brake LEXUS RX350 2019 Manual Online

378 4-5. Using the driving support systems
RX350/RX350L_U ◆ 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
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
◆ EPS (Electric Power Steering)
Employs an electric motor to reduce the amount of effort needed to turn the
steering wheelDriving 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.

3794-5. Using the driving support systems
4
Driving
RX350/RX350L_U ◆ Dynamic Torque Control AWD system (AWD models)
Automatically switches from front-wh eel drive to all-wheel drive (AWD)
according to the driving conditions, help ing to ensure reliable handling and
stability. Examples of conditions wher e the system will switch to AWD are
when cornering, going uphill, starting off or accele rating, and when the road
surface is slippery due to snow, rain, etc.
◆ Adaptive Variable Suspen sion 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. 374)
◆ VDIM (Vehicle Dynamics Integr ated Management) (if equipped)
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 engine output

3814-5. Using the driving support systems
4
Driving
RX350/RX350L_U ■
Turning off both TRAC, VSC and Trailer Sway Control systems
To turn the TRAC, VSC and Trailer Sway Co ntrol systems off, press and hold for
more than 3 seconds whil e the vehicle is stopped.
The VSC OFF indicator light will come on an d the “Traction Control Turned Off” will be
shown on the multi-information display.
*Press again to turn the systems back on.
* : On vehicles with PCS (Pre-Collision Sy stem), pre-collision brake assist and pre-
collision braking will also be disabled. The PCS warning light will come on and a
message will be displa yed on the multi-info rmation display. (  P. 290)■
When the message is displayed on the mu lti-information displa y showing that TRAC
has been disabled even if has not been pressed
TRAC cannot be operated. Contact your Lexus dealer.■
Operating conditions of hill-start assist control
When the following four conditions are met, the hill-start assist control will operate:●
The shift lever is in a position other than P or N (when starting off forward/backward on
an upward incline). ●
The vehicle is stopped ●
The accelerator pedal is not depressed ●
The parking brake is not engaged ■
Automatic system cancelation of hill-start assist control
The hill-start assist control will turn off in any of the following situations: ●
The shift lever is shifted to P or N ●
The accelerator pedal is depressed ●
The parking brake is engaged ●
2 seconds at maximum elapsed after the brake pedal is released ■
Sounds and vibrations caused by the ABS, brake assist, VSC, Trailer Sway Control,
TRAC and hill-start assist control systems ●
A sound may be heard from the engine compartment when the brake pedal is
depressed repeatedly, when the engine is started or just after the vehicle begins to
move. This sound does not indicate that a malfunction has occurred in any of these sys-
tems. ●
Any of the following conditions may occur when the above systems are operating.
None of these indicates that a malfunction has occurred.
• Vibrations may be felt through the vehicle body and steering.
• A motor sound may be heard also after the vehicle comes to a stop.
• The brake pedal may pulsate slig htly after the ABS is activated.
• The brake pedal may move down sl ightly after the ABS is activated.■
EPS operation sound
When the steering wheel is operated, a motor sound (whirring sound) may be heard.
This does not indicate a malfunction.

3834-5. Using the driving support systems
4
Driving
RX350/RX350L_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 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. 226)

384
RX350/RX350L_U 4-6. Driving tips
●
Use fluids that are appropriate to the prevailing outside temperatures.
•Engine oil
• Engine coolant
• Washer fluid ●
Have a service technician inspect the condition of the 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

3854-6. Driving tips
4
Driving
RX350/RX350L_U Accelerate the vehicle slowly, keep a sa fe 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 parkin g brake after shifting
the shift lever to P. (  P. 247)●
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

390 4-6. Driving tips
RX350/RX350L_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 engine or other
components does not occur. ●
Water entering the engine air intake will cause severe engine damage.●
Water entering the automatic transmission will cause deterioration in shift quality,
locking up of your transmission accompan ied by vibration, and ultimately damage.●
Water can wash the grease from wheel be arings, causing rusting and premature fail-
ure, and may also enter the differential, transmission and transfer (AWD models only)
case, reducing the gear oi l’s lubricating 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”.

580 7-1. Maintenance and care
RX350/RX350L_U NOTICE ■
When using a high pressure car wash ●
When washing the vehicle, do not let water of the high pressure washer hit directly or
the vicinity of the camera. Due to the shock from the high pressure water, it is possible
the device may not operate as normal. ●
Do not bring the nozzle tip close to boots (rubber or resin manufactured cover), con-
nectors or the following parts. The parts may be damaged if they come into contact
with high-pressure water.
• Traction related parts
• Steering parts
• Suspension parts
•Brake parts ●
Vehicles with towing package: Do not point
the nozzle of a high pressure washer at the
areas shown in the illustration, as high pres-
sure water may dama ge the oil cooler.

586 7-2. Maintenance
RX350/RX350L_UGeneral maintenance Listed below are the general maintenanc e items that should be performed at
the intervals specified in the “Warranty and Service Guide” or “Owner’s
Manual Supplement”. It is recommende d that any problem you notice should
be brought to the attention of your Lexu s dealer or qualified service shop for
advice.
Engine compartment Items Check points
Battery Check the connections. (  P. 601)
Brake fluid Is the brake fluid at the correct level? (  P. 600)
Engine coolant Is the engine coolant at the correct level? (  P. 598)
Engine oil Is the engine oil at the correct level? (  P. 595)
Exhaust system There should not be any fumes or strange sounds.
Radiator/condenser The radiator and condenser should be free from for-
eign objects. (  P. 599)
Washer fluid Is there sufficient washer fluid? (  P. 603)

5877-2. Maintenance
7
Maintenance and care
RX350/RX350L_U * : Vehicles with single-beam headlightsVehicle interior Items Check points
Accelerator pedal • The accelerator pedal sh ould move smoothly (with-
out uneven pedal effort or catching).
Automatic transmission
“Park” mechanism • When parked on a slope and the shift lever is in P, is
the vehicle securely stopped?
Brake pedal • Does the brake pedal move smoothly?
• Does the brake pedal have appropriate clearance
from the floor? (  P. 704)
• Does the brake pedal have the correct amount of
free play? (  P. 704)
Brakes • The vehicle should not pull to one side when the
brakes are applied.
• The brakes should work effectively.
• The brake pedal should not feel spongy.
• The brake pedal should no t get too close to the floor
when the brakes are applied.
Head restraints • Do the head restraints move smoothly and lock
securely?
Indicators/buzzers • Do the indicators and buzzers function properly?
Lights • Do all the lights come on?
• Are the headlights aimed correctly?
* (  P. 628)
Parking brake • Does the parking brake switch operate normally?
• When parked on a slope and the parking brake is on,
is the vehicle securely stopped?
Seat belts • Do the seat belts operate smoothly?
• The seat belts should not be damaged.
Seats • Do the seat controls operate properly?
Steering wheel • Does the steering wheel rotate smoothly?
• Does the steering wheel have the correct amount of
free play?
• There should not be any strange sounds coming
from the steering wheel.