2011 Lexus HS250h brake

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2-4. Using other driving systems
2
When driving
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 sp eed 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 thos e 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, sn ow, 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. 213) 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 (tra ilers with no load on board etc.)
●Motorcycles traveling in the same lane

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2-4. Using other driving systems
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 (c aused 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.

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2-4. Using other driving systems
Indication on the multi-information displayWhile the LKA system is on, the lane line display and steering wheel dis-
play (in case of lane k eeping assist 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 system, or the LKA system
functions are temporarily can-
celed.
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 system functions will be temporarily can-
celed. The functions will resume after the necessary operating conditions have
returned.
●The turn signal lever 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
pedal is released because depressing the brake pedal also cancels the dynamic
radar cruise control. (only lane departure warning function will resume)
●The vehicle speed deviates from the op erating range of the LKA system func-
tions.

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2-4. Using other driving systems
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When driving
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 6

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2-4. Using other driving systems
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When driving
■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 sy stem 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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2-4. Using other driving systems
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 br ake 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 redu ce 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 th e 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.

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2-4. Using other driving systems
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When driving
■Hill-start assist control buzzer
●When hill-start assist control is activated, the buzzer will sound once.
●In the following situations, hill-start assist control will be canceled and the
buzzer will sound twice.
• No attempt is made to drive the vehi cle within approximately 2 seconds of
releasing the brake pedal.
•Push the P position switch.
• The parking brake is applied.
• The brake pedal is depressed again.
• The brake pedal has been depressed for more than approximately 3 minutes.
■If the slip indicator comes on
It may indicate a malfunction in th e system. Contact your Lexus dealer.
CAUTION
■Hill-start assist control
●Do not overly rely on hill-start assist cont rol. Hill-start assist control may not oper-
ate effectively on extremely steep inclines or roads covered in ice.
●Unlike the parking brake, hill-start assist control is not intended to hold the vehi-
cle stationary for an extended period of time. Do not attempt to use hill-start
assist control to hold the vehicle on an incline for an extended period of time, as
doing so may lead to an accident.

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2-4. Using other driving systems
Pre-Collision System
: If equipped
When the radar sensor detects possibilit y of a frontal collision, the pre-col-
lision system 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 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 5 )
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, warning display* and buzzer. If the system
determines that a collision is unavoidable, 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 1 4 )
■Driver monitor system (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 continue s to be not facing forward, and a high
possibility of a frontal collision is dete cted, PCS informs the driver of high
possibility of a frontal collision by perf orming slight braking to provide a
physically warning (pre-collision alert braking). ( P. 2 3 8 )