2017 TOYOTA MIRAI Ion

3978-2. Steps to take in an emergency
MIRAI_OM_USA_OM62023U
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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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3988-2. Steps to take in an emergency
MIRAI_OM_USA_OM62023U
If the electronic key does not operate
properly
■Doors
Use the mechanical key
(→ P. 117) in order to perform
the following operations
(driver’s door only):
Locks all doors
Unlocks the door
Turning the key rearward
unlocks the driver’s door. Turn-
ing the key once again unlocks
the other doors.
■
Tr u n k
Turn the mechanical key clock-
wise to open.
If communication between the electronic key and vehicle is
interrupted ( →P. 134) or the electronic key cannot be used
because the battery is depleted, the smart key system and wire-
less remote control cannot be used. In such cases, the doors
can be opened and the fuel cell system can be started by follow-
ing the procedure below.
Locking and unlocking the doors

3998-2. Steps to take in an emergency
MIRAI_OM_USA_OM62023U
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When trouble arises
■Key linked functions
Depress the brake pedal.
Touch the power switch with the
Toyota emblem side of the elec-
tronic key facing away from the
switch.
When the electronic key is
detected, a buzzer sounds and the
power switch will turn to ON mode.
When the smart key system is
deactivated in customization set-
ting, the power switch will turn to
ACCESSORY mode.
Firmly depress the brake pedal
and check that message is dis-
played on the multi-information
display.
Press the power switch.
In the event that the fuel cell syst em still cannot be started, contact
your Toyota dealer.
Closes the windows* (turn and hold)
Opens the windows
* (turn and hold)
*: These settings must be customized at your Toyota dealer. ( →P. 437)
Starting the fuel cell system
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4008-2. Steps to take in an emergency
MIRAI_OM_USA_OM62023U
■Stopping the fuel cell system
Shift the shift position to P and press the power switch as you normally do
when stopping the fuel cell system.
■ Replacing the key battery
As the above procedure is a temporary measure, it is recommended that the
electronic key battery be replaced immediately when the battery is depleted.
(→P. 353)
■ Alarm
Using the mechanical key to lock the doors will not set the alarm system.
If a door is unlocked using the mechanical key when the alarm system is set,
the alarm may be triggered. ( →P. 75)
■ When the electronic key does not work properly
●Make sure that the smart key system has not been deactivated in the cus-
tomization setting. If it is off, turn the function on.
(Customizable features →P. 436)
● Check if battery-saving mode is set. If it is set, cancel the function.
(→P. 133)
■ Changing power switch modes
Release the brake pedal and press the power switch in step above.
The fuel cell system does not start and modes will be changed each time the
switch is pressed. (→P. 174)
WARNING
■ When using the mechanical key and operating the power windows
Operate the power window after checking to make sure that there is no pos-
sibility of any passenger having any of their body parts caught in the win-
dow.
Also, do not allow children to operate the mechanical key. It is possible for
children and other passengers to get caught in the power window.
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4028-2. Steps to take in an emergency
MIRAI_OM_USA_OM62023U
Connect the jumper cables according to the following procedure:Connect a positive jumper cabl e clamp to the exclusive jump
starting terminal on your vehicle.
Connect the clamp on the other e nd of the positive cable to the
positive (+) battery terminal on the second vehicle.
Connect a negative cable clamp to the negative (-) battery termi-
nal on the second vehicle.
Connect the clamp at the other end of the negative cable to a
solid, stationary, unpainted metallic point away from the exclusive
jump starting terminal and any moving parts, as shown in the
illustration.
Start the engine of the second v ehicle. Increase the engine speed
slightly and maintain at that level for approximately 5 minutes to
recharge the 12-volt battery of your vehicle.
Maintain the engine speed of the second vehicle and start the fuel
cell system of your vehicle by turn ing the power switch to ON mode.
Make sure the “READY” indicato r comes on. If the indicator does
not come on, contact your Toyota dealer.
Once the fuel cell system has started, remove the jumper cables in
the exact reverse order from which they were connected.4
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4038-2. Steps to take in an emergency
MIRAI_OM_USA_OM62023U
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When trouble arises
