2021 TOYOTA SIENNA HYBRID warning

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.

4236-3. Do-it-yourself maintenance
6
Maintenance and care
Remove the cover.
Make sure that the 12-volt bat-
tery terminals are not corroded
and that there are no loose con-
WARNING
●Wear protective safety glasses
when working near the 12-volt
battery.
●Keep children away from the
12-volt battery.
■Where to safely charge the
12-volt battery
Always charge the 12-volt battery
in an open area. Do not charge
the 12-volt battery in a garage or
closed room where there is insuf-
ficient ventilation.
■Emergency measures regard-
ing electrolyte
●If electrolyte gets in your eyes
Flush your eyes with clean water
for at least 15 minutes and get
immediate medical attention. If
possible, continue to apply water
with a sponge or cloth while trav-
eling to the nearest medical facil-
ity.
●If electrolyte gets on your skin
Wash the affected area thor-
oughly. If you feel pain or burning,
get medical attention immediately.
●If electrolyte gets on your
clothes
It can soak through clothing on to
your skin. Immediately take off the
clothing and follow the procedure
above if necessary.
●If you accidentally swallow elec-
trolyte
Drink a large quantity of water or
milk. Get emergency medical
attention immediately.
■When replacing the 12-volt
battery
Use a 12-volt battery designed for
this vehicle. Failu re to do so may
cause gas (hydrogen) to enter the
passenger compartment, causing
a fire or explosion.
For replacement of the 12-volt
battery, contact your Toyota
dealer.
■When there is insufficient 12-
volt battery fluid
Do not use if ther e is insufficient
fluid in the 12-volt battery. There
is a possible danger that the 12-
volt battery may explode.
NOTICE
■When recharging the 12-volt
battery
Never recharge t he 12-volt bat-
tery while the hybrid system is
operating. Also, be sure all acces-
sories are turned off.
Removing the 12-volt bat-
tery cover
Exterior

4266-3. Do-it-yourself maintenance
Rotate the tires in the order
shown.
To equalize tire wear and extend
tire life, Toyota recommends that
tire rotation is carried out at the
same interval as tire inspection.
Do not fail to initialize the tire pres-
sure warning system after tire rota-
tion.
■When rotating the tires
Make sure that the power switch is
OFF. If the tires are rotated while
the power switch is in ON, the tire
WARNING
■When inspecting or replacing
tires
Observe the following precautions
to prevent accidents.
Failure to do so may cause dam-
age to parts of t he drive train as
well as dangerous handling char-
acteristics, which may lead to an
accident resulting in death or seri-
ous injury.
●Do not mix tires of different
makes, models or tread pat-
terns.
Also, do not mix tires of remark-
ably different treadwear.
●Do not use tire sizes other than
those recommende d by Toyota.
●Do not mix differently con-
structed tires (radial, bias-belted
or bias-ply tires).
●Do not mix summer, all season
and snow tires.
●Do not use tires that have been
used on another vehicle.
Do not use tires if you do not
know how they were used previ-
ously.
●Vehicles with compact spare
tire: Do not tow if your vehicle
has a compact spare tire
installed.
●Vehicles without spare tire: Do
not tow anything if a tire that has
been repaired using the emer-
gency tire puncture repair kit is
installed. The load on the tire
may cause unexpected damage
to the tire.
NOTICE
■Driving on rough roads
Take particular care when driving
on roads with loose surfaces or
potholes.
These conditions may cause
losses in tire inflation pressure,
reducing the cushioning ability of
the tires. In addition, driving on
rough roads may cause damage
to the tires themselves, as well as
the vehicle’s wheels and body.
■If tire inflation pressure of
each tire becomes low while
driving
Do not continue driving, or your
tires and/or wheels may be
ruined.
Tire rotation

