2011 INFINITI QX56 service

BR-1
BRAKES
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SECTION BR
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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

BR-2
BRAKE CALIPER ASSEMBLY ................................36
BRAKE CALIPER ASSEMBLY : Exploded View ....36
BRAKE CALIPER ASSEMBLY : Removal and In-
stallation .................................................................
37
BRAKE CALIPER ASSEMBLY : Disassembly and
Assembly ................................................................
38
BRAKE CALIPER ASSEMBLY : Inspection ...........39
REAR DISC BRAKE ..........................................41
BRAKE PAD .......................................................... ...41
BRAKE PAD : Exploded View ................................41
BRAKE PAD : Removal and Installation .................41
BRAKE PAD : Inspection ........................................42
BRAKE CALIPER ASSEMBLY ............................. ...42
BRAKE CALIPER ASSEMBLY : Exploded View ....42
BRAKE CALIPER ASSEMBLY : Removal and In-
stallation ............................................................... ...
43
BRAKE CALIPER ASSEMBLY : Disassembly and
Assembly ................................................................
44
BRAKE CALIPER ASSEMBLY : Inspection ............45
SERVICE DATA AND SPECIFICATIONS
(SDS) .......... ................................................
47
SERVICE DATA AND SPECIFICATIONS
(SDS) .............................................................. ...
47
General Specification ........................................... ...47
Brake Pedal ............................................................47
Brake Booster .........................................................47
Front Disc Brake .....................................................47
Rear Disc Brake ......................................................47
Revision: 2010 May2011 QX56

PRECAUTIONSBR-3
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PRECAUTION
PRECAUTIONS
Precaution for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000006228171
The Supplemental Restraint System such as “A IR BAG” and “SEAT BELT PRE-TENSIONER”, used along
with a front seat belt, helps to reduce the risk or severi ty of injury to the driver and front passenger for certain
types of collision. This system includes seat belt switch inputs and dual stage front air bag modules. The SRS
system uses the seat belt switches to determine the front air bag deployment, and may only deploy one front
air bag, depending on the severity of a collision and whether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the “SRS AIR BAG” and “SEAT BELT” of this
Service Manual.
WARNING:
• To avoid rendering the SRS inoper ative, which could increase the risk of personal injury or death in
the event of a collision that would result in air ba g inflation, all maintenance must be performed by
an authorized NISSAN/INFINITI dealer.
 Improper maintenance, including in correct removal and installation of the SRS, can lead to personal
injury caused by unintentional act ivation of the system. For removal of Spiral Cable and Air Bag
Module, see the “SRS AIR BAG”.
 Do not use electrical test equipm ent on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harnesses can be identi fied by yellow and/or orange harnesses or har-
ness connectors.
PRECAUTIONS WHEN USING POWER TOOLS (AIR OR ELECTRIC) AND HAMMERS
WARNING:
 When working near the Air Bag Diagnosis Sensor Unit or other Air Bag System sensors with the
ignition ON or engine running, DO NOT use air or electric power tools or strike near the sensor(s)
with a hammer. Heavy vibration could activate the sensor(s) and deploy the air bag(s), possibly
causing serious injury.
 When using air or electric power tools or hammers , always switch the ignition OFF, disconnect the
battery, and wait at least 3 minutes before performing any service.
Precaution Necessary for Steering Wh eel Rotation after Battery Disconnect
INFOID:0000000006228172
NOTE:
 Before removing and installing any control units, first tu rn the push-button ignition switch to the LOCK posi-
tion, then disconnect both battery cables.
 After finishing work, confirm that all control unit connectors are connected properly, then re-connect both
battery cables.
 Always use CONSULT-III to perform self-diagnosis as a part of each function inspection after finishing work.
If a DTC is detected, perform trouble diagnos is according to self-diagnosis results.
For vehicle with steering lock unit, if the battery is disconnected or discharged, the steering wheel will lock and
cannot be turned.
If turning the steering wheel is required with the batte ry disconnected or discharged, follow the operation pro-
cedure below before starting the repair operation.
OPERATION PROCEDURE
1. Connect both battery cables. NOTE:
Supply power using jumper cables if battery is discharged.
2. Turn the push-button ignition switch to ACC position. (At this time, the steering lock will be released.)
3. Disconnect both battery cables. The steering lock wil l remain released with both battery cables discon-
nected and the steering wheel can be turned.
4. Perform the necessary repair operation.
Revision: 2010 May2011 QX56

