brake sensor INFINITI QX56 2011 Factory Workshop Manual

BRC-142
< SYSTEM DESCRIPTION >[BRAKE ASSIST (WITH PREVIEW FUNCTION)]
COMPONENT PARTS
SYSTEM DESCRIPTION
COMPONENT PARTS
Component Parts LocationINFOID:0000000006248456
1. ICC steering switch 2. Information display, ICC system
warning lamp, IBA OFF indicator
lamp, buzzer
(On the combination meter)3. BCM
Refer to BCS-4, "
BODY CONTROL
SYSTEM : Component Parts Loca-
tion"
4. Transfer control unit
Refer to DLN-10, "
Component Parts
Location"
5. ICC brake hold relay 6. ECM
Refer to EC-16, "
Component Parts
Location"
7. ICC sensor 8. TCM
Refer to TM-10, "
A/T CONTROL
SYSTEM : Component Parts Loca-
tion"
9. ABS actuator and el ectric unit (con-
trol unit)
Refer to BRC-10, "
Component Parts
Location"
10. Stop lamp switch 11. ICC brake switch 12. IBA OFF switch
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Revision: 2010 May2011 QX56

COMPONENT PARTSBRC-143
< SYSTEM DESCRIPTION > [BRAKE ASSIST (WITH PREVIEW FUNCTION)]
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Component DescriptionINFOID:0000000006248457
× : Applicable
13. Steering angle sensor
Refer to BRC-10, "
Component Parts
Location"
14. ADAS control unit
Refer to DAS-13, "
Component Parts
Location"
A. Back side of engine room (RH) B. Front bumper (center) C. Upper side of brake pedal
D. Under side of instrument lower driver
panel
Component Function
Description
Vehicle-to-vehicle distance control mode
Conventional (fixed speed) cruise control mode Intelligent Brake Assist (IBA)
Brake Assist (with preview function)
ADAS control unit ×××× ADAS control unit calculates a target distance between vehicles
and a target speed, based on signals received from each sensor
and switch to transmit an engine torque command value to ECM
and a brake fluid pressure cont rol signal to ABS actuator and
electric unit (control unit) via CAN communication
 ADAS control unit transmits buzzer output signal to combination
meter via CAN communication
ICC sensor ×××× ICC sensor detects light reflected from a vehicle ahead by irra-
diating laser forward and calculates a distance from the vehicle
ahead and a relative speed, based on the detected signal
 ICC sensor transmits the presence/absence of vehicle ahead and the distance from the vehicle to ADAS control unit via ITS
communication
ECM ×××× ECM transmits the accelerator pedal position signal, ICC brake
switch signal, stop lamp switch signal, ICC steering switch sig-
nal, etc. to ADAS control unit via CAN communication
 ECM controls the electric throttle control actuator based on the engine torque demand received from the ADAS control unit via
CAN communication
ABS actuator and electric unit
(control unit) ×××× ABS actuator and electric unit (c
ontrol unit) transmits the vehicle
speed signal (wheel speed), stop lamp signal and VDC/TCS/
ABS system operation condition to ADAS control unit via CAN
communication
 ABS actuator and electric unit (c ontrol unit) controls the brake,
based on a brake fluid pressure control signal received from the
ADAS control unit via CAN communication
BCM ×BCM transmits the front wiper request signal to ADAS control unit
via CAN communication
TCM ××TCM transmits the signal related to A/T control to ADAS control
unit via CAN communication
Revision: 2010 May2011 QX56

