2023 TOYOTA MIRAI coolant

822-1. Fuel cell electric vehicle
Owners Manual_USA_M62064_en
■High-voltage and high-temperature components
The fuel cell electric vehicle has high-voltage components (abo ut
650 V maximum) such as a fuel c ell stack, traction battery, power
control unit, fuel cell converter, high-voltage cables (which a re distin-
guished from low-voltage cables b y their orange covers), electric
motor (traction motor), etc., and high-temperature parts such a s the
radiator for cooling. Pay attention to all warning labels attached to
the vehicle.
This diagram is for illustrative purposes only and may differ f rom the actual
vehicle.
Warning label
Radiator for inverter cooling
Radiator for fuel cell stack cooling
Fuel cell water pump
Fuel cell converter and auxiliary inverter
Power control unit
Cabin coolant heater
Traction battery
Service plug

842-1. Fuel cell electric vehicle
Owners Manual_USA_M62064_enhydrogen tanks or valves need to
be disposed.
■Fuel cell stack coolant
●Fuel cell stack coolant uses a spe-
cifically-designed fluid with high
electrical insulation properties, in
order to safely cool the high-volt-
age fuel cell stack.
●Never add water or other coolants
to the fuel cell st
ack cooling sys-
tem, as they will cause permanent
damage.
●Consult your Toyota dealer for
replenishing or changing the fuel
cell stack coolant.
■Ion filter
●An ion filter is inst alled in the cool-
ant lines for the fuel cell stack, in
order to maintain the normal insu-
lation properties of the coolant.
●It is necessary to periodically
change the ion filter. ( P.466)
Contact your Toyota dealer for this
periodic maintenance.
■Tailpipe
●When the power switch is turned
off and the fuel cell system is
stopped ( P.182) after driving,
exhaust water is discharged. Be
careful when standing behind the
vehicle to avoid dripping or spray-
ing.
●It is possible to manually purge
the exhaust. Thi s may be desir-
able, for instance, before parking
in a garage. This is done by press-
ing the H
2O switch. ( P.196)
●On cold days, water vapor in the
exhaust may appe ar as a white
mist emitted from the tailpipe. This
is not a malfunction. A white mist
may be emitted from the vehicle
side depending on the wind direc-
tion. If it is a concern, consult with
a Toyota dealer.
●If the tailpipe is blocked, the fuel
cell system will stop.
●In the following state when cold, a white mist may be emitted. Water
vapor is being emitted as a sys-
tem protection and it is not a mal-
function.
• If several minutes have passed after opening the fuel lid, such as
refueling.
• Several hours have passed after the power switch was turned off.
■Hydrogen detectors
When the power switch is turned to
ON, the hydrogen detectors are
activated.
■Power output restriction
When the power output is restricted,
the vehicle may fa il to accelerate or
even decelerate, even though the
accelerator pedal is depressed. If a
safe driving speed cannot be main-
tained, stop the ve hicle in a safe
place away from the traffic. This
may be caused by the following con-
ditions:
●The coolant temperature may be
too high. This can be caused by
driving conditions such as
repeated sudden acceleration and
deceleration, continuous driving
on an incline, continuous driving
at high altitudes with a high load,
etc. In such situations, “FCV sys-
tem overheated Output power
reduced” is displayed on the multi-
information display, and the power
output is restricted. Once the cool-
ant returns to normal temperature,
the power output will retu rn to nor-
mal. ( P.464)
●The remaining fuel may be low.
After the low fuel level warning
light comes on, the output power
will be gradually restricted in order
to extend the possible driving dis-
tance. Once getting to this point,
the remaining driving distance
possible is short. Immediately refill
the vehicle with hydrogen.
●On cold days, the low fuel level
warning light comes on faster than
usual and the output power is
restricted.

