brake sensor INFINITI QX56 2011 Factory Owner's Manual

SYSTEMBRC-17
< SYSTEM DESCRIPTION > [WITH VDC]
C
D
E
G H
I
J
K L
M A
B
BRC
N
O P*1: Communication line between yaw rate/side/decal G s ensor and ABS actuator and electric unit (control unit)
*2: Models with 4WD system
VALVE OPERATION
Each valve is operated and fluid pressure of brake caliper is controlled.
When Ordinary Brake is Applied
NOTE:
Control pressure sensor is applied to model s with Advanced Driver Assistance System.
TCMMainly transmits the following signals to ABS actuator and electric unit (control unit) via CAN
communication.
 Shift position signal
 Current gear position signal
Transfer control unit
*2Mainly transmits the following signals to ABS actuator and electric unit (control unit) via CAN
communication.
 Current 4WD mode signal
Steering angle sensor Mainly transmits the following signals to ABS actuator and electric unit (control unit) via CAN
communication.
 Steering angle sensor signal
Combination meter Mainly receives the following signals from ABS actuator and electric unit (control unit) via CAN
communication.
 ABS warning lamp signal
 Brake warning lamp signal
 VDC warning lamp signal
 VDC OFF indicator lamp
Component Signal description
Name Not activated When depressing brake pedal
Cut valve 1 Power supply is not supplied (open) Power supply is not supplied (open)
Cut valve 2 Power supply is not supplied (open) Power supply is not supplied (open)
Suction valve 1 Power supply is not supplied (close) Power supply is not supplied (close)
Suction valve 2 Power supply is not supplied (close) Power supply is not supplied (close)
JPFIC0150GB
Revision: 2010 May2011 QX56

BRC-18
< SYSTEM DESCRIPTION >[WITH VDC]
SYSTEM
Front RH caliper
 Pressurized brake fluid from accumulator is supplied
to front RH caliper through master cylinder part, cut
valve 1 and ABS IN valve.
Front LH caliper
 Pressurized brake fluid from accumulator is supplied to front LH caliper through master cylinder part, cut
valve 1 and ABS IN valve.
Rear RH caliper
 Pressurized brake fluid from accumulator is supplied to rear RH caliper through master cylinder part, cut
valve 2 and ABS IN valve.
Rear LH caliper
 Pressurized brake fluid from accumulator is supplied to rear LH caliper through master cylinder part, cut
valve 2 and ABS IN valve.
ABS is Operation (When Pressure Increases)
NOTE:
Control pressure sensor is applied to m odels with Advanced Driver Assistance System.
ABS IN valve Power supply is not supplied (open) Power supply is not supplied (open)
ABS OUT valve Power supply is not supplied (close) Power supply is not supplied (close)
Each caliper (fluid pressure) — Pressure increasesName Not activated When depressing brake pedal
Name Not activated When Pressure Increases
Cut valve 1 Power supply is not supplied (open) Power supply is supplied (close)
Cut valve 2 Power supply is not supplied (open) Power supply is not supplied (open)
Suction valve 1 Power supply is not supplied (close) Power supply is supplied (open)
Suction valve 2 Power supply is not supplied (close) Power supply is not supplied (close)
ABS IN valve Power supply is not supplied (open) Power supply is not supplied (open)
JPFIC0153GB
Revision: 2010 May2011 QX56

SYSTEMBRC-19
< SYSTEM DESCRIPTION > [WITH VDC]
C
D
E
G H
I
J
K L
M A
B
BRC
N
O P
Front RH caliper
 Pressurized brake fluid from accumulator is supplied to front RH caliper through master cylinder part, cut
valve 2, suction valve 1 and ABS IN valve.
Front LH caliper
 Pressurized brake fluid from accumulator is supplied to front LH caliper through master cylinder part, cut
valve 2, suction valve 1 and ABS IN valve.
Rear RH caliper
 Pressurized brake fluid from accumulator is supplied to rear RH caliper through master cylinder part, cut valve 2 and ABS IN valve.
Rear LH caliper
 Pressurized brake fluid from accumulator is supplied to rear LH caliper through master cylinder part, cut
valve 2 and ABS IN valve.
ABS is Operation (Whe n Pressure Holds)
NOTE:
Control pressure sensor is applied to model s with Advanced Driver Assistance System.
ABS OUT valve Power supp ly is not supplied (close) Power supply is not supplied (close)
Each caliper (fluid pressure) — Pressure increases Name Not activated When Pressure Increases
Name Not activated When Pressure Increases
Cut valve 1 Power supply is not supplied (open) Power supply is supplied (close)
Cut valve 2 Power supply is not supplied (open) Power supply is not supplied (open)
Suction valve 1 Power supply is not supplied (close) Power supply is supplied (open)
Suction valve 2 Power supply is not supplied (close) Power supply is not supplied (close)
ABS IN valve Power supp ly is not supplied (open) Power supply is supplied (close)
ABS OUT valve Power supp ly is not supplied (close) Power supply is not supplied (close)
Each caliper (fluid pressure) — Pressure holds
JPFIC0179GB
Revision: 2010 May2011 QX56

