Cm 870 fuel shutoff problems

[Precisionw900]

My cm 870 randomly drops dead with cel. Code 255, open circuit to fuel shutoff. Has died 4 different occasions, once while parked and idling.
Replaced fuel shutoff since I had one and just to rule out. Couldn’t make it duplicate problem until next day when it died crossing highway. After sitting for about 10 minutes it fired right up. Truck ran another few hours and died again. Luckily I took a voltmeter along and had zero power at shutoff.
At this point I hooked up a jumper to fuel shutoff and it fired right up and ran the rest of the day.

Checked harness and continuity test from pin 51 to shutoff will moving harness every way possible and have inspected plugs well. Passes every time.

I know 870 ecm’s tend to be a little wonky and as far as I can tell this one is original. Is there a possibility that it’s on the brink? Maybe ecm is momentarily killing shutoff circuit?