2021 TOYOTA SIENNA HYBRID battery

4787-2. Steps to take in an emergency
*: A buzzer sounds the first time a message is show n on the multi-informa-
tion display.
■Warning messages
The warning messages explained
below may differ from the actual
messages according to operation
conditions and vehicle specifica-
tions.
■Warning buzzer
In some cases, the buzzer may not
be heard due to being in a noisy
location or audio sound.
■If a message that indicates the
need for visiting your Toyota
dealer is displayed
The system or part shown on the
multi-information di splay is malfunc-
tioning. Have the vehicle inspected
by your Toyota dealer immediately.
■If a message that indicates the
need for referring to Owner’s
Manual is displayed
●If “Engine Coolant Temp High
Stop in a Safe Place See Owner’s
Manual” is shown, follow the
instructions ( P.514).
●If any of the following messages
are shown on the multi-informa-
tion display, it may indicate a mal-
function. Have the vehicle
inspected by your Toyota dealer
immediately.
• “Smart Key System Malfunction”
• “Hybrid System Malfunction”
• “Check Engine”
• “Hybrid Battery System Malfunc-
tion”
• “Accelerator System Malfunction”
●If any of the following messages
are shown on the multi-informa-
Warning lightWarning buzzer*Warning
Sounds
• Indicates an import ant situation, such
as when a system related to driving is
malfunctioning or that danger may
result if the correction procedure is not
performed
• Indicates a situat ion, such as when
damage to the vehicle or danger may
result
Comes on or flashesSounds
Indicates an importan t situation, such as
when the systems shown on the multi-
information display may be malfunction-
ing
Does not sound
• Indicates a condition, such as malfunc- tion of electrical components, their con-
dition, or indicat es the need for
maintenance
• Indicates a situatio n, such as when an
operation has been performed incor-
rectly, or indicates how to perform an
operation correctly

4797-2. Steps to take in an emergency
7
When trouble arises
tion display, it may indicate a mal-
function. Immediately stop the
vehicle and contact your Toyota
dealer.
•“Braking Power Low”
• “12-Volt Battery Charging System
Malfunction”
• “Oil Pressure Low”
●If any of the following messages
are shown on the multi-informa-
tion display, the vehicle may have
run out of fuel. Stop the vehicle in
a safe place and, if the fuel level is
low, refuel the vehicle.
• “Hybrid System Stopped”
• “Engine Stopped”
●If “Low Auxiliary Battery See
Owner’s Manual” is shown
• When the display goes off after
several seconds
*:
Maintain the hybri d system opera-
tion for more than 15 minutes and
charge the 12- volt battery.
• When the display does not go off:
Start up the hybrid system using the
procedures for “If the 12-volt battery
is discharged” ( P.506)
*: Displays for about 6 seconds
●If “Maintenance Required for Trac-
tion Battery Cooling Parts See
Owner’s Manual” is shown, the fil-
ter may be clogged, the air intake
vent may be blocked, or there may
be a gap in the duct. Therefore,
perform the following correction
procedure.
• If the air intake vent or filter of the hybrid battery (traction battery)
are dirty, perform the procedures
on P.443to clean them.
• If the warning message is shown when the air intake vent and filter
of the hybrid battery (traction bat-
tery) are not dirty, have the vehicle
inspected at your Toyota dealer.
■If “Engine Oil Level Low Add or
Replace” is displayed
The engine oil level may be low.
Check the level of the engine oil, and add engine oil if necessary.
This message may be displayed if
the vehicle is stopped on a slope.
Move the vehicle to a level surface
and check if the message disap-
pears.
■If “Hybrid System Stopped
Steering Power Low” is dis-
played
This message is displayed if the
hybrid system is stopped while driv-
ing.
When steering wheel operations are
heavier than usual, grip the steering
wheel firmly and operate it using
more force than usual.
■If “Hybrid System Overheated
Output Power Reduced” is
shown
The message may be shown when
driving under severe operating con-
ditions. (For example, when driving
up a long steep hill or driving up a
steep hill in reverse.)
Coping method: P.514
■If “Traction Battery Needs to be
Protected Refrain from the Use
of N Position” is shown
This message may be displayed
when the shift lever is in N.
As the hybrid battery (traction bat-
tery) can not be charged when the
shift lever is in N, shift the shift lever
to P when the vehicle is stopped.
■If “Traction Battery Needs to be
Protected Shift into P to
Restart” is shown
This message is displayed when the
hybrid battery (traction battery)
charge has becom e extremely low
because the shift lever has been left
in N for a certain amount of time.
When operating the vehicle, shift to
P and restart the hybrid system.
■If “Shift to P Before Exiting
Vehicle” is shown
Message is displayed when the
driver’s door is opened without turn-

