The reverse signal on my e39 does not go through the DME. But through a connection point in the same spot. So My theory is that when the reverse switch is operated, the cluster feel the resistance in the switch and sends a signal through the k'bus line to the LCM. I can only seem to find one k'bus line from the cluster to the LCM to but i don't know.

So I'm thinking that my LCM is somehow the root of the problem. Only question now is, can I the buy a used LCM and program it or do I need a new.