I have a service manual my son got me from Kubota, he works a KMA in R&D dept for lawn and turf div. He doesn't deal with big tractors. I thought diode in wiring by crs relay was bad, replaced diode but still same problem.
Spilt tractor to rebuild fwd and rear clutch packs, put back together won't crank, have code EN-ENG o dash. Have power to CRS relay, can ground terminal that goes to ECM and will crank and run, remove ground to shut off.