brakes LEXUS UX250H 2019 User Guide

2454-5. Using the driving support systems
4
Driving
Brake control is operating
The system determined that emergency
braking is necessary.
Multi-information display: “BRAKE!”
PKSB OFF indicator: Not illuminated
Buzzer: Short beep
Vehicle stopped by system opera-
tion
The vehicle has been stopped by brake
control operation.
Multi-information display: “Switch to
Brake” (If the accelerator pedal is not
depressed, “Press Brake Pedal” will be dis-
played.)
PKSB OFF indicator: Illuminated
Buzzer: Short beep
If the Parking Support Brake deter-
mines that a collision with a detected
object is possible, the hybrid system
output will be restricted to restrain any
increase in the vehicle speed. (Hybrid
system output restriction control: See
figure 2 below.)
Additionally, if the accelerator pedal
continues to be depressed, the brakes
will be applied automatically to reduce
the vehicle speed. (Brake control: See
figure 3 below.)
Figure 1 When the PKSB (Parking
Support Brake) is disabled Hybrid system output
Braking force
Time
 Figure 2 When hybrid system out-
put restriction control operates
Hybrid system output
Braking force
Time
Hybrid system output restriction
control begins operating (The sys-
tem determines that possibility of
collision with detected object is
high)
“BRAKE!” is displayed on the multi-infor-
mation display.
Hybrid system output reduced
 Figure 3 When brake control oper-
ates
System overview
A
B
C
A
B
C
D
E

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

2564-5. Using the driving support systems
the “Eco” indicator comes on.
3Sport mode
Assists acceleration response by con-
trolling the hybrid system and steering.
Suitable for when precise handling is desir-
able, for example when driving on moun-
tain roads.
When not in Sport mode, if the driving
mode select switch is turned backward, the
“Sport” indicator comes on and the Hybrid
System Indicator changes to the tachome-
ter. ( P.78, 82)
■Operation of the air conditioning sys-
tem in Eco drive mode
Eco drive mode controls the heating/cool-
ing operations and fan speed of the air con-
ditioning system to enhance fuel efficiency.
To improve air condit ioning performance,
perform the following operations:
●Turn off eco air conditioning mode
(  P.278)
●Adjust the fan speed ( P.276, 279)
●Turn off Eco drive mode
■Automatic deactivation of Sport mode
If the power switch is turned off after driving
in Sport mode, the driving mode will be
changed to Normal mode.
■Driving mode pop-up display (vehicles
with 10.3-inch display model)
When the driving mode is changed, the
selected driving mode will be temporarily
displayed on the side display. ( P.273)
■ECB (Electronically Controlled
Brake System)
The electronically controlled system
generates braking force correspond-
ing to the brake operation
■ABS (Anti-lock Brake System)
Helps to prevent wheel lock when the
brakes are applied suddenly, or if the
brakes are applied while driving on a
slippery road surface
■Brake assist
Generates an increased level of brak-
ing force after the brake pedal is
depressed when the system detects a
panic stop situation
■VSC (Vehicle Stability Control)
Helps the driver to control skidding
when swerving sudden ly or turning on
slippery road surfaces
■Enhanced VSC (Enhanced Vehi-
cle Stability Control)
Provides cooperative control of the
ABS, TRAC, VSC and EPS.
Driving assist systems
To keep driving safety and perfor-
mance, the following systems oper-
ate automatically in response to
various driving situations. Be aware,
however, that these systems are
supplementary and should not be
relied upon too heavily when oper-
ating the vehicle.
Summary of the driving assist
systems

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,

2604-5. Using the driving support systems
WARNING
●When driving with tire chains
●When driving over bumps in the road
●When driving over roads with potholes
or uneven surfaces
■TRAC/VSC may not operate effec-
tively when
Directional control and power may not
be achievable while driving on slippery
road surfaces, even if the TRAC/VSC
system is operating.
Drive the vehicle carefully in conditions
where stability and power may be lost.
■Active Cornering Assist does not
operate effectively when
●Do not rely solely upon Active Cor-
nering Assist. Active Cornering Assist
may not operate effectively when
accelerating down slopes or driving on
slippery road surfaces.
●When Active Cornering Assist fre-
quently operates, Active Cornering
Assist may temporarily stop operating
to ensure proper operation of the
brakes, TRAC, VSC.
■Hill-start assist control does not oper-
ate effectively when
●Do not overly rely on the hill-start
assist control. Hill-start assist control
may not operate effectively on steep
inclines and roads covered with ice.
●Unlike the parking brake, hill-start
assist control is not intended to hold
the vehicle stationary for an extended
period of time. Do not attempt to use
hill-start assist control to hold the vehi-
cle on an incline, as doing so may lead
to an accident.
■When the TRAC/ABS/VSC is acti-
vated
The slip indicator light flashes. Always
drive carefully. Re ckless driving may
cause an accident. Exercise particular
care when the indicator light flashes.
■When the TRAC/VSC systems are
turned off
Be especially careful and drive at a speed
appropriate to the road conditions. As
these are the systems to help ensure
vehicle stability and driving force, do not
turn the TRAC/VSC systems off unless
necessary.
■Secondary Collision Brake
Do not overly rely on the Secondary Col-
lision Brake. This system is designed to
help reduce the possibility of further
damage due to a secondary collision,
however, that effect changes according
to various conditions. Overly relying on
the system may result in death or serious
injury.
■Replacing tires
Make sure that all ti res are of the speci-
fied size, brand, tread pattern and total
load capacity. In addition, make sure that
the tires are inflated to the recom-
mended tire inflation pressure level.
The ABS, TRAC and VSC systems will
not function correctly if different tires are
installed on the vehicle.
Contact your Lexus dealer for further
information when replacing tires or
wheels.
■Handling of tires and the suspension
Using tires with any kind of problem or
modifying the suspensi on will affect the
driving assist systems, and may cause a
system to malfunction.

