2011 INFINITI QX56 BATTERY

BCS
BCM
BCS-53
< ECU DIAGNOSIS INFORMATION >
C
D E
F
G H
I
J
K L
B A
O P
N
90
(Y) Ground Push-button ignition
switch illumination OutputPush-button ig-
nition switch illu-
mination ON 12 V
OFF 0 V
91
(O) Ground LOCK indicator lamp Output LOCK indicator
lampOFF (Ignition switch OFF) Battery voltage
ON 0 V
92
(L) Ground Push-button ignition
switch illumination
ground Output Tail lamp OFF 0 V
ON
NOTE:
When the illumination brighten-
ing/dimming level is in the neutral position
6.0 - 7.0 V
93
(GR/R) GroundIntelligent Key warn-
ing buzzer
OutputIntelligent Key
warning buzzer Sounding 0 V
Not sounding 12 V
94
(Y/G) Ground Steering lock unit
communication Input/
Output Steering lock LOCK status 12 V
LOCK or UNLOCK
For 15 seconds after UN-
LOCK
12 V
15 seconds or later after
UNLOCK 0 V
95
(W) Ground
Steering lock unit
power supply Output Ignition switch OFF or ACC 12 V
ON 0 V
96
(BR) Ground ACC relay control Output Ignition switch OFF 0 V
ACC or ON 12 V
97
(R/W) Ground Starter relay control Output Ignition switch
ONWhen selector lever is in
P or N position
12 V
When selector lever is not
in P or N position 0 V
98
(O) Ground Ignition relay (IPDM
E/R) control
Output Ignition switch OFF or ACC 12 V
ON 0 V
99
(R) Ground Ignition relay-1 con-
trol
Output Ignition switch OFF or ACC 0 V
ON 12 V
100
(SB) Ground
Push-button ignition
switch (push switch) InputPush-button ig-
nition switch
(push switch) Pressed 0 V
Not pressed 12 V
101
(W/B) Ground Ignition power sup-
ply No. 2 Output Ignition switch OFF or ACC 0 V
ON 12 V
Terminal No.
(Wire color) Description
Condition Va l u e
(Approx.)
Signal name Input/
Output
+ −
JPMIA1554GB
JMKIA0066GB
Revision: 2010 May2011 QX56

BCS-54
< ECU DIAGNOSIS INFORMATION >
BCM
*: For Canada
Fail-safeINFOID:0000000006274820
FAIL-SAFE CONTROL BY DTC
BCM performs fail-safe control when any DTC are detected.
102
(BR) Ground P/N position Input Selector lever P or N position 12 V
Except P and N positions 0 V
104
(R/B) Ground A/T shift selector
(detention switch)
power supply Output Ignition switch ON 12 V
105
(O/L) Ground Stop lamp switch 2 Input Ignition switch OFF Battery voltage
106
(Y/G) Ground
Blower fan motor re-
lay control Output Ignition switch OFF or ACC 0 V
ON 12 V
107 (L) Ground
Steering lock condi-
tion No. 1 Input Steering lock LOCK status 0 V
UNLOCK status 12 V
108 (P) Ground
Steering lock condi-
tion No. 2 Input Steering lock LOCK status 12 V
UNLOCK status 0 V
109
(L/W) Ground ACC indicator lamp Output Ignition switch OFF (LOCK indicator is
not illuminated)
Battery voltage
ACC 0 V
Te r m i n a l N o .
(Wire color) Description
Condition Va l u e
(Approx.)
Signal name Input/
Output
+ −
Display contents of CONSULT Fail-safe Cancellation
B2013: ID DISCORD BCM-S/ L Inhibit engine cranking When communication between BCM and steering lock unit are commu-
nicated normally.
B2014: CHAIN OF S/L-BCM Inhibit engine cranking When communication between BCM and steering lock unit are commu-
nicated normally.
B2192: ID DISCORD BCM-ECM Inhibit engine cranking Erase DTC
B2193: CHAIN OF BCM-ECM Inhibit engine cranking Erase DTC
B2195: ANTI-SCANNING Inhibit engine cranking Ignition switch ON → OFF
B2198: NATS ANTENNA AMP Inhibit engine cranking Erase DTC
B2557: VEHICLE SPEED In hibit steering lockWhen the following CAN signal status (vehicle speed signal) becomes
consistent
 Vehicle speed signal (ABS)
 Vehicle speed signal (Meter)
B2601: SHIFT POSITION Inhibit steering lock 500 ms after the following signal reception status becomes consistent
 Selector lever P position switch signal
 P range signal (CAN)
B2602: SHIFT POSITION Inhibit steering lock 5 seconds after the following BCM recognition conditions are fulfilled
 Ignition switch is in the ON position
 Selector lever P position switch signal: Except P position (battery volt-
age)
 Vehicle speed: 4 km/h (2.5 MPH) or more
Revision: 2010 May2011 QX56

