brake LEXUS RX350 2020 Repair Manual

2644-5. Using the driving support systems
■When the accelerator pedal is depressed excessively
■When the vehicle moves in the unintend ed direction due to the wrong shift
lever position
 P.247
Types of sensors
WARNING
■To ensure the Parking Support Brake
can operate properly
Observe the following precautions
regarding the sensors (
P.247). Failure
to do so may cause a sensor to not oper-
ate properly, and may cause an accident.
●Do not modify, disassemble or paint
the sensors.
●Do not replace a sensor with a part
other than a genuine part.
●Do not subject a sensor or its sur-
rounding area to a strong impact.
●Do not damage the sensors, and
always keep them clean.

2654-5. Using the driving support systems
4
Driving
■The Parking Support Brake function
(static object) will operate when
The function will operate when the PKSB
OFF indicator is not illuminated or flashing
(  P.71, 72) and all of the following condi-
tions are met:
●Engine output restriction control
• The Parking Support Brake is enabled.
• The vehicle speed is 9 mph (15 km/h) or less.
• There is a static object in the traveling direction of the vehicle and 6 to 13 ft. (2
to 4 m) away.
• The Parking Support Brake determines that a stronger-than-normal brake opera-
tion is necessary to avoid a collision.
●Brake control
• Engine output restriction control is oper-
ating.
• The Parking Support Brake determines that an immediate brake operation is nec-
essary to avoid a collision.
■The Parking Support Brake function
(static objects) will stop operating when
The function will stop operating if any of the
following conditions are met:
●Engine output restriction control
• The Parking Support Brake is disabled.
• The system determines that the collision has become avoidable with normal brake
operation.
• The static object is no longer 6 to 13 ft. (2
to 4 m) away from the vehicle or in the
WARNING
■Handling the suspension
Do not modify the suspension, as
changes to the height or inclination of the
vehicle may prevent the sensors from
detecting objects correctly or cause the
system to not operate or operate unnec-
essarily.
■If the Parking Support Brake function
(static objects) operates unnecessar-
ily, such as at a railroad crossing
In the event that the Parking Support
Brake function (static objects) operates
unnecessarily, such as at a railroad cross-
ing, brake control w ill be canceled after
approximately 2 seconds, allowing you
to proceed forward and leave the area,
brake control can also be canceled by
depressing the brake pedal. Depressing
the accelerator pedal after brake control
is canceled will allow you to proceed for-
ward and leave the area.
■Notes when washing the vehicle
Do not apply intensive bursts of water or
steam to the sensor area.
Doing so may result in the sensor mal-
functioning.
●When using a high pressure washer to
wash the vehicle, do not spray the sen-
sors 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 sen-
sor to malfunction.
■When to disable the Parking Support
Brake
In the following situations, disable the
Parking Support Brake as the system
may operate even though there is no
possibility of a collision.
●When inspecting the vehicle using a
chassis 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 othe r than specified are
installed
●If the front of the vehicle is raised or
lowered due to the carried load
●When equipment that may obstruct a
sensor is installed, such as a towing
eyelet, bumper protector (an addi-
tional trim strip, etc.), bicycle carrier, or
snow plow
●When using an automatic car wash

2664-5. Using the driving support systems
traveling direction of the vehicle.
●Brake control
• The Parking Support Brake is disabled.
• Approximately 2 seconds have elapsed since the vehicle was stopped by brake
control.
• The brake pedal is depressed after the vehicle is stopped by brake control.
• The static object is no longer 6 to 13 ft. (2 to 4 m) away from the vehicle or in the
traveling direction of the vehicle.
■Re-enabling the Parking Support Brake
function (static objects)
 P.262
■Detection range of the Parking Support
Brake function (static objects)
The detection range of the Parking Support
Brake function (static objects) differs from
the detection range of the intuitive parking
assist. ( P.250) Therefore, even if the intu-
itive parking assist detects an object and
provides a warning, the Parking Support
Brake function (static objects) may not start
operating.
■Objects that the Parking Support Brake
function (static obje cts) may not detect
The sensors may not be able to detect cer-
tain objects, such as the following:
●Pedestrian
●Cotton cloth, snow, and other materials
that are poor reflectors of ultrasonic
waves
●Objects which are not perpendicular to
the ground, are not perpendicular to the
traveling direction of the vehicle, are
uneven or are waving
●Low objects
●Thin objects such as wires, fences, ropes
and signposts
●Objects that are extremely close to the
bumper
●Sharply-angled objects
●Tall objects with upper sections project-
ing outwards in the direction of your vehi-
cle
■Situation in which the Parking Support
Brake function (static objects) may not
operate
When driving with the shift lever in N.
■Intuitive parking assist buzzer
Regardless of whether the intuitive parking
assist system is enabled or not ( P.248), if
the Parking Support Brake function (static
objects) is enabled ( P.259), the front or
rear sensors detect an object and brake
control is performed, the intuitive parking
assist buzzer will sound to notify the driver
of the approximate distance to the object.
■Situations in which the Parking Support
Brake function (static objects) may
operate even if there is no possibility of a
collision
In some situations, such as the following, the
Parking Support Brake function (static
objects) may operate even though there is
no possibility of a collision.
●Vehicle surroundings
• When driving on a narrow road
• When driving on a gravel road or in an area with tall grass
• When driving toward a banner, flag, low-hanging branch or boom barrier
(such as those used at railroad crossings,
toll gates and parking lots)
• When driving on a narrow path sur-
rounded by a structure, such as in a tun-
nel or on an iron bridge

