brake Lexus IS250C 2014 Owner's Guide

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2-4. Using other driving systems
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When driving
IS250C/350C_U
When the VSC/TRAC systems are operatingThe slip indicator light flashes to
indicate that the VSC/TRAC sys-
tems have been engaged.
■VDIM (Vehicle Dynamics Integrated Management)
Provides integrated control of the ABS, brake assist, TRAC, VSC, and
EPS systems.
Helps to maintain vehicle stability when swerving on slippery road sur-
faces by controlling the brakes, engine output and steering assist.
■PCS (Pre-Collision System) (if equipped)
→ P. 222

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2-4. Using other driving systems
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When driving
IS250C/350C_U
■When the message is displayed on the multi-information display showing that
TRAC has been disabled even if the VSC off switch has not been pressed
TRAC and hill-start assist control cannot be operated. Contact your Lexus dealer.
■Automatic reactivation of the TRAC/VSC systems
If the TRAC/VSC systems are turned off, re-starting the engine 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 and TRAC systems
●A sound may be heard from the engine compartment if the brake pedal is
depressed repeatedly 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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2-4. Using other driving systems
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Hill-start assist control
■Hill-start assist control can be operated when
●The shift lever 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
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When driving
IS250C/350C_U
■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 vehicle within approximately 2 seconds ofreleasing the brake pedal.
• The shift lever is moved to P.
• 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 the system. Contact your Lexus dealer.
CAUTION
■Hill-start assist control
●Do not overly rely on hill-start assist control. 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
IS250C/350C_U
PCS (Pre-Collision System)∗
When the radar sensor detects possibility of a frontal collision, the pre-col-
lision systems such as the brakes and seat belts are automatically engaged
in an attempt to lessen damage.
■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. 7 2 )
However, the system will not operate in the event of skidding when the
VSC systems are disabled.
■ 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. The pre-collision braking function
can be turned on and off using the satellite switch.
∗: If equipped

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2-4. Using other driving systems
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When driving
IS250C/350C_U
Disabling the pre-collision brakingThe pre-collision braking function
can be turned on and off using the
satellite switch. (→P. 366)
Press “ <” or “> ” to display the PCS
brake setting ( ). Then, press the
“ON/OFF” button in the middle of
the switch to select either “ON” or
“OFF” ( ).
It may take approximately 3 sec-
onds for the display to change after
the satellite switch is operated.
The pre-collision system warning
light flashes when “OFF” is
selected.
Radar sensor
Detects 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
■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.

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2-4. Using other driving systems
IS250C/350C_U
■The pre-collision system is operational when
●Pre-collision seat belt (type A)
• Vehicle speed is above 4 mph (5 km/h).
• The speed at which your vehicle is approaching the obstacle or the vehicle isgreater than 19 to 25 mph (30 to 40 km/h).
• The front occupants are wearing a seat belt.
●Pre-collision seat belts (type B)
• Vehicle speed exceeds 19 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 19 mph (30 km/h).
• The speed at which your vehicle is approaching the obstacle or the vehicle is greater than 19 to 25 mph (30 to 40 km/h).
• The brake pedal is depressed.
●Pre-collision braking:
• The pre-collision braking function is activated.
• Vehicle speed is above 10 mph (1 5 km/h).
• The speed at which your vehicle is approaching the obstacle or the vehicle is greater than 10 mph (15 km/h).
■Situations in which the pre-collision system does not function properly
The system may not function effectively in situations such as the following:
●On roads with sharp bends or uneven surfaces
●If a vehicle suddenly moves in front of your vehicle, such as at an intersection
●If a vehicle suddenly cuts in front of your vehicle, such as when overtaking
●In inclement weather such as heavy rain, fog, snow or sand storms
●When your vehicle is skidding with the VSC system off
●When an extreme change in vehicle height occurs
●When the axis of the radar is out of adjustment

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When driving
IS250C/350C_U
■ Conditions that may trigger the system even if there is no possibility 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 a grade separation/interchange, sign, billboard, or other structure
appears to be directly in the vehicle’s line of travel.
●When an overhead billboard or other metallic structure appears to be in the
vehicle’s direct line of travel due to driving on a hill.
●When an extreme change in vehicle height occurs
●When the axis of the radar is out of adjustment
●When passing through certain toll gates
●When driving on a bridge.
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.
■Automatic cancelation of the pre-collision system
When a malfunction occurs due to sensor contamination, etc. that results in the
sensors being unable to detect obstacles, the pre-collision system will be automati-
cally disabled. In this case, the system will not activate even if there is a collision pos-
sibility.
■When there is a malfunction in the system
Warning lights and/or warning messages will turn on or flash. ( →P. 491, 500)

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IS250C/350C_U
CAUTION
■Limitations of the pre-collision system
Do not rely on the pre-collision system. Always drive safely, taking care to observe
your surroundings and checking for any obstacles or other road hazards.
Failure to do so may cause an accident resulting in death or serious injury.
■Cautions regarding the assist contents of the system
By means of alarms and brake control, the pre-collision system is intended to assist
the driver in avoiding collisions through the process of LOOK-JUDGE-ACT. There
are limits to the degree of assistance the system can provide, so please keep in mind
the following important points.
●Assisting the driver in watching the road
The pre-collision system is only able to detect obstacles directly in front of the
vehicle, and only within a limited range. It is not a mechanism that allows careless
or inattentive driving, and it is not a system that can assist the driver in low-visibil-
ity conditions. It is still necessary for the driver to pay close attention to the vehi-
cle’s surroundings.
●Assisting the driver in making correct judgment
When attempting to estimate the possibility of a collision, the only data available
to the pre-collision system is that from obstacles it has detected directly in front of
the vehicle. Therefore, it is absolutely necessary for the driver to remain vigilant
and to determine whether or not there is a possibility of collision in any given situ-
ation.
●Assisting the driver in taking action
The pre-collision system’s braking assist feature is designed to help reduce the
severity of a collision, and so only acts when the system has judged that a collision
is unavoidable. This system by itself is not capable of automatically avoiding a col-
lision or bringing the vehicle to a stop safely. For this reason, when encountering a
dangerous situation the driver must take direct and immediate action in order to
ensure the safety of all involved.

231
2-5. Driving information
2
When driving
IS250C/350C_UAs shown in the above example, if the number of occupants increases,
the cargo and luggage load equaling the combined weight of the occu-
pants who got on later, by an amount. In other words, if an increase in the
number of occupants causes an excess of the total load capacity (com-
bined weight of occupants plus cargo and luggage load), you must
reduce the cargo and luggage on your vehicle.
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 brake or accelerator pedal and prevent the pedals from being
depressed properly, block the driver’s vision, or hit the driver or passengers,
causing an accident.
• At the feet of the driver
• On the front passenger or rear seats (when stacking items)
• On the package tray
• On the instrument panel
• On 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.