service INFINITI QX56 2009 Factory Owner's Manual
Page 408 of 4171
BCS-34
< COMPONENT DIAGNOSIS >[BCM]
COMBINATION SWITCH INPUT CIRCUIT
YES >> GO TO 4
NO >> Replace BCM. Refer to
BCS-56, "Removal and Installation"
.
4. CHECK COMBINATION SWITCH
Check combination switch. Refer to BCS-36, "Description"
.
Is the check result normal?
YES >> Replace BCM. Refer to BCS-56, "Removal and Installation".
NO >> Replace the combination switch (applicable parts). Refer to EXL-152, "Removal and Installation"
.
Special Repair RequirementINFOID:0000000003776415
1. ADDITIONAL SERVICE WHEN REPLACING BCM
>> Refer to BCS-3, "ADDITIONAL SERVICE WHEN RE PLACING CONTROL UNIT : Special Repair
Requirement".
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BCS
COMBINATION SWITCH OUTPUT CIRCUITBCS-35
< COMPONENT DIAGNOSIS > [BCM]
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COMBINATION SWITCH OUTPUT CIRCUIT
Diagnosis ProcedureINFOID:0000000003776416
1. CHECK OUTPUT 1 - 5
SYSTEM CIRCUIT FOR OPEN
1. Turn ignition switch OFF.
2. Disconnect BCM and combination switch.
3. Check continuity between BCM harness connector and combi- nation switch harness connector.
Does continuity exist?
YES >> GO TO 2
NO >> Repair or replace harness.
2. CHECK OUTPUT 1 - 5 SYSTEM CIRCUIT FOR SHORT
Check for continuity between BCM harness connector and ground.
Does continuity exist?
YES >> Repair or replace harness.
NO >> GO TO 3
3. CHECK COMBINATION SWITCH
Check combination switch. Refer to BCS-36, "Description"
.
Is the check result normal?
YES >> Replace BCM. Refer to BCS-56, "Removal and Installation".
NO >> Replace combination switch (applicable parts). Refer to EXL-152, "Removal and Installation"
.
Special Repair RequirementINFOID:0000000003776417
1. ADDITIONAL SERVICE WHEN REPLACING BCM
>> Refer to BCS-3, "ADDITIONAL SERVICE WHEN RE PLACING CONTROL UNIT : Special Repair
Requirement".
SystemBCM Combination switch
Continuity
Connector Terminal Connector Terminal
OUTPUT 1
M18(A) 36
M28(B) 1
Ye s
OUTPUT 2 35 2
OUTPUT 3 34 3
OUTPUT 4 33 4
OUTPUT 5 32 5
ALMIA0278ZZ
System
BCM
GroundContinuity
Connector Terminal
OUTPUT 1
M1836
No
OUTPUT 2 35
OUTPUT 3 34
OUTPUT 4 33
OUTPUT 5 32
ALMIA0279ZZ
Revision: December 20092009 QX56
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BCS-54
< PRECAUTION >[BCM]
PRECAUTIONS
PRECAUTION
PRECAUTIONS
Precaution for Supplemental Restraint S
ystem (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000005851887
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 w hether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the SR and SB section of this Service Man-
ual.
WARNING:
To avoid rendering the SRS inopera tive, which could increase the risk of personal injury or death in
the event of a collision which would result in air bag inflation, all maintenance must be performed by
an authorized NISS AN/INFINITI dealer.
Improper maintenance, including in correct removal and installation of the SRS, can lead to personal
injury caused by unintent ional activation of the system. For re moval of Spiral Cable and Air Bag
Module, see the SR section.
Do not use electrical test equipmen t 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 Airbag Diagnosis Sensor Unit or other Airbag System sensors with the Igni-
tion ON or engine running, DO NOT use air or electri c 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 minu tes before performing any service.
Precaution Necessary for Steering W heel Rotation After Battery Disconnect
INFOID:0000000005851888
NOTE:
This Procedure is applied only to models with Intelli gent Key system and NATS (NISSAN ANTI-THEFT SYS-
TEM).
Remove and install all control units after disconnecting both battery cables with the ignition knob in the
″LOCK ″ position.