2674-5. Using the driving support systems
4
Driving
• When parallel parking
• When there is a rut or hole in the surface of the road
• When driving on a metal cover (grating), such as those used for drainage ditches
• When driving on a steep slope
• If a sensor is hit by a large amount of
water, such as when driving on a flooded
road
●Weather
• If a sensor is covered with ice, snow, dirt,
etc. (when cleared, the system will return
to normal)
• If heavy rain or water strikes a sensor
• When driving in incl ement weather such
as fog, snow or a sandstorm
• When strong winds are blowing
●Other ultrasonic wave sources
• When vehicle horns, vehicle detectors,
motorcycle engines, air brakes of large
vehicles, the clearance sonar of other
vehicles or other devices which produce
ultrasonic waves are near the vehicle
• If a sticker or an el ectronic component,
such as a backlit license plate (especially
fluorescent type), fog lights, fender pole
or wireless antenna is installed near a
sensor
●Changes in the vehicle posture
• If the vehicle is significantly tilted
• If the front of the vehicle is raised or low-
ered due to the carried load
• If the orientation of a sensor has been
changed due to a collision or other
impact
■Situations in which the Parking Support
Brake function (stati c objects) may not
operate properly
In some situations, such as the following, this
function may not operate properly.
●Weather
• When a sensor or the area around a sen- sor is extremely hot or cold • When strong winds are blowing
• If a sensor is covered with ice, snow, dirt,
etc. (when cleared, the system will return
to normal)
• If heavy rain or water strikes a sensor
• When driving in incl ement weather such
as fog, snow or a sandstorm
• When the sensor is frozen (Once the
sensor thaws, the system will return to
normal)
●Vehicle surroundings
• When an object that cannot be detected is between the vehicle and a detected
object
• If an object such as a vehicle, motorcycle, bicycle or pedestrian cuts in front of the
vehicle or runs out from the side of the
vehicle
• The vehicle is approaching a tall or
curved curb.
• On an extremely bumpy road, on an incline, on gravel, or on grass.
• If objects draw too close to the sensor.
●Other ultrasonic waves sources
• When vehicle horns, vehicle detectors, motorcycle engines, air brakes of large
vehicles, the clearance sonar of other
vehicles or other de vices which produce
ultrasonic waves are near the vehicle
• If a sticker or an electronic component, such as a backlit license plate (especially
fluorescent type), fog lights, fender pole
or wireless antenna is installed near a
sensor

2694-5. Using the driving support systems
4
Driving
*:If equipped
This function will operate in situations such as the following if a vehicle is detected
in the traveling direction of the vehicle.
■When reversing, a vehicle is appr oaching and the brake pedal is not
depressed, or is depressed late
 P.242
Parking Support Brake function (rear-crossing vehicles)*
If a rear radar sensor detects a vehicle a pproaching from the right or left at the
rear of the vehicle and the system determ ines that the possibility of a collision
is high, this function will perform brak e control to reduce the likelihood of an
impact with the approaching vehicle.
Examples of function operation
Types of sensors
WARNING
■To ensure the Parking Support Brake
function (rear-crossing vehicles) can
operate properly
Observe the following precautions
regarding the rear radar sensors
(
P.242). Failure to do so may cause a
sensor to not operate properly, and may
cause an accident.
●Do not modify, disassemble or paint
the sensors.
●Do not replace a rear radar sensor
with a part other than a genuine part.
●Do not damage the rear radar sensors,
and always keep the radar sensors and
their surrounding area on the bumper
clean.

