tires LEXUS RX450h 2018 User Guide

2894-5. Using the driving support systems
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Driving
RX450h_RX450hL _U_OM48F85UWARNING ■
When to disable the pre-collision system
In the following situations, di sable the system, as it may not operate properly, possibly
leading to an accident resultin g in death or serious injury:●
When the vehicle is being towed ●
When your vehicle is towing another vehicle ●
When transporting the vehicle via truck, bo at, train or similar means of transportation●
When the vehicle is raised on a lift with th e hybrid system on and the tires are allowed
to rotate freely ●
When inspecting the vehicle using a drum tester such as a chassis dynamometer or
speedometer tester, or when using an on vehicle wheel balancer ●
When a strong impact is applied to the fron t bumper or front grille, due to an accident
or other reasons ●
If the vehicle cannot be driven in a stable manner, such as when the vehicle has been
in an accident or is malfunctioning ●
When the vehicle is driven in a sporty manner or off-road●
When the tires are not properly inflated ●
When the tires are very worn ●
When tires of a size other than specified 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 camera sensor is
temporarily installed to the vehicle

2954-5. Using the driving support systems
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RX450h_RX450hL _U_OM48F85U• 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 making 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 wheels are misaligned
• If a wiper blade is blocking the camera sensor
• The vehicle is wobbling.
• The vehicle is being driven at extremely high speeds.
• When driving on a hill
• If the radar sensor or ca mera sensor is misaligned●
In some situations such as the following, sufficient braking forc e 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●
Some pedestrians such as the following may not be detected by the radar sensor and
camera sensor, preventing the system from operating properly:
• Pedestrians shorter than approximately 3.2 ft. (1 m) or taller than approximately 6.5
ft. (2 m)
• Pedestrians wearing oversized clothing (a ra in coat, long skirt, etc.), making their sil-
houette obscure
• Pedestrians who are carrying large baggage, holding an umbrella, etc., hiding part
of their body
• Pedestrians who are bending forward or squatting
• Pedestrians who are pushing a stroller , wheelchair, bicycle or other vehicle
• Groups of pedestrians which are close together
• Pedestrians who are wearing white and look extremely bright
• Pedestrians in the dark, such as at night or while in a tunnel
• Pedestrians whose clothing appears to be nearly the same color or brightness as
their surroundings
• Pedestrians near walls, fences , guardrails, or large objects
• Pedestrians who are on a metal object (manhole cover, steel plate, etc.) on the road
• Pedestrians who are walking fast
• Pedestrians who are changing speed abruptly
• Pedestrians running out from be hind a vehicle or a large object
• Pedestrians who are extremely close to the side of the vehicle (outside rear view
mirror, etc.)• If the front of the vehicle is raised or low-
ered

300 4-5. Using the driving support systems
RX450h_RX450hL _U_OM48F85UWARNING ■
Before using LKA system
Do not rely solely upon the LKA system. LKA is not a system which automatically
drives the vehicle or reduces the amount of attention that must be paid to the area in
front of the vehicle. The driver must always assume full responsibility for driving safely
by always paying careful attention to the surrounding conditions and operate the steer-
ing wheel to correct the path of the vehicle. Also, make sure to take adequate breaks
when fatigued, such as from driv ing for a long period of time.
Failure to perform appropriate driving operat ions and pay careful attention may lead to
an accident, resulting in death or serious injury. ■
To avoid operating LKA by mistake
When not using the LKA system, use the LKA switch to turn the system off. ■
Situations unsuitable for LKA
Do not use the LKA system in the following situations.
The system may not operate properly and lead to an accident, resulting in death or
serious injury. ●
A spare tire, tire chains, etc., are equipped. ●
When the tires have been excessively worn, or when the tire inflation pressure is low. ●
Tires which differ by structure, manufacturer, brand or tread pattern are used. ●
Objects or patterns that could be mistaken for white (yellow) lines are present on the
side of the road (guardrails, cu rbs, reflective poles, etc.).●
Vehicle is driven on a snow-covered road. ●
White (yellow) lines are difficult to see due to rain, snow, fog, dust, etc.●
Asphalt repair marks, white (y ellow) line marks, etc., are present due to road repair.●
Vehicle is driven in a temporary lane or restricted lane due to construction work.●
Vehicle is driven on a road surface which is slippery due to rainy weather, fallen snow,
freezing, etc. ●
Vehicle is driven in traffic lanes ot her than on highways and freeways.●
Vehicle is driven in a construction zone. ●
When your vehicle is towing a trailer or during emergency towing ■
Preventing LKA system malfunctions and operations perf ormed by mistake●
Do not modify the headlights or place stickers, etc., on the surface of the lights.●
Do not modify the suspension etc. If the suspension etc. needs to be replaced, con-
tact your Lexus dealer. ●
Do not install or place anything on the hood or grille. Also, do not install a grille guard
(bull bars, kangaroo bar, etc.). ●
If your windshield needs repair s, contact your Lexus dealer.

