sensor LEXUS UX250H 2019 Owner's Manual

1964-5. Using the driving support systems
■If a warning message is displayed on the multi-information display
A system may be temporarily unavailable or there may be a malfunction in the system.
●In the following situations, perform the actions specified in the table. When the normal
operating conditions are detected, the message will disappear and the system will
become operational.
If the message does not disappear, contact your Lexus dealer.
SituationActions
When the area around a sensor is covered
with dirt, moisture (f ogged up, covered with
condensation, ice, etc. ), or other foreign
matterTo clean the part of the windshield in front of
the front camera, use the windshield wipers
or the windshield defogger of the air condi-
tioning system ( P.277).

1974-5. Using the driving support systems
4
Driving
●In the following situations, if the situation has changed (or the vehicle has been driven for
some time) and the normal operating conditions are detected, the message will disappear
and the system will become operational.
If the message does not disappea r, contact your Lexus dealer.
When the temperature around the radar sensor is outside of the operational range, such as
when the vehicle is in the sun or in an extremely cold environment
When the front camera cannot detect objects in fr ont of the vehicle, such as when driving in
the dark, snow, or fog, or when bright lights are shining into the front camera
When the temperature around the front
camera is outside of the operational range,
such as when the vehicle is in the sun or in an
extremely cold environment
If the front camera is hot, such as after the
vehicle had been parked in the sun, use the
air conditioning system to decrease the tem-
perature around the front camera.
If a sunshade was used when the vehicle was
parked, depending on its type, the sunlight
reflected from the surface of the sunshade
may cause the temperature of the front cam-
era to become excessively high.
If the front camera is cold, such after the
vehicle is parked in an extremely cold envi-
ronment, use the air conditioning system to
increase the temperature around the front
camera.
The area in front of the front camera is
obstructed, such as when the hood is open
or a sticker is attached to the part of the
windshield in front of the front camera.
Close the hood, remove the sticker, etc. to
clear the obstruction.
SituationActions

1984-5. Using the driving support systems
The system can detect the following:
Vehicles
 Bicyclists
 Pedestrians
■Pre-collision warning
When the system determines that the
possibility of a frontal collision is high, a
buzzer will sound and a warning mes-
sage will be displayed on the multi-
information display to urge the driver to take evasive action.
■Pre-collision brake assist
When the system determines that the
possibility of a frontal collision is high,
the system applies greater braking
force in relation to how strongly the
brake pedal is depressed.
■Pre-collision braking
If the system determines that the possi-
bility of a frontal collision is extremely
high, the brakes are automatically
applied to help avoid the collision or
reduce the impact of the collision.
PCS (Pre-Collision System)
The pre-collision system uses a
radar sensor and front camera to
detect objects ( P.198) in front of
the vehicle. When the system
determines that the possibility of a
frontal collision with an object is
high, a warning operates to urge
the driver to take evasive action
and the potential brake pressure is
increased to help the driver avoid
the collision. If the system deter-
mines that the possibility of a frontal
collision with an object is extremely
high, the brakes are automatically
applied to help avoid the collision or
help reduce the impact of the colli-
sion.
The pre-collision system can be dis-
abled/enabled and the warning tim-
ing can be changed. ( P.200)
Detectable objects
System functions
WARNING
■Limitations of the pre-collision system
●The driver is solely responsible for safe
driving. Always drive safely, taking
care to observe your surroundings. Do
not use the pre-collision system
instead of normal braking operations
under any circumstances. This system
will not prevent collisions or lessen col-
lision damage or injury in every situa-
tion. Do not overly rely on this system.
Failure to do so may lead to an acci-
dent, resulting in death or serious
injury.

2004-5. Using the driving support systems
■Enabling/disabling the pre-colli-
sion system
The pre-collision system can be
enabled/disabled on ( P.87) of
the multi-information display.
The system is automatically enabled each
time the power switch is turned to ON.
If the system is disabled, the PCS warn-
ing light will turn on and a message will
be displayed on the multi-information
display.
■Changing the pre-collision warn-
ing timing
The pre-collision warning timing can
be changed on ( P.87) of the
multi-information display.
The warning timing setting is retained
when the power switch is turned off. How-
ever, if the pre-collisio n system is disabled
and re-enabled, the operation timing will
return to the default setting (middle).
1Early
2
Middle
This is the default setting.
3Late
■Operational conditions
The pre-collision system is enabled and the system determines that the possibility of a frontal
collision with a detect ed object is high.
WARNING
●When the tires are very worn
●When tires of a size other than speci-
fied are installed
●When tire chains are installed
●When a compact spare tire or an
emergency tire puncture repair kit is
used
●If equipment (snow plow, etc.) that may
obstruct the radar sensor or front cam-
era is temporarily installed to the vehi-
cle
Changing settings of the pre-col-
lision system

