2011 INFINITI QX56 4WD

BRC-120
< DTC/CIRCUIT DIAGNOSIS >[WITH VDC]
VDC OFF SWITCH
Is the inspection result normal?
YES >> GO TO 3.
NO >> Repair or replace error-detected parts.
3.CHECK VDC OFF SWITCH
Check VDC OFF switch. Refer to BRC-120, "
Component Inspection".
Is the inspection result normal?
YES >> GO TO 4.
NO >> Replace VDC OFF switch. Refer to BRC-140, "
Removal and Installation".
4.CHECK VDC OFF SWITCH SIGNAL
With CONSULT-III.
1. Connect ABS actuator and electric unit (control unit) harness connector.
2. Connect SNOW MODE / TOW MODE / VDC OFF switch assembly (2WD models) or 4WD switch assem-
bly (4WD models) harness connector.
3. Select “ABS”, “DATA MONITOR” and “OFF SW” accord ing to this order. Check VDC OFF switch signal.
Is the inspection result normal?
YES >> INSPECTION END
NO >> GO TO 5.
5.CHECK TERMINAL
 Check ABS actuator and electric unit (control unit) pin terminals for damage or loose connection with har-
ness connector.
 Check SNOW MODE / TOW MODE / VDC OFF switch assembly (2WD models) or 4WD switch assembly (4WD models) pin terminals for damage or loose connection with harness connector.
Is the inspection result normal?
YES >> Replace ABS actuator and electr ic unit (control unit). Refer to BRC-137, "Removal and Installa-
tion".
NO >> Repair or replace error-detected parts.
Component InspectionINFOID:0000000006222648
NOTE:
VDC OFF switch is integrated in SNOW MODE / TOW MODE / VDC OFF switch assembly (2WD models) or
4WD switch assembly (4WD models).
1.CHECK VDC OFF SWITCH
1. Turn the ignition switch OFF.
2. Disconnect SNOW MODE / TOW MODE / VDC OFF s witch assembly (2WD models) or 4WD switch
assembly (4WD models) harness connector.
3. Check continuity between terminals of SNOW MO DE / TOW MODE / VDC OFF switch assembly (2WD
models) or 4WD switch assembly (4WD models) connector.
Is the inspection result normal?
YES >> INSPECTION END
Condition DATA MONITOR
When VDC OFF switch is pressed and VDC OFF indicator
lamp in combination meter is in ON status On
When VDC OFF switch is pressed and VDC OFF indicator
lamp in combination meter is in OFF status Off
SNOW MODE / TOW MODE / VDC OFF
switch assembly (2WD models) or 4WD switch assembly (4WD models) Condition Continuity
Terminal
1 – 20 When VDC OFF switch is pressed Existed
When VDC OFF switch is not pressed Not existed
Revision: 2010 May2011 QX56

EXCESSIVE OPERATION FREQUENCYBRC-127
< SYMPTOM DIAGNOSIS > [WITH VDC]
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BRC
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SYMPTOM DIAGNOSIS
EXCESSIVE OPERATION FREQUENCY
DescriptionINFOID:0000000006222657
VDC function, TCS function, ABS functi on, EBD function, hill start assist function and brake limited slip differ-
ential (BLSD) function operates in excessive operation frequency.
Diagnosis ProcedureINFOID:0000000006222658
1.CHECK BRAKING FORCE
Check brake force using a brake tester.
Is the inspection result normal?
YES >> GO TO 2.
NO >> Check brake system.
2.CHECK FRONT AND REAR AXLE
Check that there is no excessive looseness in front and rear axle.
 Front axle: Refer to FA X - 7 , "
Inspection" (2WD), FAX-16, "Inspection" (4WD).
 Rear axle: Refer to RAX-5, "
Inspection"
Is the inspection result normal?
YES >> GO TO 3.
NO >> Repair or replace error-detected parts.
3.CHECK WHEEL SENSOR
Check wheel sensor.
 Check installation and damage of wheel sensor.
 Check connection of wheel sensor harness connector.
 Check terminal of wheel sensor harness connector.
Is the inspection result normal?
YES >> GO TO 4.
NO >> Repair or replace wheel sensor.  Front wheel sensor: Refer to BRC-134, "
FRONT WHEEL SENSOR : Removal and Installation".
 Rear wheel sensor: Refer to BRC-135, "
REAR WHEEL SENSOR : Removal and Installation".
4.CHECK WARNING LAMP TURNS OFF
Check that ABS warning lamp, brake warning lamp and VDC warning lamp turn OFF approx. 1 second after
key switch is turned ON and stay in OFF status during driving.
CAUTION:
Brake warning lamp turns ON when parking brake is operated (parking brake switch is ON) or brake
fluid is less than the specified level (brake fluid level switch is ON).
Is the inspection result normal?
YES >> Normal
NO >> Perform self-diagnosis for “ABS” with CONSULT-III.
Revision: 2010 May2011 QX56

