Abstract: An electronic system that monitors a trailer hitch assembly having a plate hitch with a throat for receiving a kingpin of a trailer and a locking mechanism for locking the kingpin within the throat. The electronic system determines whether the trailer hitch assemblies is properly coupled to the trailer, and comprises a first magnet creating a first magnetic flux, and a first Hall-effect sensor for sensing the position of the kingpin of the trailer relative to the throat of the hitch plate by measuring the first magnetic flux. The system further comprises a control circuit operably coupled with the first Hall-effect sensor in determining whether the first magnetic flux indicates a proper location of the kingpin of the trailer relative to the throat of the hitch plate. The electronic system discriminates between the kingpin and foreign materials, thereby assuring proper locking of the locking mechanism.