2009 Cummins ISX CM871 communication error? or not?

[Bengy88]

I wouldn’t rule out your omnitrac, that would be the easiest to check, unplug it and run it. We have all seen e logs cause issues. But my personal opinion it sounds like you have power or ground problems to your ecm. The absolute first thing I would check is the wiring between battery power and ground to the ecm. Check for corrosion, loose pins, hanging wires, etc. ohm the wires from one end to the other. You can also pull each end of the wire loose and power a headlight through the circuit to make sure the bulb burns bright. Not saying it’s your issue but it really sounds like that’s where you should start