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Driving
PCS (Pre-Collision System)
The system can detect the following:
●Vehicles
● Bicyclists
● Pedestrians
The pre-collision system uses a radar sensor and front camera
to detect objects ( P. 379) in front of the vehicle. When the sys-
tem determines that the possibility of a frontal collision with an
object is high, a warning operates to urge the driver to take e va-
sive action and the potential brake pressure is increased to he lp
the driver avoid the collision. If the system determines that t he
possibility of a frontal collision with an object is extremely high,
the brakes are automatically applied to help avoid the collisio n
or help reduce the impa ct of the collision.
The pre-collision system can b e disabled/enabled and the warnin g
timing can be changed. ( P. 3 8 3 )
Detectable objects
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5-5. Using the driving support systems
■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.
■Pre-collision brake assist
When the system determines that the possibility of a frontal colli-
sion is high, the system applies greater braking force in relat ion to
how strongly the brake pedal is depressed.
■Pre-collision braking
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 th e impact of the collision.
System functions
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PRIUS PRIME_OM_OM47E74U_(U)
3815-5. Using the driving support systems
5
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 o perations
under any circumstances. This system will not prevent collision s or lessen
collision damage or injury in every situation. Do not overly re ly on this sys-
tem. Failure to do so may lead to an accident, resulting in dea th or serious
injury.
● Although this system is designed to help avoid a collision or h elp 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. 385
• Conditions under which the system may not operate properly: P. 387
● Do not attempt to test the operation of the pre-collision syste m yourself.
Depending on the objects used for testing (dummies, cardboard o bjects
imitating detectable objects, etc.), the system may not operate properly,
possibly leading to an accident.
■ Pre-collision braking
● When the pre-collision braking function is operating, a large a mount 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 function 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 syst em 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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5-5. Using the driving support systems
■Operational conditions
The pre-collision system is enabled and the system determines that the pos-
sibility of a frontal collision with a detected object is high.
Each function is operational at the following speed
●Pre-collision warning
● Pre-collision brake assist
● Pre-collision braking
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 ti me
● If the shift position is in R
● When the VSC OFF indicator is illuminated (only the pre-collisi on warning
function will be operational)
Detectable objectsVehicle speedRelative speed between your vehicle and object
VehiclesApprox. 7 to 110 mph
(10 to 180 km/h)Approx. 7 to 110 mph
(10 to 180 km/h)
Bicyclists and pedestri-
ansApprox. 7 to 50 mph
(10 to 80 km/h)Approx. 7 to 50 mph
(10 to 80 km/h)
Detectable objectsVehicle speedRelative speed between your vehicle and object
VehiclesApprox. 20 to 110 mph
(30 to 180 km/h)Approx. 20 to 110 mph
(30 to 180 km/h)
Bicyclists and pedestri-
ansApprox. 20 to 50 mph
(30 to 80 km/h)Approx. 20 to 50 mph
(30 to 80 km/h)
Detectable objectsVehicle speedRelative speed between your vehicle and object
VehiclesApprox. 7 to 110 mph
(10 to 180 km/h)Approx. 7 to 110 mph
(10 to 180 km/h)
Bicyclists and pedestri-
ansApprox. 7 to 50 mph
(10 to 80 km/h)Approx. 7 to 50 mph
(10 to 80 km/h)
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PRIUS PRIME_OM_OM47E74U_(U)
3895-5. Using the driving support systems
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Driving
• If the wheels are misaligned
• If a wiper blade is blocking the front camera
• The vehicle is being driven at extremely high speeds
• When driving on a hill
• If the radar sensor or front camera is misaligned
● In some situations such as the following, sufficient braking fo rce may not be
obtained, preventing the system from performing properly:
• If the braking functions cannot operate to their full extent, such as when
the brake parts are extremely cold, extremely hot, or wet
• If the vehicle is not properly maintained (brakes or tires are excessively
worn, improper tire inflation pressure, etc.)
• When the vehicle is being driven on a gravel road or other sli ppery sur-
face
■ If VSC is disabled
●If VSC is disabled ( P. 498), the pre-collision brake assist and pre-collision
braking functions are also disabled.
● The PCS warning light will turn on and “VSC Turned Off Pre-Coll ision Brake
System Unavailable” will be displayed on the multi-information display.
• If the front of the vehicle is raised or
lowered
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Example of constant speed cruising
When there are no vehicles ahead
The vehicle travels at the speed set by the driver.
Example of deceleration crui sing and follow-up cruising
When a preceding vehicle driving slower than the set speed
appears
When a vehicle is detected running ahead of you, the system automatically
decelerates your vehicle. When a greater reduction in vehicle s peed is
necessary, the system applies the brakes (the stop lights will come on at
this time). The system will respond to changes in the speed of the vehicle
ahead in order to maintain the vehicle-to-vehicle distance set by the driver.
Approach warning warns you when the system cannot decelerate su ffi-
ciently to prevent your vehicle fr om closing in on the vehicle ahead.
When the vehicle ahead of you stops, your vehicle will also stop (vehicle is
stopped by system control). After the vehicle ahead starts off, pushing the
cruise control lever up or depressing the accelerator pedal (st art-off opera-
tion) will resume follow-up cruising. If the start-off operatio n is not per-
formed, system control continues to keep your vehicle stopped.
When the turn signal lever is operated and your vehicle moves to an over-
taking lane while driving at 50 mph (80 km/h) or more, the vehi cle will
accelerate to help to overtake a passing vehicle.
The system’s identification of what is an overtaking lane may b e deter-
mined solely based on the location of the steering wheel in the vehicle (left
side driver position versus right side driver position.) If the vehicle is driven
to a region where the overtaking lane is on a different side fr om where the
vehicle is normally driven, the vehicle may accelerate when the turn signal
lever is operated in the opposite direction to the overtaking l ane (e.g., if the
driver normally operates the vehicle in a region where the overtaking lane
is to the right but then drives to a region where the overtaking lane is to the
left, the vehicle may accelerate when the right turn signal is activated).
Example of acceleration
When there are no longer any preceding vehicles driving slower
than the set speed
The system accelerates until the set speed is reached. The syst em then
returns to constant speed cruising.
1
2
3
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After the vehicle ahead of you
starts off, push the lever up.
Your vehicle will also resume fol-
low-up cruising if the accelerator
pedal is depressed after the vehi-
cle ahead of you starts off.
Pulling the lever toward you
cancels the speed control.
The speed control is also canceled
when the brake pedal is
depressed.
(When the vehicle has been
stopped by system control,
depressing the brake pedal does
not cancel the setting.)
Pushing the lever up resumes the cruise control and returns veh icle
speed to the set speed.
Resuming follow-up cruising when the vehicle has been stopped
by system control (vehicle-to- vehicle distance control mode)
Canceling and resuming the speed control
1
2
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PRIUS PRIME_OM_OM47E74U_(U)
4195-5. Using the driving support systems
5
Driving
When your vehicle is too close to
a vehicle ahead, and sufficient
automatic deceleration via the
cruise control is not possible, the
display will flash and the buzzer
will sound to alert the driver. An
example of this would be if
another driver cuts in front of you
while you are following a vehicle.
Depress the brake pedal to
ensure an appropriate vehicle-to-
vehicle distance.
■Warnings may not occur when
In the following instances, war nings may not occur even when th e
vehicle-to-vehicle distance is small.
● When the speed of the preceding vehicle matches or exceeds
your vehicle speed
● When the preceding vehicle is traveling at an extremely slow
speed
● Immediately after the cruise control speed was set
● When depressing the accelerator pedal
Approach warning (vehicle-to-v ehicle distance control mode)