2020 TOYOTA MIRAI hydrogen leak

932. Fuel cell vehicle
2
Fuel cell system
MIRAI_OM_USA_OM62073U
There is an air intake vent beside
the rear left seat for the purpose
of cooling the traction battery. If
the air intake vent is blocked, it
could lead to a reduction in trac-
tion battery output.
■If a warning light comes on, a warning message is displayed, or the
12-volt battery connection is disconnected
The fuel cell system may not be able to restart.
If the “READY” indicator does not come on, even when the start procedure is
repeated, contact your Toyota dealer.
■ If “Hydrogen Leakage Detected Visit Your Dealer” is displayed on the
multi-information display
A small amount of hydrogen gas may be leaking. Have the vehicle inspected
immediately at the nearest Toyota dealer.
■ If “FC System Shutdown due to Hydrogen Leakage Stop Your Vehicle in
a Safe Place and Contact Your Dealer” is displayed on the multi -informa-
tion display
● Hydrogen gas may be leaking.
When hydrogen gas is leaking or some other malfunction is detected:
P. 98
● The air conditioning system will shut off automatically.
■ Running out of fuel
When the vehicle has run out of fuel and the fuel cell system c annot be
started, refuel the vehicle until the low fuel level warning li ght (P. 420) turns
off before trying to restart. It may not be able to restart if the refueled amount
is too low (less than about 2.7 lb. [1.2 kg]).
Traction battery air intake vent

972. Fuel cell vehicle
2
Fuel cell system
MIRAI_OM_USA_OM62073U■
Hydrogen Gas Characteristics
●Hydrogen gas ignites more easily than gasoline. However, it is lighter than
air and disperses quickly. So even if hydrogen were to leak from the system,
it would quickly dilute until it is no longer flammable.
● As with gasoline and natural gas, hydrogen gas is not dangerous if it is han-
dled properly. Thoroughly read and understand the characteristi cs shown in
the table below.
Hydrogen gas
LPG
(Liquid Petroleum Gas)
Gasoline
Normal stateGaseous
(Lighter than air)Gaseous
(Heavier than air)
Volatile liquid
(evaporates
easily)
(Heavier than air)
Ease of
ignitionEasier than
gasolineAt the same level
as gasoline—
Ease of
accumulation
• Disperses
upward and is
diluted to safe
concentrations
in open air
• Does not adhere to
clothing
• Spreads on the
ground or floor
• Does not adhere to
clothing• Spreads on theground or floor
• Adheres to clothing
Detectability
•Due to itscolorless and
odorless state,
difficult to detect
by sight or smell
• Vehicle
hydrogen
detectors will
display a
warning on the
multi-
information
display
• Detectable by odor and gas
leaking noise• Detectable bycolor and odor

982. Fuel cell vehicle
MIRAI_OM_USA_OM62073U■
Basic concepts of hydrogen safety
●Prevent leakage
The pipe joints of the hydrogen pipelines are designed to preve nt leaks.
The joints are checked for gas leakage at every official vehicle inspection.
● Detect to stop leakage
• The vehicle is equipped with hydrogen detectors. If the hydrog en detec-
tors detect a leak, the hydrogen tank valves automatically clos e to pre-
vent more hydrogen from escaping.
• The vehicle is equipped with a collision sensor. If the collis ion sensor
detects a collision, the hydrogen tank valves automatically clo se to pre-
vent hydrogen gas from leaking from any damaged components.
● Disperse the leaked hydrogen gas
The hydrogen tanks and pipelines are located outside of the passenger
compartment, so any leaked gas will disperse into the atmospher e by
design.
● Eliminate sources of fire
No source of fire is located near the hydrogen pipelines by des ign.
WARNING
■Hydrogen-related components
● Never alter, customize, or disassemble any hydrogen-related par ts.
● The hydrogen tanks, fuel cell stack, hydrogen pipelines, and co nnecting
components are filled with hydrogen gas. Do not remove or disassemble
these parts. Doing so can cause a hydrogen gas leak, resulting in fire or
explosion of the vehicle, which may result in death or serious injury.
■ When hydrogen gas leak or other malfunction is detected
● If a large amount of hydrogen gas leaking is noticed, turn off the power
switch, exit the vehicle, and stay far away from it. Display wa rning signs
and keep sources of fire away from the vehicle. If possible, get assistance.
When the above is done, immediately contact your Toyota dealer.
● If you notice gas leaking or any other malfunction, immediately stop the
vehicle in a safe and well-ventilated place, exit the vehicle, and stay far
away from it.
● If a warning message is shown on the multi-information display, immedi-
ately stop the vehicle in a safe, well-ventilated place.

