2021 TOYOTA PRIUS PLUG-IN HYBRID stop start

5515-5. Using the driving support systems
Prius Plug-in Hybrid_OM_OM47D72E_(EE)
5
Driving
■When the operation is suspended
When assist control starts, the vehicle proceeds in a
direction opposite to the guidance.
Follow the guidance provided by the system
to proceed forward.
The maximum number of movements for multi-turn
maneuvering is reached during assist control, or the
target parking spot cannot be reached due to the
control being used on a road with steep grade.
Follow the assist control guidance and use
the system in a wide space that does not have
a steep grade.
MessageSituation/Handling method
MessageSituation/Handling method
The driver holds the
steering wheel during
assist control.Stop the vehicle and
rest your hands on the
steering wheel without
applying any force.
Then press the S-IPA
switch to restart assist
control.
The vehicle speed
exceeds 7 km/h
(4 mph) during assist
control.
The S-IPA switch is
pressed while assist
control is temporarily
stopped and the
steering wheel is
firmly held.Rest your hands on the
steering wheel without
applying any force.
Then stop the vehicle to
restart assist control.
The S-IPA switch is
pressed while assist
control is temporarily
stopped and the vehi-
cle is moving.

5525-5. Using the driving support systems
Prius Plug-in Hybrid_OM_OM47D72E_(EE)
Assist control is tem-
porarily stopped
(able to be restarted)Stop the vehicle and
rest your hands on the
steering wheel without
applying any force.
Then press the S-IPA
switch to restart assist
control.
The vehicle moved
too close to an obsta-
cle in front of the
vehicle.Press the S-IPA switch
after changing the shift
position to R to restart
assist control.
The vehicle moved
too close to an obsta-
cle to the rear of the
vehicle.Press the S-IPA switch
after changing the shift
position to D to restart
assist control.
MessageSituation/Handling method

5575-5. Using the driving support systems
Prius Plug-in Hybrid_OM_OM47D72E_(EE)
5
Driving
WARNING
● Observe the following precautions, as the sensors may stop functioning
properly which may lead to an accident.
• Do not subject the sensor to strong shocks by hitting it, etc. The sen-
sors may not function properly.
• When using a high-pressure washer to wash the vehicle, do not spray
water directly on the sensors. Equipment may not function properly if
subjected to an impact from strong water pressure. If the vehicle
bumper strikes something, equipment may not operate properly due to
a sensor malfunction. Have the vehicle inspected at any authorized
Toyota retailer or Toyota authoriz ed repairer, or any reliable repairer.
● In the following situations, the sensors may not operate normally and may
lead to an accident. Drive carefully.
• Obstacles cannot be detected in the side areas until a scan of the side
areas is completed. ( P. 505)
• Even after the scan of the side areas is completed, obstacles such as
other vehicles, people or animals that approach from the sides cannot
be detected.
• The sensor is frozen (if it thaws, the system returns to normal).
A warning message may display at particularly low temperatures due to
the sensor freezing and it may not detect parked vehicles.
• The sensor is blocked by someone’s hand.
• The vehicle is tilted a large amount.
• The temperature is extremely hot or cold.
• The vehicle is driven on undulating roads, slopes, gravel roads, in areas
with tall grass, etc.
• An ultrasonic wave source is nearby, such as the horn or sensors of
another vehicle, a motorcycle engine or the air brake of a large vehicle.
• Heavy rain or a water strikes the vehicle.
• The angle of the sensor may be deviated when assist control starts
even if there is a parked vehicle in the target parking spot. Have the
vehicle inspected at any authorized Toyota retailer or Toyota authorized
repairer, or any reliable repairer.
• Do not install any accessories within the sensor detection range.

5595-5. Using the driving support systems
Prius Plug-in Hybrid_OM_OM47D72E_(EE)
5
Driving
Driving assist systems
◆ECB (Electronically Controlled Brake System)
The electronically controlled system generates braking force corre-
sponding to the brake operation
◆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.
◆VSC+ (Vehicle Stability Control+)
Provides cooperative control of the ABS, TRC, VSC and EPS.
Helps to maintain directional stability when swerving on slippery
road surfaces by controlling steering performance.
◆TRC (Traction Control)
Helps to maintain drive power and prevent the drive wheels from
spinning when starting the vehicle or accelerating on slippery roads
◆Hill-start assist control
Helps to reduce the backward movement of the vehicle when start-
ing on an uphill
To keep 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 vehi-
cle.

