cooling TOYOTA SIENNA 2018 Owners Manual (in English)

3385-1. Using the air conditioning system and defogger
SIENNA_OM_OM08019U_(U)
■Using automatic mode
Fan speed is adjusted automatically according to the temperatur e setting and
the ambient conditions.
Therefore, the fan may stop for a while until warm or cool air is ready to flow
immediately after the “AUTO” button is pressed.
■ When the outside temperature exceeds 75°F (24°C) and the air co ndition-
ing system is on
● In order to reduce the air conditioning power consumption, the air condition-
ing system may switch to recirculated air mode automatically.
This may also reduce fuel consumption.
● Recirculated air mode is selected as a default mode when the en gine switch
is turned to the “ON” position (vehicles without a smart key sy stem) or
IGNITION ON mode (vehicles with a smart key system).
● It is possible to switch to outside air mode at any time by pre ssing .
■ Fogging up of the windows
●The windows will easily fog up when the humidity in the vehicle is high.
Pressing “A/C” button on will dehumidify the air from the outle ts and defog
the windshield effectively.
● If you turn “A/C” off, the windows may fog up more easily.
● The windows may fog up if the recirculated air mode is used.
■ Outside/recirculated air mode
●When driving on dusty roads such as tunnels or in heavy traffic , set
to the recirculated air mode. This is effective in preventing outside air from
entering the vehicle interior. During cooling operation, setting the recircu-
lated air mode will also cool the vehicle interior effectively.
● Outside/recirculated air mode may automatically switch dependin g on the
temperature setting or the inside temperature.

406
SIENNA_OM_OM08019U_(U)
6-3. Do-it-yourself maintenance
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:
■When working on the engine compartment:
● Keep hands, clothing and tools away from the moving fan and eng ine
drive belt.
● Be careful not to touch the engine, radiator, 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 r ags, in the
engine compartment.
● Do not smoke, cause sparks or expose an open flame to fuel or t he bat-
tery. Fuel and battery fumes are flammable.
● Be extremely cautious when working on the battery. It contains poisonous
and corrosive sulfuric acid.
■ When working near the electric cooling fans or radiator grille
Be sure the engine switch is in the “LOCK” position (vehicles without a
smart key system) or off (vehicles with a smart key system). With the engine
switch in the “ON” position (vehicles without a smart key system) or IGNI-
TION ON mode (vehicles with a smart key system), the electric cooling fans
may automatically start to run if the air conditioning is on an d/or the coolant
temperature is high. ( P. 415)
■ Safety glasses
Wear safety glasses to prevent flying or falling material, fluid spray, etc.
from getting in your eyes.
NOTICE
■If you remove the air cleaner filter
Driving with the air cleaner filter removed may cause excessive engine wear
due to dirt in the air.

410
SIENNA_OM_OM08019U_(U)
6-3. Do-it-yourself maintenance
Engine compartment
Washer fluid tank (P. 419)
Engine oil filler cap ( P. 412)
Engine oil level dipstick ( P. 4 1 1 )
Engine coolant reservoir ( P. 413) Brake fluid reservoir (
P. 4 1 5 )
Fuse box ( P. 4 3 9 )
Battery ( P. 4 1 6 )
Electric cooling fans
Condenser ( P. 4 1 5 )
Radiator (P. 4 1 5 )1
2
3
4
5
6
7
8
9
10

414
SIENNA_OM_OM08019U_(U)
6-3. Do-it-yourself maintenance
■Coolant selection
Only use “Toyota Super Long Life Coolant” or similar high quali ty ethylene
glycol based non-silicate, non-amine, non-nitrite, and non-bora te coolant with
long-life hybrid organic acid technology.
U.S.A.:
“Toyota Super Long Life Coolant” is a mixture of 50% coolant and 50% deion-
ized water.
(Minimum temperature: -31 F [-35C])
Canada:
“Toyota Super Long Life Coolant” is a mixture of 55% coolant and 45% deion-
ized water.
(Minimum temperature: -44 F [-42C])
For more details about engine coolant, contact your Toyota deal er.
■ If the coolant level drops within a short time of replenishing
Visually check the radiator, hoses, engine coolant reservoir ca ps, radiator
cap, drain cock and water pump.
If you cannot find a leak, have your Toyota dealer test the cap and check for
leaks in the cooling system.
WARNING
■ When the engine is hot
Do not remove the radiator/engine coolant reservoir cap.
The cooling system may be under pressure and may spray hot coolant if the
cap is removed, causing serious injuries, such as burns.
NOTICE
■When adding coolant
Coolant is neither plain water nor straight antifreeze. The cor rect 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
Be sure to wash it off with water to prevent it from damaging p arts or paint.

