traction control INFINITI QX56 2011 Factory Service Manual

SYSTEMBRC-37
< SYSTEM DESCRIPTION > [WITH VDC]
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SYSTEM DIAGRAM
INPUT SIGNAL AND OUTPUT SIGNAL
Major signal transmission between each unit via communication lines is shown in the following table.
*: Communication line between yaw rate/side/decal G s ensor and ABS actuator and electric unit (control unit)
BRAKE LIMITED SLIP DIFFERENTIAL (BLSD) FUNCTION
BRAKE LIMITED SLIP DIFFERENTIAL (BLSD) FUNCTION : System Description
INFOID:0000000006222577
 LH and RH driving wheel spin is always monitored. If necessary, appropriate brake force is independently
applied to LH or RH driving wheel so that one-sided wheel spin is avoided and traction is maintained. Mainly
starting ability is improved.
JPFIC0145GB
Component Signal description
Yaw rate/side/decel G sensor Mainly transmits the following signals to ABS actuator and electric unit (control unit) via com-
munication line *.
 Yaw rate signal
 Side G sensor signal
 Decel G sensor signal
ECM Mainly transmits the following signals to ABS actuator and electric unit (control unit) via CAN
communication.
 Accelerator pedal position signal
 Engine speed signal
Mainly receives the following signals from ABS actuator and electric unit (control unit) via CAN
communication.
 Target throttle position signal
TCM Mainly transmits the following signals to ABS actuator and electric unit (control unit) via CAN
communication.
 Shift position signal
Combination meter Mainly receives the following signals from ABS actuator and electric unit (control unit) via CAN
communication.
 VDC warning lamp signal
 VDC OFF indicator lamp signal
Revision: 2010 May2011 QX56

NORMAL OPERATING CONDITIONBRC-133
< SYMPTOM DIAGNOSIS > [WITH VDC]
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NORMAL OPERATING CONDITION
DescriptionINFOID:0000000006222669
Symptom Result
Brake pedal slightly vibrates and operation sound (motor sound and sound from suspen-
sion) occurs when VDC function, TCS function, ABS function, EBD function, hill start assist
function and brake limited slip differential (BLSD) function operates. This is not a malfunction, The symptom
occurs VDC function
, TCS function, ABS
function, EBD function, hill start assist
function and brake limited slip differential
(BLSD) function that are normally operat-
ed.
Brake stopping distance may become longer than models without ABS function depending
on the road conditions, when
ABS function is operated on slip pery road like rough road,
gravel road or snowy road.
Brake pedal vibrates and operation sound occurs during sudden acceleration and corner-
ing, when VDC function, TCS function, hill start assist function and brake limited slip differ-
ential (BLSD) function is operated.
Brake pedal vibrates and motor sound from the engine room occurs, when the engine starts
or the vehicle starts just after starting the engine This is not a malfunction. The symptom
occurs during the brake fluid accumula-
tion in the accumulator and operational
check of the ABS actuator and electric
unit (control unit).
Acceleration may be felt insufficient depending on the road conditions. This is not a malfunction. The symptom occurs TCS function that puts the highest
priority to obtain the optimum traction
(stability).
TCS may operate momentarily, while driving on a road where friction coefficient varies, or
when downshifting or fully depressing accelerator pedal
ABS warning lamp and VDC warning lamp may turn ON, when the vehicle is on a rotating
turntable or is given a strong shaking or large vibrations on a ship while the engine is run-
ning.
In this case, restart the engine on a nor-
mal road. If the normal condition is re-
stored, there is no malfunction. In that
case, erase self-diagnosis result memory
for “ABS” with CONSULT-III.
VDC warning lamp may turn ON and VDC function, TCS function, hill start assist function
and brake limited slip differential (BLSD) function may not normally operate, when driving
on a special road the is extremely slanted (bank in a circuit course).
A malfunction in yaw rate/side/decel G sensor system may be detected when the vehicle
sharply turns during a spin turn, acceleration turn or drift driving while VDC function and
TCS function are OFF (VDC OFF switch is pressed and VDC OFF indicator lamp is in ON
status).
The vehicle speed does not increase, when the accelerator pedal is depressed while the
vehicle is on a 2-wheel chassis dynamometer for speedometer check.
This is not malfunction. (When checking
the vehicle on a chassis dynamometer,
operate VDC OFF switch so that TCS
function is OFF.)
The VDC warning lamp, ABS warn ing lamp and brake warning lamp turn ON and DTC
“C118E” may be detected in self-diagnosis resu lt of “ABS” when the brake pedal is exces-
sively operated, such as air bleeding. This is not a system malfunction because
this occurs due to the temporary de-
crease in accumulator fluid pressure. The
system returns to no
rmal condition when
the accumulator fluid pressure reaches
the specified pressure with the ignition
switch ON and the VDC warning lamp,
ABS warning lamp, a nd brake warning
lamp turn OFF. After these steps, ABS
self-diagnosis results are erased.
VDC OFF indicator lamp turns ON and TCS function is not operate when 4WD mode is “4L”.
(Models with 4WD system) This is not a malfunction. When the 4WD
mode becomes “4L” state, the TCS func-
tion is disabled. This function is enabled
when the 4WD mode becomes “AUTO”
or “4H”.
Revision: 2010 May2011 QX56

