An end of train unit includes a positioning system such as a GPS receiver and is configured to transmit a message including the EOT unit's location when the EOT unit detects a loss of air pipe pressure and/or it is tipped over and/or a low battery condition is detected. In highly preferred embodiments, the EOT unit periodically re-transmits the message until an acknowledgment message is received. In some embodiments, information from the positioning system is used to create a signal as a substitute for a motion sensor. In other embodiments, information from the positioning system is used to determine the speed of the end of the train. End of train unit tracking is also performed.