953-1. Instrument cluster
Owners Manual_USA_M62064_en
3
Vehicle status information and indicators
The units used on the meters and some indicators may differ dep ending on
the target region.
Warning lights inform the driver
of malfunctions in the indicated
vehicle’s systems.
Warning lights
Hydrogen leak warn-
ing light
*1 (  P.454)
(U.S.A.)
Brake system warn-
ing light
*1 ( P.454)
(Canada)
(Red)
Brake system warn-
ing light
*1 ( P.454)
(Yellow)
Brake system warn-
ing light
*1 ( P.454)
(Red)
High coolant tempera-
ture warning light
( P.455)
Fuel cell system over-
heat warning light
*2
(  P.455)
Charging system
warning light
*2
(  P.455)
SRS warning light
*1
(  P.455)
Pop Up Hood warning
light
*1 (  P.455)
(U.S.A.)
ABS warning light*1
(  P.456)
(Canada)
ABS warning light*1
(  P.456)
(Red)
Electric power steer-
ing system warning
light
*1 ( P.456)
(Yellow)
Electric power steer-
ing system warning
light
*1 ( P.456)
(Flashes or
illuminates)
PCS warning light*1
(  P.456)
(Orange)
LTA i n d i c a t o r
( P.457)
Intuitive parking assist
OFF indicator
*3 (if
equipped) ( P.457)
PKSB OFF indica-
tor
*1 (if equipped)
(  P.457)
(Flashes)
RCTA OFF indicator*1
(if equipped) ( P.458)
(Flashes or
illuminates)
RCD OFF indicator (if
equipped) ( P.458)
Slip indicator light
*1
(  P.458)
Inappropriate pedal
operation warning
light
*2 (  P.459)
(Flashes)
Brake hold operated
indicator
*1 ( P.459)
(U.S.A.)
(Flashes)
Parking brake indica-
tor ( P.459)

963-1. Instrument cluster
Owners Manual_USA_M62064_en
*1: These lights turn on when the power switch is turned to ON to
indicate that a system check is
being performed. They will turn
off after the fuel cell system is
on, or after a few seconds. There
may be a malfunction in a sys-
tem if the light does not come on,
or turn off. Have the vehicle
inspected by your Toyota dealer.
*2: This light illuminates on the multi-informatio n display with a
message.
*3: Intuitive parking assist OFF indi- cator turns on when the power
switch is turned to ON while the
Intuitive parking assist function is
on. It will turn off after a few sec-
onds.
*4: Refer to “Toyota Teammate Advanced Drive OWNER’S
MANUAL” at Toyota.com.
(Canada)
(Flashes)
Parking brake indica-
tor ( P.459)
Tire pressure warning
light
*1 (  P.460)
Low fuel level warn-
ing light ( P.460)
Driver’s and front pas-
senger’s seat belt
reminder light
(  P.460)
Rear passengers’ seat
belt reminder lights
(  P.461)
Advanced Drive warn-
ing light (if
equipped)
*1, 4
WARNING
■If a safety system warning
light does not come on
Should a safety system light such
as the ABS and SRS warning light
not come on when you start the
fuel cell system, this could mean
that these system s are not avail-
able to help protect you in an acci-
dent, which could result in death
or serious injury. Have the vehicle
inspected by you r Toyota dealer
immediately if this occurs.
NOTICE
■To prevent damage to the fuel
cell system and its compo-
nents
This vehicle is equipped with high
coolant temperature warning light
(  P.490), instead of, coolant tem-
perature gauge.
The fuel cell sys tem may be over-
heating if the high coolant tem-
perature warning light flashes or
comes on. In this case, immedi-
ately stop the vehicle in a safe
place, and check the fuel cell sys-
tem after it has cooled completely.

973-1. Instrument cluster
Owners Manual_USA_M62064_en
3
Vehicle status information and indicators
The indicators inform the driver
of the operating state of the
vehicle’s various systems.
Indicators
Turn signal indicator
(  P.190)
(U.S.A.)
Headlight indicator
( P.198)
(Canada)
Tail light indicator
( P.198)
Headlight high beam indi-
cator ( P.200)
AHB indicator ( P.200)
(Blue)
Low coolant temperature
indicator
*1
Smart key system indica-
tor
*2 ( P.180)
Cruise control indicator
(  P.244)
Dynamic radar cruise
control indicator
(  P.244)
Cruise control “SET” indi-
cator ( P.244)
(*3)
LTA indicator ( P.220,
236)
Intuitive parking assist
OFF indicator
*4, 5 (if
equipped) ( P.262)
PKSB OFF indicator
*4, 6
(if equipped) ( P.283)
(Flashes)
Slip indicator light*6
(  P.323)
VSC OFF indicator
*4, 6
(  P.323)
PCS warning light
*4, 6
(  P.222)
BSM outside rear view
mirror indicators
*6, 7 (if
equipped) ( P.257, 272)
BSM OFF indicator
*4, 6 (if
equipped) ( P.257)
RCTA OFF indicator
*4, 6
(if equipped) ( P.273)
RCD OFF indicator
*4 (if
equipped) ( P.278)
Brake hold standby indi-
cator
*6 (  P.194)
Brake hold operated indi-
cator
*6 (  P.194)
Security indicator
*8
(  P.70, 71)
“READY” indicator
(  P.180)
Low outside temperature
indicator
*9 (  P.100)
(U.S.A.)
Parking brake indicator
( P.191)
(Canada)
Parking brake indicator
( P.191)
Br mode indicator
(  P.185)
Eco drive mode indicator
(  P.320)