4807-2. Steps to take in an emergency
ing the power switch to OFF with the
shift lever in any position other than
P.
Shift the shift lever to P.
■If “Shift Is in N Release Acceler-
ator Before Shifting” is shown
Message is displayed when the
accelerator pedal has been
depressed and the shift lever is in N.
Release the accelerator pedal and
shift the shift lever to D or R.
■If “Accelerator Pedal is
Pressed” is displayed
The accelerator pedal has been
depressed when the shift lever is in
P. Release the accelerator pedal.
■If “Press Brake When Vehicle Is
Stopped Hybrid System May
Overheat” is shown
Message is displayed when the
accelerator pedal is depressed to
maintain the vehicle position when
stopped on a upward slope, etc.
If this continues, the hybrid system
may overheat.
Release the accelerator pedal and
depress the brake pedal.
■If “Auto Power Off to Conserve
Battery” is shown
Power was turned off due to the
automatic power off function.
Next time when starting the hybrid
system, operate th e hybrid system
for approximatel y 5 minutes to
recharge the 12-volt battery.
■If “High Power Consumption
Power to Climate Temporarily
Limited” is displayed
Turn off unnecessary electronic
equipment to reduce power con-
sumption.
Please wait until th e power supply
returns to normal.
■If “Headlight System Malfunc-
tion Visit Your D ealer” is dis-
played
The following systems may be mal- functioning.
Have the vehicle inspected by your
Toyota dealer immediately.
●The LED headlight system
●Automatic High Beam
■If “Radar Cruise Control
Unavailable” is shown
The dynamic radar cruise control
with full-speed range system is sus-
pended temporarily or until the prob-
lem shown in the message is
resolved. (causes and coping meth-
ods: P.265)
■If a message that indicates the
malfunction of front camera is
displayed
The following systems may be sus-
pended until the problem shown in
the message is resolved. (P.265,
466)
●PCS (Pre-Collision System)
●LTA (Lane Tracing Assist)
●Automatic High Beam
●RSA (Road Sign Assist) (if
equipped)
●Dynamic radar cruise control with
full-speed range
■If “Oil Maintenance Required
Soon” is displayed
Indicates that the engine oil should
be scheduled to be changed.
Check the engine oil and change it if
necessary.
After changing the engine oil, make
sure to reset t he message.
(  P.418)
■If “Oil Maintenance Required
Visit Your Deale r” is displayed
Indicates that the engine oil should
be changed.
Check and change the engine oil
and oil filter by yo ur Toyota dealer.
After changing the engine oil, make
sure to reset t he message.
(  P.418)

4817-2. Steps to take in an emergency
7
When trouble arises
■Warning buzzer
 P.473
NOTICE
■“High Power Consumption
Power to Climate Temporar-
ily Limited” is frequently
shown
There is a possible malfunction
relating to the charging system or
the 12-volt battery may be deteri-
orating. Have the vehicle
inspected by your Toyota dealer.
■If “Low Auxiliary Battery See
Owner’s Manual” is displayed
frequently
The 12-volt battery may have
deteriorated.
As the battery m ay discharge in
this state when left unattended,
have the battery inspected by
your Toyota dealer.
If you have a flat tire
(vehicles without
spare tire)
Your vehicle is not
equipped with a spare tire,
but instead is equipped with
an emergency tire puncture
repair kit. A puncture
caused by a nail or screw
passing through the tire
tread can be repaired tem-
porarily using the emer-
gency tire puncture repair
kit. (The kit contains a bottle
of sealant. The sealant can
be used only once to tempo-
rarily repair one tire without
removing the nail or screw
from the tire.) Depending on
the damage condition of the
flat tire, it may not be able to
repaired with the emer-
gency tire puncture repair
kit. ( P.482)
After temporarily repairing
the tire with the kit, have the
tire repaired or replaced by
your Toyota dealer.

