BMW E34 retrofitted OBC won't store details

[Inphinity]

Hello..

Today I tried to do the correction of fuel consumption.
But the OBC won't store, when I press S/R it kinda resets the info.

Like if you press 1827corr and press S/R it resets back to 1000.
The same with the CODE function.

Anyone who knows what to do?

Its the big OBC from af EU M5 92 retrofitted the coding plug fitted in the obc, in a 520

Appreciate any answers that may help

[coolvegase34]

My e34's obc incorrectly records my mpg. I usually just divide my mileage by gallons pumped and get the answer that way. I didn't realize that you could reset the mpg.

[Inphinity]

Its when the consumption reading is totally out, and you want to correct it, then you have the oppertunity to correct it with a 4 digit factor. But when I put a new number in, and press the S/R button it just goes back to 1000 insted of remembering the new number..