Development of OBD-II interface for remote diagnosis of vehicles

This Master Thesis documents the development of an On Board Diagnosis (OBD-II) interface for remote diagnosis of vehicles. The Master Thesis is part of a project at the company Wayfinder Systems in Lund. The purpose of this thesis was to design a scantool that communicates with a vehicle through its OBD-II port using relevant standards. In order to make the OBD-II interface development easier, a car simulator was first built. Both the car simulator and the OBD-II interface were implemented using a linux computer running a C-program with serial communication with an external electrical interface. When the OBD-II interface was working satisfactory, tests were also made in a car – with good results. The most difficult thing in the project was to meet the timing requirements in the standard specifications. To be able to communicate with all cars that have an OBD-II port, further development of the OBD-II interface is required, because the OBD-II interface does not use all standards