brake sensor LEXUS UX250H 2019 User Guide

2474-5. Using the driving support systems
4
Driving
If this message continues to be displayed
even after initialization, have the vehicle
inspected by your Lexus dealer.
■If a 12-volt battery terminal has been
disconnected and reconnected
The system needs to be initialized. To initial-
ize the system, drive the vehicle straight
ahead for 5 seconds or more at a speed of
approximately 22 mph (35 km/h) or more.*: If equipped
This function will operate in situations
such as the following if an object is
detected in the traveling direction of
the vehicle.
Parking Support Brake func-
tion (static objects)*
If the sensors detect a static object,
such as a wall, in the traveling direc-
tion of the vehi cle and the system
determines that a collision may
occur due to the vehicle suddenly
moving forward due to an acciden-
tal accelerator pedal operation, the
vehicle moving the unintended
direction due to the wrong shift
position being selected, or while
parking or traveling at low speeds,
the system will operate to lessen
the impact with the detected static
object and reduce the resulting
damage.
Examples of function operation

2484-5. Using the driving support systems
■When traveling at a low speed and
the brake pedal is not depressed,
or is depressed late
■When the accelerator pedal is
depressed excessively
■When the vehicle moves in the
unintended direction due to the
wrong shift position being selected
 P.232
Types of sensors
WARNING
■To ensure the Parking Support Brake
(static objects) can operate properly
Observe the following precautions
regarding the sensors ( P.232). Failure
to do so may cause a sensor to not oper-
ate properly, and may cause an accident.
●Do not modify, disassemble or paint
the sensors.
●Do not replace a sensor with a part
other than a genuine part.
●Do not subject a sensor or its sur-
rounding area to a strong impact.
●Do not damage the sensors, and
always keep them clean.
●If the area around a radar sensor is
subjected to an impact, the system
may not operate properly due to a
sensor malfunction. Have the vehicle
inspected by your Lexus dealer.

2494-5. Using the driving support systems
4
Driving
■The Parking Support Brake function
(static object) will operate when
The function will operate when the PKSB
OFF indicator is not illuminated or flashing
(  P.75, 76) and all of the following condi-
tions are met:
●Hybrid system output restriction control
• The Parking Support Brake is enabled.
• The vehicle speed is 10 mph (15 km/h) or less.
• There is a static object in the traveling direction of the vehicle and 6 to 13 ft. (2
to 4 m) away.
• The Parking Support Brake determines that a stronger-than-normal brake opera-
tion is necessary to avoid a collision.
●Brake control
• Hybrid system output restriction control
is operating.
• The Parking Support Brake determines that an immediate brake operation is nec-
essary to avoid a collision.
■The Parking Support Brake function
(static objects) will stop operating when
The function will stop operating if any of the
following conditions are met:
●Hybrid system output restriction control
• The Parking Support Brake is disabled.
• The system determines that the collision has become avoidable with normal brake
operation.
• The static object is no longer 6 to 13 ft. (2
to 4 m) away from the vehicle or in the
WARNING
■Handling the suspension
Do not modify the suspension, as
changes to the height or inclination of the
vehicle may prevent the sensors from
detecting objects correctly or cause the
system to not operate or operate unnec-
essarily.
■If the Parking Support Brake function
(static objects) operates unnecessar-
ily, such as at a railroad crossing
In the event that the Parking Support
Brake function (static objects) operates
unnecessarily, such as at a railroad cross-
ing, brake control w ill be canceled after
approximately 2 seconds, allowing you
to proceed forward and leave the area,
brake control can also be canceled by
depressing the brake pedal. Depressing
the accelerator pedal after brake control
is canceled will allow you to proceed for-
ward and leave the area.
■Notes when washing the vehicle
Do not apply intensive bursts of water or
steam to the sensor area.
Doing so may result in the sensor mal-
functioning.
●When using a high pressure washer to
wash the vehicle, do not spray the sen-
sors directly, as doing so may cause a
sensor to malfunction.
●When using steam to clean the vehicle,
do not direct steam too close to the
sensors as doing so may cause a sen-
sor to malfunction.
■When to disable the Parking Support
Brake (static objects)
In the following situations, disable the
Parking Support Brake (static objects) as
the system may operate even though
there is no possibility of a collision.
●When inspecting the vehicle using a
chassis roller, chassis dynamo or free
roller
●When loading the vehicle onto a boat,
truck or other transport vessel
●If the suspension has been modified or
tires of a size other than specified are
installed
●If the front of the vehicle is raised or
lowered due to the carried load
●When equipment that may obstruct a
sensor is installed, such as a towing
eyelet, bumper protector (an addi-
tional trim strip, etc.), bicycle carrier, or
snow plow
●When using an automatic car wash

