2021 TOYOTA PRIUS Owners Manual (in English)

PRIUS_OM_OM47E09U_(U)
4174-5. Using the driving support systems
4
Driving
WARNING
●Do not rely solely upon the Simple Advanced Parking Guidance Sy stem.
As with unequipped vehicles, move forward and back up carefully while
directly confirming the safety of your surroundings and the are a to the rear
of the vehicle.
● Do not back up while viewing the multi-information display. Bac king up
while only viewing the monitor screen may cause a collision or lead to an
accident, as the image displayed on the monitor screen may diff er from
actual conditions. Make sure to visually check the surrounding areas and
the area to the rear of the vehicle with and without the mirror while backing
up.
● Drive slowly while adjusting your speed by depressing the brake pedal
when backing up or moving forward.
● If it seems the vehicle may make contact with a pedestrian, ano ther vehi-
cle or any other obstacles, stop the vehicle by depressing the brake pedal,
and then press the S-APGS switch to turn off the system.
● Use the system in a parking lot with a flat surface.
● Observe the following precautions, as the steering wheel automa tically
turns during use.
• There is risk of a necktie, scarf, your arm, etc. being caught on the
steering wheel. Please do not allow your upper body to be close to the
steering wheel. Also, do not allow children close to the steeri ng wheel.
• There is a possibility of injury when the steering wheel turns if you have long fingernails.
• In case of emergency, stop the vehicle by depressing the brake pedal,
and then press the S-APGS switch to turn off the system.
● Always confirm that there is appropriate space before attemptin g to park
the vehicle and operate the system.

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PRIUS_OM_OM47E09U_(U)
4-5. Using the driving support systems
WARNING
●Do not use the system in the following situations, as the syste m may be
unable to correctly assist you in reaching the target parking s pot and may
lead to an unexpected accident.
• In an area that is not a parking lot
• A parking lot that is not paved and has no parking space lines, such as a sand or gravel parking lot
• A parking lot that has a slope or undulations in the road
• A frozen, snow-covered or slippery road
• The asphalt is melting due to hot weather
• There is an obstacle between the vehicle and the target parking spot
• Using tire chains or compact spare tire (if equipped)
● Do not use tire other than that provided by the manufacturer. The system
may not operate properly. When replacing tires, contact your Toyota
dealer.
● The system may not be able position the vehicle in the set location in the
following situations.
• The tires are extremely worn or the tire pressure is low
• The vehicle is carrying very heavy load
• The vehicle is tilted due to having luggage, etc. located on one side of
the vehicle
• There are road heaters installed in the parking lot to prevent the road
surface from freezing.
In any other situations when the set position and vehicle posit ion greatly
differ, have the vehicle inspected by your Toyota dealer.
● Make sure to observe the following precautions regarding the exit parallel
parking assist mode.
Exit parallel parking assist mode is a function used when depar ting from a
parallel parking spot. However, this function may not be usable if obsta-
cles or people are detected in front of the vehicle. Only use t his function
when departing from a parallel parking spot. In the event that the steering
control operates, either turn the system off using the S-APGS s witch or
operate the steering wheel to stop the control.
● If exit parallel parking assist mode is mistakenly used in the following situ-
ations, the vehicle may make contact with an obstacle.
The departure function is operated in a direction where an obst acle is
present, but the obstacle is not detected by the side sensors ( situations
such as when the vehicle is directly beside a pole).

PRIUS_OM_OM47E09U_(U)
4194-5. Using the driving support systems
4
Driving
WARNING
●Observe the following precautions, as the sensors may stop func tioning
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 prope rly if
subjected to an impact from strong water pressure. If the vehic le
bumper strikes something, equipment may not operate properly du e to
a sensor malfunction. Have the vehicle inspected at your Toyota dealer.
● 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. 368)
• 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 norma l).
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 road s, in areas
with tall grass, etc.
• An ultrasonic wave source is nearby, such as the horn or senso rs of
another vehicle, a motorcycle engine or the air brake of a larg e vehicle.
• Heavy rain or a water strikes the vehicle.
• The angle of the sensor may be deviated when assist control st arts
even if there is a parked vehicle in the target parking spot. Have the
vehicle inspected at your Toyota dealer.
• Do not install any accessories within the sensor detection ran ge.

420
PRIUS_OM_OM47E09U_(U)
4-5. Using the driving support systems
Driving assist systems
◆ECB (Electronically Controlled Brake System)
The electronically controlled system generates braking force co rre-
sponding to the brake operation
◆ABS (Anti-lock Brake System)
Helps to prevent wheel lock when the brakes are applied suddenl y,
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 p edal
is depressed when the system de tects a panic stop situation
◆VSC (Vehicle Stability Control)
Helps the driver to control skidding when swerving suddenly or
turning on slippery road surfaces.
◆Enhanced VSC (Enhanced Vehicle Stability Control)
Provides cooperative control of the ABS, TRAC, VSC and EPS.
Helps to maintain directional stability when swerving on slippe ry
road surfaces by controlling steering performance.
◆TRAC (Traction Control)
Helps to maintain drive power and prevent the drive wheels from
spinning when starting the vehicl e or accelerating on slippery roads
◆Active Cornering Assist (ACA)
Helps to prevent the vehicle from drifting to the outer side by per-
forming inner wheel brake control when attempting to accelerate
while turning
To keep driving safety and perf ormance, the following systems
operate automatically in respon se to various driving situations.
Be aware, however, that these systems are supplementary and
should not be relied upon too heav ily when operating the vehi-
cle.

