Toyota Prius (2022 year). Manual in english - page 19

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WARNING

●

There are shadows on the road that run parallel with, or cover, the white
(yellow) lines.

●

The vehicle is driven in an area without white (yellow) lines, such as in
front of a tollgate or checkpoint, or at an intersection, etc.

●

The white (yellow) lines are cracked, “Botts’ dots”, “Raised pavement
marker” or stones are present.

●

The white (yellow) lines cannot be seen or are difficult to see due to sand,
etc.

●

The vehicle is driven on a road surface that is wet due to rain, puddles,
etc.

●

The traffic lines are yellow (which may be more difficult to recognize than
lines that are white).

●

The white (yellow) lines cross over a curb, etc.

●

The vehicle is driven on a bright surface, such as concrete.

●

If the edge of the road is not clear or straight.

●

The vehicle is driven on a surface that is bright due to reflected light, etc.

●

Vehicle is driven where the road
diverges, merges, etc.

●

Repair marks of asphalt, white (yellow)
lines, etc. are present due to road
repair.

306

WARNING

●

The vehicle is driven in an area where the brightness changes suddenly,
such as at the entrances and exits of tunnels, etc.

●

Light from the headlights of an oncoming vehicle, the sun, etc. enters the
camera.

●

The vehicle is driven on a slope.

●

The vehicle is driven on a road which tilts left or right, or a winding road.

●

The vehicle is driven on an unpaved or rough road.

●

The traffic lane is excessively narrow or wide.

●

The vehicle is extremely tilted due to carrying heavy luggage or having
improper tire pressure.

●

The distance to the preceding vehicle is extremely short.

●

The vehicle is moving up and down a large amount due to road conditions
during driving (poor roads or road seams).

●

When driving in a tunnel or at night with the headlights off or when a head-
light is dim due to its lens being dirty or it being misaligned.

●

The vehicle is struck by a crosswind.

●

The vehicle is affected by wind from a vehicle driven in a nearby lane.

●

The vehicle has just changed lanes or crossed an intersection.

●

Tires which differ by structure, manufacturer, brand or tread pattern are
used.

●

When tires of a size other than specified are installed.

●

Snow tires, etc. are equipped.

●

The vehicle is being driven at extremely high speeds.

307

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■

Lane departure alert function

When  the  system  determines
that  the  vehicle  might  depart
from  its  lane  or  course

, a

warning is displayed on the
multi-information display, and a
warning buzzer will sound to
alert the driver.

When  the  warning  buzzer
sounds,  check  the  area  around
your vehicle and carefully  oper-
ate  the  steering  wheel  to  move
the vehicle back to the center of
the lane.

: Boundary between asphalt and the side of the road, such as grass, soil, or

a curb

Functions included in LTA system

308

■

Steering assist function

When  the  system  determines
that  the  vehicle  might  depart
from  its  lane  or  course

, the

system provides assistance as
necessary by operating the
steering

wheel

small

amounts for a short period of
time to keep the vehicle in its
lane.

If  the  system  detects  that  the
steering  wheel  has  not  been
operated  for  a  fixed  amount  of
time or the steering wheel is not
being  firmly  gripped,  a  warning
is  displayed  on  the  multi-infor-
mation  display  and  the  function
is temporarily canceled.

: Boundary between asphalt and the side of the road, such as grass, soil, or

a curb

■

Vehicle sway warning function

When  the  vehicle  is  swaying
within  a  lane,  the  warning
buzzer  will  sound  and  a  mes-
sage  will  be  displayed  on  the
multi-information display to alert
the driver.

309

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■

Lane centering function

This  function  is  linked  with
dynamic  radar  cruise  control
with  full-speed  range  and  pro-
vides  the  required  assistance
by operating the steering wheel
to keep the vehicle in its current
lane.

When dynamic radar cruise con-
trol  with  full-speed  range  is  not
operating,  the  lane  centering
function does not operate.
In  situations  where  the  white
(yellow) lane lines are difficult to
see  or  are  not  visible,  such  as
when  in  a  traffic  jam,  this  func-
tion will operate to help follow a
preceding vehicle by monitoring
the  position  of  the  preceding
vehicle.
If the system detects that the steering wheel has not been operated for
a fixed amount of time or the steering wheel is not being firmly gripped,
a warning is displayed on the multi-information display and the function
is temporarily canceled.

