2011 INFINITI QX56 brake sensor

BRC-34
< SYSTEM DESCRIPTION >[WITH VDC]
SYSTEM
Transfer control unit is appli
ed to models with 4WD system.
INPUT SIGNAL AND OUTPUT SIGNAL
Major signal transmission between each unit via communication lines is shown in the following table.
*1: Communication line between yaw rate/side/decal G s ensor and ABS actuator and electric unit (control unit)
*2: Models with 4WD system
EBD FUNCTION
EBD FUNCTION : System DescriptionINFOID:0000000006222575
 By preventing rear wheel slip increase through rear wheel brake force (brake fluid pressure) control that is
electronically controlled when slight skip on front and r ear wheels are detected during braking, stability dur-
ing braking is improved.
JPFIC0184GB
Component Signal description
Yaw rate/side/decel G sensor Mainly transmits the following si
gnals to ABS actuator and electric unit (control unit) via com-
munication line
*1.
 Yaw rate signal
 Side G sensor signal
 Decel G sensor signal
Transfer control unit
*2Mainly transmits the following si gnals to ABS actuator and electric unit (control unit) via CAN
communication.
 Current 4WD mode signal
Combination meter Mainly receives
the following signals from ABS actuator and electric unit (control unit) via CAN
communication.
 ABS warning lamp signal
Revision: 2010 May2011 QX56

SYSTEMBRC-35
< SYSTEM DESCRIPTION > [WITH VDC]
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G H
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BRC
N
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 EBD function is expanded and developed from conventi onal ABS function and corrects rear wheel brake
force to appropriate level by electronic control according to load weight (number of passengers).
 During braking, control unit portion compares slight slip on front and rear wheels by wheel speed sensor signal, transmits drive sig-
nal to actuator portion when rear wheel slip exceeds front wheel
slip for the specified value or more, and controls rear wheel brake
force (brake fluid pressure) so t hat increase of rear wheel slip is
prevented and slips on front wheel and rear wheel are nearly
equalized. ABS control is applied when slip on each wheel
increases and wheel speed is the threshold value of ABS control or
less.
 CONSULT-III can be used to diagnose the system diagnosis.
 Fail-safe function is adopted. When a malfunction occurs in EBD function, the control is suspended for VDC function, TCS function,
ABS function, EBD function, hill start assist function and brake lim-
ited slip differential (BLSD) func tion. The vehicle status becomes
the same as models without VDC function, TCS function, ABS
function, EBD function, hill start assist function and brake limited
slip differential (BLSD) function. Refer to BRC-25, "
Fail-safe".
JPFIC0142GB
JPFIC0143GB
Revision: 2010 May2011 QX56

SYSTEMBRC-37
< SYSTEM DESCRIPTION > [WITH VDC]
C
D
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G H
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K L
M A
B
BRC
N
O P
SYSTEM DIAGRAM
INPUT SIGNAL AND OUTPUT SIGNAL
Major signal transmission between each unit via communication lines is shown in the following table.
*: Communication line between yaw rate/side/decal G s ensor and ABS actuator and electric unit (control unit)
BRAKE LIMITED SLIP DIFFERENTIAL (BLSD) FUNCTION
BRAKE LIMITED SLIP DIFFERENTIAL (BLSD) FUNCTION : System Description
INFOID:0000000006222577
 LH and RH driving wheel spin is always monitored. If necessary, appropriate brake force is independently
applied to LH or RH driving wheel so that one-sided wheel spin is avoided and traction is maintained. Mainly
starting ability is improved.
JPFIC0145GB
Component Signal description
Yaw rate/side/decel G sensor Mainly transmits the following signals to ABS actuator and electric unit (control unit) via com-
munication line *.
 Yaw rate signal
 Side G sensor signal
 Decel G sensor signal
ECM Mainly transmits the following signals to ABS actuator and electric unit (control unit) via CAN
communication.
 Accelerator pedal position signal
 Engine speed signal
Mainly receives the following signals from ABS actuator and electric unit (control unit) via CAN
communication.
 Target throttle position signal
TCM Mainly transmits the following signals to ABS actuator and electric unit (control unit) via CAN
communication.
 Shift position signal
Combination meter Mainly receives the following signals from ABS actuator and electric unit (control unit) via CAN
communication.
 VDC warning lamp signal
 VDC OFF indicator lamp signal
Revision: 2010 May2011 QX56

