2008 INFINITI QX56 engine

BR-10
< BASIC INSPECTION >
BRAKE BOOSTER
BRAKE BOOSTER
InspectionINFOID:0000000004894486
OPERATION
With engine stopped, change vacuum to atmospheric pressure by
depressing brake pedal several times. Then with brake pedal fully
depressed, start engine and when vacuum pressure reaches the
standard, make sure that clearance between brake pedal and floor
panel decreases.
AIR TIGHT
• Run engine at idle for approximately 1 minute, and stop it afterapplying vacuum to booster. Depress brake pedal normally to
change vacuum to atmospheric pressure. Make sure that distance
at intervals of 5 seconds between brake pedal and floor panel
gradually increases.
• Depress brake pedal while engine is running, and stop engine with pedal depressed. The pedal stroke should not change after holding pedal down for 30 seconds.
BRA0037D
SBR365AA
Revision: March 2010 2008 QX56

BR-14
< BASIC INSPECTION >
BRAKE TUBE AND HOSE
1. Check brake lines (tubes and hoses) and connections for fluid leaks, damage, twists, deformation, con-
tacts with other parts, and loose connections. Replace any parts as necessary. Refer to BR-21, "
Removal
and Installation of Front Brake Piping and Brake Hose".
2. While depressing brake pedal under a force of 785 N (80 kg-f, 177 lb-f) with engine running for approxi- mately 5 seconds, check each part for fluid leaks.
REAR BRAKE
REAR BRAKE : InspectionINFOID:0000000004894491
INSPECTION AFTER REMOVAL
CAUTION:
Brake tubes and hoses are important safety parts. Always disassemble the parts and retighten their fit-
tings, if a brake fluid leak is detected. Replace appl icable part with a new one, if damaged part is
detected.
1. Check brake lines (tubes and hoses) and connections fo r fluid leaks, damage, twists, deformation, con-
tacts with other parts, and loose connections. Replace any parts as necessary. Refer to BR-22, "
Removal
and Installation of Rear Brake Piping and Brake Hose".
2. While depressing brake pedal under a force of 785 N (80 kg-f, 177 lb-f) with engine running for approxi- mately 5 seconds, check each part for fluid leaks.
Revision: March 2010 2008 QX56

BR-16
< ON-VEHICLE MAINTENANCE >
BRAKE PEDAL
2. Loosen lock nut (A) on the input rod, then turn input rod to adjustthe brake pedal to the specified height. When finished adjusting,
tighten the lock nut (A) to specification.
CAUTION:
Make sure that the screw portion of the end of input rod is
located inside the clevis.
3. With the brake pedal pulled up and held by hand, press the stop lamp switch and the ASCD cancel switch in until the threaded
ends contact the brake pedal bracket.
4. With the threaded ends of the stop lamp switch and ASCD switch contacting the pedal bracket, turn the switches 45 ° clock-
wise to lock in place. Check that the stop lamp switch and ASCD
cancel switch threaded end to brake pedal bracket gap (C) is
within specifications.
CAUTION:
Make sure that the gap (C) between the brake pedal bracket
and stop lamp switch and ASCD cancel switch threaded
ends are within specification.
5. Check the brake pedal for smooth operation. CAUTION:
Make sure that the stop lamp goes off when the brake pedal
is released.
6. Start the engine and check the height of the brake pedal when depressing it. Lock nut (A) : 18.7 N·m (1.9 kg-m, 14 ft-lb)
PFIA0436E
Revision: March 2010
2008 QX56

BR-24
< ON-VEHICLE REPAIR >
BRAKE TUBE AND HOSE
1. Check brake lines (tubes and hoses), and connections for fluid leaks, damage, twist, deformation, contact
with other parts, and loose connections. Replace any parts as necessary. Refer to BR-13, "
Hydraulic Cir-
cuit".
2. While depressing brake pedal under a force of 785 N (80 kg-f, 177 lb-f) with engine running for approxi- mately 5 seconds, check each part for fluid leaks.
Revision: March 2010 2008 QX56

BR-28
< ON-VEHICLE REPAIR >
VACUUM LINES
VACUUM LINES
Removal and InstallationINFOID:0000000004894512
REMOVAL
1. Remove engine room cover. Refer to EM-24, "Removal and Installation"
2. Disconnect vacuum hose from hose clip.
3. Release clamps and disconnect vacuum hose.
4. Remove check valve from brake booster.
INSTALLATION
Installation is in the reverse order of removal.
CAUTION:
• Insert vacuum hose for at least 24 mm (0.94 in).
• Do not use lubricating oil during assembly.
1. Hose clip2. Clamp3. Vacuum hose
4. Check valve
LFIA0216E
SBR225B
Revision: March 2010 2008 QX56

