brake sensor INFINITI QX56 2011 Factory Repair Manual
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SYSTEM
BRC-153
< SYSTEM DESCRIPTION > [INTELLIGENT BRAKE ASSIST]
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Fail-safe Indication
NOTE:
When the IBA turns OFF, the IBA OFF indicator lamp will illuminate.
Condition Description Indication on the combination meter
When the 4WD shift switch is in the 4H or 
4L position The system is temporary unavailable.
(Without the warning chime)
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Condition Description Indication on the combination meter
 When the sensor window is dirty
 When the system malfunction The system will be cancelled automatically 
with a beep sound.
When driving into a strong light
(i.e. sunlight) The system is temporary unavailable.
(Without the warning chime)
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NORMAL OPERATING CONDITIONBRC-157
< SYMPTOM DIAGNOSIS > [INTELLIGENT BRAKE ASSIST]
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NORMAL OPERATING CONDITION
DescriptionINFOID:0000000006228304
PRECAUTIONS FOR INTELLIGENT BRAKE ASSIST
 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 prov ide a warning or brake in certain conditions.
 The system will not detect the following objects:
- Pedestrians, animals, or obstacles in the roadway
- Oncoming vehicles in the same lane
 The system will not detect under the following conditions:
- When the sensor gets dirty and it is impossibl e to detect the distance from the vehicle ahead.
- When driving into a strong light (i.e. sunlight)
 The sensor generally detects the signals returned from  the reflectors on a vehicle ahead. Therefore, the sys-
tem may not function properly under the following conditions:
- When the reflectors of the vehicle ahead are positioned  high or close each other (including a small vehicle
such as motorcycles).
- When the sensor gets dirty or and it is impossi ble to detect the distance from the vehicle ahead.
- When the reflectors on the vehicle ahead is missing, damaged or covered.
- When the reflector of the vehicle ahead is covered with dirt, snow and road spray.
- When visibility is low (such  as rain, fog, snow, etc.).
- When snow or road spray from traveling vehicles are raised up.
- When dense exhaust or other smoke (black smoke) fr om vehicles reduces the sensor visibility.
- When excessively heavy baggage is loaded in the rear seat or the luggage room of vehicle.
- When abruptly accelerating or decelerating.
- On steep downhill or roads with sharp curves.
- When there is a highly reflective object near the vehicle ahead (i.e. very close to other vehicle, signboard,
etc.).
- While towing a trailer or other vehicle.
 Depending on certain road conditions (curved, beginning of  a curve), vehicle conditions (steering position,
vehicle position), or preceding vehicle ′s conditions (position in lane, etc. ), the system may not function prop-
erly.
 The system may not function in offset conditions.
 The system may not function when the distanc e to the vehicle ahead is extremely close.
 The system detect highly reflective objects such as reflectors, signs, white markers, and other  stationary objects on the road or
near the traveling lane, and when in extreme conditions, detection
of these objects may caus e the system to function.
 The system is designed to automatically check the sensor ′s func-
tionality. If the sensor is covered  with ice, a transparent or translu-
cent plastic bag, etc., the system  may not detect them. In these
instances the system may not be able to warn properly. Be sure to
check and clean the sensor regularly.
 Excessive noise will interfere with the warning chime sound, and the chime may not be heard.
 Never step in under the brake pedal to avoid an accident when IBA
system turns ON.
 Sudden appearance of the vehicle in front (i.e. it abrupt ly cuts in) may not be detected and the system may
not warn soon enough.
 The system will be cancelled automatically with a beep  sound and the IBA OFF indicator lamp will illuminate
under the following conditions:
- When the sensor window is dirty
- When the system malfunctions
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CCS-2
WIRING DIAGRAM  .....................................57
INTELLIGENT CRUISE CONTROL  ............... ...57
Wiring Diagram  .................................................... ...57
BASIC INSPECTION ...................................69
DIAGNOSIS AND REPAIR WORK FLOW  ..... ...69
Work Flow ............................................................ ...69
ADDITIONAL SERVICE WHEN REPLACING 
ICC SENSOR  .....................................................
71
Description ........................................................... ...71
Work Procedure ......................................................71
LASER BEAM AIMING ADJUSTMENT  ............72
Description ........................................................... ...72
Work Procedure (Preparation) ................................72
Work Procedure (Setting The ICC Target Board) ...72
Work Procedure (Laser Beam Aiming Adjustment) 
...
75
ACTION TEST  ...................................................77
Description ........................................................... ...77
Work Procedure (Vehicle-To-Vehicle Distance 
Control Mode)  .........................................................
77
Work Procedure [Conventional (Fixed Speed) 
Cruise Control Mode] ..............................................
