For older Volkswagen models (Mk3, Mk4), is a legendary resource. While not officially affiliated with VW, it houses an archive of technical documents and diagrams that mirror what you would find in ERWIN. It is completely free to browse.
Without ERWIN, diagnosing a 2018 VW Tiguan with a CAN bus fault or replacing a mechatronic unit in a DSG gearbox is almost impossible. vw erwin free access
Access to full repair manuals, wiring diagrams, and technical service bulletins (TSBs) requires a "Flatrate" booking. Official Factory Repair Information - Ross-Tech Wiki For older Volkswagen models (Mk3, Mk4), is a