2034-5. Using the driving support systems
4
Driving
that may contact your vehicle, such as
thick grass, tree branches, or a banner
• When driving through steam or smoke
• When driving near an object that reflects
radio waves, such as a large truck or
guardrail
• When driving near a TV tower, broad- casting station, electric power plant, or
other location where strong radio waves
or electrical noise may be present
■Situations in which the system may not
operate properly
●In some situations such as the following,
an object may not be detected by the
radar sensor and front camera, prevent-
ing the system from operating properly:
• When a detectable object is approaching
your vehicle
• When your vehicle or a detectable object
is wobbling
• If a detectable object makes an abrupt maneuver (such as sudden swerving,
acceleration or deceleration)
• When your vehicle approaches a detect- able object rapidly
• When a detectable object is not directly
in front of your vehicle
• When a detectable object is near a wall, fence, guardrail, manhole cover, vehicle,
steel plate on the road, etc.
• When a detectable object is under a structure
•When part of a detect able object is hid-
den by an object, such as large baggage, an umbrella, or guardrail
• When multiple dete ctable objects are
close together
• If the sun or other light is shining directly on a detectable object
• When a detectable object is a shade of
white and looks extremely bright
• When a detectable ob ject appears to be
nearly the same color or brightness as its
surroundings
• If a detectable object cuts or suddenly emerges in front of your vehicle
• When the front of your vehicle is hit by water, snow, dust, etc.
• When a very bright light ahead, such as
the sun or the head lights of oncoming
traffic, shines direct ly into the front cam-
era
• When approaching the side or front of a vehicle ahead
• If a vehicle ahead is a motorcycle
• If a vehicle ahead is narrow, such as a per-
sonal mobility vehicle
• If a preceding vehicle has a small rear
end, such as an unloaded truck
• If a preceding vehicle has a low rear end, such as a low bed trailer
• If a vehicle ahead has extremely high ground clearance
• If a vehicle ahead is carrying a load which protrudes past its rear bumper
• If a vehicle ahead is irregularly shaped,
such as a tractor or side car
• If a vehicle ahead is a child sized bicycle, a bicycle that is carrying a large load, a

2044-5. Using the driving support systems
bicycle ridden by more than one person,
or a uniquely shaped bicycle (bicycle with
a child seat, tandem bicycle, etc.)
• If a pedestrian/or the riding height of a bicyclist ahead is shorter than approxi-
mately 3.2 ft. (1 m) or taller than approxi-
mately 6.5 ft. (2 m)
• If a pedestrian/bicyclist is wearing over- sized clothing (a rain coat, long skirt,
etc.), making their silhouette obscure
• If a pedestrian is bending forward or squatting or bicyclist is bending forward
• If a pedestrian/bicyclist is moving fast
• If a pedestrian is pushing a stroller, wheel- chair, bicycle or other vehicle
• When driving in incl ement weather such
as heavy rain, fog, snow or a sandstorm
• When driving through steam or smoke
• When the surrounding area is dim, such
as at dawn or dusk, or while at night or in
a tunnel, making a detectable object
appear to be nearly the same color as its
surroundings
• When driving in a place where the sur-
rounding brightness changes suddenly,
such as at the entrance or exit of a tunnel
• After the hybrid system has started the
vehicle has not been driven for a certain
amount of time
• While making a left/right turn and for a
few seconds after makin g a left/right turn
• While driving on a curve and for a few seconds after driving on a curve
• If your vehicle is skidding
• If the front of the vehicle is raised or low- ered
• If the wheels are misaligned
• If a wiper blade is blocking the front cam- era
• The vehicle is being driven at extremely high speeds
• When driving on a hill
• If the radar sensor or front camera is mis-
aligned●In some situations su ch as the following,
sufficient braking force may not be
obtained, preventing the system from
performing properly:
• If the braking functions cannot operate to their full extent, such as when the brake
parts are extremely cold, extremely hot,
or wet
• If the vehicle is not properly maintained
(brakes or tires are excessively worn,
improper tire inflation pressure, etc.)
• When the vehicle is being driven on a
gravel road or other slippery surface
■If VSC is disabled
●If VSC is disabled ( P.257), the pre-col-
lision brake assist and pre-collision brak-
ing functions are also disabled.
●The PCS warning light will turn on and
“VSC Turned OFF Pre-Collision Brake
System Unavailable” will be displayed on
the multi-information display.

