTS" .
CAUTION:
Do not reuse gasket.
InspectionADS000RO
FLUID LEAKAGE AND FLUID LEVEL
1. Check fluid level from filler plug mounting hole as shown in the figure.
2. Before installing filler plug, set a new gasket. Install filler plug on transfer and tighten to the specified torque. Refer to TF-45,
"COMPONENTS" .
CAUTION:
Do not reuse gasket.
SDIA2087E
Fluid capacity
: Approx. 1.25 (2-5/8 US pt, 2-1/4 lmp pt)
SDIA2028E
SDIA2028E

TF-10
AWD SYSTEM
Revision: 2005 July 2005 FX
AWD SYSTEMPFP:41650
Power Transfer DiagramADS000RV
System DescriptionADS000RW
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

AWD SYSTEM TF-11
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Revision: 2005 July 2005 FX
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

TF-12
AWD SYSTEM
Revision: 2005 July 2005 FX
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 DiagramADS000RX
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

AWD SYSTEM TF-13
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Revision: 2005 July 2005 FX
COMPONENTS FUNCTION DESCRIPTION
CAN CommunicationADS000RY
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.
For details, refer to LAN-30, "
CAN Communication Unit" .
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.

TF-14
TROUBLE DIAGNOSIS
Revision: 2005 July 2005 FX
TROUBLE DIAGNOSISPFP:00004
Fail-Safe FunctionADS000S1

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 DiagnosisADS000S2
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

TROUBLE DIAGNOSIS TF-15
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Revision: 2005 July 2005 FX
Location of Electrical PartsADS000ST
SDIA2272E

TF-16
TROUBLE DIAGNOSIS
Revision: 2005 July 2005 FX
Circuit DiagramADS000RZ
TDWM0015E

TROUBLE DIAGNOSIS TF-17
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Revision: 2005 July 2005 FX
Wiring Diagram — AWD —ADS000S0
TDWM0012E