TRAILER BRAKING THROUGH TRAILER SUPPLY LINE

Systems and methods allow for controlling brakes of a trailer coupled to a tractor. The systems and methods utilize an inversion valve input between an emergency brake controller and a trailer connection at the tractor. The inversion valve receives a supply air from an output of the emergency brake controller, and a control air output from a treadle valve of the tractor. Depending on the control air, the emergency brakes at the tractor may be released/activated to simulate service brake control without requiring connecting the tractor to the trailer service brake line.