2021 TOYOTA SIENNA HYBRID cooling

3535-1. Using the air conditioning system and defogger
5
Interior features
system will blow ambient tempera-
ture air or heated air.
“SYNC” switch ( P.355)
Vehicles with “3-ZONE” mode: If
the indicator on the “SYNC” switch
is off, the temperature for the driver,
front passenger and rear seats can
be adjusted separately.
Vehicles with “4-ZONE” mode: The
temperature for the driver, front
passenger, left-hand side rear
seats and right-hand side rear
seats can be adjusted separately.
Set eco air conditioning
mode
The air conditioning is controlled
with low fuel consumption priori-
tized such as reducing fan speed,
etc.
■Option control screen
Select “Options” to display the
option control screen.
The functions can be switched on
and off.
When the function i s on, the indica-
tor illuminates on the screen.
“SYNC” switch ( P.355)
Vehicles with “3-ZONE” mode: If
the indicator on the “SYNC” switch
is off, the temperature for the driver,
passenger and rear seats can be adjusted separately.
Vehicles with “4-ZONE” mode: The
temperature for the driver, front
passenger, left-hand side rear
seats and right-hand side rear
seats can be adjusted separately.
Set cooling and dehumidifi-
cation function
If “A/C” switch is not pressed, the
system will blow ambient tempera-
ture air or heated air.
Set eco air conditioning
mode
The air conditioning is controlled
with low fuel con
sumption priori-
tized such as reducing fan speed,
etc.
1 Press the “AUTO” switch on
the air conditioning operation
panel or select the “AUTO”
switch on the control screen.
The dehumidification function
begins to operate. Air outlets and
fan speed are automatically
adjusted according to the tempera-
ture setting and humidity.
2 Adjust the temperature set-
ting.
3 To stop the operation, press
the “OFF” switch on the air
conditioning operation panel
or select the “OFF” switch on
the control screen.
If the fan speed setting or air
flow modes are operated, the
automatic mode indicator goes
off. However, automatic mode
I
J
A
Using automatic mode
B
C

3765-4. Using the other interior features
Rear of console box
Luggage compartment
■When turning the power
outlets off
1 Turn the connected devices
off.
2 Press the AC120V switch to
turn the power outlets off.
3 Disconnect each plug from
the power outlet.
4 Close the lid of each power
outlet.
■The power outlet can be used
when
The READY indicato r is illuminated.
■Rules/regulations regarding
idling stop
The engine will start automatically to
charge the hybrid battery (traction
battery) if its charge becomes low.
In some municipalities, if the engine
starts while the vehicle is parked or stopped, it may violate local rules or
regulations regarding idling stop and
you may be penalized. Make sure to
check the local rules and regula-
tions before using the power outlets
while the vehicle is parked or
stopped.
■Power outlets
●When connecting a device, make
sure that the to
tal power con-
sumption of all devices connected
to the 120 VAC power outlets is
less than 1500 W. If a device is
connected and the power con-
sumption is exce eded, a protec-
tion circuit will cut the power
supply and the p ower outlets will
not be able to be used.
●Depending on the device to be
used, the current flow may be high
and the initial peak wattage may
exceed 1500 W.
In this case, the protection circuit
may operate, and the power out-
lets may not be able to be used.
●Depending on the connected
device, it may cause interference
with TV and radio broadcasts.
●The voltage of the power outlets
cannot be measured with a com-
mercially available electrical tes-
ter. If it is necessary to check the
voltage, have the vehicle
inspected by your Toyota dealer.
●While a power outlet is being
used, a cooling fan sound may be
heard from near a rear seat. This
does not indicate a malfunction.
■Devices which may not operate
correctly
The following 120 VAC devices may
not operate properly even if their
power consumption is less than
1500 W:
●Devices with high initial peak watt-
age
●Measuring devices that process
precise data
●Devices that require an extremely

