2018 LEXUS RX450h warning

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.

3874-5. Using the driving support systems
4
Driving
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)

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.

394 4-6. Driving tips
RX450h_RX450hL _U_OM48F85U●
Specific design characteristics give it a higher center of gravity than ordinary
passenger cars. This vehicle design feature causes this type of vehicle to be
more likely to rollover. And, utility vehi cles have a significantly higher rollover
rate than other types of vehicles. ●
An advantage of the higher ground cl earance is a better view of the road
allowing you to anticipate problems. ●
It is not designed for cornering at the same speeds as ordinary passenger cars
any more than low-slung sports cars are designed to perform satisfactorily
under off-road conditions. Therefore, sharp turns at excessive speeds may
cause the vehicle to rollover.Utility vehicle precautions This vehicle belongs to the utility vehicl e class, which has higher ground clear-
ance and narrower tread in relation to the height of its center of gravity.
Utility vehicle feature
WARNING ■
Utility vehicle precautions
Always observe the following precautions to minimize the risk of death, serious injury
or damage to your vehicle: ●
In a rollover crash, an unbelted person is si gnificantly more likely to die than a person
wearing a seat belt. Therefore, the driver and all passengers should always fasten
their seat belts. ●
Avoid sharp turns or abrupt maneuvers, if at all possible.
Failure to operate this vehicle correctly may result in loss of control or vehicle rollover
causing death or serious injury. ●
Loading cargo on the roof lu ggage carrier will make the ce nter of the vehicle gravity
higher. Avoid high speeds, sudden starts, sharp turns, sudden braking or abrupt
maneuvers, otherwise it may re sult in loss of control or vehicle rollover due to failure
to operate this vehicle correctly. ●
Always slow down in gusty crosswinds. Be cause of its profile and higher center of
gravity, your vehicle is more sensitive to side winds than an ordinary passenger car.
Slowing down will allow you to have better control. ●
Do not drive horizontally across steep slopes . Driving straight up or straight down is
preferred. Your vehicle (or any similar off- road vehicle) can tip over sideways much
more easily than forward or backward.

396 4-6. Driving tips
RX450h_RX450hL _U_OM48F85U [
WARNING ■
Off-road driving precautions
Always observe the following precautions to minimize the risk of death, serious injury
or damage to your vehicle: ●
Drive carefully when off the road. Do not ta ke unnecessary risks by driving in danger-
ous 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 effectiveness immediately after driving in sand, mud,
water or snow. ●
After driving through tall grass, mud, rock , sand, rivers, etc., check that there is no
grass, bush, paper, rags, stone, sand, etc. adhering or trapped on the underbody.
Clear off any such matter from the underbody. If the vehicle is used with these materi-
als trapped or adhering to the underbody, a breakdown or fire could occur. ●
When driving off-road or in rugged terrain , do not drive at excessive speeds, jump,
make sharp turns, strike obje cts, etc. This may cause loss of control or vehicle rollover
causing death or serious injury. You are also risking expensive damage to your vehi-
cle’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 compartment may cause severe damage to the hybrid
system. Water entering the interior may cause the hybrid battery (traction battery)
stowed under the rear seats to short circuit.●
Water entering the hybrid transmission and rear electric motor (traction motor) will
cause deterioration in transmission qualit y. The malfunction indicator may come on,
and the vehicle may not be drivable. ●
Water can wash the grease from wheel be arings, causing rusting and premature fail-
ure, and may also enter the hybrid transmissi on case, reducing the gear oil’s lubricat-
ing qualities. ■
When you drive through water
If driving through water, such as when cro ssing shallow streams, first check the depth of
the water and the bottom of the riverbed for firmness. Drive slowly and avoid deep
water. ■
Inspection after off-road driving ●
Sand and mud that has accumulated around brake discs may affect braking efficiency
and may damage brake system components. ●
Always perform a maintenance inspection afte r each day of off-road driving that has
taken you through rough terrain, sand, mud, or water. For scheduled maintenance
information, refer to the “Warranty and Services Guide/Owner’s Manual Supple-
ment/Scheduled Maintenance”.

4055-1. Basic Operations
5
Lexus Display Audio system
RX450h_RX450hL _U_OM48F85U■
When using the screen ●
Under extremely cold conditions, the Lexus Display Audio controller may react slowly.●
If the screen is cold, the display may be da rk, or the system may seem to be operating
slightly slower than normal. ●
The screen may seem dark and hard to see when viewed through sunglasses. Change
your angle of viewing, adjust the display on the “D isplay” screen ( → P. 417) or remove
your sunglasses. ■
Using cellular phones
Interference may be heard through the audi o system’s speakers if a cellular phone is
being used inside or close to the vehicle while the audio system is operating.
WARNING ■
Using the Lexus Display Audio controller
Be careful when touching the Lexus Display Audio controller in extreme temperatures
as it may become very hot or cold due to the temperature inside the vehicle. ■
Laser product ●
CAUTION
USE OF CONTROL OR ADJUSTMENT OR PERFORMANCE OF PROCE-
DURES OTHER THAN THOSE SPECIFIED HEREIN MAY RESULT IN HAZARD-
OUS RADIATION EXPOSURE. ●
CAUTION
THE USE OF OPTICAL INSTRUMENTS WITH THIS PRODUCT WILL
INCREASE EYE HAZARD.
NOTICE ■
To prevent Lexus Display Au dio controller malfunction●
Do not allow the Lexus Display Audio controll er to come into contact with food, liq-
uid, stickers or lit cigarettes as doing so may cause it to change color, emit a strange
odor or stop functioning. ●
Do not subject the Lexus Display Audio cont roller to excessive pressure or strong
impact as the controller may bend or break off.■
To prevent battery discharge
Do not leave the audio system on longer than necessary when the engine is off. ■
To avoid damaging the audio system
Take care not to spill drinks or other fluids on the audio system.

406 5-1. Basic Operations
RX450h_RX450hL _U_OM48F85UVolume switch
• Increases/decreases volume
• Press and hold: Continuously
increases/decreases volume
Radio mode:
• Press: Select a radio station
• Press and hold: Seek up/down
CD, MP3/WMA/AAC disc, Bluetooth ®
, iPod or USB mode:
• Press: Select a track/file/video
• Press and hold: Quickly move up/d own through tracks/files/videos.
“MODE” switch
• Turns the power on, selects audio source
• Press and hold this switch to mute or pause the current operation. To can-
cel the mute or pause, press and hold.Steering wheel audio switches Some audio features can be controlled using the switches on the steering
wheel.
Operation may differ depending on th e type of audio system or navigation
system. For details, refer to the manual provided with the audio system or nav-
igation system.
Operating the audio system us ing the steering wheel switches1
2
WARNING ■
To reduce the risk of an accident
Exercise care when operating the audio switches on the steering wheel. 3