2023 TOYOTA MIRAI coolant reservoir

4087-3. Do-it-yourself maintenance
Owners Manual_USA_M62064_en
Inverter coolant reservoir ( P.411)
Fuel cell stack coolant reservoir ( P.411)
Fuse boxes ( P.438)
Brake fluid reservoir ( P.412)
Washer fluid tank ( P.412)
Inverter coolant radiator ( P.411)
Electric cooling fan
Condenser ( P.411)
Fuel cell stack coolant radiator ( P. 4 1 1 )
■12-volt battery
 P. 4 1 3
Fuel cell unit compartment
Components

4107-3. Do-it-yourself maintenance
Owners Manual_USA_M62064_en
■Installing the fuel cell stack
cover
Install the fuel cell stack cover.
1 Attach the hooks on the rear
side of the fuel cell stack
cover.
2 Insert the front side of the
fuel cell stack cover on the
pins.
The coolant level is satisfactory
if it is between the “MAX” and
“MIN” lines on the reservoir when the fuel cell system is
cold.
Fuel cell stack reservoir cap
“MAX” line
“MIN” line
If the level is on or below the “MIN”
line, add coolant up to the “MAX”
line. ( P.490)
The coolant level is satisfactory
if it is between the “MAX” and
“MIN” lines on the reservoir
when the fuel cell system is
cold.
NOTICE
■Checking the fuel cell stack
cover after installation
Make sure that the cover is
securely installed in its original
position.
Checking the fuel cell
stack coolant
NOTICE
■Fuel cell stack coolant
An exclusive coola nt for the fuel
cell system is filled in the fuel cell
stack coolant reservoir. Do not
use any substitute. It may dam-
age your vehicle.
Checking the inverter
coolant

4117-3. Do-it-yourself maintenance
Owners Manual_USA_M62064_en
7
Maintenance and care
Inverter coolant reservoir cap
“MAX” line
“MIN” line
If the level is on or below the “MIN”
line, add coolant up to the “MAX”
line. ( P.490)
■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.
U.S.A.:
“Toyota Super Long Life Coolant” is
a mixture of 50% coolant and 50%
deionized water. (Minimum tem-
perature: -31°F [-35°C])
Canada:
“Toyota Super Long Life Coolant” is
a mixture of 55% coolant and 45%
deionized water. (Minimum tem-
perature: -44°F [-42°C])
For more details about coolant, con-
tact your Toyota dealer.
■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 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 condi-
tion, have your vehicle
inspected by your Toyota dealer.
WARNING
■When the cell system is hot
Do not remove the coolant reser-
voir caps. ( P.493)
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
Be sure to wash it off with water to
prevent it from damaging parts or
paint.
Checking the radiator and
condenser
WARNING
■When the fuel cell system is
hot
Do not touch the radiator or con-
denser as they may be hot and
cause serious injuries, such as
burns.

4908-2. Steps to take in an emergency
Owners Manual_USA_M62064_en
Label
Fuel cell stack coolant reservoir
Inverter coolant reservoir
If your vehicle overheats
The following may indicate that your vehicle is overheating.
The high coolant temperature warning light ( P.455) comes on
or flashes, or a loss of fuel cell system power is experienced.
(For example, the vehicle speed does not increase.)
 The fuel cell system overheat warning light ( P.455) comes on
 Steam comes out from under the hood.
Parts name for cooling components

4918-2. Steps to take in an emergency
Owners Manual_USA_M62064_en
8
When trouble arises
If the high coolant tempera-
ture warning light comes on or
flashes
1 Stop the vehicle in a safe
place and turn off the air con-
ditioning system, and then
stop the fuel cell 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 fuel cell system has
cooled down sufficiently,
inspect the hoses and radia- tor core (radiator) for any
leaks.
Electric cooling fan
Fuel cell stack coolant radia-
tor
If a large amount of coolant leaks,
immediately contact your Toyota
dealer.
4
The fuel cell stack coolant
level is satisfactory if it is
between the “MAX” and
“MIN” lines on the reservoir.
Fuel cell stack coolant reser-
voir
“MAX” line
“MIN” line
If the amount of fuel cell stack
coolant is low:
Immediately contact your Toyota
dealer.
NOTICE
■Fuel cell stack coolant
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, immediately contact your
Toyota dealer.
Correction procedures

4928-2. Steps to take in an emergency
Owners Manual_USA_M62064_en
If the amount of fuel cell stack
coolant is not low:
Have the vehicle inspected at
the nearest Toyota dealer.
Even if the fuel cell stack cool-
ant is low, do not refill it.
If the fuel cell system over-
heat warning light comes on
1 Stop the vehicle in a safe
place and turn off the air con-
ditioning system, and then
stop the fuel cell system.
2 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.
3 After the fuel cell system has
cooled down, inspect the hoses and radiator core (radi-
ator) for any leaks.
Electric cooling fan
Inverter coolant radiator
If a large amount of coolant leaks,
immediately contact your Toyota
dealer.
4
The inverter coolant level is
satisfactory if it is between
the “MAX” and “MIN” lines on
the reservoir.
Inverter coolant reservoir
“MAX” line
“MIN” line
5 Add inverter coolant if neces-
sary.
Water can be used in an emer-
gency if inverter coolant is unavail-