SYSTEMBRC-21
< SYSTEM DESCRIPTION > [WITH VDC]
C
D
E
G H
I
J
K L
M A
B
BRC
N
O P
 Being returned to reservoir tank through ABS OUT valve, fluid pressure of rear LH caliper is decreased.
VDC is Operation (When Pressure Increases)
NOTE:
Control pressure sensor is applied to models with Advanced Driver Assistance System.
Example: When other than rear LH wheel is operation in the figure.
Front RH caliper Pressurized brake fluid from accumulator is supplied to front RH caliper through suction valve 2, suction
valve 1 and ABS IN valve. When not increases, ABS IN valve is closed and brakes fluid is not supplied to
front RH caliper.
Front LH caliper
 Pressurized brake fluid from accumulator is supplied to front LH caliper through suction valve 2, suction
valve 1 and ABS IN valve. When not increases, ABS IN valve is closed and brakes fluid is not supplied to
front LH caliper.
Rear RH caliper
Name Not activated When Pressure Increases
Cut valve 1 Power supply is not supplied (open) Power supply is supplied (close)
Cut valve 2 Power supply is not supplied (open) Power supply is supplied (close)
Suction valve 1 Power supply is not supplied (close) Power supply is supplied (open)
Suction valve 2 Power supply is not supplied (close) Power supply is supplied (open)
ABS IN valve Power supply is not supplied (open) Only wheel that the pressure is to be in-
creased: Power supply is not supplied (open)
Wheel other than the one that the pressure
is to be increased: Power supply is supplied (close)
ABS OUT valve Power supp ly is not supplied (close) Power supply is not supplied (close)
Each caliper (fluid pressure) — Pressure increases (only wheel that the
pressure is to be increased)
JPFIC0154GB
Revision: 2010 May2011 QX56

BRC-22
< SYSTEM DESCRIPTION >[WITH VDC]
SYSTEM
 Pressurized brake fluid from accumulator is supplied to rear RH caliper through suction valve 2 and ABS IN
valve. When not increases, ABS IN valve is closed and brakes fluid is not supplied to rear RH caliper.
Rear LH caliper Pressurized brake fluid from accumulator is supplied to rear LH caliper through suction valve 2 and ABS IN
valve. When not increases, ABS IN va lve is closed and brakes fluid is not supplied to rear LH caliper.
VDC is Operation (When Pressure Holds)
NOTE:
Control pressure sensor is applied to m odels with Advanced Driver Assistance System.
Example: When other than front LH wheel is operation in the figure.
Front RH caliper ABS IN valve is close, fluid pressure of front RH caliper is holds.
Front LH caliper
 ABS IN valve is close, fluid pressure of front LH caliper is holds.
Rear RH caliper
 ABS IN valve is close, fluid pressure of rear RH caliper is holds.
Name Not activated When Pressure holds
Cut valve 1 Power supply is not supplied (open) Power supply is supplied (close)
Cut valve 2 Power supply is not supplied (open) Power supply is supplied (close)
Suction valve 1 Power supply is not supplied (close) Power supply is supplied (open)
Suction valve 2 Power supply is not supplied (close) Power supply is supplied (open)
ABS IN valve Power supply is not supplied (open) Only wheel that the pressure is to be holds:
Power supply is supplied (close)
Wheel other than the one that the pressure
is to be holds: Power supply is not supplied (open)
ABS OUT valve Power supply is not supplied (close) Power supply is not supplied (close)
Each caliper (f luid pressure) — Pressure holds (only wheel that the pres-
sure is to be holds)
JPFIC0180GB
Revision: 2010 May2011 QX56

