2010 Lexus HS250h Owner's Manual

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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 bright 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-and-down motion such as when driving
on an extremely rough road or on a seam in the pavement.
●When headlight brightness is reduced due to dirt on the lenses, or when the
headlights are misaligned.
●When driving with a strong crosswind.

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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.

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Driving assist systems
To help enhance driving safety and performance, the following systems
operate automatically in response to various driving situations. Be aware,
however, that these systems are supplementary and should not be relied
upon too heavily when operating the vehicle.
■ ABS (Anti-lock Brake System)
Helps to prevent wheel lock when the brakes are applied suddenly, or if
the brakes are applied while driving on a slippery road surface
■Brake assist
Generates an increased level of braking force after the brake pedal is
depressed when the system detects a panic stop situation
■VSC (Vehicle Stability Control)
Helps the driver to control skidding when swerving suddenly or turning on
slippery road surfaces
■TRAC (Traction Control)
Helps to maintain drive power and prevent the drive wheels from spinning
when starting the vehicle or accelerating on slippery roads
■EPS (Electric Power Steering)
Employs an electric motor to reduce the amount of effort needed to turn
the steering wheel
■Enhanced VSC (Enhanced vehicle stability control)
Provides cooperative control of the ABS, TRAC, VSC and EPS.
Helps to maintain directional stability when swerving on slippery road sur-
faces by controlling steering performance.
■PCS (Pre-Collision System) (if equipped)
→ P. 2 3 2

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When the VSC/TRAC systems are operatingIf the vehicle is in danger of slip-
ping or if any of the drive wheels
spins, the slip indicator light flashes
to indicate that the VSC/TRAC
systems are operating.
A buzzer (intermittent) sounds to
indicate that VSC is operating.
Disabling the TRAC/VSC systemsIf the vehicle gets stuck in fresh snow or mud, the TRAC and VSC sys-
tems may reduce power from the hybrid system to the wheels. You may
need to turn the system off to enable you to rock the vehicle in order to
free it.
■ Turning off the TRAC system only
To turn the TRAC system off,
quickly press and release the but-
ton.
A message will be shown on the
multi-information display.
Press the button again to turn the
system back on.

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Turning off both TRAC and VSC systems
To turn the TRAC and VSC sys-
tems off, press and hold the button
for more than 3 seconds while the
vehicle is stopped.
A message will be shown on the
multi-information display and
“VSC OFF” indicator will come on.
Press the button again to turn the
systems back on.
■Sounds and vibrations caused by the ABS, brake assist, VSC and TRAC
●A sound may be heard from the engine compartment when the hybrid system is
started, just after the vehicle begins to move, if the brake pedal is depressed
forcefully or repeatedly, or 1-2 minutes after the hybrid system is stopped. This
sound does not indicate that a malfunction has occurred in any of these systems.
●Any of the following conditions may occur when the above systems are operat-
ing. None of these indicates that a malfunction has occurred.
• Vibrations may be felt through the vehicle body and steering.
• A motor sound may be heard after the vehicle comes to a stop.
• The brake pedal may pulsate slightly after the ABS is activated.
• The brake pedal may move down slightly after the ABS is activated.
■EPS operation sound
When the steering wheel is operated, a motor sound (whirring sound) may be
heard. This does not indicate a malfunction.
■Reactivation of the TRAC /VSC systems
Turning off the hybrid system after turning off the TRAC/VSC systems will automat-
ically reactivate them.
■Reactivation of the TRAC system linked to vehicle speed
When only the TRAC system is turned off, the TRAC system will turn on when vehi-
cle speed increases. However, when both TRAC and VSC systems are turned off,
the systems will not turn on even when vehicle speed increases.

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■Reduced effectiveness of the EPS system
The effectiveness of the EPS system is reduced to prevent the system from over-
heating when there is frequent steering input over an extended period of time. The
steering wheel may feel heavy as a result. Should this occur, refrain from excessive
steering input or stop the vehicle and turn the hybrid system off. The EPS system
should return to normal within 10 minutes.
CAUTION
■The ABS does not operate effectively when
●Tires with inadequate gripping ability are used (such as excessively worn tires on
a snow covered road).
●The vehicle hydroplanes while driving at high speed on wet or slick road.
■Stopping distance when the ABS is operating will exceed that of normal condi-
tions
The ABS is not designed to shorten the vehicle’s stopping distance. Always main-
tain a safe distance from the vehicle in front of you in the following situations:
●When driving on dirt, gravel or snow-covered roads
●When driving with tire chains
●When driving over bumps in the road
●When driving over roads with potholes or roads with uneven surfaces
■TRAC may not operate effectively when
Directional control and power may not be achievable while driving on slippery road
surfaces, even if the TRAC system is operating.
Do not drive the vehicle in conditions where stability and power may be lost.
■When the VSC is activated
The slip indicator light flashes and a warning buzzer sounds. Always drive carefully.
Reckless driving may cause an accident. Exercise particular care when the indica-
tor light flashes and a buzzer sounds.
■When the TRAC/VSC systems are turned off
Be especially careful and drive at a speed appropriate to the road conditions. As
these are the systems to ensure vehicle stability and driving force, do not turn the
TRAC/VSC systems off unless necessary.

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CAUTION
■Replacing tires
Make sure that all tires are of the specified size, brand, tread pattern and total load
capacity. In addition, make sure that the tires are inflated to the recommended tire
inflation pressure level.
The ABS and VSC systems will not function correctly if different tires are installed
on the vehicle.
Contact your Lexus dealer for further information when replacing tires or wheels.
■Handling of tires and the suspension
Using tires with any kind of problem or modifying the suspension will affect the driv-
ing assist systems, and may cause a system to malfunction.

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Hill-start assist control
■Hill-start assist control can be operated when
●The shift position is in a position other than P.
●The parking brake is not applied.
●The accelerator pedal is not depressed.
■Hill-start assist control
●While hill-start assist control is operating, the brakes remain automatically
applied after the driver releases the brake pedal. The stop lights and the high
mounted stoplight turn on.
●Hill-start assist control operates for about 2 seconds after the brake pedal is
released.
●If the slip indicator does not flash and the buzzer does not sound when the brake
pedal is further depressed, slightly reduce the pressure on the brake pedal (do
not allow the vehicle to roll backward) and then firmly depress it again. If the sys-
tem still does not operate, check if the operating conditions explained above
have been met.
Hill-start assist control helps to prevent the vehicle from rolling backwards
when starting on an incline or slippery slope.
To engage hill-start assist con-
trol, further depress the brake
pedal when the vehicle is
stopped completely.
A buzzer will sound once to
indicate the system is activated.
The slip indicator will also start
flashing.