brake LEXUS RX450h 2021 Service Manual

1924-2. Driving procedures
and D, make sure that the vehicle is com-
pletely stopped.
■Shift lock system
The shift lock system is a system to prevent
accidental operation of the shift lever in
starting.
The shift lever can be shifted from P only
when the power switch is in ON mode and
the brake pedal is being depressed.
■If the shift lever cannot be shifted from P
First, check whether the brake pedal is
being depressed.
If the shift lever cannot be shifted with your
foot on the brake pedal, there may be a
problem with the shift lock system. Have the
vehicle inspected by your Lexus dealer
immediately.
The following steps may be used as an
emergency measure to ensure that the shift
lever can be shifted.
Releasing the shift lock:
1 Turn the power switch to ON mode and
check that the parking brake is set.
( P.187, 195)
2 Turn the power switch to off.
3 Depress the brake pedal.
4 Pry the cover up with a flathead screw-
driver or equivalent tool.
To prevent damage to the cover, cover the
tip of the screwd river with a rag.
5 Press the shift lock override button.
The shift lever can be shifted while the but- ton is pressed.

P.281
To drive using temporary shift range
selection, operate the “-” paddle shift
switch. Changing the shift range
enables the level of engine braking
force to be selected. The shift range
can then be selected by operating the
“-” and “+” paddle shift switches.
WARNING
■To prevent an accident when releas-
ing the shift lock
Before pressing the shift lock override
button, make sure to set the parking
brake and depress the brake pedal.
If the accelerator pe dal is accidentally
depressed instead of the brake pedal
when the shift lock override button is
pressed and the shift lever is shifted out
of P, the vehicle may suddenly start, pos-
sibly leading to an accident resulting in
death or serious injury.
Selecting the driving mode
Selecting shift ranges in the D
position

1954-2. Driving procedures
4
Driving
( P.480)
■Using the manual mode
The parking brake can be set and
released manually.
U.S.A.
Canada
Parking brake light
1 Pull the parking brake switch to set
the parking brake
Parking brake
The parking brake can be set or
released automatically or manually.
In automatic mode, the parking
brake can be set or released auto-
matically according to the shift
lever operation. Also, even in auto-
matic mode, the parking brake can
be set or released manually.
Operating instructions
A
B
C

1964-2. Driving procedures
The parking brake indicator light and park-
ing brake light will turn on.
Pull and hold the parking brake switch if an
emergency occurs and it is necessary to
operate the parking brake while driving.
2Push the parking brake switch to
release the parking brake
Operate the switch while depressing the
brake pedal or slowly depressing the
accelerator pedal.
Make sure that the pa rking brake indicator
light and parking brake light turn off.
If the parking brake indicator light and
parking brake light flashes, operate the
switch again. ( P.424)
■Turns automatic mode on
While the vehicle is stopped, pull and
hold the parking brake switch until
“Automatic Mode On” will be dis-
played on the multi-information dis-
play.
When the automatic mode is turned
on, the parking brake operates as fol-
lows.
 When the shift lever is moved out of
P, the parking brake will be released,
and the parking brake indicator light
and parking brake light turn off.
 When the shift lever is moved into P,
the parking brake will be set, and the parking brake indicator light and
parking brake light turn on.
Operate the shift lever with the brake
pedal depressed.
■Turns automatic mode off
While the vehicle is stopped, press and
hold the parking brake switch until
“Automatic Mode Off” will be dis-
played on the multi-information dis-
play.
■Parking brake operation
●When the power swit ch is not in ON
mode, the parking brake cannot be
released using the parking brake switch.
●When the power swit ch is not in ON
mode, automatic mode (automatic brake
setting and releasing) is not available.
■Parking brake automatic release func-
tion
The parking brake is automatically released
when slowly depress the accelerator pedal.
The parking brake will be released auto-
matically under the following conditions:
• The driver’s door is closed.
• The driver’s seatbelt is fastened.
• Shift the shift lever is in a forward or reverse position.
• The malfunction indicator lamp or brake system warning light is not illuminated.
If the automatic release function does not
operate, manually release the parking
brake.

