Design of vehicle bus data acquisition and fault diagnosis system

This paper introduces the overall design of vehicle bus data acquisition and fault diagnosis system on the basis of OBD, focusing on its lower computer system and the upper computer system design principles. This system is based on the widely used CAN bus technology, to extract the vehicle´s status or fault information. The CAN bus adopts the SAE J1939 protocol standards, maximize the superiority of it. The system acquires and analyses the data from the CAN bus under the SAEJ1939 protocol, which provides about 400 faults. The system displays the faults on the LCD screen in the way of the fault tree, so the users can check them easily. It can send data to the upper computer system or management center by General Packet Radio Service (GPRS), to view the vehicle status or fault information far away, and to achieve the remote monitoring of the vehicle and fault diagnosis.