Idea: A)Buy one of those devices made to pump oil out of your crank case through the dip stick tube
B) suck out all of fluid on active side
C) fill up passive side
Start her up and see if DEF light comes on. You might have to be pateinet and give the system a little bit correction time. If DEF light stays on, wouldn't this be grounds for transfer pump indictment?
does the light come on from a active side or passive side sensor?