I've had two failures of diesel fuel shut-off systems over the years.
One was on a 2005 JD compact utility- could have been 3 different modules, I guessed wrong the first time, ended up getting JD tech out, and $500 and 3 weeks later, it was fixed.
Other was on an IH 504 diesel. Manual shut-off broke. Bought a universal choke cable, cut it to length, and put it on. 6 bucks and 15 minutes later, it was fixed.
Not a big fan of electronics on tractors. Or cars, for that matter.