Various examples of a controller, method and system for monitoring a tractor-trailer vehicle train are disclosed. In one example a tractor controller is manually-initiated or a user-initiated tractor controller and includes an electrical control port for receiving an electrical sync signal and an electrical start signal, and a communications port for receiving data. A processing unit of the tractor controller includes control logic and is in communication with the electrical control port. The control logic is capable of receiving a data signal at the communications port which includes a time value and a unique identification which corresponds to the towed vehicle in response to the electrical start signal. At a predetermined response time, the tractor controller determines the position of the towed vehicle in the tractor-trailer vehicle train based on the data received from the towed vehicles.