PREPARATIONBR-5
< PREPARATION >
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PREPARATION
PREPARATION
Commercial Service ToolsINFOID:0000000006222460
Tool name Description
Power tool Loosening bolts and nuts
Pin punch
a: 4 mm (0.16 in) Removing and installing reservoir tank
Brake caliper wrench Return the piston
PBIC0190E
NT410
NNFIA0040ZZ
Revision: 2010 May2011 QX56

HYDRAULIC BOOSTER ASSEMBLYBR-31
< REMOVAL AND INSTALLATION >
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2. Remove the reservoir tank mounting pin with a pin punch (com- mercial service tool).
3. Remove bolt and remove the reservoir tank and grommets from the ABS actuator and electric unit (control unit).
CAUTION:
Never drop the removed parts. The parts must not be
reused if they are dropped.
4. Slide the clamp and remove brake hose assembly.
5. Remove the brake tube with a flare nut wrench. CAUTION:
Never scratch the flare nut and the brake tube.
6. Remove the cap with a suitable tool (A).
7. Remove grommets and screws ( ) and remove motor/accumu- lator assembly harness.
8. Cut harness band. CAUTION:
Never damage the harness.
9. Remove motor/accumulator assembly from ABS actuator and electric unit (control unit).
10. Remove bushings and collars from motor/accumulator assem- bly.
11. Remove brackets and bushing fr om ABS actuator and electric
unit (control unit).
12. Remove pin mount.
13. After replacing motor/accumulator assembly, always follow the accumulator disposal procedure to discard the motor/accumulator assembly. Refer to BR-33, "
Disposal".
ASSEMBLY
Note the following, and assembly in the reverse order of disassembly.
 Never use mineral oils such as kerosene or gasoline and rubber grease during the cleaning and assembly
process.
 Never drop the removed parts when installing. The parts must not be reused if they are dropped.
 Never allow foreign matter (e.g. dust) and oils ot her than brake fluid to enter the reservoir tank.
 For non reusable parts, refer to BR-28, "
Exploded View".
 When connecting motor/accumulator assembly harness, check the order of harness colors.
 Temporarily tighten the brake tube flare nut to the motor/accumula- tor assembly and ABS actuator and electric unit (control unit) by
hand. Then tighten it to the specified torque with a crowfoot and
torque wrench.
CAUTION:
Never scratch the flare nut and the brake tube.
JPFIA0750ZZ
JPFIA0752ZZ
JPFIA0751ZZ
A: Black
B: Red
JPFIA0753ZZ
Revision: 2010 May2011 QX56

SERVICE DATA AND SPECIFICATIONS (SDS)
BR-47
< SERVICE DATA AND SPECIFICATIONS (SDS)
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SERVICE DATA AND SPECIFICATIONS (SDS)
SERVICE DATA AND SPECIFICATIONS (SDS)
General SpecificationINFOID:0000000006222502
Unit: mm (in)
Brake PedalINFOID:0000000006222503
Unit: mm (in)
Brake BoosterINFOID:0000000006222504
Unit: mm (in)
Front Disc BrakeINFOID:0000000006222505
Unit: mm (in)
Rear Disc BrakeINFOID:0000000006222506
Unit: mm (in)
Front brake Cylinder bore diameter 50.8 (2.000)
× 2
Pad length × width × thickness 151.6 (5.97) × 56.5 (2.224) × 12.0 (0.472)
Rotor outer diameter × thickness 350 (13.78) × 30.0 (1.181)
Rear brake Cylinder bore diameter 48.1 (10894)
Pad length
× width × thickness 110.0 (4.43) × 41.0 (1.614) × 9.0 (0.354)
Rotor outer diameter × thickness 350 (13.78) × 20.0 (0.787)
Control valve Valve type Electric brake force distribution
Recommended brake fluid Refer to MA-10, "
Fluids and Lubricants".
Item Standard
Brake pedal height 168.5 (6.63) – 178.5 (7.03)
Depressed brake pedal height
[Depressing 490 N (50 kg, 110 lb) while turning the engine ON] 100 (3.94) or more
Clearance between stop lamp switch and brake switch threaded end and the
brake pedal bracket 0.2 (0.008) – 1.96 (0.0772)
Brake pedal play 3 (0.12) – 11 (0.43)
Item Standard
Input rod length 202.2 (7.96)
Item Limit
Brake pad Wear thickness 1.5 (0.059)
Disc rotor Wear thickness 28.5 (1.122)
Thickness variation (measured at 8 positions) 0.015 (0.0006)
Runout (with it attached to the vehicle) 0.053 (0.0021)
Item Limit
Brake pad Wear thickness 2.0 (0.079)
Disc rotor Wear thickness 18.0 (0.709)
Thickness variation (measured at 8 positions) 0.015 (0.0006)
Runout (with it attached to the vehicle) 0.05 (0.0020)
Revision: 2010 May2011 QX56

