2021 TOYOTA SIENNA HYBRID trailer

2524-3. Operating the lights and wipers
fog, mist, ice, dirt, etc.
• The windshield is cracked or dam- aged
• The front camera is deformed or
dirty
• When the temperature of the front
camera is extremely high
• Surrounding brightness levels are equal to those of h eadlights, tail
lights or fog lights
• When headlights or tail lights of vehicles ahead are turned off,
dirty, changing color, or not aimed
properly
• When the vehicle is hit by water,
snow, dust, etc. fr om a preceding
vehicle
• When driving thr ough an area of
intermittently changing brightness
and darkness
• When frequently and repeatedly
driving ascending/descending
roads, or roads with rough, bumpy
or uneven surfaces (such as
stone-paved roads, gravel roads,
etc.)
• When frequently and repeatedly
taking curves or driving on a wind-
ing road
• There is a highly reflective object
ahead of the vehicle, such as a
sign or mirror
• The back of a vehicle ahead is
highly reflective, such as a con-
tainer on a truck
• The vehicle’s headlights are dam-
aged or dirty, or are not aimed
properly
• The vehicle is listing or titling due
to a flat tire, a trailer being towed,
etc.
• The high beam and low beam are
repeatedly being switched
between in an abnormal manner
• The driver believes that the high
beam may be causing problems
or distress to other drivers or
pedestrians nearby
■Temporarily lowering sensor
sensitivity
The sensitivity of the sensor can be
temporarily lowered. 1
Turn the power s witch off while
the following conditions are met.
●The headlight switch is in or
position.
●The headlight switch lever is in the
original position.
●Automatic High Beam switch is
on.
2 Turn the power switch to ON.
3 Within 60 seconds after step 2,
repeat pushing the headlight
switch lever to the high beam
position then pulling it to the orig-
inal position quickly 10 times,
then leave the lever in the origi-
nal position.
4 If the sensitivity is changed, the
Automatic High Beam indicator
turns on and off 3 times.
■Switching to the high
beams
Push the lever away from you.
The Automatic High Beam indicator
will turn off and the headlight high
beam indicator will turn on.
Pull the lever to its original position
to activate the Automatic High
Beam system again.
■Switching to the low beams
Press the Automatic High Beam
Turning the high beam
on/off manually

2734-5. Using the driving support systems
4
Driving
• 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

2764-5. Using the driving support systems
WARNING
●Vehicle is driven in a construc-
tion zone.
●A spare tire, tire chains, etc. are
equipped.
●When the tires have been
excessively worn, or when the
tire inflation pressure is low.
●When your vehicle is towing a
trailer or during emergency tow-
ing
■Preventing LTA system mal-
functions and operations per-
formed by mistake
●Do not modify the headlights or
place stickers, etc. on the sur-
face of the lights.
●Do not modify the suspension
etc. If the suspension etc. needs
to be replaced, contact your
Toyota dealer.
●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 your Toyota
dealer.
■Conditions in which functions
may not operate properly
In the following situations, the
functions may not operate prop-
erly 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 dis-
play is displayed ( P.281) and
the preceding vehicle changes
lanes. (Your veh icle may follow
the preceding vehicle and also
change lanes.)
●When the follow-up cruising dis-
play is displayed ( P.281) and
the preceding vehicle is sway-
ing. (Your vehicle may sway
accordingly and depart from the
lane.)
●When the follow-up cruising dis-
play is displayed ( P.281) and
the preceding vehicle departs
from its lane. (Your vehicle may
follow the preceding vehicle and
depart from the lane.)
●When the follow-up cruising dis-
play is displayed ( P.281) and
the preceding vehicle is being
driven extremely close to the
left/right lane line. (Your vehicle
may follow the preceding vehi-
cle and depart from the lane.)
●Vehicle is being driven around a
sharp curve.