COMPONENT PARTSDLN-11
< SYSTEM DESCRIPTION > [TRANSFER: ATX90A]
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Component DescriptionINFOID:0000000006222215
Transfer Control UnitINFOID:0000000006222216
 Transfer control unit operates transfer control act uator, 4WD warning lamp and 4WD mode indicator lamp
according to input signal from 4WD shift switch and each sensor and control unit.
 When 4WD system is malfunctioning, 4WD warning la mp turns ON and fail-safe status activates.
 When protection is necessary, 4WD warning la mp blinks and protection status activates.
Transfer Control ActuatorINFOID:0000000006222217
Transfer control actuator integrates transfer motor, transfer internal position sensor, and transfer motor tem-
perature sensor, and switches 4WD mode (AUTO ⇔4H ⇔4L).
TRANSFER MOTOR
Transfer motor operates according to signal from transfer control unit and switches 4WD mode
(AUTO ⇔4H ⇔4L). It also performs front and rear distri bution of traction force during AUTO mode.
TRANSFER INTERNAL SPEED SENSOR
Transfer internal speed sensor detects rotation status of transfer motor and transmits signal to transfer control
unit.
TRANSFER MOTOR TEMPERATURE SENSOR
 Transfer motor temperature sensor m easures temperature of transfer motor.
Component parts Reference/Function
Transfer control unit DLN-11, "
Transfer Control Unit"
Transfer control actua-
torTransfer motor
DLN-11, "
Transfer Control Actuator"
Transfer internal speed
sensorDLN-11, "Transfer Control Actuator"
Transfer motor temper-
ature sensor
DLN-11, "Transfer Control Actuator"
Transfer Hi-Lo position sensor
DLN-12, "Transfer Hi-Lo Position Sensor"
Transfer rotary position sensorDLN-12, "Transfer Rotary Position Sensor"
Transfer lock position sensorDLN-12, "Transfer Lock Position Sensor"
Transfer fluid temperature sensorDLN-12, "Transfer Fluid Temperature Sensor"
4WD mode switchDLN-18, "4WD SYSTEM : System Description"
4WD indicator lampDLN-18, "4WD SYSTEM : System Description"
4WD warning lampDLN-18, "4WD SYSTEM : System Description"
AT P w a r n i n g l a m pDLN-18, "4WD SYSTEM : System Description"
ABS actuator and electric unit (control unit)Transmits the following signals via CAN communication line to transfer control unit.
 Vehicle speed signal (ABS)
 Stop lamp switch signal (brake signal)
 ABS operation signal
 VDC operation signal
 TCS operation signal
Steering angle sensor Transmits the following signals via CAN communication line to transfer control unit.
 Steering angle sensor signal
ECM Transmits the following signals via CAN communication line to transfer control unit.
 Accelerator pedal position signal
 Engine speed signal
 Engine torque signal
TCM Transmits the following signals via CAN communication line to transfer control unit.
 Shift position signal
 Gear position signal
 Output shaft revolution signal
Revision: 2010 May2011 QX56

