2015 Lexus IS250 brake sensor

1744-3. Operating the lights and wipers
IS350/250_U (OM53C50U)
With the headlights on, push the
lever away from you to turn on the
high beams.
Pull the lever toward you to the center
position to turn the high beams off.
Pull the lever toward you and release
it to flash the high beams once.
You can flash the high beams with the
headlights on or off.
■Daytime running light system
●To make your vehicle more visible to other drivers, the parking lights turn on automati-
cally (at an increased intensity) whenever th e engine is started and the parking brake is
released. Daytime running lights are not designed for use at night.
●Compared to turning on the headlights, the daytime running light system offers greater
durability and consumes less electricity, so it can help improve fuel economy.
■Headlight control sensor
■Automatic light off system
When the light switch is in , or : The headlights and tail lights turn off 30
seconds after the engine switch is turned to ACCESSORY mode or turned off and a
door is opened and all of th e doors and trunk are closed. (The lights turn off immediately
if on the key is pressed twice after all the doors are closed.)
To turn the lights on again, turn the engine switch to IGNITION ON mode, or turn the
light switch off once and then back to or .
If any of the doors or trunk lid is left open , the lights automatically turn off after 20 min-
utes.
■Automatic headlight leveling system
The level of the headlights is automatically adjusted according to the number of passen-
gers and the loading condition of the vehicle to ensure that the headlights do not inter-
fere with other road users.
Turning on the high beam headlights
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2
The sensor may not function properly if an
object is placed on the sensor, or anything that
blocks the sensor is affixed to the windshield.
Doing so interferes with the sensor detecting
the level of ambient light and may cause the
automatic headlight system to malfunction.

2004-5. Using the driving support systems
IS350/250_U (OM53C50U)
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 following 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-vehicle dis-
tance can also be set by operating the vehicle-to-vehicle distance control.
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 deceler-
ates 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 suf-
ficiently to prevent your vehicle from closing in on the vehicle ahead.
Example of follow-up cruising
When following a vehicle driving slower than the set speed
The system continues follow-up cruising wh ile adjusting for changes in the speed of
the vehicle ahead in order to maintain the vehicle-to-vehicle distance set by the driver.
Example of acceleration
When there are no longer any vehicles ahead driving slower than the set
speed
The system accelerates until the set speed is reached. The system then returns to con-
stant speed cruising.
Driving in vehicle-to-vehicle distance control mode
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2064-5. Using the driving support systems
IS350/250_U (OM53C50U)
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 result-
ing 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 su dden 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
●During emergency towing
■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. 201) 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
■Conditions under which the ve hicle-to-vehicle distance control may not function cor-
rectly
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 functioning
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

2194-5. Using the driving support systems
4
Driving
IS350/250_U (OM53C50U)
■Sensor detection information
●The sensor’s detection areas are limited to the areas around the vehicle’s front corner
and rear bumpers.
●Certain vehicle conditions and the surrounding environment may affect the ability of
the sensor to correctly detect obstacles. Particular instances where this may occur are
listed below.
• There is dirt, snow or ice on the sensor . (Wiping the sensors will resolve this prob-
lem.)
• The sensor is frozen. (Thawing th e area will resolve this problem.)
In especially cold weather, if a sensor is frozen the screen may show an abnormal
display, or obstacles may not be detected.
• The sensor is covered in any way.
• The vehicle is leaning co nsiderably to one side.
• On an extremely bumpy road, on an incline, on gravel, or on grass.
• The vicinity of the vehicle is noisy due to vehicle horns, motorcycle engines, air
brakes of large vehicles, or other loud noises producing ultrasonic waves.
• There is another vehicle equipped with parking assist sensors in the vicinity.
• The sensor is coated with a sheet of spray or heavy rain.
• The vehicle is equipped with a fender pole or wireless antenna.
• Towing eyelets are installed.
• The bumper or sensor receives a strong impact.
• The vehicle is approaching a tall or curved curb.
• In harsh sunlight or intense cold weather.
• The area directly under the bumpers is not detected.
• If obstacles draw too close to the sensor.
• A non-genuine Lexus suspension (lowered suspension etc.) is installed.
• People may not be detected if they are wearing certain types of clothing.
In addition to the examples above, there are instances in which, because of their shape,
signs and other objects may be judged by the sensor to be closer than they are.
●The shape of the obstacle may prevent the sensor from detecting it. Pay particular
attention to the following obstacles:
• Wires, fences, ropes, etc.
• Cotton, snow and other materials that absorb sound waves
• Sharply-angled objects
• Low obstacles
• Tall obstacles with upper sections projecting outwards in the direction of your vehi-
cle
●The following situations may occur during use.
• Depending on the shape of the obstacle and other factors, the detection distance may shorten, or detect ion may be impossible.
• Obstacles may not be detected if they are too close to the sensor.
• There will be a short delay between obst acle detection and display. Even at slow
speeds, there is a possibility that the obstacl e will come within the sensor’s detection
areas before the display is shown and the warning beep sounds.
• Thin posts or objects lower than the sensor may not be detected when approached, even if they have been detected once.
• It might be difficult to hear beeps due to the volume of the audio system or air flow noise of the air conditioning system.

