2010 Lexus IS250C sensor

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2-3. Operating the lights and windshield wipers
10_IS250C/350C_U
AFS (Adaptive Front-lighting System) (vehicles with discharge headlights)
AFS (Adaptive Front-lighting System) improves visibility at intersections
and on curves by automatically adjusting the level of the headlights
according to vehicle speed and the degree of the tire angle that are con-
trolled by steering input.
Operates at speeds of 6 mph (10 km/h) or higher.
■Deactivating AFS
How to switch: →P. 3 4 9
“AFS OFF” turns on when the AFS is deactivated.
■Daytime running light system
To make your vehicle more visible to other drivers, the headlights turn on automati-
cally (at a reduced intensity) whenever the engine is started and the parking brake
is released. Daytime running lights are not designed for use at night.
■Headlight control sensor
The sensor may not function properly if an
object is placed on the sensor, or anything
that blocks the sensor is affixed to the wind-
shield.
Doing so interferes with the sensor detecting
the level of ambient light and may cause the
automatic headlight system to malfunction.

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2-3. Operating the lights and windshield wipers
2
When driving
10_IS250C/350C_U
■Automatic light off system
●When the headlights comes on: The headlights and tail lights turn off 30 sec-
onds after a door is opened and closed if the “ENGINE START STOP” switch
has been switched to ACCESSORY mode or turned OFF. (The light turns off
immediately if on the key is pressed after both side doors are locked.)
●When only the tail lights come on: The tail lights turn off automatically if the
“ENGINE START STOP” switch is switched to ACCESSORY mode or turned
OFF and driver’s door is opened.
To turn the lights on again, switch to IGNITION ON mode, or turn the light switch
off once and then back to or
.
■Automatic headlight leveling system (vehicles with discharge headlights)
The level of the headlights is automatically adjusted according to the number of
passengers and the loading condition of the vehicle to ensure that the headlights do
not interfere with other road users.
■If “AFS OFF” flashes... (vehicles with discharge headlights)
It may indicate a malfunction in the system. Contact your Lexus dealer.
■Customization that can be configured at Lexus dealer
Settings (e.g. light sensor sensitivity) can be changed.
(Customizable features →P. 5 5 7 )
NOTICE
■To prevent battery discharge
Do not leave the lights on longer than necessary when the engine is not running.

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2-3. Operating the lights and windshield wipers
10_IS250C/350C_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
When is selected, the wipers will operate automatically when
the sensor detects falling rain. The system automatically adjusts wiper
timing in according to rain volume and vehicle speed.
When is selected, the sensor sensitivity can be adjusted as fol-
lows by turning the switch ring:
Off
Rain-sensing wind-
shield wiper operation
Low speed windshield
wiper operation
High speed wind-
shield wiper operation
Temporary operation

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2-3. Operating the lights and windshield wipers
2
When driving
10_IS250C/350C_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.)

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2-3. Operating the lights and windshield wipers
10_IS250C/350C_U
■Rain drop sensor (vehicles with the rain-sensing windshield wipers)
■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 7 )
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 subject to vibration in “AUTO” mode. Take care that your fingers or
anything else do not become caught in the windshield wipers.
The sensor judges the amount of raindrops.

191
2-4. Using other driving systems
2
When driving
10_IS250C/350C_U
Driving in vehicle-to-vehicle distance control mode
This mode employs a radar sensor to detect the presence of vehicles
within 400 ft. (120 m) ahead and to judge the distance between your
vehicle and those vehicles.
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): 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)

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2-4. Using other driving systems
10_IS250C/350C_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 7 2 )
■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 be accelerated normally.
■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.

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2-4. Using other driving systems
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When driving
10_IS250C/350C_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