2614-6. Driving tips
4
Driving
4-6.Driving tips
When using Eco drive mode, the
torque corresponding to the accelera-
tor pedal depression amount can be
generated more smoothly than it is in
normal conditions. In addition, the
operation of the air conditioning sys-
tem (heating/cooling) will be mini-
mized, improving the fuel economy.
( P.255)
The Eco-friendly driving is possible by
keeping the indicate of Hybrid System
Indicator within Eco area. ( P.79, 84)
Shift the shift lever to D when stopped
at a traffic light, or driving in heavy traf-
fic, etc. Shift the shift lever to P when
parking. When using the N, there is no
positive effect on fuel consumption. In
the N, the gasoline engine operates
but electricity cannot be generated.
Also, when using the air conditioning
system, etc., the hybrid battery (trac-
tion battery) power is consumed. 
Drive your vehicle smoothly. Avoid
abrupt acceleration and decelera-
tion. Gradual acceleration and
deceleration will make more effec-
tive use of the electric motor (trac-
tion motor) without having to use
gasoline engine power.
 Avoid repeated acceleration.
Repeated acceleration consumes
hybrid battery (traction battery)
power, resulting in poor fuel con-
sumption. Battery power can be
restored by driving with the acceler-
ator pedal slightly released.
Make sure to operate the brakes gently
and in a timely manner. A greater
amount of electrical energy can be
regenerated when slowing down.
Repeated acceleration and decelera-
tion, as well as long waits at traffic
lights, will lead to bad fuel economy.
Check traffic reports before leaving
and avoid delays as much as possible.
When driving in a traffic jam, gently
release the brake pedal to allow the
vehicle to move forward slightly while
avoiding overuse of the accelerator
pedal. Doing so can help control
excessive gasoline consumption.
Hybrid vehicle driving tips
For economical and ecological
driving, pay attention to the follow-
ing points:
Using Eco drive mode
Use of Hybrid System Indicator
Shift lever operation
Accelerator pedal/brake pedal
operation
When braking
Delays

2624-6. Driving tips
Control and maintain the vehicle at a
constant speed. Before stopping at a
toll booth or similar, allow plenty of
time to release the accelerator and
gently apply the brakes. A greater
amount of electrical energy can be
regenerated when slowing down.
Use the air conditioning only when
necessary. Doing so can help reduce
excessive gasoline consumption.
In summer: When the ambient tem-
perature is high, use the recirculated
air mode. Doing so will help to reduce
the burden on the air conditioning sys-
tem and reduce fuel consumption as
well.
In winter: Because the gasoline engine
will not automatically cut out until it and
the interior of the vehicle are warm, it
will consume fuel. Also, fuel consump-
tion can be improved by avoiding over-
use of the heater.
Make sure to check the tire inflation
pressure frequently. Improper tire infla-
tion pressure can cause poor fuel
economy.
Also, as snow tires can cause large
amounts of friction, their use on dry
roads can lead to poor fuel economy.
Use tires that are appropriate for the
season. Carrying heavy luggage will lead to
poor fuel economy. Avoid carrying
unnecessary luggage.
Installing a large
roof rack will also cause poor fuel
economy.
Since the gasoline engine starts up and
cuts out automatically when cold,
warming up the engine is unnecessary.
Moreover, frequently driving short dis-
tances will cause the engine to repeat-
edly warm up, which can lead to excess
fuel consumption.
Highway driving
Air conditioning
Checking tire inflation pressure
Luggage
Warming up before driving