BRC-24
< SYSTEM DESCRIPTION >[WITH VDC]
SYSTEM
Rear LH caliper Being returned to reservoir tank through ABS OUT valve, fluid pressure of rear LH caliper is decreased.
Component Parts and Function
*: Models with Advanced Driver Assistance System
CONDITION FOR TURN ON THE WARNING LAMP
ABS Warning Lamp
 Turns ON at the same time as VDC warning lamp
when either ABS function or EBD function is malfunction-
ing.
 Turns ON when ignition switch turns ON and turns OFF when the system is normal, for bulb check purposes.
Brake Warning Lamp
 Turns ON at the same time as ABS warning lamp and VDC warning lamp when EBD function, motor/accu- mulator assembly or motor system is malfunctioning.
 Turns ON when ignition switch turns ON and turns OFF when the system is normal, for bulb check purposes.
Component Function
Pump Operates the pump drive according
to signals from ABS actuator and electric unit (control unit) by
the motor.
Motor Operates the motor driv e according to signals from ABS actuator and electric unit (control unit).
Accumulator The accumulator accumulates brake fluid conveyed by the motor and pump.
ABS IN valve Increases, holds or decreases the fluid pressure of each caliper according to signals from ABS ac-
tuator and electric unit (control unit).
ABS OUT valve Increases, holds or decreases the fluid pressure of each caliper according to signals from ABS ac-
tuator and electric unit (control unit).
Cut valve 1
Cut valve 2 Shuts off the ordinary brake line fr
om master cylinder to signals from ABS actuator and electric unit
(control unit).
Suction valve 1 Suction Valve 1 switches the brake line to convey accumulator pressure to the front system, accord-
ing to a signal transmitted from the ABS ac
tuator and electric unit (control unit).
Suction valve 2 Suction valve 2 releases
accumulator pressure, acco rding to a signal transmitted from the ABS ac-
tuator and electric unit (control unit).
Control pressure sensor
*Detects the brake fluid pressure of rear brake caliper and transmits a signal to ABS actuator and
electric unit (control unit).
Accumulator pressure sensor The accumulator pressure sensor detects brake fluid pressure accumulated in the accumulator and
conveys the detected result to the ABS actuator and electric unit (control unit).
Master cylinder pressure sensor Detects the brake fluid pressure of master cylinder part and transmits a signal to ABS actuator and
electric unit (control unit).
Condition (status) ABS warning lamp
Ignition switch OFF OFF
For approx. 1 seconds after the ignition switch is turned ON ON
Approx. 1 seconds after ignition switch is turned ON (when the
system is in normal operation) OFF
ABS function is ma lfunctioning ON
EBD function is malfunctioning ON
Condition (status) Brake warning lamp
Ignition switch OFF OFF
For approx. 1 seconds after the ignition switch is turned ON ON
Approx. 1 seconds after ignition switch is turned ON (when the
system is in normal operation) OFF
After engine starts OFF
When parking brake operates (parking brake switch ON) ON
Revision: 2010 May2011 QX56

BRC-26
< SYSTEM DESCRIPTION >[WITH VDC]
SYSTEM
ABS FUNCTION
ABS warning lamp and VDC warning lamp in combinati
on meter turn ON when a malfunction occurs in system
[ABS actuator and electric unit (control unit)]. The c ontrol is suspended for VDC function, TCS function, ABS
function, hill start assist function and brake limited sl ip differential (BLSD) function. The vehicle status
becomes the same as models without VDC function, TCS f unction, ABS function, hill start assist function and
brake limited slip differential (BLSD) function. However, EBD function is operated normally.
NOTE:
ABS self-diagnosis sound may be heard the same as in the normal condition, because self-diagnosis is per-
formed when ignition switch turns ON and when vehicle initially starts.
EBD FUNCTION
ABS warning lamp, brake warning lamp and VDC warning lamp in combination meter turn ON when a mal-
function occurs in system [ABS actuator and electric unit (control unit)]. The control is suspended for VDC
function, TCS function, ABS function, EBD function, hill start assist function and brake limited slip differential
(BLSD) function. The vehicle status becomes the sa me as models without VDC function, TCS function, ABS
function, EBD function, hill star t assist function and brake limited slip differential (BLSD) function.
DTC Malfunction detected condition Fail-safe condition
C1101 When an open circuit is detected in rear RH wheel sensor circuit.
The following functions are sus-
pended.
 VDC function
 TCS function
 ABS function
 EBD function (only when both 2 rear wheels are malfunctioning)
 hill start assist function
 Brake limited slip differential
(BLSD) function
C1102 When an open circuit is detected in rear LH wheel sensor circuit.
C1103 When an open circuit is detected in front RH wheel sensor circuit.
C1104 When an open circuit is detected in front LH wheel sensor circuit.
C1105
 When power supply voltage of rear RH wheel sensor is low.
 When distance between rear RH wheel sensor and rear RH wheel sensor rotor is
large.
 When installation of rear RH wheel sensor or rear RH wheel sensor rotor is not
normal.
C1106  When power supply voltage of rear LH wheel sensor is low.
 When distance between rear LH wheel sensor and rear LH wheel sensor rotor is
large.
 When installation of rear LH wheel sensor or rear LH wheel sensor rotor is not nor- mal.
C1107  When power supply voltage of front RH wheel sensor is low.
 When distance between front RH wheel sensor and front RH wheel sensor rotor
is large.
 When installation of front RH wheel sensor or front RH wheel sensor rotor is not normal.
C1108  When power supply voltage of front LH wheel sensor is low.
 When distance between front LH wheel sensor and front LH wheel sensor rotor is
large.
 When installation of front LH wheel sensor or front LH wheel sensor rotor is not normal.
C1109  When ignition voltage is 10 V or less.
 When ignition voltage is 16 V or more. The following functions are sus-
pended.
 VDC function
 TCS function
 ABS function
 EBD function
 hill start assist function
 Brake limited slip differential
(BLSD) function
C 1111
 When a malfunction is detected in motor or motor relay.
 When a low pressure malfunction is detected in accumulator.
 When a malfunction is detected in accumulator pressure sensor.
C 111 5 When difference in wheel speed between any wheel and others is detected during
the vehicle is driven, because of installation of other tires than specified. The following functions are sus-
pended.
 VDC function
 TCS function
 ABS function
 hill start assist function
 Brake limited slip differential
(BLSD) function
C 111 6
 When stop lamp switch signal is not input when brake pedal depress.
 When stop lamp switch signal is not input when stop lamp relay operates.
C 111 8
*1When a malfunction is detected in transfer control unit system.
Revision: 2010 May2011 QX56