Always use CONSULT-III to perform self-diagnosis as a part of each function inspection after finishing work.
If DTC is detected, perform trouble diagnosis according to self-diagnostic results.
For models equipped with the Intelligent Key system and NATS, an electrically controlled steering lock mech-
anism is adopted on the key cylinder.
For this reason, if the battery is disconnected or if the battery is discharged, the steering wheel will lock and
steering wheel rotation will become impossible.
If steering wheel rotation is required when battery pow er is interrupted, follow the procedure below before
starting the repair operation.
OPERATION PROCEDURE
1. Connect both battery cables. NOTE:
Supply power using jumper cables if battery is discharged.
2. Use the Intelligent Key or mechanical key to turn the ignition switch to the ″ACC ″ position. At this time, the
steering lock will be released.
3. Disconnect both battery cables. The steering lock will remain released and the steering wheel can be
rotated.
4. Perform the necessary repair operation.
Revision: December 20092009 QX56
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BR-1
BRAKES
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SECTION BR
A
B
BR
N
O P
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 Brake System ....................................4
PREPARATION ............................................5
PREPARATION .............................................. .....5
Special Service Tool ........................................... ......5
Commercial Service Tool ..........................................5
FUNCTION DIAGNOSIS ...............................6
NOISE, VIBRATION AND HARSHNESS
(NVH) TROUBLESHOOTING ........................ .....
6
NVH Troubleshooting Chart ................................ ......6
BASIC INSPECTION ....................................7
FRONT DISC B RAKE .................................... .....7
BRAKE PAD .......................................................... ......7
BRAKE PAD : Inspection ..........................................7
DISC ROTOR ......................................................... ......7
DISC ROTOR : Inspection ........................................7
REAR DISC BRAKE ...................................... .....9
BRAKE PAD .......................................................... ......9
BRAKE PAD : Inspection ..........................................9
DISC ROTOR ......................................................... ......9
DISC ROTOR : Inspection ........................................9
BRAKE BOOSTER ............................................10
Inspection ............................................................ ....10
VACUUM LINES ............................................. ....11
Inspection ............................................................ ....11
BRAKE MASTER CYLINDER ..........................12
On Board Inspection ................................................12
BRAKE TUBE AND HOSE ...............................13
Hydraulic Circuit ......................................................13
FRONT BRAKE ..................................................... ....13
FRONT BRAKE : Inspection ......................... ...........13
REAR BRAKE ........................................................ ....14
REAR BRAKE : Inspection ........................ ..............14
ON-VEHICLE MAINTEN ANCE ....................15
BRAKE PEDAL .................................................15
Inspection and Adjustment .................................. ....15
BRAKE FLUID ..................................................17
On Board Inspection ............................................ ....17
Drain and Refill ........................................................17
Bleeding Brake System ...........................................17
ON-VEHICLE REPAIR .................................19
BRAKE PEDAL .................................................19
Removal and Installation ..................................... ....19
BRAKE TUBE AND HOSE ...............................21
Hydraulic Circuit ......................................................21
Removal and Installation of Front Brake Piping
and Brake Hose .......................................................
21
Removal and Installation of Rear Brake Piping
and Brake Hose .......................................................
22
Inspection After Installation .....................................23
BRAKE MASTER CYLINDER ..........................25
Removal and Installation .........................................25
BRAKE BOOSTER ...........................................26
Removal and Installation ..................................... ....26
VACUUM LINES ...............................................28
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BR-2
Removal and Installation ........................................28
FRONT DISC BRAKE ........................................29
Exploded View of Brake Pads ............................. ...29
Removal and Installation of Brake Pads .................29
Brake Burnishing Procedure ...................................30
Exploded View of Brake Caliper .............................31
Removal and Installation of Brake Caliper and Ro-
tor ...........................................................................
31
REAR DISC BRAKE ..........................................34
Exploded View of Brake Pads ............................. ...34
Removal and Installation of Brake Pad ..................34
Brake Burnishing Procedure ...................................35
Exploded View of Brake Caliper .............................35
Removal and Installation of Brake Caliper and
Disc Rotor ............................................................ ...
