2011 INFINITI QX56 brakes

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QUICK REFERENCE INDEX
AGENERAL INFORMATIONGIGeneral Information
BENGINEEMEngine Mechanical
LUEngine Lubrication System
COEngine Cooling System
ECEngine Control System
FLFuel System
EXExhaust System
STRStarting System
ACCAccelerator Control System
CHYBRIDHBCHybrid Control System
HBBHybrid Battery System
HBRHybrid Brake System
DTRANSMISSION & DRIVE-
LINECLClutch
TMTransaxle & Transmission
DLNDriveline
FAXFront Axle
RAXRear Axle
ESUSPENSIONFSUFront Suspension
RSURear Suspension
SCSSuspension Control System
WTRoad Wheels & Tires
FBRAKESBRBrake System
PBParking Brake System
BRCBrake Control System
GSTEERINGSTSteering System
STCSteering Control System
HRESTRAINTSSBSeat Belt
SBCSeat Belt Control System
SRSRS Airbag
SRCSRS Airbag Control System
IVENTILATION, HEATER &
AIR CONDITIONERVTLVentilation System
HAHeater & Air Conditioning System
HACHeater & Air Conditioning Control System
JBODY INTERIORINTInterior
IPInstrument Panel
SESeat
ADPAutomatic Drive Positioner
KBODY EXTERIOR,
DOORS, ROOF & VEHICLE
SECURITYDLKDoor & Lock
SECSecurity Control System
GWGlass & Window System
PWCPower Window Control System
RFRoof
HDHood
EXTExterior
BRMBody Repair
LDRIVER CONTROLSMIRMirrors
EXLExterior Lighting System
INLInterior Lighting System
WWWiper & Washer
DEFDefogger
HRNHorn
MELECTRICAL & POWER
CONTROLPWOPower Outlet
BCSBody Control System
LANLAN System
PCSPower Control System
CHGCharging System
PGPower Supply, Ground & Circuit Elements
NDRIVER INFORMATION &
MULTIMEDIAMWIMeter, Warning Lamp & Indicator
WCSWarning Chime System
SNSonar System
AVAudio, Visual & Navigation System
OCRUISE CONTROL &
DRIVER ASSISTANCECCSCruise Control System
DASDriver Assistance System
DMSDrive Mode System
PMAINTENANCEMAMaintenance
All rights reserved. No part
of this Service Manual may
be reproduced or stored in a
retrieval system, or transmit-
ted in any form, or by any
means, electronic, mechani-
cal, recording or otherwise,
without the prior written per-
mission of NISSAN MOTOR
CO., LTD.
Edition: May 2010
Publication No. SM1E-1Z62U0

BR-1
BRAKES
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CONTENTS
BRAKE SYSTEM
PRECAUTION ................ ...............................3
PRECAUTIONS .............................................. .....3
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" ............................................................. ......
3
Precaution Necessary for Steering Wheel Rota-
tion after Battery Disconnect .....................................
3
Precaution for Procedure without Cowl Top Cover ......4
Precaution for Brake system .....................................4
PREPARATION ............................................5
PREPARATION .............................................. .....5
Commercial Service Tools .................................. ......5
SYMPTOM DIAGNOSIS ...............................6
NOISE, VIBRATION AND HARSHNESS
(NVH) TROUBLESHOOTING ........................ .....
