tow LEXUS RX450h 2021 Service Manual

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)

2484-5. Using the driving support systems
Outside rear view mirror indicators
When a vehicle is detected in a blind spot
of the outside rear view mirrors or
approaching rapidly from behind into a
blind spot, the outside rear view mirror
indicator on the detected side will illumi-
nate. If the turn signal lever is operated
toward the detected side, the outside rear
view mirror indicator flashes.
BSM indicator
Illuminates when the Blind Spot Monitor is
enabled
■Outside rear view mirror indicator visi-
bility
In strong sunlight, the outside rear view mir-
ror indicator may be difficult to see.
■When “Blind Spot Monitor Unavailable”
is shown on the multi-information dis-
play
Ice, snow, mud, etc., may be attached to the
rear bumper around the sensors. ( P.249)
The system should return to normal opera-
tion after removing the ice, snow, mud, etc.
from the rear bumper. Additionally, the sen-
sors may not operate normally when driving
in extremely hot or cold environments.
■Customization
Some functions can be customized.
(  P.480)
■Certification
Except for vehicles sold in Canada
B
C

2574-5. Using the driving support systems
4
Driving
■The system can be operated when
●The power switch is in ON mode.
●Intuitive parking assist function is on.
●The vehicle speed is less than about 6
mph (10 km/h).
●A shift lever other than P.
■Setting the buzzer volume
The buzzer volume can be adjusted on the
multi-information display. ( P.253)
■If “Parking Assist Unavailable” is dis-
played on the multi-information display
●Water may be continuously flowing over
the sensor surface, such as in a heavy
rain. When the system determines that it
is normal, the system will return to nor-
mal.
●Initialization may not have been per-
formed after a battery terminal was dis-
connected and reconnected. Initialize the
system. ( P.257) If this message contin-
ues to be displayed even after initializa-
tion, have the vehicle inspected by your
Lexus dealer.
■If “Parking Assist Unavailable Clean
Parking Assist Sensor” is displayed on
the multi-information display
A sensor may be covered with ice, snow,
dirt, etc. Remove the ice, snow, dirt, etc.,
from the sensor to return the system to nor-
mal.
Also, due to ice forming on a sensor at low
temperatures, a warn ing message may be
displayed or the sensor may not be able to
detect an object. Once the ice melts, the
system will return to normal.
■If a 12-volt battery terminal has been
disconnected and reconnected
The system needs to be initialized. To initial-
ize the system, drive the vehicle straight
ahead for 5 seconds or more at a speed of
approximately 22 mph (35 km/h) or more.
■Sensor detection information
●The following situations may occur
during use.
• The sensor's detection areas are limited to the areas around the vehicle front and
rear bumpers.
• Depending on the shape of the object and other factors, the detection distance
may shorten, or detection may be impos-
WARNING
●Towing eyelets are installed.
●A backlit licence pl ate is installed.
■When using intuitive parking assist
In the following situations, the system
may not function correctly due to a sen-
sor malfunction, etc. Have the vehicle
checked by your Lexus dealer.
●The intuitive parking assist operation
display flashes or shows continuously,
and a buzzer sounds when no objects
are detected.
●If the area around a sensor collides
with something, or is subjected to
strong impact.
●If the bumper or grille collides with
something.
●If the display flashes or is displayed
continuously and a buzzer does not
sound, except when the mute function
has been turned on.
●If a display error occurs, first check the
sensor.
If the error occurs even when there is
no ice, snow or mud on the sensor, it is
likely that the sensor is malfunctioning.
■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.

