2021 TOYOTA SIENNA HYBRID battery

SIENNA_OM_OM08031U_(U)
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Pictorial indexSearch by illustration
For safety
and securityMake sure to read through them
(Main topics: Child seat, theft deterrent system)
Vehicle status
information and
indicatorsReading driving-related information
(Main topics: Meters, multi-information display)
Before driving
Opening and closing the doors and windows,
adjustment before driving
(Main topics: Keys, doors, seats, power windows)
Driving
Operations and advice which are necessary for
driving
(Main topics: Starting hybrid system, refueling)
Interior featuresUsage of the interior features
(Main topics: Air conditioner, storage features)
Maintenance
and careCaring for your vehicle and maintenance
procedures
(Main topics: Interior and exterior, light bulbs)
When trouble
arisesWhat to do in case of malfunction and emergency
(Main topics: 12-volt battery discharge, flat tire)
Vehicle
specificationsVehicle specifications, customizable features
(Main topics: Fuel, oil, tire inflation pressure)
For ownersReporting safety defects for U.S. owners, and seat
belt and SRS airbag instructions for Canadian
owners
IndexSearch by symptom
Search alphabetically

4TABLE OF CONTENTS
5-3. Using the storage featuresList of storage features . 366
Luggage compartment fea- tures ............................ 372
5-4. Using the other interior fea- tures
Other interior features ... 374
Garage door opener...... 392
6-1. Maintenance and care Cleaning and protecting the vehicle exterior ............ 400
Cleaning and protecting the vehicle interior ............. 403
6-2. Maintenance Maintenance requirements.................................... 406
General maintenance.... 407
Emission inspection and maintenance (I/M) programs.................................... 410
6-3. Do-it-yourself maintenance Do-it-yourself service precau-tions............................. 411
Hood ............................. 413
Positioning a floor jack .. 415
Engine compartment ..... 416
12-volt battery ............... 422
Tires .............................. 424
Tire inflation pressure ... 438
Wheels ......... .................440
Air conditioning filter ...... 441
Cleaning the hybrid battery (traction battery) air intake
vents and filters ........... 443Electronic key battery ....
447
Checking and replacing fuses .................................... 449
Light bulbs ..................... 451
7-1. Essential information Emergency flashers....... 458
If your vehicle has to be stopped in an emergency.................................... 459
If the vehicle is trapped in ris- ing water ...................... 460
7-2. Steps to take in an emer- gency
If your vehicle needs to be
towed ........................... 462
If you think something is wrong........................... 465
If a warning light turns on or a warning buzzer sounds 466
If a warning message is dis- played .......................... 477
If you have a flat tire (vehicles without spare tire) ........ 481
If you have a flat tire (vehicles with spare tire) ............. 491
If the hybrid system will not start ............................. 501
If you lose your keys...... 502
If the fuel filler door cannot be opened ......... ...............503
If the electronic key does not operate properly .......... 50
4
If the 12-
volt battery is dis-
charged ....................... 506
If your vehicle overheats 511
6Maintenance and care
7When trouble arises

791-4. Hybrid system
1
For safety and security
1-4.Hybrid system
The illustration is an example for explanation and may differ from the actual
item.
Gasoline engine
Front electric motor (traction motor)
Rear electric motor (traction motor)
*
*: AWD models only
■When stopped/during start
off
The gasoline engine stops
*
when the vehicle is stopped.
During start off, the electric
motor (traction motor) drives the vehicle. At slow speeds or when
traveling down a gentle slope,
the engine is stopped
* and the
electric motor (traction motor) is
used.
When the shift lever is in N, the
hybrid battery (traction battery)
Hybrid system features
Your vehicle is a hybrid vehicle. It has characteristics differ ent
from conventional vehicles. Be sure you are closely familiar
with the characteristics of your vehicle, and operate it with
care.
The hybrid system combines the use of a gasoline engine and
an electric motor (traction motor) according to driving condi-
tions, improving fuel efficiency and reducing exhaust emis-
sions.
System components
A
B
C

