Genuine OEM Audi Engine Control Unit, part number 05E906018D. This is the Engine Control Unit (ECU) specifically designed for Otto cycle (gasoline) engines. It is the brain of the engine management system, responsible for controlling fuel injection, ignition timing, and other critical parameters to ensure optimal performance, fuel efficiency, and emissions control. Genuine OEM ECUs come with the correct firmware and calibration for seamless integration and reliable operation.