Research On On-Line Fault Diagnosis Technology And Test Bench For Electronic-Controlled Engine

With people’s requirements for the automotive comfort and safety increase every year, as well as national laws and regulations on vehicle performance and emissions become increasingly stringent. The Technology of on-line fault diagnosis is playing a more and more important and obvious role on electronic control unit.CAN has been developed rapidly and applied by most global car companies since it came out in1980s.According to the comparison of two KWP2000diagnostic protocols which are respectively based on CAN-bus and K-line, on the platform of electronic control unit for Four cylinder engine based on MC9S12XEP100designed by Freescale, firstly this thesis accomplishes the diagnostic services of the network layer and part application layer of the KWP2000diagnostic protocol which is based on CAN-bus.After this further research and exploration have been made on the function development of on-line fault diagnosis. According to the related description of KWP2000diagnostic protocol, the management module of diagnostic has been designed. With the example of electronic throttle system’s diagnostic module, this thesis describes the model-based development methodology of modern automotive electronics.To develop a fully functional and stable and reliable on-line fault diagnosis system of the engine electronic control unit, large amounts of Diagnostic tests in different cases are requisite. And it will keep the system’s reliability by continuously improving. This thesis comes up with a rapid fault-simulated platform that it is used to test the on-line fault diagnosis system function. In the process of actual usage, this platform will supply tests when it comes to the developing of diagnostic protocol and diagnostic arithmetic.