| abstract |
An abnormality diagnosing device used in an exhaust gas purification device, the abnormality diagnosing device comprising: an adsorption amount detection unit that detects the actual adsorption amount of ammonia in a catalyst, that is, the actual adsorption amount; and an electronic control unit configured of are: i) estimating the ammonia adsorption amount of the catalyst when it is assumed that the ammonia supply device is normal, that is, the estimated adsorption amount; When the difference between the actual adsorption amounts is larger than the threshold value, it is diagnosed that the ammonia supply device is abnormal. |