Toyota Prius Prime (2020 year). Owner's manual - part 27

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5-5. Using the driving support systems

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  your  Toyota
dealer.
• 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.

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5-5. Using the driving support systems

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The Blind Spot Monitor function uses radar sensors to detect vehicles
that are traveling in an adjacent lane in the area that is not reflected in
the outside rear view mirror (the blind spot), and advises the driver of
the vehicle’s existence via the outside rear view mirror indicator.

The areas that vehicles can be detected in are outlined below.
The range of the detection area extends to:

Approximately  11.5  ft.  (3.5  m)
from the side of the vehicle

The  first  1.6  ft.  (0.5  m)  from  the
side  of  the  vehicle  is  not  in  the
detection area

Approximately 9.8 ft. (3 m) from
the rear bumper
Approximately 3.3 ft. (1 m) for-
ward of the rear bumper

The Blind Spot Monitor function

The Blind Spot Monitor function detection areas

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5-5. Using the driving support systems

■

The Blind Spot Monitor function is operational when

●

The BSM system is set to on (

P. 244)

●

Vehicle speed is greater than approximately 10 mph (16 km/h)

■

The Blind Spot Monitor function will detect a vehicle when

●

A vehicle in an adjacent lane overtakes your vehicle.

●

You overtake a vehicle in adjacent lane slowly.

●

Another vehicle enters the detection area when it changes lanes.

■

Conditions under which the Blind Spot Monitor function will not detect a
vehicle
The Blind Spot Monitor function is not designed to detect the following types
of vehicles and/or objects:

●

Small motorcycles, bicycles, pedestrians etc.

*

●

Vehicles traveling in the opposite direction

●

Guardrails, walls, signs, parked vehicles and similar stationary objects

*

●

Following vehicles that are in the same lane

*

●

Vehicles driving 2 lanes across from your vehicle

*

●

Vehicles which are being overtaken rapidly by your vehicle

*

*

: Depending on conditions, detection of a vehicle and/or object may occur.

WARNING

■

Cautions regarding the use of the system
The driver is solely responsible for safe driving. Always drive safely, taking
care to observe your surroundings.
The Blind Spot Monitor function is a supplementary function which alerts the
driver that a vehicle is present in the blind spot. Do not overly rely on the
Blind Spot Monitor function. The function cannot judge if it is safe to change
lanes, therefore over reliance could cause an accident resulting in death or
serious injury.
According  to  conditions,  the  system  may  not  function  correctly. Therefore
the driver’s own visual confirmation of safety is necessary.

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■

Conditions under which the Blind Spot Monitor function may not func-
tion correctly

●

The Blind Spot Monitor function may not detect vehicles correctly in the fol-
lowing situations:
• When the sensor is misaligned due to a strong impact to the sensor or its

surrounding area

• When mud, snow, ice, a sticker, etc. is covering the sensor or surround-

ing area on the rear bumper

• When driving on a road surface that is wet with standing water during bad

weather, such as heavy rain, snow, or fog

• When multiple vehicles are approaching with only a small gap between

each vehicle

• When the distance between your vehicle and a following vehicle is short
• When there is a significant difference in speed between your vehicle and

the vehicle that enters the detection area

• When the difference in speed between your vehicle and another vehicle

is changing

• When  a  vehicle  enters  a  detection  area  traveling  at  about  the  same

speed as your vehicle

• As your vehicle starts from a stop, a vehicle remains in the detection area
• When driving up and down consecutive steep inclines, such as hills, dips

in the road, etc.

• When driving on roads with sharp bends, consecutive curves, or uneven

surfaces

• When vehicle lanes are wide, or when driving on the edge of a lane, and

the vehicle in an adjacent lane is far away from your vehicle

• When a bicycle carrier or other accessory is installed to the rear of the

vehicle

• When there is a significant difference in height between your vehicle and

the vehicle that enters the detection area

• Immediately after the Blind Spot Monitor function is turned on

●

Instances of the Blind Spot Monitor function unnecessarily detecting a vehi-
cle and/or object may increase in the following situations:
• When the sensor is misaligned due to a strong impact to the sensor or its

surrounding area

• When the distance between your vehicle and a guardrail, wall, etc. that

enters the detection area is short

• When driving up and down consecutive steep inclines, such as hills, dips

in the road, etc.

