HONDA FCX - Manual (Page 9)

Built-In Safety Features
5
Occupant Protection Features
The FCX has lap/shoulder belts in all four
seating positions, dual front airbags, and
pyrotechnic seat belt tensioners for the
driver and a front passenger. To disable the
airbags and tensioners, the key switch must
be in the LOCK (0) position for at least 3
minutes, or the 12-volt battery must be
disconnected for at least 3 minutes.
Crash Detection System
The FCX is equipped with sensors that can
detect a serious impact to the front, rear, or
either side of the vehicle. If the impact is
severe enough, the control unit
automatically shuts off the flow of
electricity from the fuel cell module and the
capacitor module. In less than 1 second,
there is no electric current in the high-
voltage cables.
Hydrogen Tank Safety Valves
Each hydrogen tank contains three internal
safety valves. One prevents any backflow
while the tank is being refilled, another
shuts off the flow of hydrogen when
signaled by the power control unit, and the
third is a pressure relief device designed to
release all hydrogen if the temperature in
the tanks exceeds approximately 221°F
(105°C).
When the pressure relief device is activated,
hydrogen is routed through a line and out of
the vehicle through the pressure relief tube
under the right rear bumper. Pressure Relief Tube
(rear view of vehicle)