BCS-56
< ECU DIAGNOSIS INFORMATION >
BCM
FAIL-SAFE CONTROL BY RAIN SENSOR MALFUNCTION
BCM detects the light and rain sensor serial link error and the rain sensor malfunction.
BCM controls the following fail-safe when rain sensor has a malfunction.
 Front wiper switch AUTO and sensing rain drop: The condition just before the activation of fail-safe is main-
tained until the front wiper switch is turned OFF.
 Front wiper switch AUTO and not sensing rain drop: Front wiper is LO operation until the front wiper switch is
turned off.
REAR WIPER MOTOR PROTECTION
BCM detects the rear wiper stopping position acco rding to the rear wiper stop position signal.
When the rear wiper stop position signal does not c hange for more than 5 seconds while driving the rear
wiper, BCM stops power supply to protect the rear wiper motor.
Condition of cancellation
1. More than 1 minute is passed after the rear wiper stop.
2. Turn rear wiper switch OFF.
3. Operate the rear wiper swit ch or rear washer switch.
FAIL-SAFE CONTROL OF COMBINATION SWITCH READING FUNCTION CAUSED BY LOW
POWER SUPPLY VOLTAGE
If voltage of battery power supply lower, BCM maintain s combination switch reading to the status when input
voltage is less than approximately 9 V.
NOTE:
When voltage of battery power supply is approximately 9 V or more, combination switch reading function
returns to normal operation.
DTC Inspection Priority ChartINFOID:0000000006274821
If some DTCs are displayed at the same time, perfo rm inspections one by one based on the following priority
chart.
B26F3: START CONT RLY ON Inhibit engine cranking When the following conditions are fulfilled
 Starter control relay signal (CAN: Transmitted from BCM): OFF
 Starter control relay signal (CAN: Transmitted from IPDM E/R): OFF
B26F4: START CONT RLY OFF Inhibit engine cranking When the following conditions are fulfilled
 Starter control relay signal (CAN: Transmitted from BCM): ON
 Starter control relay signal (CAN: Transmitted from IPDM E/R): ON
B26F7: BCM Inhibit engine cranking
by Intelligent Key sys-
temWhen room antenna and luggage room antenna functions normally
U0415: VEHICLE SPEED Inhibit steering lock When vehicle speed signal (Meter) (CAN) is received normally
Display contents of CONSULT Fail-safe Cancellation
Priority DTC
1 B2562: LOW VOLTAGE
2  U1000: CAN COMM
 U1010: CONTROL UNIT (CAN)
3  B2192: ID DISCORD BCM-ECM
 B2193: CHAIN OF BCM-ECM
 B2195: ANTI-SCANNING
 B2198: NATS ANTENNA AMP
Revision: 2010 May2011 QX56

BCS
POWER SUPPLY AND GROUND CIRCUITBCS-75
< DTC/CIRCUIT DIAGNOSIS >
C
DE
F
G H
I
J
K L
B A
O P
N
POWER SUPPLY AND GROUND CIRCUIT
Diagnosis ProcedureINFOID:0000000006274841
1.CHECK FUSE AND FUSIBLE LINK
Check that the following fuse and fusible link are not blown.
Is the fuse fusing?
YES >> Replace the blown fuse or fusible link after repairing the affected circuit if a fuse or fusible link is blown.
NO >> GO TO 2.
2.CHECK POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect BCM connectors.
3. Check voltage between BCM harness connector and ground.
Is the measurement value normal?
YES >> GO TO 3.
NO >> Repair harness or connector.
3.CHECK GROUND CIRCUIT
Check continuity between BCM harness connector and ground.
Does continuity exist?
YES >> INSPECTION END
NO >> Repair harness or connector.
Signal name Fuse and fusible link No.
Battery power supply K
10
Te r m i n a l s
Vo l ta g e
(Approx.)
(+) (
−)
BCM
Ground
Connector Terminal
M70 70
Battery voltage
57
BCM
GroundContinuity
Connector Terminal
M70 67 Existed
Revision: 2010 May2011 QX56

BR-1
BRAKES
C
DE
G H
I
J
K L
M
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 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

PRECAUTIONSBR-3
< PRECAUTION >
C
DE
G H
I
J
K L
M A
B
BR
N
O P
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

BR-4
< PRECAUTION >
PRECAUTIONS
5. When the repair work is completed, re-connect both 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:0000000006228173
When performing the procedure after removing cowl top cover, cover
the lower end of windshield with urethane, etc.
Precaution for Brake systemINFOID:0000000006222459
WARNING:
Clean any dust from the front brake and rear brake wi th a vacuum dust collector. Never blow with 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.
 Always clean with new brake fluid when cleaning the brake caliper and other components.
 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).
 Brake system is an important safety part. If a brake fluid leak is detected, always disassemble the affected part. If a malfunction is
detected, replace part with a new one.
 Always connect the battery terminals when moving the vehicle.
 Turn the ignition switch OFF and disconnect the hydraulic booster assembly harness connector or the battery negative terminal
before performing the work.
 Check that no brake fluid leakage is present after replacing the
parts.
 Burnish the brake contact surfaces after refinishing or replacing rotors, after replacing pads, or if a soft pedal occurs at very low mileage.
- Front brake pad: Refer to BR-16, "
BRAKE PAD : Inspection and Adjustment".
- Front disc rotor: Refer to BR-16, "
DISC ROTOR : Inspection and Adjustment".
- Rear brake pad: refer to BR-18, "
BRAKE PAD : Inspection and Adjustment".
- Rear disc rotor: BR-18, "
DISC ROTOR : Inspection and Adjustment".
PIIB3706J
JPFIA0001ZZ
Revision: 2010 May2011 QX56

BRC-1
BRAKES
C
DE
G H
I
J
K L
M
SECTION BRC
A
B
BRC
N
O P
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