DLN-16
< SYSTEM DESCRIPTION >[TRANSFER: ATX90A]
STRUCTURE AND OPERATION
1. Transfer control unit supplies command current to transfer motor.
2. Transfer motor operates and actuator shaft rotates clockwise.
3. Shift fork operates according to rotation of actuator shaft. Sun gear and Hi-Lo sleeve are engaged.
4. Ball ramp lever operates in axial direction via cam fixed on actuator shaft according to traction torque of
transfer motor, presses piston, and thrusts multiple plate clutch.
5. Torque is transmitted to front wheels according to thrusting pressure of multiple plate clutch. NOTE:
Torque transmitted to the front wheel is determined according to the command current.
4L MODE
1. Main shaft 2. Ball lamp lever 3. Piston
4. Clutch 5. Hi-Lo sleeve 6. Sun gear
7. Shift fork 8. Actuator shaft 9. Transfer control actuator
JPDIE0278GB
Revision: 2010 May2011 QX56

DLN-18
< SYSTEM DESCRIPTION >[TRANSFER: ATX90A]
SYSTEM
SYSTEM
4WD SYSTEM
4WD SYSTEM : System DescriptionINFOID:0000000006222224
 In AUTO mode, distribution of traction force is cont
rolled from 2WD status (0:100) to 4WD status (50:50)
according to signal from each sensor and switch.
 In accordance with fail-safe function, when system is malfunctioning, 4WD warning lamp on combination meter turns ON and 4WD control stops. For fail-safe function, refer to DLN-20, "
4WD SYSTEM : Fail-Safe".
 When a high load status continues for transfer assembly (transfer control actuator or transfer fluid), 4WD
control temporarily becomes 4H or 2WD status, according to protection function.
NOTE:
4WD system is not malfunctioning.
SYSTEM DIAGRAM
INPUT/OUTPUT SIGNAL
It transmits/receives each signal from the followi ng transfer control unit via CAN communication line.
JPDIE0272GB
Component parts Control signal
ABS actuator and electric unit (control unit) Transmits the following signals via CAN communication line to transfer control unit.
 Vehicle spee
d signal (ABS)
 Stop lamp switch signal (brake signal)
 ABS operation signal
 VDC operation signal
 TCS operation signal
ECM Transmits the following signals via CAN communication line to transfer control unit.
 Accelerator pedal position signal
 Engine speed signal
 Engine torque signal
Revision: 2010 May2011 QX56

ABBREVIATIONSGI-17
< HOW TO USE THIS MANUAL >
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ABBREVIATION DESCRIPTION P/S Power steering
PBR Potentio balance resistor
PCV Positive crankcase ventilation
PNP Park/Neutral position PSP Power steering pressurePTC Positive temperature coefficient
PTO Power takeoff
PWM Pulse width modulation
ABBREVIATION DESCRIPTION RAM Random access memoryRAS Rear active steer RH Right-hand
ROM Read only memory RPM Engine speed RR Rear
ABBREVIATION DESCRIPTION SAE Society of Automoti ve Engineers, Inc.
SCK Serial clock
SDS Service Data and Specifications SRT System readiness testSST Special Service Tools
ABBREVIATION DESCRIPTION TC Turbocharger
TCM Transmission control module TCS Traction control system TP Throttle position
TPMS Tire pressure monitoring system TSS Turbine shaft speed
TWC Three way catalytic converter
ABBREVIATION DESCRIPTION VDC Vehicle dynamics control systemVIN Vehicle identification number
VSS Vehicle speed sensor
ABBREVIATION DESCRIPTION WOT Wide open throttle
ABBREVIATION DESCRIPTION 1
11st range first gear
Revision: 2010 May2011 QX56