So only one of the MCU has this problem? And you swapped out the entire bottom board to test that the current sensors were okay? All the little connectors were verified to be inserted okay?
Did you have a tool to clear this code from the EV-ECU memory?
There is another thread with pictures of the boards and IGBTs, the cover can be removed to visually inspect for damage to the dies.
This is the 3 big IGBTs underneath the big capacitor
This is the guts of a IGBT with the cover off to inspect for burn damage, there is a clear jelly filling