The diagnostics and monitoring of the running condition of a car engine is very important and smart way to enhance the efficiency and maintenance of the engine. In the modern era almost all modern vehicles include an On Board Diagnostic (OBD) system. The OBD system can always monitor the running condition of engine. When the OBD system detects a malfunction in any of sensors or engine parameters, OBD regulations require the Electronic Control Unit (ECU) of the vehicle to save a standardized Diagnostic Trouble Code (DTC) about the information of malfunction in the memory. These DTC's can be processed and read by connecting external scanner to OBD system which then shows the diagnostic results. But this project removes the need of external scanner. The purpose of this study is to make the information of different sensors of engine and parameters of vehicle freely available to drivers or mechanics on an embedded screen device. This system eliminates the need of any external scanner required to show the diagnostic results of OBD system and solves these problems by providing many useful functions such as real time display of sensor data, diagnostic trouble code (DTC) reading and displaying information of different sensors and parameters of engine in a simple and an easily understandable language for the user (driver).

Model-based diagnosis On-board diagnostics system vehicle parameters monitoring.