2023 TOYOTA MIRAI battery

4367-3. Do-it-yourself maintenance
Owners Manual_USA_M62064_en
■If the electronic key battery is
depleted
The following symptoms may occur:
●The smart key system and wire-
less remote control will not func-
tion properly.
●The operational range will be
reduced.
 Flathead screwdriver
 Small flathead screwdriver
 Lithium battery CR2032
■Use a CR2032 lithium battery
●Batteries can be purchased at
your Toyota dealer, local electrical
appliance shops or camera stores.
●Replace only with the same or
equivalent type recommended by
the manufacturer.
●Dispose of used batteries accord-
ing to local laws.
NOTICE
●Do not install anything to the air
intake vent other than the exclu-
sive filter for this vehicle or use
the vehicle without the filter
installed.
■To prevent damage to the fil-
ter
Observe the following precau-
tions.
If the filter is damaged, have it
replaced with a new filter by your
Toyota dealer.
●Do not use an air blow gun, etc.
●Do not press hard a vacuum
cleaner, etc. against the filter.
●Do not use a hard brush, such
as a metal brush.
●Do not break the fold of the fil-
t er.
Electronic key batter y
Replace the battery with a
new one if it is depleted.
As the key may be damaged
if the following procedure is
not performed properly, it is
recommended that key bat-
tery replacement be per-
formed by your Toyota
dealer.
Items to prepare

4377-3. Do-it-yourself maintenance
Owners Manual_USA_M62064_en
7
Maintenance and care
1 Take out the mechanical key.
2 Remove the cover.
To prevent damage to the key,
cover the tip of the flathead screw-
driver with a rag.
3Remove the depleted battery.
Insert a new battery with the “+” ter-
minal facing up.
Replacing the batteryWARNING
■Battery precautions
Observe the following precau-
tions.
Failure to do so may result in
death or serious injury.
●Do not swallow the battery.
Doing so may cause chemical
burns.
●A coin battery or button battery
is used in the electronic key. If a
battery is swa llowed, it may
cause severe chemical burns in
as little as 2 hours and may
result in death or serious injury.
●Keep away new and removed
batteries from children.
●If the cover cannot be firmly
closed, stop using the electronic
key and stow the key in the
place where children cannot
reach, and then contact your
Toyota dealer.
●If you accidentally swallow a
battery or put a battery into a
part of your b ody, get emer-
gency medical attention imme-
diately.
■To prevent battery explosion
or leakage of flammable liq-
uid or gas
●Replace the battery with a new
battery of the same type. If a
wrong type of battery is used, it
may explode.
●Do not expose batteries to
extremely low pr essure due to
high altitude or extremely high
temperatures.
●Do not burn, bre ak or cut a bat-
tery.

4387-3. Do-it-yourself maintenance
Owners Manual_USA_M62064_en
1Turn the power switch off.
2 Open the fuse box cover.
Fuel cell unit compartment:
type A fuse box
Push the tabs in and lift the lid off.
Fuel cell unit compartment:
type B fuse box
Remove the fuel cell unit compart-
ment cover ( P.409) and push the
tabs in and lift the lid off.
NOTICE
■When replacing the battery
Use a flathead screwdriver of
appropriate size. Applying exces-
sive force may deform or damage
the cover.
■For normal operation after
replacing the battery
Observe the following precautions
to prevent accidents:
●Always work with dry hands.
Moisture may cau se the battery
to rust.
●Do not touch or move any other
component inside the remote
control.
●Do not bend either of the battery
terminals.
Checking a nd replac-
ing fuses
If any of the electrical com-
ponents do not operate, a
fuse may have blown. If this
happens, check and replace
the fuses as necessary.
Checking and replacing
fuses

