2017 TOYOTA MIRAI Coolant

3197-3. Do-it-yourself maintenance
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Maintenance and care
WARNING
The motor 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 motor compartment
● Be careful not to touch the high-voltage parts or hydrogen-related parts.
● Make sure that the “READY” indicator is off.
● Keep hands, clothing and tools away from the moving fans.
● Be careful not to touch the motor, inverter, radiator, etc., right after driving
as they may be hot. Coolant and other fluids may also be hot.
● Do not leave anything that may burn easily, such as paper and rags, in the
motor compartment.
● Do not smoke, cause sparks or expose an open flame to the 12-volt bat-
tery. 12-volt battery fumes are flammable.
● Be extremely cautious when working on the 12-volt battery. It contains poi-
sonous and corrosive sulfuric acid.
● Take care because brake fluid can harm your hands or eyes and damage
painted surfaces. If fluid gets on your hands or in your eyes, flush the
affected area with clean water immediately.
If you still experience discomfort, consult a doctor.
● Never touch, disassemble, remove or replace the high-voltage parts,
cables and their connectors. It can cause severe burns or electric shock
that may result in death or serious injury.
■ When working near the electric cooling fans or radiator grille
Be sure the power switch is off.
With the power switch in ON mode, t he electric cooling fans may automati-
cally start to run if the air conditioning is on and/or the coolant temperature
is high. ( →P. 325)
■ 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 motor wear
due to dirt in the air.

3237-3. Do-it-yourself maintenance
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Maintenance and care
Motor compartment
Washer fluid tank (→P. 327)
Brake fluid reservoir (→ P. 326)
Inverter coolant reservoir (→ P. 324)
Fuse boxes ( →P. 355)
Fuel cell stack coolant radiator (→ P. 325) Inverter coolant radiator
(→ P. 325)
Condenser ( →P. 325)
Electric cooling fans
Fuel cell stack coolant reser-
voir ( →P. 324)
Fuel cell stack coolant sub
radiator ( →P. 325)

3247-3. Do-it-yourself maintenance
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The coolant level is satisfactory if it is between the “FULL” and “LOW”
lines on the reservoir when the fuel cell system is cold.“FULL” line
“LOW” line
If the level is on or below the
“LOW” line, contact your Toyota
dealer.
The coolant level is satisfactory if it is between the “FULL” and “LOW”
lines on the reservoir when the fuel cell system is cold.Inverter coolant reservoir cap
“FULL” line
“LOW” line
If the level is on or below the
“LOW” line, add coolant up to the
“FULL” line.
■Inverter coolant selection
Only use “Toyota Super Long Life Coolant” or a similar high quality ethylene
glycol based non-silicate, non-amine, non-nitrite, and non-borate coolant with
long-life hybrid organic acid technology.
“Toyota Super Long Life Coolant” is a mixture of 50% coolant and 50% deion-
ized water. (Minimum temperature: -31 °F [-35° C])
For more details about inverter coolant, contact your Toyota dealer.
Fuel cell stack coolant
NOTICE
■ Fuel cell stack coolant
An exclusive coolant for the fuel cell system is filled in the fuel cell stack
coolant reservoir. Do not use any substitute. It may damage your vehicle.
Inverter coolant

3257-3. Do-it-yourself maintenance
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Maintenance and care
■If the inverter coolant level drops within a short time of replenishing
Visually check the radiators, hoses, inverter coolant reservoir 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.
Check the radiator and condenser and clear away any foreign objects.
If either of the above parts is ex tremely dirty or you are not sure of
their condition, have your vehicle inspected by your Toyota dealer.
WARNING
■ When the fuel cell system is hot
Do not remove the coolant reservoir caps.
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 stra ight 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.
Radiator and condenser
WARNING
■When the fuel cell system is hot
Do not touch the radiator or condenser as they may be hot and cause seri\
-
ous injuries, such as burns.

3688-2. Steps to take in an emergency
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If you think something is wrong
●Fluid leaks under the vehicle.
(Water dripping from the air co nditioning after use is normal.)
● Flat-looking tires or uneven tire wear
● The high coolant temperature warning light flashes or comes on
● Excessive tire squeal when cornering
● Strange noises related to the suspension system
● Pinging or other noises related to the fuel cell system
● Stumbling or running roughly
● Appreciable loss of power
● Vehicle pulls heavily to one side when braking
● Vehicle pulls heavily to one side when driving on a level road
● Loss of brake effectiveness, spon gy feeling, pedal almost touches
the floor
If you notice any of the follow ing symptoms, your vehicle proba-
bly needs adjustment or repair. Contact your Toyota dealer as
soon as possible.
Visible symptoms
Audible symptoms
Operational symptoms

3698-2. Steps to take in an emergency
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When trouble arises
If a warning light turns on or a warning
buzzer sounds
Calmly perform the following actions if any of the warning lights
comes on or flashes. If a light comes on or flashes, but then
goes off, this does not necessarily indicate a malfunction in the
system. However, if this continues to occur, have the vehicle
inspected by your Toyota dealer.
Warning light and warning buzzer list
Warning lightWarning light/Details/Actions
Hydrogen leak warning light (warning buzzer) When a hydrogen gas leak is detected, a buzzer sounds,
a light comes on, and a warning message is displayed on
the multi-information display.
→ P. 8 5
Brake system warning light (warning buzzer)*1
Indicates that:
• The brake fluid level is low; or
• The brake system is malfunctioning
→ Immediately stop the vehicle in a safe place and con-
tact your Toyota dealer. Continuing to drive the vehi-
cle may be dangerous.
Charging system warning light
Indicates a malfunction in the vehicle’s charging system
→ Immediately stop the vehicle in a safe place and con-
tact your Toyota dealer.
High coolant temperature warning light
Indicates that the coolant temperature is abnormal
→P. 406
→ Immediately stop the vehicle in a safe place and con-
tact your Toyota dealer.
Brake system warning light
Indicates a malfunction in:
• The regenerative braking system; or
• The electronically controlled brake system
→ Have the vehicle inspected by your Toyota dealer
immediately.

4068-2. Steps to take in an emergency
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If your vehicle overheats
The following may indicate that your vehicle is overheating.
● The high coolant temperature warning light ( →P. 369) comes on
or flashes, or a loss of fuel ce ll system power is experienced. (For
example, the vehicle s peed does not increase.)
● “FC System Overheat Out put Power is Limited” (→P. 376) is dis-
played on the multi- information display
● Steam comes out from under the hood.
Label
Fuel cell stack coolant
reservoir Inverter coolant reservoir

4078-2. Steps to take in an emergency
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When trouble arises
■If the high coolant temperature warning light comes on or
flashes
Stop the vehicle in a safe place and turn off the air conditioning sys-
tem, and then stop the fuel cell system.
If you see steam or coolant leaks:
Carefully lift the hood after the steam subsides.
If you do not see steam or coolant leaks:
Carefully lift the hood.
After the fuel cell system has
cooled down sufficiently,
inspect the hoses and radiator
core (radiator) for any leaks.
Fuel cell stack coolant sub
radiator
Fuel cell stack coolant radia-
tor
Electric cooling fans
If a large amount of coolant
leaks, immediately contact your
Toyota dealer.
NOTICE
Correction procedures
The fuel cell stack coolant is exclusive for
fuel cell stack usage. Damage may occur
when water or any other type of coolant
is used, so never use any other fluid.
If the fuel cell stack coolant is low, imme-
diately contact your Toyota dealer.
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