Genuine OEM Volkswagen Engine Control Unit, part number 05E906018AT. This is the main computer that controls engine functions. Its precise calibration ensures optimal performance and emissions. The unit is located within the engine bay assembly. Dimensions: 0.185m x 0.17m x 0.038m. Genuine OEM ECUs are critical for correct engine operation as they contain specific firmware and calibration unique to the vehicle's engine management system.