445
Owners Manual_USA_M62064_en
8
8
When trouble arises
When trouble arises
8-1. Essential informationEmergency flashers .... 446
If your vehicle has to be stopped in an emergency.................................. 446
If the vehicle is submerged or water on the road is ris-
ing ............................. 4478-2. Steps to take in an emer-
gency
If your vehicle needs to be towed ......................... 449
If you think s omething is
wrong......................... 453
If a warning light turns on or a warning buzzer sounds.................................. 454
If a warning message is dis- played ........................ 464
If you have a flat tire .... 467
If the fuel cell system will not start ........................... 480
If you lose your keys ... 481
If the fuel door cannot be opened ........ ..............482
If the electro nic key does
not operate properly .. 482
If the 12-volt battery is dis- charged ..................... 485
If your vehicle overheats .................................. 490
If the vehicle becomes stuck .................................. 494

4468-1. Essential information
Owners Manual_USA_M62064_en
8-1.Essential information
Press the switch to flash all of
the turn signal lights.
To turn them off, press the switch
once again.
■Emergency flashers
●If the emergency flashers are
used for a long time while the fuel
cell system is not operating (while
the “READY” indicator is not illu-
minated), the 12-volt battery may
discharge.
●If any of the SRS airbags deploy
(inflate) or in the event of a strong
rear impact, the emergency flash-
ers will turn on automatically.
The emergency flashers will turn
off automatically after operating
for approximately 20 minutes. To
manually turn t he emergency
flashers off, press the switch
twice.
(The emergency flashers may not
turn on automatically depending
on the force of the impact and
conditions of the collision.)
1 Steadily step on the brake
pedal with both feet and
firmly depress it.
Do not pump the brake pedal
repeatedly as this will increase the
effort required to slow the vehicle.
2Shift the shift position to N.
If the shift position is shifted to
N
3 After slowing down, stop the
vehicle in a safe place by the
road.
4 Stop the fuel cell system.
If the shift position cannot be
shifted to N
3 Keep depressing the brake
pedal with both feet to reduce
vehicle speed as much as
possible.
4 To stop the fuel cell system,
press and hold the power
switch for 2 consecutive sec-
onds or more, or press it
Emergency flashers
The emergency flashers are
used to warn other drivers
when the vehicle has to be
stopped on the road due to
a breakdown, etc.
Operating instructions
If your vehicle has to
be stopped in an emer-
gency
Only in an emergency, such
as if it becomes impossible
to stop the vehicle in the
normal way, stop the vehicle
using the following proce-
dure:
Stopping the vehicle

4508-2. Steps to take in an emergency
Owners Manual_USA_M62064_en
In the following situations, it is
not possible to be towed by
another vehicle using cables or
chains, as the rear wheels may
be locked due to the parking
lock. Contact your Toyota dealer
or commercial towing service. 
There is a malfunction in the
shift control system. ( P.464)
 There is a malfunction in the
immobilizer system. ( P.70)
 There is a malfunction in the
smart key system. ( P.482)
 The 12-volt battery is dis-
charged. ( P.485)
The following may indicate a
problem with your transmission.
Contact your Toyota dealer or
commercial towing service
before towing.
 The fuel cell system warning
message is shown on the
multi-information display and
the vehicle does not move.
 The vehicle makes an abnor-
mal sound.
From the front
Use a towing dolly under the
WARNING