2704-5. Using the driving support systems
■The Parking Support Brake function
(rear-crossing vehicles) will operate
when
The function will oper ate when the PKSB
OFF indicator is not illuminated or flashing
(  P.71, 72) and all of the following condi-
tions are met:
●Engine output restriction control
• The Parking Support Brake is enabled.
• The vehicle speed is 9 mph (15 km/h) or
less.
• Vehicles which are approaching from the
right or left at the re ar of the vehicle at a
traveling speed of less than approxi-
mately 5 mph (8 km/h)
• The shift lever is in R.
• The Parking Support Brake determines that a stronger than normal brake opera-
tion is necessary to avoid a collision with
an approaching vehicle.
●Brake control
• Engine output restriction control is oper- ating.
• The Parking Support Brake determines that an emergency brake operation is
necessary to avoid a collision with an
approaching vehicle.
■The Parking Support Brake function
(rear-crossing vehicles) will stop operat-
ing when
The function will stop operating if any of the
following conditions are met:
●Engine output restriction control
• The Parking Support Brake is disabled.
• The collision becomes avoidable with
normal brake operation.
• A vehicle is no longer approaching from
the right or left at the rear of the vehicle.
●Brake control • The Parking Support Brake is disabled.
• Approximately 2 seconds have elapsed
since the vehicle was stopped by brake
control.
• The brake pedal is depressed after the vehicle is stopped by brake control.
• A vehicle is no longer approaching from the right or left at the rear of the vehicle.
■Re-enabling the Parking Support Brake
function (rear-crossing vehicles)
 P.262
■Detection area of the Parking Support
Brake function (rear-crossing vehicles)
The detection area of the Parking Support
Brake function (rear-crossing vehicles) dif-
fers from the detection area of the RCTA
function ( P.256). Therefore, even if the
RCTA function detects a vehicle and pro-
vides an alert, the Parking Support Brake
function (rear-crossing vehicles) may not
start operating.
■Conditions under which the Parking
Support Brake function (rear-crossing
vehicles) will not detect a vehicle
The Parking Support Brake function
(rear-crossing vehicles) is not designed to
detect the following types of vehicles and/or
objects:
●Vehicles approaching from directly
behind
●Vehicles backing up in a parking space
next to your vehicle
●Vehicles that the sensors cannot detect
due to obstructions
●Vehicles which suddenly accelerate or
decelerate near your vehicle
●Guardrails, walls, signs, parked vehicles
and similar stationary objects
●Small motorcycles, bicycles, pedestrians,
WARNING
●If the area around a rear radar sensor
is subjected to an impact, the system
may not operate properly due to a
sensor malfunction. Have the vehicle
inspected by your Lexus dealer.
●Observe the rear radar sensor han-
dling precautions. (
P.259)

2714-5. Using the driving support systems
4
Driving
etc.*
●Vehicles moving away from your vehicle
●Vehicles approaching from the parking
spaces next to your vehicle*
●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 approxi-
mately 5 mph (8 km/h)
●Vehicles which are approaching from the
right or left at the re ar of the vehicle at a
traveling speed of more than approxi-
mately 15 mph (24 km/h)
*: Depending on the conditions, detection
of a vehicle and/or object may occur.
■PKSB buzzer
If the Parking Support Brake is enabled and
brake control is performed, a buzzer will
sound to notify the driver.
■Situations in which the system may
operate even though there is no possi-
bility of a collision
In some situations such as the following, the
Parking Support Brake function
(rear-crossing vehicles) may operate even
though there is no possibility of a collision.
●When the parking space faces a street
and vehicles are being driven on the
street
●When a detected vehicle turns while
approaching the vehicle
●When a vehicle passes by the side of your
vehicle
●When the distance between your vehicle
and metal objects, such as a guardrail,
wall, sign, or parked vehicle, which may
reflect electrical waves toward the rear of
the vehicle, is short
●When there are spinning objects near
your vehicle such as the fan of an air con-
ditioning unit
●When water is spla shed or sprayed
toward the rear bumper, such as from a
sprinkler
■Situations in which the Parking Support
Brake function (rear-crossing vehicles)
may not operate properly
In some situations, such as the following, the
radar sensors may not detect an object and
this function may not operate properly
●Stationary objects
●When a sensor or the area around a sen-
sor is extremely hot or cold
●If the rear bumper is covered with ice,