3785-4. Using the other interior features
WARNING
●Do not attempt to modify, disas-
semble or repair a power outlet.
Also, do not replace the 120
VAC inverter with a commer-
cially available one. For infor-
mation on repairs, contact your
Toyota dealer.
●Be careful not to get any part of
your body caught in the power
outlet lid.
●Do not let children touch the
power outlets.
●Keep the power outlets free of
dust and foreign matter.
●If the plug of a device fits
loosely in a pow er outlet, even
though it is fully inserted,
replace the power outlet. For
information on replacement,
contact your Toyota dealer.
■Using the power outlets while
parked or stopped
Observe the following precau-
tions.
Failure to do so may lead to an
accident, possibly resulting in
death or serious injury.
●Make sure to engage the park-
ing brake and shift the shift
lever to P.
●Do not leave the vehicle unat-
tended while the READY indica-
tor is illuminated and a device is
connected to a power outlet.
●Make sure that the hood is
closed. As the engine will start
automatically depending on the
condition of the vehicle, make
sure that nothing is left near or
contacting the exhaust pipes.
Also, do not put your head or
hands anywhere inside the
engine compartment, as the
cooling fan ma y operate sud-
denly. Keep hands and clothing
(especially a tie, scarf, etc.)
away from the fan as they may
get caught in a fan.
●Do not use the power outlets in
an area with poor ventilation or
an enclosed area, such as a
garage without a ventilation or
exhaust system, o r in an area
where the vehicle may become
surrounded by snow, as the
exhaust gasses may accumu-
late, causing a lack of oxygen.
●Do not use the power outlets if
the vehicle has a vehicle cover
installed.
●Do not sleep in the vehicle while
using devices such as an elec-
tric heater.
■Devices to be connected
Make sure to read a ny instruction
manual which came with a device
and observe any w arnings on the
device. Do not connect a device
to a power outlet if the device is
malfunctioning or its plug is dam-
aged.
Do not use power outlets for med-
ical devices, as the output of the
power outlet may be cut, depend-
ing on the condition of the vehicle.

4126-3. Do-it-yourself maintenance
Hybrid bat-
tery (traction
battery) air
intake vent
( P.443)• Vacuum cleaner,
etc,
• Phillips screw- driver
Light bulbs
( P.451)
• Bulb with same
number and watt-
age rating as origi-
nal
• Phillips-head screwdriver
• Flathead screw- driver
• Wrench
Radiator and
condenser
(  P.420)

Tire inflation
pressure
( P.438)• Tire pressure
gauge
• Compressed air source
Washer fluid
( P.421)
• Water or washer
fluid containing
antifreeze (for win-
ter use)
• Funnel (used only for adding water or
washer fluid)
WARNING
The engine compartment contains
many mechanisms and fluids that
may move suddenly, become hot,
or become electrically energized.
To avoid death or serious injury,
observe the following precautions.
ItemsParts and tools■When working on the engine
compartment
●Make sure that “IGNITION ON”
on the multi-information display
and the “READY” indicator are
both off.
●Keep hands, clothing and tools
away from the moving fan.
●Be careful not to touch the
engine, power control unit, radi-
ator, exhaust manifold, etc. right
after driving as they may be hot.
Oil and other fluids may also be
hot.
●Do not leave anything that may
burn easily, such as paper and
rags, in the engine compart-
ment.
●Do not smoke, cause sparks or
expose an open flame to fuel or
the battery. Fuel and battery
fumes are flammable.
●Be extremely cautious when
working on the battery. It con-
tains poisonous and corrosive
sulfuric acid.
■When working near the elec-
tric cooling fan or radiator
grille
Be sure the power switch is OFF.
With the power switch in ON, the
electric cooling fa n may automati-
cally start to run if the air condi-
tioning is on and/or the coolant
temperature is high. ( P.420)
■Safety glasses
Wear safety gla sses to prevent
flying or falling material, fluid
spray, etc., from getting in your
eyes.

4166-3. Do-it-yourself maintenance
Fuse box (P.449)
Engine oil filler cap ( P.417)
Engine oil level dipstick ( P.416)
Brake fluid reservoir ( P.420)
Radiator ( P.420)
Electric cooling fan
Condenser ( P.420)
Power control unit coolant reservoir ( P.419)
Washer fluid tank ( P.421)
Engine coolant reservoir ( P.419)
■12-volt battery
 P.422
With the engine at operating
temperature and turned off,
Engine compartment
Components
A
B
C
D
E
F
G
H
I
J
&KHFNLQJDQGDGGLQJWKH
HQJLQHRLO

