Toyota Prius Prime (2020 year). Owner's manual — part 31

488

5-5. Using the driving support systems

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 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. 438)

• 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 your Toyota dealer.

• Do not install any accessories within the sensor detection range.

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5-5. Using the driving support systems

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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.

◆

Enhanced VSC (Enhanced Vehicle Stability Control)

Provides cooperative control of the ABS, TRAC, VSC and EPS.
Helps to maintain directional stability when swerving on slippery
road surfaces by controlling steering performance.

◆

TRAC (Traction Control)

Helps to maintain drive power and prevent the drive wheels from
spinning when starting the vehicle or accelerating on slippery roads

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.

490

5-5. Using the driving support systems

◆

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.

The slip indicator light will flash
while the TRAC/VSC/ABS sys-
tems are operating.

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.

When the TRAC/VSC/ABS systems are operating

Disabling the TRAC system

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5-5. Using the driving support systems

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■

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 light will come on and the “Traction Control Turned
Off” will be shown on the multi-information display.

*

Press

again to turn the systems back on.

*

: Pre-collision brake assist 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. 663)

■

When the message is displayed on the multi-information display show-

ing that TRAC has been disabled 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 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, 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 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.

492

5-5. Using the driving support systems

■

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.

■

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 when vehicle
speed increases
If both the TRAC and VSC systems are turned off, automatic re-enabling
will not occur when vehicle speed increases.

■

Reduced effectiveness of the EPS system
The effectiveness of the EPS system is reduced to prevent the system from
overheating when there is frequent steering input over an extended period of
time. The steering wheel may feel heavy as a result. Should this 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 warning light (warning buzzer)
P. 663

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5-5. Using the driving support systems

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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 the 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

■

TRAC/VSC may not operate effectively when
Directional control and power may not be achievable while driving on slip-
pery road surfaces, even if the TRAC/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 TRAC/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.

494

5-5. Using the driving support systems

WARNING

■

When the TRAC/VSC systems are turned off
Be especially careful and drive at a speed appropriate to the road condi-
tions. As these are the systems to help ensure vehicle stability and driving
force, do not turn the TRAC/VSC systems off unless necessary.

■

Replacing tires
Make sure that all tires are of the specified size, brand, tread pattern and
total load capacity. In addition, make sure that the tires are inflated to the
recommended tire inflation pressure level.
The ABS, TRAC and VSC systems will not function correctly if different tires
are installed on the vehicle.
Contact your Toyota dealer for further information when replacing tires or
wheels.

■

Handling of tires and the suspension
Using tires with any kind of problem or modifying the suspension will affect
the driving assist systems, and may cause a system to malfunction.

495

5-6. Driving tips

5

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Winter driving tips

● Use fluids that are appropriate to the prevailing outside tempera-

tures.

• Engine oil
• Engine/power control unit coolant
• Washer fluid

● Have a service technician inspect the condition of the 12-volt bat-

tery.

● Have the vehicle fitted with four snow tires or purchase a set of tire

chains for the front tires.

Ensure that all tires are the same size and brand, and that chains match
the size of the tires.

Perform the following according to the driving conditions:
● Do not try to forcibly open a window or move a wiper that is frozen.

Pour warm water over the frozen area to melt the ice. Wipe away
the water immediately to prevent it from freezing.

● To ensure proper operation of the climate control system fan,

remove any snow that has accumulated on the air inlet vents in
front of the windshield.

● Check for and remove any excess ice or snow that may have accu-

mulated on the exterior lights, vehicle’s roof, chassis, around the
tires or on the brakes.

● Remove any snow or mud from the bottom of your shoes before

getting in the vehicle.

Carry out the necessary preparations and inspections before
driving the vehicle in winter. Always drive the vehicle in a man-
ner appropriate to the prevailing weather conditions.

Preparation for winter

Before driving the vehicle

496

5-6. Driving tips

Accelerate the vehicle slowly, keep a safe distance between you and
the vehicle ahead, and drive at a reduced speed suitable to road con-
ditions.

