ABS light, no communication from tech 2 tool but simple code reader will communicate??

[Jake9]

I'm new to the forum.  I've got an 03 suburban 1500 5.3l that we virtually took the skin off and welded a 72 body onto.  There were no codes when it went into the shop for welding and came back,  I wired everything back up exactly as it was before and what do ya know,  my pcm was fried so I took it in and it was fried bad enough the programmer couldn't communicate at all so we took another pcm from the junkyard and programmed it to my vin. So got it back and started And there was an abs and parking brake light on. I had a random knock sensor come on as well so I plugged my simple diablo tuner from my other pickup and was able go read and clear the code but I went into the dealer and plugged the tech 2 and snap on tool in and they can't communicate with the pcm, bcm or read my abs codes. I need help because I have gone through the dash to the fuse blocks and inspected every wire,  checked and cleaned all grounds and still nothing. Is this indications of a bad bcm? Gauges,  power to the windows and heated seats all work.  Anyone ever seen this issue?

[sefiroxx]

Double check the obd2 port wiring