Toyota Prius Plug-in Hybrid (2023 year). Manual in english

376

5-5. Using the driving support systems

• When using an automatic car wash

• When driving through steam or smoke
• When driving near an object that reflects radio waves, such as a large

truck or guardrail

• When driving near a TV tower, broadcasting station, electric power plant,

or other location where strong radio waves or electrical noise may be
present

■

Situations in which the system may not operate properly

●

In some situations such as the following, an object may not be detected by
the radar sensor and front camera, preventing the system from operating
properly:
• When a detectable object is approaching your vehicle
• When your vehicle or a detectable object is wobbling
• If a detectable object makes an abrupt maneuver (such as sudden swerv-

ing, acceleration or deceleration)

• When your vehicle approaches a detectable object rapidly

• When a detectable object is near a wall, fence, guardrail, manhole cover,

vehicle, steel plate on the road, etc.

• When a detectable object is under a structure
• When part of a detectable object is hidden by an object, such as large

baggage, an umbrella, or guardrail

• When multiple detectable objects are close together
• If the sun or other light is shining directly on a detectable object
• When a detectable object is a shade of white and looks extremely bright
• When a detectable object appears to be nearly the same color or bright-

ness as its surroundings

• If a detectable object cuts or suddenly emerges in front of your vehicle
• When the front of your vehicle is hit by water, snow, dust, etc.

• When driving through or under

objects that may contact your vehicle,
such as thick grass, tree branches, or
a banner

• When a detectable object is not

directly in front of your vehicle

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5-5. Using the driving support systems

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• When a very bright light ahead, such as the sun or the headlights of

oncoming traffic, shines directly into the front camera

• When approaching the side or front of a vehicle ahead
• If a vehicle ahead is a motorcycle
• If a vehicle ahead is narrow, such as a personal mobility vehicle
• If a preceding vehicle has a small rear end, such as an unloaded truck

• If a vehicle ahead is carrying a load which protrudes past its rear bumper
• If a vehicle ahead is irregularly shaped, such as a tractor or side car
• If a vehicle ahead is a child sized bicycle, a bicycle that is carrying a large

load, a bicycle ridden by more than one person, or a uniquely shaped
bicycle (bicycle with a child seat, tandem bicycle, etc.)

• If a pedestrian/or the riding height of a bicyclist ahead is shorter than

approximately 1 m (3.2 ft.) or taller than approximately 2 m (6.5 ft.)

• If a pedestrian/bicyclist is wearing oversized clothing (a rain coat, long

skirt, etc.), making their silhouette obscure

• If a pedestrian is bending forward or squatting or bicyclist is bending for-

ward

• If a pedestrian/bicyclist is moving fast
• If a pedestrian is pushing a stroller, wheelchair, bicycle or other vehicle
• When driving in inclement weather such as heavy rain, fog, snow or a

sandstorm

• When driving through steam or smoke
• When the surrounding area is dim, such as at dawn or dusk, or while at

night or in a tunnel, making a detectable object appear to be nearly the
same color as its surroundings

• When driving in a place where the surrounding brightness changes sud-

denly, such as at the entrance or exit of a tunnel

• After the hybrid system has started the vehicle has not been driven for a

certain amount of time

• While making a left/right turn and for a few seconds after making a left/

right turn

• If a preceding vehicle has a low rear

end, such as a low bed trailer

• If a vehicle ahead has extremely high

ground clearance

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5-5. Using the driving support systems

• While driving on a curve and for a few seconds after driving on a curve
• If your vehicle is skidding

• If the wheels are misaligned
• If a wiper blade is blocking the front camera
• The vehicle is being driven at extremely high speeds
• When driving on a hill
• If the radar sensor or front camera is misaligned

●

In some situations such as the following, sufficient braking force may not be
obtained, preventing the system from performing properly:
• If the braking functions cannot operate to their full extent, such as when

the brake parts are extremely cold, extremely hot, or wet

• If the vehicle is not properly maintained (brakes or tires are excessively

worn, improper tire inflation pressure, etc.)

• When the vehicle is being driven on a gravel road or other slippery sur-

face

■

If VSC is disabled

●

If VSC is disabled (



P. 511), the pre-collision brake assist and pre-collision

braking functions are also disabled.

●

The PCS warning light will turn on and “VSC Turned Off Pre-Collision Brake
System Unavailable” will be displayed on the multi-information display.

