The usefulness of diesel vehicle onboard diagnostics (OBD) information

Abstract

The On-Board Diagnostic (OBD) socket provides a data link with the ECU and possibly also with other controllers within the vehicle. This paper discusses the various benefits that were experienced through the use of the OBD data from reading of error codes, reading/storing of vehicle specific parameters (PIDs) and communicating with a UniNOx sensor. Experimental data on levels of NOx formation with variation of Exhaust Gas Recirculation (EGR) is presented in this paper. Another research effort into Diesel Particulate Filter (DPF) clogging also benefitted from OBD data. Vehicle emulators were built in LabVIEW® to reduce testing time with real vehicles. Two types of emulators were built, one type was based on CAN which used a National Instruments PCI CAN series 2 card, while the other type was based on K line used two ELM327 devices. The CAN emulator was modified for three different vehicles, Nissan Qashqai, Toyota Auris and Volkswagen Golf. A mobile app was developed to request and store parameters related to the DPF from road driven vehicles. The mobile app uses a Bluetooth device connected to the vehicle OBD. When the app is closed the data is uploaded into our project website from where the data can be accessed.