2204-5. Using the driving support systems
IS350/250_U (OM53C50U)
■If a message is displayed on the multi-information display
→ P. 4 74
■Certification
XFor vehicles sold in the U.S.A.
This device complies with Part 15 of the FCC Rules. Operation is subject to the following
two conditions; (1) This device may not cause harmful interference, and (2) this device
must accept any interference received, including interference that may cause undesired
operation.
XFor vehicles sold in Canada
This ISM device complies with Canadian ICES-001.
Cet appareil ISM est conforme a la norme NMB-001 du Canada.
CAUTION
■When using the intuitive parking assist
Observe the following precautions.
Failing to do so may result in the vehicle being unable to be driv en safely and possibly
cause an accident.
●Do not use the sensor at speeds in excess of 6 mph (10 km/h).
●The sensors’ detection areas and reaction times are limited. When moving forward or
reversing, check the areas surrounding the vehicle (especially the sides of the vehi-
cle) for safety, and drive slowly, using the brake to control the vehicle’s speed.
●Do not install accessories within the sensors’ detection areas.
NOTICE
■When using intuitive parking assist
In the following situations, the system may not function correctly due to a sensor mal-
function etc. Have the vehicle checked by your Lexus dealer.
●The intuitive parking assist operation display flashes, and a beep sounds when no
obstacles are detected.
●If the area around a sensor collides with so mething, or is subjected to strong impact.
●If the bumper or grille collides with something.
●If the display shows continuously withou t beeping, except when the buzzer mute
switch has been turned on.
●If a display error occurs, first check the sensor.
If the error occurs even when there is no ice, snow or mud on the sensor, it is likely that
the sensor is malfunctioning.
■Notes when washing the vehicle
Do not apply intensive bursts of water or steam to the sensor area.
Doing so may result in the sensor malfunctioning.

2464-5. Using the driving support systems
IS350/250_U (OM53C50U)
◆ Pre-collision warning
When a high possibility of a frontal
collision is detected, the pre-colli-
sion system warning light flashes, a
buzzer sounds and a message is
shown on the multi-information dis-
play to urge the driver to take eva-
sive action.
◆Pre-collision brake assist
When there is a high possibility of a frontal collision, the system applies
greater braking force in relation to how strongly the brake pedal is depressed.
The system may not warn the driver usin g a warning light, warning display and
buzzer when the system detects and judges braking operations.
◆Pre-collision braking
When there is a high possibility of a frontal collision, the system warns the
driver using a warning light, warning display and buzzer. If the system deter-
mines that a collision is unavoidable, the brakes are automatically applied to
reduce the collision speed.
◆Suspension control (vehicles with Adaptive Variable Suspension System)
When the system determines that there is a high possibility of a frontal colli-
sion, the operation of Adaptive Variable Suspension System ( →P. 2 4 1 ) o p t i -
mally controls the damping force of the shock absorber.
PCS (Pre-Collision System)∗
∗
: If equipped
When the radar sensor detects the possibility of a frontal collision, brakes are
automatically engaged to lessen impa ct as well as vehicle damage.
The pre-collision system can be turned on and off as necessary by operating
the switch. ( →P. 2 4 7 )

