maintenance TOYOTA MIRAI 2023 Owner's Guide

4137-3. Do-it-yourself maintenance
Owners Manual_USA_M62064_en
7
Maintenance and care
The 12-volt battery is located in
the right-hand side of the trunk.
Remove the luggage mat: P. 3 6 1
■Before recharging
When recharging, the 12-volt bat-
tery produces hydrogen gas which
is flammable and explosive. There-
fore, observe the following precau-
tions before recharging:
●If recharging with the 12-volt bat-
tery installed on the vehicle, be
sure to disconnect the ground
cable.
●Make sure the power switch on
the charger is off when connecting
and disconnecting the charger
cables to the 12-volt battery.
■After recharging/reconnecting
the 12-volt battery
●Unlocking the doors using the
smart key system may not be pos-
sible immediately after reconnect-
ing the 12-volt battery. If this
happens, use the wireless remote
control or the mechanical key to
lock/unlock the doors.
●Start the fuel cell system with the
power switch in ACC. The fuel cell
system may not start with the
power switch turned off. However,
the fuel cell system will operate
normally from the second attempt.
WARNING
■When adding washer fluid
Do not add washer fluid when the
fuel cell system is hot or operating
as washer fluid contains alcohol
and may catch fire if spilled on the
fuel cell system, etc.
NOTICE
■Do not use any fluid other
than washer fluid
Do not use soapy water or anti-
freeze instead of washer fluid.
Doing so may cause streaking on
the vehicle’s painted surfaces, as
well as damaging the pump lead-
ing to problems of the washer
fluid not spraying.
■Diluting washer fluid
Dilute washer fluid with water as
necessary.
Refer to the freezing tempera-
tures listed on the label of the
washer fluid bottle.
12-volt batter y
Location

4147-3. Do-it-yourself maintenance
Owners Manual_USA_M62064_en
●The power switch mode is
recorded by the vehicle. If the 12-
volt battery is reconnected, the
vehicle will return the power
switch mode to the status it was in
before the 12-volt battery was dis-
connected. Make sure to turn off
the power switch before discon-
necting the 12-volt battery. Take
extra care when connecting the
12-volt battery if the power switch
mode prior to discharge is
unknown.
●When the 12-volt b attery is recon-
nected, start the fuel cell system,
depress the brake pedal, and con-
firm that it is possible to shift into
each shift position.
If the system will not start even after
multiple attempts, contact your Toy-
ota dealer.
WARNING
■Chemicals in the 12-volt bat-
tery
The 12-volt battery contains poi-
sonous and corrosi ve sulfuric acid
and may produce hydrogen gas
which is flammable and explosive.
To reduce the risk of death or seri-
ous injury, take th e following pre-
cautions while working on or near
the 12-volt battery:
●Do not cause sparks by touch-
ing the 12-volt battery terminals
with tools.
●Do not smoke or light a match
near the 12-volt battery.
●Avoid contact with eyes, skin
and clothes.
●Never inhale or swallow electro-
lyte.
●Wear protective safety glasses
when working near the 12-volt
battery.
●Keep children away from the
12-volt battery.
■Where to safely charge the
12-volt battery
Always charge the 12-volt battery
in an open area. Do not charge
the 12-volt battery in a garage or
closed room where there is insuf-
ficient ventilation.
■Emergency measures regard-
ing electrolyte
●If electrolyte gets in your eyes
Flush your eyes with clean
water for at least 15 minutes
and get immediate medical
attention. If possible, continue
to apply water with a sponge or
cloth while traveling to the near-
est medical facility.
●If electrolyte gets on your skin
Wash the affected area thor-
oughly. If you feel pain or burn-
ing, get medical attention
immediately.
●If electrolyte gets on your
clothes
It can soak through clothing on
to your skin. Imm ediately take
off the clothing and follow the
procedure above if necessary.
●If you accidentally swallow elec-
trolyte
Drink a large quantity of water
or milk. Get emergency medical
attention immediately.
■When replacing the 12-volt
battery
Use a 12-volt battery designed for
this vehicle. Failu re to do so may
cause gas (hydrogen) to enter the
passenger compartment, causing
a fire or explosion.
For replacement of the 12-volt
battery, contact your Toyota
dealer.

