Genuine OEM Volkswagen Engine Control Unit, part number 3GD906259B. This control unit is the central computer for Otto (gasoline) engines, managing critical functions like fuel injection, ignition timing, and emissions control. It is typically located within the engine bay or passenger compartment. The unit is constructed from durable materials to withstand engine operating conditions. Precise calibration and firmware are essential for correct engine operation and emissions compliance, making genuine OEM the only reliable choice.