310

Press the LTA switch to turn the
LTA system on.

The LTA indicator illuminates and a
message is displayed on the multi-
information display.
Press the LTA switch again to turn
the LTA system off.
When the LTA system is turned on
or off, operation of the LTA system
continues in the same condition
the next time the hybrid system is
started.

Turning LTA system on

311

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LTA indicator
The illumination condition of the
indicator  informs  the  driver  of
the system operation status.
Illuminated  in  green:  LTA  sys-
tem is operating.
Flashing  in  orange:  Lane
departure alert function is oper-
ating.
Steering  control  indicator  and  operation  display  of  steering  wheel
operation support
When that steering wheel assistance of the steering assist function
or lane centering function is operating, the indicator illuminates and
the operation display on the multi-information display is turned on.
Lane departure alert function display
Displayed  when  the  multi-information  display  is  switched  to  the
driving assist system information screen.

: Boundary between asphalt and the side of the road, such as grass, soil, or

a curb

Indications on combination meter



Inside of displayed lines is
white



Inside of displayed lines is
black

Indicates that the system is recog-
nizing white (yellow) lines or a
course

When

the

vehicle

departs  from  its  lane,  the  white
line  displayed  on  the  side  the
vehicle  departs  from  flashes
orange.

Indicates that the system is not
able to recognize white (yellow)
lines or a course

or is temporar-

ily canceled.

312

Follow-up cruising display

Displayed when the multi-information display is switched to the driving
assist system information screen.
Indicates that steering assist of the lane centering function is operating by
monitoring the position of a preceding vehicle.
When the follow-up cruising display is displayed, if the preceding vehicle
moves, your vehicle may move in the same way. Always pay careful atten-
tion to your surroundings and operate the steering wheel as necessary to
correct the path of the vehicle and ensure safety.

■

Operation conditions of each function

●

Lane departure alert function
This function operates when all of the following conditions are met.
• LTA is turned on.
• Vehicle speed is approximately 32 mph (50 km/h) or more.

• System recognizes white (yellow) lane lines or a course

. (When a white

[yellow] line or course

is recognized on only one side, the system will

operate only for the recognized side.)

• Width of traffic lane is approximately 9.8 ft. (3 m) or more.
• Turn signal lever is not operated.
• Vehicle is not being driven around a sharp curve.
• No system malfunctions are detected. (



P. 316)

: The function operates even if the vehicle speed is less than approxi-

mately 32 mph (50 km/h) when the lane centering function is operating.

: Boundary between asphalt and the side of the road, such as grass, soil,

or a curb

●

Steering assist function
This function operates when all of the following conditions are met in addi-
tion to the operation conditions for the lane departure alert function.

• Setting for

(“LTA Steering Assist Mode”) in

of the multi-

information display is set to “On”. (



• Vehicle is not accelerated or decelerated by a fixed amount or more.
• Steering wheel is not operated with a steering force level suitable for

changing lanes.

• ABS, VSC, TRAC and PCS are not operating.
• TRAC or VSC is not turned off.
• Hands off steering wheel warning is not displayed. (



P. 315)

313

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●

Vehicle sway warning function
This function operates when all of the following conditions are met.

• Setting for

(“Lane Sway Warning Status”) in

of the multi-

information display is set to “On”. (



• Vehicle speed is approximately 32 mph (50 km/h) or more.
• Width of traffic lane is approximately 9.8 ft. (3 m) or more.
• No system malfunctions are detected. (



P. 316)

●

Lane centering function
This function operates when all of the following conditions are met.
• LTA is turned on.
• Setting for

(“LTA Steering Assist Mode”) and

(“LTA

Center Trace On/Off”) in

of the multi-information display are set to

“On”. (

• This function recognizes white (yellow) lane lines or the position of a pre-

ceding vehicle (except when the preceding vehicle is small, such as a
motorcycle).

• The dynamic radar cruise control with full-speed range is operating in

vehicle-to-vehicle distance control mode.

