2007 INFINITI QX56 sensor

BRAKE MASTER CYLINDER
BR-13
< SERVICE INFORMATION >
C
D
E
G
H
I
J
K
L
MA
B
BR
N
O
P
BRAKE MASTER CYLINDER
On Board InspectionINFOID:0000000003532731
LEAK INSPECTION
• Check for leaks at brake master cylinder to brake booster attachment point, reservoir tank, and brake tube
connections.
Removal and InstallationINFOID:0000000003532732
REMOVAL
CAUTION:
• Be careful not to splash brake fluid on painted areas; it may cause paint damage. If brake fluid is
splashed on painted areas, wash it away with water immediately.
• Before removing brake brake master cylinder, depress the brake pedal 5-6 times with the key OFF to
deplete vacuum in the booster.
1. Drain brake fluid. Refer to BR-8, "
Drain and Refill" .
2. Disconnect harness connectors for fluid level sensor and pressure sensors.
3. Using a flare nut wrench, disconnect brake tube from brake master cylinder.
4. Remove brake master cylinder mounting nuts, and master cylinder assembly.
INSTALLATION
• Installation is in the reverse order of removal.
1. Reservoir cap 2. Fluid level sensor 3. Grommet
4. Master cylinder sub-assembly 5. Front pressure sensor 6. Rear pressure sensor
7. Seal 8. Reservoir tank B. Brake fluid
R. Rubber grease
WFIA0450E

BRAKE BOOSTER
BR-15
< SERVICE INFORMATION >
C
D
E
G
H
I
J
K
L
MA
B
BR
N
O
P
BRAKE BOOSTER
On-Vehicle ServiceINFOID:0000000003532734
OPERATING CHECK
With engine stopped, change the vacuum to the atmospheric pres-
sure by depressing brake pedal several times. Then with brake
pedal fully depressed, start engine and when the vacuum pressure
reaches the standard, make sure the clearance between brake pedal
and floor panel decreases.
CAUTION:
Depressing pedal interval is approximately 5 seconds.
AIRTIGHT CHECK
• Run engine at idle for approximately 1 minute, and stop it after
applying vacuum to booster. Depress brake pedal normally to
change the vacuum to the atmospheric pressure. Make sure dis-
tance 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.
CAUTION:
Depressing pedal interval is approximately 5 seconds.
Removal and InstallationINFOID:0000000003532735
REMOVAL
CAUTION:
• Be careful not to deform or bend brake piping while removing and installing brake booster.
• Replace clevis pin if it is damaged.
BRA0037D
SBR365AA
1. Reservoir tank 2. Brake master cylinder 3. Gasket
4. Brake pedal 5. Lock nut 6. Spacer block
7. Brake booster 8. Active booster 9. Delta stroke sensor
WFIA0381E

BR-16
< SERVICE INFORMATION >
BRAKE BOOSTER
• Be careful not to damage brake booster stud bolt threads. If brake booster is tilted or inclined during
installation, dash panel may damage the threads.
• Attach the check valve in the correct direction.
1. Remove engine room cover with power tool. Refer to EM-12, "
Removal and Installation" .
2. Remove engine air duct assembly. Refer to EM-15, "
Removal and Installation" .
3. Remove brake piping from brake master cylinder.
4. Remove brake master cylinder. Refer to BR-13, "
Removal and Installation" .
5. Remove vacuum hose from brake booster. Refer to BR-17
.
6. Disconnect active boost and delta stroke sensor harness connectors from brake booster assembly.
7. Remove brake pedal attachment snap pin and clevis pin from inside the vehicle.
8. Remove nuts on brake booster and brake pedal assembly.
9. Remove brake booster assembly from dash panel.
INSPECTION AFTER REMOVAL
Output Rod Length Inspection
1. Using a handy vacuum pump, apply a vacuum of – 66.7 kPa (–
500 mmHg, –19.69 inHg) to brake booster.
2. Check output rod length.
INSTALLATION
1. Loosen lock nut to adjust input rod length so that the length B (in
the figure) satisfies the specified value.
2. After adjusting “B”, temporarily tighten lock nut and install
booster assembly to the vehicle.
• Install a gaskets and spacer block between booster assembly
and the dash panel.
3. Connect brake pedal with clevis of input rod.
4. Install pedal bracket mounting nuts and tighten them to the
specified torque.
5. Install brake piping from brake master cylinder to ABS actuator. Refer to BR-10, "
Hydraulic Circuit".
6. Connect active boost and delta stroke sensor harness connectors to brake booster assembly.
7. Connect vacuum hose to brake booster.
8. Install master cylinder to booster assembly. Refer to BR-13, "
Removal and Installation" .
9. Adjust the height and play of brake pedal.
10. Tighten lock nut of input rod to specification.
11. Install engine air duct assembly. Refer to EM-15, "
Removal and Installation" .
12. Install engine room cover with power tool. Refer to EM-12, "
Removal and Installation" .
13. Refill with new brake fluid and bleed air. Refer to BR-8, "
Bleeding Brake System" .
SBR208E
Standard dimension : 15.6 − 15.9 mm (0.614 − 0.626 in)
[when vacuum is – 66.7 kPa (– 500 mmHg, – 19.69 inHg)]
Length “B” : 151 mm (5.94 in)
WFIA0382E