4206-3. Do-it-yourself maintenance
check for leaks in the cooling sys-
tem.
Check the radiator and con-
denser, and clear away any for-
eign objects.
If either of the above parts is
extremely dirty or you are not
sure of their condition, have
your vehicle inspected by your
Toyota dealer.
■Checking fluid level
The brake fluid level should be
between the “MAX” and “MIN”
lines on the tank.
■Adding fluid
Make sure to check the fluid
type and prepare the necessary
item.
 Fluid type
FMVSS No.116 DOT 3 or SAE
WARNING
■When the hybrid system is
hot
Do not remove the engine/power
control unit coolant reservoir
caps.
The cooling system may be under
pressure and may spray hot cool-
ant if the cap is removed, causing
serious injuries, such as burns.
NOTICE
■When adding coolant
Coolant is neither plain water nor
straight antifreeze. The correct
mixture of water and antifreeze
must be used to provide proper
lubrication, corrosion protection
and cooling. Be sure to read the
antifreeze or coolant label.
■If you spill coolant
B e s ur e t o wa sh it o ff w ith w at er to
prevent it from d amaging parts or
paint.
Checking the radiator and
condenser
WARNING
■When the hybrid system is
hot
Do not touch the radiator or con-
denser as they may be hot and
cause serious injuries, such as
burns.
■When the electric cooling fan
is operating
Do not touch the engine compart-
ment.
With the power switch in ON, the
electric cooling fa n may automati-
cally start to run if the air condi-
tioning is on and/or the coolant
temperature is high. Be sure the
power switch is OFF when work-
ing near the electric cooling fan or
radiator grille.
Checking and adding the
brake fluid

4436-3. Do-it-yourself maintenance
6
Maintenance and care
Remove the dust from the air
intake vents with a vacuum
cleaner, etc.
Make sure to only use a vacuum to
suck out dust and clogs. Attempting
to blow out dust and clogs using an
airgun, etc. may push it into the air
intake vent. (P.446)
NOTICE
■When using the air condition-
ing system
Make sure that a filter is always
installed. Using the air condition-
ing system without a filter may
cause damage to the system.
■When removing the glove box
Always follow the specified proce-
dure to remove the glove box
(  P.441). If the glove box is
removed without following the
specified procedure, the hinge of
the glove box may become dam-
aged.
■To prevent damage to the fil-
ter cover
When moving the filter cover in
the direction of arrow to release
the fitting, pay attention not to
apply excessive force to the
claws. Otherwise, the claws may
be damaged.
Cleaning the hybrid
battery (traction bat-
tery) air intake vents
and filters
To prevent the fuel econ-
omy from being affected,
visually inspect the hybrid
battery (traction battery) air
intake vents periodically for
dust and clogs. If they are
dusty or clogged or if
“Maintenance Required for
Traction Battery Cooling
Parts See Owner’s Manual”
is shown on the multi-infor-
mation display, clean the air
intake vents using the fol-
lowing procedures:
Cleaning the air intake
vents

4456-3. Do-it-yourself maintenance
6
Maintenance and care
7Install the air intake vent
cover.
Insert the tab of the cover as shown
in the illustrati on and push the
cover to engage the claws.
8 Using a Phillips screwdriver,
install the clip.
■Scheduled maintenance of the
air intake vents is necessary
when
In some situations such as when the
vehicle is used frequently or in
heavy traffic or dusty areas, the air
intake vents may need to be
cleaned more regularly. For details,
refer to “Scheduled Maintenance
Guide” or “Owner’s Manual Supple-
ment”.
■Cleaning the air intake vents
●Dust in the air in take vents may
interfere with the cooling of the
hybrid battery (traction battery). If
charging/discharging of the hybrid
battery (traction battery) becomes
limited, the distance that the vehi-
cle can be driven using the electric motor (traction motor) may be
reduced and the fuel economy
may be reduced. Inspect and
clean the air intake vents periodi-
cally.
●Improper handling of the air intake
vent covers and filters may result
in damage to them. If you have
any concerns about cleaning the
filters, contact your Toyota dealer.
■If “Maintenance Required for
Traction Battery Cooling Parts
See Owner’s Manual” is shown
on the multi-information display
●If this warning message is shown
on the multi-information display,
remove the air intake vent covers
and clean the filters. (
P.444)
●After cleaning the air intake vents,
start the hybrid system and check
that the warning message is no
longer shown.
It may take approximately 20 min-
utes after the hybrid system is
started until the warning message
disappears. If the warning mes-
sage does not disappear, have
the vehicle inspected by your
Toyota dealer.
WARNING
■When cleaning the air intake
vents
●Do not use water or other liq-
uids to clean the air intake
vents. If water is applied to the
hybrid battery (traction battery)
or other components, a mal-
function or fire may occur.
●Before cleaning the air intake
vents, make sure to turn the
power switch off to stop the
hybrid system.
■When removing the air intake
vent covers
Do not touch the service plug
located underneath the console
box. ( P.84)