6
NVH Troubleshooting Chart ................................ ......6
PERIODIC MAINTENANCE ..........................7
BRAKE PEDAL .............................................. .....7
Inspection and Adjustment .................................. ......7
BRAKE FLUID ....................................................10
Inspection ............................................................ ....10
Draining ...................................................................10
Refilling ...................................................................11
Bleeding Brake System ...........................................11
HYDRAULIC BOOSTER ASSEMBLY ...............15
Inspection ............................................................ ....15
FRONT DISC BRAKE .................................... ....16
BRAKE PAD .......................................................... ....16
BRAKE PAD : Inspection and Adjustment ..............16
DISC ROTOR ......................................................... ....16
DISC ROTOR : Inspection and Adjustment ............16
REAR DISC BRAKE .........................................18
BRAKE PAD .......................................................... ....18
BRAKE PAD : Inspection and Adjustment ...............18
DISC ROTOR ......................................................... ....18
DISC ROTOR : Inspection and Adjustment .............18
REMOVAL AND INSTALLATION ...............20
BRAKE PEDAL ................................ .................20
Exploded View ..................................................... ....20
Removal and Installation .........................................20
Inspection and Adjustment ......................................21
BRAKE PIPING ................................ .................22
FRONT ................................................................... ....22
FRONT : Exploded View .........................................22
FRONT : Hydraulic Piping .......................................23
FRONT : Removal and Installation ..........................23
FRONT : Inspection .................................................24
REAR ..................................................................... ....24
REAR : Exploded View ............................................25
REAR : Hydraulic Piping ..........................................25
REAR : Removal and Installation ............................26
REAR : Inspection ...................................................26
HYDRAULIC BOOSTER ASSEMBLY ..............28
Exploded View .........................................................28
Removal and Installation .........................................29
Disassembly and Assembly .....................................30
Inspection and Adjustment ......................................32
Disposal ...................................................................33
FRONT DISC BRAKE .......................................34
BRAKE PAD .......................................................... ....34
BRAKE PAD : Exploded View .................................34
BRAKE PAD : Removal and Installation ..................34
BRAKE PAD : Inspection . ........................................36
Revision: 2010 May2011 QX56

BRC-1
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CONTENTS
BRAKE CONTROL SYSTEM
WITH VDC
PRECAUTION ................ ...............................
5
PRECAUTIONS .............................................. .....5
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" ............................................................. ......
5
Precaution Necessary for Steering Wheel Rota-
tion after Battery Disconnect .....................................
5
Precaution for Procedure without Cowl Top Cover ......6
Precaution for Brake System ....................................6
Precaution for Brake Control System ........................6
Precaution for Harness Repair ..................................7
PREPARATION ............................................9
PREPARATION .............................................. .....9
Commercial Service Tools .................................. ......9
SYSTEM DESCRIPTION .............................10
COMPONENT PARTS ................................... ....10
Component Parts Location .................................. ....10
Component Description ...........................................13
ABS Actuator and Electric Unit (Control Unit) .........14
Wheel Sensor and Sensor Rotor ............................14
Stop Lamp Switch ...................................................15
Steering Angle Sensor ............................................15
Yaw Rate/Side/Decel G sensor ...............................15
Brake Fluid Level Switch .........................................15
Parking Brake Switch ..............................................15
VDC OFF Switch .....................................................15
SYSTEM .............................................................16
System Description ............................................. ....16
Fail-safe ..................................................................25
Protection Function .................................................28
VDC FUNCTION .................................................... ....28
VDC FUNCTION : System Description ...................28
TCS FUNCTION ..................................................... ....31
TCS FUNCTION : System Description ....................31
ABS FUNCTION .................................................... ....32
ABS FUNCTION : System Description ....................33
EBD FUNCTION .................................................... ....34
EBD FUNCTION : System Description ....................34
HILL START ASSIST FUNCTION ......................... ....36
hill start assist FUNCTION : System Description ....36
BRAKE LIMITED SLIP DIFFERENTIAL (BLSD)
FUNCTION ............................................................. ....
37
BRAKE LIMITED SLIP DIFFERENTIAL (BLSD)
FUNCTION : System Description ............................
37
DIAGNOSIS SYSTEM [ABS ACTUATOR
AND ELECTRIC UNIT (CONTROL UNIT)] .......
40
CONSULT-III Function ............................................40
ECU DIAGNOSIS INFORMATION ..............45
ABS ACTUATOR AND ELECTRIC UNIT
(CONTROL UNIT) .............................................