BRC-1
BRAKES
C
D
E
G
H
I
J
K
L
M
SECTION BRC
A
B
BRC
N
O
P
CONTENTS
BRAKE CONTROL SYSTEM
VDC/TCS/ABS
SERVICE INFORMATION ............................
3
PRECAUTIONS ...................................................3
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" ...................................................................
3
Precaution for Brake System ....................................3
Precaution When Using CONSULT-II .......................3
Precaution for Brake Control .....................................4
Precaution for CAN System ......................................4
PREPARATION ...................................................6
Special Service Tool .................................................6
Commercial Service Tool ..........................................6
SYSTEM DESCRIPTION .....................................7
System Component ...................................................7
ABS Function ............................................................8
EBD Function ............................................................8
TCS Function ............................................................8
VDC Function ............................................................8
Fail-Safe Function .....................................................8
Hydraulic Circuit Diagram .........................................9
CAN COMMUNICATION ....................................10
System Description .................................................10
TROUBLE DIAGNOSIS .....................................11
How to Perform Trouble Diagnosis for Quick and
Accurate Repair ......................................................
11
Component Parts and Harness Connector Loca-
tion ..........................................................................
14
Schematic ...............................................................15
Wiring Diagram - VDC - ..........................................16
Basic Inspection ......................................................22
Warning Lamp and Indicator Timing .......................23
Control Unit Input/Output Signal Standard ..............23
CONSULT-II Function (ABS) ..................................26
TROUBLE DIAGNOSIS FOR SELF-DIAG-
NOSTIC ITEMS .................................................
34
Wheel Sensor System Inspection ............................34
Engine System Inspection .......................................35
ABS/TCS/VDC Control Unit Inspection ...................35
Steering Angle Sensor System ................................36
Yaw Rate/Side/Decel G Sensor System Inspec-
tion ...........................................................................
37
Solenoid and VDC Change-Over Valve System
Inspection ................................................................
38
Actuator Motor, Motor Relay, and Circuit Inspec-
tion ...........................................................................
39
Stop Lamp Switch System Inspection .....................40
ABS/TCS/VDC Control Unit Power and Ground
Systems Inspection .................................................
41
Brake Fluid Level Switch System Inspection ...........42
Active Booster System Inspection ...........................43
Delta Stroke Sensor System Inspection ..................44
Pressure Sensor System Inspection .......................45
Steering Angle Sensor Safe Mode Inspection .........47
CAN Communication System Inspection .................48
ICC System Inspection ............................................48
Inspection for Self-Diagnosis Result "ST ANG
SEN SIGNAL" ..........................................................
48
Inspection for Self-Diagnosis Result "DECEL G
SEN SET" ................................................................
49
TROUBLE DIAGNOSES FOR SYMPTOMS .....50
ABS Works Frequently ............................................50
Unexpected Pedal Action ........................................50
Long Stopping Distance ..........................................51
ABS Does Not Work ................................................51
Pedal Vibration or ABS Operation Noise .................51
Vehicle Jerks During TCS/VDC Activation ..............52
Component Inspection .............................................53
ON-VEHICLE SERVICE ....................................54
Adjustment of Steering Angle Sensor Neutral Po-
sition ........................................................................
54
Calibration of Decel G Sensor .................................54

