I got this code twice this week. I have had weird things happening to my car for the last year. When I take it to the dealership they never know what's going on. Cobalt months ago my car was doing weird thing in the transmission. One day I was wiggling the ecm around to see if something was loose and it went crazy starting displaying code. Like 20 codes. Most coes were for sensors I had changed out and knew for fact they were good. Cleaned all connectors with connector cleaner and let them dry. Drove perfect again till now. Is it possible that my cobalt is finally catching onto something. When I do research for U0073 and GM verifies that its communication can bus off? A pinched or bad wire somewhere. Does anyone know anything about this code? Maybe a common spot or wire that might get rubbed on or damaged. Thanks for any help!

 

Dont know anything about the particular code. But what are the "weird" issues? From your op, I would GUESS the bcm is flaking out. BUT the pcb relays in the underhood fuse box tweak at times too. Give us some symptoms...
Also, do you have any electrical mods or messed with red and white twisted wire?