wheel TOYOTA PRIUS PRIME 2023 Repair Manual

3235-5. Using the driving support systems
5
Driving
rounding conditions
●In the following situations, system
operation may be canceled:
• When the brake control or output restriction control of a driving sup-
port system operates (For exam-
ple: PCS, drive-start control)
• When the system determines that
a detected object has moved
away from the vehicle
• When lane lines can no longer be
detected
• When the brake pedal has been depressed
• When the accelerator pedal has been depressed
• When the steering wheel has
been operated with more than a
certain amount of force
• When the turn signal lever is oper-
ated to the left/right turn position
WARNING
■Situations in which the sys-
tem may not operate properly
●Situations in which the lane may
not be detected: P.291
●When a detectable object stops
immediately before entering the
path of the vehicle
●When passing extremely close
to a detectable object behind a
guardrail, fence, etc.
●When changing lanes while
overtaking a detectable object
●When passing a detectable
object that is changing lanes or
turning left/right
●When there are objects (guard-
rails, power poles, trees, walls,
fences, poles, traffic cones,
mailboxes, etc.) in the surround-
ing area
●When there are patterns or a
painting ahead of the vehicle
that may be mistaken for a
detectable object
●When passing through a place
with a low structure above the
road (tunnel with a low ceiling,
traffic sign, signboard, etc.)
●When driving on snowy, icy, or
rutted roads
●When a detectable object is
approaching your vehicle
●When your vehicle or a detect-
able object is wandering
●When the movement of a
detectable object changes
(change in direction, sudden
acceleration or deceleration,
etc.)
●When suddenly approaching a
detectable object
●When a preceding vehicle or
motorcycle is not directly in front
of your vehicle
●When there is a structure above
a detectable object
●When part of a detectable
object is hidden by another
object (large luggage, umbrella,
guardrail, etc.)
●When multiple detectable
objects are overlapping
●When a bright light, such as the
sun or headlights of another
vehicle, is reflecting off of the
detectable object
●When the detectable object is
white and looks extremely bright
●When the color or brightness of
the detectable object causes it
to blend in with its surroundings
●When a detectable object cuts
in front of or emerges from
beside a vehicle

3245-5. Using the driving support systems
The proactive driving assist
can be enabled/disabled
through a customize setting.
( P.627)
 The settings of the proactive
driving assist can be changed
through customize settings.
( P.627)
Depending on the situation, the following indicators or icons will be
displayed.
Some icons cannot be displayed unless the display is changed to
the driving safety support function information screen.
WARNING
●When approaching a vehicle
ahead which is perpendicular or
at an angle to the vehicle, or is
facing the vehicle
●If a parked vehicle is perpendic-
ular or at an angle to the vehicle
●When a bicycle is a child sized
bicycle, is carrying a large load,
is carrying an extra passenger,
or has an unusual shape (bicy-
cles equipped with a child seat,
tandem bicycles, etc.)
●When a pedestrian or bicyclist is
shorter than approximately 3.2
ft. (1 m) or taller than approxi-
mately 6.5 ft. (2 m)
●When the silhouette of a pedes-
trian or bicyclist is unclear (such
as when they are wearing a
raincoat, long skirt, etc.)
●When a pedestrian or bicyclist is
bending forward or squatting
●When a pedestrian or bicyclist is
moving at high speed
●When a pedestrian is pushing a
stroller, wheelchair, bicycle or
other vehicle
●When a detectable object
blends in with the surrounding
area, such as when it is dim (at
dawn or dusk) or dark (at night,
in a tunnel, etc.)
●When the lane width is 13.1 ft.
(4 m) or more
●When the lane width is 8.2 ft.
(2.5 m) or less
●When the vehicle has not been
driven for a certain amount of
time after the hybrid system was
started
●While turning left or right or a
few seconds after turning left or
right
●While changing lanes or a few
seconds after changing lanes
●When entering a curve, driving
around a curve and a few sec-
onds after driving around a
curve
Changing proactive driv-
ing assist settings
System operation display

3255-5. Using the driving support systems
5
Driving
■Hands off steering wheel warn-
ing operation
In the following situations, a mes-
sage urging the driver to grip the
steering wheel and the icon shown
in the illustration will be displayed on
the display to warn the driver. If the system detects that the steering
wheel is held, the warning will be
canceled. When using the system,
make sure to grip the steering wheel
firmly, regardless of whether the
warning is operating or not.
IconMeaning

