Honda Clarity 2018 Owner's Manual page 455

Fuel Fill Cap
Holder
7. Place the fuel fill cap in the holder.
8. Insert the fuel filler nozzle fully.
u When the tank is full, the filler nozzle will
click off automatically. This leaves space
in the fuel tank in case the fuel expands
with a change in the temperature.
9. After filling, replace the fuel fill cap,
tightening it until you hear it click at least
once.
u Shut the fuel fill door by hand.
uuRefuelinguHow to Refuel
1How to Refuel
If the fuel fill door does not open after you press the
button, even after the display changes to Ready, you
can manually open the door.
2 When You Cannot Unlock the Fuel Fill Door
P. 562
An internal valve automatically closes after 30
minutes from the moment you press the fuel fill door
release button. When it does, do not continue to
refuel as fuel may spill out.
When the fuel fill door automatically opens, a vent
valve in the fuel system also opens to allow the air
and the vapors being displaced by the fuel to escape.
This valve automatically closes, however, if the
refueling is not completed within 30 minutes. If this
happens, reinstall the fuel cap, close the fuel fill door,
and then follow these steps again to restart the
system. If you decide to add fuel after the vent valve
has automatically closed (i.e. after 30 minutes), do so
very slowly. Trying to add fuel too rapidly after the
vent valve has closed will cause fuel vapors to be
pushed out the filler pipe and could cause a small
amount of liquid fuel to be spilled onto the ground.
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