Genuine OEM Volkswagen Control Unit, part number 03C906026BS5N0. This control unit is essential for managing the petrol engine's various functions, including fuel injection, ignition timing, and emissions control. It is typically mounted in a protected location within the engine bay. The unit weighs approximately 0.88 kg and has dimensions of 0.205m x 0.18m x 0.04m. Genuine OEM control units are critical for ensuring the correct firmware and sensor calibration, which directly impacts engine performance, fuel efficiency, and emissions compliance.