2011 INFINITI QX56 brake

SBC-18
< ECU DIAGNOSIS INFORMATION >
PRE-CRASH SEAT BELT CONTROL UNIT (PASSENGER SIDE)
*1: The deactivation mode differs depending on the internal malfunctioning condition of control unit
U1000 CAN communication circuit
Stops the operation in the conditions as per the following. *
1
 During emergency brake operation
 When ABS continuo
usly operates
 When lateral slippage during cornering occurs
 When Intelligent brake assistance operates
 When steering wheel is rotated for emergency
 When the vehicle inclined excessively
 A part or the whole comfort function
B2452 SEAT BLT MTR AS CIRC Fully deactivates the whole operation.
B2453 BR_STROKE_SEN_CIRC Stops the operation in the conditions as per the following.
 During emergency brake operation
 When ABS continuo
usly operates
B2455 CONTROL UNIT DR Stops the operation in the conditions as per the following. *
1
 During emergency brake operation
 When ABS continuo
usly operates
 When lateral slippage during cornering occurs
 When Intelligent brake assistance operates
 When steering wheel is rotated for emergency
 When the vehicle inclined excessively
 A part or the whole comfort function
B2456 SEAT BLT PWR AS Fully deactivates the whole operation.
B2457 CONTROL UNIT AS Fully deactivates the whole operation.*
1
B2458 LOCAL COMM
Fully deactivates the whole operation.*1
B2461 VHCL SPEED SIGNALStops the operation in the conditions as per the following.
 During emergency brake operation
 When ABS continuo
usly operates
 When lateral slippage during cornering occurs
 When steering wheel is rotated for emergency
 When the vehicle inclined excessively
 A part or the whole comfort function
B2463 ROLLOVER SIGNAL When the vehicle inclined excessively
B2466 DR/AS CONTROL UNIT Stops the operation in the conditions as per the following.
 During emergency brake operation
 When ABS continuo
usly operates
 When lateral slippage during cornering occurs
 When steering wheel is rotated for emergency
 When the vehicle inclined excessively
 A part or the whole comfort function
B2471 SYS HEAT PROTC AS  Fully deactivates the whole operation.
 Operation return
- 1 time operation becomes possible after approximately 30 seconds
- Returns to the initial condition after approximately 8 minutes
Display contents of CONSULT-III Fail-safe
Revision: 2010 May2011 QX56

SBC-38
< DTC/CIRCUIT DIAGNOSIS >
B2453 BR STROKE SEN CIRC
B2453 BR STROKE SEN CIRC
DTC LogicINFOID:0000000006237903
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.SELF-DIAGNOSIS WITH PRE-CRASH SEAT BELT CONTROL UNIT
1. Turn ignition switch ON.
2. Check “Self-diagnostic result” with CONSULT-III.
Is DTC detected?
YES >> Refer to SBC-38, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006237904
1.CHECK PRE-CRASH SEAT BELT CONTROL UNIT INPUT SIGNAL
1. Turn ignition switch ON.
2. Select “BRK PEDAL SNSR1” and “BRK PEDAL SNSR2” in “DATA MONITOR” mode with CONSULT-III.
3. Check “BRK PEDAL SNSR1” and “BRK PEDAL SNSR2” indication under the following conditions.
Is the inspection result normal?
YES >> GO TO 6.
NO >> GO TO 2.
2.CHECK BRAKE PEDAL STROKE SENSOR POWER SUPPLY
1. Turn ignition switch OFF.
2. Disconnect brake pedal stroke sensor harness connector.
3. Check voltage between brake pedal stroke sensor harness connector and ground.
Is the inspection result normal?
YES >> GO TO 4.
NO >> GO TO 3.
3.CHECK BRAKE PEDAL STROKE SENSOR POWER SUPPLY CIRCUIT
1. Disconnect pre-crash seat belt contro l unit (driver side) harness connector.
2. Check continuity between pre-crash seat belt c ontrol unit (driver side) harness connector and brake pedal
stroke sensor harness connector.
DTC No. Self-diagnosis item DTC Detection Condition Possible causes
B2453 BR STROKE SEN CIRC Circuit of brake pedal stroke sensor out-
put is open or shorted  Harness or connectors
(The sensor circuit is open or shorted)
 Pre-crash seat belt co ntrol unit (driver side)
 Brake pedal stroke sensor
Monitor item Condition Voltage (V)
(Approx.)
BRK PEDAL SNSR1 Brake released → depressed 1
→ 4
BRK PEDAL SNSR2 4 → 1
Brake pedal stroke sensor
GroundVoltage (V)
(Approx.)
Connector Terminal
E 111 2 5
Pre-crash seat belt control unit (driver side) Brake pedal stroke sensor Continuity
Connector Terminal Connector Terminal
B9 10 E111 2 Existed
Revision: 2010 May2011 QX56

