Vehicle Diagnostics using OBD-2

We published a do-it-yourself vehicle diagnosis system in Elektor Electronics back in October and November 2002. Since then, the interface has been standardised in the EU under the name EOBD, and is mandatory on all newly-registered cars, both petrol and diesel.
At the same time, the number of different protocols used for transferring data has risen from three to five, with the CAN bus protocol becoming more and more successful.