Thanks for the update.
Access to the (Simrad) NMEA 2000 network is not a problem on my boat as there is a T connector at the chart table. However, I do not know where to connect to on the engine. Mine is a D2-40. Is yours the same? If so, where did you connect the NMEA cable?
Second question, do you believe the MIDI board(?) blew as a result of connecting to NMEA 2000. I would not want to risk a £450 replacement if there is any question. Were Volvo happy to replace it on warranty?