S4 Engine Management Light Staying On

Depends what OBD plug the bike and the reader use...CELs come on for various reasons could be a genuine fault...or could just be a single out of range reading and lack of CABbus feedback can also be a cause as can bad sensor earth (most common cause).

 

probably a later version I don't know why they come my last time was for the oxygen sensor erased it on the code reader and has not come back