801-4. Hybrid system
is not being charged.
*: When the hybrid battery (traction battery) requires charging or the
engine is warming up, etc., the
gasoline engine will not automati-
cally stop. ( P.80)
■During normal driving
The gasoline engine is predomi-
nantly used. The electric motor
(traction motor) charges the
hybrid battery (traction battery)
as necessary.
■When accelerating sharply
When the accelerator pedal is
depressed heavily, the power of
the hybrid battery (traction bat-
tery) is added to that of the gas-
oline engine via the electric
motor (traction motor).
■When braking (regenera-
tive braking)
The wheels operate the electric
motor (traction motor) as a
power generator, and the hybrid
battery (traction battery) is
charged.
■Regenerative braking
In the following si tuations, kinetic
energy is converted to electric
energy and deceleration force can
be obtained in conjunction with the
recharging of the hybrid battery
(traction battery).
●The accelerator pedal is released
while driving with the shift lever in
D or S.
●The brake pedal is depressed
while driving with the shift lever in
D or S.
■EV indicator
The EV indicator comes on when
the vehicle is driven using only the
electric motor (traction motor) or the
gasoline engine is stopped.
The on/off operation of the EV indi-
cator can be changed. ( P.112)
■Conditions in which the gaso-
line engine may not stop
The gasoline engine starts and
stops automatically. However, it
may not stop automatically in the
following conditions
*:
●During gasoline engine warm-up
●During hybrid battery (traction bat-
tery) charging
●When the temperature of the
hybrid battery (traction battery) is
high or low
●When the heater is switched on*: Depending on the circumstances, the gasoline engine may also not
stop automatically in other situa-
tions.
■Charging the hybrid battery
(traction battery)
As the gasoline engine charges the
hybrid battery (trac tion battery), the
battery does not need to be charged
from an outside source. However, if
the vehicle is left parked for a long
time the hybrid battery (traction bat-
tery) will slowly dis charge. For this
reason, be sure to drive the vehicle
at least once every few months for
at least 30 minutes or 10 miles (16
km). If the hybrid battery (traction
battery) becomes fully discharged
and you are unabl e to start the

811-4. Hybrid system
1
For safety and security
hybrid system, contact your Toyota
dealer.
■Charging the 12-volt battery
 P.508
■After the 12-volt battery has dis-
charged or when the terminal
has been removed and installed
during exchange, etc.
The gasoline engine may not stop
even if the vehicle is being driven by
the hybrid battery (traction battery).
If this continues for a few days, con-
tact your To yota dealer.
■Sounds and vibrations specific
to a hybrid vehicle
There may be no engine sound or
vibration even though the vehicle is
able to move with the “READY” indi-
cator is illuminate d. For safety,
make sure to shift the shift lever to P
and apply the parking brake when
parked.
The following sounds or vibrations
may occur when the hybrid system
is operating and are not a malfunc-
tion:
●Motor sounds may be heard from
the engine compartment.
●Sounds may be heard from the
hybrid battery (traction battery)
under the front seats when the
hybrid system starts or stops.
●Relay operating sounds such as a
snap or soft clank will be emitted
from the hybrid battery (traction
battery), under the front seats,
when the hybrid system is started
or stopped.
●Sounds from the hybrid system
may be heard when the back door
is open.
●Sounds may be heard from the
transmission when the gasoline
engine starts or stops, when driv-
ing at low speeds, or during idling.
●Engine sounds may be heard
when accelerating sharply.
●Sounds may be heard due to regenerative braking when the
brake pedal is depressed or as
the accelerator pedal is released.
●Vibration may be felt when the
gasoline engine starts or stops.
●Cooling fan sounds may be heard
from the air intake vent under the
front seat.
■Maintenance, repair, recycling,
and disposal
Contact your Toyota dealer regard-
ing maintenance, repair, recycling
and disposal. Do n ot dispose of the
vehicle yourself.
When driving with the gasoline
engine stopped, a sound, which
changes in accordance with the
driving speed, will be played in
order to warn people nearby of
the vehicle’s approach. The
sound will stop when the vehicle
speed exceeds approximately
22 mph (35 km/h).
■Acoustic Vehicle Alerting Sys-
tem
In the following cases, the Acoustic
Vehicle Alerting System may be dif-
ficult for surrounding people to hear.
●In very noisy areas
●In the wind or the rain
■If “Acoustic Vehicle Alerting
System Malfunction Visit Your
Dealer” is displayed on the
multi-information display
The system may be malfunctioning.
Have the vehicle inspected by your
Toyota dealer.
Acoustic Vehicle Alerting
System