BRC-2
WHEEL SENSOR ..............................................56
Removal and Installation ........................................56
SENSOR ROTOR ..............................................57
Removal and Installation ........................................57
ACTUATOR AND ELECTRIC UNIT (ASSEM-
BLY) ...................................................................
58
Removal and Installation .........................................58
STEERING ANGLE SENSOR ...........................60
Removal and Installation .........................................60
G SENSOR ........................................................61
Removal and Installation .........................................61

BRC-4
< SERVICE INFORMATION >[VDC/TCS/ABS]
PRECAUTIONS
• If YES, GO TO 2.
• If NO, GO TO 5.
2. Is there any indication other than indications relating to CAN communication system in the self-diagnosis
results?
• If YES, GO TO 3.
• If NO, GO TO 4.
3. Based on self-diagnosis results unrelated to CAN communication, carry out the inspection.
4. Malfunctions may be detected in self-diagnosis depending on control units carrying out CAN communica-
tion. Therefor, erase the self-diagnosis results.
5. Diagnose CAN communication system. Refer to LAN-7
.
Precaution for Brake ControlINFOID:0000000003532764
• During ABS operation, the brake pedal may vibrate lightly and a mechanical noise may be heard. This is
normal.
• Just after starting vehicle, the brake pedal may vibrate or a motor operating noise may be heard from engine
compartment. This is a normal status of operation check.
• Stopping distance may be longer than that of vehicles without ABS when vehicle drives on rough, gravel, or
snow-covered (fresh, deep snow) roads.
• When an error is indicated by ABS or another warning lamp, collect all necessary information from customer
(what symptoms are present under what conditions) and check for simple causes before starting diagnosis.
Besides electrical system inspection, check booster operation, brake fluid level, and fluid leaks.
• If incorrect tire sizes or types are installed on the vehicle or brake pads are not Genuine NISSAN parts, stop-
ping distance or steering stability may deteriorate.
• If there is a radio, antenna or related wiring near control module, ABS function may have a malfunction or
error.
• If aftermarket parts (car stereo, CD player, etc.) have been installed, check for incidents such as harness
pinches, open circuits or improper wiring.
• If the following components are replaced with non-genuine components or modified, the VDC OFF indicator
lamp and SLIP indicator lamp may turn on or the VDC system may not operate properly. Components
related to suspension (shock absorbers, struts, springs, bushings, etc.), tires, wheels (exclude specified
size), components related to brake system (pads, rotors, calipers, etc.), components related to engine (muf-
fler, ECM, etc.), components related to body reinforcement (roll bar, tower bar, etc.).
• Driving with broken or excessively worn suspension components, tires or brake system components may
cause the VDC OFF indicator lamp and the SLIP indicator lamp to turn on, and the VDC system may not
operate properly.
• When the TCS or VDC is activated by sudden acceleration or sudden turn, some noise may occur. The
noise is a result of the normal operation of the TCS and VDC.
• When driving on roads which have extreme slopes (such as mountainous roads) or high banks (such as
sharp curves on a freeway), the VDC may not operate normally, or the VDC warning lamp and the SLIP indi-
cator lamp may turn on. This is not a problem if normal operation can be resumed after restarting the engine.
• Sudden turns (such as spin turns, acceleration turns), drifting, etc. with VDC turned off may cause the yaw
rate/side/decel G sensor to indicate a problem. This is not a problem if normal operation can be resumed
after restarting the engine.
Precaution for CAN SystemINFOID:0000000003532765
• Do not apply voltage of 7.0V or higher to terminal to be measured.
• Maximum open terminal voltage of tester in use must be less than 7.0V.
• Before checking harnesses, turn ignition switch OFF and disconnect battery negative cable.

