Design Of Vehicle Fault Diagnosis System Based On PC

With the Electronic Control System of modern engine being more And more complex, once there is any breakdown in the automobile, it will be more and more difficult to confirm the type of the trouble. So the automobile malfunction tester has been the indispensable equipment during repairing. However, the traditional OEM tester has Many drawbacks, such as high price, Poor versatility and not easy to carry etc. The Paper analyzes the development and current situation of domestic and foreign vehicle detecting, designed based on this stage, the most widely used second-generation On-Broad Diagnostic System of the Vehicle Fault Diagnosis System Based on PC has solved the Problems above efficiently.The fault tester, which is based on OBD-â…¡standards, adopts MCU As the main control device, employs ISO15031 as diagnostic Protocol, and uses KWP2000, ISO15765 as communication Protocols. When linked with the automobile Electronic Control Unit, the OBD-â…¡tester can read and clear the DTC. The circuit conversion module between MCU serial Port and serial interface of RS-232 or USB has been added to the hardware circuit of OBD-â…¡tester. When connected with PC, the OBD-â…¡tester will upload the DTC data.Analyzed the OBD-â…¡tester's hardware and software in this paper meanwhile demonstrated its advantages, such as low price, high dependability, easy to carry, easy to use and easy to be expanded And so on. Especially, the repairman could easily read and clear DTC Even being outdoors due to the Portable design. The article highlighted the components selection of the fault tester and the schematics and PCB design process. On the other hand the paper detailed description the developing of the PC based monitoring program and OBD-â…¡based communication protocol stack.The paper described the difficulties and focuses in design and realization of the fault tester.Trouble code, Data flow and module information transferred by K line or CAN Bus.The Vehicle Fault Diagnosis System Based on PC can replace the existing fault diagnostic products, it has high practical value for the development of similar systems.The tester has past the function experimentation on Vehicle, and the user approved the instrument has a high performance in malfunction diagnosis. In Particular, the tester is fit for common driver or maintenance Personnel to carry through daily examination and malfunction finding.