I had to read up on how the CAN system worked. It works at a low voltage with I/O data stream across a high/low parallel data line. If there is no voltage, high voltage, or a short across the high/low streams then it can basically paralyze the network. Since it's interconnected with every module, if there's a fatal problem within one module it will kill the communication to every other connected module.

Each module supplies its own power for the CAN line, so you can diagnose a module failure by disconnecting one module at a time. But as long as one module's CAN circuit fails and remains connected, you won't be able to see it in the network or communicate with it.

I don't know what exactly failed inside the DSC module, but it definitely was wreaking havoc with the CAN system.