BRC-128
< SYMPTOM DIAGNOSIS >[WITH VDC]
UNEXPECTED BRAKE PEDAL REACTION
UNEXPECTED BRAKE PEDAL REACTION
DescriptionINFOID:0000000006222659
A malfunction of brake pedal feel (height or ot
hers) is detected when brake pedal is depressed.
Diagnosis ProcedureINFOID:0000000006222660
1.CHECK FRONT AND REAR AXLE
Check that there is no excessive looseness in front and rear axle.
 Front axle: Refer to FAX-7, "
Inspection" (2WD), FAX-16, "Inspection" (4WD).
 Rear axle: Refer to RAX-5, "
Inspection"
Is the inspection result normal?
YES >> GO TO 2.
NO >> Repair or replace error-detected parts.
2.CHECK DISC ROTOR
Check disc rotor runout.
 Front: Refer to BR-16, "
DISC ROTOR : Inspection and Adjustment".
 Rear: Refer to BR-18, "
DISC ROTOR : Inspection and Adjustment".
Is the inspection result normal?
YES >> GO TO 3.
NO >> Refinish or replace disc rotor.  Front: Refer to BR-16, "
DISC ROTOR : Inspection and Adjustment".
 Rear: Refer to BR-18, "
DISC ROTOR : Inspection and Adjustment".
3.CHECK BRAKE FLUID LEACKAGE
Check fluid leakage.
 Front: Refer to BR-24, "
FRONT : Inspection".
 Rear: Refer to BR-26, "
REAR : Inspection".
Is the inspection result normal?
YES >> GO TO 4.
NO >> Repair or replace error-detected parts.
4.CHECK BRAKE PEDAL
Check each item of brake pedal. Refer to BR-7, "
Inspection and Adjustment".
Is the inspection result normal?
YES >> GO TO 5.
NO >> Adjust each item of brake pedal. Refer to BR-7, "
Inspection and Adjustment".
5.CHECK BRAKING FORCE
Check brake force using a brake tester.
Is the inspection result normal?
YES >> GO TO 6.
NO >> Check each components of brake system.
6.CHECK BRAKE PERFORMANCE
Disconnect ABS actuator and electric unit (control unit) connector so that ABS does not operate. Check that
brake force is normal in this condition. Connect harness connectors after checking.
Is the inspection result normal?
YES >> Normal
NO >> Check each components of brake system.
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

BRC-134
< REMOVAL AND INSTALLATION >[WITH VDC]
WHEEL SENSOR
REMOVAL AND INSTALLATION
WHEEL SENSOR
FRONT WHEEL SENSOR
FRONT WHEEL SENSOR : Exploded ViewINFOID:0000000006222670
CAUTION:
Replace wheel hub and bearing
assembly as an assembly when repl acing because wheel sensor can-
not be disassembled.
NOTE:
Front RH wheel sensor is symmetrically opposite of LH.
FRONT WHEEL SENSOR : Removal and InstallationINFOID:0000000006222671
CAUTION:
Replace wheel hub and bearing assembly as an assembly when repl acing because wheel sensor can-
not be disassembled.
REMOVAL
Remove wheel hub and bearing assembly. Refer to FA X - 8 , "Removal and Installation" (2WD), FAX-18,
"Removal and Installation" (4WD).
CAUTION:
Never twist or pull front wheel sensor harness.
INSTALLATION
Note the following, and install in the reverse order of the removal.
1. Front LH wheel sensor harness con-
nector 2. Front LH wheel sensor 3. Bracket
: Vehicle front
Refer to GI-4, "
Components" for symbols in the figure.
JPFIC0199GB
Revision: 2010 May2011 QX56