BRC-38
< SYSTEM DESCRIPTION >[WITH VDC]
SYSTEM
 Brake limited slip differential (BLSD) function operates
while VDC function is in non-operational status (OFF)
by VDC OFF switch.
 VDC warning lamp blinking while brake limited slip di fferential (BLSD) function is in operation and indicates
to the driver that the function is in operation.
 Slight vibrations are felt on the brake pedal and the operation noises occur, when brake limited slip differen-
tial (BLSD) function operates. This is not a malfunction because it is caused by brake limited slip differential
(BLSD) function that is normally operated.
 Fail-safe function is adopted. When a malfunction occurs in brake limited slip differential (BLSD) function,
the control is suspended for VDC function, TCS function, hi ll start assist function and brake limited slip differ-
ential (BLSD) function. The vehicle status becomes the same as models without VDC function, TCS func-
tion, hill start assist function and brake limited slip di fferential (BLSD) function. However, ABS function and
EBD function are operated normally. Refer to BRC-25, "
Fail-safe".
SYSTEM DIAGRAM
NOTE:
Transfer control unit is applied to models with 4WD system.
INPUT SIGNAL AND OUTPUT SIGNAL
Major signal transmission between each unit via communication lines is shown in the following table.
JPFIC0183GB
Component Signal description
Yaw rate/side/decel G sensor Mainly transmits the following si
gnals to ABS actuator and electric unit (control unit) via com-
munication line
*1.
 Yaw rate signal
 Side G sensor signal
 Decel G sensor signal
ECM Mainly transmits the following si
gnals to ABS actuator and electric unit (control unit) via CAN
communication.
 Accelerator pedal position signal
 Engine speed signal
Mainly receives the following signals from ABS actuator and electric unit (control unit) via CAN
communication.
 Target throttle position signal
TCM Mainly transmits the following si
gnals to ABS actuator and electric unit (control unit) via CAN
communication.
 Shift position signal
Revision: 2010 May2011 QX56

DIAGNOSIS SYSTEM [ABS ACTUATOR AND ELECTRIC UNIT (CONTROL
UNIT)]
BRC-41
< SYSTEM DESCRIPTION > [WITH VDC]
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FR RH IN SOL
(On/Off) ×Operation status of front
RH wheel ABS IN valve is dis-
played.
FR RH OUT SOL
(On/Off) ×Operation status of front
RH wheel ABS OUT valve is dis-
played.
FR LH IN SOL
(On/Off) ×
Operation status of front LH wheel ABS IN valve is dis-
played.
FR LH OUT SOL
(On/Off) ×Operation status of front LH wheel ABS OUT valve is dis-
played.
RR RH IN SOL
(On/Off) ×
Operation status of rear RH wh eel ABS IN valve is displayed
RR RH OUT SOL
(On/Off) ×
Operation status of rear RH wheel ABS OUT valve is dis-
played.
RR LH IN SOL
(On/Off) ×Operation status of rear LH
wheel ABS IN valve is dis-
played.
RR LH OUT SOL
(On/Off) ×Operation status of rear LH
wheel ABS OUT valve is dis-
played.
EBD WARN LAMP
(On/Off) Brake warning lamp ON/OFF status is displayed.
(Note 1)
STOP LAMP SW
(On/Off)××
Stop lamp switch signal input status is displayed.
MOTOR RELAY
(On/Off) ×
ABS motor and motor relay status is displayed.
ACTUATOR RLY
(On/Off) ×
ABS actuator relay status is displayed.
ABS WARN LAMP
(On/Off) ×
ABS warning lamp ON/OFF status is displayed.
(Note 1)
OFF LAMP
(On/Off) ×
VDC OFF indicator lamp ON/OFF status is displayed.(Note 1)
OFF SW
(On/Off) ××
VDC OFF switch signal input status is displayed.
SLIP/VDC LAMP
(On/Off) ×
VDC warning lamp ON/OFF status is displayed.
(Note 1)
BATTERY VOLT
(V) ××Voltage supplied to ABS actuator and electric unit (control
unit) is displayed.
GEAR ××Current gear position judged from current gear position sig-
nal is displayed.
ENGINE SPEED
(tr/min) ××
Engine speed status is displayed.
YAW RATE SEN
(d/s) ××
Yaw rate detected by yaw rate sensor is displayed.
R POSI SIG
(On/Off) R range signal input status judged from R range signal is
displayed.
4WD MODE MON
(Note 2)
(AUTO/LOCK/##) ××
4WD control status is displayed.
N POSI SIG
(On/Off) N range signal input status judged from N range signal is
displayed.
CV1
(On/Off) Cut valve 1 operation status is displayed.
CV2
(On/Off) Cut valve 2 operation status is displayed.
SV1
(On/Off) Suction valve 1 operation status is displayed.
Item (Unit)
Monitor item selection
Note
INPUT SIGNALS MAIN ITEMS
Revision: 2010 May2011 QX56

