I found that I haven't looked at the screen to see the e-diff working, and just take it on faith. You may not be missing much not having the screen. When it is engaged, I need both eyes looking outside as the driving is full-on if the e-diff needs to be working SWMBO has asked (at a most inopportune moment in the midst of a sand dune) why the light was flashing green to red, so it must work when wheels are spinning.