2007 INFINITI QX56 steering wheel

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-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

BRC-24
< SERVICE INFORMATION >[VDC/TCS/ABS]
TROUBLE DIAGNOSIS
Monitor item Display contentData monitor
Note: Error inspection
checklist
ConditionReference value in
normal operation
N POSI SIGPNP switch signal ON/
OFF conditionA/T shift position = N position ON
LAN-7
A/T shift position = other than N
positionsOFF
P POSI SIGPNP switch signal ON/
OFF conditionA/T shift position P position ON
LAN-7
A/T shift position = other than P
positionsOFF
GEAR A/T gear position1st gear 1
— 2nd gear 2
3rd gear 3
4th gear 4
5th gear 5
FR RH SENSOR
FR LH SENSOR
RR RH SENSOR
RR LH SENSORWheel speedVehicle stopped 0 [km/h (MPH)]
BRC-34, "
Wheel Sensor
System Inspection"Vehicle running (Note 1)Almost in accor-
dance with speed-
ometer display
(within ±10%)
ACCEL POS SIG Open/close condition
of throttle valve (linked
with accelerator pedal).Accelerator pedal not de-
pressed (ignition switch is ON)0%
LAN-7
Depress accelerator pedal (ig-
nition switch is ON)0 to 100%
ENGINE SPEED With engine runningWith engine stopped 0 rpm
BRC-35, "
Engine System
Inspection"Engine runningAlmost in accor-
dance with ta-
chometer display
STR ANGLE SIGSteering angle detect-
ed by steering angle
sensorStraight-ahead Approx. 0 deg
BRC-36, "
Steering Angle
Sensor System"Steering wheel turned –756 to 756 deg
YAW RATE SENYaw rate detected by
yaw rate sensorVehicle stopped Approx. 0 d/sBRC-37, "
Yaw Rate/Side/
Decel G Sensor System
Inspection"Vehicle running –100 to 100 d/s
SIDE G-SENSORTransverse G detected
by side G-sensorVehicle stopped
Approx. 0 m/s
2BRC-37, "Yaw Rate/Side/
Decel G Sensor System
Inspection"Vehicle running
–16.7 to 16.7 m/s2
BATTERY VOLTBattery voltage sup-
plied to ABS actuator
and electric unit (con-
trol unit)Ignition switch ON 10 to 16VBRC-41, "
ABS/TCS/VDC
Control Unit Power and
Ground Systems Inspec-
tion"
STOP LAMP SWStop lamp switch oper-
ationBrake pedal depressed ONBRC-40, "
Stop Lamp
Switch System Inspec-
tion"Brake pedal not depressed OFF
OFF SWVDC OFF switch
ON/OFF status VDC OFF switch ON
(When VDC OFF indicator
lamp is ON)ON
BRC-53, "
Component In-
spection"VDC OFF switch OFF
(When VDC OFF indicator
lamp is OFF)OFF
ABS WARN LAMPABS warning lamp ON
condition (Note 2)ABS warning lamp ON ON
—
ABS warning lamp OFF OFF

BRC-30
< SERVICE INFORMATION >[VDC/TCS/ABS]
TROUBLE DIAGNOSIS
Item
(Unit)Data monitor item selection
Remarks
ECU INPUT
SIGNALSMAIN
SIGNALSSELECTION
FROM MENU
GEAR×××Gear position judged by PNP switch
signal is displayed.
FR RH SENSOR
(km/h, MPH)×××Wheel speed calculated by front RH
wheel sensor signal is displayed.
FR LH SENSOR
(km/h, MPH)×××Wheel speed calculated by front LH
wheel sensor signal is displayed.
RR RH SENSOR
(km/h, MPH)×××Wheel speed calculated by rear RH
wheel sensor signal is displayed.
RR LH SENSOR
(km/h, MPH)×××Wheel speed calculated by rear LH
wheel sensor signal is displayed.
BATTERY VOLT
(V)×××Voltage supplied to ABS actuator
and electric unit (control unit) is dis-
played.
N POSI SIG – –×Shift position judged by PNP switch
signal.
P POSI SIG – –×Shift position judged by PNP switch
signal.
ACCEL POS SIG
(%)×–×Throttle valve open/close status
judged by CAN communication sig-
nal is displayed.
ENGINE SPEED
(rpm)×××Engine speed judged by CAN com-
munication signal is displayed.
STR ANGLE SIG
(deg)×–×Steering angle detected by steering
angle sensor is displayed.
YAW RATE SEN
(d/s)×××Yaw rate detected by yaw rate sen-
sor is displayed.
DECEL G-SEN
(d/s)×××Longitudinal acceleration detected
by decel G-sensor is displayed.
SIDE G-SENSOR
(m/s
2)×– ×Transverse acceleration detected
by side G-sensor is displayed.
STOP LAMP SW
(ON/OFF)×××Stop lamp switch (ON/OFF) status
is displayed.
OFF SW
(ON/OFF) ×× ×VDC OFF switch (ON/OFF) status
is displayed.
ABS WARN LAMP
(ON/OFF)–××ABS warning lamp (ON/OFF) status
is displayed.
SLIP LAMP
(ON/OFF)–××SLIP indicator lamp (ON/OFF) sta-
tus is displayed.
FR LH IN SOL
(ON/OFF)–××Front LH IN ABS solenoid (ON/
OFF) status is displayed.
FR LH OUT SOL
(ON/OFF)–××Front LH OUT ABS solenoid (ON/
OFF) status is displayed.
RR RH IN SOL
(ON/OFF)–××Rear RH IN ABS solenoid (ON/
OFF) status is displayed.
RR RH OUT SOL
(ON/OFF) –××Rear RH OUT ABS solenoid (ON/
OFF) status is displayed.
FR RH IN SOL
(ON/OFF)–××Front RH IN ABS solenoid (ON/
OFF) status is displayed.
FR RH OUT SOL
(ON/OFF)–××Front RH OUT ABS solenoid (ON/
OFF) status is displayed.

TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS
BRC-37
< SERVICE INFORMATION >[VDC/TCS/ABS]
C
D
E
G
H
I
J
K
L
MA
B
BRC
N
O
P
OK or NG
OK >> Perform ABS actuator and electric unit (control unit) self-diagnosis again.
NG >> Replace spiral cable (steering angle sensor) and adjust neutral position of steering angle sensor.
Refer to BRC-54, "
Adjustment of Steering Angle Sensor Neutral Position".
Yaw Rate/Side/Decel G Sensor System InspectionINFOID:0000000003532788
CAUTION:
Sudden turns (such as spin turns, acceleration turns), drifting, etc. when VDC function is OFF may
cause the yaw rate/side/decel G sensor system to indicate a problem. This is not a problem if normal
operation can be resumed after restarting the engine.
INSPECTION PROCEDURE
1.SELF-DIAGNOSIS RESULT CHECK
Check self-diagnosis results.
CAUTION:
If vehicle is on turn table at entrance to parking garage, or on other moving surface, VDC OFF indica-
tor lamp may illuminate and CONSULT-II self-diagnosis may indicate yaw rate sensor system malfunc-
tion. However, in this case there is no malfunction in yaw rate sensor system. Take vehicle off of turn
table or other moving surface, and start engine. Results will return to normal.
Is the above displayed in the self-diagnosis display items?
YES >> GO TO 2.
NO >> Inspection End.
2.CONNECTOR INSPECTION
Disconnect the ABS actuator and electric unit (control unit) connector E125 and yaw rate/side/decel G sensor
connector M108.
Check the terminals for deformation, disconnection, looseness or damage.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace as necessary.
3.YAW RATE/SIDE/DECEL G SENSOR HARNESS INSPECTION
1. Turn off the ignition switch and disconnect yaw rate/side/decel G sensor connector M108 and ABS actua-
tor and electric unit (control unit) connector E125.
2. Check continuity between the ABS actuator and electric unit (control unit) connector E125 and the yaw
rate/side/decel G sensor connector M108.
Steering condition Data monitor
Straight-ahead –3.5 deg to +3.5 deg
Turn wheel to the right by 90°Approx. - 90deg
Turn wheel to the left by 90°Approx. + 90deg
Self-diagnosis results
YAW R AT E S E N S O R
G-SENSOR
SIDE G-SEN CIRCUIT
ABS actuator and electric unit (control
unit) harness connector E125Yaw rate/side/decel G sensor
harness connector M108Continuity

BRC-54
< SERVICE INFORMATION >[VDC/TCS/ABS]
ON-VEHICLE SERVICE
ON-VEHICLE SERVICE
Adjustment of Steering Angle Sensor Neutral PositionINFOID:0000000003532809
After removing/installing or replacing ABS actuator and electric unit (control unit), steering angle sensor, steer-
ing and suspension components which affect wheel alignment or after adjusting wheel alignment, be sure to
adjust neutral position of steering angle sensor before running vehicle.
NOTE:
Adjustment of steering angle sensor neutral position requires CONSULT-II.
1. Stop vehicle with front wheels in straight-ahead position.
2. Connect CONSULT-II and CONSULT-II CONVERTER to data
link connector on vehicle, and turn ignition switch ON (do not
start engine).
3. Touch “START (NISSAN BASED VHCL)”, “ABS”, “WORK SUP-
PORT” and “ST ANGLE SENSOR ADJUSTMENT” on CON-
SULT-II screen in this order.
4. Touch “START”.
CAUTION:
Do not touch steering wheel while adjusting steering angle
sensor.
5. After approximately 10 seconds, touch “END”. (After approxi-
mately 60 seconds, it ends automatically.)
6. Turn ignition switch OFF, then turn it ON again.
7. Run vehicle with front wheels in straight-ahead position, then
stop.
8. Select “DATA MONITOR”, “SELECTION FROM MENU”, and
“STR ANGLE SIG” on CONSULT-II screen. Then check that
“STR ANGLE SIG” is within 0±3.5 deg. If value is more than specification, repeat steps 1 to 5.
9. Erase memory of ABS actuator and electric unit (control unit) and ECM.
10. Turn ignition switch to OFF.
Calibration of Decel G SensorINFOID:0000000003532810
After removing/installing or replacing ABS actuator and electric unit (control unit), yaw rate/side/decel G sen-
sor, steering and suspension components which affect wheel alignment or after adjusting wheel alignment, be
sure to calibrate the decel G sensor before running vehicle.
NOTE:
Calibration of decel G sensor requires CONSULT-II.
1. Stop vehicle with front wheels in straight-ahead position.
CAUTION:
• The work should be done on a level area with an unloaded vehicle.
• Keep all the tires inflated to the correct pressures. Adjust the tire pressure to the specified pres-
sure value.
2. Connect CONSULT-II with CONSULT-II CONVERTER to data link connector on vehicle, and turn ignition
switch ON (do not start engine).
CAUTION:
If CONSULT-II is used with no connection of CONSULT-II CONVERTER, malfunctions might be
detected in self-diagnosis depending on control unit which carries out CAN communication.
3. Touch “START (NISSAN BASED VHCL)”, "ABS", "WORK SUPPORT" and "DECEL G SEN CALIBRA-
TION" on CONSULT-II screen in this order. Refer to BRC-26, "
CONSULT-II Function (ABS)".
BBIA0369E
WFIA0239E