BRC-136
< REMOVAL AND INSTALLATION >[WITH VDC]
SENSOR ROTOR
SENSOR ROTOR
FRONT SENSOR ROTOR
FRONT SENSOR ROTOR : Re
moval and InstallationINFOID:0000000006222674
CAUTION:
Replace wheel hub and bearing assembly as an assem bly when replacing because sensor rotor can-
not be disassembled.
REMOVAL
Remove wheel hub and bearing assembly. Refer to FA X - 8 , "Removal and Installation" (2WD), FAX-18,
"Removal and Installation" (4WD).
INSTALLATION
Install wheel hub and bearing assembly. Refer to FA X - 8 , "Removal and Installation" (2WD), FAX-18, "Removal
and Installation" (4WD).
REAR SENSOR ROTOR
REAR SENSOR ROTOR : Removal and InstallationINFOID:0000000006222675
CAUTION:
Replace wheel hub and bearing assembly as an assem bly when replacing because sensor rotor can-
not be disassembled.
REMOVAL
Remove wheel hub and bearing assembly. Refer to RAX-7, "Removal and Installation".
INSTALLATION
Install wheel hub and bearing assembly. Refer to RAX-7, "Removal and Installation".
Revision: 2010 May2011 QX56

BRC-140
< REMOVAL AND INSTALLATION >[WITH VDC]
VDC OFF SWITCH
VDC OFF SWITCH
Removal and InstallationINFOID:0000000006222680
NOTE:
VDC OFF switch is integrated in SNOW MODE / TOW
MODE / VDC OFF switch assembly (2WD models) or
4WD switch assembly (4WD models).
REMOVAL
1. Remove console finisher assembly from center console assembly. Refer to IP-25, "Removal and Installa-
tion".
2. Disconnect SNOW MODE / TOW MODE / VDC OFF s witch assembly (2WD models) or 4WD switch
assembly (4WD models) harness connector.
3. Press SNOW MODE / TOW MODE / VDC OFF switch assembly (2WD models) or 4WD switch assembly
(4WD models) fixing pawls, and remove SNOW MODE / TOW MODE / VDC OFF switch assembly (2WD
models) or 4WD switch assembly (4WD models) from console finisher assembly.
INSTALLATION
Install in the reverse order of removal.
Revision: 2010 May2011 QX56

BRC-144
< SYSTEM DESCRIPTION >[BRAKE ASSIST (WITH PREVIEW FUNCTION)]
COMPONENT PARTS
NOTE:
Only IBA system uses
Combination meter
××××Performs the following operations using the signals received from
the ADAS control unit via the CAN communication
 Displays the ICC system operation status using the meter dis-
play signal
 Illuminates the ICC system warning lamp using the ICC warning
lamp signal
 Illuminates the IBA OFF indicator lamp using the IBA OFF indi- cator lamp signal
 Operates the buzzer (ICC warning chime) using the buzzer out- put signal
ICC steering switch ×× ICC steering switch allows the ON/OFF of the Intelligent Cruise
Control and the settings of a vehicle speed and distance be-
tween vehicles
 ICC steering switch signal is transmitted to ECM. ECM transmits the signal to the ADAS control unit via CAN communication
ICC brake switch ×××× ICC brake switch is turned OFF and stop lamp switch is turned
ON, when depressing the brake pedal
 ICC brake switch signal is input to ECM. These signals are transmitted from ECM to ADAS control unit via CAN communi-
cation
 Stop lamp switch signal is input to ECM and ABS actuator and electric unit (control unit). These signals are transmitted from
ECM and ABS actuator and electric unit (control unit) to ADAS
control unit via CAN communication
St op la mp sw i tc h
××××
ICC brake hold relay ××ICC brake hold relay activates the stop lamp by ICC brake hold re-
lay drive signal (stop lamp drive signal) outputted by the ADAS
control unit
Transfer control unit ××××Transfer control unit transmits a mode selection state of 4WD shift
switch to the ADAS control unit via CAN communication
IBA OFF switch ×
NoteIBA OFF switch signal is input to the ADAS control unit
Steering angle sensor ×Measures the rotation amount, rotation speed, and rotation direc-
tion of steering wheel, and then transmits them to ADAS control
unit via CAN communication
Component
Function
Description
Vehicle-to-vehicle distance control mode
Conventional (fixed speed) cruise control mode Intelligent Brake Assist (IBA)
Brake Assist (with preview function)
Revision: 2010 May2011 QX56