The Audi 80-90 B3 (1986-1991) is a versatile diagnostic tool that provides mechanics with the ability to activate and interrogate the vehicle's fault memory, as well as erase fault codes. Additionally, it can be used to perform system output checks, when installed. By connecting to the vehicle's diagnostic connectors, the Audi 80-90 B3 (1986-1991) enables technicians to efficiently identify and troubleshoot malfunctions within the vehicle's electronic systems.