TOYOTA SIENNA HYBRID 2023 Owners Manual

2694-5. Using the driving support systems
4
Driving
tional.
If the message does not disapp ear, contact your Toyota dealer.
• 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 e xtremely cold
environment
• When the front camera cannot d etect objects in front of the vehicle, such
as when driving in the dark, sno w, or fog, or when bright lights are shining
into the front camera
• Depending on the conditions in the vicinity of the vehicle, th e radar may
judge the surrounding environment can not be properly recognize d. In that
case, “Pre-Collision System Unavailable” is displayed.

2704-5. Using the driving support systems
The system can detect the fol-
lowing:
Vehicles
 Bicyclists
 Pedestrians
■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
collision 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 colli-
sion is extremely high, the
brakes are automatically applied
to help avoid the collision or
reduce the impact of the colli-
sion.
PCS (Pre-Collision Sys-
tem)
The pre-collision system
uses a radar sensor and
front camera to detect
objects ( P.270) in front of
the vehicle. When the sys-
tem determines that the
possibility of a frontal colli-
sion with an object is high,
a warning operates to urge
the driver to take evasive
action and the potential
brake pressure is increased
to help the driver avoid the
collision. If the system
determines that the possi-
bility of a frontal collision
with an object is extremely
high, the brakes are auto-
matically 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.272)
Detectable objects
System functions

2714-5. Using the driving support systems
4
Driving
WARNING
■Limitations of the pre-colli-
sion system
●The driver is solely responsible
for safe driving. Always drive
safely, taking care to observe
your surroundings.
Do not use the pre-collision sys-
tem instead of normal braking
operations under any circum-
stances. This system will not
prevent collisions or lessen col-
lision damage or injury in every
situation. Do not overly rely on
this system. Failure to do so
may lead to an accident, result-
ing in death or serious injury.
●Although this system is
designed to help avoid a colli-
sion 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 sys- tem may operate even if there is
no possibility of a collision:
 P.274
• Conditions under which the sys- tem may not operate properly:
 P.275
●Do not attempt to test the oper-
ation of the pre-collision system
yourself.
Depending on the objects used
for testing (dummies, card-
board objects imitating detect-
able objects, etc.), the system
may not operate properly, pos-
sibly 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 function, the pre-colli-
sion braking function operation
will be canceled after approxi-
mately 2 seconds. Depress the
brake pedal as necessary.
●The pre-collision braking func-
tion 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-collision braking function
from operating.
●In some situations, while the
pre-collision brak ing function is
operating, operation of the func-
tion 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 t he driver is tak-
ing evasive action and possibly
delay the operation timing of the
pre-collision braking function.
■When to disable the pre-colli-
sion system
In the following situations, disable
the system, as it may not operate
properly, possibly leading to an
accident resulting in death or seri-
ous injury:
●When the vehicle is being towed

2724-5. Using the driving support systems
■Enabling/disabling the pre-
collision system
The pre-collision system can be
enabled/disabled on
( P.112) of the multi-informa-
tion display.
The system is automatically
enabled each time the power
switch is turned to ON.
If the system is disabled, the
PCS warning light will turn on
and a message will be displayed
on the multi-information display.
■Changing the pre-collision
warning timing
The pre-collision warning timing
can be changed on
( P.112) of the multi-informa-
tion display.
The warning timing setting is
retained when the power switch is
turned to OFF. However, if the pre-
collision system is disabled and re-
enabled, the operation timing will
return to the default setting (mid-
dle).
WARNING
●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 speed-
ometer tester, or when using an
on vehicle wheel balancer
●When a strong impact is applied
to the front bumper or front
grille, due to a n accident or
other reasons
●If the vehicle cannot be driven in
a stable manner, such as when
the vehicle has been in an acci-
dent 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 sen-
sor or front camera is temporar-
ily installed to the vehicle
Changing settings of the
pre-collision system

2734-5. Using the driving support systems
4
Driving
1Early 2
Middle
This is the default setting.
3Late
■Operational conditions
The pre-collision syst em is enabled and the system determines t hat the pos-
sibility of a frontal c ollision with a detected object is high.
Each function is operatio nal at the following speed
●Pre-collision warning
●Pre-collision brake assist
Detectable objectsVehicle speedRelative speed between
your vehicle and object
VehiclesApprox. 7 to 110 mph (10 to 180 km/h)Approx. 7 to 110 mph (10 to 180 km/h)
Bicyclists and pedestri- ansApprox. 7 to 50 mph (10 to 80 km/h)Approx. 7 to 50 mph (10 to 80 km/h)
Detectable objectsVehicle speedRelative speed between your vehicle and object
VehiclesApprox. 20 to 110 mph (30 to 180 km/h)Approx. 20 to 110 mph (30 to 180 km/h)
Bicyclists and pedestri- ansApprox. 20 to 50 mph (30 to 80 km/h)Approx. 20 to 50 mph (30 to 80 km/h)