2504-5. Using the driving support systems
traveling direction of the vehicle.
●Brake control
• The Parking Support Brake is disabled.
• Approximately 2 seconds have elapsed since the vehicle was stopped by brake
control.
• The brake pedal is depressed after the vehicle is stopped by brake control.
• The static object is no longer 6 to 13 ft. (2 to 4 m) away from the vehicle or in the
traveling direction of the vehicle.
■Detection range of the Parking Support
Brake function (static objects)
The detection range of the Parking Support
Brake function (static objects) differs from
the detection range of the intuitive parking
assist. ( P.236) Therefore, even if the intu-
itive parking assist detects an object and
provides a warning, the Parking Support
Brake function (static objects) may not start
operating.
■Objects that the Parking Support Brake
function (static obje cts) may not detect
The sensors may not be able to detect cer-
tain objects, such as the following:
●Pedestrian
●Cotton cloth, snow, and other materials
that are poor reflectors of ultrasonic
waves
●Objects which are not perpendicular to
the ground, are not perpendicular to the
traveling direction of the vehicle, are
uneven or are waving
●Low objects
●Thin objects such as wires, fences, ropes
and signposts
●Objects that are extremely close to the
bumper
■Situations in which the Parking Support
Brake function (stati c objects) may not
operate
When driving with the shift lever in N
■Intuitive parking assist buzzer
Regardless of whether the intuitive parking
assist function is enabled or not ( P.233),
if the Parking Support Brake function (static
objects) is enabled ( P.244), the front or
rear sensors detect an object and hybrid system output restriction control or brake
control is performed, the intuitive parking
assist buzzer will sound to notify the driver
of the approximate distance to the object.
■Situations in which the Parking Support
Brake function (static objects) may
operate even if there is no possibility of a
collision
In some situations, such as the following, the
Parking Support Brake function (static
objects) may operate even though there is
no possibility of a collision.
●Vehicle surroundings
• When driving on a narrow road
• When driving on a gravel road or in an area with tall grass
• When driving toward a banner, flag, low- hanging branch or boom barrier (such as
those used at railroad crossings, toll gates
and parking lots)
• When driving on a narrow path sur-
rounded by a structure, such as in a tun-
nel or on an iron bridge
• When parallel parking
• When there is a rut or hole in the surface
of the road
• When driving on a metal cover (grating),
such as those used for drainage ditches
• When driving on a steep slope
• If a sensor is hit by a large amount of water, such as when driving on a flooded
road
●Weather

2514-5. Using the driving support systems
4
Driving
• If a sensor is covered with ice, snow, dirt, etc. (when cleared, the system will return
to normal)
• If heavy rain or water strikes a sensor
• When driving in incl ement weather such
as fog, snow or a sandstorm
●Other ultrasonic wave sources
• When vehicle horns, vehicle detectors,
motorcycle engines, air brakes of large
vehicles, the clearance sonar of other
vehicles or other devices which produce
ultrasonic waves are near the vehicle
• If a sticker or an el ectronic component,
such as a backlit license plate (especially
fluorescent type), fog lights, fender pole
or wireless antenna is installed near a
sensor
●Changes in the vehicle posture
• If the vehicle is significantly tilted
• If the front of the vehicle is raised or low-
ered due to the carried load
• If the orientation of a sensor has been
changed due to a collision or other
impact
■Situations in which the Parking Support
Brake function (stati c objects) may not
operate properly
In some situations, such as the following, this
function may not operate properly.
●Weather
• When a sensor or the area around a sen- sor is extremely hot or cold
• When strong winds are blowing • If a sensor is covered with ice, snow, dirt,
etc. (when cleared, the system will return
to normal)
• If heavy rain or water strikes a sensor
• When driving in incl ement weather such
as fog, snow or a sandstorm
●Vehicle surroundings
• When an object that cannot be detected
is between the vehicle and a detected
object
• If an object such as a vehicle, motorcycle,
bicycle or pedestrian cuts in front of the
vehicle or runs out from the side of the
vehicle
●Other ultrasonic waves sources
• When vehicle horns, vehicle detectors,
motorcycle engines, air brakes of large
vehicles, the clearance sonar of other
vehicles or other de vices which produce
ultrasonic waves are near the vehicle
• If a sticker or an electronic component, such as a backlit license plate (especially
fluorescent type), fog lights, fender pole
or wireless antenna is installed near a
sensor
●Changes in the vehicle posture
• If the vehicle is significantly tilted
• If the front of the vehicle is raised or low-
ered due to the carried load
• If the orientation of a sensor has been
changed due to a collision or other
impact