45
Reference Value .................................................. ....45
Fail-safe ...................................................................47
Protection Function ..................................................50
DTC Inspection Priority Chart ..................................50
DTC Index ...............................................................51
WIRING DIAGRAM ......................................53
BRAKE CONTROL SYSTEM ...........................53
Wiring Diagram .................................................... ....53
BASIC INSPECTION ...................................60
DIAGNOSIS AND REPAIR WORK FLOW .......60
Work Flow ............................................................ ....60
Diagnostic Work Sheet ............................................61
Revision: 2010 May2011 QX56

BRC-6
< PRECAUTION >[WITH VDC]
PRECAUTIONS
5. When the repair work is completed, re-connect bot
h battery cables. With the brake pedal released, turn
the push-button ignition switch from ACC position to ON position, then to LOCK position. (The steering
wheel will lock when the push-button igniti on switch is turned to LOCK position.)
6. Perform self-diagnosis check of all control units using CONSULT-III.
Precaution for Procedure without Cowl Top CoverINFOID:0000000006228176
When performing the procedure after removing cowl top cover, cover
the lower end of windshield with urethane, etc.
Precaution for Brake SystemINFOID:0000000006222556
WARNING:
Clean any dust from the front brake and rear brake using a vacuum dust collector. Never blow by com-
pressed air.
 Brake fluid use refer to MA-10, "
Fluids and Lubricants".
 Never reuse drained brake fluid.
 Never spill or splash brake fluid on painted surfaces. Brake fluid may seriously damage paint. Wipe it off
immediately and wash with water if it gets on a painted surface.
 Always confirm the specified tightening torque when installing the brake pipes.
 After pressing the brake pedal more deeply or harder t han normal driving, such as air bleeding, check each
item of brake pedal. Adjust brake pedal if it is outside the standard value.
 Never use mineral oils such as gasoline or light oil to clean. They may damage rubber parts and cause
improper operation.
 Always loosen the brake tube flar e nut with a flare nut wrench.
 Tighten the brake tube flare nut to the specified torque with a crow-
foot (A) and torque wrench (B).
 Always connect the battery terminal when moving the vehicle.
 Turn the ignition switch OFF and disconnect the ABS actuator and
electric unit (control unit) harness connector or the battery negative
terminal before performing the work.
 Check that no brake fluid leakage is present after replacing the parts.
Precaution for Brak e Control SystemINFOID:0000000006222557
 Slight vibrations are felt on the brake pedal and the operation noises occur, when VDC function, TCS func-
tion, ABS function, EBD function, hill start assist function or brake limited slip differential (BLSD) function
operates. This is not a malfunction because it is caus ed by VDC function, TCS function, ABS function, EBD
function, hill start assist function or brake limited sl ip differential (BLSD) function that is normally operated.
 When starting engine or when starting vehicle just after starting engine, brake pedal may vibrate or motor
operating noise may be heard from engine compartment. This is normal condition.
 Brake stopping distance may become longer than models without ABS function depending on the road con-
ditions, when ABS function is operated on slippery r oad like rough road, gravel road or snowy road.
 When a malfunction is indicated, always collect info rmation from the customer about conditions of occur-
rence, estimate cause and perform operation. Check brake booster operation, brake fluid level and brake
fluid leakage, as well as electrical system.
 The optimum performance is achieved by control for V DC function, TCS function, ABS function, EBD func-
tion, hill start assist function or brake limited slip di fferential (BLSD) function when all of brakes, suspensions
PIIB3706J
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Revision: 2010 May2011 QX56

SYSTEMBRC-21
< SYSTEM DESCRIPTION > [WITH VDC]
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 Being returned to reservoir tank through ABS OUT valve, fluid pressure of rear LH caliper is decreased.
VDC is Operation (When Pressure Increases)
NOTE:
Control pressure sensor is applied to models with Advanced Driver Assistance System.
Example: When other than rear LH wheel is operation in the figure.
Front RH caliper Pressurized brake fluid from accumulator is supplied to front RH caliper through suction valve 2, suction
valve 1 and ABS IN valve. When not increases, ABS IN valve is closed and brakes fluid is not supplied to
front RH caliper.
Front LH caliper
 Pressurized brake fluid from accumulator is supplied to front LH caliper through suction valve 2, suction
valve 1 and ABS IN valve. When not increases, ABS IN valve is closed and brakes fluid is not supplied to
front LH caliper.
