Got a question on your outputs,
The outputs A5/6/7/8. Do they have the option of being high side drivers?
The BMW MS42/43 ECU’s I have opened have the fuel control relay as high side so that when the ECU loses power(blown fuse), the relay won’t energise. If they are low side, they will ground when ECU power is lost, turning on the relay which will power the injectors/Ignition coil. The injectors/coils will then operate because the drivers for them are low side. The fuel control relay is used to supply power to both the injectors and the ignition coils.