SYSTEMBRC-27
< SYSTEM DESCRIPTION > [WITH VDC]
C
D
E
G H
I
J
K L
M A
B
BRC
N
O P
C1120 When a malfunction is detec ted in front LH ABS IN valve.
The following functions are sus-
pended.
 VDC function
 TCS function
 ABS function
 EBD function
 hill start assist function
 Brake limited slip differential (BLSD) function
C1121 When a malfunction is detec
ted in front LH ABS OUT valve.
C1122 When a malfunction is detected in front RH ABS IN valve.
C1123 When a malfunction is det ected in front RH ABS OUT valve.
C1124 When a malfunction is detected in rear LH ABS IN valve.
C1125 When a malfunction is detected in rear LH ABS OUT valve.
C1126 When a malfunction is det ected in rear RH ABS IN valve.
C1127 When a malfunction is detected in rear RH ABS OUT valve.
C1130 When a malfunction is detected in ECM system. The following functions are sus-
pended.
 VDC function
 TCS function
 hill start assist function
 Brake limited slip differential
(BLSD) function
C1140 When a malfunction is detected in actuator relay. The following functions are sus-
pended.
 VDC function
 TCS function
 ABS function
 EBD function
 hill start assist function
 Brake limited slip differential
(BLSD) function
C1142
*2When a malfunction is detected in master cylinder pressure sensor or control pres-
sure sensor. The following functions are sus-
pended.
 VDC function
 TCS function
 hill start assist function
 Brake limited slip differential
(BLSD) function
C1143 When a malfunction is detected in steering angle sensor.
C1144 When neutral position adjustment of steering angle sensor is not complete.
C1145
 When a malfunction is detected in yaw rate signal.
 When yaw rate signal is not continuously received for 2 seconds or more.
 When side G signal is not continuously received for 2 seconds or more.
 When decel G signal is not continuously received for 2 seconds or more.
The following functions are sus-
pended.
 VDC function
 TCS function
 ABS function
 hill start assist function
 Brake limited slip differential
(BLSD) function
C1146 When a malfunction is detected in side/decel G signal.
C1155
 When brake fluid level low signal is detected.
 When an open circuit is detected in brake fluid level switch circuit.
C1160 When calibration of yaw rate/side/decal G sensor is not complete.
C1164 When a malfunction is detected in cut valve 1. The following functions are sus- pended.
 VDC function
 TCS function
 ABS function
 EBD function
 hill start assist function
 Brake limited slip differential (BLSD) function
C1165 When a malfunction is detected in cut valve 2.
C1166 When a malfunction is detected in suction valve 1.
C1167 When a malfunction is detected in suction valve 2.
C1170 When the informatio
n in ABS actuator and electric unit (control unit) is not the same.The following functions are sus-
pended.
 VDC function
 TCS function
 ABS function
 hill start assist function
 Brake limited slip differential
(BLSD) function
DTC Malfunction detected condition Fail-safe condition
Revision: 2010 May2011 QX56