1974-2. Driving procedures
4
Driving
■If “Parking Brake Overheated Parking
Brake Unavailable” is displayed on the
multi-information display
If the parking brake is operated repeatedly
over a short period of time, the system may
restrict operation to prevent overheating. If
this happens, refrain from operating the
parking brake. Normal operation will return
after about 1 minute.
■If “EPB Activation Stopped Incom-
pletely” or “Parking Brake Unavailable”
is displayed on th e multi-information
display
Operate the parking brake switch. If the
message does not disappear after operat-
ing the switch several times, the system may
be malfunctioning. Have the vehicle
inspected by your Lexus dealer immedi-
ately.
■Parking brake operation sound
When the parking brake operates, a motor
sound (whirring sound) may be heard. This
does not indicate a malfunction.
■Parking brake indicator light and park-
ing brake light
●Depending on the power switch mode,
the parking brake in dicator light and
parking brake light will turn on and stay
on as described below:
ON mode: Comes on until the parking
brake is released.
Not in ON mode: Stays on for approxi-
mately 15 seconds.
●When the power switch is turned off with
the parking brake set, the parking brake
indicator light and parking brake light will
stay on for about 15 seconds. This does
not indicate a malfunction.
■Changing the mode
When changing the automatic mode on/off,
the message will be shown on the
multi-information display and the buzzer
sounds.
■Parking the vehicle
 P.164
■Parking brake engaged warning buzzer
A buzzer will sound if the vehicle is driven
with the parking brake engaged. “Release Parking Brake” is displayed on the
multi-information display.
■Warning messages and buzzers
Warning messages and buzzers are used to
indicate a system malfunction or to inform
the driver of the need for caution. If a warn-
ing message is shown on the multi-informa-
tion display, read the message and follow
the instructions.
■If the brake system warning light comes
on
 P.418
■Usage in winter time
 P.293
WARNING
■When parking the vehicle
Do not leave a child in the vehicle alone.
The parking brake may be released unin-
tentionally and there is the danger of the
vehicle moving that may lead to an acci-
dent resulting in death or serious injury.
■Parking brake switch
Do not set any objects near the parking
brake switch. Objects may interfere with
the switch and may lead the parking
brake to unexpectedly operate.
NOTICE
■When parking the vehicle
Before you leave the vehicle, shift the
shift lever to P, set the parking brake and
make sure that the vehicle does not
move.
■When the system malfunctions
Stop the vehicle in a safe place and
check the warning messages.

1984-2. Driving procedures
Turns the brake hold system on
The brake hold standby indicator (green) comes on. While the system is holding
the brake, the brake hold operated indica-
tor (yellow) comes on.
■Brake hold system operating conditions
The brake hold system cannot be turned on
in the following conditions:
●The driver’s door is not closed.
●The driver is not wearing the seat belt.
If any of the conditions above are detected
when the brake hold system is enabled, the
system will turn off and the brake hold
standby indicator light will go off. In addi-
tion, if any of the conditions are detected
while the system is holding the brake, a
warning buzzer will sound and a message
will be shown on the multi-information dis-
NOTICE
■When the parking brake cannot be
released due to a malfunction
Driving the vehicle with the parking
brake set will lead to brake components
overheating, which may affect braking
performance and increase brake wear.
Have the vehicle inspected by your
Lexus dealer immediately if this occurs.
Brake Hold
The brake hold system keeps the
brake applied when the shift lever is
in D, S or N with the system on and
the brake pedal has been
depressed to stop the vehicle. The
system releases the brake when the
accelerator pedal is depressed with
the shift lever in D or S to allow
smooth start off.
Enabling the system
A
B

1994-2. Driving procedures
4
Driving
play. The parking brake will then be set
automatically.
■Brake hold function
●If the brake pedal is left released for a
period of about 3 minutes after the sys-
tem has started holding the brake, the
parking brake will be set automatically. In
this case, a warning buzzer sounds and a
message is shown on the multi-informa-
tion display.
●To turn the system off while the system is
holding the brake, firmly depress the
brake pedal and press the button again.
●The brake hold function may not hold the
vehicle when the vehicle is on a steep
incline. In this situation, it may be neces-
sary for the driver to apply the brakes. A
warning buzzer will sound and the
multi-information display will inform the
driver of this situation. If a warning mes-
sage is shown on the multi-information
display, read the message and follow the
instructions.
■When the parking brake is set automati-
cally while the system is holding the
brakes
Perform any of the follo wing operations to
release the parking brake.
●Depress the accelerator pedal. (The
parking brake will not be released auto-
matically if the seat belt is not fastened.)
●Operate the parking brake switch with
the brake pedal depressed.
Make sure that the pa rking brake indicator
light goes off. ( P.195)
■When an inspection at your Lexus
dealer is necessary
When the brake hold standby indicator
(green) does not illuminate even when the
brake hold switch is pressed with the brake
hold system operating conditions met, the
system may be malfun ctioning. Have the
vehicle inspected at your Lexus dealer.
■If “Brake Hold Fault Depress Brake to
Deactivate Visit Your Dealer” or “Brake
Hold Malfunction Visit Your Dealer” is
displayed on the multi-information dis-
play
The system may be ma lfunctioning. Have
the vehicle inspected by your Lexus dealer.
■Warning messages and buzzers
Warning messages and buzzers are used to
indicate a system malfunction or to inform
the driver of the need for caution. If a warn-
ing message is shown on the multi-informa-
tion display, read the message and follow
the instructions.
■If the brake hold operated indicator
flashes
 P.425
WARNING
■When the vehicle is on a steep incline
When using the brake hold system on a
steep incline exercise caution. The brake
hold function may not hold the vehicle in
such a situation.
■When stopped on a slippery road
The system cannot stop the vehicle when
the gripping ability of the tires has been
exceeded. Do not use the system when
stopped on a slippery road.
NOTICE
■When parking the vehicle
The brake hold system is not designed
for use when parking the vehicle for a
long period of time. Turning the power
switch off while the system is holding the
brake may release the brake, which
would cause the vehicle to move. When
operating the power switch, depress the
brake pedal, shift the shift lever to P and
set the parking brake.