BRC-42
< SYSTEM DESCRIPTION >[WITH VDC]
DIAGNOSIS SYSTEM [
ABS ACTUATOR AND ELECTRIC UNIT (CONTROL
UNIT)]
Note 1: Refer to BRC-16, "System Description" for ON/OFF conditions of each warning lamp and indicator
lamp.
Note 2: Models with 4WD System
Note 3: Models with Advanced Driver Assistance System
Note 4: USS means “hill start assist”
ACTIVE TEST
The active test is used to determine and identify details of a malfunction, based on self-diagnosis test result
sand data obtained in the DATA MONITOR. In response to instructions from CONSULT-III, instead of those
SV2
(On/Off) Suction valve 2 operation status is displayed.
STOP LAMP SW2
(On/Off) Stop lamp switch signal input status is displayed.
ACCEL POS SIG
(%) ×
Displays the Accelerator pedal position
SIDE G-SENSOR
(m/s
2) ×
Side G detected by side G sensor is displayed.
STR ANGLE SIG
( ° ) ×
Steering angle detected by steering angle sensor is dis-
played.
PRESS SENSOR
(bar) ×Detects the brake fluid pressure of master cylinder part is
displayed.
ACCUM PRESS SEN
(bar) Detects the brake fluid pressure of accumulator is dis-
played.
CONT PRESS SEN
(Note 3)
(bar) Detects the brake fluid pressure of control pressure sensor
is displayed
EBD SIGNAL
(On/Off) EBD operation status is displayed.
ABS SIGNAL
(On/Off) ABS operation status is displayed.
TCS SIGNAL
(On/Off) TCS operation status is displayed.
VDC SIGNAL
(On/Off) VDC operation status is displayed.
EBD FAIL SIG
(On/Off) EBD fail-safe signal status is displayed.
ABS FAIL SIG
(On/Off) ABS fail-safe signal st
atus is displayed.
TCS FAIL SIG
(On/Off) TCS fail-safe signal status is displayed.
VDC FAIL SIG
(On/Off) VDC fail-safe signal status is displayed.
CRANKING SIG
(On/Off) Cranking status is displayed.
FLUID LEV SW
(On/Off) ×Brake fluid level signal input status via CAN communication
is displayed.
PARK BRAKE SW
(On/Off) ×Parking brake switch signal input status via CAN communi-
cation is displayed.
STP ON RLY
(On/Off) Stop lamp switch relay status is displayed.
USS SIG
(Note 4)
(On/Off) hill start assist operation status is displayed.
Item (Unit)
Monitor item selection
Note
INPUT SIGNALS MAIN ITEMS
Revision: 2010 May2011 QX56

ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)BRC-45
< ECU DIAGNOSIS INFORMATION > [WITH VDC]
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G H
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BRC
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ECU DIAGNOSIS INFORMATION
ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)
Reference ValueINFOID:0000000006222579
CONSULT-III DATA MONITOR STANDARD VALUE
Monitor item Condition Reference values in normal operation
FR LH SENSOR Vehicle stopped 0.00 km/h (MPH)
When driving
(Note 1)Nearly matches the speedometer dis-
play (within
±10%)
FR RH SENSOR Vehicle stopped 0.00 km/h (MPH)
When driving
(Note 1)Nearly matches the speedometer dis-
play (within
±10%)
RR LH SENSOR Vehicle stopped 0.00 km/h (MPH)
When driving
(Note 1)Nearly matches the speedometer dis-
play (within
±10%)
RR RH SENSOR Vehicle stopped 0.00 km/h (MPH)
When driving
(Note 1)Nearly matches the speedometer dis-
play (within
±10%)
DECEL G-SEN When stopped Approx. 0 G
During acceleration Positive value
During deceleration Negative value
FR RH IN SOL Active On
Inactive Off
FR RH OUT SOL Active On
Inactive Off
FR LH IN SOL Active On
Inactive Off
FR LH OUT SOL Active On
Inactive Off
RR RH IN SOL Active On
Inactive Off
RR RH OUT SOL Active On
Inactive Off
RR LH IN SOL Active On
Inactive Off
RR LH OUT SOL Active On
Inactive Off
EBD WARN LAMP When brake warning lamp is ON
(Note 2)On
When brake warning lamp is OFF
(Note 2)Off
STOP LAMP SW Brake pedal depressed On
Brake pedal not depressed Off
MOTOR RELAY Active On
Inactive Off
ACTUATOR RLY Active On
Inactive (in fail-safe mode) Off
Revision: 2010 May2011 QX56

BRC-46
< ECU DIAGNOSIS INFORMATION >[WITH VDC]
ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)
ABS WARN LAMPWhen ABS warning lamp is ON
(Note 2)On
When ABS warning lamp is OFF
(Note 2)Off
OFF LAMP When VDC OFF indicator lamp is ON
(Note 2)On
When VDC OFF indicator lamp is OFF
(Note 2)Off
OFF SW VDC OFF switch ON On
VDC OFF switch OFF Off
SLIP/VDC LAMP When VDC warning lamp is ON or Blinking
(Note 2)On
When VDC warning lamp is OFF
(Note 2)Off
BATTERY VOLT Ignition switch ON 10 – 16 V
GEAR Driving 1 – 7
Depending on shift status
ENGINE SPEED Engine stopped 0 tr/min
Engine running Almost same reading as tachometer
YAW RATE SEN Vehicle stopped Approx. 0 d/s
Turning right Negative value
Turning left Positive value
R POSI SIG When selector lever is in the R position On
When selector lever is in the other position than R Off
4WD MODE MON
(Note 3)
When 4WD sift switch is AUTO position AUTO
When 4WD sift switch is 4H position LOCK
When 4WD sift switch is 4L position ##
N POSI SIG When selector lever is in the N position On
When selector lever is in the other position than N Off
CV1 Active On
Inactive Off
CV2 Active On
Inactive Off
SV1 Active On
Inactive Off
SV2 Active On
Inactive Off
STOP LAMP SW2 Brake pedal depressed On
Brake pedal not depressed Off
ACCEL POS SIG Never depress accelerator pedal
(with ignition switch ON)
0%
Depress accelerator pedal
(with ignition switch ON) 0 – 100%
SIDE G-SENSOR Vehicle stopped
Approx. 0 m/s
2
Right turn Negative value
Left turn Positive value
STR ANGLE SIG When driving straight 0
±2.5 °
When steering wheel is steered to LH by 90 °Approx. +90 °
When steering wheel is steered to RH by 90 °Approx. –90 °
Monitor item Condition Reference values in normal operation
Revision: 2010 May2011 QX56