4157-3. Do-it-yourself maintenance
Owners Manual_USA_M62064_en
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Maintenance and care
Make sure that the 12-volt bat-
tery terminals are not corroded
and that there are no loose con-
nections, cracks, or loose
clamps. Terminals
Hold-down clamp
Check the 12-volt battery condi-
tion by indicator color. Blue: Good condition
Red: Charging is necessary.
Have the vehicle inspected
by your Toyota dealer.
Clear: Replacement is nec-
essary.
Have the 12-volt battery
checked by your Toyota
dealer.
NOTICE
■When recharging the 12-volt
battery
Never recharge the 12-volt bat-
tery while the fue l cell system is
operating. Also, be sure all acces-
sories are turned off.
Exterior
Checking the 12-volt bat-
tery condition

4167-3. Do-it-yourself maintenance
Owners Manual_USA_M62064_en
Check if the treadwear indica-
tors are showing on the tires.
Also check the tires for uneven
wear, such as excessive wear
on one side of the tread.
New tread
Worn tread
Treadwear indicator
The location of treadwear indicators
is shown by a “TWI” or “ ” mark,
etc., molded into the sidewall of
each tire. Replace the tires if the treadwear
indicators are s
howing on a tire.
■When to replace your vehicle’s
tires
Tires should be replaced if:
●The treadwear indicators are
showing on a tire.
●You have tire damage such as
cuts, splits, cracks deep enough
to expose the fabric, and bulges
indicating internal damage
●A tire goes flat repeatedly or can-
not be properly repaired due to the
size or location of a cut or other
damage
If you are not sure, consult with your
Toyota dealer.
■Tire life
Any tire over 6 years old must be
checked by a qualified technician
even if it has seldom or never been
used or damage is not obvious.
■Maximum load of tire
Check that the maximum load of the
replacement tire is greater than 1/2
of the Gross Axle Weight Ratings
(GAWR) of either the front axle or
the rear axle, whi chever is greater.
For the GAWR, see the Certification
Label.
For the maximum load of the tire,
see the load limit at maximum cold
tire inflation pressure mentioned on
the sidewall of the tire. ( P.502)
■Tire types
●Summer tires
Summer tires are high-speed perfor-
Tires
Replace or rotate tires in
accordance with mainte-
nance schedules and tread-
wear.
Checking tires

4177-3. Do-it-yourself maintenance
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Maintenance and care
mance tires best suited to highway
driving under dry conditions. Since
summer tires do not have the same
traction performanc e as snow tires,
summer tires are inadequate for
driving on snow-covered or icy
roads. For driving on snow-covered
roads or icy roads, the use of snow
tires is recommended. When install-
ing snow tires, be sure to replace all
four tires.
●All season tires
All season tires are designed to pro-
vide better traction in snow and to
be adequate for driving in most win-
ter conditions a s well as for use
year-round. All season tires, how-
ever, do not have adequate traction
performance compared with snow
tires in heavy or loose snow. Also,
all season tires fall short in accelera-
tion and handling performance com-
pared with summer tires in highway
driving.
●Snow tires
For driving on snow-covered roads
or icy roads, we recommend using
snow tires. If you need snow tires,
select tires of the same size, con-
struction and load capacity as the
originally installed tires. Since your
vehicle has radial tires as original
equipment, make sure your snow
tires also have radial construction.
Do not install stud ded tires without
first checking local regulations for
possible restrictions. Snow tires
should be installed on all wheels.
(  P.327)
■If the tread on snow tires wears
down below 0.16 in. (4 mm)
The effectiveness of the tires as
snow tires is lost.
WARNING
■When inspecting or replacing
tires
Observe the following precautions
to prevent accidents.
Failure to do so may cause dam-
age to parts of the drive train as
well as dangerous handling char-
acteristics, which may lead to an
accident resulting in death or seri-
ous injury.
●Do not mix tires of different
makes, models or tread pat-
terns.
Also, do not mix tires of remark-
ably different treadwear.
●Do not use tire sizes other than
those recommended by Toyota.
●Do not mix differently con-
structed tires (radial, bias-belted
or bias-ply tires).
●Do not mix summer, all season
and snow tires.
●Do not use tires that have been
used on another vehicle.
Do not use tires if you do not
know how they were used previ-
ously.
NOTICE
■Driving on rough roads
Take particular care when driving
on roads with loose surfaces or
potholes.
These conditions may cause
losses in tire inflation pressure,
reducing the cushioning ability of
the tires. In addition, driving on
rough roads may cause damage
to the tires themselves, as well as
the vehicle’s wheels and body.

