2021 TOYOTA SIENNA HYBRID warning light

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.

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

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

4326-3. Do-it-yourself maintenance
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, initialization 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.
■When initializing
●Initialization is performed while
driving at a vehicle speed of
approximately 25 mph (40 km/h)
or more.
●Make sure to carry out initializa-
tion after adjusting the tire inflation
pressure. Also, make sure the
tires are cold before carrying out
initialization or tir e inflation pres-
sure adjustment.
●The tire pressure warning system
can be initialized by yourself, but
depending on the driving condi-
tions and driving environment, ini-
tialization may take some time to
complete.
■The initialization operation
●If you have accidentally turned the
power switch to OFF during initial-
ization, it is not necessary to
restart the initia lization again as
initialization will restart automati-
cally when the power switch has
been turned to ON for the next
time.
●If you accidentally perform initial-
ization when initi alization is not
necessary, adjust the tire inflation
pressure to the specified level
when the tires are cold, and con-
duct initialization again.
●While the position of each tire is being determined and the inflation
pressures are not being displayed
on the multi-information display, if
the inflation pressure of a tire
drops, the tire pressure warning
light will come on.
■If the tire pressure warning sys-
tem is not initia
lized properly
●In the following situations, initial-
ization may take longer than usual
to be completed or may not be
possible. Normally, initialization
completes within approximately
30 minutes.
• Vehicle is not driven at approxi-
mately 25 mph (40 km/h) or more
• Vehicle is driven on unpaved roads
• Vehicle is driven near other vehi- cles and system cannot recog-
nize tire pressure warning valve
and transmitters o f your vehicle
over those of other vehicles.
• If the vehicle is driven in heavy
traffic or another situation where
other vehicles are driven close by,
it may take time f or the system to
recognize the ti re pressure warn-
ing valve and transmitters of your
vehicle over those of other vehi-
cles.
●If initialization does not complete
after driving for 1 hour or more,
park the vehicle in a safe place for
approximately 20 minutes and
then drive the v ehicle again.
●If the vehicle is reversed during
initialization, the data up to that
point is reset, so p erform the ini-
tialization procedure again from
the beginning.
●In the following situations, initial-
ization will not be started or was
not completed properly and the
system will not oper ate properly.
Perform the initialization proce-
dure again.
• If, when attempting to start initial- ization, the tire pressure warning
light does not blink 3 times.
• If, when the veh icle has been
driven for about 20 minutes after

4336-3. Do-it-yourself maintenance
6
Maintenance and care
performing initialization, the tire
pressure warning light blinks for
approximately 1 minute and then
illuminates.
If the inflation pressure of each tire
is still not displayed, have the vehi-
cle inspected by your Toyota dealer.
Every tire pressure warning
valve and transmitter has a
unique ID code. When replacing
a tire pressure warning valve
and transmitter, it is necessary
to register the ID code.
When registering the ID codes,
perform the following procedure.
With 4.2-inch display
1 Park the vehicle in a safe
place, wait for approximately
20 minutes, and then start
the hybrid system.
2 Press or of the meter
control switches on the steer-
ing wheel and select .
3 Press or of the meter
control switches and select “Vehicle Settings”, and then
press and hold “OK”.
4 Press or of the meter
control switches and select
“TPWS Setting”, and then
press “OK”.
5 Press or of the meter
control switches and select
“Identifying Each Wheel &
Position”. Then press and
hold “OK” until the tire pres-
sure warning light starts
slowly blinking 3 times.
The change wheel set mode is acti-
vated and registra tion is started.
Then a message will be displayed
on the multi-information display.
When registration is being per-
formed, the tire pressure warning
light will blink for approximately 1
minute then illuminate and “--” will
be displayed for the inflation pres-
sure of each tire on the multi-infor-
mation display.
6 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 registration is completed, the
tire pressure warning light will go off
and the inflation pressure of each
tire will be displayed on the multi-
WARNING
■When initializing the tire pres-
sure warning system
Do not initializing tire inflation
pressure without first adjusting
the tire inflation pressure to the
specified level. Otherwise, the tire
pressure warning light may not
come on even if the tire inflation
pressure is low, or it may come on
when the tire inflation pressure is
actually normal.
Registering ID codes

4346-3. Do-it-yourself maintenance
information display.
Even if the vehicle is not driven at
approximately 25 mph (40 km/h) or
more, registration can be com-
pleted by driving for a long time.
However, if registration does not
complete after driving for 1 hour or
more, perform the procedure again
from the beginning.
7Initialize the tire pressure
warning system. ( P.430)
With 7-inch display
1 Park the vehicle in a safe
place, wait for approximately
20 minutes, and then start
the hybrid system.
2 Press or of the meter
control switches on the steer-
ing wheel and select .
3 Press or of the meter
control switches and select
, and then press and hold
“OK”.
4 Press or of the meter
control switches and select
“TPWS Setting”, and then
press “OK”.
5 Press or of the meter
control switches and select
“Identifying Each Wheel &
Position”. Then press and
hold “OK” until the tire pres-
sure warning light starts
slowly blinking 3 times.
The change wheel set mode is acti-
vated and registration is started.
Then a message w ill be displayed
on the multi-info rmation display.
When registration is being per- formed, the tire pressure warning
light will blink for
approximately 1
minute then illumi nate and “--” will
be displayed for the inflation pres-
sure of each tire o n the multi-infor-
mation display.
6 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 registration is completed, the
tire pressure warning light will go off
and the inflation pressure of each
tire will be displaye d on the multi-
information display.
Even if the vehicle is not driven at
approximately 25 mph (40 km/h) or
more, registration can be com-
pleted by driving for a long time.
However, if registr ation does not
complete after driving for 1 hour or
more, perform the p rocedure again
from the beginning.
7 Initialize the tire pressure
warning system. ( P.430)
■When registering ID codes
●ID code registrati on is performed
while driving at a vehicle speed of
approximately 25 mph (40 km/h)
or more.
●Before performing ID code regis-
tration, make sure that no wheels
with tire pressure warning valve
and transmitters installed are near
the vehicle.