5625-5. Using the driving support systems
Prius Plug-in Hybrid_OM_OM47D72E_(EE)
■Operating conditions of hill-start assist control
When the following four conditions are met, the hill-start assist control will
operate:
●The shift position is in a position other than P or N (when starting off forward/
backward on an upward incline)
●The vehicle is stopped
●The accelerator pedal is not depressed
●The parking brake is not engaged
■Automatic system cancelation of hill-start assist control
The hill-start assist control will turn off in any of the following situations:
●Shift the shift position to P or N
●The accelerator pedal is depressed
●The parking brake is engaged
●No more than 2 seconds have elapsed after the brake pedal is released.
■Sounds and vibrations caused by the ABS, brake assist, VSC, TRC and
hill-start assist control systems
●A sound may be heard from the engine compartment when the brake pedal
is depressed repeatedly, when the hybrid system 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
operating. 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 also after the vehicle comes to a stop.
■ECB operating sound
ECB operating sound may be heard in the following cases, but it does not
indicate that a malfunction has occurred.
●Operating sound heard from the engine compartment when the brake pedal
is operated.
●Motor sound of the brake system heard from the front part of the vehicle
when the driver’s door is opened.
●Operating sound heard from the engine compartment when one or two min-
utes passed after the stop of the hybrid system.
■EPS operation sound
When the steering wheel is operated, a motor sound (whirring sound) may be
heard. This does not indicate a malfunction.

5645-5. Using the driving support systems
Prius Plug-in Hybrid_OM_OM47D72E_(EE)
WARNING
■The ABS does not operate effectively when
● The limits of tire gripping performance have been exceeded (such as
excessively worn tires on a snow covered road).
● The vehicle hydroplanes while driving at high speed on wet or slick roads.
■ Stopping distance when the ABS is operating may exceed that of nor-
mal conditions
The ABS is not designed to shorten t he vehicle’s stopping distance. Always
maintain a safe distance from the vehicle in front of you, especially in the
following situations:
● When driving on dirt, gravel or snow-covered roads
● When driving with tire chains
● When driving over bumps in the road
● When driving over roads with potholes or uneven surfaces
■ TRC/VSC may not operate effectively when
Directional control and power may not be achievable while driving on slip-
pery road surfaces, even if the TRC/VSC system is operating. Drive the
vehicle carefully in conditions where stability and power may be lost.
■ Hill-start assist control does not operate effectively when
● Do not overly rely on hill-start assist control. Hill-start assist control may
not operate effectively on steep inclines and roads covered with ice.
● Unlike the parking brake, hill-start assist control is not intended to hold the
vehicle stationary for an extended period of time. Do not attempt to use
hill-start assist control to hold the vehicle on an incline, as doing so may
lead to an accident.
■ When the TRC/ABS/VSC is activated
The slip indicator light flashes. Always drive carefully. Reckless driving may
cause an accident. Exercise particular care when the indicator light flashes.

5796-1. Using the air conditioning system and defogger
Prius Plug-in Hybrid_OM_OM47D72E_(EE)
6
Interior features
■ Heating
● In HV mode, the gasoline engine may operate in order to extract heat from
the engine coolant via the heater.
● In EV mode, heating is done by a heat pump system.
• When the outside temperature is low or it is snowing, compared to con-
ventional vehicles, heating may be less effective and warm air may not
come out.
• If frost has formed on the outside heat exchanger, the heating perfor-
mance will decline. The frost can be removed from the outside heat
exchanger by operating the Remote Ai r Conditioning System before driv-
ing ( P. 585). When frosted over, the heating operation of the Remote
Air Conditioning System starts after defrosting.
• When is turned on, the heating is controlled optimally. Therefore,
the set heating performance may not be achieved even if the fan speed
setting is increased.
● In the following situations the gasoline engine may operate in order to
extract heat from the engine coolant via the heater even in EV mode.
• The outside temperature is approx imately -10°C (14°F) or low
• is operating
■ Using automatic mode
Fan speed is adjusted automatically according to the temperature setting and
the ambient conditions.
Therefore, the fan may stop for a while until warm or cool air is ready to flow
immediately after is pressed.
• When the outside heat exchanger is
frosted over, fan speed declines and it
may become harder to heat the inte-
rior. However, it is not a malfunction.
In this situation, the air temperature
from the outlets may not change even
though the set temperature is raised.Outside heat exchanger

5876-1. Using the air conditioning system and defogger
Prius Plug-in Hybrid_OM_OM47D72E_(EE)
6
Interior features
■When using the Remote Air Conditioning System
A charging message will be displayed on the multi-information display. Differ-
ent messages will be displayed depending on when the Remote Air Condi-
tioning System was started (after charging or during charging).
■While the Remote Air Conditioning System is operating
●Depending on the operating condition of the Remote Air Conditioning Sys-
tem, the electric fan may spin and an operating noise may be heard.
However, this does not indicate a malfunction.
●The Remote Air Conditioning System may stop operating temporarily if
other features that use electricity (for example, the seat heater, lights, wind-
shield wipers) are in operation or if the charge level of the 12-volt battery
becomes low.
●The headlights, windshield wiper, combination meter, etc. will not operate
while the Remote Air Conditioning System is operating.
■Electronic key battery depletion
P. 280
■When the electronic key battery is fully depleted
P. 688
■Customization
Setting (e.g. Operation using “A/C” on the wireless remote control) can be
changed. (Customizable features: P. 782)