4276-3. Do-it-yourself maintenance
6
Maintenance and care
position information will not be
updated. If this accidentally occurs,
either turn the power switch to OFF
and then to ON, or initialize the sys-
tem after checking that the tire pres-
sure is properly adjusted.
Your vehicle is equipped with a
tire pressure warning system
that uses tire pressure warning
valves and transmitters to detect
low tire inflation pressure before
serious problems arise.
The tire pressure warning sys-
tem of this vehicle adopts a 2-
type warning system
 When “Adjust Pressure” is
displayed (Normal Warning)
The tire pressure warning light
comes on and a buzzer sounds
when the tire inflation pressure
becomes low due to natural air
leakage or outside temperature.
(Ways of coping: P.472, 525)
 When “Immediately Check
tire when Safe” is displayed
(Emergency Warning)
The tire pressure warning light
comes on and a buzzer sounds
when the tire inflation pressure
becomes low suddenly due to a
blowout. (Ways of coping: P.472,
481, 491) However, the system
may not be able to detect sudden
tire ruptures (bursting, etc.).
The tire pressure detected by the
tire pressure warning system can
be displayed on the multi-informa-
tion display. The unit can be changed.
With 4.2-inch display
With 7-inch display
■How to change the unit
With 4.2-inch display
1 Park the vehicle in a safe
place and turn the power
switch off.
Changing the unit cannot be per-
formed while the vehicle is moving.
2Turn the power switch to ON.
3 Press or of the meter
control switches on the steer-
ing wheel and select .
4 Press or of the meter
control switches and select
“Vehicle Settings”, and then
press and hold “OK”.
5 Press or of the meter
control switches and select
Tire pressure warning
system
35
35 35
35

4286-3. Do-it-yourself maintenance
“TPWS Setting”, and then
press “OK”.
6 Press or to select
“Setting UNIT”.
7 Press or to select the
desired unit and then press
“OK”.
With 7-inch display
1 Park the vehicle in a safe
place and turn the power
switch off.
Changing the unit cannot be per-
formed while the vehicle is moving.
2Turn the power switch to ON.
3 Press or of the meter
control switches on the steer-
ing wheel and select .
4 Press or of the meter
control switches and select
, and then press and hold
“OK”.
5 Press or of the meter
control switches and select
“TPWS Setting”, and then
press “OK”.
6 Press or to select
“Setting UNIT”.
7 Press or to select the
desired unit and then press
“OK”.
■Routine tire inflation pressure
checks
The tire pressure warning system
does not replace routine tire inflation
pressure checks. Make sure to check tire inflation pressure as part
of your routine o
f daily vehicle
checks.
■Tire inflation pressure
●It may take a few minutes to dis-
play the tire inflation pressure
after the power switch is turned to
ON. It may also take a few min-
utes to display the tire inflation
pressure after infl ation pressure
has been adjusted.
●Tire inflation pressure changes
with temperature.
The displayed values may also be
different from the values mea-
sured using a tire pressure gauge.
■Situations in which the tire
pressure warning system may
not operate properly
●In the following cases, the tire
pressure warning system may not
operate properly.
• If non-genuine Toyota wheels are
used.
• A tire has been replaced with a tire that is not an OE (Original
Equipment) tire.
• A tire has been replaced with a tire that is not of the specified size.
• Tire chains, etc. are equipped.
• An auxiliary-support ed run-flat tire
is equipped.
• If a window tint that affects the radio wave signals is installed.
• If there is a lot of snow or ice on
the vehicle, particularly around the
wheels or wheel housings.
• If the tire inflation pressure is
extremely higher than the speci-
fied level.
• If wheel withou t tire pressure
warning valves and transmitters
are used.
• If the ID code on the tire pressure warning valves and transmitters is
not registered in the tire pressure
warning computer.
●Performance may be affected in
the following situations.
• Near a TV tower, electric power
plant, gas station, radio station,

4296-3. Do-it-yourself maintenance
6
Maintenance and care
large display, airport or other facil-
ity that generates strong radio
waves or electrical noise
• When carrying a portable radio, cellular phone, cordless phone or
other wireless communication
device
If tire position information is not cor-
rectly displayed due to the radio
wave conditions, the display may be
corrected by driving and changing
the radio wave conditions.
●When the vehicle is parked, the
time taken for the warning to start
or go off could be extended.
●When tire inflation pressure
declines rapidly for example when
a tire has burst, the warning may
not function.
■Warning performance of the tire
pressure warning system
The warning of the tire pressure
warning system will change in
accordance with th e conditions
under which it was initialized. For
this reason, the system may give a
warning even if the tire pressure
does not reach a low enough level,
or if the pressure is higher than the
pressure that was adjusted to when
the system was initialized.
When replacing tires or wheels,
tire pressure warning valves and
transmitters must also be
installed.
When new tire pressure warning
valves and transmitters are
installed, new ID codes must be
registered in the tire pressure
warning computer and the tire pressure warning system must
be initialized. (
P.433)
■When replacing the tires and
wheels
If the ID code of the tire pressure
warning valve and tr ansmitter is not
registered, the tire pressure warning
system will not work properly. After
driving for about 20 minutes, the tire
pressure warning light blinks for 1
minute and stays on to indicate a
system malfunction.
Installing tire pressure
warning valves and trans-
mitters
NOTICE
■Repairing or replacing tires,
wheels, tire pressure warn-
ing valves, transmitters and
tire valve caps
●When removing or fitting the
wheels, tires or the tire pressure
warning valves and transmit-
ters, contact your Toyota dealer
as the tire pressure warning
valves and transmitters may be
damaged if not handled cor-
rectly.
●Make sure to install the tire
valve caps. If the tire valve caps
are not installed, water could
enter the tire pressure warning
valves and the tire pressure
warning valves could be bound.
●When replacing tire valve caps,
do not use tire valve caps other
than those specified.
The cap may become stuck.