• If the front of the vehicle is raised or

lowered

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5-5. Using the driving support systems

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LTA (Lane Tracing Assist)

While driving on a road with clear white (yellow) lane lines, the LTA
system warns the driver if the vehicle may deviate from the current
lane or course

, and also can slightly operate the steering wheel to

help avoid deviation from the lane or course

. Also, while the dynamic

radar cruise control with full-speed range is operating, this system will
operate the steering wheel to maintain the vehicle’s lane position.
The LTA system recognizes white
(yellow) lane lines or a course

using the front camera. Addition-
ally, it detects preceding vehicles
using the front camera and radar.

: Boundary between asphalt and the

side of the road, such as grass, soil,
or a curb

Summary of functions

380

5-5. Using the driving support systems

WARNING

■

Before using LTA system

●

Do not rely solely upon the LTA system. The LTA system does not auto-
matically drive the vehicle or reduce the amount of attention that must be
paid to the area in front of the vehicle. The driver must always assume full
responsibility for driving safely by paying careful attention to the surround-
ing conditions and operating the steering wheel to correct the path of the
vehicle. Also, the driver must take adequate breaks when fatigued, such
as from driving for a long period of time.

●

Failure to perform appropriate driving operations and pay careful attention
may lead to an accident, resulting in death or serious injury.

●

When not using the LTA system, use the LTA switch to turn the system off.

■

Situations unsuitable for LTA system

In the following situations, use the LTA switch to turn the system off. Failure
to do so may lead to an accident, resulting in death or serious injury.

●

Vehicle is driven on a road surface which is slippery due to rainy weather,
fallen snow, freezing, etc.

●

Vehicle is driven on a snow-covered road.

●

White (yellow) lines are difficult to see due to rain, snow, fog, dust, etc.

●

Vehicle is driven in a temporary lane or restricted lane due to construction
work.

●

Vehicle is driven in a construction zone.

●

A spare tire, tire chains, etc. are equipped.

●

When the tires have been excessively worn, or when the tire inflation pres-
sure is low.

●

During emergency towing.

■

Preventing LTA system malfunctions and operations performed by
mistake

●

Do not modify the headlights or place stickers, etc. on the surface of the
lights.

●

Do not modify the suspension etc. If the suspension etc. needs to be
replaced, contact any authorized Toyota retailer or Toyota authorized
repairer, or any reliable repairer.

●

Do not install or place anything on the hood or grille. Also, do not install a
grille guard (bull bars, kangaroo bar, etc.).

●

If your windshield needs repairs, contact any authorized Toyota retailer or
Toyota authorized repairer, or any reliable repairer.

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WARNING

■

Conditions in which functions may not operate properly

In the following situations, the functions may not operate properly and the
vehicle may depart from its lane. Drive safely by always paying careful
attention to your surroundings and operate the steering wheel to correct the
path of the vehicle without relying solely on the functions.

●

When the follow-up cruising display is displayed (



P. 389) and the pre-

ceding vehicle is swaying. (Your vehicle may sway accordingly and depart
from the lane.)

●

When the follow-up cruising display is displayed (



P. 389) and the pre-

ceding vehicle departs from its lane. (Your vehicle may follow the preced-
ing vehicle and depart from the lane.)

●

When the follow-up cruising display is displayed (



P. 389) and the pre-

ceding vehicle is being driven extremely close to the left/right lane line.
(Your vehicle may follow the preceding vehicle and depart from the lane.)

●

Vehicle is being driven around a sharp curve.

●

When the follow-up cruising display is
displayed (



P. 389) and the preceding

vehicle changes lanes. (Your vehicle
may follow the preceding vehicle and
also change lanes.)

●

Objects or patterns that could be mis-
taken for white (yellow) lines are pres-
ent on the side of the road (guardrails,
reflective poles, etc.).

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5-5. Using the driving support systems

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, “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.

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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.

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5-5. Using the driving support systems

■

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

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■

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 in 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.

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5-5. Using the driving support systems

■

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.

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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

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5-5. Using the driving support systems

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.

Indications on combination meter

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5-5. Using the driving support systems

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

a curb

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.



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.

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5-5. Using the driving support systems

■

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 50 km/h (32 mph) 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 3 m (9.8 ft.) or more.
• Turn signal lever is not operated.
• Vehicle is not being driven around a sharp curve.
• No system malfunctions are detected. (



P. 394)

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

mately 50 km/h (32 mph) 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”. (



P. 220)

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



P. 393)

●

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”. (



P. 220)

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



P. 394)

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5-5. Using the driving support systems

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●

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”. (



P. 220)

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



P. 394)

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



P. 393)

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

Toyota Prius Plug-in Hybrid (2023 year). Manual in english - page 23