parking brake LEXUS RX450h 2021 Service Manual

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

2754-5. 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

2774-5. 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.249
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 side radar sensors
(
P.249). 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 side radar sen-
sor with a part other than a genuine
part.
●Do not damage the rear side radar
sensors, and always keep the radar
sensors and their surrounding area on
the bumper clean.

2784-5. 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.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.
• 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
• Hybrid system output restriction control is operating.
• 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:
●Hybrid system 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.270
■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.263). 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,
etc.*
●Vehicles moving away from your vehicle
●Vehicles approaching from the parking
WARNING
●If the area around a rear side radar
sensor is subjected to an impact, the
system may not operate properly due
to a sensor malfunct ion. Have the vehi-
cle inspected by your Lexus dealer.

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

2854-5. Using the driving support systems
4
Driving
■Disabling the TRAC system
If the vehicle gets stuck in mud, dirt or snow,
the TRAC system may reduce power from
the hybrid system to the wheels. Pressing
the switch 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 switch.
The “Traction Control Turned Off” will be
shown on the multi-information display.
Press the switch again to turn the sys-
tem back on.
■Turning off both TR AC, VSC and Trailer
Sway Control systems
To turn the TRAC, VSC and Trailer Sway
Control systems off, press and hold the
switch for more th an 3 seconds while
the vehicle is stopped.
The VSC OFF indicator light will come on
and the “Traction Cont rol Turned Off” will
be shown on the mult i-information display.
*
Press the switch again to turn the sys-
tem back on.
*: On vehicles with PCS (Pre-Collision
System), PCS will also be disabled (only Pre-Collision warning is available). The
PCS warning light will come on and a
message will be di
splayed on the
multi-information display. ( P.220)
■When the message is displayed on the
multi-information display showing that
TRAC has been disabled even if the
switch has not been pressed
TRAC is temporary deactivated. If the infor-
mation continues to show, 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/back-
ward 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 con-
trol systems
●A sound may be heard from the engine
compartment when the brake pedal is
depressed repeatedly, when the hybrid
system is started or just after the vehicle
begins to move. This sound does not indi-
cate that a malfunction has occurred in
any of these systems.
●Any of the following conditions may
occur when the above systems are oper-
ating. None of these indicates that a mal-
function has occurred.

2874-5. Using the driving support systems
4
Driving
WARNING
■Stopping distance when the ABS is
operating may exceed that of normal
conditions
The ABS is not designed to shorten the
vehicle’s stopping di stance. Always main-
tain a safe distance from the vehicle in
front of you, especially in the following
situations:
●When driving on dirt, gravel or
snow-covered roads
●When driving with tire chains
●When driving over bumps in the road
●When driving over roads with potholes
or uneven surfaces
■TRAC/VSC may not operate effec-
tively when
Directional control and power may not
be achievable while driving on slippery
road surfaces, even if the TRAC/VSC
system is operating. Drive the vehicle
carefully in conditions where stability and
power may be lost.
■Active Cornering Assist does not
operate effectively when
●Do not overly rely on Active Corner-
ing Assist. Active Cornering Assist
may not operate effectively when
accelerating down slopes or driving on
slippery road surfaces.
●When Active Cornering Assist fre-
quently operates, Active Cornering
Assist may temporarily stop operating
to ensure proper operation of the
brakes, TRAC and VSC.
■Hill-start assist control does not oper-
ate 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 extended
period of time. Do not attempt to use
hill-start assist control to hold the vehi-
cle on an incline, as doing so may lead
to an accident.
■When the TRAC/ABS/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 condi-
tions. As these are the systems to help
ensure vehicle stab ility and driving
force, do not turn the
TRAC/VSC/Trailer Sway Control sys-
tems off unless necessary.
●Trailer Sway Control is part of the VSC
system and will not operate if VSC is
turned off or experiences a malfunc-
tion.
■Replacing tires
Make sure that all ti res are of the speci-
fied size, brand, tread pattern and total
load capacity. In addition, make sure that
the tires are inflated to the recom-
mended tire inflation pressure level.
The ABS, TRAC, Trailer Sway Control
and VSC systems will not function cor-
rectly if different tire s are installed on the
vehicle.
Contact your Lexus dealer for further
information when replacing tires or
wheels.
■Handling of tires and the suspension
Using tires with any kind of problem or
modifying the suspensi on will affect the
driving assist systems, and may cause a
system to malfunction.

