2022 LEXUS RX450h brake

2194-5. 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.222
• Conditions under which the system may not operate properly:
P.223
●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
canceled if the ac celerator 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

2214-5. Using the driving support systems
4
Driving
collision with a detected object is high.
Each function is operatio nal 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.223)
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)

2244-5. 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/bicyc list is moving fast
• If a pedestrian is pushing a stroller, wheel- chair, bicycle or other vehicle
• When driving in inclement 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 making 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.280), 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.

2394-5. 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 sl opes, the vehicle-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 clos ing 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 of f, pushing the cruise control lever up or
depressing the accelerator peda l (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 your vehicle moves to an overtaking lane while
driving at 50 mph (80 km/h) or more, the vehi cle will accelerate to help to overtake a
passing vehicle.
The system’s identification of what is an overtaking lane may be dete rmined 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

2424-5. 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
traveling 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)

2444-5. 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.
●When the brake control or output restric-
tion control of a driving support system
operates.
(For example: Pre-Collision System,
Drive-Start Control)
●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.
●When the brake control or output restric-
tion control of a driving support system
operates.
(For example: Pre-Collision System,
Drive-Start Control)
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 response 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 display, read the message
and follow the instructions.( P.216,420)
■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.242) 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.)

2454-5. 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

2554-5. Using the driving support systems
4
Driving
●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 detected if they are
wearing certain types of clothing.
■Situations in which the system may not
operate properly
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.
●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.
●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
●A sensor is coated with a sheet of spray
or heavy rain.
●If objects draw too close to the sensor.
●When a pedestrian is wearing clothing
that does not reflect ultrasonic waves (ex. skirts with gathers or frills).
●When objects that are not perpendicular
to the ground, not perpendicular to the
vehicle traveling direction, uneven, or
waving are in the detection range.
●Strong wind is blowing
●When driving in inclement weather such
as fog, snow or a sandstorm
●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
●If the orientation of a sensor has been
changed due to a collision or other
impact
●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 front of the vehicle is raised or low-
ered due to the carried load
●If the vehicle cannot be driven in a stable
manner, such as when the vehicle has
been in an accident or is malfunctioning
●When a tire chains, compact spare tire or
an emergency tire punc ture repair kit is
used
■Situations in which the system may
operate even if there is no possibility of a
collision
In some situations, such as the following, the
system may operate even though there is no
possibility of a collision.
●When driving on a narrow road
●When driving toward a banner, flag,
low-hanging branch or boom barrier