2021 TOYOTA SIENNA HYBRID towing

2694-5. Using the driving support systems
4
Driving
■Enabling/disabling the pre-
collision system
The pre-collision system can be
enabled/disabled on the
screen ( P.112) of the multi-
information 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 the
screen ( P.112) of the multi-
information 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

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

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

4186-3. Do-it-yourself maintenance
■Engine oil consumption
A certain amount of engine oil will
be consumed while driving. In the
following situatio ns, oil consump-
tion may increase, and engine oil
may need to be ref illed in between
oil maintenance intervals.
●When the engine is new, for
example directly after purchasing
the vehicle or after replacing the
engine
●If low quality oil or oil of an inap-
propriate viscosity is used
●When driving at high engine
speeds or with a heavy load,
when towing, or when driving
while accelerating o r decelerating
frequently
●When leaving the engine idling for
a long time, or wh en driving fre-
quently through heavy traffic
■After changing the engine oil
The engine oil maintenance data
should be reset. Perform the follow-
ing procedures:
4.2-inch display
1 Press or of the meter
control switches to select on
the multi-information display.
2 Press or of the meter
control switches, select “Vehicle
Settings” and then press and
hold “OK”.
7-inch display
1 Press or of the meter
control switches to select on
the multi-information display.
2 Press or of the meter
control switches, select and
then press and hold “OK”.
3 Press or of the meter
control switch es, select “Oil Maintenance” and then press
“OK”.
4 Select “Yes” and press “OK”.
A message will be displayed on the
multi-informat ion display.
WARNING
■Used engine oil
●Used engine oil contains poten-
tially harmful contaminants
which may cause skin disorders
such as inflammation and skin
cancer, so care should be taken
to avoid prolonged and
repeated contact. To remove
used engine oil from your skin,
wash thoroughly with soap and
water.
●Dispose of used oil and filters
only in a safe and acceptable
manner. Do not dispose of used
oil and filters in h ousehold trash,
in sewers or onto the ground.
Call your Toyota dealer, service
station or auto parts store for
information concerning recy-
cling or disposal.
●Do not leave used engine oil
within the reach of children.
NOTICE
■To prevent serious engine
damage
Check the oil le vel on a regular
basis.
■When replacing the engine oil
●Be careful not to spill engine oil
on the vehicle components.
●Avoid overfilling, or the engine
could be damaged.
●Check the oil level on the dip-
stick every time you refill the
vehicle.

4627-2. Steps to take in an emergency
7-2.Steps to take in an emergency
If your vehicle needs
to be towed
If towing is necessary, we
recommend having your
vehicle towed by your
Toyota dealer or commer-
cial towing service, using a
wheel-lift type truck or flat-
bed truck.
Use a safety chain system
for all towing, and abide by
all state/provincial and local
laws.
2WD models: If towing your
vehicle with a wheel-lift type
truck from the front, the
vehicle’s rear wheels and
axles must be in good con-
ditions. (P.462, 463)
If they are damaged, use a
towing dolly or flatbed
truck.
AWD models: If towing your
vehicle with a wheel-lift type
truck, use a towing dolly.
( P.462, 463)
WARNING
Observe the following precau-
tions. Failure to do so may result
in death or serious injury.
■When towing the vehicle
2WD models: Be sure to transport
the vehicle with th e front wheels
raised or with all four wheels
raised off the ground. If the vehi-
cle is towed with th e front wheels
contacting the ground, the drive-
train and related parts may be
damaged or electricity generated
by the operation of the motor may
cause a fire to occur depending
on the nature of the damage or
malfunction.
AWD models: Be sure to transport
the vehicle with all four wheels
raised off the ground. If the vehi-
cle is towed with th e tires contact-
ing the ground, the drivetrain or
related parts may be damaged,
the vehicle may fly off the truck, or
electricity generated by the opera-
tion of the motor may cause a fire
to occur depending on the nature
of the damage or malfunction.

4637-2. Steps to take in an emergency
7
When trouble arises
The following may indicate a
problem with your transmission.
Contact your Toyota dealer or
commercial towing service
before towing. 
The hybrid system warning
message is shown on the
multi-information display and
the vehicle does not move.
 The vehicle makes an abnor-
mal sound.
From the front (2WD models)
Release the parking brake.
Turn automatic mode off.
( P.244)
From the front (AWD models)
Use a towing dolly under the
rear wheels.
NOTICE
■To prevent damage to the
vehicle when towing using a
wheel-lift type truck
●Do not tow the vehicle from the
rear when the power switch is
off. The steering lock mecha-
nism is not strong enough to
hold the front wheels straight.
●When raising the vehicle,
ensure adequate ground clear-
ance for towing at the opposite
end of the raised vehicle. With-
out adequate clearance, the
vehicle could be damaged while
being towed.
■To prevent damage to the
vehicle when towing with a
sling-type truck
Do not tow with a sling-type truck,
either from the front or rear.
■Recreational towing (behind
motor home, etc.)
Never dinghy tow your vehicle to
prevent causing serious damage
to the AWD system and transmis-
sion. ( P.230)
Situations when it is nec-
essary to contact dealers
before towing
Towing with a wheel-lift
type truck