Close the exclusive jump starting terminal cover, reinstall the motor
cover and the fuse box cover to its original position.
Once the fuel cell system starts, have the vehicle inspected at your
Toyota dealer as soon as possible.
■ Starting the fuel cell system when the 12-volt battery is discharged
The fuel cell system cannot be started by push-starting.
■ To prevent 12-volt battery discharge
●Turn off the headlights and the audio system while the fuel cell system is off.
● Turn off any unnecessary electrical components when the vehicle is running
at a low speed for an extended period, such as in heavy traffic.
■ Charging the 12-volt battery
The electricity stored in the 12-volt battery will discharge gradually even when
the vehicle is not in use, due to natural discharge and the draining effects of
certain electrical appliances. If the vehicle is left for a long time, the 12-volt
battery may discharge, and the fuel cell system may be unable to start. \
(The
12-volt battery recharges automatically while the fuel cell system is operat-
ing.)
■ When the 12-volt battery is removed or discharged
●In some cases, it may not be possible to unlock the doors using the smart
key system when the 12-volt battery is discharged. Use the wireless remote
control or the mechanical key to lock or unlock the doors.
● The fuel cell system may not start on the first attempt after the 12-volt bat-
tery has recharged but will start normally after the second attempt. This is
not a malfunction.
● The power switch mode is memorized by the vehicle. When the 12-volt bat-
tery is reconnected, the system will return to the mode it was in before the
12-volt battery was discharged. Before disconnecting the 12-volt battery,
turn the power switch off.
If you are unsure what mode the power switch was in before the 12-volt bat-
tery discharged, be especially careful when reconnecting the 12-volt battery.
● If the 12-volt battery is depleted with the shift position in P, it will not be pos-
sible to shift the shift position other than P. In this case, the vehicle cannot
be towed without lifting both front wheels because the front wheels are
locked by the parking lock. ( →P. 363)
● When the 12-volt battery is reconnected, start the fuel cell system, depress
the brake pedal, and confirm that it is possible to shift into each shift posi-
tion.
● Make sure that the key is not inside the vehicle when recharging or replac-
ing the 12-volt battery. The key may be locked in the vehicle if the alarm is
activated. ( →P. 75)
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4048-2. Steps to take in an emergency
MIRAI_OM_USA_OM62023U■
When exchanging the 12-volt battery
Use a Central Degassing type 12-volt battery (Japanese Industrial Stan-
dards). Also, use 12-volt batteries with case sizes similar to one prior the
exchange and an equivalent 20 hour rate capacity (20HR) or greater.
• If the sizes differ, the 12-volt battery 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 fuel cell
system may not be able to start.
For details, consult your Toyota dealer.
WARNING
■ Avoiding 12-volt battery fires or explosions
Observe the following precautions to prevent accidentally igniting the flam-
mable gas that may be emitted from the 12-volt battery:
● Make sure each jumper cable is connected to the correct terminal and that
it is not unintentionally in contact with any other than the intended terminal.
● Do not allow the other end of the jumper cable connected to the “+” termi-
nal 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 lighters or allow open flame near
the 12-volt battery.
■ 12-volt battery precautions
The 12-volt battery contains poisonous and corrosive acidic electrolyte,
while related parts contain lead and lead compounds. Observe the following
precautions when handling the 12-volt battery:
● When working with the 12-volt battery, always wear safety glasses 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 medical
attention.
Place a wet sponge or cloth over the affected area until medical attention
can be received.
● Always wash your hands after handling the 12-volt battery support, termi-
nals, and other battery-related parts.
● Do not allow children near the 12-volt battery.

4068-2. Steps to take in an emergency
MIRAI_OM_USA_OM62023U
If your vehicle overheats
The following may indicate that your vehicle is overheating.
● The high coolant temperature warning light ( →P. 369) comes on
or flashes, or a loss of fuel ce ll system power is experienced. (For
example, the vehicle s peed does not increase.)
● “FC System Overheat Out put Power is Limited” (→P. 376) is dis-
played on the multi- information display
● Steam comes out from under the hood.
Label
Fuel cell stack coolant
reservoir Inverter coolant reservoir