brake LEXUS RX450h 2021 Workshop Manual

2234-5. Using the driving support systems
4
Driving
collision with a detected object is high.
Each function is operational at the following speed
●Pre-collision warning
●Pre-collision brake assist
●Pre-collision braking
The system may not operate in the following situations:
●If a 12-volt battery terminal has been disco nnected and reconnected and then the vehicle
has not been driven for a certain amount of time
●If the shift lever is in R
●When the VSC OFF indicator is illuminated (only the pre-collision warning function will
be operational)
■Object detection function
The system detects ob jects based on their
size, profile, motion, etc. However, an object
may not be detected depending on the sur-
rounding brightness and the motion, pos-
ture, and angle of the detected object,
preventing the system from operating prop-
erly. ( P.225)
The illustration shows an image of detect-
able objects.
Detectable objectsVehicle speedRelative speed between your
vehicle and object
VehiclesApprox. 7 to 110 mph (10 to
180 km/h)Approx. 7 to 110 mph (10 to
180 km/h)
Bicyclists and pedestriansApprox. 7 to 50 mph (10 to
80 km/h)Approx. 7 to 50 mph (10 to
80 km/h)
Detectable objectsVehicle speedRelative speed between your vehicle and object
VehiclesApprox. 20 to 110 mph (30
to 180 km/h)Approx. 20 to 110 mph (30
to 180 km/h)
Bicyclists and pedestriansApprox. 20 to 50 mph (30
to 80 km/h)Approx. 20 to 50 mph (30
to 80 km/h)
Detectable objectsVehicle speedRelative speed between your vehicle and object
VehiclesApprox. 7 to 110 mph (10 to
180 km/h)Approx. 7 to 110 mph (10 to
180 km/h)
Bicyclists and pedestriansApprox. 7 to 50 mph (10 to
80 km/h)Approx. 7 to 50 mph (10 to
80 km/h)

2264-5. Using the driving support systems
• If a vehicle ahead is a child sized bicycle, a bicycle that is carrying a large load, a
bicycle ridden by more than one person,
or a uniquely shaped bicycle (bicycle with
a child seat, tandem bicycle, etc.)
• If a pedestrian/or the riding height of a
bicyclist ahead is shorter than approxi-
mately 3.2 ft. (1 m) or taller than approxi-
mately 6.5 ft. (2 m)
• If a pedestrian/bicyclist is wearing over- sized clothing (a rain coat, long skirt,
etc.), making their silhouette obscure
• If a pedestrian is bending forward or squatting or bicyclist is bending forward
• If a pedestrian/bicyclist is moving fast
• If a pedestrian is pushing a stroller, wheel-
chair, bicycle or other vehicle
• When driving in incl ement weather such
as heavy rain, fog, snow or a sandstorm
• When driving through steam or smoke
• When the surrounding area is dim, such as at dawn or dusk, or while at night or in
a tunnel, making a detectable object
appear to be nearly the same color as its
surroundings
• When driving in a place where the sur- rounding brightness changes suddenly,
such as at the entrance or exit of a tunnel
• After the hybrid system has started the vehicle has not been driven for a certain
amount of time
• While making a left/right turn and for a few seconds after makin g a left/right turn
• While driving on a curve and for a few seconds after driving on a curve
• If your vehicle is skidding
• If the front of the vehicle is raised or low-
ered
• If the wheels are misaligned
• If a wiper blade is blocking the front cam- era
• The vehicle is being driven at extremely
high speeds
• When driving on a hill • If the radar sensor or front camera is mis-
aligned
●In some situations su ch as the following,
sufficient braking force may not be
obtained, preventing the system from
performing properly:
• If the braking functions cannot operate to their full extent, such as when the brake
parts are extremely cold, extremely hot,
or wet
• If the vehicle is not properly maintained
(brakes or tires are excessively worn,
improper tire inflation pressure, etc.)
• When the vehicle is being driven on a
gravel road or other slippery surface
■If VSC is disabled
●If VSC is disabled ( P.285), the
pre-collision brake assist and pre-colli-
sion braking functions are also disabled.
●The PCS warning light will turn on and
“VSC Turned Off Pre-Collision Brake
System Unavailable” will be displayed on
the multi-information display.

