2023 TOYOTA MIRAI warning light

4648-2. Steps to take in an emergency
Owners Manual_USA_M62064_en
■Warning messages
The warning messages explained
below may differ from the actual
messages according to operation
conditions and vehicle specifica-
tions.
■Warning buzzer
A buzzer may sound when a mes-
sage is displayed.
In some cases, the buzzer may not
be heard due to being in a noisy
location or audio sound.
■If “FCV System Stopped Steer-
ing Power Low” is displayed
This message is displayed if the fuel
cell system is stopped while driving.
When steering wheel operations are
heavier than usual, grip the steering
wheel firmly and operate it using
more force than usual.
■If “FCV System High Temp. FCV
Power Reduced” or “FCV
Power Reduced Due to Exces-
sive Acceleration” is displayed
1 Lower the speed while check the
safety, and run the vehicle like
this for several minutes.
2 If the message goes off, the vehi-
cle can be driven as is, since it
temporarily overheated.
This message may be displayed
when driving under severe operat-
ing conditions. (For example, when
driving up a l ong steep hill.)
■If “FCV Power Significantly
Reduced” is displayed
The output power of the fuel cell
system is greatly restrained. If it is
displayed frequently, contact your
Toyota dealer.
■If “Stop Vehicle in a Safe Place
Push P Switch” is displayed
There may be a malfunction in the
fuel cell system or the shift position
may be shifted to N for a long time.
Immediately stop the vehicle and
contact your Toyota dealer.
■If “Shift is in N Release Acceler-
ator Before Shifting” is dis-
played
The accelerator pedal has been
depressed when the shift position is
in N.
Release the accelerator pedal and
shift the shift position to D or R.
■If “Press brake when vehicle is
stopped FCV system may over-
heat” is displayed
The message may be displayed
when the accelerator pedal is
If a war ning message
is displayed
The multi-information dis-
play shows warnings for
system malfunctions and
incorrectly performed oper-
ations, and messages that
indicate a need for mainte-
nance. When a message is
displayed, perform the
appropriate corrective
action for the message.
If a warning message is dis-
played again after the
appropriate actions have
been performed, contact
your Toyota dealer.
Additionally, if a warning
light comes on or flashes at
the same time that a warn-
ing message is displayed,
take the appropriate correc-
tive action for the warning
light. ( P.454)

4778-2. Steps to take in an emergency
Owners Manual_USA_M62064_en
8
When trouble arises
3 Disconnect the hose from the
valve, remove the air release cap
from the hose and then recon-
nect the hose.
4 Turn the compressor switch on
and wait for several seconds,
and then turn it off. Check that
the air pressure indicator shows
the specified air pressure.
( P.501)
If the air pressure is under the des-
ignated pressure, turn the compres-
sor switch on again and repeat the
inflation procedure until the speci-
fied air pressure is reached.
■The valve of a tire that has been
repaired
After a tire is repaired with the emer-
gency tire puncture repair kit, the
valve should be replaced.
■After a tire is repaired with the
emergency tire puncture repair
kit
●The tire pressure warning valve
and transmitter should be
replaced.
●Even if the tire inflation pressure is
at the recommended level, the tire
pressure warning light may come
on/flash.
■Note for checking the emer-
gency tire puncture repair kit
Check the sealant expiry date occa-
sionally.
The expiry date is shown on the bot-
tle. Do not use sealant whose expiry
date has already passed. Other-
wise, repairs conducted using the
emergency tire puncture repair kit
may not be performed properly.
■Emergency tire puncture repair
kit
●The emergency tire puncture
repair kit is for filling the car tire
with air.
●The sealant has a limited life
span. The expiry date is marked
on the bottle. The sealant should
be replaced before the expiry date. Contact your Toyota dealer
for replacement.
●The sealant stored in the emer-
gency tire puncture repair kit can
be used only once to temporarily
repair a single tire. If the sealant in
the bottle and other parts of the kit
have been used and need to be
replaced, contact your Toyota
dealer.
●The compressor can be used
repeatedly.
●The sealant can be used when the
outside temperature is from -40°F
(-40°C) to 140°F (60°C).
●The kit is exclusi
vely designed for
size and type of ti res originally
installed on your vehicle. Do not
use it for tires that a different size
than the original ones, or for any
other purposes.
●If the sealant gets on your clothes,
it may stain.
●If the sealant adhe res to a wheel
or the surface of the vehicle body,
the stain may not be removable if
it is not cleaned at once. Immedi-
ately wipe away the sealant with a
wet cloth.
●During operation of the repair kit,
a loud operation noise is pro-
duced. This does not indicate a
malfunction.
●Do not use to check or to adjust
the tire pressure.
WARNING
■Do not drive the vehicle with
a flat tire
Do not continue driving with a flat
tire.
Driving even a short distance with
a flat tire can damage the tire and
the wheel beyond repair.
Driving with a flat tire may cause a
circumferential groove on the side
wall. In such a cas e, the tire may
explode when using a repair kit.

