SENSOR ABNORMALITY DETECTING DEVICE AND SENSOR ABNORMALITY DETECTING METHOD

摘要

Provided are a device and a method for always accurately detecting abnormalities of a sensor in an exhaust filter device. The sensor abnormality detecting device is composed of a filter upstream pressure sensor; a filter downstream pressure calculating means, which subtracts the actual measurement value of a difference between the upstream pressure and the downstream pressure of the filter from the filter upstream pressure value detected by the filter upstream pressure sensor, and calculates a pressure value in the downstream of the filter; a filter downstream pressure estimating means for estimating a pressure value in the downstream of the filter, based on the operating status of an internal combustion; and an abnormality detecting means, which compares the difference between the calculated pressure value and the estimated pressure value with a threshold, and detects that at least one of the functions of a differential pressure sensor and the filter upstream pressure sensor is not normally operating.