2021 TOYOTA SIENNA HYBRID service

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

4116-3. Do-it-yourself maintenance
6
Maintenance and care
6-3.Do-it-yourself maintenance
Do-it-yourself service
precautions
If you perform maintenance
by yourself, be sure to fol-
low the correct procedure as
given in these sections.
Maintenance
ItemsParts and tools
12-volt bat-
tery condi-
tion
( P.422)•Grease
• Conventional
wrench (for termi-
nal clamp bolts)
Brake fluid
level
( P.420)
• FMVSS No.116
DOT 3 or SAE
J1703 brake fluid
• FMVSS No.116 DOT 4 or SAE
J1704 brake fluid
• Rag or paper towel
• Funnel (used only for adding brake
fluid)
Engine/power
control unit
coolant level
( P.419)
• “Toyota Super
Long Life Cool-
ant” or a similar
high quality eth-
ylene glycol-based
non-silicate, non-
amine, non-nitrite
and non-borate
coolant with long-
life hybrid organic
acid technology
For the U.S.A.:
“Toyota Super
Long Life Cool-
ant” is pre-mixed
with 50% coolant
and 50% deion-
ized water.
For Canada:
“Toyota Super
Long Life Cool-
ant” is pre-mixed
with 55% coolant
and 45% deion-
ized water.
• Funnel (used only for adding coolant)
Engine oil
level
( P.416)
• “Toyota Genuine
Motor Oil” or
equivalent
• Rag or paper towel
• Funnel (used only for adding engine
oil)
Fuses
( P.449)• Fuse with same
amperage rating
as original
ItemsParts and tools

4186-3. Do-it-yourself maintenance
■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.

4416-3. Do-it-yourself maintenance
6
Maintenance and care
Use only Toyota wheel nuts
and wrenches designed for
use with your aluminum
wheels.
 When rotating, repairing or
changing your tires, check
that the wheel nuts are still
tight after driving 1000 miles
(1600 km).
 Vehicles with 17-inch or 18-
inch tires: Be careful not to
damage the aluminum wheels
when using tire chains.
 Use only Toyota genuine bal-
ance weights or equivalent
and a plastic or rubber ham-
mer when balancing your
wheels. 1
Turn the power switch off.
2 Open the glove box and slide
off the damper.
3 Push in each side of the
glove box to disconnect the
claws, and then slowly and
fully open the glove box while
supporting it.
NOTICE
■Replacing tire pressure warn-
ing valves and transmitters
●Because tire repair or replace-
ment may affect the tire pres-
sure warning valves and
transmitters, make sure to have
tires serviced by your Toyota
dealer or other qualified service
shop. In addition, make sure to
purchase your tire pressure
warning valves and transmit-
ters at your Toyota dealer.
●Ensure that only genuine
Toyota wheels are used on your
vehicle.
Tire pressure warning valves
and transmitters may not work
properly with non-genuine
wheels.
Aluminum wheel precau-
tions
Air conditioning filter
The air conditioning filter
must be changed regularly
to maintain air conditioning
efficiency.
Removal method

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)

4627-2. Steps to take in an emergency
7-2.Steps to take in an emergency
If your vehicle needs
to be towed
If towing is necessary, we
recommend having your
vehicle towed by your
Toyota dealer or commer-
cial towing service, using a
wheel-lift type truck or flat-
bed truck.
Use a safety chain system
for all towing, and abide by
all state/provincial and local
laws.
2WD models: If towing your
vehicle with a wheel-lift type
truck from the front, the
vehicle’s rear wheels and
axles must be in good con-
ditions. (P.462, 463)
If they are damaged, use a
towing dolly or flatbed
truck.
AWD models: If towing your
vehicle with a wheel-lift type
truck, use a towing dolly.
( P.462, 463)
WARNING
Observe the following precau-
tions. Failure to do so may result
in death or serious injury.
■When towing the vehicle
2WD models: Be sure to transport
the vehicle with th e front wheels
raised or with all four wheels
raised off the ground. If the vehi-
cle is towed with th e front wheels
contacting the ground, the drive-
train and related parts may be
damaged or electricity generated
by the operation of the motor may
cause a fire to occur depending
on the nature of the damage or
malfunction.
AWD models: Be sure to transport
the vehicle with all four wheels
raised off the ground. If the vehi-
cle is towed with th e tires contact-
ing the ground, the drivetrain or
related parts may be damaged,
the vehicle may fly off the truck, or
electricity generated by the opera-
tion of the motor may cause a fire
to occur depending on the nature
of the damage or malfunction.

4637-2. Steps to take in an emergency
7
When trouble arises
The following may indicate a
problem with your transmission.
Contact your Toyota dealer or
commercial towing service
before towing. 
The hybrid system warning
message is shown on the
multi-information display and
the vehicle does not move.
 The vehicle makes an abnor-
mal sound.
From the front (2WD models)
Release the parking brake.
Turn automatic mode off.
( P.244)
From the front (AWD models)
Use a towing dolly under the
rear wheels.
NOTICE
■To prevent damage to the
vehicle when towing using a
wheel-lift type truck
●Do not tow the vehicle from the
rear when the power switch is
off. The steering lock mecha-
nism is not strong enough to
hold the front wheels straight.
●When raising the vehicle,
ensure adequate ground clear-
ance for towing at the opposite
end of the raised vehicle. With-
out adequate clearance, the
vehicle could be damaged while
being towed.
■To prevent damage to the
vehicle when towing with a
sling-type truck
Do not tow with a sling-type truck,
either from the front or rear.
■Recreational towing (behind
motor home, etc.)
Never dinghy tow your vehicle to
prevent causing serious damage
to the AWD system and transmis-
sion. ( P.230)
Situations when it is nec-
essary to contact dealers
before towing
Towing with a wheel-lift
type truck

5298-1. Specifications
8
Vehicle specifications
emission control system may be
adversely affected.
The malfunction indicator lamp on
the instrument cluster may come on.
If this happens, contact your Toyota
dealer for service.
■If your engine knocks
●Consult your Toyota dealer.
●You may occasionally notice light
knocking for a short time while
accelerating or driving uphill. This
is normal and there is no need for
concern.
NOTICE
■Notice on fuel quality
●Do not use impro per fuels. If
improper fuels are used, the
engine will be damaged.
●Do not use leaded gasoline.
Leaded gasoline can cause
damage to your vehicle’s three-
way catalytic converters caus-
ing the emission control system
to malfunction.
●Do not use gasohol other than
the type previously stated.
Other gasohol may cause fuel
system damage or vehicle per-
formance problems.
●Using unleaded gasoline with
an octane number or rating
lower than the l evel previously
stated will cause persistent
heavy knocking.
At worst, this will lead to engine
damage.
■Fuel-related poor driveability
If poor driveability (poor hot start-
ing, vaporization, engine knock-
ing, etc.) is encountered after
using a different type of fuel, dis-
continue the use of that type of
fuel.
■When refueling with gasohol
Take care not to spill gasohol. It
can damage your vehicle’s paint.