2010 Lexus IS250 sensor

170
2-3. Operating the lights and windshield wipers
IS350/250_U
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
IS350/250_U
■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
IS350/250_U
■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 4 9 )
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
IS350/250_U
Driving in vehicle-to-vehicle distance control mode
This mode employs a radar sensor to detect the presence of vehicles up
to 400 ft. (120 m) ahead of you and to judge the distance between your
vehicle and those vehicles.
Note that vehicle-to-vehicle distance will close when traveling on long
downhill slopes.
Example of constant speed cruising (when there are no vehicles
ahead): When set to 62 mph (100 km/h)
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
switch.
Example of deceleration cruising (when the vehicle ahead is driving
slower than the set speed): When fixed speed cruising is set at 62 mph
(100 km/h) and the vehicle ahead is driving at 50 mph (80 km/h)
When a vehicle is detected running ahead of you, in the same lane, the sys-
tem automatically decelerates your vehicle. When a greater reduction in
vehicle speed is necessary, the system applies the brakes. A warning tone
warns you when the system cannot decelerate sufficiently to prevent your
vehicle from closing on the vehicle ahead.
Example of follow-up cruising (when following a vehicle driving slower
than the set speed): When the speed is set to 62 mph (100 km/h) and
the vehicle ahead is driving at 50 mph (80 km/h)

184
2-4. Using other driving systems
IS350/250_U
The system continues follow-up cruising while adjusting for changes in the
speed of the vehicle ahead in order to maintain the vehicle-to-vehicle dis-
tance set by the driver.
Example of acceleration (when there are no longer vehicles driving
slower than the set speed in the lane ahead): When the speed is set to
62 mph (100 km/h) and the vehicle ahead driving at 50 mph (80
km/h) is out of the lane
When the vehicle ahead of you executes a lane change, the system slowly
accelerates until the set vehicle speed is reached. The system then returns to
fixed speed cruising.
■Dynamic radar cruise control warning lights, messages and buzzers
Warning lights, messages and buzzers are used to indicate a system malfunction or
to alert you to the need for caution while driving. ( →P. 4 8 0 )
■The dynamic radar cruise can be set when
●The shift lever is in the D position or S position. However, it cannot be set if any
of the ranges 1 through 3 has been selected.
●Vehicle speed is more than approximately 30 mph (50 km/h).
■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.
■Automatically canceling vehicle-to-vehicle distance control
Vehicle-to-vehicle distance control driving is automatically canceled in the follow-
ing situations.
●Vehicle speed falls below 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 “ECT SNOW” switch is set to snow mode.
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.

185
2-4. Using other driving systems
2
When driving
IS350/250_U
■Automatically cancelling constant speed control
The set speed is automatically canceled in the following situations.
●Actual vehicle speed is more than 10 mph (16 km/h) below the preset vehicle
speed
At this time, the memorized set speed is not retained.
●Vehicle speed falls below 25 mph (40 km/h)
●VSC is activated
■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 or plastic
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 210 ft. (65 m)
MediumApproximately 150 ft. (45 m)
ShortApproximately 100 ft. (30 m)
Grille cover
Radar sensor

188
2-4. Using other driving systems
IS350/250_U
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 control of speed 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 or snow
●On steep downhills, or where there are sudden changes between sharp up and
down gradients
●At entrances to expressways
●When weather conditions are bad enough that they may prevent the sensors
from functioning correctly (fog, snow, sandstorm, etc.)
●When a buzzer can be heard often
●When your vehicle is towing a trailer
■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 prox-
imity alarm (→P. 480) will not be activated, and an 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

189
2-4. Using other driving systems
2
When driving
IS350/250_U
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 an 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 clean at all times.
Clean the sensor and front grille 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 or surrounding area.
●Do not modify or paint the sensor and grille.
■To ensure the radar sensor functions correctly
Do not do the following to the sensor or grille cover as doing so may cause the sen-
sor not to function correctly and could result in an accident.
●Stick or attach anything to them
●Leave them dirty
●Disassemble, or subject them to strong shocks
●Modify or paint them
●Replace them with non-genuine parts