warning TOYOTA PRIUS PLUG-IN HYBRID 2020 Owners Manual

4455-5. Using the driving support systems
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5
Driving
RSA (Road Sign Assist)
The RSA system recognizes spe-
cific road signs using the front
camera and/or navigation system
(when speed limit information is
available) to provide information
to the driver via the display.
If the system judges that the vehicle is being driven over the speed
limit, performing prohibited actions, etc. according to the recognized
road signs, it notifies the driver through a visual notification and notifi-
cation buzzer.
Summary of function
WARNING
■ Before using the RSA
Do not rely solely upon the RSA system. RSA is a system which supports
the driver by providing information, but it is not a replacement for a driver’s
own vision and awareness. Drive safely by always paying careful attention
to the traffic rules.

4525-5. Using the driving support systems
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WARNING
■Before using dynamic radar cruise control with full-speed range
● Driving safely is the sole responsibility of the driver. Do not rely solely on
the system, and drive safely by always paying careful attention to your sur-
roundings.
● The dynamic radar cruise control with full-speed range provides driving
assistance to reduce the driver’s burden. However, there are limitations to
the assistance provided.
Read the following conditions carefully. Do not overly rely on this system
and always drive carefully.
• When the sensor may not be correctly detecting the vehicle ahead:
 P. 466
• Conditions under which the vehicle-to-vehicle distance control mode
may not function correctly: P. 467
● Set the speed appropriately depending on the speed limit, traffic flow, road
conditions, weather conditions, etc. The driver is responsible for checking
the set speed.
● Even when the system is functioning normally, the condition of the preced-
ing vehicle as detected by the system may differ from the condition
observed by the driver. Therefore, t he driver must always remain alert,
assess the danger of each situation and drive safely. Relying solely on this
system or assuming the system ensures safety while driving can lead to
an accident, resulting in death or serious injury.
● Switch the dynamic radar cruise control with full-speed range setting to off
using the “ON-OFF” button when not in use.

4535-5. Using the driving support systems
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Driving
WARNING
■ Cautions regarding the driving assist systems
Observe the following precautions, as there are limitations to the assistance
provided by the system.
Failure to do so may cause an accident resulting in death or serious injury.
● Assisting the driver to measure following distance
The dynamic radar cruise control with full-speed range is only intended to
help the driver in determining the fo llowing distance between the driver’s
own vehicle and a designated vehicle traveling ahead. It is not a mecha-
nism that allows careless or inattentive driving, and it is not a system that
can assist the driver in low-visibility conditions. It is still necessary for
driver to pay close attention to the vehicle’s surroundings.
● Assisting the driver to judge proper following distance
The dynamic radar cruise control with full-speed range determines
whether the following distance between the driver’s own vehicle and a
designated vehicle traveling ahead is within a set range. It is not capable
of making any other type of judgement. Therefore, it is absolutely neces-
sary for the driver to remain vigila nt and to determine whether or not there
is a possibility of danger in any given situation.
● Assisting the driver to operate the vehicle
The dynamic radar cruise control with full-speed range does not include
functions which will prevent or avoid collisions with vehicles ahead of your
vehicle. Therefore, if there is ever any possibility of danger, the driver must
take immediate and direct control of the vehicle and act appropriately in
order to ensure the safety of all involved.

4545-5. Using the driving support systems
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WARNING
■Situations unsuitable for dynamic radar cruise control with full-speed
range
Do not use dynamic radar cruise control with full-speed range in any of the
following situations.
Doing so may result in inappropriate speed control and could cause an acci-
dent resulting in death or serious injury.
● Roads where there are pedestrians, cyclists, etc.
● In heavy traffic
● On roads with sharp bends
● On winding roads
● On slippery roads, such as those covered with rain, ice or snow
● On steep downhills, or where there are sudden changes between sharp up
and down gradients
Vehicle speed may exceed the set speed when driving down a steep hill.
● At entrances to freeways and highways
● When weather conditions are bad enough that they may prevent the sen-
sors from detecting correctly (fog, snow, sandstorm, heavy rain, etc.)
● When there is rain, snow, etc. on the front surface of the radar or front
camera
● In traffic conditions that require frequent repeated acceleration and decel-
eration
● During emergency towing
● When an approach warning buzzer is heard often

4565-5. Using the driving support systems
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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 cruising 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 speed 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 suffi-
ciently to prevent your vehicle from 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 (start-off opera-
tion) will resume follow-up cruising. If the start-off operation 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 80 km/h (50 mph) or more, the vehicle will
accelerate to help to overtake a passing vehicle.
The system’s identification of what is an overtaking lane may be 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 from where the
vehicle is normally driven, the vehicle may accelerate when the turn signal
lever is operated in the opposite direction to the overtaking lane (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 system then
returns to constant speed cruising.
1
2
3