• When vehicle lanes are narrow, or when driving on the edge of a lane,

and a vehicle traveling in a lane other than the adjacent lanes enters the
detection area

• When driving on roads with sharp bends, consecutive curves, or uneven

surfaces

• When the tires are slipping or spinning
• When the distance between your vehicle and a following vehicle is short
• When a bicycle carrier or other accessory is installed to the rear of the

vehicle

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5-5. Using the driving support systems

The Rear Cross Traffic Alert functions when your vehicle is in reverse.
It can detect other vehicles approaching from the right or left rear of
the vehicle. It uses radar sensors to alert the driver of the other vehi-
cle’s existence through flashing the outside rear view mirror indicators
and sounding a buzzer.

The Rear Cross Traffic Alert function

IO55PH087

Approaching vehicles

Detection areas

WARNING

■

Cautions regarding the use of the system
The driver is solely responsible for safe driving. Always drive safely, taking
care to observe your surroundings.
The Rear Cross Traffic Alert function is only an assist and is not a replace-
ment for careful driving. The driver must be careful when backing up, even
when  using  the  Rear  Cross  Traffic Alert  function.  The  driver’s  own  visual
confirmation of behind you and your vehicle is necessary and be sure there
are no pedestrians, other vehicles etc. before backing up. Failure to do so
could cause death or serious injury.
According  to  conditions,  the  system  may  not  function  correctly. Therefore
the driver’s own visual confirmation of safety is necessary.

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The areas that vehicles can be detected in are outlined below.

To give the driver a more consistent time to react, the buzzer can alert
for faster vehicles from farther away.
Example:

■

The Rear Cross Traffic Alert function is operational when

●

The BSM system is set to on. (

P. 244)

●

The shift position is in R.

●

Vehicle speed is less than approximately 5 mph (8 km/h).

●

Approaching vehicle speed is between approximately 5 mph (8 km/h) and
18 mph (28 km/h).

The Rear Cross Traffic Alert function detection areas

IO55PH088

Approaching vehicle

Speed

Approximate 
alert distance

Fast

18 mph (28 km/h)

65 ft. (20 m)

Slow

5 mph (8 km/h)

18 ft. (5.5 m)

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■

Conditions  under  which  the  Rear  Cross  Traffic  Alert  function  will  not
detect a vehicle
The Rear Cross Traffic Alert function is not designed to detect the following
types of vehicles and/or objects:

●

Vehicles approaching from directly behind

●

Vehicles backing up in a parking space next to your vehicle

●

Guardrails, walls, signs, parked vehicles and similar stationary objects

*

●

Small motorcycles, bicycles, pedestrians, etc.

*

●

Vehicles moving away from your vehicle

●

Vehicles approaching from the parking spaces next to your vehicle

*

*

: Depending  on  the  conditions,  detection  of  a  vehicle  and/or  object  may

occur.

■

Conditions  under  which  the  Rear  Cross  Traffic Alert  function  may  not
function correctly

●

The Rear Cross Traffic Alert function may not detect vehicles correctly in the
following situations:
• When the sensor is misaligned due to a strong impact to the sensor or its

surrounding area

• When mud, snow, ice, a sticker, etc. is covering the sensor or surround-

ing area on the rear bumper

• When driving on a road surface that is wet with standing water during bad

weather, such as heavy rain, snow, or fog

• When multiple vehicles are approaching with only a small gap between

each vehicle

• When a vehicle is approaching at high speed

●

Vehicles that the sensors cannot detect
due to obstructions

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• Immediately after the Blind Spot Monitor function is turned on
• Immediately after the hybrid system is started with the Blind Spot Monitor

function on

• When  backing  up  on  a  slope  with  a

sharp change in grade

• When backing out of a shallow angle

parking spot

• When  the  sensors  cannot  detect  a

vehicle due to obstructions

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5-5. Using the driving support systems

●

Instances of the Rear Cross Traffic Alert function unnecessarily detecting a
vehicle and/or object may increase in the following situations:
• When a vehicle passes by the side of your vehicle

• When  the  distance  between  your  vehicle  and  metal  objects,  such  as  a

guardrail, wall, sign, or parked vehicle, which may reflect electrical waves
toward the rear of the vehicle, is short

• When  the  parking  space  faces  a

street  and  vehicles  are  being  driven
on the street

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Intuitive parking assist



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

The intuitive parking assist can be

enabled/disabled  on  the 

screen  (

P.  244)  of  the  multi-

information display.