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Conditions in which functions may not operate properly
In the following situations, the camera sensor may not detect white (yellow) lines and var-
ious functions may not operate normally. ●
There are shadows on the road that run parallel with, or cover, the white (yellow) lines. ●
The vehicle is driven in an ar ea without white (yellow) lines, such as in front of a tollgate
or checkpoint, or at an intersection, etc.●
The white (yellow) lines are cracked, “Botts ’ dots”, “Raised pavement marker” or stones
are present. ●
The white (yellow) lines cannot be seen or are difficult to see due to sand, etc. ●
The vehicle is driven on a road surface that is wet due to rain, puddles, etc. ●
The traffic lines are yellow (which may be more difficult to recognize than lines that are
white). ●
The white (yellow) lines cross over a curb, etc. ●
The vehicle is driven on a bright surface, such as concrete. ●
The vehicle is driven on a surface that is bright due to reflected light, etc. ●
The vehicle is driven in an area where the brightness changes suddenly, such as at the
entrances and exits of tunnels, etc.●
Light from the headlights of an oncoming vehicle, the sun, etc., enters the camera.●
The vehicle is driven where the road diverges, merges, etc. ●
The vehicle is driven on a slope. ●
The vehicle is driven on a road which t ilts left or right, or a winding road.●
The vehicle is driven on an unpaved or rough road. ●
The vehicle is driven around a sharp curve. ●
The traffic lane is excessively narrow or wide. ●
The vehicle is extremely tilted due to carry ing heavy luggage or having improper tire
pressure. ●
The distance to the preceding vehicle is extremely short. ●
The vehicle is moving up and down a large am ount due to road conditions during driv-
ing (poor roads or road seams). ●
The headlight lenses are dirty and emit a faint amount of light at night, or the beam axis
has deviated. ●
The vehicle is struck by a crosswind. ●
The vehicle has just changed lane s or crossed an intersection.●
Snow tires, etc., are equipped. ■
If the LKA indicator is illuminated in ambe r and a warning message is displayed on the
multi-information display
→ P. 660 ■
Customization
Some functions can be customized. ( → P. 108)

326 4-5. Using the driving support systems
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Conditions under which the BSM function may not function correctly ●
The BSM function may not detect vehicles correctly in the following situations:
• When the sensor is misaligned due to a stro ng impact to the sensor or its surround-
ing area
• When mud, snow, ice, a sticke r, etc. is covering the sensor or surrounding area on
the rear bumper
• When driving on a road surf ace that is wet with standi ng water during bad weather,
such as heavy rain, snow, or fog
• When multiple vehicles are approaching wi th only a small gap between each vehicle
• When the distance between your vehicle and a following vehicle is short
• When there is a significant difference in speed between your vehicle and the vehicle
that enters the detection area
• When the difference in speed between your vehicle and another vehicle is changing
• When a vehicle enters a detection area traveling at about the same speed as your
vehicle
• As your vehicle starts from a stop, a vehicle remains in the detection area
• When driving up and down cons ecutive steep inclines, such as hills, dips on the road,
etc.
• When driving on roads with sharp bends, consecutive curves, or uneven surfaces
• When vehicle lanes are wide, or when driving on the edge of a lane, and the vehicle
in an adjacent lane is far away from your vehicle
• When towing a trailer (vehicles with towing package)
• When items such as a bicycle carrier are installed on the rear of the vehicle
• When there is a significant difference in height between your vehicle and the vehicle
that enters the detection area
• Immediately after the BSM function is turned on ●
Instances of the BSM function unnecessarily detecting a vehicle and/or object may
increase in the following situations:
• When the sensor is misaligned due to a stro ng impact to the sensor or its surround-
ing area
• When the distance between your vehicle and a guardrail, wall, etc. that enters the
detection area is short
• When driving up and down cons ecutive steep inclines, such as hills, dips on the road,
etc.
• When vehicle lanes are narrow, or when driv ing on the edge of a lane, and a vehicle
traveling in a lane other than the ad jacent lanes enters the detection area
• When driving on roads with sharp bends, consecutive curves, or uneven surfaces
• When the tires are slipping or spinning
• When the distance between your vehicle and a following vehicle is short
• When a bicycle carrier or other accessory is installed to the rear of the vehicle
• When towing a trailer (vehicles with towing package)