Rear RH caliper
Name Not activated When Pressure Increases
Cut valve 1 Power supply is not supplied (open) Power supply is supplied (close)
Cut valve 2 Power supply is not supplied (open) Power supply is supplied (close)
Suction valve 1 Power supply is not supplied (close) Power supply is supplied (open)
Suction valve 2 Power supply is not supplied (close) Power supply is supplied (open)
ABS IN valve Power supply is not supplied (open) Only wheel that the pressure is to be in-
creased: Power supply is not supplied (open)
Wheel other than the one that the pressure
is to be increased: Power supply is supplied (close)
ABS OUT valve Power supp ly is not supplied (close) Power supply is not supplied (close)
Each caliper (fluid pressure) — Pressure increases (only wheel that the
pressure is to be increased)
JPFIC0154GB
Revision: 2010 May2011 QX56

BRC-22
< SYSTEM DESCRIPTION >[WITH VDC]
SYSTEM
 Pressurized brake fluid from accumulator is supplied to rear RH caliper through suction valve 2 and ABS IN
valve. When not increases, ABS IN valve is closed and brakes fluid is not supplied to rear RH caliper.
Rear LH caliper Pressurized brake fluid from accumulator is supplied to rear LH caliper through suction valve 2 and ABS IN
valve. When not increases, ABS IN va lve is closed and brakes fluid is not supplied to rear LH caliper.
VDC is Operation (When Pressure Holds)
NOTE:
Control pressure sensor is applied to m odels with Advanced Driver Assistance System.
Example: When other than front LH wheel is operation in the figure.
Front RH caliper ABS IN valve is close, fluid pressure of front RH caliper is holds.
Front LH caliper
 ABS IN valve is close, fluid pressure of front LH caliper is holds.
Rear RH caliper
 ABS IN valve is close, fluid pressure of rear RH caliper is holds.
Name Not activated When Pressure holds
Cut valve 1 Power supply is not supplied (open) Power supply is supplied (close)
Cut valve 2 Power supply is not supplied (open) Power supply is supplied (close)
Suction valve 1 Power supply is not supplied (close) Power supply is supplied (open)
Suction valve 2 Power supply is not supplied (close) Power supply is supplied (open)
ABS IN valve Power supply is not supplied (open) Only wheel that the pressure is to be holds:
Power supply is supplied (close)
Wheel other than the one that the pressure
is to be holds: Power supply is not supplied (open)
ABS OUT valve Power supply is not supplied (close) Power supply is not supplied (close)
Each caliper (f luid pressure) — Pressure holds (only wheel that the pres-
sure is to be holds)
JPFIC0180GB
Revision: 2010 May2011 QX56

BRC-152
< SYSTEM DESCRIPTION >[INTELLIGENT BRAKE ASSIST]
SYSTEM
SYSTEM
INTELLIGENT BRAKE ASSIST
INTELLIGENT BRAKE ASSIST : System DescriptionINFOID:0000000006228299
FUNCTION DESCRIPTION
Intelligent Brake Assist (IBA) syst
em warns the driver by a vehicle ahead detection indicator and chime when
there is a risk of a collision with the vehicle ahead in the traveling lane and the driver must take avoidance
action immediately. The system helps reduce the rear -end collision speed by applying the brakes when it
judges a collision can not be avoided.
CAUTION:
The IBA system is a not collision avoidance system. It is the driver ′s responsibility to stay alert, drive
safely and be in control of the vehicle at all times. As there is a performance limit, it may not provide a
warning or brake in certain conditions.
NOTE:
 The IBA system shares component parts and diagnosis wi th the Intelligent Cruise Control (ICC) system.
New parts added to the IBA system is the IBA OFF indica tor lamp in the combination meter and the IBA OFF
switch on the instrument driver lower panel.
 The ICC sensor integrated unit shares the parts with the ICC, but the IBA system will operate even when the
ICC system is turned to OFF.
OPERATION DESCRIPTION
The IBA system uses an ICC sensor located below t he front bumper to measure the distance to a vehicle
ahead. When the system judges that the distance gets shorter, the vehicle ahead detection indicator on the
combination meter blinks and the warning chime sounds.
To turn the system OFF/ON, push and hold the IBA OFF switch after starting the engine for more than 1 sec-
ond.