BRC-144
< SYSTEM DESCRIPTION >[BRAKE ASSIST (WITH PREVIEW FUNCTION)]
COMPONENT PARTS
NOTE:
Only IBA system uses
Combination meter
××××Performs the following operations using the signals received from
the ADAS control unit via the CAN communication
 Displays the ICC system operation status using the meter dis-
play signal
 Illuminates the ICC system warning lamp using the ICC warning
lamp signal
 Illuminates the IBA OFF indicator lamp using the IBA OFF indi- cator lamp signal
 Operates the buzzer (ICC warning chime) using the buzzer out- put signal
ICC steering switch ×× ICC steering switch allows the ON/OFF of the Intelligent Cruise
Control and the settings of a vehicle speed and distance be-
tween vehicles
 ICC steering switch signal is transmitted to ECM. ECM transmits the signal to the ADAS control unit via CAN communication
ICC brake switch ×××× ICC brake switch is turned OFF and stop lamp switch is turned
ON, when depressing the brake pedal
 ICC brake switch signal is input to ECM. These signals are transmitted from ECM to ADAS control unit via CAN communi-
cation
 Stop lamp switch signal is input to ECM and ABS actuator and electric unit (control unit). These signals are transmitted from
ECM and ABS actuator and electric unit (control unit) to ADAS
control unit via CAN communication
St op la mp sw i tc h
××××
ICC brake hold relay ××ICC brake hold relay activates the stop lamp by ICC brake hold re-
lay drive signal (stop lamp drive signal) outputted by the ADAS
control unit
Transfer control unit ××××Transfer control unit transmits a mode selection state of 4WD shift
switch to the ADAS control unit via CAN communication
IBA OFF switch ×
NoteIBA OFF switch signal is input to the ADAS control unit
Steering angle sensor ×Measures the rotation amount, rotation speed, and rotation direc-
tion of steering wheel, and then transmits them to ADAS control
unit via CAN communication
Component
Function
Description
Vehicle-to-vehicle distance control mode
Conventional (fixed speed) cruise control mode Intelligent Brake Assist (IBA)
Brake Assist (with preview function)
Revision: 2010 May2011 QX56

SYSTEM
BRC-145
< SYSTEM DESCRIPTION > [BRAKE ASSIST (WITH PREVIEW FUNCTION)]
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SYSTEM
BRAKE ASSIST (WITH PREVIEW FUNCTION)
BRAKE ASSIST (WITH PREVIEW F UNCTION) : System DescriptionINFOID:0000000006228293
FUNCTION DESCRIPTION
When the Preview Function identifies the need to apply emergency braking by sensing a vehicle ahead in the
same lane and the distance and relative speed from it, it applies the brake pre-pressure before the driver
depress the brake pedal and helps improve brake response by reducing pedal free play.
The Preview Function shares component parts and diagnosis with the Intelligent Cruise Control (ICC) system.
CAUTION:
This system is only an aid to assist braking oper ation and is not a collision warning or avoidance
device. It is the driver ′s responsibility to stay aler t, drive safely and be in control of the vehicle at all
times.
OPERATION DESCRIPTION
 The system detects the distance to the vehicle in fr ont with the ICC sensor of ICC and judges the necessity
of emergency braking.
 The system detects the accelerator pedal release operati on of the driver by the accelerator pedal position
sensor and estimates the driver's brake operation intention.
 If the system is judged that the emergency braking is nec essary and that the driver has the intention to oper-
ate the brake, the ABS actuator and electric unit (control unit) applies pre-pressure to reduce brake pedal
play.
NOTE:
This system will not operate under the following conditions:
 When the vehicle is moving at approx imately 32 km/h (20 MPH) or less.
 When the 4WD shift switch is in the 4H or 4L position.
END OF OPERATION
The pre-pressure function ceases when the following conditions are met:
1. When the driver depresses the acce lerator pedal or the brake pedal.
2. If the driver does not operate the accelerator pedal or brake pedal within approximately 1 second.
Revision: 2010 May2011 QX56

NORMAL OPERATING CONDITIONBRC-147
< SYMPTOM DIAGNOSIS > [BRAKE ASSIST (WITH PREVIEW FUNCTION)]
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SYMPTOM DIAGNOSIS
NORMAL OPERATING CONDITION
DescriptionINFOID:0000000006228295
PRECAUTIONS FOR PREVIEW FUNCTION
 This system is only an aid to assist braking operation and is not a collision warning or avoidance device. It is
the driver ′s responsibility to stay alert, drive safely and be in control of the vehicle at all times.
 As there is a performance limit to the Preview Function, never rely solely on this system. This system does
not correct careless inattentive or absent-minded driving, or overcome poor visibility in rain, fog, or other bad
weather. Reduce vehicle speed by depressing the brake pedal , in order to maintain a safe distance between
vehicles.
 The system may not detect a vehicle ahead, depending on road or weather conditions. While the vehicle still
travels and the Brake Assist Syst em operates under normal conditions, the Preview Function may operate
improperly under the following conditions:
- When rain, snow or dirt adhere to the system sensor
- When strong light (for example, at sunrise or sunset ) is directly shining on the front of the vehicle
- Winding or hilly roads may cause the sensor to tem porarily not detect a vehicle in the same lane or may
detect objects or vehicles in other lanes.
- Vehicle position in the lane may cause the sensor to te mporarily not detect a vehicle in the same lane or may
detect objects or vehicles in other lanes.
 The system will not detect:
- Pedestrians or objects in the roadway
- Oncoming vehicles in the same lane
- Motorcycles traveling offset in the travel lane as illustrated
 When the Preview Function operates, the brake pedal may move slightly and may make a small noise. This is not a system malfunc-
tion.
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Revision: 2010 May2011 QX56