2414-5. Using the driving support systems
4
Driving
328 ft. (100 m) ahead, determines the current vehicle-to-vehicle following dis-
tance, and operates to maintain a suitab le following distance from the vehicle
ahead. The desired vehicle-to-vehicle distance can also be set by operating the
vehicle-to-vehicle distance switch.
When driving on downhill slopes, the vehicl e-to-vehicle distance may become shorter.
Example of constant speed cruising
When there are no vehicles ahead
The vehicle travels at the speed set by the driver.
Example of deceleration cruising and follow-up cruising
When a preceding vehicle driving slower than the set speed appears
When a vehicle is detected running ahead of you, the system automatically decelerates
your vehicle. When a greater reduction in vehicle speed is necessary, the system applies
the brakes (the stop lights will come on at this time). The system will respond to changes in
the speed of the vehicle ahead in order to maintain the vehicle-to-vehicle distance set by
the driver. Approach warning warns you when th e system cannot decelerate sufficiently to
prevent your vehicle from closing in on the vehicle ahead.
When the vehicle ahead of you stops, your vehi cle will also stop (vehicle is stopped by sys-
tem control). After the vehicle ahead starts off, pushing the cruise control lever up or
depressing the accelerator pedal (start-off operation) will resume follow-up cruising. If the
start-off operation is not performed, system control continues to keep your vehicle
stopped.
When the turn signal lever is operated and yo ur vehicle moves to an overtaking lane while
driving at 50 mph (80 km/h) or more, the vehicle will accelerate to help to overtake a
passing vehicle.
The system’s identification of what is an over taking lane may be determined solely based on
the location of the steering wheel in the vehicl e (left side driver position versus right side
driver position.) If the vehicle is driven to a re gion where the overtaking lane is on a different
side from where the vehicle is normally driven, the vehicle may accelerate when the turn
A
B

2444-5. Using the driving support systems
After the vehicle ahead of you starts
off, push the lever up.
Your vehicle will also resume follow-up
cruising if the accelerator pedal is
depressed after the vehicle ahead of
you starts off.
1Pulling the lever toward you can-
cels the speed control.
The speed control is also canceled when
the brake pedal is depressed. (When the
vehicle has been stopped by system con-
trol, depressing the brake pedal does not
cancel the setting.)
2Pushing the lever up resumes the
cruise control and returns vehicle
speed to the set speed.
When your vehicle is too close to a
vehicle ahead, and sufficient automatic
deceleration via the cruise control is
not possible, the display will flash and
the buzzer will sound to alert the driver.
An example of this would be if another
driver cuts in front of you while you are
following a vehicle. Depress the brake
pedal to ensure an appropriate vehi-
cle-to-vehicle distance.
■Warnings may not occur when
In the following instances, warnings
may not occur even when the vehi-
cle-to-vehicle distance is small.
 When the speed of the preceding
vehicle matches or exceeds your
vehicle speed
 When the preceding vehicle is trav-
eling at an extremely slow speed
 Immediately after the cruise control
speed was set
 When depressing the accelerator
Resuming follow-up cruising
when the vehicle has been
stopped by system control (vehi-
cle-to-vehicle distance control
mode)
Canceling and resuming the
speed control
Approach warning (vehi-
cle-to-vehicle distance control
mode)