4618-2. Steps to take in an emergency
Owners Manual_USA_M62064_en
8
When trouble arises
■Rear passengers’ seat belt reminder lights (warning buzzer)*
*: Rear passengers’ seat belt warning buzzer:
The rear passengers’ seat belt war ning buzzer sounds to alert the rear
passenger that his or her seat belt is not fastened. If the sea t belt is
unfastened, the buzzer sounds int ermittently for a certain period of time,
after the seat belt is fastened and unfastened and the vehicle reaches a
certain speed.
■Warning buzzer
In some cases, the buzzer may not
be heard due to being in a noisy
location or audio sound.
■Front passenger detection sen-
sor, seat belt reminder and
warning buzzer
●If luggage is placed on the front
passenger seat, the front passen-
ger detection sensor may cause
the warning light to flash and the
warning buzzer to sound even if a
passenger is not sitting in the
seat.
●If a cushion is placed on the seat,
the sensor may n ot detect a pas-
senger, and the warning light may
not operate properly.
■SRS warning light
This warning light system monitors
the airbag sensor assembly, front
impact sensors, side impact sensors
(front door), side impact sensors
(front), side impact sensors (rear),
driver’s seat position sensor,
driver’s seat belt buckle switch, front
passenger occupant classification
system (ECU and sensors), “AIR-
BAG ON” indicator light, “AIRBAG
OFF” indicator light, front passen-
ger’s seat belt buc kle switch, seat
belt pretensioners, airbags, inter-
connecting wiring and power
sources. ( P. 3 4 )
■Electric power steering system
warning light (warning buzzer)
When the 12-volt battery charge
becomes insufficient or the voltage
temporarily drops, the electric power
steering system warning light may
come on and the warning buzzer
may sound.
■When the tire pressure warning
light comes on
Inspect the tires to check if a tire is
punctured.
If a tire is punctured: P. 4 6 7
If none of the tires are punctured:
Turn the power switch off then turn it
to ON. Check if th e tire pressure
warning light com es on or blinks.
If the tire pressure warning light
blinks for approximately 1 minute
then stays on
There may be a malfunction in the
tire pressure warning system. Have
the vehicle inspected by your Toyota
dealer immediately.
If the tire pressur e warning light
comes on
1 After the temperature of the tires
has lowered sufficiently, check
the inflation pressure of each tire
and adjust them to the specified
level.
2 If the warning light does not turn
off even after several minutes
have elapsed, check that the
inflation pressure of each tire is
Warning lightDetails/Actions
Warns the rear passengers to fasten their seat belts
 Fasten the seat belt.

4658-2. Steps to take in an emergency
Owners Manual_USA_M62064_en
8
When trouble arises
depressed to hold the vehicle while
the vehicle is stopped on an incline,
etc. The fuel cell system may over-
heat. Release the accelerator pedal
and depress the brake pedal.
■If “Auto Power OFF to Conserve
Battery” is displayed
Power was turned off due to the
automatic power off function. Next
time when starting the fuel cell sys-
tem, operate the fuel cell system for
approximately 5 minutes to
recharge the 12-volt battery.
■If “Headlight System Malfunc-
tion Visit Your Dealer” is dis-
played
The following systems may be mal-
functioning. Have the vehicle
inspected by your Toyota dealer
immediately.
●The LED headlight system
●The automatic headlight leveling
system (if equipped)
●AHB (Automatic High Beam)
■If “Radar Cruise Control
Unavailable See Owner’s Man-
ual” is displayed
The dynamic radar cruise control
with full-speed range system is sus-
pended temporarily or until the prob-
lem shown in the message is
resolved. (Causes and coping meth-
ods: P.217)
■If “Radar Cruise Control
Unavailable” is displayed
The dynamic radar cruise control
with full-speed range system cannot
be used temporarily. Use the system
when it becomes available again.
■If a message that indicates the
malfunction of front camera is
displayed
The following sys tems may be sus-
pended until the pr oblem shown in
the message is resolved. ( P.217,
454)
●PCS (Pre-Collision system)
●LTA (Lane Tracing Assist)
●AHB (Automatic High Beam)
●RSA (Road Sign Assist) (if
equipped)
●Dynamic radar cruise control with
full-speed range
■If a message that indicates the
malfunction of radar sensor is
displayed
The following systems may be sus-
pended until the problem shown in
the message is resolved. (P.217,
454)
●PCS (Pre-Collision system)
●LTA (Lane Tracing Assist)
●Dynamic radar cruise control with
full-speed range
■If “Shift System Malfunction
Shifting Unavailable Drive to a
Safe Place and Stop” or “Shift
System Malfunction Driving
Unavailable” is displayed
There is a malfunc tion in the shift
control system. Have the vehicle
inspected by your Toyota dealer
immediately.
■If a message that indicates the
need for the shift lever opera-
tion is displayed
To prevent the shift lever from being
operated incorrectl y or the vehicle
from moving unexpectedly, a mes-
sage that requires shifting the shift
position may be displayed on the
multi-information display. In that
case, follow the in struction of the
message and shift the shift position.
■If a message regarding
Advanced Drive is displayed
Refer to “Toyota Teammate
Advanced Drive OWNER’S MAN-
UAL” at Toyota.com for details.