Iveco Stralis EBS light on dash

Hi All got a 10 plate stralis here, plugged in using Delphi diagnostic and if you can see in the photo it comes up 4604 - unknown fault code anybody able to shed any light?, I would go in on the dash but for some reason the arrows aren’t working :imp:

clear fault and road test see if it comes up again. iveco computer comes up with unknown codes occasionally.