Genuine OEM Volkswagen Engine Control Unit, part number 03L906018RE360. This is the primary control module for the diesel engine, responsible for managing fuel injection, ignition timing, and other critical engine parameters. It is typically located in the engine bay. The unit has dimensions of 0.205m x 0.18m x 0.04m and weighs 0.88 kg. Genuine OEM engine control units are essential for ensuring the precise calibration, firmware, and sensor compatibility required for optimal engine performance and longevity.