80
DTC/CIRCUIT DIAGNOSIS ...................... ...83
C1A00 CONTROL UNIT  ................................. ...83
ADAS CONTROL UNIT  ......................................... ...83
ADAS CONTROL UNIT : DTC Logic  ......................83
ADAS CONTROL UNIT : Diagnosis Procedure ......83
ICC SENSOR  ......................................................... ...83
ICC SENSOR : DTC Logic  .....................................83
ICC SENSOR : Diagnosis Procedure  .....................83
C1A01 POWER SUPPLY CIRCUIT 1, C1A02 
POWER SUPPLY CIRCUIT 2  ............................
85
ADAS CONTROL UNIT  ......................................... ...85
ADAS CONTROL UNIT : DTC Logic  ......................85
ADAS CONTROL UNIT : Diagnosis Procedure ......85
ICC SENSOR  ......................................................... ...85
ICC SENSOR : DTC Logic  .....................................85
ICC SENSOR : Diagnosis Procedure  .....................86
C1A03 VEHICLE SPEED SENSOR  ..................87
DTC Logic ............................................................ ...87
Diagnosis Procedure  ..............................................87
C1A04 ABS/TCS/VDC SYSTEM  .......................89
DTC Logic ............................................................ ...89
Diagnosis Procedure  ..............................................89
C1A05 BRAKE SW/STOP LAMP SW  ...............90
DTC Logic ............................................................ ...90
Diagnosis Procedure  ..............................................90
Component Inspection (ICC Brake Switch)  ......... ...93
Component Inspection (Stop Lamp Switch) ............93
C1A06 OPERATION SW  ...................................94
DTC Logic  ............................................................ ...94
Diagnosis Procedure ...............................................94
Component Inspection  ............................................95
C1A12 LASER BEAM OFF CENTER  ...............96
ADAS CONTROL UNIT .......................................... ...96
ADAS CONTROL UNIT : DTC Logic  ......................96
ADAS CONTROL UNIT : Diagnosis Procedure  ......96
ICC SENSOR .......................................................... ...96
ICC SENSOR : DTC Logic ......................................96
ICC SENSOR : Diagnosis Procedure  .....................96
C1A13 STOP LAMP RELAY  .............................97
DTC Logic  ............................................................ ...97
Diagnosis Procedure ...............................................97
Component Inspection  ..........................................102
C1A14 ECM  ......................................................103
DTC Logic  ............................................................ .103
Diagnosis Procedure .............................................103
C1A15 GEAR POSITION  .................................104
Description ........................................................... .104
DTC Logic  .............................................................104
Diagnosis Procedure .............................................104
C1A16 RADAR STAIN ................................... ..106
ADAS CONTROL UNIT .......................................... .106
ADAS CONTROL UNIT : DTC Logic  ....................106
ADAS CONTROL UNIT : Diagnosis Procedure  ....106
ICC SENSOR .......................................................... .106
ICC SENSOR : DTC Logic ....................................106
ICC SENSOR : Diagnosis Procedure  ...................107
C1A17 ICC SENSOR ........................................108
DTC Logic  ............................................................ .108
Diagnosis Procedure .............................................108
C1A18 LASER AIMING INCMP  .......................109
ADAS CONTROL UNIT .......................................... .109
ADAS CONTROL UNIT : DTC Logic  ....................109
ADAS CONTROL UNIT : Diagnosis Procedure  ....109
ICC SENSOR .......................................................... .109
ICC SENSOR : DTC Logic ....................................109
ICC SENSOR : Diagnosis Procedure  ...................110
C1A21 UNIT HIGH TEMP .................................111
ADAS CONTROL UNIT .......................................... .111
ADAS CONTROL UNIT : DTC Logic  ....................111
ADAS CONTROL UNIT : Diagnosis Procedure  ....111
ICC SENSOR .......................................................... .111
ICC SENSOR : DTC Logic ....................................111
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CCS
COMPONENT PARTSCCS-9
< SYSTEM DESCRIPTION > [ICC]
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SYSTEM DESCRIPTION
COMPONENT PARTS
Component Parts LocationINFOID:0000000006224265
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
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CCS-10
< SYSTEM DESCRIPTION >[ICC]
COMPONENT PARTS
Component Description
INFOID:0000000006224266
× : 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
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CCS
COMPONENT PARTSCCS-11
< SYSTEM DESCRIPTION > [ICC]
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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)
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CCS
SYSTEMCCS-13
