If encountering "No ECU Found" or "RX Timeout," check the COM port, check that the car's Kline is connected correctly, or try Vagdashcan if dealing with specialized clusters.
Its success depends entirely on following the correct setup procedure. If you need to retrieve an immobilizer PIN from a 2001 Audi A3 or correct the mileage on a 2002 VW Passat, this tool can still get the job done. For anything else, especially any car manufactured after 2004, you will need a modern, more capable alternative. vag eeprom programmer 119g work