PDU (Power Distribution Unit) Design
This is the Block Diagram for the PDU (Power Distribution Unit)
Looks like we have one low voltage connector and 10 high voltage connectors +1 DCFC connector. So that would mean they have 12v and a 400v (300v?) components.
The 12v input seems to power the entire module. It also handles the HVIL (High voltage interlock) and would cut the contactors. It seems the HVIL detects disconnections of the connectors and a Lid detection. The HVIL loop goes out to the LV connector so there are likely external interlocks also considered by the system.
Unlike all other connections the wheel motor inverters are unfused as is the DCFC connector. They may be fused with a non-user replaceable fuse. But at least the wheel inverters and the DCFC plug have their own contactors and there is a pyro fuse on the +side of the battery.
The battery has independent/dual serial communications with the battery (MMB IsoSPI)
What is missing from this diagram is where the AC rectifier is. You can see the DCFC (300-400v) connector is separate from the OBC/DCDC (A/C Rectifier). I am assuming the listed DCFC connector in the diagram is only the one on the PDU and not the actual Tesla plug at the back of the car. This may be what they need to work on now that they agreed to put DCFC on the LE. With only L1 and L2 charging you just need a rectifier and the wiring to get to the PDU. Now you need significantly heavier wiring and a way to switch over from AC to DC charging.
One question I have is why do they have a bypass (Contactor P) and in inline contactor (5) on the high voltage negative side? Could it have to do with the solar charging?