2012 Lexus HS250h brake sensor

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Event data recorder
Your vehicle has computers that monitor and control certain aspects of your vehi-
cle. These computers assist in driving and maintaining optimal vehicle performance.
Besides storing data useful for troubleshooting, there is an event data recorder
(EDR) that records data in a crash or near crash event.
The SRS airbag sensor assembly contains the EDR. In a crash or near crash event,
this device may record the following information:
• Engine speed
• Whether the brake pedal was depressed or not
•Vehicle speed
• To what extent the accelerator pedal was depressed
• The transmission shift position
• Whether the driver and front passenger wore seat belts or not
• Driver’s seat position
• SRS airbag deployment data
• SRS airbag system diagnostic data
• Front passenger’s occupant classification
The information above is intended to be used for the purpose of improving vehicle
safety performance. Unlike general data recorders, the EDR does not record sound
data such as conversation between passengers.
●Disclosure of the EDR data
Lexus will not disclose the data recorded in an EDR to a third party except when:
• An agreement from the vehicle’s owner (or the leasing company for a leased vehicle) is obtained
• In response to an official request by the police, a court of law or a government agency
• Necessary, for use as a defense for Lexus in a law suit
However, if necessary, Lexus will:
• Use the data for research on Lexus vehicle safety performance
• Disclose the data to a third party for research purposes without disclosing details of the vehicle owner, and that only when deemed necessary
• Disclose summarized data cleared of vehicle identification information to a non-
Lexus organization for research purposes

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2-3. Operating the lights and windshield wipers
HS250h_U_75050UPress the “ENTER” switch to
change to OFF.
The “AFS OFF” indicator will come
on.
Each pressing of the switch turns
AFS on and off.
Press the menu switch to change to
the normal display.
■Daytime running light system
●To make your vehicle more visible to other drivers, the headlights turn on auto-
matically (at a reduced intensity) whenever the hybrid system is started and the
parking brake is released. Daytime running lights are not designed for use at
night.
For the U.S.A.: Daytime running lights can be turned off by operating the switch.
●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
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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2-4. Using other driving systems
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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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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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When driving
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Pre-Collision System∗∗
: If equipped
When the radar sensor detects possibility of a frontal collision, the pre-col-
lision system such as the brakes and seat belts are automatically engaged
to lessen impact as well as vehicle damage.
■Pre-collision seat belts (front seat belts only)
If the pre-collision sensor detects that a collision is unavoidable, the pre-
collision system will retract the seat belt before the collision occurs.
The same will happen if the driver makes an emergency braking or loses
control of the vehicle. ( →P. 7 8 )
However, when the VSC system is disabled, the system will not operate in
the event of skidding.
■ 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.
■Pre-collision braking
When there is a high possibility of a frontal collision, the system warns the
driver using a warning light, warnin g display* and buzzer. If the system
determines that a collision is unavoi dable, the brakes are automatically
applied to reduce the collision speed . Pre-collision braking can be dis-
abled using the pre-collision braking off switch.
*: When the pre-collision braking system activates, “BRAKE!” will appear on the multi-information display and head-up display (if equipped), and
the warning light will begin flashing rapidly. ( →P. 5 2 0 )
■Driver monitor sys tem (if equipped)
When the system determines that there is a possibility of a frontal collision,
and the driver is not facing forward, PCS warnings are given in advance to
warn the driver. If the driver continues to be not facing forward, and a high
possibility of a frontal collision is detected, PCS informs the driver of high
possibility of a frontal collision by performing slight braking to provide a
physically warning (pre-collision alert braking). ( →P. 2 4 7 )

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2-4. Using other driving systems
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When driving
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Driver monitor sensor (if equipped)The driver monitor sensor detects
the direction the driver is facing.
The system determines whether
the driver is facing forward.
■The pre-collision seat belts are operational when
Pre-collision seat belts will activate in the following situations.
●Situation 1:
• Vehicle speed is greater than 19 mph (30 km/h).
• The system detects sudden braking or skidding.
• The front occupants are wearing a seat belt.
●Situation 2:
• Vehicle speed is greater than 4 mph (5 km/h).
• The speed at which your vehicle is approaching the obstacle or the vehiclerunning ahead of you is greater than 19 mph (30 km/h).
• The front occupants are wearing a seat belt.
■The pre-collision systems (other than seat belts) are operational when
●Pre-collision brake assist:
• Vehicle speed is greater than 19 mph (30 km/h).
• The speed at which your vehicle is approaching the obstacle or the vehicle running ahead of you is greater than 19 mph (30 km/h).
• The brake pedal is depressed.
●Pre-collision braking:
• The pre-collision braking off switch is not pressed.
• Vehicle speed is greater than 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 10 mph (15 km/h).

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●Pre-collision alert braking (vehicle with driver monitor system):
• The pre-collision braking off switch is not pressed.
• The system determines that the driver is not facing forward.
• Vehicle speed is greater than 10 mph (15 km/h).
• The speed at which your vehicle is approaching the obstacle or the vehiclerunning ahead of you is greater than 25 mph (40 km/h).
■Conditions that may trigger the system even if there is no possibility 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 (nose up, nose down)
●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 climbing a steep hill causes an overhead billboard or other metallic struc-
ture to appear directly in the vehicle’s line of travel
●When a railing, bar, or similar object can be seen in front of the vehicle
●When the radar sensor is out of alignment ( →P. 252)
●When passing through an overpass
When the system is activated in the situations described above, there is also a possi-
bility that the seat belts will retract quickly and the brakes will be applied with a force
greater than normal. When the seat belt is locked in the retracted position, stop the
vehicle in a safe place, release the seat belt and refasten it.