PRIUS_OM_OM47E09U_(U)
4214-5. Using the driving support systems
4
Driving
◆Hill-start assist control
Helps to reduce the backward movement of the vehicle when start -
ing on an uphill
◆EPS (Electric Power Steering)
Employs an electric motor to reduce the amount of effort needed to
turn the steering wheel
◆E-Four (Electronic On-Demand AWD system) (AWD models)
Automatically switches from fron t-wheel drive to all-wheel drive
(AWD) according to the driving conditions, helping to ensure re li-
able handling and stability. Ex amples of conditions where the s ys-
tem will switch to AWD are when cornering, going uphill, starting off
or accelerating, and when the road surface is slippery due to s now,
rain, etc.
The slip indicator light will flash
while the TRAC/VSC/ABS sys-
tems are operating.
When the TRAC/VSC/ABS systems are operating

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PRIUS_OM_OM47E09U_(U)
4-5. Using the driving support systems
If the vehicle gets stuck in mud, dirt or snow, the TRAC system may
reduce power from the hybrid system to the wheels. Pressing
to turn the system off may make it easier for you to rock the vehicle in
order to free it.
To turn the TRAC system off,
quickly press and release
.
The “Traction Control Turned Off”
will be shown on the multi-informa-
tion display.
Press
again to turn the sys-
tem back on.
■ Turning off both TRAC and VSC systems
To turn the TRAC and VSC systems off, press and hold for more than
3 seconds while the vehicle is stopped.
The VSC OFF indicator will come on and the “Traction Control Tu rned Off”
will be shown on the multi-information display.
*
Press again to turn the systems back on.
*: On vehicles with pre-collision system, pre-collision brake ass ist and pre-
collision braking will also be disabled. The PCS warning light will come on
and the message will be shown on the multi-information display. ( P. 593)
■ When the message is displayed on the multi-information display show-
ing that TRAC has been disab led even if has not been pressed
TRAC is temporary deactivated. If the information continues to show, contact
your Toyota dealer.
■ Operating conditions of hill-start assist control
When the following four conditions are met, the hill-start assi st control will
operate:
● The shift position is in a position other than P or N (when sta rting off forward/
backward on an upward incline)
● The vehicle is stopped
● The accelerator pedal is not depressed
● The parking brake is not engaged
Disabling the TRAC system

PRIUS_OM_OM47E09U_(U)
4234-5. Using the driving support systems
4
Driving
■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 re leased.
■ Sounds and vibrations caused by the ABS, brake assist, VSC, TRAC 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 mal function has
occurred in any of these systems.
● Any of the following conditions may occur when the above system s are
operating. None of these indicates that a malfunction has occur red.
• Vibrations may be felt through the vehicle body and steering.
• A motor sound may be heard also after the vehicle comes to a s top.
■ 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 brak e pedal
is operated.
● Motor sound of the brake system heard from the front part of th e vehicle
when the driver’s door is opened.
● Operating sound heard from the engine compartment when one or t wo min-
utes passed after the stop of the hybrid system.
■ Active Cornering Assist operation sounds and vibrations
When the Active Cornering Assist is operated, operation sounds and vibra-
tions may be generated from the brake system, but this is not a malfunction.
■ EPS operation sound
When the steering wheel is operated, a motor sound (whirring so und) may be
heard. This does not indicate a malfunction.
■ Automatic reactivation of TRAC and VSC systems
After turning the TRAC and VSC systems off, the systems will be automati-
cally re-enabled in the following situations:
● When the power switch is turned off
● If only the TRAC system is turned off, the TRAC will turn on wh en vehicle
speed increases
If both the TRAC and VSC systems are turned off, automatic re-e nabling
will not occur when vehicle speed increases.

424
PRIUS_OM_OM47E09U_(U)
4-5. Using the driving support systems
■Operating conditions of Active Cornering Assist
The system operates when the following occurs.
●TRAC/VSC can operate
● The driver is attempting to accelerate while turning
● The system detects that the vehicle is drifting to the outer si de
● The brake pedal is released
■ Reduced effectiveness of the EPS system
The effectiveness of the EPS system is reduced to prevent the s ystem from
overheating when there is frequent steering input over an exten ded period of
time. The steering wheel may feel heavy as a result. Should thi s occur, refrain
from excessive steering input or stop the vehicle and turn the hybrid system
off. The EPS system should return to normal within 10 minutes.
■ Electric power steering system wa rning light (warning buzzer)
P. 593
■ When a message related to AWD system is displayed on the multi-infor-
mation display (AWD models)
Perform the following actions.
MessageDetailsActions
“AWD System Overheated
Switching to 2WD Mode”AWD system is over-
heating.Stop the vehicle for a
certain amount of time
or drive the vehicle at
approximately 6 mph
(10 km/h) or more to
reduce the overload to
the system. Once the
display message on the
multi-information dis-
play turns off, there is
no problem continuing
to drive.
“AWD System Overheated 2WD Mode Engaged”
The vehicle switched
from all-wheel drive
(AWD) to front wheel
drive due to over-
heating.
“AWD System Malfunction
2WD Mode EngagedVisit Your Dealer”
A malfunction
occurred in the AWD
system, and the
vehicle switched to
front wheel drive.
Have the vehicle
inspected by your Toy-
ota dealer immediately.