Ummmm...the normal shutdown of a diesel (like my Cummins equipped Dodge) IS to
kill the electrical supply. Thereby closing the fuel shut off valve. Had a
problem once with the starter bypass ckt once that required pulling the
electrical plug off the fuel valve to kill the motor. My owners manual does
say that the engine will run away if there is enough fuel vapor available in
the area and to remove the supply of air to stop things. Same with a bad turbo
seal that allows the motor to consume its own lube oil.
Mike