4615-5. Using the driving support systems
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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, warnings may not occur even when the
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-vehicle distance control mode)

4655-5. Using the driving support systems
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Driving
■Automatic cancelation of constant speed control mode
Constant speed control mode is automatically canceled in the following situa-
tions:
●Actual vehicle speed is more than approximately 16 km/h (10 mph) below
the set vehicle speed.
●Actual vehicle speed falls below approximately 30 km/h (20 mph).
●VSC is activated.
●TRC is activated for a period of time.
●When the VSC or TRC system is turned off.
●Pre-collision braking is activated.
If constant speed control mode is automatically canceled for any reasons
other than the above, there may be a malfunction in the system. Contact any
authorized Toyota retailer or Toyota authorized repairer, or any reliable
repairer.
■The Dynamic Radar Cruise Control with Road Sign Assist may not oper-
ate properly when
As the Dynamic Radar Cruise Control with Road Sign Assist may not oper-
ate properly in conditions in which RSA may not operate or detect correctly
(P. 449), when using this function, make sure to check the speed limit
sign displayed.
In the following situations, the set speed may not be changed to the recog-
nized speed limit by pushing the lever up or down.
●If speed limit information is not available
●When the recognized speed limit is the same as the set speed
●When the recognized speed limit is outside of the speed range that the
dynamic radar cruise control system can operate
■Brake operation
A brake operation sound may be heard and the brake pedal response may
change, but these are not malfunctions.
■Warning messages and buzzers for dynamic radar cruise control with
full-speed range
Warning messages and buzzers are used to indicate a system malfunction or
to inform the driver of the need for caution while driving. If a warning message
is shown on the multi-information display, read the message and follow the
instructions. (P. 416, 723)

4665-5. Using the driving support systems
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■When the sensor may not be correctly detecting the vehicle ahead
In the case of the following and depending on the conditions, operate the
brake pedal when deceleration of the system is insufficient or operate the
accelerator pedal when acceleration is required.
As the sensor may not be able to correctly detect these types of vehicles, the
approach warning (P. 461) may not be activated.
●Vehicles that cut in suddenly
●Vehicles traveling at low speeds
●Vehicles that are not moving in the same lane
●Vehicles with small rear ends (trailers with no load on board, etc.)
●Motorcycles traveling in the same lane
●When water or snow thrown up by the surrounding vehicles hinders the
detecting of the sensor
●When your vehicle is pointing upwards
(caused by a heavy load in the luggage
compartment, etc.)
●Preceding vehicle has an extremely high
ground clearance

4725-5. Using the driving support systems
Prius Plug-in Hybrid_OM_OM47D72E_(EE)
■Automatic speed limiter cancellation
The set speed is automatically canceled in any of the situations:
● Cruise control is activated.
● When the VSC system and/or TRC system is turned off by pressing the
VSC OFF switch.
■ If the “Check Speed Limiter System” is displayed on the multi-informa-
tion display
Stop in a safe location, turn the power switch off and back on again, and then
set the speed limiter. If the speed limiter cannot be set, the system may be
malfunctioning. Even though the vehicle can be driven normally, have the
vehicle inspected by any authorized Toyota retailer or Toyota authorized
repairer, or any reliable repairer.
WARNING
■ To avoid operating the speed limiter by mistake
Keep the speed limiter switch off when not in use.
■ Situations unsuitable for speed limiter
Do not use the speed limiter in either of the following situations.
Doing so may result in control of the vehicle being lost and could cause a
serious or fatal accident.
● On slippery roads, such as those covered with rain, ice or snow
● On steep hills
NOTICE
When a warning is issued using the meter display and buzzer after exceed-
ing the set speed limit on a steep decline, depress the brake pedal to decel-
erate.

4885-5. Using the driving support systems
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WARNING
■Handling the radar sensor
● Keep the sensor and its surrounding area on the bumper clean at all times.
● Do not subject a sensor or its surrounding area on the rear bumper to a
strong impact.
If a sensor is moved even slightly off position, the system may malfunction
and vehicles may not be detected correctly.
In the following situations, have your vehicle inspected by any authorized
Toyota retailer or Toyota authorized repairer, or any reliable repairer.
• A sensor or its surrounding area is subject to a strong impact.
• If the surrounding area of a sensor is scratched or dented, or part of
them has become disconnected.
● Do not disassemble the sensor.
● Do not attach accessories or stickers to the sensor or surrounding area on
the bumper.
● Do not modify the sensor or surrounding area on the bumper.
● Do not paint the rear bumper any color other than an official Toyota color.
One Blind Spot Monitor sensor is
installed inside the left and right side of
the vehicle rear bumper respectively.
Observe the following to ensure the Blind
Spot Monitor can function correctly.