• Width of traffic lane is approximately 10 to 13 ft. (3 to 4 m).
• Turn signal lever is not operated.
• Vehicle is not being driven around a sharp curve.
• No system malfunctions are detected. (



P. 316)

• Vehicle does not accelerate or decelerate by a fixed amount or more.
• Steering wheel is not operated with a steering force level suitable for

changing lanes.

• ABS, VSC, TRAC and PCS are not operating.
• TRAC or VSC is not turned off.
• Hands off steering wheel warning is not displayed. (



P. 315)

• The vehicle is being driven in the center of a lane.
• Steering assist function is not operating.

314

■

Temporary cancelation of functions

●

When operation conditions are no longer met, a function may be temporarily
canceled. However, when the operation conditions are met again, operation
of the function is automatically restored. (



P. 312)

●

If the operation conditions (

P. 313) are no longer met while the lane cen-

tering function is operating, the buzzer may sound to indicate that the func-
tion has been temporarily canceled.

■

Steering assist function/lane centering function

●

Depending on the vehicle speed, lane departure situation, road conditions,
etc., the driver may not feel the function is operating or the function may not
operate at all.

●

The steering control of the function is overridden by the driver’s steering
wheel operation.

●

Do not attempt to test the operation of the steering assist function.

■

Lane departure alert function

●

The warning buzzer may be difficult to hear due to external noise, audio
playback, etc.

●

If the edge of the course

is not clear or straight, the lane departure alert

function may not operate.

●

Do not attempt to test the operation of the lane departure alert function.

: Boundary between asphalt and the side of the road, such as grass, soil, or

a curb

315

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■

Hands off steering wheel warning

●

When  the  system  determines  that  the  driver  is  driving  without  holding  the
steering wheel while the system is operating
If  the  driver  continues  to  keep  their  hands  off  of  the  steering  wheel,  the
buzzer  sounds,  the  driver  is  warned  and  the  function  is  temporarily  can-
celed. This warning also operates in the same way when the driver continu-
ously operates the steering wheel only a small amount.

●

When the system determines that the vehicle may deviate from the lane
while driving around a curve while the lane centering function is operating
Depending on the vehicle condition and road conditions, the warning may
not operate. Also, if the system determines that the vehicle is driving
around a curve, warnings will occur earlier than during straight-lane driving.

●

When  the  system  determines  that  the  driver  is  driving  without  holding  the
steering wheel while the steering wheel assist of the steering assist function
is operating.
If the driver continues to keep their hands off of the steering wheel and the
steering  wheel  assist  is  operating,  the  buzzer  sounds  and  the  driver  is
warned.  Each  time  the  buzzer  sounds,  the  continuing  time  of  the  buzzer
becomes longer.

■

Vehicle sway warning function

In the following situations, a warning mes-
sage urging the driver to hold the steering
wheel and the symbol shown in the illus-
tration are displayed on the multi-informa-
tion  display  to  warn  the  driver.  The
warning  stops  when  the  system  deter-
mines  that  the  driver  holds  the  steering
wheel.  Always  keep  your  hands  on  the
steering  wheel  when  using  this  system,
regardless of warnings.

When  the  system  determines  that  the
vehicle is swaying while the vehicle sway
warning  function  is  operating,  a  buzzer
sounds  and  a  warning  message  urging
the driver to rest and the symbol shown in
the  illustration  are  simultaneously  dis-
played on the multi-information display.
Depending on the vehicle and road condi-
tions, the warning may not operate.

316

■

Warning message

If the following warning message is displayed on the multi-information display
and the LTA indicator illuminates in orange, follow the appropriate trouble-
shooting procedure. Also, if a different warning message is displayed, follow
the instructions displayed on the screen.

●

“LTA Malfunction Visit Your Dealer”
The system may not be operating properly. Have the vehicle inspected by
your Toyota dealer.

●

“LTA Unavailable”
The system is temporarily canceled due to a malfunction in a sensor other
than the front camera. Turn the LTA system off, wait for a little while, and
then turn the LTA system back on.

●

“LTA Unavailable at Current Speed”
The function cannot be used as the vehicle speed exceeds the LTA opera-
tion range. Drive slower.

