OBD-II standard car engine diagnostic software development

Modern car engine has a control unit that serves to control all aspects of the car known as the Engine Control Unit (ECU). The control unit was developed by the manufacturer to assist in optimizing engine performance, and has proven to be very useful Unfortunately, the existence of ECU means independent repair shops can´t do engine repair and maintenance without help from manufacturer. This paper is written to help third parties on developing car engine diagnostics software that communicate with the ECU through the OBD-II, a standard developed by the European Union (EU) to ensure manufacturers can conform to EU emission standards and do not have a monopoly in the auto repair business. The system was developed in the Java environment, using the Scala programming language. There is no problem in development because of the simplicity of OBD-II. Unfortunately, the use of Serial Port (RS232) to communicate with the ECU made the system can´t provide an accurate real-time information, because of the limitations of the RS232 itself.