2894-6. Driving tips
4
Driving
4-6.Driving tips
When using Eco drive mode, the
torque corresponding to the accelera-
tor pedal depression amount can be
generated more smoothly than it is in
normal conditions. In addition, the
operation of the air conditioning sys-
tem (heating/cooling) will be mini-
mized, improving the fuel economy.
( P.281)
The Eco-friendly driving is possible by
keeping the indicator needle (except F
SPORT models) or bar display (F
SPORT models) of Hybrid System
Indicator within Eco area. ( P.85)
Shift the shift lever to D when stopped
at a traffic light, or driving in heavy traf-
fic, etc. Shift the shift lever to P when
parking. When using the N, there is no
positive effect on fuel consumption. In
the N, the gasoline engine operates
but electricity cannot be generated.
Also, when using the air conditioning
system, etc., the hybrid battery (trac-
tion battery) power is consumed. 
Drive your vehicle smoothly. Avoid
abrupt acceleration and decelera-
tion. Gradual acceleration and
deceleration will make more effec-
tive use of the electric motor (trac-
tion motor) without having to use
gasoline engine power.
 Avoid repeated acceleration.
Repeated acceleration consumes
hybrid battery (traction battery)
power, resulting in poor fuel con-
sumption. Battery power can be
restored by driving with the acceler-
ator pedal slightly released.
Make sure to operate the brakes gently
and in a timely manner. A greater
amount of electrical energy can be
regenerated when slowing down.
Repeated acceleration and decelera-
tion, as well as long waits at traffic
lights, will lead to bad fuel economy.
Check traffic reports before leaving
and avoid delays as much as possible.
When driving in a traffic jam, gently
release the brake pedal to allow the
vehicle to move forward slightly while
avoiding overuse of the accelerator
pedal. Doing so can help control
excessive gasoline consumption.
Hybrid vehicle driving tips
For economical and ecological
driving, pay attention to the follow-
ing points:
Using Eco drive mode
Use of Hybrid System Indicator
Shift lever operation
Accelerator pedal/brake pedal
operation
When braking
Delays

2924-6. Driving tips
immediately to prevent it from
freezing.
 To ensure proper operation of the
climate 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 accumu-
lated on the exterior lights, vehicle’s
roof, chassis, around the tires or on
the brakes.
 Remove any snow or mud from the
bottom of your shoes before getting
in the vehicle.
Accelerate the vehicle slowly, keep a
safe distance between you and the
vehicle ahead, and drive at a reduced
speed suitable to road conditions.
 Park the vehicle and move the shift
lever to P without setting the park-
ing 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. Fail-
ure to do so may be dangerous
because it may cause the vehicle to
move unexpectedly, possibly lead-
ing to an accident.
When the parking brake is in automatic
mode, release the parking brake after shift-
ing the shift lever to P. ( P.196)
 If the vehicle is parked without set-
ting the parking brake, confirm that
the shift lever cannot be moved out
of P
*.
*: The shift lever will be locked if it is
attempted to be shifted from P to any
other position with out depressing the
brake pedal. If the shift lever can be
shifted from P, there may be a problem
with the shift lock system. Have the vehi-
cle inspected by your Lexus dealer
immediately.
Use the correct tire chain size when
mounting the tire chains.
Chain size is regulated for each tire
size.
Side chain (0.12 in. [3 mm] in diam-
eter)
Side chain (0.43 in. [10.8 mm] in
width)
Side chain (0.98 in. [25 mm] in
length)
Cross chain (0.15 in. [3.9 mm] in
diameter)
Cross chain (0.54 in. [13.8 mm] in
width)
Cross chain (1.00 in. [25.3 mm] in
When driving the vehicle
When parking the vehicle
Selecting tire chains
A
B
C
D
E
F