2754-5. Using the driving support systems
4
Driving
economy through moderate throttle char-
acteristics and by controlling the operation
of the air conditioning system (heat-
ing/cooling).
When not in Eco drive mode, if the driving
mode select switch is turned to the left, the
Eco drive mode indicator will come on.
3Sport mode
Controls the transmission and engine to
provide quick, powerful acceleration. This
mode also changes the steering feel, mak-
ing it suitable for when agile driving
response is desired, such as when driving
on roads with many curves.
When not in sport mode, if the driving
mode select switch is turned to the right,
the “Sport” indicator will comes on.
■Operation of the air conditioning sys-
tem in Eco drive mode
Eco drive mode controls the heating/cool-
ing operations and fan speed of the air con-
ditioning system to enhance fuel efficiency.
To improve air condit ioning performance,
adjust the fan speed or turn off Eco drive
mode.
■Automatic deactivation of sport mode
and custom mode
If the engine switch is turned off after driv-
ing in sport mode or custom mode, the
drive mode will be changed to normal
mode.
■Driving mode pop-up display (12.3-inch
display only)
When the driving mode is changed, the
selected driving mode will be temporarily
displayed on the side display. ( P.292)
Press the switch.
The torque of the engine is distributed
to the rear wheels to the maximum
extent possible in accordance with
driving conditions.
Pressing the switch again cancels
all-wheel drive lock mode and returns
the Dynamic Torque Control AWD
system to normal mode. ( P.278)
■All-wheel drive lock mode can be oper-
ated when
The engine switch is in IGNITION ON
mode.
■Automatic release for the all-wheel
drive lock mode
●All-wheel drive lock mode is canceled
when the brakes are applied to ensure
the ABS and VSC systems operate effec-
tively.
All-wheel drive lock switch
(AWD models)
All-wheel drive lock mode can be
used when a large amount of drive
power needs to be applied to all the
wheels, such as when the vehicle
gets stuck in mud and you need to
free it.
Using All-wheel drive lock mode

2764-5. Using the driving support systems
●All-wheel drive lock mode is canceled
when the vehicle speed exceeds 25 mph
(40 km/h).
■ABS (Anti-lock Brake System)
Helps to prevent wheel lock when the
brakes are applied suddenly, or if the
brakes are applied while driving on a
slippery road surface
■Brake assist
Generates an increased level of brak-
ing force after the brake pedal is
depressed when the system detects a
panic stop situation
■VSC (Vehicle Stability Control)
Helps the driver to control skidding
when swerving sudden ly or turning on
slippery road surfaces
■Enhanced VSC (Enhanced Vehi-
cle 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 perfor-
mance.
Driving assist systems
To keep driving safety and perfor-
mance, the following systems oper-
ate automatically in response to
various driving situations. Be aware,
however, that these systems are
supplementary and should not be
relied upon too heavily when oper-
ating the vehicle.
Summary of the driving assist
systems

2774-5. Using the driving support systems
4
Driving
■Trailer Sway Control (if equipped)
Helps the driver to control trailer sway
by selectively applying brake pressure
for individual wheels and reducing
driving torque when trailer sway is
detected.
■TRAC (Traction Control)
Helps to maintain drive power and pre-
vent the drive wheels from spinning
when starting the vehicle or accelerat-
ing on slippery roads
■Active Cornering Assist (ACA)
Helps to prevent the vehicle from drift-
ing to the outer side by performing
inner wheel brake control when
attempting to accelerate while turning
■Hill-start assist control
Helps to reduce the backward move-
ment 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 wheel
■Dynamic Torque Control AWD
system (AWD models)
Automatically switches from
front-wheel drive to all-wheel drive
(AWD) according to the driving condi-
tions, helping to ensure reliable han-
dling and stability. 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 Sys-
tem (if equipped)
Controls the damping force of the
shock absorber of each wheel accord-
ing to the road and driving conditions,
helping 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 damp-
ing force will become more suitable for
sporty driving. ( P.274)
■VDIM (Vehicle Dynamics Inte-
grated 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, engine output
and steering assist.
■The Secondary Collision Brake
When the SRS airbag sensor detects a
collision and the system operates, the
brakes and brake lights are automati-
cally controlled to reduce the vehicle
speed and help reduce the possibility
of further damage due to a secondary
collision.
■When the TRAC/VSC/Trailer Sway
Control systems are operating
The slip indicator light will flash while the
TRAC/VSC/Trailer Sway Control systems
are operating.