White: Monitoring for detectable
objects
 Green: Detectable object crossing
the road or detectable object on
the side of the road assistance
operating
A pedestrian has been detected as
crossing the road or on the side of
the road and brake or steering assis-
tance is operating
A vehicle has been detected on the
side of the road and brake or steer-
ing operation assistance is being
performed
Steering operation assistance is
being performed to prevent the
vehicle from approaching too close
to a detectable object on the side
of the road
 When the steering assist is operat-
ing
Preceding vehicle deceleration
assistance is being performed
Warning to maintain appropriate
vehicle-to-vehicle distance
Curve deceleration assistance is
being performed

3265-5. Using the driving support systems
●When assistance to a detectable
object crossing the road or assis-
tance to a detectable object on the
side of the road is performed and
the system determines the driver
is not holding the steering wheel
If no operations are detected for a
certain amount of time, a buzzer will
sound, the warning will operate.
This warning may also operate if the
driver only operates steering wheel
a small amount continuously.
■Warning operation after preced-
ing vehicle deceleration assis-
tance has ended
After preceding vehicle decelera-
tion assistance has ended, if the
driver does not operate the brake
pedal or accelerator pedal and the
vehicle approaches the preceding
vehicle, the display will flash and a
buzzer will sound to urge the driver
to decelerate. If the system deter-
mines that the driver is operating the
brake pedal or accelerator pedal,
the warning will be canceled.
*: If equipped
 When the system detects a
vehicle approaching from the
left or right in front of your
vehicle when approaching an
intersection, a notification will
be displayed.
 When the system determines
that your vehicle may be
about to enter an intersection
even though a vehicle is
approaching from the left or
right in front of your vehicle, a
buzzer will sound and a mes-
sage will be displayed to urge
you to depress the brake
pedal.
• Multi-information display
FCTA (Front Cross
Traffic Alert)*
When approaching an inter-
section, etc., at a low speed,
vehicles approaching from
the left and right of the front
of the vehicle can be
detected and the driver
informed of these vehicles.
FCTA system control

3385-5. Using the driving support systems
●When a preceding vehicle brakes
suddenly
●When changing lanes at low
speeds, such as in a traffic jam
■Conditions for extended
resume time (Vehicles with
Traffic Jam Assist)
Extended resume ti me is activated
when all of the following conditions
are satisfied:
●The connected service that
Toyota provides is subscribed to.
Contact your Toyota dealer for
details.
●The vehicle is driving on a vehicle-
only road, such as an express-
way.
●There is a preceding vehicle and
the system is able to detect it.
●No vehicle interruptions occur.
●The preceding vehicle has not
been replaced.
●Clearance sonar and FCTA are
not detecting the object in front of
you.
●The driver monitor judges that the
driver is looking forward.
●The steering wheel has not been
operated.
●The brake pedal has not been
operated.
In situations where the vehicle
approaches a preceding vehicle
and the system cannot provide
sufficient deceleration, such as
if a vehicle cuts in front of the
vehicle, a warning display will
flash and a buzzer will sound to
alert the driver. Depress the
brake pedal to ensure appropri-
ate vehicle-to-vehicle distance.
■Warnings may not occur
when
In the following situations, the
warning may not operate even
though the vehicle-to-vehicle
distance is short.
 When the preceding vehicle is
traveling at the same speed
or faster than your vehicle
 When the preceding vehicle is
traveling at an extremely low
speed
 Immediately after the vehicle
speed has been set
 When the accelerator pedal is
depressed
When a curve is detected, the
vehicle speed will begin being
reduced. When the curve ends,
the vehicle speed reduction will
end.
Depending on the situation, the
vehicle speed will then return to the
set vehicle speed.
In situations where vehicle-to-vehi-
cle distance control needs to oper-
ate, such as when a preceding
vehicle cuts in front of your vehicle,
the curve speed reduction function
will be canceled.
Approach warning
Curve speed reduction
function

