Not the ecm

[Mrkentee]

I have a J1939 connection problem that won’t let the truck start.
I’ve checked fuses and wiring, etc.
Put new ecm in, started right up. Ran for 10 minutes. Hooked up my trailer, drove 8 minutes to truck stop. While being reprogrammed lost connection. Now won’t start again.
on the dash it shows no faults with key off. Turn key on and it shows J1939 failure, and ABS J1939 failure. So it may well be an ABS module or sensor. Got someone coming in the morning with a scanner. Hopefully they find something. It’s a 2010 PB 386.