Toyota Prius Prime (2020 year). Owner's manual - part 28

440

5-5. Using the driving support systems

WARNING

■

Sensors
Certain vehicle conditions and the surrounding environment may affect the
ability of the sensor to correctly detect obstacles. Particular instances where
this may occur are listed below.

●

There is dirt, snow or ice on the sensor. (Wiping the sensors will resolve
this problem.)

●

The sensor is frozen. (Thawing the area will resolve this problem.) 
In especially cold weather, if a sensor is frozen, the screen may show an
abnormal display, or obstacles may not be detected.

●

The sensor is covered in any way.

●

In harsh sunlight or intense cold weather

●

On an extremely bumpy road, on an incline, on gravel, or on grass

●

The  vicinity  of  the  vehicle  is  noisy  due  to  vehicle  horns,  motorcycle
engines, air brakes of large vehicles, or other loud noises producing ultra-
sonic waves.

●

The sensor is splashed with water or drenched with heavy rain.

●

The sensor is drenched with water on a flooded road.

●

The vehicle is leaning considerably to one side.

●

The vehicle is equipped with a fender pole or wireless antenna.

●

The vehicle is approaching a tall or curved curb.

●

The area directly under the bumpers is not detected.

●

If obstacles draw too close to the sensor.

●

The bumper or sensor receives a strong impact.

●

A non-genuine Toyota suspension (lowered suspension etc.) is installed.

●

There is another vehicle equipped with parking assist sensors in the vicin-
ity.

●

Towing eyelets are installed.

●

A backlit license plate is installed.

In addition to the examples above, depending on the shape and condition of
obstacles,  detection  may  not  be  possible,  or  the  detection  range  may  be
shortened.

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WARNING

■

Side sensors
In the following situations, the intuitive parking assist may not operate nor-
mally and may result in an unexpected accident. Drive carefully.

●

Obstacles may not be detected in the side areas until the vehicle is driven
for a short time and 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.

●

Even after the scan of the side areas is completed, obstacles may not be
detected depending on the surrounding situation of the vehicle.
At that time, the side sensor operation displays (

P. 434) temporary turn

off.

■

Obstacles which may not be properly detected
The  shape  of  the  obstacle  may  prevent  the  sensor  from  detecting  it.  Pay
particular attention to the following obstacles:

●

Wires, fences, ropes, etc.

●

Cotton, snow and other materials that absorb sound waves

●

Sharply-angled objects

●

Low obstacles

●

Tall obstacles with upper sections projecting outwards in the direction of
your vehicle

●

People may not be detected if they are wearing certain types of clothing.

●

Moving objects such as people or animals

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5-5. Using the driving support systems

NOTICE

■

When using intuitive parking assist
In the following situations, the system may not function correctly due to a
sensor malfunction etc. Have the vehicle checked by your Toyota dealer.

●

Intuitive parking assist operation display flashes, and a beep sounds when
no obstacles are detected.

●

If  the  area  around  a  sensor  collides  with  something,  or  is  subjected  to
strong impact.

●

If the bumper collides with something.

●

If the display shows up and remains on without a beep.

●

If a display error occurs, first check the sensor.
If the error occurs even when there is no ice, snow or mud on the sensor, it
is likely that the sensor is malfunctioning.

■

Notes when washing the vehicle

●

Do not apply intensive bursts of water or steam to the sensor area.
Doing so may result in the sensor malfunctioning.

●

When using steam to wash the vehicle, do not direct steam too close to
the sensors. The sensors may not function properly if subjected to steam.

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Parking Support Brake function



The system operates in the following situations when an obstacle is
detected in the traveling direction of the vehicle.

◆

The vehicle is driven at low speeds and the brake pedal is not
depressed, or is depressed too late

◆

The accelerator pedal is depressed too far



: If equipped

When  a  collision  may  occur  with  an  obstacle  while  parking  or
traveling at low speeds, when the vehicle suddenly moves for-
ward due to mistaken accelerator pedal operation, or when the
vehicle  moves  due  to  the  wrong  shift  position  being  selected,
the sensors detect obstacles to the front or rear in the traveling
direction  of  the  vehicle,  and  the  system  operates  to  lessen
impact with obstacles such as walls, and reduce resulting dam-
age.

Examples of system operation

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5-5. Using the driving support systems

◆

The  vehicle  moves  due  to  the  wrong  shift  position  being
selected

Front corner sensors
Front center sensors
Rear corner sensors
Rear center sensors

The Parking Support Brake function can be enabled/disabled on the

 screen (

P. 244) of the multi-information display.

When  the  Parking  Support  Brake
function is off, the PKSB OFF indi-
cator illuminates.

