Genuine OEM Audi Control Unit for Diesel Engine, part number 04L906026NQ. This electronic control module manages various engine functions, including fuel injection, ignition timing, and emissions control. It is a critical component for the proper operation of the diesel engine. The precise calibration and integration of this unit are essential for maintaining optimal performance, fuel efficiency, and compliance with emissions standards. Genuine OEM parts ensure correct firmware and sensor calibration for reliable operation.