So this is the CANBus layout (only slightly different for newer ones with DC charging). There are 4 busses exposed to the outside: EV HS-CAN, HS-CAN, MS-CAN and I-CAN. I believe there is another inside the battery itself. All the arrows that don't have a little resistor icon are unterminated connections to modules and the diagnostic socket. That gateway module passes traffic between busses and then each bus terminates at some other module. The BCM (same as BdyCM) also acts as a gateway to bridge traffic across busses.
If there is a short on one of those busses, you may see faults from modules that connect to it or no messages from them at all. You might also get codes from other modules if they are not getting data they expect, so you can see faults from modules on other busses as well.
EV HS-CAN Errors: BECM, PCM, GFM, ABS, TCM
No Errors: SOBDM, ACCM, DCDC, GWM
HS-CAN Errors: BCM, SASM, RCM
No Errors: OCS, PSCM, PAM, GWM
MS-CAN Errors: BCM, IPMB, RFA, IPC, DDM, HVAC, GPSM, APIM
No Errors: PDM, GWM
I-CAN Errors: IPC, FCIM, ACM, APIM
No Errors: GWM
Unfortunately, the selection of faults doesn't seem to narrow anything down. You might consider clearing all the faults and doing individual module diagnostics. Track down the service manual that has been linked in other threads and look up the codes. Strike out any module fault codes that don't clearly indicate a problem in the module itself like "low input voltage". Hopefully that narrows things down further.