| 摘要 |
<p>Provided are a fault diagnosis device for a reducing agent supply device, and a reducing agent supply device, with which the restrictions on the period during which fault diagnosis is performed and the adjustments therefor can be reduced, and with which the fault diagnosis for the reducing agent supply device can be performed easily. The fault diagnosis device is equipped with: a reducing agent injection valve control means that obtains the on/off duty ratio for energization in response to the specified injection amount for the reducing agent, and directs the driving of a reducing agent injection valve; a pump control means that obtains the on/off duty ratio for energization on the basis of the deviation between the detected pressure in the reducing agent passage and the system pressure, and directs the driving of a pump, so as to maintain the pressure in the reducing agent passage at a prescribed system pressure; and a fault diagnosis means that diagnoses faults with the reducing agent supply device on the basis of the duty ratio for the reducing agent injection valve and the duty ratio for the pump for a prescribed period of time.</p> |
