2018 TOYOTA PRIUS Owners Manual (in English)

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4-5. Using the driving support systems
4
Driving
PCS (Pre-Collision System)∗
◆Pre-collision warning
When the system determines
that the possibility of a frontal
collision is high, a buzzer will
sound and a warning message
will be displayed on the multi-
information display to urge the
driver to take evasive action.
∗: If equipped
The pre-collision system uses a radar sensor and camera sen-
sor to detect vehicles and pedest rians in front of your vehicle.
When the system determines that the possibility of a frontal col-
lision with a vehicle or pedestrian is high, a warning operates to
urge the driver to take evasive action and the potential brake
pressure is increased to help the dr iver avoid the collision. If the
system determines that the possibi lity of a frontal collision with
a vehicle or pedestrian is extremely high, the brakes are auto-
matically applied to help avoid the collision or help reduce the
impact of the collision.
The pre-collision system can be disabled/enabled and the warning
timing can be changed. ( →P. 285)

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◆Pre-collision brake assist
When the system determ ines that the possibility of a frontal colli-
sion is high, the system applies gr eater braking force in relation to
how strongly the brake pedal is depressed.
◆Pre-collision braking
When the system determ ines that the possibility of a frontal colli-
sion is high, the system warns th e driver. If the system determines
that the possibility of a frontal collision is extremely high, the brakes
are automatically applied to help avoid the collision or reduce the
collision speed.

PRIUS_OM_OM47B89U_(U)
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Driving
WARNING
■Limitations of the pre-collision system
● The driver is solely responsible for safe driving. Always drive safely, taking
care to observe your surroundings.
Do not use the pre-collision system instead of normal braking operations
under any circumstances. This system will not prevent collisions or lessen
collision damage or injury in every situation. Do not overly rely on this sys-
tem. Failure to do so may lead to an accident, resulting in death or serious
injury.
● Although this system is designed to help avoid a collision or help reduce
the impact of the collision, its effectiveness may change according to vari-
ous conditions, therefore the system may not always be able to achieve
the same level of performance.
Read the following conditions carefully. Do not overly rely on this system
and always drive carefully.
• Conditions under which the system may operate even if there is no pos-
sibility of a collision: →P. 287
• Conditions under which the system may not operate properly: →P. 289
● Do not attempt to test the operation of the pre-collision system yourself, as
the system may not operate properly, possibly leading to an accident.
■ Pre-collision braking
● When the pre-collision braking function is operating, a large amount of
braking force will be applied.
● If the vehicle is stopped by the operation of the pre-collision braking func-
tion, the pre-collision braking func tion operation will be canceled after
approximately 2 seconds. Depress the brake pedal as necessary.
● The pre-collision braking function may not operate if certain operations are
performed by the driver. If the accelerator pedal is being depressed
strongly or the steering wheel is being turned, the system may determine
that the driver is taking evasive action and possibly prevent the pre-colli-
sion braking function from operating.
● In some situations, while the pre-collision braking function is operating,
operation of the function may be canceled if the accelerator pedal is
depressed strongly or the steering wheel is turned and the system deter-
mines that the driver is taking evasive action.
● If the brake pedal is being depressed, the system may determine that the
driver is taking evasive action and possibly delay the operation timing of
the pre-collision braking function.

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WARNING
■When to disable the pre-collision system
In the following situations, disable the system, as it may not operate prop-
erly, possibly leading to an accident resulting in death or serious injury:
● When the vehicle is being towed
● When your vehicle is towing another vehicle
● When transporting the vehicle via truck, boat, train or similar means of
transportation
● When the vehicle is raised on a lift with the hybrid system operating and
the tires are allowed to rotate freely
● When inspecting the vehicle using a drum tester such as a chassis dyna-
mometer or speedometer tester, or when using an on vehicle wheel bal-
ancer
● When a strong impact is applied to the front bumper or front grille, due to
an accident or other reasons
● If the vehicle cannot be driven in a stable manner, such as when the vehi-
cle has been in an accident or is malfunctioning
● When the vehicle is driven in a sporty manner or off-road
● When the tires are not properly inflated
● When the tires are very worn
● When tires of a size other than specified are installed
● When tire chains are installed
● When a compact spare tire or an emergency tire puncture repair kit is used
● If equipment (snow plow, etc.) that may obstruct the radar sensor or cam-
era sensor is temporarily installed to the vehicle

