If Your Vehicle Overheats - Toyota MIRAI 2021 Owner's Manual

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8-2. Steps to take in an emergency

If your vehicle overheats

The following may indicate that your vehicle is overheating.
 The high coolant temperature warning light (P.444) comes on
or flashes, or a loss of fuel cell system power is experienced.
(For example, the vehicle speed does not increase.)
 The fuel cell system overheat warning light (P.444) comes on
 Steam comes out from under the hood.
Parts name for cooling components
Label
A
Fuel cell stack coolant reservoir
B
Inverter coolant reservoir
C
MIRAI Owners Manual_USA_M62034_en