Anyone knows what is the round switch that is near the ECU, behind the battery for? It is labelled with numbers from 1 to 7 (or 8, I don't remember). Is it R16?
My car has another similar switch marked "S" and "N", near the ignition unit, at the other side of the hood.

It is a 190E 2.3 8valve, 1992.

Thanks!

This is a detail of the second switch I have talked about. The other behind the battery is similar, but with numbers on it and a tamperproof seal.

Best regards

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As far as I know, the second is to adapt the ignition to the quality of the fuel.

The first one I do not know, but interested to know (I read somewhere "ECE resistors, connector" )