2524-5. Using the driving support systems
*: If equipped
This function will operate in situations
such as the following if a vehicle is
detected in the traveling direction of
the vehicle.
■When reversing, a vehicle is
approaching and the brake pedal is
not depressed, or is depressed late
 P.228
■The Parking Support Brake function
(rear-crossing vehicles) will operate
when
The function will operate when the PKSB
OFF indicator is not illuminated or flashing
(  P.75, 76) and all of the following condi-
tions are met:
●Hybrid system output restriction control
• The Parking Support Brake is enabled.
• The vehicle speed is 10 mph (15 km/h) or less.
• Vehicles are approaching from the right or left at the rear of the vehicle at a travel-
ing speed of more than approximately 5
mph (8 km/h)
• The shift lever is in R.
• The Parking Support Brake determines
that a stronger than normal brake opera-
tion is necessary to avoid a collision with
Parking Support Brake func-
tion (rear-crossing vehicles)*
If a rear radar sensor detects a vehi-
cle approaching from the right or
left at the rear of the vehicle and the
system determines that the possi-
bility of a collision is high, this func-
tion will perform brake control to
reduce the likelihood of an impact
with the approaching vehicle.
Examples of function operation
Types of sensors
WARNING
■To ensure the Parking Support Brake
(rear-crossing vehicles) can operate
properly
Observe the following precautions
regarding the rear radar sensors
(  P.228). Failure to do so may cause a
sensor to not operate properly, and may
cause an accident.
●Do not modify, disassemble or paint
the sensors.
●Do not replace a rear radar sensor
with a part other than a genuine part.
●Do not damage the rear radar sensors,
and always keep the radar sensors and
their surrounding area on the bumper
clean.
■To prevent a rear radar sensor from
malfunctioning
●If the area around a rear radar sensor
is subjected to an impact, the system
may not operate properly due to a
sensor malfunction. Have the vehicle
inspected by your Lexus dealer.
●Observe the rear radar sensor han-
dling precautions. ( P.228)

