2017 TOYOTA SIENNA cooling

4186-1. Using the air conditioning system and defogger
SIENNA_OM_OM08007U_(U)
■Using automatic mode
Fan speed is adjusted automatically according to the temperature 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 condition-
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 engine switch
is turned to the “ON” position (vehicles without a smart key system) or
IGNITION ON mode (vehicles with a smart key system).
● It is possible to switch to outside air mode at any time by pressing .
■ 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 outlets 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 depending on the
temperature setting or the inside temperature.

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7-3. 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 engine
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 rags, in the
engine compartment.
● Do not smoke, cause sparks or expose an open flame to fuel or the 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 and/or the coolant
temperature is high. ( P. 491)
■ 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.

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7-3. Do-it-yourself maintenance
Engine compartment
Washer fluid tank (P. 495)
Engine oil filler cap ( P. 488)
Engine oil level dipstick ( P. 487)
Engine coolant reservoir ( P. 489) Brake fluid reservoir (
P. 491)
Fuse box ( P. 514)
Battery ( P. 492)
Electric cooling fans
Condenser ( P. 491)
Radiator (P. 491)1
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7-3. Do-it-yourself maintenance
■Coolant selection
Only use “Toyota Super Long Life Coolant” or similar high quality ethylene
glycol based 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% 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 dealer.
■ If the coolant level drops within a short time of replenishing
Visually check the radiator, hoses, engine coolant reservoir caps, 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 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 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
Be sure to wash it off with water to prevent it from damaging parts or paint.

5938-2. Steps to take in an emergency
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When trouble arises
WARNING
■Avoiding battery fires or explosions
Observe the following precautions to prevent accidentally igniting 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 intended 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 into contact
with each other.
● Do not smoke, use matches, cigarette lighters or allow open flame near
the battery.
■ Battery precautions
The battery contains poisonous and corrosive acidic electrolyte, while
related parts contain lead and lead compounds. Observe the following pre-
cautions when handling the battery:
●When working with the battery, always wear safety glasses and take care
not to allow any battery fluids (acid) to come into contact with 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 medical attention
can be received.
● Always wash your hands after handling the battery support, terminals, 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 become 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.

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8-2. Steps to take in an emergency
If your vehicle overheats
●The needle of the engine coolant temperature gauge ( P. 8 8 )
enters the red zone or a loss of engine power is experienced. (For
example, the vehicle sp eed does not increase.)
● The warning message indicating overheats is shown on the multi-
information display. ( P. 559)
● Steam is coming from under the hood.
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 su fficiently, inspect the hoses and
radiator core (radiator) 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.
Correction procedures
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5958-2. Steps to take in an emergency
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When trouble arises
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 air conditioning system on to check
that the radiator cooling fans oper ate 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 by 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 an d contact your Toyota dealer.
If the fans are operating:
Have the vehicle in spected at the nearest Toyota dealer.
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5968-2. Steps to take in an emergency
SIENNA_OM_OM08007U_(U)
WARNING
■When inspecting under the 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 hood 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 while 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 sufficiently. Adding
cool coolant to a hot engine too quickly can cause damage to the engine.
■ To prevent damage to the cooling system
Observe the following precautions:
●Avoid contaminating the coolant with foreign matter (such as sand or dust
etc.).
● Do not use any coolant additive.