2010 Lexus IS250 sensor

170
2-3. Operating the lights and windshield wipers
Wash/wipe operation
Wipers operate automatically.
(After operating several times,
the wipers operate one more
time after a short delay to pre-
vent dripping.)
Rain-sensing windshield wipers
With “AUTO” selected, the wipers will operate automatically when
the sensor detects falling rain. The system automatically adjusts
wiper timing in accordance with rain.
Rain-sensing wiper operation
Low speed wiper operation
High speed wiper operation
Temporary operation

171
2-3. Operating the lights and windshield wipers
2
When driving
■The windshield wipers and washer can be operated when
The “ENGINE START STOP” switch is in IGNITION ON mode.
■Effects of vehicle speed on wiper operation
Vehicle speed affects the following even when the wipers are not in “AUTO” mode.
●Intermittent wiper interval
●Wiper operation when the washer is being used (delay until drip prevention
wiper sweep occurs)
Low speed wiper operation selected, wiper operation will be switched from low
speed to intermittent wiper operation only when the vehicle is stationary.
(However, the mode cannot be switched when the adjustment dial for the intermit-
tent wiper interval is set to the lowest setting.)
Sensor sensitivity (high)
Sensor sensitivity (low)
Wash/wipe operation
Wipers operate automatically.
(After operating several times,
the wipers operate one more
time after a short delay to pre-
vent dripping.)

172
2-3. Operating the lights and windshield wipers
■Rain drop sensor (vehicles with rain-sensing windshield wipers)
●If the wiper switch is turned to the “AUTO” position while the “ENGINE START
STOP” switch is in IGNITION ON mode, the wiper will operate once to show
that auto mode is activated.
●If the temperature of the raindrop sensor is 194°F (90°C) or higher, or -22°F
(-30°C) or lower, automatic operation may not occur. In this case, operate the
wipers in any mode other than “AUTO”.
■Outside rear view mirror defogger activation linked to windshield wiper opera-
tion
The outside rear view mirror defogger automatically turns on when you operate the
windshield wipers.
■If no windshield washer fluid sprays
Check that the washer nozzles are not blocked if there is washer fluid in the wind-
shield washer fluid reservoir.
■Customization that can be configured at Lexus dealer
Settings (e.g. drip prevention function) can be changed.
(Customizable features P. 5 5 0 )
CAUTION
■Caution regarding the use of windshield wipers in “AUTO” mode
The windshield wipers may operate unexpectedly if the sensor is touched or the
windshield is subjected vibration in “AUTO” mode. Take care that your fingers etc.
do not become caught in the windshield wipers.
●The sensor judges the amount of rain-
drops.

183
2-4. Using other driving systems
2
When driving
Driving in vehicle-to-vehicle distance control mode
This mode employs a sensor to detect the presence of vehicles up to
approximately 400 ft. (120 m) ahead and to judge the distance between
your vehicle and those the vehicle ahead of you.
Note that vehicle-to-vehicle distance will close when traveling on long down-
hill 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.

186
2-4. Using other driving systems
■Dynamic radar cruise can be set when
●The shift lever is in the D or range 4 or higher of S has been selected.
●Range 4 or higher has been selected by using the paddle shift.
(vehicles with paddle shift switch)
●Vehicle speed is above approximately 30 mph (50 km/h).
■Switching modes
The mode cannot be switched to constant speed control mode if vehicle-to-vehicle
distance control mode has been used. The mode also cannot be switched from
constant speed control to vehicle-to-vehicle distance control mode. Turn the sys-
tem off by pressing the “ON-OFF” button, and turn it on again.
■Accelerating
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).
●VSC is activated
●The sensor cannot operate correctly because it is covered in some way.
●The windshield wipers are operating at high speed.
●The driving mode select switch is set to snow mode.
●When the shift lever is in the D position and any of the ranges 1 through 3 is
selected using the “-” paddle shift switch. (vehicles with paddle shift switch)
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.

187
2-4. Using other driving systems
2
When driving
■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).
●VSC is activated.
●When the shift lever is in the D position and any of the ranges 1 through 3 is
selected using the “-” paddle shift switch. (vehicles with paddle shift switch)
■Vehicle-to-vehicle distance settings
Select a distance from the table below. Note that the distances shown correspond
to a vehicle speed of 50 mph (80 km/h). Vehicle-to-vehicle distance increases/
decreases in accordance with vehicle speed.
■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.
Distance optionsVehicle-to-vehicle distance
LongApproximately 160 f t. (50 m)
MediumApproximately 130 ft. (40 m)
ShortApproximately 100 f t. (30 m)
Grille cover
Radar sensor

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2-4. Using other driving systems
CAUTION
■To avoid inadvertent cruise control activation
Switch the cruise control off using the “ON-OFF” button when not in use.
■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 your vehicle is towing a trailer or during emergency towing
■When the radar 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. 480) 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

191
2-4. Using other driving systems
2
When driving
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:
●Keep the sensor and front grille cover clean at all times.
Clean the sensor and front 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.