air LEXUS UX250H 2019 Workshop Manual

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

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

2554-5. Using the driving support systems
4
Driving
• When backing out of a shallow angle parking spot
• When backing up on a slope with a sharp change in grade
• When a vehicle turns into the detection area
Except F SPORT models
F SPORT models
1 Normal mode
Provides an optimal ba lance of fuel econ-
omy, quietness, and dynamic performance.
Suitable for city driving.
Press the switch to change the Normal
mode when not in Normal mode.
2 Eco drive mode
Helps the driver acce lerate in an eco-
friendly manner and improve fuel economy
through moderate thro ttle characteristics
and by controlling the operation of the air
conditioning system (heating/cooling).
When not in Eco drive mode, if the driving
mode select switch is turned toward you,
Driving mode select switch
The driving modes can be selected
to suit driving conditions.
Selecting the driving mode
A
B

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,

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

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

2634-6. Driving tips
4
Driving
Use fluids that are appropriate to
the prevailing outside temperatures.
• Engine oil
• Engine/power control unit coolant
• Washer fluid
Have a service technician inspect
the condition of the 12-volt battery.
 It is recommended that the vehicle is
fitted with four snow run-flat tires or
purchase a set of tire chains for the
front tires.
Ensure that all tires are the same size and
brand, and that chains match the size of the
tires.
Perform the following according to the
driving conditions:
Do not try to forcibly open a window
or move a wiper that is frozen. Pour
warm water over the frozen area to
melt the ice. Wipe away the water
immediately to prevent it from
Winter driving tips
Carry out the necessary prepara-
tions and inspections before driving
the vehicle in winter. Always drive
the vehicle in a manner appropriate
to the prevailing weather condi-
tions.
Preparation for winter
WARNING
■Driving with snow tires
Observe the following precautions to
reduce the risk of accidents.
Failure to do so may result in a loss of
vehicle control and cause death or seri-
ous injury.
●Use tires of the specified size.
●Maintain the recommended level of air
pressure.
●Do not drive in excess of 75 mph (120
km/h), regardless of the type of snow
tires being used.
●Use snow tires on all, not just some
wheels.
■Driving with tire chains
Observe the following precautions to
reduce the risk of accidents.
Failure to do so may result in the vehicle
being unable to be driven safely, and may
cause death or serious injury.
●Do not drive in excess of the speed
limit specified for the tire chains being
used, or 30 mph (50 km/h), which-
ever is lower.
●Avoid driving on bumpy road surfaces
or over potholes.
●Avoid sudden acceleration, abrupt
steering, sudden br aking and shifting
operations that cause sudden engine
braking.
●Slow down sufficiently before entering
a curve to ensure that vehicle control is
maintained.
●Do not use LTA (Lane Tracing Assist).
NOTICE
■Repairing or replacing snow tires
Request repairs or replacement of snow
tires from Lexus dealers or legitimate tire
retailers.
This is because the removal and attach-
ment of snow tires affects the operation
of the tire pressure warning valves and
transmitters.
Before driving the vehicle

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