5087-2. Steps to take in an emergency
SIENNA_OM_OM08019U_(U)
WARNING
■Avoiding battery fires or explosions
Observe the following precautions to prevent accidentally ignit ing the flam-
mable gas that may be emitted from the battery:
● Make sure the jumper cable is connected to the correct terminal and that it
is not unintentionally in contact with any other than the inten ded terminal.
● Do not allow the other end of the jumper cable connected to the “+” termi-
nal to come into contact with any other parts or metal surfaces in the area,
such as brackets or unpainted metal.
● Do not allow the + and - clamps of the jumper cables to come in to contact
with each other.
● Do not smoke, use matches, cigarette lighters or allow open fla me near
the battery.
■ Battery precautions
The battery contains poisonous and corrosive acidic electrolyte , while
related parts contain lead and lead compounds. Observe the foll owing pre-
cautions when handling the battery:
● When working with the battery, always wear safety glasses and t ake care
not to allow any battery fluids (acid) to come into contact wit h skin, clothing
or the vehicle body.
● Do not lean over the battery.
● In the event that battery fluid comes into contact with the skin or eyes,
immediately wash the affected area with water and seek medical attention.
Place a wet sponge or cloth over the affected area until medica l attention
can be received.
● Always wash your hands after handling the battery support, term inals, and
other battery-related parts.
● Do not allow children near the battery.
NOTICE
■When handling jumper cables
When connecting the jumper cables, ensure that they do not beco me entan-
gled in the cooling fans or belt.
■ To prevent damage to the engine cover
● When removing the cover, make sure that you pull the cover towards you
after lifting the front edge to remove the fixed pins.
● When installing the cover, do not force the cover or subject it to strong
shocks.

509
SIENNA_OM_OM08019U_(U)
7-2. Steps to take in an emergency
7
When trouble arises
If your vehicle overheats
Stop the vehicle in a safe place and turn off the air conditioning sys-
tem, and then stop the engine.
If you see steam:
Carefully lift the hood after the steam subsides.
If you do not see steam:
Carefully lift the hood.
After the engine has cooled down sufficiently, inspect the hoses and
radiator core (radiat or) for any leaks.
Radiator
Cooling fans
If a large amount of coolant
leaks, immediately contact your
Toyota dealer.
The following may indicate that your vehicle is overheating.
● The needle of the engine c oolant temperature gauge (P. 90)
enters the red zone or a loss of engine power is experienced. ( For
example, the vehicle s peed does not increase.)
● “Engine Coolant Temp is High” is shown on the multi-information
display.
● Steam is coming from under the hood.
Correction procedures
1
2
3
1
2

5107-2. Steps to take in an emergency
SIENNA_OM_OM08019U_(U)
The coolant level is satisfactory if it is between the “FULL” and
“LOW” lines on the reservoir.
Reservoir
“FULL” line
“LOW” line
Radiator cap
Add coolant if necessary.
Water can be used in an emer-
gency if coolant is unavailable.
Start the engine and turn the ai r conditioning system on to check
that the radiator cooling fans operate and to check for coolant leaks
from the radiator or hoses.
The fans operate when the air conditioning system is turned on immedi-
ately after a cold start. Confirm that the fans are operating b y checking the
fan sound and air flow. If it is difficult to check these, turn the air condition-
ing system on and off repeatedly. (The fans may not operate in freezing
temperatures.)
If the fans are not operating:
Stop the engine immediately and contact your Toyota dealer.
If the fans are operating:
Have the vehicle ins pected at the nearest Toyota dealer.
4
1
2
3
4
5
6
7