1002. Fuel cell vehicle
MIRAI_OM_USA_OM62073U
WARNING
■Precautions in case of an accident
In the event of an accident, observe the following precautions. Failure to do
so can cause fire or electric shocks, resulting in death or ser ious injury.
● Stop the vehicle in a safe place to prevent subsequent accident s. Shift the
shift position to P and apply the parking brake.
● Check for hydrogen gas leakage.
Hydrogen leaks will cause a warning message to be shown on the multi-
information display. Larger leaks may also be audible.
● If a large amount of hydrogen gas leaking is noticed, turn off the power
switch, exit the vehicle, and stay far away from it. Display wa rning signs
and keep sources of fire away from the vehicle. If possible, get assistance.
When the above is done, immediately contact your Toyota dealer.
● Do not touch the high-voltage parts, cables (orange), or connec tors.
● If electric wires are exposed inside or outside your vehicle, an electric
shock may occur. Never touch exposed electric wires.
● If a fluid leak occurs, do not touch the fluid as it may be the strong alkaline
electrolyte from the traction battery. If it comes into contact with your skin
or eyes, wash it off immediately with a large amount of water, and seek
immediate medical attention.
● In case of a vehicle fire, the hydrogen gas in the hydrogen tan ks is
released via the hydrogen tank valves toward the rear of the ve hicle
angled downward, in order to reduce the damage to the hydrogen tanks.
Keep away from the vehicle.
● If a vehicle fire occurs, it can be extinguished with a Class A , B, or C fire
extinguisher. If using water, apply a large amount from a hydrant.
● If your vehicle needs to be towed, do so with the front wheels lifted. If the
wheels are touching the ground, the electric motor (traction mo tor) may
continue to generate electricity. This may cause a fire.

1073. Instrument cluster
3
Instrument cluster
MIRAI_OM_USA_OM62073U
Warning lights inform the driver of malfunctions in the indicated vehi-
cle’s systems.
Warning lights
*1Hydrogen leak warning
light ( P. 418)*1
(Red/
Ye l l o w )
Electric power steering
system warning light
( P. 419)
*1
(U.S.A.)
Brake system warning
light ( P. 418)
(Yellow)
LDA indicator ( P. 419)
*1
(Red)
(Canada)
Brake system warning
light ( P. 418)*1
(Flashes)
PKSB OFF indicator
(P. 419)
Charging system
warning light ( P. 418)
*1
(Flashes
or illumi- nates)
PCS warning light
(P. 420)
*1High coolant
temperature warning
light ( P. 418)*1, 2
Slip indicator ( P. 420)
*1
(Yellow)
Brake system warning
light (P. 418)
(U.S.A.)
Parking brake warning
light (P. 420)
*1
SRS warning light
(P. 419)
(Canada)
Parking brake warning
light ( P. 420)
*1
(U.S.A.)
ABS warning light
(P. 419)Open door warning light
(P. 420)
*1
(Canada)
ABS warning light
(P. 419)Low fuel level warning
light ( P. 420)