B2453 BR STROKE SEN CIRCSBC-39
< DTC/CIRCUIT DIAGNOSIS >
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3. Check continuity between pre-crash seat belt control unit (driver side) harness connector and ground.
Is the inspection result normal?
YES >> Replace pre-crash seat belt c ontrol unit (driver side). Refer to SB-6, "SEAT BELT RETRACTOR :
Removal and Installation".
NO >> Repair or replace harness or connector.
4.CHECK BRAKE PEDAL STROKE SENSOR CIRCUIT
1. Disconnect pre-crash seat belt control unit (driver side) harness connector.
2. Check continuity between pre-crash seat belt c ontrol unit (driver side) harness connector and brake pedal
stroke sensor harness connector.
3. Check continuity between pre-crash seat belt control unit harness connector (driver side) and ground.
Is the inspection result normal?
YES >> GO TO 5.
NO >> Repair or replace harness or connector.
5.CHECK BRAKE PEDAL STROKE SENSOR
Refer to SBC-39, "
Component Inspection".
Is the inspection result normal?
YES >> GO TO 6.
NO >> Replace brake pedal stroke sensor. Refer to SBC-63, "
Removal and Installation".
6.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
>> INSPECTION END
Component InspectionINFOID:0000000006237905
COMPONENT PARTS INSPECTION
1.CHECK BRAKE PEDAL STROKE SENSOR
1. Turn ignition switch OFF.
2. Disconnect brake pedal stroke sensor connector.
3. Check resistance between brake pedal stroke sensor terminal as per the following.
Pre-crash seat belt control unit (driver side)
GroundContinuity
Connector Terminal
B9 10 Not existed
Pre-crash seat belt control unit (driver side) Brake pedal stroke sensor Continuity
Connector Terminal Connector Terminal
B9 2
E 111 1
Existed
12 3
17 4
Pre-crash seat belt control unit (driver side) GroundContinuity
Connector Terminal
B9 2
Not existed
12
17
Revision: 2010 May2011 QX56

SBC-40
< DTC/CIRCUIT DIAGNOSIS >
B2453 BR STROKE SEN CIRC
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace brake pedal stroke sensor. Refer to SBC-63, "
Removal and Installation".
Brake pedal stroke sensor
ConditionResistance (k
Ω)
(Approx.)
Terminal
2 1
Brake released → depressed 1.0
→ 0.2
30.2 → 1.0
Revision: 2010 May2011 QX56

BRAKE PEDAL STROKE SENSORSBC-63
< REMOVAL AND INSTALLATION >
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REMOVAL AND INSTALLATION
BRAKE PEDAL STROKE SENSOR
Exploded ViewINFOID:0000000006237943
Removal and InstallationINFOID:0000000006237944
REMOVAL
1. Remove the instrument panel lower cover LH. Refer to IP-14, "Removal and Installation".
2. Disconnect the brake pedal stroke sensor connector.
3. Remove the screws (A).
4. Remove the brake pedal stroke sensor (1).
INSTALLATION
Install in the reverse order of removal.
1. Brake pedal stroke sensor
JMHIA0712ZZ
JMHIA0726ZZ
Revision: 2010 May2011 QX56

PRECAUTIONSSCS-5
< PRECAUTION > [HBMC]
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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 ignition switch is turned to LOCK position.)
6. Perform self-diagnosis check of a ll control units using CONSULT-III.
Precaution for Procedure without Cowl Top CoverINFOID:0000000006256138
When performing the procedure after removing cowl top cover, cover
the lower end of windshield with urethane, etc.
Precaution for Hydraulic Body-Motion Control SystemINFOID:0000000006255996
WARNING:
 Always check the piping for loose co nnections, damage, or twists before starting operation, since
pressure in hydraulic circuit becom es high during air bleeding operation.
 When repairing or replacing a malfunctioning pa rt, always release pressure from hydraulic circuit,
since dangerous conditions may be created when oil leakage occurs during air bleeding operation.
 Clean surrounding areas of oil inlet and air bleeder usi ng steam before starting operation, since there may
be mud on it.
 Always decrease pressure when removing a system related part, since system pressure is high.
 Seal the removed part using vinyl tape for preventi ng dirt from getting on or entering the removed part.
 Check system pressure again 1 day or more after bleeding operation is complete, since system pressure may decrease when air bleeding is insufficient.
 Use Genuine NISSAN Hydraulic Suspension Fluid for suspension fluid.
 Never reuse drained suspension fluid.
 Check for suspension fluid leakage after removing a system-related part.
PIIB3706J
Revision: 2010 May2011 QX56

SCS-46
< REMOVAL AND INSTALLATION >[HBMC]
HYDRAULIC BODY-MOTION CONTROL SYSTEM
3. Remove lower side pipe (A) of rear shock absorber RH.
4. Remove pipe (A) from left side rear joint (B).
5. Remove mounting bolts of bracket of rear tube assembly B.
6. Remove mounting bolts of bracket of rear left brake hose, and
then free hose.
7. Remove rear tube assembly B from the vehicle.
8. Perform inspection after removal. Refer to SCS-46, "
REAR
TUBE ASSEMBLY : Inspection".
INSTALLATION
Note the following, and install in the reverse order of removal.
 Apply genuine NISSAN hydraulic suspension fluid to O-ring.
 Check connection portion of each piping for dirt or dust.
REAR TUBE ASSEMBLY : InspectionINFOID:0000000006256034
INSPECTION AFTER REMOVAL
 O-ring must be free of scratches and damage.
 Pipe and tube must be free of scratches and damage.
INSPECTION AFTER INSTALLATION
Check oil leakage, twists, deformation, contact with other parts, and loose connections.
ADJUSTMENT AFTER INSTALLATION
Perform air bleeding. Refer to SCS-18, "Work Procedure".
JSEIA0212ZZ
JSEIA0204ZZ
Revision: 2010 May2011 QX56

SCS-48
< PRECAUTION >[AIR LEVELIZER CONTROL SYSTEM]
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:0000000006256139
When performing the procedure after removing cowl top cover, cover
the lower end of windshield with urethane, etc.
Precaution for Air Levelizer Control SystemINFOID:0000000006256038
 Never allow water and dust to enter the inside of air compressor.
 Never disassemble the vehicle height sensor.
PIIB3706J
Revision: 2010 May2011 QX56