2744-5. Using the driving support systems
●Pre-collision braking
The system may not operate in the following situations:
●If a 12-volt battery te rminal has been disc onnected and reconne cted and
then the vehicle has not been dr iven for a certain amount of time
●If the shift lever is in R
●When the VSC OFF indicator is illuminated (only the pre-collision warning
function will be operational)
■Object detection function
The system detects objects based
on their size, profile, motion, etc.
However, an object may not be
detected depending on the sur-
rounding brightness and the motion,
posture, and angle of the detected
object, preventing the system from
operating properly. ( P.275)
The illustration sh ows an image of
detectable objects.
■Cancelation of t he pre-collision
braking
If either of the fo llowing occur while
the pre-collision braking function is
operating, 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 possibility of a colli-
sion
●In some situations such as the fol-
lowing, the system may determine
that there is a possibility of a fron-
tal collision and operate.
• When passing a detectable
object, etc.
• When changing lanes while over- taking a detectable object, etc.
• 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 winding road
• When rapidly closing on a detect- able object, etc.
• When approaching objects on the roadside, such as detectable
objects, guardrails, utility poles,
trees, or walls
• When there is a d etectable object
or other object by the roadside at
Detectable objectsVehicle speedRelative speed between
your vehicle and object
VehiclesApprox. 7 to 110 mph (10 to 180 km/h)Approx. 7 to 110 mph (10 to 180 km/h)
Bicyclists and pedestri- ansApprox. 7 to 50 mph (10 to 80 km/h)Approx. 7 to 50 mph (10 to 80 km/h)

2754-5. Using the driving support systems
4
Driving
the entrance of a curve
• When there are patterns or paint in front of your vehicle that may be
mistaken for a detectable object
• When the front of your vehicle is
hit by water, snow, dust, etc.
• When overtaking a detectable object that is ch anging 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 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 sur- rounded 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 passing under an object (road sign, billboard, etc.)
• When approaching an electric toll gate barrier, parking area barrier,
or other barrier that opens and
closes
• When using an automatic car
wash
• When driving through or under objects that may contact your
vehicle, such as thick grass, tree
branches, or a banner
• 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 elec-
trical noise may be present
■Situations in which the system
may not operate properly
●In some situations such as the fol-
lowing, an object may not be
detected by the radar sensor and
front camera, pre venting the sys-
tem from opera ting properly:
• When a detectable object is approaching your vehicle
• When your vehicle or a detectable object is wobbling

2764-5. Using the driving support systems
• If a detectable object makes an abrupt maneuver (such as sudden
swerving, accelera tion or deceler-
ation)
• When your vehicle approaches a detectable object rapidly
• When a detectable object is not directly in front of your vehicle
• 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
brightness as its surroundings
• If a detectable object cuts or sud-
denly emerges in front of your
vehicle
• When the front of your vehicle is
hit by water, snow, dust, etc.
• 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 preceding vehicle has a low rear end, such as a low bed trailer
• If a vehicle ahead has extremely high ground clearance
• 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 3.2 ft. (1 m) or taller
than approximate ly 6.5 ft. (2 m)
• If a pedestrian/bic yclist is wearing
oversized clothing (a rain coat,
long skirt, etc.), making their sil-
houette obscure
• If a pedestrian is bending forward or squatting or bicyclist is bending
forward
• If a pedestrian/bicyclist is moving fast
• If a pedestrian is pushing a
stroller, wheelchair, bicycle or
other vehicle
• When driving in inclement weather

2774-5. Using the driving support systems
4
Driving
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 t unnel, making a
detectable object appear to be
nearly the same color as its sur-
roundings
• When driving in a place where the surrounding brightness changes
suddenly, 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
• While driving on a curve and for a
few seconds after driving on a
curve
• If your vehicle is skidding
• If the front of the vehicle is raised
or lowered
• 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 fol-
lowing, sufficien t braking force
may not be obtained, preventing
the system from performing prop-
erly:
• 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 main-
tained (brakes or tires are exces-
sively worn, imprope r tire inflation
pressure, etc.)
• When the vehicle is being driven on a gravel road or other slippery
surface
■If VSC is disabled
●If VSC is disabled ( P.337), the
pre-collision brak e assist and pre-
collision braking functions are also
disabled.
●The PCS warning light will turn on
and “VSC Turned Off Pre-Colli-
sion Brake System Unavailable”
will be displayed on the multi-
information display.

2784-5. Using the driving support systems
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 con-
trol with full-speed range
P.291 is operating, this sys-
tem will operate the steering
wheel to maintain the vehi-
cle’s lane position.
The LTA system recognizes
white (yellow) lane lines or a
course
* using the front cam-
era. Additionally, 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
WARNING
■Before using LTA system
●Do not rely solely upon the LTA
system. The LTA system does
not automatically drive the vehi-
cle or reduce the amount of
attention that m ust be paid to
the area in front of the vehicle.
The driver must always assume
full responsibilit y for driving
safely by paying careful atten-
tion to the surrounding condi-
tions 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 care-
ful attention may lead to an
accident, resulting in death or
serious injury.
●When not using the LTA sys-
tem, 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 sur-
face which is slippery due to
rainy weather, fallen snow,
freezing, etc.
●Vehicle is driven on a snow-cov-
ered road.
●White (yellow) lin es 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.