brake Lexus IS250 2010 Owner's Guide

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2-4. Using other driving systems
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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.
• Towing eyelets are 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
■When the display flashes and a message is displayed
→ P. 4 8 0

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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)
Maintains drive power and prevents the rear wheels (2WD models) or all
wheels (AWD models) from spinning wh en starting the vehicle or acceler-
ating on slippery roads.
■ Hill-start assist control (vehicles with an automatic transmission)
Prevents the vehicle from rolling backwards when starting on an incline or
slippery slope.
■EPS (Electric Power Steering)
Employs an electric motor to reduce the amount of effort needed to turn
the steering wheel.

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When the VSC/TRAC/hill-start assist control systems are operatingIf the vehicle is in danger of slip-
ping, rolling backwards when
starting on an incline, or if the rear
wheels (2WD) or 4 wheels
(AWD) spin, the slip indicator light
flashes to indicate that the VSC/
TRAC/hill-start assist control sys-
tems have been engaged.
A buzzer (intermittent) sounds to
indicate that VSC is operating.
The stop lights and high mounted
stoplight turn on when the hill-start
assist control system is operating.
■VDIM (Vehicle Dynamics Integrated Management)
Provides integrated control of the ABS, brake assist, TRAC, VSC, hill-start
assist control, and EPS systems.
Maintains vehicle stability when swerving on slippery road surfaces by
controlling the brakes and engine output.
■PCS (Pre-Collision System) (if equipped)
→ P. 2 0 2

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■Reactivation of the TRAC/VSC systems after turning off the engine
Turning off the engine after turning off the TRAC/VSC systems will automatically
reactivate them.
■Automatic TRAC reactivation
If only the TRAC system is turned off, the TRAC system will turn on when vehicle
speed increases.
■Automatic TRAC and VSC reactivation
If the TRAC and VSC systems are turned off, the systems will not turn on even when
vehicle speed increases.
■Sounds and vibrations caused by the ABS, brake assist, VSC, TRAC and hill-start
assist control systems
●A sound may be heard from the engine compartment when the engine is
started or just after the vehicle begins to move. 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.

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■Hill-start assist control is operational when
●The shift lever is in the D or S position.
●The brake pedal is not depressed.
■EPS operation sound
When the steering wheel operates, a motor sound (whirring sound) may be heard.
This does not indicate a malfunction.
■Reduced effectiveness of EPS
The effectiveness of EPS is reduced to prevent the system from overheating 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 engine OFF. The system should return to normal within
10 minutes.
■If the slip indicator comes on
It may indicate a malfunction in the VSC, TRAC or hill start assist control function.
Contact your Lexus dealer.
CAUTION
■The ABS does not operate effectively when
●The limits of tire gripping performance have been exceeded.
●The vehicle hydroplanes while driving at high speed on the 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

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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
Safety systems such as the brakes and seat belts are automatically
engaged to lessen impact and injuries to occupants as well as vehicle dam-
age when the radar sensor detects an unavoidable frontal collision.
■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 4 )
■Pre-collision brake assist
Applies greater braking force in relation to how strongly the brake pedal is
depressed.
■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.
∗: If equipped

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■The pre-collision system is operational when
●Pre-collision seat belt (linked to the radar sensor):
• Vehicle speed is above 3 mph (5 km/h).
• The speed at which your vehicle is approaching the obstacle or oncomingvehicle exceeds 18 to 24 mph (30 to 40 km/h).
• The front occupants are wearing a seat belt.
●Pre-collision seat belts (linked to brake operation):
• Vehicle speed exceeds 18 mph (30 km/h).
• The system detects sudden braking or skidding.
• The front occupants are wearing a seat belt.
●Pre-collision brake assist:
• Vehicle speed is above 18 mph (30 km/h).
• The speed at which your vehicle is approaching the obstacle or the vehicle is greater than 18 to 24 mph (30 to 40 km/h).
• The brake pedal is depressed.
■Conditions that may trigger the system even if there is no danger of collision
●When there is an object by the roadside at the entrance to a curve
●When passing an oncoming vehicle on a curve
●When driving over a narrow iron bridge
●When there is a metal object on the road surface
●When driving on an uneven road surface
●When passing an oncoming vehicle on a left-turn
●When your vehicle rapidly closes on the vehicle in front
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. 4 7 1 , 4 8 0 )

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CAUTION
■Things that must not be carried in the trunk
The following things may cause a fire if loaded in the trunk.
●Receptacles containing gasoline
●Aerosol cans
■Storage precautions
Observe the following precautions.
Failing to do so may result in death or serious injury.
●Do not place cargo or luggage in or on the following locations as the item may
get under the clutch, brake or accelerator pedal and prevent the pedals from
being depressed properly, block the driver's vision, or hit the driver or passen-
gers, causing an accident.
• The feet of the driver
• The front passenger or rear seats (when stacking items)
• The package tray
• The instrument panel
• The dashboard
●Secure all items in the occupant compartment, as they may shift and injure some-
one during sudden braking, sudden swerving or an accident.
■Capacity and distribution
●Do not exceed the maximum axle weight rating or the total vehicle weight rating.
●Even if the total load of occupant's weight and the cargo load is less than the total
load capacity, do not apply the load unevenly. Improper loading may cause dete-
rioration of steering or braking control which may cause death or serious injury.

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2-5. Driving information
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Winter driving tips
Carry out the necessary preparations and inspections before driving the
vehicle in winter. Always drive the vehicle in a manner appropriate to the
prevailing weather conditions.
■Pre-winter preparations
● Use fluids that are appropriate to the prevailing outside tempera-
tures.
• Engine oil
• Engine coolant
• Washer fluid
● Have a service technician inspect the level and specific gravity of
battery electrolyte.
● Have the vehicle fitted with four snow tires or purchase a set of
tire chains for the rear tires.
Ensure that all tires are the specified size and the same brand, and that
chains match the size of the tires.
■Before driving the vehicle
Perform the following according to the driving conditions.
● Do not try to forcibly open a window or move a wiper that is fro-
zen. Pour warm water over the frozen area to melt the ice. Wipe
away the water immediately to prevent it from freezing.
● To ensure proper operation of the climate control system fan,
remove any snow that has accumulated on the air inlet vents in
front of the windshield.
● Remove any ice that has accumulated on the vehicle chassis.
● Periodically check for and remove any excess ice or snow that
may have accumulated in the wheel well or on the brakes.

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2-5. Driving information
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Selecting tire chainsTire chains can be mounted on 16- and 17-inch tires. They cannot be
mounted on 18-inch tires. Use the correct tire chain size when mounting
the tire chains. Chain size is regulated for each tire size. Side chain
(0.12 in. [3 mm] in diameter)
Cross chain
(0.16 in. [4 mm] in diameter)
Regulations on the use of tire chains
● Regulations regarding the use of tire chains vary according to location
and type of road. Always check local regulations before installing
chains.
● Install the chains on the rear tires.
● Retighten the chains after driving 1 /4  1 /2 mile (0.5  1.0 km).
■When driving the vehicle
Accelerate the vehicle slowly and drive at a reduced speed suitable
to road conditions.
■ When parking the vehicle
Park the vehicle and move the shift lever to P (automatic transmis-
sion) or 1 or R (manual transmission) without setting the parking
brake. The parking brake may freeze up, preventing it from being
released. If necessary, block the wheels to prevent inadvertent slid-
ing or creeping.