brake sensor Lexus IS F 2012 Owner's Manual

IS F_U
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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.

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2-3. Operating the lights and windshield wipers
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Turning on the high beam headlightsWith the headlights on, push the
lever forward to turn on the high
beams.
Pull the lever back to the center
position to turn the high beams off.
Pull the lever toward you to turn
on the high beams.
Release to turn them off. You can
flash the high beams with the head-
lights on or off.
■Daytime running light system
●To make your vehicle more visible to other drivers, the parking light turn on
automatically (at a increased intensity) whenever the 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 sensorThe 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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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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When driving
IS F_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 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 corr ectly 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. 183) 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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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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■Sensor detection information
●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.
• The sensor is frozen.
• The sensor is covered in any way.
• The vehicle is leaning considerably 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.
• A towing eyelet is 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
In addition to the examples above, there are instances in which, because of their
shapes, 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 particu-
lar attention to the following obstacles.
• Wires, fences, ropes etc.
• Cotton, snow and other materials that absorb radio waves
• Sharply-angled objects
•Low obstacles
• Tall obstacles with upper sections projecting outwards in the direction of your
vehicle
■If the display flashes and a message is displayed
→ P. 4 7 3

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2-4. Using other driving systems
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When driving
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PCS (Pre-Collision System)∗
Radar sensorDetects vehicles or other obsta-
cles on or near the road ahead and
determines whether a collision is
imminent based on the position,
speed, and heading of the obsta-
cles. Grille cover
Radar sensor
∗: If equipped
When the radar sensor detects possibility of a frontal collision, the pre-
collision system such as the brakes and seat belts are automatically
engaged to lessen impact and injuries to occupants as well as vehicle dam-
age.
■Pre-collision seat belts
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. 6 6 )
However, the system will not operate in the event of skidding when the
VSC system are disabled.
■ 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, warning display and buzzer. If the system
determines that a collision is unavoi dable, the brakes are automatically
applied to reduce the collision speed. The pre-collision braking function
can be turned on and off using the satellite switch.

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2-4. Using other driving systems
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Disabling the pre-collision braking
The pre-collision braking function
can be turned on and off using the
satellite switch. (→P. 343)
Press “ <” or “ >” to display the
“PCS BRAKE” setting ( ). Then,
press the “ON/OFF” button in the
middle of the switch to select either
“ON” or “OFF” ( ).
It may take approximately 3 sec-
onds for the display to change after
the satellite switch is operated.
The “PCS” warning light flashes
when “OFF” is selected.
■Obstacles not detected
The sensor cannot detect plastic obstacles such as pylons. There may also be occa-
sions when the sensor cannot detect pedestrians, animals, bicycles, motorcycles,
trees, or snowdrifts.

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●When an extreme change in vehicle height occurs
●When the axis of the radar is out of adjustment
●When passing through certain toll gates
●When driving on a bridge.
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.
■When there is a malfunction in the system
Warning lights and/or warning messages will turn on or flash. ( →P. 463, 473)
■Situations in which the pre-collision system does not function properly
The system may not function effectively in situations such as the following:
●On roads with sharp bends or uneven surfaces
●If a vehicle suddenly moves in front of your vehicle, such as at an intersection
●If a vehicle suddenly cuts in front of your vehicle, such as when overtaking
●In inclement weather such as heavy rain, fog, snow or sand storms
●When your vehicle is skidding with the VSC system off
●When an extreme change in vehicle height occurs
●When the axis of the radar is out of adjustment
■Automatic cancelation of the pre-collision system
When a malfunction occurs due to sensor contamination, etc. that results in the
sensors being unable to detect obstacles, the pre-collision system will be automati-
cally disabled. In this case, the system will not activate even if there is a collision pos-
sibility.

5
When trouble arises
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5-2. Steps to take in an emergency
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(Flashing and then con-tinuously on)
(Flashing)
(If equipped)Indicates that the radar
cruise control sensor is
dirty or covered with ice.
Clean the sensor.
(Flashing and then con- tinuously on)
(Flashing)
(If equipped)Indicates that the radar
cruise control system is
unable to judge vehicle-
to-vehicle distance.
• Switch the driving mode to either the normal or
“Sport” mode.
• If the windshield wipers are on, turn them off or
set them to either the
intermittent or the slow
mode.
(Flashing)
(If equipped)
Indicates that your vehi-
cle is nearing the vehicle
ahead (in radar cruise
mode).
Slow the vehicle by apply-
ing the brakes.
Wa r n i n g m e s s a g eDetailsCorrection procedure