Seeing how a month has passed by and there has been no response, have you had any luck in getting this resolved? Can't imagine all these good summer days going by and that issue still going on. It might help some other members here as well.Its an enclosed trailer. I pulled this trailer about a thousand miles with my old Jeep GC with a 6 cylinder and it had a brake controller. It was all the Jeep wanted when it came to hills. I was just wondering if MB had an integrated brake controller with the GLE350 or if one needed to be installed in order to have trailer brakes. My MB dealer hasn't been very helpful in this respect.
That might be your best bet, which manufacture did you go with? Would be interested in seeing what sort of information they list. But even with whatever information they provide you I still think you should get a second opinion.I too would like to know because I've been looking around and the few suggestions I've found told me to refer to the trailer manufacturer about it.