BRC-148
< PRECAUTION >[INTELLIGENT BRAKE ASSIST]
PRECAUTIONS
PRECAUTION
PRECAUTIONS
Precautions for IBA System ServiceINFOID:0000000006228296
CAUTION:
 Never look straight into the laser beam
discharger when adjusting laser beam aiming.
 Never use the ICC sensor removed from vehicle. Never disassemble or remodel.
 Erase DTC when replacing parts of ICC system. Then check the operation of ICC system after adjust-
ing laser beam aiming if necessary.
 Never change IBA system state ON/OFF without the consent of the customer.
NOTE:
IBA system automatically returns to ON, when erasing self-diagnosis result of “ICC/ADAS” with CONSULT-III.
Revision: 2010 May2011 QX56

COMPONENT PARTSBRC-149
< SYSTEM DESCRIPTION > [INTELLIGENT BRAKE ASSIST]
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SYSTEM DESCRIPTION
COMPONENT PARTS
Component Parts LocationINFOID:0000000006248458
1. ICC steering switch 2. Information display, ICC system warning lamp, IBA OFF indicator
lamp, buzzer
(On the combination meter)3. BCM
Refer to BCS-4, "
BODY CONTROL
SYSTEM : Compon ent Parts Loca-
tion"
4. Transfer control unit
Refer to DLN-10, "
Component Parts
Location"
5. ICC brake hold relay 6. ECM
Refer to EC-16, "
Component Parts
Location"
7. ICC sensor 8. TCM
Refer to TM-10, "
A/T CONTROL
SYSTEM : Compon ent Parts Loca-
tion"
9. ABS actuator and electric unit (con-
trol unit)
Refer to BRC-10, "
Component Parts
Location"
10. Stop lamp switch 11. ICC brake switch 12. IBA OFF switch
JSOIA0362ZZ
Revision: 2010 May2011 QX56

BRC-150
< SYSTEM DESCRIPTION >[INTELLIGENT BRAKE ASSIST]
COMPONENT PARTS
Component Description
INFOID:0000000006248459
× : Applicable
13. Steering angle sensor
Refer to BRC-10, "
Component Parts
Location"
14. ADAS control unit
Refer to DAS-13, "
Component Parts
Location"
A. Back side of engine room (RH) B. Front bumper (center) C. Upper side of brake pedal
D. Under side of inst rument lower driver
panel
Component Function
Description
Vehicle-to-vehicle distance control mode
Conventional (fixed speed) cruise control mode Intelligent Brake Assist (IBA)
Brake Assist (with preview function)
ADAS control unit ×××× ADAS control unit calculates a target distance between vehicles
and a target speed, based on signals received from each sensor
and switch to transmit an engine torque command value to ECM
and a brake fluid pres sure control signal to ABS actuator and
electric unit (control unit) via CAN communication
 ADAS control unit transmits buzzer output signal to combination
meter via CAN communication
ICC sensor ×××× ICC sensor detects light reflected from a vehicle ahead by irra-
diating laser forward and calculates a distance from the vehicle
ahead and a relative speed, based on the detected signal
 ICC sensor transmits the presence/absence of vehicle ahead and the distance from the vehicle to ADAS control unit via ITS
communication
ECM ×××× ECM transmits the accelerator pedal position signal, ICC brake
switch signal, stop lamp switch signal, ICC steering switch sig-
nal, etc. to ADAS control unit via CAN communication
 ECM controls the electric throttle control actuator based on the engine torque demand received from the ADAS control unit via
CAN communication
ABS actuator and electric unit
(control unit) ×××× ABS actuator and electric unit (control unit) transmits the vehicle
speed signal (wheel speed), stop lamp signal and VDC/TCS/
ABS system operation condition to ADAS control unit via CAN
communication
 ABS actuator and electric unit (control unit) controls the brake, based on a brake fluid pressure control signal received from the
ADAS control unit via CAN communication
BCM ×BCM transmits the front wiper request signal to ADAS control unit
via CAN communication
TCM ××TCM transmits the signal related to A/T control to ADAS control
unit via CAN communication
Revision: 2010 May2011 QX56