When the Parking Support Brake function is switched off, system operation

does not resume until the function is switched back on through the 
screen  on  the  multi-information  display.  (System  operation  does  not
resume by operating the power switch.)

Types of sensors

1
2
3
4

Changing settings of the Parking Support Brake function

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When the Parking Support Brake function detects an obstacle with a
probability of collision, hybrid system output is restricted to restrain an
increase in vehicle speed. (Hybrid system output restriction control: A)
Furthermore, when the accelerator pedal continues to be depressed,
the brakes are applied to reduce the vehicle speed. (Brake control: B)

Operation

DOWN

DOWN

UP

ON

OFF

ON

OFF

ON

OFF

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5-5. Using the driving support systems

Accelerator pedal
Brake pedal
Hybrid system output
Braking force

Control starts
Collision is possible
Collision is likely

1
2
3
4

5
6
7

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■

Operation starting conditions
When  the  PKSB  OFF  indicator  is  not  illuminated  or  flashing
(

P. 452, 664) and all of the following conditions are met, the

system operates.



Hybrid system output restriction control

● The Parking Support Brake function is on.
● The vehicle speed is 10 mph (15 km/h) or less.
● There is an obstacle in the traveling direction of the vehicle (6 to

13 ft. [2 to 4 m ahead]).

● The system determined that a stronger-than-normal brake opera-

tion was necessary to avoid a collision.



Brake control

● Hybrid system output restriction control is being performed.
● The system determined that an emergency brake operation was

necessary to avoid a collision.

■

Operation ending conditions
In any of the following situations, the system stops operating.



Hybrid system output restriction control

● The  Parking  Support  Brake  function  has  been  turned  off

(stopped).

● The collision became avoidable with normal brake operation.
● The obstacle is no longer in the traveling direction of the vehicle

(6 to 13 ft. [2 to 4 m ahead]).



Brake control

● The  Parking  Support  Brake  function  has  been  turned  off

(stopped).

● Approximately 2 seconds elapsed after the vehicle was stopped

by brake control.

● The brake pedal was depressed after the vehicle was stopped by

brake control.

● The obstacle is no longer in the traveling direction of the vehicle

(6 to 13 ft. [2 to 4 m ahead]).

Operation conditions

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5-5. Using the driving support systems

When  the  hybrid  system  output  restriction  control  or  brake  control
operates, the buzzer sounds and a message is displayed on the multi-
information display to alert the driver.

Depending  on  the  situation,  output  restriction  control  operates  to  either
limit acceleration or restrict output as much as possible.

Display and buzzer for hybrid system output restriction control
and brake control

Control

Situation

Multi-information 

display

PKSB 

OFF Indi-

cator

Buzzer

Hybrid  sys-
tem 

output

restriction
control 

is

operating
(accelera-
tion 

limita-

tion control)

Acceleration
at  a  certain
speed 

or

higher  is  not
possible.

Not illumi-

nated

Short 

beep

Hybrid  sys-
tem 

output

restriction
control 

is

operating
(control 

to

restrict  out-
put  as  much
as possible)

A  stronger-
than-normal
brake  opera-
tion is neces-
sary

Not illumi-

nated

Brake 

con-

trol is operat-
ing

Emergency
braking 

is

necessary

The  vehicle
is stopped by
system  oper-
ation

The  vehicle
is 

stopped

after 

brake

control  oper-
ation

Illumi-

nated

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■

Sensor detection range
The  detection  range  of  the  Parking  Support  Brake  function  differs  from  the
detection range of the intuitive parking assist. (

P. 437)

Therefore,  even  if  the  intuitive  parking  assist  detects  an  obstacle  and  pro-
vides a warning, the Parking Support Brake function may not start operating.

■

System operation
When the vehicle is stopped by system operation, the Parking Support Brake
function stops and the PKSB OFF indicator illuminates.

■

System recovery
When  the  Parking  Support  Brake  function  is  stopped  by  system  operation
and  you  would  like  to  resume  operation,  either  turn  the  Parking  Support
Brake function on again (

P. 444), or turn the power switch off and then back

on. Furthermore, when the vehicle moves with an obstacle no longer in the
traveling direction of the vehicle, or when the traveling direction of the vehicle
changes  (such  as  when  switching  from  moving  forward  to  backing  up,  and
vice versa), system operation automatically resumes.

■

Obstacles not detected by the sensors
The following obstacles may not be detected by the sensors.

●

Objects such as people, cloth and snow, that are difficult for sonic waves to
reflect off of. (In particular, people may also not be detected depending on
the type of clothing they are wearing.)

