FAILURE DETECTION DEVICE FOR EXHAUST GAS PURIFICATION FILTER

Provided is a DPF failure detection device not only capable of a quick detection but also having less erroneous and a small power consumption. The DPF failure detection device, after starting applying a dust collecting voltage to a dust collecting electrode, applies a measuring voltage to a measuring electrode while the dust collection voltage is being applied, thereby measuring the capacitance of a sensor device. The DPF failure detection device also stops applying the dust collecting voltage to the dust collecting electrode in response to the fact that the measured value (C COL ) of this capacitance exceeds a completion criterion (C COL_TH ). Further, the DPF failure detection device applies the measuring voltage to the measuring electrode, thereby measuring the capacitance of the sensor device and obtaining a measured value (C PM ), on the basis of which a DPF failure is determined.