The idea of putting zero electronics was to appeal to those familiar with the many frustrated tractor owners who've got dog tired of POS revenue driven electronics being a necessary part of their more recent purchases. The title to them would indicate it was both not
fly by wire as well as an absence of overly complicated control boxes being essential for the machine to work. Obviously the tractor has electrics which includes such things as lights, batteries, alternator and starter motor, and probably basic half century proven basic electronic components such that drives signals and instrumentation.
As a side note, there's not an adequate explanation for what P pumped injector means or its significance. [1]
[1] https://4btengines.com/6bt-vs-isb-comparing-the-p-pumped-12-...