36
DISASSEMBLY AND ASSEMBLY .............37
BRAKE MASTER CYLINDER ........................ ...37
Disassembly and Assembly ................................. ...37
FRONT DISC BRAKE .......................................39
Disassembly and Assembly ................................. ...39
REAR DISC BRAKE ....................................... ...42
Disassembly and Assembly ................................. ...42
SERVICE DATA AND SPECIFICATIONS
(SDS) .......... ................................. ...............
45
SERVICE DATA AND SPECIFICATIONS
(SDS) .............................................................. ...
45
General Specification ........................................... ...45
Brake Pedal ............................................................45
Brake Booster .........................................................46
Check Valve ............................................................46
Front Disc Brake .....................................................46
Rear Disc Brake ......................................................46
Revision: December 20092009 QX56
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PRECAUTIONSBR-3
< PRECAUTION >
C
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M A
B
BR
N
O P
PRECAUTION
PRECAUTIONS
Precaution for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000005864602
The Supplemental Restraint System such as “AIR 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 w hether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the SR and SB section of this Service Man-
ual.
WARNING:
• To avoid rendering the SRS inoper ative, which could increase the risk of personal injury or death in
the event of a collision which would result in air bag 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 SR section.
• 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 Airbag Diagnosis Sensor Un it or other Airbag System sensors with the Igni-
tion ON or engine running, DO NOT use air or el ectric 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 Wheel Rotation After Battery Disconnect
INFOID:0000000005864603
NOTE:
• This Procedure is applied only to models with Intelligent Key system and NATS (NISSAN ANTI-THEFT SYS-
TEM).
• Remove and install all control units after disconnecti ng both battery cables with the ignition knob in the
″ LOCK ″ position.
• Always use CONSULT-III to perform self-diagnosis as a part of each function inspection after finishing work.
If DTC is detected, perform trouble diagnosis according to self-diagnostic results.
For models equipped with the Intelligent Key system and NATS , an electrically controlled steering lock mech-
anism is adopted on the key cylinder.
For this reason, if the battery is disconnected or if the battery is discharged, the steering wheel will lock and
steering wheel rotation will become impossible.
If steering wheel rotation is required when battery power is interrupted, follow the procedure below before
starting the repair operation.
OPERATION PROCEDURE
1. Connect both battery cables. NOTE:
Supply power using jumper cables if battery is discharged.
2. Use the Intelligent Key or mechanical key to turn the ignition switch to the ″ACC ″ position. At this time, the
steering lock will be released.
3. Disconnect both battery cables. The steering lock will remain released and the steering wheel can be
rotated.
4. Perform the necessary repair operation.
Revision: December 20092009 QX56
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PREPARATIONBR-5
< PREPARATION >
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PREPARATION
PREPARATION
Special Service ToolINFOID:0000000003772410
The actual shapes of Kent-Moore tools may differ from those of special service tools illustrated here.
Commercial Service ToolINFOID:0000000003772411
Tool number
(Kent-Moore No.)
Tool name Description
—
(J-46532)
Brake and clutch pedal height measure-
ment tool Measuring brake pedal height
38-PFM90.5
(—)
Pro-Cut PFM90 On-Car Brake Lathe Turning rotors
LFIA0227E
ALFIA0092ZZ
Tool name
Description
1. Flare nut crowfoot
2. Torque wrench Removing and installing each brake pip-
ing.
a: 10 mm (0.39 in) / 12 mm (0.47 in)
Power tool Removing nuts, bolts and screws.
S-NT360
PBIC0190E
PBIC0191E
Revision: December 20092009 QX56
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FRONT DISC BRAKEBR-7
< BASIC INSPECTION >
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BASIC INSPECTION
FRONT DISC BRAKE
BRAKE PAD
BRAKE PAD : InspectionINFOID:0000000003772414
PA D W E A R
Check pad thickness from the inspection holes on cylinder body.
Check using a scale if necessary.
DISC ROTOR
DISC ROTOR : InspectionINFOID:0000000003772415
VISUAL
Check surface of disc rotor for uneven wear, cracks, and serious damage. Replace as necessary.