2644-6. Driving tips
freezing.
 To ensure proper operation of the
climate control system fan, remove
any snow that has accumulated on
the air inlet vents in front of the
windshield.
 Check for and remove any excess
ice or snow that may have accumu-
lated on the exterior lights, vehicle’s
roof, chassis, around the tires or on
the brakes.
 Remove any snow or mud from the
bottom of your shoes before getting
in the vehicle.
Accelerate the vehicle slowly, keep a
safe distance between you and the
vehicle ahead, and drive at a reduced
speed suitable to road conditions.
 Park the vehicle and move the shift
lever to P without setting the park-
ing brake. The parking brake may
freeze up, preventing it from being
released. If the vehicle is parked
without setting the parking brake,
make sure to block the wheels.
Failure to do so may be dangerous
because it may cause the vehicle to
move unexpectedly, possibly lead-
ing to an accident.
When the parking brake is in automatic
mode, release the parking brake after shift-
ing the shift lever to P. ( P.172)
 If the vehicle is left parked with the brakes damp in cold temperatures,
there is a possibility of the brakes
freezing.
 If the vehicle is parked without set-
ting the parking brake, confirm that
the shift lever cannot be moved out
of P
*.
*: The shift lever will be locked if it is
attempted to be shifted from P to any
other position with out depressing the
brake pedal. If the shift lever can be
shifted from P, there may be a problem
with the shift lock system. Have the vehi-
cle inspected by your Lexus dealer
immediately.
Use the correct tire chain size when
mounting the tire chains. Chain size is
regulated for each tire size.
Side chain:
0.12 in. (3 mm) in diameter
0.39 in. (10 mm) in width
When driving the vehicle
When parking the vehicle
WARNING
■When parking the vehicle
When parking the vehicle without apply-
ing the parking brake, make sure to
chock the wheels. If you do not chock the
wheels, the vehicle may move unexpect-
edly, possibly result ing in an accident.
Selecting tire chains
A
B

2674-6. Driving tips
4
Driving
Drive your vehicle only in areas
where off-road vehicles are permit-
ted to travel.
 Respect private property. Get
owner’s permission before entering
private property.
 Do not enter areas that are closed.
Honor gates, barriers and signs that
restrict travel.
 Stay on established roads. When
conditions are we t, driving tech-
niques should be changed or travel
delayed to prevent damage to
roads.
 AWD models: Avoid driving on very
steep, slippery roads and other sur-
faces, such as sand, where the tires
are liable to lose traction. Your vehi-
cle may not perform as well as con-
ventional AWD on-road vehicles on
these surfaces.
■Additional informatio n for off-road driv-
ing
For owners in U.S. mainland, Hawaii and
Puerto Rico:
To obtain additional information pertaining
to driving your vehicle off-road, consult the
following organizations.
●State and Local Parks and Recreation
Departments
●State Motor Vehicle Bureau
●Recreational Vehicle Clubs
●U.S. Forest Service and Bureau of Land
Management
WARNING
■Off-road driving precautions
Always observe the following precau-
tions to minimize the risk of death or seri-
ous injury or damage to your vehicle:
●Drive carefully when off the road. Do
not take unnecessary risks by driving in
dangerous places.
●Do not grip the steering wheel spokes
when driving off-road. A bad bump
could jerk the wheel and injure your
hands. Keep both hands and especially
your thumbs on the outside of the rim.
●Always check your brakes for effec-
tiveness immediately after driving in
sand, mud, water or snow.
●After driving through tall grass, mud,
rock, sand, water, et c., check that there
is no grass, bush, paper, rags, stone,
sand, etc. adhering or trapped to the
underbody. Clear of f any such matter
from the underbody. If the vehicle is
used with these materials trapped or
adhering to the underbody, a break-
down or fire could occur.
●When driving off-road or in rugged
terrain, do not drive at excessive
speeds, jump, make sharp turns, strike
objects, etc. This may cause loss of
control or vehicle rollover causing
death or serious injury. You are also
risking expensive damage to your
vehicle’s suspension and chassis.
NOTICE
■To prevent water damage
Take all necessary safety measures to
ensure that water damage to the hybrid
battery (traction battery), hybrid system
or other components does not occur.
●Water entering the engine compart-
ment may cause seve re damage to the
hybrid system. Water entering the inte-
rior may cause the hybrid battery
stowed under the re ar seats to short
circuit.

3306-2. Maintenance
Luggage compartment
ItemsCheck points
12-volt batteryCheck the connections.
( P.342)
Vehicle interior
ItemsCheck points
Accelerator
pedal
• The accelerator pedal
should move smoothly
(without uneven pedal
effort or catching).
Brake pedal
• Does the brake pedal move smoothly?
• Does the brake pedal have appropriate clear-
ance from the floor?
• Does the brake pedal have the correct amount
of free play?
Brakes
•The vehicle should not pull to one side when the
brakes are applied.
• The brakes should work effectively.
• The brake pedal should not feel spongy.
• The brake pedal should not get too close to the
floor when the brakes
are applied.
Head
restraints• Do the head restraints move smoothly and lock
securely?
Hybrid trans-
mission “Park”
mechanism• When parked on a slope and the shift lever is in P,
is the vehicle securely
stopped?
Indica-
tors/buzzers• Do the indicators and buzzers function prop-
erly?
Lights
• Do all the lights come on?
• Are the headlights aimed correctly?
Parking brake
• Does the parking brake switch operate nor-
mally?
• When parked on a slope and the parking brake is
on, is the vehicle
securely stopped?
Seat belts
• Do the seat belts oper-ate smoothly?
• The seat belts should not be damaged.
Seats• Do the seat controls operate properly?
Steering
wheel
• Does the steering wheel rotate smoothly?
• Does the steering wheel have the correct amount
of free play?
• There should not be any strange sounds coming
from the steering wheel.
Vehicle exterior
ItemsCheck points
Doors• Do the doors operate smoothly?
Engine hood
• Does the engine hood lock system work prop-
erly?
ItemsCheck points