2914-5. Using the driving support systems
4
Driving
This mode employs a radar to detect the presence of vehicles up to
approximately 328 ft. (100 m) ahead, determines the current vehicle-
to-vehicle following distance, and operates to maintain a suitable fol-
lowing distance from the vehicle ahead. The desired vehicle-to- vehi-
cle distance can also be set by operating the vehicle-to-vehicle
distance switch.
When driving on downhill slopes, the vehicle-to-vehicle distanc e may
become shorter.
WARNING
●When weather conditions are
bad enough that they may pre-
vent the sensors from detecting
correctly (fog, snow, sandstorm,
heavy rain, etc.)
●When there is rain, snow, etc.
on the front surface of the radar
or front camera
●In traffic conditions that require
frequent repeated acceleration
and deceleration
●When your vehicle is towing a
trailer or during emergency tow-
ing
●When an approach warning
buzzer is heard often
Driving in vehicle-to-vehicle distance control mode

2984-5. Using the driving support systems
●Pre-collision braking is activated.
●The parking brake is operated.
If constant speed control mode is
automatically canceled for any rea-
sons other than the above, there
may be a malfunction in the system.
Contact your Toyota dealer.
■Brake operation
A brake operation sound may be
heard and the brake pedal response
may change, but the se are not mal-
functions.
■Warning messages and buzzers
for dynamic radar cruise con-
trol with full-speed range
Warning messages and buzzers are
used to indicate a system malfunc-
tion or to inform the driver of the
need for caution while driving. If a
warning message is shown on the
multi-information display, read the
message and follow the instructions.
(  P.265, 477)
■When the sensor may not be
correctly detecting the vehicle
ahead
In the case of the following and
depending on the conditions, oper-
ate the brake pedal when decelera-
tion of the system is insufficient or
operate the accelerator pedal when
acceleration is required.
As the sensor may not be able to
correctly detect these types of vehi-
cles, the approach warning
(  P.295) may not be activated.
●Vehicles that cut in suddenly
●Vehicles traveling at low speeds
●Vehicles that are not moving in
the same lane
●Vehicles with small rear ends
(trailers with no load on board,
etc.)
●Motorcycles traveling in the same
lane
●When water or snow thrown up by
the surrounding vehicles hinders
the detecting of the sensor
●When your vehicle is pointing
upwards (caused by a heavy load
in the luggage compartment, etc.)
●Preceding vehicle has an
extremely high ground clearance
■Conditions under which the
vehicle-to-vehic le distance con-
trol mode may not function cor-
rectly
In the case of the following condi-
tions, operate the brake pedal (or
accelerator pedal, depending on the
situation) as necessary.
As the sensor may not be able to
correctly detect vehicles ahead, the
system may not operate properly.
●When the road curves or when the
lanes are narrow

3054-5. Using the driving support systems
4
Driving
when driving on the edge of a
lane, and the vehicle in an adja-
cent lane is far away from your
vehicle
• When an accessory (such as a hitch-mounted bicycle carrier) is
installed to the r ear of the vehicle
• When the vehicle is heavily loaded in the luggage compart-
ment
• When there is a significant differ- ence in height between your vehi-
cle and the vehicle that enters the
detection area
• Immediately after the BSM func-
tion/RCTA function are turned on
• When towing a trailer
●Instances of the BSM function
unnecessarily detecting a vehicle
and/or object may increase in the
following situations:
• When the sensor is misaligned
due to a strong impact to the sen-
sor or its surrounding area
• When the distanc e between your
vehicle and a guar drail, wall, etc.
that enters the detection area is
short
• When driving up and down con-
secutive steep inclines, such as
hills, dips in the road, etc.
• When vehicle lanes are narrow, or
when driving on the edge of a
lane, and a vehicle traveling in a
lane other than the adjacent lanes
enters the detection area
• When driving on roads with sharp bends, consecutive curves, or
uneven surfaces
• When the tires are slipping or spinning
• When the distanc e between your
vehicle and a following vehicle is
short
• When an accessory (such as a hitch-mounted bicycle carrier) is
installed to the r ear of the vehicle
• When the vehicle throws up water
or snow behind.
■Operation of the RCTA
function
The RCTA function uses radar
sensors to detect vehicles
approaching from the right or left
at the rear of the vehicle and
alerts the driver of the presence
of such vehicles by flashing the
outside rear view mirror indica-
tors and sounding a buzzer.
Approaching vehicles
Detection areas
■RCTA icon display (if
equipped)
When a vehicle approaching
from the right or left at the rear
of the vehicle is detected, the
following will be displayed on
the audio system screen.
 When the Toyota parking
assist monitor (if equipped) is
displayed
The Rear Cross Traffic
Alert function (if
equipped)
A
B