2134-5. Using the driving support systems
4
Driving
●When the system determines that the
driver is driving without holding the steer-
ing wheel while the system is operating
If the driver continue s to keep their hands
off of the steering wheel, the buzzer sounds,
the driver is warned and the function is tem-
porarily canceled. This warning also oper-
ates in the same way when the driver
continuously operates the steering wheel
only a small amount.
The buzzer also sounds even if the alert
type is set to “Steering wheel vibration”.
●When the system determines that the
vehicle may not turn and instead depart
from its lane while driving around a curve
Depending on the vehicle condition and
road conditions, the warning may not oper-
ate. Also, if the system determines that the
vehicle is driving around a curve, warnings
will occur earlier than during straight-lane
driving.
●When the system determines that the
driver is driving without holding the steer-
ing wheel while the st eering wheel assist
of the steering assist function is operat-
ing.
If the driver continue s to keep their hands
off of the steering wheel and the steering
wheel assist is operating, the buzzer sounds
and the driver is warned. Each time the
buzzer sounds, the continuing time of the
buzzer becomes longer.
The buzzer also sounds even if the alert
type is set to “Steering wheel vibration”.
■Vehicle sway warning function
When the system determines that the vehi- cle is swaying while the vehicle sway warn-
ing function is operating, a buzzer sounds
and a warning message urging the driver to
rest and the symbol sh
own in the illustration
are simultaneously di splayed on the multi-
information display.
Depending on the vehicle and road condi-
tions, the warning may not operate.
■Warning message
If the following warning message is dis-
played on the multi-in formation display and
the LTA indicator illuminates in orange, fol-
low the appropriate troubleshooting proce-
dure. Also, if a different warning message is
displayed, follow the instructions displayed
on the screen.
●“LTA Unavailable”
The system is temporarily canceled due to a
malfunction in a sensor other than the front
camera. Turn the LTA system off, wait for a
little while, and then turn the LTA system
back on.
●“LTA Unavailable at Current Speed”
The function cannot be used as the vehicle
speed exceeds the LTA operation range.
Drive slower.
■Customization
Function settings can be changed.
(Customizable features: P.441)

2174-5. Using the driving support systems
4
Driving
■Operation switchesVehicle-to-vehicle distance switch
“+RES” switch
Cruise control main switch
Cancel switch
“-SET” switch
WARNING
■Before using dynamic radar cruise
control with full-speed range
●Driving safely is the sole responsibility
of the driver. Do not rely solely on the
system, and drive safely by always pay-
ing careful attention to your surround-
ings.
●The dynamic radar cruise control with
full-speed range pr ovides driving
assistance to reduce the driver’s bur-
den. However, there are limitations to
the assistance provided.
Read the following co nditions carefully.
Do not overly rely on this system and
always drive carefully.
• When the sensor ma y not be correctly
detecting the vehicle ahead:  P.224
• Conditions under which the vehicle- to-vehicle distance control mode may
not function correctly: P.225
A
B
C
D
E
●Set the speed appropriately depend-
ing on the speed limit, traffic flow, road
conditions, weather conditions, etc.
The driver is responsible for checking
the set speed.
●Even when the system is functioning
normally, the condition of the preced-
ing vehicle as detected by the system
may differ from the condition
observed by the driver. Therefore, the
driver must always remain alert, assess
the danger of each situation and drive
safely. Relying solely on this system or
assuming the system ensures safety
while driving can lead to an accident,
resulting in death or serious injury.
●Switch the dynamic radar cruise con-
trol with full-speed range setting to off,
using the cruise control main switch
when not in use.
■Cautions regarding the driving assist
systems
Observe the following precautions, as
there are limitations to the assistance
provided by the system.
Failure to do so may cause an accident
resulting in death or serious injury.
●Assisting the driver to measure follow-
ing distance
The dynamic radar cruise control with
full-speed range is only intended to help
the driver in determining the following
distance between the driver’s own vehi-
cle and a designated vehicle traveling
ahead. It is not a mechanism that allows
careless or inattentive driving, and it is
not a system that can assist the driver in
low-visibility conditions.
It is still necessary for driver to pay close
attention to the vehicle’s surroundings.

