high LEXUS RX450H 2019 Service Manual

2674-3. Operating the lights and wipers
4
Driving
RX450h_RX450hL_U
Operating the lever operates the wipers or washer as follows.
When “AUTO” is selected, the wipers will operate automatically when the sensor
detects falling rain. The system automatically adjusts wiper timing in accordance
with rain volume and vehicle speed.
The sensor sensitivity can be adju sted when “AUTO” is selected.
(U.S.A.) or (Canada)
Off
Rain-sensing operation
(U.S.A.) or (Canada)
Low speed operation
(U.S.A.) or (Canada)
High speed operation
(U.S.A.) or (Canada)
Temporary operation
Increases the sensitivity
Decreases the sensitivity
Windshield wipers and washer
Operating the wiper lever
1
2
3
4
5
6
7

2684-3. Operating the lights and wipers
RX450h_RX450hL_U
Washer/wiper dual opera-
tion
Pulling the lever op erates the wipers
and washer.
The wipers will automatically operate a
couple of times afte r the washer squirts.
Vehicles with headlight cleaners:
When the power switch is in ON mode
and the headlights are on, if the lever is
pulled, the headlight cleaners will oper-
ate once. After this, the headlight clean-
ers will operate every 5th time the lever
is pulled.
■The windshield wipers and washer can be operated when
The power switch is in ON mode.
■Dripping prevention wiper sweep
After washing and wiping operation several times, the wipers operate one more time
after a short delay to prevent dripping. However, this function will not operate while driv-
ing.
■Effects of vehicle speed on wiper operation
Vehicle speed affects the Intermittent wiper interval.
■Raindrop sensor
●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 activated.
●When the sensor sensitivity ring is turned toward high while in “AUTO” position, the
wipers will operate once to indicate that the sensor sensitivity 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 ar e not blocked if there is washer fluid in the washer fluid
tank.
8
●The raindrop sensor judges the amount of
raindrops.
An optical sensor is ad opted. It may not oper-
ate properly when sunlight from the rising or
setting of the sun inte rmittently strikes the
windshield, or if bugs, etc. are present on the
windshield.

279
4
Driving
RX450h_RX450hL_U4-5. Using the driving support systems
◆PCS (Pre-Collision System)

P. 286
◆LKA (Lane-Keeping Assist)
P. 297
◆Automatic High Beam
P. 262
◆Dynamic radar cruise contro l with full-speed range
 P. 306
Lexus Safety System+
The Lexus Safety System+ consists of the following drive assist systems and
contributes to a safe and comfo rtable driving experience:
WARNING
■Lexus Safety System+
The Lexus Safety System+ is designed to operate under the assumption that the driver
will drive safely, and is designed to help reduce the impact to the occupants and the
vehicle in the case of a collision or assist the driver in normal driving conditions.
As there is a limit to the degree of reco gnition accuracy and control performance that
this system can provide, do not overly rely on this system. The driver is always responsi-
ble for paying attention to the vehicle's surroundings and driving safely.

2864-5. Using the driving support systems
RX450h_RX450hL_U
PCS (Pre-Collision System)
The pre-collision system uses a radar sensor and camera sensor to detect
vehicles and pedestrians
in front of your vehicle. When the system determines
that the possibility of a frontal collision with a vehicle or pedestrian 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
determines that the possibility of a fr ontal collision with a vehicle or pedes-
trian is extremely high, the brakes are automatically applied to help avoid the
collision or help reduce the impact of the collision.
The pre-collision system can be disabled/enabled and the warning timing can
be changed. ( P. 290)

2874-5. Using the driving support systems
4
Driving
RX450h_RX450hL_U
◆Pre-collision warning
When the system determines that
the possibility of a frontal collision is
high, a buzzer will sound and a warn-
ing message 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
When the system determines that the po ssibility of a frontal collision is high,
the system warns the driver. If the syst em determines that the possibility of a
frontal collision is extremely high, the br akes are automatically applied to help
avoid the collision or reduce the collision speed.
◆Suspension control (if equipped)
When the system determines that the po ssibility of a frontal collision is high,
the Adaptive Variable Suspension System ( P. 383) will control the damp-
ing force of the shock absorbers to help maintain an appropriate vehicle pos-
ture.

