brake LEXUS RX450H 2019 Repair Manual

3274-5. Using the driving support systems
4
Driving
RX450h_RX450hL_U
The RCTA function uses radar sensors to detect vehicles approaching from the
right or left at the rear of the vehicle and alerts the driver of the presence of such
vehicles by flashing the outside rear view mirror indicators and sounding a
buzzer.
Approaching vehicles
Detection areas of approaching vehicles
■Rear Cross Traffic Auto Brake function
When the Intelligent Clearance Sonar wi th Rear Cross Traffic Auto Brake is
enabled and a vehicle approaching from the right or left at the rear of the vehi-
cle is detected, the Rear Cross Traffic Auto Brake function will perform brake
control to reduce the likelihood of an impact with the approaching vehicle.
Intelligent Clearance Sonar with Re ar Cross Traffic Auto Brake: P. 342
RCTA function
1
2

3394-5. Using the driving support systems
4
Driving
RX450h_RX450hL_U
●Vehicles with a navigation system (12.3-inch display): If the intuitive parking assist dis-
play is set to on, detected objects will also be displayed on the panoramic view monitor.
For details, refer to “NAVIGATION SYSTEM OWNER’S MANUAL”.
■Sensor detectio n information
●The sensor’s detection areas are limited to the areas around the vehicle’s bumper.
●Certain vehicle conditions and the surrounding environment may affect the ability of a
sensor to correctly detect an object. Particular instances where this may occur are
listed below.
• There is dirt, snow or ice on the sensor . (Wiping the sensors will resolve this prob-
lem.)
• The sensor is frozen. (Thawing the area will resolve this problem.) In especially cold weather, if a sensor is frozen the screen may show an abnormal
display, or obstacles may not be detected.
• The sensor is covered in any way.
• The vehicle is leaning considerably to one side.
• When a sensor or the area around a sensor is extremely hot or cold.
• On an extremely bumpy road, on an incline, on gravel, or on grass.
• The vicinity of the vehicle is noisy due to vehicle horns, motorcycle engines, air
brakes of large vehicles, or other loud noises producing ultrasonic waves.
• There is another vehicle equipped with parking assist sensors in the vicinity.
• The sensor is coated with a sheet of spray or heavy rain.
• The bumper or sensor re ceives a strong impact.
• If the vehicle is significantly tilted.
• The vehicle is approaching a tall or curved curb.
• In harsh sunlight or intense cold weather.
• The area directly under the bumpers is not detected.
• If objects draw too close to the sensor.
• People may not be detected if they are wearing certain types of clothing.
In addition to the examples above, there ar e instances in which, because of their shape,
signs and other objects may be judged by a sensor to be closer than they are.
●The shape of the object may prevent a sensor from detecting it. Pay particular attention
to the following objects:
• Wires, fences, ropes, etc.
• Cotton, snow and other materi als that absorb sound waves
• Sharply-angled objects
• Low obstacles
• Tall obstacles with upper sections projecting outwards in the direction of your vehi-
cle
●The following situations may occur during use.
• Depending on the shape of the object and other factors, the detection distance may
shorten, or detection may be impossible.
• Objects may not be detected if they are too close to the sensor.
• There will be a short dela y between object detection and display. Even at slow
speeds, there is a possibility that the obje ct will come within the sensor’s detection
areas before the display is shown and the buzzer sounds.
• Thin posts or objects lower than the sens or may not be detected when approached,
even if they have been detected once.
• It might be difficult to hear beeps due to th e volume of audio system or air flow noise
of the air conditioning system.