4888-2. Steps to take in an emergency
Owners Manual_USA_M62064_en
■When replacing the 12-volt bat-
tery
●Use a Central Degassing type 12-
volt battery (European Regula-
tions).
●Use a 12-volt battery with the
same case size as the previous
12-volt battery and an equivalent
20 hour rate capacity (20HR) or
greater.
• If the sizes differ, the 12-volt bat- tery cannot be properly secured.
• If the 20 hour rate capacity is low,
even if the time period where the
vehicle is not used is a short time,
the 12-volt battery may discharge
and the fuel cell system may not
be able to start.
●Use a 12-volt battery with a han-
dle. If a 12-volt b attery without a
handle is used, removal is more
difficult.
●After replacing, firmly attach the
following items to the exhaust hole
of the 12-volt battery.
• Use the exhaust hose that was
attached to the 12-volt battery
before replacing an d confirm that
it is firmly connected to the hole
section of t he vehicle.
• Use the exhaust hole plug included with the 12-volt battery
replaced or the one installed on
the 12-volt battery prior to the
replacement. (Depending on the
12-volt battery to be replaced, the
exhaust hole may be plugged.)
Exhaust hole plug
Exhaust hole
Exhaust hose For details, consult your Toyota
dealer.
WARNING
■When removing the 12-volt
battery terminals
Always remove the negative (-)
terminal first. If the positive (+) ter-
minal contacts any metal in the
surrounding area when the posi-
tive (+) terminal is removed, a
spark may occur, leading to a fire
in addition to ele ctrical shocks
and death or serious injury.
■Avoiding 12-volt battery fires
or explosions
Observe the following precautions
to prevent accidentally igniting the
flammable gas that may be emit-
ted from the 12-volt battery:
●Make sure each jumper cable is
connected to the correct termi-
nal and that it is not unintention-
ally in contact with any other
than the intended terminal.
●Do not allow the other end of
the jumper cable connected to
the “+” terminal 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 lighter s or allow open
flame near the 1 2-volt battery.
■12-volt battery precautions
The 12-volt battery contains poi-
sonous and corrosive acidic elec-
trolyte, while related parts contain
lead and lead compounds.
Observe the following precautions
when handling the 12-volt battery:

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-

5019-1. Specifications
Owners Manual_USA_M62064_en
9
Vehicle specifications
the brake system warning light is not illuminated when the fuel cell sys-
tem is operating. (If the brake system warning light is illuminated, refer to
P.454.)
*2: Make sure to confirm that the brake warning light (yellow) doe s not illumi-
nate. (If the brake warning light illuminates, refer to P.454.)
19-inch tires
20-inch tires
Steering
Free playLess than 1.2 in. (30 mm)
Tires and wheels
Tire size235/55R19 101V
Tire inflation pressure
(Recommended cold tire
inflation pressure)Front: 33 psi (230 kPa, 2.3 kgf/cm2 or bar)
Rear: 33 psi (230 kPa, 2.3 kgf/cm
2 or bar)
Wheel size19  8J
Wheel nut torque103 ft•lbf (140 N•m, 14.3 kgf•m)
Tire size245/45ZR20 103Y
Tire inflation pressure
(Recommended cold tire
inflation pressure)Front: 33 psi (230 kPa, 2.3 kgf/cm2 or bar)
Rear: 33 psi (230 kPa, 2.3 kgf/cm
2 or bar)
Wheel size20  8 1/2J
Wheel nut torque103 ft•lbf (140 N•m, 14.3 kgf•m)

Owners Manual_USA_M62064_en
541What to do if... (Troubleshooting)
Is the electronic key any-
where detectable inside the
vehicle? ( P.136)
 Is the electronic key battery
weak or depleted?
In this case, the fuel cell system
can be started in a temporary way.
( P.484)
 Is the 12-volt battery dis-
charged? ( P.485)
 Is the window lock switch
pressed?
The power window except for the
one at the driver’s seat cannot be
operated if the win dow lock switch
is pressed. ( P.164)
 The auto power off function
will be operated if the vehicle
is left in ACC for a period of
time. ( P.184)
 The seat belt reminder light is
flashing
Are the driver and the front passen-
ger wearing the seat belts?
( P.460)
 The parking brake indicator is
on
Is the parking br ake released?
(  P.191)
Depending on the situation,
other types of warning buzzer
may also sound. ( P.454, 464)
 Did anyone inside the vehicle
open a door during setting the
alarm?
The sensor detects it and the alarm
sounds. ( P. 7 1 )
Do one of the following to deac-
tivate or stop the alarms:
 Except for Canada: Unlock
the doors.
 Except for Canada: Unlock
the trunk using the mechani-
cal key.
 For Canada: Unlock the doors
or trunk using the entry func-
tion or wireless remote con-
trol.
 Turn the power switch to ACC
or ON, or start the fuel cell
system. (The alarm will be
deactivated or stopped after a
few seconds.)
The windows do not
open or close by operat-
ing the power window
switches
The power switch is
turned off a utomatically
A warning buzzer sounds
during driving
An alarm is activated and
the horn sounds