3395-5. Using the driving support systems
5
Driving
■Situations in which the curve
speed reduction function may
not operate
In situations such as the following,
the curve speed reduction function
may not operate:
●When the vehicle is being driven
around a gentle curve
●When the accelerator pedal is
being depressed
●When the vehicle is being driven
around an extremely short curve
While a warning of the driver
monitor is being displayed, the
vehicle acceleration will be
restrained.
When the warning of the driver
monitor disappears, the restrained
acceleration control will end.
If your vehicle is being driven at
approximately 50 mph (80 km/h)
or more and a lane change to
the passing lane is performed,
when the turn signal lever is
operated and the lane is
changed, the vehicle will accel- erate up to the set speed to
assist in overtaking.
The system’s recognition of
which lane is the passing lane
may be based solely on the
location of the steering wheel in
the vehicle (left-hand drive/right-
hand drive). If the vehicle is
driven in a location where the
passing lane is on the opposite
side of that where the vehicle
was originally sold, the vehicle
may accelerate when the turn
signal lever is operated away
from the passing lane. (e.g. The
vehicle was manufactured for a
right-hand traffic location, but is
being driven in a left-hand traffic
location. The vehicle may accel-
erate when the turn signal lever
is operated to the right.)
If your vehicle is being driven at
approximately 50 mph (80 km/h)
or more and the lane is changed
to that with a vehicle traveling
slower than your vehicle, when
the turn signal lever is operated
the vehicle will
gradually decel-
erate to assist in changing
lanes.
The settings of Dynamic radar
cruise control can be changed
through customize settings.
( P.628)
Driver Monitor support
function (if equipped)
Support for lane changeChanging Dynamic radar
cruise control settings

3455-5. Using the driving support systems
5
Driving
Emergency Driving
Stop System
The emergency driving stop
system is a system which
automatically decelerates
and stops the vehicle within
its lane if the driver
becomes unable to continue
driving the vehicle, such as
if they have suffered a medi-
cal emergency, etc.
During LTA (Lane Tracing
Assist) control, if the sys-
tem does not detect driving
operations, such as if the
driver is not holding the
steering wheel, and deter-
mines the driver is not
responsive, the vehicle will
be decelerated and stopped
within its current lane to
help avoid a collision or
reduce the impact of a colli-
sion.
The vehicle will also decel-
erate/stop during the Traffic
Jam Assist (if equipped)
controls, when no driver’s
response to the vehicle’s
warning to hold the steering
wheel is detected.
WARNING
■For safe use
●Driving safely is solely the
responsibility of the driver. Pay
careful attention to the sur-
rounding conditions in order to
ensure safe driving. The emer-
gency driving stop system is
designed to provide support in
an emergency where it is diffi-
cult for the driver to continue
driving, such as if they have had
a medical emergency. It is not
designed to support driving
while drowsy or in poor physical
health, or inattentive driving.
●Although the emergency driv-
ing stop system is designed to
decelerate the vehicle within its
lane to help avoid or help
reduce the impact of a collision
if the system determines that it
is difficult for the driver to con-
tinue driving, its effectiveness
may change according to vari-
ous conditions. Therefore, it
may not always be able to
achieve the same level of per-
formance. Also, if the operating
conditions are not met, this
function will not operate.
●After the emergency driving
stop system operates, if driving
becomes possible again, imme-
diately begin driving again or, if
necessary, park the vehicle on
the shoulder of the road and set
a warning reflector and flare to
warn other drivers of your
stopped vehicle.
●After this system operates, pas-
sengers should attend to the
driver as necessary and take
appropriate hazard prevention
measures, such as moving to a
place where safety can be
ensured, such as the shoulder
of the road or behind a guard-
rail.

