Genuine OEM Volkswagen Control Unit, part number 04E906027JA. This is the main electronic control unit for the petrol engine, responsible for managing ignition timing, fuel injection, and other critical engine functions. It is typically mounted in the engine bay. The unit has dimensions of 0.185m x 0.15m x 0.055m and weighs 0.623 kg. Genuine OEM ensures correct firmware and sensor calibration for reliable engine operation.