4306-3. Do-it-yourself maintenance
■The tire pressure warning
system must be initialized
in the following circum-
stances:
 When rotating the tires.
 When changing the tire.
 After registering the ID codes.
( P.433)
 When changing between two
registered wheel sets.
When the tire pressure warning
system is initialized, the current
tire inflation pressure is set as
the benchmark pressure.
■How to initialize the tire
pressure warning system
With 4.2-inch display
1 Park the vehicle in a safe
place and stop the hybrid
system for 20 minutes or
more.
Initialization cannot be performed
while the vehicle is moving.
2Adjust the tire inflation pres-
sure to the specified cold tire
inflation pressure level.
( P.525)
Make sure to adjust the tire pres-
sure to the specifie d cold tire infla-
tion pressure level. The tire
pressure warning system will oper-
ate based on this pressure level.
3Start the hybrid system.
4 Press or of the meter
control switches on the steer-
ing wheel and select .
5 Press or of the meter
control switches, select
“Vehicle Settings” and then
press and hold “OK”.
6 Press or of the meter
control switches, select
“TPWS Setting” and then
press “OK”.
7 Press or of the meter
control switches, select the
“Setting Pressure”. Then
press and hold “OK”.
“Setting Tire Pressure Warning
System” will be displayed on the
multi-information display and the
tire pressure warning light will blink
NOTICE
■To avoid damage to the tire
pressure warning valves and
transmitters (vehicles without
spare tire)
When a tire is repaired with liquid
sealants, the tire pressure warn-
ing valve and transmitter may not
operate properly. If a liquid seal-
ant is used, conta ct your Toyota
dealer as soon as possible. After
use of liquid sealant, make sure to
replace the tire pressure warning
valve and transmitter when repair-
ing or replacing the tire. ( P.429)
Initializing the tire pres-
sure warning system
OK

4316-3. Do-it-yourself maintenance
6
Maintenance and care
3 times.
When the message disappears, ini-
tialization is complete.
A message is displayed on the
multi-information display. Also, “--”
is displayed for inflation pressure of
each tire on the multi-information
display while the tire pressure
warning system determines the
position.
8 Drive straight (with occa-
sional left and right turns) at
approximately 25 mph (40
km/h) or more for approxi-
mately 10 to 30 minutes.
When initialization is complete, the
inflation pressure of each tire will be
displayed on the multi-information
display.
Even if the vehicle is not driven at
approximately 25 mph (40 km/h) or
more, initializat ion can be com-
pleted by driving for a long time.
However, if initia lization does not
complete after driving for 1 hour or
more, park the vehicle in a safe
place for approximately 20 minutes
and then drive th e vehicle again.
With 7-inch display
1 Park the vehicle in a safe
place and stop the hybrid
system for 20 minutes or
more.
Initialization cannot be performed
while the vehicle is moving.
2Adjust the tire inflation pres-
sure to the specified cold tire
inflation pressure level.
( P.525)
Make sure to adjust the tire pres-
sure to the specifie d cold tire infla-
tion pressure level. The tire
pressure warning system will oper-
ate based on this pressure level.
3 Start the hybrid system. 4
Press or of the meter
control switches on the steer-
ing wheel and select .
5 Press or of the meter
control switches, select
and then press and hold
“OK”.
6 Press or of the meter
control switches, select
“TPWS Setting” and then
press “OK”.
7 Press or of the meter
control switches, select the
“Setting Pressure”. Then
press and hold “OK”.
“Setting Tire Pressure Warning
System” will be displayed on the
multi-information display and the
tire pressure warn ing light will blink
3 times.
When the message disappears, ini-
tialization is complete.
A message is displayed on the
multi-information di splay. Also, “--”
is displayed for inflation pressure of
each tire on the m ulti-information
display while the tire pressure
warning system determines the
position.
8 Drive straight (with occa-
sional left and right turns) at
approximately 25 mph (40
OK