Toyota Prius (2023 year). Manual in english

294

4-5. Using the driving support systems

■

If a warning message is displayed on the multi-information display

A system may be temporarily unavailable or there may be a malfunction in
the system.

●

In the following situations, perform the actions specified in the table. When
the normal operating conditions are detected, the message will disappear
and the system will become operational.

If the message does not disappear, contact any authorized Toyota retailer or
Toyota authorized repairer, or any reliable repairer.

Situation

Actions

When the area around a cam-
era is covered with dirt, mois-
ture (fogged up, covered with
condensation, ice, etc.), or
other foreign matter

Using the wiper and A/C function,
remove the dirt and other attached mat-
ter. (



P. 462)

When the temperature around
the front camera is outside of
the operational range, such as
when the vehicle is in the sun or
in an extremely cold environ-
ment

If the front camera is hot, such as after
the vehicle had been parked in the sun,
use the air conditioning system to
decrease the temperature around the
front camera.

If a sunshade was used when the vehi-
cle was parked, depending on its type,
the sunlight reflected from the surface
of the sunshade may cause the tem-
perature of the front camera to become
excessively high.

If the front camera is cold, such after the
vehicle is parked in an extremely cold
environment, use the air conditioning
system to increase the temperature
around the front camera.

The area in front of the front
camera is obstructed, such as
when the hood is open or a
sticker is attached to the part of
the windshield in front of the
front camera.

Close the hood, remove the sticker, etc.
to clear the obstruction.

When “Pre-Collision System
Unavailable” is displayed.

Check whether there is attached materi-
als on the radar sensor and radar sensor
cover, and if there is, remove it.

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4-5. Using the driving support systems

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●

In the following situations, if the situation has changed (or the vehicle has
been driven for some time) and the normal operating conditions are
detected, the message will disappear and the system will become opera-
tional.

If the message does not disappear, contact any authorized Toyota retailer or
Toyota authorized repairer, or any reliable repairer.

• When the temperature around the radar sensor is outside of the opera-

tional range, such as when the vehicle is in the sun or in an extremely
cold environment

• When the front camera cannot detect objects in front of the vehicle, such

as when driving in the dark, snow, or fog, or when bright lights are shining
into the front camera

• Depending on the conditions in the vicinity of the vehicle, the radar may

judge the surrounding environment can not be properly recognized. In
that case, “Pre-Collision System Unavailable” is displayed.

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4-5. Using the driving support systems

PCS (Pre-Collision System)



The system can detect the following:

●

Vehicles

●

Bicyclists

●

Pedestrians



: If equipped

The pre-collision system uses a radar sensor and front camera
to detect objects (



P. 296) in front of the vehicle. When the sys-

tem determines that the possibility of a frontal collision with an
object is high, a warning operates to urge the driver to take eva-
sive action and the potential brake pressure is increased to help
the driver avoid the collision. If the system determines that the
possibility of a frontal collision with an object is extremely high,
the brakes are automatically applied to help avoid the collision
or help reduce the impact of the collision.

The pre-collision system can be disabled/enabled and the warning
timing can be changed. (



P. 300)

Detectable objects

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■

Pre-collision warning

When the system determines
that the possibility of a frontal
collision is high, a buzzer will
sound and a warning message
will be displayed on the multi-
information display to urge the
driver to take evasive action.

■

Pre-collision brake assist

When the system determines that the possibility of a frontal colli-
sion is high, the system applies greater braking force in relation to
how strongly the brake pedal is depressed.

■

Pre-collision braking

If the system determines that the possibility of a frontal collision is
extremely high, the brakes are automatically applied to help avoid
the collision or reduce the impact of the collision.

System functions

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4-5. Using the driving support systems

WARNING

■

Limitations of the pre-collision system

●

The driver is solely responsible for safe driving. Always drive safely, taking
care to observe your surroundings.
Do not use the pre-collision system instead of normal braking operations
under any circumstances. This system will not prevent collisions or lessen
collision damage or injury in every situation. Do not overly rely on this sys-
tem. Failure to do so may lead to an accident, resulting in death or serious
injury.

●

Although this system is designed to help avoid a collision or help reduce
the impact of the collision, its effectiveness may change according to vari-
ous conditions, therefore the system may not always be able to achieve
the same level of performance.
Read the following conditions carefully. Do not overly rely on this system
and always drive carefully.
• Conditions under which the system may operate even if there is no pos-

sibility of a collision:



P. 302

• Conditions under which the system may not operate properly:



P. 304

●

Do not attempt to test the operation of the pre-collision system yourself.
Depending on the objects used for testing (dummies, cardboard objects
imitating detectable objects, etc.), the system may not operate properly,
possibly leading to an accident.

■

Pre-collision braking

●

When the pre-collision braking function is operating, a large amount of
braking force will be applied.

●

If the vehicle is stopped by the operation of the pre-collision braking func-
tion, the pre-collision braking function operation will be canceled after
approximately 2 seconds. Depress the brake pedal as necessary.

●

The pre-collision braking function may not operate if certain operations are
performed by the driver. If the accelerator pedal is being depressed
strongly or the steering wheel is being turned, the system may determine
that the driver is taking evasive action and possibly prevent the pre-colli-
sion braking function from operating.

●

In some situations, while the pre-collision braking function is operating,
operation of the function may be canceled if the accelerator pedal is
depressed strongly or the steering wheel is turned and the system deter-
mines that the driver is taking evasive action.