2644-5. Using the driving support systems
■The RCTA function is operational when
The RCTA function operates when all of the
following conditions are met:
●The power switch is in ON mode.
●The RCTA function is on.
●The shift lever is in R.
●The vehicle speed is less than approxi-
mately 5 mph (8 km/h).
●The approaching vehicle speed is
between approximately 5 mph (8 km/h)
and 18 mph (28 km/h).
■Setting the buzzer volume
The buzzer volume can be adjusted on the
multi-information display. ( P.253)
Use the meter control switches to change
settings. ( P.89)
■Conditions under which the RCTA func-
tion will not detect a vehicle
The RCTA function 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
●Guardrails, walls, signs, parked vehicles
and similar stationary objects*
●Small motorcycles, bicycles, pedestrians,
etc.*
●Vehicles moving away from your vehicle
●Vehicles approaching from the parking
spaces next to your vehicle*
*
: Depending on the conditions, detection of a vehicle and/or object may occur.
■Conditions under which the RCTA func-
tion may not function correctly
●The RCTA function may not detect vehi-
cles correctly in the following situations:
• When a sensor is misaligned due to a strong impact to the sensor or its sur-
rounding area
• When mud, snow, ice, a sticker, etc. is covering a sensor or its surrounding area
on the rear bumper
• When driving on a road surface that is wet with standing water during bad
weather, such as heavy rain, snow, or fog
• When multiple vehicles are approaching with only a small gap between each vehi-
cle
• If a vehicle is approaching the rear of your vehicle rapidly
• When a towing eyelet is installed to the rear of the vehicle.
• When backing up on a slope with a sharp
change in grade
• When backing out of a shallow angle parking spot
• Immediately after the RCTA function is

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

2734-5. 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.79, 80) and all of the following condi-
tions are met:
●Hybrid system 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
• Hybrid system output restriction control
is operating.
• 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:
●Hybrid system 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

2744-5. 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.270
■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.258) 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.256), if
the Parking Support Brake function (static
objects) is enabled ( P.266), 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

2794-5. Using the driving support systems
4
Driving
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,
snow, dirt, etc.
●When it is raining he avily or water strikes
the vehicle
●If the vehicle is significantly tilted
●When equipment that may obstruct a
sensor is installed, such as a towing eye-
let, bumper protector (an additional trim
strip, etc.), bicycle carrier, or snow plow
●If the suspension has been modified or

2884-5. Using the driving support systems
WARNING
■Trailer Sway Control precaution
The Trailer Sway Control system is not
able to reduce trailer sway in all situa-
tions. Depending on many factors such
as the conditions 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 seri-
ous injury.
●Firmly grip the steering wheel. 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.
■Secondary Collision Brake
Do not rely solely upon the Secondary
Collision Brake. This system is designed
to help reduce the possibility of further
damage due to a secondary collision,
however, that effect changes according
to various conditions. Overly relying on
the system may result in death or serious
injury.

2954-6. Driving tips
4
Driving
WARNING
●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 effec-
tiveness 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 materials trapped or
adhering to the underbody, a break-
down or fire could occur.
●When driving off-road or in rugged
terrain, do not drive at excessive
speeds, jump, make sharp turns, strike
objects, etc. This may cause loss of
control or vehicle rollover causing
death or serious injury. You are also
risking expensive damage to your
vehicle’s suspension and chassis.
NOTICE
■To prevent water damage
Take all necessary sa fety measures to
ensure that water da mage to the hybrid
battery (traction battery), hybrid system
or other components does not occur.
●Water entering the engine compart-
ment may cause severe damage to the
hybrid system. Water entering the inte-
rior may cause the hybrid battery
(traction battery) stowed under the
rear seats to short circuit.
●Water entering the hybrid transmis-
sion and rear electr ic motor (traction
motor) will cause deterioration in
transmission quality. The malfunction
indicator may come on, and the vehi-
cle may not be drivable.
●Water can wash the grease from wheel
bearings, causing rusting and prema-
ture failure, and may also enter the
hybrid transmission case, reducing the
gear oil’s lubricating qualities.
■When you drive through water
If driving through water, such as when
crossing 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 sys-
tem components.
●Always perform a maintenance
inspection after each day of off-road
driving that has taken you through
rough terrain, sand, mud, or water. For
scheduled maintena nce information,
refer to the “Warranty and Services
Guide/Owner’s Manual Supple-
ment/Scheduled Maintenance”.