4187-3. Do-it-yourself maintenance
Owners Manual_USA_M62064_en
Rotate the tires in the order
shown.
Front
To equalize tire wear and extend
tire life, Toyota recommends that
tire rotation is c arried out at the
same interval as tire inspection.
Do not fail to initialize the tire pres-
sure warning system after tire rota-
tion.
Your vehicle is equipped with a
tire pressure warning system
that uses tire pressure warning
valves and transmitters to detect
low tire inflation pressure before
serious problems arise.
 The tire pressure detected by
the tire pressure warning sys-
tem can be displayed on the
multi-information display.
( P. 111 ) 
If the tire pressure drops
below a predetermined level,
the driver is warned by a
screen display and a warning
light. ( P.460)
■Routine tire inflation pressure
checks
The tire pressure warning system
does not replace routine tire inflation
pressure checks . Make sure to
check tire inflation pressure as part
of your routine o f daily vehicle
checks.
■Tire inflation pressure
●It may take a few minutes to dis-
play the tire inflation pressure
after the power switch is turned to
ON. It may also take a few min-
utes to display the tire inflation
pressure after infl ation pressure
has been adjusted.
●Tire inflation pressure changes
with temperature. The displayed
values may also be different from
the values measured using a tire
pressure gauge.
Tire rotation
Tire pressure warning
system

4197-3. Do-it-yourself maintenance
Owners Manual_USA_M62064_en
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Maintenance and care
■Situations in which the tire
pressure warning system may
not operate properly
●In the following cases, the tire
pressure warning system may not
operate properly.
• If non-genuine Toyota wheels are used.
• If a tire has been replaced with a tire that is not an OE (Original
Equipment) tire.
• If a tire has been replaced with a tire that is not of the specified size.
• If tire chains, etc. are installed.
• If a window tint that affects the
radio wave signals is installed.
• If there is a lot of snow or ice on
the vehicle, particularly around the
wheels or wheel housings.
• If the tire inflation pressure is
much higher than the specified
level.
• If wheels not equipped with tire
pressure warning valves and
transmitter are used.
• If the ID code on the tire pressure
warning valves and transmitters is
not registered in the tire pressure
warning computer.
●Performance may be affected in
the following situations.
• When driving near a TV tower, electric power plant, gas station,
radio station, large display, airport
or other facility that generates
strong radio waves or electrical
noise
• When carrying a portable radio, cellular phone, cordless phone or
other wireless communication
device
If tire position information is not cor-
rectly displayed due to the radio
wave conditions, the display may be
corrected by changing the location
of the vehicle as the radio wave
conditions may change.
●When the vehicle is stopped, the
time taken for the warning to start
or turn off may be longer.
●When the inflation pressure of a
tire drops rapidly, for example when a tire has burst, the warning
may not operate.
■Warning performance of the tire
pressure warning system
The warning of the tire pressure
warning system w ill change in
accordance the conditions under
which it was initia lized. For this rea-
son, the system may give a warning
even if the tire pressure does not
reach a low enough level, or if the
pressure is higher than the pressure
that was adjusted to when the sys-
tem was initialized.
■Tire pressure warning system
certification
 P.569
When replacing the tires or
wheels, the tire pressure warn-
ing valves and transmitters must
be installed to the wheels which
will be installed to the vehicle.
When new tire pressure warning
valves and transmitters are
installed, new ID codes must be
registered in the tire pressure
warning computer and the tire
pressure warning system must
be initialized. ( P.422)
■Replacing tires and wheels
If the ID codes of the tire pressure
warning valves and transmitters are
not registered, the tire pressure
warning system will not work prop-
erly. In this case, after driving for
about 10 minutes, the tire pressure
warning light will blink for approxi-
mately 1 minute and then illuminate
to indicate a system malfunction.
Installing tire pressure
warning valves and trans-
mitters

4207-3. Do-it-yourself maintenance
Owners Manual_USA_M62064_en
■The tire pressure warning
system must be initialized
in the following circum-
stances:
 When the tire inflation pres-
sure is changed such as
when changing traveling
speed or load weight.
 When the tire inflation pres-
sure is changed such as
when the tire size is changed.
 When rotating the tires.
 After performing the transmit-
ter ID code registration proce-
dure. ( P.422) When the tire pressure warning
system is initialized, the current
tire inflation pressure is set as
the benchmark pressure.
■How to initialize the tire
pressure warning system
1 Park the vehicle in a safe
place, turn the power switch
off and wait 20 minutes or
more.
Initialization cannot be performed
while the vehicle is moving.
2Adjust the tire inflation pres-
sure to the specified cold tire
inflation pressure level.
Make sure to adjust the tire pres-
sure to the specifie d cold tire infla-
tion pressure level. The tire
pressure warning system will oper-
ate based on this pressure level.
3Start the fuel cell system.
4 Press or of the meter
control switch to select .
5 Press or to select
“Vehicle Settings” and then
press and hold .
6 Press or to select
“TPWS” and then press .
7 Press or to select “Set
Pressure”. Then press and
hold until the tire pressure
warning light starts blinking.
A message is displayed on the
multi-information di splay. Also, “--”
is displayed for inflation pressure of
NOTICE
■Repairing or replacing tires,
wheels, tire pressure warn-
ing valves, transmitters and
tire valve caps
●When removing or fitting the
wheels, tires or the tire pressure
warning valves and transmit-
ters, contact your Toyota dealer
as the tire pr essure warning
valves and transmitters may be
damaged if not handled cor-
rectly.
●Make sure to install the tire
valve caps. If the tire valve caps
are not installed, water could
enter the tire pressure warning
valves, corrode the valve, and
cause sticking and air leaks.
●When replacing ti re valve caps,
do not use tire valve caps other
than those specified. The cap
may become stuck.
Initializing the tire pres-
sure warning system