●

If the brake pedal is being depressed, the system may determine that the
driver is taking evasive action and possibly delay the operation timing of
the pre-collision braking function.

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WARNING

■

When to disable the pre-collision system

In the following situations, disable the system, as it may not operate prop-
erly, possibly leading to an accident resulting in death or serious injury:

●

When the vehicle is being towed

●

When your vehicle is towing another vehicle

●

When transporting the vehicle via truck, boat, train or similar means of
transportation

●

When the vehicle is raised on a lift with the hybrid system on and the tires
are allowed to rotate freely

●

When inspecting the vehicle using a drum tester such as a chassis
dynamometer or speedometer tester, or when using an on vehicle wheel
balancer

●

When a strong impact is applied to the front bumper or front grille, due to
an accident or other reasons

●

If the vehicle cannot be driven in a stable manner, such as when the vehi-
cle has been in an accident or is malfunctioning

●

When the vehicle is driven in a sporty manner or off-road

●

When the tires are not properly inflated

●

When the tires are very worn

●

When tires of a size other than specified are installed

●

When tire chains are installed

●

When a compact spare tire or an emergency tire puncture repair kit is used

●

If equipment (snow plow, etc.) that may obstruct the radar sensor or front
camera is temporarily installed to the vehicle

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4-5. Using the driving support systems

■

Enabling/disabling the pre-collision system

The pre-collision system can be enabled/disabled on

(



P. 153)

of the multi-information display.

The system is automatically enabled each time the power switch is
turned to ON mode.

If the system is disabled, the
PCS warning light will turn on
and a message will be dis-
played on the multi-information
display.

■

Changing the pre-collision warning timing

The pre-collision warning timing can be changed on

(



P. 153)

of the multi-information display.

The warning timing setting is retained when the power switch is turned
off.
However, if the pre-collision system is disabled and re-enabled, the
operation timing will return to the default setting (middle).

Early
Middle

This is the default setting.

Late

Changing settings of the pre-collision system

1
2

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■

Operational conditions

The pre-collision system is enabled and the system determines that the pos-
sibility of a frontal collision with a detected object is high.
Each function is operational at the following speed

●

Pre-collision warning

●

Pre-collision brake assist

●

Pre-collision braking

The system may not operate in the following situations:

●

If a 12-volt battery terminal has been disconnected and reconnected and
then the vehicle has not been driven for a certain amount of time

●

If the shift position is in R

●

When the VSC OFF indicator is illuminated (only the pre-collision warning
function will be operational)

Detectable objects

Vehicle speed

Relative speed between

your vehicle and object

Vehicles

Approx. 10 to 180 km/h
(7 to 110 mph)

Bicyclists and pedestri-
ans

Approx. 10 to 80 km/h
(7 to 50 mph)

Detectable objects

Vehicle speed

Relative speed between

your vehicle and object

Vehicles

Approx. 30 to 180 km/h
(20 to 110 mph)

Bicyclists and pedestri-
ans

Approx. 30 to 80 km/h
(20 to 50 mph)

Detectable objects

Vehicle speed

Relative speed between

your vehicle and object

Vehicles

Approx. 10 to 180 km/h
(7 to 110 mph)

Bicyclists and pedestri-
ans

Approx. 10 to 80 km/h
(7 to 50 mph)

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4-5. Using the driving support systems

■

Object detection function

■

Cancelation of the pre-collision braking

If either of the following occur while the pre-collision braking function is oper-
ating, it will be canceled:

●

The accelerator pedal is depressed strongly.

●

The steering wheel is turned sharply or abruptly.

■

Conditions under which the system may operate even if there is no pos-
sibility of a collision

●

In some situations such as the following, the system may determine that
there is a possibility of a frontal collision and operate.
• When passing a detectable object, etc.
• When changing lanes while overtaking a detectable object, etc.

• When rapidly closing on a detectable object, etc.
• When approaching objects on the roadside, such as detectable objects,

guardrails, utility poles, trees, or walls

The system detects objects based on
their size, profile, motion, etc. However,
an object may not be detected depending
on the surrounding brightness and the
motion, posture, and angle of the
detected object, preventing the system
from operating properly. (



P. 304)

The illustration shows an image of detect-
able objects.

• When approaching a detectable

object in an adjacent lane or on the
roadside, such as when changing the
course of travel or driving on a wind-
ing road

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• When there are patterns or paint in front of your vehicle that may be mis-

taken for a detectable object

• When the front of your vehicle is hit by water, snow, dust, etc.

• When a detectable object approaches very close and then stops before

entering the path of your vehicle

• If the front of your vehicle is raised or lowered, such as when on an

uneven or undulating road surface

• When driving on a road surrounded by a structure, such as in a tunnel or

on an iron bridge

• When there is a metal object (manhole cover, steel plate, etc.), steps, or a

protrusion in front of your vehicle

• When approaching an electric toll gate barrier, parking area barrier, or

other barrier that opens and closes

• When there is a detectable object or

other object by the roadside at the
entrance of a curve

• When overtaking a detectable object

that is changing lanes or making a
right/left turn

• When passing a detectable object in

an oncoming lane that is stopped to
make a right/left turn

• When passing under an object (road

sign, billboard, etc.)

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4-5. 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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4-5. 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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4-5. 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. 443), 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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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



: If equipped

Summary of functions

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4-5. 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. 317) 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. 317) 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. 317) 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. 317) 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.).

Toyota Prius (2023 year). Manual in english - page 18