2464-5. Using the driving support systems
●TRAC is activated for a period of time.
●When the VSC or TRAC system is
turned off.
●The sensor cannot detect correctly
because it is covered in some way.
●Pre-collision braking is activated.
●The parking brake is operated.
●The vehicle is stopped by system control
on a steep incline.
●The following are detected when the
vehicle has been stopped by system con-
trol:
• The driver is not wearing a seat belt.
• The driver’s door is opened.
• The vehicle has been stopped for about 3 minutes.
If vehicle-to-vehicle distance control mode
is automatically canceled for any reasons
other than the above, there may be a mal-
function in the system . Contact your Lexus
dealer.
■Automatic cancelation of constant
speed control mode
Constant speed control mode is automati-
cally canceled in the following situations:
●Actual vehicle speed is more than
approximately 10 mph (16 km/h) below
the set vehicle speed.
●Actual vehicle speed falls below approxi-
mately 20 mph (30 km/h).
●VSC is activated.
●TRAC is activated for a period of time.
●When the VSC or TRAC system is
turned off.
●Pre-collision braking is activated.
If constant speed cont rol mode is automati-
cally canceled for any reasons other than
the above, there may be a malfunction in the
system. Contact your Lexus dealer.
■Brake operation
A brake operation sound may be heard and
the brake pedal respon se may change, but
these are not malfunctions.
■Warning messages and buzzers for
dynamic radar cruise control with
full-speed range
Warning messages and buzzers are used to
indicate a system malfunction or to inform
the driver of the need for caution while driv-
ing. If a warning messa ge is shown on the
multi-information displa y, read the message
and follow the instructions.( P.218,428)
■When the sensor may not be correctly
detecting the vehicle ahead
In the case of the fo llowing and depending
on the conditions, operate the brake pedal
when deceleration of the system is insuffi-
cient or operate the accelerator pedal
when acceleration is required.
As the sensor may not be able to correctly
detect these types of vehicles, the approach
warning ( P.244) may not be activated.
●Vehicles that cut in suddenly
●Vehicles traveling at low speeds
●Vehicles that are not moving in the same
lane
●Vehicles with small rear ends (trailers
with no load on board, etc.)
●Motorcycles traveling in the same lane
●When water or snow thrown up by the
surrounding vehicles hinders the detect-
ing of the sensor
●When your vehicle is pointing upwards
(caused by a heavy load in the luggage
compartment, etc.)

2474-5. Using the driving support systems
4
Driving
●Preceding vehicle has an extremely high
ground clearance
■Conditions under which the vehi-
cle-to-vehicle distance control mode
may not function correctly
In the case of the following conditions,
operate the brake pedal (or accelerator
pedal, depending on the situation) as nec-
essary.
As the sensor may not be able to correctly
detect vehicles ahead, the system may not
operate properly.
●When the road curves or when the lanes
are narrow
●When steering wheel operation or your
position in the lane is unstable
●When the vehicle ahead of you deceler-
ates suddenly
●When driving on a road surrounded by a
structure, such as in a tunnel or on a
bridge
●While the vehicle speed is decreasing to
the set speed after the vehicle acceler-
ates by depressing the accelerator pedal
*: If equipped
Meter control switches
Turning the Blind Spot Monitor on/off.
BSM (Blind Spot Monitor)*
The Blind Spot Monitor is a system
that uses rear side radar sensors
installed on the inner side of the
rear bumper on the left and right
side to assist the driver in confirm-
ing safety when changing lanes.
WARNING
■Cautions regarding the use of the sys-
tem
The driver is solely responsible for safe
driving. Always drive safely, taking care
to observe your surroundings.
The Blind Spot Monitor is a supplemen-
tary function which alerts the driver that a
vehicle is in a blind spot of the outside
rear view mirrors or is approaching rap-
idly from behind into a blind spot. Do not
overly rely on the Blind Spot Monitor. As
the function cannot judge if it is safe to
change lanes, over re liance could lead to
an accident resulting in death or serious
injury.
As the system may not function correctly
under certain conditio ns, the driver’s own
visual confirmation of safety is necessary.
System components
A