2004-3. Operating the lights and wipers
4-3.Operating the lights and wipers
Operating the switch turns on
the lights as follows:U.S.A.
Canada
1 The side marker, parking, tail,
license plate, instrument panel
lights, and daytime running lights
( P.200) turn on.
2 The headlights and all lights
listed above (except daytime run-
ning lights) turn on.
3 The headlights, daytime run-
ning lights ( P.200) and all the lights listed above turn on and off
automatically.
(When the power switch is in ON
mode.)
4 (U.S.A.) Off
■Daytime running light system
●The daytime running lights illuminate
using the same lights as the parking lights
and illuminate brighter than the parking
lights.
●To make your vehicle more visible to
other drivers during daytime driving, the
daytime running lights turn on automati-
cally when all of the following conditions
are met. (The daytime running lights are
not designed for use at night.)
• The hybrid system is started
• The parking brake is released
• The headlight switch is in the or
* position
*: When the surroundings are bright
The daytime running lights remain on after
they illuminate, even if the parking brake is
set again.
●For the U.S.A.: Daytime running lights
can be turned off by operating the switch.
●Compared to turning on the headlights,
the daytime running light system offers
greater durability and consumes less
electricity, so it can help improve fuel
economy.
■Headlight control sensor
The sensor may not function properly if an
object is placed on the sensor, or anything
that blocks the sensor is affixed to the wind-
shield.
Headlight switch
The headlights can be operated
manually or automatically.
Operating instructions
A
B

2084-3. Operating the lights and wipers
●If the wiper switch is turned to the
“AUTO” position while the power switch
is in ON mode, the wipers will operate
once to show that AUTO mode is acti-
vated.
●When the sensor sensitivity ring is turned
toward high while in “AUTO” position, the
wipers will operate once to indicate that
the sensor sensitiv ity is enhanced.
●If the temperature of the raindrop sensor
is 194°F (90°C) or higher, or 5°F (-15°C)
or lower, automatic operation may not
occur. In this case, operate the wipers in
any mode other than AUTO mode.
■If no windshield washer fluid sprays
Check that the washer nozzles are not
blocked, if there is washer fluid in the
washer fluid tank.
■Front door opening linked windshield
wiper stop function
When “AUTO” is selected and the wind-
shield wipers are operatin g, if a front door is
opened, the operation of the windshield
wipers will be stopped to prevent anyone
near the vehicle from being sprayed by
water from the wipers, provided the vehicle
is stopped with the parking brake applied or
the shift lever in P. When the front door is
closed, wiper operation will resume.
■Customization
Some functions can be customized.
(  P.480)
When the windshield wipers are not
being used, they retract to below the
hood. To enable the windshield wipers
to be lifted when parking in cold condi-
tions or when replacing a windshield
wiper insert, change the rest position of
the windshield wipers to the service
position using the wiper lever.
WARNING
■Caution regarding the use of wind-
shield wipers in AUTO mode
The windshield wipers may operate
unexpectedly if the sensor is touched or
the windshield is subj ect to vibration in
A U T O m o d e . T a k e c a r e t h a t y o u r f i n g e r s ,
etc. do not become caught in the wind-
shield wipers.
■Caution regarding the use of washer
fluid
When it is cold, do not use the washer
fluid until the windshield becomes warm.
The fluid may freeze on the windshield
and cause low visibility. This may lead to
an accident, resulting in death or serious
injury.
NOTICE
■When the washer fluid tank is empty
Do not operate the switch continually as
the washer fluid pump may overheat.
■When a nozzle becomes blocked
In this case, contact your Lexus dealer.
Do not try to clear it with a pin or other
object. The nozzle will be damaged.
Changing the windshield wiper
rest position/Lifting the wind-
shield wipers

