... professional technicians that need to read VAG diagnostic trouble codes (DTCs) from the on-board computers(ECUs) of 1990 and newer ... / Passat and more sold worldwide since 19902. Reads and erases Diagnostic Trouble Codes (DTCs) of engine, ABS, airbags, transmission, radio, ... parking brake.2.Switch on the ignition and then plug the code reader into the 16-pin diagnostic socket (OBD-II connector) ...