battery TOYOTA MIRAI 2017 1.G Workshop Manual

3317-3. Do-it-yourself maintenance
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Maintenance and care
NOTICE
■When recharging the 12-volt battery
Never recharge the 12-volt battery while the fuel cell system is operating.
Also, be sure all accessories are turned off.

3537-3. Do-it-yourself maintenance
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Maintenance and care
Electronic key battery
●Flathead screwdriver
● Small flathead screwdriver
● Lithium battery CR2032
Take out the mechanical key.
(→ P. 1 1 7 )
Remove the cover.
To prevent damage to the key,
cover the tip of the flathead screw-
driver with a rag.
Remove the depleted battery.
Insert a new battery with the “+”
terminal facing up.
Replace the battery with a new one if it is depleted.
You will need the following items:
Replacing the battery
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3547-3. Do-it-yourself maintenance
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■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 manu-
facturer.
● Dispose of used batteries according to local laws.
■ If the electronic key battery is depleted
The following symptoms may occur:
●The smart key system and wireless remote control will not function properly.
● The operational range will be reduced.
WARNING
■ Removed battery and other parts
These parts are small and if swallowed by a child, they can cause choking.
Keep away from children. Failure to do so could result in death or serious
injury.
NOTICE
■For normal operation after replacing the battery
Observe the following precautions to prevent accidents:
● Always work with dry hands.
Moisture may cause the battery to rust.
● Do not touch or move any other component inside the remote control.
● Do not bend either of the battery terminals.

359
8When trouble arises
MIRAI_OM_USA_OM62023U8-1. Essential information
Emergency flashers .......... 360
If your vehicle has to be stopped in an
emergency ...................... 361
8-2. Steps to take in an emergency
If your vehicle needs to be towed ......................... 362
If you think something is wrong .............................. 368
If a warning light turns on or a warning buzzer
sounds ............................ 369
If a warning message is displayed......................... 376
If you have a flat tire.......... 381
If the fuel cell system will not start ..................... 396
If the electronic key does not operate properly........ 398
If the 12-volt battery is discharged ................... 401
If your vehicle overheats ........................ 406
If the vehicle becomes stuck ............................... 412

3628-2. Steps to take in an emergency
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If your vehicle needs to be towed
In the following situations, it is not possible to be towed by another
vehicle using cables or chains, as the front 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. 378)
● There is a malfunction in the immobilizer system. ( →P. 72)
● There is a malfunction in the smart key system. ( →P. 398)
● The 12-volt battery is discharged. ( →P. 401)
If towing is necessary, we re commend having your vehicle
towed by your Toyota dealer or commercial towing service,
using a wheel-lift type truck or flatbed truck.
Use a safety chain system for all towing, and abide by all state/
provincial and local laws.
Situations when it is not possibl e to be towed by another vehicle

