sensor Lexus HS250h 2012 Owner's Guide

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2-3. Operating the lights and windshield wipers
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Washer/wiper dual operation
The wipers will automatically
operate a couple of times after
the washer squirts.
If the headlights are on, the
headlight cleaners will operate
once. (→P. 211)
Rain-sensing windshield wipers (if equipped)
When 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.
When is selected, the sensor sensitivity can be adjusted as fol-
lows by turning the switch ring:
Type A
Rain-sensing wiper
operation
Low speed wiper
operation
High speed wiper
operation
Temporary operation

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2-3. Operating the lights and windshield wipers
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When driving
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■The windshield wipers and washer can be operated when
The “POWER” switch is in ON mode.
■Effects of vehicle speed on wiper operation (vehicles with rain-sensing wind-
shield wipers)
Even when the wipers are not in AUTO mode, wiper operation varies depending
on vehicle speed when the washer is being used (delay until drip prevention wiper
sweep occurs).
■Raindrop sensor (vehicles with rain-sensing windshield wipers)
●If the wiper switch is turned to the position while the “POWER” switch is
in ON mode, the wipers will operate once to show that AUTO mode is acti-
vated.
●If the temperature of the raindrop sensor is 194 °F (90 °C) or higher, or 14 °F
(-10 °C) or lower, automatic operation may not occur. In this case, operate the
wipers in any mode other than “AUTO”.
Washer/wiper dual operation
The wipers will automatically
operate a couple of times after
the washer squirts.
(After operating several times,
the wipers operate one more
time after a short delay to pre-
vent dripping.)
If the headlights are on, the
headlight cleaners will operate
once. ( →P. 211)
●The raindrop sensor judges the amount of
raindrops.
An optical sensor is adopted. It may not
operate properly when sunlight from the
rising or setting of the sun intermittently
strikes the windshield, or if bugs etc. are
present on the windshield.

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2-3. Operating the lights and windshield wipers
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■If no windshield washer fluid sprays
Check that the washer nozzles are not blocked if there is washer fluid in the washer
fluid tank.
CAUTION
■Caution regarding the use of windshield wipers in AUTO mode (vehicles with
rain-sensing windshield wipers)
The windshield wipers may operate unexpectedly if the sensor is touched or the
windshield is subject to vibration in AUTO mode. Take care that your fingers etc. do
not become caught in the windshield wipers.
NOTICE
■When the windshield is dry
Do not use the wipers, as they may damage the windshield.
■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
Do not try to clear it with a pin or other object. The nozzle will be damaged.
■To prevent 12-volt battery discharge
Do not leave the wipers on longer than necessary when the hybrid system is off.

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2-4. Using other driving systems
2
When driving
HS250h_U_75050U
Driving in vehicle-to-vehicle distance control mode
This mode employs a radar sensor to detect the presence of vehicles up
to approximately 400 ft. (120 m) ahead, determines the current vehicle-
to-vehicle following distance, and operates to maintain a suitable follow-
ing distance from the vehicle ahead.
Note that vehicle-to-vehicle distance will close in when traveling on long
downhill slopes.
Example of constant speed cruising
When there are no vehicles ahead
The vehicle travels at the speed set by the driver. The desired vehicle-to-vehi-
cle distance can also be set by operating the vehicle-to-vehicle distance con-
trol.
Example of deceleration cruising
When the vehicle ahead is driving slower than the set speed
When a vehicle is detected running ahead of you, the system automatically
decelerates your vehicle. When a greater reduction in vehicle speed is nec-
essary, the system applies the brakes. A warning tone warns you when the
system cannot decelerate sufficiently to prevent your vehicle from closing in
on the vehicle ahead.

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2-4. Using other driving systems
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■Dynamic radar cruise control can be set when
●The shift position is in D.
●Vehicle speed is above approximately 30 mph (50 km/h).
■Accelerating after setting the vehicle speed
The vehicle can accelerate normally. After acceleration, the set speed resumes.
However, during vehicle-to-vehicle distance control mode, the vehicle speed may
decrease below the set speed in order to maintain the distance to the vehicle
ahead.
■Automatic cancelation of vehicle-to-vehicle distance control
Vehicle-to-vehicle distance control driving is automatically canceled in the follow-
ing situations:
●Actual vehicle speed falls below approximately 25 mph (40 km/h).
●Enhanced VSC is activated.
●The sensor cannot operate correctly because it is covered in some way.
●The windshield wipers are operating at high speed (when the wiper switch is set
to the AUTO mode or the high speed wiper operating position).
If vehicle-to-vehicle distance control driving is automatically canceled for any other
reason, there may be a malfunction in the system. Contact your Lexus dealer.

