I would also check for any open recalls on your car, like the battery cable recall.
I think some guys have had this problem and it turned out to be the ABS/DTC block module under the hood. And that DSC block isn't cheap. I think 2k euros.
IF this is the case, there is a German company that can repair the ABS/DTC Block(valve body) called:
tachopix.de
They can also repair the failed pixels on radio displays and other common electrical gremlins that are common to modern cars. I used tachopix to repair my failed pixels on my e39.
First step is to read the code and see whats what. Clear said code and see IF it comes back.
Dackel