2145-4. Refueling
MIRAI_OM_USA_OM62073U
WARNING
■When filling
Observe the following precautions while fueling the vehicle.
Failure to do so may result in death or serious injury.
● Turn the power switch off before fueling.
● Ensure the hydrogen gas nozzle is locked onto the vehicle recep tacle
before filling. This can be done by pulling on the hydrogen gas nozzle to
check that it cannot be pulled off.
Failure to do so may result in injury or damage to the hydrogen gas nozzle
or vehicle.
● Do not smoke while fueling.
● Because the fuel is cold, the hydrogen gas nozzle and vehicle r eceptacle
surface will become cold, and frost may develop. After fueling is com-
pleted, remove the hydrogen gas nozzle by the plastic handle on ly. Do not
touch any other parts of the hydrogen gas nozzle or vehicle rec eptacle
with bare hands immediately after fueling, as frostbite may occ ur.
NOTICE
■When filling
● Fuel only with compressed hydrogen gas at stations compliant with the
Society of Automotive Engineers (SAE) J2601 fueling protocol or laws that
may supersede such SAE protocols.
If improper fuels are used, the fuel cell stack will be damaged .
● Do not swing or drop the hydrogen gas nozzle, or subject it to a large
amount of force. Doing so may cause damage.
● If the hydrogen gas nozzle cannot be removed after fueling, it may be fro-
zen to the vehicle receptacle. Wait for the hydrogen gas nozzle to thaw
before attempting to remove. Do not pull or rotate the hydrogen gas nozzle
forcibly. Failure to follow these precautions may cause damage.
● Be sure to replace the cap after filling. If foreign material g ets in the vehicle
receptacle, it may cause damage.
● Do not put anything sharp, such as a screwdriver, blade, or any foreign
object into the mouth of the vehicle receptacle. If the vehicle receptacle is
damaged, hydrogen gas may leak during fueling.
● If you notice anything unusual about the vehicle receptacle, pl ease notify
your Toyota dealer.
● If you notice anything unusual with the hydrogen dispenser or h ydrogen
gas nozzle, please notify the hydrogen station operator. Contac t informa-
tion is usually displayed on the dispenser.

4188-2. Steps to take in an emergency
MIRAI_OM_USA_OM62073U
If a warning light turns on or a war ning
buzzer sounds
Calmly perform the following actions if any of the warning ligh ts
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 w arning 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. 93
(U.S.A.)
(Red)
(Canada)
Brake system warning li ght (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. 457
 Immediately stop the vehicle in a safe place and con-
tact your Toyota dealer.
(Yellow)
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.

4568-2. Steps to take in an emergency
MIRAI_OM_USA_OM62073U
WARNING
■12-volt battery precautions
The 12-volt battery contains poisonous and corrosive acidic ele ctrolyte,
while related parts contain lead and lead compounds. Observe th e following
precautions when handling the 12-volt battery:
● When working with the 12-volt battery, always wear safety glass es and
take care not to allow any 12-volt battery fluids (acid) to come into contact
with skin, clothing or the vehicle body.
● Do not lean over the 12-volt battery.
● In the event that 12-volt battery fluid comes into contact with the skin or
eyes, immediately wash the affected area with water and seek me dical
attention.
Place a wet sponge or cloth over the affected area until medica l attention
can be received.
● Always wash your hands after handling the 12-volt battery suppo rt, termi-
nals, and other battery-related parts.
● Do not allow children near the 12-volt battery.
■ After recharging the 12-volt battery
Have the 12-volt battery inspected at your Toyota dealer as soo n as possi-
ble.
If the 12-volt battery is deteriorating, continued use may caus e the 12-volt
battery to emit a malodorous gas, which may be detrimental to the health of
passengers.
■ When exchanging the 12-volt battery
After exchanging, securely attach the exhaust hose and exhaust hole plug
to the exhaust hole of the exchanged 12-volt battery. If not pr operly
installed, gases (hydrogen) may leak into the vehicle interior, and there is
the possible danger of the gas igniting and exploding.
■ When replacing the 12-volt battery
 P. 376
NOTICE
■To prevent damaging the vehicle
The exclusive jump starting terminal is to be used when chargin g the 12-volt
battery from another vehicle in an emergency. It cannot be used to jump
start another vehicle.
■ When handling jumper cables
When connecting the jumper cables, ensure that they do not beco me entan-
gled in the cooling fans.