3465-5. Using the driving support systems
Operation of this system is sep-
arated into 4 control states.
Through control state “warning
phase 1” and “warning phase 2”,
the system determines if the
driver is aware and responsive
while outputting a warning and
controlling the vehicle speed. If
the system determines the
driver is not responsive, it will
operate in control state “deceler-
ation stop phase” and “stop hold
phase” and decelerate and stop
the vehicle. It will then operate
continuously in “stop hold
phase”.
■Operating conditions
This system operates when all of
the following conditions are met:
●When the LTA is on
Or during the Traffic Jam Assist (if
equipped) controls
●When the vehicle speed is
approximately 30 mph (50 km/h) or more
During the Traffic Jam Assist con-
trols (if equipped), the system may
operate at below 30 mph (50 km/h).
■Operation cancelation condi-
tions
In the following si tuations, system
operation will be canceled:
●When LTA control has been can-
celed (the LTA switch has been
pressed, etc.)
●When the dynamic radar cruise
control has been canceled
●When driver operations are
detected (the steering wheel is
held, the brake pedal, accelerator
pedal, parking brake, emergency
flasher switch, or turn signal lever
is operated)
●When the driving assist switch is
pressed while in the stop and hold
phase
●When the power switch has been
turned from ON to off
●Situations in which some or all of
the functions of the system cannot
operate: P.291
■LTA control when operation is
canceled
When emergency driving stop sys-
tem operation is canceled, LTA con-
trol may also be canceled.
If driving operations are not
detected after the hands off
steering wheel warning oper-
ates, a buzzer will sound inter-
mittently and a message will be
displayed to warn the driver, and
the system will judge if the driver
is responsive or not. If driving
operations, such as holding the
steering wheel, are not per-
WARNING
●This system detects the condi-
tion of the driver through the
operation of the steering wheel.
This system may operate if the
driver is aware but intentionally
and continuously does not oper-
ate the vehicle. Also, the system
may not operate if it cannot
determine that the driver is not
responsive, such as if they are
leaning on the steering wheel.
●Situations in which the driver
monitor may not operate prop-
erly: P.291
Summary of the system
Warning phase 1

3475-5. Using the driving support systems
5
Driving
formed within a certain amount
of time, the system will enter
warning phase 2.
Vehicles with a driver monitor
camera: Depending on the type
of detection of the driver’s unre-
sponsiveness, the system may
skip warning phase 1 and start
the control of warning phase 2.
After entering warning phase 2,
a buzzer will sound in short
intervals and a message will be
displayed to warn the driver, and
the vehicle will slowly deceler-
ate. If driving operations, such
as holding the steering wheel,
are not performed within a cer-
tain amount of time, the system
will determine that the driver is
not responsive and enter the
deceleration stop phase.
The audio system will be muted
until the driver becomes respon-
sive.
When the vehicle is decelerat-
ing, the brake lights may illumi-
nate, depending on the road
conditions, etc.
After entering the deceleration
stop phase, a buzzer will sound
continuously and a message will
be displayed to warn the driver,
and the vehicle will slowly decel-erate and stop. After the vehicle
stops, the system will enter the
stop and hold phase.
After the vehicle is stopped, the
parking brake will be applied
automatically. After entering the
stop and hold phase, the buzzer
will continue sounding continu-
ously and the emergency flash-
ers (hazard lights) will flash to
warn other drivers of the emer-
gency.
■Restricted functions after the
operation is canceled
After shifting to the deceleration
stop phase, the following functions
will not be available until the hybrid
system is re-started even though
the emergency driving stop system
is canceled:
●LTA
●LCA (if equipped)
●Traffic Jam Assist (if equipped)
Warning phase 2
Deceleration stop phase
Stop hold phase

3485-5. Using the driving support systems
*: If equipped
■Precautions for use
 P.289
 Sensors which detect the sur-
rounding conditions ( P.286)
 Sensors which detect the
driver condition ( P.286)
■Situations in which some or all
of the functions of the system
cannot operate
 P.291
■Changes in brake operation
sound and pedal response
 P.291
■Situations in which the driver
monitor may not operate prop-
erly
 P.291
P.345
 P.333
The Traffic Jam Assist function,
through confirmation of the con-
ditions by the driver, provides
lane keeping, accelerat-
ing/decelerating and stopping
support on some highways and
expressways.
This function is operable when
all of the operation conditions
are met. When this function is
operating, it is possible to take
your hands off of the steering
wheel.
Before using the Traffic Jam Assist
function, familiari ze yourself with
the content of the dynamic radar
cruise control and the LTA (Lane
Tracing Assist).
Make sure that the driver steers the
vehicle when entering a service
area/parking area or toll gate, or
when changing lanes.
■Driver monitor camera
recording
When the operation of Traffic
Traffic Jam Assist*
Traffic Jam Assist is a sys-
tem which, through confir-
mation of the conditions by
the driver, provides lane
keeping, accelerating/decel-
erating, stopping, and start-
ing off support on some
highways and express-
ways. Also, in an emer-
gency, the system can
decelerate and stop, to help
avoid a collision or help
reduce the impact of a colli-
sion.
Sensors that support the
Traffic Jam Assist
Emergency Driving Stop
System
Extended resume time of
dynamic radar cruise con-
trol
Traffic Jam Assist Func-
tion