3554-5. Using the driving support systems
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Driving
RX450h_RX450hL _U_OM48F85UNOTICE ■
To prevent the system from malfunctioning ●
If the area around a sensor is subjected to an impact, the system may not operate
properly due to the sensor being misaligned. Have the vehicle inspected by your
Lexus dealer. ●
When using a high pressure washer to wa sh the vehicle, do not spray the sensors
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 sensor to malfunction. ■
To prevent a radar sensor from malfunctioning ●
If the area around a radar sensor is subjected to an impact, the system may not oper-
ate properly due to a sensor malfunction. Have the vehicle inspected by your Lexus
dealer. ●
Observe the radar sensor handling precautions. ( → P. 322)■
To prevent unnecessary operation of the Intelligent Clearance Sonar system
In the following situations, disable the Inte lligent Clearance Sonar system as the system
may operate even though there is no possibility of a collision.●
When inspecting the vehicle using a chassi s 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 ●
If towing eyelets are installed

3614-5. Using the driving support systems
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Situations in which the Rear Cross Traffic Auto Brake function may not operate prop-
erly
In some situations such as the following , this function may not operate properly.●
Objects and vehicles which the radar sensors are not designed to detect
• Stationary objects
• Vehicles which are moving away from your vehicle
• Pedestrians, motorcycles, bicycles, etc.*
• 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 approximately 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 approximately 15 mph (24 km/h)
* : Depending on conditions, detection of a vehicle and/or object may occur.●
Situations in which the radar sensors may not be able to detect an object
• When a sensor or the area around a sensor is extremely hot or cold
• If the rear bumper is covere d with ice, snow, dirt, etc.
• If heavy rain or water strikes the vehicle
• When the detection area of a radar sensor is obstructed by an adjacent vehicle
• If the vehicle is significantly tilted
• If towing eyelets are installed
• 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 lowered due to the carried load
• If a sticker or an electronic component, su ch as a backlit license plate (especially flu-
orescent type), fog lights, a fender pole or wireless antenna is installed near a radar
sensor
• If the orientation of a rada r sensor has been changed due to a collision or other
impact or removal and installation
• When multiple vehicles are approaching wi th only a small gap between each vehicle
• When a vehicle is approaching at high speed ●
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
• When backing out of a shallow angle park-
ing spot

3774-5. Using the driving support systems
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Driving
RX450h_RX450hL _U_OM48F85UWARNING ■
When using the Lexus parking assist monitor system
The parking assist monitor is a supplemental device intended to assist the driver when
backing up. When backin g up, be sure to check visually behind and all around the vehi-
cle before proceeding.
Observe the following precautions to avoid an accident that could result in death or
serious injuries. ●
Never depend on the parking assist monitor entirely when backing up. The image
and the position of the guide lines displaye d on the screen may differ from the actual
state.
Use caution, just as you woul d when backing up any vehicle.●
Be sure to back up slowly, depressing the brake pedal to control vehicle speed. ●
If you seem likely to hit nearby vehicles, obstacles, people or mount the shoulder,
depress the brake pedal to stop the vehicle. ●
The instructions given are only guidelines.
When and how much to turn the steering wheel will vary according to traffic condi-
tions, road surface conditions, vehicle condit ion, etc. when parking. It is necessary to
be fully aware of this before using the parking assist system. ●
When parking, be sure to check that the parking space will accommodate your vehi-
cle before maneuvering into it. ●
Do not use the parking assist monitor in the following cases:
• On icy or slick road surfaces, or in snow
• When using tire chains or emergency tires
• When the back door is not closed completely
• On roads that are not flat or stra ight, such as curves or slopes.●
In low temperatures, the screen may darken or the image may become faint. The
image could distort when the vehicle is movi ng, or you may become unable to see the
image on the screen. Be sure to check dire ct visually and with the mirrors all around
the vehicle before proceeding. ●
If the tire sizes are changed, the position of the guide lines displayed on the screen
may change. ●
The camera uses a special lens. The distances between objects and pedestrians that
appear in the image displayed on the screen will differ from the actual distances.
( → P. 371) ●
Estimated course line display mode: If the st eering wheel is stra ight and the vehicle
width guide lines and the estimated course lines are not in alignment, have the vehicle
inspected by your Lexus dealer.