COMPONENT PARTSBRC-151
< SYSTEM DESCRIPTION > [INTELLIGENT BRAKE ASSIST]
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NOTE:
Only IBA system uses
Combination meter ××××Performs the following operations using the signals received from
the ADAS control unit via the CAN communication
 Displays the ICC system operation status using the meter dis-
play signal
 Illuminates the ICC system warning lamp using the ICC warning
lamp signal
 Illuminates the IBA OFF indicator lamp using the IBA OFF indi- cator lamp signal
 Operates the buzzer (ICC warning chime) using the buzzer out- put signal
ICC steering switch ×× ICC steering switch allows the ON/OFF of the Intelligent Cruise
Control and the settings of a vehicle speed and distance be-
tween vehicles
 ICC steering switch signal is transmitted to ECM. ECM transmits the signal to the ADAS control unit via CAN communication
ICC brake switch ×××× ICC brake switch is turned OFF and stop lamp switch is turned
ON, when depressing the brake pedal
 ICC brake switch signal is input to ECM. These signals are transmitted from ECM to ADAS control unit via CAN communi-
cation
 Stop lamp switch signal is in put to ECM and ABS actuator and
electric unit (control unit). These signals are transmitted from
ECM and ABS actuator and electric unit (control unit) to ADAS
control unit via CAN communication
Stop lamp switch
××××
ICC brake hold relay ××ICC brake hold relay activates the stop lamp by ICC brake hold re-
lay drive signal (stop lamp drive signal) outputted by the ADAS
control unit
Transfer control unit ××××Transfer control unit transmits a mode selection state of 4WD shift
switch to the ADAS control unit via CAN communication
IBA OFF switch ×
NoteIBA OFF switch signal is input to the ADAS control unit
Steering angle sensor ×Measures the rotation amount, rotation speed, and rotation direc-
tion of steering wheel, and then transmits them to ADAS control
unit via CAN communication
Component
Function
Description
Vehicle-to-vehicle distance control mode
Conventional (fixed speed) cruise control mode Intelligent Brake Assist (IBA)
Brake Assist (with preview function)
Revision: 2010 May2011 QX56

BRC-152
< SYSTEM DESCRIPTION >[INTELLIGENT BRAKE ASSIST]
SYSTEM
SYSTEM
INTELLIGENT BRAKE ASSIST
INTELLIGENT BRAKE ASSIST : System DescriptionINFOID:0000000006228299
FUNCTION DESCRIPTION
Intelligent Brake Assist (IBA) syst
em warns the driver by a vehicle ahead detection indicator and chime when
there is a risk of a collision with the vehicle ahead in the traveling lane and the driver must take avoidance
action immediately. The system helps reduce the rear -end collision speed by applying the brakes when it
judges a collision can not be avoided.
CAUTION:
The IBA system is a not collision avoidance system. It is the driver ′s responsibility to stay alert, drive
safely and be in control of the vehicle at all times. As there is a performance limit, it may not provide a
warning or brake in certain conditions.
NOTE:
 The IBA system shares component parts and diagnosis wi th the Intelligent Cruise Control (ICC) system.
New parts added to the IBA system is the IBA OFF indica tor lamp in the combination meter and the IBA OFF
switch on the instrument driver lower panel.
 The ICC sensor integrated unit shares the parts with the ICC, but the IBA system will operate even when the
ICC system is turned to OFF.
OPERATION DESCRIPTION
The IBA system uses an ICC sensor located below t he front bumper to measure the distance to a vehicle
ahead. When the system judges that the distance gets shorter, the vehicle ahead detection indicator on the
combination meter blinks and the warning chime sounds.
To turn the system OFF/ON, push and hold the IBA OFF switch after starting the engine for more than 1 sec-
ond.
NOTE:
 The system ON/OFF condition will be memorized even if the ignition switch turns OFF.
 The IBA system operates under the following conditions.
- The IBA system will function when the vehicle is driv en at speeds of approximately 15 km/h (10 MPH) and
above, and when the vehicle ′s speed is approximately 15 km/h (10 MPH) faster than that of the vehicle
ahead.
Switch and Indicators
Temporary unavailable indication
1. IBA OFF switch 2. Vehicle ahead detection indicator 3. IBA OFF indicator lamp
A. Under side of Instrument lower panel
(LH) B. On the combination meter
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Revision: 2010 May2011 QX56