2564-5. Using the driving support systems
Center Display (vehicles with a Pan-
oramic view monitor)
A graphic will be displayed on the Center
Display.
Use the meter control switches to
enable/disable the Lexus parking
assist-sensor. ( P.89)
1 Press or to select .
2 Press or to select “PKSA”
and then press .
3 Press or to select and
then press .
When the intuitive parking assist func-
tion is disabled, the intuitive parking
assist OFF indicator ( P.78) illumi-
nates. To re-enable the system, select on
the multi-information display, select
and turn it on. If the system is dis-
abled, it will remain off even if the
power switch is tu rned to ON mode
after the power switch has been turned
off.
Turning intuitive parking assist
on/off
WARNING
■When using the intuitive parking
assist
Observe the following precautions.
Failing to do so may result in the vehicle
being unable to be driven safely and pos-
sibly cause an accident.
●Do not use the sensor at speeds in
excess of 6 mph (10 km/h).
●The sensors’ detection areas and reac-
tion times are limited. When moving
forward or reversin g, check the areas
surrounding the vehicle (especially the
sides of the vehicl e) for safety, and
drive slowly, using the brake to control
the vehicle’s speed.
●Do not install accessories within the
sensors’ detection areas.
●The area directly under the bumpers is
not detected.
Thin posts or objects lower than the
sensor may not be detected when
approached, even if they have been
detected once.
■When to disable the function
In the following situations, disable the
function as it may operate even though
there is no possibility of a collision.
●The vehicle is equipped with a fender
pole, wireless antenna or fog lights.
●The front or rear bumper or a sensor
receives a strong impact.
●A non-genuine Lexus suspension
(lowered suspension, etc.) is installed.

2584-5. Using the driving support systems
sible.
• There will be a short delay between object detection and display. Even at low
speeds, there is a possibility that the
object will come within the sensor’s
detection areas before the display is
shown and the warning beep sounds.
• It might be difficult to hear the buzzer due to the volume of the audio system or air
flow noise of the air conditioning system.
• It may be difficult to hear the buzzer if buzzers for other systems are sounding.
■Conditions under which the function
may not function correctly
Certain vehicle conditions and the sur-
rounding environment may affect the ability
of a sensor to correctly detect objects. Par-
ticular instances where this may occur are
listed below.
●There is dirt, snow or ice on a sensor.
(Cleaning the sensors will resolve this
problem.)
●A sensor is frozen. (Thawing the area will
resolve this problem.)
In especially cold weather, if a sensor is
frozen the sensor display may be dis-
played abnormally, or objects, such as a
wall, may not be detected.
●A sensor is covered in any way.
●When a sensor or the area around a sen-
sor is extremely hot or cold.
●On an extremely bumpy road, on an
incline, on gravel, or on grass.
●The vicinity of the vehicle is noisy due to
vehicle horns, motorcycle engines, air
brakes of large vehicles, or other loud
noises producing ultrasonic waves.
●There is another vehicle equipped with
parking assist sensors in the vicinity.
●A sensor is coated with a sheet of spray
or heavy rain.
●If a sensor is hit by a large amount of
water, such as when driving on a flooded
road.
●If the vehicle is significantly tilted.
●The vehicle is approaching a tall or
curved curb.
●If objects draw too close to the sensor.
■Objects which may not be properly
detected
The shape of the object may prevent the
sensor from detectin g it. Pay particular
attention to the following objects:
●Wires, fences, ropes, etc.
●Cotton, snow and other materials that
absorb sound waves
●Sharply-angled objects
●Low objects
●Tall objects with upper sections project-
ing outwards in the direction of your vehi-
cle
People may not be de tected if they are
wearing certain types of clothing.
■Detection range of the sensors
Approximately 3.3 ft. (100 cm)
Approximately 4.9 ft. (150 cm)
Approximately 2.0 ft. (60 cm)
The diagram shows the detection range of
the sensors. Note that the sensors cannot
detect objects that are extremely close to
the vehicle.
The range of the sensors may change
depending on the shape of the object, etc.
Sensor detection display, object
distance
A
B
C