5117-2. Steps to take in an emergency
SIENNA_OM_OM08019U_(U)
7
When trouble arises
WARNING
■When inspecting under th e hood of your vehicle
Observe the following precautions.
Failure to do so may result in serious injury such as burns.
● If steam is seen coming from under the hood, do not open the ho od until
the steam has subsided. The engine compartment may be very hot.
● Keep hands and clothing (especially a tie, a scarf or a muffler ) away from
the fan and belts. Failure to do so may cause the hands or clothing to be
caught.
● Do not loosen the radiator cap or the coolant reservoir cap whi le the
engine and radiator are hot. High temperature steam or coolant could
spray out.
NOTICE
■ When adding engine coolant
Add coolant slowly after the engine has cooled down sufficientl y. Adding
cool coolant to a hot engine too quickly can cause damage to th e engine.
■ To prevent damage to the cooling system
Observe the following precautions:
● Avoid contaminating the coolant with foreign matter (such as sa nd or dust
etc.).
● Do not use any coolant additive.

520
SIENNA_OM_OM08019U_(U)
8-1. Specifications
Cooling system
Capacity
Without towing package
12.2 qt. (11.5 L, 10.1 Imp.qt.)
With towing package
12.5 qt. (11.8 L, 10.4 Imp.qt.)
Coolant type Use either of the following.
• “Toyota Super Long Life Coolant”
• A similar high-quality ethylene glycol-based non-silicate, non-amine, non-nitrite, and non-
borate coolant with long-life hybrid organic
acid technology
Do not use plain water alone.
Ignition system
Spark plug
Make
Gap DENSO FK20HBR8
0.03 in. (0.8 mm)
NOTICE
■
Iridium-tipped spark plugs
Use only iridium-tipped spark plugs. Do not adjust spark plug g ap.
Electrical system
Battery
Open voltage at
68F (20 C): 12.3 V or more
If the voltage is lower than the standard value,
charge the battery.
(After charging the battery, turn on the high beam
headlights for 30 seconds with the engine switch in
the “LOCK” position [vehicles without smart key
system] or off [vehicles with smart key system],
and turn the headlights off.)
Charging rates 5 A max.

572Alphabetical index
SIENNA_OM_OM08019U_(U)
Child safety ................................ 57Airbag precautions .................. 41
Back door precautions .......... 139
Battery precautions ........ 418,508
Child restraint system ............. 58
How your child should wear
the seat belt .......................... 34
Installing child restraints ......... 62
Moon roof precautions .......... 191
Power window lock switch .... 184
Power window precautions ... 186
Removed key battery
precautions ......................... 438
Seat belt extender
precautions ........................... 37
Seat belt precautions .............. 36
Seat heater precautions........ 344
Sliding door child-protectors ................... 125
Child-protectors....................... 125
Cleaning
Aluminum wheels.................. 393
Exterior ................................. 392
Interior................................... 395
Seat belts .............................. 396
Clock
*
Compass .................................. 381
Condenser ................................ 415
Console box ............................. 352
Conversation mirror ................ 364
Cooling system ........................ 413 Engine overheating ............... 509
Cruise control
Dynamic radar cruise control................................. 289
Warning message ................. 299
Cup holders.............................. 354
Curtain shield airbags ............... 38
Customizable features ............ 540 Daytime running light
system.................................... 244
Defogger Outside rear view mirrors ..... 336
Rear window ......................... 336
Windshield ............................ 336
Differential Rear differential .................... 521
Dimension ................................ 516
Dinghy towing.......................... 224
Display Drive information .................... 94
Dynamic radar cruise control ................................ 289
Fuel consumption information ........................... 99
LDA
(Lane Departure Alert) ....... 283
Multi-information display ......... 92
Warning messages ............... 481
Do-it-yourself maintenance .... 405
Door courtesy lights Door courtesy lights .............. 347
Wattage ................................ 525
Doors Automatic door locking and unlocking system......... 115
Back door ............................. 133
Door lock .............. 110, 121, 133
Front doors ........................... 110
Outside rear view mirrors ..... 181
Sliding door child-protectors................... 125
Sliding doors ......................... 121
D