2244-5. Using the driving support systems
below approximately 20 mph [30 km/h],
the set speed will be set to approximately
20 mph [30 km/h].)
■Accelerating after setting the vehicle
speed
The vehicle can accelerate by operating the
accelerator pedal. After accelerating, the
set speed resumes. However, during vehi-
cle-to-vehicle distance control mode, the
vehicle speed may decrease below the set
speed in order to maintain the distance to
the preceding vehicle.
■When the vehicle stops while follow-up
cruising
●Pressing the “+RES” switch while the
vehicle ahead stops w ill resume follow-up
cruising if the vehicle ahead starts off
within approximately 3 seconds after the
switch is pressed.
●If the vehicle ahead starts off within 3 sec-
onds after your vehicle stops, follow-up
cruising will be resumed.
■Automatic cancelation of vehicle-to-
vehicle distance control mode
Vehicle-to-vehicle dist ance control mode is
automatically canceled in the following situ-
ations.
●VSC is activated.
●TRAC is activated for a period of time.
●When the VSC or TRAC system is
turned off.
●The sensor cannot detect correctly
because it is covered in some way.
●Pre-collision braking is activated.
●The parking brake is operated.
●The vehicle is stopped by system control
on a steep incline.
●The following are detected when the
vehicle has been stopped by system con-
trol:
• The driver is not wearing a seat belt.
• The driver’s door is opened.
• The vehicle has been stopped for about 3 minutes
If vehicle-to-vehicle distance control mode
is automatically canceled for any reasons
other than the above, there may be a mal- function in the system. Contact your Lexus
dealer.
■Automatic cancelation of constant
speed control mode
Constant speed control mode is automati-
cally canceled in the following situations:
●Actual vehicle speed is more than
approximately 10 mph (16 km/h) below
the set vehicle speed.
●Actual vehicle speed falls below approxi-
mately 20 mph (30 km/h).
●VSC is activated.
●TRAC is activated for a period of time.
●When the VSC or TRAC system is
turned off.
●Pre-collision braking is activated.
If constant speed control mode is automati-
cally canceled for any reasons other than
the above, there may be a malfunction in the
system. Contact your Lexus dealer.
■Brake operation
A brake operation sound may be heard and
the brake pedal response may change, but
these are not malfunctions.
■Warning messages and buzzers for
dynamic radar cruise control with full-
speed range
Warning messages and buzzers are used to
indicate a system malfunction or to inform
the driver of the need for caution while driv-
ing. If a warning messa ge is shown on the
multi-information displa y, read the message
and follow the instructions. ( P.196, 395)
■When the sensor may not be correctly
detecting the vehicle ahead
In the case of the fo llowing and depending
on the conditions, operate the brake pedal
when deceleration of the system is insuffi-
cient or operate the accelerator pedal
when acceleration is required.
As the sensor may not be able to correctly
detect these types of vehicles, the approach
warning ( P.222) may not be activated.
●Vehicles that cut in suddenly
●Vehicles traveling at low speeds
●Vehicles that are not moving in the same

2254-5. Using the driving support systems
4
Driving
lane
●Vehicles with small rear ends (trailers
with no load on board, etc.)
●Motorcycles traveling in the same lane
●When water or snow thrown up by the
surrounding vehicles hinders the detect-
ing of the sensor
●When your vehicle is pointing upwards
(caused by a heavy load in the luggage
compartment, etc.)
●Preceding vehicle has an extremely high
ground clearance
■Conditions under which the vehicle-to-
vehicle distance control mode may not
function correctly
In the case of the following conditions,
operate the brake pedal (or accelerator
pedal, depending on the situation) as nec-
essary.
As the sensor may not be able to correctly
detect vehicles ahead, the system may not
operate properly.
●When the road curves or when the lanes are narrow
●When steering wheel operation or your
position in the lane is unstable
●When the vehicle ahead of you deceler-
ates suddenly
●When driving on a road surrounded by a
structure, such as in a tunnel or on a
bridge
●While the vehicle speed is decreasing to
the set speed after the vehicle acceler-
ates by depressing the accelerator pedal