2021 TOYOTA SIENNA HYBRID battery

4006-1. Maintenance and care
6-1.Maintenance and care
Working from top to bottom,
liberally apply water to the
vehicle body, wheel wells and
underside of the vehicle to
remove any dirt and dust.
 Wash the vehicle body using
a sponge or soft cloth, such
as a chamois.
 For hard-to-remove marks,
use car wash soap and rinse
thoroughly with water.
 Wipe away any water.
 Wax the vehicle when the
waterproof coating deterio-
rates.
If water does not bead on a clean
surface, apply wax when the vehi-
cle body is cool.
■Automatic car washes
●Before washing the vehicle:
• Fold the mirrors
• Disable the powe r sliding door
system
• Disable the power back door sys- tem (if equipped)
Start washing from the front of the
vehicle. Make sure to extend the
mirrors before driving.
●Brushes used in automatic car
washes may scratch the vehicle
surface, parts (wheel, etc.) and
harm your vehicle’s paint.
●Rear spoiler may not be washable
in some automatic car washes.
There may also be an increased
risk of damage to vehicle.
■High pressure car washes
As water may enter the cabin, do
not bring the nozzle tip near the
gaps around the doors or perimeter
of the windows, or spray these
areas continuously.
■Note for a smart key system
If the door handle becomes wet
while the electronic key is within the
effective range, t he door may lock
and unlock repeatedly. In that case,
follow the following correction pro-
cedures to wash the vehicle:
●Place the key in a position 6 ft. (2
m) or more separate from the
vehicle while the vehicle is being
washed. (Take care to ensure that
the key is not stolen.)
●Set the electronic key to battery-
saving mode to disable the smart
key system. ( P.165)
●If the electronic key is inside the
vehicle and a door handle
becomes wet during a car wash, a
buzzer may sound outside the
vehicle and “Key Detected in
Vehicle” may be shown on the
multi-information d isplay. To turn
off the alarm, lock all the doors.
■Wheels and wheel ornaments
●Remove any dirt immediately by
using a neutral detergent.
●Wash detergent off with water
immediately after use.
●To protect the paint from damage,
make sure to obs erve the follow-
ing precautions.
• Do not use acidic, alkaline or
abrasive detergent
• Do not use hard brushes
• Do not use detergent on the
Cleaning a nd protect-
ing the vehicle exte-
rior
Perform the following to
protect the vehicle and
maintain it in prime condi-
tion:
Cleaning instructions

4046-1. Maintenance and care
WARNING
■Water in the vehicle
●Do not splash or spill liquid in
the vehicle, such as on the floor,
on the front seats, in the hybrid
battery (traction battery) air
intake vent or in the luggage
compartment. ( P.85)
Doing so may cause the hybrid
battery, electrical components,
etc. to malfunction or catch fire.
●Do not get any of the SRS com-
ponents or wiring in the vehicle
interior wet.
(  P.42)
An electrical malfunction may
cause the airbags to deploy or
not function properly, resulting
in death or serious injury.
●Vehicles with wireless charger:
Do not let the wireless charger
(  P.381) get wet. Failure to do
so may cause the charger to
become hot and cause burns or
could cause electric shock
resulting in death or serious
injury.
■Cleaning the interior (espe-
cially instrument panel)
Do not use a polis h wax or polish
cleaner. The instrument panel
may reflect off the windshield,
obstructing the dr iver’s view and
leading to an accident, resulting in
death or serious injury.
NOTICE
■Cleaning detergents
●Do not use the following types
of detergent, as they may dis-
color the vehicle interior or
cause streaks or damage to
painted surfaces:
• Non-seat portions: Organic sub- stances such as benzene or
gasoline, alkaline or acidic solu-
tions, dye, and bleach
• Seats: Alkaline or acidic solu- tions, such as thinner, benzene,
and alcohol
●Do not use a polish wax or pol-
ish cleaner. The instrument
panel’s or other interior part’s
painted surface may be dam-
aged.
■Water on the floor
Do not wash the v ehicle floor with
water.
Vehicle systems such as the
audio system may be damaged if
water comes into contact with
electrical components such as the
audio system above or under the
floor of the vehicle. Water may
also cause the body to rust.
■When cleaning the inside of
the windshield
Do not allow glass cleaner to con-
tact the lens. Also, do not touch
the lens. ( P.262)
■Cleaning the inside of the rear
window
●Do not use a gla ss cleaner to
clean the rear window, as this
may cause damage to the rear
window defogger heater wires.
Use a cloth dampened with
lukewarm water to gently wipe
the window clean. Wipe the win-
dow in strokes running parallel
to the heater wires.

4066-2. Maintenance
6-2.Maintenance
■Repair and replacement
It is recommended that genuine
Toyota parts be used for repairs to
ensure performanc e of each sys-
tem. If non-Toyota p arts are used in
replacement or if a repair shop other
than a Toyota dealer performs
repairs, confirm the warranty cover-
age.
■Allow inspection and repairs to
be performed by a Toyota
dealer
●Toyota technicians are well-
trained specialists and are kept up
to date with the latest service
information. They are well
informed about the operations of
all systems on your vehicle.
●Keep a copy of the repair order. It
proves that the maintenance that
has been performed is under war-
ranty coverage. If any problem
should arise while your vehicle is
under warranty, your Toyota
dealer will promptly take care of it.
General maintenance should be
performed on a daily basis. This
can be done by yourself or by a
Toyota dealer.
Scheduled maintenance should
be performed at specified inter-
vals according to the mainte-
nance schedule.
For details about maintenance
items and schedules, refer to the
“Scheduled Maintenance Guide” or
“Owner’s Manual Supplement”.
Maintenance require-
ments
To ensure safe and econom-
ical driving, day-to-day care
and regular maintenance
are essential. It is the
owner’s responsibility to
perform regular checks.
Toyota recommends the fol-
lowing maintenance:
WARNING
■If your vehicle is not properly
maintained
Improper maintenance could
result in serious damage to the
vehicle and possible death or seri-
ous injury.
■Handling of the 12-volt bat-
tery
●Engine exhaust, some of its
constituents, and a wide variety
of automobile components con-
tain or emit chemicals known to
the State of California to cause
cancer and birth defects and
other reproductive harm. Work
in a well ventilated area.
●Oils, fuels and fluids contained
in vehicles as well as waste pro-
duced by component wear con-
tain or emit chemicals known to
the State of California to cause
cancer and birth defects or
other reproductive harm. Avoid
exposure and wash any
affected area immediately.
●12-volt battery posts, terminals
and related accessories con-
tain lead and lead compounds
which are known to cause brain
damage. Wash your hands after
handling. ( P.422)
General maintenance
Scheduled maintenance

