One of the most common failures on N54s is the MSD80 (ECU) failing. This happens because the MOSFETs in the ECU stop working. This will throw the fault codes 30BA (Injector Circuit Failure 1-3 or DME Internal Fault) or 30BB (Injector Circuit Failure 4-6 or DME Internal Fault). With the MSD81, the MOSFETs had a design change, making them l