When on is selected, intuitive park-
ing assist indicator will come on.

Once off is selected, the intuitive parking assist will not return to on until it

is turned to on by the 

 screen of multi-information display again. (The

system does not automatically return to on even when the hybrid system is
restarted.)



: If equipped

The distance from your vehicle to nearby obstacles when paral-
lel  parking  or  maneuvering  into  a  garage  is  measured  by  the
sensors  and  communicated  via  the  displays  and  a  buzzer.
Always check the surrounding area when using this system.

Types of sensors

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Turning the intuitive parking assist on/off

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5-5. Using the driving support systems

When  the  sensors  detect  an  obstacle,  the  following  displays  inform
the driver of the position and distance to the obstacle.

■

Multi-information display

Front  center  sensor  opera-
tion
Front  corner  sensor  opera-
tion
Front side sensor operation
Rear side sensor operation
Rear corner sensor operation
Rear center sensor operation

• The operation display is gray when the sensors are operating.
• The front side sensor operation displays and rear side sensor opera-

tion  displays  are  not  shown  until  a  scan  of  the  side  areas  is  com-
pleted.

Display

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■

Distance display
Sensors that detect an obstacle will illuminate continuously or blink.

*

: The images may differ from those shown in the illustrations depending on

the detection status. (

P. 434)

Sensor detection display, obstacle distance

Display

*

Approximate distance to obstacle

Front corner, front 

center and front side 

sensors

Rear corner, rear 

center and rear side 

sensors

(continuous)

3.3 ft. (100 cm) to 
2.0 ft (60 cm)

4.9 ft. (150 cm) to 
2.0 ft. (60 cm)

(continuous)

2.0 ft. (60 cm) to 
1.5 ft (45 cm)
2.0 ft. (60 cm) to 
1.5 ft. (45 cm)
3.3 ft. (100 cm) to 
2.3 ft. (70 cm)

3.3 ft. (100 cm) to 
2.3 ft. (70 cm)
2.0 ft. (60 cm) to 
1.5 ft (45 cm)
2.0 ft. (60 cm) to 
1.5 ft. (45 cm)

(continuous)

1.5 ft. (45 cm) to 
1.2 ft. (35 cm)
1.5 ft. (45 cm) to 
1.2 ft. (35 cm)
2.3 ft. (70 cm) to 
1.0 ft. (30 cm)

2.3 ft. (70 cm) to 
1.0 ft. (30 cm)
1.5 ft. (45 cm) to 
1.2 ft. (35 cm)
1.5 ft. (45 cm) to 
1.2 ft. (35 cm)

(blinking)

Less than 
1.2 ft. (35 cm)
Less than 
1.2 ft. (35 cm)
Less than 
1.0 ft. (30 cm)

Less than 
1.0 ft. (30 cm)
Less than 
1.2 ft. (35 cm)
Less than 
1.2 ft. (35 cm)

Far

Near

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4

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6

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4

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6

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4

5

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Front center sensors
Front corner sensors
Front side sensors

Rear side sensors
Rear corner sensors
Rear center sensors

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4
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6

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5-5. Using the driving support systems

When an obstacle is detected, the buzzer sounds.
● As  the  obstacle  is  approached,  the  buzzer  sounds  more  rapidly.

When  the  obstacle  is  extremely  close,  the  buzzer  switches  from
sounding intermittently (short beeps) to continuously (a long beep).

• Distance to obstacle detected by front corner sensor is approxi-

mately 1.2 ft. (35 cm) or less

• Distance  to  obstacle  detected  by  front  side  sensor  or  rear  side

sensor is approximately 1.0 ft. (30 cm) or less

• Distance  to  obstacle  detected  by  front  sensor  is  approximately

1.2 ft. (35 cm) or less

• Distance to obstacle detected by rear corner sensor is approxi-

mately 1.2 ft. (35 cm) or less

• Distance  to  obstacle  detected  by  back  sensor  is  approximately

1.2 ft. (35 cm) or less

● When an obstacle is detected by multiple sensors simultaneously,

the buzzer sounds according to the distance to the closest obsta-
cle.

