N51 Engine: Service Engine Soon Lamp Illuminated - Loss of Power and Various Faults Stored in the DME. The customer complains that the Service Engine Soon lamp is illuminated. The vehicle has lost power; the engine cranks but will not start; and various faults are stored in the DME for engine misfire and/or mixture adaptations. CAUSE The vehicle has lost fuel system delivery pressure due to a loose or split fuel line inside the fuel tank. The failure is related to an unfavorable stacking of tolerances between the rubber fuel hose and the plastic regulator nipple or deterioration of the rubber hose construction material.