| 摘要 |
An engine (1) is provided with, in an exhaust passage (26), a urea aqueous solution supply mechanism (200) for supplying urea aqueous solution. The urea aqueous solution supply mechanism (200) includes a tank (210) for storing the urea aqueous solution, a pump (220) for delivering the urea aqueous solution, a supply pipe (240), a tank heater for heating the urea aqueous solution in the tank (210), a pump heater for heating the urea aqueous solution in the pump (220), and a passage heater for heating the urea aqueous solution in the supply pipe (240). A controller (80) adds urea by activating the pump (220) after heating control begins by way of the tank heater, pump heater, and passage heater. Then, the controller (80) outputs a signal indicating a tank heater abnormality when the urea aqueous solution pressure in the supply pipe (240) decreases while adding the urea and the amount of remaining urea aqueous solution detected by a level sensor (250) indicates that urea aqueous solution is remaining in the tank (210). |