BRC-6
< SERVICE INFORMATION >[VDC/TCS/ABS]
PREPARATION
PREPARATION
Special Service ToolINFOID:0000000003532766
The actual shapes of Kent-Moore tools may differ from those of special service tools illustrated here.
Commercial Service ToolINFOID:0000000003532767
Tool number
(Kent-Moore No.)
Tool nameDescription
—
(J-45741)
ABS active wheel sensor testerChecking operation of ABS active wheel sen-
sors
WFIA0101E
Tool nameDescription
1. Flare nut crowfoot
2. Torque wrenchRemoving and installing brake piping
a: 10mm (0.39 in)/12mm (0.47 in)
S-NT360

BRC-8
< SERVICE INFORMATION >[VDC/TCS/ABS]
SYSTEM DESCRIPTION
ABS Function
INFOID:0000000003532769
• The Anti-Lock Brake System detects wheel revolution while braking and improves handling stability during
sudden braking by electrically preventing wheel lockup. Maneuverability is also improved for avoiding obsta-
cles.
• If the electrical system malfunctions, the Fail-Safe function is activated, the ABS becomes inoperative and
the ABS warning lamp turns on.
• The electrical system can be diagnosed using CONSULT-II.
• During ABS operation, the brake pedal may vibrate lightly and a mechanical noise may be heard. This is
normal.
• Just after starting the vehicle, the brake pedal may vibrate or a motor operating noise may be heard from
engine compartment. This is a normal status of operation check.
• Stopping distance may be longer than that of vehicles without ABS when vehicle drives on rough, gravel, or
snow-covered (fresh, deep snow) roads.
EBD FunctionINFOID:0000000003532770
• Electronic Brake Distribution is a function that detects subtle slippages between the front and rear wheels
during braking, and it improves handling stability by electronically controlling the brake fluid pressure which
results in reduced rear wheel slippage.
• If the electrical system malfunctions, the Fail-Safe function is activated, the EBD and ABS become inopera-
tive, and the ABS warning lamp and BRAKE warning lamp are turned on.
• The electrical system can be diagnosed using CONSULT-II.
• During EBD operation, the brake pedal may vibrate lightly and a mechanical noise may be heard. This is
normal.
• Just after starting the vehicle, the brake pedal may vibrate or a motor operating noise may be heard from
engine compartment. This is a normal status of operation check.
TCS FunctionINFOID:0000000003532771
• Spinning of the drive wheels is detected by the ABS actuator and electric unit (control unit) using inputs from
the wheel speed sensors. If wheel spin occurs, the drive wheel right and left brake fluid pressure control and
engine fuel cut are activated while the throttle value is restricted to reduce the engine torque and decrease
the amount of wheel spin. In addition, the throttle opening is controlled to achieve the optimum engine
torque.
• Depending on road condition, the vehicle may have a sluggish feel. This is normal, because optimum trac-
tion has the highest priority during TCS operation.
• TCS may be activated during sudden vehicle acceleration, wide open throttle acceleration, sudden transmis-
sion shifts or when the vehicle is driven on a road with a varying surface friction coefficient.
• The SLIP indicator lamp flashes to inform the driver of TCS operation.
VDC FunctionINFOID:0000000003532772
• In addition to the ABS/TCS function, the driver steering amount and brake operation amount are detected
from the steering angle sensor and front and rear pressure sensors, and the vehicle's driving status (amount
of under steering/over steering) is determined using inputs from the yaw rate sensor/side G sensor, wheel
speed sensors, etc. and this information is used to improve vehicle stability by controlling the braking and
engine torque application to the wheels.
• The SLIP indicator lamp flashes to inform the driver of VDC operation.
• During VDC operation, the vehicle body and brake pedal may vibrate lightly and a mechanical noise may be
heard. This is normal.
• The ABS warning lamp, VDC OFF indicator lamp and SLIP indicator lamp may turn on when the vehicle is
subject to strong shaking or large vibration, such as when the vehicle is on a turn table or a ship while the
engine is running or on a steep slope. In this case, restart the engine on a normal road and if the ABS warn-
ing lamp, VDC OFF indicator lamp and SLIP indicator lamp turn off, there is no problem.
Fail-Safe FunctionINFOID:0000000003532773
CAUTION:
If the Fail-Safe function is activated, perform the Self Diagnosis for ABS/TCS/VDC system.
ABS/EBD SYSTEM