● When obstacles are simultaneously detected to the front and rear

of  the  vehicle,  separate  buzzers  sound  patterns  according  to  the
distance to each obstacle.

The volume and timing of the buzzer can be changed. (

P. 741)

Buzzer

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Approximately 3.3 ft. (100 cm)
Approximately 4.9 ft. (150 cm)
Approximately 2.0 ft. (60 cm)
Approximately 3.3 ft. (100 cm)

• The detection range is shown in

the illustration to the right. How-
ever,  the  sensor  will  not  detect
the obstacle if it is too close.

• For  details  regarding  obstacle

detection in the side areas. 
(

P. 438)

• The distance at which an obsta-

cle can be detected and whether
it  can  be  detected  depends  on
the  shape  and  condition  of  the
obstacle.

The obstacle detection range can be changed. (

P. 741)

■

Operation conditions
The power switch is turned on.

●

Front corner sensors:
• Shift position is not in P
• Vehicle speed is approximately 6 mph (10 km/h) or less

●

Front side sensors/rear side sensors:
• Shift position is not in P
• Vehicle speed is approximately 6 mph (10 km/h) or less
• Steering wheel is turned approximately 90

 or more

●

Front center sensors:
• Shift position is not in P or R
• Vehicle speed is approximately 6 mph (10 km/h) or less

●

Rear corner sensors/rear center sensors:
Shift position is in R

■

Intuitive parking assist pop-up display
P. 459

Detection range of the sensors

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5-5. Using the driving support systems

■

Sensor detection information

●

The sensor’s detection areas are limited to the areas around the vehicle’s
bumper.

●

Depending on the shape of the obstacle and other factors, the detection dis-
tance may shorten, or detection may be impossible.

●

Obstacles may not be detected if they are too close to the sensor.

●

There  will  be  a  short  delay  between  obstacle  detection  and  display.  Even
when traveling at a low speed, if you come too close to an obstacle before
the display and buzzer activate, the display and buzzer may not activate at
all.

●

Thin  posts  or  objects  lower  than  the  sensor  may  not  be  detected  when
approached, even if they have been detected once.

●

It might be difficult to hear beeps due to the volume of audio system or air
flow noise of the air conditioning system.

■

Obstacle warning function
When  an  obstacle  in  the  side  areas  is  within  the  vehicle  course  while  the
vehicle is moving forward or backward, this function inform the driver by the
display and the buzzer. (

P. 435, 436)

■

Obstacle detection in side areas

●

Obstacles in the side areas are detected while driving by scanning the side
areas with the side sensors. Recognized obstacles are retained in memory
for up to approximately 2 minutes.

●

Obstacles may not be detected in the side areas until the scan completes.
After  the  power  switch  is  turned  on,  scanning  completes  after  driving  the
vehicle for a short period of time.

●

When an obstacle such as another vehicle, pedestrian or animal is detected
by the side sensors, the obstacle may continue to be detected even after it
has left the side sensor detection area.

Obstacle
Calculated vehicle course

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■

If  “Clean  Parking Assist  Sensor”  is  displayed  on  the  multi-information
display
A  sensor  may  be  dirty  or  covered  with  snow  or  ice.  In  such  cases,  if  it  is
removed from the sensor, the system should return to normal.
Also, due to the sensor being frozen at low temperatures, a malfunction dis-
play may appear or an obstacle may not be detected. If the sensor thaws out,
the system should return to normal.

■

If “Parking Assist Malfunction” is displayed on the multi-information dis-
play
Depending on the malfunction of the sensor, the device may not be working
normally. Have the vehicle inspected by your Toyota dealer.

■

Certification (Canada only)
This ISM device complies with Canadian ICES-001.

■

Customization
Settings (e.g. buzzer volume) can be changed.
(Customizable features: 

P. 741)

WARNING

■

When using intuitive parking assist
Observe the following precautions to avoid an unexpected accident.

●

Do not exceed the speed limit of 6 mph (10 km/h).

●

The sensors’ detection areas and reaction times are limited. When moving
forward or reversing, check the areas surrounding the vehicle (especially
the  sides  of  the  vehicle)  for  safety,  and  drive  slowly,  using  the  brake  to
control the vehicle’s speed.

●

Do not install accessories within the sensors’ detection areas.