2023 TOYOTA SIENNA HYBRID Owners Manual

4156-3. Do-it-yourself maintenance
6
Maintenance and care
■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.

4166-3. Do-it-yourself maintenance
The coolant level is satisfactory
if it is between the “FULL” and
“LOW” lines on the reservoir
when the hybrid system is cold.
■Engine coolant reservoir
Reservoir cap
“FULL” line
“LOW” line
If the level is on or below the “LOW”
line, add coolant up to the “FULL”
line. ( P.509)
■Power control unit coolant
reservoir
Reservoir cap
“FULL” line
“LOW” line
If the level is on or below the “LOW”
line, add coolant up to the “FULL”
line. ( P.510)
■Coolant selection
Only use “Toyota Super Long Life
Coolant” or a similar high quality
ethylene glycol ba sed non-silicate,
non-amine, non-nitrite, and non-
borate coolant with long-life hybrid
organic acid technology.
U.S.A.:
“Toyota Super Long Life Coolant” is
a mixture of 50% c oolant and 50%
deionized water. (Minimum tem-
perature: -31°F [-35°C])
Canada:
“Toyota Super Long Life Coolant” is
a mixture of 55% c oolant and 45%
deionized water. (Minimum tem-
perature: -44°F [-42°C])
For more details about coolant, con-
tact your Toyota dealer.
■If the coolant level drops within
a short time of replenishing
Visually check the radiators, hoses,
engine/power control unit coolant
reservoir caps, drain cock and water
pump.
If you cannot find a leak, have your
Toyota dealer, test the cap and
NOTICE
●Be sure the engine oil filler cap
is properly tightened.
■If oil is spilled on the engine
cover
To prevent the engine cover from
being damaged, remove any
engine oil from the engine cover
as soon as possible using a neu-
tral detergent. Do not use an
organic solvent such as brake
cleaner.
Checking the coolant
A
B
C
A
B
C

4176-3. Do-it-yourself maintenance
6
Maintenance and care
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

4186-3. Do-it-yourself maintenance
J1703 brake fluid
FMVSS No.116 DOT 4 or SAE
J1704 brake fluid
Item
Clean funnel
■Brake fluid can absorb moisture
from the air
Excess moisture in the brake fluid
can cause a dangerous loss of brak-
ing efficiency. Use only newly
opened brake fluid.
If any washer does not work or
“Windshield Washer Fluid Low”
is shown on the multi-informa-
tion display, the washer tank
may be empty. Add washer
fluid.
WARNING
■When filling the reservoir
Take care as brake fluid can harm
your hands and eyes and damage
painted surfaces.
If fluid gets on your hands or in
your eyes, flush th e affected area
with clean water immediately.
If you still experien ce discomfort,
see a doctor.
NOTICE
■If the fluid level is low or high
It is normal for the brake fluid level
to go down slightly as the brake
pads wear out or when the fluid
level in the accumulator is high.
If the reservoir needs frequent
refilling, there may be a serious
problem.
Adding the washer fluid
WARNING
■When adding washer fluid
Do not add washer fluid when the
hybrid system is hot or operating
as washer fluid contains alcohol
and may catch fire if spilled on the
hybrid system, etc.
NOTICE
■Do not use any fluid other
than washer fluid
Do not use soapy water or engine
antifreeze instead of washer fluid.
Doing so may cause streaking on
the vehicle’s painted surfaces, as
well as damaging the pump lead-
ing to problems of the washer
fluid not spraying.
■Diluting washer fluid
Dilute washer fluid with water as
necessary.
Refer to the freezing tempera-
tures listed on the label of the
washer fluid bottle.

4196-3. Do-it-yourself maintenance
6
Maintenance and care
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
●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.
●Wear protective safety glasses
when working near the 12-volt
battery.
●Keep children away from the
12-volt battery.

4206-3. Do-it-yourself maintenance
Remove the cover.
Make sure that the 12-volt bat-
tery terminals are not corroded
and that there are no loose con-
nections, cracks, or loose
clamps.
WARNING
■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. Failure 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

4216-3. Do-it-yourself maintenance
6
Maintenance and care
Terminals
Hold-down clampCheck if the treadwear indica-
tors are showing on the tires.
Also check the tires for uneven
wear, such as excessive wear
on one side of the tread.
Check the spare tire condition
and pressure if not rotated.
New tread
Worn tread
Treadwear indicator
The location of treadwear indicators
is shown by a “TWI” or “ ” mark,
A
B
Tires
Replace or rotate tires in
accordance with mainte-
nance schedules and tread-
wear.
Checking tires
A
B
C

4226-3. Do-it-yourself maintenance
etc., molded into the sidewall of
each tire.
Replace the tires if the treadwear
indicators are showing on a tire.
■When to replace your vehicle’s
tires
Tires should be replaced if:
●The treadwear indicators are
showing on a tire.
●You have tire damage such as
cuts, splits, cracks deep enough
to expose the fabric, and bulges
indicating internal damage.
●A tire goes flat repeatedly or can-
not be properly repaired due to
the size or location of a cut or
other damage.
If you are not sure, consult with your
Toyota dealer.
■Tire life
Any tire over 6 years old must be
checked by a qualified technician
even if it has seldom or never been
used or damage i s not obvious.
■Maximum load of tire
Check that the maximum load of the
replacement tire is greater than 1/2
of the Gross Axle Weight Ratings
(GAWR) of either t he front axle or
the rear axle, whichever is greater.
For the GAWR, see the Certification
Label. For the maximum load of the
tire, see the load limit at maximum
cold tire inflation pressure men-
tioned on the sidewall of the tire.
(  P.528)
■Tire types
●Summer tires Summer tires are high-speed perfor-
mance tires best suited to highway
driving under dry conditions. Since
summer tires do not have the same
traction performance as snow tires,
summer tires are inadequate for
driving on snow-covered or icy
roads. For driving on snow-covered
roads or icy roads, the use of snow
tires is recommended. When install-
ing snow tires, be sure to replace all
four tires.
●All season tires
All season tires are designed to pro-
vide better traction in snow and to
be adequate for driving in most win-
ter conditions as well as for use
year-round. All season tires, how-
ever, do not have adequate traction
performance compared with snow
tires in heavy or loose snow. Also,
all season tires fall short in accelera-
tion and handling performance com-
pared with summer tires in highway
driving.
●Snow tires
For driving on snow-covered roads
or icy roads, we recommend using
snow tires. If you need snow tires,
select tires of the same size, con-
struction and load capacity as the
originally installed tires. Since your
vehicle has radial tires as original
equipment, make sure your snow
tires also have radi al construction.
Do not install studded tires without
first checking local regulations for
possible restrictions. Snow tires
should be installed on all wheels.
(  P.344)
■If the tread on snow tires wears
down below 0.16 in. (4 mm)
The effectiveness of the tires as
snow tires is lost.