Park the vehicle and shift the shift position to P and block the wheel
under the vehicle without setting the parking brake. The parking brake
may freeze up, preventing it from being released. If the vehicle is
parked without setting the parking brake, make sure to block the
wheels.
Failure to do so may be dangerous because it may cause the vehicle
to move unexpectedly, possibly leading to an accident.

Use the correct tire chain size when mounting the tire chains. Chain
size is regulated for each tire size.
Side chain

0.12 in. (3.0 mm)
1.18 in. (30.0 mm)
0.39 in. (10.0 mm)

Cross chain

0.16 in. (4.0 mm)
0.98 in. (25.0 mm)
0.55 in. (14.0 mm)

Regulations regarding the use of tire chains vary depending on loca-
tion and type of road. Always check local regulations before installing
chains.

When driving the vehicle

When parking the vehicle

Selecting tire chains

1
2
3

4
5
6

Regulations on the use of tire chains

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5-6. Driving tips

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■

Tire chain installation
Observe the following precautions when installing and removing chains:

●

Install and remove tire chains in a safe location.

●

Install tire chains on the front tires only. Do not install tire chains on the rear
tires.

●

Install tire chains on front tires as tightly as possible. Retighten chains after
driving 1/4 - 1/2 mile (0.5 - 1.0 km).

●

Install tire chains following the instructions provided with the tire chains.

■

Consumption of fuel and electricity
In cold temperatures, resistance of the parts of a vehicle (transmission, tires,
etc.) generally increases, resulting in increase of energy consumption. As a
result, fuel economy is likely to decrease.
Consumption of fuel and electricity of this vehicle is also likely to become
worse in cold temperatures.

WARNING

■

Driving with snow tires
Observe the following precautions to reduce the risk of accidents.
Failure to do so may result in a loss of vehicle control and cause death or
serious injury.

●

Use tires of the specified size.

●

Maintain the recommended level of air pressure.

●

Do not drive in excess of 75 mph (120 km/h), regardless of the type of
snow tires being used.

●

Use snow tires on all, not just some wheels.

■

Driving with tire chains
Observe the following precautions to reduce the risk of accidents.
Failure to do so may result in the vehicle being unable to be driven safely,
and may cause death or serious injury.

●

Do not drive in excess of the speed limit specified for the tire chains being
used, or 30 mph (50 km/h), whichever is lower.

●

Avoid driving on bumpy road surfaces or over potholes.

●

Avoid sudden acceleration, abrupt steering, sudden braking and shifting
operations that cause sudden engine braking.

●

Slow down sufficiently before entering a curve to ensure that vehicle con-
trol is maintained.

●

Do not use LDA (Lane Departure Alert with steering control).

■

When parking the vehicle
When parking the vehicle without applying the parking brake, make sure to
chock the wheels. If you do not chock the wheels, the vehicle may move
unexpectedly, possibly resulting in an accident.

498

5-6. Driving tips

NOTICE

■

Repairing or replacing snow tires
Request repairs or replacement of snow tires from Toyota dealers or legiti-
mate tire retailers.
This is because the removal and attachment of snow tires affects the opera-
tion of the tire pressure warning valves and transmitters.

■

Fitting tire chains
The tire pressure warning valves and transmitters may not function correctly
when tire chains are fitted.