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2854-5. Using the driving support systems
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Driving
■Enabling/disabling th e pre-collision system
The pre-collision system can be enabled/disabled on ( →P. 139)
of the multi-information display.
The system is automatically enabled each time the power switch is
turned to ON mode.
If the system is disabled, the
PCS warning light will turn on.
■Changing the pre-colli sion warning timing
The pre-collision warning timi ng can be changed on ( →P. 139)
of the multi-information display.
The operation timing setting is retained when the power switch is turned
off.
Far
The warning will begin to oper-
ate earlier than with the default
timing.
Middle
This is the default setting.
Near
The warning will begin to oper-
ate later than with the default
timing.
Changing settings of th e pre-collision system
1
2
3

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■Operational conditions
The pre-collision system is enabled and the system determines that the pos-
sibility of a frontal collision wi th a vehicle or pedestrian is high.
Each function is operational at the following speeds:
● Pre-collision warning:
• Vehicle speed is between approximately 7 and 110 mph (10 and 180 km/h).
(For detecting a pedestrian, vehicle speed is between approximately 7 and
50 mph [10 and 80 km/h].)
• The relative speed between your vehicle and the vehicle or pedestrian ahead is approximately 7 mph (10 km/h) or more.
● Pre-collision brake assist:
• Vehicle speed is between approximately 20 and 110 mph (30 and 180 km/h).
(For detecting a pedestrian, vehicle speed is between approximately 20 and
50 mph [30 and 80 km/h].)
• The relative speed between your vehicle and the vehicle or pedestrian ahead is approximately 20 mph (30 km/h) or more.
● Pre-collision braking:
• Vehicle speed is between approximately 7 and 110 mph (10 and 180 km/h).
(For detecting a pedestrian, vehicle speed is between approximately 7 and
50 mph [10 and 80 km/h].)
• The relative speed between your vehicle and the vehicle or pedestrian
ahead is approximately 7 mph (10 km/h) or more.
The system may not operate in the following situations:
● If a 12-volt battery terminal has been disconnected and reconnected and
then the vehicle has not been driven for a certain amount of time
● If the shift position is in R
● If VSC is disabled (only the pre-collision warning function will be opera-
tional)
■ Pedestrian detection function
■ Cancelation of the pre-collision braking
If either of the following occur while the pre-collision braking function is oper-
ating, it will be canceled:
●The accelerator pedal is depressed strongly.
● The steering wheel is turned sharply or abruptly.
The pre-collision system detects pedestri-
ans based on the size, profile, and motion
of a detected object. However, a pedes-
trian may not be detected depending on
the surrounding brightness and the
motion, posture, and angle of the
detected object, preventing the system
from operating properly. (→P. 291)

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Driving
■Conditions under which the system ma y operate even if there is no pos-
sibility of a collision
● In some situations such as the following, the system may determine that
there is a possibility of a frontal collision and operate.
• When passing a vehicle or pedestrian
• When changing lanes while overtaking a preceding vehicle
• When overtaking a preceding vehicle that is changing lanes
• When rapidly closing on a vehicle ahead
• If the front of the vehicle is raised or lowered, such as when the road sur-
face is uneven or undulating
• When approaching objects on the roadside, such as guardrails, utility poles, trees, or walls
• When overtaking a preceding vehicle
that is making a left/right turn
• When passing a vehicle in an oncom- ing lane that is stopped to make a
right/left turn
• When driving on a road where relative location to vehicle ahead in an adja-
cent lane may change, such as on a
winding road
• When there is a vehicle, pedestrian, or object by the roadside at the
entrance of a curve

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• When driving on a narrow path surrounded by a structure, such as in a
tunnel or on an iron bridge
• When there is a metal object (manhole cover, steel plate, etc.), steps, or a protrusion on the road surface or roadside
• When rapidly closing on an electric toll gate barrier, parking area barrier, or other barrier that opens and closes
• When using an automatic car wash
• When the vehicle is hit by water, snow, dust, etc. from a vehicle ahead
• When driving through steam or smoke
• When there are patterns or paint on the road or a wall that may be mis-
taken for a vehicle or pedestrian
• When driving near an object that reflects radio waves, such as a large truck or guardrail
• When a crossing pedestrian
approaches very close to the vehicle
• When passing through a place with a low structure above the road (low ceil-
ing, traffic sign, etc.)
• When passing under an object (bill- board, etc.) at the top of an uphill road
• When driving through or under objects that may contact the vehicle,
such as thick grass, tree branches, or
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