2021 TOYOTA SIENNA HYBRID stop start

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)

457
7
7
When trouble arises
When trouble arises
7-1. Essential informationEmergency flashers .... 458
If your vehicle has to be stopped in an emergency.................................. 459
If the vehicle is trapped in rising 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 (vehi- cles without spare tire) 481
If you have a flat tire (vehi- cles 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 .. 504
If the 12-volt battery is dis- charged ..................... 506
If your vehicle overheats .................................. 511If the vehicle becomes stuck
.................................. 514

4767-2. Steps to take in an emergency
WARNING
As an added safety feature, your
vehicle has been equipped with a
tire pressure m onitoring system
(TPMS-tire pressure warning sys-
tem) that illuminates a low tire
pressure telltale (tire pressure
warning light) when one or more
of your tires is significantly under-
inflated. Accordingly, when the
low tire pressure telltale (tire pres-
sure warning light) illuminates,
you should stop and check your
tires as soon as possible, and
inflate them to the proper pres-
sure. Driving on a significantly
under-inflated tire causes the tire
to overheat and can lead to tire
failure. Under-inflation also
reduces fuel efficiency and tire
tread life, and may affect the vehi-
cle’s handling and stopping abil-
ity.
Please note that the TPMS (tire
pressure warning system) is not a
substitute for pro per tire mainte-
nance, and it is the driver’s
responsibility to maintain correct
tire pressure, even if under-infla-
tion has not reach ed the level to
trigger illumination of the TPMS
low tire pressure telltale (tire pres-
sure warning light).
Your vehicle has also been
equipped with a TPMS (tire pres-
sure warning system) malfunc-
tion indicator to indicate when the
system is not operating properly.
The TPMS (tire pressure warning
system) malfunction indicator is
combined with the low tire pres-
sure telltale (tire pressure warning
light). When the system detects a
malfunction, the te lltale will flash
for approximately one minute and
then remain continuously illumi-
nated. This sequence will con-
tinue upon subsequent vehicle
start-ups as long as the malfunc-
tion exists. When the malfunction
indicator is illuminated, the sys-
tem may not be ab le to detect or
signal low tire pressure as
intended.
TPMS (tire pressure warning sys-
tem) malfunctions may occur for a
variety of reasons, including the
installation of replacement or
alternate tires or wheels on the
vehicle that prevent the TPMS
(tire pressure warning system)
from functioning properly. Always
check the TPMS (tire pressure
warning system) malfunction tell-
tale after replacing one or more
tires or wheels on your vehicle to
ensure that the replacement or
alternate tires and wheels allow
the TPMS (tire pressure warning
system) to continue to function
properly.
NOTICE
■To ensure the tire pressure
warning system operates
properly
Do not install tires with different
specifications or manufacturers
as the tire pressure warning sys-
tem may not operate properly.

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)

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

5127-2. Steps to take in an emergency
“LOW” line
5 Add coolant if necessary.
Water can be us ed in an emer-
gency if engine coolant is unavail-
able.
6 Start the hybrid system and
turn the air conditioning sys-
tem on to check that the radi-
ator cooling fan operates and
to check for coolant leaks
from the radiator or hoses.
The fan operates when the air con-
ditioning system is turned on imme-
diately after a cold start. Confirm
that the fan is op erating by check-
ing the fan sound and air flow. If it is
difficult to check th ese, turn the air
conditioning system on and off
repeatedly. (The f an may not oper-
ate in freezing temperatures.)
7 If the fan is not operating:
Stop the hybrid system
immediately and contact your
Toyota dealer.
If the fan is operating:
Have the vehicle inspected at
the nearest Toyota dealer.
8 Check if “Engine Coolant
Temp High Stop in a Safe
Place See Owner’s Manual”
is shown on the multi-infor-
mation display.
If the message does not disappear:
Stop the hybrid system and contact
your Toyota dealer.
If the message is not displayed:
Have the vehicle inspected at the
nearest Toyota dealer.
■If “Hybrid System Over-
heated Output Power
Reduced” is shown on the
multi-information display
1 Stop the vehicle in a safe
place.
2 Stop the hybrid system and
carefully lift the hood.
3 After the hybrid system has
cooled down, inspect the
hoses and radiator core (radi-
ator) for any leaks.
Radiator
Cooling fan
If a large amount of coolant leaks,
immediately contact your Toyota
dealer.
4The coolant level is satisfac-
tory if it is between the
C
A
B

5137-2. Steps to take in an emergency
7
When trouble arises
“FULL” and “LOW” lines on
the reservoir.
Reservoir
“FULL” line
“LOW” line
5 Add coolant if necessary.
Water can be used in an emer-
gency if power control unit coolant
is unavailable.
6After stopping the hybrid sys-
tem and waiting for 5 minutes
or more, start the hybrid sys-
tem again and check for the
multi-information display.
If the message does not disappear:
Stop the hybrid system and contact
your Toyota dealer.
If the message is not displayed:
The hybrid system temperature has
dropped and the vehicle may be
driven normally.
However, if the message appears
again frequently, contact your Toyota dealer.
A
B
C
WARNING
■When inspecting under the
hood of your vehicle
Observe the following precau-
tions.
Failure to do so may result in seri-
ous injury such as burns.
●If steam is seen coming from
under the hood, do not open the
hood until the steam has sub-
sided. The engine compart-
ment may be very hot.
●After the hybrid system has
been turned off , check that the
“READY” indicator is off.
When the hybrid system is oper-
ating, the gasoline engine may
automatically start, or the cool-
ing fan may suddenly operate
even if the gasoline engine
stops. Do not touch or approach
rotating parts such as the fan,
which may lead to fingers or
clothing (especially a tie, a scarf
or a muffler) getting caught,
resulting in serious injury.
●Do not loosen the coolant reser-
voir cap while the hybrid system
and radiator are hot.
High temperature steam or
coolant could spray out.
NOTICE
■When adding engine/power
control unit coolant
Add coolant slowly after the
hybrid system has cooled down
sufficiently. Adding cool coolant to
a hot hybrid system too quickly
can cause damage to the hybrid
system.