3404-5. Using the driving support systems
RX450h_RX450hL_U
■If “Clean Parking Assist Sensor” is di splayed on the multi-information display
A sensor may be dirty or covered with snow or ic e. In such cases, if it is removed from the
sensor, the system should return to normal.
Also, due to the sensor being frozen at low temperatures, a malfunction display may
appear or an object may not be detected. If the sensor thaws out, the system should
return to normal.
■If “Parking Assist Malfunction” is di splayed on the multi-information display
Depending on the malfunction of the sensor, the device may not be working normally.
Have the vehicle inspected by your Lexus dealer.
■Certification
For vehicles sold in Canada
This ISM device complies with Canadian ICES-001.
Cet appareil ISM est conforme a la norme NMB-001 du Canada.
■Customization
Some functions can be customized. ( P. 338, 736)
WARNING
■When using the intuitive parking assist
Observe the following precautions.
Failing to do so may result in the vehicle be ing unable to be driven safely and possibly
cause an accident.
●Do not use the sensor at speeds in excess of 6 mph (10 km/h).
●The sensors’ detection areas and reaction ti mes are limited. When moving forward or
reversing, check the areas surrounding the vehicle (especially the sides of the vehi-
cle) for safety, and drive slowly, using the brake to control the vehicle’s speed.
●Do not install accessories within the sensors’ detection areas.
●The vehicle is equipped with a fender pole or wireless antenna.
●The front or rear bumper or a se nsor receives a strong impact.
●A non-genuine Lexus suspension (lower ed suspension, etc.) is installed.
●Towing eyelets are installed.
●A backlit license plate is installed.
■When using intuitive parking assist
In the following situations, the system may not function correctly due to a sensor mal-
function, etc. Have the vehicle checked by your Lexus dealer.
●The intuitive parking assist operation disp lay flashes, and a buzzer sounds when no
obstacles are detected.
●If the area around a sensor co llides with something, or is subjected to strong impact.
●If the bumper collides with something.
●If the display shows continuously without beeping, except when the buzzer mute
switch has been turned on.
●If a display error occurs, first check the sensor.
If the error occurs even if there is no ice, sn ow or mud on the sensor, it is likely that the
sensor is malfunctioning.

3424-5. Using the driving support systems
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The system will operate in situations such as the following if a stationary 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
Intelligent Clearance Sonar (ICS)
: If equipped
If a collision with a wall or other stationary object may occur due to the vehicle
suddenly moving forward due to an ac cidental accelerator pedal operation,
the vehicle moving the unintended dire ction due to the wrong shift position
being selected, or while parking or tr aveling at low speeds, the sensors sta-
tionary detect objects, such as a wall, in the traveling direction of the vehicle,
and the system operates to lessen an impact with a stationary object and
reduce the resulting collision damage.
Examples of system operation

3444-5. Using the driving support systems
RX450h_RX450hL_U
If a rear radar sensor detects a vehicle ap proaching 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 brake control to reduce the likelihood of an
impact with the approaching vehicle.
■Examples of system operation
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 approaching and the brake pedal is not
depressed, or is depressed late
Rear Cross Traffic Auto Brake function

3464-5. Using the driving support systems
RX450h_RX450hL_U
If the hybrid system output restriction control or brake control operates, a buzzer
will sound and a message will be displa yed on the multi-information display to
alert the driver.
Depending on the situation, hybrid system output restriction control will operate to
either limit acceleration or restrict output as much as possible.
Displays and buzzers for hybrid sys tem output restriction control and
brake control
ControlSituationMulti-information displayICS OFFIndicatorBuzzer
Hybrid system out-
put restriction con-
trol is operating
(acceleration
restriction)Acceleration
greater than a cer-
tain amount is not
possible.“Object Detected
Acceleration
Reduced”
Not illu-
minated
Short
beep
Hybrid system out-
put restriction con-
trol is operating
(output restricted as
much as possible)Stronger-than-nor-
mal brake operation
is necessary.
“BRAKE!”
Brake control is
operatingEmergency braking
is necessary.
Vehicle stopped by
system operationThe vehicle has been
stopped by brake
control operation.
“Switch to Brake”Illumi-
nated

