FAILURE DIAGNOSIS METHOD FOR PRESSURE SENSOR AND COMMON RAIL TYPE FUEL INJECTION CONTROLLER

摘要

Diagnosis of a failure of a pressure sensor is enabled with a simple configuration without providing a dedicated circuit for failure diagnosis. In the common rail type fuel injection controller, a pressure control valve (12) is provided on a fuel return path from a common rail (1), and an electronic control unit (4) drives and controls the pressure control valve (12) so that a rail pressure detected by a pressure sensor (11) can be controlled to be a target rail pressure calculated based on operation information of an engine (3). The controller is configured so that learning processing for storing and updating a correction factor (Cv), stored in the electronic control unit (4), for compensating the energization characteristics of a center portion of the pressure control valve (12) as a learned value is executed, and it is judged whether or not the learning value of the compensation factor (Cv) is within a predetermined range, and if it is judged that the learning value is out of the range, it is judged that the pressure sensor (11) is in failure.