2534-5. Using the driving support systems
4
Driving
an approaching vehicle.
●Brake control
• Hybrid system output restriction control is operating.
• The Parking Support Brake determines
that an emergency brake operation is
necessary to avoid a collision with an
approaching vehicle.
■The Parking Support Brake function
(rear-crossing vehicles) will stop operat-
ing when
The function will stop operating if any of the
following conditions are met:
●Hybrid system output restriction control
• The Parking Support Brake is disabled.
• The collision becomes avoidable with normal brake operation.
• A vehicle is no longer approaching from the right or left at the rear of the vehicle.
●Brake control
• The Parking Support Brake is disabled.
• Approximately 2 seconds have elapsed
since the vehicle was stopped by brake
control.
• The brake pedal is depressed after the vehicle is stopped by brake control.
• A vehicle is no longer approaching from
the right or left at the rear of the vehicle.
■Detection area of the Parking Support
Brake function (rear-crossing vehicles)
The detection area of the Parking Support
Brake function (rear-crossing vehicles) dif-
fers from the detection area of the RCTA
function ( P.240). Therefore, even if the
RCTA function detects a vehicle and pro-
vides an alert, the Parking Support Brake
function (rear-crossing vehicles) may not
start operating.
■Conditions under which the Parking
Support Brake function (rear-crossing
vehicles) will not detect a vehicle
The Parking Support Brake function (rear-
crossing vehicles) is not designed to detect
the following types of vehicles and/or
objects:
●Vehicles approaching from directly
behind
●Vehicles backing up in a parking space
next to your vehicle
●Vehicles that the sensors cannot detect
due to obstructions
●Vehicles which suddenly accelerate or
decelerate near your vehicle
●Guardrails, walls, signs, parked vehicles
and similar stationary objects*
●Small motorcycles, bicycles, pedestrians,
etc.*
●Vehicles moving away from your vehicle
●Vehicles approaching from the parking
spaces next to your vehicle*
●Objects which are extremely close to a
radar sensor*
●Vehicles which are approaching from the
right or left at the rear of the vehicle at a
traveling speed of less than approxi-
mately 5 mph (8 km/h)
●Vehicles which are approaching from the
right or left at the rear of the vehicle at a
traveling speed of more than approxi-
mately 15 mph (24 km/h)
*: Depending on the conditions, detection
of a vehicle and/or object may occur.
■RCTA buzzer
Regardless of whether th e RCTA function is
enabled or not ( P.239), if the Parking
Support Brake function is enabled
(  P.244) and brake control is performed,
a buzzer will sound to notify the driver.
■Situations in which the system may
operate even though there is no possi-
bility of a collision
In some situations such as the following, the
Parking Support Brake function (rear-
crossing vehicles) may operate even
though there is no possibility of a collision.
●When the parking space faces a street

2544-5. Using the driving support systems
and vehicles are being driven on the
street
●When a detected vehicle turns while
approaching the vehicle
●When a vehicle passes by the side of your
vehicle
●When the distance between your vehicle
and metal objects, such as a guardrail,
wall, sign, or parked vehicle, which may
reflect electrical waves toward the rear of
the vehicle, is short
●When there are spinning objects near
your vehicle such as the fan of an air con-
ditioning unit
●When water is splashed or sprayed toward the rear bumper, such as from a
sprinkler
■Situations in which the Parking Support
Brake function (rear-crossing vehicles)
may not operate properly
In some situations, such as the following, the
radar sensors may not detect an object and
this function may not operate properly
●Stationary objects
●When a sensor or the area around a sen-
sor is extremely hot or cold
●If the rear bumper is covered with ice,
snow, dirt, etc.
●When it is raining he avily or water strikes
the vehicle
●When the detection area of a radar sen-
sor is obstructed by an adjacent vehicle
●If the vehicle is significantly tilted
●When equipment that may obstruct a
sensor is installed, such as a towing eye-
let, bumper protector (an additional trim
strip, etc.), bicycle carrier, or snow plow
●If the suspension has been modified or
tires of a size othe r than specified are
installed
●If the front of the vehicle is raised or low-
ered due to the carried load
●If a sticker or an el ectronic component,
such as a backlit license plate (especially
fluorescent type), fog lights, fender pole
or wireless antenna is installed near a
radar sensor
●If the orientation of a radar sensor has
been changed
●When multiple vehicl es are approaching
with only a small gap between each vehi-
cle
●If a vehicle is approaching the rear of
your vehicle rapidly
●Situations in which the radar sensor may
not detect a vehicle
• When a vehicle approaches from the right or left at the rear of the vehicle while
you are turning while backing up
• When turning while backing up

