Genuine OEM Audi Engine Control Unit, part number 05E906018CP. This is the primary computer that manages all engine operations, including fuel injection, ignition timing, and emissions control. It receives data from various sensors and sends commands to actuators to ensure the engine runs efficiently and within specified parameters. The unit is typically mounted in a protected location within the engine bay. Genuine OEM engine control units come with the correct firmware and calibration, ensuring precise control and optimal performance of the engine.