brakes Lexus HS250h 2010 User Guide

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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.

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2-4. Using other driving systems
2
When driving
HS250h_U_75033U(Canada)
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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2-4. Using other driving systems
HS250h_U_75033U(Canada)
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.

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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 )

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2-4. Using other driving systems
2
When driving
HS250h_U_75033U(Canada)
●Pre-collision braking:
• The pre-collision braking off button is not pressed.
• Vehicle speed is greater than about 9 mph (15 km/h).
• The speed at which your vehicle is approaching the obstacle or the vehiclerunning ahead of you is greater than about 9 mph (15 km/h).
●Pre-collision alert braking (vehicle with driver monitor system):
• The pre-collision braking off button is not pressed.
• The system determines that the driver is not facing forward.
• Vehicle speed is greater than about 9 mph (15 km/h).
• The speed at which your vehicle is approaching the obstacle or the vehiclerunning ahead of you is greater than about 24 mph (40 km/h).
■Conditions that may trigger the system even if there is no danger of a 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 roll up 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 it.
■Obstacles not detected
The sensor cannot detect plastic obstacles such as traffic cones. There may also be
occasions when the sensor cannot detect pedestrians, animals, bicycles, motorcy-
cles, trees, or snowdrifts.
■When there is a malfunction in the system
Warning lights and/or warning messages will turn on or flash. ( →P. 493, 502, 505)

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2-4. Using other driving systems
HS250h_U_75033U(Canada)
CAUTION
■When the sensor may not be correctly detecting the vehicle ahead
Apply the brakes as necessary in any of the following situations.
●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 luggage
compartment etc.)
●Vehicles that cut in suddenly
●Vehicles with small rear ends (trailers with no load on board etc.)
●Motorcycles traveling in the same lane
■Handling the radar sensor
Observe the following to ensure the pre-collision system can function effectively:
●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 your 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.
■Determining the direction the driver is facing (vehicles with driver monitor sen-
sor)
The direction the driver is facing may not be determined correctly if the following
conditions exist:
●There is an object between the driver monitor sensor and the driver’s face, such
as when the sensor is blocked.
●A part of the driver’s face is covered.
●The sensor or the driver’s face is exposed to intense light such as sunlight.
●The driving posture is improper.

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2-5. Driving information
HS250h_U_75033U(Canada)
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/power control unit coolant
• Washer fluid
● Have the vehicle fitted with four snow tires or purchase a set of
tire chains for the front tires.
Ensure that all tires are the same size and 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.
■ When driving the vehicle
Accelerate the vehicle slowly and drive at a reduced speed suitable to the
road conditions.

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4-2. Maintenance
HS250h_U_75033U(Canada)
Vehicle interior
ItemsCheck points
Accelerator pedal
• The accelerator pedal should move smoothly (without uneven pedal
effort or catching).
Brake pedal
• Does the brake pedal move smoothly?
• Does the brake pedal have appro- priate clearance from the floor?
(→ P. 5 5 6 )
• Does the brake pedal have the cor- rect amount of free play?
(→ P. 5 5 6 )
Brakes
• The vehicle should not pull to one
side when the brakes are applied.
• The brakes should work effectively.
• The brake pedal should not feel spongy.
• The brake pedal should not get too close to the floor when the brakes
are applied.
Head restraints• Do the head restraints move smoothly and lock securely?
Hybrid transmission “Park” mecha-
nism• Can the vehicle be held securely on an incline with the shift position
in P?
Indicators/buzzers• Do the indicators and buzzers
function properly?
Lights
• Do all the lights come on?
• Are the headlights aimed cor-rectly? ( →P. 4 6 7 )

5
When trouble arises
483
5-1. Essential information
HS250h_U_75033U(Canada)
If your vehicle needs to be towed
Before towingThe following may indicate a problem with your hybrid transmission.
Contact your Lexus dealer before towing.
● The hybrid system is operating but the vehicle will not move.
● The vehicle makes an abnormal sound.
Emergency towing
If a tow truck is not available in an
emergency, your vehicle may be
temporarily towed using a cable or
chain secured to the emergency
towing eyelet(s). This should only
be attempted on hard surfaced
roads for short distances at under
18 mph (30 km/h).
A driver must be in the vehicle to
steer and operate the brakes. The
vehicle’s wheels, drive train, axles,
steering and brakes must be in
good condition.
If towing is necessary, we recommend having your vehicle towed by your
Lexus dealer or a commercial towing service, using a lift-type truck or a
flatbed truck.
Use a safety chain system for all towing, and abide by all state/provincial
and local laws.

5
When trouble arises
487
5-1. Essential information
HS250h_U_75033U(Canada)
■Before emergency towingTurn the “POWER” switch to ON mode. ( →P. 1 4 6 )
Do not turn the “POWER” switch to ACCESSORY mode.
Release the parking brake.
Change the shift position to N.
When the “POWER” switch is in ACCESSORY mode, the shift position
cannot be changed to N.
■Emergency towing eyelet location
→ P. 5 2 1
CAUTION
■Caution while towing
●Use extreme caution when towing the vehicle.
Avoid sudden starts or erratic driving maneuvers which place excessive stress on
the emergency towing eyelets and the cables or chains. Always use caution for
the surroundings and other vehicles while towing.
●Do not turn off the power switch.
This may lead to accidents as the parking lock will be engaged.
●If the hybrid system is off, the power assist for the brakes and steering will not
function, making steering and braking more difficult.
■Installing towing eyelets to the vehicle
Make sure that the towing eyelets are installed securely.
If not securely installed, the towing eyelets may come loose during towing. This may
lead to accidents that cause serious injury or even death.