The customer reports that the engine warning light illuminates sporadically. The engine may have reduced performance without significant loss of power or stalling. Noise is heard coming from the engine compartment, specifically from the High Pressure Fuel Pumps 2. DTCs are stored in the engine control module (ECM). The fuel metering valve of the high-pressure fuel pump is controlled by a specific on/off ratio. If there is a low system voltage, the on/off ratio may not be enough to keep the fuel metering valve constant in all areas. In such a situation, the fuel metering valve is deactivated and the high-pressure fuel pump switches to full supply mode. Because the increased rail pressure does not match the respective driving situation, the DTC appears.
