No Crank/ No Communication 2010 Chevrolet Express 6.0

Have a van that is throwing me in a loop. The van is a 2010 Chevrolet express van that is a no crank concern. guy had the van sitting at idle and all of the sudden the starter was staying engaged and he battery began to smoke. guy managed to replace the battery and starter but now the van will not crank. I removed the starter and verified voltage to power wire and battery voltage and noticed the signal wire was not getting voltage on crank command from ignition. I traced wire back to fuse which is good relay is good but am not getting power to the control side of the relay from ECM. upon trying to scan vehicle noticed I could not communicate with any of the high speed can bus modules, and no gear display on dash. pins 6 and 14 show 60ohms with key out doors closed but I have 0 voltage on either pin. Now here is where it gets weird if I unplug my BCM x3 connector I have voltage back and can communicate with the ECM but if I plug my BCM back up I lose communication and voltage, However if I Unplug my ECM can bus connector I can communicate with my BCM and EBCM but the same thing happens if I plug my ECM connector back in. Still have not been able to communicate with Fuel pump flow control module or TCM. Any help / ideas?

Thanks. 

Have you checked your can lines for a short to ground? I’d personally take my test light connected to battery voltage and touch pins 6 and 14, if it lights you’ll have to start unplugging modules until you find the short, could also be a short somewhere in the harness. The other thing I’d check is your serial data wake up signal (dark blue wire at the ecm) if it is shorted to ground none of your modules will be allowed to talk on the network