Method, device and system for diagnosing faults of vehicle running part

The embodiment of the invention discloses a method for diagnosing faults of a vehicle running part, comprising the steps that a data receiving unit receives the existing working condition type data of the vehicle running part sent by a train extension; a transfer-coding unit codes the working condition type data sent by the train extension for a multifunction vehicle bus (MVB), and sends the working condition type data converted to the MVB data stream form to a display coding unit through the MVB; the display coding unit codes such data for display, converts such data to a display code form displayed on a cab displayer availably, and sends such converted data to the cab displayer through the MVB; and the cab displayer displays the received data. With the adoption of the method, a device and a system for diagnosing the faults of the vehicle running part, the cab displayer can receives the working condition type data of the running part through an original MVB network and further displays such data through the use of an MVB board card in the train extension; and therefore, the cost is saved greatly, and the integrity of a train is promoted.