RUNOUT
1. Attach disc rotor to wheel hub using wheel nuts (at two or more positions).
2. Inspect runout using a dial gauge placed at 10 mm (0.39 in) inside the disc edge.
NOTE:
Before measuring, make sure that wheel bearing axial end play
is within the specification. Refer to RAX-6, "
On-Vehicle Inspec-
tion and Service".
3. When runout exceeds limit value, displace mounting positions of disc rotor by one hole. And then find a position of the minimum value for runout.
4. If runout is outside the specified value after performing the above operation, turn disc rotor using Tool.
THICKNESS
Standard thickness : Refer to BR-46, "Front Disc
Brake".
Repair limit thickness : Refer to BR-46, "
Front Disc
Brake".
WFIA0522E
Runout limit : Refer to BR-46, "Front Disc
Brake".
(with it attached to the vehicle)
Tool number : 38-PFM90.5 ( — )
BRA0580D
Revision: December 20092009 QX56
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REAR DISC BRAKEBR-9
< BASIC INSPECTION >
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REAR DISC BRAKE
BRAKE PAD
BRAKE PAD : InspectionINFOID:0000000003772417
PA D W E A R
Check pad thickness from the inspection holes on cylinder body.
Check using a scale if necessary.
DISC ROTOR
DISC ROTOR : InspectionINFOID:0000000003772418
VISUAL
Check surface of disc rotor for uneven wear, cracks, and serious damage. Replace as necessary.
RUNOUT
1. Attach disc rotor to wheel hub using wheel nuts (at two or more positions).
2. Inspect runout using dial gauge placed at 10 mm (0.39 in) inside disc edge.
NOTE:
Before measuring, make sure that wheel bearing axial end play
is within the specification. Refer to RAX-6, "
On-Vehicle Inspec-
tion and Service".
3. When runout exceeds limit value, displace mounting positions of disc rotor by one hole. And then find a position of the minimum value for runout.
4. If runout is outside the specified value after performing the above operation, turn disc rotor using Tool.
THICKNESS
Check the thickness of the disc rotor using a micrometer. Replace
disc rotor if the thickness is less than the wear limit. Standard thickness : Refer to
BR-46, "
Rear Disc
Brake".
Repair limit thickness : Refer to BR-46, "
Rear Disc
Brake".
BRA0010D
Runout limit : Refer to BR-46, "Rear Disc Brake".
(With it attached to the vehicle)
Tool number : 38-PFM90.5 ( — )
BRA0697D
Standard thickness : Refer to BR-46, "Rear
Disc Brake".
Repair limit thickness : Refer to BR-46, "
Rear
Disc Brake".
Thickness variation
(Measured at 8 positions) : Refer to
BR-46, "
Rear
Disc Brake".
SFIA2284E
Revision: December 20092009 QX56
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BR-40
< DISASSEMBLY AND ASSEMBLY >
FRONT DISC BRAKE
4. Remove piston seals from cylinder body, using a suitable tool.CAUTION:
• Be careful not to damage cylinder inner wall.
• Do not reuse piston seals.
CALIPER INSPECTION
Cylinder Body
Check inside surface of cylinder for score, rust, wear, damage or foreign materials. If any of the above condi-
tions are observed, replace cylinder body.
Minor damage from rust or foreign materials may be el iminated by polishing surface with a fine emery paper.
Replace cylinder body if necessary.
CAUTION:
Use new brake fluid for cleaning. Do not use mineral oils such as gasoline or kerosene.
Torque Member
Check for wear, cracks, and damage. If damage or def ormation is present, replace the affected part.
Piston
Check piston for score, rust, wear, damage or presence of foreign materials. Replace if any of the above con-
ditions are observed.
CAUTION:
Piston sliding surface is plated, do not polish with emery paper even if rust or foreign materials are
stuck to sliding surface.
Sliding Pins, and Sliding Pin Boots
Check sliding pin and sliding pin boot for wear, damage, and cracks. If damage or deformation is present,
replace the affected part.
CAUTION:
Trailing/upper slidi ng pin must be replaced at each service.
ASSEMBLY
1. Install bleed valve and cap.
2. Apply rubber grease to new piston seals and insert seals into
grooves on cylinder body.
CAUTION:
Do not reuse piston seals.
SFIA0141E
SFIA2399E
Revision: December 20092009 QX56