2010 Lexus HS250h Basic Information Before Operation / LEXUS 2010 HS250H OWNERS MANUAL (OM75006U)

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2-4. Using other driving systems
2
When driving
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 vehicl e may deviate from its lane, it
alerts the driver using rapid beepin g, 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 acti ve. 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.

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2-4. Using other driving systems
■Turning the LKA system on
The lane departure warning function and lane keeping assist func-
tion will be activated depending on the recognit ion condition of lane
markers, vehicle speed and the setting of radar cruise control (vehi-
cle-to-vehicle dist ance control mode).
Press the “LKA” switch to acti-
vate the system.
“LKA” indicator will come on.
Press the switch again to turn
the LKA system off.

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2-4. Using other driving systems
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When driving
■Operating conditions for each function
*1: Vehicle speed is between about 30 and 125 mph (48 and 200 km/h)
*2: Vehicle speed is between about 45 and 112 mph (72 and 180 km/h).
“LKA”
switchCruise control
(vehicle-to-vehicle
distance control mode)Lane departure warning
function
*1
Lane keeping
assist function*2
On
OffAv a i l a b l eNot available
On
(While cruising in vehi- cle-to-vehicle distance
control mode with the set vehicle speed
approx. 44 mph [approx. 71 km/h] or less)
Av a i l a b l eNot available
On
(While cruising in vehi- cle-to-vehicle distance
control mode with the set vehicle speed
approx. 45 mph [approx.
72 km/h] or more)
Av a i l a b l eAvailable

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2-4. Using other driving systems
Indication on the multi-information display
While the LKA system is on, the lane line display and steering wheel dis-
play (in case of lane k eeping as
sist function) are shown on the multi-infor -
mation display to inform that the LKA system is on.
Steering wheel display
The lane keeping assist function is
active.
Dynamic radar cruise control
display
Lane line display
When thin lines are shown:
A lane marker is not recognized by
the s
ystem, or the LKA system
functions are temporarily can -
celed. (When the lane keeping
as
sist function is canceled, buzzer
will beep twice.)
When solid lane lines are shown: 
The lane departure warning func -
tion is active.
■Temporary cancellation of the LKA system functions
If any of the following occurs, the LKA sy stem
functions will be temporarily can-
celed. The functions will resume after the necessary operating conditions have
re
turned.
●The turn signal le ver is operated.
●The steering wheel is turned as far as necessary to cause the vehicle to change
lanes.
●The brake pedal is depressed. 
However, the lane keeping assist function will not resume even after the brake
pe
dal is released because depressing the brake pedal also cancels the dynamic
radar cruise control. (only lane departure warning function will resume)

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2-4. Using other driving systems
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When driving
●The vehicle speed deviates from the operating range of the LKA system func-
tions.
●When the lane lines cannot be recognized while driving.
●Low speed or high speed wiper operation states. 
The buzzer may not beep when the LKA system functions are canceled
because the notification of dynamic radar cruise control cancellation takes pri-
ority over the LKA system and cancels the function.
●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 cab in decreases and the temperature around
the camera sensor becomes suitable for it s operation, the functions will begin to
operate.
■Warning lights and messages for LKA
Warning lights and messages ar e used to indicate a system malfunction or to inform
the driver of the need for caution while driving. ( P. 493, 505)

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2-4. Using other driving systems
CAUTION
■Before using the LKA system
Do not rely on the LKA system to remain within a selected lane. The LKA system is
not designed to enable inattentive driving. The steering wheel should be operated
by the driver to maintain the vehicle in a suitable position within its lane. Always
drive carefully.
■Turn the LKA off while driving in any of the following conditions:
Do not use LKA in any of the following situations. 
Otherwise, the system may not function correctly and could result in an accident.
●When driving with snow ti res, snow chains, a spare tire, or similar equipment.
●When driving with non-standard parts or aftermarket equipment installed.
(including modified tires and suspensions, etc.)
●When towing a trailer.
●When there are objects or structures alon g the roadside that might be misinter-
preted as lane markers. (such as guardrails, curb, reflector posts, etc.)
●Where there are wheel ruts, icy trademarks, etc. or if snow remains on the road
surface.
●When there are shadows on the road running parallel with lane markers, or if a
shadow covers the lane markers.
●When there are visible lines on the pavement from road repairs, or if the remains
of old lane markers are still visible on the road.
●When driving on slippery roads, such as those covered with rain, ice or snow.
●When driving in a lane other than the driving or passing lanes on a freeway or
highway.
●When driving on a road with lane closur es due to maintenance, or when driving
in a temporary lane.
●When driving on winding roads or roads that are rough or uneven.

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2-4. Using other driving systems
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When driving
NOTICE
■In the following situations, the LKA will not work, or will not perform reliably:
●When lane markers are interrupted or are not present, such as before a tollbooth.
●When lane markers are only on one side of the road.
●When driving on a sharp curve.
●When lanes are extremely narrow or extremely wide.
●When the vehicle leans to one side an unusual amount due to a heavy load or
improper tire inflation pressure.
●When the following distance between your vehicle and the vehicle ahead is
extremely short.
●When the lane markers are broken, “Botts’ dots”, or “Raised pavement marker”.
●When lane markers are obscured or partially obscured by sand, dirt, etc.
●When driving on a particularly brig ht road surface, such as concrete.
●When driving on a road surface that is bright due to reflected light.
●When driving in a location where the light level changes rapidly, such as the
entrance to or exit from a tunnel.
●When sunlight or the headlights of oncoming vehicles are shining directly into the
camera lens.
●When driving on roads that are branching or merging.
●When pavement lane markers are difficult to see due to rain, snow, fog, etc.
●When driving on a road surface that is wet due to rain, previous rainfall, standing
water, etc.
●When the vehicle experiences strong up-a nd-down motion such as when driving
on an extremely rough road or on a seam in the pavement.
●When headlight brightness is reduced du e to dirt on the lenses, or when the
headlights are misaligned.
●When driving with a strong crosswind.

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2-4. Using other driving systems
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 stro ng impact or force, and do not disas-
semble the camera sensor.
Observe the following to ensure that the LKA
system functions correctly.