I'll be back on tonight (eastern uSA time). Gotta get to work.

For now, your work is cut out for you, this will probably get expensive. You said yourself that they replaced what they had to so as to get it running. There is more work to do, likely the controller unit is gone. With all communications between modules on the CAN bus, you need the STAR system to read what's going on on that bus. Replacing modules until it works may be your only route to take.