radiator TOYOTA SIENNA HYBRID 2021 Owners Manual (in English)

4086-2. Maintenance
Exhaust sys-
temThere should not
be any fumes or
strange sounds.
Radiator/con-
denser
The radiator and
condenser should
be free from for-
eign objects.
( P.420)
Washer fluid
Is there sufficient
washer fluid?
( P.421)
Luggage compartment
ItemsCheck points
12-volt batteryCheck the connec-
tions. ( P.422)
Vehicle interior
ItemsCheck points
Accelerator
pedal
• The accelerator
pedal should
move smoothly
(without uneven
pedal effort or
catching).
Hybrid trans-
mission “Park”
mechanism
• When parked on a slope and the
shift lever is in P,
is the vehicle
securely
stopped?
ItemsCheck points
Brake pedal
• Does the brake pedal move
smoothly?
• Does the brake pedal have
appropriate
clearance from
the floor?
( P.524)
• Does the brake pedal have the
correct amount
of free play?
( P.524)
Brakes
• The vehicle
should not pull to
one side when
the brakes are
applied.
• The brakes should work
effectively.
• The brake pedal should not feel
spongy.
• The brake pedal should not get
too close to the
floor when the
brakes are
applied.
Head
restraints
• Do the head restraints move
smoothly and
lock securely?
Indica-
tors/buzzers
• Do the indica-tors and buzzers
function prop-
erly?
Lights• Do all the lights come on?
ItemsCheck points

4126-3. Do-it-yourself maintenance
Hybrid bat-
tery (traction
battery) air
intake vent
( P.443)• Vacuum cleaner,
etc,
• Phillips screw- driver
Light bulbs
( P.451)
• Bulb with same
number and watt-
age rating as origi-
nal
• Phillips-head screwdriver
• Flathead screw- driver
• Wrench
Radiator and
condenser
(  P.420)

Tire inflation
pressure
( P.438)• Tire pressure
gauge
• Compressed air source
Washer fluid
( P.421)
• Water or washer
fluid containing
antifreeze (for win-
ter use)
• Funnel (used only for adding water or
washer fluid)
WARNING
The engine compartment contains
many mechanisms and fluids that
may move suddenly, become hot,
or become electrically energized.
To avoid death or serious injury,
observe the following precautions.
ItemsParts and tools■When working on the engine
compartment
●Make sure that “IGNITION ON”
on the multi-information display
and the “READY” indicator are
both off.
●Keep hands, clothing and tools
away from the moving fan.
●Be careful not to touch the
engine, power control unit, radi-
ator, exhaust manifold, etc. right
after driving as they may be hot.
Oil and other fluids may also be
hot.
●Do not leave anything that may
burn easily, such as paper and
rags, in the engine compart-
ment.
●Do not smoke, cause sparks or
expose an open flame to fuel or
the battery. Fuel and battery
fumes are flammable.
●Be extremely cautious when
working on the battery. It con-
tains poisonous and corrosive
sulfuric acid.
■When working near the elec-
tric cooling fan or radiator
grille
Be sure the power switch is OFF.
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. ( P.420)
■Safety glasses
Wear safety gla sses to prevent
flying or falling material, fluid
spray, etc., from getting in your
eyes.

4166-3. Do-it-yourself maintenance
Fuse box (P.449)
Engine oil filler cap ( P.417)
Engine oil level dipstick ( P.416)
Brake fluid reservoir ( P.420)
Radiator ( P.420)
Electric cooling fan
Condenser ( P.420)
Power control unit coolant reservoir ( P.419)
Washer fluid tank ( P.421)
Engine coolant reservoir ( P.419)
■12-volt battery
 P.422
With the engine at operating
temperature and turned off,
Engine compartment
Components
A
B
C
D
E
F
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4196-3. Do-it-yourself maintenance
6
Maintenance and care
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 reservoirReservoir cap
“FULL” line
“LOW” line
If the level is on or below the “LOW”
line, add coolant up to the “FULL”
line. ( P.511)
■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.512)
■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

4206-3. Do-it-yourself maintenance
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

5117-2. Steps to take in an emergency
7
When trouble arises
■If the engine coolant tem-
perature gauge enters the
red zone or “Engine Cool-
ant Temp High Stop in a
Safe Place See Owner’s
Manual” is shown on the
multi-information display
1 Stop the vehicle in a safe
place and turn off the air con-
ditioning system, and then
stop the hybrid system. 2
If you see steam:
Carefully lift the hood after
the steam subsides.
If you do not see steam:
Carefully lift the hood.
3 After the hybrid system has
cooled down sufficiently,
inspect the hoses and radia-
tor core (radiator) 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
“FULL” and “LOW” lines on
the reservoir.
Reservoir
“FULL” line
If your vehicle over-
heats
The following may indicate
that your vehicle is over-
heating.
The needle of the engine
coolant temperature gauge
( P.97, 101) enters the red
zone, or a loss of hybrid
system power is experi-
enced. (For example, the
vehicle speed does not
increase.)
 “Engine Coolant Temp High
Stop in a Safe Place See
Owner’s Manual” or “Hybrid
System Overheated Output
Power Reduced” is shown
on the multi-information dis-
play.
 Steam comes out from
under the hood.
Correction procedures
A
B
A
B

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.

Alphabetical Index579
P
Panic mode ............................. 130
Parking assist sensors (intuitive parking assist) ...................... 308
Parking brake Operation ............................. 243
Parking brake engaged warning buzzer ................................ 245
Warning light ........................ 472
Warning message ................ 244
Parking lights Light switch .......................... 248
Replacing light bulbs ............ 451
Parking Support Brake (PKSB) ............................................... 319Indicator ................................. 95
Parking Support Brake function (rear-crossing vehicles) ...... 329
Parking Support Brake function (static objects) .................... 323
Warning light ........................ 470
PCS (Pre-Collision System) Enabling/disabling the pre-colli-sion system ........................ 269
Function ............................... 267
Warning light ........................ 469
Warning message ........ 265, 480
Personal lights ....................... 364 Switch................................... 364
Wattage ................................ 526
PKSB (Parking Support Brake) ............................................... 319Indicator ................................. 95
Parking Support Brake function (rear-crossing vehicles) ...... 329
Parking Support Brake function (static objects) .................... 323
Warning light ........................ 470
Power back door switch ........ 154
Power outlets .................. 374, 375
Power sliding door main switch ...............................................149
Power steering (Electric Power Steering system)...................336Warning light ........................468
Power switch...........................231 Auto power off fun ction.........235
Changing the power switch modes.................................234
Starting the hybrid system ....231
Power windows Door lock linked window opera-tion......................................202
Jam protection function ........201
Operation..............................201
Window lock switch ..............203
Pre-Collision System (PCS) Enabling/disabling the pre-colli-sion system ........................269
Function................................267
Warning light ........................469
Warning messag e ........265, 480
R
Radar cruise control
Dynamic radar cruise control with full-speed range ..........288
Radiator ...................................420
RCD (Rear Came ra Detection)
Function................................315
Warning message . ...............317
RCTA (Rear Cross Traffic Alert) RCTA Function .....................305
Warning message . ...............301
Rear automatic air conditioning system ...................................358
Rear Cross Traffic Alert (RCTA) ...............................................299
Rear heater system ................358
Rear passengers’ seat belt reminder light........................473
Rear seat Head restraints .....................182