2018 LEXUS RX450h snow chains

2894-5. Using the driving support systems
4
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

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.

3774-5. Using the driving support systems
4
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.

386 4-5. Using the driving support systems
RX450h_RX450hL _U_OM48F85U■
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.

390 4-6. Driving tips
RX450h_RX450hL _U_OM48F85U●
Use fluids that are appropriate to the prevailing outside temperatures.
•Engine oil
• Engine/power cont rol unit coolant
• Washer fluid ●
Have a service technician inspect the condition of the 12-volt battery. ●
Have the vehicle fitted with four snow tires or purchase a set of tire chains for
the front tires. Ensure that all tires are of the specified size and the same 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 me lt the ice. Wipe away the water imme-
diately to prevent it from freezing. ●
To ensure proper operation of the c limate 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 accumulated on
the exterior lights, vehicle’s roof, chassi s, around the tires or on the brakes.●
Remove any snow or mud from the bottom of your shoes before getting in the
vehicle.Winter driving tips Carry out the necessary preparations an d inspections before driving the vehi-
cle in winter. Always drive the vehicle in a manner appropriate to the prevail-
ing weather conditions.
Pre-winter preparations
Before driving the vehicle

392 4-6. Driving tips
RX450h_RX450hL _U_OM48F85UTo enable the windshield wi pers to be lifted when he avy snow or icy conditions
are expected, change the rest position of the windshield wipers from the
retracted position below the hood to th e service position using the wiper lever.
( →
P. 270) ■
Tire chain installation
Observe the following precautions when installing and removing chains: ●
Install and remove tire chains in a safe location. ●
Install tire chains on the front tires only. Do not install tire chains on the rear tires. ●
Install tire chains on front tires as tightly as possible. Retighten chains after driving
1/4 - 1/2 mile (0.5 - 1.0 km). ●
Install tire chains following the instru ctions provided with the tire chains. Windshield wipers
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 vehi cle control and cause death or serious 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 dr iven 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), whichever is lower. ●
Avoid driving on bumpy road surfaces or over potholes.●
Avoid sudden acceleration, abrupt steering, sudden braking and shifting operations
that cause sudden engine braking. ●
Slow down sufficiently before entering a cu rve to ensure that vehicle control is main-
tained. ●
Do not use the LKA (Lane-Keeping Assist) system.

3934-6. Driving tips
4
Driving
RX450h_RX450hL _U_OM48F85UNOTICE ■
Repairing or replacing snow tires
Request repairs or replacement of snow ti res from Lexus dealers or legitimate tire
retailers.
This is because the removal an d attachment of snow tires affects the operation of the
tire pressure warning va lves and transmitters.■
Fitting tire chains
The tire pressure warning valv es and transmitters may not function correctly when tire
chains are fitted.

616 7-3. Do-it-yourself maintenance
RX450h_RX450hL _U_OM48F85U■
Situations in which the tire pressure warning system may not operate properly ●
In the following cases, the tire pressure warning system may not operate properly.
• If non-genuine Lexus wheels are used.
• A tire has been replaced with a tire that is not an OE (Original Equipment) tire.
• A tire has been replaced with a tire that is not of the specified size.
• Tire chains, etc. are equipped.
• If a window tint that affects th e radio wave signals is installed.
• If there is a lot of snow or ice on the vehi cle, particularly around the wheels or wheel
housings.
• If the tire inflation pressure is extr emely higher than the specified level.
• If wheel without the tire pressure warning valve and transmitter is used.
• If the ID code on the tire pressure warning valves and transmitters is not registered
in the tire pressure warning computer. ●
Performance may be affected in the following situations.
• Near a TV tower, electric power plant, gas station, radio station, large display, air-
port or other facility that generates st rong radio waves or electrical noise.
• When carrying a portable radio, cellular phone, cordless phon e or other wireless
communication device.
If tire position information is not correctl y displayed due to the radio wave conditions,
the display may be corrected by driving and changing the radio wave conditions. ●
When the vehicle is parked, the time taken for the warning to start or go off could be
extended. ●
When tire inflation pressure declines rapidly for example when a tire has burst, the
warning may not function. ■
The initialization operation ●
Make sure to carry out initialization afte r adjusting the tire inflation pressure.
Also, make sure the tires are cold before carryi ng out initialization or tire inflation pres-
sure adjustment. ●
If you have accidentally turned the power switch off during in itialization, it is not neces-
sary to press the reset switch again as initialization will re start automatically when the
power switch has been turned to ON mode for the next time. ●
If you accidentally press the re set switch when initialization is not necessary, adjust the
tire inflation pressure to the specified leve l when the tires are co ld, and conduct initial-
ization again. ●
While the position of each tire is being de termined and the inflation pressures are not
being displayed on the multi-info rmation display, if the inflat ion pressure of a tire drops,
the tire pressure warning light will come on.