NOTE:
 The system ON/OFF condition will be memorized even if the ignition switch turns OFF.
 The IBA system operates under the following conditions.
- The IBA system will function when the vehicle is driv en at speeds of approximately 15 km/h (10 MPH) and
above, and when the vehicle ′s speed is approximately 15 km/h (10 MPH) faster than that of the vehicle
ahead.
Switch and Indicators
Temporary unavailable indication
1. IBA OFF switch 2. Vehicle ahead detection indicator 3. IBA OFF indicator lamp
A. Under side of Instrument lower panel
(LH) B. On the combination meter
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CCS
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< SYSTEM DESCRIPTION > [ICC]
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With ICC system, the driver can maintain the same speed as other vehicles without the constant need to
adjust the set speed as driver would with a normal cruise control system.
The following items are controlled in the vehicle-to-vehicle distance control mode
 When there are no vehicles traveling ahead, the vehi cle-to-vehicle distance control mode maintains the
speed set by the driver. The set speed range is between approximately 32 and 144 km/h (20 and 90 MPH).
 When there is a vehicle traveling ahead, the vehicle- to-vehicle distance control mode adjusts the speed to
maintain the distance, selected by driver, from a vehicle ahead. The adjusting speed range is up to the set
speed.
 When the vehicle traveling ahead has moved out from its lane of travel, the vehicle-to-vehicle distance con-
trol mode accelerates and maintains vehicle speed up to the set speed.
CAUTION:
If the vehicle ahead comes to stop, the vehicle decel erates to a standstill within the limitations of the
system. The system will cancel once it judges that the vehicle has come to a standstill and sound a
warning chime.
To prevent the vehicle from moving, th e driver must depress the brake pedal.
NOTE:
When the accelerator pedal is depressed, the brake oper ation and the warning are not performed by the ICC
system.
OPERATION DESCRIPTION
Quickly push (less than 1.5 seconds) and release the MAIN switch ON.
The MAIN switch indicator, set distance indicator, own vehicle indicator, and set vehicle speed indicator come
on and ICC system is set to a standby state.
ADAS control unit performs the control as per the following:
Set Condition
Under a standby state, pushing down the SET/ COAST switch will start system control.
 When vehicle speed is between approximately 32 km/h and 144 km/h (20 MPH and 90 MPH).
 When vehicle speed is below approximately 32 km/h ( 20 MPH) if the vehicle ahead is detected. The set
vehicle speed becomes 32 km/h (20 MPH).
If the system is canceled by conditi ons 1-6 below, the system will resume c ontrol at the last set cruising speed
by pushing up the RESUME/ACCELERATE switch.
NOTE:
 When the SET/COAST switch is pushed under the following condi- tions, the system cannot be set and the set vehicle speed indicator
will blink for approximately 2 seconds.
- When traveling below 32 km/h (20 MPH) and the vehicle ahead is not detected.
- When the selector lever is not in the “D” position or manual mode.
- When the front wipers are operating at HI.
(If the vehicle is equipped with a rain sensing auto-wiper, the sys-
tem may cancel when the wipers are set to AUTO)
- When the parking brakes are applied.
- When the brakes are operated by the driver.
Constant
speed Comparing the set vehicle speed with the current vehicle speed, transmit the command to ECM via CAN communication
to reach the set vehicle speed, and controls the electric throttle control actuator
Decelera-
tion When a vehicle ahead (slower than driver set vehicle speed) appears or when a vehicle ahead slows down, the system
controls the electric throttle control actuator into the close direction and decelerates the vehicle. If greater deceleration
is necessary, the system
transmits the brake fluid pressure control signal to the ABS actuator and electric unit (control
unit) via CAN communication and operates the brake
Following The system controls the electric throttle control actuator and the brake fluid pressure to keep the proper distance between
the vehicles according to the vehicle speed change of the vehicle ahead
Accelera-
tion When a vehicle ahead is not detected because of it changes lanes or own vehicle changes lanes during the following
driving, the system controls the electric throttle control actu
ator in the open direction and accelerates the vehicle to the
set vehicle speed slowly
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Revision: 2010 May2011 QX56