2914-5. Using the driving support systems
4
Driving
RX450h_RX450hL_U
■Operational conditions
The pre-collision system is enabled and the system determines that the possibility of a
frontal collision with a vehicle or pedestrian is high.
Each function is operationa l at the following speeds:
●Pre-collision warning:
• Vehicle speed is between approximately 7 and 110 mph (10 and 180 km/h). (For
detecting a pedestrian, vehicle speed is between approximately 7 and 50 mph [10
and 80 km/h].)
• The relative speed between your vehicle and the vehicle or pedestrian ahead is approximately 7 mph (10 km/h) or more.
●Pre-collision brake assist:
• Vehicle speed is between approximately 20 and 110 mph (30 and 180 km/h). (For
detecting a pedestrian, vehicle speed is between approximately 20 and 50 mph
[30 and 80 km/h].)
• The relative speed between your vehicle and the vehicle or pedestrian ahead is
approximately 20 mph (30 km/h) or more.
●Pre-collision braking:
• Vehicle speed is between approximately 7 and 110 mph (10 and 180 km/h). (Fordetecting a pedestrian, vehicle speed is between approximately 7 and 50 mph [10
and 80 km/h].)
• The relative speed between your vehicle and the vehicle or pedestrian ahead is approximately 7 mph (10 km/h) or more.
The system may not operate in the following situations:
●If a 12-volt battery terminal has been disconnected and reconnected and then the vehi-
cle has not been driven for a certain amount of time
●If the shift lever is in R
●If VSC is disabled (only the pre-collis ion warning function will be operational)
■Pedestrian detection function
■Cancelation of the pre-collision braking
If either of the following occur while the pre-co llision braking function is operating, it will
be canceled:
●The accelerator pedal is depressed strongly.
●The steering wheel is turned sharply or abruptly.
The pre-collision system detects pedestrians
based on the size, prof
ile, and motion of a
detected object. However, a pedestrian may not
be detected depending on the surrounding
brightness and the motion, posture, and angle of
the detected object, preventing the system from
operating properly. ( P. 295)

2944-5. Using the driving support systems
RX450h_RX450hL_U
■Situations in which the system may not operate properly
●In some situations such as the following, a vehicle may not be detected by the radar
sensor and camera sensor, preventing the system from operating properly:
• If an oncoming vehicle is approaching your vehicle
• If a vehicle ahead is a motorcycle or bicycle
• When approaching the side or front of a vehicle
• If a preceding vehicle has a small rear end, such as an unloaded truck
• If a vehicle ahead is carrying a load which protrudes past its rear bumper
• If a vehicle ahead is irregularly shap ed, such as a tractor or side car
• If the sun or other light is shin ing directly on a vehicle ahead
• If a vehicle cuts in front of your ve hicle or emerges from beside a vehicle
• If a vehicle ahead makes an abrupt maneuver (such as sudden swerving, accelera-
tion or deceleration)
• When suddenly cutting behind a preceding vehicle
• When driving in inclement we ather such as heavy rain, fog, snow or a sandstorm
• When the vehicle is hit by water, sn ow, dust, etc. from a vehicle ahead
• When driving through steam or smoke
• When driving in a place where the surrounding brightness changes suddenly, such as at the entrance or exit of a tunnel
• When a very bright light, such as the sun or the headlights of on coming traffic, shines
directly into the camera sensor
• When the surrounding area is dim, such as at dawn or dusk, or while at night or in a tunnel
• If a preceding vehicle has a low rear end,
such as a low bed trailer
• If a vehicle ahead has extremely high ground clearance
• When a vehicle ahead is not directly in front of your vehicle