■

Customization

Function settings can be changed.
(Customizable features:



P. 151)

317

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RSA (Road Sign Assist)



The RSA system recognizes spe-
cific road signs using the front
camera to provide information to
the driver via the display.

If the system judges that the vehicle is being driven over the speed
limit, performing prohibited actions, etc. according to the recognized
road signs, it notifies the driver through a visual notification and notifi-
cation buzzer.



: If equipped

Summary of function

WARNING

■

Before using the RSA

Do not rely solely upon the RSA system. RSA is a system which supports
the driver by providing information, but it is not a replacement for a driver’s
own vision and awareness. Drive safely by always paying careful attention
to the traffic rules.

318

When the front camera recognizes a sign, the sign will be displayed
on the main display or multi-information display.

●

When the driving assist system
information is selected in multi-
information display, a maximum
of 2 signs can be displayed on
the multi-information display.
(

●

When a tab other than the driv-
ing assist system information is
selected, the following types of
road signs will be displayed on
the main display. (

P. 115)

• Speed limit sign
• Do Not Enter sign (when

notification is necessary)

If signs other than speed limit signs are recognized, they will be displayed
in an overlapping stack under the current speed limit sign.

The following types of road signs, including electronic signs and blink-
ing signs, are recognized.

A non-official or a recently introduced traffic sign may not be recognized.

Indication on the main display or multi-information display

Supported types of road signs

Speed limit

Do Not Enter

Stop

Yield

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In the following situations, the RSA system will notify the driver.

●

When the vehicle speed exceeds the speed notification threshold of
the speed limit sign displayed, the sign display will be emphasized
and a buzzer will sound.

●

When the RSA system recognizes a do not enter sign and deter-
mines that your vehicle has entered a no-entry area, the displayed
sign will flash and a buzzer will sound.

Depending on the situation, a notification function may not operate
properly.

■

Setting procedure

P. 151

■

Automatic turn-off of RSA sign display

In the following situations, a displayed speed limit sign and/or do not enter
sign will stop being displayed automatically:

●

No sign has been recognized for a certain distance.

●

The road changes due to a left or right turn, etc.

In the following situations, stop and yield signs will stop being displayed auto-
matically:

●

The system determines that your vehicle has passed the sign.

●

The road changes due to a left or right turn, etc.

■

Conditions in which the function may not operate or detect correctly

In the following situations, RSA does not operate normally and may not rec-
ognize signs, display the incorrect sign, etc. However, this does not indicate a
malfunction.

●

The front camera is misaligned due to a strong impact being applied to the
sensor, etc.

●

Dirt, snow, stickers, etc. are on the windshield near the front camera.

●

In inclement weather such as heavy rain, fog, snow or sand storms

●

Light from an oncoming vehicle, the sun, etc. enters the front camera.

●

The sign is dirty, faded, tilted or bent.

●

The contrast of electronic sign is low.

●

All or part of the sign is hidden by the leaves of a tree, a pole, etc.

●

The sign is only visible to the front camera for a short amount of time.

●

The driving scene (turning, lane change, etc.) is judged incorrectly.

●

If a sign not appropriate for the currently traveled lane, but the sign exists
directly after a freeway branches, or in an adjacent lane just before merging.

●

Stickers are attached to the rear of the preceding vehicle.

Notification function

320

●

A sign resembling a system compatible sign is recognized.

●

Side road speed signs may be detected and displayed (if positioned in sight
of the front camera) while the vehicle is traveling on the main road.

●

Roundabout exit road speed signs may be detected and displayed (if posi-
tioned in sight of the front camera) while traveling on a roundabout.

●

The front of the vehicle is raised or lowered due to the carried load

●

The surrounding brightness is not sufficient or changes suddenly.

●

When a sign intended for trucks, etc. is recognized.

●

The speed information displayed on the meter and on the navigation system
may be different due to the navigation system using map data.

■

Speed limit sign display

If the power switch was last turned off while a speed limit sign was displayed
on the main display or multi-information display, the same sign displays again
when the power switch is turned to ON mode.

■

If “RSA Malfunction Visit Your Dealer” is shown

The system may be malfunctioning. Have the vehicle inspected by your Toy-
ota dealer.

■

Customization

Some functions can be customized. (Customizable features: