brake LEXUS RX450h 2022 Repair Manual

2684-5. Using the driving support systems
Hybrid system output
Braking force
Time
 Figure 2 When hybrid system ou tput restriction control operates
Hybrid system output
Braking force
Time
Hybrid system output restrict ion control begins operating
System determines that possibility of collision with detected object is high
Hybrid system output reduced
Example: Multi-information display: “BRAKE!”
 Figure 3 When brake control operatesA
B
C
A
B
C
D
E
F
G

2694-5. Using the driving support systems
4
Driving
Hybrid system output
Braking force
Time
Hybrid system output restriction control begins operating
System determines that possibility of collision with detected object is high
Hybrid system output reduced
System determines that possibility of col lision with detected object is extremely
high
Brake control begins operating
Brake control strength increased
Example: Multi-information display: “BRAKE!”
Example: Multi-information display: “Switch to Brake”
■If the Parking Support Brake has oper-
ated
If the vehicle is stoppe d due to operation of
the Parking Support Brake, the Parking
Support Brake will be disabled and the
PKSB OFF indicator will illuminate. If the
Parking Support Brake operates unneces-
sarily, brake control can be canceled by
depressing the brake pedal or waiting for
approximately 2 seconds for it to automati-
cally be canceled. Then, the vehicle can be
operated by depressing the accelerator
pedal.■Re-enabling the Parking Support Brake
To re-enable the Parking Support Brake
when it has been disabled due to system
operation perform any of the following
operations.
At this time, the PKSB OFF indicator will
turn off. ( P.80)
●Turn the PKSB (Parking Support Brake)
on ( P.266)
●The shift lever is in P.
●Drive with no operation targets in the
traveling direction of the vehicle
●Change the travelin g direction of the
vehicle
A
B
C
D
E
F
G
H
I
J
K

2704-5. Using the driving support systems
■If “Parking Support Brake Unavailable”
is displayed on the multi-information
display and the PKSB OFF indicator is
flashing
If this message is displayed only when the
shift lever is in any position other than R, a
sensor on the front or rear bumper may be
dirty. Clean the sensors and their surround-
ing area on the bumpers.
■If “Parking Assist Unavailable” and
“Parking Assist Unavailable Clean
Parking Assist Sensor” are displayed on
the multi-information display and the
PKSB OFF indicator is flashing
●A sensor may be covered with ice, snow,
dirt, etc. Remove the ice, snow, dirt, etc.,
from the sensor to return the system to
normal.
If this message is shown even after
removing dirt from the sensor, or shown
when the sensor was not dirty to begin
with, have the vehicle inspected by your
Lexus dealer.
●A sensor may be frozen. Once the ice
melts, the system will return to normal.
●Water may be continuo usly 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.
■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.
Additionally, for vehicles with the Parking
Support Brake function, turn the steering
wheel fully to the left and right with the vehi-
cle stopped.

2714-5. Using the driving support systems
4
Driving
*:If equipped
This function will operate in situations such as the following if an object is detected
in the traveling direction of the vehicle.
■When traveling at a low speed and the brake pedal is not depressed, or is
depressed late
Parking Support Brake function (static objects)*
If the sensors detect a static object, such as a wall, in the travelling direction of
the vehicle and the system determines that a collision ma y occur due to the
vehicle suddenly moving forward due to an accidental accelerator pedal oper-
ation, the vehicle moving the unintended direction due to the wrong shift lever
position, or while parking or traveling at low speeds, the system will operate to
lessen the impact with the detected static object and reduce the resulting
damage.
Examples of function operation

2724-5. 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.252
■The Parking Support Brake function
(static object) will operate when
The function will operate when the PKSB
OFF indicator is not illuminated or flashing
Types of sensors
WARNING
■To ensure the system can operate
properly
 P.253
■If the Parking Support Brake function
(static objects) operates unnecessar-
ily, such as at a railroad crossing
P.253
■Notes when washing the vehicle
P.254

2734-5. Using the driving support systems
4
Driving
( 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 approximately 9 mph (15 km/h) or less.
• There is a static ob ject in the traveling
direction of the vehicle and approxi-
mately 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 br ake 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 approxi- mately 6 to 13 ft. (2 to 4 m) away from the
vehicle or in the 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 approxi- mately 6 to 13 ft. (2 to 4 m) away from the
vehicle or in the traveling direction of the
vehicle.
■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.256) 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.
■Situations in which the system may not
operate properly
P.255
■Situations in which the system may
operate even if there is no possibility of a
collision
P.255

2744-5. Using the driving support systems
*:If equipped
This function will operate in situations such as the followi ng if a vehicle is detected
in the traveling direction of the vehicle.
■When reversing, a vehicle is app roaching and the brake pedal is not
depressed, or is depressed late
 P.246
■The Parking Support Brake function
(rear-crossing vehicles) 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 approximately 9 mph (15 km/h) or less.
• Vehicles which are ap proaching from the
right or left at the rear of the vehicle at a
traveling speed of approximately 5 mph
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 system can operate
properly
 P.246

2754-5. Using the driving support systems
4
Driving
(8 km/h) or more.
• 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 th e 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 th e rear of the vehicle.
■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.261). 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.
■Situations in which the system may not
operate properly
P.262
■Situations in which the system may
operate even if there is no possibility of a
collision
P.263

2784-5. Using the driving support systems
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.
3 Sport mode
Controls the hybrid system to provide
quick, powerful acce leration. This mode
also changes the steering feel, making 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 contro ls 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 power switch is turned off after driving
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.294)
■ECB (Electronically Controlled
Brake System)
The electronically controlled system
generates braking force correspond-
ing to the brake operation
■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 suddenly or turning on
slippery road surfaces
■Enhanced VSC (Enhanced Vehi-
cle Stability Control)
Provides cooperative control of the
ABS, TRAC, VSC and EPS.
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

2794-5. Using the driving support systems
4
Driving
Helps to maintain directional stability
when swerving on slippery road sur-
faces by controlling steering perfor-
mance.
■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
■E-Four
Electronic On-Demand AWD system.
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.276)
■VDIM (Vehicle Dynamics Inte-
grated Management)
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, hybrid system
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/ABS/Trailer
Sway Control systems are operating
The slip indicator light will flash while the
TRAC/VSC/ABS/Trailer Sway Control
systems are operating.