2010 Lexus HS250h sensor

212
2-4. Using other driving systems
HS250h_U_75033U(Canada)
■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 and plas-
tic objects, cannot be detected by the obstruction sensor.)
Dynamic radar cruise control is canceled if an obstruction is detected.
■Warning lights and messages for dynamic radar cruise control
Warning lights and messages are used to indicate a system malfunction or to inform
the driver of the need for caution while driving. (→P. 493, 502, 505)
■Approach warning
In the following instances, there is a possibility that the warnings will not occur:
●When the speed of the vehicle ahead matches or exceeds your vehicle speed
●When the vehicle ahead is traveling at an extremely slow speed
●Immediately after the cruise control speed was set
●At the instant the accelerator is applied Grille cover
Radar sensor

215
2-4. Using other driving systems
2
When driving
HS250h_U_75033U(Canada)
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
●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.)
●Where a 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. 210) 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

216
2-4. Using other driving systems
HS250h_U_75033U(Canada)
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 front grille cover clean at all times.
Clean the sensor and front 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.

217
2-4. Using other driving systems
2
When driving
HS250h_U_75033U(Canada)
LKA (Lane-Keeping Assist)∗∗
: If equipped
While driving on a freeway or motor highway that has lane markers, this
system recognizes the lanes using a camera as a sensor to assist the driver
with staying in the lane. The LKA system has two functions.
■Lane departure warning function
If the system judges that the vehicle may deviate from its lane, it
alerts the driver using rapid beeping, indications on the multi-infor-
mation display, and a sensory warning
* given via the steering wheel.
*: A slight steering torque is applied for a short period of time in the
direction of the center of the lane.
■ Lane keeping assist function
This function will be active when the vehicle-to-vehicle distance
control mode of the cruise control ( →P. 205) is set with vehicle
speed above approx. 45 mph (approx. 72 km/h) and while the lane
departure warning function is active. When the lane keeping assist
function is active, a slight steering torque will be applied, to help the
driver maintain the vehicle inside the lane.

221
2-4. Using other driving systems
2
When driving
HS250h_U_75033U(Canada)
●When the lane lines cannot be recognized while driving.
●Low speed or high speed wiper operation states.
●The no-handed driving warning activates while the lane keeping assist function
is active. (The buzzer will beep twice.)
■No-handed driving warning
If the steering wheel is not operated for about 15 seconds on a straight road or
about 5 seconds on a curve, the buzzer will beep twice, indicators on the multi-
information display will flash, and the lane keeping assist function will be temporarily
canceled. If you drive the vehicle with your hands lightly touching the steering
wheel, this may also be detected as no-handed driving.
■When the vehicle has been parked in the sun
The LKA system functions may not be available for a while after driving has started.
In such cases, turn the LKA system off and turn it on again after normal temperature
returns. When the temperature in the cabin decreases and the temperature around
the camera sensor becomes suitable for its operation, the functions will begin to
operate.
■Warning lights and messages for LKA
Warning lights and messages are used to indicate a system malfunction or to inform
the driver of the need for caution while driving. (→P. 4 9 3 , 5 0 5 )

224
2-4. Using other driving systems
HS250h_U_75033U(Canada)
NOTICE
■Camera sensor
●Keep the windshield clean at all times.
LKA performance may deteriorate due to the presence of raindrops, condensa-
tion, ice or snow on the windshield.
●Do not attach a sticker or other items to the windshield near the camera sensor.
●When adjusting the rear-view mirror, make sure that it does not block the camera
lens.
●When it is cold, using the heater with air blowing to the feet may allow the upper
part of the windshield to fog up. This will have a negative effect on the images. In
such a case, use the windshield defogger to provide warm, dry air to the wind-
shield.
●Do not place anything on the dashboard.
The camera sensor may recognize the image reflected on the windshield as lane
markers by mistake.
●Do not scratch the camera lens, or let it get dirty.
●Do not change the installation position of the camera sensor or remove it. The
direction of the camera sensor is precisely adjusted.
●Do not subject the camera sensor to strong impact or force, and do not disas-
semble the camera sensor.
Observe the following to ensure that the LKA
system functions correctly.

232
2-4. Using other driving systems
HS250h_U_75033U(Canada)
Pre-Collision System∗∗
: If equipped
When the radar sensor detects an unav oidable frontal collision, safety sys-
tems such as the brakes and seat belts are automatically engaged to lessen
impact and injuries to occupants 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 roll up 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. 74 )
However, when the TRAC/VSC systems are 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, warning 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 button.
■ Driver monitor sys tem (if equipped)
When the system determines that there is a possibility of a 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
probable collision is detected, PCS informs the driver of danger by per-
forming slight braking to provide a physically warning (pre-collision alert
braking). (→P. 2 3 4 )

233
2-4. Using other driving systems
2
When driving
HS250h_U_75033U(Canada)
Disabling pre-collision brakingPre-collision braking disabled
Pre-collision braking enabled
The “PCS” warning light will
come on when pre-collision
braking is disabled.
Radar sensorThe radar sensor detects vehicles
or other obstacles on or near the
road ahead and determines
whether a collision is imminent
based on the position, speed, and
heading of the obstacles.
For vehicles equipped with the lane
keeping assist, in addition to the
radar sensor, the vehicle uses a
lane recognition camera in order
to determine whether or not a colli-
sion is likely to occur. (→P. 2 2 4 )