2020 TOYOTA MIRAI radiator cap

3717-3. Do-it-yourself maintenance
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Maintenance and care
■If the inverter coolant level drops within a short time of repl enishing
Visually check the radiators, hoses, inverter coolant reservoir cap, drain cock
and water pump.
If you cannot find a leak, have your Toyota dealer test the cap and check for
leaks in the cooling system.
Check the radiator and condenser and clear away any foreign objects.
If either of the above parts is extremely dirty or you are not sure of
their condition, have your vehic le inspected by your Toyota dea ler.
WARNING
■When the fuel cell system is hot
Do not remove the coolant reservoir caps.
The cooling system may be under pressure and may spray hot coolant if the
cap is removed, causing serious injuries, such as burns.
NOTICE
■When adding coolant
Coolant is neither plain water nor straight antifreeze. The cor rect mixture of
water and antifreeze must be used to provide proper lubrication , corrosion
protection and cooling. Be sure to read the antifreeze or coolant label.
■ If you spill coolant
Be sure to wash it off with water to prevent it from damaging p arts or paint.
Radiator and condenser
WARNING
■When the fuel cell system is hot
Do not touch the radiator or condenser as they may be hot and c ause seri-
ous injuries, such as burns.

4618-2. Steps to take in an emergency
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When trouble arises
Start the fuel cell system and turn the air conditioning system on
to check that the radiator coo ling fans operate and to check fo r
coolant leaks from t he radiator or hoses.
The fans operate when the air conditioning system is turned on immedi-
ately after a cold start. Confirm that the fans are operating b y checking
the fan sound and air flow. If it is difficult to check these, turn the air con-
ditioning system on and off repeatedly.
(The fans may not operate in freezing temperatures.)
If the fans are not operating:
Stop the fuel cell system immed iately and contact your Toyota
dealer.
If the fans are operating:
Have the vehicle inspected at the neare st Toyota dealer.
WARNING
■When inspecting under th e hood of your vehicle
Observe the following precautions.
Failure to do so may result in serious injury such as burns.
● If steam is seen coming from under the hood, do not open the ho od until
the steam has subsided. The motor compartment may be very hot.
● After the fuel cell system has been turned off, check that the “READY”
indicator is off.
When the fuel cell system is operating, the cooling fans may suddenly
operate even if the fuel cell system stops. Do not touch or app roach rotat-
ing parts such as the fans, which may lead to fingers or clothing (espe-
cially a tie, a scarf or a muffler) getting caught, resulting i n serious injury.
● Do not loosen the coolant reservoir caps or radiator cap, while the fuel cell
system and radiator are hot.
High temperature steam or coolant could spray out.
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4699-1. Specifications
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Vehicle specifications
*: The fluid capacity is a reference quantity.If replacement is necessary, contact your Toyota dealer.
Cooling system
Capacity*
Fuel cell
stack 20.7 qt. (19.6 L, 17.2 Imp.qt.)
Inverter 5.0 qt. (4.7 L, 4.1 Imp.qt.)
Coolant
type
Fuel cell
stack“Toyota Genuine FC Stack Coolant”
• In order to safely cool the fuel cell stack,
which is at high voltages, the fuel cell stack
coolant is an exclusive high insulation prod-
uct.
• Never use water or other kinds of coolants as they will cause damage.
• Coolant changes are unnecessary.
• Do not reuse coolant that has been removed from the radiator.
• Coolant is colorless.
• Consult your Toyota dealer about replenish- ing or changing the fuel cell stack coolant.
Inverter Use either of the following:
• “Toyota Super Long Life Coolant”
• A similar high-quality ethylene glycol-based
non-silicate, non-amine, non-nitrite, and
non-borate coolant with long-life hybrid
organic acid technology
Do not use plain water alone.
NOTICE
The fuel cell stack coolant is exclusive for
fuel cell stack usage. Damage may occur
when water or any other type of coolant
is used, so never use any other fluid.
If the fuel cell stack coolant is low, imme-
diately contact your Toyota dealer.

522Alphabetical index
MIRAI_OM_USA_OM62073U
P position switch ..................... 194
Parking brake ........................... 200Operation .............................. 200
Parking brake engaged warning buzzer/message ... 200
Warning light ......................... 420
Parking lights ........................... 201 Light switch ........................... 201
Replacing light bulbs............. 405
Parking Support Brake function
(for static objects) ................. 274
Function ................................ 274
Warning light ......................... 419
Warning message ......... 279, 426
PCS (Pre-Collision System) .... 226 Function ................................ 226
Warning light ......................... 420
Warning message ................. 426
Personal lights ......................... 318
Switch ................................... 318
Wattage ................................ 471
Power control unit ..................... 91
Power easy access system .... 153
Power outlet ............................. 331
Power steering (Electric power steering) ...... 296
Warning light ......................... 419
Power switch............................ 186
Power windows........................ 167 Jam protection function......... 168
Operation .............................. 167
Window lock switch............... 167
Pre-Collision System (PCS) .... 226 Function ................................ 226
Warning light ......................... 420
Warning message ................. 426 Radar cruise control (dynamic
radar cruise control) ............. 253
Radiator .................................... 371
Radio
*
Rear Crossing Traffic Alert..... 300
Rear interior lights .................. 318 Wattage ................................ 471
Rear side marker lights........... 201
Light switch ........................... 201
Replacing light bulbs ............ 405
Rear turn signal lights ............ 199
Replacing light bulbs ............ 405
Turn signal lever ................... 199
Rear view mirror
Inside rear view mirror .......... 162
Outside rear view mirrors ..... 164
Rear view monitor system
*
Rear window defogger ............ 309
Refueling .................................. 213 Capacity................................ 468
Fuel types ............................. 468
Opening the fuel door ........... 215
Regenerative braking ................ 89
Replacing
Electronic key battery ........... 400
Fuses .................................... 402
Light bulbs ............................ 405
Tires...................................... 386
Reporting safety defects for U.S. owners...................... 496
Road accident cautions .......... 100
RSA (Road Sign Assist) .......... 248 Function ................................ 248
Warning message......... 252, 426
PR