BRC-1
BRAKES
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SECTION BRC
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BRC
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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-2
ADDITIONAL SERVICE WHEN REPLACING
ABS ACTUATOR AND ELECTRIC UNIT
(CONTROL UNIT) ..............................................
63
Description ........................................................... ...63
ADJUSTMENT OF STEERING ANGLE SEN-
SOR NEUTRAL POSITION ...............................
64
Description ........................................................... ...64
Work Procedure ......................................................64
CALIBRATION OF DECEL G SENSOR ...........66
Description ........................................................... ...66
Work Procedure ......................................................66
DTC/CIRCUIT DIAGNOSIS ...................... ...68
C1101, C1102, C1103, C1104 WHEEL SEN-
SOR ................................................................. ...
68
DTC Logic ............................................................ ...68
Diagnosis Procedure ..............................................68
C1105, C1106, C1107, C1108 WHEEL SEN-
SOR ....................................................................
70
DTC Logic ............................................................ ...70
Diagnosis Procedure ..............................................70
C1109 POWER AND GROUND SYSTEM .........72
Description ........................................................... ...72
DTC Logic ...............................................................72
Diagnosis Procedure ..............................................72
C1111 PUMP MOTOR .......................................75
DTC Logic ............................................................ ...75
Diagnosis Procedure ..............................................75
C1115 WHEEL SENSOR ...................................77
DTC Logic ............................................................ ...77
Diagnosis Procedure ..............................................77
C1116 STOP LAMP SWITCH ............................79
DTC Logic ............................................................ ...79
Diagnosis Procedure ..............................................79
Component Inspection (Stop lamp Switch) ............85
Component Inspection (Stop Lamp Relay) .............86
C1118 TRANSFER CONTROL UNIT ................87
DTC Logic ............................................................ ...87
Diagnosis Procedure ..............................................87
C1120, C1122, C1124, C1126 ABS IN VALVE
SYSTEM .......................................................... ...
88
DTC Logic ............................................................ ...88
Diagnosis Procedure ..............................................88
C1121, C1123, C1125, C1127 ABS OUT
VALVE SYSTEM ................................................
90
DTC Logic ............................................................ ...90
Diagnosis Procedure ..............................................90
C1130 ENGINE SIGNAL ...................................92
DTC Logic ............................................................ ...92
Diagnosis Procedure ............................................ ...92
C1140 ACTUATOR RELAY SYSTEM ..............93
DTC Logic ............................................................ ...93
Diagnosis Procedure ...............................................93
C1142 PRESS SENSOR ...................................95
DTC Logic ............................................................ ...95
Diagnosis Procedure ...............................................95
C1143 STEERING ANGLE SENSOR ...............97
DTC Logic ............................................................ ...97
Diagnosis Procedure ...............................................97
C1144 INCOMPLETE STEERING ANGLE
SENSOR ADJUSTMENT ..................................
99
DTC Logic ............................................................ ...99
Diagnosis Procedure ...............................................99
C1145, C1146 YAW RATE/SIDE/DECEL G
SENSOR ...........................................................
100
DTC Logic ............................................................ .100
Diagnosis Procedure .............................................100
C1155 BRAKE FLUID LEVEL SWITCH ..........103
DTC Logic ............................................................ .103
Diagnosis Procedure .............................................103
Component Inspection ..........................................104
C1160 DECEL G SEN SET ..............................105
DTC Logic ............................................................ .105
Diagnosis Procedure .............................................105
C1164, C1165 CV SYSTEM .............................106
DTC Logic ............................................................ .106
Diagnosis Procedure .............................................106
C1166, C1167 SV SYSTEM .............................108
DTC Logic ............................................................ .108
Diagnosis Procedure .............................................108
C1170 VARIANT CODING ...............................110
DTC Logic ............................................................ .110
Diagnosis Procedure .............................................110
C118E ACCUMULATOR ..................................111
DTC Logic ............................................................ .111
Diagnosis Procedure .............................................111
U1000 CAN COMM CIRCUIT ...........................112
Description ........................................................... .112
DTC Logic .............................................................112
Diagnosis Procedure .............................................112
POWER SUPPLY AND GROUND CIRCUIT ....113
Description ........................................................... .113
Diagnosis Procedure .............................................113
PARKING BRAKE SWITCH .............................117
Component Function Check ................................ .117
Diagnosis Procedure .............................................117
Component Inspection ..........................................118
Revision: 2010 May2011 QX56