4217-3. Do-it-yourself maintenance
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Maintenance and care
each tire on the multi-information
display while the tire pressure
warning system determines the
position.
8 Drive at approximately 25
mph (40 km/h) or more for
approximately 10 to 30 min-
utes.
When initialization is complete, the
inflation pressure of each tire will be
displayed on the multi-information
display.
Even if the vehicle is not driven at
approximately 25 mph (40 km/h) or
more, initializat ion can be com-
pleted by driving for a long time.
However, if initia lization does not
complete after driving for 1 hour or
more, park the vehicle in a safe
place for approximately 20 minutes
and then drive th e vehicle again.
■When initializing
●Initialization is performed while
driving at a vehicle speed of
approximately 25 mph (40 km/h)
or more.
●Make sure to carry out initializa-
tion after adjusting the tire inflation
pressure. Also, make sure the
tires are cold before carrying out
initialization or tir e inflation pres-
sure adjustment.
●The tire pressure warning system
can be initialized by yourself, but
depending on the driving condi-
tions and driving environment, ini-
tialization may take some time to complete.
■The initialization operation
●If you have accidentally turned the
power switch off during initializa-
tion, it is not necessary to manu-
ally restart the initialization again,
as initialization will restart auto-
matically the next time the power
switch is turned to ON.
●If you accidentally perform initial-
ization when initia
lization is not
necessary, adjust the tire inflation
pressure to the s pecified level
when the tires are cold, and con-
duct initialization again.
●While the position of each tire is
being determined and the inflation
pressures are not being displayed
on the multi-information display, if
the inflation pressure of a tire
drops, the tire pressure warning
light will come on.
■If the tire pressure warning sys-
tem is not initia lized properly
●In the following situations, initial-
ization may take longer than usual
to be completed or may not be
possible. Normally, initialization
completes within approximately
30 minutes.
• Vehicle is not dr iven at approxi-
mately 25 mph (40 km/h) or more
• Vehicle is driven on unpaved roads
• Vehicle is driven near other vehi-
cles and system cannot recog-
nize tire pressure warning valve
and transmitters o f your vehicle
over those of other vehicles
If initialization does not complete
after driving for 1 hour or more, park
the vehicle in a safe place for
approximately 20 minutes and then
drive the vehicle again.
●If the vehicle is reversed during
initialization, the data up to that
point is reset, so p erform the ini-
tialization procedure again from
the beginning.

4227-3. Do-it-yourself maintenance
Owners Manual_USA_M62064_en
●In the following situations, initial-
ization will not be started or was
not completed properly and the
system will not operate properly.
Perform the initialization proce-
dure again.
• If, when attempting to start initial- ization, the tire pressure warning
light does not blink 3 times.
• If, when the vehicle has been driven for about 20 minutes after
performing initialization, the tire
pressure warning light blinks for
approximately 1 minute and then
illuminates.
If initialization cannot be completed
after performing the above proce-
dure, contact your Toyota dealer.
Every tire pressure warning
valve and transmitter has a
unique ID code. When replacing
a tire pressure warning valve
and transmitter, it is necessary
to register the ID codes.
When registering the ID codes,
perform the following procedure.
1 When registering the ID
codes, perform the following
procedure.Park the vehicle in
a safe place and turn the power switch off, wait for
approximately 15 minutes or
more and perform the proce-
dure.
2 Start the fuel cell system.
( P.180)
3 Press or of the meter
control switch to select .
4 Press or to select
“Vehicle Settings” and then
press and hold .
5 Press or to select
“TPWS” and then press .
6 Press or to select
“Change Wheel”. Then press
and hold until the tire
pressure warning light blinks
slowly 3 times.
Then a message will be displayed
on the multi-information display.
When registration is being per-
formed, the tire pressure warning
light will blink for approximately 1
minute then illuminate and “--” will
be displayed for the inflation pres-
sure of each tire on the multi-infor-
mation display.
WARNING
■When initializing the tire pres-
sure warning system
Do not initialize the tire pressure
warning system without first
adjusting the tire inflation pres-
sure to the specified level. Other-
wise, the tire pressure warning
light may not come on even if the
tire inflation press ure is low, or it
may come on when the tire infla-
tion pressure is actually normal.
Registering ID codes