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2-4. Using other driving systems
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When driving
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■Automatic cancelation of constant speed control
The cruise control will stop maintaining the vehicle speed in the following situations:
●Actual vehicle speed is more than approximately 10 mph (16 km/h) below the
set vehicle speed.
At this time, the memorized set speed is not retained.
●Vehicle speed falls below approximately 25 mph (40 km/h).
●Enhanced VSC is activated.
■Radar sensor and grille cover
Always keep the sensor and grille cover clean to ensure that the vehicle-to-vehicle
distance control operates properly. (Some obstructions, such as snow, ice and plas-
tic objects, cannot be detected by the obstruction sensor.)
Dynamic radar cruise control is canceled if an obstruction is detected.
■Warning lights, messages and buzzers for dynamic radar cruise control
Warning lights, messages and buzzers are used to indicate a system malfunction or
to inform the driver of the need for caution while driving. (→P. 503, 513, 516)
Grille cover
Radar sensor

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2-4. Using other driving systems
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CAUTION
■Situations unsuitable for dynamic radar cruise control
Do not use dynamic radar cruise control in any of the following situations.
Doing so may result in inappropriate speed control and could cause an accident
resulting in death or serious injury.
●In heavy traffic
●On roads with sharp bends
●On winding roads
●On slippery roads, such as those covered with rain, ice and snow
●On steep downhills, or where there are sudden changes between sharp up and
down gradients
Vehicle speed may exceed the set speed when driving down a steep hill.
●At entrances to expressways
●When weather conditions are bad enough that they may prevent the sensors
from functioning correctly (fog, snow, sandstorm, heavy rain, etc.)
●When an approach warning buzzer is heard often
■When the sensor may not be correctly detecting the vehicle ahead
Apply the brakes as necessary when any of the following types of vehicles are in
front of you.
As the sensor may not be able to correctly detect these types of vehicles, the
approach warning (→P. 222) will not be activated, and a fatal or serious accident
may result.
●Vehicles that cut in suddenly
●Vehicles traveling at low speeds
●Vehicles that are not moving
●Vehicles with small rear ends (trailers with no load on board etc.)
●Motorcycles traveling in the same lane

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2-4. Using other driving systems
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When driving
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CAUTION
■Conditions under which the vehicle-to-vehicle distance control may not function
correctly
Apply the brakes as necessary in the following conditions as the radar sensor may
not be able to correctly detect vehicles ahead, and a fatal or serious accident may
result:
●When water or snow thrown up by the surrounding vehicles hinders the function-
ing of the sensor
●When your vehicle is pointing upwards (caused by a heavy load in the trunk etc.)
●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 decelerates suddenly
■Handling the radar sensor
Observe the following to ensure the cruise control system can function effectively.
Otherwise, the system may not function correctly and could result in an accident.
●Keep the sensor and grille cover clean at all times.
Clean the sensor and grille cover with a soft cloth so you do not mark or damage
them.
●Do not subject the sensor or surrounding area to a strong impact.
If the sensor moves even slightly off position, the system may malfunction. If the
sensor or surrounding area is subject to a strong impact, always have the area
inspected and adjusted by a Lexus dealer.
●Do not disassemble the sensor.
●Do not attach accessories or stickers to the sensor, grille cover or surrounding
area.
●Do not modify or paint the sensor and grille cover.
●Do not replace them with non-genuine parts.

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2-4. Using other driving systems
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LKA (Lane-Keeping Assist)∗∗
: If equipped
While driving on a freeway or motor highway that has lane markers, this
system recognizes the lanes using a camera as a sensor to assist the driver
with staying in the lane. The LKA system has two functions.
■Lane departure warning function
If the system judges that the vehicle may deviate from its lane, it
alerts the driver using rapid beeping, indications on the multi-infor-
mation display, and a sensory warning
* given via the steering wheel.
*: A slight steering torque is applied for a short period of time in the
direction of the center of the lane.
■ Lane keeping assist function
This function will be active when the vehicle-to-vehicle distance
control mode of the cruise control ( →P. 216) is set with vehicle
speed above approx. 45 mph (approx. 72 km/h) and while the lane
departure warning function is active. When the lane keeping assist
function is active, a slight steering torque will be applied, to help the
driver maintain the vehicle inside the lane.

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●When the lane lines cannot be recognized while driving.
●The wiper operates continuously.
●When the lane departure warning function is activated.
The lane departure warning function will be temporarily canceled and will not
resume until a few seconds elapse after it is activated.
■No-handed driving warning
If the steering wheel is not operated for about 15 seconds on a straight road or
about 5 seconds on a curve, the buzzer will beep twice, indicators on the multi-
information display will flash, and the lane keeping assist function will be temporarily
canceled. If you drive the vehicle with your hands lightly touching the steering
wheel, this may also be detected as no-handed driving.
■When the vehicle has been parked in the sun
The LKA system functions may not be available for a while after driving has started.
In such cases, turn the LKA system off and turn it on again after normal temperature
returns. When the temperature in the cabin decreases and the temperature around
the camera sensor becomes suitable for its operation, the functions will begin to
operate.
■Warning lights and messages for LKA
Warning lights and messages are used to indicate a system malfunction or to inform
the driver of the need for caution while driving. (→P. 5 0 3 , 5 1 6 )