Abstract: An exemplary embodiment of the invention is a method for detecting a potentially locked axle on a vehicle propelled by an AC motor. The method includes conducting a speed test by estimating axle speed and comparing estimated axle speed to measured vehicle speed. The existence of a potential locked axle condition is determined based on the comparing of estimated axle speed to measured vehicle speed. Additional tests are disclosed for determining a potential locked axle condition and a sensor fault condition.

Abstract: A system for detecting a failure of a speed sensor on a locomotive propelled by an AC traction motor is disclosed. The system includes a locomotive including a processor for executing a detection method. The method comprises conducting an evaluation of symptoms exhibited by a speed sensor. A health value representative of health of the speed sensor is generated and modified as a function of an evaluation, and as a result from the modification of the health value, a modified health value is generated. A motor control methodology responsive to the modified health value is selected.