4086-2. Maintenance
Exhaust sys-
temThere should not
be any fumes or
strange sounds.
Radiator/con-
denser
The radiator and
condenser should
be free from for-
eign objects.
( P.420)
Washer fluid
Is there sufficient
washer fluid?
( P.421)
Luggage compartment
ItemsCheck points
12-volt batteryCheck the connec-
tions. ( P.422)
Vehicle interior
ItemsCheck points
Accelerator
pedal
• The accelerator
pedal should
move smoothly
(without uneven
pedal effort or
catching).
Hybrid trans-
mission “Park”
mechanism
• When parked on a slope and the
shift lever is in P,
is the vehicle
securely
stopped?
ItemsCheck points
Brake pedal
• Does the brake pedal move
smoothly?
• Does the brake pedal have
appropriate
clearance from
the floor?
( P.524)
• Does the brake pedal have the
correct amount
of free play?
( P.524)
Brakes
• The vehicle
should not pull to
one side when
the brakes are
applied.
• The brakes should work
effectively.
• The brake pedal should not feel
spongy.
• The brake pedal should not get
too close to the
floor when the
brakes are
applied.
Head
restraints
• Do the head restraints move
smoothly and
lock securely?
Indica-
tors/buzzers
• Do the indica-tors and buzzers
function prop-
erly?
Lights• Do all the lights come on?
ItemsCheck points

4106-2. Maintenance
The OBD system determines
that a problem exists some-
where in the emission control
system. Your vehicle may not
pass the I/M test and may need
to be repaired. Contact your
Toyota dealer to service the
vehicle.
When the 12-volt battery is
disconnected or discharged
Readiness codes that are set
during ordinary driving are
erased.
Also, depending on your driv-
ing habits, the readiness
codes may not be completely
set.
 When the fuel tank cap is loose
The malfunction indicator
lamp comes on indicating a
temporary malfunction and
your vehicle may not pass the
I/M test.
The error code in the OBD sys-
tem will not be cleared unless
the vehicle is driven 40 or more
times.
Contact your Toyota dealer to
prepare the vehicle for re-test-
ing.
Emission inspection
and maintenance (I/M)
programs
Some states have vehicle
emission inspection pro-
grams which include OBD
(On Board Diagnostics)
checks. The OBD system
monitors the operation of
the emission control sys-
tem.
If the malfunc tion indica-
tor lamp comes on
Your vehicle may not
pass the I/M test in the fol-
lowing situations:
When the malfunction
indicator lamp still
remains on after several
driving trips
If your vehicle does not
pass the I/M test

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
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4226-3. Do-it-yourself maintenance
The 12-volt battery is located in
the right-hand side of luggage
compartment.
■Before recharging
When recharging, the 12-volt bat-
tery produces hydrogen gas which
is flammable and explosive. There-
fore, observe the following precau-
tions before recharging:
●If recharging with the 12-volt bat-
tery installed on the vehicle, be
sure to disconnect the ground
cable.
●Make sure the power switch on
the charger is off when connecting
and disconnecting the charger
cables to the 12-volt battery.
■After recharging/reconnecting
the 12-volt battery
The hybrid system may not start.
Follow the procedure below to ini-
tialize the system.
1 Shift the shift lever to P.
2 Open and close any of the doors.
3 Restart the hybrid system.
●Unlocking the doors using the
smart key system may not be pos-
sible immediately after reconnect-
ing the 12-volt battery. If this
happens, use the wireless remote
control or the mechanical key to lock/unlock the doors.
●Start the hybrid system with the
power switch in ACC. The hybrid
system may not start with the
power switch turned off. How-
ever, the hybrid system will oper-
ate normally from the second
attempt.
●The power switch mode is
recorded by the vehicle. If the 12-
volt battery is reconnected, the
vehicle will return the power
switch mode to the status it was in
before the 1
2-volt battery was dis-
connected. Make sure to turn off
the power switch before discon-
nect the 12-volt battery. Take
extra care when connecting the
12-volt battery if the power switch
mode prior to discharge is
unknown.
If the hybrid system will not start
even after multiple attempts at all
methods above, contact your
Toyota dealer.
12-volt battery
Location
WARNING
■Chemicals in the 12-volt bat-
tery
The 12-volt battery contains poi-
sonous and corrosive sulfuric acid
and may produce hydrogen gas
which is flammable and explosive.
To reduce the risk of death or
serious injury, take the following
precautions while working on or
near the 12-volt battery:
●Do not cause sparks by touch-
ing the 12-volt battery terminals
with tools.
●Do not smoke or light a match
near the 12-volt battery.
●Avoid contact with eyes, skin
and clothes.
●Never inhale or swallow electro-
lyte.