Chevy Express 3500 electrical problem BCM & TCM
 

I don't know if this is the correct place to post this but I am losing my mind trying to get my truck repaired. I took my 2011 6.0 vortec 3500 cutaway truck to the dealership because it will intermittently go in to limpmode and have the ebrake, abs, oil light, and enginelight come on,while the fuel gauge, speedo, oil pressure, and gear selector guages all quit working.

They first said it was the TCM, it was replaced and that wasn't the problem. Now they said it is the BCM and it was replaced and that isn't the problem. Now they are supposed to be looking some more.

What can it be? I have never had somany issues with getting a problem on a vehicle diagnosed and repaired in my life. I hate modern rolling computers at this point...