499

6

Interior features

6-1. Using the air conditioning

system and defogger

Automatic air conditioning

system (vehicles with
7-inch display). . . . . 500

Automatic air conditioning

system (vehicles with
11.6-inch display). . . 511

Remote Air Conditioning

System . . . . . . . 522

Heated steering wheel/

seat heaters . . . . . 526

6-2. Using the interior lights

Interior lights list . . . . 528

• Front interior light. . .. 529
• Front personal lights . . 529
• Rear interior light . . .. 530

6-3. Using the storage features

List of storage features . . 531

• Glove box. . . . . .. 532
• Console box. . . . .. 532
• Cup holders . . . . .. 533
• Bottle holders/

door pockets . . . . . 534

• Auxiliary boxes. . . .. 535
• Seat back pockets . . 535

Luggage compartment

features. . . . . . ... 536

6-4. Using the other interior

features

Other interior features . ... 540

• Sun visors . . . . . . 540
• Vanity mirrors. . . . 540
• Power outlets . . . . 541
• USB charging ports. ... 542
• Wireless charger. . ... 544
• Armrest . . . . . . . 553
• Coat hooks. . . . . 553
• Assist grips . . . . ... 554

Garage door opener. . .. 555

500

6-1. Using the air conditioning system and defogger

Automatic air conditioning system (vehi-

cles with 7-inch display)

■

Adjusting the temperature setting
Move the temperature setting
knob upwards to increase the
temperature and downwards to
decreases the temperature.

If

is not pressed, the sys-

tem will blow ambient tempera-
ture air or heated air.

■

Fan speed setting
Move the fan speed setting
knob upwards to increase the
fan speed and downwards to
decrease the fan speed.

The fan speed is shown on the
display. (7 levels)

Press

to turn the fan off.

Air outlets and fan speed are automatically adjusted according
to the temperature setting.

Air conditioning controls

Temperature
setting knob

Fan speed
setting knob

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6-1. Using the air conditioning system and defogger

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■

Change the airflow mode
Move the airflow change knob
upwards or downwards to
change the airflow mode.

The air outlets used are
switched each time the knob is
operated.

Air flows to the upper body
Air flows to the upper body
and feet
Air flows to the feet
Air flows to the feet and the
windshield defogger oper-
ates

■

S-FLOW mode
In S-FLOW mode, priority for the airflow is given to the front seats,
reducing the airflow and air conditioning effect on the rear seats.
When a passenger is not detected in the front passenger seat,
depending on the set temperature and ambient temperature, prior-
ity for the airflow will be given to the driver’s seat only.

However, air will always be blown from the side outlet of the front pas-
senger seat.

The following S-FLOW modes are available:



Automatic S-FLOW mode
The system determines whether or not a rear passenger is in the
vehicle by the opening and closing of a rear door. When a rear
passenger is determined to be in the vehicle, S-FLOW mode will
be automatically disabled.
To enable S-FLOW mode again, press

and enter manual

S-FLOW mode. (

P. 507)

The

indicator will illuminate when S-FLOW mode is

enabled.

Airflow change
knob

1
2

3
4

502

6-1. Using the air conditioning system and defogger



Manual S-FLOW mode

When

is pressed, S-FLOW mode will be manually

enabled/disabled. (

P. 507)

The

indicator will illuminate when S-FLOW mode is enabled.

When the power switch is turned to ON mode, the system is oper-
ated in automatic S-FLOW mode.

■

Other functions
● Switching between outside air and recirculated air modes

(

P. 503)

● Defogging the windshield (P. 504)
● Defogging the rear window and outside rear view mirrors

(

P. 504)

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6-1. Using the air conditioning system and defogger

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Press

.

Adjust the temperature setting. (

P. 500)

To stop the operation, press

.

■

Automatic mode indicator

If the fan speed setting or air flow modes are operated, the

indicator goes off. However, automatic mode for functions other
than that operated is maintained.

■

Switching between outside air and recirculated air modes

Press

.

The mode switches between outside air mode and recirculated air mode

each time

is pressed.

The

indicator illuminates when the recirculated air mode is

selected.

■

Air conditioning eco mode
The air conditioning system is controlled with low fuel consumption
prioritized such as reducing fan speed, etc.

Press

.

The air conditioning eco mode switches between on and off each time

is pressed.

“ECO” is displayed on the air conditioning screen when the air condi-
tioning eco mode is on.

Using automatic mode

Other functions

1

2

3