Hi, what would that code be ?

The check-engine light with C0301

Thanks

It is PLX Kiwi 3 bluetooth device.

Hm, googling that code was not very helpful, there was like a million answers. You could wait for a tech on here, or you could post it on reddit/mechanicadvice i know there's Mercedes techs there

That code is "generic" - and if you erase it and it comes back (like right away) - ou will need a Star equivalent scanner to get to the "real" MB proprietary code of the issue

Take it to the dealer.