●

Objects not perpendicular with the ground, objects not at a right angle to the
traveling direction of the vehicle, uneven objects or waving objects

●

Low objects

●

Thin objects such as wires, fences, ropes and signposts

●

Objects that are extremely close to the bumper

■

Intuitive parking assist buzzer
Regardless of whether the intuitive parking assist is on or off (

P. 433), if the

Parking Support Brake function is not stopped (

P. 444), when the front or

rear sensors detect an obstacle and brake control is performed, the intuitive
parking assist buzzer also sounds and a notification of the approximate dis-
tance to the obstacle is provided.

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■

Situations when the system may operate even though there is no possi-
bility of a collision
In the following situations, the system may operate even though there is no
possibility of a collision.

●

Environmental influence

• The vehicle is driven toward a banner or flag, a low-hanging branch or a

boom  barrier  (such  as  those  used  at  railroad  crossings,  toll  gates  and
parking lots).

• There  is  an  obstacle  on  the  shoulder  of  the  road  (when  the  vehicle  is

driven in a narrow tunnel, on a narrow bridge or on a narrow road)

• The vehicle is being parallel parked
• There is a rut or hole in the surface of the road
• When the vehicle is driven on a metal cover (grating), such as those used

for drainage ditches

• The vehicle is driven on a steep slope
• The sensor is covered by water on a flooded road

●

Influence from the weather
• Ice, snow, dirt, etc., has adhered to the sensor (if removed, the system

returns to normal)

• Heavy rain or water strikes the vehicle
• In severe weather such as fog, snow or a sand storm

●

Influence from other sonic waves
• An ultrasonic wave source is nearby, such as the horn or parking assist

sensors of another vehicle, a vehicle detector, a motorcycle engine or the
air brake of a large vehicle

• Electronic  components  (such  as  a  backlit  license  plate  (especially  fluo-

rescent  types),  fog  lights,  a  fender  pole  or  a  wireless  antenna)  are
installed near the sensors

• The  vehicle  is  driven  on  a  narrow

road

• The vehicle is driven on a gravel road

or in an area with tall grass

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●

Changes in the vehicle
• The vehicle is tilted a large amount
• The height of the vehicle has drastically changed due to the carried load

(the nose tilts up or down)

• The direction of the sensor has deviated due to a collision or other impact

■

In the unlikely event that the Parking Support Brake function mistakenly
operates at a crossing or elsewhere
Even in the unlikely event that the Parking Support Brake function mistakenly
operates at a crossing or elsewhere, brake control is canceled after approxi-
mately 2 seconds, allowing you to proceed forward and leave the area. Fur-
thermore, brake control is also canceled when the brake pedal is depressed.
Depressing  the  accelerator  pedal  again  allows  you  to  proceed  forward  and
leave the area.

■

Situations in which the system may not operate normally
In the following situations, the system may not operate normally.

●

Environmental influence
• There  is  an  obstacle  that  cannot  be  detected  between  the  vehicle  and

another obstacle that can be detected

• An obstacle such as another vehicle, a motorcycle, a bicycle or a pedes-

trian cuts in front of the vehicle or jumps out from the side.

●

Influence from the weather

• Ice, snow, dirt, etc., has adhered to the sensor (if removed, the system

returns to normal)

• Heavy rain or water strikes the vehicle
• In severe weather such as fog, snow or a sand storm

• The  area  around  the  sensor  is

extremely hot or cold 

• The wind is strong

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●

Influence from other sonic waves
• An ultrasonic wave source is nearby, such as the horn or parking assist

sensors of another vehicle, a vehicle detector, a motorcycle engine or the
air brake of a large vehicle

• Electronic  components  (such  as  a  backlit  license  plate  (especially  fluo-

rescent  types),  fog  lights,  a  fender  pole  or  a  wireless  antenna)  are
installed near the sensors

●

Changes in the vehicle
• When driving with the shift position in N
• The vehicle is tilted a large amount
• The height of the vehicle has drastically changed due to the carried load

(the nose tilts up or down)

• The direction of the sensor has deviated due to a collision or other impact

■

Parking  Support  Brake  function  while  the  Simple  Advanced  Parking
Guidance System is operating
P. 457

■

When removing and installing the 12-volt battery
The system needs to be initialized.
The system can be initialized by driving the vehicle straight ahead for 5 sec-
onds or more at a speed of approximately 22 mph (35 km/h) or higher.

■

When “PKSB Unavailable” is displayed on the multi-information display
and the PKSB OFF indicator flashes

●

Ice, snow, dirt, etc., may have adhered to the sensor. If this occurs, remove
the ice, snow, dirt, etc., from the sensor to return the system to normal.
Also, a warning message may be displayed at low temperatures due to ice
forming on the sensor, and the sensor may not detect obstacles. Once the
ice melts, the system will return to normal.