3074-5. Using the driving support systems
4
Driving
●Guardrails, walls, signs, parked
vehicles and similar stationary
objects
*
●Small motorcycles, bicycles,
pedestrians, etc.*
●Vehicles moving away from your
vehicle
●Vehicles approaching from the
parking spaces next to your vehi-
cle
*
*
: Depending on conditions, detec- tion of a vehicle and/or object may
occur.
■Conditions under which the
RCTA function may not func-
tion correctly
●The RCTA function may not
detect vehicles correctly in the fol-
lowing situations:
• When the sensor is misaligned
due to a strong impact to the sen-
sor or its surrounding area
• When mud, snow, ice, a sticker, etc. is covering the sensor or sur-
rounding area on the rear bumper
• When driving on a road surface that is wet with standing water
during bad weather, such as
heavy rain, snow, or fog
• When multiple vehicles are
approaching with only a small gap
between each vehicle
• When a vehicle is approaching at
high speed
• When parking on a steep incline, such as hills, a dip in the road, etc.
• When an accessory (such as a
hitch-mounted bicycle carrier) is
installed to the r ear of the vehicle
• When backing up on a slope with
a sharp change in grade • When backing out of a shallow
angle parking spot
• Immediately after the RCTA func- tion is turned on
• Immediately after the hybrid sys- tem is started with the RCTA func-
tion on
• When towing a trailer
• When the sensors cannot detect a vehicle due to obstructions
●Instances of the RCTA function
unnecessary detecting a vehicle
and/or object may increase in the
following situations:
• When a vehicle passes by the
side of your vehicle
• When the parking space faces a street and vehicles are being

3354-5. Using the driving support systems
4
Driving■ECB (Electronically Con-
trolled Brake System)
The electronically controlled
system generates braking force
corresponding to the brake
operation
■ABS (Anti-lock Brake Sys-
tem)
Helps to prevent wheel lock
when the brakes are applied
suddenly, or if the brakes are
applied while driving on a slip-
pery road surface
■Brake assist
Generates an increased level of
braking force after the brake
pedal is depressed when the
system detects a panic stop sit-
uation
■VSC (Vehicle Stability Con-
trol)
Helps the driver to control skid-
ding when swerving suddenly or
turning on slippery road sur-
faces.
■Enhanced VSC (Enhanced
Vehicle Stability Control)
Provides cooperative control of
the ABS, TRAC, VSC and EPS.
Helps to maintain directional
stability when swerving on slip-
pery road surfaces by con-
trolling steering performance.
■Trailer Sway Control
Helps the driver to control trailer
sway by selectively applying
brake pressure for individual
wheels and reducing driving
torque when trailer sway is
detected.
■TRAC (Traction Control)
Helps to maintain drive power
and prevent the drive wheels
from spinning when starting the
vehicle or accelerating on slip-
pery roads
■Active Cornering Assist
(ACA)
Helps to prevent the vehicle
from drifting to the outer side by
performing inner wheel brake
control when attempting to
accelerate while turning
■Hill-start assist control
Helps to reduce the backward
Driving assist systems
To keep driving safety and
performance, the following
systems operate automati-
cally in response to various
driving situations. Be
aware, however, that these
systems are supplementary
and should not be relied
upon too heavily when oper-
ating the vehicle.
Summary of the driving
assist systems