< SYSTEM DESCRIPTION > [ICC]
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Transmit unit Signal name Description
ECM CAN com-
munica-
tionClosed throttle position signal Receives idle position state (ON/OFF)
Accelerator pedal position signal Receives accelerator pedal position (angle)
ICC prohibition signal
Receives an operable/inoperable state of the ICC sys-
tem
ICC steering switch 
signal Main switch signal
Receives the operational state of the ICC steering 
switch
SET/COAST switch 
signal
CANCEL switch sig-
nal
RESUME/ACCEL-
ERATE switch signal
DISTANCE switch 
signal
Engine speed signal Receives engine speed
Stop lamp switch signal Receives an operational state of the brake pedal
ICC brake switch signal Receives an operational state of the brake pedal
Snow mode signal Receives an operational state of the snow mode
TCM CAN com-
munica-
tionInput speed signal Receives the number of revolutions of input shaft
Current gear position signal Receives a current gear position
Shift position signal Receives a selector lever position
Output shaft revolution signal Receives the number of revolutions of output shaft
ABS actuator 
and electric unit 
(control unit) CAN com-
munica-
tionABS malfunction signal Receives 
a malfunction state of ABS
ABS operation signal Receives an  operational state of ABS
ABS warning lamp signal Receives an  ON/OFF state of ABS warning lamp
TCS malfunction signal Receives a malfunction state of TCS
TCS operation signal Receives an operational state of TCS
VDC OFF switch signal Receives an ON/OFF state of VDC
VDC malfunction signal Receives a malfunction state of VDC
VDC operation signal Receives an operational state of VDC
Vehicle speed signal (ABS) Receives  wheel speeds of four wheels
Stop lamp switch signal Receives an operational state of the brake pedal
Yaw rate signal Receives yaw rate acting on the vehicle
Combination 
meter CAN com-
munica-
tion
Parking brake switch signal Receives an operational state of the parking brake
BCM CAN com-
munica-
tion
Front wiper request signal Receives an operational state of front wiper(s)
Steering angle 
sensor CAN com-
munica-
tionSteering angle sensor malfunction signal Receives a malfunction state of steering angle sensor
Steering angle sensor signal
Receives the number of revolutions, turning direction of 
the steering wheel
Steering angle speed signal Receives the turning angle speed of the steering wheel
Transfer control 
unit CAN com-
munica-
tion
Current 4WD mode signal Receives a mode selection state of the 4WD mode
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CCS-14
< SYSTEM DESCRIPTION >[ICC]
SYSTEM
Output Signal Item
DESCRIPTION
Intelligent Cruise Control
The Intelligent Cruise Control (ICC) system maintains a se
lected distance from the vehicle in front of own vehi-
cle within the speed range of 0 to 144 km/h (0 to 90 MPH) up to the set speed.
The set speed can be selected by the driver between 32 to 144 km/h (20 to 90 MPH).
The vehicle travels at a set speed when the road ahead is clear.
The ICC system can be set to one  of two cruise control modes:
CAUTION:
Never set the cruise speed exceed ing the posted speed limit.
Vehicle-to-vehicle Distance Control Mode
ICC sensorITS com-
munica-
tionICC sensor signal
Receives detection results, such as the presence or ab-
sence of a leading vehicle and distance from the vehicle
IBA OFF switch IBA OFF switch signal Receives an ON/OFF state of the IBA OFF switch Transmit unit Signal name Description
Reception unit Signal name Description
ECM CAN commu-
nicationICC operation signal
Transmits an ICC operation signal necessary for Intel-
ligent Cruise Control
TCM CAN commu-
nicationICC operation signal Transmits an ICC operation signal necessary for Intel-
ligent Cruise Control via ECM
ABS actuator 
and electric 
unit (control 
unit) CAN commu-
nication
Brake fluid pressure control signal
Transmits a brake fluid pressure control signal to acti-
vates the brake
Combination 
meter CAN commu-
nicationMeter display 
signal Own vehicle indicator 
signal
Transmits a signal to display a state of the system on 
the information display
Vehicle ahead detec-
tion indicator signal
Set vehicle speed indi-
cator signal
Set distance indicator 
signal
SET switch indicator 
signal
MAIN switch indicator 
signal
ICC warning lamp signal Transmits an ICC warning lamp signal to turn ON the 
ICC system warning lamp
IBA OFF indicator lamp signal  Transmits a signal to turn ON the IBA OFF indicator 
lamp
 Transmits an ON/OFF state of the intelligent brake 
assist
Buzzer output signal Transmits a buzzer output signal to turn ON the buzz-
er of the following systems:
 Intelligent Cruise Control (ICC)
 Intelligent Brake Assist (IBA)
ICC sensor ITS commu-
nication
Vehicle speed signal Transmits a vehicle speed calculated by the ADAS 
control unit
ICC brake hold 
relay ICC brake hold relay drive signal
Activates the brake hold relay and turns ON the stop 
lamp
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SYSTEMCCS-15
< SYSTEM DESCRIPTION > [ICC]
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For maintaining a selected distance between own vehicle and the vehicle in front of own vehicle up to t\
he pre-
set speed. Refer to  CCS-15, "
VEHICLE-TO-VEHICLE DISTANCE CO NTROL MODE FUNCTION : System
Description".
