Can't answer your problem but as you are using the CX5 for towing I'll take the opportunity to pass on a hint although it is somewhat off topic. On long tows, and it happens each and every time, up pops a warning on my car advising that the vehicles overtaking you function (can't recall now the tech. name) but it's that little orange vehicle sign in the external rear view mirrors, is not working. After a long while, or vehicle restart, the system resets so I'm guessing that the rear bumper sensors don't much like having a caravan/trailer hanging off the back. And yes, towbar and electrics are Mazdas own and Mazda fitted. Just a heads up if this should happen to you.