3474-5. Using the driving support systems
4
Driving
RX450h_RX450hL_U
If the Intelligent Clearance Sonar function detects that a collision with a wall or
other stationary object is possible, the hy brid system output will be restricted to
restrain any increase in the vehicle speed . (Hybrid system output restriction con-
trol: See A below.)
Additionally, if the accelerator pedal continues to be depressed, the brakes will
be applied automatically to reduce the vehicle speed. (Brake control: See B
below.)
Intelligent Clearance Sonar function

3484-5. Using the driving support systems
RX450h_RX450hL_U
On Off
Time
Down
OnOff
Time
On Off
Time
Down
Up
Accelerator pedal
Brake pedal
Hybrid system output
Braking force Start of control
High possibility of a collision
Extremely high possibility of a colli-
sion1
2
3
4
5
6
7

3494-5. Using the driving support systems
4
Driving
RX450h_RX450hL_U
■The Intelligent Clearance Sonar function will operate when
The function will operate when the ICS OFF indicator is not illuminated or flashing (P.
345, 353) and all of the fo llowing conditions are met:
●Hybrid system output restriction control
• The Intelligent Clearance Sonar system is enabled.
• The vehicle speed is 10 mph (15 km/h) or less.
• There is a stationary object in the traveling direction of the vehicle and 6 to 13 ft. (2
to 4 m) away.
• The system determines that a stronger-t han-normal brake operation is necessary to
avoid a collision.
●Brake control
• Hybrid system output restri ction control is operating.
• The system determines that an emergenc y brake operation is necessary to avoid a
collision.
■The Intelligent Clearance Sonar fu nction will stop operating when
The function will stop operating if an y of the following conditions are met:
●Hybrid system output restriction control
• The Intelligent Clearance Sonar system is disabled.
• The collision becomes avoidable with normal brake operation.
• The stationary object is no lo nger 6 to 13 ft. (2 to 4 m) away in the traveling direction
of the vehicle.
●Brake control
• The Intelligent Clearance Son ar system is disabled.
• Approximately 2 seconds elapse after the vehicle is stopped by brake control.
• The brake pedal is depressed after the vehicle is stopped by brake control.
• The stationary object is no lo nger 6 to 13 ft. (2 to 4 m) away in the traveling direction
of the vehicle.
■Detection range of the Intellig ent Clearance Sonar function
The detection range of the Intelligent Cleara nce Sonar function differs from the detec-
tion range of the intu itive parking assist. (P. 337)
Therefore, even if the intuitive parking assist detects an object and provides a warning,
the Intelligent Clearance Sonar function may not start operating.
■If the Intelligent Clearance Sonar function has operated
If the vehicle is stopped due to operation of the Intelligent Clearance Sonar function, the
Intelligent Clearance Sonar system will be di sabled and the ICS OFF indicator will illumi-
nate.

3504-5. Using the driving support systems
RX450h_RX450hL_U
■Re-enabling the Intelligent Clearance Sonar system
To re-enable the Intelligent Clearance Sonar system when it is disabled due to operation
of the Intelligent Clearance Sonar function, either enable the system again ( P. 345), or
turn the power switch off an d then back to ON mode.
Additionally, if the object becomes no longer in the traveling direction of the vehicle or if
the traveling direction of the vehicle change s (such as changing from moving forward to
backing up, or from backing up to moving fo rward), the system will be re-enabled auto-
matically.
■Objects that the Intelligent Clearance Sonar function may not detect
The sensors may not be able to detect certain objects, such as the following.
●Cotton cloth, snow, and other materials that are poor reflectors of ultrasonic waves.
(People may also not be detected depending on the type of clothing they are wearing.)
●Objects which are not perpendicular to the ground, are not perpendicular to the travel-
ing 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
■Intuitive parking assist buzzer
Regardless of whether the in tuitive parking assist system is enabled or not ( P. 332), if
the Intelligent Clearance Sonar system is enabled ( P. 345), 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.