983-1. Instrument cluster
Owners Manual_USA_M62064_en
*1: Indicates the coolant tempera-ture is cool.
*2: This light illuminates on the multi-informatio n display with a
message.
*3: Depending on the operating con- ditions of the system, the color
and state (illuminated/blinking) of
the indicator change.
*4: The light comes on when the system is turned off.
*5: Intuitive parking assist OFF indi-cator turns on when the power
switch is turned to ON while the
Intuitive parking assist function is
on. It will turn off a fter a few sec-
onds.
*6: These lights turn on when the power switch is turned to ON to
indicate that a system check is
being performed. They will turn
off after the fuel cell system is
on, or after a few seconds. There
may be a malfunction in a sys-
tem if the lights do not turn on, or
turn off. Have the vehicle
inspected by your Toyota dealer.
*7: This light illumi nates on the out-
side rear view mirrors.
*8: This light illumi nates on the cen-
ter panel.
*9: When the outside temperature is approximately 37°F (3°C) or
lower, the indicator will flash for
approximately 10 seconds, then
stay on.
*10: Refer to “Toyota Teammate Advanced Drive OWNER’S
MANUAL” at Toyota.com.
Sport mode indicator
(
 P.320)
Snow mode indicator
(  P.321)
“AIRBAG ON/OFF” indi-
cator
*6, 8 (  P. 4 6 )
Advanced Drive indica-
tor
*10 (if equipped)

4017-2. Maintenance
Owners Manual_USA_M62064_en
7
Maintenance and care
warranty coverage.
The use of Toyota repair manuals is
recommended.
For details about warranty cover-
age, refer to the separate “Owner’s
Warranty Information Booklet” or
“Owner’s Manual Supplement”.
General maintenance
Listed below are the general
maintenance items that
should be performed at the
intervals specified in the
“Owner’s Warranty Informa-
tion Booklet” or “Owner’s
Manual Supplement/Sched-
uled Maintenance Guide”. It
is recommended that any
problem you notice should
be brought to the attention
of your Toyota dealer or
qualified service shop for
advice.
WARNING
■If the fuel cell system is oper-
ating
Turn the fuel cell system off and
ensure that there is adequate
ventilation before performing
maintenance checks.
Fuel cell unit compart-
ment
ItemsCheck points
Brake fluid
Is the brake fluid at
the correct level?
(  P.412)
Coolant
Is the coolant at
the correct level?
( P.410)

4047-3. Do-it-yourself maintenance
Owners Manual_USA_M62064_en
7-3.Do-it-yourself maintenance
Do-it-yourself ser vice
precautions
If you perform maintenance
by yourself, be sure to fol-
low the correct procedure
as given in these sections.
Maintenance
ItemsParts and tools
12-volt battery
condition
( P.413)
•Grease
• Conventional
wrench (for ter-
minal clamp
bolts)
Brake fluid
level ( P.412)
• FMVSS No.116
DOT 3 or SAE
J1703 brake fluid
FMVSS No.116
DOT 4 or SAE
J1704 brake fluid
• Rag or paper towel
• Funnel (used only for adding
brake fluid)
Inverter cool-
ant level
( P.410)
• “Toyota Super
Long Life Cool-
ant” or a similar
high quality eth-
ylene glycol-
based non-sili-
cate, non-amine,
non-nitrite and
non-borate cool-
ant with long-life
hybrid organic
acid technology
For the U.S.A.:
“Toyota Super
Long Life Cool-
ant” is pre-mixed
with 50% cool-
ant and 50%
deionized water.
For Canada:
“Toyota Super
Long Life Cool-
ant” is pre-mixed
with 55% cool-
ant and 45%
deionized water.
• Funnel (used only for adding
coolant)
Fuses
( P.438)
• Fuse with same
amperage rating
as original
• Flathead screw- driver
Headlight aim
( P.442)• Phillips-head
screwdriver
Radiator and
condenser
( P.411)

ItemsParts and tools