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Navigation: MTune Settings > Inputs

BSD Protocol input

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Some BMW vehicles uses a BSD protocol to communicate with some modules, like oil level sensors and the alternator control.

Our special BSD board is REQUIRED for this functionality.



Wiring information

DIN 3 (GPO 7) needs to be wired to the BSD board DIN activated as BMW BSD bus 1 Input.

Any available GPO (GND) output needs to be wired to BSD board GPO and activated as BMW BSD Bus 1 Output.

Switched +12V.

Engine GND.

BSD to the BSD peripheral wire.




1. Our special BSD board (product ID 2134) is required to communicate with these BMW peripherals.



2. Wire the BSD peripheral BSD output wire to the DIN 3 of your MaxxECU and activate input as BMW BSD bus 1 Input.

Note: ONLY DIN3 can be used, DIN3 is actually the GPO7 Used as digital input 3.



3. Wire the BSD board GPO to ANY MaxxECU GPO (GND) and activate the output as BMW BSD bus 1 Output.



4. Control settings is now visible under Inputs --> BSD Protocol Input 1 in MTune.



5. A few more RealTime Data values are now available in the system.



Oil level sender


oil sensor communication

Enable the oil level sender communication.





Alternator communication

Enable the alternator communication.


target voltage

Specifies the alternator target voltage.



Confirmed BMW oil level senders