3738-2. Steps to take in an emergency
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When trouble arises
■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 posit ion sensor, driver’s seat belt buckle
switch, front passenger occupant classification system (ECU and sensors),
“AIR BAG ON” indicator light, “AIR BAG OFF” indicator light, front passen-
ger’s seat belt buckle switch, seat belt pretensioners, airbags, interconnect-
ing wiring and power sources. ( →P. 38)
■ Front passenger detection sensor, seat belt reminder and warning
buzzer
● If luggage is placed on the front passenger seat, the front passenger de\
tec-
tion 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 not detect a passenger,
and the warning light may not operate properly.
■ Electric power steering system warning light (warning buzzer)
When the 12-volt battery charge becomes insufficient or the voltage tempo-
rarily drops, the electric power steer ing system warning light may come on
and the warning buzzer may sound.
■
When the tire pressure warning light comes on
Inspect the appearance of the tire to check that the tire is not punctured.
If the tire is punctured: → P. 381
If the tire is not punctured:
After turning the power switch to off, turn it to ON mode again and make
sure the tire pressure warning light comes on or blinks.
The tire pressure warning light comes on
After the temperature of the tires have lowered sufficiently, check the
tire inflation pressure and adjust it to the specified level.
If the warning light does not go out even after several minutes, check
that the tire inflation pressu re is at the specified level.
If the warning light does not go out even after several minutes, have the
vehicle inspected by your Toyota dealer immediately.
The tire pressure warning light is blinking for 1 minute, and then comes
on
Malfunction in the tire pressure warning system. Have the system
checked by your Toyota dealer immediately.
■The tire pressure warning light may come on due to natural causes
The tire pressure warning light may come on due to natural causes such
as natural air leaks and tire inflat ion pressure changes caused by tem-
perature. In this case, adjusting the ti re inflation pressure will turn off the
warning light (afte r a few minutes).
■Conditions that the tire pressure warning system may not function
properly
→ P. 3 3 6
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3778-2. Steps to take in an emergency
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When trouble arises
*: A buzzer sounds the first time a message is shown on the multi-informa-tion display.
■ System warning lights
The master warning light does not come on or flash in the following cases.
Instead, a separate system warning light will come on along with a message
shown on the multi-information display.
●Malfunction of the ABS
The ABS warning light comes on. ( →P. 370)
● Malfunction of the charging system
The charging system warning light comes on. ( →P. 369)
■ If “High FC Temperature Re duced Power” is displayed
Lower the speed while check the safety, and run the vehicle like this for
several minutes.
If the message goes off, the vehicle can be driven as is, since it temporarily
overheated.
This message may be displayed when driving under severe operating con-
ditions.
(For example, when driving up a long steep hill.)
■ If “Maintenance Required for Hybr id Battery Cooling Parts at Your
Dealer” is displayed
The filter may be clogged, or the air intake vent or duct may be blocked. Have
the vehicle inspected by your Toyota dealer.
■ If “Shift to P Before Exiting Vehicle” is displayed
Message is displayed when the driver’s door is opened without turning the
power switch to off with the shift position in any position other than P.
Shift the shift position to P.
■ If “Shift is in N Release Accelerat or Before Shifting” is displayed
Message is displayed when the accelerator pedal has been depressed and
the shift position is in N. Release the accelerator pedal and shift the shift posi-
tion to D or R.
Comes on⎯Does not sound
Indicates a condition, such as mal-
function of electrical components,
their condition, or indicates the
need for maintenance
Flashes⎯Does not sound
Indicates a situation, such as
when an operation has been per-
formed incorrectly, or indicates
how to perform an operation cor-
rectly
System
warning
light
Warning buzzer*Warning
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3798-2. Steps to take in an emergency
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When trouble arises
■If “[P] Switch Malfunction When Parking, Apply Parking Brake Securely
then See Owner’s Manual” is displayed
The shift position may not switch to P even though the P position switch is
pressed.
When parking, choose a flat surface and be sure to engage the parking
brake.
Have the vehicle inspected by your Toyota dealer immediately.
■ If “Shift System Malfunction See Owner’s Manual” is displayed
If left as is, the system may not operate properly and an unexpected hazard
or damage may occur.
Have the vehicle inspected by your Toyota dealer immediately.
■ If “Insufficient Aux Battery Charge When Parking, Apply Parking Brake
Securely then See Owner’s Manual” is displayed
●The parking lock mechanism may not operate.
● The power switch may not turn off. In that case, engage the parking brake
and the switch can be turned to off.
● Even after charging the 12-volt battery, the warning message may continue
to be displayed until the shift position is shifted from P to a position other
than P.
● The fuel cell system may not be able to be started.
When parking, choose a flat surface and be sure to engage the parking
brake.
Have the 12-volt battery charged or replaced.
■ If “Insufficient Aux Battery Charge Shift is Unavailable See Owner’s
Manual” is displayed
Due to the voltage of the 12-volt battery being in a declined condition, when
trying to shift the shift position the warning message is displayed.
Have the 12-volt battery charged or replaced.
■ If “Shifting Temporarily Unavailable Wait a Moment and Try Again” is
displayed
A warning message is displayed when the shift lever and P position switch
are repeatedly operated over a short period of time.
Shift the shift position after waiting for short amount of time.
■ If “Shifting to [Br] Mode Unavailable Shift to [D] once, then Shift to [Br]”
is displayed
When the shift position is in P or N, a warning message is displayed when try-
ing to shift to Br mode.
Shift to Br mode after the shift position had been set to D.
■ If “Shifted to [N] Position Shift to [D] once, then Shift to [Br]” is dis-
played
When the shift position is in R, a warning message is displayed when trying to
shift to Br mode.
The shift position is changed to N.
Shift to Br Mode after the shift position has been set to D.

3968-2. Steps to take in an emergency
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If the fuel cell system will not start
One of the following may be the cause of the problem:
●The electronic key may not be functioning properly. ( →P. 398)
● There may not be sufficient fuel in the vehicle’s tank.
Refuel the vehicle.
● The fuel door may be open. ( →P. 201)
● There may be a malfunction in the immobilizer system.
( → P. 72)
● There may be a malfunction in the shift control system.
* (→ P. 378)
● The fuel cell system may be malf unctioning due to an electrical
problem such as electronic key ba ttery depletion or a blown fuse.
However, depending on the type of malfunction, an interim mea-
sure is available to start the fuel cell system. ( →P. 177, 397)
● The electronic key may be in battery-saving mode. ( →P. 133)
*: It may not be possible to shift the shift position from P to another position.
One of the following may be the cause of the problem:
● The 12-volt battery may be discharged. ( →P. 401)
● The 12-volt battery terminal connections may be loose or corroded.
(→ P. 328)
Reasons for the fuel cell system not starting vary depending on
the situation. Check the follo wing and perform the appropriate
procedure:
The fuel cell system will not start even though the correct start-
ing procedure is being followed. ( →P. 172)
The interior lights and headlights are dim, or the horn does not
sound or sounds at a low volume.

3978-2. Steps to take in an emergency
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When trouble arises
One of the following may be the cause of the problem:
●The 12-volt battery may be discharged. ( →P. 401)
● One or both of the 12-volt batter y terminals may be disconnected.
Contact your Toyota dealer if the problem cannot be repaired, or if repair
procedures are unknown.
When the fuel cell system does not start, the following steps can be
used as an interim measure to star t the fuel cell system if the power
switch is functioning normally.
Do not use this starting procedure except in case of emergency.
Set the parking brake.
Turn the power switch to ACCESSORY mode.
Press and hold the power switch for about 15 seconds while
depressing the brake pedal firmly.
Even if the fuel cell system can be started using the above steps, the
system may be malfunctioning. Have the vehicle inspected by your
Toyota dealer.
The interior lights and headlight s do not turn on, or the horn
does not sound.
Emergency start function
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