Trailer Brake lights fixed!!
I was trying to get my trailer brake lights to work for 3 weeks, and I realized that I need to get into coding to solve it, the other lights works fine. after installing programs, read hours about it I could coded my X5 2013 with auto folding mirror with keyfob, Digital speed, etc... I went to my dealer and they couldnt found the issue, and they asked me to leave the car there for 3 or 4 days... no way for me on holiday season, Ok lets go into business, this is what happened, there is a module that handles the trailer electrical system called AHM, Dealers sometimes can missed this, mine did it, they coded it with default values and the first entry in the programming file was LAENDERVARIANTE_AHM and it was set to "ECE", ECE means Europe, under this circunstances the AHM module thinks that it will be receiving a Europe compliant connector trailer and the braking signal is actually routed to one of the pins of the 7 default pin connector, but this pin is not rerouted when you plug the converter that comes with the OEM harnessd to the 4 pin US connector, on this 4 pin connector the braking signal should comes from LT and RT together, in order to make this work you just need to recode the AHM with LAENDERVARIANTE_AHM set to "US" and you will be ready to go.