2011 z4 intermittent electric assist steering failure that goes away for weeks

[Dannheisser]

This happens intermittently but almost always starts working. Seems if an electronic part actually failed it wouldn't ever work. Is there a possible grounding issue? Has anyone ever resolved without replacing rack?

Why would it disappear fir weeks?

 

[B21]

Usually it’s the ECU in the rack that fails..as usual and as always fault code reading is the first step…