BRC-28
< SYSTEM DESCRIPTION >[WITH VDC]
SYSTEM
*1: Models with 4WD System
*2: Models with Advanced Driver Assistance System
Protection FunctionINFOID:0000000006228185
The VDC warning lamp, ABS warning lamp and brake warning lamp turns ON and DTC “C118E” may be
detected in self-diagnosis result of “ABS” when the br
ake pedal is excessively operated, such as air bleeding.
This is not a system malfunction because this occurs due to the temporary decrease in accumulator fluid pres-
sure. The system returns to normal condition when the accu mulator fluid pressure reaches the specified pres-
sure with the ignition switch ON and the VDC warning lamp, ABS warning lamp, and brake warning lamp turn
OFF. After these steps, erase self-diagnos is results for “ABS” with CONSULT-III.
NOTE:
D T C “ C 1111 ” i s d e t e c t e d i n s e l f - d i agnosis results of “ABS” when the a ccumulator system has a malfunction.
VDC FUNCTION
VDC FUNCTION : System DescriptionINFOID:0000000006222572
 Side slip or tail slip may occur while driving on a slippery road or intending an urgent evasive driving. VDC
function detects side slip status using each sensor when side slip or tail slip is about to occur and improves
vehicle stability by brake control and engine output control during driving.
 In addition to ABS function, EBD function and TCS functi on, target side slip amount is calculated according
to steering operation amount from steering angle sensor and brake operation amount from pressure sensor.
By comparing this information with vehicle side slip amount that is calculated from information from yaw rate/
C118EWhen performing excessive brake pedal operation with the vehicle stopped. [When
accumulator fluid pressure reaches 11.43 MPa (114 bar, 116.6 kg/cm2, 1657 psi) af-
ter reaching 17.3 MPa (173 bar, 176.5 kg/cm2, 2509 psi.] The following functions are sus-
pended.
 VDC function
 TCS function
 ABS function
 EBD function
 hill start assist function
 Brake limited slip differential
(BLSD) function
U1000 When CAN communication signal is not continuously received for 2 seconds or
more. The following functions are sus-
pended.
 VDC function
 TCS function
 ABS function
 hill start assist function
 Brake limited slip differential
(BLSD) function
DTC Malfunction detected condition Fail-safe condition
DTC
 VDC warning lamp
 ABS warning lamp
 Brake warning lamp
Condition Description protection function
C118E ON When temporary decrease in accumulator fluid pres-
sure.
NOTE:
System is not malfunction. The following functions are suspended
temporarily
 VDC function
 TCS function
 ABS function
 EBD function
 hill start assist function
 Brake limited slip differential (BLSD)
function
Revision: 2010 May2011 QX56

SYSTEMBRC-29
< SYSTEM DESCRIPTION > [WITH VDC]
C
D
E
G H
I
J
K L
M A
B
BRC
N
O P
side/decel G- sensor and wheel sensor, vehicle drivi ng conditions (conditions of understeer or oversteer) are
judged and vehicle stability is improved by brake forc e control on all 4 wheels and engine output control.
 Control unit portion automatically improves driving st ability by performing brake force control as well as
engine output control, by transmitting drive signal to actuator portion according to difference between target
side slip amount and vehicle side slip amount
 VDC function can be switched to non-operational status (OFF) by operating VDC OFF switch. In this case,
VDC OFF indicator lamp turns ON.
 VDC function is not operate when 4WD mode is “4L”. (Models with 4WD system)
 VDC warning lamp blinking while VDC function is in oper ation and indicates to the driver that the function is
in operation.
 Slight vibrations are felt on the brake pedal and t he operation noises occur, when VDC function operates.
This is not a malfunction because it is caus ed by VDC function that is normally operated.
 CONSULT-III can be used to diagnose the system diagnosis.
 Fail-safe function is adopted. When a malfunction occurs in VDC function, the control is suspended for VDC
function, TCS function, hill start as sist function and brake limited slip di fferential (BLSD) function. The vehi-
cle status becomes the same as m odels without VDC function, TCS functi on, hill start assist function and
brake limited slip differential (BLSD) function. Ho wever, ABS function and EBD function are operated nor-
mally. Refer to BRC-25, "
Fail-safe".
NOTE:
VDC has the characteristic as de scribed here, but it is not the device that helps reckless driving.
SYSTEM DIAGRAM
NOTE:
Transfer control unit is applied to models with 4WD system.
INPUT SIGNAL AND OUTPUT SIGNAL
JPFIC0133GB
JPFIC0183GB
Revision: 2010 May2011 QX56