●

If this message is shown even after removing dirt from the sensor, or shown
when the sensor was not dirty to begin with, have the vehicle inspected at
your Toyota dealer.

●

System initialization may not have been performed after removal and instal-
lation of the 12-volt battery. Perform system initialization. 

■

When  “PKSB  Malfunction  Visit Your  Dealer”  is  displayed  on  the  multi-
information  display,  the  PKSB  OFF  indicator  flashes  and  the  buzzer
sounds
The  system  may  not  be  operating  properly.  Have  the  vehicle  inspected  at
your Toyota dealer.

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■

For safe use
Do  not  rely  solely  upon  the  system.  Relying  solely  upon  the  system  may
lead to an unexpected accident.

●

Driving safely is the sole responsibility of the driver. Pay careful attention
to the surrounding conditions in order to ensure safe driving. The Parking
Support Brake function can provide support to lessen the severity of colli-
sions. However, it may not operate depending on the situation.

●

The  Parking  Support  Brake  function  is  not  a  system  designed  to  com-
pletely stop the vehicle. Furthermore, even if the Parking Support Brake
function is able to stop the vehicle, brake control is canceled after approxi-
mately 2 seconds, so depress the brake pedal immediately.

■

In order for the system to operate properly
Make  sure  to  observe  the  following  precautions  regarding  the  sensors
(

P.  444).  Failure  to  observe  these  precautions  may  cause  the  sensors

not to operate properly, and may result in an unexpected accident.

●

Do not perform work such as modification, disassembly or painting

●

Only perform replacements using genuine parts

●

Do not subject the area around the sensors to any impacts

●

Do not damage the sensors, and always keep them clean

■

Handling the suspension
Do  not  modify  the  suspension,  as  changes  to  the  height  or  incline  of  the
vehicle  may  prevent  the  sensors  from  correctly  detecting  obstacles,  may
cause the system not operate, or may cause the system to operate unnec-
essarily.

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NOTICE

■

Preventing sensor malfunctions

●

If the area around a sensor is subjected to an impact, equipment may not
operate properly due to a sensor malfunction. Have the vehicle inspected
at your Toyota dealer.

●

When  using  a  high-pressure  washer  to  wash  the  vehicle,  do  not  spray
water  directly  on  the  sensors.  The  sensors  may  not  function  properly  if
subjected to an impact from strong water pressure.

●

When using steam to wash the vehicle, do not direct steam too close to
the sensors. The sensors may not function properly if subjected to steam.

■

Preventing unnecessary operation
In the following situations, turn the Parking Support Brake function off. The
system may operate even though there is no possibility of a collision.

●

A chassis roller, chassis dynamo, free roller or similar equipment is being
used for an inspection, etc.

●

The vehicle is being loaded onto a ship, truck or other transport vessel

●

The suspension has been lowered or tires that have a different size than
the genuine tires are equipped

●

The height of the vehicle has drastically changed due to the carried load
(the nose tilts up or down).

●

A towing eyelet is installed

●

When using an automatic car wash

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S-APGS (Simple Advanced Parking Guidance 

System)



■

Function summary
The  Simple  Advanced  Parking  Guidance  System  automatically
operates the steering wheel to provide support when backing into
an area near a target parking spot, and when departing from a par-
allel  parking  spot.  (Changing  the  shift  position  and  speed  adjust-
ment  when  moving  forward  or  backing  up  are  not  performed
automatically.)
● The Simple Advanced Parking Guidance System does not park

the  vehicle  automatically.  It  is  a  system  that  provides  support
when pulling out of a perpendicular or parallel parking spot.

● The Simple Advanced Parking Guidance System provides steer-

ing  wheel  operation  assistance  to  guide  the  vehicle  toward  the
selected  intended  parking  spot.  The  selected  intended  parking
spot may not always be reachable, depending on road and vehi-
cle  conditions  at  the  time  of  parking,  and  the  distance  to  the
intended parking spot.

■

Linking with the Parking Support Brake function
While the Simple Advanced Parking Guidance System is operating,
if the system detects an obstacle that could result in a collision, the
emergency brakes operate, regardless of whether the Parking Sup-
port Brake function is on or off. (

P. 457)



: If equipped

Simple Advanced Parking Guidance System

WARNING

●

When  backing  up  or  proceeding  forward,  be  sure  to  directly  confirm  the
safety of the area to the front or rear, and the area around the vehicle, and
slowly  back  up  or  proceed  forward  while  adjusting  the  vehicle  speed  by
depressing the brake pedal.

●

If it seems the vehicle may make contact with a pedestrian, another vehi-
cle or any other obstacles, stop the vehicle by depressing the brake pedal,
and then press the S-APGS switch (

P. 458) to turn the system off.