wheel LEXUS RX450H 2019 Repair Manual

3824-5. Using the driving support systems
RX450h_RX450hL_U
◆ECB (Electronically Controlled Brake System)
The electronically controlled system generates braking force corresponding
to the brake operation
◆ABS (Anti-lock Brake System)
Helps to prevent wheel lock when the br akes are applied suddenly, or if the
brakes are applied while drivin g on a slippery road surface
◆Brake assist
Generates an increased level of br aking force after the brake pedal is
depressed when the system detects a panic stop situation
◆VSC (Vehicle Stability Control)
Helps the driver to contro l skidding when swerving suddenly or turning on
slippery road surfaces.
◆Enhanced VSC (Enhanced Vehicle Stability Control)
Provides cooperative control of the ABS, TRAC, VSC and EPS.
Helps to maintain directional stability when swerving on slippery road sur-
faces by controlling steering performance.
◆Trailer Sway Control (if equipped)
Helps the driver to control trailer sway by selectively applying brake pressure
for individual wheels and reducing dr iving torque when trailer sway is
detected.
◆TRAC (Traction Control)
Helps to maintain drive power and pr event the drive wheels from spinning
when starting the vehicle or accelerating on slippery roads
◆Hill-start assist control
Helps to reduce the backward movement of the vehicle when starting on an
uphill
Driving assist systems
To keep driving safety and performance, the following systems operate auto-
matically in response to various drivin g situations. Be aware, however, that
these systems are supplementary and shou ld not be relied upon too heavily
when operating the vehicle.

3834-5. Using the driving support systems
4
Driving
RX450h_RX450hL_U
◆EPS (Electric Power Steering)
Employs an electric motor to reduce the amount of effort needed to turn the
steering wheel
◆E-Four
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 st ability. 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.
◆Adaptive Variable Suspension System (if equipped)
Controls the damping force of the shock absorber of each wheel according to
the road and driving conditions, helpin g achieve a comfortable ride, excellent
driveability and a high level of stability.
If SPORT S+ mode is selected using the driving mode select switch, the
damping force will become more su itable for sporty driving. (P. 380)
◆VDIM (Vehicle Dynamics Integrated Management)
Provides integrated control of the ABS, brake assist, TRAC, VSC, hill-start
assist control and EPS systems
Helps to maintain vehicle stability when swerving on slippery road surfaces by
controlling the brakes and hybrid system output

3844-5. Using the driving support systems
RX450h_RX450hL_U
The slip indicator light will flash while
the TRAC/VSC/ABS/Trailer Sway
Control systems are operating.
If the vehicle gets stuck in mud, dirt or snow, the TRAC system may reduce
power from the hybrid system to the wheels. Pressing 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 “Traction Control Turned Off”
will be shown on the multi-informa-
tion display. Press again to
turn the system back on.
When the TRAC/VSC/ABS/ Trailer Sway Control systems are operat-
ing
Disabling the TRAC system

3864-5. Using the driving support systems
RX450h_RX450hL_U
■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, automatic 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 and power may not be achievable wh ile driving on slippery road
surfaces, even if the TRAC/VSC system is op erating. Drive the vehicle carefully in con-
ditions where stability and power may be lost.

3874-5. Using the driving support systems
4
Driving
RX450h_RX450hL_U
WARNING
■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 control 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 Sway Control is activated
The slip indicator light flashes. Always drive carefully. Reckless 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 will 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)

3914-6. Driving tips
4
Driving
RX450h_RX450hL_U
Accelerate the vehicle slowly, keep a safe distance between you and the vehicle
ahead, and drive at a reduced spee d suitable to road conditions.
●Park the vehicle and move the shift lever to P without setting the parking
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 leading to an accident.
When the parking brake is in automatic mo de, release the parking brake after shifting
the shift lever to P. ( P. 253)
●If the vehicle is parked without setting the parking brake, confirm that the shift
lever cannot be moved out of P
*.
*: The shift lever will be locked if it is atte mpted to be shifted from P to any other posi-
tion without depressing the brake pedal. If the shift lever can be shifted from P, there
may be a problem with the shift lock sy stem. Have the vehicle inspected by your
Lexus dealer immediately.
Use the correct tire chain size when mounti ng the tire chains. Chain size is regu-
lated for each tire size.
Side chain:
0.12 in. (3 mm) in diameter
0.43 in. (10.8 mm) in width
0.98 in. (25 mm) in length
Cross chain: 0.15 in. (3.9 mm) in diameter
0.54 in. (13.8 mm) in width
1.00 in. (25.3 mm) in length
Regulations regarding the use of tire chains vary depending on location and type
of road. Always check local regu lations before installing chains.
When driving the vehicle
When parking the vehicle
Selecting tire chains
1
2
3
4
5
6
Regulations on the use of tire chains

3924-6. Driving tips
RX450h_RX450hL_U
To enable the windshield wi pers to be lifted when heavy 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 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), 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.

3964-6. Driving tips
RX450h_RX450hL_U
[
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”.

398
RX450h_RX450hL_U
5-1. Basic OperationsLexus Display Audio system ......................................... 400
Steering wheel audio switches.......................................406
Mobile Assistant......................... 407
USB/AUX ports ........................409
5-2. Setup Setup menu ....................................412
General settings .......................... 413
Voice settings ............................... 416
Display settings .............................417
5-3. Using the audio system Selecting the audio source ........................................... 418
Optimal use of the audio system ........................................... 419
Audio settings ............................. 420
Audio menu screen operation .................................... 423
5-4. Using the radio Radio operation.......................... 426
5-5. Playing an audio CD and MP3/WMA/AAC discs
CD player operation ................ 433
5
Lexus Display Audio system

399
5
Lexus DisplayAudio system
RX450h_RX450hL_U
5-6. Using an external device
Listening to an iPod .................. 440
Using USB memory device...........................................444
Using the AUX port ................ 448
5-7. Connecting Bluetooth
®
Steps for using Bluetooth®
devices .........................................449
Registering a Bluetooth
®
device............................................ 451
Selecting a Bluetooth
®
device ...........................................452
Connecting a Bluetooth
®
audio player ...............................453
Connecting a Bluetooth
®
phone ...........................................454
Displaying a Bluetooth
®
device details ........................... 455
Detailed Bluetooth
®
settings.........................................456
5-8. Bluetooth
® Audio
Listening to Bluetooth
®
Audio............................................459 5-9. Bluetooth
® Phone
Using a Bluetooth
®
Phone ............................................ 461
Making a call ................................ 463
Receiving a call ........................... 466
Speaking on the phone............ 467
Using a Bluetooth
® phone
message ...................................... 469
Using the steering wheel switches.........................................471
Bluetooth
® phone
settings ........................................ 472
5-10. Phonebook Contact settings ......................... 474
Messaging setting...................... 477
5-11. Bluetooth
®
What to do if... (Troubleshooting)................... 478
Bluetooth
®................................... 482
5-12. Other function “Information” screen................ 488
USB photo ....................................490
Weather information................ 492
Voice command system ......... 493