2954-5. Using the driving support systems
4
Driving
RX450h_RX450hL_U• 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 wheels are misaligned
• If a wiper blade is blocking the camera sensor
• The vehicle is wobbling.
• The vehicle is being driven at extremely high speeds.
• When driving on a hill
• If the radar sensor or ca mera sensor is misaligned
●In some situations such as the following, sufficient braking forc e 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
●Some pedestrians such as the following may not be detected by the radar sensor and
camera sensor, preventing the system from operating properly:
• Pedestrians shorter than approximately 3.2 ft. (1 m) or taller than approximately 6.5
ft. (2 m)
• Pedestrians wearing oversized clothing (a ra in coat, long skirt, etc.), making their sil-
houette obscure
• Pedestrians who are carrying large baggage, holding an umbrella, etc., hiding part
of their body
• Pedestrians who are bending forward or squatting
• Pedestrians who are pushing a stroller , wheelchair, bicycle or other vehicle
• Groups of pedestrians which are close together
• Pedestrians who are wearing white and look extremely bright
• Pedestrians in the dark, such as at night or while in a tunnel
• Pedestrians whose clothing appears to be nearly the same color or brightness as
their surroundings
• Pedestrians near walls, fences , guardrails, or large objects
• Pedestrians who are on a metal object (manhole cover, steel plate, etc.) on the road
• Pedestrians who are walking fast
• Pedestrians who are changing speed abruptly
• Pedestrians running out from be hind a vehicle or a large object
• Pedestrians who are extremely close to the side of the vehicle (outside rear view mirror, etc.)
• If the front of the vehicle is raised or low-
ered

2974-5. Using the driving support systems
4
Driving
RX450h_RX450hL_U
When driving on highways and freeways with white or yellow lines, this function
alerts the driver when the vehicle might depart from its lane and provides assis-
tance by operating the steering wheel to keep the vehicle in its lane. Further-
more, the system also provides steering assistance when dynamic radar cruise
control with full-speed range is operat ing to keep the vehicle in its lane.
The LKA system recognizes visible
white or yellow lines with the camera
sensor on the upper portion of the
windshield.
LKA (Lane-Keeping Assist)
Summary of functions

3004-5. Using the driving support systems
RX450h_RX450hL_U
WARNING
■Before using LKA system
Do not rely solely upon the LKA system. LKA is not a system which automatically
drives the vehicle or reduces the amount of attention that must be paid to the area in
front of the vehicle. The driver must always assume full responsibility for driving safely
by always paying careful attention to the surrounding conditions and operate the steer-
ing wheel to correct the path of the vehicle. Also, make sure to take adequate breaks
when fatigued, such as from driv ing for a long period of time.
Failure to perform appropriate driving operat ions and pay careful attention may lead to
an accident, resulting in death or serious injury.
■To avoid operating LKA by mistake
When not using the LKA system, use the LKA switch to turn the system off.
■Situations unsuitable for LKA
Do not use the LKA system in the following situations.
The system may not operate properly and lead to an accident, resulting in death or
serious injury.
●A spare tire, tire chains, etc., are equipped.
●When the tires have been excessively worn, or when the tire inflation pressure is low.
●Tires which differ by structure, manufacturer, brand or tread pattern are used.
●Objects or patterns that could be mistaken for white (yellow) lines are present on the
side of the road (guardrails, cu rbs, reflective poles, etc.).
●Vehicle is driven on a snow-covered road.
●White (yellow) lines are difficult to see due to rain, snow, fog, dust, etc.
●Asphalt repair marks, white (yellow) line marks, etc., are present due to road repair.
●Vehicle is driven in a temporary lane or restricted lane due to construction work.
●Vehicle is driven on a road surface which is slippery due to rainy weather, fallen snow,
freezing, etc.
●Vehicle is driven in traffic lanes ot her than on highways and freeways.
●Vehicle is driven in a construction zone.
●When your vehicle is towing a trailer or during emergency towing
■Preventing LKA system malfunctions and operations perf ormed by mistake
●Do not modify the headlights or place stickers, etc., on the surface of the lights.
●Do not modify the suspension etc. If the suspension etc. needs to be replaced, con-
tact your Lexus dealer.
●Do not install or place anything on the hood or grille. Also, do not install a grille guard
(bull bars, kangaroo bar, etc.).
●If your windshield needs repair s, contact your Lexus dealer.