| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an abnormality determination device of a particulate filter which can accurately determine an abnormality of the filter as early as possible by using a fore-and-aft pressure difference of the particulate filter.SOLUTION: An abnormality determination device of a particulate filter acquires a temporary determination value (pressure difference increase rate S1) A having a correlation in a fore-and-aft pressure difference of a DPF when a DPF passage gas flow rate is within a middle flow rate, decreases an EGR gas flow rate when it is determined that the temporary determination value A is smaller than a temporary determination threshold Sath, and increases the DPF passage gas flow rate up to a flow rate in a large flow rate range. The device acquires a regular determination value (pressure difference increase rate S2) B having a correlation in the fore-and-aft pressure difference of the DPF when the DPF passage gas flow rate is within the large flow rated range, and when it is determined that the regular determination value B is smaller than a regular determination threshold Sbth, determines that an abnormality occurs in the DPF.</p> |