2204-5. Using the driving support systems
The system can detect the following:
Vehicles
 Bicyclists
 Pedestrians
■Pre-collision warning
When the system determines that the
possibility of a frontal collision is high, a
buzzer will sound and a warning mes-
sage will be displayed on the
multi-information display to urge the driver to take evasive action.
■Pre-collision brake assist
When the system determines that the
possibility of a frontal collision is high,
the system applies greater braking
force in relation to how strongly the
brake pedal is depressed.
■Pre-collision braking
If the system determines that the possi-
bility of a frontal collision is extremely
high, the brakes are automatically
applied to help avoid the collision or
reduce the impact of the collision.
■Suspension control (if equipped)
When the system determines that the
possibility of a frontal collision is high,
the Adaptive Variable Suspension Sys-
tem ( P.284) will control the damp-
ing force of the shock absorbers to
help maintain an appropriate vehicle
posture.
PCS (Pre-Collision System)
The pre-collision system uses a
radar sensor and front camera to
detect objects ( P.220) in front of
the vehicle. When the system
determines that the possibility of a
frontal collision with an object is
high, a warning operates to urge
the driver to take evasive action
and the potential brake pressure is
increased to help the driver avoid
the collision. If the system deter-
mines that the possibility of a frontal
collision with an object is extremely
high, the brakes are automatically
applied to help avoid the collision or
help reduce the impact of the colli-
sion.
The pre-collision system can be dis-
abled/enabled and the warning tim-
ing can be changed. ( P.222)
Detectable objects
System functions

2214-5. Using the driving support systems
4
Driving
WARNING
■Limitations of the pre-collision system
●The driver is solely responsible for safe
driving. Always drive safely, taking
care to observe your surroundings.
Do not use the pre-collision system
instead of normal braking operations
under any circumstances. This system
will not prevent collisions or lessen col-
lision damage or injury in every situa-
tion. Do not overly rely on this system.
Failure to do so may lead to an acci-
dent, resulting in death or serious
injury.
●Although this system is designed to
help avoid a collision or help reduce
the impact of the collision, its effective-
ness may change according to various
conditions, therefore the system may
not always be able to achieve the same
level of performance.
Read the following conditions care-
fully. Do not overly rely on this system
and always drive carefully.
• Conditions under which the system may operate even if there is no possi-
bility of a collision:
P.224
• Conditions under which the system may not operate properly:
P.225
●Do not attempt to test the operation of
the pre-collision system yourself.
Depending on the objects used for
testing (dummies, cardboard objects
imitating detectable objects, etc.), the
system may not operate properly, pos-
sibly leading to an accident.
■Pre-collision braking
●When the pre-collision braking func-
tion is operating, a large amount of
braking force will be applied.
●If the vehicle is stopped by the opera-
tion of the pre-collision braking func-
tion, the pre-collision braking function
operation will be canceled after
approximately 2 seco nds. Depress the
brake pedal as necessary.
●The pre-collision braking function may
not operate if certain operations are
performed by the driver. If the acceler-
ator pedal is being depressed strongly
or the steering wheel is being turned,
the system may determine that the
driver is taking evasive action and pos-
sibly prevent the pre-collision braking
function from operating.
●In some situations, while the pre-colli-
sion braking function is operating,
operation of the function may be can-
celed if the accelerator pedal is
depressed strongly or the steering
wheel is turned and the system deter-
mines that the driver is taking evasive
action.
●If the brake pedal is being depressed,
the system may determine that the
driver is taking evasive action and pos-
sibly delay the operat ion timing of the
pre-collision braking function.
■When to disable the pre-collision sys-
tem
In the following situations, disable the
system, as it may not operate properly,
possibly leading to an accident resulting
in death or serious injury:
●When the vehicle is being towed
●When your vehicle is towing another
vehicle
●When transporting the vehicle via
truck, boat, train or similar means of
transportation
●When the vehicle is raised on a lift with
the hybrid system on and the tires are
allowed to rotate freely
●When inspecting the vehicle using a
drum tester such as a chassis dyna-
mometer or speedometer tester, or
when using an on vehicle wheel bal-
ancer
●When a strong impact is applied to the
front bumper or front grille, due to an
accident or other reasons