5017-2. Steps to take in an emergency
7
When trouble arises
One of the following may be the
cause of the problem:
The electronic key may not be
functioning properly.
( P.504)
 There may not be sufficient
fuel in the vehicle’s tank.
Refuel the vehicle. ( P.259)
 There may be a malfunction
in the immobilizer system.
( P.88)
 There may be a malfunction
in the steering lock system.
 The hybrid system may be
malfunctioning due to an elec-
trical problem such as elec-
tronic key battery depletion or
a blown fuse. However,
depending on the type of mal-
function, an interim measure
is available to start the hybrid
system. ( P.501) One of the following may be the
cause of the problem:

The 12-volt battery may be
discharged. ( P.506)
 The 12-volt battery terminal
connections may be loose or
corroded. ( P.423)
One of the following may be the
cause of the problem:
 The 12-volt battery may be
discharged. ( P.506)
 One or both of the 12-volt bat-
tery terminals may be discon-
nected. ( P.423)
Contact your Toyota dealer if
the problem cannot be repaired,
or if repair procedures are
unknown.
When the hybrid system does
not start, the following steps can
be used as an interim measure
to start the hybrid system if the
power switch is functioning nor-
If the hybrid system
will not start
Reasons for the hybrid sys-
tem not starting vary
depending on the situation.
Check the following and
perform the appropriate
procedure:
The hybrid system will not
start even though the cor-
rect starting procedure is
being followed ( P.231)
The interior lights and
headlights are dim, or the
horn does not sound or
sounds at a low volume
The interior lights and
headlights do not turn on,
or the horn does not
sound
Starting the hybrid sys-
tem in an emergency

5047-2. Steps to take in an emergency
■When the electronic key does
not work properly
●Make sure that the smart key sys-
tem has not been deactivated in
the customization setting. If it is
off, turn the function on.
(Customizable features: P.544)
●Check if battery-saving mode is
set. If it is set, cancel the function.
( P.166)
Use the mechanical key
( P.131) in order to perform the following operations.
1
Locks all the doors
2 Unlocks the door
■Key linked functions
The opening and closing of the
power windows and moon roof can
be linked to key operation by a cus-
tomized setting at your Toyota
dealer.
1 Closes the windows and the
moon roof
* (turn and hold)
2 Opens the windows and the
moon roof
* (turn and hold)
*: If equipped
If the electronic key
does not op erate prop-
erly
If communication between
the electronic key and vehi-
cle is interrupted ( P.166)
or the electronic key cannot
be used because the battery
is depleted, the smart key
system and wireless remote
control cannot be used. In
such cases, the doors can
be opened and the hybrid
system can be started by
following the procedure
below.
NOTICE
■In case of a smart key system
malfunction, or other key
related problems
Take your vehicle with all the
electronic keys provided with your
vehicle to your Toyota dealer.
Locking and unlocking
the doors

5057-2. Steps to take in an emergency
7
When trouble arises
1Ensure that the shift lever is
in P and depress the brake
pedal.
2 Touch the electronic key to
the power switch as shown in
the illustration.
When the electronic key is
detected, a buzzer sounds and the
power switch will turn to ON.
When the smart key system is
deactivated in customization set-
ting, the power switch will turn to
ACC.
3Firmly depress the brake
pedal and check that is displayed on the multi-infor-
mation display.
4 Press the power switch
shortly and firmly.
In the event that t he hybrid system
still cannot be started, contact your
Toyota dealer.
■Stopping the hybrid system
Shift the shift lever to P, set the
parking brake and press the power
switch as you normally do when
stopping the hybrid system.
■Replacing the key battery
As the above proce dure is a tempo-
rary measure, it is recommended
that the electronic key battery be
replaced immediately when the bat-
tery is depleted. ( P.447)
■Changing power switch modes
Release the brake pedal and press
the power switch in step 3 above.
The hybrid system does not start
and modes will be changed each
time the switch is pressed.
(  P.234)
WARNING
■When using the mechanical
key and operating the power
windows or the moon roof (if
equipped)
Operate the power window or the
moon roof after checking to make
sure that there is n o possibility of
any passenger having any of their
body parts caught in the window
or the moon roof. Also, do not
allow children to operate the
mechanical key. It is possible for
children and other passengers to
get caught in the power window or
the moon roof.
Starting the hybrid sys-
tem

5067-2. Steps to take in an emergency
If you have a set of jumper (or
booster) cables and a second
vehicle with a 12-volt battery,
you can jump start your vehicle
by following the steps below.
1Vehicles with alarm: Confirm
that the electronic key is
being carried.
When connecting the jumper (or
booster) cables, depending on the
situation, the ala rm may activate and the doors locked. (
P.90)
2 Open the hood ( P.413) and
fuse box cover.
Push claw , and to com-
pletely release the lock, and then lift
up the cover.
3 Open the exclusive jump
starting terminal cover.
4 Connect a positive jumper cable clamp to on your vehicle and
connect the clamp on the other end of the positive cable to on
the second vehicle. Then, connect a negative cable clamp to
If the 12-volt battery is
discharged
The following procedures
may be used to start the
hybrid system if the vehi-
cle’s 12-volt battery is dis-
charged.
You can also call your
Toyota dealer or a qualified
repair shop.
Restarting the hybrid sys-
tem
ABC
A
B
C