This AdBlue supply module delivers diesel exhaust fluid from the tank to the injection point in the exhaust stream. It is part of the selective catalytic reduction system that reduces nitrogen oxide emissions. The module contains an electric pump and internal control electronics that regulate fluid pressure and flow rate based on signals from the engine control unit. A failing module typically triggers a warning light and may cause the engine to enter a derated power mode. The component is built to the original manufacturer's specifications, which ensures the electrical connector and mounting bracket match the factory harness and chassis location. When replacing, verify that the fluid lines are free of contamination and that the electrical connector is fully seated and latched.