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ECB operating sound
ECB operating sound may be heard in the followi ng cases, but it does not indicate that a
malfunction has occurred. ●
Operating sound heard from the engine compartment when the brake pedal is oper-
ated. ●
Motor sound of the brake system heard from the front part of the vehicle when the
driver’s door is opened. ●
Operating sound heard from the engine compartment when one or two minutes
passed after the stop of the hybrid system. ■
EPS operation sound
When the steering wheel is operated, a motor sound (whirring sound) may be heard.
This does not indicate a malfunction. ■
Automatic reactivation of TRAC, Tr ailer Sway Control and VSC systems
After turning the TRAC, Trailer Sway Contro l and VSC systems off, the systems will be
automatically re-enabled in the following situations: ●
When the power switch is turned off ●
If only the TRAC system is turned off, the TRAC will turn on when vehicle speed
increases
If both the TRAC and VSC systems are turned off, au tomatic re-enabling will not
occur when vehicle speed increases. ■
Reduced effectiveness of the EPS system
The effectiveness of the EPS system is reduced to prevent the system from overheating
when there is frequent steering input over an extended period of time. The steering
wheel may feel heavy as a result . Should this occur, refrain from excessive steering input
or stop the vehicle and turn the hybrid system off. The EPS system should return to nor-
mal within 10 minutes.
WARNING ■
The ABS does not operate effectively when ●
The limits of tire gripping performance have been exceeded (such as excessively
worn tires on a snow covered road). ●
The vehicle hydroplanes while driving at high speed on wet or slick roads.■
Stopping distance when the ABS is operating may exceed that of normal conditions
The ABS is not designed to shorten the vehi cle’s stopping distance . Always maintain a
safe distance from the vehicle in front of you, especially in the following situations: ●
When driving on dirt, grav el or snow-covered roads●
When driving with tire chains ●
When driving over bumps on the road ●
When driving over roads with potholes or uneven surfaces■
TRAC/VSC may not operate effectively when
Directional control an d power may not be achievable wh ile driving on slippery road
surfaces, even if the TRAC/VSC system is op erating. Drive the vehi cle carefully in con-
ditions where stability and power may be lost.

3874-5. Using the driving support systems
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RX450h_RX450hL _U_OM48F85UWARNING ■
Hill-start assist control does not operate effectively when ●
Do not overly rely on 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 co ntrol is not intended to hold the vehicle
stationary for an exte nded period of time. Do not atte mpt to use hill-start assist con-
trol to hold the vehicle on an incline, as doing so may lead to an accident. ■
When the TRAC/VSC/Trailer Sw ay Control is activated
The slip indicator light flashes. Always drive carefully. Reckle ss driving may cause an
accident. Exercise particular care when the indicator light flashes.■
When the TRAC/VSC/Trailer Sway Control 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 stab ility and driving force, do not turn the
TRAC/VSC/Trailer Sway Contro l systems off unless necessary.
Trailer Sway Control is part of the VSC syst em and will not operate if VSC is turned off
or experiences a malfunction. ■
Replacing tires
Make sure that all tires are of the specified size, brand, tread pattern and total load
capacity. In addition, make sure that the tire s are inflated to the recommended tire infla-
tion pressure level.
The ABS, TRAC, Trailer Sway Control and VS C systems will not function correctly if
different tires are installed on the vehicle.
Contact your Lexus dealer for further in formation when replacing tires or wheels.■
Handling of tires and the suspension
Using tires with any kind of problem or modi fying the suspension w ill affect the driving
assist systems, and may cause a system to malfunction. ■
Trailer Sway Control precaution
The Trailer Sway Control system is not able to reduce trailer sway in all situations.
Depending on many factors such as the condit ions of the vehicle, trailer, road surface,
and driving environment, the Trailer Sway Control system may not be effective. Refer to
your trailer owner’s manual for information on how to tow your trailer properly. ■
If trailer sway occurs
Observe the following precautions.
Failing to do so may cause death or serious injury. ●
Firmly grip the steering wh eel. Steer straight ahead.
Do not try to control trailer sway by turning the steering wheel.●
Begin releasing the accelerator pedal immediately but very gradually to reduce
speed.
Do not increase speed. Do not apply vehicle brakes.
If you make no extreme correction with the steering or brakes, your vehicle and trailer
should stabilize. ( → P. 234)