2484-5. Using the driving support systems
IS350/250_U (OM53C50U)
■The pre-collision system is operational when
The PCS OFF switch is not pressed an d the following conditions are met:
●Pre-collision warning:
• Vehicle speed is greater than about 10 mph (15 km/h).
• The speed at which your vehicle is approaching the obstacle or the vehicle running
ahead of you is greater than about 10 mph (15 km/h).
●Pre-collision brake assist:
• The VSC OFF switch is not pressed.
• Vehicle speed is greater than about 19 mph (30 km/h).
• The speed at which your vehicle is approaching the obstacle or the vehicle runningahead of you is greater than about 19 mph (30 km/h).
• The brake pedal is depressed.
●Pre-collision braking:
• The VSC OFF switch is not pressed.
• Vehicle speed is greater than about 10 mph (15 km/h).
• The speed at which your vehicle is approaching the obstacle or the vehicle running ahead of you is greater than about 10 mph (15 km/h).
●Suspension control (vehicles with Adaptive Variable Suspension System):
• Vehicle speed is greater than about 4 mph (5 km/h).
• The speed at which your vehicle is approaching the obstacle or the vehicle runningahead of you is greater than about 19 mph (30 km/h).
■Conditions that may trigger the system ev en if there is no danger of a collision
●When there is an object by the roadside at the entrance to a curve
●When passing an oncoming vehicle on a curve
●When driving over a narrow iron bridge
●When there is a metal object on the road surface
●When driving on an uneven road surface
●When passing an oncoming vehicle on a left-turn
●When your vehicle rapidly closes on the vehicle in front
●When a grade separation/interchange, sign, billboard, or other structure appears to be
directly in the vehicle’s line of travel
●When there is a metal plate in the road in front of the vehicle on a downhill slope
●When climbing a steep hill causes an overhe ad billboard or other metallic structure to
appear directly in the vehicle’s line of travel
●When driving under an overpass
●When an extreme change in vehicle height occurs
●When passing through certain toll gates
●When passing through a tunnel
●When the radar sensor moves off position due to its surrounding area being subjected
to a strong impact
When the system is activated in the situations described above, there is also a possibility
that the brakes will be applied with a force greater than normal.

2514-5. Using the driving support systems
4
Driving
IS350/250_U (OM53C50U)
CAUTION
■Limitations of the pre-collision system
Do not overly rely on the pre-collision system. Always drive safely, taking care to
observe your surroundings and checking for any obstacles or other road hazards.
Failure to do so may cause an accident resulting in death or serious injury.
■Handling the radar sensor
Observe the following to ensure the pre-collision 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 positi on, the system may malfunction. If the sen-
sor or surrounding area is subject to a strong impact, always have the area inspected
and adjusted by your Lexus dealer.
●Do not disassemble the sensor.
●Do not attach accessories or stickers to th e sensor, grille cover or surrounding area.
●Do not modify or paint the sensor and grille cover.
●Do not replace them with non-genuine parts.
■Cautions regarding the assist contents of the system
By means of alarms and brake control, the pr e-collision system is intended to assist the
driver in avoiding collisions through the process of LOOK-JUDGE-ACT. There are
limits to the degree of assistance the system can provide, so please keep in mind the
following important points.
●Assisting the driver in watching the road
The pre-collision system is only able to detect obstacles directly in front of the vehicle,
and only within a limited range. It is not a mechanism that allows careless or inatten-
tive driving, and it is not a system that can as sist the driver in low-visibility conditions. It
is still necessary for the driver to pay close attention to the vehicle’s surroundings.
●Assisting the driver in making correct judgment
When attempting to estimate the possibility of a collision, the only data available to
the pre-collision system is that from obstacles it has detected directly in front of the
vehicle. Therefore, it is absolutely necessary for the driver to remain vigilant and to
determine whether or not there is a possibility of collision in any given situation.
●Assisting the driver in taking action
The pre-collision system’s braking assist feature is designed to help reduce the sever-
ity of a collision, and so on ly acts when the system has judged that a collision is
unavoidable. This system by itself is not capable of automatically avoiding a collision
or bringing the vehicle to a stop safely. For this reason, when encountering a danger-
ous situation the driver must take direct and immediate action in order to ensure the
safety of all involved.