VCDS uses multiple diagnostic protocols such as KWP-2000, KWP1281 and UDS (Unified Diagnostic Services) to communicate with the vehicle's onboard computer system. KWP-2000 is an older protocol that is used in many Volkswagen Group vehicles built between 1996 and 2006. KWP1281 is a newer protocol that is used in many Volkswagen Group vehicles built between 2006 and 2016. UDS (Unified Diagnostic Services) is a more recent protocol that is used in many Volkswagen Group vehicles built from 2016 onwards, it uses the CAN bus as the communication channel. By using these protocols, VCDS can be used to diagnose and adjust various systems in a wide range of Volkswagen Group vehicles, not just Volkswagen and Audi models. It also allows for access to a wide range of modules, including Engine, Automatic Transmission, Airbags, ABS, etc, and also to perform advanced functions like coding and adaptation.