821-4. Hybrid system
*: This function can only be used in
the mainland U.S.A. It cannot be
used in other states and territo-
ries, including Alaska and Hawaii.
This system operates based on
the driving situation and traffic
information to enhance fuel
economy.
For details about Predictive effi-
cient drive, refer to “NAVIGA-
TION AND MULTIMEDIA
SYSTEM OWNER’S MANUAL”.
■Predictive deceleration sup-
port
 When the vehicle approaches
to predictive deceleration sup-
port points registered in the
navigation system, the “Refer-
ence operation range” ( ) of
the ECO Accelerator Guid-
ance ( P.108) on the multi-
information display will be
turned off to encourage the
driver to reduce excessive
acceleration.
 The engine braking force will be increased according to the
driving conditions to more effi-
ciently charge the hybrid bat-
tery (traction battery) after the
accelerator pedal is released.
■Predictive SOC control
The following types of control
are performed based on data
such as road and traffic informa-
tion during route guidance by
the navigation system to help
ensure that the vehicle effi-
ciently uses electricity.
 When there is a long downhill
slope along the route, the sys-
tem reduces the hybrid bat-
tery (traction battery) level
before reaching the slope to
help ensure charging capacity
for regenerative braking while
traveling downhill.
 When traffic congestion is
predicted along the route, the
system helps ensure a certain
battery level before reaching
congested roads to reduce
the frequency of starting the
engine to charge the hybrid
battery (traction battery) due
to low battery levels.
Predictive efficient drive
(vehicles with navigation
system)
*
A

831-4. Hybrid system
1
For safety and security
The illustration is an example for explanation and may differ from the actual
item.
Warning label
Service plug
Rear electric motor (traction motor)
*
Hybrid battery (traction battery)
High voltage cables (orange)
Front electric motor (traction motor)
Power control unit
Air conditioning compressor
*: AWD models only
Hybrid system precautions
Take care when handling the hybrid system, as it is a high
voltage system (about 650V at maximum) as well as contains
parts that become extremely hot when the hybrid system is
operating. Obey the warning labels attached to the vehicle.
System components
A
B
C
D
E
F
G
H

841-4. Hybrid system
■Running out of fuel
When the vehicle has run out of fuel
and the hybrid system cannot be
started, refuel th e vehicle with at
least enough gasoline to make the
low fuel level warning light ( P.472)
go off. If there is only a small
amount of fuel, th e hybrid system
may not be able to start. (The stan-
dard amount of fuel is about 3.1 gal.
[11.9 L, 2.6 Imp. gal.], when the
vehicle is on a level surface. This
value may vary whe n the vehicle is
on a slope. Add ext ra fuel when the
vehicle is inclined.)
■Electromagnetic waves
●High voltage parts and cables on
hybrid vehicles incorporate elec-
tromagnetic shielding, and there-
fore emit approximately the same
amount of electromagnetic waves
as conventional gasoline pow-
ered vehicles or home electronic
appliances.
●Your vehicle may cause sound
interference in so me third party-
produced radio parts.
■Hybrid battery (tr action battery)
The hybrid battery (traction battery)
has a limited service life. The lifes-
pan of the hybrid battery (traction
battery) can change in accordance
with driving style and driving condi-
tions.
WARNING
■High voltage precautions
This vehicle has high voltage DC
and AC systems as well as a 12-
volt system. DC and AC high volt-
age is very dangerous and can
cause severe burns and electric
shock that may result in death or
serious injury.
●Never touch, disassemble,
remove or replace the high volt-
age parts, cables or their con-
nectors.
●The hybrid system will become
hot after starting as the system
uses high voltage. Be careful of
both the high voltage and the
high temperature, and always
obey the warning labels
attached to the vehicle.
●Never try to open the service
plug access hole located under-
neath the console box. The ser-
vice plug is used only when the
vehicle is serviced and is sub-
ject to high voltage.
■Road accident cautions
Observe the following precautions
to reduce the risk of death or seri-
ous injury:
●Pull your vehicle off the road,
shift the shift le ver to P, apply
the parking brake, and turn the
hybrid system off.
●Do not touch the high voltage
parts, cables and connectors.
●If electric wires are exposed
inside or outside your vehicle,
an electric shock may occur.
Never touch exposed electric
wires.
●If a fluid leak occurs, do not
touch the fluid as it may be
strong alkaline electrolyte from
the hybrid battery (traction bat-
tery). If it comes into contact
with your skin or eyes, wash it
off immediately with a large
amount of water or, if possible,
boric acid solution. Seek imme-
diate medical attention.