A computer-implemented system and method of contemporaneously testing a respective system on-board each of a plurality of locomotives with a common user interface where the locomotives are in electrical communication with one another for transmitting electronic signals among the locomotives. An electronic signal may be transmitted to the plurality of locomotives instructing a respective on-board computer of each locomotive to synchronously engage a self-load sequence. An electronic signal may be transmitted to the plurality of locomotives instructing a respective engine of each locomotive to execute a testing sequence. Operating parameter data associated with the respective systems may be downloaded from each of the plurality of locomotives through the common user interface to a database engine to determine whether the downloaded operating parameter data is within acceptable operating limits.