INSPECTION AND ADJUSTMENTBRC-9
< BASIC INSPECTION > [VDC/TCS/ABS]
C
D
E
G H
I
J
K L
M A
B
BRC
N
O P
>> GO TO 2
2.PERFORM THE NEUTRAL POSITION ADJUST MENT FOR THE STEERING ANGLE SENSOR
1. On the CONSULT-III screen, touch “WORK SUPP ORT” and “ST ANG SEN ADJUSTMENT” in order.
2. Touch “START”. CAUTION:
Do not touch steering wheel whil e adjusting steering angle sensor.
3. After approximately 10 seconds, touch “END”. NOTE:
After approximately 60 seconds, it ends automatically.
4. Turn ignition switch OFF, then turn it ON again. CAUTION:
Be sure to perform above operation.
>> GO TO 3
3.CHECK DATA MONITOR
1. Run vehicle with front wheels in straight-ahead position, then stop.
2. Select “DATA MONITOR”. Then make sure “STR ANGLE SIG” is within 0 ±2.5 °.
Is the steering angle within the specified range?
YES >> GO TO 4
NO >> Perform the neutral position adjustment fo r the steering angle sensor again, GO TO 1
4.ERASE THE SELF-DIAGNOSIS MEMORY
Erase the self-diagnosis memory of the ABS ac tuator and electric unit (control unit) and ECM.
• ABS actuator and electric unit (control unit): Refer to BRC-24, "
CONSULT-III Function (ABS)".
• ECM: Refer to EC-63, "
CONSULT-III Function (ENGINE)".
Are the memories erased?
YES >> Inspection End
NO >> Check the items indica ted by the self-diagnosis.
CALIBRATION OF DECEL G SENSOR
CALIBRATION OF DECEL G SENSOR : DescriptionINFOID:0000000001686237
Refer to the table below to determine if calibration of the decel G sensor is required.
×: Required –: Not required
CALIBRATION OF DECEL G SENSOR : Special Repair RequirementINFOID:0000000001686238
CALIBRATION OF DECEL G SENSOR
CAUTION:
To calibrate the decel G sensor, make sure to use CONSULT-III
Situation Calibration of decel G sensor
Removing/Insta lling ABS actuator and electr ic unit (control unit) —
Replacing ABS actuator and elec tric unit (control unit) ×
Removing/Installing steering angle sensor ×
Replacing steering angle sensor ×
Removing/Installing steering components ×
Replacing steering components ×
Removing/Installing suspension components ×
Replacing suspension components ×
Change tires to new ones —
Tire rotation —
Adjusting wheel alignment ×
Revision: March 2010 2008 QX56

BRC-10
< BASIC INSPECTION >[VDC/TCS/ABS]
INSPECTION AND ADJUSTMENT
(Calibration cannot be
done without CONSULT-III)
1.ALIGN THE VEHICLE STATUS
Stop vehicle with front wheels in straight-ahead position.
>> GO TO 2
2.PERFORM CALIBRATION OF DECEL G SENSOR
1. On the CONSULT-III screen, touch “WORK SUPPORT” and “DECEL G SEN CALIBRATION” in order.
2. Touch “START”.
3. After approximately 10 seconds, touch “END”. NOTE:
After approximately 60 seconds, it ends automatically.
4. Turn ignition switch OFF, then turn it ON again.
CAUTION:
Be sure to perform above operation.
>> GO TO 3
3.CHECK DATA MONITOR
1. Run vehicle with front wheels in straight-ahead position, then stop.
2. Select “DATA MONITOR”. Then make sure “DECEL G SEN” is within ± 0.08G.
Is the inspection result normal?
YES >> GO TO 4
NO >> Perform calibration of decel G sensor again, GO TO 1
4.ERASE THE SELF-DIAGNOSIS MEMORY
Erase the self-diagnosis memory of the ABS ac tuator and electric unit (control unit) and ECM.
• ABS actuator and electric unit (control unit): Refer to BRC-24, "
CONSULT-III Function (ABS)".
• ECM: Refer to EC-63, "
CONSULT-III Function (ENGINE)".
Are the memories erased?
YES >> Inspection End
NO >> Check the items indicated by the self-diagnosis.
Revision: March 2010 2008 QX56

BRC-12
< FUNCTION DIAGNOSIS >[VDC/TCS/ABS]
VDC
Hydraulic Circuit Diagram
INFOID:0000000005875001
System DescriptionINFOID:0000000001686240
• Vehicle Dynamics Control system detects driver ′s steering operation amount and brake pedal travel from
steering angle sensor and pressure sensors. Using information from yaw rate/side/decel G sensor and
wheel sensor, VDC judges driving condition (conditions of under steer and over steer) to improve vehicle
driving stability by controlling brake application to 4 wheels and engine output.
• During VDC operation, it inform s driver of system operation by flashing SLIP indicator lamp.
• Electrical system diagnosis by CONSULT-III is available.
WFIA0187E
Revision: March 2010 2008 QX56