2574-5. Using the driving support systems
4
Driving
Helps to maintain directional stability
when swerving on slippery road sur-
faces by controlling steering perfor-
mance.
■Secondary Collision Brake
When the airbag sensor detects a colli-
sion, the brakes and brake lights are
automatically controlled to reduce the
vehicle speed and that helps reduce
the possibility of further damage due to
a secondary collision
■TRAC (Traction Control)
Helps to maintain drive power and pre-
vent the drive wheels from spinning
when starting the vehicle or accelerat-
ing on slippery roads
■Active Cornering Assist (ACA)
Helps to prevent the vehicle from drift-
ing to the outer side by performing
inner wheel brake control when
attempting to accelerate during cor-
nering
■Hill-start assist control
Helps to reduce the backward move-
ment of the vehicle when starting on an
uphill
■EPS (Electric Power Steering)
Employs an electric motor to reduce
the amount of effort needed to turn the
steering wheel
■E-Four (AWD models)
Electronic On-Demand AWD system.
Automatically switches from front-
wheel drive to all-wheel drive (AWD)
according to the driving conditions,
helping to ensure reliable handling and stability. Examples of
conditions where
the system will switch to AWD are
when cornering, going uphill, starting
off or accelerating, and when the road
surface is slippery due to snow, rain,
etc.
■When the TRAC/VSC/ABS systems are
operating
The slip indicator light will flash while the
TRAC/VSC/ABS systems are operating.
■Disabling the TRAC system
If the vehicle gets stuck in mud, dirt or snow,
the TRAC system may reduce power from
the hybrid system to the wheels. Pressing
the switch to turn the system off may
make it easier for you to rock the vehicle in
order to free it.
To turn the TRAC system off, quickly press
and release the switch.
The “Traction Co ntrol Turned Off” will be
shown on the multi-information display.
Press the switch again to turn the sys-
tem back on.
■Disabling both TRAC and VSC systems
To turn the TRAC and VSC systems off,

2594-5. Using the driving support systems
4
Driving
systems are turned off, automatic re-
enabling will not occur when vehicle
speed increases.
■Secondary Collision Brake operating
conditions
The vehicle speed is approximately 6 mph
(10 km/h) or more and the airbag sensor
detects a collision. (The Secondary Colli-
sion Brake will not operate when the vehicle
speed is below approximately 6 mph [10
km/h].)
■Secondary Collision Brake automatic
cancellation
The Secondary Collision Brake is automati-
cally canceled in the following situations.
●The vehicle speed drops below approxi-
mately 6 mph (10 km/h)
●A certain amount of time elapses during
operation
●The accelerator pedal is depressed a
large amount
■Operating conditions of Active Corner-
ing Assist
The system operates in the following situa-
tions.
●TRAC/VSC can operate
●The system determines that the vehicle is
drifting to the outer side when attempting
to accelerate during cornering
●The brake pedal is released
■Reduced effectiveness of the EPS sys-
tem
The effectiveness of the EPS system is
reduced to prevent the system from over-
heating when there is frequent steering
input over an extended period of time. The
steering wheel may feel heavy as a result.
Should this occur, re frain from excessive
steering input or stop the vehicle and turn
the hybrid system off. The EPS system
should return to normal within 10 minutes.
■If a message about AWD system is
shown on the multi-information display
(AWD models)
If one of the following messages is shown on
the multi-information di splay, perform each
action.
●“AWD System Overheated Switching to
2WD Mode”
The AWD system is overheating. Reduce
load on the system by stopping the vehicle
for a while or driving the vehicle at a speed
of 6 mph (10 km/h) or more. If the message
disappears, it is possible to drive the vehicle
normally.
●“AWD System Overheated 2WD Mode
Engaged”
The AWD system has been canceled and
switched to the front-wheel drive due to
overheating. Reduce load on the system by
stopping the vehicle for a while or driving
the vehicle at a speed of 6 mph (10 km/h)
or more. If the message disappears, it is
possible to drive the vehicle normally.
●“AWD System Malfunction 2WD Mode
Engaged Visit Your Dealer”
The AWD system has been stopped and
switched to the front-wheel drive due to a
malfunction. Have your vehicle inspected
by your Lexus dealer immediately.
WARNING
■The ABS does not operate effectively
when
●The limits of tire gripping performance
have been exceeded (such as exces-
sively worn tires on a snow covered
road).
●The vehicle hydroplanes while driving
at high speed on wet or slick road.
■Stopping distance when the ABS is
operating may exceed that of normal
conditions
The ABS is not designed to shorten the
vehicle’s stopping distance. Always main-
tain a safe distance from the vehicle in
front of you, especially in the following
situations:
●When driving on dirt, gravel or snow-
covered roads