Conventional (Fixed Speed) Cruise Control Mode
For cruising at a preset speed. Refer to  CCS-18, "CONVENTIONAL (FIXED SPEED) CRUISE CONTROL
MODE FUNCTION : System Description".
NOTE:
In the Conventional (Fixed Speed) Cruise Control Mode,  a warning chime will not sound to warn driver if own
vehicle are too close to the vehicle ahead.
WARNING:
Always drive carefully and attentively when using ei ther cruise control mode. To avoid serious injury
or death, do not rely on the system to prevent accide nts or to control the vehicle's speed in emer-
gency situations. Do not use cr uise control except in appropriat e rode and traffic conditions.
Distance Control Assist (DCA) System
DCA share the systems and component s with ICC system. Refer to DAS-68, "System Description".
Forward Collision Warning (FCW) System
FCW share the systems and component s with ICC system. Refer to DAS-218, "System Description".
Intelligent Brake Assist (IBA) System
IBA system share the systems and components with  ICC system. Refer to BRC-152, "INTELLIGENT BRAKE
ASSIST : System Description".
Brake Assist (with preview function)
Brake Assist (with preview function) share t he systems and components with ICC system. Refer to  BRC-145,
"BRAKE ASSIST (WITH PREVIEW FUNCTION) : System Description".
Fail-safe (ADAS Control Unit)INFOID:0000000006224268
If a malfunction occurs in each system, ADAS control unit cancels eac h control, sounds a beep, and turns ON
the warning lamp or indicator lamp.
Fail-safe (ICC Sensor)INFOID:0000000006224269
If a malfunction occurs in the ICC sensor, ADAS cont rol unit cancels control, sounds a beep, and turns ON the
ICC system warning lamp in the combination meter.
VEHICLE-TO-VEHICLE DISTANCE CONTROL MODE FUNCTION
VEHICLE-TO-VEHICLE DISTANCE CONTRO L MODE FUNCTION : System Descrip-
System Buzzer Warning lamp/Indicator lamp Description
Vehicle-to-vehicle distance control mode High-pitched 
toneICC system warning lamp Cancel
Conventional (fixed speed) cruise control mode High-pitched 
tone
ICC system warning lamp Cancel
Intelligent Brake Assist (IBA) High-pitched 
toneIBA OFF indicator lamp Cancel
Forward Collision Warning (FCW) High-pitched 
toneIBA OFF indicator lamp Cancel
Distance Control Assist (DCA) High-pitched 
tone
ICC system warning lamp Cancel
Lane Departure Warning (LDW) — Lane departure warning lamp Cancel
Lane Departure Prevention (LDP) Low-pitched 
toneLane departure warning lamp Cancel
Blind Spot Warning (BSW) — BSW warning lamp Cancel
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CCS
OPERATIONCCS-23
< SYSTEM DESCRIPTION > [ICC]
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NOTE:
The display of the DCA system is given priority when  the DCA system is ON in a standby mode. (The set vehi-
cle speed indicator, set distance indicator, and own vehicle indicator are not displayed). 
APPROACH WARNING DISPLAY
If own vehicle comes closer to a vehicle ahead due to rapi d deceleration of that vehicle or if another vehicle
cuts in, the system warns the driver with the chim e and ICC system display. Decelerate by depressing the
brake pedal to maintain a safe vehicle distance if:
 The chime sounds.
 The vehicle ahead detection indicator and set distance indicator blink.
The warning chime may not sound in some cases when there is a short distance between vehicles. Some
examples are:
 When the vehicles are traveling at the same s peed and the distance between vehicles is not changing.
 When the vehicle ahead is traveling faster and the distance between vehicles is increasing.
 When a vehicle cuts in at near own vehicle.
The warning chime will not sound when own vehicle approac hes vehicles that are parked or moving slowly.
The warning chime will not sound when the accele rator pedal is depressed, overriding the system.
The approach warning chime may sound and the system disp lay may blink when the ICC sensor detects some
reflectors which are fitted on vehicles in  other lanes or on the side of the road.
This may cause the ICC system to dec elerate or accelerate the vehicle.
The ICC sensor may detect these reflectors when the  vehicle is driven on winding roads, hilly roads or when
entering or exiting a curve.
The ICC sensor may also detect reflectors  on narrow roads or in road construction zones.
In these cases driver will have to manually  control the proper distance ahead of own vehicle.
Also, the sensor sensitivity can be affected by vehicle  operation (steering maneuver or driving position in the
lane) or traffic or vehicle condition (for example, if a vehicle is being driven with some damage).
Control mode With a vehicle 
aheadSet vehicle distance (Long)
Set vehicle distance (Middle)
Set vehicle distance (Short)
When the vehicle speed exceeds the set speed
Condition Display on ICC system display
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