2654-5. Using the driving support systems
4
Driving
turned on
• Immediately after the hybrid system is started with the RCTA function on
• When the sensors cannot detect a vehi- cle due to obstructions
●Instances of the RCTA function unneces-
sarily detecting a vehicle and/or object
may increase in the following situations:
• When a vehicle passes by the side of your vehicle
• When the parking space faces a street
and vehicles are being driven on the
street
• 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 a towing eyelet is installed to the
rear of the vehicle
*: If equipped
■Parking Support Brake function
(static objects) (if equipped)
Ultrasonic sensors are used to detect
static objects, such as a wall, in the
detection area when driving at a low
speed or backing up. ( P.271)
■Parking Support Brake function
(rear-crossing vehicles) (if
equipped)
Rear radar sensors are used to detect
approaching vehicles in the detection
area behind the vehicle when backing
up. ( P.277)
PKSB (Parking Support
Brake)*
The Parking Support Brake system
consists of the following functions
that operate when driving at a low
speed or backing up, such as when
parking. When the system deter-
mines that the possibility of a colli-
sion with a detected object is high, a
warning operates to urge the driver
to take evasive action. If the system
determines that the possibility of a
collision with a detected object is
extremely high, the brakes are
automatically applied to help avoid
the collision or help reduce the
impact of the collision.
PKSB (Parking Support Brake)
system

2664-5. Using the driving support systems
The Parking Support Brake can be
enabled/disabled on the multi-informa-
tion display. All of the Parking Support
Brake functions (static objects and
rear-crossing vehicles) are
enabled/disabled simultaneously.Use the meter control switches to
enable/disable the parking support
brake. (
P.89)
1 Press or to select .
2 Press or to select
and then press .
When the Parking Support Brake is dis-
abled, the PKSB OFF indicator ( P.78)
illuminates on the multi-information dis-
play.
To re-enable the system when it was dis-
abled, select on the multi-information
display, select and turn it on. If the
system is disabled, it wi ll remain off even if
the power switch is turned to ON mode
after the power switch has been turned off.
If the hybrid system output restriction con-
trol or brake control operates, a buzzer will
sound and a message wi ll be displayed on
the Center Display and multi-information
display, to alert the driver. On vehicles with
a head-up display, the head-up display (if
equipped) will display the same message
as the multi-information display.
Depending on the situat ion, hybrid system
output restriction control will operate to
either limit acceleration or restrict output
as much as possible.
 Hybrid system output restriction
control is operating (acceleration
restriction)
Acceleration greater than a certain
amount is restricted by the system.
Center Display (Panoramic view monitor)
(If equipped): No warning displayed
WARNING
■Limitations of the Parking Support
Brake system
Do not overly rely on the system, as
doing so may lead to an accident.
●The driver is solely responsible for safe
driving. Always drive carefully, taking
care to observe your surroundings.
The Parking Support Brake system is
designed to provide support to lessen
the severity of collis ions. However, it
may not operate in some situations.
●The Parking Support Brake system is
not designed to stop the vehicle com-
pletely. Additionally, even if the system
has stopped the vehicl e, it is necessary
to depress the brake pedal immedi-
ately as brake control will be canceled
after approximately 2 seconds.
NOTICE
■If “Parking Support Brake Unavail-
able” is displayed on the multi-infor-
mation display and the PKSB OFF
indicator is flashing
If this message is displayed immediately
after the power switch is changed to ON
mode, operate the vehicle carefully, pay-
ing attention to your surroundings. It may
be necessary to drive the vehicle for a
certain amount of time before the system
returns to normal. (If the system is not
return to normal after driving for a while,
clean the sensors and their surrounding
area on the bumpers.)
Enabling/Disabling the Parking
Support Brake
Displays and buzzers for hybrid
system output restriction con-
trol and brake control